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27,404 Article Results

Impact of FACTS Devices in Optimal Generation in Deregulated Power System

10.11591/ijape.v4.i3.pp118-125
Pramod Kumar Gouda , Prakash Kumar Hota
Since Gencos and Discos compete primarily based on the price in a deregulated market, minimizing the losses or regulating the voltage or controlling the power flow within the rating of power system components such as cables, transformers, transmission lines become extremely difficult. Recent developments in FACTS devices increases the number of constraints and nonlinearity, and henceachieving the optimal solution becomes further complicated. The Optimal Power Flow Problem, determines the best way to operate a power system at any given instant. It solves the power system load flow with an aim to optimize system operating conditions while automatically adjusting control variable settings without violating the system operating constraints. In this paper such constraints based OPF scheme is developed and presented which also incorporates various Flexible AC Transmission Devices. In this work three different types of FACTS devices namely SVC, TCSC, UPFC are separately included into the OPF problem in addition to the conventional constraints that govern an OPF solution. An IEEE 30 bus system is considered and the results obtained for three different loading conditions with three different FACTS devices and their performance are evaluated.
Volume: 4
Issue: 3
Page: 118-125
Publish at: 2015-12-01

Optimal Coordination of Overcurrent and Distance Relays Using Cuckoo Optimization Algorithm

10.11591/ijeecs.v16.i3.pp389-400
Farhad Namdari , Sajad Samadinasab , Nader Shojaei , Mohammad Bakhshipour
The duty of protective systems is the timely detection of fault and removing it from the power network. The accuracy of the results and reducing the execution time of the optimizing algorithm are two crucial elements in selecting optimizing algorithms in protective functions. The most important protective elements that are used in power networks are distance and overcurrent relays. In this article, a new algorithm is presented to solve the optimization problem of coordination of overcurrent and distance relays by using Cuckoo Optimization Algorithm which considers the non-linear model overcurrent relays at all stages of setting. The proposed method is tested on a standard 8-bus power system network. Also the results obtained have been compared with other evolutionary algorithms. The results show that the proposed approach can be provide more effective and practical solutions to minimize the time function of the relays and achieving optimal coordination in comparison with previous studies on optimal coordination of overcurrent and distance relays in power system networks.
Volume: 16
Issue: 3
Page: 389-400
Publish at: 2015-12-01

Performance Comparison of Routing Protocols in Bipartite Wireless Sensor Network

10.11591/ijece.v5i6.pp1417-1423
Devashish Gosain , Itu Snigdh
This paper evaluates and ranks the suitability of routing algorithms for bipartite wireless sensor network topology. The network considered in this paper, consists of an irregular combination of fixed and mobile nodes, which leads to construction of a bipartite graph among them. A wireless sensor network is usually constrained by the energy limitations and processing capabilities. We therefore, consider the important metrics for analysis namely, carried load, energy consumption and the average delay incurred. We present the possibilities of employing the routing algorithms subject to the quality of service required by the wireless sensor networks applications
Volume: 5
Issue: 6
Page: 1417-1423
Publish at: 2015-12-01

Predictive Control Fed by An Indirect Converter With and Without Energy Storage Using PSO Optimization

10.11591/ijape.v4.i3.pp104-117
Zakaria Lammouchi , Kamel Barra
The paper presents an improved predictive direct control of a variable speed. The method is based on finite states space model of the converter. The proposed control method selects the optimal switching state of (Indirect Converter with and without energy storage for rectified and inverter) that minimizes the error between orthogonal torque, fluxs, and the reactive power components predictions to their computed values for all different voltage vectors. The optimal voltage vector that minimizes a cost function is then applied to the output of the power converter. The main aim of this paper is to propose an online optimization of the weighting factors by the Particle Swarm Optimization (PSO) approach well known by its robustness and fast convergence to the global optimum. Simulation results show that PSO strategy is very efficient to design accurately and quickly these weighting factors.
Volume: 4
Issue: 3
Page: 104-117
Publish at: 2015-12-01

Graph-Based Concept Clustering for Web Search Results

10.11591/ijece.v5i6.pp1536-1544
Supakpong Jinarat , Choochart Haruechaiyasak , Arnon Rungsawang
A search engine usually returns a long list of web search results corresponding to a query from the user. Users must spend a lot of time for browsing and navigating the search results for the relevant results. Many research works applied the text clustering techniques, called web search results clustering, to handle the problem. Unfortunately, search result document returned from search engine is a very short text. It is difficult to cluster related documents into the same group because a short document has low informative content. In this paper, we proposed a method to cluster the web search results with high clustering quality using graph-based clustering with concept which extract from the external knowledge source. The main idea is to expand the original search results with some related concept terms. We applied the Wikipedia as the external knowledge source for concept extraction. We compared the clustering results of our proposed method with two well-known search results clustering techniques, Suffix Tree Clustering and Lingo. The experimental results showed that our proposed method significantly outperforms over the well-known clustering techniques.
Volume: 5
Issue: 6
Page: 1536-1544
Publish at: 2015-12-01

Using Hybrid Automata for Diagnosis of Hybrid Dynamical Systems

10.11591/ijece.v5i6.pp1396-1406
Lotfi Mhamdi , Lobna Belkacem , Hedi Dhouibi , Zineb Simeu Abazi
Physical systems can fail. For this reason the problem of identifying and reacting to faults has received a large attention in the control and computer science communities. In this paper we study the fault diagnosis problem and modeling of Hybrid Dynamical Systems (HDS). Generally speaking, HDS is a system mixing continuous and discrete behaviors that cannot be faithfully modeled neither by using formalism with continuous dynamics only nor by a formalism including only discrete dynamics. We use the well known framework of hybrid automata for modeling hybrid systems, because they combine the continous and discretes parts on the same structure. Hybrid automaton is a states-transitions graph, whose dynamic evolution is represented by discretes and continous steps alternations, also, continous evolution happens in the automaton apexes, while discrete evolution is realized by transitions crossing (arcs) of the graph. Their simulation presents many problems mainly the synchronisation between the two models. Stateflow, used to describe the discrete model, is co-ordinated with Matlab, used to describe the continuous model. This article is a description of a case study, which is a two tanks system.
Volume: 5
Issue: 6
Page: 1396-1406
Publish at: 2015-12-01

Feature Reduction in Clinical Data Classification using Augmented Genetic Algorithm

10.11591/ijece.v5i6.pp1516-1524
Srividya Sivasankar , Sruthi Nair , M.V Judy
In clinical data, we have a large set of diagnostic feature and recorded details of patients for certain diseases. In a clinical environment a doctor reaches a treatment decision based on his theoretical knowledge, information attained from patients, and the clinical reports of the patient. It is very difficult to work with huge data in machine learning; hence to reduce the data, feature reduction is applied. Feature reduction has gained interest in many research areas which deals with machine learning and data mining, because it enhances the classifiers in terms of faster execution, cost-effectiveness, and accuracy. Using feature reduction we intend to find the relevant features of the data set. In this paper, we have analyzed Modified GA (MGA), PCA and combination of PCA and Modified Genetic algorithm for feature reduction. We have found that correctly classified rate of combination of PCA and Modified Genetic algorithm higher compared to other feature reduction method.
Volume: 5
Issue: 6
Page: 1516-1524
Publish at: 2015-12-01

Practical Measurements for Electric Properties of Polyethylene Nanocomposite Thin Films Under Thermal Conditions

10.11591/ijape.v4.i3.pp126-136
Ahmed Thabet , Youssef Mobarak
Polymer properties can be experimentally tailored by adding small amounts of different nanoparticles to enhance its mechanical, thermal and electrical properties; thus, it has been widely anticipated that the combination of nanoparticles with traditional resin systems. This paper has been studied the enhancement and controlling electric and dielectric properties of low density polyethylene (LDPE), and high density polyethylene (HDPE) polymer materials by cost-fewer nanoparticles. Certain percentages of clay and fumed silica nanoparticles have been enhanced electric and dielectric properties of polyethylene nanocomposite films. Dielectric spectroscopy has been measured the electric and dielectric properties of each polyethylene nanocomposite with and without nanoparticles at various frequencies up to1kHz under different thermal conditions (20oC and 60oC). Also, it has been investigated the optimum types and percentages of cost-fewer nanoparticles for enhancing electric and dielectric characterization at low and high temperatures.
Volume: 4
Issue: 3
Page: 126-136
Publish at: 2015-12-01

Combining Fuzzy Logic and Dempster-Shafer Theory

10.11591/ijeecs.v16.i3.pp583-590
Andino Maseleno , Md. Mahmud Hasan , Norjaidi Tuah
This research aims to combine the mathematical theory of evidence with the rule based logics to refine the predictable output. Integrating Fuzzy Logic and Dempster-Shafer theory by calculating the similarity between Fuzzy membership function. The novelty aspect of this work is that basic probability assignment is proposed based on the similarity measure between membership function. The similarity between Fuzzy membership function is calculated to get a basic probability assignment. The Dempster-Shafer mathematical theory of evidence has attracted considerable attention as a promising method of dealing with some of the basic problems arising in combination of evidence and data fusion. Dempster-Shafer theory provides the ability to deal with ignorance and missing information. The foundation of Fuzzy logic is natural language which can help to make full use of expert information.
Volume: 16
Issue: 3
Page: 583-590
Publish at: 2015-12-01

Enhancement the Performance of OFDM based on Multiwavelets Using Turbo Codes

10.12928/telkomnika.v13i4.1846
Sameer A.; University Malaysia Perlis (UniMAP) Dawood , F.; University Malaysia Perlis (UniMAP) Malek , M. S.; University Malaysia Perlis (UniMAP) Anuar , HA; University Malaysia Perlis (UniMAP) Rahim
In wireless communication systems, the main challenge is to provide a high data rate and reliable transmission over a frequency selective fading channel. Orthogonal Frequency Division Multiplexing (OFDM) is a very attractive technique for high data rate transmission with better bandwidth efficiency. In this paper, the effectiveness of turbo codes is utilized to develop a new approach for an OFDM system based on a Discrete Multiwavelet Critical-Sampling Transform (OFDM-DMWCST). The use of turbo coding in an OFDM-DMWCST system is useful in providing the desired performance at higher data rates. Two types of turbo codes were used in this work, i.e., Parallel Concatenated Convolutional Codes (PCCCs) and Serial Concatenated Convolutional Codes (SCCCs). In both types, the decoding is performed by the iterative decoding algorithm based on the log-MAP (Maximum A Posteriori) algorithm. The simulationresults showed that, the turbo-coded OFDM-DMWCST system achieves large coding gain with lower Bit-Error-Rate (BER), therefore, offering a higher data rate under different channel conditions. In addition, thePCCCs offer better performance than SCCCs.
Volume: 13
Issue: 4
Page: 1225-1232
Publish at: 2015-12-01

Power Generation Using Speed Breakers

10.11591/ijeecs.v16.i3.pp417-422
Shehar Bano , Anns Nadeem , Abrar Ahmad , Umer Shuja
In the current scenario demand of power is increasing day by day with increasing population. On the other hand energy crisis is also a main issue of today’s life and all there is a shortage of conventional energy resources due to its large usage. So, we have to sort out this problem with a technique which will not only overcome this energy crisis but also should be eco-friendly. Many conventional resources are creating pollution so that’s why focus is towards eco-friendly solution. This project emphasizes on idea which shows that power could be generated by specially designed speed breakers. A large amount of kinetic energy is being wasted on roads on daily basis in different forms which could be use to generate power and this power can be stored in batteries. This project shows clearly how we can generate power by using rack-pinion method where basically linear motion is converted into rotatory motion and then can be used to generate electricity. Large amount of electricity can be generated using this method and this method is eco-friendly.
Volume: 16
Issue: 3
Page: 417-422
Publish at: 2015-12-01

A Sparse Representation Image Denoising Method Based on Orthogonal Matching Pursuit

10.12928/telkomnika.v13i4.1901
Xiaojun; Jiangsu University of Technology Yu , Defa; Hunan University of Commerce Hu
Image denoising is an important research aspect in the field of digital image processing, and sparse representation theory is also one of the research focuses in recent years. The sparse representation of the image can better extract the nature of the image, and use a way as concise as possible to express the image. In image denoising based on sparse representation, the useful information of the image possess certain structural features, which match the atom structure. However, noise does not possess such property, therefore, sparse representation can effectively separate the useful information from noise to achieve the purpose of denoising. Aiming at image denoising problem of low signal-to-noise ratio (SNR) image, combined with Orthogonal Matching Pursuit and sparse representation theory, this paper puts forward an image denoising method. The experiment shows that compared with the traditional image denoising based on Symlets, image denoising based on Contourlet transform, this method can delete noise in low SNR image and keep the useful information in the original image more efficiently.
Volume: 13
Issue: 4
Page: 1330-1336
Publish at: 2015-12-01

Cost Analysis of Hybrid Restructuration for Distribution System to Improve Voltage and Minimize Losses

10.11591/ijeecs.v16.i3.pp431-438
Firas M.F Flaih , Lin Xiangning , Samir M. Dawoud , Mohammed R. Almallah
Current situation in Iraq had led to extensive blackouts which needs an expansion in generation capacity. On the other hand the government has reduced the budget allocated for energy resource development and it seems this situation will sustain for the coming years.  So the fulfilment of the load demand is the biggest challenge for the ministry of electricity with limited budget. In this paper the authors have proposed a method to reduce the power losses and therefore improve the voltage profile for low voltage (LV) distribution system that results in reduction of blackouts. The method involves the repositioning of the distribution transformer (DTR) from the existing location and the replacement of the overhead conductor cross section area for an existing low voltage distribution system (LVDS). This method has been applied to a 20-node low voltage radial distribution network in the general directorate of north distribution electricity (GDNDE), Iraq, where voltage profile and losses are unsatisfactory. Results demonstrate the effectiveness of the proposed method also in terms of the economic feasibility. It is observed that the system average voltage profile is improved by 15%, tail end voltage enhanced by 19.7% and losses are reduced by 78% for existing the LVDS.
Volume: 16
Issue: 3
Page: 431-438
Publish at: 2015-12-01

Influence of Sensor Nodes on the Invulnerability of Tree Network

10.12928/telkomnika.v13i4.3104
Lifeng; Air Force Engineering University Jiang , Fengming; Air Force Engineering University Zhang , Rennong; Air Force Engineering University Yang , Kun; Air Force Aviation University Xu
In the transformation process from the complex system of great industrial era to the information era, the component having sensing function plays an important role in the evolution of complex system. To abstract the complex system of “tree” structure as “tree” network, To abstract the components include the component having sensing function as nodes, and how the sensor nodes in the network affect network invulnerability is studied quantitatively in this paper. Firstly, the experimental program for network invulnerability is designed; secondly, the indicators for measuring the network invulnerability and the importance of node are proposed; then, the invulnerability experiments are carried out in two conditions-with or without sensor nodes in “tree” network; finally the experimental data are statistically analyzed. Results show that after the addition of sensor nodes, the invulnerability of “tree” network is promoted when subject to random attack and particular attack. The research results are of reference significance for improving self-invulnerability in the transformation process from complex system to information. The experimental program and the relevant conclusions obtained by experiment in this paper have certain innovation.
Volume: 13
Issue: 4
Page: 1242-1250
Publish at: 2015-12-01

Transmission of Real-time Video Signal with Interference Density and Human Traffic

10.12928/telkomnika.v13i4.2738
Rizal Broer; Mercu Buana University Bahaweres , Oki Teguh; KompasTV Karya , Mudrik; Mercu Buana University Alaydrus
The use of mobile phone as a communication tool so rapidly increase, as well as various types of functions therein. Among of the many applications on the mobile phone, which are used skype android-based for teleconferencing via mobile phone. Things can not be separated from these applications is the need of qualified internet network access for these applications can be felt up function. One of the network access to the Internet is widely used today's society is a wi-fi network. Access to the Internet does not always provide the best performance, this is due to many factors, one of which is the presence of interference. In this study, we tested transmission of video signals in real-time using an application skype on the mobile phone. Skype run on wi-fi network, which is influenced by the presence of interference or objects such as human traffic in the network. Wireshark were used to obtain data reliability wi-fi network, known as QoS. While evalvid used to obtain the data QoE restricted only get the data PSNR (Peak Signal To Noise Ratio) and MSE (Mean Square Error).
Volume: 13
Issue: 4
Page: 1352-1360
Publish at: 2015-12-01
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