• 한국멀티미디어학회논문지
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• 제2권4호
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• pp.419-429
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• 1999

본 논문에서는 멀티미디어 원격 CAI(Computer Assistant Instruction) 기술과 자바(Java) 기술을 이용하여 웹을 기반으로 하는 실시간 원격교육 시스템을 설계하고 구현하였다. 본 시스템은 웹 기반의 코스웨어(Courseware) 및 텍스트 기반의 문자강의 그리고 원격OHP를 실시간으로 제공한다. 코스웨어는 컴퓨터 기초교육을 제공하며 , 오소웨어 (Authorware)를 이용하여 구축하였다 실시간 원격교육을 위한 문자강의 및 원격 OHP의 클라이언트/서버 프로그램은 자바 애플릿(Applet)과 자바 애플리케이션(Application)으로 개발되었고, 자바 서블릿(Servlet)을 이용하여 본 시스템의 CGI프로그램을 작성하였다.

• 한국과학교육학회지
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• 제8권2호
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• pp.17-22
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• 1988

Computer based instruction in the elementary science curriculum will be played an important role through the fifth curriculum reform from the 1989 school year. This is essential for the science instruction because the strategies on the problem-solvings and inquiry approaches can be utilized for the science classroom. Computer education can be thought as the education about the computer and the education using the computer. Of them the education using the computer means the computer assisted instruction(CAI) what is called all the possible activities using the computer in the classroom. Student achievement as the result of CAI depends on the learning activities of students and the instructional techniques and strategies of teachers using the computer. However, computer based education to enhance the student achievement is pointed out the lacks of the standardized Korean alphabet code and the compatibility of qualified software. These problems will be relieved according to the coding for the Korean alphabet of SUPER PILOT program language.

• 한국가정과교육학회지
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• 제9권1호
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• pp.95-110
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• 1997

The purpose of this study are (1) to analysis the Paradigm’s changes in Educational Technology, (2) to examine its practice in Home Economics Education (H.E.E.), especially the researches about CAI in H.E.E. and (3) to propose the ideal practice of Educational Technology in H.E.E. As results, the paradigms of Educational Technology have been changed from media-centered to human-centered, and from objectivism(behaviorism and cognitivism) to constructivism. Related on Educational Technology, there have been six conceptual distortions or confusions in H.E.E. The Analyzed seven previous works on CAI in H.E.E. show the traditions of the Objectivism. And suggestions for ideal practice of Educational Technology in H.E.E. are presented.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.171-174
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• 2004

In order to improve the damage tolerance of the conventional laminated composites, three­dimensional fiber structures incorporated with stitching yams have been utilized in this study. From the newly developed process termed as TAPIS(TApe Placement Incorporated with Stitching), carbon/epoxy composites have been fabricated. Two-dimensional composites with the same stacking sequence as 3D counterparts have also been fabricated for the property comparison. To examine the damage resistance performance the low speed drop weight impact test has been adopted. For the assessment of damage after the impact loading, specimens were subjected to C-scan nondestructive inspection compression after impact(CAI) were also conducted to evaluate residual compressive strength. Although the damage area of 3D composites was greatly reduced$(30-40\%)$ compared with that of 2D composites, the CAI strength did not show drastic improvement.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.91-94
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• 2003

Laminated composites are liable to fatal damage under impact load due to the fact that they have no reinforcement in the thickness direction. To overcome the inherent weakness, three dimensional (3D) textile reinforcements have drawn much interests. In this paper, impact performance of 2D and 3D textile composites has been characterized. For 2D composites, fiber bundle size and fiber pattern have been varied. For 3D composites, orthogonal woven preforms of different density and type of through-thickness fibers have been studied. To assess the damage after the impact loading, specimens were subjected to C-scan nondestuctive inspection. Compression after impact (CAI) were also conducted in order to evaluate residual compressive strength.

• 한국컴퓨터정보학회지
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• 제2권2호
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• pp.27-40
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• 1996

During the 21st century of informational society, in the learning of various field will utilize the education using multi-media more extensively than ever before. The biggest question is how effective the education using multi-media will be. For effective education, wide-spread supply of not only the hardware and various kinds of CBT or CAI that are being developed in the learning of various fields. It is also felt that the skill for application of more convenient multi-media authoring tool is needed. If the producter of such multi-media authoring tool can store various types of information in a form of data bank, accessing the right information at right time and its application would be possible. It can also provide a lot of information to many out-of town learmers. As seen above, the scope of usage for multi-media authoring tool will be broadened. However, no matter how excellent the Authoring Tool is, the results can be very different depending on the method employed. In order to develop CBT or CAI that can be better used in the learning of various fields, examination and on-site training, more reseach should be done in Authoring Tool using virtual reality and artifical intelligence technology.

• 소성∙가공
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• 제24권6호
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• pp.431-436
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• 2015

MR fluid can change viscosity in the presence of a magnetic field. A characteristic of MR fluid is reduced scattering during jetting. For these reasons a MR fluid jet polishing system can be used for ultra-precision polishing. In the current paper, the polishing path was calculated considering the aspherical lens profile equation and the experimental conditions for the MR fluid jet polishing system. Then the polishing of an aspherical lens mold core using the MR fluid jet polishing system with the calculated path control was made and the results were compared before and after polishing.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 1998년도 가을 학술발표논문집 Vol.25 No.2 (2)
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• pp.138-140
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• 1998

본 연구실에서 개발하였던 클라이언트/서버 환경에서의 분산 멀티미디어를 이용한 CAI 시스템을 인터넷 환경에서 m:n 통신을 자유롭게 할 수 있도록 CORBA를 이용한 웹 기반의 원격 교육 시스템으로 구현한다. CORBA는 플랫폼과 개발 언어에 독립적으로 클라이언트와 서버의 객체들 사이에서 데이터를 상호 전달하도록 하는 미들웨어이다. 기존에 개발한 클라이언트/서버 원격 CAI 시스템의 경우는 클라이언트에 시스템의 일부가 구현되어야 함으로 클라이언트 측의 부담이 커지고, 학습자에게 공간상의 제한을 요하며 서버 측의 변화에 대해 클라이언트는 민감해진다. 이들 문제점을 CORBA를 이용하여 웹 상에 구현함으로써 학습자는 클라이언트에서 웹 브라우저만으로 학습이 가능하며 서버 측의 어떠한 변화에도 투명성을 가진다. 시스템의 개발에 있어서도 클라이언트와 서버를 서로 독립적으로 개발하므로 효과적이고, 객체 지향 언어를 사용함으로 재사용성 등의 장점을 가진다. 또한 시스템의 확장에 있어 많은 편리함을 제공한다.

• 동력기계공학회지
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• 제13권3호
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• pp.5-10
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• 2009

This work deals with a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. The fuel is injected indirectly into electrically heated inlet air flow. In order to keep a homogeneous air-fuel mixing, the fuel injector is cooled by the water of a specially designed coolant passage. The engine emission characteristics were investigated under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet air temperature. The ultra lean-burn can be achieved by the auto-ignition of gasoline fuel due to the heated inlet air in the compression ignition gasoline engine. It is confirmed that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxide can be significantly reduced by CAI combustion compared with the combustion of a conventional spark ignition engine.

• 한국정밀공학회지
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• 제16권10호
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• pp.172-181
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• 1999

The objective of this research is to develop a measurement error model for sculptured surfaces in On-Machine Measurement (OMM) process based on a closed-loop configuration. The geometric error model of each axis of a vertical CNC Machining center is derived using a 4${\times}$4 homogeneous transformation matrix. The ideal locations of a touch-type probe for the scupltured surface measurement are calculated from the parametric surface representation and X-, Y- directional geometric errors of the machine. Also, the actual coordinates of the probe are calculated by considering the pre-travel variation of a probe and Z-directional geometric errors. Then, the step-by-step measurement error analysis method is suggested based on a closed-loop configuration of the machining center including workpiece and probe errors. The simulation study shows the simplicity and effectiveness of the proposed error modeling strategy.