• 한국시뮬레이션학회논문지
• /
• 제9권4호
• /
• pp.41-50
• /
• 2000

We have many simulation constraints to meet as a modeled system becomes large and complex. Real-time simulations are the examples in that they are constrained by certain non-function constraints (e.g., timing constraints). In this paper, an enhanced hierarchical modeling methodology is proposed to efficiently deal with constraint-simulations. The proposed modeling method enhances hierarchical modeling methods to provide multi-resolution model. A simulation model is composed by determining the optimal level of abstraction that is guaranteed to meet the given simulation constraints. Four modeling activities are defined in the proposed method: 1) Perform the logical architectural design activity to produce a multi-resolution model, 2) Organize abstraction information of the multi-resolution model with AT (Abstraction Tree) structure, 3) Formulate the given constraints based on U (Integer Programming) approach and embrace the constraints to AT, and 4) Compose a model based on the determined level of abstraction with which the multi-resolution model can satisfy all given simulation constraints. By systematically handling simulation constraints while minimizing the modeler's interventions, we provide an efficient modeling environment for constraint-simulations.

• Asia pacific journal of information systems
• /
• 제14권1호
• /
• pp.79-100
• /
• 2004

As a part of ebXML(Electronic Business using eXtensible Markup Language) framework, BPSS(Business Process Specification Schema) has been provided to support the direct specification of the set of elements required to configure a runtime system in order to execute a set of ebXML business transactions. The BPS,' is available in two stand-alone representations, a UML version and an XML version. Due to the limitations of UML notations and XML syntax, however, current ebXML BPSS specification fails to specify formal semantic constraints completely. In this study, we propose a constraint classification scheme for the BPSS specification and describe how to formally represent those semantic constraints using OCL(Object Constraint Language). As a way to validate p Business Process Specification(BPS) with the formal semantic constraints, we suggest a rule-based approach to represent the formal constraints and demonstrate its detailed mechanism for applying the rule-based constraints to the BPS with a prototype implementation.

• 한국정밀공학회지
• /
• 제13권9호
• /
• pp.84-93
• /
• 1996

This paper describes the development of new feature positioning method which embedded into the top-down assembly modeling system supporting conceptual design. In this work, the user provides the geometric constraints representing the position and size of features, then the system calculates their proper solution. The use of geometric constraints which are easy to understand intuitively enables the user to represent his design intents about geometric shapes, and enables the system to propagate the changes automatically when some editing occurs. To find the proper solution of given constraints, the Selective Solving Method in which the redundant or conflict equations are detected and discarded is devised. The validity of feature shapes satisfying the constraints can be maintained by this technique, and under or over constrained user-defined constraints can also be estimated. The problems such as getting the initial guess, controlling the multiple solutions, and dealing with objects of rotational symmetry are also resolved. Through this work, the feature based modeling system can support more general and convenient modeling method, and keeps the model being valid during modifying models.

• 한국CDE학회논문집
• /
• 제5권4호
• /
• pp.301-311
• /
• 2000

For effective part modifications which is necessary in the design process frequently, variational geometric modeling with constraint management being used in a wide. Most variational geometric modeling methods, however, manage just the constraints about sketch elements used for generation of primitives. Thus, not only constraint propagation but also re-build of various modeling operations stored in the modeling history is necessary iota part geometry modifications. Especially, re-build of high-cost Boolean operations is apt to deteriorate overall modeling efficiency abruptly. Therefore, in this paper we proposed an algorithm that can handle all geometric entities of the part directly. For this purpose, we introduced eight type geometric constraints to the various geometric calculations about all geometric entities in sweepings and Boolean operations as well as the existing constraints of the sketch elements. The algorithm has a merit of rapid part geometric modifications through only constraint propagation without rebuild of modeling operations which are necessary in the existing variational geometric modeling method.

• 한국지구과학회지
• /
• 제38권4호
• /
• pp.303-320
• /
• 2017

본 연구의 목적은 과학적 모델의 사회적 구성 수업을 적용한 야외지질학습에서 학생들이 만드는 조별 모델 구성 과정에 대해 제약조건을 중심으로 이해하는 것이다. S 영재원 지구과학분과 3조, 12명의 학생들을 대상으로 진행하였다. '관악산은 어떻게 형성되었을까?'를 주제로 야외지질답사 2차시, 과학적 모델의 사회적 구성 수업 3차시로 진행하였다. 조별 모델 구성과정에 관해서는 Nersessian (2008)이 제시한 제약조건을 이론적 근거로 하여 반-구조화된 인터뷰, 야외지질답사, '과학적 모델의 사회적 구성 수업'의 모든 담화, 활동지를 분석하였다. 연구결과는 다음과 같다. 첫 번째 야외지질학습에 적용한 과학적 모델의 사회적 구성 수업에 나타난 제약조건의 출처는 과학 이론, 야외지질답사에서 관찰한 내용, 과학적 모델의 사회적 구성 수업에서 추가로 제공된 것이 있었다. 두 번째 조별 모델링에 영향을 미치는 3가지 종류의 제약조건이 있다. 조별 모델에는 조별 구성원 모두가 동일하게 가지고 있던 것으로 '공통적인 제약조건', 조별 구성원 일부가 가지고 있던 것 중 조별 모델에 반영된 '채택된 제약조건', 마지막으로 초기 모델에는 없었으나 조별 모델 구성과정에서 새롭게 나타난 '생성된 제약조건'이 있었다. 이번 연구는 학교 과학에서 제약조건을 기반으로 조별 모델이 만들어지는 과정을 이해할 수 있을 뿐만 아니라 야외지질학습이라는 수업 사례를 보여줌으로서 실제 적용하는데 이바지 하고자 하였다는 점에서 의의가 있다.

• 한국CDE학회논문집
• /
• 제12권5호
• /
• pp.395-404
• /
• 2007

Feature-based modeling and history-based modeling are the two main paradigms that are used in most of current CAD systems. Although these modeling paradigms make it easier for designers to create solid model, it may pose dependency constraints on features that are interacting one with another. When editing such features, these constraints often cause unpredictable and unacceptable results. For example, when a parent feature is deleted, the child features of the parent feature are also deleted. This entails re-generations of the deleted features, which requires additional modeling time. In order to complement this situation, we propose a method to delete only the features of interest by disconnecting the dependency constraints. This method can provide designers with more efficient way of model modification.

• 한국초등과학교육학회지:초등과학교육
• /
• 제36권1호
• /
• pp.16-30
• /
• 2017

The purpose of this study was to interpret modeling-based elementary science lessons from a perspective of distributed cognition. Data sources included three consecutive elementary science lessons dealing with particle models of gases and students' worksheet generated from modeling activities during the lessons. The data were analyzed in ways that could reveal the affordances and constraints of students' mental models and an external model in the science textbook, as well as the evolution of the models. The results showed that the students' mental models and the external model provided both affordances for and constraints to scientific problem solving and that the models evolved in the process of overcoming the constraints. Implications for science lessons and science education research were suggested.

• 산업공학
• /
• 제25권3호
• /
• pp.300-308
• /
• 2012

For convenient business process modeling we propose a mathematical approach to obtain appropriate process structures. In this paper, we define business process structural constraints, on which basis, using Social Network Analysis (SNA), we analyze the frequency of handover occurrences among performers in social network. We here present, therefrom, a new, mathematical approach to business process modeling that proceeds by identifying the social relations among activities.

• 제어로봇시스템학회논문지
• /
• 제21권7호
• /
• pp.654-661
• /
• 2015

Stairs are the most popular obstacles in buildings and factories. To enlarge the application areas of a field robotic platform, stair-climbing is very important mission. One important reason why a stair-climbing is difficult is that stairs are various in sizes. To achieve autonomous climbing of various-sized stairs, dynamic modeling is essential. In this research, an inverse dynamic modeling is performed to enable an autonomous stair climbing. Stair-climbing robotic platform with flip locomotion, named FilpBot, is analyzed. The FlipBot platform has advantages of robust stair-climbing of various sizes with constant speed, but the autonomous operation is not yet capable. Based on external constraints and the postures of the robot, inverse dynamic models are derived. The models are switched by the constraints and postures to analyze the continuous motion during stair-climbing. The constraints are changed according to the stair size, therefore the analysis results are different each other. The results of the inverse dynamic modeling are going to be used in motor design and autonomous control of the robotic platform.

• 한국전자거래학회:학술대회논문집
• /
• 한국전자거래학회 2004년도 e-Biz World Conference
• /
• pp.318-326
• /
• 2004

The ebXML (Electronic Business using eXtensible Markup Language) Specification Schema is to provide nominal set of specification elements necessary to specify a collaboration between business partners based on XML. As a part of ebXML Specification Schema, BPSS (Business Process Specification Schema) has been provided to support the direct specification of the set of elements required to configure a runtime system in order to execute a set of ebXML business transactions. The BPSS is available in two stand-alone representations, a UML version and an XML version. Due to the limitations of UML notations and XML syntax, however, current ebXML BPSS specification is insufficient to specify formal semantic constraints of modeling elements completely. In this study, we propose a classification schema for the BPSS semantic constraints and describe how to represent those semantic constraints formally using OCL (Object Constraint Language). As a way to verify a Business Process Specification (BPS) with the formal semantic constraint modeling, we suggest a rule-based approach to represent the formal constraints and to use the rule-based constraints specification to verify BPSs in a CLIPS prototype implementation.