• Composites Research
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• v.18 no.4
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• pp.44-51
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• 2005

In this paper, we developed the direct numerical simulation(DNS) model considering the geometry of yams which consist of 3D orthogonal woven composite materials, and using this model, the dynamic behavior of under transverse low-velocity impact has been studied. To build up the micromechanical model considering tow spacing and waviness, an accurate unit structure is presented and used in building structural plate model based on DNS. For comparison, DNS results are compared with those of the micromechanical approach which is based on the global equivalent material properties obtained by DNS static numerical tests. The effects with yarn geometrical irregularities which are difficult to consider in a macroscopic approach are also investigated by the DNS model. Finally, the multiscale model based on the DNS concepts is developed to enhance efficiency of analysis with real sized numerical specimen and macro/micro characteristics are presented.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.459-461
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• 2009

시스템 개발을 위해서는 시스템이 제공하는 기능을 명료하게 기술함은 물론 목표 시스템이 참조하는 외부 시스템의 기능을 명확하게 식별하여야 한다. 이는 목표 시스템의 범위를 명확하게 한정하기 위해 매우 중요하다. 그러나 현재의 유스케이스 모델링 기법에서는 외부 시스템은 액터로만 표현된다. 이는 외부 레거시 시스템을 간결하게 표현할 수 있다는 장점이 있으나, 외부 시스템의 기능 중 목표 시스템이 참조하는 유스케이스만을 식별하기 어렵게 만드는 단점도 갖는다. 이러한 불명확성은 유스케이스 명세 시 모델 작성을 어렵게 하여 유스케이스 모델의 이해도를 저하시키는 원인이 된다. 본 논문에서는 외부 유스케이스를 이용한 확장 모델링 기법을 제시한다. 확장 모델링은 레거시 시스템에 존재하는 외부 유스케이스를 표현하고, 내부 유스케이스와 관계성을 가질 수 있도록 확장 메커니즘을 지원한다. 확장을 위해서는 UML 확장 메커니즘 중 하나인 스테레오타입(Stereotype)을 활용하며, 따라서 기존 유스케이스 모델과의 호환성을 그대로 유지함으로써, 기존 모델링 기법과 일관되게 적용 가능하다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.6
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• pp.530-536
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• 2016

The handling quality simulator including high fidelity flight mechanics model is indispensable component to design and verify the flight control system. Korea Aerospace Industries, LTD. (KAI) has been performing LCH (Light Civil Helicopter) core technology development program regarding automatic flight control system (AFCS) software development. And KAI has been developing flight mechanics model using FLIGHTLAB to design and evaluate the AFCS flight control law. This paper presents the handling quality assessment environment development results through the combining FLIGHTLAB with a legacy simulator. And this paper details the FLIGHTLAB model, application development process and FLIGHTLAB interface design. The developed handling quality assessment environment has been demonstrated with the ADS-33E hover and pirouette MTE (Mission Task Element) maneuver simulation.

• Journal of Korea Multimedia Society
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• v.14 no.4
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• pp.554-566
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• 2011

Service-oriented architecture(SOA) is a paradigm where reusable units are independently executable and only accessible through outer interfaces. Standardized methodology based on SOA has not been decided yet although a lot of efforts have been made for systems using SOA. Therefore Development of system using SOA is facing many difficulties currently. In this paper, service oriented methodology of function based model for supporting legacy system is proposed. Standardized methods for function based reusability through analysing SOA methodology are proposed and guide lines for improvement of service reusability are presented.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.17-18
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• 2019

오픈플랫폼 기반 주택시장 분석 플랫폼은 Linux(CentOS) 서버를 운영체제로 주택 분야 빅데이터 수집/가공/분석/예측을 위하여 Hadoop 기반으로 구축한 플랫폼이다. 오픈소스 플랫폼을 기반으로 다양한 대규모 데이터를 분석하고, 미시/거시 모델을 적용하여 그 예측력을 검증하고자 한다. 본 연구에서는 기존 방식으로 분석하던 Windows 기반의 E-Views 거시 분석 모형을 오픈소스 분석 플랫폼을 구축하고 이와 연계하여 결과를 도출하는 방안을 제시하고자 한다.

• 한국IT서비스학회:학술대회논문집
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• 2003.11a
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• pp.609-615
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• 2003

본 논문은 레거시 시스템을 컴포넌트 기반 시스템으로 재공학하는 절차 및 기법을 제공하는 마르미-RE의 전체 단계 중 계획 단계에 대한 상세한 프로세스를 서술한다. 계획 단계는 11개의 작업으로 이루어져 있고, 이들은 각각 4개의 활동인 현황 파악, 개선 비즈니스 도출, 개선 전략 수립, 개발 계획 수립으로 그룹핑 된다. 현황 파악 활동은 업무의 전반적인 정보 분석을 통해 조직의 구조와 업무의 흐름 및 문제점을 파악하고, 개선 비즈니스 모델 도출은 유스케이스 모델링과 객체 모델링을 통해 사용자의 요구사항을 수집하여 개선 업무 모델을 도출한다. 개선 전략 수립 활동은 변환을 위한 전략을 수립하고, 마지막으로 개발 계획 수립 활동에서 변환을 위한 프로젝트 계획서가 작성된다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.6
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• pp.569-577
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• 2010

A multiscale particle simulation technique that can be applied to a multiphase fluid system has been developed. In the boundary region where the macroscopic- and microscopic-scale models overlap each other, three distinctive features are introduced in the simulation. First, a wall is set up between the gas and liquid phases to separate them and match the phases respectively to the macroscopic conditions stably. Secondly, the interfacial profile is obtained near the matching region and the wall translates and rotates to accommodate the change in the liquid-vapor interfacial position in the molecular model. The contact angle thus obtained can be sent to the macroscopic model. Finally, a state of mass and temperature in the region is maintained by inserting and deleting the particles. Good matching results are observed in the cases of the complete and partial wetting fluid systems.

• Korean Journal of Social Welfare
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• v.58 no.4
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• pp.313-339
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• 2006

The purpose of this study is to analysis empirically the socio-structural causes of working poor. This study used raw data of of Korea National Statistical Office from 1982 to 2004, and put in operation time series multiple regression analysis to use socio-economic factors of macro-economy environment, labor market, distribution system. Contrary to assertion of growth-concentrated people, economic growth rate has had significantly positive effect on the change of working poor size. In the growth period there has been trickle down effect of economic growth, but in the post-Fordism period there has not been valid circular relation. Recent introduction of the U. S. type capitalism resulted in negative phenomenon like aggravation of income distribution, deterioration of employment quality, enlargement of working poor. And there rise a question on socio-economic durability due to de-compensation on intra-institution. It is necessary to grope transition to the high road social market model - that is stable and sustainable - correspond to Korea that is stable and sustainable.

• Journal of KIISE:Software and Applications
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• v.32 no.7
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• pp.601-611
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• 2005

Due to not only proven stability and reliability but a significant investment and years of accumulated -experience and knowledge, legacy systems have supported the core business applications of a number of organizations over many years. While the emergence of Web-based e-business environments requires externalizing core business processes to the Web. This is a competitive advantage in the new economy. Consequently, organizations now need to mine the business value buried in the legacy systems for reuse in new e-business applications. In this paper we suggest a systematic approach to mining components that perform specific business services and that consist of the legacy system's assets to be leveraged on the modem platform. The proposed activities are divided into several tasks. First, use cases that realize the business processes are captured. Secondly, a design model is constructed for each identified use case in order to integrate the use cases with the similar functionalities. Thirdly, we identify component candidates from the design model and then adjust the component candidates by considering common elements among the candidate components. And also business components are divided into three more fine-grained components to deploy them onto J2EE/EJB environments. finally, we define the interfaces of components which provide functionalities of the components as operations.

• Journal of the Korea Society for Simulation
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• v.30 no.1
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• pp.75-85
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• 2021

In this paper, we present a deep neural network-based prediction model that processes and analyzes the corporate credit and personal credit information of individual business owners as a new method to predict the default rate of individual business more accurately. In modeling research in various fields, feature selection techniques have been actively studied as a method for improving performance, especially in predictive models including many features. In this paper, after statistical verification of macroeconomic indicators (macro variables) and credit information (micro variables), which are input variables used in the default rate prediction model, additionally, through the credit information feature selection method, the final feature set that improves prediction performance was identified. The proposed credit information feature selection method as an iterative & hybrid method that combines the filter-based and wrapper-based method builds submodels, constructs subsets by extracting important variables of the maximum performance submodels, and determines the final feature set through prediction performance analysis of the subset and the subset combined set.