• Title/Summary/Keyword: Surge Control

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A Simulation of Lightning Faults Reducing Effects on the 154 kV Transmission Tower by Auxiliary Grounding (보조접지선 시공에 의한 송전선로의 내뢰성 향상효과 모의)

  • Kwak, Joo-Sik;Shim, Jeong-Woon;Shim, Eung-Bo;Choi, Jong-Gi
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1843-1846
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    • 1997
  • This paper describes the fault reducing effects of the 154 kV transmission tower by auxiliary grounding from the top of the tower to ground. The grounding surge impedance of the auxiliary grounding system is calculated by CDEGS(:Current Distribution Electromagnetic Interference Grounding and Soil Structure Analysis), and the critical lightning back flashover current and arcing horn dynamic characteristics are simulated by EMTP/TACS(:Electromagnetic Transient Program/Transient Analysis of Control Systems). The calculated results of total LFOR(Lightning Flashover Rate) shows that the LFOR can be reduced from 5.2(count/100km. year) to 3.4 by auxiliary grounding on the 154 kV transmission tower with one ground wire shielding system.

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Development of a Remotely Operated Aerial Robot-kit based on the Balloon (풍선기반 원격조종 공중로봇키트 개발)

  • Kim, Hyun-Sik
    • The Journal of Korea Robotics Society
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    • v.7 no.3
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    • pp.216-221
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    • 2012
  • Recently, although the need of marine robots being raised in extreme areas, the basis is very deficient. Fortunately, as the robot competition is vitalizing and the need of the robot education is increasing, it is desirable to establish the basis of the R&D and industrialization of marine robots and to train professionals through the development and diffusion of marine robot kits. However, in conventional case, there is no remotely operated aerial robot-kit based on the balloon for the marine robot competition, which has the abilities of the airborne locomotion and obstacle avoidance. To solve this problem, an aerial robot-kit which has the abilities of the airborne locomotion and remote control, is developed. To verify the performance of the developed kit, test and evaluation such as surge, yaw and pitch is performed. The test and evaluation results show that the possibility of the real applications of the developed kit.

Simulation Study on Dynamic Analysis of Spring Type Needle Valve to Absorb Surge Pressure in Pneumatic Cushion Cylinder (공압 쿠션 실린더의 충격압 흡수를 위한 스프링형 니들밸브의 동특성에 관한 연구)

  • Lee J.G.;Xiaofei Qin;Lee J.;Lee J.C.;Shin H.M.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.2 no.1
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    • pp.15-22
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    • 2005
  • The purpose of this study is to find the effective dynamic characteristics of an improved pneumatic cushion cylinder with a spring type needle valve. The dynamic model represented the peak pressure control method when the pneumatic cushion cylinder is moving forward or backward in the horizontal direction. It was found from the simulation results that the peak pressure in the cushion chamber is affected by the spring, which helps to understand the performance of the pneumatic cushion cylinder and to improve or design a better cushion needle valve component. From the simulation results, the stability of pneumatic cushion cylinder with a spring type needle valve was superior and its cushion capability was also better than that without the spring.

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The Role of Hippo Pathway in Cancer Stem Cell Biology

  • Park, Jae Hyung;Shin, Ji Eun;Park, Hyun Woo
    • Molecules and Cells
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    • v.41 no.2
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    • pp.83-92
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    • 2018
  • The biological significance and deregulation of the Hippo pathway during organ growth and tumorigenesis have received a surge of interest in the past decade. The Hippo pathway core kinases, MST1/2 and LATS1/2, are tumor suppressors that inhibit the oncogenic nuclear function of YAP/TAZ and TEAD. In addition to earlier studies that highlight the role of Hippo pathway in organ size control, cell proliferation, and tumor development, recent evidence demonstrates its critical role in cancer stem cell biology, including EMT, drug resistance, and self-renewal. Here we provide a brief overview of the regulatory mechanisms of the Hippo pathway, its role in cancer stem cell biology, and promising therapeutic interventions.

Carbonization Behavior due to Surface Tracking (연면 트래킹에 의한 탄화 거동)

  • Jung, Yeon-Ha;Jang, Tae-Jun;Shong, Kil-Mok;Roh, Young-Su;Kwak, Hee-Ro
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.2
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    • pp.28-33
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    • 2007
  • In this paper, we are studied on the direction and formation of carbonized conductive path according to surface leakage current between electrodes. The characteristics of the tracking as surface is broken down between exposed live parts. Using the HSIS(high speed imaging system. 100,000[fps], redlake ltd., USA), it took photographs by arc growth mechanism occurred in on/off surge, ground fault and discharge between electrodes. Then the results was analyzed. Hereafter, it expected effects that application of energy utility technology through the arc control.

The direction and formation of carbonized conductive path according to surface leakage between electrodes (전극간 표면누설에 의한 탄화도전로의 생성과 방향성)

  • Shong, Kil-Mok;Han, Woon-Ki;Lee, Ki-Yoen;Kwak, Hee-Ro
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1525-1526
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    • 2006
  • Electrical current always travels through the minimum resistance path. In this paper, we are studied on the direction and formation of carbonized conductive path according to surface leakage between electrodes. The analysis of characteristics of the arc discharge as surface is broken down between exposed live parts. Using the HSIS(high speed imaging system, 100,000fps, redlake ltd., USA), it took photographs by arc growth mechanism occurred in on/off surge, ground fault and discharge between electrodes. Therefore, it recommended for results of technology development and application such as theoretic verification of an arc direction and economic security according to a technology about connecting arc generation in surfaces of insulators. Hereafter, it expected effects that application of energy utility technology through the arc control.

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Modeling and Development of an Integrated Controller for a Ship with Propellers and Additional Propulsion Units (프로펠러와 부가추력장치를 갖는 특수선의 모델링 및 통합제어기 개발)

  • Kim Jong Hwa;Lim Jae Kwon;Lee Byung Kyul
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.2
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    • pp.236-242
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    • 2005
  • Dynamic Positioning(DP) system maintains ship's position (fixed location or predetermined track) exclusively by means of CPPs and thrusters. To generate the control input adequate to various situation an integrated controller for CPPs and thrusters is required. The integrated controller is composed of a thrust calculation algorithm and a thrust allocation algorithm. The thrust calculation algorithm generates thrusts in the surge direction and the sway direction from the desired forward and lateral speed and generates a moment about the yaw axis from desired heading angle. The thrust allocation algorithm allocates the generated thrusts and moment to each CPP and thruster. Computer simulations are executed to confirm the effectiveness of the suggested controller.

Design of Automatic Distribution System (자동화 물류시스템에 대한 설계)

  • Shim, Jae-Hwe;Lee, Dong-Hyuk;Kim, Eun;Kim, Su-Hyun;Lee, Jun-Ha
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.420-421
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    • 2009
  • According as the industry develops recently, the import and export freight amount is increasing sharply, but physical distribution processing equipment ability had achieved conveyance, surge and setup of physical distribution by human's labor ability. This study intends to discuss the Design of Automatic Distribution System. Study is consisted hardware structure and software control system.

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Design of Automatic Distribution System (자동화 물류시스템에 대한 설계)

  • Shim, Jae-Hwe;Lee, Dong-Hyuk;Kim, Eun;Kim, Su-Hyun;Lee, Jun-Ha
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.900-901
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    • 2009
  • According as the industry develops recently, the import and export freight amount is increasing sharply, but physical distribution processing equipment ability had achieved conveyance, surge and setup of physical distribution by human's labor ability. This study intends to discuss the Design of Automatic Distribution System. Study is consisted hardware structure and software control system.

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Representation of small passenger ferry maneuvering motions by practical modular model

  • Wicaksono, Ardhana;Hashimoto, Naoya;Takahashi, Tomoyasu
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.57-64
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    • 2021
  • Maneuvering motions of a ship in calm water are studied through the concept of MMG model. Governing forces are defined by the use of available empirical formulae that require only main ship particulars as input variables. In order to validate the calculation tool, a full-scale sea experiment was carried out in Osaka Bay using a 17-m twin-screw passenger ferry. Test execution and data measurement were performed through the utilization of an autopilot control unit and satellite compass. The result of a straight running test confirms the acceptable accuracy in addressing the surge motion problem. Reasonable agreement between simulation and experiment is also confirmed for 5°/5° and 10°/10° zig-zag tests despite the strong environmental disturbance. The current model can generally represent the subject ship maneuvering motions and is promising for the application to other ship hulls.