• Nuclear Engineering and Technology
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• 제41권6호
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• pp.765-774
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• 2009

For over 30 years, investigations of the thermohydraulic behavior of pressurized-water reactors under accident conditions have been carried out in the PKL test facility at AREVA NP in Erlangen, Germany. The PKL facility models the entire primary side and significant parts of the secondary side of a of pressurized water reactor at a height scale of 1:1. Volumes, power ratings and mass flows are scaled with a ratio of 1:145. The experimental facility consists of four primary loops with circulation pumps and steam generators (SGs) arranged symmetrically around the reactor pressure vessel (RPV). The investigations carried out encompass a very broad spectrum from accident scenario simulations with large, medium, and small breaks, over the investigation of shutdown procedures after a wide variety of accidents, to the systematic investigation of complex thermohydraulic phenomena. The PKL tests began in the mid 1970s with the support of the German Research Ministry. Since the mid 1980s, the project has also been significantly supported by the German PWR operators. Since 2001, 25 partner organizations from 15 countries have taken part in the PKL investigations with the support and mediation of the OECD/ NEA (Nuclear Energy Agency). After an overview of PKL history and a short description of the facility, this paper focuses on the investigations carried out since the beginning of the international cooperation, and shows, by means of some examples, what insights can be derived from the tests.

• Kyungpook Mathematical Journal
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• 제28권2호
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• pp.129-139
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• 1988

Let $T^{\alpha}_{\lambda}$(p, A, B) denote the class of functions $$f(z)=z^p-{\sum\limits^{\infty}_{k=1}}{\mid}a_{p+k}{\mid}z^{p+k}$$ which are regular and p valent in the unit disc U = {z: |z| <1} and satisfying the condition $\left|{\frac{{e^{ia}}\{{\frac{f^{\prime}(z)}{z^{p-1}}-p}\}}{(A-B){\lambda}p{\cos}{\alpha}-Be^{i{\alpha}}\{\frac{f^{\prime}(z)}{z^{p-1}}-p\}}}\right|$<1, $z{\in}U$, where 0<${\lambda}{\leq}1$, $-\frac{\pi}{2}$<${\alpha}$<$\frac{\pi}{2}$, $-1{\leq}A$<$B{\leq}1$, 0<$B{\leq}1$ and $p{\in}N=\{1,2,3,{\cdots}\}$. In this paper, we obtain sharp results concerning coefficient estimates, distortion theorem and radius of convexity for the class $T^{\alpha}_{\lambda}$(p, A, B). It is further shown that the class $T^{\alpha}_{\lambda}$(p, A, B) is closed under "arithmetic mean" and "convex linear combinations". We also obtain class preserving integral operators of the form $F(z)=\frac{p+c}{z^c}{\int^z_0t^{c-1}}f(t)dt$, c>-p, for the class $T^{\alpha}_{\lambda}$(p, A, B). Conversely when $F(z){\in}T^{\alpha}_{\lambda}$(p, A, B), radius of p valence of f(z) has also determined.

• 인터넷정보학회논문지
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• 제17권6호
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• pp.113-122
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• 2016

Information and Communication Technology (ICT) has revolutionized the world and has profound impact on the social and economic development of a country. Implementation, practice and accessibility of ICT is viewed as an integral part of any countries' strategy today. These new technologies are becoming popular due to their ability to produce, distribute and provide instant access to massive information in no time. ICT has pervaded almost every aspect of human endeavor that may include health, education, economics, governance, entertainment etc. Tourism is one such vital industry that find enormous application of ICT in its strategic and operational level, to promise long term benefits and enhance economic growth. Tourism industry in western world and some developed countries of Asia have applied ICT for more than 30 years, and have gained tremendous benefits. Nepal which is also growing as one of the favourite tourist destinations lacks proper implementation of ICT in this industry. In our study we examined how the ICT can play a vital role in developing the tourism industry of Nepal. This study is an exploratory research based on primary data collected from tourist visiting Nepal, supported by information from tour operators, government agencies, NGOs and INGOS. A framework is devised on the basis of data and information collected and finally, discussions elaborate on the prospect and challenges of implementation of ICT in tourism industry of $Nep{\grave{a}}l$.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2218-2229
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• 2006

A conservative finite-volume numerical method for unstructured grids with the cell-centered method has been developed for computing flow and heat transfer by combining the attractive features of the existing pressure-based procedures with the advances made in unstructured grid techniques. This method uses an integral form of governing equations for arbitrary convex polyhedra. Care is taken in the discretization and solution procedure to avoid formulations that are cell-shape-specific. A collocated variable arrangement formulation is developed, i.e. all dependent variables such as pressure and velocity are stored at cell centers. For both convective and diffusive fluxes the forms superior to both accuracy and stability are particularly adopted and formulated through a systematic study on the existing approximation ones. Gradients required for the evaluation of diffusion fluxes and for second-order-accurate convective operators are computed by using a linear reconstruction based on the divergence theorem. Momentum interpolation is used to prevent the pressure checkerboarding and a segregated solution strategy is adopted to minimize the storage requirements with the pressure-velocity coupling by the SIMPLE algorithm. An algebraic solver using iterative preconditioned conjugate gradient method is used for the solution of linearized equations. The flow analysis code (PowerCFD) developed by the present method is evaluated for its application to several 2-D structured-mesh benchmark problems using a variety of unstructured quadrilateral and triangular meshes. The present flow analysis code by using unstructured grids with the cell-centered method clearly demonstrate the same accuracy and robustness as that for a typical structured mesh.

• Human Ecology Research
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• 제52권5호
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• pp.457-471
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• 2014

Family instability has a negative effect on not only an individual household but also the society. The government continues to operate family support centers as a countermeasure to family instability issues. A healthy and multicultural family support center is considered an effective support system that extends from a family unit to the local community. In this study, the satisfaction and demand levels of each center, located in Seoul and Incheon, were examined with respect to items such as operation contents, physical space, and organizational structure. The results showed that various efforts for creating a family-friendly community were implemented in healthy family support centers and multicultural family support centers. It was found that the center organizers and operators focused more on software and programs than on the physical environment. There was mostly a shortage of physical and environmental space. This space shortage limited the planned and ongoing activities in terms of the residents' self-directed participation and space formation for a family-friendly educational culture. Therefore, it was necessary to set up the space-related criteria for each center in order to solve this environmental issue. We identified the baseline data of the criteria for a center's physical and spatial design and size. In particular, it was suggested that a more strategic physical and spatial design is needed to achieve an integral and effective operation for the connection of the family with the local society.

• 한국공간정보시스템학회 논문지
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• 제6권1호
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• pp.31-50
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• 2004

무선통신망과 GPS(Global Positioning System)를 탑재한 모바일 단말기의 발달로 사람이나 사물의 위치정보를 파악하고 이용하는 위치기반 서비스의 영역이 확대되고 있다. 위치기반서비스와 같은 응용분야에서는 시간에 따라 연속적으로 움직이는 이동객체를 효율적으로 저장하고 처리할 수 있는 데이터베이스가 주요한 기술이다. 본 논문에서는 이동객체 데이터베이스를 개발하기 위한 하나의 서브시스템으로서, 이동객체에 대한 질의를 처리하기 위한 컴포넌트를 설계 및 개발한다. 이동객체에 대한 질의를 처리하기 위해서 대표적인 질의표현 및 처리방법을 조사하고, 기존에 개발된 이동객체에 대한 데이터모델과 연산자를 기반으로 SQL형태의 이동객체 질의어를 새로이 정의한다. 사용자는 본 연구에서 제공하는 이동객체 질의어를 이용하여 이동객체의 위치정보에 대한 영역질의, 위상질의, 궤적질의, 최근접질의 등을 표현할 수 있다. 이동객체 질의처리 컴포넌트는 각 질의 들을 분석한 후 이를 효율적으로 처리하기 위한 모듈들을 설계하고 구현한다. 또한, 다른 이동객체 응용시스템을 개발할 때 본 시스템의 활용을 높일 수 있도록 ADO.NET 인터페이스를 제공하고 XML을 이용하여 질의의 결과를 표현할 수 있는 기능을 제공한다.

• 교육녹색환경연구
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• 제23권1호
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• pp.1-11
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• 2024

우리나라는 인구감소와 시민들의 문화 및 복지에 대한 수요 증가로 학교시설의 복합화 사업을 통해 공공시설에 대한 기대와 수요를 충족 하려고 한다. 이에 본 연구에서는 모범사례인 화성시 '이음터'를 기반으로 학교시설 복합화의 개념을 정리하고, 교육프로그램 및 공간 특성을 분석하여 효율적인 교육프로그램을 수행할 수 있는 방안을 제시하는 것을 목적으로 하였다. 사례연구의 대상은 화성시의 7개의 이음터를 선정하여, 현장답사 및 시설운영자를 대상으로 현장 관찰과 인터뷰를 진행하였다. 사례분석의 결과로 교육프로그램 유형은 학습 나눔, 공동 소통, 평생 배움으로 도출하였다. 학습 나눔은 교육과 체육시설로 지역사회의 연대감과 교류를 증진 시키는 역할을 수행하며, 주민들의 높은 이용률과 활성화된 지역사회의 중심으로 자리 잡고 있음을 알 수 있었다. 공동 소통은 커뮤니티, 편의시설 유형으로 분류하였다. 커뮤니티시설로는 다목적홀과 소통홀, 편의시설로는 주차장과 카페 프로그램이 운영되고 있었다. 평생 배움은 다양한 문화시설의 프로그램을 제공하며, 화성시만의 차별화된 특화 프로그램으로 이음터 중 가장 활발히 운영되고 있음을 확인할 수 있었다. 향후 다원화된 사용자 계층에 따른 적합한 교육프로그램과 운영을 위한 학교와 복합화의 일체형 연계유형 연구도 필요하다.