• Title/Summary/Keyword: So Chong

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Improvement the Junction Temperature Measurement System Considering the Parasitic Capacitance in LED (LED 기생 커패시턴스를 고려한 접합온도 측정 시스템의 개선)

  • Park, Chong-Yun;Yoo, Jin-Wan
    • Journal of Industrial Technology
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    • v.29 no.B
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    • pp.187-191
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    • 2009
  • Recently, we have used LEDs to illumination because it has a high luminous efficiency and prolong lifespan. However the light power and lifetime is reduced by junction temperature increment of LED. So it is important to measure the junction temperature accurately. In case of using a electrical method measuring junction temperature of LED. Temperature measurement errors are spontaneously generated because of a parasitic capacitances in LED. In this paper, we proposed a method that reducing LED's parasitic capacitance effects for electrical measurement. It was demonstrated by the experimental result that is more correct than established method.

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Open Trade Technical Model using ebXML for FTA with China and Korea

  • Jung, Yong Gyu;Kang, Min Soo;Jung, Ga-Woon;Cha, Kwang Seung;Chong, Agatha
    • International Journal of Advanced Culture Technology
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    • v.2 no.1
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    • pp.25-29
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    • 2014
  • China and South Korea have effectively reached a free trade agreement. The deal now faces legal and parliament reviews in the two countries. We need to discuss the recommendations on XML conversion with UN / CEFACT electronic documents. To solve this problem of interworking between these standards, Two kinds of translation rules is proposed for exchanging to UN / CEFACT Tag smoothly. For development and distribution of electronic documents to be conformed to international standards, it is enough to have the role of international activities continue to supply part of the domestic industry and the trends in participation and international standard. Our principal focus is on facilitating national and international transactions, through the simplification and harmonization of processes, procedures and information flows, and so contributing to the growth of global commerce. The agreement with South Korea will be China's ninth bilateral FTA.

Design of autopilot for a guided missile using model reference adaptive control (기준모델 적응제어에 의한 유도 비행체의 자동조종장치 설계에 관한 연구)

  • Lim, Ho;Park, Jeong-Il;Kim, Won-kyu;Park, Chong-Kug
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.499-502
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    • 1989
  • This paper is concerned with the stability analysis and the design of an auto pilot using direct model reference adaptive control for BTT missile with unknown dynamics when subjected to the longitudinal and lateral gusts. A motion of BTT missile can be separated into the longtudinal and lateral motione. The proposed algorithm is introduced different leakage terms about each motion into adaptation so as to prevent drift of the adaptive gain and alleviate gust effects and cross-coupling. The algorithm is applied to the 6DOF motion of an EMRAAT missile.

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A Preprocess of Channel Routing for Gate Arrays (게이트 어레이의 채널 배선을 위한 전처리)

  • Kim, Seung-Youn;Lee, Keon-Bae;Chong, Jong-Wha
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.5
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    • pp.145-151
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    • 1989
  • A new preprocess technique is presented which can improve the routing efficiency in the gate array layout designs. In order to resolve the cycle problem in the detailed routing, we exchange the logically equivalent pins in each channel. The signal nets are divided, and doubly connected signal net components are removed, so that the increase in the number of tracks can be controlled.

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Bandwidth Tracing Arbitration Algorithm for Mixed-Clock Systems with Dynamic Priority Adaptation

  • Kwon, Young-Su;Kyung, Chong-Min
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.959-962
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    • 2003
  • At the processing capabilities and operating frequency of embedded system are growing, so is the needed data bandwidth to fully utilize the processing capability. The ability to transfer huge amount of data between the embedded core and external devices is required for efficient system operation. In this paper, the data communication architecture for the mixed-clock system is proposed. The dynamic priority adaptation algorithm for bus arbitration is proposed for bandwidth guarantee. The communication architecture that incorporates the proposed arbitration algorithm adapts the priority of communication components dynamically based on the information from FIFO. The experiments show that the measured bandwidth of each component traces the required bandwidth well compared to the other arbitration algorithms

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A New Dynamic Analysis of 6-3 Stewart Platform Manipulator (6-3 스튜워트 플랫폼 운동장치의 운동방정식 해석)

  • Kim, Nak-In;Lee, Chong-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.11
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    • pp.1820-1828
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    • 2001
  • The dynamics of the 6-3 Stewart platform manipulator (SPM) is newly derived based on the kinematic relations particularly developed fur the SPM. The essence of the analysis is to deal with three subsystems of the SPM, each consisting of the command and feedback line links associated with two joined neighboring actuators. The dynamics of the command and feedback line links are first formulated using Lagrange and Newton-Euler method and then combined to derive the dynamic equations of motion fur the SPM. The derived nonlinear equations of motion are so computationally effective that it can be easily applied to real-time high-speed tracking control of 6-3 SPM.

Robust Design and Tolerancing for the Performance Improvement of Stabilized Mirror System under Vehicle Vibration (차량진동에 대한 안정거울장치의 성능향상을 위한 강건설계 및 공차할당)

  • Lee, Chong-Won;Jeong, Ho-Seop;Sohn, Seok-Man
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.5
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    • pp.859-869
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    • 1997
  • In this paper, the robust design and tolerancing of the stabilized mirror is performed to increase its stabilization performance under vehicle vibration. Based on the sensitivity analysis, the seven important control factors are first identified, and then the optimal as well as robust values in the sense of Taguchi method are obtained. Finally, the tolerances associated with each design variables are determined based on a successive sensitivity analysis of the simulated system response so that the deviation in the response from the target value meets the specification requirements. The proposed tolerancing method features that it is a robust but conservative design method and that the computational effort is much less than the Monte Carlo simulation method.

A Study on the Vowel lengthening and a Morphophonological Interpretatipon for its function (홀소리 길이의 늘어짐(Vowel lengthening)의 기능 및 형태음운론적 해석)

  • Kim, Chong-Dok
    • Proceedings of the KSPS conference
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    • 2005.04a
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    • pp.9-13
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    • 2005
  • The aim of this paper is to analyze the vowel lengthening in Korean, whose function is distinctive in the word's level. In this paper, I examined two acoustic parameters : vowel length and formants(F1 and F2) to distinguish or to identify the long vowel and his short correspondant, for exemple, /a:/ and /a/. According to the results of experimental analysis and to the discussion on the vowel length's relation and its influence to Korean phonological system, I considered a vowel lengthening as a prosodeme, so as a prosodic element in Korean phonological system.

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Identification of Dynamic Stiffness of Squeeze Film Damper using Active Magnetic Bearing System as an Exciter (자기베어링 시스템을 가진지로 이용한 스퀴즈 필름 댐퍼의 동강성 계수 규명)

  • Kim, Keun-Joo;Lee, Chong-Won
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.342.1-342
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    • 2002
  • In this work, the dynamic characteristics of an oil-lubricated, short SFD with a central feeding groove are derived based on a theoretical analysis considering the effect of a groove. The validity of the analysis is investigated experimentally using an Active Magnetic Bearing (AMB) system as an exciter. For the theoretical solution, the fluid film forces of a grooved SFD are analytically derived so that the dynamic coefficients of a SFD are expressed in terms of its design parameters. (omitted)

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Anodic Oxidation of Iodate to Periodate by Lead Peroxide Anode (전착과산화납양극에 의한 옥소산염 전해산화)

  • Chong Woo Nam;Hak Joon Kim
    • Journal of the Korean Chemical Society
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    • v.15 no.6
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    • pp.324-329
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    • 1971
  • In order to evaluate the mechanism of electrolytic oxidation of iodate and to determine the optimum conditions for the electrolysis, studies were made using the cells without diaphragm and the lead peroxide anode. Results are summarized as followings: 1) Current density vs. anode potential curve by lead peroxide electrode had the different limiting current densities from platinum electrode and was more positive than platinum electrode. 2) Additions of potassium bichromate in the electrolyte contribute to maintain high current efficiency. 3) In the acid and alkaline regions, the current efficiencies decreased by reduction of iodate and discharge of hydroxyl ion, so maximum current efficiency was shown at pH 7. 4) Higher current density lowered the current efficiency in the region of 60-80% conversion of iodate. 5) Influence of the conversion on current efficiency in the region of 60-80% conversion of iodate.

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