• Title/Summary/Keyword: Pivot

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A Study on the Modeling and Control of High-Speed/High-Accuracy Position Control System (고속/정밀 위치제어시스템의 모델인 및 제어에 관한 연구)

  • Park, Min-Gyu;Han, Chang-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.5
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    • pp.399-406
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    • 2001
  • This paper presents a dynamic modeling and a sliding mode controller for the high-speed/high-accuracy position control system. The selected target system is the wire bonder assembly which is used in the semiconductor assembly process. This system is a reciprocating one around the pivot point that consists of VCM(voice coil motor) as an actuator and transducer horn as a bonding tool. For the modeling elements, the sys-tem is divided into electrical circuit, magnetic circuit and mechanical system. Each system is modeled using the bond graph method and united into the full system. Two major aims are considered in the design of the controller. The first one is that the horn must track the given reference trajectory. The second one is that the controller must be realizable by using the DSP board. Computer simulation and experimental results show that the designed sliding mode controller provides better performance than the PID controller.

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유한 요소법을 이용한 중소하천 유역에서의 이동호우에 대한 유출특성 분석

  • Cho, Hyeon-Kyeong;Lee, Yeung-Hwa;Choi, Yun-Yeong
    • Journal of Environmental Science International
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    • v.7 no.4
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    • pp.415-424
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    • 1998
  • In the rainfalll-runoff relation, consideration of the spatial movement of storms is very unportant in designing a hydraulic structure or evaluating an environmental influence for land usage. Because of thins reason, this study has suggested the finite element model which consider the spatial movement of a storm and it was applied on a small river basin(Wi stream basin). In the application of the model, the basin was treated as a pivot point and the storms are simulated 10 movement in each directions. As a result, It shows that the storms moving from north to south have higher peak discharge and faster peak time than the storms moving in other directions. So these characteristics have to be considered In the designation of a hydraulic structure or evaluation of an environmental influence.

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Research about SMT Performance Improvement Through Automatic Corpus Expansion (말뭉치 자동 확장을 통한 SMT 성능 향상에 대한 연구)

  • Choi, Gyu-Hyun;Shin, Jong-Hun;Kim, Young-Kil
    • 한국어정보학회:학술대회논문집
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    • 2016.10a
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    • pp.296-299
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    • 2016
  • 현재 자동번역에는 통계적 방법에 속하는 통계기반 자동번역 시스템(SMT)이 많이 사용되고 있지만, 학습 데이터로 사용되는 대용량의 병렬 말뭉치를 수동으로 구축하는데 어려움이 있다. 본 연구의 목적은 통계기반 자동번역의 성능을 향상시키기 위해 기존 다른 언어쌍의 말뭉치와 SMT 자동번역 기술을 이용하여 대상이 되는 언어쌍의 SMT 병렬 말뭉치를 자동으로 확장하는 방법을 제안한다. 제안 방법은 서로 다른언어 B와 C의 병렬 말뭉치를 얻기 위해, A와 B의 SMT 자동번역 시스템을 구축하고 기존의 A-C 말뭉치의 A를 SMT를 통해 B로 번역하여 B와 C의 말뭉치를 자동으로 확장한다. 실험을 통해 확장한 병렬 말뭉치가 통계기반 자동번역 시스템의 성능을 향상시킬 수 있음을 확인한다.

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Pivot-based Bilingual Lexicon Extraction Using Word2Vec and CCA (중간언어 기반의 Word2Vec와 CCA를 이용한 이중언어 사전 추출)

  • Kim, Jeong-Tae;Kim, Chang-Hyun;Cheon, Min-Ah;Kim, Jae-Hoon;Kim, Jae-Hwan
    • 한국어정보학회:학술대회논문집
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    • 2016.10a
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    • pp.307-309
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    • 2016
  • 이중언어 사전은 자연어처리 분야에서 매우 유용한 자원으로 사용되고 있다. 그러나 초기사전이나 병렬말뭉치 등 자원이 부족한 언어 쌍에 대해서 이중언어 사전을 추출하는 것은 쉽지 않다. 이러한 문제를 해결하기 위해 본 논문에서는 중간 언어 기반으로 Word2Vec와 CCA를 이용하여 이중언어 사전을 추출하는 방법을 제안한다. 본 논문에서 제안하는 방법의 성능을 평가하기 위해서 중간언어로 영어를 사용하여 스페인어-한국어에 대한 이중언어 사전을 추출하는 실험을 하였다. 무작위로 뽑은 200개의 단어에 대한 번역 정확도를 구하였다. 그 결과 최상위에서 37.5%, 상위 10위에서 63%, 그리고 상위 20위에서는 69.5%의 정확도를 얻을 수 있었다.

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Development of the Injection Molded Ball Seat for Automobile Suspension (자동차 서스펜션용 볼 시트 사출성형품 개발)

  • Ye, Sang-Don;Min, Byeong-Hyeon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.4
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    • pp.50-56
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    • 2011
  • Injection molding process is one of the popular manufacturing methods to produce plastic parts with high efficiency and low cost. Ball seat for automobile suspension is made by an injection molding process as a part to support pivot function of ball joint consisted of ball stud and housing. It is necessary for a ball seat to have a dimensional stability in the three dimensional inner area to be contacted with ball stud. In this paper, the dimensional stability of inner surface is indirectly analyzed by checking the difference of inner diameter around the circumferential direction and the thickness variation at the top part of ball seat. Measurement was performed by using the coordinate measuring machine and the fixture to hold ball seat. Optimization of injection molding processes such as injection time, cooling time and temperatures of cylinder barrel was derived to reduce the difference of inner diameter and the thickness variation at the top part of ball seat based on the Taguchi method.

A Study on Situation Awareness of Helicopter Pilot (헬리콥터 조종사의 상황인식에 관한 연구)

  • Choi, Sung-Ho;Lee, Yeong-Heok;Choi, Yeon-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.15 no.1
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    • pp.54-60
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    • 2007
  • According to U.S. NTSB, from 1989 to 1992, Situation Awareness (SA) was a major factor causing 80% of all aircraft accidents in scheduled airlines. Therefore, the prevention of accidents through effective training in SA became a pivot in aviation safety. Furthermore, during the past 10 years, since all helicopter accidents in Korea were caused by the factors related to SA, an appropriate countermeasure has been required. This study, which uses survey data, examines various factors related to SA that could affect helicopter pilots. Recognition of and countermeasures for the factors in emergency situations were analyzed. The results show that, while the factors associated with SA and vigilance have lower correlations with each other, the factors associated with recognition, diagnosis, and generation and implementation of solutions have higher correlations with each other. Thus, the results demonstrate the need for better SA through educational training.

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Style Selection for Korean Generation under the Pivot MT System (피봇 기계번역시스템에서의 한국어생성을 위한 문제선정)

  • 이종혁
    • Korean Journal of Cognitive Science
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    • v.1 no.2
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    • pp.279-291
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    • 1989
  • Major difficulties in the style selection,which guarantees the synthesis of good-styled natural expressions under the PIOVT MT system, are an absence of surface-level extra-information in the languageinde-pendent intermediate representation and the language-specific style of expressions due to cultural differences.This paper describes an attempt on the style selection with capabilities of guaranteeing more natural Korean expressions,which includes pragmatic and stylistic decision on target voice genertaion under heavy passive constraints,stylistic changes of sentence-structures,and meaning-supplementation of function words with content words.

A Study for Animation Using 3D Laser Scanned Body Data (인체 전신 레이저 스캔 데이터를 대상으로 한 인체 애니메이션 연구)

  • Yoon, Geun-Ho;Cho, Chang-Suk
    • Journal of Korea Multimedia Society
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    • v.15 no.10
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    • pp.1257-1263
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    • 2012
  • An implementation of animation module using the 3D body data scanned by laser scanner is reported in this paper. Characteristic points of the skeleton in human body were picked up as pivot point for 3D rotation. The body data set wes reconstructed as objects built in hierarchical tree structure, which is based on skeleton model. In order to implement the 3D animation of the laser scanned body data, the vertexes of the objects were connected as skeleton structure and animated to follow dynamic patterns inputted by user.

Durability Evaluation of Platform Safety Step System (승강장 안전발판 시스템의 내구성 평가)

  • Park, Min Heung;Kwak, Hee Man;Kim, Min Ho
    • Journal of Applied Reliability
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    • v.16 no.2
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    • pp.125-133
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    • 2016
  • Purpose: The purpose of this study is to evaluate durability of platform safety step system in railway. Method: We performed finite element analysis & durability analysis of platform safety step system with VPD (Virtual Product Development) techniques and examined the durability standard & qualification life through the rig test during no failure test time in reliability qualification test. We continued to test 1 million cycles in KRS (Korea Railway Standard) for system's robust design performance. Result: FEM analysis results are 14.9MPa & 14.7MPa of pin-joint, pivot and durability analysis result is above 1 million cycles. we calculated theoretically no failure test time 855,000 cycles and through the 1 million cycles durability rig test in KRS standard we confirmed product quality. Conclusion: This platform safety step system was designed very safe in terms of a mechanical strength & durability.

The Five-Element Pattern of "River Table(河圖)" in the "Naegyeong(內經)" and the Analysis of Its Concerned Issues ($\ll$내경(内经)$\gg$적하도오행모식급궤개상관문제적해석(的河图五行模式及几个相关问题的解析))

  • Sun, Guang-Ren;Gao, Bo;Cha, Yong-Jin
    • Journal of Korean Medical classics
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    • v.22 no.4
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    • pp.29-32
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    • 2009
  • We have explored the five-element pattern of "River Table(河圖)" in the "Naegyeong(內經)", and conclude that this pattern is one of the five-element patterns applied in the "Naegyeong". Based on this pattern, we can exactly understand the eum(陰) and yang(陽) range of five Jang-organs, why the spleen is the extreme eum, why the spleen is the isolated Jang, how the spleen governs four seasons, the ascending and descending of visceral gi(氣), as well as why it can be applied in clinic that the spleen and stomach are the pivot of the ascending and descending of visceral gi(氣).

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