• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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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.

• Communications for Statistical Applications and Methods
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• v.28 no.5
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• pp.511-520
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• 2021

Over the last decade, Bitcoin has attracted a great deal of public interest and Bitcoin market has grown rapidly. One of the main characteristics of the market is that it often undergoes some events or incidents that cause outlying observations. To obtain reliable results in the statistical analysis of Bitcoin data, these outlying observations need to be carefully treated. In this study, we are interested in change point analysis for Bitcoin return series having such outlying observations. Since these outlying observations can affect change point analysis undesirably, we use a robust test for parameter change to locate change points. We report some significant change points that are not detected by the existing tests and demonstrate that the model allowing for parameter changes is better fitted to the data. Finally, we show that the model with parameter change can improve the forecasting performance of Value-at-Risk.

• Korean Journal of Computational Design and Engineering
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• v.19 no.2
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• pp.103-110
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• 2014

Engineering changes are indispensable engineering and management activities for manufactures to develop competitive products and to maintain consistency of its product data. Analysis of engineering changes provides a core functionality to support decision makings for engineering change management. This study aims to develop a method for analysis of engineering changes based on On-Line Analytical Processing (OLAP), a proven database analysis technology that has been applied to various business areas. This approach automates data processing for engineering change analysis from product databases that follow an international standard for product data management (PDM), and enables analysts to analyze various aspects of engineering changes with its OLAP operations. The study consists of modeling a standard PDM database and a multidimensional data model for engineering change analysis, implementing the standard and multidimensional models with PDM and data cube systems and applying the implemented data cube to core functions of engineering change management, the evaluation and propagation of engineering changes.

• Journal of Information Processing Systems
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• v.6 no.4
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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.

• Journal of Climate Change Research
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• v.8 no.3
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• pp.275-285
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• 2017

Chungnam region has established and executed the 2nd Climate Change Adaptation Initiative Execution Plan (2017~2021) based on the Framework Act on Low Carbon, Green Growth. The Execution Plan is established based on the results of climate change vulnerability assessment using the CCGIS, LCCGIS, and VESTAP analysis tools. However, the previously developed climate change vulnerability assessment tools (CCGIS, LCCGIS, VESTAP) cannot reflect the local records and the items and indices of new assessment. Therefore, this study developed a prototype of climate change vulnerability assessment analysis tool that, unlike the previous analysis tools, designs the items and indices considering the local characteristics and allows analysis of grid units. The prototype was used to simulate the vulnerability to forest fires of eight cities and seven towns in Chungcheongnam-do Province in the 2010s, 2020s, and 2050s based on the RCP (Representative Concentration Pathways) 8.5 Scenario provided by the Korea Meteorological Administration. Based on the analysis, Chungcheongnam-do Province's vulnerability to forest fires in the 2010s was highest in Seocheon-gun (0.201), followed by Gyeryong-si (0.173) and Buyeo-gun (0.173) and the future prospects in the 2050s was highest in Seocheon-gun (0.179), followed by Gyeryong-si (0.169) and Buyeo-gun (0.154). The area with highest vulnerability to forest fires in Chungcheongnam-do Province was Biin-myeon, Seocheon-gun and the area may become most vulnerable was Pangyo-myeon, Seocheon-gun. The prototype and the results of analysis may be used to establish the directions and strategies in regards to the vulnerability to wild fires to secure each local government's 2nd execution plan and attainability.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.4
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• pp.115-127
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• 2009

Recently, Natural disasters are increasing the damage according to the influence of the abnormal climate and climate change. This study analyzed change characteristic of Design Rainfall according to the different data periods. First, 14 observatories were selected at Meteorological Administration. Second, frequency analysis carried out 5 cases by different data periods. At the results of the frequency analysis, the design rainfall could confirm the increase in most areas of Korea. Also, the change and trend analysis carried out for characteristic analysis by design rainfall and observed rainfall. The change and trend analysis of observed annual maximum rainfall did not appeared, but the change and trend analysis of design rainfall significantly appeared using statistic methods. The result of the change and trend analysis, design rainfall increased in most areas of Korea. Although, it could be the necessity for reestimating defense ability of flood, existing river systems, and new establishment of structure about the change characteristic.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.163-168
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• 2008

KOMPSAT-3 is expected to provide data with 80-cm spatial resolution, which can be used to detect environmental change and create thematic maps such as land-use and land-cover maps. However, to analyze environmental change, change-detection technologies that use multi-resolution and high-resolution satellite images simultaneously must be developed and linked to each other. This paper describes a GIS-based strategy and methodology for revealing global and local environmental change. In the pre-processing step, we performed geometric correction using satellite, auxiliary, and training data and created a new classification system. We also describe the available technology for connecting global and local change-detection analysis.

• The Research Journal of the Costume Culture
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• v.4 no.3
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• pp.383-394
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• 1996

Even it's not easy to in the cycle of the change without the qualification of the data, but we can try to figure out a cycle of change in fashion as Kroeber used content analysis. As content analysis with quantitative data increases the objectivity, especially in the case of highly complex materials like s appearance, multi-directional research method; quantitative and qualitative methods are combined in this study. In this research, first the change in hair length(HL), hair width(HW), hair height(HH) was examined to find out possible cyclic aspects of change in each elements and the significant relationships among the hair style was probed and the cyclic aspects between hair style elements and skirt style elements were compared. The data was analyzed by using Time series analysis and Pearson correlation coefficients. The statistical analysis of the hair style of 20th century showed that the hair style's elements changed independently and indicated the cyclic aspects in hair style as Kroeber's fashion cycle. To consider of this result, the hair style changed in a cyclic pattern, its pattern were different from skirt style's. And as hair style's change was affected by change, the hair styles change appeared during wars and disappeared during a social stabilization; this result supports social change theory.

• Journal of KIISE
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• v.43 no.10
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• pp.1104-1114
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• 2016

Software is continuously changing during development and after development. When a change is required, it is difficult to precisely grasp the scope of impact intuitively. A systematic method is needed to accomplish the required change. The purpose of impact analysis on software change is to avoid missing any information by recognizing the ripple effect that the change might cause. This paper proposes a dynamic method that can easily identify the scope of change request by using the association between use-case scenarios and artifacts of UML modeling in object-oriented development environment. By using this approach, the scope of impact that the change might have on other components such as class diagram and sequence diagram in use-case scenarios can be identified by forward tracing. In addition, analysis of influence of possible further changes due to changes in other components can be identified iteratively through backward tracing. The results of this paper are not limited to impact analysis on artifacts and change type. They can also be used as basic guidelines during impact analysis for various change requests.