• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1998년도 Proceedings of International Workshop on Advanced Image Technology
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• pp.73-78
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• 1998

Our platform introduced in this paper is based on DAVIC specifications which define high quality multimedia services with some extensions to provide user friendly and uniform interface to its users. We designed and implemented an integrated service platform for high quality interactive multimedia services, swithed digital broadcasting, and Internet services. The integration in terms of a service provider system, a delivery system, and a service user system is taken into account. Our research results in the development of integrated high quality interactive and digital broadcasting multimedia services with web-based common user interface and its experience will be feedback to the field trial service which will be launched from next year.

• 한국통신학회논문지
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• 제21권2호
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• pp.417-426
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• 1996

The end-to-end service clock recovery is a critical issue in providing constandt bit rate service through ATM network. The Synchronous Residual Time Stamp(SRTS) algorithm is used to recovery the source clock using time stamp of transmitter. In thispaper, we propose a Differential Residual Time Stamp (DRTS) transmission mechanism to effectively deliver the timing information of source clock in SRTS algorithm. The RTS transmission method simple in its hardware. From the results of field trial of DS3 rate interactive video communication system through B-ISDN testbed, it can be identified that DRTS method is superior to the RTS method.

• 동력기계공학회지
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• 제3권1호
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• pp.45-49
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• 1999

Lots of products are made in various working conditions, depending on the size and the shape of them. Usually, at first, the die for new items had been designed on the basis of experience and know-how, and then modified through trial and error. At a die design stage most of drawings have been drawn manually. Recently some forging companies save design time by repeated utilization of standardized parts with registered data base. In this study the automated die design technique for forward extrusion of axisymmetric products is developed. A standardized die system is proposed from the investigation of ones employed frequently in the metal forming field and the design rules for cold extrusion die. A design example of forward extrusion die is given and discussed.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
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• pp.1-9
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• 1999

Plant biotechnology including plant tissue culture is the most important science to rescue human beings from the crisis of biosphere of the earth which they will face in the 21st century. Global area other than Asia of trangenic crops increased more than 16 times from 1996 to 1998. In Asian countries, micropropagation using tissue culture techniques has been well developed and has contributed to agricultural production. Although researches on levels of laboratory and test field trial of transgenic crops have been performed actively in some Asian countries, areas of growing transgenic crops are still small in Asia countries except in China. In this paper, the status of plant biotechnology in global and Asian countries are reviewed and the future prospect of plant biotechnology in Asia and roles of Korean and Japanese plant scientists in it are discussed.

• Journal of Electrical Engineering and information Science
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• 제3권3호
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• pp.385-390
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• 1998

In this paper, the oscillator strengths of both the heavy-hole and the light-hole excitons in GaAs-A\ulcornerGa\ulcornerAs and In\ulcornerGa\ulcornerAs-InP quantum wells with the effect of a magnetic field applied along the growth axis are studied. The calculation is carried out usig a variational approach, based on a simple trial exction wave function. The exciton oscillator strengths are found to decrease with increasing well width and to increase with the applied magnetic fields which lead to additional quantum confinement for moderately wide well sizes. Also, the oscillator strengths for the heavy-hole exciton are found to be large than those of the light-hole exciton in these quantum well structures.

• 한국컴퓨터교육학회 학술대회
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• 한국컴퓨터교육학회 2018년도 하계학술대회
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• pp.33-34
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• 2018

우리나라는 2015 개정 교육 과정에 초 중학교에서의 소프트웨어 교육을 필수화하고, 다양한 소프트웨어 교육 정책을 펼치며 컴퓨터 정보 소양 교육을 강화하고 있다. 이러한 변화에 따라 실제 우리나라 학생들의 컴퓨터 정보 소양에 미치는 영향을 분석할 필요가 있다. 또한, ICILS 2013 이후 우리나라의 컴퓨터 정보 소양 교육 환경은 급격한 변화를 맞이하였기 때문에 이러한 교육 환경의 변화를 면밀히 파악할 필요가 있다. 본 연구는 ICILS 2018 예비검사에 참여한 전국 32개 중학교를 대상으로 소프트웨어 교육 현황을 조사하고 분석하였다.

• 한국CDE학회논문집
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• 제3권3호
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• pp.168-176
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• 1998

This paper deals with an application on the mould machining of air intake hose product by using 3-dimensional parametric modeling techniques. The detailed domain is the 3-dimensional product with similar shapes and different sizes which needs too much working time for preparation of modeling or machining due to making a trial and errors repeatedly. Decision making rules for selection of modeling order and technique, and for calculation of cutting conditions, and for determination of sequence and method concerning machining operations are required by interview of expert engineers in the field. The developed expert system of modeling and machining is programmed by using a user programming language under the CAD/CAM software of the Personal Designer. The developed system that aids a mould engineer who is working in the modeling and machining section which deal with air intake hose product provides strong and useful capabilities.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.574-576
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• 2018

DOCSIS 3.1 표준을 준수하는 케이블모뎀을 개발하였고, 실제 HFC 가입자 망에서의 연동 시험을 실시하였다. 1024, 4096 QAM 등 고차 변조방식을 사용하여 2.5Gbps 이상의 고속 데이터 서비스가 가능함을 확인하였다.

• 전기학회논문지P
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• 제50권3호
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• pp.125-129
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• 2001

ln this paper, a ozone generator using superimposition of silent discharge has been designed and manufactured. This type ozone generator is equipped with three electrodes and two gaps. Ozone is generated by superimposition of silent discharge, which is respectively come from two gaps. The maximum values of ozone concentration, ozone generation flow and ozone energy field were obtained 4,750[ppm], 2.37[g/h], 102.3[g/kWh]. Also, the result of reaction of 1,8921ppm] ozone and the sampling water from the lake, the water quality was improved from IV grade to In grade, and obtained 100[%] sterilization rate of Escherichia coli within 5.0(min).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.253-255
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• 1999

In this paper, a shape optimization algorithm of superconducting magnet using finite element method is presented. Since the superconductor loses its superconductivity over the critical magnetic field and critical current density, this material property should be taken into account in the design process. Trial and error approach of repeating the change of the design variables costs much time and it sometimes does not guarantee an optimal design. This paper presents a systematic and efficient design algorithm for the superconducting magnet. We employ the sensitivity analysis based on finite element formulation. As for optimization algorithm, the inequality constraint for the superconducting state is removed by modifying the objective function and the nonlinear equality constraint of constant volume is satisfied by the gradient projection method. This design algorithm is applied to an optimal design problem of a solenoid air-cored superconducting magnet that has a design objective of the maximum energy storage.