• 한국정밀공학회지
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• 제20권1호
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• pp.151-158
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• 2003

Design changes frequently occur while design activities are performed. If the impact of design changes is estimated, design efficiency can be improved. But, the types of design changes are various and they can affect other design parts. Hence, it is difficult to deal with design changes directly. The purpose of this research is to develop systematic algorithms for change propagation tracing and change impact analysis, and then to implement a change impact analysis system. We have selected a process-based design and a design environment which is composed of design parameters and constraints. The algorithm for change propagation tracing tracks the change propagation of design parameters and finds design parameters, constraints and tasks which are probably changed. In the algorithm for change impact analysis, a change impact value is calculated from the list of changeable tasks. These two algorithms have been implemented into change impact analysis system (CIAS). CIAS has been applied to the redesign of 2 stage gear drives. CIAS can improve the efficiency of design activities. If there are many alternatives for a design change at the redesign step, designers can calculate the change impact value of each alternative and perform design change activities in the direction of minimizing design change impact.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.355-360
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• 2000

There are many changed while a design is completed. Therefore, if the impact of the design changes is estimated, it may result in the improvement of design efficiency. But, the design changes have various types and affect other parts of the design system. Hence, it is difficult to deal with design changes directly. The purpose of this research is to develop a systematic change propagation tracing algorithm and a method of change impact analysis and then, to implement a change impact analysis system. Process based design is set up for the field of this research. Also the design, composed of design parameters and constraints, is set up for the subject of the research. Change propagation tracing algorithm traces change propagation based on the following concept : If the design parameters are changed, other parameters within the constrains including them may be changed. Using the result of change propagation tracing algorithm, changeable parameters, constraints and tasks can be found. The method of change impact analysis, to calculate change impact value from this changeable tasks, is developed. Change propagation tracing algorithm and the method of change impact analysis are implemented into change impact analysis system and it is applied to the redesign of 2 stage gear drives. It can support different kinds of design activities systematically. especially, at the redesign step, where many design change alternatives exist, change impact value of each alternative exist, change impact value of each alternative is calculated and design change is performed toward direction to minimize the impact of design change. Consequently, it is expected to improve the efficiency of the whole design.

• Journal of Information Processing Systems
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• 제6권4호
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• pp.597-608
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• 2010

Software evolution is an ongoing process carried out with the aim of extending base applications either for adding new functionalities or for adapting software to changing environments. This brings about the need for estimating and determining the overall impact of changes to a software system. In the last few decades many such change/impact analysis techniques have been developed to identify consequences of making changes to software systems. In this paper we propose a new approach of estimating change/impact analysis by classifying change based on type of change classification e.g. (a) nature and (b) extent of change propagation. The impact set produced consists of two dimensions of information: (a) statements affected by change propagation and (b) percentage i.e. statements affected in each category and involving the overall system. We also propose an algorithm for classifying the type of change. To establish confidence in effectiveness and efficiency we illustrate this technique with the help of an example. Results of our analysis are promising towards achieving the aim of the proposed endeavor to enhance change classification. The proposed dynamic technique for estimating impact sets and their percentage of impact will help software maintainers in performing selective regression testing by analyzing impact sets regarding the nature of change and change dependency.

• 정보과학회 논문지
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• 제43권10호
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• pp.1104-1114
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• 2016

소프트웨어의 변경은 개발 기간 또는 개발 이후에도 지속적으로 요구된다. 변경 요청 시 영향의 범위를 직관적으로 정확히 파악하는 것은 어려운 일이며, 체계적인 방법을 통해 변경 영향의 범위를 보다 정확하게 파악하는 과정이 필요하다. 변경 영향 분석은 변경에 의해 야기되는 파급 효과를 인식하여 누락되는 부분이 없도록 하는 것을 그 목적으로 한다. 본 논문은 객체지향 개발 환경에서 유스케이스 시나리오와 UML 모델링 산출물들 간의 연관 관계를 이용하여 변경 요청으로 인한 영향의 범위를 쉽게 파악할 수 있는 방법을 제시한다. 이 방법은 유스케이스 시나리오의 변경으로 인해 다른 구성요소들(클래스 다이어그램, 시퀀스 다이어그램)이 받을 수 있는 영향의 범위를 순방향 추적을 통해 파악하고, 구성요소의 변경으로 인해 추가적으로 발생할 수 있는 변경 가능성에 대한 영향 분석은 역방향 추적 과정을 통해 순환적으로 이루어진다. 본 논문의 결과는 영향 분석 대상(산출물)이나 변경 유형에 제한을 받지 않아, 다양한 변경 요청으로 인한 영향 분석 시 기초적인 가이드라인으로 활용할 수 있다.

• 한국건설관리학회논문집
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• 제6권5호
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• pp.69-77
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• 2005

Change is inevitable and is a reality of construction projects. Most construction contracts include change clauses and allowing contractors an equitable adjustment to the contract price and duration caused by change. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative Impact of the changes. A number of studies have attempted to quantify the impact of change orders on project costs and schedule. Many of these attempted to develop regression models to quantify the loss. However, regression analysis has shortcomings in dealing with many qualitative or noisy input data. This study develops ANN models to classify and quantify the labor productivity losses that are caused by the cumulative impact of change orders. The results skew that ANN models give significantly improved performance compared to traditional statistical models.

• 전기학회논문지P
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• 제58권2호
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• pp.95-100
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• 2009

Recent advances in computer technology have brought more dependence on software to railway systems. Hence, the safety assurance of the vital software running on the railway system is very critical task and yet, not many works have been done. While much efforts have been reported to improve electronic hardware's safety, not so much systematic approaches to evaluate software's safety. In this paper, we suggested an automated analysis tool for S/W change impact in railway system, and presented its result of implementation. The analysis items in the implemented tool had referred to the international standards in relation to the software for railway system, such as IEC 61508 and IEC 62279. In these international standards, 'change impact analysis' for railway system S/W has to be required mandatorily. The proposed tool can be utilized at the assessment stage and also the software development stage.

• 한국정밀공학회지
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• 제20권6호
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• pp.230-237
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• 2003

On this study, we operated the dynamic response for impact load of impact absorbing system for spreader by the finite element analysis and showed respectively the spring constant and the damping coefficient which the reaction force by impact was the lowest value for three types impact absorbing system according to the change of system, also we presented the change of impact reaction force according to the spring constant and the damping coefficient. Additionally, among the three types impact absorbing system according to the change of system, the reaction force of model II was the lowest value and the next model which has higher value than model II was model Iand model III has the highest value in the three types.

• 지능정보연구
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• 제10권2호
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• pp.111-131
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• 2004

소프트웨어 유지보수 단계에서는 고객니즈, 마케팅 정책, 법, 제도의 변화 등으로 인한 다양한 시스템 변경 요구를 수용하여야 한다. 그러나, 소프트웨어의 비가시성문제로 인해 새로운 변경 요구사항 발생 시 수정 대상 모듈을 발견하는데 지대한 시간이 요구될 뿐 아니라 모듈의 재 사용을 어렵게 만들어 중복 모듈이 양산 됨으로써 향후 장애의 근원이 되는 악순환이 전개된다. 이에 본 연구에서는 시맨틱 웹(Semantic Web) 기술을 활용하여 이동통신사의 과금/청구 도메인의 관리자와 개발자들이 공유하고 있는 개념과 개념간 관계를 명시적으로 표현하고 이를 이용하여 변경대상 모듈을 쉽게 발견 할 뿐 아니라, 발견된 모듈에 대해 구조적 호출 및 조립 관계를 분석하도록 지원하는 온톨로지 기반 변경 영향 분석 시스템(OntCIA; Ontology based Change Impact Analysis System)을 제시한다. OntCIA는 스트링 매칭과는 근본적으로 다른 의미적 모듈검색을 지원하며 잦은 변경이 요구되는 호출 및 조립 구조 정보는 데이터 베이스에서 관리하고 도메인 지식은 온톨로지로 관리함으로써 유지 보수가 용이한 구조를 가진다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.2044-2049
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• 2009

Recent advances in computer technology have brought more dependence on software to railway signaling systems. Hence, the safety assurance of the vital software running on the railway signaling system is very critical task and yet, not many works have been done. While much efforts have been reported to improve electronic hardware's safety, not so much systematic approaches to evaluate software's safety. In this paper, we suggested an automated analysis tool for S/W change impact in railway signaling system, and presented its result of implementation. The analysis items in the implemented tool had referred to the international standards in relation to the software for railway signaling system, such as IEC 61508 and IEC 62279. In these international standards, 'change impact analysis' for railway signaling system S/W has to be required mandatorily. The proposed tool can be utilized at the assessment stage and also the software development stage.

• Tribology and Lubricants
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• 제27권1호
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• pp.34-39
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• 2011

In this study, finite element analysis of particle-surface collision using 2-dimensional elements was performed to observe the effects of abrasive size and impact angle. The result of the simulation on the change in abrasive size revealed that larger abrasive particle induced larger contact stress due to force transfer through slurry fluid as the particle moved and pushed the fluid. This observation brought an important finding that the slurry fluid could make the workpiece surface soften and then change the mechanical properties of the surface layer such as elastic modulus and yield strength. As for the impact angle, it was found that the contact stress increased with the angle of impact and jumped up at a specific angle. Such result would be attributed to the complex effects of the impact velocity and angle.