• Title/Summary/Keyword: 효율 성

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The Effect of STS Modules Reflected Ansan's Local Characteristics for Chemistry I (안산 지역 특성이 반영된 STS 모듈의 효과: 화학 I 단원을 중심으로)

  • Gil, Hye-Jeong;Kim, Hyun-Kyung;Choi, Byung-Soon
    • Journal of the Korean Chemical Society
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    • v.55 no.4
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    • pp.703-714
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    • 2011
  • The purpose of this study was to investigate the effect of STS modules reflecting Ansan's geological characteristics in Chemistry I on high school students' science related attitudes and preference for STS lessons. The subjects were 10th grade students from K High School in Ansan and comprised 71 students in the experiment group and 78 students in the control group from 2 classes each. Pretest-posttest control group design was employed for the purpose of research. Four STS modules with lesson plans and teaching materials with themes of water, air, and energy, all of which are closely related to high school Chemistry I were developed and applied to the experiment group. The science related attitudes and preference for STS lessons were then examined in pre- and post-tests. The science related attitudes of the experiment group were significantly high in three out of five domains compared to the control group who was taught traditionally. The preference for STS lessons of the experiment group were highly positive in all five areas and were particularly high in the area of 'relation to society'. Such results imply that in order to make effective high school Chemistry I curriculum units related to STS, emphasized by both the 7th National Curriculum and the Revised 7th National Curriculum, it is necessary to use episodes reflecting local characteristics in which students show greater interest and active participation.

Comparison between Numerical Results of 1D Beam and 2D Plane Stress Finite Element Analyses Considering Aspect Ratio of Cantilever Beams (캔틸레버보의 형상비에 따른 1차원 보와 2차원 평면응력 유한요소해석 결과의 비교)

  • Kang, Yoo-Jin;Sim, Ji-Soo;Cho, Hae-Sung;Shin, Sang-Joon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.5
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    • pp.459-465
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    • 2015
  • There exist different kinds of aircrafts, such as conventional airplane, rotorcraft, fighter, and unmanned aerial vehicle. Their shape and feature are dependent upon their own assigned mission. One of the fundamental analyses performed during the aircraft design is the structural analysis. It becomes more complicated and requires severe computations because of the recent complex trends in aircraft structure. In order for efficiency in the structural analysis, a simplified approach, such as equivalent beam or plate model, is preferred. However, it is not clear which analysis will be appropriate to analyze the realistic configuration, such as an aircraft wing, i.e., between an equivalent beam and plate analysis. It is necessary to assess the limitation for both the one-dimensional beam analysis and the two-dimensional plate theory. Thus, in this paper, the static structural analysis results obtained by EDISON solvers were compared with the three-dimensional results obtained from MSC NASTRAN. Before that, EDISON program was verified by comparing the results with those from MSC NASTRAN program and other analytic solutions.

Level Set Based Shape Optimization of Linear Structures using Topological Derivatives (위상민감도를 이용한 선형구조물의 레벨셋 기반 형상 최적설계)

  • Yoon, Minho;Ha, Seung-Hyun;Kim, Min-Geun;Cho, Seonho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.1
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    • pp.9-16
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    • 2014
  • Using a level set method and topological derivatives, a topological shape optimization method that is independent of an initial design is developed for linearly elastic structures. In the level set method, the initial domain is kept fixed and its boundary is represented by an implicit moving boundary embedded in the level set function, which facilitates to handle complicated topological shape changes. The "Hamilton-Jacobi(H-J)" equation and computationally robust numerical technique of "up-wind scheme" lead the initial implicit boundary to an optimal one according to the normal velocity field while minimizing the objective function of compliance and satisfying the constraint of allowable volume. Based on the asymptotic regularization concept, the topological derivative is considered as the limit of shape derivative as the radius of hole approaches to zero. The required velocity field to update the H-J equation is determined from the descent direction of Lagrangian derived from optimality conditions. It turns out that the initial holes are not required to get the optimal result since the developed method can create holes whenever and wherever necessary using indicators obtained from the topological derivatives. It is demonstrated that the proper choice of control parameters for nucleation is crucial for efficient optimization process.

Development of 3-Dimensional Rebar Detail Design and Placing Drawing System (3차원 배근설계 및 배근시공도 작성 자동화 시스템 개발)

  • Choi, Hyun-Chul;Lee, Yunjae;Lee, Si Eun;Kim, Chee Kyeong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.4
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    • pp.289-296
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    • 2014
  • The rebar detailing is an important work influencing the final performance and quality of RC structures. But it is one of the most irrational and illogical activity in construction site. Many groups of workers, including main contractors, structural engineers, shop drawers, rebar fabricators, and etc., participate in this activity. A loosely-organized process for this activity is apt to produce a big amount of rebar loss or even degraded structures. A 3-dimensional rebar auto-placing system, called as Rebar Hub, has been designed and implemented in this research. Rebar Hub provides a totally integrated service from 3D structural modeling of buildings to rebar auto-placing considering anchorage, splice, and the length of ordered rebar. In addition, Rebar Hub can recognize the 2D drawing CAD files and then build 3D structural models which are used for the start point of 3D rebar auto-placing. After rebar auto-placing, each members of the 3D structural model have rebar information belonging to them. It means that the rebar information can be used for the afterward works such as quantity-survey, manufacturing and fabrication of rebars. Rebar Hub is showing outstanding performance while applying to practical projects. It has almost five times productivity and reduces the rebar loss up to 3~8% of the initially-surveyed amount of rebar.

Structural Design and Analysis of a Hydraulic Coiling Arm for Offshore Wind-turbine Submarine Cable (해상풍력 해저케이블 하역용 유압식 코일링 암 구조설계 및 해석)

  • Kim, Myung-Hwan;Kim, Dong-Hyun;Oh, Min-Woo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.1
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    • pp.1-7
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    • 2013
  • Structural design and analysis of a coiling arm unloading machine for submarine cable have been originally conducted in this study. Three-dimensional CAD modeling process is practically applied for the structural design in detail. Finite element method(FEM) and multi-body dynamics(MBD) analyses are also used to verify the safety and required motions of the designed coiling arm structure. The effective moving functions of the designed coiling arm with respect to rotational and radial motions are achieved by adopting bearing-roller mechanical parts and hydraulic system. Critical design loading conditions due to its self weight, carrying cables, offshore wind, and hydraulic system over operation conditions are considered for the present structural analyses. In addition, possible inclined ground conditions for the installation of the designed coiling arm are also considered to verify overturn stability. The present hydraulic type coiling arm system is originally designed and developed in this study. The developed coiling arm has been installed at a harbor, successfully tested its operational functions, and finished practical unloading mission of the submarine cable.

The Impact of Korean SMEs' R&D Effort on Innovation - The Moderating Effects of Government Policy Supports - (국내중소기업의 R&D 노력이 혁신에 미치는 영향 - 정부정책지원의 조절효과를 중심으로 -)

  • Kang, Seok-Min
    • Management & Information Systems Review
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    • v.32 no.1
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    • pp.1-18
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    • 2013
  • Previous studies related with the relationship between R&D and innovation have focused on the role of R&D on innovation, and the empirical results have been not consistent. Although government policy supports have been considered a crucial factor to make innovation, it is true that there are little studies investigating the moderating effects of government policy supports on the relationship between R&D and innovation. The studies related with government policy supports mainly examined the direct effects of government policy supports on innovation. Using 2008 innovation activity table from STEPI, this study investigated the effect of R&D on innovation and the moderating effects of government policy support on the relationship between R&D and innovation. The data used in this study contains 532 Korean small and medium sized firms and information was collected over 3 years(2006-2008). The empirical results reports that R&D positively influences innovation and the moderating effects of government policy on the relationship is statistically significant. Therefore, This study suggests that R&D is required to firms for innovation and government policy supports are needed for connecting the R&D and innovation.

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A Study on the Effects of Training Factors on Transfer of Training, Training Satisfaction and Retraining Intentions - Based on the management consultation project for foreign customer service restaurant in Chungnam province - (교육훈련요인이 교육훈련전이, 교육훈련만족도 및 재교육의도에 미치는 영향 - 충남 외국인 이용 음식점 경영 컨설팅 사업 사례를 중심으로 -)

  • Jung, Yung-Woo
    • Culinary science and hospitality research
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    • v.17 no.5
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    • pp.74-91
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    • 2011
  • The purpose of this study is to investigate the efficiency of a government-supported project developed to improve the quality and hygiene levels of food, service, and restaurant facilities for foreign customers in Chungnam province. Data was collected from 53 restaurant owners and restaurant managers. This study empirically analyzes and presents a mode with key factors influencing transfer of training and training satisfaction. Multiple regression analysis methods were used to test the relationships among four factors for transfer of training, training satisfaction, and retraining intentions. There are three main findings. First, teaching methods and relevance factors had a significant effect on transfer, but instructor and education environment factors did not. Second, the teaching methods, instructor and education environment factors had a direct influence on training satisfaction, but the relevance factor didn't. Third, transfer and satisfaction both were influenced significantly by retraining. Based on the findings of this study, a trainer, designing training curriculum for a production environment, should emphasize the role of the trainer and focus on learning tools. Finally, a thorough learning design is needed for learner's satisfaction.

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The Effect of Job Rotation on Motivation and Job Satisfaction - Focused on F&B Employees of First Grade Hotels in Seoul - (직무 순환이 동기 부여 및 직무 만족에 미치는 영향에 관한 연구 - 서울 특1급 호텔 F&B 종사원을 중심으로 -)

  • Kwon, Na-Kyung;Kim, Hye-Lin;Seo, Won-Seok
    • Culinary science and hospitality research
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    • v.16 no.4
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    • pp.163-176
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    • 2010
  • The purpose of this study is to find out the effect of job rotation on employees' motivation and satisfaction. That is, it is the ultimate aim to know why employees want job rotation or why not, whether the rotation has an effect on their motivation, and finally whether the motivation gives direct job satisfaction. As a result of the survey, the efficiency and procedure of job rotation have influence on motivation. The employees also think that regular rotation can help them to find the proper position to meet their aptitude. And motivation also affects employees' achievement, benefits, and relationship with their bosses. Especially, when they feel great achievement and pride in their jobs, their satisfaction appeared to be very high. And when they are paid properly in comparison with their workload, or they learn special knowledge from their bosses, they usually content themselves.

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CALS환경에서 기업간 정보공유의 범위에 관한 연구

  • 고일상
    • Proceedings of the CALSEC Conference
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    • 1999.07a
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    • pp.41-50
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    • 1999
  • 최근의 CALS 시스템 구축 가속화 및 전자상거래 활성화 분위기는 정보기술의 전략적 활용의 초점을 개별기업 위주에서 기업간 협력체제 구축과 이를 바탕으로 하는 기업간 전자적 결합(Electronic Integration)으로 옮기고 있다. 우리는 정보기술의 공유를 기반으로 새로운 기업간의 관계를 구축할 수 있으며, 이러한 관계를 전략적으로 활용함으로써 기존 사업에서의 경쟁우위 뿐만 아니라, 새로운 사업기회를 창출할 수 있다. 관련기업간의 데이터 표준화를 통한 정보의 공유는 CALS 시스템 구축의 바탕이 된다고 할 수 있는데, 정보공유의 범위는 산업별 특성과 제품별 특성에 따라 달라질 수밖에 없으며, 관련기업간의 교섭력(Bargaining Power)에 의해서도 영향을 받게된다. CALS 환경에서는 개별기업의 정보전략에 따라 수직적 협력관계에 있는 기업들간의 정보공유 정도와 수평적 협력관계에 있는 기업들간의 정보공유 정도가 결정된다고 할 수 있다. 정보공유의 범위를 설정하는 데에는 기업간에 이루어지는 업무의 성격, 공급-제조-유통으로 연결되는 관련기업간의 구조 등도 크게 영향을 미치는 것으로 파악되고 있다. 이 연구에서는 CALS 시스템 구축과정에서 우리가 고려할 수 있는 정보공유의 범위를 관련업무공유, 시스템공유, 부품 설비공유, 시설공유 등의 관점에서 분석하여 봄으로써, 각 산업별로 진행되고 있는 시범사업들의 시스템 영역의 범위를 재조명해보고자 한다. 이 연구에서 집중적으로 다루게 될 정보공유의 범위에 대한 내용은 CALS 시스템을 개발하려는 기업들의 응용서비스 개발 및 정보전략 구축에 중요한 공헌을 할 수 있을 것으로 기대된다.진" 사업에 대한 표준 설정을 위하여 노스캐롤라이나주 지방보건소의 "보건교육/건강증진" 표준체제를 예로 들었다. 다음으로, 경제적인 효율면에서 볼 때 "보건교육/건강증진" 사업에는 단기 혹은 장기 투자가치가 있는가 하는 것이다. 새로 태어나는 미국 지방 보건소의 "보건교육/건강증진" 활동은 지역 시민 및 그 단체가 광범위하고도 자연 다발적으로 참여할 때만 성공할 수 있다고 결론 지울 수 있다.한 분야별 전문가시스템 개발을 지양하고 MCRDR이론을 기반으로 한 범용성 있는 전문가시스템 개발 툴의 개발에 관한 연구를 소개한다. 후 새로운 지식을 얻는 반복적인 Explanation-based Data Mining Architecture를 제시하였다. 본 연구의 의의로는 데이타 마이닝을 통한 귀납적 지식생성에 있어 귀납적 오류의 발생을 고메인 지식을 통해 설명가능 함을 보임으로 검증하고 아울러 이러한 설명을 통해 연역적으로 새로운 가설지식을 생성시켜 이를 가설검증방식으로 검증함으로써 귀납적 접근과 연역적 접근의 통합 데이타 마이닝 접근을 제시하였다는데 있다.gical learning to give information necessary to improve the making. program and policy decision making, The objectives of the study are to develop the methodology of modeling the socioeconomic evaluation, and build up the practical socioeconomic evaluation model of the HAN projec

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A Table Parametric Method for Automatic Generation of Parametric CAD Models in a Mold Base e-Catalog System (몰드베이스 전자 카탈로그 시스템의 파라메트릭 CAD 모델 자동 생성을 위한 테이블 파라메트릭 방법)

  • Mun, Du-Hwan;Kim, Heung-Ki;Jang, Kwang-Sub;Cho, Jun-Myun;Kim, Jun-Hwan;Han, Soon-Hung
    • The Journal of Society for e-Business Studies
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    • v.9 no.4
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    • pp.117-136
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    • 2004
  • As the time-to-market gets more important for competitiveness of an enterprise in manufacturing industry, it becomes important to shorten the development cycle of a product. Reuse of existing design models and e-Catalog for components are required for faster product development. To achieve this goal, an electric catalog must provide parametric CAD models since parametric information is indispensable for configuration design. There are difficulties in building up a parametric library of all the necessary combination using a CAD system, since we have too many combinations of components for a product. For example, there are at least 80 million combinations of components on one page of paper catalog of a mold base. To solve this problem, we propose the method of table parametric for the automatic generation of parametric CAD models. Any combination of mold base can be generated by mapping between a classification system of an electric catalog and the design parameters set of the table parametric. We propose how to select parametric models and to construct the design parameters set.

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