• 제목/요약/키워드: Differential Mechanism

검색결과 456건 처리시간 0.216초

Configuration sensitivity analysis of mechanical dynamics

  • Bae, Daesung
    • 한국공작기계학회논문집
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    • 제10권1호
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    • pp.112-119
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    • 2001
  • Design sensitivity is an important is an important device in improving a mechanical system design. A continuum design consists of the shape and orientation design. This research develops the shape and orientation design sensitivity method. The configura-tion design variables of multibody systems define the shape and orientation changes. The equations of motion are directly differentiated to obtain the governing equations for the design sensitivity. The governing equation of the design sensitivity is formulated as an over determined differential algebraic equation and treated as ordinary differential equations on mani-folds. The material derivative of a domain functional is performed to obtain the sensitivity due to shape and orientation changes. The configuration design sensitivities of a fly-ball governor system and a spatial four bar mechanism are obtained using the proposed method and are validated against those obtained from the finite difference method.

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Modeling and parameter estimation of a fish-drying control system

  • Sakai, Y.;Wada, K.;Nakamura, H.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.440-445
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    • 1992
  • The major purpose here is to estimate the drying time required in the fish-drying process employed. The basic element of the prediction of the drying time is the model or the equation, which governs the change in weight. By an intuitive consideration on the mechanism of dehydration, a mathematical model of the fish-drying process is built, which is described by a system of linear differential equations. Further, a modified system of linear differential equations for a model of drying is also proposed for more accurate estimation. The parameter estimation of this system of equations provides the prediction of necessary drying time.

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매설관 하부지반-보강재 상호작용의 수치모델 연구 (Numerical Modeling of Soil-Reinforcement Interaction Under a Buried Pipeline)

  • 손준익;정하익
    • 전산구조공학
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    • 제4권3호
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    • pp.129-135
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    • 1991
  • 본 논문에서는 유한요소해석을 통하여 부등침하를 받는 매설관 기초지반 보강의 적용성과 지반보강 상호작용에 의하여 매설관 연결부 하부에서의 부등침하를 최소화 할 수 있는 방안에 관하여 다루었다. 매설관의 일단이 구조물에 고정되어 있는 경계조건에 대하여 상호비교하여 지반보강에 따른 응력전이 효과와 이로인한 배설관 침하억제 효과를 수치적으로 분석하였다.

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피스톤핀 옵셋이 피스톤운동과 운동에너지 손실에 미치는 영향에 관한 연구 (A Study on the Effect of Piston Pin Offset on a Piston Motion and Kinetic Energy Loss)

  • 한덕주;최재권
    • 한국자동차공학회논문집
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    • 제1권3호
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    • pp.22-33
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    • 1993
  • A theoretical analysis of predicting the detailed motion of a piston-crank mechanism within piston-guide clearance is presented, and the analysis is applied to the piston motion in a gasoline engine. A piston movement program is developed to calculate the piston attitude relative to the bore, the piston to bore impact velocity and kinetic energy loss and the net transverse force acting on the piston. This paper presents the formulation of a set of differential equations governing the transverse and rotational motion of a piston. These equations of motion were solved by well established Runge-Kutta method. As a result of this study, it is possible to predict the effects of piston geometry and piston pin offset on a piston motion and kinetic energy loss.

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Electrochemical Study on the Coumarin Derivatives

  • Kim, Il Kwang;Chun, Hyun Ja;Paik, Soon Ok;Park, Sung Woo
    • 분석과학
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    • 제8권4호
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    • pp.655-661
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    • 1995
  • The electrochemical reduction of coumarin derivatives in 0.1M TEAP acetonitrile solution was investigated by the direct current, differential pulse polarography, cyclic voltammetry and controlled potential coulometry. The electrochemical reduction of 7-acetoxy-4-bromomethyl-coumarin(ABMC) was proceeded as an irreversible three steps(-0.58, -1.63 and -2.25 volts) of electrochemical transfer before chemical reaction. The solution color turned to yellow after the carboxyl group was reduced at 2nd step(-1.63 volts vs. Ag-AgCl) and the change in color was independant to the bromo group. Upon the basis of the results on the products analysis and the interpretaton of polarograms, a possible electrochemical reaction mechanism was suggested.

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Concealment of iris features based on artificial noises

  • Jiao, Wenming;Zhang, Heng;Zang, Qiyan;Xu, Weiwei;Zhang, Shuaiwei;Zhang, Jian;Li, Hongran
    • ETRI Journal
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    • 제41권5호
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    • pp.599-607
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    • 2019
  • Although iris recognition verification is considered to be the safest method of biometric verification, studies have shown that iris features may be illegally used. To protect iris features and further improve the security of iris recognition and verification, this study applies the Gaussian and Laplacian mechanisms and to hide iris features by differentiating privacy. The efficiency of the algorithm and evaluation of the image quality by the image hashing algorithm are selected as indicators to evaluate these mechanisms. The experimental results indicate that the security of an iris image can be significantly improved using differential privacy protection.

Comparison of Expression Profiles between Trophozoite and Cyst of Acanthamoeba castellanii

  • Moon, Eun-Kyung;Kong, Hyun-Hee
    • 대한의생명과학회지
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    • 제18권3호
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    • pp.313-318
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    • 2012
  • Acanthamoeba is an opportunistic pathogen known to cause granulomatous amoebic encephalitis and amebic keratitis. Acanthamoeba exhibits life cycle consisting of trophozoite and cyst, and the cyst is highly resistant to variable antibiotics and therapeutic agents. To understand the encystation mechanism of Acanthamoeba, the expression profiles of trophozoite and cyst were compared by gene ontology (GO) analysis. Ribosomal proteins and cytoskeletal proteins were highly expressed in trophozoite. In cyst, various protease, and signal transduction - and protein turnover - related proteins were highly expressed. These results correlated with eukaryotic orthologous groups (KOG) assignment and microarray analysis of Acanthamoeba trophozoite and cyst ESTs. The information of differential expression profiles of trophozoite and cyst would provide important clues for research on encystation mechanism of cyst forming protozoa including Acanthamoeba.

초소형 전자 개폐기 개발 (Development of Mini Magnetic Switch)

  • 이경구;김준호;김견묵;박지홍;조현길;안길영;서정민
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.134-136
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    • 2003
  • This paper proposes moving mechanism theory & magnetic core analysis regarding mini magnetic contactor and differential mechanism & bimetal analysis regarding mini thermal overload relay. In shortage of technique, we have experienced many difficulties in magnetic switch development. By this research, we developed core parts about mini magnetic switch and applied the results to optimum mini magnetic switch development

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차동유성형 마찰드라이브의 개발 (Developement of planetary differential type traction drive)

  • 이종원;오세훈;최동엽;이대길;전한수
    • 한국정밀공학회지
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    • 제14권3호
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    • pp.35-40
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    • 1997
  • The traction drive has advantages of having high efficiency and transmitting the power without blacklash. However, when high ratio of speed reduction is desired, excessively large size is required. In this study, a new type of traction drive is invented, designed and manufactured so that stable speed reduction mech- anisms are available by adopting a cross roller type drive. It has a simple structure, but produces high speed reduction ratio. Power loss is observed, and also, driving torque and torque transfer efficiency are calculated. Pre-loads are needed in order that the traction drive transfers power without slipping, and the spacer is enlarged due to the pre-loading. After all, the key point of pre-load mechanism is that the spacer's diameter becomes larger as pre-loads are applied.

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H/V-버스 병렬컴퓨터의 설계 및 성능 분석 (Design and Performance Analysis of the H/V-bus Parallel Computer)

  • 김종현
    • 한국시뮬레이션학회논문지
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    • 제3권1호
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    • pp.29-42
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    • 1994
  • The architecture of a MIMD-type parallel computer system is specified: a simulator is developed to support design and evaluation of systems based on the architecture: and conducted with the simulator to evaluate system performance. The horizontal/vertical-bus(H/V-bus) system architecture provides an NxN array of processing elements which communicate with each other through a network of N horizontal buses and N vertical buses. The simulator, written in SLAM II and FORTRAN, is designed to provide high-resolution in simulating the IPC mechanism. Parameters provide the user with independent control of system size, PE speed and IPC mechanism speed. Results generated by the simulator include execution times, PE utilizations, queue lengths, and other data. The simulator is used to study system performance when a partial differential equation is solved by parallel Gauss-Seidel method. For comparisons, the benchmark is also executed on a single-bus system simulator that is derived from the H/V-bus system simulator. The benchmark is also solved on a single PE to obtain data for computing speedups. An extensive analysis of results is presented.

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