• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1307-1312
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• 2007

This paper proposes an optimal design scheme to reduce the noise of the engine cooling fan by adapting Kriging with two meta-heuristic techniques. An engineering model has been developed for the prediction of the noise spectrum of the engine cooling fan. The noise of the fan is expressed as the discrete frequency noise peaks at the BPF and its harmonics and line spectrum at the broad band by noise generation mechanisms. The object of this paper is to find the Optimal Design for Noise Reduction of the Engine Cooling Fan. We firstly show a comparison of the measured and calculated noise spectra of the fan for the validation of the noise prediction program. Orthogonal array is applied as design of experiments because it is suitable for Kriging. With these simulated data, we can estimate a correlation parameter of Kriging by solving the nonlinear problem with genetic algorithm and find an optimal level for the noise reduction of the cooling fan by optimizing Kriging estimates with simulated annealing. We notice that this optimal design scheme gives noticeable results. Therefore, an optimal design for the cooling fan is proposed by reducing the noise of its system.

• Asian Oncology Nursing
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• v.11 no.1
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• pp.83-92
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• 2011

Purpose: This study was to analyze the characteristics and effect size of intervention studies in reference to cancer pain. Methods: In order to conduct a meta-analysis, a total of 208 studies were retrieved from search engine. And 29 studies published from 2000 to 2010 were selected upon their satisfaction with the inclusion criteria. The data was analyzed by the RevMan 5.0 program of Cochrane library. Results: 1) Intervention studies included 7 studies on reflexology (24.1%), 5 for pain management education (17.2%), 3 studies for each music therapy, spiritual care and hand massage (10.3%, respectively), and 2 studies for each hospice and horticultural therapy (6.7%, respectively). 2) The effect size of the intervention studies were high in hand massage (d=-0.98), reflexology (d=-0.74), spiritual care (d=-0.72), pain management education (d=-0.66), music therapy (d=-0.41), and horticultural therapy (d=-0.32). Conclusion: This study suggest that non-drug therapy can reduce the levels of cancer pain intensity, even though the numbers of intervention studies and randomized controlled trials are very rare.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.267-272
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• 2007

One of the roles of the Semantic Web services is to execute dynamic intra-organizational services including the integration and interoperation of business processes. Since different organizations design their processes differently, the retrieval of similar semantic business processes is necessary in order to support inter-organizational collaborations. Most approaches for finding services that have certain features and support certain business processes have relied on some type of logical reasoning and exact matching. This paper presents our approach of using imprecise matching fur expanding results from an exact matching engine to query the OWL MIT Process Handbook. In order to use the MIT Process Handbook for process retrieval experiments, we had to export it into an OWL-based format. We model the Process Handbook meta-model in OWL and export the processes in the Handbook as instances of the meta-model. Next, we need to find a sizable number of queries and their corresponding correct answers in the Process Handbook. We devise diverse similarity algorithms based on values of process attributes and structures of business processes. We perform retrieval experiments to compare the performance of the devised similarity algorithms.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.214-219
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• 2007

생성 규칙(Production Rule)과 이를 기반으로 하는 규칙 엔진(Rule Engine)을 기반으로 한 OWL 추론 엔진은 메타 규칙((Meta Rule)에 의존해 왔다. 메타 규칙은 OWL의 의미론 (Semantics)을 표현하기 용이하여 보다 손쉽게 OWL 추론 엔진을 구현할 수 있다는 장점을 제공하였으나 OWL 추론 성능에 있어 추론 속도와 대용량 온톨로지 처리 측면에서 모두 만족할 만한 성과를 얻지 못하였다. 본 논문은 DLP(Description Logic Programming)의 번역 접근법을 기반으로 한 번역 규칙(Translation Rules)을 메타 규칙과 혼용하는 OWL 추론 기법을 소개한다. LUBM 벤치마크를 통해 이 기법이 메타 규칙만을 이용했을 때 보다 100% 이상 추론 성능을 향상시켰을 뿐 아니라 메모리 사용량도 대폭 축소시켰음을 확인할 수 있었다. 또한, 번역을 통해 제한없는 차수 제약(Cardinality Restriction) 관련 추론을 지원하는 등 보다 넓은 범위의 OWL 추론을 지원할 수 있다.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.1
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• pp.1-7
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• 2017

As a part of studies to lower the infrared (IR) emissivity from the surface of exhaust nozzle in the turbo jet engine, stainless steel plate was coated with copper particle/meta-aramid resin composites and the IR emissivity of the plate were investigated. Binders of filler particles based on synthetic polymers generally undergo thermal decomposition before $300^{\circ}C$. It was found that the meta aramid resin was thermally stable after the test at $320^{\circ}C$, confirming the excellent thermal stability. Contents of copper particles in the composites were varied from 0 to 70% by volume. It was observed that the copper particle/meta aramid resin composites showed good adhesion after the tests at $320^{\circ}C$. The specimen coated with the composite containing 50 vol% of copper particles showed the lowest IR emissivity, 0.6, at $320^{\circ}C$.

• Journal of the Korea Computer Graphics Society
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• v.30 no.3
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• pp.61-69
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• 2024

Mixed reality(MR) technology combines the advantages of virtual reality(VR) and augmented reality(AR) technology, allowing MR users to interact with virtual objects against the background of the real world. In addition, since virtual objects interact with the real world, users can experience a higher immersion. This study proposes electric circuit practical training content using Meta Quest Pro to produce immersive MR content based on reality. To this end, first, the development process for producing MR content by linking Meta Quest Pro equipment with the Unity 3D engine is organized. Then, based on the traditional electric circuit practical training method used in elementary school science classes, virtual electric circuit practical training content with the same training method and operation process is produced based on MR. Finally, survey experiments are conducted to analyze the presence and experience of the MR-based educational environment provided using the produced content. Through this, the usability of the proposed practical training content is evaluated and future research directions are suggested.

• Journal of Korean Society for Quality Management
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• v.38 no.3
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• pp.333-339
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• 2010

It is difficult to determine an optimal inventory level of aircraft engine and modules to achieve the target operational availability since F100-PW-200 & 229 engines of the F-16 & KF-16 aircraft are consisted of 5 modules with different failure rates and costs. This study presents a decision model, combining an integer programming problem and a regression metamodel. Data for the metamodel was attained from results of a simulation model, that represents operational and repair process of F-16 and KF-16. The objective function of an integer programming problem is maximizing the operational availability, representing pessimistic circumstances. Finally, an integer programming problem with a metamodel can make an optimal decision of the inventory level.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.10a
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• pp.91-94
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• 1998

전 세계적으로 산재한 검색엔진들은 그 수가 많아짐에 따라 일관성이 없는 정보를 제공하고 있거나 어느 특정한 곳에 집중된 정보를 제공하는 경우도 있어 사용자가 원하는 정보를 얻기 위해서는 많은 검색 엔진들을 일일이 조사해야 하고, 각각의 검색 엔진들의 특성을 알아야 하는 불편한 점이 있다. 본 논문에서는 기존의 검색엔진과 메타엔진의 2단계 방식의 클라이언트서버 운용에 따르는 서버 시스템의 부하와 네트웍의 트래픽을 줄일 수 있는 Component의 할당정책을 제시하고, 또한 CORBA를 이용한 메타엔진을 설계하고 구현하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.10a
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• pp.359-364
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• 1998

지금까지 정보 검색에 대한 많은 연구가 있어 왔지만, 여전히 여러 가지 문제들로 인해 사용자는 많은 시간을 소비하게 된다. 본 논문에서는 이러한 문제를 해결하기 위해 검색결과를 분석하여 중복된 URL을 제거하고, 접근이 불가능한 URL 정보를 사용자에게 보여준다. 해결 방안으로는 멀티쓰레드를 이용한 로봇 에이젼트가 자동으로 각 URL을 방문함으로써 가능하게 했으며, 사용자는 직접 방문하지 않고도 접근 불가능한 이유를 미리 알게된다. 구현된 메타 검색 엔진을 기존의 검색 엔진들과 비교 했을 때 약 13%의 효율성 향상을 가져왔으며, 앞으로 시소러스 등을 이용한 더 많은 연구가 진행될 것이다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.217-219
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• 2000

정보의 바다라고 일컬어지는 인터넷에서 원하는 정보를 찾기란 쉽지 않다. 웹 검색엔진이 나날이 발전하고 있기는 하지만, 이들 검색엔진은 개인에게 특화된 것이 아니기 때문에 검색 결과의 양이 엄청나게 많은 뿐만아니라 원하지 않는 정보인 경우가 많다. 따라서 사용자의 기호를 반영하여 원하는 정보만을 찾아줄 수 있는 시스템이 필요하다. 본 논문에서는 사용자의 기호를 반영하여 개인에게 특화된 웹 검색 시스템을 개발하기 위하여 유전자 알고리즘으로 최적화된 다중에이전트 시스템을 제안한다. 실험결과 사용자 프로파일 벡터가 사용자기호에 따라 변화하여 제안한 시스템이 유용함을 알 수 있었다.