• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.873-879
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• 2012

Metamodels have been developed with a variety of design optimization techniques in the field of structural engineering over the last decade because they are efficient, show excellent prediction performance, and provide easy interconnections into design frameworks. To construct a metamodel, a sequential procedure involving steps such as the design of experiments, metamodeling techniques, and validation techniques is performed. Because validation techniques can measure the accuracy of the metamodel, the number of presampled points for an accurate kriging metamodel is decided by the validation technique in the sequential kriging metamodel. Because the interpolation model such as the kriging metamodel based on computer experiments passes through responses at presampled points, additional analyses or reconstructions of the metamodels are required to measure the accuracy of the metamodel if existing validation techniques are applied. In this study, we suggest a sensitivity validation that does not require additional analyses or reconstructions of the metamodels. Fourteen two-dimensional mathematical problems and an engineering problem are illustrated to show the feasibility of the suggested method.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.477-480
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• 2002

본 연구는 UML로 작성된 객체지향 다이어그램의 일관성과 정착성을 검증하기 위한 메타모델에 관한 연구이다. 일관성이란 하나의 요구사항으로 표현된 여러 가지 UML 다이어그램이 통일된 의미로 표현되었는가를 나타내는 성질이고, 정확성은 UML로 작성한 다이어그램이 UML의 표준에 적합하게 작성이 되었는가를 나타내는 성질이다. 이러한 일관성과 정확성을 검증하기 위해서는 각 다이어그램의 표준모델과 다이어그램간의 관계를 파악할 필요가 있으며 메타모델이 다이어그램간의 관계와 다이어그램 자체의 표준모델을 적절하게 표현하여 주므로 메타모델을 구성하는 작업이 필요하다. 본 연구에서는 기존의 메타모델에 관한 연구를 분석하여 새로운 형태의 구성요소와 관계로 표현된 메타모델을 제시하고 일관성과 정확성을 검증하기 위한 구성요소를 도출한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.5
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• pp.541-547
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• 2010

The rigorous validation of the accuracy of metamodels is an important topic in research on metamodel techniques. Although a leave-k-out cross-validation technique involves a considerably high computational cost, it cannot be used to measure the fidelity of metamodels. Recently, the mean$_0$ validation technique has been proposed to quantitatively determine the accuracy of metamodels. However, the use of mean$_0$ validation criterion may lead to premature termination of a sampling process even if the kriging model is inaccurate. In this study, we propose a new validation technique based on the mean and variance of the response evaluated when sequential sampling method, such as maximum entropy sampling, is used. The proposed validation technique is more efficient and accurate than the leave-k-out cross-validation technique, because instead of performing numerical integration, the kriging model is explicitly integrated to accurately evaluate the mean and variance of the response evaluated. The error in the proposed validation technique resembles a root mean squared error, thus it can be used to determine a stop criterion for sequential sampling of metamodels.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.2007-2010
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• 2002

본 연구는 UML(Unified Modeling Language) 표준에 의해 작성된 객체지향 다이어그램의 일관성과 정확성을 검증하는 방법에 관한 연구이다. 일관성은 하나의 요구사항으로 표현된 여러 가지 UML 다이어그램이 통일된 의미로 표현되었는가를 나타내는 성질이고, 정확성은 사용자가 작성한 다이어그램이 UML 표준에 적합하게 작성이 되었는가를 나타내는 성질이다. 정확성을 검증하기 위해서는 관계를 가지는 다이어그램들의 관계요소를 파악할 필요가 있다. 메타모델을 유도한 후에는 각 메타모델을 기초로 일관성 및 정확성 검증 규칙을 유도해 내고 검증의 자동화를 위하여 정형적 명세로 표현한다. 본 연구에서는 다이어그램별로 작성한 메타모델에서 규칙을 유도하고 그러한 규칙을 OCL(Obiect Constraint Language) 형태로 표현하여 검증하는 방법을 제안한다.

• Journal of KIISE:Software and Applications
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• v.30 no.12
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• pp.1158-1171
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• 2003

The UML is a widely accepted standard in object-oriented modeling. As the UML is semantically rich, we can describe in detail the system that will be developed, but we cannot guarantee the correctness and consistency of the designed model. Therefore, it is important to minimize the error by verifying user models in an early stage. In this paper, we propose a method for verifying the consistency of UML structural diagrams and behavioral diagrams using OCL verification rules and meta-metamodel. The consistency is a nature for checking whether the structural diagrams and behavioral diagrams are coherently designed according to a specific requirement. First we build meta-metamodels of the structural diagram and behavioral diagram that are described with the UML diagrams and the related elements, we derive rules for verifying the consistency from each meta-metamodels, and then formally specify with the language such as OCL for automatic verification. Finally, we verify the usefulness of the rule through a case study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6458-6465
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• 2015

Frequent change of mobile applications has become a burden to management of mobile services. Therefore, the development of mobile Web services, which the central management is easy, has increased. Tools which developers, as well as general users can easily develop, have been developed for mobile Web services. However, researches of standardized metamodel for implementing mobile Web service dynamically by general users is the inadequate situation. In this paper, we propose a dynamic metamodel for developing mobile Web services. The dynamic metamodel consists of a mobile Web pages, mobile Web page instance and dynamic connection using XDPL structure. we study a connection metamodel for condition connection, split connection and join connection, and combile entire metamodel, finally. Also, we carry out a case study in order to verify the suitability of metamodel by based on XPDL.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4057-4064
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• 2014

In this paper, attempts were made to design a preform for a final punch inexpensively using the proposed approximate optimization method or metamodel-based simulation optimization. The design objective of this work is to achieve a uniform distribution of effective strains, the angle dimension of the preformed punch is chosen as a design variable, and maximum underfill ratio is used as a constraint. For this optimization, a computer simulation of a practical punch forging process is run using DEFORM software, in which a preformed punch(workpiece), a master punch(upper die), and a bottom die are dealt with. A validation method is introduced to determine if the simulation results match the actual forging process. In addition, this work presents the detailed design optimization procedure consisting of (i) generation of an initial metamodel, (ii) metamodel optimization, (iii) validation of metamodel-predicted optimum, and (iv) metamodel improvement.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.971-982
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• 2003

The consistency of UML diagrams is a nature for checking whether diagrams are coherently designed with only one requirements and the correctness of UML Diagrams, especially it uses OCL(Object Constraint Language) which is standard constraint language in UML. Firstly we devise metamodels that are described with conponent and relationships, then we derive verification rules from each matamodels for verifying correctness and consistency, and then we formally specify the rules with OCL for automatic verification. Finally we verify the rules with USE TOOL.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.308-313
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• 2016

Modern systems have become more and more complex due to the ever-increasing user requirements and rapid advance of technology. As such, the frequency of accidents due to system design errors or failure has been increasing. When the damage incurred by accidents to human beings or property is serious, the underlying systems are referred to as safety-critical systems. The development of such systems requires special efforts to ensure the safety of the human beings operating them. To cope with such a requirement, in this paper an approach is employed in which we consider safety starting from the conceptual design phase of the systems. Specifically, a systems design method that can detect functional failure is proposed by utilizing meta-models and M&S methods. To accomplish this, the safety design data from international safety standards are first extracted and also a meta-model is generated using SysML (systems modeling language). Then, a SysML-based system design method is proposed based on the use of the developed meta-model. We also discuss how the safety requirements can be created and verified using a simulation method. Finally, through a case study in automotive design, it is demonstrated that the detection of a functional failure and the verification of a safety requirement can be accomplished using the SysML-based M&S method. This study indicates that the use of meta-models can be useful for collecting and managing safety data and that the meta-model based M&S method can make it possible to satisfy the system requirements by reducing the design errors.

• Journal of KIISE:Software and Applications
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• v.32 no.6
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• pp.486-501
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• 2005

XPDL is a XML-based language for process definition exchange that is proposed by WfMC. This paper propose a model which model XPDL document structure (Schema) using UML in order to define and to exchange workflow process, and make business flow understanding ease for inter-business cooperation. So, we define mapping rules in which map XPDL documents into UML class diagram and UML activity diagram. By these mapping rules, elements composing XPDL process meta-model are mapped into UML class diagram, and process activities are mapped into UML activity diagram. Also, we apply proposed mapping technique to model a workflow of (')Credit card state check system.(')