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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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The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 59, Issue 12 - Dec 2010
Volume 59, Issue 11 - Nov 2010
Volume 59, Issue 10 - Oct 2010
Volume 59, Issue 9 - Sep 2010
Volume 59, Issue 8 - Aug 2010
Volume 59, Issue 7 - Jul 2010
Volume 59, Issue 6 - Jun 2010
Volume 59, Issue 5 - May 2010
Volume 59, Issue 4 - Apr 2010
Volume 59, Issue 3 - Mar 2010
Volume 59, Issue 2 - Feb 2010
Volume 59, Issue 1 - Jan 2010
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Reliability Assessment and Transmission Capability Calculation in Power System using Well-being Method
Son, Hyun-Il ; Bae, In-Su ; Kim, Jin-O ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 841~846
Reliability in electrical power system refers to normal operation for schedule time in some system that action consists. It means that if there is no contingency of electric power supply decrease or load curtailment, reliability of the system is high. In this paper, a method for evaluation of transmission capability is proposed considering reliability standards. Deterministic and probabilistic methods for evaluation of transmission capability has been studied. These researches considered uncertainty of system components or N-1 contingency only. However, the proposed method can inform customers and system operators more suitable transmission capability. Well-being method using state probabilities of system components proves to be a more effective method in this paper comparing with calculation of LOLE(Loss of Load Expectation). The length of calculation is shorter but it can give more practical information to the exact system operators. Well-being method is applied to IEEE-RTS 24bus system to evaluate reliability in case study. The result is compared with a existing way to evaluate reliability with LOLE and it shows that transmission capability connected with adjacent networks. This paper informs system operators and power suppliers of reliable information for operating power system.
Effects of Reclosing for Insulation Coordination in 345kV Combined Transmission Lines
Lee, Jong-Beom ; Jung, Chae-Kyun ; Lim, Kwang-Sik ; Kang, Ji-Won ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 847~853
This paper describes switching surge analysis for reclosing decision in 345kV combined transmission line with XLPE power cable. Reclosing operation should be decided based on the detailed technical analysis in combined transmission line because this line includes power cable section which is week on insulation. Insulation of power cable can be breakdown at the week point in case of reclosing moment. Therefore the detailed analysis has to be carried out by considering several conditions such as length ratio of power cable section, arrestor, inserting resistance, charging rate, grounding resistance, etc.. On the other hand sheath voltage on IJ(Insulated Joint) is analyzed to check dangerous condition on cable cover. Analysis is performed by EMTP/ATP. Analysis results show that reclosing can be operated as the single line-to-ground fault occurs on overhead line in 345kV combined transmission line, if the inserting resistance is considered before the operation of main circuit breaker.
An Auto-drawing Algorithm for the Single Line Diagram of Distribution Systems
Son, Ju-Hwan ; Lim, Seong-Il ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 854~859
Distribution Automation System(DAS) is designed to improve operational efficiency by acquisition and control of remote data using its components such as central computation units, communication network and feeder remote terminal units. A conventional human machine interface of the DAS adopts a schematic diagram which is made by drawing power equipments on the geographic information system map. The single line diagram is more useful than the schematic diagram for the main tasks of distribution system operation such as protective relay coordination, service restoration and loss minimization. Since the configuration of the distribution line is changed according to the relocation of the open tie switches, the auto-drawing algorithm based on the connection between the sections and the switches is an essential technique. This paper proposes a new auto-drawing algorithm for a single line diagram of distribution systems based on tertiary tree and collision avoidance method. The feasibility of the proposed algorithm has been testified for various cases using practical distribution system with 12 feeders.
Analytical Analysis of PT Ferroresonance in the Transient-State
Kang, Yong-Cheol ; Lee, Byung-Eun ; Zheng, Tai-Ying ; Kim, Yeon-Hee ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 860~865
When a circuit breaker is opened, a large capacitance around the buses, the circuit breaker and the potential transformer (PT) might cause PT ferroresonance. During PT ferroresonance, the iron core repeats saturation and unsaturation even though the supplied voltage is a rated voltage. This paper describes an analytical analysis of PT ferroresonance in the transient-state. To analyze ferroresonance analytically, the iron core is modelled by a simplified two-segment core model in this paper. Thus, a nonlinear ordinary differential equation (ODE) for the flux linkage is changed into a linear ODE with constant coefficients, which enables an analytical analysis. In this simplified model, each state, which is either saturated or unsaturated state, corresponds to one of the three modes, i.e. overdamping, critical damping and underdamping. The flux linkage and the voltage in each state are obtained analytically by solving the linear ODE with constant coefficients. The proposed transient analysis is effective in the more understanding of ferroresonance and thus can be used to design a ferroresonance prevention or suppression circuit of a PT.
Harmony Search Algorithm for Optimal Placement Problem of Distributed Generations
Rhee, Sang-Bong ; Kim, Kyu-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 866~870
This paper presents a application of Harmony Search (HS) algorithm for optimal placement of distributed generations(DGs) in distribution systems. In optimization procedure, the HS algorithm denotes the searching ability for the global optimal solution with simple coding of the iteration procedure, and shows the fast convergence characteristics for getting solutions. The HS algorithm is tested on 9 buses and 69 buses distribution systems, and the results prove its effectiveness to determine appropriate placement points of DGs and reducing amount of active power without the occurrence of any mis-determination in selection of its capacity.
Analysis of Loss Compensation Efficiency Factor in the Uniform Price Market
Hahn, Tae-Kyung ; Kim, Jin-Ho ; Park, Jong-Keun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 871~881
In the uniform price electricity market or bilateral electricity market, the energy transactions in which the network is not considered and ISO's system operation costs which ISO try to minimize are settled separately. In this paper, transmission loss, one of the ISO's system operation costs, was dealt. The conventional marginal loss allocation method gives economic signals but three aspects have to be considered; excessiveness, arbitrariness and cross-subsidy. In this paper, marginal loss compensation efficiency method was suggested which consider those aspects of the conventional marginal loss allocation method. Also the characteristics of the marginal loss compensation efficiency were analyzed in the appendixes. And simple 2-bus system and IEEE 14 bus system were used to explain these characteristics.
Development of Three Phase Optimal Power Flow for Distributed Generation Systems
Song, Hwa-Chang ; Cho, Sung-Koo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 882~889
This paper presents a method of finding the optimal operating point minimizing a given objective function with 3 phase power flow equations and operational constraints, called 3 phase optimal power flow (3POPF). 3 phase optimal power flow can provide operation and control strategies for the distribution systems with distributed generation assets, which might be frequently in unbalanced conditions assuming that high penetration rate of renewable energy sources in the systems. As the solution technique for 3POPF, this paper adopts a simulation-based method of particle swarm optimization (PSO). In the PSO based 3POPF, a utility function needs to be defined for evaluation of the degree in operational improvement of each particle's current position. To evaluate the utility function, in this paper, NR-based 3 phase power flow algorithm was developed which can deal with looped distributed generation systems. In this paper, illustrative examples with a 5-bus and a modified IEEE 37-bus test systems are given.
The Study of Analysis on Water Vapor Condensation on Automobile Headlamp Using the Numerical Model
Jung, Young-Guk ; Lee, Ju-Han ; Oh, Sang-June ; Seo, Tae-Beom ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 890~896
Increasing styling features for automotive headlamps speed up the focus of understanding condensation at inner surfaces. Water vapor condensation on the inside surface of the headlamp lens is an essential factor that affects secure front view and headlamp life. One of the headlamps of automobile which is one of the most popular in Korea was chosen for the present analysis. In the basis of the experimental data of automobile given by a manufacturer, boundary conditions were defined and free convection of the air inside the headlamp and radiation from the bulb to the other surfaces are considered. As a result, temperature distribution of the inside surface of the headlamp lens are approximately the same as the experimental result.
A Study on the Optimization Strategy using Permanent Magnet Pole Shape Optimization of a Large Scale BLDC Motor
Woo, Sung-Hyun ; Shin, Pan-Seok ; Oh, Jin-Seok ; Kong, Yeong-Kyung ; Bin, Jae-Goo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 897~903
This paper presents a response surface method(RSM) with Latin Hypercube Sampling strategy, which is employed to optimize a magnet pole shape of large scale BLDC motor to minimize the cogging torque. The proposed LHS algorithm consists of the multi-objective Pareto optimization and (1+1) evolution strategy. The algorithm is compared with the uniform sampling point method in view points of computing time and convergence. In order to verify the developed algorithm, a 6 MW BLDC motor is simulated with 4 design parameters (arc length and 3 variables for magnet) and 4 constraints for minimizing of the cogging torque. The optimization procedure has two stages; the fist is to optimize the arc length of the PM and the second is to optimize the magnet pole shape by using the proposed hybrid algorithm. At the 3rd iteration, an optimal point is obtained, and the cogging torque of the optimized shape is converged to about 14% of the initial one. It means that 3 iterations aregood enough to obtain the optimal design parameters in the program.
The Electronic Ballast Design of Acoustic Resonance Free and Transient Over Current Limit for High Power MHL
Kim, Ki-Nam ; Park, Jong-Yun ; Choi, Young-Min ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 904~911
This paper presents the design of acoustic resonance free and over current limit during transient state consideration electronic ballast for 1.5kW Metal-Halide Lamp(MHL) that employs frequency modulation (FM) technique. The proposed ballast consists of a Full-Bridge(FB) rectifier, a passive power factor correction (PFC) circuit, a full-bridge inverter, an ignitor using LC resonance and a control circuit for frequency modulation. The frequency modulation technique is the most effective solution to eliminate acoustic resonance among other technique. It spreads power spectrum of lamp to reduce the supplied power spectrum under the energy level of eigen-value frequency. Moreover, the proposed ballast is simple and cost effective above conventional ballast. A new PFC circuit is proposed which combines with LCD type and PCSR filter. A new PFC circuit has higher PF and lower THD than conventional LCD type and secure high reliability. Finally, to protected switching components in transient state, the surge current into ballast is limited by increase the switching frequency. Performance of the proposed ballast was validated through computer simulation using Pspice, experimentation and by applying it to an electronic ballast for a prototype 1.5kW MHL.
Estimating for Properties of Insulating Degradation for Cellulose paper with Aging Temperature and Correlation by Statistical Treatment
Kim, Jae-Hoon ; Kim, Dae-Sik ; Han, Sang-Ok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 912~917
It was known that oil-filled transformer's life depended on insulating paper which was applied to transformers for insulating of transformer. Therefore when paper was aged, its electrical, mechanical and chemical characteristics were changed. Especially if operating temperature was high, paper was quickly damaged. As cellulose paper which was mainly used for solid insulation of transformers was degraded, the cellulose polymer chains broke down into shorter lengths and gases such as CO,
and so on were produced from paper. Also by-product known as furan compounds were producted from paper and it were dissolved within insulating oil. In this paper accelerating aging cell was aged during 60 hours at 100, 150, 180 and
, respectively, so evaluating the chemical characteristics of cellulose paper by thermal. An it were performed analysis such as tensile strength(TS), dissolved gas analysis(DGA) and high performance liquid chromatography(HPLC). Also for analyzing of correlation between insulating degradation characteristics, it was performed linear regression method as statistical treatment.
The Study on Dielectric layer Design and Manufactor for Luminance Improvement of Red Organic Light Emitting Device
Ki, Hyun-Chul ; Kim, Seon-Hoon ; Kim, Doo-Gun ; Kim, Sang-Gi ; Jeong, Haeng-Yun ; Choi, Young-Sung ; Hong, Kyung-Jin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 918~921
We have proposed an dielectric layer to improve the luminance of red organic light emitting device. Here, we have calculated refractive index of dielectric layer material that was revised refractive index of organic material, ITO and glass. Refractive index of dielectric layer material was 1.711. The structure of dielectric layer was designed in organic material/ITO/dielectric layer/glass. Dielectric material changed thickness that deposited by ion-assisted deposition system. Transmittances of ITO were 95.66-98.85 [%]. Red OLED was fabricated with the structure of TPD(
). Turn-on voltage and Luminance of Red OLED were 10 [V] and 5,857 cd/m2.
Surface Plasmon Resonance Based on ZnO Nano-grating Structure
Kim, Doo-Gun ; Kim, Seon-Hoon ; Ki, Hyun-Chul ; Kim, Hwe-Jong ; Oh, Geum-Yoon ; Choi, Young-Wan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 922~926
We have investigated the grating coupled surface plasmon resonance (GC-SPR) sensors using ZnO nano-grating structures to enhance the sensitivity of an SPR sensor. The GC-SPR sensors were analyzed using the finite-difference time-domain method. The optimum resonance angles of 49 degrees are obtained in the 150 nm wide grating structure with a period of 300 nm for the ZnO thickness of 30 nm. Then, the ZnO nano-grating patterns were fabricated by using laser interference lithography. The measured resonance angle of nano-grating patterns was around 49 degrees. Here, an enhanced evanescent field is obtained due to the surface plasmon on the edge of the bandgap when the ZnO grating structures are used to excite the surface palsmon.
Properties of Electrical and Optical for OLED using Zn(HPB)q as Electron Transporting Layer
Kim, Dong-Eun ; Park, Jun-Woo ; Kim, Byoung-Sang ; Lee, Burm-Jong ; Kwon, Young-Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 927~931
Recently, high luminance and high efficiency were realized in OLED with multilayer structure including emitting materials such as metal-chelate complexes. We synthesized a new luminescent material, namely, [2-(2-hydroxyphenyl)quinoline] (Zn(HPB)q) which has low molecular compound and emitted in yellowish green region. The ionization potential(IP) and electron affinity(EA) of Zn(HPB)q were measured by cyclic-voltammetry(CV). As a result, IP and EA of Zn(HPB)q were calculated 6.8 eV and 3.5 eV, respectively. We fabricated the devices and observed the possibility of Zn(HPB)q as electron transporting layer. We have obtained an improvement of luminance and decrease of turn-on voltage using Zn(HPB)q as electron transporting layer.
A Study on the Improvement of Decomposition Efficiency of Organic Substances Using Plasma Process and Catalytic Surface Chemical Reaction
Han, Sang-Bo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 932~938
This paper proposed the effective treatment method for organic substances using the barrier discharge plasma process and catalytic chemical reaction followed from ozone decomposition. The decomposition by the plasma process of organic substances such as trichloroethylene, methyl alcohol, acetone, and dichloromethane carried out, and ozone is generated effectively at the same time. By passing through catalysts, ozone easily decomposed and further decomposed organic substances. And, 2-dimensional distribution of ozone using the optical measurement method is performed to identify the catalytic surface chemical reaction. In addition, CO is easily oxidized into
by this chemical reaction, which might be induced oxygen atom radicals formed at the surface of catalyst from ozone decomposition.
Fabrication and Operation Testing of an Air-cored Pulse Transformer for Charging a High Voltage Pulse Forming Line
Jin, Yun-Sik ; Kim, Young-Bae ; Kim, Jong-Soo ; Ryoo, Hong-Je ; Cho, Chu-Hyun ; Rim, Geun-Hee ; Lim, Soo-Won ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 939~944
A high voltage air-cored helical strip/wire type pulse transformer has been fabricated for charging of a high voltage pulse forming line. As a primary coil, copper strip of 25mm width was wound helically around a MC nylon cylinder. For a secondary coil, copper enameled wire of 1mm diameter was wound around conical cylinder in order to provide insulation between two windings. The coupling coefficient of 0.53 was obtained when two coils were combined coaxially in the insulation oil filled chamber. Voltage gain and energy transfer efficiency were investigated by varying the parameters of primary and secondary circuit. Test results shows that the voltage gain increases up to 17 with increasing the primary capacitance up to 200nF. And highest energy transfer efficiency of 44% was obtained when the dual resonant operation condition was nearly satisfied. The pulse transformer developed in this study can be used for charging the middle conductor of a Blumlein pulse forming line.
A New Robust Variable Structure Controller for Uncertain Affine Nonlinear Systems with Mismatched Uncertainties
Lee, Jung-Hoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 945~949
In this paper, a systematic design of a new robust nonlinear variable structure controller based on state dependent nonlinear form is presented for the control of uncertain affine nonlinear systems with mismatched uncertainties and matched disturbance. After an affine uncertain nonlinear system is represented in the form of state dependent nonlinear system, a systematic design of a new robust nonlinear variable structure controller is presented. To be linear in the closed loop resultant dynamics, the linear sliding surface is applied. A corresponding control input is proposed to satisfy the closed loop exponential stability and the existence condition of the sliding mode on the linear sliding surface, which will be investigated in Theorem 1. Through a design example and simulation study, the usefulness of the proposed controller is verified.
A MIMO VSS with an Integral-Augmented Sliding Surface for Uncertain Multivariable Systems
Lee, Jung-Hoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 950~960
In this paper, a multi-input multi-output(MIMO) integral variable structure system with an integral-augmented sliding surface is designed for the improved robust control of uncertain multivariable system under the matched persistent disturbance. To effectively remove the reaching phase problems, the integral augmented sliding surface is proposed. Then for its design, the eigenstructure assignment technique is introduced to. To guarantee the designed performance against the persistent disturbance, the stabilizing control for multi-input system is also designed to generate the sliding mode on the integral sliding surface. The stability of the global system together with the existence condition of the sliding mode are investigated and proved for the case of multi input system in the presence of uncertainty and disturbance. The reaching phase is completely removed in proposed MIMO VSS by satisfying the two requirements. An example and computer simulations will be present for showing the usefulness of algorithm.
On the Design of a Finite Time Reduced Order Observer
Lee, Kee-Sang ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 961~965
A reduced order observer with finite time convergence characteristics is proposed for linear time invariant systems. The proposed finite time reduced order observer(FTROO) is a dual observer scheme in which two reduced order Luenberger observers with asymptotic convergence characteristics and a finite time delay element are employed. The FTROO can be constructed so as to converge in the designer specified finite time independent of the eigenvalues of the reduced order observers. A numerical example is given to show the finite-time convergence characteristics of the proposed FTROO.
Adaptive Observer for a System with Sinusoidal Disturbance in Measurement Output
Son, Young-Ik ; Kim, In-Hyuk ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 966~971
An adaptive state observer is presented for a class of LTI systems that have a sinusoidal disturbance in the measurement output. Adaptation rules are developed for identifying the unknown sinusoidal disturbance signal from the system output. For the application of the identification result to the state estimation problem, the sinusoidal signal with arbitrary initial phase has been considered in this paper. In order to test the performance of proposed algorithm, comparative computer simulations have been carried out with an existing robust observer. The simulation results show the effectiveness of the proposed method.
The Design of Optimized Fuzzy Cascade Controller: Focused on Type-2 Fuzzy Controller and HFC-based Genetic Algorithms
Kim, Wook-Dong ; Jang, Han-Jong ; Oh, Sung-Kwun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 972~980
In this study, we introduce the design methodology of an optimized type-2 fuzzy cascade controller with the aid of hierarchical fair competition-based genetic algorithm(HFCGA) for ball & beam system. The ball & beam system consists of servo motor, beam and ball, and remains mutually connected in line in itself. The ball & beam system determines the position of ball through the control of a servo motor. Consequently the displacement change of the position of the moving ball and its ensuing change of the angle of the beam results in the change of the position angle of a servo motor. The type-2 fuzzy cascade controller scheme consists of the outer controller and the inner controller as two cascaded fuzzy controllers. In type-2 fuzzy logic controller(FLC) as the expanded type of type-1 fuzzy logic controller(FLC), we can effectively improve the control characteristic by using the footprint of uncertainty(FOU) of membership function. The control parameters(scaling factors) of each fuzzy controller using HFCGA which is a kind of parallel genetic algorithms(PGAs). HFCGA helps alleviate the premature convergence being generated in conventional genetic algorithms(GAs). We estimated controller characteristic parameters of optimized type-2 fuzzy cascade controller applied ball & beam system such as maximum overshoot, delay time, rise time, settling time and steady-state error. For a detailed comparative analysis from the viewpoint of the performance results and the design methodology, the proposed method for the ball & beam system which is realized by the fuzzy cascade controller based on HFCGA, is presented in comparison with the conventional PD cascade controller based on serial genetic algorithms.
Structural Design of FCM-based Fuzzy Inference System : A Comparative Study of WLSE and LSE
Park, Wook-Dong ; Oh, Sung-Kwun ; Kim, Hyun-Ki ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 981~989
In this study, we introduce a new architecture of fuzzy inference system. In the fuzzy inference system, we use Fuzzy C-Means clustering algorithm to form the premise part of the rules. The membership functions standing in the premise part of fuzzy rules do not assume any explicit functional forms, but for any input the resulting activation levels of such radial basis functions directly depend upon the distance between data points by means of the Fuzzy C-Means clustering. As the consequent part of fuzzy rules of the fuzzy inference system (being the local model representing input output relation in the corresponding sub-space), four types of polynomial are considered, namely constant, linear, quadratic and modified quadratic. This offers a significant level of design flexibility as each rule could come with a different type of the local model in its consequence. Either the Least Square Estimator (LSE) or the weighted Least Square Estimator (WLSE)-based learning is exploited to estimate the coefficients of the consequent polynomial of fuzzy rules. In fuzzy modeling, complexity and interpretability (or simplicity) as well as accuracy of the obtained model are essential design criteria. The performance of the fuzzy inference system is directly affected by some parameters such as e.g., the fuzzification coefficient used in the FCM, the number of rules(clusters) and the order of polynomial in the consequent part of the rules. Accordingly we can obtain preferred model structure through an adjustment of such parameters of the fuzzy inference system. Moreover the comparative experimental study between WLSE and LSE is analyzed according to the change of the number of clusters(rules) as well as polynomial type. The superiority of the proposed model is illustrated and also demonstrated with the use of Automobile Miles per Gallon(MPG), Boston housing called Machine Learning dataset, and Mackey-glass time series dataset.
Hybrid Retrieval Machine for Recognizing 3-D Protein Molecules
Lee, Hang-Chan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 990~995
Harris corner detector is commonly used to detect feature points for recognizing 2-D or 3-D objects. However, the feature points calculated from both of query and target objects need to be same positions to guarantee accurate recognitions. In order to check the positions of calculated feature points, we generate a Huffman tree which is based on adjacent feature values as inputs. However, the structures of two Huffman trees will be same as long as both of a query and targets have same feature values no matter how different their positions are. In this paper, we sort feature values and calculate the Euclidean distances of coordinates between two adjacent feature values. The Huffman Tree is generated with these Euclidean distances. As a result, the information of point locations can be included in the generated Huffman tree. This is the main strategy for accurate recognitions. We call this system as the HRM(Hybrid Retrieval Machine). This system works very well even when artificial random noises are added to original data. HRM can be used to recognize biological data such as proteins, and it will curtail the costs which are required to biological experiments.
VLC Wireless Data Transmission of High Luminance LED Irradiated by the High Dose-Rate Gamma-Ray
Cho, Jai-Wan ; Choi, Young-Soo ; Hong, Seok-Boong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 996~1000
In order to apply VLC (visible light communication) in harsh environment of nuclear power plant in-containment building, the high luminance LEDs, which are key components of the VLC system, have been gamma irradiated at the dose rate of 4 kGy/h during 72 hours up to a total dose of 288 kGy. The radiation induced coloration effect in the high luminance LED bulb made of acryl or plastic material was observed. In the VLC wireless data transmission experiment using the high luminance LEDs irradiated by high dose rate gamma-ray, the radiation induced coloration effect of the high luminance LED bulb extended the communication distance compared to non-irradiated LEDs.
Nonlinear ANC using a NPVSS-NLMS algorithm and online modelling of an acoustic linear feedback path
Seo, Jae-Beom ; Nam, Sang-Won ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 1001~1004
Acoustic feedback and background noise variation can degrade the performance of an active noise control (ANC) system. In this paper, nonlinear ANC using a non-parametric VSS-NLMS (or NPVSS-NLMS) algorithm and online feedback path modeling is proposed, whereby the conventional linear ANC with online acoustic feedback-path modeling is further extended to nonlinear Volterra ANC with a linear acoustic feedback path. In particular, the step-size of the NPVSS-NLMS algorithm is controlled to reduce the effect of background noise variation in the ANC system. Simulation results demonstrate that the proposed approach yields better nonlinear ANC performance compared with the conventional nonlinear ANC method.
Filter Calibration using Self Oscillation of Biquad RC Filter
Ahn, Deok-Ki ; Hwang, In-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 5, 2010, Pages 1005~1009
This paper presents a digitally-controlled filter calibration technique for biquad RC filter using self oscillation. The biquad RC filter is converted to a fully-differential ring oscillator by changing its resistor connections, where the oscillation frequency reflects the cut-off frequency. The proposed calibration circuit measures the oscillation frequency by counting with a fixed higher-frequency clock and then tunes it to a desired frequency with a digital frequency-locked loop including a PI controller. Because the proposed circuit directly measures the cut-off frequency of the filter itself and calibrates it with the small area digital circuits, the area and the power consumption are much small compared with conventional works. When it is implemented in a 65nm CMOS process, the calibration circuit except the filter consumes the area of 80um X 50um and power consumption is 443uA at 1.2 V supply voltage.