• 한국정밀공학회지
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• 제20권8호
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• pp.115-125
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• 2003

To analyze the applications of all types of mechanical systems, general purpose analysis programs have been developed and commercialized. However, it is customary to develop and use customized programs even though they sometimes require more work than a general purpose program. A customized program is simplified to adapt to a particular application from the beginning, is designed for small computers, and developed with hardware-in-the-loop in mind so it can be applied effectively. By adding design knowledge and bundling know-how to an analysis program, analysis time can be reduced. And because an analysis has to work in conjunction with other analysis programs, a proprietary program that the user can easily modify can be useful. In this thesis, a multi-body dynamics analysis system is presented using one of the most useful programming techniques, object-oriented concept. The object-oriented concept defines a problem from the physical world as an abstract object, an abstract model. The object becomes encapsulated with the data and method. Simulation is performed using the object's interface. It is then possible for the user and the developer to modify and upgrade the program without having particular knowledge of the analysis program. The method presented in this thesis has the following advantages. Since the mechanical components of the multi-body system converts independent modeling into a class, the modification, exchange, distribution, and reuse of elements are increased. It becomes easier to employ a new analysis method and interface with other S/W and H/W systems. To employ a new analysis method, there is no need to modify elements of the main solver and the Library. In addition, information can be communicated to each object through messaging. It makes the modeling of new elements easier using inheritance. When developing a S/W for the computer simulation of physical system, it is reasonable to use object-oriented modeling. Also, for multi-body dynamics analysis, it is possible to develop a solver that is user-oriented.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권2호
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• pp.122-129
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• 2014

Effective information gathering and retrieval of the most relevant web documents on the topic of interest is difficult due to the large amount of information that exists in various formats. Current information gathering and retrieval techniques are unable to exploit semantic knowledge within documents in the "big data" environment; therefore, they cannot provide precise answers to specific questions. Existing commercial big data analytic platforms are restricted to a single data type; moreover, different big data analytic platforms are effective at processing different data types. Therefore, the development of a common big data platform that is suitable for efficiently processing various data types is needed. Furthermore, users often possess more than one intelligent device. It is therefore important to find an efficient preference profile construction approach to record the user context and personalized applications. In this way, user needs can be tailored according to the user's dynamic interests by tracking all devices owned by the user.

• Journal of Information Processing Systems
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• 제13권1호
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• pp.57-67
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• 2017

In this paper, Atanassov's intuitionistic fuzzy set theory is used to handle the uncertainty of students' knowledgeon domain concepts in an E-learning system. Their knowledge on these domain concepts has been collected from tests that were conducted during their learning phase. Atanassov's intuitionistic fuzzy user model is proposed to deal with vagueness in the user's knowledge description in domain concepts. The user model uses Atanassov's intuitionistic fuzzy sets for knowledge representation and linguistic rules for updating the user model. The scores obtained by each student were collected in this model and the decision about the students' knowledge acquisition for each concept whether completely learned, completely known, partially known or completely unknown were placed into the information table. Finally, it has been found that the proposed scheme is more appropriate than the fuzzy scheme.

• Asia pacific journal of information systems
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• 제9권3호
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• pp.47-73
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• 1999

Nowadays, the modeling of information systems have been enabled by various models and methodologies that are used for different purposes and perspectives upon the systems. The integrated modeling methodology that integrates these models and methodologies has become important concerns in system integration such as CIM and PDM. The primary objective of this paper is to propose a comprehensive integrated modeling methodology that integrates the OOIDEFO function model, OOIDEFO information model, node model, user interface model, and organization model for an effective analysis, design and implementation for system integration. This methodology covers the generic requirements of modeling methodology such as graphical notations, modeling processes, and abstraction mechanisms. Also, this methodology uses an 00 paradigm throughout the entire systems development life cycle. In order to prove the consistency and efficiency of the proposed methodology, the CIMS for ship production is modeled and prototyped.

• Management Science and Financial Engineering
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• 제5권1호
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• pp.27-49
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• 1999

WebME is an Web-based integrated modeling environment that implements a multi-facetted modeling approach to mathematical model representation and management. Key features of WebME include the following: (i) sharing of modeling knowledge on the Web, (ii) a user-friendly interface for creating, maintaining, and solving models, (iii) independent management of mathematical models from conceptual models, (iv) object-oriented conceptual blackboard concept, (v) multi-facetted mathematical modeling modeling, and (vi) declarative representation of mathematical knowledge. This paper presents details of design and implementation issues that were encountered in the development of WebME.

• International Journal of Precision Engineering and Manufacturing
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• 제4권6호
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• pp.61-70
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• 2003

A multibody system dynamics analysis program is presented using one of the most useful programming methodologies, the object-oriented modeling, The object-oriented modeling defines a problem from the physical world as an abstract object. The object becomes encapsulated with the data and method, Analysis is performed using the object's interface, It is then possible for the user and the developer to modify and upgrade the program without having particular knowledge of the analysis program, The method presented in this paper has several advantages, Since the mechanical components of the multi-body system are converted into the class, the modification, exchange, distribution and reuse of classes are increased. It becomes easier to employ a new analysis method and interface with other S/W and H/W systems, Information can be communicated to each object through messaging. This makes the modeling of new classes easier using the inheritance, When developing a S/W for the computer simulation of a physical system, it is reasonable to use object-oriented modeling.

• International Journal of CAD/CAM
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• 제9권1호
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• pp.93-102
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• 2010

Shaping realistic hairstyles for digital characters is a difficult, long and tedious task. The lack of appropriate interaction metaphors enabling efficient and simple, yet accurate hair modeling further aggravates the situation. This paper presents 3D interaction metaphors for modeling virtual hair using haptic interfaces. We discuss user tasks, ergonomic aspects, as well as haptics-based styling and fine-tuning tools on an experimental prototype. In order to achieve faster haptic rates with respect to the hair simulation and obtain a transparent rendering, we adapt our simulation models to comply with the specific requirements of haptic hairstyling actions and decouple the simulation of the hair strand dynamics from the haptic rendering while relying on the same physiochemical hair constants. Besides the direct use of the discussed interaction metaphors in the 3D modeling area, the presented results have further application potential in hair modeling facilities for the entertainment industry and the cosmetic sciences.

• International Journal of CAD/CAM
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• 제2권1호
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• pp.13-21
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• 2002

It is not possible to exchange parametric information of CAD models based on the current version of STEP. The design intent can be lost during the STEP transfer of CAD models. The Parametrics Group of ISO/TC184/SC4 has proposed the SMCH schema, which includes constructs for exchange of parametric information. This paper proposes a macro-parametric approach that is intended to provide capabilities to transfer parametric information including design intents. In this approach, CAD models are exchanged in the form of macro files. The macro file contains the history of user commands, which are used in the modeling phase. To exchange CAD models using the macro-parametric approach, the modeling commands of several commercial CAD systems are analyzed. Those commands are classified and a set of standard modeling commands has been defined. Mapping relations between the standard modeling commands and the native modeling commands of commercial CAD systems are defined. The scope of the current version is limited to parts modeling, not assemblies.

• 대한교통학회지
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• 제23권4호
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• pp.37-45
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• 2005

본 연구는 Nash의 협력게임인 협상게임(bargaining game)과 Wardrop의 사용자 균형해와의 관계를 규명하는 데 목적이 있다. Wardrop의 균형은 다수의 운전자들이 교통상황을 정확히 알고 있고(perfect information), 동시에 합리적으로 경로를 선택(rationality)한다는 경직된 가정이 존재하는데, 이는 실제로 존재하는 운전자 상호간의 교류나 타협을 배제하고 있다. 이런 측면에서 운전자간의 교류와 조절과정을 Nash게임의 협상과정(bargaining process)으로 표현할 경우, Wardrop의 경직된 기본가정들을 어느 정도 완화할 수 있을 것으로 보인다. 이를 위하여 본 연구에서는 Nash의 협상게임에 대한 교통망측면의 검토와 Nash의 협상해(bargaining solution)가 Wardrop의 사용자 균형(user equilibrium)과 동일함을 정리(theorem)를 통하여 증명하고 몇 가지 예제로 이를 확인한다. 협상게임은 대표적인 2인 협조게임(two-person cooperative game)으로 본 연구에서도 주로 2인 게임에 대해서 기술하며, 향후 n-인게임(n-person game) 모형에 대해서는 간략히 언급토록 한다.

• 경영정보학연구
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• 제23권1호
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• pp.1-22
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• 2021

본 연구에서는 퍼지논리 에이전트 기반 모델링(ABM: Agent-Based Modeling)을 이용한 시뮬레이션 기법을 이용하여 대표적 온라인 게임 장르인 MMORPG게임과 스포츠게임별로 게임 사용자들의 아이템 거래 행동특성을 분석하고자 한다. 온라인 게임 시장에서 아이템 거래는 게임회사의 수익성을 좌우하는 핵심변수이다. 그럼에도 불구하고, 기존 온라인 게임 연구에서는 게임 장르별로 게임 사용자들의 아이템 거래 행동특성을 면밀하게 분석하는 연구가 부족하였다. 이는 온라인 게임시장의 특성상 실증분석이 어렵기 때문이다. 이 같은 기존 연구의 한계를 극복하기 위한 방법으로 본 연구에서는 ABM을 이용한다. 한편, 게임 사용자들의 행동 특성은 게임 장르별로 달라지며 주어진 게임의 특성에 따라서 많은 편차를 보이기 때문에 그만큼 모호성과 불확실성이 수반된다. 이러한 상황을 고려하여 본 연구에서는 ABM과 퍼지 논리를 결합한 방법을 적용한다. 본 연구에서 고려한 온라인 게임 장르는 MMORPG와 스포츠게임이다. ABM과 퍼지 논리를 결합한 시뮬레이션 결과 MMORPG 게임장르에서는 사용자들이 고성능 아이템에 값비싼 가격을 지불할 동기가 있음이 확인되었다. 반면, 스포츠게임 장르의 경우 게임 사용자들은 아이템 성능 자체에는 민감하게 반응하지 않으며, 상대적으로 합리적인 가격대에서 게임 아이템 거래를 하고자 함을 알 수 있었다. 이 같은 본 연구의 분석결과로 미루어 볼 때 본 연구에서 제안하는 퍼지논리 기반의 ABM 시뮬레이션 기법은 온라인 게임사가 게임 아이템 관리 및 고객 이탈방지전략 수립 시 유용하게 사용될 가능성이 충분한 도구임을 알 수 있었다.