• 디지털산업정보학회논문지
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• 제6권4호
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• pp.45-56
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• 2010

This paper suggests constraint data modeling based on constraint data presentation techniques to perform complex spatial database operation naturally. We were able to identify the limitation of extendibility of dimension and non-equal framework via relevant research for former schema of spatial database and query processing. Therefore we described generalized tuple of spatial data and the definition of suggested constraint data modeling. Also we selected MLPQ/PReSTO tool among constraint database prototype and compare standard functionality of ARC/VIEW. Then we design scenario for spatial operation using MLPQ/PReSTO and we suggested application effect after query processing. Based on above explanation, we were able to identify that we can process spatial data naturally and effectively using simple constraint routine on same framework via constraint data modeling.

• 한국CDE학회논문집
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• 제3권4호
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• pp.211-222
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• 1998

Parametric design is an important modeling paradigm in CAD/CAM applications, enabling efficient design modifications and variations. One of the major issues in parametric design is to develop a geometric constraint solver that can handle a large set of geometric configurations efficiently and robustly. In this appear, we propose a new approach to geometric constraint solving that employs a graph-based method to solve the ruler-and-compass constructible configurations and a numerical method to solve the ruler-and-compass non-constructible configurations, in a way that combines the advantages of both methods. The geometric constraint solving process consists of two phases: 1) planning phase and 2) execution phase. In the planning phase, a sequence of construction steps is generated by clustering the constrained geometric entities and reducing the constraint graph in sequence. in the execution phase, each construction step is evaluated to determine the geometric entities, using both approaches. By combining the advantages of the graph-based constructive approach with the universality of the numerical approach, the proposed approach can maximize the efficiency, robustness, and extensibility of geometric constraint solver.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권5호
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• pp.408-417
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• 2005

Increasing numbers of value added chemicals are being produced using microbial fermentation strategies. Computational modeling and simulation of microbial metabolism is rapidly becoming an enabling technology that is driving a new paradigm to accelerate the bioprocess development cycle. In particular, constraint-based modeling and the development of genome-scale models of industrial microbes are finding increasing utility across many phases of the bioprocess development workflow. Herein, we review and discuss the requirements and trends in the industrial application of this technology as we build toward integrated computational/experimental platforms for bioprocess engineering. Specifically we cover the following topics: (1) genome-scale models as genetically and biochemically consistent representations of metabolic networks; (2) the ability of these models to predict, assess, and interpret metabolic physiology and flux states of metabolism; (3) the model-guided integrative analysis of high throughput 'omics' data; (4) the reconciliation and analysis of on- and off-line fermentation data as well as flux tracing data; (5) model-aided strain design strategies and the integration of calculated biotransformation routes; and (6) control and optimization of the fermentation processes. Collectively, constraint-based modeling strategies are impacting the iterative characterization of metabolic flux states throughout the bioprocess development cycle, while also driving metabolic engineering strategies and fermentation optimization.

• 한국시뮬레이션학회논문지
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• 제9권4호
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• pp.41-50
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• 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.

• 한국멀티미디어학회논문지
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• 제11권4호
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• pp.516-524
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• 2008

본 논문은 기존에 연구되지 않았던 옷의 독특한 특징들을 묵시적 제한방법을 사용하여 강력한 제한력으로 구현하는 새로운 모델링 방법을 제안한다. 기존의 명시적 제한방법인 Baumgarte 안정화 방법은 해에 빠르게 수렴하도록 하기 위해 사용자가 시뮬레이션에 따라서 값이 달라지는 안정화 변수 값을 선택해야 하고, 시뮬레이션의 시간 간격 사용에 있어서 안정화에 한계가 있는 단점들이 있다. 본 논문은 큰 시간 간격에도 안정적이고, 안정화 변수 값을 요구하지 않고, 물리적으로도 적합한 물체의 움직임을 보장하는 묵시적 제한방법을 사용한다. 또한 묵시적 제한 방법의 계산 복잡도는 Baumgarte 안정화 방법과 같다. 본 논문은 묵시적 제한방법의 수식과 제한의 오차 분석을 설명하였고 옷의 솔기, 단추, 옷 주름, 옷의 구김, 과잉 늘어짐 방지 등의 복잡한 옷의 요소들에 대한 모델링 방법을 제시하였다. 본 논문에서 제안된 방법은 외부 상황에 의해 각종 제한들이 자동적으로 설정되고 제거되어 계산 비용을 절약함과 동시에 옷의 독특한 특징들의 구현을 통해 현실감 있는 옷 시뮬레이션의 결과들을 얻었다.

• 대한기계학회논문집
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• 제19권7호
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• pp.1604-1618
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• 1995

In the process of mechanical assembly design, assembly modeling systems have been used mainly for the design verification before manufacturing by enabling to check the interference and/ or the dynamic and kinematic performance. However, the conventional assembly modeling systems have a shortcoming that they can not be used in the initial design stage but can be used only after the design is fully completed. In other words conventional assembly modeling systems provide bottom-up modeling which means that the detailed modeling of components must precede the definition of relationships between them. To resolve this problem, an assembly modeling system is proposed to provide a top-down modeling environment in which components and assembly can be modeled simultaneously. To this end, an assembly data structure suitable for top-down assembly modeling has been established. Feature positioning Module(FPM) using geometric constraints has been also developed. The Sekective Solving Method proposed for FPM is based on the priority between the constraint equations and enables the designer's intent expressed by geometric constraints to be maintained throughout the whole modeling process. Finally, the feature based modeling technique using two-level features has been developed. Two-level features include an abstract model and a detailed model in a merged form in non-manifold data frame.

• 한국지리정보학회지
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• 제12권1호
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• pp.81-95
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• 2009

지리정보시스템(GIS)과 같은 대용량 공간 데이터 처리에 대한 새로운 패러다임이 바로 제약 데이터베이스(CDB) 모델이다. 이 논문에서는 기존의 공간 데이터베이스의 관련연구를 통하여 스키마 구성 및 질의처리의 한계점을 찾아내고 보다 효율적인 처리방식의 제약 데이터 모델을 제안한다. 제약 데이터 모델의 개념, 표현방법, 질의처리의 예를 제시했으며, 특히 평면자료에 높이를 표시하는 불규칙 삼각망(TIN)을 제약 데이터 모델로 표현하고, 기존 공간 데이터 모델과 비교 평가했다. 우리는 제약 데이터모델링을 통하여 단순하고 우아하게 형식화할 수 있다는 것을 확인하였다.

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

• 한국CDE학회논문집
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• 제16권3호
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• pp.167-177
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• 2011

This paper describes an ontology-based intelligent CAD system for injection mold design, which has been developed based on a commercial CAD system called Unigraphics and an ontological framework for representing the implicit design knowledge as well as the explicit based on the extended function-behavior-structure (FBS) engineering design model that includes the constraint. The system also provides various convenient solid modeling capabilities for mold design and the design process modeling capability that facilitates mold redesign process.

• 한국CDE학회논문집
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• 제6권2호
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• pp.78-88
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• 2001

In order to adopt feature-based parametric modeling, CAD/CAM applications must have a geometric constraint solver that can handle a large set of geometric configurations efficiently and robustly. In this paper, we describe a graph constructive approach to solving geometric constraint problems. Usually, a graph constructive approach is efficient, however it has its limitation in scope; it cannot handle ruler-and-compass non-constructible configurations and under-constrained problems. To overcome these limitations. we propose an algorithm that isolates ruler-and-compass non-constructible configurations from ruler-and-compass constructible configurations and applies numerical calculation methods to solve them separately. This separation can maximize the efficiency and robustness of a geometric constraint solver. Moreover, the solver can handle under-constrained problems by classifying under-constrained subgraphs to simplified cases by applying classification rules. Then, it decides the calculating sequence of geometric entities in each classified case and calculates geometric entities by adding appropriate assumptions or constraints. By extending the clustering types and defining several rules, the proposed approach can overcome limitations of previous graph constructive approaches which makes it possible to develop an efficient and robust geometric constraint solver.