• Title/Summary/Keyword: 기구

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A Study on the Optimal Design of a R-S-S-R Three Dimensional Mechanism (3次元 R-S-S-R 機構의 最適設計 에 관한 硏究)

  • 김호룡;김경률
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.9 no.4
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    • pp.528-538
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    • 1985
  • A R-S-S-R three dimensional mechanism is designed for crank-rocker type through the optimization technique. The nonlinear kinematic equation of the mechanism is formulated by adopting the concept of structural error and precision points. Taking this equation as an objective function, the required mechanism is optimally synthesized by the Fletcher-Davidon-Powell's method of optimization techniques. The structural errors due to the various positions of precision points are compared, and the results from the use of two penalty functions suggested respectively by Fiacco-McCormick and by Powell are also compared on their effectiveness. The mobility of the optimally designed mechanism is checked for the possibility of its motion, and when a mechanism is optimally designed, it is strongly suggested that the mobility must be checked on the designed mechanism.

An Educational Program of Luminaire Design based on Component Attributes (성분적 속성에 기초한 조명기구디자인 교육프로그램)

  • 박우성
    • Archives of design research
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    • v.14 no.2
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    • pp.57-66
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    • 2001
  • This research was carried with emphasis on the technical contents of lighting design which had various knowledge system in the educational viewpoint. First of all, phisiolosical and physical factors were considered with the process of vision between human and light. Next, components of attributes in the lighting fixture were prescribed to analyze concept of the fixture. Finally, I proposed educational program in the instruction to meet the purpose of this research. As a result, in overall research concerning the basic direction and structure, instruction should have balance to reconcile theory and practice about lighting. Second, in terms of expansion of cognition about lighting, experimental education that is considered with interface is needed to make practical verification through relationship with man-made environment and scientific data.

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A Mechanism for the Hydroperoxide Decomposition in a Soybean oil during Thermal Oxidation (가열산화중인 콩기름에서의 하이드로퍼로키사이드(hydroperoxide)의 분해기구)

  • Shin, Ae-Ja;Kim, Dong-Hoon
    • Korean Journal of Food Science and Technology
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    • v.17 no.2
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    • pp.71-74
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    • 1985
  • In the present study, a tentative mechanism for the decomposition of the hydroperoxide formed during the thermal oxidation of an edible soybean oil was proposed. The soybean oil was thermally oxidized at $120^{\circ}C$ for 7 hrs with air injection at a rate of 120 ml/min. Through kinetic studies of the decomposition process based on the tentative mechanism and the actual experimental data obtained from the hydroperoxide decomposition at 100, 120, 150 and $180^{\circ}C$, it was found that the reaction order of the hydroperoxide decomposition in these conditions was of first order. It was also estimated that the dissociation energy for the hydroperoxide in the same conditions was 15.876 kcal/g. mol.

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Microwave Cooking of Rice (II) - The comparison with pressure and electric cooker - (Microwave Oven을 이용한 취반에 관한 연구(II) -압력솥 및 전기밥솥 취반미와의 취반특성 비교 -)

  • 김영아
    • Korean journal of food and cookery science
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    • v.14 no.4
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    • pp.416-420
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    • 1998
  • The Properties of cooked rice prepared by microwave oven was compared with those by pressure cooker There was no significant difference in sensory evaluation between microwave-cooked and pressure-cooked rices, however, the rice cooked by electric cooker was less preferred to others. The hardness of pressure-cooked rice was greater than others. As the storage time for cooked rice increased, the extent of gelatinization decreased, however, there were no significant differences among three samples.

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System Analysis of Research Trends of Assistive Devices for People with Disabilities Using Semantic Network Analysis: 2002 to 2014 (언어 네트워크 분석(Semantic Network Analysis)을 활용한 장애인보조기구 연구동향 분석: 2002년 ~ 2014년)

  • Kim, ChangGeol;Kang, JungBae
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.10 no.1
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    • pp.93-100
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    • 2016
  • This study analyzed research trends of assistive devices used to prevent and support disability and increase convenience for people with disabilities in their daily lives. As a result, related research has continuously increased, and the research area has expanded from survey research to service-related research and assistive device development research. In addition, with regard to the use of related terms, terms such as 'rehabilitation engineering' and 'rehabilitation assistive technology' were used in the early stages. Currently, terms such as 'assistive technology', 'assistive technology service', 'assistive technology device', and 'assistive device' have been mainly used.

Optimum Shape Synthesis of Cam And Follower in Cam-Valve System to Minimize Contact Force (캠-밸브 기구에서 접촉력 최소화를 위한 캠과 종동자 형상 최적 합성)

  • 김성훈;전혁수;박윤식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.3
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    • pp.534-546
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    • 1990
  • In this work, an optimum shape synthesis for rolling contact components was done to minimize contact forces considering dynamic characteristics of the system. Even this method was applied to an OHC type cam follower system, it can be expanded to general rolling contact shape design problems which are strictly forced to follow predetermined motion. First, the follower optimum angular motion was derived to minimize the valve peak acceleration while satisfying all the constraints of valve motion. Then the cam and follower contact shape were synthesized to give the proposed follower motion. Theoretically, two components shape to generate a predetermined motion can not be uniquely determined. So the cam shape was syntehsized with parametric synthesis method to minimize the peak contact force between cam and follower when the follower shape is assumed as a circle or an ellipse.

A Study on the Kinematic and Dynamic Analyses of Spatial Complex Kinematic Chain (공간 복합기구연쇄의 기구학 및 동역학 해석에 관한 연구)

  • 김창부;김효식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.10
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    • pp.2543-2554
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    • 1993
  • In this paper, the kinematic and dynamic analyses of spatial complex kinematic chain are studied. Through the new method both using the set of identification numbers and applying the DenavitHartenberg link representation method to the spatial complex kinematic chain, the kinematic configuration of the chain is represented. Some link in the part of closed chain being fictitiously cutted, the complex kinematic chain is transformed to the branched chain. The kinematic constraint equations are derived from the constraint conditions which the cutted sections of the link have to satisfy. And the joint variables being partitioned in the independent joint variables and the dependent joint variables, the dependent variables are calculated from the independent variables by using the Newton-Raphson iterative method and the pseudoinverse matrix. The equations of motion are derived under the independent joint variables by using the principle of virtual work. Algorithms for dynamic analysis are presented and simulations are done to verify accuracy and efficiency of the algorithms.

Design of Leg Length for a Legged Walking Robot Based on Theo Jansen Using PSO (PSO를 이용한 테오얀센 기반의 보행로봇 다리설계)

  • Kim, Sun-Wook;Kim, Dong-Hun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.5
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    • pp.660-666
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    • 2011
  • In this paper, we proposed a Particle Swarm Optimization(PSO) to search the optimal link lengths for legged walking robot. In order to apply the PSO algorithm for the proposed, its walking robot kinematic analysis is needed. A crab robot based on four-bar linkage mechanism and Jansen mechanism is implemented in H/W. For the performance index of PSO, the stride length of the legged walking robot is defined, based on the propose kinematic analysis. Comparative simulation results present to illustrate the viability and effectiveness of the proposed method.

항로표지를 이용한 한국형 e-Navigation 발전 전략

  • Kim, Jong-Uk;Yu, Yong-Su;Han, Ju-Seop;Choe, Su-Bong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2014.10a
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    • pp.331-332
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    • 2014
  • 최근 해양 분야에서는 해상과 육상의 다양한 데이터를 통합, 활용하여 해상에서의 선박의 안전 운항, 해양 환경 및 자원의 보호 등의 활동에 필요한 정보를 적시에 제공하는 정보 서비스 체계로 e-Navigation에 대한 관심이 높아지고 있다. 국제해사기구(IMO)를 비롯한 해양 분야 국제기구 등은 e-Navigation을 위한 정책, 표준, 관련 기술 및 시스템 개발 등 e-Navigation을 주도하기 위한 많은 노력을 기울이고 있다. UN산하 해사안전 분야 전문기구인 국제해사기구(IMO)는 인적과실에 의한 해양사고를 줄이기 위해 2006년 e-Navigation 도입을 결정, 2018년부터 시행하기 위해 국제협약 제 개정 등을 추진하고 있다. 해양수산부는 국제해상안전 규제동향에 선제적으로 대응함으로써 해양안전을 강화하는 한편, 관련 분야 신산업 육성과 일자리 창출 등을 목표로 하는 "한국형 e-Navigation 대응전략"을 발표하였다. 항로표지는 해상에서의 안전한 활동을 지원하는 필수 시설로써 e-Navigation 시스템의 중요한 운영자원으로 활용될 예정이며 이에 국내에서도 e-Navigation 시스템 운영을 위한 항로표지시설에 대한 기술 개발이 절실한 실정이다. 이러한 항로표지를 이용한 한국형 e-Navigation 운영을 위한 발전 방안에 대하여 기술하였다.

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Focal Mechanism Solutions of Microearthquakes in the Southwestern Part of the Korea Peninsula (한반도 남서부에서 발생한 미소지진의 진원 기구해 분석)

  • Cho, Hee-Kyu;Kang, Tae-Seob;Kyung, Jai-Bok
    • Journal of the Korean earth science society
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    • v.27 no.3
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    • pp.341-347
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    • 2006
  • Focal mechanisms were analyzed for the seven earthquakes which occurred in the southwestern part of the Korea Peninsula from 2001 to 2005. Grid searches are performed to fit distributions of P-wave first-motion polarities and SH/P amplitude ratios for each event. The focal mechanism solutions imply that most of the events have strike-slip sense including partially thrust component. The compressional axes of the solutions are predominantly ENE-WSW or NE-SW indirections. This result is similar to the directions of the principal compressional axes for major earthquakes occurred around the Korea Peninsula.