• Title/Summary/Keyword: Control Transition

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Transition Zone Behavioral Characteristics with Increase the Speed of High Speed railroad (고속철도 열차 증속에 따른 접속부 거동특성 분석)

  • Park, Hyo-Sung;Kim, Nak-Seok;Kang, Yun-Suk
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1583-1593
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    • 2011
  • As we see the continuation of the increase in the speed of the High Speed railroad worldwide, there is a concern for a possible problem in the connecting transition zone in the railway infrastructure. Honam High Speed railroad's transition zone in the hub for the rotation structures and other supporting structures such as approach slab, sub slab, approach block, etc. Due to its increase in speed of the design speed, and its important role on the driving stability and credibility of the bearing ground performance, we must seek and fine a prevention plan for a cause of differential settlement, as well as the cause of the derailment. In this dissertation, domestic, as well as international design manuals and the applicability of the control standards are studied. Also through the study target, Honam High Speed railroad zone 4-1, we evaluated the connecting componant of the Yeon-Jeong bridge through the eigenvalue and weight transfer of the train when operated at 300km/h, 350km/h, 400km/h, 450km/h, and were able to achieve detailed assessment by checking track behaviors, looking at various components such as the rotation acceleration according to the inversion of the distance length, displace length, displacement and stress distribution. Through these studied, possibility of operating at 400km/h was evaluated based on the condition of the current design basis.

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The transition and medical system of Traditional Medicine in North Korea (북한 전통의학의 시대적 발전과정 및 의료체계)

  • Han, Chang-Hyun;Park, Sun-Hee;Shin, Mi-Suk;Choi, Sun-Mi
    • Korean Journal of Oriental Medicine
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    • v.13 no.2 s.20
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    • pp.37-45
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    • 2007
  • Background : The 'Korean Medicine' is the traditional medicine in Korea, which has preserved its homogeneous quality in the long historic period. But since 1945 when Korea was divided, the Korean Medicine has also been independently developed in South and North Korea. As a Result, it has lost its national homogeneity. Objective : In order to illuminate the past and an actuality of the transition and medical system of traditional medicine in North Korea. Method : Overview a preceding research paper and the various data of traditional medicine in North Korea. Result : 1. The name of North Korea traditional medicine from 'East medicine' was changed history with 'Korean medicine', It with the method which combines a traditional medicine and a Western medicine is endeavoring to modernization. 2. The administrative systems which take charge of the traditional medicine of North Korea are the organization which manages the Korean medicine and the Bureau of The Korean medicine production control. Also there is relation of the Bureau of the treatment prevention. 3. There are 8 medical colleges other than P'yongyang medical college. There is 6 years 6 months and 7 years 7 month follows in curriculum. Conclusions : It evaluated the past and an actuality of the transition and medical system of traditional medicine in North Korea.

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Zero-Voltage-Transition PWM DC-DC Converter Using A New Active-Snubber-Cell (새로운 액티브 스너버 셀을 적용한 ZVT PWM DC-DC 컨버터)

  • Tran, Hai N.;Naradhipa, Adhistira M.;Kim, Sun-Ju;Choi, Se-Wan
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.4
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    • pp.273-280
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    • 2018
  • This paper proposes a zero-voltage-transition pulse-width modulation (PWM) DC-DC converter that uses a new active-snubber-cell. The converter main switch can be turned on and off with ZVS, while the snubber switch is turned on with ZCS and turned off with ZVS. Other semiconductor devices are operated under the soft-switching condition. Normal PWM control can be used, the proposed active-snubber-cell does not impose any additional voltage and current stresses. The active-snubber-cell is suitable for high-power applications due to its easy integration into interleaved converters. This paper discusses the operation of the converter, presents some design guidelines, and provides the results of an experiment with a 100 kHz and 1 kW prototype. A peak efficiency of 97.8% is recorded.

A Visual Concurrent Programming Based on Extended State Transition Graph (확장 상태 전이 그래프에 기반을 둔 시각 병렬 프로그래밍)

  • Chung, Won-Ho;Hur, Hye-Jung
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.8
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    • pp.2430-2441
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    • 2000
  • A visual concurrent programming environment, called ESTGVP is designed and implemented, which is easy to understand, highly portable, and can represent parallel behaviors. For our purpose, a conventional state transition graph is extended so as to enable both of synchronous and asynchronous parallel operations. We call it extended state transition graph (ESTG). ESTGVP uses the ESTG and texts for programming, and makes it easy programming sequential and parallel behaviors. Also, it is easy to understand the control structure of a program because ESTGVP is a visual programming environment based on the graph. ESTGVP is written in Tel language and thus it is highly portable on various operating systems. It consists of three major components; edition, transformation and execution. If necessary, ESTG can be transformed into C or Tel language, and its execution is based on Tel.

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An Impact Analysis of Community Energy System (CES) on The Grid (지역 에너지 시스템(CommunityEnergysystem)의 개통 연계 운전 특성)

  • Park Y. U.;Kim K. H.;Jang S. I.
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.120-122
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    • 2004
  • This paper analyse impacts of Community Energy System (CES) on the grid during transition periods for integrating of the CES and the grid. In the near future, CES might be one of major energy supply structures. The basic concept of CES is that it supplies electrical and thermal energy to the local customer loads through the islanded power network separated from the grid. Therefore, the interconnection with the grid occurs only when the energy supply from the CES generators does not meet the demand of the local load. For avoiding impacting the grid during the transition operation modes of CES, it is necessary to thoroughly analyse the influences on the grid during those periods. In order to show them, in this paper, we model the CES with 2.34 WVA DG and simulate the impacts on the grid due to interconnection of CES The simulation results show that, in order to reduce bad influences of CES on the grid, CES need the efficient load management and generation control schemes during the transition periods.

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Liquid Crystal Based Optical Sensor for Imaging Trypsin Activity at Interfaces Between Aqueous Phases and Thermotropic Liquid Crystals

  • Zhang, Minmin;Jang, Chang-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.34 no.10
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    • pp.2973-2977
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    • 2013
  • In this study, we developed a liquid crystal (LC)-based optical sensor for monitoring enzymatic activity through orientational changes in liquid crystals (LCs) coupled to the properties of a poly-${\small{L}}$-lysine (PLL)-based polymeric membrane. We prepared a PLL-based polymeric membrane at the planar interface between the thermotropic liquid crystal and aqueous phases. The PLL-based polymeric membrane was obtained by contacting the PLL solution with water immiscible LCs, 4-cyano-4'-pentyl-biphenyl (5CB) doped with adipoyl chloride. We then investigated the membrane properties by examining the permeability of the membrane to phospholipids, 1,2-didodecanoyl-rac-glycero-3-phosphocholine (DLPC). The permeability of the membrane to transport phospholipids was monitored through the orientational transition of 5CB in contact with the dispersions of DLPC. Since trypsin can enzymatically catalyze the hydrolysis of PLL, we incubated an aqueous trypsin solution with the membrane for 2 h at room temperature to cause an increase in the permeability of the polymeric membrane to DLPC. As a result, a bright to dark optical shift of LCs was observed, which implied that an enzymatic reaction between trypsin and PLL-based membrane occurred. Two control experiments using chymotrypsin and bovine serum albumin (BSA) revealed no sign of improved permeability based on the orientational transition of LCs.

Color enhancement system Based on the improvement of Transition Time and color detdetion Stability (천이 시간 개선과 색검출 안정화 기반의 색 향상 시스템)

  • Lee, Eung-Joo
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.3
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    • pp.715-719
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    • 1998
  • In this paper, we propose a color enhancement system which is based on the improvement of transition time problem and specific color detection stability. The proposcd system apply the time difference correction step to corrects time difference which is taken place at the transimission process between color signal and color subcarrier signal and to reduce detection errors. And also, we proposed stability method to improve transition time problem and detection efficiency as the control of reference color. The proposed system controls specific color when the mean difference value of detected voltages greater than the value of minimum discriminate voltages of two adjacent color signals. Thus, the color enhancement system improves detection efficiency and controls specific color from the color signal without overlapping of correction range.

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Cooperative control of multiple mobile robots (다 개체 이동 로봇의 협동 제어)

  • 이경노;이두용
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.720-723
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    • 1997
  • This paper presents a cooperative control method for multiple robots. This method is based on local sensors. The proposed method integrates all information obtained by local perception through a set of sensors and generates commands without logical conflicts in designing control logic. To control multiple robots effectively, a global control strategy is proposed. These methods are constructed by using AND/OR logic and transition firing sequences in Petri nets. To evaluate these methods, the object-searching task is introduced. This task is to search an object like a box by two robots and consists of two sub-tasks, i.e., a wall tracking task and a robot tracking task. Simulation results for the object-searching task and the wall tracking task are presented to show the effectiveness of the method.

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Slices Method of Petri Nets Using the Transitive Matrix for Scheduling Analysis in FMS (유연생산 시스템 스케쥴링 분석을 위한 추이적 행렬을 이용한 패트리 넷의 분할)

  • Song, You-Jin;Kim, Jong-Wuk;Lee, Jong-Kun
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.4
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    • pp.292-298
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    • 2002
  • We focus on the slicing off some sub-nets using the transitive matrix. Control flows in the Petri nets is done based on the token flows. One control f]ow explains the independent tokens status and if the token-in divides into several tokens after firing a transition then the control flow divides to several flows, as well. Accordingly, we define that the basic unit of concur-rency (short BUC) is a set of the executed control flows based on the behavioral properties in the net. The BUC is S-invariant which has one control flow. We show the usefulness of transitive matrix to slice off some subnets from the original net based on BUC-through on an example.

Sensorless Vector Control for Maximum Torque of SynRM in the Field Weakening Region (약계자 영역에서 SynRM의 최대 토크제어를 위한 센서리스 벡터제어)

  • Lee, Jung-Chul;Chung, Dong-Hwa
    • Journal of the Korean Society of Safety
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    • v.17 no.2
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    • pp.32-38
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    • 2002
  • In this paper, a new approach for the SynRM(Synchronous Reluctance Motor) control which ensures producing MTPA(Maximum Torque per Ampere) over the entire field weakening region is presented. In addition, this paper presents a speed sensorless control scheme of SynRM using flux observer. Also, by adjusting the base speed for the field weakening operation according to the flux level, the current and voltage limit, the smooth and precise transition into the field weakening operation can be achieved. The validity of the proposed scheme is verified through simulation.