• Korean Journal of Computational Design and Engineering
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• v.5 no.2
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• pp.144-154
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• 2000

We propose an algorithm for obtaining a triangular approximation of a trimmed NLRBS surface. Triangular approximation is used in the pre-processing step of many applications such as RP(Rapid Prototyping), NC(Numerical Control) and FEA(Finite Element Analysis), etc. The algorithm minimizes the number of triangular elements within tolerance and generates a valid triangular mesh for STL file and NC tool path generation. In the algorithm, a subdivision method is used. Since a patch is a basic element of triangular mesh creation, boundary curves of a patch are divided into line segments and the division of curves is applied for the interior of the surface. That is, boundary curves are subdivided into line segments and two end points of each line segment are propagated to the interior of the surface. For the case of a trimmed surface, triangulation is carried out using a model space information. The algorithm is superior because the number of elements can be controlled as the curvature of the surface varies and it generates the triangular mesh in a trimmed region efficiently. To verify the efficiency, the algorithm was implemented and tested for several 3D objects bounded by NURBS surfaces.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.225-228
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• 2011

핸드폰에 의한 모바일 콘텐츠의 사용량이 날로 증가하고 있으며 이러한 추세에 맞추어 다양한 콘텐츠들이 다양한 플렛폼에서 생산되고 있다. 모바일 플랫폼에서 사용 가능한 콘텐츠 생산성은 플랫폼의 특수성으로 인해 생산 속도가 느리고 인력 투입이 많은 것이 문제점으로 지적되고 있다. 또한 무선 플랫폼에서 사용 가능한 콘텐츠 제작시 다양한 하드웨어 플랫폼으로 인한 액정 크기의 다양성과 사용 가능한 콘텐츠 개발 언어의 다양성으로 인한 문제점도 많은 것으로 알려져 있다. 본 연구에서는 이러한 생산성 저하의 원인으로 대표되는 문제점들과 다양한 하드웨어 플랫폼으로 인해 발생하는 문제점들을 해결하기 위한 모바일 콘텐츠를 통합 제작하고 테스트하는 PC용 소프트웨어를 개발하였다. xHTML 언어로 제작된 모바일 콘텐츠를 다양한 언어로 변환하기 위하여 패턴매칭 알고리즘을 사용한 변환 모듈을 개발하였다. 또한, 변환된 콘텐츠들을 각 플랫폼별로 테스팅 하기 위하여 개발자의 직접적 개입이 없이 모든 콘텐츠를 자동으로 검사하고 결과를 리포트 생성하는 자동 테스트 부분과 개발자의 육안으로 확인하고 테스트하여 결과 리포트를 생성하는 수동 테스트 부분으로 나누어진 소프트웨어 엔진을 개발하였다. 이상의 변환엔진을 사용하여 xHTML로 제작한 원본 콘텐츠는 다양한 플랫폼에서 이용 가능한 콘텐츠로 생산이 용이해 졌으며, 두 테스트 엔진을 사용하여 기본적인 콘텐츠 오류들을 쉽게 찾아내고 수정할 수 있는 개발 환경을 구축하였다.

• Journal of Applied Reliability
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• v.8 no.3
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• pp.113-124
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• 2008

In reliability engineering, failure reporting, analysis, and corrective action system (FRACAS) is an useful tool for effective failure reporting and related operations. FRACAS is generally mainly focused on implementation of its closed-loop process, but also includes various related information which has to be effectively managed such as failure types, failure modes, failure mechanisms, and corrective actions. In this study, we adopt and utilize the concept of process knowledge, and create it through abstraction of FRACAS information. At each step of closed-loop process, the necessary type of knowledge, priority and usability are clearly defined. This study also suggests corresponding management tools such as business process management system, knowledge management system, and their key elements and functions to deal with process knowledge. A prototype system using simple closed-loop process with its process knowledge is presented to demonstrate the feasibility of the proposed work.

• Korean Journal of Child Studies
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• v.35 no.4
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• pp.17-40
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• 2014

The aims of this study were three-fold; to analyze the trends of research on children's media, to anticipate any transitions in the direction of the research and finally to provide a guidance for future directions in the research. For this purpose, 55 research papers were chosen. The tool used for this analysis was that developed by Meyrowitz(1998; 1999), which classifies(1998, 1999) three main viewpoints towards media. Based on these three viewpoints, this study found that the most common category is 'media as a vessel.' Furthermore, it was verified that some studies in 'media as a vessel' have a tendency to be mixed with the notion of 'media as a language.' Subsequently, all the research papers in the category of 'media as a language' were subcategorized into 6 digital literacy competencies, in the manner proposed by Hobbs(2010). Consequently, the studies in the category of 'creation' were revealed to be the most common, and it was further confirmed that the research included in the categories of 'reflection' and 'social action' both begins to partially appear. Based on these results, this study speculates on a number of educational points supporting the development of media education in the digital era.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.122-131
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• 2010

In this paper, we design and implement CTOC, a new bytecode analysis and translation tool. We also propose E-Tree, a new intermediate code, to efficiently deal with intermediate codes translated from bytecodes. E-Tree is expressed in a tree form by combining relevant bytecode instructions in basic blocks of eCFG to overcome the weaknesses of bytecodes such as complexity and analytical difficulty. To demonstrate the usefulness and possible extensibility of CTOC, we show the creation process of eCFG and E-Tree through practical bytecode analysis and translation and shows the optimization process of a bytecode program as an example of possible extensibility.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.347-355
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• 2013

This study analyzed President Lee's speeches of Korea and the policy of SMES and ventures in the field of information technology using cognitive map analysis. The relationship analysis between policy tool variables and policy goal variables was employed to derive policy direction of IT SMEs and ventures. This paper suggests growth competence reinforcement, investment revitalization, revitalization of start-up companies, enhancement of technology competition, globalization and job creation to the policy direction of IT SMEs and ventures. In this paper, we constructed a cognitive map on the policy vision of SMEs and ventures in the field of information technology. This study also showed that this cognitive map could be characterized by a scarcity of feedback loops and a strong emphasis on the positive loops in the structure of virtuous circle.

• Journal of Korea Multimedia Society
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• v.20 no.9
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• pp.1606-1618
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• 2017

The explosion effect of computer graphics Visual Effects(VFX) used in films and animations is an important element that determines the completeness of the film, and its usage is getting extended. The realistic explosion effect of VFX should be made according to observations and analysis of various factors of actual explosion in real world. This experimental research would suggest the efficient production guideline for the technical characteristics of underwater explosion of VFX. For this research process, first, the comparison of actual explosion and VFX explosion effect, classification of actual explosion, and characteristics of underwater explosion effect will be addressed. Second, based on the literature reviews, the four steps of experimental production analysis tool will be derived. Third, the experimental research will be processed in along with technical factors four steps of the underwater explosion effect, (1)realistic creation and emission of fluid, (2)fluid expansion control by water pressure, (3)bubble effect, and (4)motion of bubble & dissipation of fluid. The effective method of fluid simulation production will be verified through experimental studies based on the characteristics of the actual explosion process. This experimental study suggested the VFX production technique is expected to be used as the basic data for related research field.

• Journal of KIISE:Software and Applications
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• v.31 no.10
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• pp.1266-1275
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• 2004

Bioinformatics is concerned with the creation and development of advanced information and computational technologies for problems in biology. It is divided into genomics, proteomics and metabolimics. In metabolimics, an organism is represented by metabolic pathway, i.e., well-displayed graph, and so the graph drawing tool to draw pathway well is necessary to understand it comprehensively. In this paper, we design an improved drawing algorithm. It enhances the readability by making use of the bipartite graph. Also it is possible to draw large graph properly by considering the facts that metabolic pathway graph is scale-free network and is composed of circular components, hierarchic components and linear components.

• 한국연소학회:학술대회논문집
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• 2003.12a
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• pp.109-113
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• 2003

Low pressure or vacuum carburizing(LPC) has undergone major further developments since 1980 and now it has achieved industrial maturity. The advantage of low pressure vacuum carburizing over gas carburizing is not only the creation of surface entirely free of oxide and environmentally friendly but also a reduction in batch times, lower gas and energy consumption and the prevention of soot. In this study the experiment was carried out to investigate the effects of vacuum atmosphere in the heating furnace. Heat transfer rate and uniformity of temperatures of test samples in the pressure range of a few 0.1torr was examined on a test charge of 100kg. It is found that the fuel saving rate due to decreasing heating time reach to 20% in the vacuum heating mode as compared with atmospheric heating mode. Also the uniformity of temperatures in the samples was improved significantly in the vacuum heating mode. Also the effects of the RC fan for stirring atmosphere inside furnace was examined. Results shows RC fan appears to provide a reasonable tool for improving uniformity of temperature in the atmospheric heating mode.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.689-694
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• 1994

In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interference check between solids, the structural design of machine tools and robots and so on.