• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.346-349
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• 1994

This paper is concerned with a motion control of a manipulator under parametric uncertainties and external disturbances. The parametric uncertainties are regarded as internally generated disturbances in the manipulator. Based on this idea, we formulate a model reference control problem with desired disturbance attenuation. The solution of this control problem not only reduces the worst-case effect on tracking error due to internal and external disturbances (combined disturbances) as much as possible, but also achieve optimal tracking when perturbations are absent. In order to solve the control problem which is formulated in this paper we reduce it to a constrained minmax cost control problem. A differential game theory is used to treat this constrained minmax cost control problem. The differential game theory leads to a sufficient condition for the global solvability of the model reference control problem with desired disturbance attenuation.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.353-360
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• 2001

An analysis procedure of 2-dimensional bridge dynamics has been developed by using force-deformation model, which simulates the pier motion under biaxial bending due to the bi-directional input seismic excitations. A three-dimensional mechanical model is utilized, which can consider the other major phenomena such as pounding, rotation of the superstructure, abutment stiffness degradation, and motions of the foundation motions. The bi-directional dynamic behaviors of the bridge are then examined by investigating the relative displacements of each oscillator to the ground. It is found that the nonlinearity of the pier due to biaxial bending affects the pier motions, but the global bridge behaviors are greatly governed by the pounding phenomena and stiffness degradation of the abutment-backfill system. Especially, the relative displacement of the abutment system (A2) with movable supports to the ground is increased about 30% due to the abutment stiffness degradation.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.150.1-150
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• 2001

This paper introduces a real time inspecting and monitoring system by using wireless communication and image processing technique. The communication system is developed by using 80c196kc microprocessor and it has data acquisition function for several kinds of sensors such as pluviometer, temperature, tension meter, elinometer and so on. The image processing method adopts Lalacian of Gaussian operator and least square method to extract line features for the captured images and uses a relaxation matching algorithm based in global structure constraint satisfaction to distinguish the matching error for those features. When the algorithm is processed, motion parameters of displacement area and its direction are computed. Once movement is recognized ...

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.313-316
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• 2003

This paper proposes a new measurement method of face region size for real-time serveillance systems. The proposed method consists of three steps. In the first step, it detects global face area based on the block-based difference images. In the second step, it measures the face region size using face color information. In the third step, it estimates the face position in the next input image using the trajectory of face regions. The experimental results have shown that the proposed algorithm measures the face size within 20％ relative error on average, which is a]towable for most surveillance systems.

• Journal of Mechanical Science and Technology
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• v.17 no.7
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• pp.1044-1053
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• 2003

There are two major differences between the centerless infeed grinding process and the centerless through-feed grinding process. One is an axial movement of workpieces, and the other is that several workpieces are ground simultaneously and continuously by through-feeding. Because of these differences, through-feed ground parts inherently possess not only the roundness error but also the tapering error. The aims of the research reported in this paper are to examine this inherent tapering characteristic and to find the effects of grinding variables (center height angle, regulating wheel tilt angle, and shape of grinding wheel surface). To accomplish the objectives, experiments were carried out using two types of cylindrical workpiece shapes. Also, computer simulations were performed using the 3-D through-feed grinding model.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.46-48
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• 2010

최근 스마트폰 동향은 기존에 연구되고 개발되어진 기술들이 다양한 현실 환경에 응용 가능하도록 새로운 기술들과 접목되어져 많은 어플리케이션에 사용되어지고 있다. 본 논문에서는 개발자와 사용자들에게 각광받고 있는 기술들로 GPS(Global Positioning System), 증강현실(Augmented Reality), 동작인식(Motion Detection)등의 기술사용을 접목한 게임사례들의 기술적 요소에 접근하여 자체기술을 활용한 게임디자인을 제안하고자 한다. 기존 휴대폰이라는 매체의 제한된 속성에서 한 단계 발전한 스마트폰 어플리케이션 기반 게임의 분석은 게임의 새로운 장르 발전과 사용자의 통합적 감각 경험에 의한 가상공간에서의 만족도를 증진시킬 수 있으리라 기대하며 이러한 기술을 토대로 차후 게임제작에 적용되었을 때 더 나은 효과를 발휘하리라 사료된다.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1598-1606
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• 2007

In this paper, we present a thin circular beam finite element for the out-of-plane vibration analysis of curved beams. The element stiffness matrix and the element mass matrix are derived respectively from the strain energy and the kinetic energy by using the natural shape functions which are obtained from an integration of the differential equations of the finite element in static equilibrium. The matrices are formulated with respect to the local polar coordinate system or to the global Cartesian coordinate system in consideration of the effects of shear deformation and rotary inertias. Some example problems are analysed. The FEM results are compared with the theoretical ones to show that the presented finite element can describe quite efficiently and accurately the out-of-plane motion of thin curved beams.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.25-28
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• 2002

The path planning of autonomous mobile robot use two method. One is global path planning and another is local path planning. In this paper, We study the local path planning of autonomous mobile robot move in unknown enviroment. This local path planning is based on neural network using the direction indicator rules learning. also the system is made up of sensor system. The motion control system for real-time execution. The experimental results show that the developed direction indicator system operates properly and strongly at circumstance.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.114-117
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• 2009

A new video inpainting algorithm is proposed for removing unwanted objects or error of sources from video data. In the first step, the block bundle is defined by the motion information of the video data to keep the temporal consistency. Next, the block bundles are arranged in the 3-dimensional graph that is constructed by the spatial and temporal correlation. Finally, we pose the inpainting problem in the form of a discrete global optimization and minimize the objective function to find the best temporal bundles for the grid points. Extensive simulation results demonstrate that the proposed algorithm yields visually pleasing video inpainting results even in a dynamic scene.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.605-610
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• 1994

Optimal design of fault-tolerant, spatial type maniplators is treated in this paper. Design objective is to guarantte three degree-of-freedom translational motions in the task space, upon failure of one arbitrary joint of 4 degree-of -freedom manipulators. Realizing the nonfault-tolerant characteristics of current, wrist-type industrial manipulators, several 4 degree-of-freedom redundant structures with one joint redundancy are suggested as the fault-tolerant spatial -type manipulators. Fault-tolerant charactersitics are investigated basedon the analysis of the self-motion and the null-space elements, of a redundant manipulator. Finally, in order to maximize the fault-tolerant capability,optimal design is performed for a spatial-type manipulator with respect to the global isotropic index, and the performance enhancement of the optimized case is shown by simulation.