• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.14 no.4
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• pp.293-299
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• 1985

This paper describes an economical prediction procedure for heat transfer phenomenon through a channel containing an abrupt asymmetric expansion in flow cross-seetional area. Numerical solutions for the flow field are obtained by the finite difference numerical method applied to the modified boundary layer equations. Modified boundary energy equation is used to analyze heat transfer as modified boundary momentum equation. Predictions of the method compare very favorable with exprimental data. Results of this study by modified boundary layer equation are as follows : 1. The computation time required for the scheme is at least an order of magnitude less than for the numerical solution of the full Navier-stokes and Energy eguations. 2. In laminar flow, the maximum heat transfer occurs downstream of the reattachment point.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.539-540
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• 2022

본 논문에서는 Bounding Box가 포함된 증강 이미지 데이터셋을 손쉽게 생성할 수 있는 독립형 GUI 프로그램을 제안한다. 본 논문의 연구를 통하여 직관적인 마우스 클릭 동작만으로 적은 수의 이미지 파일과 annotation 파일로부터 필요한 만큼의 증강 이미지 데이터셋을 짧은 시간 내에 생성하고, 다양한 아키텍처의 학습용 이미지 데이터셋 증강에 적용할 수 있다.

• Annual Conference of KIPS
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• 2024.10a
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• pp.845-846
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• 2024

최근 기업 및 기관은 온-프레미스에서 클라우드로 전환이 급증하였다. 이에 따라 기존의 경계보안장비 방식이 아닌 제로 트러스트 시스템 구축이 확대되고 있다. 제로 트러스트 시스템은 MFA 인증을 통해 접근 인증이 된 사용자만 리소스 접근이 가능해져 보안 강화를 더 용이하게 할 수 있다. 각 기업에서 관리자는 대시보드를 통해 실시간으로 시스템을 모니터링 할 수 있으며, 사용자들은 자동화된 시스템을 통해 리소스를 편리하게 사용할 수 있도록 구성했다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.1999-2010
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• 1992

The fixed slab analogy device which can measure stress intensity factors(S.I.F) experimentally by slab analogy theory is developed in this paper. The margin of errors resulted from the new testing apparatus are between 0.02% and 8.25%. Therefore, it is assured that this one can be effectively used for the more accurate measurement of S.I.F.( $k_{I}$, $k_{I I}$) than conventional apparatus. The pitch of master grating used in this experiment is 0.1mm It is known that the ratio of the distance from crack tip to the crack length on obtaining the accurate stress intensity factor is between 0.4 and 0.7. The optimum curvature radius of slab is about 125mm. The thickness of slab(plate) used in the fixed slab analogy device is 0.05mm(P.V.C. ; E = 64 MN/ $m^{2}$, .nu.=0.38), which is proved to be suitable for the test. The optimum material for the frame(slab`s external boundary) is a alloy tool steel(SKS 5) plate and its thickness is 1mm. In this research, the rigid cracks are directly bonded to the slab surface by cyanoacrylate adhesive for the easiness of slab making and conformity to the practical crack figure. The material of rigid crack is thin steel plate. It is expected that the developed method can be used effectively for the analysis of $k_{I}$ and $k_{I I}$ of arbitrary shaped or distributed cracks.cks.

• Journal of Information Technology and Architecture
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• v.10 no.4
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• pp.435-449
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• 2013

The performance of Enterprise Architecture (EA) in the Korea's public IT domain produces mixed results and responses. On the one hand, EA earns positive remarks and enthusiasm as a central government-wide IT governance framework with its significant IT budget saving records. At the same time, however, the response to EA at the department and agency level is tainted with disappointment, fatigue, and reluctance. This essay suggests that this is perhaps caused by the sterile lackluster concept of EA Business Architecture employed in the current EA practice of the enterprise. The possibility for liberating and reviving the concept of EA Business Architecture is explored. Various conceptual axes and branches of EA Business Architecture are identified based upon extensive EA field experience and observations, and discussions are made on how the concept of EA Business Architecture can be expanded and amplified on those conceptual axes and branched. The resulting EA Business Architecture conceptualization is consolidated into an illustrative typology for EA Business Architecture. In the end the theoretical and practical implications of the research are discussed along with its contribution and limitation.

• Journal of Digital Convergence
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• v.12 no.1
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• pp.281-286
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• 2014

Humanities knowledge makes the learners overcome the boundaries of study and can be applied variously by means of contents for study. This paper suggests application contents plans designed as the learning tools for blended learning, which can be sure of the possibility to the extension of other fields. Literary education with application contents has effects followings: First, smart device based on the web under the ubiquitous circumstances has the information system like the neuron's. So the application selects the necessary information and makes the contents for infusion into the education. Also it provides with more abundant and extended information system. With this approach, learners are able to get further literary knowledge and promote the ability for tapping them for new knowledge as well. Lastly, literature applied to the class with web contents is based on the foundation that creates new knowledge necessary for culture, arts, and so on. As a result, the education using web contents achieves the boundless of study, which is the final goal of the blended learning.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.383-390
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• 2018

The purpose of this study is to find out how the evolution of digital play in virtualization and digital play tools are combined with and stereotyping the properties of traditional play. Virtualization characteristics and play theory were examined and the case was derived in four types and analyzed in four play properties with Roser Cailliois. In the case of Agon, the targets of mutual competition are expanded to singular and plural, computer and oneself of the future, and Mimicry showed the ambiguity of the segments and boundaries crossing the on-off line boundary, and in the case of Alea, the diversity of accident occurrence by immediacy and simultaneity has been strengthened, and in the case of Ilinx, the maximization of immersion has been developed and experimented with a variety of techniques for the utilization of senses and tools and the virtuality for this. As a result, play is developing due to the tendency to expand and coexist in time and space by various fusion combinations.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.775-779
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• 2009

최근 이상기후 및 국지성 돌발호우 등 여러 가지 형태의 예기치 못한 기상이변으로 인하여 매년 수재해는 빈번히 발생하고 있으며, 이를 위해 하천에서 실시간으로 신속하고 안정성있는 수리학적 하도추적모형의 구축은 지속적으로 연구해야 할 사항이다. 현재 주요 수계 홍수통제소에서는 홍수예보를 위해 주로 수리학적 및 수문학적 모형이 병행되어 적용되고 있으나, 한강과 금강하류를 제외한 나머지 수계에서는 아직까지 개념적 수문학적 모형만을 이용하여 홍수예보를 수행하고 있는 실정이다. 그러나, 신속하고 안정적인 수문학적 모형이 가지고 있는 몇가지 장점에도 불구하고, 실시간 분석 및 신속한 상황대처를 위해서는 정교한 하천흐름해석 기술인 수리학적분석이 반드시 필요하다. 그러나, 대부분의 모형운영자가 직면하게 되는 수리학적 하도추적모형에서 발생하는 수치적 불안정성인 발산의 문제점은 상당한 어려움으로 작용하고 있다. 이는 다양한 원인들이 있을 수 있으나, 대표적으로 단면의 불규칙성을 고려할 수 있다. 실제단면들을 모형에 반영할 때 수치계산의 과정 중에 급확대/급축소/특이단면에 따른 잦은 발산이 발생하게 되며, 이를 방지하기 위해서 단면의 보간 및 평활화 작업 등을 수행하게 된다. 이때 단면의 형상을 최대한 반영한 보간 및 평활화 작업이 되지 않으면, 물리적 개념이 무시된 비합리적인 계산이 수행될 수 있다. 발산의 요인을 제거한 최적의 단면형태를 선정하는 것은 모형의 안정성을 확보하는 데 중요한 요인이 된다. 또한 모형수행에 있어 발산의 요인으로서 하구와 만나게 되는 지점에서의 경계조건으로서 조위영향이 있다. 수리학적 하도추적모형의 중요한 요인인 하구에서의 흐름을 조위와 연계하여 가장 합리적인 하류 경계조건을 제시하는 것이 모형의 발산 방지 및 정확도를 향상시키는데 중요한 인자로 작용하고 있다. 본 연구에서는 이와 같은 수리학적 하도추적모형의 안정성 검증을 위하여, 아직까지 수리학적 하도추적모형이 구축되어 있지 않는, 금강상류구간인 용담댐$^{\sim}$대청댐구간을 설정하여 수리학적 모형의 입력자료를 구축하고, 그에 따른 영향검토를 지속적으로 추진할 계획이다. 대상구간에서 향후 검증될 다양한 수리학적 안정화 기술은 향후 타 수계에서 적용시, 신속하고 합리적인 입력자료 구축에 많은 도움을 줄것이며, 현재 하천에서 발생하는 계산의 불안정성을 빠르게 수정하는 것이 가능하다.

• Spatial Information Research
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• v.3 no.2
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• pp.91-102
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• 1995

The purposes of this paper are to find ways to detect ecotone between two eco'||'&'||'not;systems, measure the width and size of ecotone around the Mt. Pukhansan National Park, and investigate environmental impacts, if any, on the forest ecosystem of the park by human activities. Normalized Difference Vegetation Index(NDVI) derived from TM data and the ana'||'&'||'not;lytical capabilities of GIS are used to investigate characteristics of the ecotone, or the impact zone, of the park. Major findings of the study can be summarized as follows: First, it was found that ecotone of the park could be identified from NDVI -distance curves deri"ed by a series of buffering op'||'&'||'not;erations. Second, NDVIs of all three years of the national park are about 14 percent higher than surrounding areas. Third, width of ecotone were found to be closely related to phenology, adjacent land use, environmental degradation, etc. Third, ecotone of the study area was nearly douvled during 1985-1993 period, which might be caused by heavy trampling of visitors. Thus it can be concluded that further studies are needed to find exact causes of the deterioration of plant communities of the ecotone of the park.

• Journal of the Korean Geographical Society
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• v.33 no.1
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• pp.41-56
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• 1998

The main purpose of this study is to delimit the boundary of central business district and to describe the internal structure of CBD in Seoul. To delimit the CBD boundary, we used the locational matrices of main CBD functions, which were ofganized through fieldworks. CBD functions are classified into 20 categories. They are retail sales, corporation managements, administration managements, business, and unclassified services, customer(personal)services, and manufacturings. The core area of CBD in Seoul is at Chongro and Chung Gu area that shows the locational consistency comparing to 1970s. Although the boundary is slightly expanded into west, south and east, the extent of horizontal expansion in CBD can be negligible comparing to the remarkable growth of Korean economy after 1970s. The reasons why CBD showed little expansion can be found out from the process of restructuring in Seoul metropolitan area, such as the growth of subcenters, decentralization of central functions, construction of highrise buildings, redevelopment in central area and so on. Internal structure of Seoul's CBD shows 5 specialized functional subdistricts. They are CBD core area, subdistrict of department and office functions, retail sales, customer services and light manufacturings.