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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Transactions of The Korean Institute of Electrical Engineers
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Journal DOI :
The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 60, Issue 12 - Dec 2011
Volume 60, Issue 11 - Nov 2011
Volume 60, Issue 10 - Oct 2011
Volume 60, Issue 9 - Sep 2011
Volume 60, Issue 8 - Aug 2011
Volume 60, Issue 7 - Jul 2011
Volume 60, Issue 6 - Jun 2011
Volume 60, Issue 5 - May 2011
Volume 60, Issue 4 - Apr 2011
Volume 60, Issue 3 - Mar 2011
Volume 60, Issue 2 - Feb 2011
Volume 60, Issue 1 - Jan 2011
Selecting the target year
IEC 61968/61970 based Distribution Management System Suggestion
Kim, Taw-Wan ; Lim, Il-Hyung ; Choi, Myeon-Song ; Lee, Seung-Jae ; Kwon, Sung-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 231~238
DOI : 10.5370/KIEE.2011.60.2.231
A role of Distribution Automation System(DAS) is required to be changed from observing and control to complex and various new system including functions which monitoring, control, prediction, operation and management of EMS type according to be gradually Smart Grid of distribution operation system for development of further power system industrial. IEC(International Electrotechnical Commission) published communication standards which interface and data model of distribution operation system to IEC 61968 and of host system like EMS(Energy Management System) to IEC 61970. So far, each standards are emphasizing themselves, but if they are applied by designed integration of the standards, it could be more efficiency system. So, in this paper, integration application of IEC standards and structure of further distribution operation system to use them are proposed by gradually increasing importance of communication protocols, functions and roles in further distribution management system considering Smart Grid.
Analysis on Operation Characteristics of Hybrid Superconductor Fault Current Limiter(SFCL) with First Half Cycle Non-Limiting Operation
You, Il-Kyoung ; Kim, Jin-Seok ; Kim, Myoung-Hoo ; Lim, Sung-Hun ; Kim, Jae-Chul ; Choi, Jong-Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 239~244
DOI : 10.5370/KIEE.2011.60.2.239
Due to large demand, the increase of fault current has caused the capacity of power machines in power grid to increase. Among several countermeasures, the superconducting fault current limiter (SFCL) has been noticed as one of the promising countermeasures to solve these problems. However, in spite of excellent current limiting performances of the SFCL, the application of SFCL to power system has been delayed due to both the limited space for the SFCL`s installation and its longer recovery time after the fault removal. In order to solve these problems, a hybrid type SFCL was developed. In this paper, we studied the operation characteristics of the hybrid SFCL with first half cycle non-limiting operation by modelling using PSCAD/EMTDC and experiment. It was shown through the simulation using PSCAD/EMTDC and the simulated experiment that the fault current limiting and the fast recovery operations of the hybrid SFCL with the first half cycle non-limiting operation were achieved.
Application of Data Processing Technology on Large Clusters to Distribution Automation System
Lee, Sung-Woo ; Ha, Bok-Nam ; Seo, In-Yong ; Jang, Moon-Jong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 245~251
DOI : 10.5370/KIEE.2011.60.2.245
Quantities of data in the DMS (Distribution management system) or SCADA (Supervisory control and data acquisition) system is enormously large as illustrated by the usage of term flooding of data. This enormous quantity of data is transmitted to the status data or event data of the on-site apparatus in real-time. In addition, if GIS (Geographic information system) and AMR (Automatic meter reading), etc are integrated, the quantity of data to be processed in real-time increases unimaginably. Increase in the quantity of data due to addition of system or increase in the on-site facilities cannot be handled through the currently used Single Thread format of data processing technology. However, if Multi Thread technology that utilizes LF-POOL (Leader Follower -POOL) is applied in processing large quantity of data, large quantity of data can be processed in short period of time and the load on the server can be minimized. In this Study, the actual materialization and functions of LF POOL technology are examined.
Channel Capacity Analysis for Indoor PLC Networks with Considering the Effect of Loading conditions of Networks on Channel State Information
Shin, Jae-Young ; Jeong, Ji-Chai ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 252~256
DOI : 10.5370/KIEE.2011.60.2.252
We analyze the channel capacity with considering the effect of the loading conditions of indoor PLC networks on channel state information. We consider various numbers of load for two kinds of the networks with regular length branches and a deployed network of indoor PLC. For calculating the channel capacity degradation, two noise scenarios and impedances are considered. From the simulation results, we suggest the robust regression lines for modeling the channel capacity degradation. In the cases of 0
loads, natural log and linear function curve show the best goodness of fit, respectively. For the deployed indoor PLC network with 0
loads, compared with the networks with regular length branches, the goodness of fit decreases by the amount of 0.12 and 0.15 for low noise and high noise scenarios, respectively. Using the regression lines, we can estimate the channel capacity degradation without measurement.
LMP Calculation with Consideration of Transaction Strategy and Quadratic Congestion Cost Function
Kim, Jae-Wook ; Jung, Sung-Hun ; Min, Kyung-Il ; Moon, Young-Hyun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 257~265
DOI : 10.5370/KIEE.2011.60.2.257
As the competitive market system has been introduced to the electrical power trade, the priority concern would be that the price of electrical power should be reasonable. It is because, when this rule is solid, we can avoid the distortion of competition and assure the greater efficiency in management. LMP(Locational Marginal Price) means marginal price at each bus. This components consist of energy, loss and congestion cost. At this point, the LMP result that is calculated by traditional model is changeable by the location of the slack and can not be used in bilateral Transaction. This paper proposed algorithm is proved its rationality and credibility by comparing the result of the simulation of virtual 6_bus system that is calculated by traditional method, and showed that the LMP components are changed according to the Transaction Strategy. Furthermore, It shows the effect of additional congestion cost on the transmission line that has bottle neck frequently by simulation.
Evaluation of a Load Serving Entity Revenue in the Real Time Pricing Considering Customer`s Utility
Noh, Jun-Woo ; Kim, Mun-Kyeom ; Kim, Do-Han ; Yoo, Tae-Hyun ; Park, Jong-Keun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 266~272
DOI : 10.5370/KIEE.2011.60.2.266
Real Time Pricing(RTP) is used not only to stabilize the price volatility in electricity market, but to hedge the price risk for Load Serving Entity(LSE). This paper presents an efficient method to reduce the risk of the price volatility in real-time electricity market. For designing the RTP, load patterns of customer are calculated by applying the demand elasticity and customer`s utility is also analyzed to compute the RTP revenue through the risk-attribute of the LSE. In the end, the distribution of the LSE`s profits can be evaluated to lead the optimal RTP value, depending on the level of customer`s participation. Results from the case study based on PJM data are reported to illustrate the proposed method.
A Study on Optimal Battery Capacity with Windfarm Considering Reliability Cost
Kim, Wook-Won ; Kim, Sung-Yul ; Kim, Kyu-Ho ; Kim, Jin-O ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 273~278
DOI : 10.5370/KIEE.2011.60.2.273
By introducing RPS(Renewable Portfolio Standard) for reduction of greenhouse gas, Renewable energy has becoming widespread gradually. Due to a large number of advantages, wind power, which is one of Renewable energy, has standing in the spot-light rather than other Renewable energy. Wind power, however, is difficult to control output and because of severe output fluctuation, it would cause some problems when it is connected with system. Using battery as a solution for these problems has been researched all over the world. In this paper, the reliability modeling of windfarm connected battery and reliability evaluation of system are executed. Also the optimum battery capacity is selected through evaluating reliability cost.
Harmonic Current Compensation Method Using Inverter-Interfaced Distributed Generators
Chung, Il-Yop ; Kang, Hyun-Koo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 279~284
DOI : 10.5370/KIEE.2011.60.2.279
Harmonic distortions in current waveform may cause significant problems in electric power system facility and operation. This paper presents an adaptive parameter estimation method to detect harmonic current components caused by nonlinear loads. In addition, a coordination strategy for multiple inverter-interfaced distributed generators to compensate the harmonic currents is discussed. The coordination strategy is realized by distributing the harmonic compensation participation index to individual distributed generators. The harmonic compensation participation index can be determined by the amount of remaining power generation capacity of each distributed generator. Simulation results based on switching-level inverter models show that the proposed harmonic detection method has good performance and the coordination strategy can improve harmonic problems efficiently.
Integrated Protection Method for DC Railway Systems
Kang, Sang-Hee ; Choi, Chang-Young ; Lee, Won-Seok ; Jung, Ho-Sung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 285~292
DOI : 10.5370/KIEE.2011.60.2.285
DC traction power system is operated ungrounded so that minimize the stray current. Because the stray current is still present, a rail potential is increased. The ground faults in the DC railway systems are usually detected by a potential relay(64P). Moreover, if the rail potential goes high in the ordinary operating state because of the traction load, the potential relay would be maloperated. A presented protective relaying algorithm that can identify exactly the faulted region and can distinguish a ground fault from the potential rising of the rail is presented in this paper. This paper presents simulation technique that is very similar to the real operation situation using PSCAD/EMTDC.
Neural Network Parameter Estimation of IPMSM Drive using AFLC
Ko, Jae-Sub ; Choi, Jung-Sik ; Chung, Dong-Hwa ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 293~300
DOI : 10.5370/KIEE.2011.60.2.293
A number of techniques have been developed for estimation of speed or position in motor drives. The accuracy of these techniques is affected by the variation of motor parameters such as the stator resistance, stator inductance or torque constant. This paper is proposed a neural network based estimator for torque and stator resistance and adaptive fuzzy learning contrroller(AFLC) for speed control in IPMSM Drives. AFLC is chaged fuzzy rule base by rule base modifier for robust control of IPMSM. The neural weights are initially chosen randomly and a model reference algorithm adjusts those weights to give the optimum estimations. The neural network estimator is able to track the varying parameters quite accurately at different speeds with consistent performance. The neural network parameter estimator has been applied to slot and flux linkage torque ripple minimization of the IPMSM. The validity of the proposed parameter estimator and AFLC is confirmed by comparing to conventional algorithm.
Short Circuit Electromagnetic Force Prediction by Coupled Electromagnetic-Mechanical Field Analysis of Dry-Type Transformer
Ahn, Hyun-Mo ; Hahn, Sung-Chin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 301~308
DOI : 10.5370/KIEE.2011.60.2.301
This paper deals with the coupled electromagnetic-mechanical field analysis for short-circuit electromagnetic force of the dry-type transformer. The short-circuit currents are calculated using external circuit in accordance with short-circuit test equipment. According to short-circuit current, the generated magnetic leakage flux density in dry-type transformer model is calculated by finite element method. The radially-directed electromagnetic forces in windings are calculated using electromagnetic field analysis and then axially-directed electromagnetic forces in windings are calculated using electromagnetic-mechanical field analysis. The calculated axially-directed electromagnetic forces in high voltage winding are compared to those of measured ones and showed good agreement with experimental results.
Design of Outer Rotor Type In-Wheel SRM for Welfare Neighborhood Electric Vehicle
Jeong, Kwang-Il ; Lee, Dong-Hee ; Ahn, Jin-Woo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 309~314
DOI : 10.5370/KIEE.2011.60.2.309
Outer rotor type in-wheel switched reluctance motor for Welfare neighborhood electric vehicle is researched. In-wheel system is to drive the electric vehicle without mechanical transmission, shaft, differential gears or other mechanical system. To calculate drive power for each wheels, the elder`s and disable`s safety driving conditions are considered. The designed outer rotor SRM has a 6-stator and 8-rotor pole. The determined dimensions as well as the stator and rotor pole arc are simulated and tested with CAD and finite element analysis to verify the performance of the proposed motor.
A Design of 8-bit Switched-Capacitor Cyclic DAC with Mismatch Compensation of Capacitors
Yang, Sang-Hyeok ; Song, Ji-Seop ; Kim, Su-Ki ; Lee, Kye-Shin ; Lee, Yong-Min ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 315~319
DOI : 10.5370/KIEE.2011.60.2.315
A switched-capacitor cyclic DAC scheme with mismatch compensation of capacitors is designed. In cyclic DAC, a little error between two capacitors is accumulated every cycle. As a result, the accumulated error influences the final analog output which is wrong data. Therefore, a mismatch compensation technique was proposed and the error can be effectively reduced, which alleviates the matching requirement. In order to verify the operation of the proposed DAC, an 8-bit switched-capacitor cyclic DAC is designed through HSPICE simulation and implemented through magna 0.18um standard CMOS process.
Phase-Locked Loops using Digital Calibration Technique with counter
Jeong, Chan-Hui ; Abdullah, Ammar ; Lee, Kwan-Joo ; Kim, Hoon-Ki ; Kim, Soo-Won ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 320~324
DOI : 10.5370/KIEE.2011.60.2.320
A digital technique is adopted to calibrate the current mismatch of the charge pump (CP) in phase-locked loops. A 2 GHz charge pump PLL (CPPLL) is used to justify the proposed calibration technique. The proposed digital calibration technique is implemented simply using a counter. The proposed calibration technique reduces the calibration time by up to a maximum of 50% compared other with techniques. Also by using a dual-mode CP, good current matching characteristics can be achieved to compensate
current mismatch in CP. It was designed in a standard
CMOS technology. The maximum calibration time is
and the average power is 18.38mW with 1.5V power supply and effective area is
A 10bit 1MS/s 0.5mW SAR ADC with Double Sampling Technique
Lee, Ho-Kyu ; Kim, Moo-Young ; Kim, Chul-Woo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 325~329
DOI : 10.5370/KIEE.2011.60.2.325
This paper introduces the 10b 1MS/s SAR ADC with double sampling technique to reduce the power consumption. The SAR ADC is implemented in CMOS 1P8M 65nm technology and occupies 0.11um2. The maximum sampling rate is 1MS/s. The simulated SNDR and SFDR are 55.6dB and 62.7dB at 484kHz input frequency, respectively. The implemented data converter consumes 507uW with 1.2-V supply.
Fuzzy Speed Regulator based on a Fuzzy Acceleration Observer for Vector Control of Permanent Magnet Synchronous Motors
Jung, Jin-Woo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 330~337
DOI : 10.5370/KIEE.2011.60.2.330
This paper presents a new fuzzy speed controller based on a fuzzy angular acceleration observer to realize a robust speed control of permanent magnet synchronous motors(PMSM). The proposed speed controller needs the information of the angular acceleration, thus the first-order fuzzy acceleration observer is designed. The LMI existence condition is given for the proposed fuzzy speed controller, and the gain matrices of the controller are calculated. It is verified that the augmented control system consisting of the fuzzy speed controller and the fuzzy acceleration observer is mathematically stable. To validate the effectiveness of the proposed acceleration observer-based fuzzy speed controller, the simulation and experimental results are shown under motor parameter variations. It is definitely proven that the proposed control scheme can precisely track the speed of a permanent magnet synchronous motor.
Influence of Temperature and Benzotriazole on the Flow Electrification by aging Mineral, Vegetable Oil
Choi, Sun-Ho ; Jeong, Jung-Il ; Huh, Chang-Su ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 338~343
DOI : 10.5370/KIEE.2011.60.2.338
In this paper, the FT-IR, conductivity and flow electrification phenomena of Vegetable oils were discussed. Vegetable oil has high flash point and eco-friendly properties compared to conventional mineral oil. Accelerated aging transformer oil samples produced in the oven at 140[
] for 500 hours, 1000 hours, 1500 hours, 2000 hours. Serial device to measure the flow electrification phenomena was designed and fabricated. Pico ammeter and the Labview data measurements were utilized. The effects of Temperature and antistatic agent on fluid flow electrification were investigated. Both Mineral and vegetable oil showed similar trends for temperature change. The polarity reversal occurred in mineral oil with antistatic agent above 10 ~ 30[ppm] and in vegetable oil with antistatic agent above 5[ppm].
Improvement of Charge Transfer Efficiency of Dye-sensitized Solar Cells by Blocking Layer Coatings
Choi, Woo-Jin ; Kim, Kwang-Tae ; Kwak, Dong-Joo ; Sung, Youl-Moon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 344~348
DOI : 10.5370/KIEE.2011.60.2.344
A layer of
thin film less than ~200nm in thickness, as a blocking layer, was deposited by 13.56 MHz radio frequency magnetron sputtering method directly onto the anode electrode to be isolated from the electrolyte in dye-sensitized solar cells (DSCs). This is to prevent the electrons from back-transferring from the electrode to the electrolyte (
). The presented DSCs were fabricated with working electrode of F:
(FTO) glass coated with blocking
layer, dye-attached nanoporous
layer, gel electrolyte and counter electrode of Pt-deposited FTO glass. The effects of blocking layer were studied with respect to impedance and conversion efficiency of the cells. The, electrochemical impedances of DSCs using this electrode were
: 10.9 and
impedance related by electron movement from nanoporous
to TCO showed lower than that of normal DSCs. The photo-conversion efficiency of prepared DSCs was 5.97% (
: 10.5 mA/
, ff: 0.75) and approximately 1% higher than general DSCs sample.
Electromagnetic Characteristics of Superconducting Ceramics for Electrical Power Devices
Lee, Sang-Heon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 349~351
DOI : 10.5370/KIEE.2011.60.2.349
The formation of oxide superconducting phase fabrication of superconducting wire materials and fabrication of precise superconducting material were studied for developing superconductor application technique. The
addition reduced the particle size
trapped in the matrix after the sintering growth. The added
was converted to fine particles of
which is the conventional sintering temperature for YBaCuO,
and CuO are formed as by products of the reaction between
and YBaCuO phase. The formation of highly
particle appears to be responsible for the refinement of
phase after the citric acid sintering process.
Study on the Crystal Growth Behavior and Opto-Electrical Properties of Transparent Conducting Oxide Films with Au-Interlayer Fabricated by Using a Low-temperature Process
Ji, Young-Seok ; Choi, Yong ; Lee, Sang-Heon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 352~356
DOI : 10.5370/KIEE.2011.60.2.352
Transparent conducting oxide films like ITO/Au/ITO and AZO/Au/AZO were fabricated with a sputter at a low-temperature of less then
and their crystallization and opto-electrical properties were studied. X-ray diffractiometry showed that single-ITO layer was amorphous, whereas, ITO of ITO/Au/ITO multi-layer was crystal. The ITO crystallization and its orientation depended on Au crystallization. Surface roughness of the ITO-multi-layers were in the range of 29-88% of that of ITO-single layer. ITO on amorphous gold layer had more rough surface than ITO on crystal gold. The gold layer between ITO improved electrical conductivity. Carrier density, mobility, resistivity and sheet resistance of ITO-single layer were
, respectively. Those of ITO/Au/ITO-multi-layers depended on Au-interlayer-thickness, which were in the range of
, respectively. The sheet resistances of the single-layer ITO and the multi-layer ITO were 310 and
, respectively. That of AZO/Au/AZO was
, which was better than the single-layer ITO.
Evaluation of Discharge Current Employing Generalized Energy Method and Integral Ohm`s Law Using Finite Element Method
Lee, Ho-Young ; Kim, Hong-Joon ; Lee, Se-Hee ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 357~361
DOI : 10.5370/KIEE.2011.60.2.357
The terminal current in voltage driven systems is an essential role for characterizing the pattern of electric discharge such as corona, breakdown, etc. Until now, to evaluate this terminal current, Sato`s equation has been widely used in areas of high voltage and plasma discharge. Basically Sato`s equation was derived by using the energy balance equation and its final form described physical meaning explicitly. To give more general abilities in Sato`s equation, we present a generalized approach by directly using the Poynting`s theorem incorporating the finite element method. When the magnetic field effect or the time-dependent voltage source is considered, this generalized energy method can be easily applicable to those problems with any dielectric media such as gas, fluid, and solid. As an alternative approach, the integral Ohm`s law resulting in small numerical errors has an ability to be applied to multi-port systems. To test the generalized energy method and integral Ohm`s law, first, the results from two prosed methods were compared to those from Sato`s approach and an analytic solution in parallel plane electrodes. After verification, the generalized method was applied to the tip-sphere electrodes for evaluating the terminal current with three carriers and the Fowler-Nordheim field emission condition. From these results, we concluded that the generalized energy method can be a consistent technique for evaluating the discharge current with various dielectric materials or large magnetic field.
Optimization of Fused Quartz Cantilever DRIE Process and Study on Q-factors
Song, Eun-Seok ; Kim, Yong-Kweon ; Baek, Chang-Wook ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 362~369
DOI : 10.5370/KIEE.2011.60.2.362
In this paper, optimal deep reactive ion etching (DRIE) process conditions for fused quartz were experimentally determined by Taguchi method, and fused quartz-based micro cantilevers were fabricated. In addition, comparative study on Q-factors of fused quartz and silicon micro cantilevers was performed. Using a silicon layer as an etch mask for fused quartz DRIE process, different 9 flow rate conditions of
and He gases were tested and the optimum combination of these factors was estimated. Micro cantilevers based on fused quartz were fabricated from this optimal DRIE condition. Through conventional silicon DRIE process, single-crystalline silicon micro cantilevers whose dimensions were similar to those of quartz cantilevers were also fabricated. Mechanical Q-factors were calculated to compare intrinsic damping properties of those two materials. Resonant frequencies and Q-factors were measured for the cantilevers having fixed widths and thicknesses and different lengths. The Q-factors were in a range of 64,000 - 108,000 for fused quartz cantilevers and 31,000 - 35,000 for silicon cantilevers. The experimental results supported that fused quartz had a good intrinsic damping property compared to that of single crystalline silicon.
RFID Antenna Module with High Isolation Characteristic between Tx and Rx
Park, Dong-Hoon ; Kim, Gui-Sung ; Kim, Hyung-Eun ; Park, Hye-Mi ; Wei, Kai ; Lim, Eun-Cheon ; Lee, Moon-Que ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 370~375
DOI : 10.5370/KIEE.2011.60.2.370
In this paper, we propose an antenna module with high isolation between Tx and Rx in RFID reader module. The proposed module consists of a quadrafilar antenna and a directional coupler with a switchable dummy load to improve the directivity. The proposed module achieves the isolation higher than 20 dB between Tx and Rx. To show the validity of the proposed scheme, we have performed the measurement of tagging range and multi-tagging ability. The experiment results show that the detecting range and multi-tagging ability are enhanced by 81% and 200%, respectively.
Delay-dependent Stability Criteria for Fuzzy Markovian Jumping Hopfield Neural Networks of Neutral Type with Time-varying Delays
Park, Myeong-Jin ; Kwon, Oh-Min ; Park, Ju-Hyun ; Lee, Sang-Moon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 376~382
DOI : 10.5370/KIEE.2011.60.2.376
This paper proposes delay-dependent stability conditions of the fuzzy Markovian jumping Hopfield neural networks of neutral type with time-varying delays. By constructing a suitable Lyapunov-Krasovskii`s (L-K) functional and utilizing Finsler`s lemma, new delay-dependent stability criteria for the systems are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. A numerical example is given to illustrate the effectiveness of the proposed methods.
Hammerstein-Wiener Model based Model Predictive Control for Fuel Cell Systems
Lee, Sang-Moon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 383~388
DOI : 10.5370/KIEE.2011.60.2.383
In this paper, we consider Hammerstein-Wiener nonlinear model for solid oxide fuel cell (SOFC). A nonlinear model predictive control (MPC) is proposed to trace the constant stack terminal power by Hydrogen flow as control input. After the stability of the closed-loop system with static output feedback controller is analysed by Lyapunov method, a nonlinear model predictive control based on the Hammerstein-Wiener model is developed to control the stack terminal power of the SOFC system. Simulation results verify the effectiveness of the proposed control method based on the Hammerstein-Wiener model for SOFC system.
Path Planning for Autonomous Mobile Robots by Modified Global DWA
Yoon, Hee-Sang ; Park, Tae-Hyoung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 389~397
DOI : 10.5370/KIEE.2011.60.2.389
The global dynamic window approach (DWA) is widely used to generate the shortest path of mobile robots considering obstacles and kinematic constraints. However, the dynamic constraints of robots should be considered to generate the minimum-time path. We propose a modified global DWA considering the dynamic constraints of robots. The reference path is generated using A* algorithm and smoothed by cardinal spline function. The trajectory is then generated to follows the reference path in the minimum time considering the robot dynamics. Finally, the local path is generated using the dynamic window which includes additional terms of speed and orientation. Simulation and experimental results are presented to verify the performance of the proposed method.
Design of Particle Swarm Optimization-based Polynomial Neural Networks
Park, Ho-Sung ; Kim, Ki-Sang ; Oh, Sung-Kwun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 398~406
DOI : 10.5370/KIEE.2011.60.2.398
In this paper, we introduce a new architecture of PSO-based Polynomial Neural Networks (PNN) and discuss its comprehensive design methodology. The conventional PNN is based on a extended Group Method of Data Handling (GMDH) method, and utilized the polynomial order (viz. linear, quadratic, and modified quadratic) as well as the number of node inputs fixed (selected in advance by designer) at Polynomial Neurons located in each layer through a growth process of the network. Moreover it does not guarantee that the conventional PNN generated through learning results in the optimal network architecture. The PSO-based PNN results in a structurally optimized structure and comes with a higher level of flexibility that the one encountered in the conventional PNN. The PSO-based design procedure being applied at each layer of PNN leads to the selection of preferred PNs with specific local characteristics (such as the number of input variables, input variables, and the order of the polynomial) available within the PNN. In the sequel, two general optimization mechanisms of the PSO-based PNN are explored: the structural optimization is realized via PSO whereas in case of the parametric optimization we proceed with a standard least square method-based learning. To evaluate the performance of the PSO-based PNN, the model is experimented with using Gas furnace process data, and pH neutralization process data. For the characteristic analysis of the given entire data with non-linearity and the construction of efficient model, the given entire system data is partitioned into two type such as Division I(Training dataset and Testing dataset) and Division II(Training dataset, Validation dataset, and Testing dataset). A comparative analysis shows that the proposed PSO-based PNN is model with higher accuracy as well as more superb predictive capability than other intelligent models presented previously.
Design of Optimized Fuzzy Controller for Rotary Inverted Pendulum System Using Differential Evolution
Kim, Hyun-Ki ; Lee, Dong-Jin ; Oh, Sung-Kwun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 407~415
DOI : 10.5370/KIEE.2011.60.2.407
In this study, we propose the design of optimized fuzzy controller for the rotary inverted pendulum system by using differential evolution algorithm. The structure of the differential evolution algorithm has a simple structure and its convergence to optimal values is superb in comparison to other optimization algorithms. Also the differential evolution algorithm is easier to use because it have simpler mathematical operators and have much less computational time when compared with other optimization algorithms. The rotary inverted pendulum system is nonlinear and has a unstable motion. The objective is to control the position of the rotating arm and to make the pendulum to maintain the unstable equilibrium point at vertical position. The output performance of the proposed fuzzy controller is considered from the viewpoint of performance criteria such as overshoot, steady-state error, and settling time through simulation and practical experiment. From the result of both simulation and practical experiment, we evaluate and analyze the performance of the proposed optimal fuzzy controller from the comparison between PGAs and differential evolution algorithms. Also we show the superiority of the output performance as well as the characteristic of differential evolution algorithm.
Remote user Access control Mechanism in Smart Grid environments
Oh, Soo-Hyun ; Eun, Sun-Ki ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 416~422
DOI : 10.5370/KIEE.2011.60.2.416
Smart grid is the next generation intelligent power grid that combines the existing electric power infrastructure and information infrastructure. It can optimize the energy efficiency in both directions, suppliers and power consumers to exchange information in real time. In smart grid environments, with existing network security threats due to the smart grid characteristics, there are additional security threats. In this paper, we propose a security mechanism that provides mutual authentication and key agreement between a remote user and the device. The proposed mechanism has some advantages that provides secure mutual authentication and key agreement and secure against a replay attack and impersonation attacks.
Subband IPNLMS Adaptive Filter for Sparse Impulse Response Systems
Sohn, Sang-Wook ; Choi, Hun ; Bae, Hyeon-Deok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 423~430
DOI : 10.5370/KIEE.2011.60.2.423
In adaptive filtering, the sparseness of impulse response and input signal characteristics are very important factors of it`s performance. This paper presents a subband improved proportionate normalized least square (SIPNLMS) algorithm which combines IPNLMS for impulse response sparseness and subband filtering for prewhitening the input signal. As drawing and combining the advantage of conventional approaches, the proposed algorithm, for impulse responses exhibiting high sparseness, achieve improved convergence speed and tracking ability. Simulation results, using colored signal(AR(4)) and speech input signals, show improved performance compared to fullband structure of existing methods.
A Wide-band Multi-layer Antenna Design using Double Resonance
Lee, Kook-Joo ; Zhang, Mei-Shan ; Lee, Jung-Aun ; Han, Myeong-Woo ; Kim, Moon-Il ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 431~434
DOI : 10.5370/KIEE.2011.60.2.431
In this paper, bandwidth enhanced design of dielectric resonator antenna fabricated in multi-layer substrate is introduced. The proposed dielectric resonator antenna is operating with fundamental TE101 mode and higher-order TM111 mode. Each resonance frequency is dependent on resonator dimensions. As increasing the height of radiating aperture, the higher-order TM111 mode resonance frequency approach the fundamental TE101 mode resonance frequency and the antenna bandwidth increase by double resonance. Three different aperture height size antennas that operated at 7GHz are fabricated in FR4 multi-layer substrate. Measured 10 dB matching bandwidth is 8 percent for single resonace antenna and 18 percent for double resonance antenna.
Touchless User Interface for Real-Time Mobile Devices
Jung, Il-Lyong ; Nikolay, Akatyev ; Jang, Won-Dong ; Kim, Chang-Su ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 435~440
DOI : 10.5370/KIEE.2011.60.2.435
A touchless user interface system is proposed for real-time mobile devices in this work. The proposed system first recognizes the position of pattern to interact various applications based on the scene taken from mobile camera. Then, the proposed system traces the route of the pattern, which estimates the motion of pattern based on the mean-shift method. Based on this information, we control menu and keypad for the various applications. Differ from other user interface systems, the proposed system provides the new experience to even for the user of low-end mobile without additional hardware. Simulation results demonstrate that the proposed algorithm provides better interaction performances than the conventional method, while achieving real-time user interacting for mobile devices.
Panoramic Video Generation Method Based on Foreground Extraction
Kim, Sang-Hwan ; Kim, Chang-Su ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 441~445
DOI : 10.5370/KIEE.2011.60.2.441
In this paper, we propose an algorithm for generating panoramic videos using fixed multiple cameras. We estimate a background image from each camera. Then we calculate perspective relationships between images using extracted feature points. To eliminate stitching errors due to different image depths, we process background images and foreground images separately in the overlap regions between adjacent cameras by projecting regions of foreground images selectively. The proposed algorithm can be used to enhance the efficiency and convenience of wide-area surveillance systems.
Tunable Bandpass 4th Order SC Sigma-delta Modulator with Novel Structure
Kim, Jae-Bung ; Yoo, Nam-Hee ; Cho, Seong-Ik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 446~450
DOI : 10.5370/KIEE.2011.60.2.446
Tunable SC(Switched Capacitor) bandpass
(Sigma-Delta) modulator used in wireless system receiver occurs a signal attenuation according to tuning of center frequency in signal bandwidth. In this paper, tunable bandpass 4th order SC bandpass
modulator with novel structure is proposed for rejection of signal attenuation in signal bandwidth. The existing structure uses a ten variable coefficient values for rejection of signal reduction in the modulator. But the proposed structure only use a two variable coefficient values for rejection of signal attenuation in the modulator. Also, an adder and comparator is replaced with a comparator having 4 inputs in the modulator. Therefore, the existing structure has one more OP-AMP. The purposed modulator was designed in
CMOS technology. The resolution of the modulator within 310 kHz bandwidth and 40 MHz sampling frequency under 6.67 MHz, 10 MHz and 13.33 MHz intermediate frequency are over 10 bit.
A Wideband Clock Generator Design using Improved Automatic Frequency Calibration Circuit
Jeong, Sang-Hun ; Yoo, Nam-Hee ; Cho, Seong-Ik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 451~454
DOI : 10.5370/KIEE.2011.60.2.451
In this paper, a wideband clock generator using novel Automatic frequency calibration(AFC) scheme is proposed. Wideband clock generator using AFC has the advantage of small VCO gain and wide frequency band. The conventional AFC compares whether the feedback frequency is faster or slower then the reference frequency. However, the proposed AFC can detect frequency difference between reference frequency with feedback frequency. So it can be reduced an operation time than conventional methods AFC. Conventional AFC goes to the initial code if the frequency step changed. This AFC, on the other hand, can a prior state code so it can approach a fast operation. In simulation results, the proposed clock generator is designed for DisplayPort using the CMOS ring-VCO. The VCO tuning range is 350MHz, and a VCO frequency is 270MHz. The lock time of clock generator is less then 3us at input reference frequency, 67.5MHz. The phase noise is -109dBC/Hz at 1MHz offset from the center frequency. and power consumption is 10.1mW at 1.8V supply and layout area is
Design of 1/4-rate Clock and Date Recovery Circuit for High-speed Serial Display Interface
Jung, Ki-Sang ; Kim, Kang-Jik ; Cho, Seong-Ik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 455~458
DOI : 10.5370/KIEE.2011.60.2.455
4:10 deserializer is proposed to recover 1:10 serial data using 1/4-rate clock. And then, 1/4-rate CDR(Clock and Data Recovery) circuit was designed for SERDES of high-speed serial display interface. The reduction of clock frequency using 1/4-rate clocking helps relax the speed limitation when higher data transfer is demanded. This circuit is composed of 1/4-rate sampler, PEL(Phase Error Logic), Majority Voting, Digital Filter, DPC(Digital to Phase Converter) and 4:10 deserializer. The designed CDR has been designed in a standard
1P6M CMOS technology and the recovered data jitter is 14ps in simulation.
Electromagnetic Field Distribution of Reactors for Matrix-type SFCLs under Triple Lines-to-Ground Faults
Chung, Dong-Chul ; Han, Tae-Hee ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 2, 2011, Pages 459~463
DOI : 10.5370/KIEE.2011.60.2.459
In this paper we reported the characteristics of 1 line, 2 lines and 3 lines-to-ground fault of matrix-type SFCLs (MFCLs) and the electromagnetic field distribution of reactors for MFCLs under the same cases of ground faults. To do this, we fabricated MFCLs with 6 reactors for 3 phases. Each reactor had the length of 270 mm and diameter of 80 mm. 6 reactors were made by Bakelite. We reported experimental results, including fault currents, fault voltages and magnetic field distribution according to phase differences between each phase. We confirmed that experimental results will be useful in next future plan for real power grid.