• 대한조선학회지
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• 제20권2호
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• pp.51-59
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• 1983

The versatile practical use of electron beam welding which is very high energy density is still in early stage, but in the special welding field, the welding process is used in manufactured goods. The investigation for electron beam welding up to the present was almost achieved not for the mechanical properties of welded joint but for the process itself. On this investigation, the fatigue strength, crack propergation phenomena and hardness of weld metal and heat affected zone of partially penetrated welded joint of HT80 steel by electron beam welding was accomplished. The tensile fatigue strength in weld line direction of the joint was about $25kg/mm^2$. There still appeared spikes on the tips of penetration, and the crack initiated at the tips of spikes not from the roots. The hardness of the weld metal was higher than it of base metal because of production of martensite by rapid cooling.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.52-55
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• 1997

This paper discusses an automatic visual-servoing system, in which a laser and a CCD camera are used for imaging the pattern of joint groove. The algorithm used here is simple and robust to find out the gap width and gap center. As a consequence, the speed of algorithm is very fast and optimized. A feature of this system is that it processes only by summing the vertical line and horizontal line of screen without any image preprocessing in order to get the energy information of lines alternatively. It is practical and useful for the system requiring a fast process time of vision.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.994-999
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• 1993

To service with high quality electricity to customer, the utilities consider the DAS (Distribution Automation System) as a good means of it. The backbone of the DAS are communication and computer technique. Most of all, from the economical and functional point of view, the selection of transmission media for system communication is the key factor to achieve a successful DAS. In this paper author propose the method of the DAS communication which share its channel with CATV transmission line and analyze the effect.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.433-437
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• 1988

Direct measurement of the relative position between the end effector of robot and moving objects reduces difficulties caused by the joint encoder reading and transformation. For those purpose, the on-line sensing method using PSD sensor was developed in this paper. The sensor was calibrated on the precision table. Then, the relative position of a moving objects on the conveyor was measured while the robot was tracking the one.

• 한국정보보호학회:학술대회논문집
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• 한국정보보호학회 1994년도 종합학술발표회논문집
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• pp.193-202
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• 1994

In this paper, we investigate possible scrambling methods for the JPEG(Joint Photographic Export Group) still image compression standard. In particular, we compare the conventional line rotation and line permutation methods to the DCT block scrambling in terms of the number of bits to be increased and the easiness of buffer control. Computer simulation results show that the DCT block scrambling method is suitable for both data security and buffer control in one-chip JPEG applications.

• 한국컴퓨터정보학회논문지
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• 제26권3호
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• pp.43-50
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• 2021

본 논문에서는 키넥트 센서를 기반으로 한 휘트니스(Fitness) 동작의 정확성을 피드백 하는 윈도우 애플리케이션 KITNESS를 설계하고 구현한다. 이 애플리케이션의 특징은 키넥트의 카메라와 관절 인식 센서를 활용하여 사용자가 정확한 휘트니스 자세로 운동할 수 있도록 피드백을 주는 것이다. 이때 키넥트의 IR Emitter와 IR Depth Sensor를 이용하여 사용자와 키넥트 간의 거리를 측정하고, 사용자의 관절 위치인 조인트(Joint)와 각 관절의 스켈레톤(Skeleton) 데이터를 측정한다. 이러한 데이터를 이용하여 사용자의 관절 위치와 자세마다 일정 거리를 계산하고 자세의 정확도를 판단한다. 그리고 키넥트의 RGB 카메라를 통해 사용자가 본인의 자세를 확인할 수 있도록 구현한다. 즉, 사용자의 자세가 정확하면 스켈레톤 정보를 초록색 선으로 표시하고, 정확하지 않으면 정확하지 않은 부분을 빨간색 선으로 표시하여 직관적으로 알려준다. 사용자는 이 애플리케이션을 통하여 운동하는 자세의 정확도를 피드백 받기 때문에 혼자서도 정확한 자세로 운동할 수 있다. 이 애플리케이션은 운동 부위를 목, 허리, 다리 세 가지 영역으로 분류하고, 각 운동 부위의 자세에서 관절이 겹쳐서 키넥트가 인식하지 못하는 자세를 제외함으로써 키넥트의 인식률을 높인다. 그리고 애플리케이션 종료 시에는 마지막 운동 모습을 이미지로 5초간 보여줌으로써 성취감을 고취시키고 지속적으로 운동할 수 있도록 구현한다.

• 한국레이저가공학회지
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• 제7권2호
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• pp.19-26
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• 2004

The effect of shield gas on the weldability, mechanical properties and formability of CO2 laser weld joint in 600MPa grade high strength steel was investigated. Bead on plate welds were made under various welding speed and shield gas. Tensile test was carried out under the load of perpendicular and parallel direction to the weld line, Formability of the joint was evaluated by Erichsen test. As the welding speed increases, the porosity fraction decreases. The porosity fraction in the joint used Ar-$50\%He$ mixed gas as a shield gas was lower than that of the joint used Ar gas. Hardness at the weld metal of full penetrated joint was nearly equal to that of water quenched raw metal. In a tensile test under a perpendicular load to the weld axis, strength and elongation of joint produced by optimum condition were nearly equal to those of base metal. However, the strength of joint in a tensile test under a parallel load to weld axis was higher than that of raw metal, but the elongation of joint was lower than that of raw metal. Elongation and formability were further increased by the method of using Ar+He mixed gas as a shield gas as compared with Ar gas. Formabilities of joints were recorded ranging from $58\%\;to\;70\%$ of that of base metal with different shield gases.

• 전기학회논문지
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• 제56권4호
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• pp.817-819
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• 2007

The purpose of this work is to develop a measurement system of the pendulum test with minimal restriction of experimental environment and little influence of noise. In this work, we developed a vision system without any line between markers and a camera. The system performance is little influenced by the experimental environment, if light are sufficient to recognize markers. For the validation of the system, we compared knee joint angle trajectories measured by the developed system and by the magnetic sensor system during the nominal pendulum test and the maximum speed voluntary knee joint rotation. The joint angle trajectories of the developed system during both tests matched well with those of the magnetic system. Therefore, we suggest the vision system as an alternative to the previous systems with limited practicality for the pendulum test.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2006년도 추계학술대회
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• pp.134-137
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• 2006

Satisfying the customer orders with a short lead-time is one of the essential and competitive factors for business units under a mass customization environment. To shorten the lead-time for fulfilling various orders entails the production capacity expansion and efficient operational policy. Most business firms utilize the multiple production lines or facilities to cope with this business and manufacturing environment by making the manufacturing and distribution more flexible. In this study, we introduce the operational problem determining the joint production and delivery policy in an environment where multiple products are manufactured with more than one production lines. Also, we propose the heuristic solution approach for determining the product-line selection and joint lot size for this problem.

• Journal of Welding and Joining
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• 제10권4호
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• pp.240-249
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• 1992

The objective of this study is to investigate the characteristics of welded joints on the Zircaloy-4 resistance upset welding for HWR(Heavy Water reactor)fuel rods. To estimate the characteristics of welded joints, the various tests were performed on the test coupons systematically with a wide range of each welding parameters in terms of a tensile test, burst test, knoop hardness test and metallography. Major results obtained in this study are as follows: 1. The tube and machined with 120.deg. projection was the reliable weld joint design for the nuclear fuel rod end cap welding. 2. As the weld current and the amount of upset increased linearly with increasing welding main heat input, it could make an estimate of their variation in accordance with the phase shift control. 3. It was found that an increase in squeeze force has an effect on the upset contour of welded joint because the amount of upset were increased by the change of squeeze force.