• Title/Summary/Keyword: 전속도

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Performance Improvement of Reduced Order Extended Luenberger Observer(ROELO) based Sensorless Vector Control Fed by Matrix Converter With Non-linearity Modeling (비선형모델을 이용한 matrix convertor로 구동되는 축소차원 확장 루엔버거 관측기기반의 유도전동기 센서리스 벡터제어의 성능개선)

  • Lee Kyo-Beum
    • The Transactions of the Korean Institute of Power Electronics
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    • v.10 no.4
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    • pp.363-372
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    • 2005
  • This paper presents an improved sensorless vector control system for high performance induction motor drives fed by a matrix converter with non-linearity compensation. The nonlinear voltage distortion that is caused by commutation delay and on-state voltage drop in switching devices is corrected by a new matrix converter model. A Reduced Order Extended Luenberger Observer (ROELO) is employed to bring better response in the whole speed operation range and a method to select the observer gain is presented. Experimental results are shown to illustrate the performance of the proposed system.

A Conceptual Design of the Dual-Mode Propulsion System for a Geosynchronous Communication Satellite (이중모드시스템을 적용한 정지궤도 통신위성 추진시스템 개념설계)

  • 박응식;김정수;양군호;김중표
    • Journal of the Korean Society of Propulsion Engineers
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    • v.4 no.4
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    • pp.98-106
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    • 2000
  • A conceptual design of propulsion system for a geosynchronous communication satellite with 12 years design life is presented in this paper. Propellant mass budget for the design life is calculated using total velocity increment ($\Delta$V) flowed-down from mission requirement analysis. Sizes of the fuel and oxidizer tank are derived based on the calculated propellant mass budget, and mass of the pressurant as well as the size and Pressure of pressurant tank are calculated too. Thruster positioning, number of rocket engines, and position of tank are determined through trade-off study with Structure & Mechanical Subsystem. Propulsion system configuration and its schematics are presented finally.

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A Study of Method to Use Meta Information for Wireless Internet Services (무선 인터넷 서비스를 위한 베타정보 활용 방안연구)

  • 김시중;김경석
    • Proceedings of the Korea Multimedia Society Conference
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    • 2001.11a
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    • pp.71-75
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    • 2001
  • WAF의 등장으로 무선 인터넷 서비스의 발전은 급속도로 진행되고 있으며 찬선 단막기와 무선인터넷 전속 및 서비스 제공 기술의 발전은 유선 인터넷의 거의 모든 분야를 무선 인터넷으로 옮겨오고 있다. 하지만 휴대용 전화기나 PDA, 휴대폰 등 무선 단말기는 계산 및 저장 능력, 화면 크기 등에서 기존의 인터넷 호스트에 비해 많은 제약 사항을 가지고 있어서 각종 서비스들을 사용자에게 제공하기가 까다롭다. 따라서 본 논문에서는 무선 단말기에서 데이터를 요구할 때 제공되는 메타정보를 이용하여 사용자의 단말기에 적절한 페이지의 제공과 사용자 인증을 해결하는 방안들을 제안하여 열악한 유저 인터페이스와 느린 전송속도를 보완하여 사용자에게 편의를 제공하고자 한다.

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Centralized Backoff Control Scheme for CDMA S-ALOHA System (CDMA S-ALOHA 시스템에서 중앙 집중형 백오프 제어 기법)

  • 임인택
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.11a
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    • pp.441-444
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    • 2003
  • 본 논문에서는 CDMA S-ALOHA 시스템에서 단말기들의 공평한 패킷 전송을 보장하기 위한 중앙 집중형 백오프 기법을 제안하고 이에 대한 성능을 분석한다. 전용 코드 방식의 CDMA 시스템에서는 각 단말기들이 고유의 확산코드를 이용하여 패킷을 전송하므로 패킷 충돌로 인한 전송 실패는 없는 반면, 다원 전속 간섭에 의한 비트 오류가 패킷 전송의 실패 요인이 된다. 제안한 기법에서는 기지국이 망의 부하에 따라 단말기들의 백오프를 위한 확률을 계산하여 방송하고, 단말기에서는 이를 기반으로 패킷 전송을 시도한다.

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A study on the idle speed control under load disturbance (변동에 강인한 공회전속도 제어에 관한 연구)

  • 최후락;장광수
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1115-1119
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    • 1996
  • The objective of this paper is to study on the idle speed control sing the fuzzy logic controller under load disturbance. The inputs of the fuzzy controller are error of rpm and rpm variation. The output of fuzzy controller is an ISC motor step. The airflow is controlled by the ISC motor movement and the idle speed is controlled by the airflow control. During the control, air to fuel ratio was checked by LAMBDA sensor. All experiments were carried in real vehicle.

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문화와 경쟁(II) : 노예계약? 스타변심?

  • 서헌제
    • Journal of Korea Fair Competition Federation
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    • no.117
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    • pp.2-7
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    • 2005
  • 연예계에 있어서 강자와 약자의 지위는 고정된 것이 아니라 대중의 인기라는 매우 불안정한 상황에 의존한다. 그러므로 연예인 매니지먼트 전속계약의 효력에 대해서는 단순히 강자와 약자라는 고착화된 논리로서 접근할 것이 아니라 기획사와 소속 연예인들 간에 상생이라는 관점에서 신인발굴에서부터 훈련 그리고 스타로서 뜬 이후의 상황 등을 종합적으로 고려하여 그 불공정성 여부를 가려내어야 할 것이다. 그리고 이러한 종합적인 기준에 기초해서 당사자간에 합당한 계약조항을 표준계약이나 표준약관의 형식으로 제정하여 보급하는 것도 분쟁의 예방에 있어서 좋은 방법이 될 것이다.

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People Inside - 에드워드 권(Edward Kwon, 이케이푸드 대표)

  • Jang, Seong-Yeong
    • KOREAN POULTRY JOURNAL
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    • v.45 no.3
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    • pp.88-90
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    • 2013
  • 세계 최고의 7성급 명품 호텔 두바이 버즈알아랍 수석총괄주방장으로 활약했던 한국인 요리사가 있다. 에드워드 권(본명 권영민) 셰프는 내로라하는 세계 유명 셰프들 가운데 요리실력 만큼은 최고로 인정받아 스타 셰프로 부상했다. 몇 년 전 해외활동을 접고 귀국해 각종 방송 개인 사업으로 바쁜 와중 (주)체리부로 전속모델로 활약하며 명품 닭고기를 홍보하는 그. 진공저온요리라고 일컫는 수비드(Sous Vide) 조리법을 사용하면서 기름기 없는 닭가슴살을 부드럽게 요리해 고객들이 입맛을 사로잡을 수 있다고 말한다. 월간양계 People Inside 코너를 통해 만난 그와의 인터뷰 내용을 정리했다.

Maximum Torque Control of IPMSM with Adoptive Leaning Fuzzy-Neural Network (적응학습 퍼지-신경회로망에 의한 IPMSM의 최대토크 제어)

  • Chung, Dong-Hwa;Ko, Jae-Sub;Choi, Jung-Sik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.5
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    • pp.32-43
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    • 2007
  • Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. This paper proposes maximum torque control of IPMSM drive using adaptive learning fuzzy neural network and artificial neural network. This control method is applicable over the entire speed range which considered the limits of the inverter's current and voltage rated value. This paper proposes speed control of IPMSM using adaptive learning fuzzy neural network and estimation of speed using artificial neural network. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The proposed control algorithm is applied to IPMSM drive system controlled adaptive learning fuzzy neural network and artificial neural network, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper proposes the analysis results to verify the effectiveness of the adaptive learning fuzzy neural network and artificial neural network.

The Spatial Restructuring and Changes of Locational Pattern of Auto Parts Industry in Korea (자동차 부품산업의 공간적 재구조화와 입지 패턴 변화)

  • Kim, Tae-Whan
    • Journal of the Korean Geographical Society
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    • v.42 no.3 s.120
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    • pp.434-452
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    • 2007
  • The globalization of the economy has strengthened competition in all industries. Facing an intensely competitive environment, the firm's choice of location is one of the most important strategies in enhancing its competitiveness. This paper aims to examine the locational changes and the spatial restructuring of suppliers firm with regard to modularization and customer diversification which result from the process of assembler's restructuring after the financial crisis. Some experimental findings which have been identified throughout this study can be summarized as follows: First, a number of suppliers has been located in the southern Seoul metropolitan area and northern Chungcheong area. And Hyundai's suppliers has been enlarged in the Seoul metropolitan area and Kia's in the Southeastern area. Second, suppliers who transact with several assemblers(network trade) tend to be more dispersed, but dedicated(exclusive) suppliers are more concentrated on assembly plants. Also it was confirmed that 'JIS(Just In Sequence)' system which is more detailed than 'JIT(Just In Time)'system has been used. Third, it was Prominent that suppliers are internalizing in order to reach economies of scale compare to assemblers are externalizing.

A Study on the Estimation Method of EHP of Fishing Boats Use Statistical Regression Analysis (통계적 회귀계수를 이용한 어선의 유효 마력 추정법에 관한 연구)

  • Lee, Guen-Moo;Park, Jai-Woung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.31 no.2
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    • pp.199-209
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    • 1995
  • From the results of model tests, statistical regression analysis of EHP estimation based on hull form parameters is adopted in this study. From this result, the method for estimation of EHP at the initial design stage of fishing boats is developed. This method is applied to four standard fishing boats with chine lines and two standard fishing boats with round bottom. The EHP's are estimated and compared to experimental results. In the case of six fishing boats, the estimated EHP corresponds well and approximates well with experimental results through out all the range tested. From these results it can be concluded that this numerical method is very efficient in estimating EHP of fishing boats having chine line and round bottom. Therefore, by applying the proposed method to design of fishing boats, we can improve the resistance characteristics. Further, this method can contribute to reduction of design time and thus down the total expenses.

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