• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.990-995
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• 1991

The integration of intelligent robots into manufacturing systems should positively impact the product quality and productivity. A new theory of object location and recognition using the supporting plane is presented. The unknown supporting points are determined by image coordinates, known camera parameters, and joint coordinates of the robot manipulators. This is developed by using the geometrical interpretation of perspective projection and the geometrical constraints of industrial environments. This can be applied to solve typical robot vision problems such as determination of position, orientation, and recognition of objects.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.419-424
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• 1986

A technique is developed which allows a designer to interactively create an assembly of components by specifying mating contions between the individual components. Once establishing the relationships between components via the mating conditions, each component's location and orientation in the final assembly is computed. The joint information for a kinematic and dynamic analysis can be derived from the mating conditions, therefore this work may be extended to incorporate this analysis. Thorugh this development it will no longer be necessary for a designer to specify cumbersome and error prone transformation matrices in order to create an assembly. The designer also will be able to perform a kinematic or a dynamic analysis directly from an assembly model if the joint information can be automatically derived.

• 지질공학
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• 제18권4호
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• pp.483-492
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• 2008

낙동강 중류 지역(함안근, 창령군, 의령군)의 백악기 퇴적암의 단열계 특성(단열 방향성과 단열계 밀도도)을 파악하고, 단열과 단층, 수계 그리고 연구지역내 지하수공의 일일 사용량과의 관련성을 분석하였다. 단열계는 JI($N90^{\circ}-110^{\circ}E$), J2($N0^{\circ}-35^{\circ}E$), J3($N0^{\circ}-35^{\circ}W$)로 분류되며, 주로 남북방향과 동서방향 단열군의 방항성이 우세하다. 연구지역의 동편과 서편의 함안층 분포지역에서는 남북방향의 단열계가 우세한 반면에, 연구지역의 중간부분인 칠곡층 분포지역에서는 동서방향의 단열계기 우세하다. 이는 연구지역의 동편과 서편에 위치하는 북북동-남남서 방향의 단층계와 관련되는 것으로 보인다. 또한 낙동강 주변에서도 단열 밀도가 높게 나타나며, 이는 동서방향의 단열계가 낙동강과 연관됨을 암시한다. 한편, 연구지역내 지하수공의 일일 사용량과 단열 밀도 간에는 약한 양의 상관성을 보이며, 지하수 비양수량과 단열 밀도간에는 음의 상관성을 보인다. 이는 단열 밀도가 지하수 산출량을 결정하는 주요 요인이 될 수 없음을 지시한다.

• Journal of Welding and Joining
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• 제16권6호
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• pp.35-43
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• 1998

In this paper, the fracture toughness evaluation of the various microstructures such as HAZ, F.L and W.M in weldment of TMCP steel which has the softening zone owing to high heat input welding was carried out by using of the small punch(SP) test. In addition, the fracture toughness with the specimen orientation of rolled TMCP steel was investigated by means of SP test and the crack opening displacement (COD) test and then was compared with that of conventional SM50YB steel. From the results of SP test for TMCP steel, it could be seen that the SP energy transition curves of three different orientation were shifted to higher temperature side in order of S, T and L. But the {TEX}$DBTT_{SP}${/TEX} of each orientation specimen did not show a lot of differences and were quite lower than those of conventional SM50YB steel. The mechanical properties of HAZ structure in weldment of TMCP steel such as hardness, SP energy at room temperature and -196$^{\circ}C$ and the upper shelf energy of SP energy transition curve were lower than those of base metal due to softening. The {TEX}$DBTT_{SP}${/TEX} of each microstructure in weldment of TMCP steel increased in order of HAZ, F.L and W.M against base metal, but all microstructures showed a quite lower {TEX}$DBTT_{SP}${/TEX} than those of SM50YB steel.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.182-185
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• 2005

Satellite cameras are calibrated before launch in detail and in general, but it cannot be guaranteed that the geometry is not changing during launch and caused by thermal influence of the sun in the orbit. Modem satellite imaging systems are based on CCD-line sensors. Because of the required high sampling rate the length of used CCD-lines is limited. For reaching a sufficient swath width, some CCD-lines are combined to a longer virtual CCD-line. The images generated by the individual CCD-lines do overlap slightly and so they can be shifted in x- and y-direction in relation to a chosen reference image just based on tie points. For the alignment and difference in scale, control points are required. The resulting virtual image has only negligible errors in areas with very large difference in height caused by the difference in the location of the projection centers. Color images can be related to the joint panchromatic scenes just based on tie points. Pan-sharpened images may show only small color shifts in very mountainous areas and for moving objects. The direct sensor orientation has to be calibrated based on control points. Discrepancies in horizontal shift can only be separated from attitude discrepancies with a good three-dimensional control point distribution. For such a calibration a program based on geometric reconstruction of the sensor orientation is required. The approximations by 3D-affine transformation or direct linear transformation (DL n cannot be used. These methods do have also disadvantages for standard sensor orientation. The image orientation by geometric reconstruction can be improved by self calibration with additional parameters for the analysis and compensation of remaining systematic effects for example caused by a not linear CCD-line. The determined sensor geometry can be used for the generation? of rational polynomial coefficients, describing the sensor geometry by relations of polynomials of the ground coordinates X, Y and Z.

• 한국컴퓨터그래픽스학회논문지
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• 제1권2호
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• pp.201-212
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• 1995

This paper presents a new method of dynamics-based synthesis of bipedal, especially human, walking. The motion of the body at a time point is determined by ground reaction force and torque under the support foot and joint torques of the body at that time point. Motion synthesis involves specifying conditions that constrain ground reaction force and torque, and joint torques so that a given desired motion may be achieved. There are conditions on a desired motion which end-users can think of easily, e.g. the goal position and orientation of the swing foot for a single step and the time period of a single step. In this paper, we specify constraints on the motion of the support foot, which end-users would find difficult to specify. They are constraints which enforce non-sliding, non-falling, and non-spinning the support foot. They are specified in terms of joint torques and ground reaction force and torque. To satisfy them, both joint torques and ground reaction force and torque should be determined appropriately. The constraints on the support foot themselves do not give any good clues as to how to determine ground reaction force and torque. For that purpose, we specify desired trajectories of the application point of vertical ground reaction force (ground pressure) and the application point of horizontal ground reaction (friction) force. The application points of vertical pressure and friction force are good control variables, because they are indicators to kinds of walking motions to synthesize. The synthesis of a bipedal walking motion, then, consists of finding a trajectory of joint torques to achieve a given desired motion, so that the constraints are satisfied under the condition of the prescribed center of pressure and center of friction. Our approach is distinguished from many other approaches, e.g. the inverted-pendulum approach, in that it captures and formulates dynamics of the support foot and reasonable constraints on it.

• 한국콘텐츠학회논문지
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• 제18권10호
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• pp.134-144
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• 2018

본 연구는 고관절 수술 환자에게 섬망 예방프로그램을 적용하여 그 효과를 검증하기 위한 비동등성 대조군 사후설계를 이용한 유사실험연구이다. 연구대상은 일 종합병원에서 고관절 수술후 외과계중환자실에 입실한 65세 이상 노인 환자였으며 실험군 33명, 대조군 31명이었다. 실험군에게 섬망 예방프로그램을 적용하였으며 구체적 내용은 오리엔테이션 중재, 활동 중재, 생리적 중재, 영양 중재, 수면 중재, 환경 중재로 구성되었다. 자료분석은 ${\chi}^2-test$, independent t-test로 분석하였다. 연구결과 실험군은 대조군 보다 섬망 발생률이 낮은 것으로 나타났다(${\chi}^2=7.048$, p=.008). 실험군은 대조군 보다 중환자실 재실일수와 재원일수가 적었으나 통계적으로 유의하지 않은 것으로 나타났다. 본 연구에서 적용한 섬망 예방프로그램은 고관절 수술환자의 섬망을 예방하는데 효과적임을 확인하였으며 향후 고관절 수술환자 섬망 예방을 위해 실무에 적용할 수 있을 것으로 기대한다.

• 문화경제연구
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• 제17권2호
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• pp.29-62
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• 2014

대표적인 지식기반산업, 창조산업으로 인식되고 있는, 문화콘텐츠 산업의 하나인 게임산업은 전통적인 제조업의 해외진출과는 달리, 제품 혹은 프로젝트 기반으로 해외진출에 대한 전략과 성과가 달라진다. 따라서 이에 대한 접근도 각각의 콘텐츠 단위로 달리해야 하며, 어떠한 요인들로 인해 이들의 해외진출 의사결정과 결과가 달라지는지 살펴볼 필요가 있다. 이에 본 연구에서는 게임 산업에서 해외시장 진입 선택에 영향을 미치는 '전략적 지향성' 요인을 중심으로, 이들의 선행변수 및 후행변수에 대해 살펴보고자 한다. 본 논문에서는 팀 단위(team level)로 제품이 개발되어 각각의 해외시장별로 어떠한 전략적 지향성을 띄며 진입유형 선택에 이르게 되는지 살펴보기 위해 온라인 게임 252개의 케이스를 가지고 살펴봤다. 본 연구결과에 따르면, 팀 흡수역량이 혁신지향성에 미치는 관계를 제외한 모든 잠재변수들(창의성, 흡수역량, 시장지향성, 혁신지향성, 해외시장 성과)간의 인과관계가 유의하게 나타났다. 본 연구는 창의성과 흡수역량, 시장지향성 및 혁신지향성을 해외시장 진입 방식과 통합적으로 연결시킴으로써 기존의 전략 및 국제경영 관련 이론들을 보충하고, 문화콘텐츠 상품의 해외진입(배급) 전략을 설명하기 위한 이론적 및 실무적인 시사점을 제공해준다.

• 터널과지하공간
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• 제2권2호
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• pp.212-223
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• 1992

The distinct element method(DEM) si well suited to the kinematic analysis of blocky rock masses. Two distinctive problems, a rock avalache and tunnel in jointed rock masses, are chosen to apply the DEM which is based on perfectly rigid behaviour of blocks. Investigated for both problems are the effects of the input parameters such as contact stiffnesses, friction coefficient and damping property. Using various types of models of the avalanche and tunne, an extensive parametric study is done to gain experiences in the method, and then to alleviate difficulties in determining parameter values suitable for a given problem. The coefficient of frictio has significant effects on all aspects of avalanche motion(travel distance, velocity and travel time), while the stiffnesses affect the rebounding and jumping motions after collision. The motion predicted by the models having single and mutiple blocks agrees well to the observations reported on the actual avalache. For the tunnel problem, the behaviour of the key block in an example tunnel is compared by testing values of the input parameters. The stability of the tunnel is dependent primarily on the friction coefficient, while the stiffness and damping properties influence the block velocity. The kinematic stability of a tunnel for underground unclear waste repository is analyzed using the joint geometry data(orientation, spacing and persistence) occurred in a tailrace tunnel. Allowing a small deviation to the mean orientation results in different modes of failure of the rock blocks around the tunnel. Of all parameters tested, the most important to the stability of the tunnel in blocky rock masses are the geometry of the blocks generated by mapping the joint and tunnel surfaces in 3-dimensions and also the friction coefficient of the joints particularly for the stability of the side walls.

• 대한기계학회논문집A
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• 제41권10호
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• pp.983-989
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• 2017

본 논문에서는 첨단복합재의 볼트단일접합 베어링강도에 대한 시험적 평가 결과를 수록하였다. 볼트단일접합 시험은 stabilized 접합과 unstabilized 접합에 대하여 수행하였다. Stabilized 접합은 접합부 면외회전을 제한하는 접합이다. Unstabilized 접합은 면외변위를 제한하지 않는 접합이다. 볼트 단일접합에서 적층판의 베어링강도 값은 적층판 내 적층각 $0^{\circ}$, $+45^{\circ}$, $-45^{\circ}$ 및 $90^{\circ}$ 비율에 영향이 없음을 보여준다. 볼트접합부 면외거동의 영향으로 unstabilized 볼트 단일접합 베어링 강도값이 stabilized 볼트 단일접합 베어링 강도값 보다 작음을 보여주고 있다. 본 논문에 사용된 복합재료는 $177^{\circ}C(350^{\circ}F)$에서 경화되는 Carbon/Epoxy UD Tape 프리프레그이다. 표준각 $0^{\circ}$, $+45^{\circ}$, $-45^{\circ}$ 및 $90^{\circ}$ 층으로 적층된 8종류의 적층판에서 총 112개 볼트단일접합 시험시편을 구성하였다. Stabilized 접합과 unstabilized 접합의 시험방법은 ASTM-D-5961M 규정을 사용하였다.