• 한국CDE학회논문집
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• 제22권1호
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• pp.28-36
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• 2017

Sharing of CAD data plays a key role in the PLM and a lightweight model is widely used for visualizing and sharing a large data. The lightweight model is mainly composed of triangular elements to minimize file size. There is no problem at all to visually confirm the shape based on these triangular elements but there is a limit to numerically calculate the exact position on the curve or surface. In this paper, a boundary curve generation method using triangular elements is proposed to increase the utilization of lightweight models. After matching connectivity of triangular elements, boundary element edges are extracted. Boundary curves are generated by connecting of these boundary element edges. This proposed method has been tested on several models to demonstrate the feasibility.

• 한국통신학회논문지
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• 제28권7C호
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• pp.733-742
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• 2003

유니캐스트와는 달리 멀티캐스트 환경에는 상당히 많은 전송 링크가 존재하기 때문에 그 만큼 보안을 위협하는 요소들이 많이 존재한다. 따라서 안전한 멀티캐스트 통신을 위해서는 멀티캐스트 트래픽을 보호하는 메커니즘이 필수적이고 이러한 메커니즘의 핵심적인 요소 기술은 그룹키를 효율적으로 그룹 구성원들에게 분배하는 것이다. 멀티캐스트 환경에서 보안성을 제공하기 위해 최근가지 진행되어 오고 있는 연구들은 대부분 그룹키 분배에 관련된 것들이다. 본 논문에서는 멀티캐스트 환경에서 키 서버의 트래픽 집중을 효율적으로 분산시킬 수 있는 그룹키 관리 구조를 제안하였다. 제안한 프로토콜은 분산된 키 관리 구조와 서브 그룹 단위로 그룹키를 갱신한다. 시뮬레이션을 통하여 제안한 멀티캐스트 그룹키 관리 프로토콜을 기존의 연구들과 비교한 결과 가입 및 탈퇴 지연시간과 데이터 전송 지연 시간 측면에서 향상된 성능을 나타냄을 알 수 있었다.

• 공학교육연구
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• 제16권2호
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• pp.37-49
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• 2013

In this paper, articles in full body of JEER in Korea and JEE in U.S. were classified into two categories- Research area and Key words-to endeavor a comparative study of the engineering education research(EER) topics and their temporal changes. In the recent 4 year term, 'Accreditation of Engineering Education' and 'Courses & Curriculum' were the most common key words appearing in JEER and 'Researches on EER' and 'Learner's Factor' in JEE. If we put curriculum/teaching materials/teaching as the input elements and learning/assessment as the output elements for education achievement, JEE demonstrates that many of the research topics have shifted from input to output in the recent years, while JEER research is in the transient stage.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1067.1-1067.4
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• 2000

During the last three decades power electronics has gone through energetic technical evolution. The technical needs from wide area such as in industrial, commercial, consumer, aerospace and environmental applications have driven the environment favorably for the power electronics. In the future, two extreme technology-expansion trends are expected: one into low power, and the other into very high power. The former is based on the high frequency and the circuit miniature using VLSI circuit and surface mounting aiming for the system-on-chip (SOC) technology. The latter includes the application areas of power utility such as HVDC, FACTS and SVC and large science area of electrophsycal apparatus such as thermonuclear fusion, acclerators, and electric guns. This paper describes the technology status of some major elements which are available today and the key roles of the power electronics from view points of applications. The author would like to take this opportunity to raise discussions about the future technology development trend of power electronics in our country with the fellow power electronics engineers.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.71-74
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• 2008

This paper aims at studying the key design elements for the optimal ventilation system design, developing the design models and suggesting the design guidelines. The key elements include the basic exhaust emission rate, wall friction coefficient, vehicle drag coefficient and slip streaming effect, jet fan operating efficiency, natural ventilation force and installation scheme for jet fans and ventilation monitors in tunnel. The design models developed in this study are one-dimensional ventilation simulator to analyze the air flow, pressure profile and pollutant dispersion inside and outside tunnel, expert model to choose the optimal ventilation method, and the ventilation characteristic chart to evaluate the preliminary ventilation system. The study results are reflected in the design guideline for road tunnel ventilation system.

• Structural Engineering and Mechanics
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• 제81권4호
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• pp.513-522
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• 2022

Steel-concrete composite segments replacing the conventional reinforced concrete segments can provide the rectangular shield tunnel superiorities on bearing capacity, ductility and economy. A simplified model with high-efficiency on computation is proposed for investigating the nonlinear response of the rectangular tunnel lining composed of composite segments. The simulation model is developed by an assembly of nonlinear fiber beam elements and spring elements to express the transfer mechanism of forces through components of composite segments, and radial joints. The simulation is conducted with the considerations of material nonlinearity and geometric nonlinearity associated with the whole loading process. The validity of the model is evaluated through comparison of the proposed nonlinear simulation with results obtained from the full-scale test of the segmental tunnel lining. Furthermore, a parameter study is conducted by means of the simplified model. The results show that the stiffness of the radial joint at haunch of the ling and the thickness of inner steel plate of segments have remarkable influence on the behaviour of the lining.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.587-591
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• 2005

The case of laboratory-acquired SARS Corona virus infection in Taiwan has revealed a number of weaknesses in management, construction, and oversight of laboratories. Also, with the increased demands for bio-safety laboratory, there is an urgent need to develop a uniform and comprehensive guidance for architects and construction engineers in the preparation of design and construction. This research investigates the key elements for designers, engineers, and potential owners in biosafety laboratory design and construction. It defines key elements and determines major relationships and standards that should be adhered to when developing site layout. In addition to layout planning and design guidance of biosafety laboratory, this research also interviews the perspective of architects and survey the state-of-the-art technology in Taiwan. It represents the portraits by site investigation. The purpose of the research is to provide guideline of design and avoid potential future conflict to ensure the critical continuity of functions.

• Interaction and multiscale mechanics
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• 제3권2호
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• pp.192-211
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• 2010

In most framed structures the nonlinearities and the damages are localized, extending over a limited length of the structural member. In order to capture the details of the local damage, the segments of a member that have entered the nonlinear range may need to be analyzed using the three-dimensional element (3D) model whereas the rest of the member can be analyzed using the simpler one-dimensional (1D) element model with fewer degrees of freedom. An Element-Coupling model was proposed to couple the small scale solid 3D elements with the large scale 1D beam elements. The mixed dimensional coupling is performed imposing the kinematic coupling hypothesis of the 1D model on the interfaces of the 3D model. The analysis results are compared with test results of a reinforced concrete pipe column and a structure consisting of reinforced concrete columns and a steel space truss subjected to static and dynamic loading. This structure is a reduced scale model of a direct air-cooled condenser support platform built in a thermal power plant. The reduction scale for the column as well as for the structure was 1:8. The same structures are also analyzed using 3D solid elements for the entire structure to demonstrate the validity of the Element-Coupling model. A comparison of the accuracy and the computational effort indicates that by the proposed Element-Coupling method the accuracy is almost the same but the computational effort is significantly reduced.

• 한국유기농업학회지
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• 제28권4호
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• pp.505-534
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• 2020

The purpose of this study is to explore the key elements of the regional innovative milieu by analyzing the role of regional innovative elements and case organizations that promoted the emergence of 'Songakdongnesaramdeul (the people of the Songak town),' and to present pertinent policy implications. For the purpose, this study set the "Songakdongnesaramdeul," a residential community organization founded for regional innovation to revitalize the village community, as a case organization from the perspective of regional innovation system theory. The result of the study showed that creating an innovative milieu through the creation of various innovation elements to revitalize the village community is crucial. Especially, this study confirmed that the existence of regional development organizations is the key element of the innovative milieu. such as case organization that contributes to regional development while promoting interaction between actors, common learning and systemization, and new value creation activities. The implications derived through the study can be summarized in four points. First, a variety of means to promote the formation of subjects in response to the public debate of the village agenda is needed. Second, it is highly important to create innovative elements, for example, organizations and programs, resources, and spaces that promote regional innovation. Third, forming a close network between various innovative resources existing in the region and establishing regional capabilities that allow to mobilize and utilize such innovative resources are important. Fourth, the establishment of a promotion mechanism such as a case organization is suggested as a major task, to revitalize the village community. Specifically, forming and revitalizing numerous private-based community organizations with regional developmental capabilities to establish local governance also has significant importance. In this vein, based on the point of view of the regional innovation system theory, the establishment of regional policies to construct a regional innovation milieu, such as creating innovative elements that can actively promote the regeneration of the village community and establishing a promotion system, can be presented as major tasks.

• 수산해양교육연구
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• 제27권2호
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• pp.546-555
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• 2015

The aims of this study were to analyze the coastal Fisherman's awareness for the Fisheries and Maritime Job Skills. Fisheries & Maritime key competencies were defined as the abilities that include the essential knowledge, skills, attitude, and experiences required for the workforce on the fisheries and maritime job condition. This research collected preliminary data from 65 coastal fishermen. Data were analyzed to obtain content validity analysis. The results of the study were as follows; First, Fisheries & Maritime key competencies were divided into 6 elements in coastal fisheries. Second, Fisheries & Maritime key competencies were consisted of basic skills, marine vocational ethics, marine information capacity, marine elementary knowledge, marine safety management skill and marine consciousness. Third, CVR proves that the value analyzed in the study was validation. In consequence, the study suggested that Fisheries & Maritime key competencies were different in accordance with work environment.