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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 57, Issue 12 - Dec 2008
Volume 57, Issue 11 - Nov 2008
Volume 57, Issue 10 - Oct 2008
Volume 57, Issue 9 - Sep 2008
Volume 57, Issue 8 - Aug 2008
Volume 57, Issue 7 - Jul 2008
Volume 57, Issue 6 - Jun 2008
Volume 57, Issue 5 - May 2008
Volume 57, Issue 4 - Apr 2008
Volume 57, Issue 3 - Mar 2008
Volume 57, Issue 2 - Feb 2008
Volume 57, Issue 1 - Jan 2008
Selecting the target year
Applying Security Algorithms using Authentication Against Cyber Attacks in DAS Communication Network
Lim, Il-Hyung ; Choi, Myeon-Song ; Lee, Seung-Jae ; Lim, Seong-Il ; Lee, Sung-Woo ; Ha, Bok-Nam ; Hong, Sug-Won ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 327~335
As communication is becoming increasingly prevalent and especially communication architecture is more relying on the open standard communication protocols, the security issues become major concerns. In this paper we consider possible cyber attacks in the applications based on the current distribution communication architecture, and then derive the security goals. Next we propose how the security algorithms can be adapted to achieve these security goals. We intend to adapt the most efficient ways of secure message exchange, taking the resource-constrained FRTUs into account Finally we show some experiments to validate the protocols.
A Dynamic Characteristics on Non-linear Voltage Electric Equipment under Voltage Sag
Lee, Hyun-Chul ; Jeong, Sung-Won ; Gim, Jae-Hyeon ; Lee, Geun-Joon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 336~343
In this study, a transition of power quality was characterized by non-linear voltage electric equipments under voltage sag. The test was inputted voltage sag to IPC(Sag Generator) from AVR, and then to equipments by IPC which adjust voltage magnitude and duration. The load test which non-linear voltage electric equipments used PLC, Magnetic Contactor, SMPS, HID Lamp. The test result was different from each other according to a manufacturing companys, models, and equipments. PLC was greatly described to be stabilized voltage sag in case of no load then rated load. Magnetic Contactor was made a difference to phase angles on voltage sag, which was
. HPD Lamp was described to be stabilized the sodium lamp, and to be unstabilized the metal hailed lamp. The test result was showed CBEMA curve that stand for evaluated responsiveness of voltage sag. This study was tested description to dynamic characteristics on non-linear voltage electric equipment under voltage sag. There was hoped that power system designed the essential particulars.
Method for Safety-Decision to Apply International Standard Grounding Systems to Domestic Power System by Computer Simulation
Lee, Soon ; Kim, Jung-Hoon ; Park, Jung-Wook ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 344~353
To apply the appropriate new grounding system to domestic power system, safety has to be guaranteed under the given circumstances. It is not possible to decide the safety of grounding systems by the experimental test because safety experiments directly relate to the human life and the installed electric machines. Therefore, the computer simulation program to decide the safety of grounding systems based on the IEC standard systems, has to be developed. This paper proposes the computer simulation based method to decide the safety of grounding system with the concepts of touch voltage, step voltage, human resistivity, and applied electric current according to the several conditions of human body located in the corresponding grounding systems. The proposed method is implemented by Matlab/Simulink and Visual C++ programming tools for its visualization.
Transient Stability Analysis Based on OOP
Park, Ji-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 354~362
This paper presents the new method of power system transient stability simulation, which combines the desirable features of both the time domain technique based on OOP(Object-oriented Programming) and the direct method of transient stability analysis using detailed generator model. OOP is an alternative to overcome the problems associated with the development, maintenance and update of large software by electrical utilities. Several papers have already evaluated this approach for power system applications in areas such as load flow, security assessment and graphical interface. This paper applied the object-oriented approach to the problem of power system dynamics simulation. The modeling method is that each block of dynamic system block diagram is implemented as an object and connected each other. In the transient energy method, the detailed synchronous generator model is so-called two-axis model. For the excitation model, IEEE type1 model is used. The developed mothed was successfully applied to New England Test System.
Sensitivity Analysis of Power System Oscillation Modes Induced by Periodic Switching Operations of SVC by the RCF Method
Kim, Deok-Young ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 363~368
In this paper, the Resistive Companion Form(RCF) analysis method is applied to analyze small signal stability of power systems including thyristor controlled FACTS equipments such as SVC. The eigenvalue sensitivity analysis algorithm in discrete systems based on the RCF analysis method is presented and applied to the power system including SVC. As a result of simulation, the RCF analysis method is proved very effective to precisely calculate the variations of eigenvalues or newly generated unstable oscillation modes after periodic switching operations of SVC. Also the eigenvalue sensitivity analysis method based on the RCF analysis method enabled to precisely calculate eigenvalue sensitivity coefficients of controller parameters about the dominant oscillation mode after periodic switching operations in discrete systems. These simulation results are different from those of the conventional continuous system analysis method such as the state space equation and proved that the RCF analysis method is very effective to analyze the discrete power systems including periodically operated switching equipments such as SVC.
Estimation of Rebate Level for Energy Efficiency Programs Using Optimization Technique
Park, Jong-Jin ; So, Chol-Ho ; Kim, Jin-O ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 369~374
This paper presents the evaluation procedures and the estimation method for the estimation of optimal rebate level for EE(Energy Efficiency) programs. The penetration amount of each appliance is estimated by applying price function to preferred diffusion model resulted from model compatibility test. To estimate the optimal rebate level, two objective functions which express the maximum energy saving and operation benefit are introduced and by multi-objective function which can simultaneously consider two objective functions the optimal rebate level of each appliance is estimated. And then, using the decided rebate level and each penetration amount, the priority order for reasonable investment of each high-efficiency appliance is estimated compared to the results of conventional method. Finally, using a benefit/cost analysis based on California standard practice manual, the economic analysis is implemented for the four perspectives such as participant, ratepayer impact measure, program administrator cost and total resource cost.
Reduction and Analysis for Cogging Torque of Permanent Magnet Synchronous Generators with Multi-Pole Rotor for Wind Power Application
Jang, Seok-Myeong ; Lee, Sung-Ho ; Choi, Jang-Young ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 375~383
This paper deals with reduction and analysis of cogging torque for permanent magnet synchronous generators with multi-pole rotor for wind power applications. Open-circuit field solutions are derived using a magnetic vector potential and a two-dimensional (2-d) polar coordinate systems. On the basis of derived open-circuit field solutions and 2-d permeance functions, we also derive open-circuit field solutions considering stator slotting effects. By using open-circuit field solutions considering stator slotting effects and energy variation methods, this paper analytically predicts the cogging torque considering skew effects. All analytical results are shown in good agreement with those obtained from finite element (FE) analyses. In order to reduce the cogging torque, by predicting the variation of the cogging torque according to pole arc/pitch ratio using analytical and FE methods, pole arc/pitch ratio which makes the cogging torque minimum are determined. However, we confirm that measured value for cogging torque of the PMG with determined pole arc/pitch ratio is twice higher than predicted value. Therefore, the reason for an error between measured and predicted cogging torque is discussed in terms of a shape of PMs and is proved experimentally.
Fabrication and Test Results of an HTS Magnet with Pancake Windings Excited by Multiple Power Sources
Lee, K.Y. ; Hun, K.M. ; Lee, Y.S. ; Lee, H.J. ; Cha, G.S. ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 384~389
The cental magnetic field of an HTS magnet consisting of pancake windings can be increased if the magnet is excited by multiple power sources. Multiple power sources enable all pancake windings to conduct their critical currents. The HTS magnet consisting of pancake windings was excited by separate power sources in this paper. Critical currents of each pancake winding were determined by using optimization technique. Fabrication of the BSCCO magnet consisting of 10 pancake windings is described and test results of the BSCCO magnet are given. Central magnetic field and perpendicular magnetic field of the magnet excited by multiple power sources were compared with those of the magnet excited by a single power source.
A Study on the V-skew Model for Minimization of Detent Force and Lateral Force in PMLSM
Hwang, In-Cheol ; Jang, Ki-Bong ; Kim, Gyu-Tak ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 390~397
Permanent Magnet Linear Synchronous Motor (PMLSM) has high efficiency, high energy density, and high control-ability. But, the detent force always is produced by the structure of slot-teeth. There are the disadvantages such as noise and vibration of the apparatuses are induced and the control ability is curtailed because detent force acts as thrust ripple. Therefore, the detent force reduction is an essential requirement in PMLSM. Generally, the method, skewing permanent magnet or slot-teeth, is used to reduce the detent force. But the thrust is decreased at the same time. If permanent magnet is skewed, the lateral force which operates as the perpendicular direction of skew direction is generated in linear guide of PMLSM. So, V-skew model is proposed for the reduction of lateral force. The lateral force acts as braking force in linear motion guide, and it has bad influence to the characteristics of PMLSM. However, these problems will not be solved by 2-dimensional Finite Element Analysis (FEA). So, in this paper 3-dimensional FEA is applied to analyze the PMLSM where permanent magnet is skewed and has overhang. The detent force and thrust characteristics considering skew and overhang effects of permanent magnet are analyzed by 3-dimensional FEA and the results are compared with experimental values to verify the propriety of analysis.
Development of Distribution Superconducting Fault Current Limiter and its Monitoring System for Power IT Application
Park, Dong-Keun ; Seok, Bok-Yeol ; Ko, Tae-Kuk ; Kang, Hyoung-Ku ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 398~402
Recently, the development of superconducting fault current limiters (SFCLs) has been required as power demands increase in the power system. A distribution-level prototype resistive SFCL using coated conductor (CC) has been developed by Hyundai Heavy Industries Co., Ltd. and Yonsei University for the first time in the world. The ratings of the SFCL are 13.2kV/630A at normal operating condition. A novel non-inductive winding method is used in fabricating coils so there is almost zero impedance during normal operation. The distribution SFCL is cooled by sub-cooled liquid nitrogen
of 65K and 3 bar to enhance cryo-dielectric performance, critical current density, and thermal conductivity. In order to make reliable operation of an SFCL in real power systems, we monitored and controled its operation conditions by using supervisory control and data acquisition (SCADA) method. Thus, a monitoring system for the SFCL employing information technology (IT) is proposed and developed to be on the lookout for the operation conditions such as inside temperature, inside pressure,
level, voltage and current. Since operation temperature should be kept constant, bang-bang control for temperature feedback with a heater attached to the cold head of cryo-cooler is applied to the system. Short-circuit tests with prospective fault current of 10kA and AC dielectric withstand voltage tests up to 143kV for 1 minute were successfully performed at Korea Electrotechnology Research Institute. This paper deals with the development of a distribution level SFCL and its monitoring system for reliable operation.
The Gyro High Voltage Power Supply Design for Attitude Control in the Satellite
Kim, Eui-Chan ; Lee, Heung-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 403~408
The gyroscope is the sensor for detecting the rotation in inertial reference frame and constitute the navigation system together an accelerometer. As the inertial reference equipment for attitude determination and control in the satellite, the mechanical gyroscope has been used but it bring the disturbance for mass unbalance so the disturbance give a bad influence to the observation satellite mission because the mechanical gyroscope has the rotation parts. During the launch. The mechanical gyroscope is weak in vibration, shock and has the defect of narrow operating temperature range so it need the special design in integration. Recently the low orbit observation satellite for seeking the high pointing accuracy of image camera payload accept the FOG(Fiber Optic Gyro) or RLG(Ring Laser Gyro) for the attitude determination and control. The Ring Laser Gyro makes use of the Sanac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. It need the 1000V DC to create the He-Ne plasma in discharge tube. In this paper, the design process of the High Voltage Power Supply for RLG(Ring Laser Gyroscope) is described. The specification for High Voltage Power Supply (HVPS) is proposed. Also, The analysis of flyback converter topology is explained. The Design for the HVPS is composed of the inverter circuit, feedback control circuit, high frequency switching transformer design and voltage doubler circuit.
A New Optimal Design Method of the Electronic Ballast for MHL with Stable Run-up Current
Lim, Byoung-Loh ; Jang, Mog-Soon ; Lim, Ki-Seung ; Park, Chong-Yeun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 409~415
This paper proposed a new optimal design method of the electronic ballast with stable run-up current for Metal Halide lamp during the ignition condition. In order to avoid operation in the acoustic resonance frequency band and to supply the optimal ignition current without demage of inverter switching components during the ignition period, the values of the series inductor Ls, the series capacitor Cs, and the parallel capacitor Cp were determined by analysis of characteristics of inverter transfer function depend on Lamp operating power and resistance of ignition condition and steady state operating condition. For the prototype ballast for a 400W Metal Halide Lamp, experimental results are presented in order to validate the proposed method.
Signal Reflection Elimination Technique for Interconnects in Digital System
Sung, Bang-Hyun ; Noh, Kyung-Woo ; Baek, Jong-Humn ; Kim, Seok-Yoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 416~420
This paper proposes a new method to improve signal characteristics at branches frequently met in system-level routing. We also introduce the numerical formula which can estimate the time delay due to branches and the simple design guideline for system-level routing. Finally, we propose the routing method which can eliminate the signal reflection for the case of one driver and two receivers (multi-drop topology).
An Efficient Scheduling Method based on Dynamic Voltage Scaling for Multiprocessor System
Noh, Kyung-Woo ; Park, Chang-Woo ; Kim, Seok-Yoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 421~428
The DVS(Dynamic Voltage Scaling) technique is the method to reduce the dynamic energy consumption. As using slack times, it extends the execution time of the big load operations by changing the frequency and the voltage of variable voltage processors. Researches, that controlling the energy consumption of the processors and the data transmission among processors by controlling the bandwidth to reduce the energy consumption of the entire system, have been going on. Since operations in multiprocessor systems have the data dependency between processors, however, the DVS techniques devised for single processors are not suitable to improve the energy efficiency of multiprocessor systems. We propose the new scheduling algorithm based on DVS for increasing energy efficiency of multiprocessor systems. The proposed DVS algorithm can improve the energy efficiency of the entire system because it controls frequency and voltages having the data dependency among processors.
Effect of Metal Oxide of Ceramic Superconductor for Neutron beam Irradiation
Lee, Sang-Heon ; Choi, Yong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 429~432
Much studies have been concentrated to develop the fabrication technique for high critical current density but still there are a lot of gap which should be overcome for large scale application of superconducting materials at liquid nitrogen temperature. The improvement of the critical current can be achieved by forming the nano size defect working as a flux pinning center inside the superconductor. In this paper, the establishment of fabrication condition and additive effects of second elements were examined so as to improve the related properties to the practical use of superconductor.
Analyses on Current Densities Induced Inside a Worker Using AC Arc Welder
Park, Jun-Hyeong ; Min, Suk-Won ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 433~438
This paper analyses current densities induced inside a worker using AC arc welder. Applying the boundary element method, we calculate current densities induced in organs inside a worker in case he was located at 1cm, 3cm, 5cm, 10cm, 15cm, 20cm far from a power cable of AC arc welder. As results of study, we find a maximum current density induces at a heart surface and may be higher than
of ICNIRP guideline if he works within 15cm from a power cable.
Preliminary EMC Analysis between the COMS and the GEO Launch Vehicles
Kim, Eui-Chan ; Lee, Heung-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 439~445
In this paper, the preliminary EMC analysis process between the Communication, Ocean and Meteorological Satellite (COMS) and Geostationary Earth Orbit (GEO) launch vehicles in the frequency range [1MHz-47MHz] is described. The considered launch vehicles are arian V, sea Launch, land Launch, atlas III&V, delta IV, proton M/breeze M, soyuz, HII-A and Angara. The launch vehicle Radiated Emission (RE) specifications have been compared to COMS satellite Radiated Susceptibility (RS) limits. The COMS RS limits are the RS qualification levels of COMS units during launch. As a result, The radiated emission levels of arian V, sea launch, atlas III&V, delta IV, proton M/breeze M, HII-A and angara are compliant with COMS RS limits. The negative margins appear between land launch or soyuz launch vehicle RE and COMS RS. Then, if the land launch or soyuz is chosen by the customer, The tests should be performed at satellite level in order to demonstrate the compatibility with respect to launch vehicles specifications.
Fast Algorithm for Design of Spiral Inductor using Genetic Algorithm with Distributed Computing
Sa, Ki-Dong ; Ahn, Chang-Hoi ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 446~452
To design a spiral inductor a genetic algorithm is applied with fast computing technique. For the inductance extraction of the given geometry the fast multipole method is used, also the distributed computing technique using 10 personal computers is introduced for the massive computation of the genetic algorithm. A few important design parameters are used as genes for the optimization in the genetic algorithm. The target function is chosen as mean square error of the inductance at several sampling frequency points. A large-scaled inductor is fabricated and compared with the simulated data.
The Power Rating Design of Inductively Coupled Plasma Light Source and The Electrical Dependency Between Parameters
Kim, Hyun-Il ; Park, Dae-Hee ; Chang, Hong-Soon ; Baek, Soo-Hyun ; Yim, Youn-Chan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 453~457
We studied on the dependency of parameters which those were used to design a ballast of ICP light source. These parameters were derived from Barkhausen criterion equation about the oscillating condition of ballast. Comparing with a change of turns, we can suggest that a change of l is suitable to control a
of an ICP light source. According to the Z-l equation, we can find an optimum rating power of ICP light sources corresponding to l.
Non-fragile Guaranteed Cost Controller Design for Uncertain Time-delay Systems via Delayed Feedback
Kwon, Oh-Min ; Park, Ju-Hyun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 458~465
In this paper, we propose a non-fragile guaranteed cost controller design method for uncertain linear systems with constant delyas in state. The norm bounded and time-varying uncertainties are subjected to system and controller design matrices. A quadratic cost function is considered as the performance measure for the system. Based on the Lyapunov method, an LMI(Linear Matrix Inequality) optimization problem is established to design the controller which uses information of delayed state and minimizes the upper bound of the quadratic cost function for all admissible system uncertainties and controller gain variations. Numerical examples show the effectiveness of the proposed method.
Genetic Optimization of Fuzzy C-Means Clustering-Based Fuzzy Neural Networks
Choi, Jeoung-Nae ; Kim, Hyun-Ki ; Oh, Sung-Kwun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 466~472
The paper concerns Fuzzy C-Means clustering based fuzzy neural networks (FCM-FNN) and the optimization of the network is carried out by means of hierarchal fair competition-based parallel genetic algorithm (HFCPGA). FCM-FNN is the extended architecture of Radial Basis Function Neural Network (RBFNN). FCM algorithm is used to determine centers and widths of RBFs. In the proposed network, the membership functions of the premise part of fuzzy rules do not assume any explicit functional forms such as Gaussian, ellipsoidal, triangular, etc., so its resulting fitness values directly rely on the computation of the relevant distance between data points by means of FCM. Also, as the consequent part of fuzzy rules extracted by the FCM-FNN model, the order of four types of polynomials can be considered such as constant, linear, quadratic and modified quadratic. Since the performance of FCM-FNN is affected by some parameters of FCM-FNN such as a specific subset of input variables, fuzzification coefficient of FCM, the number of rules and the order of polynomials of consequent part of fuzzy rule, we need the structural as well as parametric optimization of the network. In this study, the HFCPGA which is a kind of multipopulation-based parallel genetic algorithms(PGA) is exploited to carry out the structural optimization of FCM-FNN. Moreover the HFCPGA is taken into consideration to avoid a premature convergence related to the optimization problems. The proposed model is demonstrated with the use of two representative numerical examples.
Fuzzy Inference for Idle Time Optimization of Hard Disk Drive
Jun, Jin-Wan ; Kim, Gyu-Taek ; Lee, Jee-Hyong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 473~479
Generally, HDDs are widely used as data storage device in office, home and mobile machineries. So, it is used for various applications or tasks, such as file copy, file download, music and movie play etc., in various environment. In spite of this kind of varieties in tasks and environment in which HDDs perform, most commercial HDDs hardly control its operations adaptively to these varieties. Thus, it is preferred to optimize the performance and energy consumption of HDDs according to the task and/or the environment. So, this paper proposes a new fuzzy inference algorithm which adaptively controls HDDs operations and may also easily be implemented as the firmware of HDDs and run in the restricted environment such as embedded systems.
Smart Adapted Service in Ubiquitous
Ahn, Ho-Seok ; Sa, In-Kyu ; Baek, Young-Min ; Ahn, Youn-Seok ; Choi, Jin-Young ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 480~487
In this paper, we propose a Smart Adapted Service which can manage a schedule automatically. Smart Adapted Service gives a notice beforehand regarding information associated with the schedule, by searching the Internet. If the user has written down the name of goods or food which he wants to buy, Smart Adapted Service finds the most suitable store nearby him using the user's favorite list. The user's favorite list is created by Outlook Web Access System by analysing the schedule and habits of the user. User can access Smart Document System remotely through the Internet using Outlook Web Access System. We developed an Auto AP Roaming System for seamless communication and Smart Document System for arranging the information. We evaluated the system and verified that it is convenient to use and working well.
Design and Implementation of the Dual-Mode Type Reliable PLC Modem Chip
Lee, Won-Tae ; Choi, Sung-Soo ; Yun, Sung-Ha ; Rhee, Young-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 488~493
This paper represents a dual-mode type transmission technique for a high reliable narrow-band power line communication(PLC) modem, and its design and implementation of a system-on-chip(SoC). The proposed transmission technique is based on a Chirp modulation for the purpose of overcoming time variations of power line channel environments in the narrow-bandwidth of the frequency range of 95-145.5 kHz. The designed modem is fabricated utilizing a mixed 0.18
CMOS technology. Especially, according to the power line channel environments the data transmission rate can be selectively changed into 2.5 kbps and 480 bps. The total hardware complexity of the implemented chip is about 50,000 gates, the power consumption is about 26mW, and the operating frequency is up to 5.12 MHz.
Analysis of Series Arc-Fault Signals Using Wavelet Transform
Bang, Sun-Bae ; Park, Chong-Yeun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 494~500
This paper presents the analyzed result of the series arc fault current by using the discrete wavelet transform. The series arcing is caused by a loose connection in series with the load circuit. The series arc current is limited to a moderate value by the resistance of the device connected to the circuit, such as an appliance or a lighting system. The amount of energy in the sparks from the series arcing is less than in the case of parallel arcing but only a few amps are enough to be a fire hazard. Therefore, it is hard to detect the distinctive difference between a normal current and a intermittent arc current. This paper, presents the variation of the ratio of peak values and RMS values of the series arc fault current, and proposes the novel series arc fault detecting method by using the discrete wavelet transform. Loads such as a CFL lamp, a vacuum cleaner, a personal computer, and a television, which has the very similar normal current with the arc current, were selected to confirm the novel method.
Adoption of MFER and HL7 Standard for Shared Electronic Medical Record
Kim, Hwa-Sun ; Park, Chun-Bok ; Hong, Hae-Sook ; Cho, Hune ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 501~506
Medical environments incorporate complex and integrated data networks to transfer vast amounts of patient information, such as images, waveforms, and other digital data. To assure interoperability of images, waveforms and patient data, health level seven(HL7) was developed as an international standard to facilitate the communication and storage of medical data. We also adopted medical waveform description format encoding rule(MFER) standard for encoding waveform biosignal such as ECG, EEG and so on. And, the study converted a broad domain of clinical data on patients, including MFER, into a HL7 message, and saved them in a clinical database in hospital. According to results obtained in the test environment, it was possible to acquire the same HL7 message and biosignal data as ones acquired during transmission. Through this study, we might conclude that the proposed system can be a promising model for electronic medical record system in u-healthcare environment.
Noise Reduction and Estimating the Similarity of Ambulatory ECG Signals
Shin, Seung-Won ; Lee, Jeong-Whan ; Lee, Kang-Hwi ; Kim, Dong-Jun ; Kim, Kyeong-Seop ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 507~513
In this study, we develope an ambulatory ECG acquisition system by implementing a patch-style and wireless electrode. To alleviate the inherent noisy characteristics of the mobile signal, we apply a matched filter and concurrently detect R-peak values. Moreover, the measure for resolving shape distance is computed to estimate the relative similarity between two ECG signals and to decide whether the abnormal characteristics in ECG exist or not.
A Development of Remote Medical Treatment System for Stroke Recovery using ZigBee-based Wireless Brain Stimulator and Internet
Kim, G.H. ; Ryu, M.H. ; Kim, J.J. ; Kim, N.G. ; Yang, Y.S. ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 514~517
Ubiquitous healthcare (U-healthcare) system is one of potential applications of embedded system. Conventional U-healthcare systems are used in health monitoring or chronic disease care based on measuring and transmission of various vital signs. However, future U-healthcare system can be of benefit to more people such as stroke patients which have limited activity by providing them proper medical care as well as continuous monitoring. Recently, an electric brain stimulation treatments have been found to be a better way compared to conventional ones and many are interested in using the method toward the treatment of stroke. In this study, we proposed a remote medical treatment system using ZigBee-based wireless electric brain stimulator that can help them to get a treatment without visiting their doctors. The developed remote medical treatment system connects the doctors to the brain stimulator implanted in the patients via the internet and ZigBee communication built in the brain stimulator. Also, the system receive personal information of the connected patients and cumulate the total records of electric stimulation therapy in a database. Doctors can easily access the information for better treatment planning with the help of graphical visualization tools and management software. The developed remote medical treatment system can extend their coverage to outdoors being networked with hand-held devices through ZigBee.
A Study of Position Control Performance Enhancement in a Real-Time OS Based Laparoscopic Surgery Robot Using Intelligent Fuzzy PID Control Algorithm
Song, Seung-Joon ; Park, Jun-Woo ; Shin, Jung-Wook ; Lee, Duck-Hee ; Kim, Yun-Ho ; Choi, Jae-Soon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 518~526
The fuzzy self-tuning PID controller is a PID controller with a fuzzy logic mechanism for tuning its gains on-line. In this structure, the proportional, integral and derivative gains are tuned on-line with respect to the change of the output of system under control. This paper deals with two types of fuzzy self-tuning PID controllers, rule-based fuzzy PID controller and learning fuzzy PID controller. As a medical application of fuzzy PID controller, the proposed controllers were implemented and evaluated in a laparoscopic surgery robot system. The proposed fuzzy PID structures maintain similar performance as conventional PID controller, and enhance the position tracking performance over wide range of varying input. For precise approximation, the fuzzy PID controller was realized using the linear reasoning method, a type of product-sum-gravity method. The proposed controllers were compared with conventional PID controller without fuzzy gain tuning and was proved to have better performance in the experiment
Comparison of Algorithms Estimating Linear Regression Line from Surface EMG Signals
Lee, Jin ; Kwon, Hyok-Mok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 57, issue 3, 2008, Pages 527~535
Many signal processing techniques have been described in the literature for estimating amplitude, frequency and duration variables of the surface EMG signal detected during constant voluntary contractions. They have been used in different application areas for the non-invasive assessment of muscle function. The main purpose of our research is to compare the most frequently used algorithms for information extraction from surface EMG signals under varying conditions in terms of the different window lengths, muscle contraction levels, muscles and subjects. In particular we focus on the issue of estimating the slope and intercept to resolve an linear regression line with utilizing real SEMG signals which represents voluntary contractions during thirty seconds.