• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.241-248
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• 1999

Structural damage during an earthquake is caused by the response of the structure to the ground motion input at its base. The dynamic force produced in the structure are due to the inertia of its vibrating elements. The response of the structure exceeds the ground motion and this dynamic magnification depends on the duration and frequency content of the ground vibration, the soil properties at the site, distance from the epicenter and the dynamic characteristics of the structure. Earthquake load used in this study as a input data was artificially simulated with the design spectrum diagram in the Korean Earthquake Resistant Design Code. This paper presents the seismic analysis of the continuous preflex composite girder bridges according to variation of pier's height and span's length.

• 대한인간공학회지
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• 제7권1호
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• pp.31-37
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• 1988

This paper designs, in the teleoperation task, the world coordinate system by the functional analysis of each of the robot joint so that the human operator performs easily the task. Also, it constructs the heuristic rules of the equal motion line coordinates for the position and the posture control of the robot within the knowledge base so that the robot hand reaches-possibly in any position of the robot's work space. As shown in the result of the experiments. the coordinate reading is easy because the work station is displayed to the high resolution by using the superimposer of the motion analysing computer system. Also. the task burden of the human operator reduces and the error recovery time reduces because the coordinates of the object is obtained just by touch using the digitizer.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.401-405
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• 2003

This paper presents a design strategy of the dynamic simulator for the Korean tilting train. The tilting train simulator will generate the tilting motion to the lateral acceleration date obtained from the train dynamic analysis. The simulator will be composed of five components: (1) GUI control panel, (2) train dynamic analysis part, (3) tilting control part, (4) motion base with 6 electrical-motor-driven actuators and (5) visualization system. Using the simulator, we will verify the dynamic behaviors of the tilting train, interfaces among subparts and ride comfort before manufacturing of the tilting train.

• Structural Engineering and Mechanics
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• 제54권4호
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• pp.741-754
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• 2015

This study evaluates prediction models for three EDPs (engineering demand parameters) using data from three symmetrical structures with RC walls designed according to the currently enforced Romanian seismic design code P100-1/2013. The three analyzed EDPs are: the maximum interstorey drift, the maximum top displacement and the maximum shear force at the base of the RC walls. The strong ground motions used in this study consist of three pairs of recordings from the Vrancea intermediate-depth earthquakes of 1977, 1986 and 1990, as well as two other pairs of recordings from significant earthquakes in Turkey and Greece (Erzincan and Aigion). The five pairs of recordings are rotated in a clockwise direction and the values of the EDPs are recorded. Finally, the relation between various IMs (intensity measures) of the strong ground motion records and the EDPs is studied and two prediction models for EDPs are also evaluated using the analysis of residuals.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.275-278
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• 1987

In this paper, a programming system for SCARA-type robots is designed, consisting of robot language, computational facilities and programming tools for handling interconnection environments. In designing the robot language, CLRC(C Library for Robot Control) is introduced, using the general-purpose language 'C' as base programming language. Also the motion primitives for Continuous Path control as well as Point-To-Point motion arc included. By means of frame and homogeneous transformations the system is capable of applying the SCARA-type robot efficiently and easily for any given task.

• Bulletin of the Korean Chemical Society
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• 제19권10호
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• pp.1068-1072
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• 1998

We present results of molecular dynamic (MD) simulations for the segmental motion of liquid n-butane as the base case for a consistent study for conformational transition from one rotational isomeric state to another in long chains of liquid n-alkanes. The behavior of the hazard plots for n-butane obtained from our MD simulations are compared with that for n-butane of Brownian dynamics study. The MD results for the conformational transition of n-butane by a Poisson process form the total first passage times are different from those from the separate t-g and g-t first passage times. This poor agreement is probably due to the failure of the detailed balance between the fractions of trans and gauche. The enhancement of the transitions t-g and g-t at short time regions are also discussed.

• 대한기계학회논문집B
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• 제28권8호
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• pp.968-975
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• 2004

Nanofluids have anomalously high thermal conductivities at very low fraction, strongly temperature-dependent and size-dependent conductivities, and three-fold higher critical heat flux than that of base fluids. Traditional conductivity theories such as the Maxwell or other macroscale approaches cannot explain why nanofluids have these intriguing features. So in this paper, we devise a theoretical model that accounts for the fundamental role of dynamic nanoparticles in nanofluids. The proposed model not only captures the concentration and temperature-dependent conductivity, but also predicts strongly size-dependent conductivity. Furthermore, we physically explain the new phenomena for nanofluids. In addition, based on a proposed model, the effects of various parameters such as the ratio of thermal conductivity of nanofluids to that of a base fluid, volume fraction, nanoparticle size, and temperature on the thermal conductivities of nanofluids are investigated.

• 한국공작기계학회논문집
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• 제13권3호
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• pp.113-118
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• 2004

In this paper, we propose a new weaving trajectory algorithm for the arc welding of a articulated manipulator. The algorithm uses the theory of Bezier spline. We make a comparison between the conventional algorithms using Catmull-Rom curve and the new algorithms using Bezier spline. The proposed algorithm has been evaluated based on the MATLAB environment in order to illustrate its good performance. Through simulations, the proposed algorithm can result in high-speed and flexible weaving trajectory planning so that it's trajectory cannot penetrate into a base metal compared to the conventional algorithm using Catmull-Rom curve.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.807-811
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• 2002

As the requirements on precision and speed of motion in chip mounter increase, vibration forces are always exerted on operating conditions. To insure safety of the chip mounter, the vibration must be kept within an acceptable limit. The focus of this paper is on the identification of dynamic load characteristics and the estimation of static and dynamic stiffness characteristics for Frame Base by judicious selection of the number and the location of the support points. This study carried an analytical and experimental method to estimate the dynamic characteristics in structure.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.390-395
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• 2009

본 논문은 이동형 햅틱 장치(mobile haptic interface; MHI)의 실제적인 문제점과 그 개선사항들에 대해 다루고 있다. 1) 전체 좌표계에서의 haptic interface point (HIP) 위치 추정 정확도에 대한 개선, 2) MHI 가 사용자와 장애물들을 피해 움직이도록 하는 포텐셜-필드 방식에 기반한 이동 계획 알고리즘, 3) MHI 의 움직임으로부터 발생하는 원하지 않는 힘이 사용자에게 전해지는 것을 막기 위한 closed-loop 컨트롤 등을 소개한다.