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25,002 Article Results

Frequency Control by Decentralized Controllable Heating Loads with H∞ controller

10.12928/telkomnika.v9i3.745
Yoshihisa; University of the Ryukyus Kinjyo , Kosuke; University of the Ryukyus Uchida , TomonobuSenjyu; University of the Ryukyus TomonobuSenjyu
Many isolated small power systems are powered by diesel generators, which results in greater operating costs than interconnected large grids. It is therefore desirable to integrate renewable energy sources such as wind power into these small grids. However, due to the fluctuating power generation from renewable energy sources, frequency deviations of power systems become problematic. Distributed intelligent load control can be used to significantly increase renewable energy penetration and cut diesel fuel consumption. This paper presents a methodology for grid frequency control by electric water heaters as controllable loads. This system consists of diesel generator, wind farm, and loads. By applying a power consumption controller adopted from H∞control theory, grid frequency deviation is maintained around rated value. In order to verify the effectiveness of the proposed system, MATLAB/Simulink is used for simulations.
Volume: 9
Issue: 3
Page: 531-538
Publish at: 2011-12-01

Focused Crawler Optimization Using Genetic Algorithm

10.12928/telkomnika.v9i3.730
Banu Wirawan; Universitas Kristen Satya Wacana Yohanes , Handoko; Universitas Kristen Satya Wacana Handoko , Hartanto Kusuma; Universitas Kristen Satya Wacana Wardana
As the size of the Web continues to grow, searching it for useful information has become more difficult. Focused crawler intends to explore the Web conform to a specific topic. This paper discusses the problems caused by local searching algorithms. Crawler can be trapped within a limited Web community and overlook suitable Web pages outside its track. A genetic algorithm as a global searching algorithm is modified to address the problems. The genetic algorithm is used to optimize Web crawling and to select more suitable Web pages to be fetched by the crawler. Several evaluation experiments are conducted to examine the effectiveness of the approach. The crawler delivers collections consist of 3396 Web pages from 5390 links which had been visited, or filtering rate of Roulette-Wheel selection at 63% and precision level at 93% in 5 different categories. The result showed that the utilization of genetic algorithm had empowered focused crawler to traverse the Web comprehensively, despite it relatively small collections. Furthermore, it brought up a great potential for building an exemplary collections compared to traditional focused crawling methods.
Volume: 9
Issue: 3
Page: 403-410
Publish at: 2011-12-01

Virtual View Image over Wireless Visual Sensor Network

10.12928/telkomnika.v9i3.740
Nyoman Putra; Institut Teknologi Sepuluh Nopember, Universitas Udayana Sastra , Wirawan; Institut Teknologi Sepuluh Nopember Wirawan , Gamantyo; Institut Teknologi Sepuluh Nopember Hendrantoro
In general, visual sensors are applied to build virtual view images. When number of visual sensors increases then quantity and quality of  the information improves. However, the view images generation is a challenging task in Wireless Visual Sensor Network environment due to energy restriction, computation complexity, and bandwidth limitation. Hence this paper presents a new method of virtual view images generation from selected cameras on Wireless Visual Sensor Network. The aim of the paper is to meet  bandwidth and energy limitations without reducing information quality. The experiment results showed that this method could minimize number of transmitted imageries with sufficient information..
Volume: 9
Issue: 3
Page: 489-496
Publish at: 2011-12-01

The Digital Microscope and Its Image Processing Utility

10.12928/telkomnika.v9i3.749
Sri; Universitas Gadjah Mada Hartati , Agus; Universitas Gadjah Mada Harjoko , Tri Wahyu; Universitas Gadjah Mada Supardi
Many institutions, including high schools, own a large number of analog or ordinary microscopes. These microscopes are used to observe small objects. Unfortunately, object observations on the ordinary microscope require precision and visual acuity of the user. This paper discusses the development of a high-resolution digital microscope from an analog microscope, including the image processing utility, which allows the digital microscope users to capture, store and process the digital images of the object being observed. The proposed microscope is constructed from hardware components that can be easily found in Indonesia. The image processing software is capable of performing brightness adjustment, contrast enhancement, histogram equalization, scaling and cropping. The proposed digital microscope has a maximum magnification of 1600x, and image resolution can be varied from 320x240 pixels up to 2592x1944 pixels. The microscope was tested with various objects with a variety of magnification, and image processing was carried out on the image of the object. The results showed that the digital microscope and its image processing system were capable of enhancing the observed object and other operations in accordance with the user need. The digital microscope has eliminated the need for direct observation by human eye as with the traditional microscope.
Volume: 9
Issue: 3
Page: 565-574
Publish at: 2011-12-01

Automated Navigation System based on Weapon-Target Assignment

10.12928/telkomnika.v9i3.735
Gayuh Titis; Telkom Institute of Technology Permana , Maman; Telkom Institute of Technology Abdurohman , Mohammad; Universitas Negeri Yogyakarta Khairudin , Mohammad; Telkom Institute of Technology Lutfi
Operating of weapon on the tank is mostly by manually. It is not desired performance for a critical operation. An automatic control system is required to operate the weapon with the target while maintaining the accuracy. In this paper has designed an automatic weapon control system using object image proccessing. Various an image processing methods used to improve the weapon accuracy to obtain the intended target. The method used in digital image processing is the Camshift motion tracking method. This method is compared with the Lucas Canade motion tracking method. This comparison is conducted to found more precise results between the two methods. Results of object image processing are used to control the direction of the weapon that towards the desired goal. The results show that the implementation of the Lucas Canade motion tracking method using fire simulation tools have been successful. The performance of the Lucas Canade motion tracking methods is better than the CamShift method. Using Lucas Canade method for weapon controller is accordance with the purposes.
Volume: 9
Issue: 3
Page: 445-452
Publish at: 2011-12-01

FPGA for Robotic Applications: from Android/Humanoid Robots to Artificial Men

10.12928/telkomnika.v9i3.4455
Tole; Universitas Ahmad Dahlan Sutikno
Researches on home robots have been increasing enormously. There has always existed a continuous research effort on problems of anthropomorphic robots which is now called humanoid robots. Currently, robotics has evolved to the point that different branches have reached a remarkable level of maturity, that neural network and fuzzy logic are the main artificial intelligence as intelligent control on the robotics. Despite all this progress, while aiming at accomplishing work-tasks originally charged only to humans, robotic science has perhaps quite naturally turned into the attempt to create artificial men. It is true that artificial men or android humanoid robots open certainly very broad prospects. This “robot” may be viewed as a personal helper, and it will be called a home-robot, or personal robot.
Volume: 9
Issue: 3
Page: 401-402
Publish at: 2011-12-01

A Thermoelectric Generator Replacing Radiator for Internal Combustion Engine Vehicles

10.12928/telkomnika.v9i3.744
Nyambayar; Chungbuk National University Baatar , Shiho; School of Integrated Technology and Yonsei Institute of Convergence Technology Kim
 We have proposed and developed a low temperature thermoelectric generator (TEG) using engine water coolant of light-duty vehicles. Experimental results from test vehicle, of which engine size is about 2.0 liters, show that fabricated prototype Thermoelectric Generator generates more than 75W for driving condition of 80 km/hour, and output power is about 28W during idle condition. The proposed TEG can replace conventional radiator without additional water pumps or mechanical devices except for basic components of legacy water cooling system of radiator.
Volume: 9
Issue: 3
Page: 523-530
Publish at: 2011-12-01

A Remote Power Management Strategy for the Solar Energy Powered Bicycle

10.12928/telkomnika.v9i3.739
Chung-Hsing; Ta-Hwa Institute of Technology Chao
In this paper, a solar energy powered bicycle by a wireless sensor network (WSN) far-end network monitoring solar energy to transfer the electrical energy storage and the effectiveness analysis is proposed. In order to achieve this goal, an embarked ZigBee by a solar-powered bicycle the far-end wireless network supervisory system is setup. Experimental results prove that our prototype, the solar energy powered bicycle, can manage the solar energy for charging two Lead-Acid batteries pack. As a result, the user by the wireless network in parking period knows the data on the amount of immediate solar radiation, the degree of illumination, the ambient temperature, and electrical energy storage capacity information by the internet interface.
Volume: 9
Issue: 3
Page: 483-488
Publish at: 2011-12-01

Optimium Planning of Hybrid Renewable Energy System Using HOMER

https://ijece.iaescore.com/index.php/IJECE/article/view/5372
J. B. Fulzele , Subroto Dutt
A hybrid renewable energy system may be used to reduce dependency on either conventional energy or renewable system. Optimization of hybrid renewable energy systems looks into the process of selecting the best components and its sizing with appropriate operation strategy to provide cheap, efficient, reliable and cost effective alternative energy. In this paper a methodology has been develop for optimum planning of hybrid PV-Wind system with some battergy backup. The local solar radiation, wind data and components database from different manufactures are analyzed and simulated in HOMER to assess the technical and economic viability of the integrated system. Performance of each component will be evaluated and finally sensitivity analysis will be performed to optimize the system at different conditions. Keywords:Optimization, Hybrid system,Renewable system, HOMER, Cost of energy.DOI:http://dx.doi.org/10.11591/ijece.v2i1.157
Volume: 2
Issue: 1
Page: 68-74
Publish at: 2011-11-17

Modeling FACTS Devices in Power System State Estimation

https://ijece.iaescore.com/index.php/IJECE/article/view/5371
Seyyed Mehdi Mahaei , Mehrdad Tarafdar Hagh , Kazem Zare
In this paper is modeled different types of control devices including various kinds of FACTS devices based on power system states. Also, the impact of each device on the amount of injection active or reactive powers as well as active and reactive power flow will be investigated. Based on the type of these devices which can be in parallel, in series or in series–shunt in power systems, proposed models is considered differently. Accordingly, case studies will be performed for three different types of control devices installed in series, in shunt and in series-shunt fashions. State estimation results based on Weighted Least Square not only confirm the proposed models’ effectiveness in accurately state estimating of the system and measurement values but also shows that the estimated values can be obtained from the states of the control devices.Keywords: State Estimation; FACTS Devises; Measurement Function; WLS EstimatorDOI:http://dx.doi.org/10.11591/ijece.v2i1.132
Volume: 2
Issue: 1
Page: 57-67
Publish at: 2011-11-13

Performance of Governor System on Minimizing Frequency Fluctuations with Wind Power Generation

https://ijece.iaescore.com/index.php/IJECE/article/view/5370
Dr. Md. Rafiqul Islam Sheikh , Md. Mejbaul Haque , M.A. Hossain
As wind turbine output is proportional to the cube of wind speed, the wind turbine generator output fluctuates due to wind speed variations. Hence, if the power capacity of wind power generators becomes large, wind power generator output can have an influence on the power system frequency. Therefore, this study investigates the influence of governor control systems of synchronous generators (SGs) for minimizing frequency fluctuations with high wind power penetration level, when a total capacity of SGs is considered as 100 MVA. It is seen that when both SGs operate as governor free (GF) operation, system perform better frequency control. But it can not be maintained to the acceptable level when SGs operate at GF-LFC or LFC-GF operation with wind power capacity about 5% of total capacity. Finally, it is seen that when several interconnected SGs are operated with different control modes, system frequency become more severe for 10% capacity of wind power.DOI:http://dx.doi.org/10.11591/ijece.v2i1.180
Volume: 2
Issue: 1
Page: 46-56
Publish at: 2011-11-13

Parametric Investigation of Near End and Far End Crosstalks in Printed Circuit Board Lands

https://ijece.iaescore.com/index.php/IJECE/article/view/40
Md. Masud Rana , Md. Rabiul Islam , Md Kamal Hosain
Multi-conductor transmission line and interconnect carry signals with wide rage of frequencies from sending end to receiving end. The signal in one transmission line may be interupted by the unwanted contributions from the neighboring line conductors. If data speed increases, high frequency effects occur and the signals suffer from difficulties such as ringing, crosstalk, reflections, and ground bounce that seriously hamper the quality of the received signal. In order to estimate the signal quality, signal integrity analysis is needed. In this paper, an attempt has been made to investigate the sensitivity of the near and far end crosstalk on the parameters such as physical geometry of the conductors, electrical property of the substrate and the rise and fall time of excitation signal. The method of moments (MOM) is used to calculate the line parameters for different geometries. The simulation studies are carried out in TNT. The time domain and frequency domain analyses are performed using transmission line model of PSPICE. Moreover, a model is developed and tested in the laboratory. It is observed that the coupling inductance and capacitance vary with the variation of physical geometry and the substrate parameter.DOI:http://dx.doi.org/10.11591/ijece.v1i2.164
Volume: 1
Issue: 2
Page: 213-219
Publish at: 2011-11-13

A Survey Report On Elliptic Curve Cryptography

https://ijece.iaescore.com/index.php/IJECE/article/view/39
Samta Gajbhiye , Monisha Sharma , Samir Dashputre
The paper presents an extensive and careful study of elliptic curve cryptography (ECC) and its applications. This paper also discuss the arithmetic involved in elliptic curve  and how these curve operations is crucial in determining the performance of cryptographic systems. It also presents  different forms of elliptic curve in various coordinate system , specifying which is most widely used and why. It also explains how isogenenies between elliptic curve  provides the secure ECC. Exentended form of elliptic curve i.e hyperelliptic curve has been presented here with its pros and cons. Performance of ECC and HEC is also discussed based on scalar multiplication and DLP. Keywords: Elliptic curve cryptography (ECC), isogenies, hyperelliptic curve (HEC) , Discrete Logarithm Problem (DLP), Integer  Factorization , Binary Field, Prime FieldDOI:http://dx.doi.org/10.11591/ijece.v1i2.86
Volume: 1
Issue: 2
Page: 195-201
Publish at: 2011-11-13

Smoothing Control of Wind Farm Output Fluctuations by Fuzzy Logic Controlled SMES

https://ijece.iaescore.com/index.php/IJECE/article/view/30
Md. Rafiqul Islam Sheikh , Tamura Junji
Due to random variations of wind speed, the output power and terminal voltage of a fixed speed wind generator fluctuate continuously. These irregularities in power output are affecting both the power quality and reliability. It is reported that STATCOM/SMES (Superconducting Magnetic Energy Storage) system can significantly decrease voltage and output power fluctuations of grid connected fixed speed wind generator. But the main problem in wind generator output power smoothing is the choice of the reference output power, because it corresponds to energy storage capacity. The storage capacity of SMES that is sufficient for the smoothing control but as small as possible is very important, considering cost effectiveness. In this paper, a fuzzy logic controlled STATCOM/SMES system is proposed, in which both SMA (Simple Moving Average) and EMA (Exponential Moving Average) are used to generate output power reference. Real wind speed data are used in the simulation analyses, whichvalidate the effectiveness of the proposed control strategy. Simulation results clearly show that the proposed STATCOM/SMES system can smooth well the wind generator output power and also maintain the terminal voltage at rated level in both cases when SMA or EMA is used to generate output reference power. Finally, it is shown that reference output power generated by EMA provides better performance with reduced SMES storage capacity than that of output power generated by SMA.Keywords: Minimization of fluctuations, fixed speed wind generator, STATCOM/SMES, simple moving average (SMA) and exponential moving average (EMA), and wind farm (WF).DOI:http://dx.doi.org/10.11591/ijece.v1i2.181
Volume: 1
Issue: 2
Page: 119-134
Publish at: 2011-11-12

Indoor Positioning by LED Visible Light Communication and Image Sensors

https://ijece.iaescore.com/index.php/IJECE/article/view/34
Mohammad Shaifur Rahman , Md. Mejbaul Haque , Ki-Doo Kim
High power white LEDs are expected to replace the existing lighting technologies in near future which are also suggested for visible light communication (VLC). We proposed an algorithm for high precision indoor positioning using lighting LEDs, VLC and image sensors. In the proposed algorithm, four LEDs transmitted their three-dimensional coordinate information which were received and demodulated by two image sensors near the unknown position. The unknown position was then calculated from the geometrical relations of the LED images created on the image sensors. We described the algorithm in details. Simulation of the proposed algorithm was done and presented in this paper. This technique did not require any angular measurement which was needed in contemporary positioning algorithms using LED and image sensor. Simulation results showed that the proposed system could estimate the unknown position within the accuracy of few centimeters. Positioning accuracy could be increased by using high resolution image sensors or by increasing the separation between the image sensors.DOI:http://dx.doi.org/10.11591/ijece.v1i2.165
Volume: 1
Issue: 2
Page: 161-170
Publish at: 2011-11-12
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