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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 56, Issue 12 - Dec 2007
Volume 56, Issue 11 - Nov 2007
Volume 56, Issue 10 - Oct 2007
Volume 56, Issue 9 - Sep 2007
Volume 56, Issue 8 - Aug 2007
Volume 56, Issue 7 - Jul 2007
Volume 56, Issue 6 - Jun 2007
Volume 56, Issue 5 - May 2007
Volume 56, Issue 4 - Apr 2007
Volume 56, Issue 3 - Mar 2007
Volume 56, Issue 2 - Feb 2007
Volume 56, Issue 1 - Jan 2007
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A Method for Optimal Location of Feeder Tie Switches for Improving Equal Load of Electric Power Equipment in Distribution Automation System
Lim, Il-Hyung ; Lim, Seong-Il ; Choi, Myeon-Song ; Lee, Seung-Jae ; Shin, Chang-Hoon ; Ha, Bok-Nam ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 821~828
This paper proposes a new algorithm to find optimal location of open switches connecting feeders in distribuion system. In order to enhance power system reliability by minimizing outage area in case of fault, the load balance among the facilities such as transformers and feeders is considered to optimize. The combination of optimal position of normal open switches can be found by moving tie along the direct path connecting two feeders related to the open switch while the whole optimization problem is separated into many small problems. The proposed algorithm is shown by case study results that, it is simple and takes short calculation time to apply to the DAS (Distribution Automation System) in KEPCO (Korea Electric Power Cooperation).
Analysis of Oscillation Modes in Discrete Power Systems Including GTO Controlled STATCOM by the RCF Method
Kim, Deok-Young ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 829~833
In this paper, the RCF method is applied to analyze small signal stability of power systems including GTO controlled parallel FACTS equipments such as STATCOM. To apply the RCF method in power system small signal stability problems, state transition equations of generator, controllers and STATCOM are presented. In eigenvalue analysis of power systems, STATCOM is modelled as the equivalents voltage source model and the PWM switching circuit model. As a result of simulation, the RCF method is very powerful to calculate the oscillation modes exactly after the switching operations, and useful to analyze the small signal stability of power systems with periodically operated switching devices such as STATCOM.
Synchronous Generator Protective Algorithm using Wavelet Transform of Fault Currents
Park, Chul-Won ; Shin, Myong-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 834~840
A generator plays an important role in transferring an electric power to power system networks. The generator protection systems in Korea have been imported and operated through a tum-key from overseas entirely. Therefore, a study of the generator protection field has in urgent need for a stable operation of the imported goods, and for preparation of next generation protection system. The paper describes the fault detection algorithm using WT(Wave!et Transform) of currents for a generator protection. The fault current signals after executing a terminal fault modeling collect using a MA TLAB package, and calculate the wavelet coefficients through the process of a multi -level decomposition (MLD). The proposed algorithm for a fault detection using the Daubechies WT (wavelet transform) was executed with a C language for the command line function and for the real time realization after analyzing MATLAB's graphical interface. The advanced technique had complemented the defects of a DFT by applying a Daubechies WT. and had improved faster a speed and more accurate of fault discriminant than a conventional DFR.
A Study on the Stability of Micro-Grid System Considering Operating Range of Micro-Sources
Son, Kwang M. ; Lee, Kye B. ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 841~847
This paper deals with the micro-grid consisting of micro-sources which adopt voltage sourced inverters with independent real and reactive power control capability for providing premium power quality. This paper presents dynamic modeling and the stable operating range of the micro-grid system varying the parameters of the micro-sources. The fundamental frequency model of the micro-source inverters are considered to form a dynamic model of the micro-grid system. Stability analysis is performed based on the linearized dynamic model of the micro-grid system. Case study results show the parameters affecting the stability of the micro-grid and the stable operating range of the micro-sources.
The Estimation of Incomplete Information in Electricity Markets by Using Load Pattern Changes
Shin, Jae-Hong ; Lee, Kwang-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 848~853
This paper presents a methodology of estimating incomplete information in electricity markets for analyzing the gaming behavior of Generating Companies (GENCOs). Each GENCO needs to model its opponents' unknown information of strategic biddings and cost functions. In electricity markets with complete information, each GENCO knows its rivals' payoff functions and tries to maximize its own profit at Nash equilibriurnl Nli) by acknowledging the rivals' cost function. On the other hand, in the incomplete information markets, each GENCO lacks information about its rivals. Load patterns can change continuously due to many factors such as weather, price, contingency, etc. In this paper, we propose the method of the estimation of the opponents' cost function using market price, transaction quantities. and customer load patterns. A numerical example with two GENCOs is illustrated to show the basic idea and effectiveness of the proposed methodology.
A Protection Algorithm Discriminating Between Internal and External Faults for Wind Farms
Kwon, Young-Jin ; Kang, Sang-Hee ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 854~859
A wind farm consists of many wind generator(WG)s therefore, it is generally a complex power system. A wind farm as a distributed generation(DG) affects utility power system. If a conventional protection schemes are applied, it is difficult to detect faults correctly and the schemes can't provide proper coordination in some cases. This paper presents a protection algorithm for a wind farm which consists of a looped collection circuit. Because the proposed algorithm can distinguish between an internal fault and an external fault in a wind farm, The proposed algorithm can disconnect the faulted section in a wind farm. This algorithm is based on an overcurrent protection technique with the change of the ratio of the output current of a generator to the current of the looped line connected to each generator to collect the each generator's power. In addition, operating time of the algorithm is shortened by using the voltage drop at a generator collection point. The performance of the proposed algorithm was verified under various fault conditions using PSCAD/EMTDC simulations.
Rotor Pole Shape Design for Reducing a Cogging Torque in Spoke Type BLDC Motor
Hwang, Kyu-Yun ; Rhee, Sang-Bong ; Yang, Byoung-Yull ; Kwon, Byung-Il ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 860~868
In this paper. design of spoke type BLDC motor which have a characteristics of concentrating fluxes and relatively high reluctance torque among IPM BLDC motors has been researched. To reduce cogging torque and torque ripple. rotor pole shape of optimal design is proposed. To clearly see the effects due to the changed rotor pole shape. magnetic circuit model. 2D FEM and design of experiments (DOE) are used. Then considering these results proper rotor pole shape which have an good effect on air gap flux density and cogging torque. back-emf is designed. Moreover. the validity of proposed model in this paper is also verified by comparison between gained experiment and analysis data.
Experimental Measurement of Magnetic Properties of a Toroidal-type Bulk Electrical Steel using B-waveform Control
Eum, Young-Hwan ; Koh, Chang-Seop ; Hong, Sun-Ki ; Shin, Pan-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 869~875
Magnetic properties of electrical steel are, in general. measured by using Epstein frame or single sheet tester (SST). These methods, however, require very strict regulation of a specimen in its size and shape. thus, can not be easily applied to various types of specimen. On the other hand, a ring-test method, which measures only the isotropic properties, can be easily applied to most cases because it requires a toroidal-type specimen of arbitrary size. This method, especially, is considered as an unique available method for a bulk-type specimen. In this paper, a ring-test method is developed, and applied to the measurement of magnetic properties of a bulk-type electrical steel with a toroidal-type specimen. In the measurement, the magnetic properties and iron losses are measured and compared with each other at the both sinusoidal magnetic flux density and sinusoidal magnetic field intensity conditions under 0.2Hz and 60Hz alternating magnetic fields excitation. Through experimental measurements, a sinusoidal magnetic flux density condition is proven appropriate for the measurement of magnetic properties, including iron loss characteristics, of electrical steels.
Study on the Distortion of Detecting Signals with the Multi-Defects in Magnetic Flux Leakage System
Seo, Kang ; Kim, Dug-Gun ; Han, Jea-Man ; Park, Gwan-Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 876~883
The magnetic flux leakage(MFL) type nondestructive testing(NDT) method is widely used to detect corrosion, defects and mechanical deformation of the underground gas pipelines. The object pipeline is magnetically saturated by the magnetic system with permanent magnet and yokes. Hall sensors detect the leakage fields in the region of the defect. The defects are sometimes occurred in group. The accuracy of the detecting signals in this defect cluster become lowered because of the complexity of the defect cluster. In this paper, the effects of the multi -defects are analyzed. The detecting signals are computed by 3-dimensional finite element method and compared with real measurement. The results say that, rather than the size of the defects, the effects of the relative position of the multi-defects are very important on the detecting signals.
Efficiency Characteristics of Half-bridge Series Resonant Converter for the Contact-less Power Supply
Lee, Hyun-Kwan ; Song, Hwan-Kook ; Kim, Eun-Soo ; Kim, Yoon-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 884~891
Comparing with the conventional transformer without the air gap, a contact-less transformer with the large air-gap (4.8cm) between the long primary winding and the secondary winding has the increased leakage inductance and the reduced magnetizing inductance. By the increased leakage inductance and the reduced magnetizing inductance on the primary of the contact-less transformer, a good deal of the primary current circulates through magnetizing inductance, which results in a massive loss and the high voltage gain characteristics for load variations in contact-less power supply (CPS). To consider these characteristics, in this paper, the efficiency characteristics of the contact-less power supply using a series resonant converter is presented, described and verified through theoretical analysis, computer simulation and experimental test of 2.5kW prototype.
The Output Characteristics Analysis by Cut-off Frequency Set-up of the LCR Filter on NPC Multi-Level Inverter with Trap-Filter
Kim, Soo-Hong ; Kim, Yoon-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 892~897
This paper presents the output filter design and the output characteristic analysis by cut-off frequency set up of the LCR filter on NPC multi-level inverter with trap-filter. The single-phase NPC three-level inverter operates at low switching frequency. The proposed LC trap filter is comprised of a conventional LCR output filter, by using LC trap filter the need for high damping resistor and low LC cut-off frequency is eliminated. Also. low damping resistor is increased the output filter system. The multilevel inverter system used NPC type inverter in proper system for high power application and controller is used DSP(TMS320C31). The effectiveness of proposed system confirmed the validity through SPICE simulation and experimental results.
Characteristic Analysis of Multi-Phase Interleaved Boost Converter in Discontinuous Inductor Current Mode
Jang, Eun-Sung ; Chung, Se-Kyo ; Shin, Hwi-Beom ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 898~904
This paper presents the generalized and explicit expressions for evaluating the performance of the multi-phase interleaved boost converter (IBC) operating in discontinuous inductor current mode (DICM). The full order averaged model is derived. The generalized transfer functions of interest are presented and the dynamic characteristics are analyzed. The generalized analysis of converter performance is verified through the experimental and simulation results.
The Natural Cooling Effects of Pre-heated Substrate during RF Magnetron Sputter Deposition of ZnO
Park, Sung-Hyun ; Lee, Neung-Hun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 905~909
Crystalline and micro-structural characteristics of ZnO thin films which were deposited on p-Si(100) with cooling naturally down of pre-heated substrate during RF magnetron sputter deposition, were investigated by XRD and SEM in this paper. The film which was prepared on the substrate which was pre-heated to
before deposition and then cooled naturally down during deposition, showed the most outstanding c-axis preferred orientation. The ZnO thin film having the best crystalline result were applied to SMR type FBAR device and resonance properties of the device were investigated by network analyzer. It showed that resonance frequency was 2.05 GHz, return loss was -30.64 dB, quality factor was 3169 and electromechanical coupling factor was 0.4 %. This deposition method would be very useful for application of surface acoustic wave filter or film bulk acoustic wave resonator.
Electrical Characteristics for Different Width of Dye-sensitized Solar Cell with Pt Electrode Deposited by Sputtering Methode
Song, Keun-Ju ; Choi, Jin-Young ; Hong, Ji-Tae ; Kim, Mi-Jeoung ; Se, Hyun-Woong ; Lee, Dong-Yoon ; Kim, Hee-Je ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 910~914
Recently, a study on the energy conversion efficiency and up sizing' technology of dye-sensitized solar cell (DSC) which is focused in considering a new alternative solar cell has been executed. But consideration for the cell characteristics about an internal electronic flow on a large-scaled DSC has not been carried out yet. In this study, we have chosen a solar cell width as a variable of a large-scaled DSCs and confirmed electric characteristics of an individual cell. First, Pt counter electrode surface of DSC is deposited by RF sputtering methode and the electrochemical properties of Pt electrodes was investigated by cyclic -voltammetry. With the Pt electrode, we fabricated DSC samples of different width. As a result, the higher the internal resistance of DSC becomes, the wider the width gets. Internal resistance makes it difficult to collect photoelectron generated from dye. Ultimately up sizing DSC causes the increase of internal resistance and then has a bad effect on the cell characteristics.
Fabrication of AIN-based FBAR Devices by Using a Novel Process and Characterization of Their Frequency Response Characteristics in terms of Various Electrode Metals
Kim, Bo-Hyun ; Park, Chang-Kyun ; Park, Jin-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 915~920
AIN-based film bulk acoustic resonator (FBAR) devices which adopt a membrane-type configuration such as Mo/AIN/bottom-metal/Si are fabricated by employing a novel process. The proposed resonator structure does not require any supporting layer above the substrate, which leads to the reduction in energy loss of the resonators. For all the FBAR devices, the frequency response characteristics are measured and the device parameters, such as return loss and input impedance, are extracted from the frequency responses, and analyzed in terms of the various metals such as Al. Cu, Mo, W used in the bottom-electrode. The mass-loading effect caused by the used bottom-electrode metals is found to be the main reason for the difference revealed in the measured characteristics of the fabricated FBAH devices. The results obtained in this study also show that the degree of match in lattice constant and thermal expansion coefficient hetween piezoelectric layers and electrode metals is crucial to determine the device performance of FEAR.
Gas Removal Characteristics of Air Clean System Applying a Magnetic Field
Shin, Soo-Youn ; Moon, Jae-Duk ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 921~925
Gas removal characteristics of an air clean system, consisted of a filter and a nonthermal discharge plasma reactor with a magnetic field, have been investigated with emphasis on the enhancing gas removal efficiency of the applied magnetic field. It is found that the magnetic field influenced significantly to the corona discharge characteristics, decreasing the corona onset voltage and increasing the corona current. As a result, the proposed air clean system with the magnetic field showed the higher removal efficiency of the gas (e.g., trimethlyamine) than that of without the magnetic field. This would be because the magnetic field applied to the discharge plasma reactor of the air clean system can elevate the corona characteristics, and activate the generation of ozone, thus the removal efficiency of the gas was concurrently enhanced. This reveals that the proposed air clean system with the magnetic field could be used as an effective means of removal an indoor pollutant gas.
On-Site Evaluation Technique of Current Transformer Comparator System
Jung, Jae-Kap ; Lee, Sang-Hwa ; Kwon, Sung-Won ; Kang, Jeon-Hong ; Kim, Myung-Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 926~932
A recently developed methods for on-site calibration of the current transformer (CT) comparator system have been reviewed in the paper. The method utilizes several traveling standards, which consist of the CT, non-reactive standard resistors, wide ratio error CT, and shunt resistors. The traveling CT is used for absolute evaluation of a standard CT belonging to industry. The non-reactive standard resistors and a wide ratio error CT are used for the linearity check of errors in the current comparator. The shunt resistors are used for evaluation of CT burden of industry.
Effect of a Cylindrical Third Electrode of a Point-Plate Type Plasma Reactor on Corona Discharge and Ozone Generation Characteristics
Moon, Jae-Duk ; Jung, Ho-Jun ; Jung, Jae-Seung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 933~937
A point plate type nonthermal plasma reactor, with a grounded cylindrical third electrode which closely- encompasses the needle point, have been investigated with an emphasis on the role of the third electrode. It was found that the point plate airgap, with the grounded third electrode, had a switching characteristic on its I V characteristics for negative and positive discharges, which is very different from that of a conventional point plate airgap without a third electrode. The corona discharge and ozone generation characteristics of the plasma reactor with the grounded cylindrical third electrode, such as the corona onset voltage. the breakdown voltage. the corona current. and the amount of output ozone, were influenced significantly by the height of the third electrode. and these characteristics can be controlled by adjusting the height of the third electrode.
Energy Conversion Efficiency Improvement of Piezoelectric Micropower Generator Adopting Low Leakage Diodes
Kim, Hye-Joong ; Kang, Sung-Muk ; Kim, Ho-Seong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 938~943
In this paper, we show that, in case of piezoelectric micropower generator, just replacing Schottky diodes in the bridge rectifier with ultra-low reverse leakage current diodes improves the mechanical-to-electrical energy conversion efficiency by more than 100%. Experimental and PSPICE simulation results show that, due to the ultra-low leakage current, the charging speed of the circuit employing PAD1 is higher than that of the circuit employing Schottky diodes and the saturation voltage of the circuit employing PAD1 is also higher. This study suggests that , when the internal impedance of source is very large (a few tens of
) such that maximum charging current is a few microamperes or less, in order to realize literally the energy scavenging system, ultra-low reverse leakage current diodes should be used for efficient energy conversion. Since low-level vibration is ubiquitous in the environment ranging from human movement to large infrastructures and the mechanical-to-electrical energy conversion efficiency is much more critical for use of these vibrations, we believe that the improvement in the efficiency using ultra-low leakage diodes, as found in this work, will widen greatly the application of piezoelectric micropower generator.
A Design of Adaptive Controller with Nonlinear Dynamic Friction Compensator for Precise Position Control of Linear Motor System
Lee, Jin-Woo ; Cho, Hyun-Cheol ; Lee, Young-Jin ; Lee, Kwom-Soon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 944~957
In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it and other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstopping control method.
A New Anti Sway Control for Container Crane Using PSD Camera and Propellers
Choe, Yeon-Wook ; Lee, Hyung-Ki ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 958~965
The spreaders on container cranes are usually controlled to stop at the same time as their trolleys are stopped. Despite the use of adequate control systems, however, the spreaders usually have comparatively large sway movements, due to their suspension from the trolleys through cables. It is, therefore, important to accurately measure the attitudes of the spreaders, in order to suppress such sways by means of secondary control. Until now, most of conventional anti sway control systems focus on the direct control of the movements of trolleys. which seems not suitable to speed up the entire process - loading and unloading of containers. In this paper, we suggest a new anti sway control system: By using extra equipments - two propellers to suppress the sway and a PSD camera to measure the spreader's attitude - installed on the spreader and the trolley. the sway of the suspended load j, considerably suppressed. The effectiveness of the proposed scheme is verified by the computer simulation and experiment with the miniature of the container crane system.
Position Control of Nonlinear Crane Systems using Dynamic Neural Network
Han, Seong-Hun ; Cho, Hyun-Cheol ; Lee, Kwon-Soon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 966~972
This paper presents position control of nonlinear three-dimensional crane systems using neural network approach. Such crane system generally includes very complicated characteristic dynamics and mechanical framework such that its mathematical model is expressed by strong nonlinearity. This leads difficulty in control design for the systems. We linearize the nonlinear system model to construct PID control applying well-known linear control theory and then neural network is utilized to compensate system perturbation due to linearization. Thus, control input of the crane system is composed of nominal PID and neural output signals respectively. Our method illustrates simple design procedure, but system perturbation and modelling error are overcome through a neural compensator. As well. adaptive neural control is constructed from online learning. Computer simulation demonstrates our control approach is superior to the classic control systems.
Development of a 3-Dimensional Measurement System using Laser Vision
Kwon, Hyo-Geun ; Chun, Young-Seok ; Suh, Young-Soo ; Ro, Young-Shick ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 973~979
A laser vision system is developed to measure the three-dimensional feature of an object. This system consists of two low cost cameras and a cross laser. One camera and a cross laser are used to measure a plane equation of an object. Using this information, the other camera measures a hole size of an object. The proposed system provides 0.05 mm accuracy measurement systems with relatively low cost.
Test Methodology for Multiple Clocks Single Capture Scan Design based on JTAG IEEE1149.1 Standard
Kim, In-Soo ; Min, Hyoung-Bok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 980~986
Boundary scan test structure(JTAG IEEE 1149.1 standard) that supports an internal scan chain is generally being used to test CUT(circuit under test). Since the internal scan chain can only have a single scan-in port and a single scan-out port; however, existing boundary test methods can not be used when multiple scan chains are present in CUT. Those chains must be stitched to form a single scan chain as shown in this paper. We propose an efficient boundary scan test structure that adds a circuit called Clock Group Register(CGR) for multiple clocks testing within the design of multiple scan chains. The proposed CGR has the function of grouping clocks. By adding CGR to a previously existing boundary scan design, the design is modified. This revised scan design overcomes the limitation of supporting a single scan-in port and out port, and it bolsters multiple scan-in ports and out ports. Through our experiments, the effectiveness of CGR is proved. With this, it is possible to test more complicated designs that have high density with a little effort. Furthermore, it will also benefit in designing those complicated circuits.
A Digital Convergence Platform based on the MPEG-21 Multimedia Framework
Oh, Hwa-Yong ; Kim, Dong-Hwan ; Lee, Eun-Seo ; Chang, Tae-Gyu ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 987~989
This paper describes a digital convergence platform(DCP) which is implemented based on the MPEG-21 multimedia framework. DCP is a newly proposed solution in this research for the convergence service of future home multimedia environment. DCP is a common platform designed to have the feature of reconfigurability, by means of S/W. which supports to run diverse digital multimedia services. A distributed peer to peer service and transaction model is also a new feature realized in DCP using the MPEG-21 multimedia framework. A prototype DCP is implemented to verify its functions of multimedia service and transactions. The developed DCPs are networked with IP clustering storage systems for the distributed service of multimedia. Successful streaming services of the MPEG-2/4 video and audio are verified with the implemented test-bed system of DCP.
Gait-Event Detection using an Accelerometer for the Paralyzed Patients
Kong, Se-Jin ; Kim, Chul-Seung ; Moon, Ki-Wook ; Eom, Gwang-Moon ; Tack, Gye-Rae ; Kim, Kyeong-Seop ; Lee, Jeong-Whan ; Lee, Young-Hee ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 5, 2007, Pages 990~992
The purpose of this study is to develop a practical gait-event detection system which is necessary for the FES (functional electrical stimulation) control of locomotion in paralyzed patients. The system is comprised of a sensor board and an event recognition algorithm. We focused on the practicality improvement of the system through 1) using accelerometer to get the angle of shank and dispensing with the foot-switches having limitation in indoor or barefoot usage and 2) using a rule-base instead of threshold to determine the heel-off/heel-strike events corresponding the stimulation on/off timing. The sensor signals are transmitted through RF communication and gait-events was detected using the peaks in shank angle. The system could detect two critical gait-events in all five paralyzed patients. The standard deviation of the gait events time from the peaks were smaller when 1.5Hz cutoff frequency was used in the derivation of the shank angle from the acceleration signals.