• Clinics in Shoulder and Elbow
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• 제1권2호
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• pp.221-229
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• 1998

평균 나이 23세.의 건강한 남자 31명을 대상으로 하여 측각도계즐 이용한 견관절운동역을 측정한 결과 Dominant arm과 Non-dominant arm 모두에서 능동운동역에 비해 수동운동역이 증가되었고, 능동운동시 견갑외전, 중립신전, 수평신전, 수평굴곡, 그리고 중립 및 수평내회전에서, 수동운동의 격우에는 견갑외전, 수평굴곡, 그리고 중립 및 수평내회전에서 Non-dominant arm의 운동증가를 보였고, 수평외회전의 경우 Dominant arm의 운동증가소견을 보였다(p〈0.05) .또한 방사선투시기를 이용하여 관절와상완각과 견갑흉곽각의 비(θGH/θST)를 측정해 본 결과 첫째로 Dominant arm과 Non-dominant arm에서 모두 완전거상시 관절와상완각과 견값흥곽각의 비(θGH/θST)는 1.6이었으며 60도이상 150도 거상때까지 지속적으로 견값흉곽운동 분율이 커지는 양상이었다. 둘째천 30도에서 완전거상시까지 운동분율(θGH/θST)은 Dominant arm과 Non-domlnant arm에서 각각 1.2 및 1.3으로 나타났다. 견갑사위는 중립위에서 약 42도였고 거상에 따라 점차 작아졌으며 완전거상시에는 약 20도로 측정되었다. 이렇게 해서 얻어진 방사선조사 각도는 단순방사선 촬영에 적용하여, 견관절 질환 치료 후 운동범위의 회복의 경과를 판정하는데 도움을 줄 수 있을 것으로 생각되었다.

• Tribology and Lubricants
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• 제15권1호
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• pp.17-23
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• 1999

A Gerotor hydraulic motor is a planar mechanism consisting of a pair of rotors one of which encloses another rotor. The motion of the inner-rotor relative to the outer-rotor is produced by the pressure difference between the adjacent chambers. A design method of inner-rotor tooth profile using unit tangential vectors is presented in this work. Based on the relationships derived, the influence of the eccentricity of inner-rotor and the radius of circular arc tooth on the flow rate, torque and curvatures were investigated. It was shown that the flow rate and mean torque is proportional to eccentricity, but inversely proportional to the radius of circular arc teeth. Also, the maximum value of the equivalent curvature is increased as the eccentricity and the radius of circular arc teeth increased.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.309-314
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• 1992

Many dynamic mechanical systems, such as parts-feeders, walking machines, and percussive power tools, are described by equations of motion which are discontinuous. The discontinuities result from kinematic constraint changes which are difficult to foresee, especially in presence of impact. A simulation algorithm for these types of systems must be able to algorithmically predict and detect the kinematic constraint changes without any prior knowledge of the system's motion. This paper presents a rule-based approach to the prediction and detection of kinematic constraint changes between bodies with arc and line boundaries. The developed algorithm's ability to accurately and automatically detect the unpredicted changes of kinematic constraints is demonstrated with a numerical example.

• 대한산업공학회지
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• 제37권1호
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• pp.10-18
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• 2011

Ergonomic product design considering users' natural use motion is of importance to improve the usability and satisfaction of a product. A five-step process of product design was developed in the present study by measuring and analyzing users' natural product-use motion with a motion capture system. The developed process was applied to ergonomic design improvement of a half guard installation part of refrigerator; new guard designs (diagonal and arc shape) were developed with the process and evaluated in terms of validity during the development as two measures (task satisfaction and similarity of natural motion). According to the evaluation result, the satisfaction at putting in- and out-task of new guard designs ($6.3{\pm}0.5$ points) was significantly higher than that of existing guard designs ($3.3{\pm}1.0$ points); the difference between natural motion and product-use motion in new guard designs ($1.0{\pm}0.3cm$) was significantly less than that of existing guard designs ($2.0{\pm}0.2cm$). The proposed process of natural motion analysis and product design is applicable to ergonomic product design and evaluation.

• 천문학회지
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• 제24권2호
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• pp.173-190
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• 1991

Disk stellar luminosity function has been derived with stars in the Lowell Proper Motion Survey which contains about 9000 stars with ${\mu}\;{\geq}\;0".27$ of arc/yr, $8\;<\;m_{pg}\;<\;17$ and with bright stars in the Smithsonian Astrophysical Observatory (SAO) Star Catalogue, Luminosity function has been obtained with stars within 20 pc by Luyten's mean absolute magnitudes method using Reduced Proper Motion Diagram to select disk stars. Magnitudes and colors, in the SAO Star Catalogue as well as in the Lowell Proper Motion Survey have been transformed to the UBV system from the published UBV data. It has been found that stars which have higher proper motion than the original limit of the proper motion survey are missed, when the relation between the absolute magnitude and reduced proper motion is applied to sample stars without considering the dispersion in magnitude. Correction factors for missing stars have been estimated according to their limits of proper motion which are dependent on the absolute magnitude. Resulting luminosity function shows Wielen's dip at $M_B{\sim}10$, and systematic enhancement of stars on the average of about ${\Delta}\log\;{\Phi}\;(M_B){\sim}0.2$ compared with Luyten's luminosity function.

• Journal of Welding and Joining
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• 제14권6호
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• pp.68-80
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• 1996

When a workpiece is to be arc welded around the outside corner, continuous welding without welding seam in the neighborhood of comer still remains a very difficult technique. Skilled welders weld comers by delicate“hand-eye coordination”while turning the workpiece manually, However, there is not a very clear solution to this problem in robotized arc welding process. In order to solve this problem, the coordination of a robot and a positioner with one or two axes is necessary. This paper presents a method of continuous welding around the corner of workpiece using the coordinated motion of a robot and a positioner. The positioner is either revolute jointed or prismatic jointed. In this paper, a clothoid curve is chosen for welding trajectory. The clothoid curve is excellent in connecting straight and curved weld-lines with good continuity and accommodates various welding conditions. By using this welding trajectory, the deceleration, which leads to widening of the melt and the heat affected zone, at comer area is reduced with strategic rotation of robot torch in coordination with a positioner providing smooth transition of welding torch orientation. Two types of special clothoid curves are developed for different weld slope conditions. These clothoid curves are applied to the case of linear and rotary Positioners at arc welding robot work-cell.

• Spatial Information Research
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• 제18권4호
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• pp.89-98
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• 2010

최근들어 대표적인 위치기반 서비스인 내비게이션은 기존 차량 중심의 서비스에서 보행자 중심의 서비스로 그 대상이 확대되고 있다. 이에 따라 최근에 보행자 내비게이션 관련하여 다양한 연구가 진행되고 있다 하지만, 내비게이션에서 가장 중요한 경로 서비스에 있어 대부분의 경우 차량 내비게이션에서 널리 활용되고 있는 노드/링크 네트워크 모델을 그대로 활용함으로써 한계점을 드러내고 있다. 그 이유로는 보행자는 차량과 달리 이동 공간이 도로로 한정되어 있지 않으며, 회전 규제, 방향 등에 제약을 받지 않고 보행이 가능한 공간에서 자유롭게 이동하는 등 보행 관련 특성들을 제대로 반영하지 못하기 때문이다. 특히, 공원, 광장 등의 오픈 페이스(open space)는 보행자기 많이 활용하는 공간임에도 불구하고 이에 대한 대안을 제공하지 못하고 있다. 따라서 본 연구에서는 게임 및 로보틱스 분야에서 객체의 이동을 계획하는 모션 플래닝(motion-planning) 기법을 응용하여 보행자 내비게이션 서비스에 적합한 경로 생성 기법을 제시하고, 그 활용 가능성을 테스트하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.382-387
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• 1992

In order to obtain desired arc welding performance, we already developed an arc welding robot system that enabled coordinated motions of dual arm robots. In this system one robot arm holds a welding target as a positioning device, and the other robot moves the welding torch. Concerning to such a dual arm robot system, the positioning accuracy of robots is one important problem, since nowadays conventional industrial robots unfortunately don't have enough absolute accuracy in position. In order to cope with this problem, our robot system employed teaching playback method, where absolute error are compensated by the operator's visual feedback. Due to this system, an ideal arc welding considering the posture of the welding target and the directions of the gravity has become possible. Another problem still remains, while we developed an original teaching method of the dual arm robots with coordinated motions. The problem is that manual teaching tasks are still tedious since they need fine movements with intensive attentions. Therefore, we developed a 3-dimensional vision guided robot control method for our welding robot system with coordinated motions. In this paper we show our 3-dimensional vision sensor to guide our arc welding robot system with coordinated motions. A sensing device is compactly designed and is mounted on the tip of the arc welding robot. The sensor detects the 3-dimensional shape of groove on the target work which needs to be weld. And the welding robot is controlled to trace the grooves with accuracy. The principle of the 3-dimensional measurement is depend on the slit-ray projection method. In order to realize a slit-ray projection method, two laser slit-ray projectors and one CCD TV camera are compactly mounted. Tactful image processing enabled 3-dimensional data processing without suffering from disturbance lights. The 3-dimensional information of the target groove is combined with the rough teaching data they are given by the operator in advance. Therefore, the teaching tasks are simplified

• 정보보호학회논문지
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• 제25권5호
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• pp.1067-1075
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• 2015

최근 모바일 게임 사용자가 증가하면서 점수 및 레벨 조작, 게임 속도 조작, 결재부정과 같은 부작용이 발생하고 있다. 특히, PC에서 모바일앱을 구동할 수 있도록 해주는 에뮬레이터를 사용하면 게임 앱을 디버깅을 하거나 게임조작을 자동화하기 쉬워지기 때문에 모바일 게임 보안관점에서 커다란 위협이 되고 있다. 따라서 본 논문에서는 모바일 게임 보안 위협 완화를 위해 최근 많이 사용되는 안드로이드 에뮬레이터인 BlueStacks, GenyMotion, Andy, YouWave와 구글 크롬에서 안드로이드를 동작 시킬 수 있는 ARC Welder 확장 프로그램을 클라이언트(앱), 게임서버 및 네트워크 관점에서 효과적으로 탐지할 수 있는 방법에 대해 연구하였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.327-330
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• 2006

With the increasing requirements for the survey and development of the ocean, the demands on the of AUV(Autonomous Underwater Vehicle) technologies have been increased. Reconstruction and replay of the AUV motion on the basis of the data stored during the execution of mission, can help the development of control strategies for AUVs such as mission planning and control algorithms. While an AUV cruises for her mission, her attitude and position data are is recorded. The data can be used for visualization of the motion in off-line. However, because most of the position data gathered from acoustic sensors have long time-interval and include intermittent faulty signal, the replayed motion by the graphic simulator can not demonstrate the motion as a smooth movie. In this paper, interpolation methods are surveyed to reconstruct the AUV position data. Then, an efficient 3D visualization method for AUV motion using the interpolation method is proposed. Simulation results arc also included to verify the proposed method.