• 제목/요약/키워드: Design change

검색결과 8,918건 처리시간 0.044초

BLDC 모터의 구동장치 개발 및 정밀 반복제어 (Development of driver for BLDC motor system and precise repetitive control)

  • 강병철;이충환;김상봉
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1257-1260
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    • 1996
  • This paper describes a fully digitalized driver for BLDC motors and the driver is realized by a single chip microprocessor. The speed change can be done by using the signal obtained from the position detecting sensor and adjusting the pulse width at the input channel of power module. In order to verify the effectiveness, an repetitive control method is adopted in the speed control tracking a periodic reference change in the BLDC motor system. The experimental results are shown for the reference tracking accurately according to the design parameter variation in the repetitive controller design.

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접지계의 경년변화 특성에 관한 연구 (A Study on the Secular Change Characteristics of Grounding Systems)

  • 김재이
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제54권5호
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    • pp.224-226
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    • 2005
  • In this paper, the secular changes of buried grounding electrodes was investigated; the electrodes are such facilities as grounding grid, grounding connector, grounding terminal and grounding rod etc.. The corrosiveness of removed substation grounding electrodes after commercial operation more than 50 years was measured and its conductivity deterioration trend was analyzed. The measuring results using three experimental methods were compared, finally the consideration for safe and economic grounding design were shown. As the result, it shows the maintenance necessity of grounding systems.

BCM2 모의 결과를 반영한 목표연도 확률강우량 산정 (Estimation of Design Rainfalls Considering BCM2 Simulation Results)

  • 이창환;김태웅;경민수;김형수
    • 대한토목학회논문집
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    • 제30권3B호
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    • pp.269-276
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    • 2010
  • 최근 지구온난화가 가속화되면서 전 세계적으로 기록적인 기상재해가 급증하고 있다. 특히 강우패턴의 변화로 인하여 강우강도가 증가하여 집중호우의 발생빈도가 높아지고 있다. 본 연구에서는 기후변화 시나리오에 따른 강우패턴의 변화를 반영하여 목표연도 확률강우량을 산정하는 비정상성 강우빈도해석법을 제안하였다. BCM2 모형(A2 시나리오)과 NCEP 자료를 K-NN 축소기법을 사용하여 축소시킨 연 총 강우량을 이용하여 연 최대 강우량 평균, 연 최대 강우량 평균과 매개변수 간 통계학적 관계를 분석하여 목표연도 확률강우량을 산정하였다. 분포형은 Gumbel 분포를 사용하였으며 매개변수 추정법은 확률가중모멘트법을 사용하였다. 국내에서 가장 긴 관측 강우자료를 가진 서울지점을 대상으로 모형의 적합성 검증을 실시하였으며, 2006년 현재 통계학적으로 증가경향성을 가진 7개의 강우관측지점에 적용한 결과를 분석하였다. 기후변화 시나리오에 따른 지역적 연 총 강우량의 변화는 미래 확률강우량의 증감에 영향을 미치는 것으로 나타났다.

실험계획법을 이용한 대형트럭 조종성 향상을 위한 설계인자 최적조합에 관한 연구 (A Study on Optimal Combination of Design Parameters for Improving Handling Performance of a Large Truck Using Design of Experiments)

  • 문일동;이동환;오재윤
    • 대한기계학회논문집A
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    • 제28권6호
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    • pp.799-806
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    • 2004
  • This paper presents a scheme for finding an optimal combination of design parameters affecting on the handling performance of a large truck using design of experiments. The average of the sum of peak-to-peak roll angles at the first and second part of the double lane is used as an objective function for design of experiments. Six design parameters are selected from all possible parameters affecting on the handling performance. The table of orthogonal arrays is made by 27 times simulations. A computational model of a large truck is developed by MSC/NASTRAN and MSC/ADAMS, and verified the reliability of it with the results of vehicle tests performed in a double lane change course. It is used for the simulations. Analyses of variance and factor effect of the table of orthogonal arrays are performed. This paper proposes an optimal combination of those six design parameters for improving the handling performance of the large truck.

FE analyses and prediction of bursting forces in post-tensioned anchorage zone

  • Kim, Joung Rae;Kwak, Hyo-Gyoung
    • Computers and Concrete
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    • 제21권1호
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    • pp.75-85
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    • 2018
  • To improve the design equation for the evaluation of the bursting force in the post-tensioned anchorage zone, this paper presents the analyses and design of the post-tensioned (PT) anchorage zone on the basis of three dimensional (3D) finite element (FE) analyses. The structural behavior was investigated through linear elastic finite element analyses upon consideration of the change in design parameters such as the bearing plate size, the eccentricity, and the tendon inclination. Moreover, consideration of the duct hole, which causes an increase of the bursting stress with a change in its distribution along the anchorage zone as well, is emphasized. Since that an exact prediction of the bursting force is the primary interest in design practice, additional parametric analyses are carried out to evaluate the relative contribution of all design parameters in determining the bursting force, and a comparison with the design guidelines mentioned in AASHTO-LRFD has been provided. Finally, an improved design guideline that takes into account the influence by the duct hole is suggested.

실험계획법과 수리적방법을 이용한 이산설계 공간에서의 다목적 최적설계 (Multi-objective Optimization in Discrete Design Space using the Design of Experiment and the Mathematical Programming)

  • 이동우;백석흠;이경영;조석수;주원식
    • 대한기계학회논문집A
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    • 제26권10호
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    • pp.2150-2158
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    • 2002
  • A recent research and development has the requirement for the optimization to shorten design time of modified or new product model and to obtain more precise engineering solution. General optimization problem must consider many conflicted objective functions simultaneously. Multi-objective optimization treats the multiple objective functions and constraints with design change. But, real engineering problem doesn't describe accurate constraint and objective function owing to the limit of representation. Therefore this study applies variance analysis on the basis of structure analysis and DOE to the vertical roller mill fur portland cement and proposed statistical design model to evaluate the effect of structural modification with design change by performing practical multi-objective optimization considering mass, stress and deflection.

수상레저용 보트 설계를 위한 협력적 필터링 기반 사용자 추천시스템 개발 (Development of Collaborative Filtering based User Recommender Systems for Water Leisure Boat Model Design)

  • 오중덕;박찬홍;김종수;성현경
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2014년도 춘계학술대회
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    • pp.413-416
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    • 2014
  • 최근 전 세계적으로 사회적 여건 변화와 소비자의 욕구 변화에 따라 여가 중심으로의 가치관이 변화하면서 다양한 레저스포츠의 수요가 점차 증가하고 있다. 특히 여름철 수상 레포츠에 대한 관심과 참여율이 증가하고 있는 실정이며, 정형화되어있는 수상레저용 보트의 다양한 선체 디자인에 대한 욕구도 증가하고 있다. 따라서 본 논문에서는 소비자들의 선체 디자인에 대한 다양한 욕구의 변화에 적극적으로 대응할 수 있도록 협력적 필터링 기법을 이용한 수상레저용 보트 디자인 설계를 위한 추천시스템을 개발하고자 한다. 이를 위하여 소비자 설문조사를 통해 보트 디자인 관련 감성을 선정하고, 요인분석과 평가로 감성을 도출하여 고객 감성 선호측면에서의 보트 디자인 배열을 제시하였다. 또한 사용자의 선호도를 반영한 보트 디자인에 따른 감성 어휘 선정을 위해서 보트의 선체, 바디, 추진 장치 등의 요소에 따라 분석하여 사용자의 선호도에 맞는 수상레저용 보트 모델을 제시하였다.

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서울숲 조성 설계공모에 대한 비판적 연구 (A Critical Review of the Seoul Forest Park Design Competition)

  • 이상민;조정송
    • 한국조경학회지
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    • 제31권6호
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    • pp.15-27
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    • 2004
  • The Seoul Woods Design Competition in 2003 was one of the most remarkable events within the field of landscape architecture in Korea since the Yeo-Ui Do Square Park Design Competition in the mid 1990s. This study examines the overall procedure, evaluations and competition guidelines for the Seoul Forest Park Design Competition and identifies the implications and issues related to Korean landscape architecture. In addition this study analyzes the design concepts, strategies and spatial composition, and programs of five selected design worts including the best awarded work. This study also examines key features and issues from the five selected design works. Finally, this study examines a new trend of landscape design in Korea, which can be observed at the Seoul Forest Park Design Competition. In this study, it is argued that the Seoul Forest Park Design Competition had significant implications for landscape architecture in Korea. Firstly, the Seoul Forest Park Design Competition was the greatest project in Korea in terms of its size. Therefore, it shows us an enhanced status of Korean landscape architecture. Secondly, the Seoul Forest Park Design Competition provided a good opportunity to redefine the concept of 'park' in Korean modern society. Thirdly, through the Seoul Forest Park Design Competition, we can observe a dramatic change and developments in Korean landscape design since the 1990s, as well as the present status of landscape design competitions in Korea. And this study identifies an emphasis of a program in design, an evolution in ecological approach an diminishment in concern of Korean tradition, and a change in design methods and media, which are some aspects of Korean contemporary landscape design observed at the Seoul Forest Park Design Competition.

아파트의 규모에 따른 리모델링 실태 연구 - 아파트 주호의 개조자료 분석을 중심으로 - (A Study on the Remodeling of Apartment Housing Unit according to the Size - Focusing on the Data Analysis of Apartment Housing Unit Remodeling-)

  • 신경주;이지영;장상옥
    • 한국실내디자인학회논문집
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    • 제13권6호
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    • pp.82-90
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    • 2004
  • The purpose of this study is to investigate the remodeling of apartments housing unit according to the area type and size in order to provide useful information for future plans for more consumer-friendly dwelling units. To achieve this goal quantitative data analyses were employed. The sample was a total of 100 apartments analysed in previous researches conducting case studies on apartments remodeling. The data were analyzed by SPSS WIN program package in terms of frequency, percentage, and x2-test. The results of the study are as follows: The change of finishing materials were made in almost all of the sample. 6.4, 8.6 and 10.6 categories were altered in the small, medium, and large apartments respectively out of 21 remodeling categories. In the case of communal areas, change of finishing materials and installation, removal, and change of lighting fixtures were most frequent. The most frequent alteration in private areas was also observed In change of finishing materials and installation, removal and change of lighting fixtures.