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About this book

This book presents innovative and interdisciplinary applications of advanced technologies. It includes the scientific outcomes of the 9th DAYS OF BHAAAS (Bosnian-Herzegovinian American Academy of Arts and Sciences) held in Banja Vrućica, Teslić, Bosnia and Herzegovina on May 25–28, 2017. This unique book offers a comprehensive, multidisciplinary and interdisciplinary overview of the latest developments in a broad section of technologies and methodologies, viewed through the prism of applications in computing, networking, information technology, robotics, complex systems, communications, energy, mechanical engineering, economics and medicine, to name just a few.

Table of Contents


Advanced Electrical Power Systems (Planning, Operation and Control)


Electric Energy Losses Estimation in Power Distribution System—Tuzla Canton Case Study

The method for estimation of electrical energy losses in distribution system from the place of taking electrical energy from network of transmission company or other suppliers to the place of delivery to the end customers and determination the structure of losses by voltage levels is presented. For part of the distribution network for which the losses are calculated, constant losses, load dependent losses and losses in components of electrodistribution network are taken into account. Distribution losses by voltage levels is made by balancing the total electrical energy losses and losses estimated by method of stationary load flow calculations on medium-voltage (MV) of certain electrodistribution network. The presented method is very practical and by its application the parts of electrodistribution system with increased losses are located with high reliability. Results of analysis of electrical energy losses, which is done by presented method, can be taken as a reliable basis for taking action in the aim of reducing total losses in electrodistribution network. The results of practical analysis are presented for the area of Tuzla Canton—Bosnia and Herzegovina.

Šeila Gruhonjić Ferhatbegović, Izet Džananović, Samir Avdaković

Application of Teager Energy Operator for the Power System Fault Identification and Localisation

Power system is constantly exposed to the disturbances. Some disturbances can cause cascading propagation and outages of other generators or transmission lines in the system. Finally that can lead to the partial or total system blackout. Wide Area Monitoring Protection and Control (WAMPAC) systems based on phasor measurement units (PMU) are strongly improving in order to eventually prevent these dangerous occurences. This platform presents base for the development of the smart grids. One of the requirements for the smart power systems is presence of the algorithms for fast and correct fault identification and localisation. In this paper Teager Energy Operator (TEO) is proposed for the processing and analysis of the synchronized measurement signals in order to perform fault identification and localisation. Several fault types are simulated in the NE 39 bus test system using DigSILENT Power Factory software. Results of the fault identification and localisation are compared with Discrete Wavelet Transform (DWT).

Nejra Čišija-Kobilica, Samir Avdaković

Analysis and Control of DG Influence on Voltage Profile in Distribution Network

Power generated by the Distributed Generator (DG) must satisfy high quality standards and ensure compatibility with network operation and customer supply requirements. The power system needs to maintain stable operating conditions and continue to meet customer load demand for the entire range of generations. This paper presents results of investigations related to reactive power and voltage control requirements for distribution network with DG. The load flow analysis is performed for minimum and maximum load levels for no generation case and range of generations up to the DG capacity for all lines in service and following single line outages. Voltage developments in the network are recorded and discussed in terms of DG reactive power requirements. Results indicate that the variable power factor operation of larger DG units must be employed in order to ensure static voltage stability and limit voltage fluctuations. This paper makes a contribution to the electrical engineering practice in terms of providing additional evidence of DG influence on static voltage profile developments and control in the practical electrical distribution system. This paper also presents basic analysis for reactive yard design required for voltage control by larger DG units.

Mirza Šarić, Jasna Hivziefendić, Lejla Bandić

Fuzzy Logic Based Approach for Faults Identification and Classification in Medium Voltage Isolated Distribution Network

Power system faults are unwelcome events which pose a safety, technical and social hazard. Power system operators are under increasing pressure from customers and regulators to maintain high levels of power system reliability. Appropriate fault identification and classifications is a crucial part of power system operation and management. This paper proposes a method for identification and classification of faults in 10 kV isolated distribution network. The proposed method uses three line voltages, available at the substation as input variable and returns the fault code as the output variable for all ten shunt fault types, as the output variable. Classification is based on the fuzzy system with three input variables and one output variable. Results show that proposed system can detect low resistance faults with 100% accuracy for all then shunt fault types that can occur in electric power distribution network. The input data (voltage waveforms) are generated in simulations performed on a model of realistic distribution system in Bosnia and Herzegovina.

Mirza Šarić, Tarik Hubana, Elma Begić

Influence of Solar PVDG on Electrical Energy Losses in Low Voltage Distribution Network

Renewable energy based distributed generation (DG) integration provides potential benefits to conventional distribution systems. However, DG has influence on the power flow in power system and hence presents one of the major concerns in modern distribution systems. It gives significant impact since distributed generators can affect the distribution system, both positively and negatively. In this paper, the influence of photovoltaic DG on electrical energy losses in low voltage network is investigated. Experimental results and data measured from Bosnia and Herzegovina low voltage distribution network are used for model development. A novel approach using Distribution Loss Factor (DLF) concept combined with power generation-demand probability is used for loss calculation. This paper does not introduce the DLF concept, but takes it from literature for the purpose of calculating losses in the considered network. This paper makes a contribution towards investigation of the exact photovoltaic distributed generation contribution to the overall cost of the network operation and managements. The obtained results are useful for distribution system operator in terms of better loss evaluation, and proposed analysis method could be accepted as an important part of the distributed generation planning process.

Edin Šemić, Mirza Šarić, Tarik Hubana

Connecting a Group of Small Hydropower Plants on the Side of Neretvica River to a Medium Voltage Distribution Grid

Since Bosnia and Herzegovina is a country famous for its river flows there has been an expansion of constructing small hydropower plants (SHP) where the whole process includes projecting, gaining concessions and building. ‘JP Elektroprivreda’ has a plan for constructing 15 small hydropower plants on the side of Neretvica. The construction is planned throughout three phases. This paper discusses the issues of connecting small hydropower plants of the planned first phase to a medium voltage distribution grid, and effects it has on the distributive grid. The already mentioned hydropower plants are to be connected to an existing 35 kV voltage grid, although the strategical commitment of JP Elektroprivreda was to leave this voltage level back. The main focuses of this paper are the models of calculating the power flow, the losses of the voltage, the short circuit calculations, and the evaluation of the effect of connecting a SHP group on the existing 35 kV distributive grid. All the calculations are made using the professional software PowerCAD. Results of analysis are showing meaningful impact of SHP group connecting to an existing distributive grid, which are mostly seen voltage changes and increases in grid loses. The parameters that are important for the work of this project stayed in the allowed domain after the simulation of the SHP group has been done.

Dino Macić, Mirza Šarić

Analysis of the Impact of Distributed Generation on Voltage Profiles (Case Study Long Feeder 10 kV Grebak)

In order to reduce carbon-dioxide emissions, Bosnia and Herzegovina will be required to achieve the renewable energy share of 20% in total energy consumption by 2020. Therefore, in the previous period an intensive construction of power plants based on renewable energy sources has been noticed. Aim of this paper was to analyze how different distributed generators (DG) impact the voltage profiles of the system. In this paper medium voltage (MV) distribution network of feeder 10 kV Grebak, and all existing and planned DGs were modeled with real parameters. The analysis was done in PSAT toolbox (MATLAB toolbox), which was used to perform load flow calculations. Furthermore, the impact of planned DGs on voltage profiles is shown for different scenarios. The obtained results show difference between the impact of existing small hydro power plants and solar power plants, as well as the effect of their capacitive and inductive regimes of reactive power production. Also, the results showed that on this feeder it is not possible to connect planned additional DG’s while maintaining voltage profiles within limits. The precise location and size of the DGs have vital influence on voltage profiles.

Aiša Ramović, Lejla Terzić, Adnan Bosović, Mustafa Musić

Power System Fault Detection, Classification and Location using Artificial Neural Networks

This article focuses on detecting, classifying and locating faults in power system using Artificial Neural Networks (ANNs). Feed-forward neural networks have been employed and trained with back-propagation algorithm. The model of WSCC 9 bus test system has been modelled in Matlab/Simulink, and used to validate the proposed fault detection system. First, normal state of the model was observed. After determination of normal state, different types of faults have been simulated on all nine buses and on all lines of the model. Voltage and current magnitudes, obtained by the fault simulation, are used as inputs of the ANN. Output of the ANN should provide information about the fault type and location in case the fault occurs. Number of hidden layers and neurons per hidden layer is determined by testing performance and training time of each developed neural network.

Almin Karić, Tatjana Konjić, Admir Jahić

Single Phase Fault Location in Distribution Network Based on Wavelet Transform of Current Traveling Waves

Determination of single-phase fault in medium voltage (MV) distribution network is important because this is by far the most common form of a fault. During single-phase faults, higher values of fault resistance are possible which adversely affect to the accuracy and reliability of distance determination from supplied substation (TS) to the fault place. The presented method, based on wavelet transformation, shows significant benefits during computer fault simulations. By application of this method, it is possible to locate single-phase faults in isolated and compensated distribution network as well as faults with significant values of a transient fault resistance.

Šeila Gruhonjić Ferhatbegović

The Analysis and Benefits of the New TS 110/x KV Interpolation on the Distribution Network

Intensive economic development in recent years, as well as growing amounts of electricity consumption in the Municipality of Tešanj, indicate the need for a systematic approach in defining the ways of meeting growing electricity demands. Taking into account the expected increase in load (through the year 2025), and using the appropriate mathematical models, this paper presents the results of an impact assessment of the interpolation of the new 110/x kV Jelah substation into the medium voltage Tešanj distribution network—specifically regarding the Jelah area. The results of the analysis of power flows, voltage conditions and losses, with respect to the expected increases in energy consumption in 2020 and 2025 in the analyzed area, indicate that the problem of overload to the existing 35/10 kV substations requires special attention when planning the development of distribution networks, and that inadequate development and untimely investments into the electricity grid could lead to significant changes in voltage and active power losses in the network, thus compromising standardized limits.

Jasmina Čučuković, Faruk Hidić, Ismet Kulović

Determination of Static Voltage Load Characteristics in BiH Electricity System

From 2015 to 2016, the Independent System Operator in Bosnia and Herzegovina (ISO BiH) performed periodic measurements in 26 substations 110/x kV, separately in winter and summer regimes. Power transformer tap changer positions were experimentally shifted in order to determine static load characteristics of complex consumer areas, ie. to determine self-regulating consumption coefficients that demonstrate the load change (in percentage) when the voltage changes by 1%. Experiments with changing different transmission ratios were realized in real exploitation conditions in BiH power system, whereby in the process of reducing the voltage, special care was taken about the security of supply of the most remote consumers. Reducing the voltage can be implemented as a system service, when there is a shortage of active power throughout the power system, or locally, as a result of problems in one part of the system, in order to provide the required level of safety and to avoid voltage collapse of the power system. The complete study and its accompanying measurements and results can be found in [1].

Husnija Ferizović, Vojislav Pantić, Senad Hadžić, Semir Hadžimuratović

Application of Modern Solutions on Grounded Neutral Point in Distribution Grid

In practice are used several neutral point grounding modes for medium voltage grids. Each mode has certain advantages, but also disadvantages. Therefore, for the final decision on the grounding method a special analysis is performed for each transformer substation, given the specificity of the distribution grid connected to it. Neutral point treatment also affects the reliability of electricity supply to consumers, which in conditions of an open electricity market is gaining more and more importance. Along to the technical of great importance is the economic aspect as some solutions differ significantly. This paper gives a specific review of basic technical characteristics for solutions with compensated (resonant) grounding of the neutral point, i.e. application of Arc Suppression Coil (ASC)—Peterson coil technology in distribution grids, which implies neutral point grounding of the power transformer through an inductive reactance. Also in the paper are given basic principles of applied protections as well as modern approaches for failure detection in distribution grids with compensated neutral points.

Alija Jusić, Zijad Bajramović

Comparison of CFD and Linear Model When Calculating Maps of Wind Potential at the Location with Complex Topography

For the assessment of wind flow model on locations in Bosnia and Herzegovina so far, linear model WASP is mainly used, while the suitability and reliability of the CFD models have rarely been studied. Due to the specific conditions which include the dominant wind from one or two directions and relatively complex topography of the potential sites of wind farms, this work aims to develop a method of assessing wind potential in locations with complex topography and the prevailing wind from one or two directions. The method is applied using empirical data and the mathematical/computer models are employed to determine and describe the impact of such a topography on the wind flow, including assessment of expected production of electricity from wind power. Such research would be an original scientific contribution to the assessment of wind potential and wind energy alone generally.

Dino Trešnjo, Alma Ademović Tahirović, Muris Torlak, Elma Redžić, Mustafa Musić

Multicriteria Decision Making Model for HPP Alternative Selection

The development and implementation of new hydropower plant projects as a way of increasing the share of electricity generation from renewable energy sources is an imperative for the energy sector. Electricity that will be produced in new hydro power plants should be the basis for sustainable development, which is conditioned by the balance between economic, technical, social and environmental demands. Therefore, in addressing the problem of making choice on technical solution variants for hydropower plant, these requirements should be considered. Since the choice of optimal variants is influenced by various factors (criteria), mostly conflicting with each other, this problem is a matter of multicriteria decision making (MCDM). This paper presents a model for multictiteria decision making on technical solution for hydro power plant from the Pareto set of alternatives. An analytic hierarchical process was applied, taking into account quantitative and qualitative criteria. The model was tested on a specific example.

Zedina Lavić, Sabina Dacić-Lepara

Power System Planning: Part I—Basic Principles

Power system planning is an activity related to the development of plans for designing and construction of the system and its elements, which will satisfy assumed future needs, starting from the given state. First paper presents basic principles of power system development planning with its concepts. Electrical energy losses as well as forecasting of energy consumption are taken in consideration. Basic principles of development planning for each subsystem (generation, transmission and distribution) are presented. In the second paper, practical application of techno-economic analysis of the transition from the voltage level of 10–20 kV in Gračanica is presented with two different investment costs using four different approaches.

Armin Demir, Nasiha Hadžijahić

Power System Planning: Part II—Practical Applications

Power system planning is an activity related to the development of plans for designing and construction of the system and its elements, which will satisfy assumed future needs, starting from the given state. First paper presents basic principles of power system development planning with its concepts. Electrical energy losses as well as forecasting of energy consumption are taken in consideration. Basic principles of development planning for each subsystem (generation, transmission and distribution) are presented. In the second paper, practical application of techno-economic analysis of the transition from the voltage level of 10–20 kV in Gračanica is presented with two different investment costs using four different approaches.

Armin Demir, Nasiha Hadžijahić

Identifications of Power System Dominant Low-Frequency Eletromechanical Oscillations Using Hilbert Marginal Spectrum

Identification of low-frequency electromechanical oscillations (LFEOs) in a power systems is an important aspect of modern systems for monitoring, control and protection. Generally, available signals from power systems are nonlinear and non-stationary, and their treatment requires adequate mathematical techniques. One of the most popular technique for time-frequency signal analysis is the Hilbert-Huang transform, with a very successful application in different fields of science. In this paper, the Hilbert marginal spectrum (HMS) obtained by the Empirical Mode Decomposition (EMD), which separates the signal into several Intrinsic Mode Functions (IMFs), is applied for the identification of the dominant LFEOs in a power system. Results of the HMS approach are tested in two examples and compared with the results obtained using the global wavelet spectrum (GWS) approach.

Maja Muftić Dedović, Samir Avdaković

Computer Science


Implementation of ICT in Education

In todays education system new techniques are being used, as well as modern methods and means of work. ICT takes an important a place in the educational process, as the application of modern media in the lower and higher grades of primary school. The use of ICT provides opportunities for every student to be more active and better and to have greater motivation. Teaching process is more interesting and clearer and is of high quality for any subject. A special place occupies application of Microsoft tools which are important for many projects in the teaching/entire teaching process. ICT provides a great advantage in the preparation and organization of teaching classes, as well as teaching the students, relatively using the modern technology in class, and demands constant education of teachers by attending many seminars. The use of ICT provides a greater performance, visual observation, better perception and faster learning. Students are prepared with the help of parents at home through creative work, they explore interesting topics on the Internet. In the teaching process, teachers as assistants are instructing students while they are doing their tasks. There is a possibility of good interaction between teacher and student. Students have the opportunity to prepare presentation or projects with the use of the Internet, as well as to prepare school quizzes. They have the opportunity to communicate with each other by e-mail, facebook, Sky Drive, GeoGebra, Geometric Scatch Pade, Mindomo, interactive games. The use of ICT has its disadvantages and advantages. Its disadvantages are that it requires more preparation for teachers, more teaching materials (crayons, school papers, etc.) and more time to prepare presentations on CD. Today’s teaching process in the classroom is unimaginable without the use of ICT in all primary schools.

Amina Delić-Zimić, Naida Gadžo

Modern Teaching Approaches

Implementation of modern media and information technology in primary schools has been increasing. Important conclusions are economy of time and proper guidance of students in use of ICT, and the constant training of teachers for lifelong learning. The use of ICT provides opportunities for every student to be more active and better and to have greater motivation. Teaching process is more interesting and clearer and is of high quality for any subject. A special place occupies application of Microsoft tools which are important for many projects in the teaching/entire teaching process. ICT provides a great advantage in the preparation and organization of teaching classes, as well as teaching the students, relatively using the modern technology in class, and demands constant education of teachers by attending many seminars. They have the opportunity to communicate with each other by e-mail, twitter, facebook, Sky Drive, Geometric Scatch Pade, GeoGebra etc.

Amina Delić-Zimić

Ferris Wheel Tree

The goal of this paper is to describe the problem of data structures sometimes having to keep track of the history of changes made upon it, and a possible solution of this problem. Of course, numerous solutions to this problem have already been implemented, however, this paper offers one that is uncomplicated, best suited for small scale applications. A new kind of binary tree is introduced—the Ferris wheel tree. While being simple to implement, it achieves partial persistence, allowing us to view particular versions of data. Each operation that can be done on this tree is defined and described. The runtime complexity of those operations is analyzed and presented, and based on that, also the variations and circumstances when this tree should best be used.

Dalila Isanovic

Influence of Schemaless Approach on Database Authorization

NoSQL databases are oriented towards managing huge amounts of data by distributing them over commodity servers. Different types of these databases exist, for different use cases. Key/value databases have the simplest interface. Document databases allow filtering based on document contents. Column-family databases are oriented towards column structuring. Their data models are simple and they do not require schema specification schemaless approach. Additionally, their primary focus isn’t data security, which includes authorization. There are different levels on which authorization can be implemented. Only a few NoSQL databases are meeting a common requirement of granular authorization. Ways of mitigating authorization requirements on application-level were listed and discussed.

Dejan Radic

Buffered Count-Min Sketch

In this paper, we present the preliminary work on the adaptation of Count-Min sketch (CMS) data structure to the external storage. CMS is a probabilistic, hashing-based data structure that is used to measure items’ frequencies using very compact space. CMS has broad applications in the streaming context, i.e., in measuring popularity (e.g., top k elements, heavy hitters, quantiles, range queries, etc.) CMS has two error parameters $$\epsilon $$ϵ and $$\delta $$δ: on the input size N, it guarantees that the overestimate of the item frequency is within $$\epsilon N$$ϵN with probability at least $$1-\delta $$1-δ. The error parameters are tunable and determine the size of the sketch. To maintain the same band of error, CMS grows linearly with the size of the dataset. Simply placing the CMS on SSD or a hard-drive results in very slow performance due to the random-write nature of UPDATE operations. We suggest two adaptations of the Count-Min sketch to alleviate this effect: Elevator Count-Min Sketch (ECMS) and Buffered Count-Min Sketch (BCMS). The two adaptations use buffering updates in RAM and hash localization, two methods similar to those used in [5] to alleviate similar issues with the Bloom filter. We show that operations on the ECMS and BCMS require asymptotically fewer I/Os than the traditional CMS placed on disk.

Ehsan Eydi, Dzejla Medjedovic, Emina Mekic, Elmedin Selmanovic

The Relationship Between the Performance of Islamic and Conventional Banks

The purpose of this paper is to research existing models of financial institutions and determine the position of Islamic finance in today’s modern world of conventional western finance. Theory suggests that Islamic financial principles are not inferior to conventional principles and perhaps may even supersede them in some aspects. This paper will attempt to empirically display the relative strengths and weaknesses of both bank types. Research was conducted in the Global Cooperation Council (GCC) region, based on a sample size of 58 banks through the years 2003–2015....

Emina Causevic

Stylometric Study of Ivo Andrić’s Short Stories

This paper presents a stylometric analysis of Ivo Andrić’s short stories written in the 54 year long-time period, and translations into English by fourteen different interpreters. The objective of this study is to analyze stylometric similarities in two languages and correlations with possible changes of author’s usage of words over time.

Edin Konjhodžić

Influence of Information Technology to Human Resources Management: Key Trends in 21st Century

Information technology (IT) has huge influence on all parts of business process and it is impossible to imagine any of the business aspects that were not, at least in some extends, applied appropriate IT technology. Human Resources Management (HRM) is not an exception especially having in mind benefits that information technologies bring to the quality of the HR processes from recruiting to talent management. Paper analyzes concept of Human Resources Technology and how technology made impact to modern Human Resource Management practices. It gives review of innovative and technological solutions to HR challenges through company examples and studies presenting impact of IT to HR management. There will be given analysis of influence of the cloud computing, smart mobile technologies, online recruiting platforms, big data and predictive analytics to processes of HR management.

Ljubisa Micic, Veselin Radosavac

Science Battle

Young minds are conditioned and trained in order to provide the fundamental background knowledge that may one day lead to greatness. In this paper we present a 3D game “Science Battle” which is an innovative attempt to develop an engaging educational tool for children to learn science. The core concept of this game is to create a learning environment where children are immersed to the extent of not realizing that they are in essence learning. Science Battle aims to make the player visualize scientific concepts represented by visually appealing 3D characters: robots. The main focus is on teaching various scientific concepts by displaying “battles” between the robots. In essence, Science Battle quizzes the player without having the player realize that he/she is being tested.

Medina Krnic, Belma Ramic-Brkic

Constraint Satisfaction Problem: Professor Weekly Schedule

A large number of problems in AI and other areas of computer science can be viewed as special cases of the constraint satisfaction problem. A number of different approaches have been developed for solving these problems. Some of them use backtracking to directly search for possible solutions. Intelligent backtracking is used in this paper, but the algorithm is not standard. A specific problem of making a weekly schedule for a professor is solved.

Mirna Udovićić

Posture Activity Prediction Using Microsoft Azure

Recently research on Human Activity Recognition (HAR) has been reported on systems showing good overall recognition performance. A machine learning based HAR classifier was proposed in several experimental setups. A public domain dataset comprising 165,633 samples was used for this purpose. Models of machine learning algorithms are built up using Azure Machine Learning studio. Based on the mentioned dataset, and previous work we have done 5 experiments. First, we have done experiments for classifying suitable algorithms for further experiments. Other experiment is trained on male data, tested on female data and vice versa. Than, we separated each subject from whole dataset. Each of them was used as a test model while other 3 subjects were in train model. In the last experiment each subject data is trained and tested separately. It achieved the highest overall performance. Currently, it is not possible to build subject-independent method for posture activity detection.

Mirza Čurić, Jasmin Kevrić

Hybrid Comparative Predictive Modeling

In this research, a hybrid predictive model was proposed for the language assignment decision-making process where predictive modeling is primarily based on personality type and learning style preference attributes. Predictive models can be built through the use of machine learning using different classifiers/algorithms to predict results as well as provide recommendations to management for placement in appropriate language programs of study and students for the adoption of appropriate study strategies and habits. A predictive model through machine learning was used in conjunction with probabilistic classification and clustering of specific segments within the data in order to increase the rate of success for an improved decision-making process. Variance in the actual and predicted results with respect to the difference in success rates can assist the decision makers in student placement. An aggregate of all the processes with the help of Cobb-Douglas utility function leads to a Hybrid Predictive Model, which combined two different phases for better placement, an increased rate of success, and an overall improved decision-making process. The introduction of Cobb-Douglas utility function can further streamline the process to check any external factors that may have influenced the predicted results.

Mohammad Asif Nawaz, Mirsad Hadzikadic

SSST-Cloud: Developing a Cloud System for a University

Cloud systems are becoming increasingly popular for sharing various types of files and accessing them from different locations. The idea behind it seems simple and ideal for different types of users. The reality, on the other hand, is quite different. Companies for example, might require certain functionalities that an off-the-shelf cloud system cannot provide. Universities have certain procedures regarding sharing of grades and other course related materials that must be met during the development of the cloud system in order for it to be useful and efficient. In this paper, we talk about the functionalities that a cloud system has to provide and the technical requirements it has to meet in order to be successfully implemented and used by a University, its students and professors. Thorough analysis was performed to analyze the drawbacks of current solutions and consequently, offer a novel approach in developing cloud systems for one particular private University.

Tarik Catic, Belma Ramic-Brkic

DIY Smart Mirror

The Internet of Things concept has become increasingly popular when it comes to providing people with technology and tools that would make their lives simpler and ease their day-to-day routines. One such tool is a multipurpose mirror used both as a mirror and a device. There have been several successful attempts of building such a device, and some of them even turned into business opportunities. However, due to its selling prices and shipping policies regarding Bosnia and Herzegovina, it is almost impossible to acquire one. The main purpose of this paper is to show how the process of building a Smart Mirror from scratch showing basic information such as time, date, weather statistics, and recent news headlines. The displayed information is accessible at any point in time. The cost-effective analysis indicates significant cost savings for produced outcome compared to available off-the-shelf solutions.

Sadeta Kulovic, Belma Ramic-Brkic

Farm: Serious Game for Addressing Child Obesity

Obesity among young adults is an increasing world health problem associated with harmful effects on the health and general well-being. Although this phenomenon is mainly connected to low and middle income countries such as Bosnia and Herzegovina, obesity levels in developed countries such as UK and USA, are significantly increasing as well. In this paper we address the possibility of reducing the problem through the use of serious games. Stimulating children through the fun and interactive play environment has been shown as an effective method in increasing physical activity and energy expenditure during the play. Using this method of playing a carefully designed serious game is one of the ways to stimulate and help children change their behaviour towards eating, physical activity and therefore, consequently, prevent and reduce child obesity. In this paper we present a game which encourages a child to move using Kinect motion sensors. The aim of the game is to move through the virtual farm and cache the healthy food items appearing on the sides. Food items are grouped in four categories across different levels of the game. In the preliminary study presented here, the effect of pleasure and user satisfaction was only tested.

Sena Bajraktarević, Belma Ramić-Brkić

Power Quality


Application of EMD and STFT Methods in Analysis of Energization of an Unloaded Overhead Line Under Different Operating Conditions

Maintaining of voltage conditions recommended by EN 50160 Standard is ultimate aim related to power quality. This issue gets an additional importance in era of modern power systems and smart grid environments. Occurrence of voltage whose magnitude exceeds the highest voltage level recommended for proper electrical equipment operation is known as overvoltage. Switching operation such as line energization can cause this type of disturbance. The paper deals with switching overvoltages occurred during energization of an unloaded overhead transmission line under different operating conditions. Namely, this process can be performed under normal or fault conditions. The latter means that some kind of fault has occured along the line and exists at the moment of energization. Switching overvoltages have to be analyzed not only from the aspect of magnitude, but also from the aspect of the existing harmonics in the harmonic spectrum. Accordingly, the Empirical Mode Decomposition and Short time Fourier Transform were used. The obtained results were compared to the calculated ones. In this way, one may get characteristic harmonics values which occur during the energization process, what would make a worthwhile contribution related to recognition of operating conditions during energization. Also, a conclusion about applied methods efficiency is drawn.

Snežana Vujošević, Saša Mujović

Voltage Flickers as Voltage Quality Problem in Industrial Sector

Very important parameter of product called electricity is voltage quality. In recent times electricity became a commodity that has its price and it is known that any commodity today must have an appropriate quality for its price. That applies for electrical energy as well. Influence of loads based on nonlinearity, power electronic and renewable energy sources connected on distribution network has great consequences on voltage quality. This paper deals with voltage quality in industrial facilities. Industrial facilities connected on distribution network can be various types. Those consumers set very high requirements for reliability and voltage quality. Supply disruption and poor voltage quality leads to production losses in facilities which results with financial losses and dissatisfaction of facility owners. In this paper several measurements in different facilities are taken and analyzed. Those measurements and their results are presented. Focus is placed on worst voltage quality parameter that appears in most measurement cases—voltage flickers. Voltage flickers might be caused due to distribution network or facilities themselves. Causes and consequences of those voltage flickers are analyzed in continuation of this paper.

Ivan Ramljak, Jurica Perko, Matej Znidarec

Power Quality Field Measurements on Photovoltaic System

Solar energy is the main driving force of climate cycles and all life cycles on Earth. It is inexhaustible and it can be used in each country all over the world. Bosnia and Herzegovina is in line with EU guidelines on mandatory reductions of greenhouse gas emissions required to increase production of electricity from the renewable energy sources. The main scope of this paper is to investigate the power quality parameters measured during different periods and weather conditions on the first photovoltaic system “Eko Energija” connected to the distribution power network in Bosnia and Herzegovina. The results of these measurements are analysed and presented in this paper.

Mia Lešić, Tatjana Konjić

Different Approaches for Analysis of Harmonics Impact on the Transformer Losses and Life Expectancy

Transformers represent the largest part of capital investment in power system. In addition, power transformer outages have a considerable economic impact on the operation of an electrical network [1]. Application of nonlinear loads in recent decades, such as power electronic loads, caused higher levels of harmonic. This kind of load can lead to creating heat, losses and therefore cause destruction of insulation and aging of transformers. Load and ambient temperatures are two important factors that influence the life of insulation in transformers. The estimated load factors and ambient temperatures are input to the IEC life consumption models to assess the consumed life of insulation. It should be recognized that liquid-filled transformers may have different load limitations than dry-type transformers and that the harmonic loading practices should treat the two transformer types differently when necessary. In this paper are presented different approaches for determination of losses and estimation of life expectancy of transformers under harmonic loads. For this purpose are used computational, analytical and measuring methods. The Finite Element Method (FEM) is very sophisticated method for design and analysis of electrical machines. FEM method could be used for estimation of parameters and performances of machines during design process and before production phase. If operator decided to change non-linear load of transformer with another non-linear load with, for example, different THD factor, operator can calculate losses using presented FEM and evaluate the effects of proposed non-linear load on transformer losses and life time. Finally, the results obtained by using different methods are presented in this paper.

Izudin Kapetanović, Jasna Hivziefendić, Majda Tešanović

Voltage Sag Propagation Caused by Faults in Medium Voltage Distribution Network

Underground cables are being increasingly constructed in modern power distribution networks, however overhead lines are still present, making the system more exposed to faults. Faults from medium voltage networks propagate throughout the network and then experienced by low-voltage customers as voltage sags. Voltage sags have become increasingly important when considering the various power quality issues that cause inconvenience to customers. For some customers voltage sags cause, especially high costs. In this paper, different fault types at the medium voltage level and the sag propagated throughout the network are analyzed. Asymmetrical faults can cause problems for protection devices since they propagate differently throughout the distribution network, and distort the phase to ground voltages on the different voltage levels. Experimental results obtained from the Bosnia and Herzegovina distribution system show the significance of appropriate voltage sag propagation understanding. The power distribution companies should understand the voltage sags experienced in their networks and develop strategies for decreasing the influence of voltage sags. Thus, voltage sags analysis should be an important part of power distribution planning and an important element in a comprehensive power system analysis.

Tarik Hubana, Elma Begić, Mirza Šarić

Architecture of the Modern Power Quality Monitoring Systems with Installation and Experiences Examples from BiH, Croatia and Slovenia

The quality of supply and reliability of the grid are main investments reason in electrical grid. To keep the track of the power quality it’s necessary to develop power quality monitoring system. Development of power quality system requires deep analysis of customer grid to properly select points of installation and project with clear goals and requirements for monitoring system. Implementation of the power quality system depends on the type of the electrical grid and existing communication infrastructure. The new system need to be compatible with all up to date technologies and provide data protection and access control. Beside the basic power quality indices, it needs to offer integration with other utilities systems like SCADA and fault location systems to improve response and benchmarking of the system.

Ivan Vlahović, Ivo Novaković

Impact of Distributed Generation on Power Quality in Medium Voltage Distribution Networks

This paper provides an analysis of the impact of mini hydropower plant “Kordići” on the 20 kV distribution network of Bugojno area in terms of power quality. Therefore, measurement and evaluation of the quality of the supplied power was carried out at the point of common coupling between the mini hydropower plant and the distribution network. Measurement was carried out for the period from March 7 to March 18, 2016 and the data were evaluated in accordance with EN 50160 standard.

Alija Jusić, Edin Jareb, Zijad Bajramović

Civil Engineering


3D Numerical Study of Sidewall Friction Influence on Small Scale Reinforced Earth Wall Behavior

Identification of failure mechanisms and behavior of reduced scale reinforced earth walls under footing pressure have been increasingly investigated in recent period. Numerical and physical modeling is introduced in research to generate data related to interaction of the particular components of these walls. Certain assumptions must be made regarding the choice of parameters for numerical model while physical modeling on scaled walls often includes boundary conditions that can be different from full scale walls. One of the model wall boundary conditions that does not exist for full scale walls is sidewall friction. Its effect can be reduced by applying silicone grease before wall construction. Since model walls are often made with transparent glass sides, lubrication of inner surfaces of sidewalls reduces its transparency and disables observation by advanced monitoring techniques. Influence of sidewall friction was investigated by 3D numerical analysis in this study. Reduction of the sidewall friction influence with increasing model width was confirmed. Results indicate that sidewall friction is not a decisive factor that governs behavior and failure mechanism even for a relatively narrow model walls.

Adis Skejić, Mladen Kapor, Senad Medić, Đenari Čerimagić

3D Modeling and Nonlinear Analysis Stability of CWR Tracks

Rail welding and forming continuous welded track provides many benefits in terms of exploitation and maintenance of railway lines, however there remains the problem of ensuring stability and prevent lateral buckling of the track. This problem is particularly expressed in areas with large temperature differences in the summer and winter period (minimum and maximum temperature) and tracks the maximum adjusted topographical conditions (applied to the minimum curvature radius and maximum longitudinal slopes). In order to solve this problem in the past have made numerous researches and developed many of the analytical method for the analysis. Many of them due to the large number of parameters are too complicated and are not applicable in engineering practice so tended their simplification, usually in a way that the calculations are not taken into consideration material and geometric nonlinearity. To analyze the stability of the CWR track in past several years used numerical models based on the finite element method, and have been developed and various software packages to analyze the stability of the track. Advantages of this method of analysis of the stability of the track-and CWR are able to make the models corresponding to the actual state of the track and the possibility of nonlinear analysis. Also, for making models can be used commercial FE software for nonlinear structural analysis, as will be shown in this paper.

Sanjin Albinovic, Samir Dolarevic, Dusan Marusic

A Study of Speed on Two-Lane Roadways

Speed represents the most important functional characteristic of roads. That is why the article attempts to give a view of the overall speed generation procedure on main (trunk) roadways (magistralne ceste) and its measuring methods. Also proposed is the back calculation approach in analyzing the conditions for main (trunk) road rehabilitation from the aspect of bringing speed to conform with the legally set limits, but also road protection from speed degradation due to elemental conditions taking place during road exploitation.

Mehmed Bublin

Adriatic-Ionian Road: Economic and Social Potential of the Adriatic-Ionian Region

General information about the Adriatic-Ionian road and its corridor are presented in the paper. Furthermore, the impact of the road on the economic and social development of a part of the southeast and the entire BiH by connecting it to the neighbouring countries is significant, as explained in the text.

Predrag Sarkinovic, Naser Morina

Browninfo Methodology and Software for Development of Interactive Brownfield Databases

Brownfields represent abandoned and disused sites, an exceptional strategic reserve of space and urban resource whose potentials are under-recognised in Bosnia and Herzegovina. The initial step towards urban renewal of these spaces is: their identification, evaluation, assessment of development potential and promotion. Interactive, GIS and web oriented digital database of brownfields is very useful tool for its promotion and visibility that makes process of brownfield regeneration more efficient and faster. Therefore, the paper presents the unique methodology for development of interactive brownfield databases and bundled software BrownInfo.

Tijana Vujičić, Dijana Simonović, Aleksandra Đukić, Maksim Šestić

Rehabilitation of the Urban Road and Pristina A.B Piles

Incoherent soil is stable as long as the angle of slope less than the friction angle of the soil. So, in this type of soil slippage occurs only if the angle of slope is greater than the internal friction and slippage occurs when at every point of the sliding surface shear stresses due to the action of external force reaches the shear resistance of the soil.

Bujar Emra, Naser Morin, Mirsad Tarić, Mirza Hadžimujović

Analysis of Economic Feasibility and Usefulness of Asphalt Mixtures of Recycled Asphalt in Relation to the New Ones

This paper describes testing of the possibilities of application recycled asphalt in the production of new asphalt mixtures. Recycled asphalt was obtained by mechanical milling of the existing asphalt pavement in the reconstruction of old asphalt pavements. Laboratory testing has researched convenience in using recycled asphalt and it is also projected composition of asphalt mix recycled asphalt and after that is made out trial production engineered of the asphalt mix. The results have enabled to draw conclusions about the applicability and the required proportion of recycled asphalt, production technology and potential savings in the production of new asphalt mixtures.

Muamer Dubravac, Edis Softić, Zlatan Talić

Seismic Vulnerability, Damage and Strengthening Evaluation of Historical Buildings in Bosnia and Herzegovina

Bosnia and Herzegovina is situated in seismic active region of South-East Europe, divided in seismic zones with PGA of 0.1–0.2 g, even 0.30–0.35 g in some parts, assuming 500 years return period. Traditionally, historical buildings were made of stone-masonry. They exhibit stiff behavior when exposed to the seismic loading. In the case of stronger earthquake motion such buildings could suffer substantial or heavy damages. Some structural elements, as domes and arches, crack already by moderate earthquake but without the loss of stability. Such buildings can be classified in vulnerability classes B and C according to European Macroseismic Scale, where A stands for the weakest seismic structures and F for those expected to have best seismic performance. Damage assessment, retrofit and strengthening of these buildings are complex tasks for structural engineers, because special attention has to be paid to conservator’s requests and conditions.

Mustafa Hrasnica

Analysis of Relations Between Freeway Geometry and Traffic Characteristics on Traffic Accidents

Modelling traffic accidents on freeways is very significant due to the fact that accidents occurring on these roads are frequent and severe and cause traffic jams. Bearing this in mind, the objective of this paper was to analyze the impact of freeway geometry and traffic characteristics on the occurrence of traffic accidents with fatalities on freeways in Serbia. The paper analyzed traffic accidents with fatalities which had on the M-1 freeway with the total length of 394 km. A regression analysis was used in the analysis of data. The developed models represent the one of the first attempt of quantifying the mentioned impacts on the freeways in Serbia. These models should contribute to the improvement of safety of the existing freeways and designing new safer freeways.

Marina Milenković, Drazenko Glavić

Artificial Neural Networks Application in the Backcalculation Process of Flexible Pavement Layers Elasticity Modulus

The mechanical properties of existing flexible pavements determine the remaining life of pavement and the moment when rehabilitation program should be implemented. The calculation of these properties can be very difficult, time consuming and non-reliable process. To determine the structural capacity of the pavement non-destructive testing equipment used. One of the most commonly used NDT techniques is falling weight deflectometer (FWD) test. Based on FWD measurements backcalculation process must be carried out in order to obtain the modulus of elasticity of pavement layers. This can be done by several methods, different in complexity and accuracy. Artificial neural networks can be successfully used for fast backcalculation process with training based on synthetic deflection basin obtained with linear elastic theory.

Ammar Saric, Mirza Pozder

BIM Project Execution Planning Suited for Road Infrastructure Pilot Project in Bosnia and Herzegovina

Being aware of the “BIM boom” in architecture, engineering and construction industry, a team of experts from the University Sarajevo Faculty of Civil Engineering and from IPSA INSTITUTE LLC Sarajevo decided to develop a scenario adopted to the current public procurement practice for road infrastructure projects in Bosnia and Herzegovina and accordingly to implement a worldwide recognized BIM project planning methodology that will lead to a successful BIM Pilot Project development. BIM Project Execution Planning suited for road infrastructure pilot project in Bosnia and Herzegovina provides technology, process and policy requirements for object-oriented modelling—1st BIM stage applicable in local conditions/environment.

Saša Džumhur, Žanesa Ljevo, Jasmina Marić

Demographic Analysis Using Modern GIS Software Tools—Case Study of the Republic of Srpska (Bosnia and Herzegovina)

This chapter introduces latest location software tools and techniques throughout the process of collecting, mapping, storing and representing statistical data of the Republic of Srpska (Bosnia and Herzegovina). Inherent in Geographic Information Systems (GIS) data is information on the attributes of features as well as their spatial distribution. Spatial analysis more than often uses methods adapted from conventional analysis to address problems in which spatial location is the most important explanatory variable. Besides subsequent raw data processing, this information is used to create geographical maps that can be observed both visually and spatially. Geospatial statistical analysis helps extract additional information from collected geodata that might not be so obvious simply by looking at the numbers information such as how attribute values are distributed, whether there are spatial trends in the data, spotting outliers (extreme high or low values), or whether the features form certain spatial patterns. In principle there is no limit to the complexity of spatial analytic techniques that might find some application in the world, and might be used to tease out interesting insights and support practical actions and decisions. In reality, some techniques are simpler, more useful, or more insightful than others, and the contents of this paper reflect that reality. Provided GIS-based software tools and suggested workflows enable feature mapping and/or importing ready-made feature geometry from various external sources, e.g. web mapping services (WMS), web feature services (WFS)—among the others. Tools enable spatial data storage instantiation and maintenance capabilities using common data store types such as file-based (e.g. SQLite, Esri SHP, Autodesk SDF…) and relational DBMS (Microsoft SQL Server, Oracle Database, PostGIS…).

Nikolina Mijic, Jovo Ateljevic

Estimation of Peak Flood Discharge for an Ungauged River and Application of 1D Hec-Ras Model in Design of Water Levels

Flood is one of the most serious environmental problems we face. It is impossible to construct a totally secure system of flood control, but is necessary to take all measures to reduce damage. The occurrence of high water level in the river bed, most commonly coincide with heavy rain, melting snow or both phenomena together. To construct hydraulic structures, it is necessary, among other data, to have information on high waters of different return period. As a large number of rivers in Bosnia and Herzegovina do not have continuous hydrological monitoring, high water cannot be defined on statistical approach. In this, empirical expressions are applied.This paper presents the application of rational methods for determining peak flood discharge of Lepenički stream, sizing river beds and determine water level along part of riverbed using software package Hec-Ras.

Emina Hadžić, Ajla Mulaomorević-Šeta, Hata Milišić, Nerma Lazović

Experimental Study on Behavior of Reinforced Concrete Beam Subjected to Cyclic Loading

Experimental investigations that have been conducted by a number of researchers have shown that the confinement of concrete using an appropriate arrangement of transverse reinforcement results in a significant increase in both the strength and ductility of confined concrete. The increase of strength and ductility of concrete due to confinement have a significant impact on the load-bearing capacity and ductility of reinforced concrete elements subjected to bending. The experimental testing includes twelve beams reinforced with same longitudinal reinforcement and different transverse confining reinforcement. The aim of this research was to investigate the effects of confinement on strength and ductility of the beam under cyclic loading. The experiments resulted in hysteresis loops showing the force-displacement dependence. Beams with different constitutive laws for concrete and reinforcement and with differently defined cross-sections were modeled using SAP 2000 software. Results of the experimental tests and numerical models were compared.

Edhem Živalj, Asad Kadić, Senad Medić, Muhamed Zlatar

Landfill Leachate Management—Control and Treatment

Sanitary landfills have been the most popular methods of municipal solid waste disposal for the last decades, all over the world, but waste management policy has been greatly turned toward waste minimizing and reuse. Incineration and energy recovery play an important role in waste reduction and energy conversion. Sanitary landfills, however, still exist and will continue to be used for solid waste and residue disposal in many countries. The designs of landfill leachate treatment and landfill closure requirement is one of the major engineering challenge for environmental compliance. The main issue is related to the question: How to select a method for landfill leachate treatment which will be in line with relevant regulations and with reasonable cost and operation complexity? Which one is a right for particular site? Bosnia and Herzegovina is facing nowadays with implementation of solid waste management project throughout the country, which includes issues related to the landfill leachate treatment. This paper presents leachate containment and treatment as well as a brief overview of the subject issue in Bosnia and Herzegovina.

Amra Serdarevic

Modeling Strategies for Masonry Structures

Three strategies in the finite element analysis are used for modeling masonry structures which, depending on complexity, pertain to micro-, meso- or macro-models. Discrete particle models, as well as combined finite element/discrete models, are employed for analysis of heterogeneous masonry elements. Specially dedicated to the analysis of masonry panels and piers is an equivalent frame or macro-element approach. Different application fields exist for each model type. TNO Diana 10.1 is employed for modeling of wallets exposed to compression and unconfined unreinforced walls loaded in shear. Numerical results are verified against the data obtained from experimental research program performed at the Faculty of Civil Engineering in Sarajevo. TREMURI, PFC2D and FEM/DEM are used to describe other modeling techniques.

Senad Medić, Mustafa Hrasnica

Modern Geodetic Technologies As a Basis of the Design and Planning

Traditional way of collecting spatial data leaves the dominant role to modern technologies, especially when it comes to mass storage of spatial forms. Modern technologies of data collection and the obvious development of geo-information technologies provide a wide range of information and indicate that the moment of transition from conventional methods to introducing new technologies for making digital topographic maps, especially when it is needed to keep track of objects of cultural and historical significance has come. This paper presents the advantages, characteristics and the components of modern surveying technologies, such as digital photogrammetry, GPS, LIDAR and UAV systems. Also, a software tool is presented-MicroSurveyCAD, which is used to process point clouds, in different variants.

Marina Davidović, Tatjana Kuzmić

Nonlinear Analysis of Hyperelastic Membrane

When analyzing structures with large displacements, the difference between initial and current configuration cannot be ignored. Most of the structural design problems can be solved with the assumption that the displacements will be small enough, with a possible error less than 1%. In this paper, a membrane submitted to small and large displacements will be analyzed. The stress-strain relationship is described as linear elastic and neo-Hookean hyperelastic. We will show the difference in results when the membrane is submitted to large displacements and why is it important to use the accurate description in constitutive models. The simplest constitutive model for geometric nonlinear analysis of membranes is hyperelastic neo-Hookean which is an extension to large deformations of the usual linear elastic model. All geometric nonlinear and linear elastic analyses were performed in MATLAB.

Rasim Šehagić, Senad Medić

Quality Factors of Process and Products in Construction Projects

Construction industry, as a project-oriented industry, represents an important sector in any economy development and the society in whole. As such, it is also the driving force of development of a wide range of economic activities. In this paper will be shown the results of study about quality of process (project management), quality of product (delivered building) and the factors affecting them. According to their importance, the factors for phase such as conception from the perspective of all respondents in BH are involvement, team work, and quality policy.

Žanesa Ljevo, Saša Džumhur, Selena Grizić

Static and Dynamic Indicators for Composite Bridges

Standard non destructive static and dynamic testing of bridges after their reconstruction serves as indicators regarding the capacity of the structure and their durability. Several steel concrete composite girder bridges were investigated and compared. Measurement from the static tests were used to make some correlation between the stiffness of the structure and dynamic properties. From the investigations it was clear that different truck weight has a direct influence of the dynamic characteristics, requiring a standardization of testing vehicle. Temperature influence was more than indicative.

Naida Ademovic

The Criteria for the Control of Condition of Railway Lines in FB&H

Construction of the railway infrastructure is a very complex activity and requires a large financial investment. For this reason, always tends to build systems that have a long lifetime. A precondition for this, other than a quality of construction work and installation of high-quality material is continuous and proper maintenance. If we disregard the obvious and unexpected irregularities, which are observed by visiting the railway and requiring emergency and urgent actions to maintain the railway and treatment of the same, measuring driving is the most important instrument for identifying irregularities of track geometry and track condition, and railway capacity in terms of planning activities to maintain the railway and the planning works. According to the concept of measuring driving means the recording geometrical parameters the railway, customized railway vehicles for this purpose, which we call the measuring vehicle. Measuring vehicles carry out recording while driving on the track at reduced speed and under specific axial load. The geometry of tracks is one of the basic parameters, based on which it determines the speed of trains and rolling stock, and therefore the level of security in railway transport and line capacity.

Mirna Hebib-Albinovic, Sanjin Albinovic

The New Topographic Information System and Establishing the Basic Topographic Database of the Federation of Bosnia and Herzegovina

The creation of topographic maps is not a traditional activity in Bosnia and Herzegovina. Making such maps were under the jurisdiction of the military Socialist Federative Republic of Yugoslavia (SFRY). Due to the technology used today and the digital spatial data, on the one hand, and compliance with the INfrastructure for SPatial Information (INSPIRE) directive, which is a requirement for entry into the European Union, on the other hand, it was necessary to make strategic decisions about the development of cartography in FB&H. So are some of the strategic decisions of the adoption of the new topographic information system and the establishment of basic topographic database 1:10000 (TTB). In this article will be talk about the new topographic information system FB&H, and data collection methods and procedures for the transfer of data that have been applied for the purposes of establishing TTB. It also speaks about the proposal visualization TTB data.

Slobodanka Kljucanin

The Regression Model for Assignment of Diverted Traffic to Planned Bypass Road

This paper presents a simplified model of traffic assignment to the planned bypass road. The purpose of such model is to provide to the planners a tool for simple, fast and inexpensive way to estimate the expected traffic volume on the planned bypass road by using data that can be obtained relatively quickly. Thus, simplified model may have application in the prefeasibility and feasibility studies, conceptual designs, as well as the development of spatial plans where it is required to reserve the corridor of the bypass and the like. The model is defined by regression analysis. Sources of data, used in this paper, were feasibility traffic studies of eight cities in Bosnia and Herzegovina.

Suada Dzebo

Transient Vibrations of Railway Track Elements and the Influence of Support Conditions

An analysis of the dynamic characteristics of railway track elements is presented within the paper. A short review of ballast condition influence on dynamics of railway track is provided. Ballast stiffness degradation and lack of ballast support are the severities that are taken into account. In addition results from transient vibration testing of in situ railway track elements are presented. Field testing focused on two track sections: one on an embankment with timber sleepers, the other close to a railway junction with concrete sleepers and the bedrock close to the surface. The impact hammer testing technique was utilized for acquiring the transient vibration data; corresponding accelerance functions are obtained for several railseats. The comparisons are made between acquired accelerance functions for sleepers from three different locations. Comments about results repeatability for tested railseats are also given. A link between obtained accelerance function and condition of supporting ballast layer is given.

Emina Balic, Ciaran McNally

Information and Communication Technologies


Smart Parking System Based on Arduino SD Card Ajax Web Server

The modern age implies a vehicle per capita which leads to many problems in traffic. Some of the problems of increased number of vehicles on the road are: an increase of traffic accidents, impeded traffic, large losses of time in finding a suitable place for parking vehicles, etc. This paper is based on problem of finding a suitable place for parking the vehicle because a waste of time is one of the things that modern people cannot afford. For large parking areas, such as huge shopping centers, drivers always hardly find a free parking place, especially during peak days such as holidays and free working days. This paper describes the smart parking system which is based on two technologies, Arduino and Ajax, i.e. control using a web server. This system uses ultrasonic sensors HC-SR04 which are connected to the Arduino board and which are used to find the free and taken parking places in the parking area. The characteristics of smart parking system include detection of free parking places, reservation and display of available parking places. The goal is to reduce the losing of time for divers while searching for free parking place and reducing the flow of traffic in the parking lots.

Edin Mujčić, Una Drakulić, Merisa Škrgić

Implementation of Audiological Measurements at Persons with Hearing Impairment

The paper presents the processing of audiological measurements with the corrective characteristics at persons with hearing impairment. Characteristic points on frequency axes are especially analysed by using a special software by manufacturers of hearing aids. Apart from analyses of audiological measurements, the psychological effect on users by the corrections has been evaluated as well. The level of correction is determined by audiological methods, matematical methods and electronic hearing aids. A special accent has been put on children in school environment.

Ferid Sofitć, Jasna Čošabić

Analysis of Techno-Economic Profitability on the Example of Construction of an Optical Suburban Access Network in Srebrenica

The realization of the access network Srebrenica is planned in two phases. In the first phase, the FTTH P2P (Fiber to The Home Point to Point) network for 400 potential customers was built. Realization of the phase two are planning to include the extension of the existing network for additional 500 customers. Realization of the phase two depends on the requirements of new users. In this analyse we have compared the costs of two different technologies for phase two: FTTH P2P and FTTH PmP—GPON (Fiber to The Home Point to multi Point-Gigabit Passive Optical Networks). The analysis has shown that using GPON technology reduces costs by 23% compared to P2P. The advantages of P2P technology on PmP GPON regarding the offered bandwidth per customer did not come to the fore because the radio link from Sarajevo to Srebrenica is limited.

Mujo Hohzic, Anis Maslo, Evin Skaljo

Synchronization Between Arduino Based Appliance and MATLAB Application

Microcontrollers have usages in various types of processes and automation systems. What makes them so convenient is their programmability, low-cost, and a big number of possible extensions. Microcontroller ATMega328 with Arduino board is common when it comes to learning and experimenting. Liquid Crystal Displays are often used with microcontrollers, and in this project one with 16 × 4 dimensions is used. The programming logic of a project is built in Arduino IDE. Standard 4 × 4 keypad with 8 output pins is used with only one pin with some modifications in connection. The device can be controlled by the application built in MATLAB environment. The application and the device are communicating by Serial communication and are in synchronization. In this way, the device can be used directly, or by the application at the same time.

Adnan Felić, Edin Mujčić

Transmission of Two Optical Signals Through the Fibber in Opposite Directions Using PLC Splitters—Practical Measurements

In this study, the use of PLC (Planar Lightwave Circuit) splitter in bi-directional WDM optical systems instead of the standard WDM (Wavelength Division Multiplex) splitters is theoretically described and practically confirmed in real telecommunications environment. The transmission of two optical signals in opposite direction over a single mode fiber is tested at slightly spaced wavelengths. The insertion and separation of opposite optical signals are realized using two 1:2 PLC splitters. The measurements are successfully completed for two different lengths of optical fibers (8055 and 61091 m). The proposed solution is cost-effective and flexible, with a wide temperature range covering a broad band of operating wavelengths.

Mujo Hodzic, Edvin Skaljo, Nermin Suljanovic, Aljo Mujcic

Soft to Hard Data Transformation Using Uncertainty Balance Principle

The paper advances our on going work in the area of uncertainty alignment and transformation between fuzzy (soft, human generated, possibilistic) and random (hard, machine generated, probabilistic) data. As reported in our previous papers, the Uncertainty Balance Principle was defined to express uncertain data vagueness as represented by a fuzzy data models, with a non uniqueness of related random data distributions. The underlying assumption is that both fuzzy and random data are described in terms of the same independent uncertain variables. The connection between fuzzy and random data is done via cumulative rather than probability density functions. In this paper we clarify and extend our previous work whereas an initial fuzzy distributions (membership functions) are supplied and the aim is to determine corresponding and related random distributions. The next step in this analysis will focus on Bayesian data mining to determine random distributions from a given large set (data base) of soft data modeled as fuzzy (triangular, trapezoidal or other convex) distributions. This work has been inspired by an ever increasing need to fuse human and machine data in order to perform decision making procedures. Areas of applications include Bank Risk Assessment in financial industry as well as Command and Control Integration in defense industry and any other applications where soft and hard data fusion is required.

Migdat Hodzic

Programming and Experimental Analysis of MELFA RV-2SDB Robot

With the development of technology and science, it became clear that robots are starting to have a major role in the modern world. Regardless of whether they’re meant to do hard work or just entertain, robotics has changed human life for the better. What makes a robot different from a man is that a robot doesn’t have the ability to make decisions by itself, so it needs to have a set of instructions previously written by a man. The topic of this paper is programming and experimental analysis of MELFA RV-2SDB robot’s work. The content of this paper is based on development of robotics as a science branch, the structure of a robot, as well as controlling one, with its kinematics and dynamics. That is followed by an explanation of controlling and programming a MELFA RV-2SDB robot. Programming has been done with CIROS Studio tool using MELFA BASIC V programming language. Practical part consists of work analysis and programming of the mentioned robot. Its task is to move LEGO cubes from one place to another, composing a desired form as the result.

Edin Mujčić, Sabina Lonić, Mersa Muminović

A Customizable Embedded WebRTC Communication System

In this paper we present a WebRTC communication system composed of a web phone and a SIP proxy as part of the Reticulum project. We combine it with Raspberry Pi to produce a platform that makes communication more accessible and portable. The proxy part is integrated with SimpleFSM, a Ruby domain specific language, in order to simplify development of custom telecom services by modeling complex call flows as finite state machine models. Results of testing we have conducted on different hardware platforms show that Reticulum has good performance and responsiveness, even on the old Raspberry Pi 1.

Edin Pjanić, Sanjin Lišić

Mechatronics, Robotics and Embedded Systems


BCIs for Electric Wheelchair

This paper presents significantly facilitated ways of controlling an electric wheelchair using the power of the human brain for persons getting motor neuron disease (MND) and the difference in efficiency and accuracy between. The proposed BCI was developed in .NET framework which uses NeuroSky Mindwave’s single dry electrode as the only way of communication with the interface. BCI developed in .NET framework shows the direction control of wheelchair in all four directions: left, right, forward, and backwards. The results of the proposed BCI in controlling the wheelchair are promising, and the advantages are compared to some existing BCI wheelchair systems. The application of the proposed BCI systems would significantly help people with motor disabilities to have an improved style of living with more autonomy.

Dalibor Đumić, Jasmin Kevrić

Brainiac’s Arm—Robotic Arm Controlled by Human Brain

This paper shows electroencephalograph (EEG) controlled robotic arm based on Brain–computer interfaces (BCI). BCIs are systems that enable bypassing conventional methods of communication (i.e., muscles and thoughts) and provide direct communication and control between the human brain and physical devices using the power of the human brain. The main goal of the project work is to develop a robotic arm that can assist the disabled people in their daily life and by it make their work independent on others.

Dalibor Đumić, Mehmed Đug, Jasmin Kevrić

Identification of Parameters for Robot PUMA 560

Design of FPGA based controller for robot PUMA 560 requires knowledge of a large number of robot parameters. Considering the fact that robot manufacturer has not published the parameters, many scientists presented their own parameter results. Considerate variability in reported results was observed in values for mass and center of mass and therefore it was recognized as a matter of scientific interest.

Dejan Jokić, Slobodan Lubura

System for Distributed Measurement of Ambient Conditions in Homes

Measurement of ambient conditions in homes is one of the main preconditions for their control what represents one of the steps toward the complete implementation of smart homes. The objective of this study is to implement a system for distributed measurement of temperature, illuminance and humidity. In this work, all parameters to be measured will be analyzed, and applied sensors will be described. In order to have better insight in the measured parameters, measurements on different locations are made and all data are sent to one place. One of the main purposes of the project is to accomplish low price of the implemented system. In addition, a simple software application is made, and it allows visualization of the measurement results and their statistical analysis.

Kenan Husić, Tarik Uzunović

Automatic SAR Target Recognition and Pose Estimation. Part 1. Geometric Methods for Pose Estimation

The paper presents geometrical methodology of determining pose angle of an object against SAR images stored in a data base. The images are separated by a pose angle (less than 2°), obtained from an air surveillance plane at a depression angle and at a distance, producing SAR images of 1 × 1 foot pixel resolution. The data base is public (US Government) for academic and defense research. The data base consists of 100s of commercial and military vehicles, as well as building structures. In this paper, we focus on three targets which have symmetric geometry, each of different size and shape. In addition, we also generate several synthetic targets of various symmetric shapes to serve as the ideal test cases. The analysis is based on simple geometrical considerations as well as edge and surface area determination using number of SAR signatures pixels. The overall methodology aims at significantly reducing data base search space to produce an effective and fast computationally viable search algorithm. The result is very accurate target pose angle determination of the order of 96–98% precision. Once the pose angle is determined, that can be further used to determine target type as well, described in “Automatic SAR Target Recognition and Pose Estimation, Part 2. Statistical Methods for Target Recognition”.

Tarik Namas, Migdat Hodžić

Automatic SAR Target Recognition and Pose Estimation. Part 2. Statistical Methods for Target Recognition

The paper presents a second part of the paper: Automatic SAR Target Recognition and Pose Estimation, in which we analyze ATR, automatic target recognition. The first part deals with pose angle determination and target data base search space reduction using a variety of geometrical methods. Both papers use US Government MSTAR, public target data base released for academic research and development. SAR target images are separated by a small pose angle (between 1° and 2°). They are obtained form an air surveillance moving plane platform at a certain depression angle and at a certain distance which all produce SAR images of 1 × 1 foot pixel resolution. The objects (targets) data base consists of 100s of commercial and military vehicles, as well as wall and building structures. We focus on three typical targets which have symmetric geometry, each of different size and shape. In addition to these three real targets we also generate several synthetic targets of various symmetric shapes to serve as the ideal test cases. The target recognition analysis is based on simple first and second order statistics including correlation and stochastic processes independence analysis. This analysis is done both in spatial as well as corresponding frequency domain. The overall methodology aims at significantly reducing computational time which is of order of fractions of a second. The end result is very accurate target type determination algorithm of the order of 97–99% precision. Once the pose angle (Part 1) and ATR (Part 2) are determined, this information can be used for target tracking. The methodologies developed in this work can be also applied to other objects, such as facial recognition. Other applications are in analysis and recognition of sound effects which may be useful to police and home land security applications.

Migdat Hodžić, Tarik Namas

BEM/MRM Formulation for Engineering Applications


Numerical Analysis of Screw Compressor Rotor and Casing Deformations

Performance and reliability of screw compressors is highly dependent on their operational clearances. Compressor structural parts including rotors and the casing are affected both by pressure and temperature of the working fluid to which they are exposed. The standard approach when simulating performance is to neglect these deformations and assume rigid compressor elements. In this paper a numerical solution which combines the solution of fluid field from Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) of solid elements is used to calculate deformations of the compressor elements. The temperature field obtained from CFD is extracted and applied to the surface of the solid parts where it was averaged in time and served as boundary conditions for solid body calculations. The FEM analysis performed in ANSYS showed encouraging results which can be used for analysis of changes in compressor clearances.

Ermin Husak, Ahmed Kovacevic, Sham Rane

Electric Field Calculation on Surface of High-Voltage Transmission Line Conductors

This paper presents a calculation of the value of the electric field on the surface of the conductors and in the immediate vicinity of the high voltage transmission line of 400 kV level. For the calculation of the values of the electric field, the CSM method is used. Verifying the established model was carried out by comparing the calculation results with results of measurements of the electric field at a height of 1 m above ground level. Measurements of the value of electric field lines below the height of 1 m above ground were carried out over the years in Bosnia and Herzegovina. The measurements and calculations were carried out on 400 kV lines of standard dimensions and reduced dimensions. Using the established model, values of the electric field on the surface of the conductors and in their immediate vicinity were calculated. The calculated values of the electric fields are used to determine the corona onset voltage gradients.

A. Carsimamovic, A. Mujezinovic, S. Carsimamovic, Z. Bajramovic, M. Kosarac

Calculation and Measurement Analysis of Transformer Station Low-Frequency Electromagnetic Fields in the Framework of Legislation on Protection from Non-ionizing Radiation

Modern researches of electromagnetic fields (EMF) are based on the concept that complicated theoretical investigations are resulting in appropriate design solutions, and they are almost exclusively developed as applied researches. Generally, two directions are presented. The first one is based on the simplification of numerical calculation models, and the second one is based on models of objectified physical measurements in hard conditions. In both cases, however, the result is the same objective, which can be summarized as follows: create the optimal variant of solving the impact of the EMF, both in existing and new power facilities. The paper presents the analysis of numerical calculation of the EMF of distribution substation and detailed operational measurement program, which includes all measurements in stationary state with measurement location. The analysis of calculations and measurements results must indicates the possible dangerous places and gives the recommendations of measures for elimination of electromagnetic influences or their reduction to an acceptable level, according to the Regulations.

Hidajet Salkić, Adnan Muharemović, Nerdina Mehinović

On the Use of Boundary Element Method for Cathodic Protection System Modeling

Metallic installations placed in the soil or sea water (such as metallic pipelines) are submissive to the processes of corrosion. Corrosion is the destruction of the metal which is placed in electrolytes. One of the most often used technique for protection of underground or underwater metallic infrastructures against corrosion is cathodic protection systems. Design of any cathodic protection system requires determination of the electric potential and current density distribution on the electrode surfaces. This paper presents numerical method based on the direct boundary element method for calculation of distribution of electric potential and current density on electrode surfaces with nonlinear polarization characteristics. Presented numerical method was used to calculate parameters of one illustrative example of cathodic protection system.

Adnan Mujezinović, Sanja Martinez, Slobodan Milojković

Robotics and Biomedical Engineering


Research and Development of New Generation Service Robots for Medial Application

The development of new technologies has contributed to the development of robotic technology. The greatest contribution to the development of robotic technology was made by information technology and sensor technology. Parallel to their development, robotic technology evolved, as well. The development of industrial robots was followed by the development of service robots. The development of information technology and advancement in sensor technology and servo-drives resulted in over 300 different types or prototypes of service robots for non-production applications. Service robots are designed to be used in professional and service workplaces, and to be used in all areas of daily life. One of the application areas of service robots is medicine. Since medicine can be classified as science, research, and human discipline, so can application of service robots present scientific contribution through huge application of variety of robotic devices for different purposes in different technological achievements in various fields of medicine. These robotic devices are used as replacement for missing limbs, perform complex surgical procedures, serve patients in hospital rooms, perform laboratory tests to diagnose the disease, and help in rehabilitation after stroke. This paper will explain the representation of service robots in medicine, as well as their application in different areas of medicine. An analysis was conducted of investment in development and research of robotic technology, with scenario of development of robot revolution to the creation of intelligent robots.

Isak Karabegovic

Rheological Models and Numerical Method for Simulation of Blood Flow

This paper describes a method and results of computational fluid dynamics (CFD) simulation of blood flow. Material properties of blood are assumed to be constant, homogeneous and isotropic. Blood is regarded as viscoplastic liquid, where two different rheological models are applied: Bingham and Casson model. Plastic viscosity and yield stress are given as a function of hematocrit. The flow regime is considered as laminar. Having applied rheological models to time dependent balance equations of mass and momentum conservation given in integral form, a finite-volume method is used for discretization. Discretization results in a set of systems of linearized algebraic equations which are solved individually, for blood velocity components and blood pressure, at every time step within a considered time interval. The method is applicable to domains of arbitrary shapes and unstructured computational meshes. The examples presented include: (a) pulsatile viscoplastic flow in a pipe representing a simplified blood vessel, where the solutions obtained with the two rheological models are compared to the numerical and analytical solution obtained with Newtonian liquid, as well as (b) blood flow in aorto-renal bifurcation and carotid artery branch. In analysis of the flow in the branch, three geometric models are tested: idealized bifurcation with the branch angle of 60° and 90°, and a realistic shape of the bifurcation.

Ejub Džaferović, Muris Torlak, Almin Halač, Amra Hasečić

Heuristic Optimization Methods in Industrial Robotics

In industrial robotics is significant numbers of problems that can be optimized which can improve functioning of industrial robots. During the time significant number of optimization methods have been developed in optimization with all their advantages and disadvantages. In this paper are presented genetic algorithm, particle swarm optimization and ant colony as heuristic optimization methods that can be used in industrial robotics.

Ermin Husak, Isak Karabegović

Impedance Control in the Rehabilitation Robotics

Physical interactions between patients and therapists during rehabilitation have served as motivation for the design of rehabilitation robots, yet there is a lack in fundamental understanding of the principles governing such human-human interactions. Review of the literature posed important open questions regarding sensorimotor interaction during human-human interactions that could facilitate the design of human-robot interactions and haptic interfaces for rehabilitation. The goal is to use the leading principles of the human-human interaction in order to define a way in which people could be in contact with robots in a more intuitive and biologically inspired way. The proposed hybrid impedance control solves the robot–environment contact problem and offers a possible solution for the rehabilitation robot interaction problem.

Zlata Jelačić

Comparison of Numerical and Experimental Results of Measuring Vehicle Movement Kinematic Parameters Integrated into Advanced Mechatronic Systems

According to statistical data only 3% of traffic accidents are caused by technical reasons (vehicles), while 97% of accidents are caused by human factors (driver). Apart from unadequate technical validity of the vehicle, main causes of traffic accidents are wrong decisions of the driver, improper estimates of circumstances or attention deficit.Introduction of mechatronic systems of driver assistance can significantly influence the improvement of safety in traffic. Analysis of kinematic parameters of vehicle movement is shown in this work (path, displacement, velocity, acceleration) and their monitoring and measuring in real conditions. The analysis was made on the theoretical model of vehicle movement, as well as on experimental mechatronic system especially designed for the purposes of this work. In order to avoid problems in describing complex spatial vehicle movement, and the system of larger number of the mass, interconnected by visco-elastic elements, one of the simplest theoretical models was used for the needs of this work—the bicycle model. Analysis of experimental measurements and comparison with theoretic results was done in order to consider the possibilities of integration of such systems into advanced drivers assistance mechatronic systems (ADAS). Experimental mechatronic system which was exhibited in the work is one of the examples how to use intelligent systems (sensors, computer, controllers etc.) for automatisation of any process, not only in car industry, and with the purpose of reducing human decision making factor to the minimum.

Semir Mehremić, Isak Karabegović

Application of Mechatronic System in the Automation Hydroforming Process

This paper gives a brief overview of the design, layout and functionality of components for hydroforming automation process of thin-walled elements. The present system includes a high pressure pump, electromagnetic directional control valve, a two-part die, the measuring system with pressure and feed sensors and supporting software for measurement and analysis, and feedback to the valve. Hydroforming process of thin-walled elements involves the production of pieces, usually a very complex shape, from tubes and sheets. Typical examples of the use of this process is the automotive, aerospace industry, manufacturing of medical equipment, and home appliances. One of the important factors for the performance of the process is a technological development of system that includes automation and process control. Mechatronic systems are characterized by certain level of autonomy. They react autonomously to changes in the environment and working conditions, using algorithms for control. They are flexible and simple. The modification of the system may be quick and easy. In practice, the combination of hydroforming and mechatronics occurs as a mechatronic hydroforming system. The mechatronic hydroforming system is an innovative approach to hydroforming of thin-walled elements wherein the process automates and controlled via software.

Edin Šemić, Safet Isić, Edina Karabegović

Modeling of Mechatronic Systems of Robot Fingers

In last few years there has been a very large increase in application of robotics in everyday life. Among the most developed robots are certainly humanoid robots, those kind of robots are similar to humans due to the large number of possibilities. For humanoid robots mechatronic system of fingers is very important, starting from the mechatronic system of one finger. In this paper it is also described mechatronic systems for robots with two, three, four and five finger, the most complicated are certainly the five fingered robots because they are the most similar to human hand and they have the largest number of degrees of freedom.

Sanela Hrnjica

Application of Service Robots for Disinfection in Medical Institutions

Service robots are increasingly present in all fields of medicine. This paper presents a review of the service robots in medicine with an emphasis on service robots for disinfection in medical institutions. It is shown and described how more and more disinfectant service robots are contributing to a very simple, fast and effective disinfection in medical institutions. Work of the service robot with all necessary components for its function as well as its good and bad sides are in details elaborated and clarified. The aim is to demonstrate the application and use these service robots in medical institutions. Use of these service robots reduces the risk of infection, cost of traditional cleaning and disinfection, and most importantly acquires confidence and security in medical facilities.

Aladin Begić

Detection of Parkinson’s Disease by Voice Signal

Detection of Parkinson Disease by Voice Signal is based on noninvasive method for disease detection. Here we used Speech Dataset of sound records which has been shown as most effective up to now. In order to detect presence of disease by using different classifiers. At the end accuracy of each of them have been calculated and compared.

Fatima Mašić, Mehmed Đug, Jasna Nuhić, Jasmin Kevrić

Modeling of Sensors for a Mechatronic Systems of an Robotic Arm

Modeling of sensors for a mechatronic systems of an robotic arm is being considered as a very complex matter, whom is being approached through several aspects. Anatomy of a human skin and structure of a most complex human sense, sense of touch, is being in details analized. Analogy between a human sense of touch and achievement of a robotic sense of touch is being pointed up. Application of which components made a robotic sense of touch realistic is also very important to mention. Sensors applicated in robotics are considered as a primary components who contributed that robots can have ability to feel things and “to know” how to properly react on stimuli from the environment. Work principle of sensors and sensors in general are also in details explained. Emphasis is placed on a tactile perception which is giving us informations about mechanical properties and position of objects, and on tactile sensors which are mimicking sensitivity of a human fingers and are placed in a robotic arm.

Silmija Ferizović

Mechanical Engineering


Modelling the Micro Coaxial Helicopter

In this paper, we investigated the flight dynamics of a micro coaxial helicopter and developed a simplified model for autonomous flight control system design purpose. The multivariable tracking and H2 control theory are employed to design the flight control system that would achieve some basic flight manoeuvres like hover, level straight or circular flight, and altitude changes, etc.

Želimir Husnić

Effects of Primary Measures in Combustion Chamber on Co-firing of Coal with Woody Biomass

In this work results of laboratory research of co-firing coals from Middle Bosnian basin with waste woody biomass are presented. Pulverized combustion under various temperatures and various technical and technological conditions is performed using previously formed fuel test matrix. This is primarily related to the different mass ratio of fuel components in the mixture, the overall coefficient of excess air and the application of different primary measures in the combustion chamber. The results and analysis of the emissions of components of the flue gases are presented and discussed, which are predominantly related to the emission of CO2, CO, NOx and SO2. In addition to determining the impact of fuel composition and process temperature on the values of the emissions of components of the flue gas, it is shown that other primary measures in the combustion chamber are resulting in more or less positive effects in terms of reducing emissions of certain components of the flue gases into the environment. This particularly stand out measures such as exponentiation of combustion air and the use of natural gas as the additional fuel: the emission of NOx is reduced from a level of 837 mg/mn3 in conventional combustion to 710 mg/mn3 using exponentiation of combustion air, or for more than 15%, and using natural gas as additional fuel it is reduced to 450 mg/mn3, or for more than 45%. Overall, the effects of the primary measures in the combustion chamber are mutually compared and quantified. In addition, the influence of applied primary measures in the combustion chamber on the behavior of ash in the co-firing process is analyzed. In this way, evaluation the fouling and slagging tendencies of the ash under given technical and technological conditions of co-firing coal with waste woody biomass is given.

N. Hodžić, S. Metović, A. Kazagić

A Heat Exchanger with Finned Tube and Phase-Change Material for Thermal-Energy Storage: Effect of Gravity and Orientation

A device for storage of thermal energy in form of latent heat is presented. The device is intended to be used either as portable or as stationary unit for storage of energy stemming from intermittent sources (such as solar power plants) or from sources with variable energy prices, to dampen temperature fluctuations (for example, in heating systems), or for waste heat recovery. Delayed and/or remote use of energy from the storage unit can increase overall energy efficiency and contribute to cost savings. In the device tested in this study, water is adopted as heat transfer fluid (HTF) both for charging and discharging of thermal energy, and its temperature is defined appropriately to the investigated process. A phase-change material (PCM) is used as storage medium due to relatively large amount of energy to be stored at relatively narrow temperature range. Heat transfer rate within the storage device turns out to be decisive for its proper performance. Low thermal conductivity of the PCM may be a drawback. Hence, a design solution based on heat exchanger with finned tube is adopted to increase the heat transfer rate from HTF to PCM and vice versa. The measurements of temperature on vertically oriented storage unit have confirmed advantage of the finned design, as compared to the plain, smooth tube. However, in vertical orientation the heat transfer rate may be a consequence of the convective effects. This paper addresses the effect of storage unit orientation and herewith related effect of gravity on the heat transfer regime possibly triggered by natural convection, and consequently their effect on the phase change process. The overall performance of the horizontally oriented storage unit is compared with the vertically oriented one.

Muris Torlak, Nijaz Delalić

Using of Remote Sensing Methods in Wind Analysis in Conditions of Local Wind Bora and Complexity of Terrain

More accurate assessment of wind potential in conditions of local wind Bora and complexity of terrain requires performing of measurement campaigns at higher levels and in several measuring places. Last measurements in Bosnia and Herzegovina were performed by using of 80 m high measurement mast, which seems measurement expensive, due to high costs of procurement and installation of equipment and its maintenance during the measurement period. For these reasons, it is effective to use different measuring methods. The analysis and comparison of collected measurement data from the measurement mast and the LIDAR remote sensing device (Windcube v2 FCR), as well as the behavior of the equipment itself in the complex terrain and wind Bora conditions at location Hrgud near the town of Stolac is presented in this paper. Ten minutes average time intervals were used for comparision of wind speed and direction. It can be concluded that the behavior of the LIDAR under harsh local weather conditions was well. The LIDAR uncorrected wind speed was in general lower than the wind speed measured by the cup anemometer at the same height. The comparison of the data of measurement methods provides reliable information on the wind speed within the considered altitude range.

Elvir Zlomušica, Suad Zalihić, Miralem Čampara, Ramiz Zaimović

Computational Study of Pulverized Coal Combustion in Boiler—Unit 7 of TPP Kakanj

Computational simulations and mathematical modelling have become an indispensable tool for analysis, solution, prediction and optimization of processes in various industries. We report on the simulation of combustion of dust-coal in a boiler Unit 7 (230 MWe) of Thermal Power Plant (TPP) Kakanj, BiH. This boiler was chosen for the study because of the high temperature corrosion detected on its side membrane walls in the furnace diffuser, suspected to be caused due to non-optimal distributions of velocity, temperature and composition of flue gases, especially of oxygen, in the wall-adjacent regions. The numerical simulation were carried out using Ansys Fluent CFD software with the comprehensive combustion model based on the RANS approach for two-phase flow of dispersed coal particles in multi-component gaseous medium, with standard chemical kinetics and radiation models. In order to obtain realistic boundary and input conditions for the simulation of combustion in the boiler, the precursor simulations were performed, first for flow of pulverized coal in a double-swirl burner, and the results interpolated to 24 burner exits into the boiler. Although computationally much more demanding, imposing the inlet data from the precursor simulations led to improved, more realistic mixing of coal dust and oxidant, and consequently to the combustion conditions closer to the real ones. The simulations confirmed the occurrence of adverse conditions prone to cause the corrosion. The results of both simulations are presented and discussed.

Adnan Ðugum, Kemal Hanjalić

The Application of Advanced Technologies in Industrial Practice

This paper representing application of the 3D technologies in engineering practice and also some theoretical basics of these technologies. References in this paper are examples from engineering department of the engineering service company “3Din d.o.o.” and partners from area of design, 3D scanning, 3D printing, and reverse engineering.

Edin Ibrahimovic

The Causes and Consequences of Deficit in Nominal Temperature of Reheated Steam After Implementation of Primary Measures for NOx Reduction on the Boiler OB-650

The most recent general reconstruction of the Block 6 of the Thermal Power Plant Tuzla resulted in dual effect on energy efficiency of the Block itself. This article deals with an analysis of modernization projects that has been done on coal boiler and steam turbine and possible consequences on boiler performances. The modern project solution, which has been implemented on the coal combustion system, has enabled the application of low emission concept of combustion and reduction of ash slugging on walls of combustion furnace. As those were the main goals of reconstruction, they have been successfully achieved. However, after reconstruction has been completed, the total heat load distribution on the surface of the boiler reheater is not able to provide enough heat to achieve the nominal temperature value of reheated steam at lower loads, particulary in exploitation conditions case which deviate from the calculated and guaranteed conditions. Accordingly, this article will provide a review of two possibilities of temperature increasement of reheated steam that leaves the boiler. That includes two situations: a.Increase the heating surface on the boiler reheater to the possible limits,b.The use of recirculated cold waste gas for regulation of the temperature of reheated steam.

Nedim Ganibegović, Amel Mešić

Transition of a Conventional Power Utility to Achieve 2050 RES and Carbon Cut Targets—EPBIH Case Study

Conventional power utilities are faced today with challenges in terms of sustainable development and decarbonisation. Different measures are used to achieve the set targets, i.e. increase of RES, increase of energy efficiency and CO2 cut. In this work, a method for achieving CO2 cut targets has been demonstrated on a real power system, i.e. EPBiH power utility, operating in Bosnia and Herzegovina. EPBiH power utility is based today on a mix of coal and hydro, while there is a great potential for RES projects; hydro, wind and biomass. So it is possible to sustainably exploit the available capacity, to drastically reduce the environmental impact of the power sector, for example by use of biomass and expansion of cogeneration in existing coal-based power plants. Also, for new thermal power units to be commissioned and being necessary for consumption coverage once when generation from RES is low, the environmental requirements are fulfilled. Those units are planned to be CHP which would additionally contribute to the decrease of overall emissions on district heating coverage area. Also, the efficient use of fuel will be maximized in accordance with the best available techniques, while biomass co-firing will significantly contribute to the set goals. The model used in this work took into account the security of supply, competitiveness and sustainability, considering environmental, economic and social indicators. Three scenarios with different CO2 cut rates by 2050 have been considered, while a range of measures have been applied to achieve the set decarbonisation targets. All scenarios involve significant increase of RES, from current 18 to 43% in LOW CO2 cut, through 62% in MID CO2 cut, up to 76% in HIGH CO2 cut scenario. As compared to 1990 level, CO2 emissions in those scenarios are decreased for 55, 65 and 80%, respectively. In all cases, attention was paid to maintaining the necessary level of stability of the power system and security of supply. SCA and MSA have been performed for sustainability assessment. SCA results show that HIGH CO2 cut scenario has advantage compared to MID CO2 cut and LOW CO2 cut scenarios, when environmental and economic OPEX indicators are considered. However, when only investment is considered, LOW CO2 cut scenario is preferable. Although electricity demand is met in all scenarios, it was found that an increase in investment in generation facilities that will contribute reducing the costs of operation and maintenance, as well as reducing CO2 emissions, in the long run will be multiply rewarded, when comparing LOW CO2 cut with HIGH CO2 cut scenario. It was confirmed by MSA analysis, which showed that no matter which relation between weighting factors is considered, HIGH CO2 cut scenario is preferable.

A. Kazagić, M. Musić, E. Redžić, A. Merzić

The Effects of the Measuring and Consumption of Thermal Energy Based Billing System in District Heating Systems of Bosnia and Herzegovina

The purpose of this paper is show opportunities for strengthen national capacities towards low carbon emission development which could be achieved through developing capacity to formulate, mobilize finance and implement activities in Bosnia and Herzegovina. Removing key informational, institutional, social, financial and market, and technical barriers is critical to paving the way for investment for the enormous low-cost energy supply improvement and GHG emission mitigation in the district heating systems.

N. Harbaš

CFD as an Enginer’s Tool for Investigation of Large-Scale-Flow-Phenomena “at Land, Sea and Air”

Along with prospective fashion of solving the engineering-tasks (if development would allow us a such approach while answering the technology-questions of some project in future), goes alternatively corrective performance of those engineering tools, used to compensate for needed changes in some already existing technical solution. A unique chance to compare the needs of traffic-intentions (while setting the modern road communications through the southern of Bosnia and Herzegovina) verses natural occurrences in the atmosphere (such is a strong north-wind in this geographic region) offers the high-way-section Pocitelj-Zvirovici. Exactly in such cases (and before the actual construction of an engineering-construction is realized) “for the sake” of prospective—and certainly self-sustainable engineering—the tool of CFD (the tool for performing the Computational Fluid Dynamics) was applied to engaged the problem. Again, in the same moment while solving prospectively (through application of the CFD-based research prospectively in) several technical issues on submarine tidal-turbines in bay-area of Swansea in Wales (UK) for electricity production, a corrective way of engineering is requested to research on both imagined fire-scenarion in road-tunnel of Vranduk, close to Zenica (Bosnia) as as well as in case of investigative observing the (large-scale) combustion of the flare-stack in the refinery in town of Lendava (Slovenia). Coming from the both steady-state (k-epsilon turbulence-treatment) and time-dependent applied CFD-based explorations (Large-Eddy Simulation in Smagorinsky-Lilly mode), the unexpected and unwanted strong gaseous flows were detected and the results coming out of this are explained and discussed.

M. Muhasilović, B. Širok, K. Ciahotny, M. O. Deville

Smart LEG Control System Optimization

This paper presents Smart Leg, an active robotic prosthesis that enables people with an above or below knee amputation to perform different types of motions that normally require power in lower limb joints. Our design integrates advanced prosthetic and hydraulic technology with the state-of-the-art machine learning algorithms capable of adapting the working of the prosthesis to the optimal gait and power consumption patterns, and which therefore provide means to customize the device to a particular user. We outline optimization of the hydraulic installation and control system that ensure stable and natural gait for the end user.

Haris Dindo, Zelimir Husnic, Remzo Dedic, Adisa Vucina


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