• 대한한방체열의학회지
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• 제4권1호
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• pp.54-60
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• 2005

Object: A study on the changes of superficial temperature as the ambient temperature varies. Method: After performing research on the physiologic mechanism of heat loss from skin, heat transfer to skin and heat productions of body, the conclusions would be drawn from experiments on temperature changes in every parts of the body as ambient temperature varies . Result and conclusion: Superficial temperature is in equilibrium with ambient temperature after a certain period. Part of the body with big change in superficial temperature tends to have slower temperature change and longer time for adaptation than the part with small change in superficial temperature. The temperature difference between left and right side of the body needs no attention. If adequate adaptation time, a short-period living supervision prior to measurements and appropriate indoor environment management are provided, meaningful conclusion would be attained for infrared thermal diagnosis.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.536-539
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• 2002

The reverse engineering (RE) technology can quickly generate 3D point cloud data of an object by capturing the surface of a model using a 3D scanner. In the rapid prototyping (RP) technology, prototypes are rapidly produced from 3D CAD models in a layer-by-layer additive basis. In this paper, a physical human head shape is duplicated using a new RP process, the Transfer-type Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-ST), after the point cloud data of a human head shape measured from 3D SNX scanner are converted to STL file. From the duplicated human head shape, it has been shown that the VLM-ST process in connection with the 3D scanner is a fast and efficient process in that shapes with free surface, such as the human head shape, can be duplicated with ease. Considering the measurement time and the shape duplication time, the use of 3D SNX scanner and the VLM-ST process is expected to reduce the lead-time fur the development of new products in comparison with the other existing RE-RP connected manufacturing systems.

• 한국정밀공학회지
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• 제22권9호
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• pp.147-154
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• 2005

A precision hi-directional actuator for a high precision leveling system with $Z{\Theta}_x{\Theta}_y$ motions is proposed and designed in this paper. The actuator is composed of a force generation structure, a guide mechanism, and a symmetric structure. At first, its driving force is generated by a change of flux in air gaps by permanent and changeable flux. The permanent flux is generated by a permanent magnet. The changeable flux is created by variable current flowing through coil. The combination of permanent and changeable flux makes various flux densities in air gaps between moving part and fixed yokes. And then, the difference between flux densities in lower and upper gaps creates forces fur the $bi-direction({\pm}z)$ motion. The guide mechanism of this actuator is composed of two circular plates and one shaft. Reducing motions generated by forces except z-motion, these circular plates endow the actuator with high stiffness for fast settling time. And the function of the shaft is to transfer motion to an object. At last, total body has a symmetric structure to be stable on thermal error. The actuator is designed by MAXWELL 2D and ProMECHANICA. The designed actuator is evaluated by 8nm laser doppler vibrometer, dynamic signal analyzer, and simple PID controller.

• Journal of Welding and Joining
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• 제21권1호
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• pp.48-53
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• 2003

The object of this study is to examine the effect of short circuit time ratio (SCTR) and current rise delay time (Td) on the spatter generation at low and medium current range in $CO_2$ welding. The spatter was evaluated by the weight generated in the welding of bead-on-plate for 30 seconds (3 times). Td was varied by order of 0, 0.4, 0.8 and 1.2 msec. At each Td, the short circuit time ratio was varied by the output voltage of the welding power source. In the low current range, it was found that the optimum SCTR was 20~25%, and the minimum spatter generation weight was obtained in the case of Td=0.4msec and SCTR=22% even though the remarkable difference was not showed by the application of Td. In the medium current range, it was confirmed that the arc was stable though the SCTR was increased from 20% to 40% by the control of current wave. Spatter generation weight depended on the variation of Td, and the lowest value of spatter generation weight occurred at Td=0.8~1.2msec.

• 정보학연구
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• 제4권1호
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• pp.109-124
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• 2001

최근 인터넷을 통한 정보 교환을 위해 XML(eXtensible Markup Language), 이러한 XML과 EDI의 기술적 특성과 장점을 이용한 XML/EDI에 대한 연구가 활발하게 진행되고 있다. EDI의 개념과 더불어 일괄처리 EDI에서부터, 실시간 EDI, 대화형 EDI, 개방형 EDI, 객체지향 EDI, 그리고 인터넷을 이용한 EDI로 발전되는 과정을 살펴보고, 특히 XML/EDI의 발전방향에 대하여 고찰하고자 한다.

• 한국경영과학회지
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• 제24권4호
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• pp.157-170
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• 1999

The web-based groupware systems hold many possibilities for system developers and users. Especially, web-based group collaborative systems are emerging as enterprise-wide information systems. Since data in group collaborative systems are apt to be shared among multiple concurrent users and modified simutaneously by them, the web-based group collaborative systems must support synchronous collaboration in order to provide users with synchronized and consistent views of shared data. However, current web technologies have limitations in supporting this, largely because the existing Hypertext Transfer Protocol(HTTP) is unidirectional and does not allow web servers to send messages to their web browsers without first receiving requests from them. This paper proposes an active web server that can overcome such limitations and facilitate synchronous collaboration in web-based group collaborative systems. To accomplish such goals, the active web server manages dependency relationships beween shared data and web browsers referencing them and actively propagates changing details of the shared data to all web browsers referencing them. And, this paper examines usefulness and effectiveness of the active web server to apply it to the ball-bearing design example of concurrent engineering design systems. The prototype system of the active web server is developed on a commercial Object-oriented Database Management System(0DBMS) called OBJECTSTERE using the C++ programming language.

• 한국위성정보통신학회논문지
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• 제1권2호
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• pp.89-94
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• 2006

OFDM(Orthogonal Frequency Division Multiplexing)방식은 유, 무선 채널에서 고속 데이터 전송에 적합한 방식으로, 최근 활발히 연구되고 있다. 이중 IEEE 802.16에 근거한 WiBro는 OFDM을 핵심기술로 사용하고 있으며, 최근 상용화를 통한 시장 확대를 추진 중에 있다. 이에 따라 가까운 미래에 고속 이동체(KTX, airplane..etc)에서 사용될 경우 OFDM system의 치명적인 단점인 DFS(Doppler Frequency Shift)에 의한 ICI(inter-carrier interference)가 발생할 수 있다. 본문에서는 위성을 통한 OFDM system operating에 있어서 Doppler effects에 대한 새로운 3가지 보상 기법을 제시하고 constellation과 BER curve를 통하여 향상된 성능을 확인한다.

• 지능정보연구
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• 제11권3호
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• pp.117-127
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• 2005

이동기기를 기반으로 하는 기술이 급격히 발달함에 따라 일반 컴퓨팅 환경의 그래픽이나 영상처리 기술들을 활용한 모바일 컨텐츠 개발이 증가하고 있다. 본 논문에서는 상호 연동성을 지원하는 국내 표준 무선인터넷 플랫폼인 WIPI를 기반으로 하여 영상처리와 얼굴인식 기술을 응용한 얼굴탐지 및 인식 지원 미들웨어를 설계하였다. 생성된 얼굴인식 미들웨어는 휴대폰 카메라를 이용한 인식보안 및 다양한 컨텐츠로 활용될 수 있도록 객체지향 개념을 도입해 각각의 미들웨어가 얼굴인식 미들웨어를 공유할 수 있다. 이는 컨텐츠 설계에 있어 주요 프로세스를 분리함으로써 컨텐츠의 개발 기간 및 비용을 단축시킬 수 있으며, 컨텐츠 보호 및 타 기업과의 기술이전에 적용될 수 있다. 얼굴인식 미들웨어는 서비스에 따라 얼굴탐지 모듈과 얼굴인식 모듈로 구성되며, WIPI 플랫폼 상에서의 얼굴인식 미들웨어 응용 컨텐츠 설계 방법에 대하여 제시한다.

• 한국항행학회논문지
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• 제16권3호
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• pp.518-525
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• 2012

광학기기가 대상물체를 영상으로 완벽하게 재현할 수는 없으므로 이러한 광학기기의 특성을 평가하는 방법으로서 변조전달함수(MTF)가 보편적으로 사용된다. 그런데 한편으로 렌즈의 수차가 적어지면 광학시스템 구경의 회절과 수차 사이의 반응이 매우 복잡해지므로 기존의 MTF의 방법으로는 광학기기를 평가하기가 어렵다. 이 경우에는 렌즈의 수치구경, 탈초점, 광경로차 및 위상차를 고려한 MTF를 구해야 한다. 본 논문에서는 이러한 방법으로서 가장 보편적으로 알려진 베셀함수를 이용하여 이의 타당성을 검증하고 실례를 통하여 이를 보여주고자 하였다.

• 제어로봇시스템학회논문지
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• 제10권9호
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• pp.847-854
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• 2004

In this paper, It is studied to control and to monitor the remote system state using HTTP(Hyper Text Transfer Protocol) object communication. The remote control system is controlled by using a web browser or a application program. This system is organized by three different part depending on functionality-server part, client part, controller part. The java technology is used to composite the server part and the client part and C language is used for a controller. The server part is waiting for the request of client part and then the request is reached, the server part saves client data to the database and send a command set to the client part. The administrator can control the remote system just using a web browser. Remote part is worked by timer that is activated per 1 second. It gets the measurement data of the controller part, and then send the request to the server part and get a command set in the command repository of server part using the client ID. After interpreting the command set, the client part transfers the command set to the controller part. Controller part can be activated by the client part. If send command is transmitted by the client part, it sends sensor monitoring data to the client part and command set is transmitted then setting up the value of the controlled system.