Recent Advances in Computer Science and Information Engineering

Usually cannonballs are treated through following steps before they are shot, such as oil-cleaning and air-dry, moisture-proof cover release, weighing, etc. Traditional treatment methods are manual. These methods have many disadvantages such as: labor-intensive, low efficiency, dangerous to operators, etc. To overcome these disadvantages, an ammunition ready system has been developed. This article focus on the program design technology based on PLC to control oil-cleaning and air-dry station, moisture-proof cover release station and weighing station. The working process, key technologies, and control flow of these stations are introduced in the article, and the system with high efficiency is safe and reliable.

This paper designs and implements a general evacuation simulation system. In resent years, the computer simulation has gradually become an important research means to evacuation, a general simulation model based on CA for evacuation is presented, it can describe the complex environment to enhance versatility using three entities which include channels, exits and unreachable areas. Evacuation simulation system based on modular design is developed, in which every entity realizes interaction by simulation affairs management module. The entities’ states are independent to each other so it is easy to expand and vindicate the modules expediently. While combining application example verifies validity and versatility of the model.

This paper introduces a realtime system which can acquire, process, store and display heart sounds and electrocardiogram(ECG) of the human body at the same time.It is composed of superior microprocessor–Atmega128L,large capacity Flash and the new type LCD.All hardwares adopt low power design and surface mounting package. The system do not affect the daily living and working of human being when it is used, so it is suited for clinical and family monitoring.

The numerical calculation related to the stochastic models driven by the QBD processes frequently uses the operations of infinity nested matrix. However, it is very difficult to express and calculate efficiently for the infinity nested matrix. Even we can use the function cell to implement in Matlab, cell-based structure does not support its direct operations. Based on the above facts, this paper uses the idea of inverse block matrix to implement the addition and multiplication of nested matrix. Experiments show cell-based structure and the idea of inverse block matrix can effectively solve the operations of infinity nested matrix.

The Apriori based Associative Rule Classifier By Category (ARC-BC) algorithm is implemented to classify text documents. In ARC-BC algorithm, each individual category is considered separately and different. Rules are extracted from documents of each category independently. The experimental result shows that the performance of ARC-BC based text categorization is very pretty efficient and effective and it is comparable to Naïve Bayesian(NB) algorithm[2] based text categorization.

The Transition Refinement and Place Refinement of Petri nets are studied. After giving the concepts of State Nondecreasing, State Nondecreasing,Fairness, S-invariant, T-invariant and Persistent properties of Transitions Refinement are presented; also theproperties of places refinement such as Fairness, Invariant in the Refinement are also given.

Compared to 2D desktop system, 3D desktop system is more realistic and more convenient to be operated, so 3D desktop system has been one of the most important directions of desktop system. Human-computer interaction system based on 3D mouse is essential for the user to interact with the computer. 3D Human-computer interaction system combine the selecting operation of OpenGL with the 3D mouse, and employ the core system of signal and slot in QT to apply to the 3D desktop system. The interaction system links the 3D virtual sense with the underlying computer, and it can reach real time control of the program installed in the operate system automatically and can configure the operate system.

In world wide web, a non-obvious but universal phenomenon called as peninsula phenomenon has been observed. The experiment results shows that the proportion

f

(

x

) of peninsulas with size

x

obey a power law distribution with exponent at least 1.913. In this paper we propose a stochastic model and prove theoretically that the size distribution of peninsulas have a stationary power law distribution with exponent 3+2

a

, where a>0. The numerical simulation results verify it too.

In this paper a new measurement of reflection coefficient based on absorption cross section is discussed in reverberation chamber. All losses in a reverberation chamber(RC) are represented by equivalent absorption cross sections(ACSs).This representation enables us to define an absorption cross section of the RC, so that we can easily measure and compare the losses of different natures in an RC directly in terms of ACS. Finally a two-dimensional model is analyzed using finite element method to verify this method.

This paper proposes a novel direction of arrival (DOA) estimation algorithm that can rapidly estimate the DOAs of incidence signals. The conventional multiple signal classification (MUSIC) algorithm should perform an eigenvalue-decomposition which has high computational complexity. In addition, the MUSIC algorithm can’t be used under complex noise environment. In contrast, the novel algorithm can rapidly obtain the signal subspace from a submatrix of a contracted quadricovariance fourth-order cumulants matrix and avoid eigenvalue decomposition. Computer simulation results show that the method is effective and still has good performance under colored Gaussian noise, non-Gaussian noise with symmetrical distributing and white noise because of the use of fourth-order cumulants.

An amplitude weighting method of forming a specific radiation pattern in far-field was proposed, which is different from the phase-array beamforming. The formula for calculating radiation amplitudes was derived in detail. Numerical results illustrated that radiation pattern with limited distribution can be closed in upon by increasing the number of elements, and it was indicated that the total number of elements can be determined in ratio of the main lobe energy to total radiation energy.

A study on the method of direction of arrival (DOA) estimation for many groups of coherent and uncorrelated sources under nonstationary noise fields is described in this paper. The proposed algorithm can separate the uncorrelated and coherent sources by making use of oblique projection, and it uses fewer sensors when estimating the same sources compared with the conventional methods. Further more, the effect of the nonstationary noise is eliminated because it is translated into white noise using improved Toeplitz matrix. At the same time, the performance of many algorithms is compared by simulation, the effectiveness and accuracy of the proposed algorithm is verified.

In real communication systems, most of the multipath channels tend to exhibit sparse behavior. By taking advantage of the sparsity, compressed sensing (CS) techniques is treated as an effective way to estimate the unknown channel frequency response. In this paper, an alternative Dantzig selector algorithm (ADS) based on CS is proposed. Simulations show that the proposed algorithm has better MSE performance compared with the traditional Least Square (LS) method and the Lasso algorithm on CS domain.

Change in topology is very common in a Mobile Ad Hoc Network (MANET) due to the frequent and unpredictable movement or depletion of energy of the battery powered nodes in the network. As a result, routes made up of multiple hops in MANET breaks very often mainly following the failure of one or more adjacent nodes. Considerable research has been conducted on handling link failure locally in ad hoc networks. Existing local route repair schemes such as Localized Route Repair (LRR) [1], AODV-BR [2] and Witness-Aided Routing (WAR) [3] try to repair route breakage locally but all suffer from inefficient route repair algorithms resulting in long delay in reestablishing new path and more specifically excessive energy consumption due to mandatory requirement for the nodes in the network to operate in promiscuous mode. All these problems were well addressed by a scheme called Quick Local Repair Scheme (QLRS-APM) that used Adaptive Promiscuous Mode [4]. QLRS-APM is a novel approach for local route repair but still consumes considerably good amount of energy which can be tuned further. Also, this approach generates excessive load in the network by blindly initiating broadcast messages during local route repair process which can be bypassed. This paper focuses on these and other problems existing in QLRS-APM and gives new proposals to enhance QLRS-APM by limiting promiscuous mode operation and eliminating the need for broadcast during local route repair.

Based on the analysis on the application of e-commerce application, a hierarchy e-commerce index system is constructed. Analytic hierarchy process has been used to quantify, index system and its feasibility is verified, and finally a linear function evaluation model is concluded, which is used to evaluate the application degree of e-commerce of enterprise.

The theory of microwave holography is introduced in the paper firstly. And then the measurement components and test results of Seshan 25m radio telescope (parabolic antenna) are described. And the system accuracy is also tested actually.

A scheme of actualizing echo cancellation on digital TV repeater using joint channel estimation is proposed based on the analysis of the echo interference in digital video broadcasting for digital terrestrial television (DVB-T) repeater. In order to realize coarse estimation by the correlation principle of CAZAC code, a train sequence CAZAC code is first added in repeater system. Then, we adopt LMS algorithm to trace the character of channel simultaneously and the cancellation signals which is close to the echo signals are produced by coupling the signal of the transmitter. Finally echo cancellation is realized by subtracting the cancellation signals from the received signals. Simulation results show the favorable performance in echo cancellation and a broad utilization prospect in practical application.

Array configuration of multiple-input multiple-output (MIMO) radar using non-uniform linear array (NLA) is proposed in this paper. Unlike a standard phased-array radar where NLA is used to generate more thinned beam patterns, in MIMO radar we exploit the property of NLA to get more distinct virtual array elements so as to obtain improved parameter identifiability. A class of NLA called the minimum redundancy linear array (MRLA) is employed for MIMO radar array configuration and a new method to construct large MRLAs is descried. Some numerical results are presented to verify the effectiveness of this kind of array configuration.

In this paper, a new blind channel estimation method for Orthogonal frequency division multiplexing (OFDM) systems is presented. The proposed method is based on the Amplitude-Phase constraints (APC) of channel frequency response (CFR), and the finite alphabet property of information symbols. Unlike existing statistical blind channel estimators, the proposed method requires short data records especially for PSK modulation.

A channel estimation algorithm for space-frequency-block-coded orthogonal frequency-division multiplexing (SFBC-OFDM) systems employing multilevel quadrature amplitude modulation (M-QAM) is presented, which is based on decoupling of different transmitter’s effect and independent least-squares (LS) estimation of subcarrier channel coefficients. It can be used in fast fading environments for decision-directed channel estimation. The proposed algorithm has improved accuracy and lower complexity than the existing algorithm using the same decoupling processing.

This paper provides analysis of the inter cell interference coordination problem in WiMAX systems. In order to reduce the interference, we use fractional frequency reuse scheme with three regions. In this scheme, each cell is partitioned into three regions: the central region, the middle region and the edge region. Frequency resources are universally used in all central region whereas users of middle and the edge regions have a frequency reuse factor strictly higher than 1. In this paper, we analyze the optimal frequency reuse factor of the middle and the edge regions users.

MIMO technology has become one of the key technologies of TD-LTE mobile communication system to achieve high data rates, high transmission quality and high system capacity. The key factor whether can it be applied to the actual system is that the detection algorithm performance is good or bad and the level of computational complexity. Several classical algorithms, such as ML (Maximum Likelihood),SD (sphere decoding),ZF (Zero-Forcing),MMSE (Minimum Mean-square Error) and ZF-(O)SIC ( Ordered Successive Interference Cancellation),MMSE-(O)SIC algorithm, are researched and analyzed in this paper. And the detail comparison of the characteristics and performances among the different algorithms is given in this paper. The results show that the improvement of systematic performances is always at the cost of complexity increase. The selection of downlink MIMO signal detection algorithms needs to strike a reasonable balance between the computational complexity and the system performance in real application.

Multiple-input multiple-output (MIMO) technology has been widely used in modern communication system for its promising advantages. It has been proved that in a rich scattering environment, a MIMO system processes more capacity and better spectrum utilization. On the other hand, as signals in MIMO system share the same space and time, the receivers is more complex. Thus, in order to promote the development of MIMO related theories and applications, the research on detection problem is of significance. In this paper, some widely used detection algorithms have been discussed to present a basic understanding and conclusion.

Introduce a circuit design based on AT89S52 for remote-control and manage the multi-channel appliance. This method can make the whole system′s hardware and software more concise by using of 8 resourses of SCM to achieve the muti-channel electrical equipment management.

Infrared remote-control is a kind of infrared on peer-to-peer communication technology that hardware and software technologies are mature. Infrared are less susceptible to electromagnetic interference, it’s frequency is not like RF control which has many restriction, so it is usually exerscised in short distance remote-control.

This design focus on the centralized management of appliances, using AT89S52 as a keyboard interface circuit and infrared emission, and also be used in receiving circuit to control the reception of signal.

In this paper, new families of zero correlation zone (ZCZ) sequences based on interleaving technique and perfect sequences are constructed. The proposed sequences have the property that, in a specified zone, the out-of-phase autocorrelation and cross-correlation values are all equal to zero. Due to this property, such sequences are suitable for quasi-synchronous code-division multiple access (QS-CDMA) systems. It is shown that that all the proposed ZCZ sequences are pairwise cyclically distinct. Furthermore, the condition under which the constructed ZCZ sequences are optimal is derived.

abstract

environment.

Multiple-input multiple-out (MIMO) technology is a very promising technology in the future high spectrum efficient wireless communication system. While the calculation complexities of most receive detection algorithms of the MIMO system are very high. Maximum likelihood decision feedback equalization (ML-DFE) algorithm is good at the balance of the performance and the complexity of detection. But it complexity is still high.

A novel algorithm aiming at reducing the calculation complexity of the ML-DFE algorithm has been developed in this article. Each layer in the searching tree, the number of the visited nodes will be reduced to a preset number. Simulation results show that the calculation complexity of the proposed algorithm drops from 24% to 42% while the performance drops little.

Correlation difference and summation peak (CDSP) algorithm based on cross-correlation difference and correlation summation peak protection is proposed to address the critical issue of symbol timing synchronization for MB-OFDM based UWB systems. The two step synchronization scheme attempts to locate the start sample of the frame sequence (FS) by firstly calculating the cross correlation difference of received symbols and predefined preamble and then finding summation of correlation peak within the timing index chosen in the first step. Therefore, the timing index could be guaranteed to be unique. The performance of the proposed algorithm is evaluated by mean square error (MSE). CDSP algorithm could implement timing synchronization for MB-OFDM based UWB systems and make the uniqueness of timing index for sure. The MSE of CDSP is evidently lower than conversional method.

Implementation of array antenna in ultra-wideband (UWB) system makes it possible to localize a node using direction-of-arrival (DOA) estimation. In this paper, a beamspace-based DOA estimation method for DS-UWB signals is proposed using frequency-domain frequency-invariant beamformers (FDFIB) algorithm. First the UWB bandwidth is divided into multiple narrowband frequency bins. Then the beam-pattern at different frequency bin is designed in order to obtain frequencyinvariant beam pattern under Chebyshev weight matrix. The spatial-spectrum estimation of UWB signals is based on beamspace multiple signal classification (MUSIC) algorithm. Simulation results show that the proposed algorithm can effectively estimate the DOAs of UWB signals. Compared with element-space based method, it has better statistical characteristics and higher robust in lower SNR circumstance.

Unlike those traditional layered architectures, a non-layered protocol architecture for WSNs is proposed in this paper. The goals are greater flexibility and reliability with less network resource consumption. Based on the concept of micro-modularization, the context-aware architecture allows functions to be automatically composed within each sensor node according to the context information. An experimental simulation shows that, our proposal efficiently utilizes network resources, meanwhile provides good network performances.

Resource limited real-time wireless sensor network is a new type of application of sensor network. In this kind of networks, there are numerous invalid real-time packets, which have already expired or are destined to expire. In this paper, a feedback-based timeout packet dropping strategy (FBTPD) is proposed. With this strategy, timestamps are piggybacked in real-time packets. So that sink node can gather the historical information and estimate the future transmitting time of some sensor node. Then the estimated transmitting time is fed back to the sensor node in a feedback packet. The sensor node hereby drops the invalid real-time packets which will expire later. Simulation experiments reveal that: compared with other dropping policies, FBTPD can drop more invalid real-time packets, and can significantly improve the throughput of the non real-time packets. Thus FBTPD can efficiently boost the resources utilization in wireless sensor networks, especially in hybrid real-time wireless sensor networks.

In wireless networks, raising the throughput and decreasing the network delay are always themain goals to solve. This paper studied the relationship between Contend Window and Backoff Time, and raised the BEEB algorithm in which the Backoff time obeys the exponential distribution and the idea of active nodes. The BEEB algorithm can effectively improve the default that nodes choose long defer time and access the channel slowly, and can shorten the idle time and decrease the time to acquire the channel by accelerating the collision process. The performance analysis and simulation results show the active-nodes can decrease the MAC access delay and increase the network throughput using BEEB algorithm.

A novel WSN location algorithm based on the frequency difference is proposed. The algorithm arbitrarily chooses two anchor nodes to send the frequency modulation signals, the distances between the unknown node and the anchor nodes can be calculated by measuring the frequency difference at the receiver, and then the localization is done using the trilateration or the maximum likelihood. The novel algorithm does not require the time synchronization and owns the strong anti-jamming capability. Meanwhile, it is applicable for both the 2-D and 3-D localization.

In the wireless sensor networks (WSNs), the battery energy of sensor node is very limited. So, how to use energy of sensor node effectively to prolong the lifetime of WSNs is a challenge. Now, we mostly adopt the routing algorithm is based on clustering, the drawback of this algorithm is rate of utilization of cluster-head node energy is very high and the network lifetime rapidly shorter. This paper puts forward a kind of routing algorithm in WSNs, it is Distributed Energy Balancing Routing algorithm (DEBR), this algorithm through energy costs (EC) control the rate of utilization of each sensor node in WSNs, thus dump energy of each sensor node is balance and prolong the lifetime of wireless sensor networks.

An improved Monte Carlo Localization and tracking algorithm based on wireless sensor network is developed for weak satellite signal area in the paper. The heretic algorithm uses controlled flooding method and cross operation to accelerate the sampling process and interpolation operation to predict the velocity and angle. The simulation results proved that the algorithm outperforms the conventional algorithm in the location accuracy and localization time cost.

To reduce end-to-end delay, traditional multi-path protocols prefer to select paths with minimal length. These paths are always physically located close together with strong interference between each other. This paper proposes a novel multi-path routing protocol Interference Disjoint Multi-path Routing (IDMR), which computes path interference to make sure all selected paths are interference free. Simulation result shows IDMR has better performance in terms of delivery ratio and delay.

Reliable bulk data propagation has become a critical need in wireless sensor networks. Most of the existing protocols are ARQ-based, in which receiving nodes use NACK to recover missing packets from the sender. In this paper, we propose an FEC-based scheme in order to reduce packet transmissions and latency in data propagation.We ran various simulations in TOSSIM. The results show that while integrated with Deluge, the FEC-based scheme brings 10%-15% reduction of packet transmissions and 40%-50% reduction of propagation latency in various networks, compared to basic Deluge.

This paper focuses on the basic concept and architecture of wireless sensor networks. Some key techniques of wireless sensor networks are deeply discussed, including node-localization, routing technology, topology control, data fusion and energy management. Characteristics and disadvantages of theses techniques are analyzed, and suggestions for improvement are given. Finally, the future research and development tendency are prospected.

In this paper, we present RWB, a single-hop broadcast protocol for asynchronous receiver-initiated MAC in WSN, which significantly reduces energy consumption by predicting the receiver’swakeup time and cutting the long back-to-back broadcast into several unicast packets. We have implemented RWB on TinyOS and evaluated its performance on testbeds. The result shows RWB consumes less energy and shortens broadcast period compared to TinyOS’s default MAC while still keeps high delivery ratio.

In the Epidemic Routing (ER) algorithm for opportunistic networks, random pair-wise exchanges of messages among mobile hosts ensure eventual message delivery. However, ER does not utilize the available network topology information to exchange data packets when two nodes encounter. To address the problem, we propose a low-delay routing algorithm based on exchange of two-hop neighborhood information (LDREN), which exchanges two-hop neighborhood information during the exchange process of packet indexes and firstly sends packets which are within two hops distant from their destinations to reduce packet delay. Moreover, in the process of sensing encountered nodes, LDREN uses ECHO messages to delete the packets reaching their destinations from nodes’ buffer. Simulation results show that LDREN outperforms the ER algorithm and one of its present improvements, ARER (Adaptive Randomized Epidemic Routing), in terms of success rate, end-to-end delay, and memory overhead.

This paper attempts to measure the performance of the Hyper Text Transfer Protocol (HTTP) (Fielding et al. 1997) in a broadband multimedia satellite communication system .The HTTP client’s access to the Internet is via a shared satellite uplink channel. The multiple access protocols we have chosen to simulate are Slotted ALOHA . We have constructed a detailed simulation of “web browsing” behavior using OPNET and have used this to simulate HTTP transfers over random access satellite channels. The purpose of this work is to determine if traditional medium access techniques are sufficient to accommodate many terrestrial users whose traffic patters are dominated by HTTP client-server behavior.

A key component in the QoS architecture of the network is congestion control algorithms. Active congestion control is a new congestion control technology based on active network. it has small feedback delay, control nimble and high utility of network resource. A new active congestion control algorithm based on secondary routing was put forward, By the study of congestion detection, secondary routing search and choosing, multi-path distributary and control, a new congestion control method by packets redirection on active node was explored. The performance of this algorithm were validated by NS2, the following works of this algorithm was given out.

Internet traffic is modest growth worldwide due to popular applications. But the growth does not change the well-known characteristic heavy-tailed of the traffic in Internet. Mice flow would dominate the next generation of ubiquitous wireless networks because the frequent and important communications would be mice flow due to the limits of terminal and network. The most important factor which affects the performance of applications is the duration time of mice flow. For a long time the modifications on traditional

TCP

protocol did not reveal the nature reasons for the duration time of mice flow:

ACK

-based slow pacing transmission and window-based conservative packet transmitting strategy. Based on the previous work of window-based transmission schedule, this paper proposes a delay-sensitive Fast-Pacing TCP (

FP-TCP

) transmission mechanism for mice flow: the definite network status and

RTO

could be obtained by measuring

RTT

for each packet in mice flow, the proper transmitting pace and rate base on the network status and the fast packet retransmission schedule. Simulated experiments show that the duration time of mice flow can be shortened by

FP-TCP

up to about 22% at most in the condition of network is busy, meanwhile only little growth is taken to the lose rate of packet.

This paper analyses the problem of the data structure of the AODV algorithm, routing setup and path finding. In the multi-tasking environment for wireless sensor networks, we propose NOC_AODV(Node Occupation Control AODV)algorithm that using a node occupation-degree to avoid the impropriated nodes, In the algorithm, according to judge the value of the node occupancy degree, it can determine the node’s action in the WSN. Using NS platform, we make some simulation in the multi-tasking environment. NOC_AODV algorithm reduces 20% about the delay, cut down 50% about the packet loss rate and eliminate the massive useless Hello packet compared with AODV algorithm.

In this paper a new method Integrated DPI(Deep Packet Inspection) and DFI(Deep Flow Inspection) is offered to identify the application protocol. First the basic concept and characteristics of DPI and DFI are studied. Then a new method is offered which integrated DPI and DFI with accomplished system. Finally some test data of the system is given to verify the function of the new method.

Wireless Mesh Network (WMN) is a key emerging technology to construct next generation wireless multi-hop network. It combines the advantages of both mobile ad-hoc network (MANET) and traditional fixed network, attracting significant industrial and academic attentions. In network layer, routing metrics are also important to the performance of communication. In this paper, we review a list of existing routing metrics in WMNs. Based on the findings, we also point out the open issues of routing metrics.

The application of MVPN techonology is more and more widely these days, the correlative correlated technic standard has been revised for nearly ten years. MVPN is a technique basing on BGP/MPLS IP VPN supporting Multicast service, that transmit multicast data via private networks by encaspsulating private multicast packet and transferring via multicast tunnels established by every size. The first part of the report majors in describing the developing status of multicast VPN according to technical draft and studying of Cisco Co. ‘s implementation. Firstly, the report introduces the technic background, then expatiate the basic theory and implementating technic of MVPN. Whereafter the paper introduces supporting things of some mainstream verdors on this technical draft.

To improve system performance related to radio spectrum handover in cognitive radio networks, a novel spectrum handoff mechanism is proposed which is based on the diversity of spectrum’s quality and the traffic requirements of secondary users. Simulations are conducted to evaluate its performance in response time, bandwidth utilization and connection keeping probability. It is shown that the designed mechanism is effective in guaranteeing the quality of services of secondary users.

An enhanced M-LWDF algorithm named EM-LWDF is designed, which strictly follows the fairness rule of QoS requirement. So its fairness is not greatly influenced by the ratio between the number of traffic users in the traffic queues and equal to 1 theoretically. Simulation results validate the theoretic analysis and also show the effectiveness in improving fairness for EM-LWDF.

An enhanced algorithm named ZCLR (ZigBee Cluster Label-based Routing) was proposed considering the weakness of ZigBee hybrid routing algorithms and energy consumption in LR-WPAN networks. The proposed scheme reduces the energy consumption of the nodes by dividing ZigBee mesh network into several clusters, then the ZigBee Router nodes could be classified as RN+ nodes and RN- nodes, according to the role which the ZigBee Router node acts as in the network. And the algorithm reduces overall energy consumption of networks by controlling the direction of RREQ packet. The analysis on simulation result indicates that the algorithm ensures the route selected to meet the requirements of data service; meanwhile it reduces energy consumption of the network and prolongs its life time.

This paper presents a design of SCADA system based on wireless communication for offshore wind farm, the characteristics of offshore wind power is analyzed, and communication in the traditional wind power SCADA system is described. The lower computer and the sensor within the offshore wind turbine communicate with Profibus fieldbus deigned in this paper. The communication between the offshore wind turbine and the SCADA system of the control room is wireless, so as to achieve the overall monitoring and management on the offshore wind farm and meet the function of remote monitoring and control requirements in the offshore wind farm.

A wireless temperature acquisition system is designed based on ZigBee wireless technology. The system is made up by three parts. The sub-node part that is in charge of collecting temperature data, it’s designed by CC2430 and DS18B20 temperature sensor. The major-node part which is responsible for temperature data received and network establishing, CC2430 is used as the main controlling module. The upper computer takes charge temperature data processing, storage and display. The sub-nodes communicate with the major-node through ZigBee network, and the major-node through serial port communicated with the upper computer. The system has an effective temperature collection with low-cost, low-power consumption of terminal device.

According to the requirement of present B2B supply chain logistics system, and combining with the unique advantages of RFID technology in data acquisition and data transfer, the paper mainly proposes the reversible tracing model based on RFID technology for supply chain logistics system, demonstrates the functional structure for enterprise s logistics real-time tracing system. With the reversible system, we can share and manage the database of products business in each link of the supply chain, realize the real-time tracing and information sharing of products. The company s logistics cost also reduced finally.

The concept of sustainable development has been widely accepted all over the world. As a kind of traffic tools which causes no pollution, bicycle is valued in many countries again. In this paper, we adopt the advanced technology –RFID to manage bicycles aiming at promoting rational development of bicycle. First, the history of RFID technology is briefly reviewed; then, we propose two systems using RFID which are called anti-theft system and bicycle rental system; at last, the effect and application scope will be discussed. This paper will focus on the bicycle rather than car management and can facilitate the digitization and intelligence of bicycle system.

In order to resolve the detection problem of coal mine gas content detection, and ensure the personal safety under the ground, we design the gas content detection system which based on the technology of ZigBee. The system includes two functional models, which are ZigBee and gas sensor. We can control the system functional model by computer net, which can realize the radio transmit by use of ZigBee technology. It can real-time work, and the precise high, transmit far away. The system hardware is simple, operate easily, cost cheap, which can be used in coal mine and safety detection.

The purpose of this study is to build an indoor air quality monitoring system using wireless sensor networks (WSNs) technology. The main functions of system include (1) providing a continuous and long term air pollutant data collecting and monitoring, (2) to analyze and predict the trend of air quality, (3) to give the patients with respiratory diseases a real time warning message when system detect an abnormal air quality condition, and (4) pursue a feedback actions such as starting air-conditioning systems to improve the air quality. Our system has been deployed at 4 different areas in Taiwan and the relative accuracy is within the range (

$\leqq$

10% standard gas) that defined in Taiwan.

In this paper, we consider the problem of co-channel interference mitigation in a TD-LTE coordinated multiple points (CoMP) system where the linear pre-coding matrix is jointly optimized across a set of coordinated sites. The objective function to be maximized is the signal to leakage and noise ratio (SLNR) of all users subject to a pooled power constraint where the channel status information (CSI) is acquired through ideal or a linear interpolation channel estimation method, respectively. We will focus on the downlink scenario where each user is equipped with one antenna. Simulation results of the perfect and estimated CSI are provided for comparison.

A reconfigurable switched-capacitor (SC) sigma delta modulator topology intended for multi-mode zero-IF receivers has been presented on the system level. The modulator is based on the cascade of a single-bit 2-1-1 topology. The loop order and oversampling ratio are reconfigurable to meet the requirements of a wide range of standards. The multirate technique is introduced in the modulator to reduce the frequency of the first stage integrators of the cascade sima delta modulator. The power consumption of the modulator is decreased because the first stage integrators in the chain primarily determine the power dissipation of the whole modulator. A peak SNR of 85/ 81/ 65/ 63/ 56/ 46 dB is achieved for GSM/ Bluetooth/ GPS / WCDMA/ WLAN/ WiMAX mode. The simulation results show that the proposed topology obtains similar performances to the conventional cascade modulator structure for the multi-mode receivers, while the speed requirements of the operational amplifiers in the first stage is relaxed.

Coordinated multiple points (CoMP) transmission is a promising technology to improve system spectrum efficiency in LTE-Advanced system. With prior knowledge on multi-user multiple-input-multiple-output (MU-MIMO) in a single cell system, signal-to-leakage-and-noise-ratio (SLNR) is a good criterion for the design of pre-coders as compared to zero-forcing (ZF) and block diagonalization (BD). In this paper, an extension of SLNR criterion is introduced to a CoMP system with joint transmission for multi-user. Performance evaluations are provided in a TD-LTE with each cell of 4 paired cross-polarized antennas at each cell. Simulation results show that the proposed MU-MIMO scheme based on SLNR criterion can efficiently improve the system performance with ideal channel state information (CSI).

This paper describes a new portable real-time remote electrocardiography (ECG) monitor based on mobile communication technology. Microprocessor of the portable monitor was embedded

μ

C/OS-II. The portable monitor integrates GPRS and CDMA module, so it could use each of them to transmit the ECG data, which guarantee continuity and integrity of the remote electrocardiography monitoring maximally.

A novel wireless network architecture using Radio over Free Space Optics (RoFSO) for wireless local area network is presented and its spectrum assignment function which can achieve efficient utilization of RF resources is studied. The result of simulation shows that the improvement in throughput performance can be obtained when the number of wireless users is increased, and RF resources are fairly used in terms of fairness index compared with the conventional WLAN architecture.

This paper has analyzed the issues of power consumption mechanism and application cost in the course of agricultural long-range monitoring and wireless data sensing, transmission and routing, and proposed to use the seamless interconnection of Zigbee network, civilian public band, GSM and Internet to form long-range wireless data routing systems. At the same time, we have probed into energy conservation mode and mechanism of wireless data sensing and long-range transmission network based on Intermittent relay power supply technology, effective and energy-saving clustering routing protocol and algorithm, the wireless data transmission mode based on multi-hop communication and built up routing access among basic nodes. These means has solved the issues of distributed data acquisition, long-distance multi-Level data transmission, data Relay, as well as the adaptive hierarchical routing of low power consumption and low-cost running and maintenance under complex environments. The experiment results show that the system has been

reliably

operating, and has advantages of low power consumption and long life-cycle during wireless transceiver and the remote transmission of data.

In this paper, we propose an adaptive bandwidth management scheme for heterogeneous wireless networks to optimize quality of service (QoS) and bandwidth utilization. The proposed scheme dynamically reserves and allocates bandwidth to different types of calls through implementing a neural network in order to balance handoff call dropping probability (HCDP) against new call blocking probability (NCBP). The performance of the proposed scheme is evaluated through simulations and proved to be more efficient than the existing schemes.

In this paper, we propose an improved complete sharing (CS) dynamic channel allocation (DCA) algorithm for TD-SCDMA. In the proposed algorithm, the voice service and the data service dynamically share all channel resources in the system, and at the same time, the voice service has the priority to use the channel resources. Simulation results show that compared with the conventional CS algorithm, the proposed algorithm significantly improves the voice service performance.

Traditional approaches have used either channel coding or retransmission mechanisms to cope with errors/losses occurring during data communications. But either of them is not sufficient to achieve highly reliable communications over error-prone wireless channels. Network coding can significantly reduce communication loads and thus improve bandwidth and energy efficiency for green communications. In this paper, we propose a new hybrid approach that integrates network coding, channel coding, and Auto Repeat Request (ARQ) mechanism to increase the coding and energy efficiency of wireless networks. In particular, the proposed approach combines the non-binary Reed-Solomon channel coding with the linear random network coding scheme and further incorporates with the ARQ technique. Performance analysis with an example network topology shows that the proposed approach can achieve significant gains for both reliable and green communications in wireless networks.

Load balancing plays an important role in the next generation communications system where cellular network and wireless local area network (WLAN) are integrated. This paper presents a novel load balancing algorithm based on analytic hierarchy process (AHP), which helps the heterogeneous wireless network system to provide better service to high-priority users without decreasing system revenue.

In this paper, the performance of energy detection in cognitive radio systems over a multipath fading channel is evaluated. The secondary user performs spectrum sensing using energy detection based on the primary signal that has traversed a multipath fading channel. The detection probability and false alarm probability are calculated and simulated. The results show that the detection probability is affected by the quadratic sum of fading coefficients while the false alarm probability keeps fixed. Moreover, more paths and larger fading coefficients may not lead to higher detection probability.

A Q-learning based network selection algorithm is proposed which is derived from the autonomy of network selection. It is based on the heterogeneous network composed of WiMax and HSDPA. The algorithm can constantly adjust its strategy for action selection according to network load conditions, traffic attribute and mobility of terminal by the constantly trial and error learning with wireless environment. Finally a suitable network can be selected for every session. Simulation results show that system blocking probability can be lowered and spectrum utility can be increased.

The mutual transformation of the Ethernet data frame at the users’ end of the next generation of DCTV network and household wireless sensors network data frame is studied in the paper. The critical net element of the mutual transformation is converging node sink. Frame format at the Ethernet side is rationally designed and configured the proportion of frame format at the wired side as well as the wireless side. The transformation algorithm is developed so as to effectively accomplish the frame format transition between the wireless sensors network at sink node and the Ethernet.

This paper introduce the application of FRA and RZ coding in ULH optical network, simulate the typical WDM network based OptiSystem, select the feasible project by the simulation result and test the feasibility of the project by network testing.

Unified Communication is a kind of new communication mode, a mode of communication in real time which combines all types of information, including Voice, fax, email, mobile short messaging, multimedia, data, etc, and integrates the computer technology and traditional communications technology. In the information age, the use of unified communications technology and its information acquisition and transmission advantages, can improve business processes, enhance intelligent decision making, reduce costs and production operations to improve customer satisfaction. This article has just appeared on the basic principles of unified communication technologies, enterprise applications and how to apply lessons learned from the process described in detail.

With advances in optical fiber communication technology, routing nodes become the bottlenecks that constraint the network. In this paper, a variety of IP switching technologies are analyzed, fast switching are designed based on Netflow, and the express forwarding is implemented based on two-layer switch to improve the router’s data forwarding capability.

In a wireless mesh network, the purpose of channel assignment is to minimize the interference within the mesh network and to improve the network connectivity. This paper proposes a new algorithm which can predict the degree of busyness of a node according to the link traffic in the networks. So the algorithm can respond to the distribution of data traffic flexibly. In the algorithm, the protocol interference model is used to reduce the interference between the links in the wireless mesh network. Simulation results show that the algorithm can reduce the waiting time while a data frame is transmitting. And the network throughput and stability can be improved significantly.

How to efficiently search the effective resources has become a key problem in unstructured P2P networks. In order to overcome the limitations of current search algorithms, this paper designs an agent-based Least Common Neighbors local search algorithm (LCN) that is based on the notion of weak ties in queries transactions, where an agent chooses the node that has the least common neighbors with the node currently occupied by the agent during searching. Our experimental results show that the LCN algorithm can achieve better performances than some related agent-based algorithms, and be adaptive to certain dynamically-evolving networks.

The explosion of P2P file sharing brings such serious problems as network congestion and traffic hindrance caused by excessive occupation of the bandwidth, including the hidden trouble in security. ISP and network operators need to manage P2P traffic to ensure the performance of traditional applications. To accomplish this goal, the system must first identify the P2P traffic. This paper describes the principal P2P traffic identification technologies and indicates the advantages and disadvantages of the P2P traffic identification methods. A variety of methods are combined to detect P2P flow more effectively.

Extending battery lifetime is one of the most critical and challenging problems in a pervasive system. The greatest utility of pervasive system is their ability to be used anywhere, and at anytime. But power limitations of the mobile devices seem to hinder this goal. A middleware service framework has been developed and deployed over a network of machines that exploit remote resources. The framework adopts a context-aware approach to make intelligent decisions on task migration and uses the achievable throughput in an end-to-end path as the context. It proved that the developed framework is novel and efficiency in a set of tasks.

Web services composition which provides a way to obtain value-added services is still a critical challenge especially for large scale semantic Web services. We propose an efficient automatic approach to composite services through three steps: 1) Preprocessing the given services and requestor to support composite types and inheritance relationships, 2) Building an And/Or graph to capture the input/output dependencies among the services within the scope of the given requestor, 3) Searching required services to meet the requestor and then obtaining the execution process. The experimental results about consuming time and success rate are presented.

An effective and convenient channel for accessing traditional Chinese medicine seeds knowledge is urgent to be established. After analyzing the different levels of demands from production, education, scientific research fully, related information of TCM plant seeds were comprehensively analyzed and synthesized, a convenient, universal and expansive information retrieval system of TCM plants seeds was built with the Apache HTTP Sever, PHP editing web pages, MySQL database management system. This database is a collection of the 230 kinds of medicinal herbs seeds belong to 86 families, each of the seeds include images, Familia, Genus, Species, name, alias, the original plant morphology, geographical distribution, fruit and seed types, 1000-grain weight, maturity and harvest time, pharmaceutical name, efficacy, seed shape, germination methods, dormancy-breaking methods, dry conditions, conserve and longevity and so on. Retrieval methods of the database is diversity and simple, even users just know one or several pieces of information of one kind of seeds such as name, alias, species or other biological information (fruit and seed shape), they could inquire and get all the information by choosing query terms and query combination The adding and deleting function of the database is very convenient for the administrator to management the background. Image management is independent of the text, this kind of structure is more flexible and could save more resources. Web page of each kind of seeds could exhibit the original plant image and seed images. This system could supply useful information conveniently in a wide range for TCM farm practices, educators, students and other persons.

The web service has got a rapid development since the web services activity was launched in 2002. In the domain of geographic information service research and development, the OGC has published a series of standards related of geographic information service, many spatial data infrastructures adopt the OGC specifications to create geographic information services. But the semantic confusion still exists in the application of geographic data and service. This paper will try to give a suggestion of the semantic geographic web service sharing framework based on the existing researches and the spatial data infrastructures. The framework includes two parts: (1) the process framework consisting of finding service, evaluating service, accessing service and using service; (2) the layer framework consisting of the portrayal layer, the data layer, the interface layer, the encoding layer, the facility layer.

In this paper, we describe the connotation of an electronic business system as well as the relationship with an ERP system and analyses the business process of E-Commerce system based on B2B mode and E-Commerce system model is constructed for enterprise. A method and application of enterprise modeling via extended UML element model is proposed and design procedure view model and organization view model for typical model of successive manufacturing enterprise. The application software framework is proposed and applied it to the dynamic enterprise modeling to manufacturing management finally.

DNS is the “nervous system” and “navigator” of the whole internet. It’s necessary to optimize traditional DNS’s system structure, resource location, mapping efficiency and security in the application of ISP environment because of traditional DNS system’s flaw by natural. The author first analysis the technical mechanism of the traditional DNS system, then optimize the structure, technique flow, protocol and security of the traditional DNS system considering the practical application demand of the DNS system in the ISP, at last the author construct the integrated proposal of the ISP Smart-DNS system. The ISP Smart-DNS system divide the traditional DNS system into forward-DNS module and backward-DNS module according to the different function of cacher query and recursive query; the forward-DNS module possess the function of domain-name’s pre-operation, realizing the elusion or redirection of the mistaken DNS request, the forbidden website’s DNS request and other ISP user’s DNS request; the backward-DNS module have the function of resource location which guide ISP users to the IDC belong to this ISP itself; the backward-DNS module have the function of TTL flag optimization which can optimize the A-record lifecycle in cache according to the times that domain name was requested, this function raise DNS system’s efficiency; the backward-DNS module also have the function of TC flag optimization which can avoid the DNS request based on TCP connection, this function not only raise DNS system’s efficiency, but avoid any network attack which is based on TCP.

Current P2P systems employ tit-for-tat strategies, where peers control her uploading behavior by her downloaded acquisition to avoid free riding. Does the employment of tit-for-tat strategies impose any limitation on system performance is a fundamental question to be answered. It has been shown that the number of cooperating peer, can, at best, grow linearly in time. However, we show that, this can be changed by a small tolerance, and such small tolerance is well accepted and common to implement in current P2P system. Under the 1-tolerant tit-for-tat strategy, exponential growth of cooperating peer is achievable.

In order to achieve the efficiency management, a student management system based on Struts and Hibernate framework is designed. The paper analyzes technical features of opensource framework Struts and Hibernate which are based on J2EE technology firstly, then proposes the system construction and analysis the main realization method of the system, finally introduces the key technologies. Through practice using, this system has been proven with the features of high efficiency, convenience, better extendibility and maintainablity.

Food security is important in ensuring people’s health and safety. It has close relationship with the coordinated development of national economy and society, and has a very important strategic significance. Advanced technologies in Internet of Things are used in this platform. RFID Electronic vehicle cards and RFID tags are used to mark vehicles and vegetables supplied to Hong Kong. All provenance information about the supply chain of vegetables from growing, harvesting, government supervision, testing, transportation, customs clearance, warehousing, repackaging, internal testing, to the supermarket retail is recorded and can be used to ensure the security of foods supplied to Hong Kong.

Internet offer a broad and convenient information communication network for people. With the rapid development of internet, net-surfer culture is undergoing great changes. Meantime, on-line marketing infuse traditional marketing with fresh blood also. In this paper, we research into net-surfer culture and analyze the structural, behavioral and psychological characteristic of net-surfer. Then we put forward some new ideas for on-line marketing, and discuss the development of on-line marketing in future.

A Bot detection method based on API invocation was proposed to improve the existing approaches on detecting unknown Bots. Characteristics of Bots executing in a host were analyzed by observing API functions invocation. Then a new approach was proposed. Firstly, processes on the host were filtered using the white list and the blacklist. Then fast detection and sequence detection were incorporated to detect Bots. A series of experiments show that this approach needs not to depend on specific signature extracting and can detect unknown Bots in a host effectively.

We propose a new mitigation mechanism against DDoS called Pseudonymous Credit Driven Mechanism (PsCredit). The primary driving force of this mechanism is a new cyberspace economic modeling - pseudonymous credit modeling, which provides a suitable ROI scheme and support for roaming and privacy. This mechanism can process packets at wire-speed, and it can defend effectively against all known DDoS attacks.

For conventional dynamic password authentication protocols (such as S/KEY, SAS, etc), the algorithm of generating a new password basically uses either two neighboring passwords or authentication factors. The relevance of the passwords can be unveiled during the protocol execution and thus vulnerable to be attacked. In this paper, a new method is proposed. This method uses indirect authentication information as an interference factor to protect authentication password and safely accomplish the authentication process.

A new key management scheme based on equilateral triangle network deployment model in wireless sensor networks is proposed in this paper. It combines the t-order binary polynomial model with the characteristics of node deployment, so the entire network is divided into several mutually non-overlapping equilateral triangle units and each pair of adjacent units adopt the same key allocation algorithm. The analysis and simulation results show that our scheme can not only keep a high level of network secure connectivity probability, but also improve the node anti-capture attack capability while reducing the consumption of node storage capacity.

Paper[1] proposed one new digital signature scheme with message recovery without using one-way hash function and message recovery scheme. This paper proposed the three new forgery attacks which mean that Chang et al.’s signature scheme with message recovery is not as secure as they claimed.

This paper mainly deals with the optimal information rate of perfect secret sharing schemes of a type of access structures on 7 participants. It is transformed to calculate the optimal information rate of 111 connected graphs. 6 methods are used, whose names for short are: Complete Multipartite Graph, Splitting Construction, 3/5-Upper Bound, L-Decomposition Technique, Geometric Construction and Decomposition Construction. The exact values of 91 connected graphs are given in Table 1, where the upper and lower bounds of the rest 20 are also computed.

The study first describes current constraints when is comes to information security in the field of M2M mobile communications such as weaknesses in existing technology, long RAB activation times, low processing capacity and small allowable payload size. The next step would be to cover the security guarantees typically required to secure applications using mobile networks. Existing cryptographic technology will be reviewed as to what security guarantees they provide then matched against the constraints of M2M mobile communications. This study shows that AEAD schemes are ideal for this type of environment.

In this paper we are focusing on closed MANETs where only authorized nodes are supposed to access the network. We denote “outsider” nodes as those nodes that are not authorized to access the network, and ‘insider” nodes as those that are. The objective of this research is to develop mechanisms that protect a closed MANET against malicious behavior from outsider nodes as well as insider nodes through packet authentication and a Trust Management System, respectively.

In this paper, we did some researches relate to the method of a modified Arnold transformation which is used to scramble digital watermark image and using chaos sequence to encrypt the scrambled watermarks. Based on odd-even extraction, we proposed matrix norm calculation on the embedded watermarks. We designed a blind extraction digital watermark algorithm which added matrix norm concept on the odd-even extraction. At first, decomposed the original image by using digital wavelet transform. Then selected the low frequency sub-band as the watermark embedding domain and decomposed it into several smaller blocks in the same size. For each block, we calculated the two matrix norm one by one. Watermark embedded position was confirmed by Arnold transformation. Finally, watermark information was embedded into matrix norm of each block by odd-even extraction algorithm. The results of the experiment show that the proposed watermark algorithm is good at robust. According to added the matrix norm concept, the proposed algorithm is better than odd-even extraction in resisting noise, cropping, JPEG compression and other attacks.

In this paper, we propose a model of spectrum allocation based on cognitive wireless network. This model completes the process of spectrum allocation by the graph theory. In this model two requirements are researched: maximizing the total benefit and minimizing the collision probability between authorized users and cognitive users. Simulation results indicate that the new model can be better to reduce the collision probability at the expense of some throughput performance. At the same time, this approach not only provides a better QoS for cognitive users, but also reduces the probability of the spectrum allocation change when the radio environment changes.

Increased complexity in IMT-Advanced communication technology brings significant challenge to correct implementation of communication protocols and protocol interaction. In this paper, we designed an experimental test system which aims to verify and test IMT-Advanced key technologies of MAC and RRC layer. The test system contains three parts, including Testing System (TS), Test Adapter (TA) and System under test (SUT). Compared with traditional TTCN-3 test framework a module called TA as a bridge connecting TS and SUT is adopted, which makes testing more simpler and flexible. The system can support both conformance testing and performance testing. A relay communication scenario is developed and the testing results show that the proposed test system is efficient and reliable.

Through analyzing the principles and structure of END network drivers in VxWorks systems, the development and implement of LAN91C111 network drivers based on ISA bus architecture are completed and network congestion problems which may encounter in the process of using this network interface card (NIC) are analyzed in detail. All of these provide many references and guidelines for developing similar NICs in VxWorks systems.

Discussed in this paper is a GPS based vehicle ranging scheme to deal with some disadvantages existing in other present systems. These disadvantages include short sensing distance, easily being interfered, and high cost. A design model of a vehicle collision preventing system is then proposed based on this ranging scheme. Each vehicle locates itself and communicates via wireless communications channels with other vehicles in surrounding area. In addition, supersonic distance measurement is employed to enhance the short distance measurement capability and to increase accuracy. Also included in the system design are a LCD display and a buzzer to generate visual and audio alarm information.

Because the orthogonality of PSP (principal states of polarization) is correlated with instantaneous differential group delay (DGD), in presence of PDL (polarization dependent loss), differential group delay (DGD) becomes complex, and the PSP orthogonality goes bad. It is investigated into the image DGD probability density function (PDF) and nonorthogonal PSP bandwidth, and the signal distortion due to image DGD is discussed. Several new properties have been found which will help us in recognizing and reforming the PMD and PDL co-existent optical networks.

Digital baseband predistorter modeled by a polynomial and implemented by an indirect learning architecture is among the most cost effective method for linearizing power amplifier. Due to high correlation between each element of polynomial, general parameter extraction algorithms, e.g. linear least square combined with Cholesky decomposition method, have worse numerical stability when higher order terms are included. This article put forward a novel method, QR decomposition, to obtain coefficients of predistorter. The method guarantees good numerical stability, and can be easily realized in real engineering. And simulation exhibits the effective of the method.

The bandwidth management issues in broadband multimedia satellite communication system using multiple frequency-time division multiple access (MF-TDMA) were concerned. The framework of bandwidth management structure was proposed in a hierarchical manner. Some key problems were reviewed from large scale, moderate scale and micro scale aspects respectively.

Based on the classical time division multi-channel communication theory, we analysis quantum teleportation of entangled photon pairs and present a scheme of quantum channel-time division multiplex (QC-TDM). Moreover, correlative frame format are proposed. According to our study, the proposed scheme of QC-TDM can carry out multi-user communication through quantum channel, and the proposed scheme also has high practicability and transplantable. The scheme of QC-TDM may play an important role in realization of the quantum multi-users secret communication and establishment of quantum communication in a large scale in the future.

VLIW is an attractive strategy to achieve higher ILP without sophisticated reordering and scheduling mechanism in processor design. However, the major limitation of popularity is the problem of binary codes compatibility. The software programs have to be recompiled from source codes but not directly execute the existed binary codes. In this paper, it proposes a new VLIW architecture, Avalon, which can execute legacy MIPS32 binary programs directly. Avalon processor is consisted of quad-way VLIW pipeline processor to execute whole MIPS32 integer instruction set. It integrates a novel instruction scheduling/packing hardware mechanism, Excalibur, to pack conventional MIPS binary instructions into VLIW instruction bundle without any compiler intervention. Accordingly, Avalon can be fully compatible with existed MIPS32 integer binary object codes without recompilation. The experimental results present that Avalon processor will achieve 3.6 times speedup in synthetic programs. After synthesis the RTL Verilog design of Avalon processor, the working frequency can achieve 105MHz by TSMC 0.13

μ

m technology library.

A full differential charge pump with low current mismatch and deviation is designed in this paper. It adopts two symmetrical complementary P-N replica circuits with half value of the reference current source to remove the current mismatch and deviation. The charging and discharging current are matched very well over a wide output range. The output current mismatch and deviation of the proposed charge pump are less than 0.772% and 0.962% while the output voltage ranges from 0.2V to 1.5V. The good current matching characteristics and low deviation effectively reduce the reference spur of charge pump phase locked loops. The proposed charge pump is implemented with TSMC 0.18

μ

m technology with 1.8V supply.

This paper presents a method to accelerate the verification of processor by establishing an ESL (Electronic System Level) model and compare the simulate results between it and RTL model under the same test bench in real-time. Through adjusting the compare granularity, the control of simulation speed and precision of error position can be realized. This method was used to verify a high performance SuperV DSP. The result shows this method can quickly detect and accurately position the errors of RTL model.

CDR(Clock and Data Recovery) and SerDes (Serializer/Deserializer) circuit is a critical circuit in the receiver of serial-data transceiver systems, and its performance affects the entire system’s function directly. This paper presents an improved scheme of the traditional dual-loop clock and data recovery circuit, which is based on special oversampling and in this scheme, the CDR and SerDes can be accomplished simultaneously. The proposed circuit is applied in a prototype system of BLVDS controlling, which consists of 5 nodes, with the longest distance of 131 meters, and speed of up to 20MHz, and through 380 tests, the circuit can work reliably, with lock time less than 10

− 6

s, and error rate lower than 10

− 9

.

Remote sensing satellites with higher resolution and more spectral bands have posed great challenges to onboard storage and downlink bandwidth capacities. Data compression is a reasonable way to deal with these challenges. Cloud detection is useful for data compression algorithms to discard regions covered by cloud in an effort to improve compression ratio. VLSI architecture for real-time cloud detection based on pixel screening and region discrimination is proposed in this essay. Pixel screening based on local statistical characteristics and binary morphological filtering is implemented by pipeline of depth 30. Equivalence sorting and regional feature extraction are performed at the same time, which avoids second scan of the original image and shortens output latency. Provisional labeled image is run-length encoded to reduce memory requirement. The design is synthesized and mapped to SMIC 0.18 um CMOS technology, resulting in clock frequency higher than 100 MHz. Simulation shows that this design fulfills real-time cloud detection requirement with reasonable performance.

The use of cryptographic algorithms within critical applications, such as banking and military, requires efficient hardware implementations. With the emergence of reconfigurable computing architectures, such modern and capable systems became the target of many applications including cryptography. This paper presents parallel reconfigurable hardware implementations of the

Serpent

(

AES

Finalist) cryptographic algorithm. Currently,

Serpent

is well known to be a simple but very strong encryption algorithm. The used system is the

MorphoSys

dynamically reconfigurable computer.Different designs for the

Serpent

corresponding to different degrees of parallelism are presented.Moreover, implementation, realization, and performance analysis and evaluation of the mapped designs are included. The

Serpent

algorithm is shown to have increased performance when mapped on

MorphoSys

.

In this paper, a novel mechanism of on chip interconnect based on Multi-Layer AHB Lite standard is proposed. On one hand it provides the feature that multiple masters are able to access the bus simultaneously as long as there is no competition for the same slave. On the other hand this mechanism is easy to scale, reuse and consumes less resources. Distributed address decoding and master arbitration are employed. Each slave has its own data selection module with a built-in arbiter attached. All the masters are connected to the master interfaces of the data selection module and the module decides which master gains the access of the slave when a bus competition occurs. External modules can be attached to each data selection module, which makes it possible to employ different master arbitration strategies for each slave. This interconnect mechanism has ultra low latency and low arbitration costs, hence is suitable for embedded systems with strong real time requirement.

In this paper, a novel low-swing strategy is proposed for multi-port register file’s design. This low-swing strategy aims at single-ended bit line structure, and the low voltage swing is achieved by sensing and feedback in this strategy without additional inner chip voltage and reference voltage. This method contains two parts: writing and reading strategy. In WRITE low-swing scheme, the self-sense amplifier memory cell or modified memory cell can be used to support low-swing WRITE. The low-swing WRITE operation can save about 30.1% power. In READ low-swing scheme, a sense amplifier is also introduced. By using low-swing READ strategy, the power dissipated in READ is reduced to 48.1%, and the proposed sense amplifier also gives about 174ps sensing delay improvement.

The size of the on-chip memory affects the chip area, cost, as well as the power and energy dissipation, which are of prime concerns for embedded systems. For real-time applications, scratchpad memories (SPMs) are preferable to caches and, furthermore, sufficient scratchpad memory should be provided in order to guarantee real-time performance. In order to avoid runtime surprises, however, embedded system designers tend to over-budget the memory size, thereby increasing its associated costs. We consider the problem of determining the minimum memory size required to fulfill the real-time requirements of a set of recurring tasks, given the tasks’ execution times as a function of the amount of memory it is allocated. Three SPM partitioning strategies are considered: private, where each task is allocated a private partition, shared, where all tasks share the SPM and therefore a context switch incurs the cost of bringing in its data from the next memory level, and hybrid, where some tasks are allocated a private partition and others share a partition. For the private strategy a polynomial-time algorithm is presented that determines the smallest amount of SPM needed to fulfill the real-time requirements. The hybrid partitioning strategy is NP-complete and an exhaustive search algorithm is presented that determines the optimal solution. In addition, two heuristics for the hybrid strategy are proposed and the algorithms are evaluated using synthetic task models with different characteristics. Results show that the heuristics produce solutions close to the exhaustive search while performing orders of magnitude better in terms of search time.

Security in networking is based on cryptography, the science and art of transforming messages to make them secure and immune to attack. Cryptography can provide confidentiality, integrity, authentication of message. Cryptography can also provide entity authentication. However, cryptographic algorithms impose tremendous processing power demands that can be a bottleneck in high-speed networks. The implementation of a cryptographic algorithm must achieve high processing rate to fully utilize the available network bandwidth. To follow the variety and the rapid changes in algorithms and standards, a cryptographic implementation must also support different algorithms and be upgradeable in field. Otherwise, interoperability among different systems is prohibited and any upgrade results in excessive cost. The ultimate solution for the problem would be an adaptive processor that can provide software-like flexibility with hardware-like performance. Efficient hardware design is essentially a resource allocation problem. When the key is generated in DES, the goal is, given the constraints, to find the optimal balance between required silicon area, operation throughput, energy consumption and design time to implement a system.

In this paper, a DVB-S2 LDPC encoder based on FPGA is proposed after detailed analysis of DVB-S2 LDPC code on the basis of irregular repeat accumulate (IRA) coding algorithm. This method not only uses pipeline technique combined with all parallel structures to improve the coding efficiency, but also makes use of VHDL language to achieve DVB-S2 encoder, which meets the requirements of DVB-S2 standard on the condition of low hardware resources.

Data intensive system based on reconfigurable computing technology can provide hardwire efficiency and software flexibility. This paper presents a method Based on universal HMI (hardware module interface) design for encryption applications. It can give an effective way to control the status of the user module, independent of the lower level implementation. The validation and performance analysis are also demonstrated by the AES and DES encryption on Xilinx Virtex-2 FPGA.

This paper introduces an integrated four-channel signal acquisition system used in low-field MRI. The system is based on FPGA, DSP and Power PC. In this paper, a design of a compact and flexible signal acquisition system was presented. Sample the multi-channel magnetic resonance signals at a high speed simultaneously and demodulate them directly. A digital down conversion (DDC) chip (AD6636) demodulate and decimate four-channel signals. DSP as a controller completes the configuration of AD6636. Power PC reads out the I/Q data, either four channels at one time,or just only one channel which is concerned. Signal sampling frequency is up to 100 MSPS, as is known to all that the higher sampling frequency, the better SNR. The system can apply to magnetic field of 1 T. Experiments show that four channels work well, and filter parameters can be changed effortless. It is optimized for compact, with high sampling rate, and rich flexible filter design. And it provides a high-performance signal acquisition design for the development of magnetic resonance imaging spectrometer.

The principle of filter bank is introduced briefly, then the realization methods based on FPGA are presented in detailed. By parallel-to-serial conversion, realization structures of FIR and FFT which can save multiplier resource are proposed. The realization structure of rounding towards nearest integer is also put forward. These measures guarantee the realizability of filter bank in single FPGA chip.