• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.645-647
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• 2000

본 논문에서는 멀티미디어나 데이터베이스 등 대용량 입출력을 효율적으로 지원하기 위하여 고속 네트웍으로 연결된 클러스터링 환경에서 동작하는 클러스터 파일 시스템인 OpenCFS를 설계하고 구현하여 성능을 평가한다. 구현된 클러스터 파일 시스템은 입출력 장치의 한계를 극복하기 위하여 스트라이핑(striping)기법을 통한 병렬 입출력(parallel I/O)을 수행하고, 능동적으로 시스템 내부 정책 병경을 가능하게 하는 오픈 임플리멘테이션(Open Implementation)방법론을 적용함으로써 응용프로그램의 시스템 내부 정책에 대한 접근 방법을 제공한다. 실험을 통하여 구현된 클러스터 파일 시스템의 성능을 분석한 결과, 사용자가 기존의 프로그래밍 환경을 유지하면서 시스템 내부 정책을 변경함으로써 개선된 성능의 입출력 서비스를 제공 받을 수 있다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.388-391
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• 2012

Intake start characteristics of a Mach 5 scramjet engine were investigated experimentally. Intake unstart was observed. The model-facility interaction or excessive internal contraction ratio were attributed to this unstart. Intake start was achieved by changing the model position to remove the model-facility interaction, and by modifying the cowl to give smaller contraction ratio.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.8
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• pp.293-298
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• 2014

Detecting and understanding the changes between RDF data is crucial in the evolutionary process, synchronization system, and versioning system on the web of data. However, current researches on detecting changes still remain unsatisfactory in that they did neither consider the large scale of RDF data nor accurately produce the RDF deltas. In this paper, we propose a scalable and effective change detection using a MapReduce framework which has been used in many fields to process and analyze large volumes of data. In particular, we focus on the structure-based change detection that adopts a strategy for the comparison of blank nodes in RDF data. To achieve this, we employ a method which is composed of two MapReduce jobs. First job partitions the triples with blank nodes by grouping each triple with the same blank node ID and then computes the incoming path to the blank node. Second job partitions the triples with the same path and matchs blank nodes with the Hungarian method. In experiments, we show that our approach is more accurate and effective than the previous approach.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2292-2299
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• 2010

The wear and abrasion mechanism of conventional PET/Cotton fabric which is used as a lining layer for thermotherapy massager was elaborately investigated in order to increase the life-span of the fabrics for Thermotherapy Massager. Based on the destruction mechanism, the feasible PET fabrics were prepared and its anti-wearing performance was evaluated. It is revealed that the wearing destruction is mainly caused by the repeat abrasion on a specific part of folded fabric as well as abrasion itself. Therefore, it is necessary that the prevention of fabric folding while massager is running is essential and the recovery from the crease on a fabric is also necessary to solve this problem. Covered elastic yarn, high twisted yarn, change of fabric structure or different fiber were utilized to prepare the possible alternatives. As a result, the anti-wearing performance of the fabrics are greatly improved to have about 2 times and 1.5 times longer life-span for the fabric with covered elastic yarn and high twisted yarn, respectively.

• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2204-2212
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• 1999

In this paper, we present techniques which perform incremental timing analysis using Timed Boolean Algebra that solves the false path problem and extracts the timing information in combinational circuits. Our algorithm sets histories of internal inputs that are substituted for internal output and extracts maximal delays through checking sensitizability of primary outputs. Once finding the sum of primitive delay terms, then it applies modified delay with referencing histories of primary output and it can extract maximal delays of primary outputs fast and efficiently. When the structure of circuit is changed, there is no need to compute the whole circuit again. We can process partial timing analysis of computing on the gates that are need to compute again. These incremental timing analysis methods are considered both delay changes and structure of circuit, and can reduce the costs of a trial error in the circuit design.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.12
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• pp.975-982
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• 2014

This study evaluates the effect of a heated circular cylinder's size on three-dimensional natural convection in a cubical enclosure. The Rayleigh number was varied between $10^3$ and $10^5$, and the Prandtl number was maintained at 0.7. In this study, the radius of the circular cylinder was changed by 0.1 L within a range of 0.1-0.4 L. The thermal and fluid flow characteristics were regarded to be independent of time in the range of the Rayleigh number and cylinder radius considered in this study. The surface-averaged Nusselt numbers of the cylinder and the enclosure were found to increase with the increase in the radius of the cylinder. The effect of the cylinder's size on natural convection in the enclosure was analyzed across the thermal and flow fields, and the distributions of the Nusselt numbers.

• Journal of Legislation Research
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• no.44
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• pp.655-688
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• 2013

Most of all the transfer of undertakings in such a service provision business as labour-intensive operation creates uncertainty of employment, aggravates terms of employment and breaks a trade union. However there are no regulations in Korea to protect employees from these undesirable situations. On the other hand Great Britain has introduced the concept of a transfer of undertakings by service provision change in 2006. It was intended to remove or at least alleviate the uncertainties and difficulties created by the need under TUPE 1981 and EU Directive to establish a transfer of a stable economic identity which retained its identity in the hands of the alleged transferee. In contrast to the words used to define transfer in the 1981 Regulations 'service provision change' is a wholly new statutory concept and distinguished from the economic entity. The new provisions seems to be straightforwards and the circumstances in which service provision change is established are clearly set out in Regulations. In this context there is no need for a judicially prescribed multi-factorial approach, as advanced by European Court of Justice like Spijkers test. The new concept of service provision change apply even though there are some minor difference or differences between the nature of the tasks carried on after service provision change as compared with before it. A commonsense and pragmatic approach is required and It is enough only to ask whether the activities carried on by the alleged transferee are fundamentally or essentially the same as those carried out by the alleged transfer. TUPE 2006 of Great Britain far exceeding the scope of the Acquired Rights Directive is full of suggestions as a model of legislation to secure a stable employment itself and favorable and fair conditions of employment. More active efforts are needed for lawmaking to prohibit a dismissal and vary conditions of employment for the reason of the transfer of undertakings itself.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.395-399
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• 2009

현재 계획 또는 설계단계에서 수행되고 있는 우수 관거 시스템의 수리계산에서는 연결관의 마찰손실만을 감안하여 수행하고 있으며, 맨홀에서의 수두손실은 고려되지 않는 실정이다. 특히 과부하 $90^{\circ}$ 접합맨홀 내부에서의 복잡한 흐름 현상에 의하여 발생하는 에너지 손실은 일반적인 직선 연결 맨홀에 의해서 발생하는 에너지 손실과 큰 차이를 보이지만 현재 우수 관거 설계 및 관리에서는 이를 대부분 고려하지 않는 실정이다. 또한 직선으로 연결된 맨홀보다 $90^{\circ}$ 접합 맨홀은 유수교란에 의한 에너지 손실이 커지므로 이에 대한 $90^{\circ}$ 접합 맨홀에서의 에너지 손실 저감에 대한 연구가 필요하다. 그러므로 본 연구에서는 합류 맨홀 중 $90^{\circ}$ 접합 맨홀에서의 에너지 손실 저감 방법의 분석을 위하여 하수도시설기준(환경부, 2005)의 표준 1호(원형), 특 1호(사각형) 맨홀을 각각 축소 제작하고, 수리실험 장치를 제작하여 수리 실험을 실시하였으며, 실험결과를 benching을 사용하지 않은 $90^{\circ}$ 접합 맨홀의 평균 손실계수를 산정한 윤세의 등(2008)의 실험 결과와 비교하였다. 접합위치를 변경한 원형 맨홀 CASE B에서의 평균 손실계수는 1.1로 산정되어 CASE A의 1.6보다 크게 감소하였다. 접합위치를 변경한 사각형 맨홀 CASE B에서는 1.5로 산정되어 손실계수의 감소폭이 적었으나, 접합위치를 변경하고 side benching을 설치한 CASE C에서의 평균 손실계수는 1.1로 산정되어 CASE A의 사각형 맨홀의 손실계수 1.6에 비하여 큰 감소 효과를 나타내었다. 따라서 $90^{\circ}$ 접합 원형 맨홀에서는 접합 위치를 변경시킨 CASE B의 형태를 사용하고, 사각형 맨홀에서는 접합 위치를 변경시키고 side benching을 설치한 CASE C의 형태를 사용하면 우수 관거 시설의 배수능력을 향상 시킬 수 있을 것으로 판단된다.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.2
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• pp.140-149
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• 1992

The new method, termed the substructural eigensensitivity synthesis method, utilizes the computational merits of the component mode synthesis technique and of sensitivity analysis for the design sensitivities of the dynamic characteristics of substructurally combined structures. It is shown that the eigensensitivities of the entire structure can be obtained by synthesizing the substructural eigensolution and the sensitivities of the eigensolution for the design variables of the modifiable substructure. The sensitivities of the eigenvalues and eigenvectors obtained by the new method are compared to exact eigensolutions in terms of accuracy and computational efficiency. The small errors in eigensensitivity due to the truncation of higher modes remain within a manageable and permissible range for further analysis. The advantage of the newly proposed method as compared to the direct application of sensitivity analysis of the whole structure is demonstrated through examples.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.424-426
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• 2004

웹 기술이 발달할수록 사회 전반의 패러다임 변화속도는 빨라지고, 사용자의 요구 사항과 웹 프로그램 내부의 복잡성은 증가한다. 또한 콘텐츠의 생명 주기는 짧아지고, 웹 프로그램의 구조 변경과 유지보수가 많아지게 된다. 따라서 동적인 변화에 빠르게 대처할 수 있는 웹 프로그램 기술이 더욱 요구되고 있다. XML은 계층적 구조를 갖고 있으면서도 구조적 변경이 가능하고, 다른 형태로의 변환이 용이하다. 본 논문에서는 이런 장점을 이용하여 개발 기간을 단축시킬 수 있는 방법의 하나로, XML을 기반으로 하는 웹 프로그램 개발 지원 서버를 이용해 쉽고 간편하게 웹 서버 프로그램을 개발하고, 유지보수 할 수 있도록 하는데 중점을 두고 웹 기반의 XML 트리를 설계하고 구현하였다. XML 트리는 파싱뿐만 아니라 계층적 구조를 이루고 있어 접근성이 우수하고, XML 스키마와 XML 스타일시트 작성에도 않은 도움을 줄 수 있을 것으로 기대된다.