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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
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Development of Dynamic Models for DFIG Wind Farms and HVDC in Jeju Power System Using PSS/E
Nam, Soon-Ryul ; Kang, Sang-Hee ; Nam, Hae-Kon ; Choi, Joon-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2183~2189
DOI : 10.5370/KIEE.2011.60.12.2183
Since main portion of the required electric power in Jeju Island is provided from the mainland through two HVDC lines, Jeju HVDC has a most significant impact on Jeju power system. Average wind speed of Jeju Island is the highest among several candidates in South Korea. So, Jeju Island has been a suitable site for the construction of wind farms where several wind farms are now operating and several others to be sited. Since the large-scale wind generation could have adverse impacts on the stable operation of Jeju power system, wind power is also important for the stability of Jeju power system. Therefore, accurate modeling of Jeju HVDC and wind farms is required for stability analysis of Jeju power system. In this paper, PSS/E-based dynamic modeling of Jeju HVDC and DFIG wind farms is proposed. Model-writing technique of PSS/E is used to develop USRAUX model and USRMDL model for controlling the frequency of HVDC and imposing an operation limit of wind power, respectively. Dynamic characteristics of Jeju HVDC and DFIG wind farms are analyzed through the dynamic simulations. The simulation results show the effectiveness of the developed models for Jeju power system.
Simulation Analysis of a Renewable Energy Based Microgrid using RTDS
Heo, Se-Rim ; Kim, Gyeong-Hun ; Lee, Hyo-Guen ; Hwang, Chul-Sang ; Park, Min-Won ; Yu, In-Keun ; Park, Jung-Do ; Yi, Dong-Young ; Lee, Sang-Jin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2190~2195
DOI : 10.5370/KIEE.2011.60.12.2190
Due to enhanced demands on quality, security and reliability of the electric power energy system, a microgrid has become a subject of special interest. In this paper, output characteristics of energy storage system (ESS) with an electric double layer capacitor (EDLC) and battery energy storage system (BESS) of a renewable energy based microgrid were analyzed under grid-connected and islanded operation modes. The microgrid which consists of photovoltaic and wind power turbine generators, diesel generator, ESS with an EDLC, BESS and loads was modeled using real time digital simulator. The results present the effective control patterns of the microgrid system.
The Effect of HVDC#3 on Jeju Power System
Park, Jung-Soo ; Jung, Hong-Ju ; Han, Young-Seong ; Kim, Rae-Young ; Chung, Chung-Choo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2196~2201
DOI : 10.5370/KIEE.2011.60.12.2196
According to the 5th national plan for electric power demand and supply, the 3rd HVDC link will be installed between KEPCO and Jeju Island system and go into operation in June, 2016. However, if it adopt LCC HVDC, Jeju power system could be in voltage instable condition. In order to solve the problem, we propose the application of VSC HVDC to the 3rd HVDC project. In the past, VSC HVDC has many disadvantages such as, inefficiency in conversion, size limit, and expensiveness, compared to LCC HVDC. Recently, the new technologies and the demand for renewable energy interconnection are leading a large growth in VSC HVDC market. In this paper, we will introduce the technical and market trends of VSC HVDC and power system stability analysis results for Jeju power system having LCC and VSC HVDCs.
Calculation of Seasonal Demand Side Management Quantity Using Time Series
Lee, Jong-Uk ; Wi, Young-Min ; Lee, Jae-Hee ; Joo, Sung-Kwan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2202~2205
DOI : 10.5370/KIEE.2011.60.12.2202
Demand side management is used to maintain the reliability of power systems and to increase the economic benefits by avoiding power plant construction. This paper presents a systematic method to calculate the quantity of seasonal demand side management using time series. A numerical example is presented to calculate the quantity of demand side management in winter season using time series.
Voltage Control of ULTC and Distributed Generations in Distribution System
Jeon, Jae-Geun ; Won, Dong-Jun ; Kim, Tae-Hyun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2206~2214
DOI : 10.5370/KIEE.2011.60.12.2206
LDC(Line Drop Compensation) is widely used in controlling ULTC(Under Load Tap Changer) output voltage at distribution substation. However, LDC may experience some difficulties in voltage control due to renewable energy resources and distributed generations. Therefore, more advanced voltage control algorithm is necessary to deal with these problems. In this paper, a modified voltage control algorithm for ULTC and DG is suggested. ULTC is operated with the voltages measured at various points in distribution system and prevents overvoltage and undervoltage in the distribution feeders. Reactive power controller in DG compensates the voltage drop in each distribution feeders. By these algorithms, the voltage unbalance between feeders and voltage limit violation will be reduced and the voltage profile in each feeder will become more flat.
Development of Short-Term Load Forecasting Method by Analysis of Load Characteristics during Chuseok Holiday
Kwon, Oh-Sung ; Song, Kyung-Bin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2215~2220
DOI : 10.5370/KIEE.2011.60.12.2215
The accurate short-term load forecasting is essential for the efficient power system operation and the system marginal price decision of the electricity market. So far, errors of load forecasting for Chuseok Holiday are very big compared with forecasting errors for the other special days. In order to improve the accuracy of load forecasting for Chuseok Holiday, selection of input data, the daily normalized load patterns and load forecasting model are investigated. The efficient data selection and daily normalized load pattern based on fuzzy linear regression model is proposed. The proposed load forecasting method for Chuseok Holiday is tested in recent 5 years from 2006 to 2010, and improved the accuracy of the load forecasting compared with the former research.
Development of Demand Response Operation System for Load Aggregators
Kim, Ji-Hui ; Moon, Guk-Hyun ; Joo, Sung-Kwan ; Oh, Jae-Cheol ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2221~2224
DOI : 10.5370/KIEE.2011.60.12.2221
During an emergency due to a shortage of power, a load aggregator (LA) can use the demand response operation system to deploy demand response resources (DRRs) through various demand response (DR) programs. This paper introduces the demand response operation system for a load aggregator to manage various demand response resources in a smart grid environment.
Characteristics Analysis of Induction Generator with a Change in Rotor Speed
Kim, Jong-Gyeum ; Park, Young-Jeen ; Kim, Il-Jung ; Kim, Young-Kuk ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2225~2229
DOI : 10.5370/KIEE.2011.60.12.2225
Squirrel cage induction motor is the main driving system of industrial field and familiar with its use in a large variety of applications. However, many engineer are unfamiliar with the induction generator, even though no difference exists between both machines except for the mode of operation. But an induction generator is commonly used for micro & small hydro power applications due to its simplicity, reliability, low cost and robustness. Input and output of induction motor has turned against at the induction generator operation. Rotation speed of induction generator is small faster than induction motor. As output of induction machines increases with the increasement of speed, so loss is same. Actually, generator efficiency is lower than motor at this condition. If induction generator is connected with mechanical load, total efficiency is decreased. In this paper, we analyzed that input, output, torque and efficiency is different from each other above and below synchronous speed.
Analysis of Electromagnetic Vibration Sources in 100kW Interior Permanent Magnet Motor for Ship Anti-heeling Pump Considering Eccentricity
Lee, Sun-Kwon ; Kang, Gyu-Hong ; Hur, Jin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2230~2235
DOI : 10.5370/KIEE.2011.60.12.2230
The purpose of this paper is to provide the unbalanced magnetic force and vibration mode comparison between two large interior permanent magnet machines(IPM) with different pole-slot combination considering stator and rotor eccentricity. Due to the punching tolerance, the mixed eccentricity of air-gap is inevitable. It will generate the asymmetric magnetic flux density in air-gap, which makes the unbalanced magnetic pull and vibration. The study is focused on the unbalanced magnetic force and their harmonic components according to eccentricity conditions such as static, dynamic and mixed. When the high vibration is produced especially resonance, the obtained results provide clues what eccentricity condition occurs in the machine.
Analysis on the Levitation Force Characteristics of Longitudinal Flux Type Levitation Magnet using Equivalent Magnetic Circuit Model
Cho, Han-Wook ; Kim, Chang-Hyun ; Lee, Jong-Min ; Han, Hyung-Suk ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2236~2245
DOI : 10.5370/KIEE.2011.60.12.2236
This paper deals with the levitation force characteristics of electromagnet for MAGLEV vehicle application. The magnetic flux density distribution and levitation force characteristics of the electromagnet are investigated by means of equivalent magnetic circuit model. Firstly, we defined the aligned and unaligned electromagnet module for the full-electromagnet, and magnetic flux paths are represented for each model including leakage and fringing flux paths. Because of the analysis model contains both the permanent magnet and electromagnet coil, we calculated the airgap magnetic flux density and levitation forces using flux superposition in electromagnetic circuit. The results are validated extensively by comparison with finite element analysis. Moreover, the 1/4 scaled magnetic levitation and propulsion test vehicle has been manufactured and tested in order to verify these predictions. The experimental results confirms the validity of the analytical prediction with equivalent magnetic circuit model for the description of a electromagnet.
On-line Compensation Method for Magnetic Position Sensor using Recursive Least Square Method
Kim, Ji-Won ; Moon, Seok-Hwan ; Lee, Ji-Young ; Chang, Jung-Hwan ; Kim, Jang-Mok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2246~2253
DOI : 10.5370/KIEE.2011.60.12.2246
This paper presents the error correction method of magnetic position sensor using recursive least square method (RLSM) with forgetting factor. Magnetic position sensor is proposed for linear position detection of the linear motor which has tooth shape stator, consists of permanent magnet, iron core and linear hall sensor, and generates sine and cosine waveforms according to the movement of the mover of the linear motor. From the output of magnetic position sensor, the position of the linear motor can be detected using arc-tan function. But the variation of the air gap between magnetic position sensor and the stator and the error in manufacturing process can cause the variation in offset, phase and amplitude of the generated waveforms when the linear motor moves. These variations in sine and cosine waveforms are changed according to the current linear motor position, and it is very difficult to compensate the errors using constant value. In this paper, the generated sine and cosine waveforms from the magnetic position sensor are compensated on-line using the RLSM with forgetting factor. And the speed observer is introduced to reduce the effect of uncompensated harmonic component. The approaches are verified by some simulations and experiments.
Analysis of PRT Station Capacity based on Micro Simulation
Kim, Baek-Hyun ; Jeong, Rag-Gyo ; Hwang, Hyeon-Chyeol ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2254~2259
DOI : 10.5370/KIEE.2011.60.12.2254
The introduction of Personal Rapid Transit (PRT) has been widely discussed in the Korean transportation research field. However, there is no robust criterion to derive the throughput of cars and passengers at PRT stations, which plays a primary role in determining the overall capacity of PRT systems. The present study provided a methodology to rigorously compute the capacity for simple-serial PRT stations with a single platform, considering three decisive factors, i.e., the demand level of incoming cars and outgoing passengers, the station structure, and the operation strategy. A micro-level simulator was developed for the analysis of station capacity. And, by using this, station capacities were presented for various combinations of the decisive factors. In particular, the relationship between capacity and station structure was investigated in detail. Station structure is represented by the numbers of platform berths, input queue berths, and output queue berths. Moreover, both waive rate and waiting time, which represent the level of passenger service, were taken into account when the station throughput was computed.
Apparatus and Method for Wave Energy Convertor using Under-water Pressure Oscillation
Song, Seung-Kwan ; Park, Jin-Bae ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2260~2264
DOI : 10.5370/KIEE.2011.60.12.2260
This paper describes the development of an wave energy convertor. We devise a new type of the wave energy convertor which generates electricity by means of under-water pressure oscillation. This wave energy convertor is installed on the seabed floor. That is, there is no exposed body on the surface of the sea. The wave energy convertor comprises an activated assembly which is adapted to be displaced in response to water pressure oscillation to vary the volume of bellows cavity and a power take off assembly which generates electricity in response to movement of the activated assembly.
Oxidation Process of GaN Schottky Diode for High-Voltage Applications
Ha, Min-Woo ; Han, Min-Koo ; Hahn, Cheol-Koo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2265~2269
DOI : 10.5370/KIEE.2011.60.12.2265
1 kV high-voltage GaN Schottky diode is realized using GaN-on-Si template by oxidizing Ni-Schottky contact. The Auger electron spectroscopy (AES) analysis revealed the formation of
at the top of Schottky contact. The Schottky contact was changed to from Ni/Au to Ni/Ni-Au alloy/Au/
by oxidation. Ni diffusion into AlGaN improves the Schottky interface and the trap-assisted tunneling current. In addition, the reverse leakage current and the isolation-leakage current are efficiently suppressed by oxidation. The isolation-leakage current was reduced about 3 orders of magnitudes. The reverse leakage current was also decreased from 2.44 A/
to 8.90 mA/
under -100 V-biased condition. The formed group-III oxides (
) during the oxidation is thought to suppress the surface leakage current by passivating surface dangling bonds, N-vacancies and process damages.
Microwave Properties of Co
Ferrite for Miniaturization of Antenna
Kim, Jae-Sik ; Choi, Eui-Sun ; Kim, Kang ; Lee, Young-Hie ; Song, Sung-Ho ; Ahn, Jong-Bok ; Kim, Byung-Hwan ; Choi, Ji-Young ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2270~2275
DOI : 10.5370/KIEE.2011.60.12.2270
The sintering behavior and microwave properties of ferrite (
ceramics) were investigated for microwave applications. Also PIFA type antenna with ferrite was simulated. All samples were prepared by the solid state reaction method and sintered at
. All ceramics had relatively density above of 92% compare with theoretical density of
ceramics. From the XRD pattens, the Z-type phase was existed as main phase in
ceramics. The permittivity and permeability of
ceramics were increased with Zn additions and decreased rapidly over frequency of 200~600 MHz. Several PIFA type antennas with ferrite and FR4 were simulated. All antenna structure had return loss of less than -10 dB at each resonant frequency. Simulated antenna using both ferrite and FR4 showed size reduction of 25% without a significant decrement of efficiency.
Effects of Oxygen Plasma Treatment on the Electrical Properties of Organic Photovoltaic Cells
Oh, Dong-Hoon ; Lee, Young-Sang ; Park, Hee-Doo ; Shin, Jong-Yeol ; Kim, Tae-Wan ; Hong, Jin-Woong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2276~2280
DOI : 10.5370/KIEE.2011.60.12.2276
An indium-tin-oxide (ITO) is normally used as a substrate in organic photovoltaic cells. We examined the effects of an oxygen (
) plasma treatment on the electrical properties of an organic photovoltaic cell. Experiments with four-point probe method and atomic force microscope revealed the lowest surface resistance of 17.64
/sq and the lowest average surface roughness of 1.39 nm at the plasma treatment power of 250 W. A device structure of ITO/CuPc/
/Al was fabricated by thermal evaporation with and without the plasma treated ITO substrate. It was found that the power conversion efficiency of the cell with the plasma treated ITO is 65 % higher than the one without the plasma treated ITO.
A Study on the SPICE Model Parameter Extraction Method for the DC Model of the High Voltage MOSFET
Lee, Un-Gu ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2281~2285
DOI : 10.5370/KIEE.2011.60.12.2281
An algorithm for extracting SPICE MOS level 2 model parameters for the high voltage MOSFET DC model is proposed. The optimization method for analyzing the nonlinear data of the current-voltage curve using the Gauss-Newton algorithm is proposed and the pre-process step for calculating the threshold voltage and the mobility is proposed. The drain current obtained from the proposed method shows the maximum relative error of 5.6% compared with the drain current of 2-dimensional device simulation for the high voltage MOSFET.
Design of Broad Band RF Components for Partial Discharge Monitoring System
Lee, Je-Kwang ; Ko, Jae-Hyeong ; Kim, Koon-Tae ; Kim, Hyeong-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2286~2292
DOI : 10.5370/KIEE.2011.60.12.2286
In this paper we present the design of Low Noise Amplifier(LNA), mixer and filter for RF front-end part of partial discharge monitoring system. The monitoring system of partial discharge in high voltage power machinery is used to prevent many kinds of industrial accidents, and is usually composed of three parts - sensor, RF front-end and digital microcontroller unit. In our study, LNA, mixer and filter are key components of the RF front-end. The LNA consists of common gate and common source-cascaded structure and uses the resistive feedback for broad band matching. A coupled line structure is utilized to implement the filter, of which size is reduced by the meander structure. The mixer is designed using dual gate structure for high isolation between RF and local oscillator signal.
Optimized Design of a Tag Antenna for RFID using a Meander Line
Kim, Hyeong-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2293~2298
DOI : 10.5370/KIEE.2011.60.12.2293
In this paper, A tag antenna structure for RFID application with resonant frequency of 920MHz is proposed using the meander line technique and Evolution Strategy. Miniaturization structure design for a tag antenna is performed by structure combining the half-wave dipole with a meander line. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is made for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The optimized tag antenna size is 63mm
1mm. And the proposed antenna is realized on FR-4 substrate (
Study on the Metamaterial Design Methodology to Reduce the Size of the Bandpass Filter for the Smart Grid IED
Kahng, Sung-Tek ; Kim, Hyeong-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2299~2304
DOI : 10.5370/KIEE.2011.60.12.2299
In this paper, we propose the methodology to make the bandpass filters for the Smart Grid IED(Intelligent Electronic Device) smaller than the conventional bandpass filters. The size-reduction of the filters and the filter performances are indebted to devising small CRLH(composite right- and left-handed) resonators and coupling them as the metamaterial structures. The design methodology is validated by the equivalent circuit to be compared with the reliable full-wave EM simulation, and the proposed metamaterial filter outperforms the standard parallel-edge coupled filter with respect to the miniaturization and frequency response.
A Dual-band Balanced Amplifier Using Meta-material Transmission Line
Lim, Jong-Sik ; Lee, Jae-Hoon ; Lee, Jun ; Jeon, Yuck-Hwan ; Jeong, Yong-Chae ; Han, Sang-Min ; Ahn, Dal ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2305~2310
DOI : 10.5370/KIEE.2011.60.12.2305
This paper describes a design of dual band balanced amplifier using a lefted handed meta-material transmission line structure for high frequency application. Meta-material transmission lines have been known to have dual band frequency responses. A dual band branch line hybrid coupler is designed using the meta-material transmission lines, and measured at first. Two identical dual band amplifiers are also designed, built and tested using the same meta-material transmission structure. The proposed dual band balanced amplifier is composed of those dual band branch line hybrid coupler and amplifiers. In order to suggest an design example, a prototype of dual band balanced amplifier is built and measured at the dual frequencies, 1800MHz(
) and 2300MHz(
). The simulation and measurement show that the fabricated balanced amplifier operates well at the desired dual frequencies bands with the gain of 11.12dB and 17.67dB at
, respectively, with a good agreement with the simulation results.
Analyses of temperature change of a u-bolometer in Focal Plane Array with CTIA bias cancellation circuit
Park, Seung-Man ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2311~2317
DOI : 10.5370/KIEE.2011.60.12.2311
In this paper, we study the temperature change of a
-bolometer focal plane array with a capacitive transimpedance amplifier bias cancellation circuit. Thermal analysis is essential to understand the performance of a
-bolometer focal plane array, and to improve the temperature stability of a focal plane array characteristics. In this study, the thermal analyses of a
-bolometer and its two reference detectors are carried out as a function of time. The analyses are done with the
focal plane array operating of 60 Hz frame rate and having a columnwise readout. From the results, the temperature increase of a
-bolometer in FPA by an incident IR is estimated as
, while the temperature increase by a pulsed bias as
, which is about 10 times larger than by IR. The temperature increase of a reference detector by a train of bias pulses may be increased much higher than that of an active
-bolometer. The suppression of temperature increase in a reference bolometer can be done by increasing the thermal conductivity of the reference bolometer, in which the selection of thermal conductivity also determines the range of CTIA output voltage.
Improving the Performance of CDGPS using the Shaping Filter on Multipath
Cho, Sung-Lyong ; Han, Young-Hoon ; Choi, Heon-Ho ; Heo, Moon-Beom ; Park, Chan-Sik ; Lee, Sang-Jeong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2318~2325
DOI : 10.5370/KIEE.2011.60.12.2318
The quality of float solution deeply influences the performance of CDGPS because the theories being used in the integer ambiguity resolution method are derived under the assumption of AWGN. But in real world, the properties of noises are far from AWGN, especially when multipath are concerned. It results in the bias in float solution which affects the success rate of integer ambiguity and the precision of position in CDGPS. This paper designs an augmented Kalman filter using shaping filter and Kalman filter for the performance improvement of CDGPS on multipath. The experimental results with real measurements show that the correct integer ambiguity is always found while the success rates of WLSQ and ordinary Kalman filter are 5% and 18%, respectively. Eventually, the position accuracy is also improved by using the proposed algorithm.
eLoran Navigation Algorithm Considering Errors Proportional to the Range
Song, Se-Phil ; Choi, Heon-Ho ; Kim, Young-Baek ; Lee, Sang-Jeong ; Park, Chan-Sik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2326~2332
DOI : 10.5370/KIEE.2011.60.12.2326
eLoran is enhanced Loran-C and eLoran is researched for as GPS backup system because this system is resistant to signal interference and has high accuracy. TOA measurements of eLoran include errors proportional to the range such as PF, SF, ASF and EF. Therefore these error factors must be compensated for improved accuracy of position. Generally, error models or GPS aided compensation methods are used, but these methods are limited by lack of infrastructure or system performance. Therefore, this paper proposes new model of error factors included in eLoran TOA measurements and navigation algorithm using this model. Error factors in this model are sum of a certain size of error and error proportional to the range. And feasibility and performance of proposed navigation algorithm are verified by using raw measurements.
Wavelet Transform Based Time-Frequency Domain Reflectometry for Underground Power Cable
Lee, Sin-Ho ; Choi, Yoon-Ho ; Park, Jin-Bae ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2333~2338
DOI : 10.5370/KIEE.2011.60.12.2333
In this paper, we develope a wavelet transform based time-frequency domain reflectometry (WTFDR) for the fault localization of underground power cable. The conventional TFDR (CTFDR) is more accurate than other reflectometries to localize the cable fault. However, the CTFDR has some weak points such as long computation time and hard implementation because of the nonlinearity of the Wigner-Ville distribution used in the CTFDR. To solve the problem, we use the complex wavelet transform (CWT) because the CWT has the linearity and the reference signal in the TFDR has a complex form. To confirm the effectiveness and accuracy of the proposed method, the actual experiments are carried out for various fault types of the underground power cable.
Estimation of Attitude and Position of Moving Objects Using Multi-filtered Inertial Navigation System
Hwang, Seo-Young ; Lee, Jang-Myung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2339~2345
DOI : 10.5370/KIEE.2011.60.12.2339
This paper proposes a new multi-filtered inertial navigation system to estimate the attitude and position of moving objects. This system has two states, the one is attitude state and the other is position/velocity state. For compensating IMU sensor errors, each of the two states uses a different filter: the attitude state uses the EKF and the position state uses the UPF. The fast and precise characteristics of the EKF have been properly utilized for the attitude estimation, while superior dynamic characteristics of the UPF have been fully adopted for the position estimation. The combination of these two filters in an inertial navigation system improves the system performance to be faster and more accurate. Experimental results demonstrate the superiority of this approach comparing to the conventional ones.
External Noise Analysis Algorithm based on FCM Clustering for Nonlinear Maneuvering Target
Son, Hyun-Seung ; Park, Jin-Bae ; Joo, Young-Hoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2346~2351
DOI : 10.5370/KIEE.2011.60.12.2346
This paper presents the intelligent external noise analysis method for nonlinear maneuvering target. After recognizing maneuvering pattern of the target by the proposed method, we track the state of the target. The external noise can be divided into mere noise and acceleration using only the measurement. divided noise passes through the filtering step and acceleration is punched into dynamic model to compensate expected states. The acceleration is the most deterministic factor to the maneuvering. By dividing, approximating, and compensating the acceleration, we can reduce the tracking error effectively. We use the fuzzy c-means (FCM) clustering as the method to divide external noise. FCM can separate the acceleration from the noise without criteria. It makes the criteria with the data made by measurement at every sampling time. So it can show the adaptive tracking result. The proposed method proceeds the tracking target simultaneously with the learning process. Thus it can apply to the online system. The proposed method shows the remarkable tracking result on the linear and nonlinear maneuvering. Finally, some examples are provided to show the feasibility of the proposed algorithm.
A Study on Static Situation Awareness System with the Aid of Optimized Polynomial Radial Basis Function Neural Networks
Oh, Sung-Kwun ; Na, Hyun-Suk ; Kim, Wook-Dong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2352~2360
DOI : 10.5370/KIEE.2011.60.12.2352
In this paper, we introduce a comprehensive design methodology of Radial Basis Function Neural Networks (RBFNN) that is based on mechanism of clustering and optimization algorithm. We can divide some clusters based on similarity of input dataset by using clustering algorithm. As a result, the number of clusters is equal to the number of nodes in the hidden layer. Moreover, the centers of each cluster are used into the centers of each receptive field in the hidden layer. In this study, we have applied Fuzzy-C Means(FCM) and K-Means(KM) clustering algorithm, respectively and compared between them. The weight connections of model are expanded into the type of polynomial functions such as linear and quadratic. In this reason, the output of model consists of relation between input and output. In order to get the optimal structure and better performance, Particle Swarm Optimization(PSO) is used. We can obtain optimized parameters such as both the number of clusters and the polynomial order of weights connection through structural optimization as well as the widths of receptive fields through parametric optimization. To evaluate the performance of proposed model, NXT equipment offered by National Instrument(NI) is exploited. The situation awareness system-related intelligent model was built up by the experimental dataset of distance information measured between object and diverse sensor such as sound sensor, light sensor, and ultrasonic sensor of NXT equipment.
A Study on the Design of Barriers for the Active Noise Barrier Development
Cha, Sang-Gon ; Kim, Dong-Hwan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2361~2367
DOI : 10.5370/KIEE.2011.60.12.2361
In this paper survey and analysis of recent trends in noise barriers and noise measurements and assessments were conducted for providing design basis of ANC barriers. Looking at the results, transparent barrier(glass) has received the most attention in domestic and foreign countries, because it has a harmony with the surrounding environment and easy installation in a small space. For optimal barrier design using computer simulation, reliability of simulation has been verified and classified into 5 groups, according to barrier's upper cross section. Evaluation results of barrier's performance and design using computer simulation are as follows : In the case of the "B-type" barrier, it has improved maximum 2.5dB(A) at each point(R1~R6) and have a good workability. Therefore, "B-type" Barriers applied to the next active noise barrier system will be possible.
Active Noise Control Barrier for Acoustic Hardware System Design
Cha, Sang-Gon ; Troshin, Andrey G. ; Kim, Dong-Hwan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2368~2373
DOI : 10.5370/KIEE.2011.60.12.2368
Traffic noise annoyance in dwelling area like private houses and apartment is becoming very important issue nowadays in South Korea. In this paper frequency analysis of the traffic noise was performed. Based on sound pressure levels analyses and its frequency content specific requirements for component of active noise control systems are formulated. Active compensational loudspeaker, microphone front end and DSP design were analysed, considered and proposed. Components specifications and design solutions are verified using modelling and experimental technique.
Estimation of Fundamental Frequency Using an Instantaneous Frequency Based on the Symmetric Higher Order Differential Energy Operator
Iem, Byeong-Gwan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2374~2379
DOI : 10.5370/KIEE.2011.60.12.2374
The fundamental frequency of the voiced speech is estimated using the instantaneous frequency based on the symmetric higher order differential energy operator. The instantaneous frequency based on the symmetric higher order energy operator shows better frequency estimation result since it is aligned to the time instance of the signal. The speech is pre-processed by a lowpass filter to remove higher frequency components. Then, it is processed by the instantaneous frequency to obtain the fundamental frequency estimates. The symmetric higher order energy operator has been used as an indicator to determine the voiced/unvoiced speech. The fundamental frequency estimates are further processed by a moving average filter to obtain the monotonically changed estimates. The obtained fundamental frequency estimates have been compared with the spectrogram of the speech to confirm its accuracy.
Encryptions of ECG Signals by Using Fiducial Features
Kim, Jeong-Hwan ; Kim, Kyeong-Seop ; Shin, Seung-Won ; Ryu, Keun-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2380~2385
DOI : 10.5370/KIEE.2011.60.12.2380
With the advent of ubiquitous healthcare technology to provide a patient with the necessary medical services in anywhere and anytime scheme, the importance of securing safe communication without tampering the medical data by the unauthorized users is getting more emphasized. With this aim, a novel method for constructing encryption keys on the basis of biometrical measurement of electrocardiogram (ECG) is suggested in this study. The experiments on MIT/BIH database show that our proposed method can achieve safe communication by successfully ciphering and deciphering ECG data including premature ventricular contraction arrhythmia signal with compromising its fiducial features as biometric key to transmit the data via the internet network.
A Control for 2-axis Gimbaled Millimeter Wave Seeker using Space Vector PWM of PMSM
Lee, Sung-Yong ; Lee, Jung-Suk ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2386~2391
DOI : 10.5370/KIEE.2011.60.12.2386
Tracking and detecting targets by the millimeter wave seeker is affected by moving of platform. In order to perform the tracking performance, stabilization of a millimeter wave seeker which consists of 2-axis gimbals was considered in this study. The feasibility of the analysis and the 2-axis gimbal servo system modeling design were verified along with some simulation results.
A Study of Improving Regenerative Energy Utilization in Urban DC Railway Systems Through Sharing Substations
Jung, Seung-Min ; Lee, Han-Sang ; Byun, Gil-Sung ; Kwon, Sae-Hyuk ; Jang, Gil-Soo ; Jung, Ho-Sung ; Kim, Hyung-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 12, 2011, Pages 2392~2396
DOI : 10.5370/KIEE.2011.60.12.2392
This paper deals with the power integration of large urban railway systems to improve regenerative energy utilization. Current regenerative energy utilization is low because there is no special plan for using this energy. If the railway system is integrated with other railway systems, the efficiency is expected to be improved. Through the case studies, to find the realistic effect of integrated operation, real system for the Seoul Metro lines, especially line 5 and 7, had been applied.