• Interaction and multiscale mechanics
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• 제1권1호
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• pp.53-81
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• 2008

The theory of microlocal analysis of hyperbolic partial differential equations shows that the energy density associated to their high-frequency solutions satisfies transport equations, or radiative transfer equations for randomly heterogeneous materials with correlation lengths comparable to the (small) wavelength. The main limitation to the existing developments is the consideration of boundary or interface conditions for the energy and power flow densities. This paper deals with the high-frequency transport regime in coupled heterogeneous structures. An analytical model for the derivation of high-frequency power flow reflection/transmission coefficients at a beam or a plate junction is proposed. These results may be used in subsequent computations to solve numerically the transport equations for coupled systems, including interface conditions. Applications of this research concern the prediction of the transient response of slender structures impacted by acoustic or mechanical shocks.

• Architectural research
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• 제14권1호
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• pp.3-9
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• 2012

Owing to the advent of ubiquitous computing technologies, the concept of Intelligent Environments has emerged, as an alternative approach to overcome the limitation of the built environment. Intelligent Environments can be more responsive to user-and context-specific human activities by automatically and dynamically modifying their settings without explicit human intervention. However, the conventional approach to the development of Intelligent Environments has mainly focused on the technical issues without paying much attention to the dynamic interrelationship between the user and the built environment. Therefore, differing or conflicting needs of multiple simultaneous users remain unresolved. The objective of this study is to present types of environmental conflicts and their resolution through agent collaboration and negotiation. For the demonstration and validation of the conflict resolution process, a set of hypothetical test cases is simulated in a 3D test environment. The result of the case simulations shows that the proposed approach is computationally feasible and applicable to the development of Intelligent Environments, and, furthermore, it can overcome the drawback of the conventional approach.

• 한국연소학회지
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• 제4권2호
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• pp.43-50
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• 1999

Liquefied petroleum gas (LPG) has been used as motor fuel due to its low emissions and low cost. The fuel feeding system has been improved with stringent requirement for exhaust emissions. LPG carburetion system was first introduced, then the system has been changed to a precisely controlled gas injection system, but this gas feeding system has a limitation on improving power output. In order to improve an engine performance, a multi-point port injection system was introduced recently, and a liquid direct injection system into a cylinder was suggested as a next generation system to maximize a fuel economy as well as a power. This study addresses the analysis of the LPG spray from diesel injectors. The spray images are visualized and compared with diesel sprays in a wide injection pressure range. The photographs show much wider dispersion of LPG sprays.

• 정보관리학회지
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• 제8권2호
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• pp.96-107
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• 1991

통계적 정보 혹은 벡터 모델을 이용하는 자동 색인은 색인어와 문서간에 관계성을 간접적으로 혹은 상대적으로 계산하기 때문에 검색의 정확도를 높이는데 한계가 있다. 이 보다는 적극적인 방법으로 언어학적 정보와 인공 지능의 기술을 이용하여 색인어의 관계성 을 계산하는 방법론을 소개한다. 동사의 격틀을 이용하여 개발된 시스템으로부터 언어적 분 석 방법의 가능성을 찾아볼 수 있다. 미래의 정보 검색은 사용자 중심으로 구성이 되어 사 용자에 대한 연구가 깊게 반영이 되어야 할 것이다.

• The Korean Journal of Pain
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• 제23권3호
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• pp.211-214
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• 2010

Spontaneous retropharyngeal hematoma is rare and difficult to diagnosis early. A 23-year-old male spontaneously developed acute onset of neck pain, limitation of neck motion, and mild dysphagia. Magnetic resonance imaging demonstrated blood products in prevertebral space from C2 to C4, suggesting a diagnosis of retropharyngeal hematoma. We report a rare case of spontaneous retropharyngeal hematoma causing neck pain.

• 대한물리치료과학회지
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• 제2권2호
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• pp.517-531
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• 1995

This article reviews the concepts of motor ability and motor skill and the models, theories, and treatment approaches of motor contorl. Reflex, hierarchical, and systems models of motor control are discussed. And muscle reeducation, neurodevelopment, motor relearning program, and contemporary task-oriented approach is also discussed. We consider that the concept of motor control is being changed and the treatment approach also is being changed. There are a number of reasons, the first is traditional trteatment approach has limitation. Second is theories of motor control is contineously developed. Third is new approach is coming to us. therefore, the therapists shoulder strive for acquisition of motor skill and motor ability. This article hope the successful integration of models and treatment approaches and its application in physical therapy practice.

• 한국항공운항학회지
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• 제18권3호
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• pp.92-98
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• 2010

The AHP methodology compares criteria, or alternatives with respect to a criterion, in a natural, pairwise mode. AHP has been applied in a wide variety of applications multi objective decision making being just one. If a group of expert with different aspect, they need some way to revise expert group. We proposed the concatenation of expert to survey the AHP pairwise question for multi-attribute decision making. In this paper, we suggest a way to revise the expert's priorities in hierarch using concept of different group opinion.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.23-28
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• 2002

As the interest on the air pollution is gradually rising up at home and abroad, automotive industries have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative aftertreatment systems, and using clean fuels. Methanol, ethanol, LNG, LPG, H2, reformulated gasoline are generally recognized as the clean fuel. Since the low price policy of government on LPG has expanded its vehicle market recently, there is concern of the exhaust emission of LPG vehicle. In this paper, we studied the value of LPG fuel as a clean fuel by comparing the results of the exhaust emission from LPG and Gasoline fueled vehicles, and discussed its limitation of LPG vehicle with mixer type as a fuel supply system. FTIR was used to understand the difference of exhaust emission components of LPG and Gasoline fueled vehicles.

• International Journal of Contents
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• 제6권4호
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• pp.22-29
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• 2010

In flash memory, many previous garbage collection methods only merge blocks statically and do not consider the contents of buffer. These schemes may cause more unnecessary block erase operations and page copy operations. However, since flash memory has the limitation of maximum rate and life cycle to delete each block, an efficient garbage collection method to evenly wear out the flash memory region is needed. This paper proposes a memory compaction scheme based on block-level buffer for flash memory. The proposed scheme not only merges the data blocks and the corresponding log block, but also searches for the block-level buffer to find the corresponding buffer blocks. Consequently, unnecessary potential page copying operations and block erasure operations could be reduced, thereby improving the performance of flash memory and prolonging the lifetime of flash memory.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2011년도 춘계 종합학술대회 논문집
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• pp.339-340
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• 2011

본 연구는 N말단 아미노산 종류에 따라 단백질의 수명(half-life)이 결정된다는 N-end rule을 기반으로 단백질 수명을 예측해주는 프로그램인 protparam의 결과와 bleach-chase를 이용한 실험 데이터를 비교 분석하였다. 단백질 수명을 결정하는 여러 요인들을 고려하지 않고 한 가지 요인만을 반영한 protparam의 결과는 실제 측정값과 현격한 차이를 나타낸다. 특히 실제 단백질은 NME(N-terminal Methionine Excision) 현상이 일어나는데 이를 고려하지 않고 유전체에서 번역한 그대로의 아미노산 서열을 가지고 단백질 수명을 계산하는 한계를 가지고 있다. 이에 본 연구에서 N말단 아미노산을 순차적으로 제거하여 N-end rule을 적용한 결과도 실험 데이터와 일치하지 않는 결과를 보여주고 있음을 확인하였다. 따라서 현재 사용되고 있는 단백질 수명 예측 프로그램은 이런 문제점을 가지고 있기 때문에 새로운 예측 알고리즘의 개발이 요구된다.