Showing papers in "International Journal of Electrical and Computer Engineering in 2011"
TL;DR: The main objective is to find the parameters of the nonlinear I–V equation by adjusting the curve at three points: open circuit, maximum power, and short circuit by developing a mathematical model of a Photovoltaic (PV) cell used matlab-simulink environment.
Abstract: Photovoltaic power supplied to the utility grid is gaining more and more visibility while the world’s powers demand is increases. Growing demand, advancements in semiconductor technology and magnetic materials such as high frequency inductor cores, has a significant impact on PV inverter topologies and their efficiencies, on the improvement of the control circuits on the potential of costs reduction. The user naturally wants to operate the Photovoltaic (PV) array at its highest energy conversion output by continuously utilizing the maximum available solar power of the array. The electrical system PV modules are powered by solar arrays requires special design considerations due to varying nature of the solar power generated resulting from unpredictable and sudden changes in weather conditions which change the solar irradiation level as well as the cell operating temperature. This paper, a mathematical model of a Photovoltaic (PV) cell used matlab-simulink environment, is developed and presented. The model is developed using basic circuit equations of the photovoltaic solar cells including the effects of solar irradiation and temperature changes. The main objective is to find the parameters of the nonlinear I–V equation by adjusting the curve at three points: open circuit, maximum power, and short circuit. the method finds the best I–V equation for the single-diode photovoltaic (PV) model including the effect of the series and parallel resistances – Key words : Photovoltaic system (PV), maximum power, PV array,PV cell DOI: http://dx.doi.org/10.11591/ijece.v2i1.117
103 citations
Journal Article•
TL;DR: This study concludes that the setup and operation cost is the vital factor for anti-islanding method selection in order to achieve minimal compromising between cost and system quality.
Abstract: The issue of unintentional islanding in PV grid interconnection still remains as a challenge in grid-connected photovoltaic (PV) systems. This paper discusses the overview of popularly used anti-islanding detection methods, practically applied in PV grid-connected systems. Anti-islanding methods generally can be classified into four major groups, which include passive methods, active methods, hybrid methods and communication base methods. Active methods have been the preferred detection technique over the years due to very small non-detected zone (NDZ) in small scale distribution generation. Passive method is comparatively simpler than active method in terms of circuitry and operations. However, it suffers from large NDZ that significant reduces its performance. Communication base methods inherit the advantages of active and passive methods with reduced drawbacks. Hybrid method which evolved from the combination of both active and passive methods has been proven to achieve accurate anti-islanding detection by many researchers. For each of the studied anti-islanding methods,the operation analysis is described while the advantages and disadvantages are compared and discussed. It is difficult to pinpoint a generic method for a specific application, because most of the methods discussed are governed by the nature of application and system dependent elements. This study concludes that the setup and operation cost is the vital factor for anti-islanding method selection in order to achieve minimal compromising between cost and system quality.
97 citations
Journal Article•
TL;DR: A new routing protocol for Unmanned Aerial Vehicles (UAVs) that equipped with directional antenna that is based on the well known protocol called Optimized Link State Routing Protocol (OLSR) and developed a heuristic that allows DOLSR protocol to minimize the number of the multipoint relays.
Abstract: In this paper, we proposed a new routing protocol for Unmanned Aerial Vehicles (UAVs) that equipped with directional antenna. We named this protocol Directional Optimized Link State Routing Protocol (DOLSR). This protocol is based on the well known protocol that is called Optimized Link State Routing Protocol (OLSR). We focused in our protocol on the multipoint relay (MPR) concept which is the most important feature of this protocol. We developed a heuristic that allows DOLSR protocol to minimize the number of the multipoint relays. With this new protocol the number of overhead packets will be reduced and the End-to-End delay of the network will also be minimized. We showed through simulation that our protocol outperformed Optimized Link State Routing Protocol, Dynamic Source Routing (DSR) protocol and Ad- Hoc On demand Distance Vector (AODV) routing protocol in reducing the End-to-End delay and enhancing the overall throughput. Our evaluation of the previous protocols was based on the OPNET network simulation tool.
94 citations
TL;DR: An algorithm for high precision indoor positioning using lighting LEDs, VLC and image sensors is proposed and results showed that the proposed system could estimate the unknown position within the accuracy of few centimeters.
Abstract: 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
91 citations
TL;DR: A methodology has been develop for optimum planning of hybrid PV-Wind system with some battergy backup using 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.
Abstract: Article history: th , 2012 Accepted Jan 22 th , 2012 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.
66 citations
Journal Article•
TL;DR: This paper presents an intelligent speed control system based on fuzzy logic for a voltage source PWM inverter-fed indirect vector controlled induction motor drive and demonstrates that the performance of the proposed controller is better than that of the conventional PI controller.
Abstract: This paper presents an intelligent speed control system based on fuzzy logic for a voltage source PWM inverter-fed indirect vector controlled induction motor drive. Traditional indirect vector control system of induction motor introduces conventional PI regulator in outer speed loop; it is proved that the low precision of the speed regulator debases the performance of the whole system. To overcome this problem, replacement of PI controller by an intelligent controller based on fuzzy set theory is proposed. The performance of the intelligent controller has been investigated through digital simulation using MATLAB-SIMULINK package for different operating conditions such as sudden change in reference speed and load torque. The simulation results demonstrate that the performance of the proposed controller is better than that of the conventional PI controller. Keywords—Fuzzy Logic, Intelligent controllers, Conventional PI controller, Induction motor drives, indirect vector control, Speed control
46 citations
Journal Article•
TL;DR: In this article, a new algorithm is proposed to detect and classify the fault and identify the fault position in a transmission line with respect to a flexible AC transmission system (FACTS) device placed in the midpoint of the transmission line.
Abstract: Distance protection of transmission lines including advanced flexible AC transmission system (FACTS) devices has been a very challenging task. FACTS devices of interest in this paper are static synchronous series compensators (SSSC) and unified power flow controller (UPFC). In this paper, a new algorithm is proposed to detect and classify the fault and identify the fault position in a transmission line with respect to a FACTS device placed in the midpoint of the transmission line. Discrete wavelet transformation and wavelet entropy calculations are used to analyze during fault current and voltage signals of the compensated transmission line. The proposed algorithm is very simple and accurate in fault detection and classification. A variety of fault cases and simulation results are introduced to show the effectiveness of such algorithm.
46 citations
Journal Article•
TL;DR: In this paper, a mixed method for reducing the order of large-scale dynamic systems is presented, where the numerator polynomial of the reduced order model is obtained by using the modified pole clustering technique while the coefficients of numerator are obtained by Pade approximations.
Abstract: The authors present a mixed method for reducing the order of the large-scale dynamic systems. In this method, the denominator polynomial of the reduced order model is obtained by using the modified pole clustering technique while the coefficients of the numerator are obtained by Pade approximations. This method is conceptually simple and always generates stable reduced models if the original high-order system is stable. The proposed method is illustrated with the help of the numerical examples taken from the literature. Keywords—Modified pole clustering, Order reduction, Pade approximation, Stability, Transfer function
41 citations
TL;DR: Numerical simulation using the dynamic model of puma 600 robot arm shows the effectiveness of the Adaptive Neuro Fuzzy Inference System (ANFIS) based computed torque controller (type PD) approach in improving the computed torque method.
Abstract: The strong dependence of the computed torque control of dynamic model of the robot manipulator makes this one very sensitive to uncertainties of modelling and to the external disturbances. In general, the vector of Coriolis torque, centrifugal and gravity is very complicated, consequently, very difficult to modelled. Fuzzy Logic Controller can very well describe the desired system behavior with simple “if-then” relations owing the designer to derive “if-then” rules manually by trial and error. On the other hand, Neural Networks perform function approximation of a system but cannot interpret the solution obtained neither check if its solution is plausible. The two approaches are complementary. Combining them, Neural Networks will allow learning capability while Fuzzy-Logic will bring knowledge representation (Neuro-Fuzzy). This paper presents the control of puma 600 robot arm using Adaptive Neuro Fuzzy Inference System (ANFIS) based computed torque controller (type PD). Numerical simulation using the dynamic model of puma 600 robot arm shows the effectiveness of the approach in improving the computed torque method. Comparative evaluation with Fuzzy computed torque (type PD) control is presented to validate the controller design. The results presented emphasize that a satisfactory trajectory tracking precision and stabilility could be achieved using ANFIS controller than Fuzzy controller. Keywords : Fuzzy computed torque control, Robot control, Adaptive neuro-fuzzy inference system (ANFIS).
33 citations
Journal Article•
TL;DR: This paper aims to present the reviews of the application of neural network in shunt active power filter (SAPF), and three out of four components of SAPF structure, which are harmonic detection component, compensating current control, and DC bus voltage control, have been adopted some of Neural network architecture as part of its component or even substitution.
Abstract: This paper aims to present the reviews of the application of neural network in shunt active power filter (SAPF). From the review, three out of four components of SAPF structure, which are harmonic detection component, compensating current control, and DC bus voltage control, have been adopted some of neural network architecture as part of its component or even substitution. The objectives of most papers in using neural network in SAPF are to increase the efficiency, stability, accuracy, robustness, tracking ability of the systems of each component. Moreover, minimizing unneeded signal due to the distortion is the ultimate goal in applying neural network to the SAPF. The most famous architecture of neural network in SAPF applications are ADALINE and Backpropagation (BP). Keywords—Active power filter, neural network, harmonic distortion, harmonic detection and compensation, non-linear load.
29 citations
TL;DR: In this paper, the authors have shown that the values of the sheath losses in some cases could be greater than conductor losses, depending on various factors such as type of cable layouts, cable parameters, cable spacing, sheath resistance, phase rotation, conductor current and cable armoring.
Abstract: Single-core underground power cables with two-points bonding induce currents in their metallic sheaths. The sheath induced currents are undesirable and generate power losses and reduce the cable ampacity. This paper has shown that the values of the sheath losses in some cases could be greater than conductor losses, depending on various factors. Such these factors are type of cable layouts, cable parameters, cable spacing, sheath resistance, phase rotation, conductor current and cable armoring. In this paper the above factors have been investigated. The calculations are carried out depending mainly on IEC 60287 by a proposed computer program using MATLAB. Keywords: Single-core cables, two-point bonding method, sheaths losses, flat, trefoil, armoring DOI: http://dx.doi.org/10.11591/ijece.v2i1.115
TL;DR: AC PTDF based approach has been proposed for multi-transaction cases using power transfer sensitivity and Jacobian calculated with three different methods, which can be implemented for any number of transactions occurring simultaneously.
Abstract: —Available transfer capability in the transmission network has become essential quantity to be declared well in advance for its commercial use in a competitive electricity market. Its fast computation using DC load flow based approach is used worldwide for on line implementation. Many authors have proposed the ATC calculation based on DC/AC load flow approach. In this paper, AC PTDF based approach has been proposed for multi-transaction cases using power transfer sensitivity and Jacobian calculated with three different methods. The methods can be implemented for any number of transactions occurring simultaneously. The results have been determined for intact and line contingency cases taking multi-transaction/simultaneous as well as single transaction cases. The main contributions of the paper are: (i) ATC determination for multi-transactions environment, (ii) ATC determination and comparison with three approaches of PTDF calculations, (iii) LODFs with line contingency cases for multi-transaction environment and thereby ATC determination. The results have also been obtained with DC method for comparison. The proposed method have been applied for IEEE 24 bus RTS. Keywords: Available transfer capability, AC load flow, AC power transfer distribution factors , line outage contingency, line outage distribution factors, multi-transactions, simultaneous transactions. DOI: http://dx.doi.org/10.11591/ijece.v1i1.61 Full Text: PDF
TL;DR: A new control strategy is presented in which three Shunt Active Power filter Configurations are developed in order to define new simple control algorithm which requires minimum number of current measurements.
Abstract: In this paper, the radiation pattern of two experimental models of circular waveguide antenna arrays on spherical surface is obtained experimentally and compared with theoretical patterns. We have omitted the phase delay of feed system signals because we have only compared measured and theoretical results in order to verify theoretical results, without trying to improve the best radiation characteristics of developed experimental models. Analysis was made with a developed moment method (MoM) program. The spectral-domain approach to the analysis of the spherical antenna arrays is briefly presented in the paper. Measurements were not performed in a well-defined anechoic environment.
TL;DR: Improved design of power transformer is presented by presenting a better and efficient solution to high frequency power transfo rmer design using genetic algorithm (GA) and simulated annealing (SA) techniques.
Abstract: This paper highlights the transformer design optimization problem. The objective of transformer design optimization problem requires minimizing the total mass (or cost) of the core and wire material by satisfying constraints imposed by international standards and transformer user specification. The constraints include appropriate limits on efficiency, voltage regulation, temperature rise, no-load current and winding fill factor. The design optimizations seek a constrained minimum mass (or cost) solution by optimally setting the transformer geometry parameters and require magnetic properties. This paper shows the above design problems can be formulated in genetic algorithm(GA) and simulated annealing (SA) format. The importance of the GA and SA format stems for two main features. First it provides efficient and reliable solution for the design optimization problem with several variables. Second, it guaranteed that the obtained solution is global optimum. This paper includes a demonstration of the application of the GP technique to transformer design. Key word — Optimization, Power Transformer, Genetic Algorithm (GA), Simulated Annealing Technique (SA) DOI: http://dx.doi.org/10.11591/ijece.v1i2.88
TL;DR: The description and validation (along with test results) of the proposed algorithm for blind image quality assessment are presented, capable of performing this comparison analytically and quantitatively at a low computational cost (real-time) and high efficiency.
Abstract: This research aims at providing means to image comparison from different image processing algorithms for performance assessment purposes. Reconstruction of images corrupted by blur and noise requires specialized filtering techniques. Due to the immense effect of these corruptive parameters, it is often impossible to evaluate the quality of a reconstructed image produced by one technique versus another. The algorithm presented here is capable of performing this comparison analytically and quantitatively at a low computational cost (real-time) and high efficiency. The parameters used for comparison are the degree of blurriness, information content, and the amount of various types of noise associated with the reconstructed image. Based on a heuristic analysis of these parameters the algorithm assesses the reconstructed image and quantify the quality of the image by characterizing important aspects of visual quality. Extensive effort has been set forth to obtain real-world noise and blur conditions so that the various test cases presented here could justify the validity of this approach well. The tests performed on the database of images produced valid results for the algorithms consistently. This paper presents the description and validation (along with test results) of the proposed algorithm for blind image quality assessment. DOI: http://dx.doi.org/10.11591/ijece.v2i1.112 Full Text: PDF
TL;DR: This paper presents particle swarm optimization technique to solve the DELD problem for the determination of the global or near global optimum dispatch solution and comparison of numerical results demonstrate the performance and applicability of the proposed method.
Abstract: Dynamic economic load dispatch (DELD) is one of the major operational decisions in power system operation and control. It is a Dynamic problem due to dynamic nature of Power system and the large variation of load demand. This absolute problem is normally solved by discretisation of the entire dispatch period into a number of small time intervals over which the load is assumed to be constant and the system is considered to be in temporal steady state. This paper presents particle swarm optimization technique to solve the DELD problem for the determination of the global or near global optimum dispatch solution. To illustrate the effectiveness of the proposed approach, three test systems consisting of 5,10 and 15 generating units, with incorporation of load balance constraints, operating limits, valve point loading, ramp constraints and network lossesare considered and tested. The comparison of numerical results demonstrate the performance and applicability of the proposed method. Keywords: Dynamic economic load dispatch (DELD), Particle Swarm Optimization, Valve - point loading effect, Ramp Rate Limits. DOI: http://dx.doi.org/10.11591/ijece.v1i1.60
Journal Article•
TL;DR: The simulation results show that the carrier-based PWM control technique provides the minimum %THD value of the source currents compared with other comparable techniques after compensation.
Abstract: This paper presents the comparison study of current control techniques for shunt active power filter. The hysteresis current control, the delta modulation control and the carrier-based PWM control are considered in the paper. The synchronous detection method is used to calculate the reference currents for shunt active power filter. The simulation results show that the carrier-based PWM control technique provides the minimum %THD value of the source currents compared with other comparable techniques after compensation. However, the %THD values of all three techniques can follow the IEEE std.519-1992.
Journal Article•
TL;DR: In this article, the authors proposed a sensorless speed control of an induction motor by means of Direct Torque Fuzzy Control (DTFC), PI-type fuzzy speed regulator and MRAS speed estimator.
Abstract: Recent developments in Soft computing techniques, power electronic switches and low-cost computational hardware have made it possible to design and implement sophisticated control strategies for sensorless speed control of AC motor drives. Such an attempt has been made in this work, for Sensorless Speed Control of Induction Motor (IM) by means of Direct Torque Fuzzy Control (DTFC), PI-type fuzzy speed regulator and MRAS speed estimator strategy, which is absolutely nonlinear in its nature. Direct torque control is known to produce quick and robust response in AC drive system. However, during steady state, torque, flux and current ripple occurs. So, the performance of conventional DTC with PI speed regulator can be improved by implementing fuzzy logic techniques. Certain important issues in design including the space vector modulated (SVM) 3-Ф voltage source inverter, DTFC design, generation of reference torque using PI-type fuzzy speed regulator and sensor less speed estimator have been resolved. The proposed scheme is validated through extensive numerical simulations on MATLAB. The simulated results indicate the sensor less speed control of IM with DTFC and PI-type fuzzy speed regulator provides satisfactory high dynamic and static performance compare to conventional DTC with PI speed regulator.
TL;DR: Performance from usage of different techniques that can be used to reroute traffic faster then the current IP rerouting methods in the case of a failure in a network are studied.
Abstract: Multi-protocol Label Switching (MPLS) has become an attractive technology of choice for Internet backbone service providers. MPLS features the ability to perform traffic engineering and provides support for Quality of Service traffic provisioning. To deliver reliable service, MPLS requires a set of procedures to provide protection for the traffic carried on Label Switched Paths (LSP). In this case Lable Switched Routers (LSRS) supports recovery mechanism when failure happened in the network.This paper studied about performance from usage of different techniques that can be used to reroute traffic faster then the current IP rerouting methods in the case of a failure in a network. Local rerouting, fast reroute one to one backs up, Haskin, PSL oriented path protection and 1+1 path protection recovery mechanism was compared by given of aggregate traffic which has self-similarity character. Packet drop, rejection probability, recovery time, service disruption time and pre-reserved resources backup will be made as comparator parameter with various bitrate and different position of link failure. Packet loss, rejection probability, recovery time and service disruption time at five recovery mechanisms influenced by position of link failure to ingress. 1+1 path protection mechanism has least packet drop, but costliest way to do recovery in the case of usage resources, as traffic is sent simultaneously in two paths which disjoint. Fast reroute one to one backup is quickest way to operate protection switching recovery after 1+1 path protection mechanism. Keywords : MPLS, recovery, rerouting, self-similar traffic, protection switching DOI: http://dx.doi.org/10.11591/ijece.v1i2.84
TL;DR: A simple method to optimize generation scheduling for thermal power plant using artificial neural network is presented and the optimal generation of generators is achieved considering operational and load constraints.
Abstract: A simple method to optimize generation scheduling for thermal power plant using artificial neural network is presented. The optimal generation of generators is achieved considering operational and load constraints. The B- Coefficients are used to evaluate transmission loss in the system. The fuel cost of each unit in a plant is computed. The effectiveness of methodology is tested with six thermal power plants. A result of proposed method is compared with classical method. The artificial neural network method is quick. Hence, artificial neural network technique can be used in central load dispatch center. Keywords- Neural network, B - Coefficients, Fuel cost, Power loss, Real power DOI: http://dx.doi.org/10.11591/ijece.v1i2.83
TL;DR: The modelling and simulation of Static Synchronous Series Compensator (SSSC) in a two area system for Automatic Generation Control (AGC) under deregulated environment reveals that due to the presence of S SSC along with TCPS, the dynamic performance of the system in terms of settling time, overshoot is greatly improved than that of without SSSC.
Abstract: This paper presents the modelling and simulation of Static Synchronous Series Compensator (SSSC) in a two area system for Automatic Generation Control (AGC) under deregulated environment. The modelling of Thyristor Controlled phase Shifter (TCPS) is also carried out and comparison is made between SSSC and TCPS. A two area hydrothermal system under deregulated environment has been considered for this purpose. The devices are modeled and attempt has been made to incorporate these devices in the two area system thus improving the dynamic response of the system. The effect of these parameters on the system is demonstrated with the help of computer simulations. A systematic method has also been demonstrated for the modeling of this component in the system. Computer simulations reveal that due to the presence of SSSC along with TCPS, the dynamic performance of the system in terms of settling time, overshoot is greatly improved than that of without SSSC. DOI: http://dx.doi.org/10.11591/ijece.v1i1.21
Journal Article•
TL;DR: A pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled induction motor drives (DTCIMD’s) in order to have better power quality conditions at the point of common coupling is presented.
Abstract: This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMD’s) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse ac-dc converters each of them consisting of three-phase diode bridge rectifier. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads. Keywords—AC–DC converter, star-connected autotransformer, power quality, 24 pulse rectifier, Pulse Doubling, direct torque controlled induction motor drive (DTCIMD).
Journal Article•
TL;DR: A method has been proposed for finding the optimum membership functions of a fuzzy system using partic le swarm optimization (PSO) algorithm and it is clearly proved that the optimized membership functions (MFs) provided better performance than a fuzzy model for the same system, when the MFs were h uristically defined.
Journal Article•
TL;DR: Simulation results show that the limitations of conventional controller can be overcome by including Neural concept and thereby the dynamic response of the system with respect to peak time, overshoot and settling time can be improved drastically.
Abstract: This paper presents the design of controller based on the principles of Neural networks. The concept of artificial intelligent techniques greatly helps in overcoming the disadvantages posed by the conventional controllers. A hierarchical architecture of three layer feed forward neural network (NN) is proposed for controller design based on back propagation algorithm (BPA). Area Control Error (ACE) is considered as input to the neural network controller and the output of the controller is provided to the governor in each area. The proposed controllers are tested for a two area hydrothermal system. Simulation results show that the limitations of conventional controller can be overcome by including Neural concept and thereby the dynamic response of the system with respect to peak time, overshoot and settling time can be improved drastically. Keywords : Automatic Generation Control, Hydrothermal system, Neural network, Back propagation algorithm, Area control error DOI: http://dx.doi.org/10.11591/ijece.v2i2.111
Journal Article•
TL;DR: This paper presents one comprehensive modelling approach for maintenance scheduling problem of thermal power units in competitive market as 0/1 mixed- integer linear programming model that incorporates long-term bilateral contracts, and weekly forecasted market prices for market auction.
Abstract: This paper presents one comprehensive modelling approach for maintenance scheduling problem of thermal power units in competitive market. This problem is formulated as a 0/1 mixed- integer linear programming model. Model incorporates long-term bilateral contracts with defined profiles of power and price, and weekly forecasted market prices for market auction. The effectiveness of the proposed model is demonstrated through case study with detailed discussion.
TL;DR: The performance evaluation of different types of QAM and PSK modulations with three different channel estimation methods in OFDM system for wireless communication in frequency domain for slow fading channel is compared.
Abstract: To recover accurate transmitted data at the receiver end, the information regarding channel state derived from channel estimation methods play a very important role in any communication system. In this paper the performance evaluation of different types of QAM and PSK modulations with three different channel estimation methods in OFDM system for wireless communication in frequency domain for slow fading channel is compared. The results must be useful in OFDM based applications like IEEE 802.16(d) and equivalent standards. DOI: http://dx.doi.org/10.11591/ijece.v1i2.148
Journal Article•
TL;DR: The results show that the inclusion of the pre classification stage has improved the accuracy of both the LDA and KNN classifiers by more than 12%.
Abstract: An automated wood recognition system is designed to classify tropical wood species.The wood features are extracted based on two feature extractors: Basic Grey Level Aura Matrix (BGLAM) technique and statistical properties of pores distribution (SPPD) technique. Due to the nonlinearity of the tropical wood species separation boundaries, a pre classification stage is proposed which consists ofKmeans clusteringand kernel discriminant analysis (KDA). Finally, Linear Discriminant Analysis (LDA) classifier and KNearest Neighbour (KNN) are implemented for comparison purposes. The study involves comparison of the system with and without pre classification using KNN classifier and LDA classifier.The results show that the inclusion of the pre classification stage has improved the accuracy of both the LDA and KNN classifiers by more than 12%. Keywords—Tropical wood species, nonlinear data, feature extractors, classification
TL;DR: The arithmetic involved in elliptic curve and how these curve operations is crucial in determining the performance of cryptographic systems is discussed.
Abstract: 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 Field DOI: http://dx.doi.org/10.11591/ijece.v1i2.86
Journal Article•
TL;DR: In this paper, a wavelet wavelet-based edge detection algorithm for cognitive radio networks is proposed, which offers efficient edge detection and provides better performance than the first-order derivative scheme.
Abstract: For cognitive radio networks, there is a major spectrum sensing problem, i.e. dynamic spectrum management. It is an important issue to sense and identify the spectrum holes in cognitive radio networks. The first-order derivative scheme is usually used to detect the edge of the spectrum. In this paper, a novel spectrum sensing technique for cognitive radio is presented. The proposed algorithm offers efficient edge detection. Then, simulation results show the performance of the first-order derivative scheme and the proposed scheme and depict that the proposed scheme obtains better performance than does the first-order derivative scheme. Keywords—cognitive radio, Spectrum Sensing, wavelet, edge detection