• Nuclear Engineering and Technology
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• 제27권1호
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• pp.96-104
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• 1995

EPRI URD requires that the reactor be capable of accommodating an unintended CEA drop without initiating a trip and operating at a reduced power with ay single CEA fully inserted. YGN 3 and 4 reactors have 12-finger CEAs, and the CPCS will trip the reactor due to their large reactivities when one of them is dropped at a high power. The ABB-CE reactor power cutback system has been proposed to be used against the 12-Finger CEA drop to avoid the reactor trips. The results of study show that the reactor power cutback can prevent the reactor trips of the 12-Finger CEA drop when the CPCS has enough operating thermal margin (more than 9％ for YGN 3&4 Cycle 1). It is noted, however, that the probability of a 12-Finger CEA drop is very low, less than one per 100 reactor years for YGN 3& and System 80$^{+}$ plants.

• 반도체디스플레이기술학회지
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• 제3권4호
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• pp.29-32
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• 2004

Fully depleted Silicon-on-Insulator (FD-SOI) devices lead to better electrical characteristics than bulk CMOS devices. However, the presence of a thin top silicon layer and a buried SiO2 layer causes self-heating due to the low thermal conductivity of the buried oxide. The electrical characteristics of FDSOI devices strongly depend on the path of heat dissipation. In this paper, we present a new three-dimensional (3-D) analysis technique for the self-heating effect of the finger-type and bar-type transistors. The 3-D analysis results show that the drain current of the finger-type transistor is 14.7% smaller than that of the bar-type transistor due to the 3-D self-heating effect. We have learned that the rate of current degradation increases significantly when the width of a transistor is smaller that a critical value in a finger-type layout. The current degradation fro the 3-D structures of the finger-type and bar-type transistors is investigated and the design issues are also discussed.

• 한국지능시스템학회논문지
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• 제7권5호
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• pp.67-76
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• 1997

In this paper, a theoretical study is presented for the force control of a miniature robotic manipulator which is driven by a pair of piezo-electric bimorph cells. In the theoretical analysis, one finger is modeled as a flexible cantilevers with a force sensor at the tip and the finger is a solid beam. The robotic finger is used to hold the objects with different stiffness such as an iron block and a living insect and a moving objcet. So it is very important to develop an adequate controller for the holding operation of the finger. The main problems in force controlling are overdamping, overshoot and unknown environment(such as the stiffness of object and unknown plant parameters). So, the main target is propose the new fuzzy compensation for unknown environment and incease the system performance. The fuzzy compensation is implemented by using PI-type fuzzy approach to identified unknown environment. And the result of proposed controller was compared with the conventaional PID and optimal controller.

• 센서학회지
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• 제21권2호
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• pp.127-134
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• 2012

Stroke patients must do the rehabilitation exercise to recover their fingers' function using a rehabilitation robot. But the rehabilitation robots mostly have not the force sensors to control the applied force to each finger. Thus, in this paper, the development of a force sensor for thumb rehabilitation robot and four two-axis force sensors for four-finger rehabilitation robot were developed. The force sensor and four two-axis force sensors could be used to measure the applied force to each finger, and the forces could be used to control the applied forces to each sensor in rehabilitation exercise using in the rehabilitation robot. The developed sensors have non-linearlity error of less than 0.05 %, repeatability error of less than 0.03 %, and the interference error of two-axis force sensor is less than 0.2 %.

• Tribology and Lubricants
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• 제28권5호
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• pp.240-245
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• 2012

In this study, we developed a new carrier finger to prevent scratches in a sheet metal forming line. The developed carrier finger was designed to have a streamlined shape with a larger radius of curvature at the edges, as well as a smaller contact area. To evaluate the scratch alleviation effect, a sliding contact analysis and scratch test using the pin on a plate wear tester were conducted for both the old and new carrier fingers. The results show that, for both transverse and longitudinal movements of the strip, the newly designed carrier finger reduces both the friction and scratch depth by its streamlined shape, which decreases the pressure spike at the edge.

• 한국정밀공학회지
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• 제29권7호
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• pp.753-761
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• 2012

This paper describes development of a hand and finger fixing system for the rehabilitation exercise of patient's fingers. In order to exercise the finger rehabilitation using a finger rehabilitation robot, a patient's hand or fingers are fixed safely. In this paper, The hand and fingers fixing system can safely fix stroke patient's hand and fingers by pressing with force control system. The characteristic test of the system was carried out. It is thought that the system could be used for fixing their fingers in stroke patient's finger rehabilitation exercise.

• 한국정보전자통신기술학회논문지
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• 제9권2호
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• pp.223-228
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• 2016

미래 스마트 러닝을 목표로 디지털 마이크로 미러 시스템(DMS : Digital Micromirror System)이 제안되어 있다. 다양한 인터페이스를 제공하기 위해 소형 프로젝터에 CMOS 센서 모듈을 내장한 시스템이다. DMS에서의 인터페이스 제공의 기본은 프로젝터에서 투사된 영상에서 손끝을 인식하는 것이다. 그러나 프로젝트 환경에서 각종 객체의 인식률은 영상열화 요인으로 인해 매우 낮다. 따라서 본 논문에서는 프로젝트 환경에서 영상열화 요인의 영향을 최소화한 Retinex 변환과 IR 구조광을 이용한 손끝 인식 알고리즘을 제안하였다. 제안한 알고리즘의 유용성을 실험을 통해 검증한 결과, 손끝을 효율적으로 인식할 수 있음을 확인하였다. DMS에 적용할 경우 사용자 인터페이스가 강화될 수 있을 것으로 판단된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.202-207
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• 1993

A theoretical and experimental study is presented for the force holding control of a miniature robotic ringer which is driven by a pair of piezoelectric unimorph cells. In the theoretical analysis, one finger is modeled as a flexible cantilever with a tactile force sensor at the tip and the mate of the finger is a solid beam supposed with sufficient stiffness. Further, the force sensor is modeled by a one-degree-of-freedom, mass-spring system and the output of sensor is then described by the sensor stiffness multiplied by the relative displacement. The problem investigated in this paper is that two typical holding tasks of the human finger are picked up and applied to the robotic finger. One is the work holding a stationary object with a prescribed, time-varying force and the other one is to keep the contacted force constant even if the object is in motion. The simple PID feedback control scheme is used to control the minute gripping force of order 0.01 Newton. It is shown both experimentally and theoretically that the artificial finger with the piezoelectric actuator works well in the minute force holding of the tiny object.

• 한국정밀공학회지
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• 제31권8호
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• pp.729-735
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• 2014

This paper presents the judgment method of the rehabilitation extent using a spherical type digital finger force measuring system (SDFFMS). Stroke patients can't use their fingers because of the paralysis of their fingers, but they can recover with rehabilitative training. The SDFFMS has been already developed by Kim (Author of this paper), and the finger grasping forces of normal people and stroke patients could be measured using it. But the SDFFMS could be not used to judge the extent of their rehabilitation, because the judgment method using it is not yet developed. In this paper, the characteristics tests for the grasping forces of normal persons and stroke patients were performed using the SDFFMS, and the judgment method of the rehabilitation extent was developed using the results. The tests confirm that the rehabilitation extent of stroke patients could be judged using the developed judgment method.

• 한국정보통신학회논문지
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• 제15권4호
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• pp.935-942
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• 2011

본 연구는 카메라를 통하여 취득한 지화를 자동으로 인식하고, 컴퓨터를 제어하는 지화인식 시스템을 설계하고 구현하는데 목적이 있다. 먼저 영상을 취득하기 위하여 일반 카메라를 개조하여 적외선 CCD 카메라를 제작하였고, 입력영상의 전처리와 손의 특징들을 찾아 분석하여 손 모양에 따라 해당되는 지화를 판독하고, 이벤트를 발생시켜 마우스 제어와 프리젠테이션을 수행할 수 있는 방법을 제시하였다. 본 연구에서 제안하는 지화인식 시스템은 미래형 정보기기의 마우스와 키보드를 대체할 수 있는 차세대 인터페이스로서의 사용가능성을 검증하였다.