• Communications for Statistical Applications and Methods
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• 제11권1호
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• pp.49-58
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• 2004

In this talk we proposed an asymptotic test for dimensionality in the latent variable model for probabilistic principal component analysis with missing values at random. Proposed algorithm is a sequential likelihood ratio test for an appropriate Normal latent variable model for the principal component analysis. Modified EM-algorithm is used to find MLE for the model parameters. Results from simulations and real data sets give us promising evidences that the proposed method is useful in finding necessary number of components in the principal component analysis with missing values at random.

• 한국컴퓨터정보학회논문지
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• 제13권5호
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• pp.163-170
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• 2008

컴포넌트에 대한 의존도 및 활용도가 증가하면서 컴포넌트의 보안성 강화를 위한 필요성이 증가하고 있다. 컴포넌트는 재사용을 통한 소프트웨어의 개발 생산성을 향상시키는 이점을 제공한다. 이러한 이점에도 불구하고 컴포넌트의 보안 취약성은 재사용에 제한을 한다. 이의 개선을 위해 컴포넌트의 보안성을 높이는 경우에 가장 문제가 되는 부분이 재사용성에 대한 제한이 확대된다는 것이다. 따라서 컴포넌트의 재사용성과 보안성을 동시에 고려하는 컴포넌트의 모델이 제공되어야 한다. 이의 해결책으로 정보은폐와 수정의 용이성을 제공하여 보안성과 재사용을 확대할 수 있도록 재사용 모델을 결합하고 포장 및 애스펙트 모델을 통합한 컴포넌트 재사용 확대를 위한 관심사의 분리보안 모델을 제안하고 응용시스템을 구축하여 모델의 적합성을 검증하였다. 이의 응용은 핵심 및 보안 관심사의 분리를 통한 컴포넌트 기능의 확장과 수정의 용이성을 제공함으로써 보안성을 높이는 동시에 재사용성을 확대한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.524-529
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• 1993

Component Cost Analysis considers any given system driven by a white noise process as an interconnection of different components, and assigns a metric called "component cost" to each component. These component costs measure the contribution of each component to a predefined quadratic cost function. One possible use of component costs is for model reduction by deleting those components that have the smallest component cost. The theory of Component Cost Analysis is extended to include finite-bandwidth colored noises. The results also apply when actuators have dynamics of their own. When the dynamics of this input are added to the plant, which is to be reduced by CCA, the algorithm for model reduction process will be called Weighted Component Cost Analysis (WCCA). Closed-form analytical expressions of component costs for continuous time case, are also derived for a mechanical system described by its modal data. This is very useful to compute the modal costs of very high order systems beyond Lyapunov solvable dimension. A numerical example for NASA's MINIMAST system is presented.presented.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2001년도 International Conference CALS/EC KOREA
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• pp.671-679
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• 2001

사례연구를 통하여 UML Component Design Process의 일관성 및 정확성을 검증한다. Business Concept Model과 Use Case Model을 이용하여 Component Specification Process의 산출물인 Interface, Component Specification 및 Component Architecture 작성 UML Notation을 확장해서 Component 명세에 적용하는 것이 올바른 것인지 확인한다. <>,<>,<>,<>,<>, <>:로 Component Specification이 충분한지를 확인 OCL을 이용하여 Component Specification 중 Component Specification, Interface Specification, Operation Specification, Constraint, Pre/Post Condition의 정의에 유용한지 확인(중략)

• Structural Engineering and Mechanics
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• 제30권5호
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• pp.619-645
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• 2008

This study presents the efficiency of simulating structural systems using a method that combines a simplified component model (SCM) and rigorous component model (RCM). To achieve a realistic simulation of structural systems, a numerical model must be adequately capturing the detailed behaviors of real systems at various scales. However, capturing all details represented within an entire structural system by very fine meshes is practically impossible due to technological limitations on computational engineering. Therefore, this research develops an approach to simulate large-scale structural systems that combines a simplified global model with multiple detailed component models adjusted to various scales. Each correlated multi-scale simulation model is linked to others using a multi-level hierarchical modeling simulation method. Simulations are performed using nonlinear finite element analysis. The proposed method is applied in an analysis of a simple reinforced concrete structure and the Reuipu Elementary School (an existing structure), with analysis results then compared to actual onsite observations. The proposed method obtained results very close to onsite observations, indicating the efficiency of the proposed model in simulating structural system behavior.

• 한국항해항만학회지
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• 제34권7호
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• pp.577-585
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• 2010

This paper analyzes the efficiency of Korean Ship Component Part Manufacturer firms using DEA model. We evaluated the CCR, BCC efficiency and RTS of 30 Korea Ship Component Part Manufacturer firms. We also suggested the Korean Ship Component Part Manufacturer firms that can be benchmarked based on analyzed information. The result showed five enterprises whose values of CCR efficiency are 1, and eleven enterprises whose values of BCC efficiency are 1. RTS indicated IRS of 1 firms, DRS of 24 firms and CRS of 5 firms.

• Steel and Composite Structures
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• 제38권6호
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• pp.637-656
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• 2021

The component-based method is widely used to analyze the initial stiffness of joint in steel structures. In this study, an analytical component model for determining the column face stiffness of square or rectangular hollow section (SHS/RHS) subjected to tension was established, focusing on endplate connections. Equations for calculating the stiffness of the SHS/RHS column face in bending were derived through regression analysis using numerical results obtained from a finite element model database. Because the presence of bolt holes decreased the bending stiffness of the column face, this effect was calculated using a novel plate-spring-based model through numerical analysis. The developed component model was first applied to predict the bending stiffness of the SHS column face determined through tests. Furthermore, this model was incorporated into the component-based method with other effective components, e.g., bolts under tension, to determine the tensile stiffness of the T-stub connections, which connects the SHS column, and the initial rotational stiffness of the joints. A comparison between the model predictions, test data, and numerical results confirms that the proposed model shows satisfactory accuracy in evaluating the bending stiffness of SHS column faces.

• 정보처리학회논문지D
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• 제9D권3호
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• pp.435-446
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• 2002

최근에 많은 기업들이 재사용 컴포넌트를 이용하여 소프트웨어를 개발하고 있다. 컴포넌트의 효과적인 재사용은 소프트웨어 개발 생산성을 높여주고, 품질 향상을 유도하며, 품질이 우수한 컴포넌트 산출물의 개발은 컴포넌트 기반 소프트웨어 개발의 이슈로 논의되는 유지보수 문제를 감소시킨다. 본 논문에서는 경험적 연구에 의한 컴포넌트 개발 문서의 품질 평가 및 개선 관한 방안을 제시한다. 컴포넌트 품질 평가 방안은 컴포넌트 품질 탐조 모델과 품질 평가 모델로 구성된다. 탐조 모델은 컴포넌트 개발자를 위한 품질 지침을 포함하며, 평가 모델은 컴포넌트 유통 및 평가기관을 위한 평가 지침을 포함하고 있다. 본 논문의 타당성을 검증하기 위해, 컴포넌트 개발 기업을 대상으로 품질평가 모델을 적용하고 개선에 관한 방안을 제시하였다. 또한, 컴포넌트 문서의 품질 개선 방법 및 개선 효과에 대한 분석 내용을 제시하였다. 본 논문에서 제시한 컴포넌트 개발 산출물의 품질평가 모델은 품질이 우수한 컴포넌트 개발 산출물의 생산을 유도하며, 합리적인 품질 평가 방안을 제공한다.

• 품질경영학회지
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• 제18권2호
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• pp.33-42
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• 1990

This paper proposes the maintenance model of multi-component system when the failure characteristics and types of components are considered. In this model, it is assumed that a system is composed of a critical component, a major component and a minor component. Also, failure types is classified into major failure and minor failure. If major failure occurs to critical component before system age replacement time, the system is renewed. If major failure does not occur until its age replacement time, preventive maintenance is performed at age replacement time T. Minimal repairs are carried out after each minor failure. Major component is minimal-repaired if any failure is discovered during operation. Minor component should be replaced as soon as any failure is found. This paper determines the optimal replacement time of the system which minimizes total maintenance cost. Numerical example illustrates these results.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.484-484
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• 2001

The sophistication of current software applications results in the increasing cost fur software development time. The component-based software development framework is proposed to overcome the difficulty and time-consuming requirements by modularity and reusability. As is the general software case, a component-based simulation framework encourages the reusability of the real system model based on the modularity of the applied simulation methodology. This paper presents a component-based simulation environment that is based on the DEVS/COM run-time infrastructure. The DEVS (Discrete Event System Specification) formalism provides a formal modeling and simulation framework for the generic dynamic systems [1] and Microsoft's COM (Component Object Model) is one of the strongest competitor fur the component standard. The reusability by the DEVS/COM simulation environment saves model development time remarkably and component technology make simulator itself to be a subparts of real application.