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23,598 Article Results

The New Multipoint Relays Selection in OLSR using Particle Swarm Optimization

10.12928/telkomnika.v10i2.804
Reza Firsandaya; Universitas Sriwijaya Malik , Tharek Abdul; Universiti Teknologi Malaysia Rahman , Razali; Universiti Teknologi Malaysia Ngah , Siti Zaiton; Universiti Teknologi Malaysia Mohd , Hashim; Universiti Teknologi Malaysia Hashim
The standard optimized link state routing (OLSR) introduces an interesting concept, the multipoint relays (MPRs), to mitigate message overhead during the flooding process. This paper propose a new algorithm for MPRs selection to enhance the performance of OLSR using particle swarm optimization sigmoid increasing inertia weight (PSOSIIW). The sigmoid increasing inertia weight has significance improve the particle swarm optimization (PSO) in terms of simplicity and quick convergence towards optimum solution. The new fitness function of PSOSIIW, packet delay of each node and degree of willingness are introduced to support MPRs selection in OLSR. The throughput, packet loss and end-to-end delay of the proposed method are examined using network simulator 2 (ns2).  Overall results indicate that OLSR-PSOSIIW has shown good performance compared to the standard OLSR and OLSR-PSO, particularly for the throughput and end-to-end delay. Generally the proposed OLSR-PSOSIIW shows advantage of using PSO for optimizing routing paths in the MPRs selection algorithm.
Volume: 10
Issue: 2
Page: 343-352
Publish at: 2012-06-01

Relationships between Harmonic Characteristics and Different Types of Voltage Source

10.12928/telkomnika.v10i2.780
Risnidar C; Universitas Sumatera Utara, University Malaysia Perlis (UniMAP) Risnidar C , I. Daut; University Malaysia Perlis, (UniMAP) I. Daut , Syafruddin H; Universitas Sumatera Utara, University Malaysia Perlis (UniMAP) Syafruddin H , Yusniati; University of Islam Sumatera Utara Yusniati
This paper discusses about harmonic characteristics due to different types of voltage sources. Ideal voltage source is sinusoid, unfortunately in actual condition load receives voltage sources from elements which produce the non sinusoidal output voltage, and consequently, the load has non pure sinusoid waveform as an input voltage. Voltage source at power of common coupling (PCC) between transformer and linear load and nonlinear load has become an example of the case. This research has been conducted by using Schhafner Power Quality Analyzer and PM300 Power Quality Analyzer, which was focused to figure out all characteristics related to harmonics such as power, voltage, current, power factor (p.f.), Harmonic Distortion, and harmonic energy losses cost. The selected load is induction motor with Adjustable Speed Drive (ASD) because this typical load is one of electronic device that causes harmonics. The voltage sources in this research are sine wave, square wave and harmonic order combinations of 3rd, 5th and 7th which can create from Schhafner Power Quality Analyzer.
Volume: 10
Issue: 2
Page: 219-228
Publish at: 2012-06-01

Google+ vs Facebook: The Comparison

10.12928/telkomnika.v10i2.814
Kevin; University of Ulster Curran , Scott; University of Ulster Morrison , Stephen; University of Ulster Mc Cauley
Social networks are a varyingly popular tool used to connect with friends, colleagues and/or family. Recently, Facebook has been at the top of the social network food chain, with Bebo and MySpace decreasing in users and the huge increase of users joining Facebook in such a short time. Google have just recently launched Google+, a social networking site. This is not the first time that Google have attempted to break into the social networking scene but it is possible that these failed attempts may have taught them something. As Facebook’s user base is extremely diverse, spreading across different countries, races, ages, professions, and interests, to name a few, this network is a good model to compare new rival Google+ to. Google+ has set out to do the same things as Facebook but better to try and steal away some of that high power and necessity that Facebook has gained. Facebook has News feed, Google has Stream. Facebook has Lists, Google has circles. Facebook has like’s, Google has +1. Facebook accounts for 10% of overall internet usage. This paper will look at various comparables between the two social networks and analyse the better functionality, design and ease of use. It will then conclude a verdict on which is the better social network to use overall. 
Volume: 10
Issue: 2
Page: 379-388
Publish at: 2012-06-01

Numerical Analysis of the Factors about Combustion Stability on Boiler

10.12928/telkomnika.v10i2.799
Li Jun; North China Electric Power University Li Jun , Yan; North China Electric Power University Weiping , Gao; North China Electric Power University Yang
Through the research of the coal pulverized catches fire and steadily combustion mechanism, the numerical simulation of the 300MW tangentially pulverized coal fired boiler by Coal-fire software, and combine the operating data of the boiler, the corresponding relation between the result of numerical simulation and combustion stability have been established. The result indicates that the higher volatile matter, lower content of ash and moisture of the coal, it helps the coal pulverized air current to catch fire. More fineness coal pulverized is favorable to catch fire. When boiler load reduced, it will influence the characteristic"lighted by itself" of the tangentially pulverized coal fired boiler, and it will cause combustion unstably. 
Volume: 10
Issue: 2
Page: 303-308
Publish at: 2012-06-01

Optimum Reactive Power Dispatch for Alleviation of Voltage Deviations

10.12928/telkomnika.v10i2.793
Abraham; Institut Teknologi Nasional (ITN) Malang Lomi , Dhadbanjan; Indian Institute of Science Thukaram
This paper presents a non-linear optimization algorithm for alleviation of under-voltage and over-voltage conditions in the day-to-day operation of power networks. Voltage control for varying load and generation conditions can be achieved by coordinated control of switchable shunt VAR compensating (SVC) devices, on load transformer taps (OLTC) and generators excitation. The proposed algorithm for voltage control uses a non-linear least square minimization technique. Results obtained for 6-Bus Ward-Hale system and a modified IEEE 30-Bus system are presented for illustration purposes.
Volume: 10
Issue: 2
Page: 257-264
Publish at: 2012-06-01

Review of Sequential Access Method for Fingerprint Identification

10.12928/telkomnika.v10i2.803
G. Indrawan; Bandung Institute of Technology G. Indrawan , B. Sitohang; Bandung Institute of Technology B. Sitohang , S. Akbar; Bandung Institute of Technology S. Akbar
Real time fingerprint identification is usually equipped with specific computation machine architecture to optimize speed factor. Focusing on achieving better speed performance of fingerprint identification on common computation machine, a disquisition was conducted on sequential access method for fingerprint identification, with its underlying data structure designed to work with parallel processing. Hypothetically, parallel processing based on multi-cores processor technology, can give faster result without reducing accuracy. If multi core processor was detected, simultaneous processes would run on fingerprint matching-pairs to find its similarity score, respectively. Experiment confirms that speed performance of fingerprint identification using sequential access method with parallel processing outperforms the one without parallel processing. For both strategy, even though using parallel processing confirms faster result, experiment shows that searching time O(n) still linearly depends on number of fingerprints in database. Avoiding such searching time trend, hypothetically, need strategy of direct access method utilization.
Volume: 10
Issue: 2
Page: 335-342
Publish at: 2012-06-01

Cost Allocation of Transmission Losses in Electric Market Mechanism

10.12928/telkomnika.v10i2.779
Hermagasantos; State Polytechnic of Bandung (POLBAN) Zein , Erwin; Unversitas Muhammadiyah Jakarta Dermawan
 This paper proposes a new method to calculate cost allocation of transmission losses based on a certain price of energy. A mathematic model is developed by manipulating of the network equation to separate losses. This model uses complex power injection and, does not use approximations and assumptions in determining the cost allocation of losses. The calculation begins from the results of load flow calculation and it is continued to calculate power distribution from a generator to every load and line. Finally, the separating of losses and cost allocation of losses are calculated. The proposed method is easy to be understood and applied. An illustration results on IEEE 14-bus system show that the method is consistent with expectancies and slightly different from several referenced methods. 
Volume: 10
Issue: 2
Page: 211-218
Publish at: 2012-06-01

A New Control and Design of PEM Fuel Cell Powered Air Diffused Aeration System

10.12928/telkomnika.v10i2.798
Doaa M.; Electronics Research Institute Atia , Faten H.; Electronics Research Institute Fahmy , Ninet M.; Electronics Research Institute Ahmed , Hassen T.; Cairo University Dorrah
Aeration of water by using PEM fuel cell power is not only a new application of the renewable energy, but also, it provides an affordable method to promote biodiversity in stagnant ponds and lakes. This paper presents a new design and control of PEM fuel cell powered by diffused air aeration system for a shrimp farm in Mersa Matruh in Egypt. Also Artificial intelligence (AI) techniques control is used to control the fuel cell output power by controlling input gases flow rate. Moreover the mathematical modeling and simulation of PEM fuel cell is introduced. A comparison study is applied between the performance of fuzzy logic control (FLC) and neural network control (NNC). The results show the effectiveness of NNC over FLC.
Volume: 10
Issue: 2
Page: 291-302
Publish at: 2012-06-01

Crosstalk Improvement of Polymer in Glass Thermo-Optical Multimode Interference Switch

10.12928/telkomnika.v10i2.813
N. Samdin; Universiti Teknologi Malaysia N. Samdin , M. Yaacob; Universiti Teknologi Malaysia M. Yaacob , M.H. Ibrahim; Universiti Teknologi Malaysia M.H. Ibrahim , A.B. Mohammad; Universiti Teknologi Malaysia A.B. Mohammad , N.M. Kassim; Universiti Teknologi Malaysia N.M. Kassim
A new structural design of combined variable optical attenuator (VOA) and optical switch has been proposed in this paper. The design is based on the multimode interference (MMI) architecture and it has been demonstrated for crosstalk improvement of optical switch. The device operates by manipulating thermo-optic (TO) effect that naturally existed in all optical waveguide material. By applying a polymer on glass material platform, the optimized VOA with optical attenuation of 21.52 dB has been achieved with applied power of 36.4 mW. The simulation result shows that the VOA helps to achieve significant improvements of optical switch performance particularly in crosstalk reduction up to 89.66%. 
Volume: 10
Issue: 2
Page: 371-378
Publish at: 2012-06-01

Comparison of Predictive Models for Photovoltaic Module Performance under Tropical Climate

10.12928/telkomnika.v10i2.783
Koumi Ngoh; University of Yaoundé I, University Institute of Technology Douala Simon , Njomo; University of Yaoundé I Donatien , Moungnutou Mfetoum; National Advanced School of Engineering Inoussah
This paper examines four models which are used to estimate the performance of photovoltaic (PV) modules when the irradiances and PV cell temperatures are known. The models were simulated and the operating temperature and irradiance dependence of PV electrical efficiency and power output were studied. The models accuracy was obtained by comparing the models and the measurements of maximum power for a polycrystalline typical MXS 60 PV module under tropical climate. The evaluated models for estimating the maximum power are the single diode, the Photovoltaic geographical information system (PVGIS), the Borowy and Salameh, and the Hatziargyriou model. The analysis of the error curves shows that the single diode and Hatziargyriou model have better accuracy. The PVGIS and Borowy approach are not appropriate as the module performance prediction in Sudanese sahelian climate.
Volume: 10
Issue: 2
Page: 245-256
Publish at: 2012-06-01

Blood Vessel Enhancement and Segmentation for Screening of Diabetic Retinopathy

10.12928/telkomnika.v10i2.802
M. Usman; Bahria University Akram , Ibaa; Bahria University Jamal , Anam; Bahria University Tariq
Diabetic retinopathy is an eye disease caused by the increase of insulin in blood and it is one of the main cuases of blindness in idusterlized countries. It is a progressive disease and needs an early detection and treatment. Vascular pattern of human retina helps the ophthalmologists in automated screening and diagnosis of diabetic retinopathy. In this article, we present a method for vascular pattern ehnacement and segmentation. We present an automated system which uses wavelets to enhance the vascular pattern and then it applies a piecewise threshold probing and adaptive thresholding for vessel localization and segmentation respectively. The method is evaluated and tested using publicly available retinal databases and we further compare our method with already proposed techniques. 
Volume: 10
Issue: 2
Page: 327-334
Publish at: 2012-06-01

Design of FPGA Based Neural Network Controller for Earth Station Power System

10.12928/telkomnika.v10i2.796
Hanaa T.; Electronics Research Institute El-Madany , Faten H.; Electronics Research Institute Fahmy , Ninet M. A.; Electronics Research Institute El-Rahman , Hassen T.; Cairo University Dorrah
Automation of generating hardware description language code of neural networks models can highly decrease time of implementation those networks into a digital devices, thus significant money savings. To implement the neural network into hardware design, it is required to translate generated model into device structure. VHDL language is used to describe those networks into hardware. VHDL code has been proposed to implement ANNs as well as to present simulation results with floating point arithmetic of the earth station and the satellite power systems using ModelSim® PE 6.6 simulator tool. Integration between MATLAB® and VHDL is used to save execution time of computation. The results shows that a good agreement between MATLAB and VHDL and a fast and flexible feed forward NN which is capable of dealing with floating point arithmetic operations; minimum number of CLB slices; and good speed of performance. FPGA synthesis results are obtained with view RTL schematic and technology schematic from Xilinix tool. Minimum number of utilized resources is obtained by using Xilinix VERTIX5. 
Volume: 10
Issue: 2
Page: 281-290
Publish at: 2012-06-01

Optimal Power Flow Solution of the Algerian Electrical Network using Differential Evolution Algorithm

10.12928/telkomnika.v10i2.778
Linda; Setif University Slimani , Tarek; Setif University Bouktir
This paper presents solution of optimal power flow (OPF) problem of a power system via differential evolution (DE) algorithm. The purpose of an electric power system is to deliver real power to the greatest number of users at the lowest possible cost all the time. So the objective is to minimize the total fuel cost of the generating units and also maintaining an acceptable system performance in terms of limits on generator reactive power outputs, bus voltages, static VAR compensator (SVC) parameters and overload in transmission lines. CPU times can be reduced by decomposing the problem in two subproblems, the first subproblem minimize the fuel cost of generation and the second subproblem is a reactive power dispatch so optimum bus voltages can be determined and reduce the losses by controlling tap changes of the transformers and the static VAR compensators (SVC). To verify the proposed approach and for comparison purposes, we perform simulations on the Algerian network with 114 buses, 175 branches (lines and transformers) and 15 generators. The obtained results indicate that DE is an easy to use, fast, robust and powerful optimization technique compared to the other global optimization methods such as PSO and GA.
Volume: 10
Issue: 2
Page: 199-210
Publish at: 2012-06-01

Optimization and Feasibility Analysis of Satellite Earth Station Power System Using Homer

10.12928/telkomnika.v10i2.812
Hanaa T.; Electronics Research Institute El-Madany , Faten H.; Electronics Research Institute Fahmy , Ninet M. A.; Electronics Research Institute El-Rahman , Hassen T.; Cairo University Dorrah
Satellite earth stations which located in remote areas are one of many applications powered by the renewable energy sources. Ground system consists of ground station and control centers working together to support the spacecraft and the data user. Earth station consists of major subsystems, transmitter, receiver, antenna, tracking equipment, terrestrial interface equipment and power supply. Power subsystem is an important part that required for supplying the earth station with electrical power to continue communicating with its remote sensing satellite. This paper deals with simulation and optimal sizing of earth station power system using HOMER software. A combination of two energy sources (solar, and wind) to provide a continuous electric power production is used to determine the optimum system operation. Three system configurations are compared with respect to the total net present cost (NPC) and levelized cost of energy (COE). Also, economical study will be analyzed for energy demand and sensitivity analysis will be performed.
Volume: 10
Issue: 2
Page: 359-370
Publish at: 2012-06-01

Modeling and Validation of the Dynamic Host Configuration Protocol with Colored Petri Nets

https://ijece.iaescore.com/index.php/IJECE/article/view/5346
Farhad Soleimanian Gharehchopogh , Reza Soufizadeh
Petri Networks with a graphical language are based on mathematical logic which have many uses and have capability for modeling and validation of distributed systems and concurrent applications. Colored Petri Networks (CPNs) are a type of Petri Network models that are used in modeling of systems which contain discrete and scattered events. In general, CPNs are used to evaluate system performance and demonstrate the correctness of systems. Dynamic Host Configuration Protocol (DHCP) is one of the main systems of protocols special for servers that are used for dynamic allocation of IP to the network computers (clients). In this paper, we highlight to analyze the correctness and authenticity of DHCPs with the use of CPNs with using the CPN Tools and to prove the accuracy of our protocol's performance.DOI:http://dx.doi.org/10.11591/ijece.v2i3.488
Volume: 2
Issue: 3
Page: 437-440
Publish at: 2012-05-29
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