• The Transactions of the Korea Information Processing Society
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• v.6 no.3
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• pp.589-602
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• 1999

There are some advantages of developing applications based on the object oriented concepts. One os them is that it is possible to reuse the existing designs and products. This paper provides a formal method for the reorganization of class hierarchies for the object extension in the object oriented design phase. In this paper, we introduce classes, and edges to represent the inheritance and aggregation relationship between classes. Based on the graph, we define an order relation(called the object extension) between class hierarchy graphs. And also we present a set of five basic transformations preserving the object extension relation. The set is proven to be correct and complete. The results of this paper help form a theoretical basis for the extension and reorganization object-oriented application systems.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.2037-2047
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• 1991

Strength is not simply a single given value but rather is a statistical one with certain distribution functions. This is because it is affected by many unknown factors such as size, shape, stress distribution, and combined stresses. In this study, a model of loss probability is proposed in view of the fact that one of the fundamental configuration of nature is hexagonal, for example, the shapes of lattice unit, grain, and so on. The model sues the concept of loss of certain element in place of Jayatilaka-Trustrum's length and angle of cracks. Using this model, the loss probability due to each loss of certain elements is obtained. Then, the maximum principal stress is calculated by the finite element method at the centroid of the elements under the tensile load for the 4,095 models of analysis. Finally, the failure probability of the brittle materials is obtained by multiplying the loss probability by the ratio of the maximum principal stress to theoretical tensile strength. Comparison of the result of the Jayatilaka-Trustrum's model and the proposed model shows that the failure probabilities by the two methods are in good agreement. Further, it is shown that the parametric relationship of semi-crack lengths for various degrees of birittleness can be determined. Therefore, the analysis of the failure probability suing the proposed model is shown to be promising as a new method for the study of the failure probability of birttle materials.

• The Korean Journal of Air & Space Law and Policy
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• v.26 no.1
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• pp.241-269
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• 2011

Solar flare and storm may give an adverse effect upon electromagnetic environment around the Earth, so that various kinds of satellite cease to normally function. This kind of space storm disaster is characterized by the uncertainty about when and what size. Recently the UN has been paying attention to this plausible disaster. Particularly the COPUOS has taken the view that this disaster would threaten the sustainable space environment. The precautionary principle, rooted and excercised in the environment protection filed, has been adopted in the case of disaster with uncertainty. The reports and opinions given by the expert and representatives of the member States have stated that the precautionary principle should be adopted for the purpose of dealing with this disaster. On the other hand, it is advanced that the principle has been already included in the space law principle enshrined in the 1967 Space Treaty. The Treaty has adopted the freedom of navigation and use of the outer space for the interest of all States as the basic principles. Sustainable environment is necessary for implementing the principle. Therefore, the rules for the protection of sustainable space environment should be based upon the space law principle.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.3
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• pp.110-121
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• 2000

Gas heating, high frequency induction heating and laser heating can be used as the heat-source of line heating. Most of shipyards have been using the gas heating method for line heating. It is difficult to control the residual deformation of gas heating. High frequency induction heating is more feasible for the automation of line heating rather than the gas heating method since it is easy to control the magnitude of heat input. In this study, a numerical model of high frequency induction heating process is proposed for the application of the line heating. The simulation process of the induction heating is composed of the electromagnetic analysis, the heat transfer analysis, and the thermal deformation analysis.

• Journal of the Korean housing association
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• v.22 no.5
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• pp.111-119
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• 2011

In recent years, the insistence that the central government should hand over the right of establishing and managing housing policies to local governments is growing. And, it is needed that local governments should pursue their own original housing policies. The purpose of this study is to explore the characteristics of the prefectural plans of the national basic act for housing in Japan to envision the future directions of regional housing policies. This study analyzed the structure, main policy contents, and the outcome indexes of all 47 prefectures' plans in Japan. The major results of this study are as follows. 1) The central government and local governments shared their roles appropriately. In addition, the local governments proactively demonstrated the unique quality of their regions when establishing their housing policies. 2) In promoting housing policies, they focused on the housing stock and the market including both public and private sectors. 3) The policy-oriented goals and performance management practices were clearly presented.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.4
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• pp.1-10
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• 2011

The purpose of this study is to analyze the guidelines and content of visual landscape planning according to the Landscape Law and to suggest improvements for it. The landscape planning guidelines were analyzed and landscape planning reports were reviewed and compared. To analyze the landscape planning guidelines, we conducted an expert survey and derived the results through statistical methods, such as t-test and importance-performance analysis(IPA). Both landscape planning reports were selected from among metropolitan cities, medium-sized cities, and counties. We analyzed and compared the reports with the landscape planning guidelines. The results of this study are as follows. The stage of visual landscape resource survey progressed systematically, but it was not practical for actual planning because of the excessively detailed guidelines. On the other hand, a greater variety of methods and techniques should be suggested for the landscape structure analysis. At the schematic planning stage, establishing contents suitable for the local government's identity and related plans is necessary. In addition, more detailed guidelines should be included in the landscape planning guidelines. At the master planning stage, the planning qualities and contents differed from cities and counties, so more substantial and detailed guidelines are necessary for the scope and contents. We suggested that some additional items be included such as the synthesis of landscape resource surveys and the viewpoint plan.

• Korean Journal of Environment and Ecology
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• v.38 no.1
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• pp.108-120
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• 2024

This study proposes measures for institutionalization and its inter-departmental linkages to increase the effectiveness of wind corridor forests in response to changing urban environmental issues and climate change. For this purpose, the study reviewed laws and regulations containing terms related to urban wind corridors, identified the roles and relationships of wind corridor forests required in relevant plans, and assessed high-level and basic plans for wind corridor forests to identify issues in the current establishment of wind corridor forests and derive key issues related to them. Based on these results, institutionalization measures for legislating wind corridor forests and their effectiveness methods were suggested. This study proposes 1) defining terms and establishing legal and institutional foundations and 2) establishing hierarchies with related plans and a legal basis for the basic plan for wind corridor forest as an institutional plan for legalization of wind corridor forest, and 1) establishing a legal and institutional foundation for constructing spatial data like analysis maps and 2) establishing the guidelines for the basic plan and for creating and managing wind corridor forests and their contents as an institutional plan for effective revitalization. It is expected that this study can be utilized as basic data for establishing laws and regulations related to wind corridor forests and can contribute to the institutionalization research of basic plans. It is also hoped to be used as basic data for systematically constructing wind corridor forests.

• Industry Promotion Research
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• v.8 no.1
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• pp.119-134
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• 2023

An Analysis of the Choice of Wedding Time Based on the Gimundungap Theory. The purpose of this study is to research the utility and validity of wedding time selection based on the principles of Ungokgimun, a recent development of Gimundungap theory. Unlike the conventional way of choosing from common auspicious hours and days deemed available for important ceremonial occasions, Ungokgimun determines the propitious heavenly wedding time catered for a particular couple based on the birth table consisting of the four pillars of the bride- and groom-to-be. Using the Hong Guk-soo numbers which are drawn from the basic principles of oriental philosophy, it utilizes a deductive approach to wedding time choice, which is considered decisive and logical. Wedding time selection for a bride and a bridegroom is determined by auspicious combinations of matching and supporting HongGuk-soo numbers. Some relevant determining factors for the time choice are three number combination of samhap, two number combination of half-hap, latitudinal combination of yuk-hap, support and control relationships between related elements, two number punishment of hyung-sal, and three number punishment of samhyung-sal, etc. The specific auspicious palace of the spouse-to-be's luck is selected on the basis of supporting or brotherly combination of numbers which are manifested on the baseline earthly plate of the bride- and groom-to-be. This is followed by the selection of the ten-year luck, and year and month luck, and finally by the selection of auspicious day and hours. The validity of this study was verified through theoretical consideration of the Ungokgimun and practical analysis of a variety of marriage cases. It was found that the way of wedding time selection using Ungok Gimundungap was relatively more effective than other conventional methods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.2
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• pp.42-49
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• 2023

When designing fixed jacket structures, overseas design standards are applied due to the absence of domestic design methods. Although the US API standards are mainly applied, API RP 2A suggests two design methods: the allowable stress design method (WSD) and the load resistance coefficient method (LRFD), and is applied according to the designer's judgment. In this study, the stress ratio of the two design methods was reviewed and compared using SACS, an analysis program dedicated to marine structures, for fixed marine structures actually installed on the domestic coast. As a result of the review, it was found that the LRFD design method showed a greater stress ratio for extreme load analysis and transportation analysis, and the WSD design method showed a greater stress ratio for loading and lifting. Therefore, when applying the design method, it is considered appropriate to select the final design method considering safety and economic feasibility after conducting an applicability review for the two design methods.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.8
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• pp.463-471
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• 2002

In order to implement virtual endoscopy, high-speed rendering algorithm that generates accurate perspective projection images and efficient collision detection method are essential. In this paper we propose an efficient virtual endoscopy system based on volume rendering technique. It is possible to skip over empty (transparent) space using the distance value produced in preprocessing time, and it does not deteriorate image quality since it is an extension of ray-casting. It also accelerates rendering speed with minimal loss of image quality by adjusting sampling interval along a ray according to direction of the ray. Using the distance information, we can simplify the collision detection of volumetric objects.