• 한국통신학회논문지
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• 제19권9호
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• pp.1680-1691
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• 1994

본 논문은 기존의 하이퍼텍스트 시스템의 문제점을 모델링 능력 미약 및 방향상실(lost in hyperspace. Disorientation)문제를 최소화 하기 위하여 데이터 모델을 확장하고 이 확장된 모델이 객체지향 데이타베이스 시스템에서 표현되는 방법을 BNF 정의를 사용하여 형식화하였다. 본 제안 모델은 모델링 능력 향상 및 개념적 항해를 위하여 링크에 의미를 부여하고, 노드와 링크를 기능에 따라 여러 타입으로 분류하여 효율적인 항해가 되도록 하였으며, 하이퍼텍스트 시스템에서 가장 문제가 되는 방향상실 문제를 방지하기 위하여 구조를 강화시키는 방법과 지능적인 항해 방법을 제안하였다.

• 한국정밀공학회지
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• 제16권5호통권98호
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• pp.91-97
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• 1999

The background of appearing MMS is to cope with the difficulty that occurred in constructing CIM with multi-vendor production devices such as CNC, PLC and robot. But so far the popularized use of MMS service in machine shop is not generalized because of economical and environmental reason. In this paper to solve this problem the CNC_VMD gateway for 3 types of heterogeneous machine tools in which MMS support is not available is developed and its performance is evaluated in shop floor having CIM environment. The developed VMD has the functions such as MMS service, driver for CNC interface and supporting for network. Non-MMS compatible machine tool can be MMS-compatible by using the developed gateway with CNC_VMD.

• 산업경영시스템학회지
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• 제23권55호
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• pp.107-116
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• 2000

Electronic Commerce is purchasing or sales a products and services to customers using computer network. It is different to traditional commerce. Also, It divide into business to business commerce and business to customer commerce. Cyber Shopping Mall is a representative type of business to customer commerce. The interest and demand of national business to customer commerce is explosively increasing with industry. It expect to reach 61 billion won in the 2000. Thus Structure of Cyber Shopping Mall is the more complex and the more vary types. It is the problem that change of established Cyber Shopping Mall structure is very difficult. The purpose of this study Is designed to Cyber Shopping Mall Purchase Process that deal with quickly changable internet environment and meet the needs of customers immediately using UML(Unified Modeling Language) in design phase determinant of Cyber Shopping Mal1 structure. Cyber Shopping Mall Purchase Process is designed to have objective-oriented development methodology's advantage. It has a flexibility in case of shopping mall structure change and acts as useful guideline in design phase of construction of Cyber Shopping Mall.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권10호
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• pp.508-512
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• 2001

This paper investigates the problem of the speed estimation of conventional speed sensorless stator flux-oriented induction machine drive in the field weakening region and proposes a new speed estimation scheme to estimate speed exactly in transients in the field weakening region. The error included in the estimated rotor speed is removed by not a low pass filter but Kalman filter so that exact speed estimation in transients is achieved.

• International Journal of CAD/CAM
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• 제8권1호
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• pp.55-62
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• 2009

Scene Transition Nets(STN) is a very useful modeling method for discrete-continuous hybrid systems. However, it is difficult to write STN in standard object-oriented programming languages because STN programming requires much skill of object-oriented programming and high knowledge of STN of designers. To overcome this problem, the authors have developed a useful GUI simulator software for modeling and simulations of STN. The experimental results of a transport system including an AGV showed the availability of our software.

• 한국과학교육학회지
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• 제12권1호
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• pp.61-73
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• 1992

In response to epoch-making development in science and technology, the innovative curricular materials have been begun to develop since the late 1950s and early 1960s. However, the new inquiry-centered materials have failed to be successfully used in teaching/learning practices of science. Among the various reasons for the failure, the very nature of the inquiry approach has been identified as the most critical problem. Nevertheless, fostering inquiry faculties on the part of the students has been emphasized as one of the most important objectives of science instruction. Therefore this study was conducted for the purpose of developing a practical inquiry-oriented instructional method. In order to obtain this goal the nature of scientific inquiry was analyzed and the status quo of science education in which inquiry-oriented instructional strategies were applied was examined. The results of the study are described in this paper.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.26-31
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• 2001

Petri nets(PN) have been introduced as a poweful analyzing and design tool for the discrete systems such as sequential control systems. However, one of the important problems in its applications is that the model can not be analyzed easily when we deal with large scale systems because of increase of the number of components of the systems. To overcome this problem, some methods for dividing or reducing of PN have been suggested. In this paper, an approach for hierarchical expression of PN based on Sequential Function Chart(SFC) and Bottom Up oriented Mehodology(BUM) is proposed. Especially, some definition and rules are defined in order to divide and compose sub PN. A measuring tank system will be described as a typical kind of discrete systems and modeled by some sub PN based on the SFC and BUM by the proposed method in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1140-1142
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• 1998

This paper presents object-oriented dynamic programing formulation of the unit commitment problem. This approach features the classification of generating units into related groups so called class. All object which share the same set of attributes and methods are grouped together in classes and designed inheritance hierarchy to minimize the number of unit combination which must be tested without precluding the optimal path. So this programming techniques will maximize the efficiency of unit commitment.

• 산업경영시스템학회지
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• 제20권43호
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• pp.163-174
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• 1997

Development of control model and system for AMS (Automated Manufacturing Systems) has long been interested by researchers. Presented in the paper is a systematic approach to constructing a Petri-nets(PNs) model of AMS and method for design a graphical model of a AMS by using a new modeling tool which is called PNs. So, the procedure of modeling in the AMS is the same as current practice of AMS design and is based on the IOM (Integrated Object-oriented Modeling) paradigm. An AMS, which consists of various machine groups, can produce machine parts in different physical dimensions and lot size. To model such a system, the method which utilizes Sub-PNs are proposed. This enables the models according to part routings. The machine group which causes bottleneck is obtained and modified to relieve the problem. By iterating these steps which consist of modelling, simulation, and performance evaluation, an AMS can e obtained which satisfies the required manufacturing conditions. Finally, the implementation issues of PN modeling are addressed. The approach is the IOM from PN modeling by Sub-PNs and the other is a development of IOM tool for the performance evaluation of AMS.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제6권2호
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• pp.65-74
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• 2002

In this paper, inquiry-oriented mathematics instruction was suggested as a teaching method to foster mathematical creativity. And it is argued that inquiry learning assist students to explore the mathematical problem actively and thus participate in mathematical activities like mathematicians. Through inquiry activities, the students learn mathematical ideas and develop new and creative mathematical ideas. Although creativity is often viewed as being associated with exceptional ability, for mathematics teacher who want to develop students' mathematical creativity, it is productive to view mathematical creativity as a mathematical ability that can be fostered in general school education. And also, both teacher and student have to think that they can develop mathematical ideas by themselves. That is very important to foster mathematical creativity in the mathematics class.