Skip to main content
main-content

Über dieses Buch

This ?ve-volume set was compiled following the 2006 International Conference on Computational Science and its Applications, ICCSA 2006, held in Glasgow, UK, during May 8–11, 2006. It represents the outstanding collection of almost 664 refereed papers selected from over 2,450 submissions to ICCSA 2006. Computational science has ?rmly established itself as a vital part of many scienti?c investigations, a?ecting researchers and practitioners in areas ranging from applications such as aerospace and automotive, to emerging technologies such as bioinformatics and nanotechnologies, to core disciplines such as ma- ematics, physics, and chemistry. Due to the shear size of many challenges in computational science, the use of supercomputing, parallel processing, and - phisticated algorithms is inevitable and becomes a part of fundamental theore- cal research as well as endeavors in emerging ?elds. Together, these far-reaching scienti?c areas contributed to shaping this conference in the realms of state-- the-art computational science researchand applications, encompassing the fac- itating theoretical foundations and the innovative applications of such results in other areas.

Inhaltsverzeichnis

Frontmatter

Workshop on Information Systems Information Technologies (ISIT 2006)

Efficient Algorithm for the Extraction of Association Rules in Data Mining

The problem of data mining is to discover the pattern or trend in huge volume of data. The problem is similar to knowledge discovery in artificial intelligence. Here our goal is to discover rules that reflect the pattern in the data. These rules are called association rules. In [AS94] an algorithm is proposed to extract these association rules from the large/frequent itemsets computed by the apriori algorithm. In this paper we present a more efficient and output sensitive algorithm to compute these association rules given the lattice L of large itemsets. Our approach is based on pruning a lot of redundant association rules that have to be tested in the algorithm of [AS94] .We use a variation of the data structure for hashing using separate chaining in our algorithm. Our algorithm, is output sensitive in the sense that its time complexity will be proportional to the number of association rules that have to be generated and it is also optimal.

Pinaki Mitra, Chitrita Chaudhuri

A Robust Digital Fingerprinting Mechanism for Digital Copyright Protection

As demand for digital fulltext-image with fast development of super high speed communication network is increasing in digital contents industry, its scale is increasing exponentially every year. However, this fulltext-image is illegally reprinting and distributing widely, and this brings about the problems of its copyrights and proprietary rights. To solve this problems, many techniques such as DRM(Digital Right Management) or digital watermarking is receiving study. The digital fingerprinting is one method of right protection of new multimedia based on digital watermarking. Consequently, we design robust watermarking algorithm, which can resist a various attack, construct digital fulltext-image framework for copyright service, and apply them in our digital fulltext-image protection system.

Sangkuk Kim, Heejun Yoon, Hwamook Yoon, Wongoo Lee

SoapFS: A Multiplatform File System

Distributed computer applications usually need processes that allow them to retrieve, store, and share data in a suitable way. As a consequence, file systems become a basic concern for these kinds of applications. Typical file systems have been designed on a computer network infrastructure whose communication and data exchange support is homogeneous. The Internet encourages the construction of file systems, which deal with heterogeneous computer platforms. This work presents SoapFS, a file system that is able to manage information in a heterogeneous environment such as the Internet. This is possible because it is based on technologies like RPC-XML and SOAP. This paper shows how a set of functions available in SoapFS allows the development of robust and heterogeneous distributed applications that involve remote data retrieval and storage. SoapFS shows competitive performance compared with popular file systems and it can connect different file systems working together like a one virtual file system.

Víctor J. Sosa, Rodolfo Pazos, Juan G. González, Santos Cáceres, Laura Cruz, Mario Guillen

An Application-Independent Multimedia Adaptation Framework for the Mobile Web

In the mobile web environment, multimedia contents adaptation services should be available through supporting various kinds of devices, network abilities and users’ preferences. If a new user wants to stream multimedia contents in a server through a new kind of terminal device, it should be considered whether the existing transcoders are able to adapt the multimedia contents. However, the existing libraries for multimedia adaptation have heavy transcoder figures which include all adaptive functions in one library. The challenge of universal access is too complex to be solved with these all-in-one solutions. In this paper, an application-independent multimedia adaptation framework which meets the QoS of new and varied mobile devices is suggested. This framework is composed of a group of unit transcoders having only one transcoding function respectively, instead of heavy transcoders. Also, the transcoder manager supporting the dynamic connections of the unit transcoders to satisfy end to end QoS is included.

Sungmi Chon, Younghwan Lim, Kyujung Kim

Effort Prediction Model Using Similarity for Embedded Software Development

In this paper, we propose an effort prediction model in which data including missing values is complemented by using the collaborative filtering [1, 2, 3] and the effort of projects is derived from a multiple regression analysis [4, 5] using the data. Because companies, recently, focus on methods to predict effort of projects, which prevent project failures such as exceeding deadline and cost, due to more complex embedded software, which brings the evolution of the performance and function enhancement [6, 7, 8]. Moreover, we conduct the evaluation experiment that compared the accuracy of our method with other two methods according to five criteria to confirm their accuracy. The results of the experiment shows that our method gives predictions the best in the five evaluation criteria.

Kazunori Iwata, Yoshiyuki Anan, Toyoshiro Nakashima, Naohiro Ishii

A Component Cohesion Metric Applying the Properties of Linear Increment by Dynamic Dependency Relationships Between Classes

In Component-Based Development(CBD), by building new software with independently developed components, we can gain the benefits promised by the software reuse such as quality improvement and rapid development. Hence, methods to design the components in component-based system are very important and the component architecture should consist of highly cohesive components. Accordingly, to design highly cohesive components in component development phase, we propose new types of dynamic dependency relationship between classes and a component-based cohesion metric applying the properties of linear increment by dynamic dependency relationships between classes. In addition, we prove the theoretical soundness of the proposed metric by the axioms of briand et al. and suggest the accuracy and practicality of the proposed metric through a comparison with the conventional metrics.

Misook Choi, Jongsuk Lee, Jongsung Ha

The Maximum Capacity and Minimum Detectable Capacity of Information Hiding in Digital Images

Information hiding capacity of digital image is the maximum information that can be hidden in an image. But the lower limit of information hiding, the minimum detectable information capacity is also an interesting problem. This paper proposes new method of the information hiding capacity bounds analysis that is based on the theories of attractors and attraction basin of neural network. The upper limit and lower limit of information hiding, namely the maximum information capacity and the minimum detectable information capacity are unified in a same theory frame. The results of research show that the attraction basin of neural network decides the upper limit of information hiding, and the attractors of neural network decide the lower limit of information hiding.

Fan Zhang, Xianxing Liu, Jie Li, Xinhong Zhang

BEAST: A Buffer Replacement Algorithm Using Spatial and Temporal Locality

Efficient buffer management is closely related to system performance. Thus, much research has been performed on various buffer management techniques. However, many of the proposed techniques utilize the temporal locality of access patterns. In spatial database environments, there exists not only the temporal locality but also spatial locality, where the objects in the recently accessed regions will be accessed again in the near future. Thus, in this paper, we present a buffer management technique, called BEAST, which utilizes both the temporal locality and spatial locality in spatial database environments. The experimental results with real-life and synthetic data demonstrate the efficiency of BEAST.

Jun-Ki Min

Performance Evaluation of the Flow-Based Router Using Intel IXP2800 Network Processors

Exponential increment of users and emergence of realtime services with QoS requirements cause a great change of Internet traffic characteristics from early best-effort characteristics. The currently developed packet-based router with MPLS and DiffServ technologies has still limitations on providing services with QoS guarantee. Hence, a flow-based router is introduced for dealing with realtime services with QoS requirements. This paper proposes a flow-based router using Intel IXP2800 network processors. By imposing flow-awareness into IXP2800, the proposed flow-based router has basic functionalities such as flow classification, flow maintenance, flow-based forwarding, and flow-based congestion resolution. And we analyze performance of the proposed flow-based router considering flow characteristics. The flow maintenance duration gives a great effect on its performance. Compared with the packet-based router using IXP2800 network processors, performance of the flow-based router is enhanced in terms of the packet processing time.

Jaehyung Park, Myoung Hee Jung, Sujeong Chang, Su-il Choi, Min Young Chung, Byung Jun Ahn

Robust 3D Face Data Acquisition Using a Sequential Color-Coded Pattern and Stereo Camera System

This paper presents a robust 3D data acquisition method that uses a sequential color-coded pattern and a stereo camera system. In this system, one projector projects a pattern on an object and two cameras capture two images. We then solved the correspondence problem between the two images by using epipolar constraint and a sequential color-coded pattern based on the YCbCr coordinate. The proposed sequential color encoding strategy not only increased the speed of 3D reconstruction but also increased the robustness to the illumination variation. The proposed method was applied to 3D face data acquisition and robustness for the illumination variation was compared with the previous method. Because the suggested pattern can generate twice of the coded pixels per frame than binary coded pattern, even though four coded colors were used, the time efficiency of the suggested method was improved by about 50%. The experimental results also show that the robustness to the illumination variation was improved compare to the binary coded method.

Ildo Kim, Sangki Kim, Sunjin Yu, Sangyoun Lee

Robust Design of Face Recognition Systems

Currently, most face recognition methods provide a number of parameters to be optimized, leaving the selection and optimization of the right parameter set is necessary for the implementation. The choice of the right parameter set that is suitable for a rich enough class of input faces in pose and illumination variations is, however, quite difficult. We propose robust parameter estimation, using the Taguchi method, when applied to 2nd order mixture of eigenfaces method that allows effective (near optimal) performance under pose and illumination variations. A number of experimental results confirm the improvement (via robustness) vis-‘a-vis conventional parameter estimation methods, and these methods promise a solution to the design of efficient parameter sets that support many multi-variable face recognition systems.

Sunjin Yu, Hyobin Lee, Jaihie Kim, Sangyoun Lee

Transmission Rate Prediction of VBR Motion Image Using the Kalman Filter

We propose a transmission rate prediction method of video data. The proposed method uses a Kalman filter for predicting transmission rate. It used algorithm to detect shot transition information by high speed in compressed domain in order to grasp precise shot transition of video data and classified into abrupt shot transition type and gradual shot transition type. Classified information is used as factors of Kalman filter and to predict transmission rate of video data. It predicted transmission rate with 96.2 ~ 97.6% in the experiment.

Won Kim, Hyo-Jong Jang, Gye-Young Kim

A Modeling and Similarity Measure Function for Multiple Trajectories in Moving Databases

In this paper, we focus on a new spatio-temporal representation scheme which can efficiently model multiple trajectories based on several moving objects in video databases. The traditional methods only consider direction property, time interval property, and spatial relations property for modeling moving objects’ trajectories. But, our method also takes into account on distance property, conceptual location information, and related object information (e.g. player name having a soccer ball). In addition, we propose a similarity measure function that improves a retrieval accuracy to measure a similarity among multiple trajectories. The proposed scheme supports content-based retrieval using moving objects’ trajectories and supports semantics-based retrieval using concepts which are acquired through the location information of moving objects. Finally, from the experimental results using real trajectories extracted from soccer video data with soccer ball and player, the performance of our scheme achieves about 15-20% performance improvement against existing schemes when the weights of angle and topological relation are over two times than that of distance.

Choon-Bo Shim, John Kim

Distributed Processing of Context-Aware Authorization in Ubiquitous Computing Environments

Context-awareness and security are critical issues in ubiquitous computing. In this paper we present a framework for context-aware authorization in ubiquitous computing environments. We present an architecture consisting of authorization infrastructure and context infrastructure. The context infrastructure provides context information and the authorization infrastructure makes decisions to grant access rights based on context-aware authorization policies and context information. This paper also describes how multiple nodes in distributed environments cooperate to perform evaluation and detection of context constraints and events included in authorization policies.

Young-Chul Shim

An Evaluation and Analysis for IP VPN Model in IPv6 Transition Environment

Many transition mechanisms and scenarios have studied for the using of IPv6 network efficiently. The VPN in IPv4 network is the main security application. Also it is necessary to use VPN during the transition period to IPv6 network. The VPN service provides the confidentiality and integrity for transmitted packets. But there are some difficulties to connect end-to-end VPN without a conversion between IPv4 and IPv6. Therefore, we analyze the suitability of the various applying model of VPN in conjunction with the transition mechanisms and evaluate the performance cost of this model. In the case of using the transition mechanism and VPN technology simultaneous, we can know the performance factors as follows: whether end points of the VPN tunnel and IP tunnel agree upon or not, the applying place of transition mechanism and VPN model according to network environment. Therefore, it should consider carefully evaluated applying model according to the required security level and connectivity.

Hyung-Jin Lim, Dong-Young Lee, Tae-Kyung Kim, Tai-Myoung Chung

Hybrid Storage Design for NC-94 Database Within the Parametric Data Model Framework

The NC-94 dataset contains the most complete records of temporal and spatial variables for climate, crop, and soil in the north central region in the United States. Scientists store and process the dataset within scientific data formats which are efficient for scientific simulations. However, it is difficult for the public to access the dataset by using ad-hoc queries because the scientific data formats are not database management systems. This paper presents a hybrid storage model to build the NC-94 database which supports ad-hoc queries. The storage is designed within the parametric data model which has advantages over conventional relational databases. In our design paradigm, the database query language supports multi-granules as well as pattern windows to extract information, reducing the needs of high-level programming languages. We expect that our proposed paradigm significantly enhance the usefulness of the existing NC-94 dataset for the public domain.

Seo-Young Noh

A Unified Index for Moving-Objects Databases

Recently, the need for Location-Based Services (LBS) has increased due to the development and widespread use of mobile devices (e.g., PDAs, cellular phones, laptop computers, GPS, and RFID etc). The core technology of LBS is a moving-objects database that stores and manages the positions of moving objects. To search for information quickly, the database needs to contain an index that supports both real-time position tracking and management of large numbers of updates. As a result, the index requires a structure operating in the main memory for real-time processing and requires a technique to migrate part of the index from the main memory to disk storage (or from disk storage to the main memory) to manage large volumes of data. To satisfy these requirements, this paper suggests a unified index scheme unifying the main memory and the disk as well as migration policies for migrating part of the index from the memory to the disk during a restriction in memory space. Migration policy determines a group of nodes, called the migration subtree, and migrates the group as a unit to reduce disk I/O. This method takes advantage of bulk operations and dynamic clustering. The unified index is created by applying various migration policies. This paper measures and compares the performance of the migration policies using experimental evaluation.

Jaekwan Park, Bonghee Hong, Kyounghwan An, Jiwon Jung

A Semantic Context-Aware Access Control in Pervasive Environments

Increasing trends in pervasive computing demonstrate a requirement for context awareness. The security problem has also become a key issue with context awareness. Access control should execute its decisions by capturing security-relevant context, such as time, location, user activity, and other environmental information available when the access requests arrive. In previous context-aware access control systems, a query issued by an authorized user could not be answered when the context specified in access control policy do not exactly match that specified in the query, even though both are semantically related. In this paper, Semantic Context-aware Access Control (SCAC), is proposed, to solve the problem mentioned prior. The proposed SCAC system takes contexts and its ontologies from context middleware and subsequently arranges contexts according to the abstraction level, to build context hierarchies. Using context hierarchies and reasoning rules extracted from the context ontologies, SCAC can overcome the semantic gap between contexts specified in the policy and contexts collected from the dynamic context sources in pervasive environments.

Hyuk Jin Ko, Dong Ho Won, Dong Ryul Shin, Hyun Seung Choo, Ung Mo Kim

Design and Implementation of an Index Structure Using Fixed Intervals for Tracing of RFID Tags

Recently, there has been a demand for RFID systems that can trace tag locations. For tracing tag locations, trajectories should be modeled and indexed in an RFID system. The trajectory of a tag is represented as a line that connects two spatiotemporal locations that are captured when the tag enters and leaves the vicinity of a reader. If a tag enters but does not leave a reader, its trajectory is represented only as the point captured at entry. When we process a query that finds the tag staying in a reader, it takes a long time to find this tag because it leads to searching the whole index. To solve this problem, we propose a data model in which trajectories of these tags are defined as intentional fixed intervals and a new index scheme called the Fixed Interval R-tree. We also propose a new insert and split policy to process queries efficiently. We evaluated the performance of the proposed index scheme and compared it with other schemes on various datasets and queries.

Sungwoo Ahn, Bonghee Hong, Chaehoon Ban, Kihyung Lee

GARPAN: Gateway-Assisted Inter-PAN Routing for 6LoWPANs

IEEE802.15.4 devices are all geared up for deployment as sensor net-orks that are ubiquitous yet cost effective. An emphasis on keeping costs down results into sensor networks that do not warrant high connectivity, thereby making routing a more crucial activity. In the purview of routing, ZigBee consortium has developed a PAN routing protocol. Other notable efforts are underway chartered by IETF as 6LoWPAN working group. In this paper, we have revisited the routing approaches suggested both for intra-PAN and mesh. Our contribution here is first to identify the plausibility of using gateways in routing functionality in 6LoWPAN networks. Second, we propose a protocol that defines the role of gateways for enhancing the routability of 6LoWPANs. Through NS2-based simulation study, our performance analysis amenably supports the applicability of our protocol.

Ali Hammad Akbar, Ki-Hyung Kim, Won-Do Jung, Ali Kashif Bashir, Seung-Wha Yoo

Design and Performance Analysis of Multimedia Teachware Making System Using 2D Barcode

With the development of information-communication infrastructure such as Internet, multimedia teachwares in good use of this infrastructure have been developed and serviced in all subjects of all school years in Korea. But there are some drawbacks. Using these multimedia teachwares requires studying and training. Even after that, it is still sophisticated to search information and make it one’s own useful materials. For purpose of overcoming these challenges and maximizing the access and applicability of multimedia teachware, a new system was suggested in this study which combined 2D barcode of ubiquitous technology and the URL(Uniform Resource Location) of multimedia teachware. Performance analysis demonstrates that this system is superior to existing one, and that the minimization of time for bridging the multimedia contents to 2D barcode enables the optimization of performance of the suggested system.

Duckki Kim, Youngsong Mun

A Traffic Conditioning Algorithm for Enhancing the Fairness Between TCP and UDP Flows in DiffServ

The Differentiated Services Network (DiffServ) aims to offer differ-ing levels of quality of service to different customers and their traffic flows. One important part of the traffic conditioner in DiffServ is measuring the traffic against the traffic profile and then marking the packets accordingly. In this paper, we propose the enhanced marking algorithm, which can assure the reserved rates of TCP and UDP flows and support fair distribution of excess bandwidth. We experiment with the proposed algorithm using ns-2 simulator. The simulation results show that our proposed marking scheme is rather insensitive of the effect of UDP on TCP throughput, and performs better both in terms of throughput assurance and fair distribution of excess bandwidth in case of well-provisioned and over-provisioned network environment.

Sungkeun Lee, Sunbok Goh, Moonsuk Jang

Adaptive Mode Switching for Internetworking of MANET and WLAN Based on HMIPv6

For extending of hot-spot of wireless LAN (WLAN), [1] proposes internetworking scheme between WLAN and mobile ad-hoc network (MANET), which employ the same layer-2 protocol with different mode. Compared to internetworking schemes between UMTS (Universal Mobile Telecommunications Systems) and WLAN [3-4], the scheme from [1] has relatively low overhead and latencies because WLAN and MANET are physically and logically similar to each other. However, the mode switching algorithm proposed in [1] for internetworking only considers signal strength and determines handoff, and mobile nodes following a zigzag course in pollution area may frequently perform handoff at short intervals. Furthermore, [1] employs mobile IPv6 (MIPv6) at base, which brings still high delay on handoff and overhead due to signal message exchange. In this paper, we present optimized internetworking scheme between WLAN and MANET, modified from [1]. To settle ping-pong handoff, we propose adaptive mode switching algorithm. HMIPv6 is employed for IP connectivity and mobility service in WLAN, which solves some shortcomings, such as high handoff overhead and vulnerable security from MIPv6. For routing in MANET, OLSR is employed, which operates with current IP protocol compatibly with no change or modification. The proposed internetworking scheme based on adaptive mode switching algorithm shows better performance than scheme from [1].

Hyewon K. Lee, Gukboh Kim, Youngsong Mun

Automated Keyword Extraction Using Category Correlation of Data

In this paper, we proposed a system that extracts keywords using thesaurus which contains data saved by category. The system enhances precision of extracted keywords based on considering correlation of the category. 30 Living Modified Organisms related experimental documents were used in order for performance measurement of the system. The proposed system showed better precision than frequency-based system by 47 % and thesaurus-based system by 18 %.

Young-Ho Woo, Do-Hyun Nam, Tai-Sung Hur, Young-Bae Park, Woong Huh, Yo-Seop Woo, Hong-Ki Min

On Cognitive Role of Negative Schema

A fundamental problem in building an intelligent agent is that an agent does not understand the meaning of its perception. However a human can perceive an object by a heuristic schema. According to Minsky, negative knowledge hidden in seemingly positive knowledge plays a controlling role in diverse areas including expert system, emotion, and search. We prove that a negated concept is defined implicitly by a hidden feature abstracted from the property common to all the objects not belonging to the concept. This paper proposes based on Minsky that there is a logical schema that enables an agent to perceive a negated concept.

Kang Soo Tae, Samuel Sangkon Lee

Qualitative Method-Based the Effective Risk Mitigation Method in the Risk Management

In the paper, we presented the method of safeguard selection for the effective risk mitigation using a qualitative method. We provided the suitable selection method of safeguard’s method/technique according to risk type, and performed cost-benefit analysis. In the selection of the safeguard method, we recommended the suitable method among risk avoidance, transference, prevention, threats reduction and impacts reduction, etc. according to risk type. After selecting the safeguard method, we chose the safeguard technique considering organization’s IT system capability such as IT system and network structure, functionality, exclusiveness and achievability of safeguard, etc. And then, we applied the safeguard technique to the safeguard method for implement effective security technology. We performed cost-benefit analysis with candidate safeguards, considering organization’s security budget. As performing this procedure, we can decide optimal safeguards with methods and techniques against risk’s types before implementing safeguards. We also can prevent redundant works and security budgets waste as analyzing the efficiency of existing safeguard. Lastly, we reflected the organization’s CEO opinions to require special safeguards for the specific information system related to their core business.

Jung-Ho Eom, Sang-Hun Lee, Hyung-Jin Lim, Tai-Myoung Chung

A Real-Time Web Contents Adaptation for Mobile User

We present a system that transforms web content in the internet effectively to the corresponding mobile content adapted to a mobile terminal such as a PDA or a mobile phone. The primary goal of this research is to reuse web contents in a wireless internet environment without any additional effort of rebuilding them at scratch for contents adaptation to reduce costs and efforts needed to develop wireless contents for mobile user. Our current target is news contents, whose content is frequently added and updated. To process them in real-time, all of the hyperlinked pages to the index page of a target web site are extracted and then stored into a web cache. The secondary goal is to develop more convenient user interfaces to read mobile contents easily with a mobile terminal. To do this, non-textual information of a web page is treated independently. It consists of a distinct mobile page hyperlinked to the page which has textual information only. Besides, we propose a technique, called

page splitting

, to navigate pages with button controls instead of conventional scroll up/down controls. Our experimental results say that by manipulation of navigation buttons with the aid of the page splitting becomes more efficient to read mobile content as its size is larger. The proposed system has been well operated for both well-known domestic and international news portal sites, including the New York Times.

Youn-Sik Hong, Ki-Young Lee

STMPE: An Efficient Movement Pattern Extraction Algorithm for Spatio-temporal Data Mining

With the recent development of LBS(Location Based Service) and Telematics, the use of spatio-temporal data mining which extracts useful knowledge such as movement patterns of moving objects gets increasing. However, the existing movement pattern extraction methods including STPMine1 and STPMine2 create lots of candidate movement patterns when the minimum support is low. As a result of that, the performance of time and space is sharply increased as a weak point. Therefore, in this paper, we suggest the STMPE (Spatio-Temporal Movement Pattern Extraction) algorithm in order to efficiently extract movement patterns of moving objects from the large capacity of spatio-temporal data. The STMPE algorithm generalizes spatio-temporal data and minimizes the use of memory. Because it produces and maintains short-term movement patterns, the frequency of database scan can be minimized. Actually, the STMPE algorithm was improved twice to 10 times better than STPMine1 and STPMine2 from the result of performance evaluation.

Dong-Oh Kim, Hong-Koo Kang, Dong-Suk Hong, Jae-Kwan Yun, Ki-Joon Han

Return on Security Investment Against Cyber Attacks on Availability

As it is getting more important to support stabilized secure services, many organizations increase the security investment to protect their assets and clients from cyber attacks. The purpose of this paper is to suggest a guideline for security managers to select a set of the security countermeasures that mitigates damages from availability attacks in a cost-effective manner. We present a sys-tematic approach to the risk analysis against availability attacks and demonstrate countermeasure benefit estimations. The risk analysis consists of three procedures: Service Value Analysis, Threat Analysis, and Countermeasure Analysis. As the outcome of the procedures, our approach produces quantitative benefit analysis for each countermeasure against availability attacks. We have applied a simulation tool developed to implement the approach to VoIP(Voice over Internet Protocol) services and the result is also presented.

Byoung Joon Min, Seung Hwan Yoo, Jong Ho Ryu, Dong Il Seo

An Approach for Document Fragment Retrieval and Its Formatting Issue in Engineering Information Management

This paper discusses engineering document fragment mark-up supported by the use of the eXstensible Stylesheet Language – Formatting Objects (XLS-FO). XLS-FO can be used to convert the native format repre-sentation of such documents as Word, Excel and PDF into XML. Once in XML, documents fragments can be retrieved at will in response to a search query. In the paper the process of a document fragment retrieval – based on the authors’ decomposition scheme approach – has been modelled and the issue of converting documents into XML addressed. Additionally, the use of document templates is discussed as a means of ensuring that the transformed XML documents are compliant with the decomposition schemes. Automating the reformatting of documents into XML and the use of templates helps make implementation of a document-fragment approach to retrieval more resource efficient, so making its adoption in industry more practicable.

Shaofeng Liu, Chris A. McMahon, Mansur J. Darlington, Steve J. Culley, Peter J. Wild

Minimum Cost Multicast Routing Based on High Utilization MC Nodes Suited to Sparse-Splitting Optical Networks

As the Internet traffic continues to grow exponentially, Wavelength Division Multiplexing (WDM) networks with tera bps bandwidth per fiber naturally emerge as backbone for next generation optical Internet. In particular, much research regarding multicast services has progressed for connecting source to destination nodes efficiently because multicast demands are increasing. However, sparse-splitting networks are more realistic than fully-splitting ones, since multicast-capable cross-connectors are expensive. In this paper, a heuristic method to minimize the cost of a multicast tree based mainly on Multicast-Capable nodes in sparse-splitting networks is proposed. According to the results of comprehensive simulations and compared to the previous algorithms, the proposed algorithm provides performance improvement up to about 16% in terms of wavelength channel cost.

Sang-Hun Cho, Tae-Jin Lee, Min Young Chung, Hyunseung Choo

Refinement Method of Post-processing and Training for Improvement of Automated Text Classification

The paper presents a method for improving text classification by using examples that are difficult to classify. Generally, researches to improve the text categorization performance are focused on enhancing existing classification models and algorithms itself, but the range of which has been limited by the feature-based statistical methodology. In this paper, we propose a new method to improve the accuracy and the performance using refinement training and post-processing. Especially, we focused on complex documents that are generally considered to be hard to classify. Our proposed method has a different style from traditional classification methods, and take a data mining strategy and fault tolerant system approaches. In experiments, we applied our system to documents which usually get low classification accuracy because they are laid on a decision boundary. The result shows that our system has high accuracy and stability in actual conditions.

Yun Jeong Choi, Seung Soo Park

An Implementation of the Vectorizing-Based Automatic Nesting Software NST

Among the processes to manufacture parts from footwear materials like upper leathers, one of the most essential processes is the cutting process for optimally arranging parts on raw footwear materials. A new nesting strategy was proposed for the 2-dimensional part layout by using a two-stage approach which can be effectively used for water jet cutting. In the initial layout stage, a SOAL(Self-Organization Assisted Layout) based on the combination of FCM (Fuzzy C-Means) and SOM(Self-Organizing Maps) were adopted. In the layout improvement stage, SA(Simulated Annealing)-based approach was adopted for a finer layout. The approach proposed in this paper saves much CPU time through a two-stage approach scheme, while other annealing-based algorithms so far reported for nesting problems are computationally expensive. The proposed nesting approach uses the stochastic process, and has a much higher possibility to obtain a global solution than the deterministic searching techniques.

We developed the automatic 2-dimensional nesting software

NST(ver.1.1)

for footwear industry by implementing these proposed algorithms. The optimized automatic nesting algorithm of

NST

has been applied for cutting without the loss of leathers, if possible, after detecting defected areas.

NST

can also consider various distinctive qualities in not only natural leathers but artificial ones. Lastly,

NST

can reduce a required time to generating NC-code, cutting time, and waste of raw materials because it automatically performs parts arrangement, cutting paths generation and finally NC-code generation, which require a lot of efforts and time to generate them manually.

Tae-Jung Lho, Dong-Joong Kang, Am-Suk Oh, Jang-Woo Kwon, Suk-Tae Bae, Kang-Hyuk Lee

A Resource Balancing Scheme in Heterogeneous Mobile Networks

Heterogeneous access networks in B3G networks can provide each proper network service to mobile users. Furthermore, mobile users can use not only a unique access network service, but also different hetero network services by connecting another access network. For using another access network service, mobile terminals must support hetero network system techniques. Hence, by this multiple system modes, mobile terminals are able to implement ISHO (Inter System Handover) for changing the network service. In the heterogeneous access network environment, new resource management can be adopted to control QoS management. In this paper, we propose a resource balancing management scheme by the ISHO to increase the network availability. From the numeric analysis, we compare the proposed scheme with a current scheme.

Sangjoon Park, Youngchul Kim, Hyungbin Bang, Kwanjoong Kim, Youngsong Mun, Byunggi Kim

Fast BU Process Method for Real Time Multimedia Traffic in MIPv6

The designation of the internet has changed. Networked devices, formerly placed at scientist and business desk, are now consumer parts and serve for information, communication and entertainment. The facing the emer-ging paradigm of ubiquitous computing and communication voice and video-conferencing over IP is on the spot to establish as standard internet solutions. However, current roaming procedures are inefficient and unstable for real-time applications. In this paper, we present when MN send BU, it send to add 1 bit for priority. HA or CN according to priority, so general performance is improved. The performance analysis and the numerical results presented in this paper show that our proposal has superior performance by 7%.

Wongil Park, Byunggi Kim

Network Intrusion Detection Using Statistical Probability Distribution

It is very difficult to select useful measures and to generate patterns detecting attacks from network. Patterns to detect intrusions are usually generated by expert’s experiences that need a lot of man-power, management expense and time. This paper proposes the statistical methods for detecting attacks without expert’s experiences. The methods are to select the detection measures from features of network connections and to detect attacks. We extracted normal and each attack data from network connections, and selected the measures for detecting attacks by relative entropy. Also we made probability patterns and detected attacks by likelihood ratio. The detection rates and the false positive rates were controlled by the different threshold in the method. We used KDD CUP 99 dataset to evaluate the performance of the proposed methods.

Gil-Jong Mun, Yong-Min Kim, DongKook Kim, Bong-Nam Noh

Network Anomaly Detection Based on Clustering of Sequence Patterns

Anomaly detection is a method for determining behaviors which do not accord with normal ones. It is mostly used for detecting abnormal behaviors, mutational and unknown attacks. In this paper, we propose a technique that generates patterns about network-based normal behaviors in blocks of a TCP network session for the anomaly detection. One session is expressed as one pattern based on a stream of the packets in the session, and thus the pattern we generate has a sequential feature. We use the ROCK algorithm to cluster the sequence patterns which have categorical attributes. This algorithm performs clustering based on our similarity function which uses Dynamic Programming. The many sequence patterns of the normal behaviors can be reduced to several representative sequence patterns using the clustering. Our detecting sensor uses profiling dataset that are constructed by the representative sequence patterns of normal behaviors. We show the effectiveness of proposed model by using results from the 1999 DARPA Intrusion Detection Evaluation.

Sang-Kyun Noh, Yong-Min Kim, DongKook Kim, Bong-Nam Noh

A Routing Protocol for Throughput Enhancement and Energy Saving in Mobile Ad Hoc Networks

Mobile nodes communicate with each others having the limited energy in mobile ad hoc networks. The large amount of control packets and the frequent flooding of control packets cause energy exhaustion of nodes. The main goal of routing protocols in mobile ad hoc networks is throughput enhancement. Hence, this paper proposes a new routing protocol for mobile ad hoc networks called the Routing Protocol for Throughput Enhancement and Energy Saving (TEES) in mobile ad hoc networks. The simulation results show that TEES increases the amount of packet delivery and reduces the control packet overhead.

HyoJin Kim, SeungJae Han, JooSeok Song

Spatial Indexing Based on the Semi-approximation Scheme of MBR

Over the last few years, the increase in spatial data has led to more research on spatial indexing. Most studies, however, are based on adding or changing various options in R-tree, and few studies have focused on increasing search performance via minimum bounding rectangle (MBR) compression. In a spatial index, a greater number of node entries lowers tree heights and decreases the number of node accesses, thereby shrinking disk I/O. This study proposes a new MBR compression scheme using semi-approximation (SA) and SAR-tree, which indexes spatial data using R-tree. Since SA decreases the size of MBR keys, halves QMBR enlargement, and increases node utilization, it improves the overall search performance. This study mathematically analyzes the number of node accesses and evaluates the performance of SAR-tree using real location data. The results show that the proposed index performs better than existing MBR compression schemes.

Jongwan Kim, SeokJin Im, Sang-Won Kang, Chong-Sun Hwang

Workflow Clustering Method Based on Process Similarity

Process-centric information systems have been accumulating a mount of process models. Process designers continue to create new process models and they long for process analysis tools in various viewpoints. This paper proposes a novel approach of process analysis. Workflow clustering facilitates to analyze accumulated workflow process models and classify them into characteristic groups. The framework consists of two phases: domain classification and pattern analysis. Domain classification exploits an activity similarity measure, while pattern analysis does a transition similarity measure. Process models are represented as weighted complete dependency graphs, and then similarities among their graph vectors are estimated in consideration of relative frequency of each activity and transition. Finally, the models are clustered based on the similarities by a hierarchical clustering algorithm. We implemented the methodology and experimented sets of synthetic processes. Workflow clustering is adaptable to various process analyses, such as workflow recommendation, workflow mining, and process patterns analysis.

Jae-Yoon Jung, Joonsoo Bae

Distributed, Scalable and Reconfigurable Inter-grid Resource Sharing Framework

Tremendous advancement and more readily availability of Grid technologies encourages organizations to establish in-house Grids and make use of their available desktop resources to solve computing intensive problems. These mini Grids, because of their limited scope and resource availability, may not serve the real world problem in every aspect and, hence, lead them to collaborate on demand with other grids while keeping themselves autonomous and independent. The specific problem that underlies in such collaborative Grids is resource scheduling among autonomously administrated Grids. In this paper*, we propose a distributed, scalable and reconfigurable inter-Grid resource sharing framework where Grids can dynamically join or resign the framework on a need base. This framework, based on peer-to-peer communication paradigm, enables resource sharing among autonomous Grid systems.

Imran Rao, Eui-Nam Huh, SungYoung Lee, TaeChoong Chung

Scalable Mobile Internet Servers: Selecting Useful Images from the Web for Mobile Services

There are many new studies on the contents for mobile devices that are all connected to networks in a seemingly ubiquitous environment. The purpose of this paper is to propose a framework for obtaining Internet content intended for computers on mobile devices. In other words, the primary concern of this paper is to select the best images for optimal performance and convert them into images that can be effectively reproduced on mobile devices. For this, the performance of the server is to be optimized through selecting useful images among the many available images and converting them while considering the display pixel rates (DPR) and the image distribution areas.

DaeHyuck Park, Maria Hong, Euisun Kang, Seongjin Ahn, YoungSong Mun, YoungHwan Lim

A Macro Mobility Handover Performance Improvement Scheme for HMIPv6

MIPv6 provides the L3 connectivity when the IPv6 mobile node moves between subnets. Nevertheless, the mobile node cannot receive IP packet because of the handover latency. The handover latency is not efficient to provide the real-time multimedia application service. Notable protocols of the extensions of MIPv6 are FMIPv6 and HMIPv6. In HMIPv6, if the mobile node moves from one access router to another in the different MAP domain, such a movement is called macro mobility handover, then the mobile node creates a new RCoA and LCoA and performs registration with the new MAP and HA. Until the address registration with MAP and HA complete, the mobile node cannot receive IP packet. Therefore, we need to execute the macro mobility handover efficiently and reduce the handover latency and packet loss. We propose a method to perform the macro mobility handover efficiently in HMIPv6. To provide seamless service and minimize packet loss when the mobile node performs the macro mobility handover, we will adjust the fast handover technology of FMIPv6 to the MAP’s characteristics in the proposed scheme. To reduce the handover latency and packet loss, we use a tunnel between the edge access routers and perform the L3 handover earlier before the L2 handover. We compare the procedure of the macro mobility handover of the proposed scheme with the original HMIPv6 by means of using the cost analysis comparison. We observe that the proposed scheme can be reduced the 82% of the total cost of the macro mobility handover of the original HMIPv6.

Kyunghye Lee, Younghwan Lim, Seongjin Ahn, Youngsong Mun

Cost Evaluation of Differentiated QoS Model in Mobile IPv6 Networks

Traditional Internet services provide the same level of service to all users without considering about their applications’ requirements. However, new applications demand better quality of service (QoS) and host mobility according to wireless and Internet technologies are more widely available. To satisfy QoS and mobility of communication, we deploy differentiated services (Diffserv) model to provide differentiated QoS in mobile IPv6 networks. The operational procedures and cost analyzing models are suggested for an MN (mobile node)’s mobility and its performance is presented by cost analysis.

Misun Kim, Youngsong Mun

Proactive Self-healing System for Application Maintenance in Ubiquitous Computing Environment

With evolving modern IT technology, one desirable characteristic of distributed of applications is self-healing, or the ability to reconfigure themselves “on the fly” to circumvent failure. Thus, the goal is to avoid catastrophic failure through prompt execution of remedial actions. This paper proposes a self-healing system that monitors, diagnoses and heals its own internal problems using self-awareness as contextual information. The proposed system consists of multi agents that analyze the log context, error events and resource status in order to perform self-diagnosis and self-healing. For rapid and efficient self-healing, for developing the proposed system, we use a

6-step

process:

monitoring, filtering, translation, diagnosis, decision and feedback

. Our experiments conducted with a prototype system confirm the effectiveness of the proposed system.

Jeongmin Park, Giljong Yoo, Chulho Jeong, Eunseok Lee

An Approach to Developing Domain Architectures Based on Variability Analysis

Software product line engineering is a method that prepares for future reuse and supports seamless reuse in the application development process. A domain architecture, sharing a common software architecture across a product line, brings a core set of knowledge and assets to the development process. Domain architectures reduce the complexity and cost of developing and maintaining code. However, technically excellent domain architectures do fail, often because they are not effectively developed. The key concept in the development of domain architecture is variability, the ability to derive various products from the product family. Variability occurs at different levels. It is important to consider variability at the higher architectural levels, and not only at the code level. In this paper, we suggest a method of producing architectures that will be core assets in the product line. We describe a domain architecture where commonality and variability are explicitly considered.

Mikyeong Moon, Keunhyuk Yeom

A Technical Assessment of SoC Methodologies and Requirements for a Full-Blown Methodology

SoC plays a key role in building software-intensive hardware systems such as embedded systems. It is commonly known that the complexity of SoC and the demand for shorter time-to-market are sharply increasing. However, current SoC methodologies do not address the trends and demands effectively. To provide SoC methodologies that satisfy these issues, the current SoC methodologies should be technically assessed so that the full requirement for future SoC methodologies can be formulated. In this paper, we first give a foundation on SoC, and summaries representative methodologies compared. For the comparison, we identified six comparison criteria and present in-depth assessments using logical reasoning in text, tables, and figures. Using the assessment, we define and elaborate three key requirements for future SoC methodologies;

Balanced Process Framework, Reuse-focused Activity,

and

Traceability

.

Du Wan Cheun, Tae Kwon Yu, Soo Ho Chang, Soo Dong Kim

Context-Aware Home Network Environment on Grid (CAHE-G)

In this paper, we present context-aware home network environment on grid that controls the room appliances providing user mobility. The current home network technology (such as Havi, Jini and UPnP) is limited to a static local area. However, we propose ubiquitous concepts of home network system of user mobility in context-aware computing. It is called as CAHE-G which is not limited to static local area, but provides ubiquitous concepts of home network. CAHE-G controls home appliances according to context information, and is divided into two parts: Agent layer and Service layer. The Service layer consists of Lookup Service (LUS), Home Controller, Grid Service Provider (GridSP). The Service layer provides home and grid services with user request. LUS provides searching and registering those services. The Agent layer consists of Grid Agent (GA) and Home Context Agent (HCA). Grid technology can be used to automatically execute the home network service depending on context information. Agent layer provides user ubiquity, autonomous execution and large computation in this system. GA consists of Execution Manager (EM), MDS Manager (MM), and File Manager (FM) in order to enable those functionalities. Also, HCA provides autonomous adaptability to user. It gathers and interprets context information, then assigns the information to GA. As a result, in CAHE-G, Grid computing provides the capabilities: autonomous execution, interoperability, and the standard approaches to, and mechanisms for basic problems. Moreover, context-aware characteristic gives merits such as user mobility and adaptability.

Seung-Hwan Jung, Tae-Dong Lee, Chang-Sung Jeong

An Efficient Binding Update Scheme in HMIPv6

Mobile IPv6 (MIPv6) allows mobile nodes to keep its connectivity to network using a permanent address and temporary address to identify mobile node’s current location when a mobile node (MN) visits a foreign network. Currently, plentiful signal traffics for handover and handover delay due to it have been proposed as a hot issue in the MIPv6. Hierarchical Mobile IPv6 (HMIPv6) is designed to reduce the signaling load and handover latency. However, HMIPv6 only improves local mobility while the handover delay still occurs in the handover between mobility anchor points. In this paper, we propose an efficient binding update scheme to reduce signaling cost and handover latency in the HMIPv6. Especially, a signal message from a MN contains another signal message, which allows the MN to originate only the half of signal messages in home registration process, compared to original protocol. The improvements contributed by the proposed scheme over the basic HMIPv6 are shown to be significant.

Jaeduck Oh, Youngsong Mun

A Scheduling Algorithm for Parallel Tasks in Peer-to-Peer Systems

Many researches have been conducted on systems that consist of heterogeneous machines, such as peer-to-peer computing and GRID system. In heterogeneous system, an important research problem is how to allocate a task to the machines. In this paper, an algorithm that can schedule and allocate parallel tasks through peer-to-peer computing was presented, and its effectiveness in the peer-to-peer system was shown.

Jeong Woo Jo, Jin Suk Kim

Automatic Configuration of IPv6 Tunneling in a Dual Stack Host

In the IPv6 transition process, coexistence with IPv4 is required, in which methods are invoked, where a user can use IPv6 easily, in a transition phase. In addition, methods also exist to manage an IPv6 network, in order to improve the activation and efficiency of IPv6 usage. In this paper, a system is proposed, with a function to measure network performance and obtain automatic connection using tunneling, where even an amateur can connect to the IPv6 system, along with an index. High performance of IPv6 can be manually verified, in order to promote the supply of IPv6, increasing the efficiency of network management.

Jaewook Lee, Jahwan Koo, Jinwook Chung, YoungSong Mun, YoungHwan Lim, Seung-Jung Shin, Seongjin Ahn

Estimation of Link Speed Using Pattern Classification of GPS Probe Car Data

In the field of Intelligent Transport Systems, there have been many attempts to predict the speed of the vehicle by adopting the pattern of the speed using artificial intelligence and statistical methods. Traffic information has been collected mainly by fixed devices which are costly and hard to maintain. Recently, traffic data is progressively being collected by the probe cars equipped with GPS receivers. Most of probe cars are comprised of public and commercial transportation such as taxis and buses since the private drivers are reluctant to give their location information due to the privacy issues. This creates problem of insufficient number of cars available and the traditional analysis methods used for analyzing the data collected by the fixed devices are not applicable. The aim of this research is to propose and test a new method of calculating the optimal link speed for the collected information from probe cars. We propose the adoption of a fuzzy c-mean method for this purpose. In this paper the GPS speed data are automatically classified into three groups of speed patterns such as low, middle, and high speed and the link speed is predicted from the pattern clusters. In performance tests, the proposed method provides significantly better results than normal average speed data.

Seung-Heon Lee, Byung-Wook Lee, Young-Kyu Yang

Storing and Querying of XML Documents Without Redundant Path Information

We propose an improved approach that stores and queries a large volume of XML documents in a relational database, while removing the redundancy of path information and using an inverted index on the reduced path information. In order to store XML documents in a relational database, the XML document is decomposed into nodes based on its tree structure, and stored in relational tables with path information from the root node to each node. The existing XML storage methods which use relational data model, usually store path information for every node. Thus, they can increase storage overhead and decrease query processing performance with the increased data volume. Our approach stores only leaf node path information in XML tree structure while finding out internal node path information from the leaf node path information. In this manner, our approach can reduce data volume for a large amount of XML documents to a degree and also reduce the size of inverted index for the path information with the smaller number of posting lists by key words. We show the effectiveness of this approach through several experiments that compare XPath query performance with the existing methods.

Byeong-Soo Jeong, Young-Koo Lee

Route Optimization Problems with Local Mobile Nodes in Nested Mobile Networks

As an extension of Mobile IPv6 to the case of network mobility (NEMO), the NEMO basic support protocol has been proposed. However, it suffers from some drawbacks such as pinball routing and large packet sizes in nested mobile networks (MoNET). In this paper we introduce new pinball routing problems associated with local mobile nodes in nested MoNETs and discuss on the effectiveness of several RO schemes in tackling the problems. Among the schemes we demonstrate that the RCS scheme can be an appropriate solution due to its low signaling overhead and short RO setup time compared to other approaches. Most importantly, we show that the RCS scheme is the unique solution for mobility support when a mobile network taking part in a nested MoNET changes its attachment point within the MoNET.

Young Beom Kim, Young-Jae Park, Sangbok Kim, Eui-Nam Huh

Design of Network Aware Resource Allocation System for Grid Applications

Grid Network applications that need to achieve reliable end-to-end performance typically make use of either reservations or adaptation. However, both techniques also have serious limitations, particularly when dealing with high-bandwidth, dynamic flow as like Grid. Fixed-capability reservations tend to be wasteful of resources and it cannot permit dynamic adaptation in application performance when resource management policies are changed. Adaptation scheme inevitably fails when congestion reduces available resources below acceptable limits. In this paper, we describe an approach to QoS that combines features of both reservation and adaptation to address the difficulties above noted. In addition, we propose extended GARA and advanced reservation and reserved resource saving scheme that provide more effective QoS.

Jonghyoun Choi, Ki-Sung Yu, Jongjin Park, Youngsong Mun

Traffic Groomed Multicasting in Sparse-Splitting WDM Backbone Networks

As the interest of the Internet multicasting increases, the huge portion of the future traffic in optical WDM networks is expected to be strongly related to multicast applications and thus the technology for grooming such traffics also becomes important. In this study, we investigate the problem of multicast traffic grooming in WDM optical mesh networks with sparse-splitting capability. The problem of constructing optimal multicast routing trees and grooming their traffics in WDM optical mesh networks is NP-hard. Therefore, we propose heuristic algorithms to solve the problem in an efficient manner. These reduce the link cost by constructing a minimal cost tree with multicast capable nodes and increase the traffic grooming effect based on the relationship of multicast sessions. Comprehensive simulation results demonstrate that the proposed schemes use the network resource more efficiently especially for link cost compared to the previous work [1] while maintaining the similar number of wavelengths.

Yeo-Ran Yoon, Tae-Jin Lee, Min Young Chung, Hyunseung Choo

2-Way Text Classification for Harmful Web Documents

The openness of the Web allows any user to access almost any type of information. However, some information, such as adult content, is not appropriate for all users, notably children. Additionally for adults, some contents included in abnormal porn sites can do ordinary people’s mental health harm. In this paper, we propose an efficient 2-way text filter for blocking harmful web documents and also present a new criterion for clear classification. It filters off 0-grade web texts containing no harmful words using pattern matching with harmful words dictionaries, and classifies 1-grade,2-grade and 3-grade web texts using a machine learning algorithm.

Youngsoo Kim, Taekyong Nam, Dongho Won

Integration of a Structural Index with a Structural Join for Accelerating Path Queries

Current techniques for processing XML queries can be divided into two groups. One is structural index techniques that reduce the search space by traversing a structural summary instead of a data graph. And the other is structural join techniques that can efficiently compute ancestor-descendant pairs from two lists of nodes without traversing the data graph. In this paper, we propose a structural index technique and a novel structural join technique and we prove that these two proposed techniques are integrated to accelerate processing of a path query in the experiments.

Jongik Kim, SooCheol Lee, Oh-Cheon Kwon

Workshop on Mobile Communications (MC 2006)

Thin-Client Computing for Supporting the QoS of Streaming Media in Mobile Devices

Due to the limited resources in thin-clients on mobile devices and the large amount of computation for decoding streaming media, it is not easy to support the QoS of streaming media for thin-client on mobile environment. To solve the problems, the terminal servers would be charged for decoding the streaming media and thin-clients have a role to update only the changed areas in their screen. In this paper, an intelligent media player is proposed to provide the improved QoS for streaming media in thin-client computing. Since the proposed method reflects the intrinsic property of streaming media, it provides both the enhanced video quality and the audio streaming fully synchronized with image frames.

Joahyoung Lee, Dongmahn Seo, Yoon Kim, Changyeol Choi, Hwangkyu Choi, Inbum Jung

MPLS Alternate Path Restoration with Guaranteed Bandwidth

This paper presents a new MPLS restoration scheme that guarantees bandwidth requirements. This scheme uses network resources more efficiently and minimizes the backup path cost effectively. The proposed restoration scheme starts the recovery action at a selected node of a working LSP. At the LSP setup, the working and backup path bandwidth and cost are evaluated and a starting node of restoration is designated. By doing so, the restoration speed could be further increased and resource utilization could be maximized with guaranteed bandwidth. Simulation is conducted to evaluate the performance of the proposed scheme. The results show that our scheme can provide fast restoration with acceptable delay and loss characteristics with higher restoration rate.

Kil-Hung Lee, Jae-Soo Kim

A Study on the WBTC and NBTC for CDMA Mobile Communications Networks

Cell sectorization and improvement of the Chip Energy/Others Interference(Ec/Io) are technologies to offer good quality of services (QoS) and coverage for new and sophisticated power control to achieve high capacity in CDMA cellular mobile communication networks. In this paper, in order to efficient cell sector and to improve the Ec/Io of the pilot channel in CDMA mobile communication systems, I analyze and compare the wide-beam trisector cell(WBTC) with the narrow-beam trisector cell(NBTC) as a method for cell sectorization. The NBTC was compared with the WBTC, using the results of a theoretical analysis, a simulation, a field measurement, in order to examine its effectiveness and validity. As a result, I confirmed that NBTC was efficient cell sector method to minimize interference from adjacent base stations and to increase cell coverage.

Sun-Kuk Noh

A Secure Multicast Routing Protocol for Ad Hoc Networks with Misbehaving Nodes

Ad hoc networks are useful in many application areas. Security is important but it is a challenging issue due to ad hoc network’s characteristics such as lack of infrastructure, communication over wireless medium, and node mobility. In this paper we present a secure multicast routing protocol for ad hoc networks. The proposed protocol makes it possible for a node to create a new multicast group and join or leave an existing group securely. It also includes a mechanism for detecting and repairing broken links securely. In addition to securely exchanging multicast packets, this paper addresses the problem of securely building and maintaining multicast trees in ad hoc networks. Moreover, the protocol guards against attacks from authorized but misbehaving nodes as well as unauthorized nodes.

Young-Chul Shim

Seamless and Reliable Mobile Multicast Mechanism in Next Generation Networks

NGN (Next Generation Network) is one of IP-based network that integrates different communication technologies interfacing with each other such as PSTN, ATM, Frame Relay, ADSL, WLAN and so on. In addition, Multicast support in NGN is essential to some specific applications for file transmission in large capacity, video broadcasting and streaming, video conference, and on-line game. To support these multicast applications, some critical problems, such as delay and packet loss in multicast communications among users on different network must be solved. This study proposes a structure to eliminate above problems and it is based on the extension of multicast router functions for efficient, optimum and reliable multicast support in NGN. In other words, our architecture solves the delay problem and dramatically cuts down implosion of feedback information concentrated on senders. Therefore, our approach could be a basic multicasting mechanism to support seamless and reliable mobile multicast in NGN environment.

Choonsung Rhee, Sunyoung Han

Adaptive Selection of MIPv6 and Hierarchical MIPv6 for Minimizing Signaling Cost

Internet engineering task force(IETF) has proposed hierarchical mobile IPv6(HMIPv6) in order to reduce a frequent location registration of a mobile node in mobile IPv6(MIPv6). All traffics toward a mobile node must be transmitted through a MAP in HMIPv6. This brings unnecessary packet latency because of the increased processing cost of packet at the MAP. At this point the processing cost of packet at the MAP is influenced both by the packet arrival rate for a mobile node and the number of mobile nodes in MAP domain. In this paper, we propose that MIPv6 and HMIPv6 are adaptively selected in order to minimize signaling cost of network as complementing weak points of MIPv6 and HMIPv6. After supposing by the packet arrival rate for a mobile node is fixed, with this in mind, we find the optimal number of mobile nodes compared the total cost of HMIPv6 with the total cost of MIPv6. Also, if mobile nodes that the MAP is able to manage are full in MAP domain, then a mobile node entering into the MAP domain is provided connection by MIPv6 instead of HMIPv6. In the conclusion, the proposed method of this paper shows that the weak points of MIPv6 and HMIPv6 are removed by adaptive selection each other.

Younghyun Kim, Youngsong Mun

DIASCOPE: Distributed Adaptation System Using Cooperative Proxies in Ubiquitous Network

With evolving modern technology, and widespread deployment of wireless devices, adaptation research is becoming an important issue for overcome various constraints in wireless networks, and maintaining an acceptable level of service. However, most existing research only focuses on wireless device resource utilization, without consideration of proxy server workload execution. In practice, adaptation jobs dynamically converting media formats, consumes a large amount of resources. In this paper, a novel adaptation system is proposed, by distributing workload through nearby cooperative proxies composed of a hierarchical structure. The proposed system has an intelligent engine, which autonomous creates rules. The system performs adaptation work based on rules. A prototype was implemented to evaluate and partly apply this research in a Healthcare scenario. Hence, the effectiveness of the system is confirmed through results, in which the system offers faster adapted content transmission to the user.

Seunghwa Lee, Eunseok Lee

A Novel Method for Energy-Efficient Clustering in Wireless Sensor Networks

Energy-efficiency, a prolonged network lifetime, and scalability are crucial requirements for wireless sensor networks. Clustering is a fundamental mechanism that designs energy-efficient wireless sensor network protocol and is an effective technique in achieving the above requirements. Recently, many clustering algorithms within various contexts have also been proposed, but to our knowledge, none of them considers outlier problem in configuring clusters. In this paper, we introduce an outlier problem in that a sensor node does not belong to any cluster.In existing clustering algorithms, we propose a solution to this outlier problem by using a relay node to transfer the sensed data of an outlier sensor node to its cluster head. Simulation results showed that the proposed scheme produced a superior performance in terms of energy-efficiency of wireless sensor networks.

Sung-Hyup Lee, Gi-Won Park, You-Ze Cho

iSCSI Multi-connection and Error Recovery Method for Remote Storage System in Mobile Appliance

The continued growth of both mobile appliance and wireless Internet technologies is bringing a new telecommunication revolution and has extended the demand of various services with mobile appliance. However, during working with wireless access devices, users have a limited amount of storage available to them due to their limited size and weight. To relieve this problem iSCSI (Internet Small Computer Interface) remote storage system would be one solution but the question is high availability and performance. In this paper, we propose a new approach of Multi-Connection in one session based remote storage system for mobile appliance with error recovery method that avoids drastic reduction of transmission rate from TCP congestion control in wireless environment as compared to traditional iSCSI.

Shaikh Muhammad Allayear, Sung Soon Park

Distributed Coordination and QoS-Aware Fair Queueing in Wireless Ad Hoc Networks

Shared channel, multihop wireless ad hoc network has some unique characteristics that make the fair scheduling in such environment challenging. In this paper we propose a new QoS-aware fair queueing model for ad hoc networks. Our proposed algorithm ensures a distributed coordination of fair channel access while maximize the throughput using spatial reuse of bandwidth. We consider the presence of both guaranteed and best effort flows. The goal is to satisfy the minimum bandwidth requirement of guaranteed flows and provide a fair share of residual bandwidth to all flows. We propose a flow weight calculation scheme to both guaranteed and best-effort flows and a distributed, localized mechanism to implement the time-stamp based ad hoc fair queueing model.

Muhammad Mahbub Alam, Md. Mamun-or-Rashid, Choong Seon Hong

Lightweight Bindings for Mobile Routers

NEtwork MObility (NEMO), which supports a moving network of mobile devices, has only recently appeared. In this paper, the Route Optimization (RO) problem on both single and nested Mobile Networks, is studied. There are several well-known heuristics [1, 6, 7, 10, 11], which attempt to solve the RO problem in the Mobile Network. However, these schemes do not entirely solve the problem, because of the additional overhead of supporting RO in the Mobile Network. In this paper, a new Binding Update (BU) scheme for RO is proposed, and analyzed using representative work of published literature. This is achieved by employing an extra Home Address Option (HAO) slot, in the registration time, resulting in a significant reduction in the overhead for the BUs. Based on performance analysis, it is demonstrated that the proposed algorithm outperforms other algorithms with regard to the delay.

Youngjin Ahn, Tae-Jin Lee, Hyunseung Choo

A Balanced Deployment Algorithm for Mobile Sensor Networks

This paper describes a grid-based deployment algorithm to maximize the network coverage in mobile sensor networks. The algorithm divides target areas with scattered mobile sensors into some grids and selects a grid header in each grid. The grid header is responsible for collecting the information of nodes in the grid. If the number of nodes in the grid is less than the average number of nodes, the grid header requests the node movement to neighboring grids. After the node movement from the neighboring grids, if the number of nodes in the grid is below the average, it requests the node movement to the two-hop grids apart through the neighboring grids. After the node movement from the two-hop grids, the grid header performs to relocate its members in the grid. By performing three procedures, the algorithm is able to deploy uniformly the given nodes in the target area. This paper presents the operation of a balanced deployment algorithm and shows performance evaluation of the deployment algorithm.

Kil-Woong Jang, Byung-Soon Kim

A Merging Clustering Algorithm for Mobile Ad Hoc Networks

Clustering is a widely used approach to ease implementation of various problems such as routing and resource management in mobile ad hoc networks (MANET)s. We propose a new fully distributed algorithm for clustering in MANETs that merges clusters to form higher level clusters by increasing their levels. We show the operation of the algorithm and analyze its time and message complexities and provide results in the simulation environment of

ns

2. Our results conform that the algorithm proposed is scalable and has a lower time and message complexities than the other algorithms.

Orhan Dagdeviren, Kayhan Erciyes, Deniz Cokuslu

Context-Aware Cross Layered Multimedia Streaming Based on Variable Packet Size Transmission

Multimedia streaming is usually disturbed by the surroundings. Especially in the ubiquitous computing environment, seamless multimedia service is difficult to provide due to harsh environment of wireless network and limited power of small mobile devices. In this paper we propose a scheme which can enhance the QoS of MPEG-4 streaming. By exhaustive experimental test, we find that the QoS of multimedia streaming significantly depends on the SNR (Signal-to-Noise Ratio). The proposed scheme employs five different packet sizes and selects a one according to the SNR value and the data on the packet delay and loss. Experiment on MPEG-4 video transmission reveals that the proposed streaming with variable packet size allows fast adaptation before the error propagates, minimizes the power consumption, and saves the buffer space compared to the streaming with fixed packet size.

Hyung Su Lee, Hee Yong Youn, Hyedong Jung

Adaptive Mobile Checkpointing Facility for Wireless Sensor Networks

In wireless sensor networks, many kinds of failures may arise on sensor nodes because the nodes can be deployed and used even in harsh environments. Therefore, fault-tolerance mechanisms are needed for the wireless sensor networks have to maintain stability and normal operation of the networks. In this paper, we propose an adaptive mobile checkpointing mechanism for wireless sensor networks that gives fault-tolerance for the networks. It is a yet another checkpointing mechanism based on the diskless checkpointing which does not use stable storage but uses the redundant memory space of neighboring nodes. Our experimental results show that the lifetime and stability of sensor networks was dramatically increased compared with the case when the proposed mechanism was used or not.

Sangho Yi, Junyoung Heo, Yookun Cho, Jiman Hong

NeMRI - Based Multicasting in Network Mobility

Mobile IP is a solution to support mobile nodes but it does not handle NEtwork MObility (NEMO). The NEMO Basic Support [2] ensures session continuity for all the nodes in the mobile network. Since the protocol is based on Mobile IP, it inherits the same fundamental problem such as tunnel convergence, when supporting the multicast for NEMO. In this paper, we propose the multicast route optimization scheme in NEMO environments. Assume that the Mobile Router (MR) has a multicast function and the Nested Mobile Router Information (NeMRI). The NeMRI is used to record a list of the CoAs of all the MRs located below it. And it covers whether MRs desire multicast services. Any Route Optimization scheme can be employed here for pinball routing. Therefore, we achieve optimal routes for multicasting based on the given architecture. We also propose cost analytic models to evaluate the performance of our scheme. We observe significantly better multicast cost in NEMO compared with other techniques such as Bi-directional Tunneling, Remote Subscription, and Mobile Multicast based on the protocol [2].

Moonseong Kim, Tae-Jin Lee, Hyunseung Choo

Improving TCP Throughput and Fairness over Multi-rate IEEE 802.11 Wireless LANs

As the increase of wireless network applications based on TCP/IP, many researchers have been trying to develop TCP according to wireless environments. However, most of the proposed schemes do not consider the multi-rate capability of WLANs. In this paper, through experiments in 802.11b WLAN based multi-rate environments having data rates of 2Mbps, 5Mbps, and 11Mbps, we show that total throughput of TCP is degraded when multiple flows with different transmission rates go through a base station and analyze the reason in details. Then, we propose a rate adaptive flow control scheme in which rate-proportional buffer allocation is performed at the BS to increase the total network throughput as well as to reduce the sensitivity of TCP throughput to the available BS buffer space by guaranteeing the temporal fairness of each flow. The performance is evaluated by simulation using

ns2

, and the results show that the proposed scheme increases the total network throughput and guarantee temporal fairness among concurrent multiple flows.

Seon-Don Lee, Dong-Hee Kwon, Woo-Jae Kim, Young-Joo Suh

Local Source Routing Based Route Optimization in Nested Mobile Networks

Network Mobility (NEMO) is concerned with managing the mobility of an entire network and included one or more Mobile Routers (MRs) which are connected as gateways to the Internet. This paper proposes a mechanism for route optimization in nested NEMO by using local source routing with uni-direction tunneling. Our scheme focuses on minimizing the number of tunnels required outside the NEMO when there are multiple levels of nesting. The simulation results demonstrate that the proposed scheme is well adapted for supporting route optimization over existing NEMO’s bi-directional tunneling scheme.

Yunkuk Kim, Sinam Woo, Sangwook Kang, Woojin Park, Sunshin An

An Efficient Movement Management Method of Mobile Node in Mobile IPv6

As the number of Mobile IP user grows, the signal message overhead which is associated with mobility management in the IP networks will be concerned. It presents a critical challenge to Mobile IP as the number of mobile environment devices scale up. This paper introduces an efficient movement management method which reduces the cost of the mobility signal messages of a mobile user. The proposed scheme uses a paging scheme and reduces the cost of paging request messages. Also the characteristic of a communication of a user is considered. This document present comparative analysis results for HMIPv6, P-HMIPv6 and proposed scheme, and show that the proposed scheme can reduce the cost of signal message which is needed by user to support the mobility management. According to the result of performance analysis, the proposed scheme can reduce the movement management signal message cost as 43% compare with the HMIPv6.

Chungsoo Shin, Byunggi Kim, Youngsong Mun

Homogeneous 2-Hops Broadcast in 2D

Given a set

S

of

n

pre-placed radio-stations and a source station

s

*

, we consider two variations of minimum cost homogeneous range assignment problem for the 2-hops broadcast from

s

*

to all the members in

S

, where the range assigned to a radio-station is either zero or a fixed value

r

. Thus, the cost of range assignment is proportional to the number of radio-stations having range

r

. The variations we study are (i) find the value of

r

and identify the radio-stations with range

r

such that the total cost is minimum, and (ii) given a real number

r

, check whether homogeneous 2-hops broadcast from

s

*

to the members in

S

is possible with range

r

, and if so, then identify the smallest subset of

S

whom range

r

is to be assigned such that 2-hops broadcast from

s

*

is possible. The first problem is solved in

O

(

n

3

) time and space. But, the second one seems to be hard. We present a 3-factor approximation algorithm for this problem, which runs in

O

(

n

2

) time. An

O

(

n

2

) time heuristic algorithm for the second problem is also presented. Most of the times, it produces optimum result for randomly placed radio-stations.

Gautam K. Das, Sandip Das, Subhas C. Nandy

A Study on the Transportation Period of the EPG Data Specification in Terrestrial DMB

With the convergence of information communication and broadcasting technology, DMB (Digital Multimedia Broadcasting) becomes the hottest issue of the next generation in the new media industry and the communications market. It is possible for people to watch seamless TV broadcast using DMB in motion, by adding video transportation specification into Eureka-147 of European digital radio broadcasting standard. DMB can select the preferred channel by using EPG (Electronic Program Guide). Since the EPG information takes a role of baseline which provides whole guidelines and services to users, its update should be performed constantly. To support scalability and compatibility on DMB, XML-based EPG and binary EPG have been proposed for the establishment of standard and these EPGs are being updated daily or weekly. However, this update period is too long to apply changes on time and also makes the update process take long time. To solve this problem, this paper proposes and implements efficient EPG system which maximizes the efficiency of EPG specification, by updating EPG of binary format per period of an hour and applying Naming Rule.

Minju Cho, Jun Hwang, Gyung-Leen Park, Junguk Kim, Taeuk Jang, Juhyun Oh, Young Seok Chae

Cluster-Based Certificate Chain for Mobile Ad Hoc Networks

A recent trend of wireless technology is to set up the wireless connections among close-by mobile nodes. This class of network is called as Mobile Ad Hoc Network (MANET). In MANET, mobile nodes can temporarily form a network and they cooperatively offer several functions. Hence, it is hard to apply traditional security techniques such as public key certification based on PKI. In this paper, we propose a practical model of public key certificate chain for MANET. Our scheme does not rely on a central server, but rather we utilize the Cluster-Based Routing Protocol (CBRP) for MANET to issue certificates in a distributed fashion. In our scheme, the certificates are chained very effectively and the signed messages can be transferred over certificate chain. Our scheme works well in a setting where the network topology is dynamically changed. Also, our scheme is more efficient than the related localized scheme [15].

GeneBeck Hahn, Taekyoung Kwon, SinKyu Kim, JooSeok Song

Optimization of Base Stations Positioning in Mobile Networks

Cell planning is a very complex task because many aspects should be taken into account including the traffic distribution, geography, antenna height of base stations, frequency, and so forth. This becomes more complicated when several constraints are considered such as the quality of service, maximum output power of transmitters, types of power control, and other network requirements. The problems are assignment of mobile stations to the appropriate base station and finding good locations of the base stations. This paper presents a constraint satisfaction problem model for base station location in 3G W-CDMA uplink environments. This is similar to a warehouse location problem, so it is NP-hard and consequently cannot be practically solved by exact methods for real size networks. Thus we apply constraint satisfaction techniques such as variable ordering and value ordering to get good approximate solutions. The algorithm has been implemented by using both integer programming and constraint programming.

Surgwon Sohn, Geun-Sik Jo

Design of Maximum Remaining Energy Constrained Directed Diffusion Routing for Wireless Sensor Networks

Since the sensor network nodes have a small size and limited battery power, there have been many studies for reducing their energy consumption. Each sensor node can show different energy usage according to the frequency of event sensing and data transmission, and thus they have different lifetime. So, some nodes may run out of energy that causes disconnection of paths and reduction of network lifetime. In this paper, we propose a new energy-efficient routing algorithm for sensor networks called Maximum remaining energy constrained directed diffusion routing (MRE-DD), that selects a least energy-consuming path among the paths formed by nodes with highest remaining energy, and thus provides long network lifetime and more uniform energy consumption by nodes. Simulation results show that our algorithm extends the network lifetime and enhances the network reliability by maintaining remaining energy distribution relatively uniform among sensor nodes.

An Kyu Hwang, Jae Yong Lee, Byung Chul Kim

A Timestamp-Based Optimistic Concurrency Control for Handling Mobile Transactions

Data broadcasting is an efficient method for disseminating data, and is widely accepted in the database applications of mobile computing environments because of its asymmetric communication bandwidth between a server and mobile clients. This requires new types of concurrency control mechanism to support mobile transactions executed in the mobile clients, which have low-bandwidths toward the server. In this paper, we propose an OCC/DTA (Optimistic Concurrency Control with Dynamic Timestamp Adjustment) protocol that can be efficiently adapted to mobile computing environments. The protocol reduces communication overhead by using client-side validation procedure and enhances transaction throughput by adjusting serialization order without violating transaction semantics. We show that the proposed protocol satisfies data consistency requirements, and simulate that this protocol can improve the performance of mobile transactions in data broadcasting environments.

Ho-Jin Choi, Byeong-Soo Jeong

Effects of PRF and Slot Interval on the Data Throughput of PPM-Based Ultra Wide-Band Systems in Multi-path Channels

In this paper, we investigate the effect of pulse repetition frequency (PRF) and slot interval on the throughput performance of the ultra wide band (UWB) wireless communication system in multi-path channels, and based on these observations, a data throughput control using PRF and slot interval is proposed for maximizing the effective throughput. Recently, due to many desirable features of the UWB system, it has drawn much attention especially for short-range high-speed data transmission. The UWB system has two parameters to determine its data throughput; pulse repetition frequency and slot interval. In the multi-path channel with additive white Gaussian noise, the UWB system suffers from the inter-pulse interference (IPI) and noise, which result in degradation of system performance. In order to maintain or improve the system performance, the UWB system can vary the two parameters. In this paper, we demonstrate the effects of the two parameters on the data throughput of the UWB system in various multi-path indoor channels through computer simulation, and show that the variable data rate approach designed based on the observations is superior to the fixed data rate one in terms of effective throughput performance.

Sungbin Im, Taehyung Park

Hierarchical Cluster Configuration Scheme for Scalable Ad Hoc Networks

Ad hoc wireless networks can be deployed quickly anywhere and, unlike mobile switching, do not rely on a fixed infrastructure, such as base stations. Hierarchical techniques have long been known to afford scalability in networks. In this paper, we describe a cluster-routing protocol based on a multilayer scheme in ad hoc networks. This paper assesses the scalability, with respect to increasing node count, of hierarchical routing in mobile ad hoc networks. This work provides scalable in ad hoc networks. We present detailed cluster head selection algorithm of ad hoc routing protocols. Our proposed protocol, called

‘Control cluster head Algorithm based on Hierarchical Cluster’

(CAHC) for ad hoc networks. The CAHC strategy takes advantage of a hierarchical architecture that is designed for scalable cluster head (CH) using new concept of control cluster head (CCH) scheme.

Keun-Ho Lee, Chong-Sun Hwang

A Route Optimization Via Recursive CoA Substitution for Nested Mobile Networks

In nested mobile networks, the undesirable effects due to nonoptimal routing tends to get aggravated, leading to excessively long packet sizes and transfer delays. In this paper, in order to resolve the non-optimal routing problem, also known as ‘pinball routing problem’ in the literature, we propose a new route optimization scheme where the care-of address (CoA) in each binding update (BU) message is recursively substituted by the intermediate mobile routers in the mobile network. Through qualitative and numerical analyses, we show that the proposed scheme indeed demonstrates a greatly reduced signaling overhead in terms of packet sizes and number of BU messages required, thereby reducing the RO setup time and end-to-end transfer delay. We also show that the proposed scheme can be a good solution for the so-called intra-MoNET routing problem.

Young Beom Kim, Kang-Yoon Lee, Hyunchul Ku, Eui-Nam Huh

Energy-Aware Routing Algorithm Using Backup Route for Ad-Hoc Networks

To extend the network lifetime, the route may be periodically alternated to prevent the energy consumption being concentrated to a small number of nodes. This method incurs large routing traffic incurred by frequent route discovery, which implies that it may not increase the network life time as much as it intends to. To solve this problem, we propose an energy efficient routing algorithm which uses two levels of route alternation. When it first finds the end to end route, it also caches the backup routes. It first changes the route using the backup routes and after the all the costs of the backup routes increase more than a certain amount, it begins to find a new end to end route and new backup routes. When it alternates routes using the backup route, the routing overhead is very small. In this way HPSR can reduce the routing overhead while distributing the cost throughout the network. We compare the performance of HPSR with existing routing algorithms using OPNET.

Se-Won Jung, Chae-Woo Lee

Mitigating Broadcast Storms in Stateless Address Auto-configuring MANETs

MANETs that form user groups on the fly may never undergo predeployment address configuration. The stateless autoconfiguration capability is therefore essential to the spontaneity of such community networks. Of several address autoconfiguration schemes, no singular scheme meets the diversity and heterogeneity of MANET environments. In this paper, we present a duplicate address detection mechanism for mobile ad hoc networks, which is distributed and poses no additional cost on the communication. Analytical results are suggestive of mitigation in broadcast storms that swarm the network every time a node assigns itself an IP address.

Shoaib Mukhtar, Ali Hammad Akbar, Shafique Ahmad Chaudhry, Won-Sik Yoon, Ki-Hyung Kim, Suk-Kyo Hong

Routing with Maximum EDPs and Wavelength Assignment with Path Conflict Graphs

The routing and wavelength assignment problem is one of the most important issues in optical transport networks based on the Wavelength Division Multiplexing (WDM) technique. In this paper, a novel approach using path conflict graphs and an algorithm for finding all edge disjoint paths is proposed. The performance of the proposed algorithm is compared with that of the bounded greedy approach for EDP (BGAforEDP). The proposed algorithm outperforms by approximately 20% under the traditional fixed topology (NSFNET) and approximately 32% under random topologies, using the BGAforEDP algorithm.

Won Jin Yoon, Duk Hun Kim, Min Young Chung, Tae-Jin Lee, Hyunseung Choo

Workshop on Authentication, Authorization and Accounting (AAA 2006)

Energy Conserving Security Mechanism for Wireless Sensor Network

This paper describes Wireless Sensor Network (WSN) security to conserve wasteful energy. Sensor networks are emerging fast and will be the next wave towards new network appliances. Security must be justified and ensured before the large scale deployment of sensors as individual sensors are prone to security compromise. In the sensor field, an adversary can compromise sensor nodes that can be used to generate random false sensing data. As these generated packets propagate through the network towards final data acquisition point, it will result in the energy consumption in a constrained low powered network. As WSN is multi-hop communication in nature, node-to-node authentication using shared secret is important for legitimate data packets to be forwarded. In this paper, we develop a security mechanism to detect energy-consuming useless data flows that propagate through network. Assuming that a sensor node can sense an event and generates multiple Message Authentication Code (MAC) using secret keys and these MACs are appended to the sensed data. The forwarding nodes along the path towards the data acquisition point verify the validity of the sensed data by checking the authenticity of the MACs attached to the original sensed data. Intuitively, early detection of the false data will make the entire network energy conserving which is one of the primary goals in the design of sensor networks. We have quantified the security strength through analysis and simulation.

Md. Abdul Hamid, Md. Mustafizur Rahman, Choong Seon Hong

Inter-domain Security Management to Protect Legitimate User Access from DDoS Attacks

In this paper, we propose a cooperative inter-domain security mana- gement to protect access of legitimate users from the DDoS attacks exploiting randomly spoofed source IP addresses. We assume that Internet is divided into multiple domains and there exists one or more domain security manager in each domain, which is responsible for identifying hosts within the domain. The security management cooperation is achieved in two steps. First, a domain security manager forwards information regarding identified suspicious attack flows to neighboring managers. Secondly, the domain security manager verifies the attack upon receiving return messages from the neighboring managers. The management method proposed in this paper is designed not only to prevent network resources from being exhausted by the attacks but also to increase the possibility that legitimate users can fairly access the target services. Through the experiment on a test-bed, the proposed method was verified to be able to maintain high detection accuracy and to enhance the normal packet survival rate.

Sung Ki Kim, Byoung Joon Min

An Authentication Scheme Between Wireless LAN and Mobile IPv6 During Handover

This study describes an authentication scheme for mutual authentication between a mobile node and AP and proposes integration with Diameter to authenticate the MIPv6 binding update message. The proposed method reduces the time to complete the handover by exchanging the binding update message protected by the secret materials formed from the interaction between 802.11 and FMIP processing during the handover. The result shows the cost-efficiency reduced up to 35% and 27% in comparing with MIPv6 and Fast Handover, respectively.

Youngsong Mun, Miyoung Kim

Mechanism of the Secure MAP Discovery in Hierarchical MIPv6

The Hierarchical Mobile IPv6 (HMIPv6) has been proposed to accommodate frequent mobility of the Mobile Node and to reduce the signaling load. A Mobility Anchor Point is a router located in a network visited by the Mobile Node. The Mobile Node uses the Mobile Anchor Point as a local Home Agent. The absence of any protections between Mobile Node and Mobile Anchor Point may lead to malicious Mobile Nodes impersonating other legitimate ones or impersonating a Mobile Anchor Point. In this paper, we propose a mechanism of the secure Mobile Anchor Point discovery in HMIPv6. The performance analysis and the numerical results presented in this paper show that our proposal has superior performance to other methods.

Jonghyoun Choi, Youngsong Mun

An Efficient Authentication Mechanism for Fast Mobility Service in MIPv6

Authentication, Authorization, and Accounting (AAA) for a mobile node should be accomplished by home domain when the mobile need continuous service on a visited network. The related recent studies have shown their drawback in the performance of AAA procedure. This study suggests a novel approach extending to the Fast Handoff scheme, which will shorten authentication delay by using Assertion mechanism. It allows mobile nodes to access visited network resources efficiently. Our model with Assertion process is an efficient approach employing authentication procedure through mutual and secure authentication between the Visit AAA servers. Especially, when the distance or the network delay between V_AAA and Home Agent (HA) become longer, it outperforms rather than the previous approaches. The proposed scheme verifies its significant efficiency in terms of cost analysis through several simulated experiments.

Seung-Yeon Lee, Eui-Nam Huh, Yang-Woo Kim, Kyesan Lee

An Improved Fingerprint-Based Remote User Authentication Scheme Using Smart Cards

In the computing environments, remote user authentication is an important part of security. Combining fingerprint verification and smart cards is one of a potential solution for strong remote user authentication. In this paper, we cryptanalyze an efficient fingerprint-based remote user authentication scheme introduced by Yoon and Yoo in 2005, and propose a new scheme improved with regard to security and efficiency. Actually, the Yoon-Yoo scheme is a security improvement on the previous Lin-Lai fingerprint-based verification scheme, while the Lin-Lai scheme is a precedent improvement on the Lee-Ryu-Yoo scheme. However, we have found that the most recent Yoon-Yoo scheme is still vulnerable to various types of impersonation attacks. Our new protocol is resistant to those attacks and more efficient than the previous schemes.

Youngkwon Lee, Taekyoung Kwon

Route Optimization with AAA in Network Mobility

In general, the nested mobile networks easily suffer from a bi-directional pinball routing with hierarchically multiple mobile routers. To handle this matter, several route optimization schemes have been proposed. But, to make network mobility feasible in public wireless Internet, well-defined authentication, authorization, and accounting protocols (AAA) should be accompanied. Hence, we combine a route optimization scheme with AAA architecture in network mobility in this paper. And we propose a new accounting system to support the combined architecture appropriately. We evaluate various existing route optimization schemes with AAA in terms of delay.

KwangChul Jeong, Tae-Jin Lee, Sungchang Lee, Hyunseung Choo

Verifier-Based Home Network Security Mechanism

The home network is expected to experience significant growth over next few years, as wireless and ubiquitous networking becomes more common and accessible. However, the broadcast nature of this technology creates new security issues. To ensure the effective deployment in home environments, network security must reach a certain level which is reasonably acceptable to the research community. The security mechanism for home networks must not require heavy computations, since usually consist of low CPUs capable, limited memory and storage, and mobility concerns. This paper presents a secure authentication and session key establishment mechanism suitable for home networks. The proposed scheme is based on the Secure Remote Password (SRP) protocol. The performance evaluation demonstrates that our proposed mechanism is more secure than previous ones while maintaining the similar level of security overhead including processing time.

Hoseong Jeon, Min Young Chung, Jaehyoun Kim, Hyunseung Choo

VO Authentication Framework in Grid Environment Using Digital Signature

We suggest authentication scheme of resource group and protection scheme of RSL or resource information in Grid environment based on web services. At present, resource group composed of job request in Grid middleware has no scheme of itself to be authenticated what it is a set of legal resources. Because of using SSL, it also breaks out heavy overload on each process as the aspects of protection for RSL or resource information towards and away between each resource groups and users. In particular, implementation of Grid service based on web services works out no plan on an above essential point. This paper provides the efficient protection scheme of RSL or resource information transmitted through network and authentication scheme of resource group in web-service based Grid environment with relating XML-Signature and resource management system.

Seoung-Hyeon Lee, Byung-Sun Choi, Jae-Seung Lee, Ki-Young Moon, Jae-Kwang Lee

Confidence Value Based Multi Levels of Authentication for Ubiquitous Computing Environments

New computing paradigm in ubiquitous computing environments is revolutionizing the way people interact with computers, services and the surrounding physical spaces. However, the deployment of this computing paradigm in real-life is hindered by the lack of proper authentication and access control techniques. In order to provide stronger authentication, MIST proposed an authentication framework for ubiquitous computing environments and assigned confidence values to some authentication methods to facility the combining. However, the assigned confidence values lack sufficient evidence. In this paper reliable confidence values for each authentication method used in MIST is proposed. These confidence values can combine multiple confidence values in some manner, producing a more accurate net confidence value. Authentication entities with confidence values allows the authentication framework to blend nicely into ubiquitous computing environments.

He Zheng, Jin Kwak, Kyungho Son, Wansuk Lee, Seungjoo Kim, Dongho Won

Workshop on Modelling of Location Management in Mobile Information Systems (MLM 06)

An Efficient Mobility Management Scheme for Hierarchical Mobile IPv6 Networks

Performance evaluation shows that Hierarchical Mobile IPv6 (HMIPv6) cannot outperform standard Mobile IPv6 (MIPv6) in all scenarios. Thus, adaptive protocol selection under certain circumstances is desired. Moreover, the registration cost of HMIPv6 needs to be reduced further. However, the performance of existing mobility based schemes is limited because they all neglected the traffic parameter of the mobile node (MN). In this paper, we propose an efficient three-level hierarchical architecture for HMIPv6 networks, in which an MN may register with either a higher/lower Mobility Anchor Point (MAP) or its home agent. By analyzing the inter-domain registration cost function, we obtain a novel parameter for MAP selection, which takes both the mobility parameter and the traffic parameter of an MN into account to minimize the overall registration cost. Simulation results show that normally the novel MAP selection algorithm achieves 25% percentage reduction of registration cost over the traditional mobility based algorithm. In addition, this algorithm obtains better performance when the mobility parameter and the traffic parameter of the MN vary.

Zheng Wan, Zhengyou Wang, Zhijun Fang, Weiming Zeng, Shiqian Wu

The Verification of Linearizer for Wibro PAM

In this paper we designe the pre-distorter of linearizer for Wibro. The proposed pre-distorter apply with phase shifter and variable attenuator can be used to vary increasingly the phase and amplitude of signals to cancel inter-modulation distortion in the in-band spurious signal of power amplifiers. It’s also need to realize generator of inter-modulation distortion (IMD generator). A better approach makes a phase shifter have full variation in state not having variation level, variable attenuator have dynamic range broadly in state not having variation of phase, and IM generator is also made to generate components of inter-modulation distortion easily. We improved result of 12 dB that multi-carrier IMD characteristics is 25 dBc to 37 dBc in same state of 20% efficiency and 26 dB gain of PAM at 25 dBm output by applied with suggested pre-distorter. Index terms—pre-distorter, phase shifter, IM generator, variable attenuator, Wibro PAM.

Inn-yeal Oh, Hyung-joon Jeon

Automatic Location Detection System for Anomaly Traffic on Wired/Wireless Networks

As use of Internet has grown, wired/wireless network backbone and access network has speed up, network environment get composed complexity. Recently network fault is often happened by worm virus, and then the major reason is anomaly traffic flowed from host inside rather than attack from outside. In this paper, using monitoring the load of network node and detecting abnormally signs about anomaly traffic, we try to design and implement automatic system which can trace the location for the affected system.

Ki-Sung Yu, Won-Hyuk Lee, Sung-Jin Ahn, Jin-Wook Chung

Road Boundary Extraction Using Shadow Path Reconstruction in Urban Areas

High-resolution aerial color image offers great possibilities for geometric and semantic information for spatial data generation. However, shadow casts by buildings and trees in high-density urban areas obscure much of the information in the image giving rise to potentially inaccurate classification and inexact feature extraction. Though many researches have been implemented for solving shadow casts, few studies have been carried out about the extraction of features hindered by shadows from aerial color images in urban areas. This paper presents a road boundary extraction technique that combines information from aerial color image and LIght Detection And Ranging (LIDAR) data. The following steps have been performed to remove shadow effects and to extract road boundary from the image. First, the shadow regions of the aerial color image are precisely located using LIDAR DSM (Digital Surface Model) and solar positions. Second, shadow regions assumed as road are corrected by shadowpath reconstruction algorithms. After that, road boundary extraction is implemented by segmentation, edge detection, and edge linking method. Finally, road boundary lines are extracted as vector data by vectorization technique. The experimental results show that this approach is effective and great potential advantages.

Kong-Hyun Yun, Hong-Gyoo Sohn, Joon Heo

Photograph Database for Highway Facility Management in Mobile Mapping System

The photologged database can provide an effective base for the management of information on construction and repair of highway and its auxiliary facilities. This paper is the design of the photograph database. The photograph data is collected with a mobile mapping system composed of the Charge-Coupled Device (CCD) cameras, the Global Positioning System (GPS), and the Inertial Navigation System (INS). This study also provides the methodology for data management with the data collected on a pilot section of highway. The proto-type of the highway facility management system can improve the cognitive power, and enables the extraction of qualitative information on the attributes and the positions of the interested objects.

Jeong Hyun Kim, Dong-Hoon Jeong, Byung-Guk Kim

High Speed Codebook Searching Algorithm for the CELP Vocoder in the Internet-Based Environment

In general CELP type vocoders provide good speech quality around 4.8kbps. Among them, G.723.1 developed for Internet Phone and videoconferencing includes two vocoders, 5.3kbps ACELP and 6.3kbps MP-MLQ. Since 6.3kbps MP-MLQ requires large amount of computation for the fixed codebook search, it is difficult to realize real time processing for the internet-based environment. In order to improve the problem this paper proposes the new method that reduces the processing time up to about 30% of codebook search time. We first decide the grid bit, and then search the codebook. Grid bit is selected by comparison between the DC-removed original speech and synthesized speech, which is synthesized with only even or odd pulses of target vector.

So Yeon Min, Eun Sook Cho, Chul Jin Kim

Algorithm and Structure to Cancel Signal Distortion in ATSC Digital TV System

In this paper we propose the 8 VSB (8 Vestigial Side Band) method which is decided as the standard of modulators for next generation digital TV System. In developing digital TV System, one of the difficult problems is how digital signal can be transmitted to the receiver without any phase & amplitude distortion. But, phase & amplitude error is liable to occur by imperfect design, circumstance variation and device degradation. These characteristics result in distortion of I, Q signal of modulator and interference in adjacent channels. In particular, the interference in modulator with a high power amplifier results in serious problems in adjacent channels. Here we analyzed problems of phase & amplitude error which are occurred when 8 levels digital signals are modulated to IF signal. And we suggested phase & amplitude error compensation algorithm and discussed the results for adaptation of the algorithm. This paper is directed to a phase and amplitude compensation apparatus and method for a digital modulator. An object of the paper is to maintain the optimum operating state of the modulator, preferably, provided in a digital television repeater.

Hyung Joon Jeon, lnn Yeal Oh

Mobility Management for INS in 3G Mobile Networks

In this paper we propose a mobility scheme to efficiently provide Intelligent Networks Service (INS) in 3G mobile networks. For reducing the load of Home Location Register (HLR), the INS profiles of Service Control Point (SCP) is distributed to the Visitor Location Register (VLR) where the user is located. If the INS call from the Mobile Host (MH) arrives, INS profile is provided by VLR where MH locates, not SCP. The proposed method is better performance results than INS management in 3G mobile networks.

Dong Chun Lee

Detection Methods for Executive Compressed Malicious Codes in Wire/Wireless Networks

This note is concerned with the executive compressed worm virus and their detection. It is difficult to detect some worm viruses recently since their file structure adopts the type of executive compression which can be run of themselves in the compressed state. In fact there are some informations about executive compression type in the sections of compressed file structure including whether it is executive compressed or not and compression method if compressed. In this research, we have adopted the reverse assembling method to investigate the effective method for detecting the many varietal malicious codes that are generated in different types by the variating the compression methods.

Seung-Jae Yoo, Kuinam J. Kim

Workshop on Ingelligent Services and the Synchronization in Mobile Multimedia Networks (ISS 2006)

A Dynamic QoS Management Scheme in B3G Networks

Service Level Agreement (SLA) management can be adapted to support the end-to-end QoS for service users in Beyond 3 Generation (B3G) networks. In B3G networks, SLA provides multiple service classes on access networks so that service classes should be managed to assure the service satis- faction for users. In this paper, we propose a dynamic QoS management scheme by IP traffic class controlling based on SLA in B3G networks. To manage dynamic traffic service, we consider Differentiated services (Diffserv) mecha-nism for the resource management by SLA. An IP service traffic class on SLA can be dynamically changed by Diffserv traffic management to support dyna-mic end-to-end QoS. Simulation results show that the proposed scheme has higher performance in comparison with non-dynamic management scheme.

Sangjoon Park, Youngchul Kim, Jongmyung Choi, Jongchan Lee, Kwanjoong Kim, Byunggi Kim

Stereo Matching Strategy for 3-D Urban Modeling

This paper proposes an effective matching strategy to reconstruct 3-D urban models in densely built-up areas. Proposed scheme includes two main steps: feature-based image matching using building recognition technique and 3-D building reconstruction using the refined Rational Function Coefficients (RFCs). Especially, our approach is focused on improving the matching efficiency in complex urban scenes. For this purpose, we first performed automatic building recognition between stereo images, and then we endowed all points of building edges with identifiers using edge tracing method. Each identifier plays an important role in reducing search space for image matching within points of same building. A standard IKONOS stereo product was used to evaluate the proposed algorithms. It turned out that the proposed method could automatically determine the initial position and could dramatically reduce search space for point matching. Also, it was demonstrated that the updated RFCs could provide high-quality 3-D urban models.

Choung-Hwan Park, Hong-Gyoo Sohn, Yeong-Sun Song

Protection Structure Building for Malicious Traffic Protecting in Intranet Systems

This paper proposes an improved protecting system against malicious traffic in intranet system. The proposed system in this thesis can reduce protect control and overloaded traffic volume by applying internal blocking method onto various channels and malicious traffic which were unable to block under the traditional structure. It has proved that the level of the intranet backbone CPU overflow can be reduced by this intranet protection method.

SiChoon Noh, Eun Jee Song, Dong Chun Lee

A Transaction Processing Model for Performance Analysis in Multilevel-Secure Database Systems

Although many concurrency control schemes have been developed, a thorough understanding of their actual performance is not enough. Numerous performance studies in non-secure centralized databases have been done in the past decade. However, their results cannot be directly applied to multilevel-secure databases, since in addition to single-level concurrency control, multilevel-secure databases deal with new problems of convert channel due to read-down conflict operations. Investigating their impact on transaction scheduling is a crucial issue. The concurrency control requirements for tran-saction processing in an MLS/DBMS are different from those in conventional transaction processing systems with respect to inclusion of covert-channel freeness. In particular, there is the need to coordinate transactions at different security levels avoiding both potential covert timing channels and the starvation of transactions at high security levels. Using a secure transaction processing model, we can evaluate the throughput and response time characteristics of multilevel-secure concurrency control schemes under a wide variety of database workloads and system configurations.

Sukhoon Kang, Seok Soo Kim, Geuk Lee

Temporal Land Information System (TLIS) for Dynamically Changing Cadastral Data

Cadastral data composed of land boundary and ownership has a very dynamic nature while conventional GIS data model assumes the world is static. In order to fill the gap, authors clarified the dynamic nature of cadastral data and presented the analysis of functional requirements, and then developed a spatio-temporal model and relevant functionalities, which can deal with real world cadastral data. The proposed model and functions were implemented using prolog, XPCE, and C++. The value of this study is to uncover the need for the integration of all historical cadastral data and the feasibility of the system development for the future.

Joon Heo, Jeong Hyun Kim, Seoungpil Kang

A Study on the Pitch Extraction Detection by Linear Approximation of Sub-band

The exact pitch(fundamental frequency) extraction is important in speech signal processing like speech recognition, speech analysis and synthesis. However the exact pitch extraction from speech signal is very difficult due to the effect of formant and transitional amplitude. So in this paper, the pitch is detected after the elimination of formant ingredients by flattening the spectrum in frequency region. The effect of the transition and change of phoneme is low in frequency region. In this paper we proposed the new flattening method of log spectrum and the performance was compared with LPC method and Cepstrum method. The results show the proposed method is better than conventional method.

Keun Wang Lee, Kwang Hyoung Lee, So Yeon Min

Hybrid Queuing Scheme to Reduce Call Blocking in Multimedia Mobile Networks

In this paper we propose a hybrid queuing strategy to reduce the blocking rate of channel allocation for multiple priority calls in Multimedia Mobile Networks (MMNs). The proposed scheme is provided with an analytic model, wherein a Two- Dimension Markov Process. In numerical results, our proposed method show correct analytic model and has better performance result than previous methods in MMNs.

Hong-Jin Kim, Sok-Pal Cho, Dong Chun Lee

General Tracks

A Study for Monitoring Technique for Home Server Based on Web Camera

A monitoring system for the security is increasingly demanded in line with the issue of the infringement of privacy. This paper has conducted the study on the monitoring technique via the Internet using PC or PDA. This is a monitoring system for web-camera based home server, which transmits the images and sound data captured by mike-embedded USB camera, through multiplexer of H.263 and internet. It integrates the operating processors of each device into a unified drive module and provides it the operator to facilitate the system operation and maintenance.

Jong-Geun Jeong, Byung-Rae Cha

New Algorithms for the Unsplittable Flow Problem

In this paper we focus on the

unsplittable flow problem

(UFP): given a directed network with arc capacities and a set of connections (requests) defined by origin node, destination node and bandwidth requirement, find a subset of the connections of maximum total demand for which each connection uses only one path and the sum of demands crossing the arc does not exceed its capacity. The UFP can be applied in survivable connection-oriented network (e.g. MPLS) for assignment of backup paths of failed connections. Since the UFP is NP-complete, we propose two new effective heuristic algorithms for the UFP. We evaluate the performance of proposed schemes by making a comparison with their counterparts using various network topologies and demand patterns. Obtained results indicate that proposed heuristics provide substantial improvement comparing to existing methods.

Krzysztof Walkowiak

Performance Evaluation of the Parallel Packet Switch with a Sliding Window Scheme

This study analyzes how parallel packet switching (PPS) performs with a sliding window (SW). The PPS involves numerous packet switches that operate independently and in parallel. The typical PPS dispatch algorithm applies a round-robin method (RR). The class of PPS is characterized by deploying parallel center-stage switches that enable all memory buffers run more slowly than the external line rate. A novel SW packet switching method for PPS, called SW-PPS, is developed. The SW-PPS operates in a pipeline fashion to ensure overall switching. The performance of the RR-PPS and SW-PPS is evaluated for a torus topology. Under identical Bernoulli, the SW-PPS provided considerably outperformed RR-PPS. Furthermore, this investigation proposes a mathematical analytical model for RR-PPS and SW-PPS.

Chia-Lung Liu, Chiou Moh, Chin-Chi Wu, Woei Lin

A Simple and Efficient RWA Algorithm Based on Priority of Edge Disjoint Paths

Routing and wavelength assignment (RWA) is an important issue in WDM optical transport networks. The objective is to find lightpaths for given demands with minimal use of wavelengths. It is typically solved using combination of linear programming and graph coloring, or heuristic path selection algorithms. Such methods are complex or yield sub-optimal paths. In this paper, we propose an efficient algorithm, RWA based on Priorities of Shortest Path (RPSP). The proposed algorithm utilizes the lengths of the shortest paths for the source-destination demand pairs and assigns disjoint lightpaths to the ordered demands. The computer simulation shows that our proposed algorithm indeed requires up to 34% fewer wavelengths with almost identical running time than the previously proposed effective BGAforEDP algorithm.

Soon-Bin Yim, Min Young Chung, Hyunseung Choo, Tae-Jin Lee

Performance Improvement of TCP over Optical Burst Switching Networks with Drop Policy

In Optical Burst Switching (OBS) networks, the TCP performance is significantly affected by burst loss. This is because burst loss in OBS networks occurs mostly due to contention instead of heavy congestion so that a Time Out (TO) event will trigger unnecessary TCP congestion control resulting in significant throughput degradation. However, there has not been much study about the impact of burst loss on the performance of TCP over OBS networks. Therefore, in this paper, we propose a Drop Policy (DP) with burst retransmission where a new concept of retransmission-count for bursts is introduced to mitigate unnecessary TCP congestion control. For the performance evaluation of the proposed DP, we provide an analytical throughput model of TCP over OBS networks. The analytical and simulation results show that the TCP throughput is improved by our proposed DP with burst retransmission.

SuKyoung Lee, LaeYoung Kim, JooSeok Song

A New Size-Based Burst Assembly Scheme for OBS Switches

We propose a new size-based burst classification algorithm which assembles arriving packets with different burst size according to classes in OBS ingress switches. In JET-based OBS scheme, because the high priority class bursts are likely to occupy channels in advance, the low priority class bursts should find void intervals between high-class bursts to avoid burst blocking. The research results show that there was close relation between blocking rate of low-class bursts and size of its bursts. By limiting the maximum length of low-class bursts, loss, throughput and assembly delay performances are improved when proposed scheme is compared to conventional scheme.

SeoungYoung Lee, InYong Hwang, HongShik Park

The E-Textile Token Grid Network with Dual Rings

In the presence of some node and link failures, the token grid network can achieve robust operations for its good ability to maintain network connectivity. This feature makes it suitable for e-textile applications. However, with high frequent wear and tear or other faults in use, e-textiles are still prone to be disabled for the destruction of the communication network. In this paper, we introduce dual rings to connect the nodes, instead of the single rings in the original e-textile token grid. The topology and the reliable operations are discussed. And we have also evaluated the uniform load capacity of the new network. Simulation results show that the new communication network can improve the ability of e-textile applications to tolerate faults.

Nenggan Zheng, Zhaohui Wu, Lei Chen, Yanmiao Zhou

A MAC Protocol Using Separate Wakeup Slots for Sensor Network

This paper presents a MAC protocol which uses separate wakeup slots for each sensor node in sensor networks. Most MAC protocols proposed for sensor network are inefficient under heavy traffic loads, in particular in high density network topology because of frequent collisions and long sleep latency. In this paper, we suggest a MAC protocol in which each node has a different wakeup schedule in the same duty cycle, and it joins the competition only for its own short wakeup slot when the receiver is ready to receive its data. Simulation results indicate that our scheme can reduce energy consumption and minimize idle listening which increases the power efficiency.

Jinsuk Pak, Jeongho Son, Kijun Han

A Study on L2/OPN Design for Grid High Performance Network

As the Internet is widely used, high performance networks and systems prompts appearance of various applications and requests higher capacity resources. Recently, studies on grid are actively conducted to reorganize each computing resource, which used to be dispersed for each application requesting these high capacity calculation resources, into a virtual high capacity resource by connecting to networks. The network needed in the grid environment has been progressed along with the WDM-base Lambda Network that can build a high-bandwidth network for relatively low cost. This paper presents two ways that improve network performance on grid environment. First way is approach to reorganize the existing network into L2/OPN (Optical Private Network) to avoid traffic congestion. And second way is manage TCP windows buffer size to present a suitable TCP size for the Grid environment system.

Min-Ki Noh, Joon-Min Gil, Ki-Sung Yoo, Seong-Jin Ahn

Reasoning Technique for Extended Fuzzy $\cal{ALCQ}$

Classical description logics are limited to dealing with crisp concepts and crisp roles. However, Web applications based on description logics should allow the treatment of the inherent imprecision. Therefore, it is necessary to add fuzzy features to description logics. A family of extended fuzzy description logics, which is a fuzzy extension of description logics by introducing cut set to describe fuzzy feature, is proposed to enable representation and reasoning for complex fuzzy information. This paper discusses the reasoning technique for reasoning tasks of a given extended fuzzy description logic extended fuzzy

$\cal {ALCQ}$

by adopting classical description logic

$\cal{ALCQ}$

to discretely simulate extended fuzzy

$\cal{ALCQ}$

in polynomial time and reusing the existing result to prove the complexity of extended fuzzy

$\cal{ALCQ}$

reasoning tasks.

Yanhui Li, Baowen Xu, Jianjiang Lu, Dazhou Kang

Reducing Delivery Delay in HRM Tree

In hierarchical reliable multicast schemes, the number of repair proxies and their locations influence the delivery delay. Low delivery delay is essential for the transmission of real time media. In this paper, we propose a method to decide optimal locations of repair proxies that minimizes the mean delivery delay of all receivers in heterogeneous network using a dynamic programming approach. The evaluation results of our optimal proposal in a simulation topology show that the mean delivery delay of all receivers can be reduced by about 10ms in network size of 1000 nodes. Our method can be used by network providers in order to reduce delivery delay in their HRM network.

Sang-Seon Byun, Chuck Yoo

Data Analysis and Utilization Method Based on Genetic Programming in Ship Design

Although Korean shipyards have accumulated a great amount of data, they do not have appropriate tools to utilize the data in practical works. Engineering data contains the experiences and know-how of experts. Data mining technique is useful to extract knowledge or information from the accumulated existing data. This paper presents a machine learning method based on genetic programming (GP), which can be one of the components for the realization of data mining. The paper deals with linear models of GP for regression or approximation problems when the given learning samples are not sufficient.

Kyung Ho Lee, Yun Seog Yeun, Young Soon Yang, Jang Hyun Lee, June Oh

An Evolutionary and Attribute-Oriented Ensemble Classifier

In the research area of decision tree, numerous researchers have been focusing on improving the predictive accuracy. However, obvious improvement can hardly be made until the introduction of the ensemble classifier. In this paper, we propose an Evolutionary Attribute-Oriented Ensemble Classifier (EAOEC) to improve the accuracy of sub-classifiers and at the same time maintain the diversity among them. EAOEC uses the idea of evolution to choose proper attribute subset for the building of every sub-classifier. To avoid the huge computation cost for the evolution, EAOEC uses the g

ini

value gained during the construction of a sub-tree as the evolution basis to build the next sub-tree. Eventually, EAOEC classifier uses uniform weight voting to combine all sub-classifiers and experiments show that EAOEC can efficiently improve the predictive accuracy.

Chien-I Lee, Cheng-Jung Tsai, Chih-Wei Ku

A Study of the Evaluation Function and the Clustering Algorithm for Semantic Web Environment

Clustering is defining inter relationship of unordered data and grouping data systematically. The systems using clustering provide the grouped information to the users. The complex metadata description generated on the basis of pre-defined ontologies serve as perfect input data for clustering. In this paper, we propose an approach for clustering ontology-based metadata. Main contribution of this paper are the definition of evaluation function to measure ontology-based metadata and study using this evaluation function within hierarchical clustering algorithm.

Je-Min Kim, Young-Tack Park

A Divergence-Oriented Approach for Web Users Clustering

Clustering web users based on their access patterns is a quite significant task in Web Usage Mining. Further to clustering it is important to evaluate the resulted clusters in order to choose the best clustering for a particular framework. This paper examines the usage of Kullback-Leibler divergence, an information theoretic distance, in conjuction with the k-means clustering algorithm. It compares KL-divergence with other well known distance measures (Euclidean, Standardized Euclidean and Manhattan) and evaluates clustering results using both objective function’s value and Davies-Bouldin index. Since it is imperative to assess whether the results of a clustering process are susceptible to noise, especially in noisy environments such as Web environment, our approach takes the impact of noise into account. The clusters obtained with KL approach seem to be superior to those obtained with the other distance measures in case our data have been corrupted by noise.

Sophia G. Petridou, Vassiliki A. Koutsonikola, Athena I. Vakali, Georgios I. Papadimitriou

Backmatter

Weitere Informationen