• Advances in aircraft and spacecraft science
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• v.4 no.5
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• pp.555-571
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• 2017

The description of transitional flows by means of RANS equations is sometimes based on non-local approaches which require the computation of some boundary layer properties. In this work a non-local Laminar Kinetic Energy model is used to predict transitional and separated flows. Usually the non-local term of this model is evaluated along the grid lines of a structured mesh. An alternative approach, which does not rely on grid lines, is introduced in the present work. This new approach allows the use of fully unstructured meshes. Furthermore, it reduces the grid-dependence of the predicted results. The approach is employed to study the transitional flows in the T106c turbine cascade and around a NACA0021 airfoil by means of a discontinuous Galerkin method. The local nature of the discontinuous Galerkin reconstruction is exploited to implement an adaptive algorithm which automatically refines the mesh in the most significant regions.

• Anxiety and mood
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• v.3 no.1
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• pp.15-19
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• 2007

Substantial rates of comorbid anxiety disorders have been found using structured research diagnostic interviews in depressed outpatients. Comorbid anxiety disorders is underrecognized in routine clinical settings, in which clinicians usually use unstructured diagnostic interviews. Recognition of comorbid conditions such as anxiety disorders in patients seeking treatment for depression is clinically important because the presence of these disorders might influence selection of treatment options or predict the chronicity of the depression. A reliable and valid self-report screening questionnaire, such as the Psychiatric Diagnostic Screening Questionnaire (PDSQ), would potentially enhance usual clinical practice as a useful diagnostic aid.

• Environmental Analysis Health and Toxicology
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• v.16 no.2
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• pp.85-95
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• 2001

This study was to investigate factors of risk perception on major environmental issues among general public and environmental experts in Korea. Structured questionnaire surveys were conducted to samples from general public and environmental experts during March and April, 2000. Total numbers of respondents were 773, general public and 353 experts. Analysis of the data showed that risk perception was correlated with health concern, environmental satisfaction, perception of environmental pollution, interest on the environmental issues, knowledge, experiences, and social-cultural consciousness, and so on. Overall environmental risk perception was affected by knowledge on environmental issues, experience of damage from environmental problems, sex and perception of environmental pollution. According to the results, environmental risk perception is not independent from social and psychological factors, and it may be desirable to consider the related factors in the process of risk communication for a more effective risk management or environmental policy.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.193-200
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• 2003

This paper proposes a novel algorithm to recognize the curve of a structured road. The proposed algorithm uses an LCF (Lane Curve Function) obtained by the transformation of a parabolic function defined on world coordinate into image coordinate. Unlike other existing methods, the algorithm needs no transformation between world coordinate and image coordinate owing to the LCF. In order to search for an LCF describing the lane best, the differential comparison between the slope of an assumed LCF and the phase angle of edge pixels in the LROI (Lane Region Of Interest) constructed by the LCF is implemented. As finding the true LCF, the lane curve is determined. The proposed method is proved to be efficient through various kinds of images, providing the reliable curve direction and the valid curvature compared to the real road.

• Journal of the Korean Applied Science and Technology
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• v.20 no.3
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• pp.243-250
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• 2003

Poly(methyl methacrylate)/clay nanocomposite particles with particle size of 275${\sim}$292 nm range were successfully prepared using emulsion polymerization. The content of montmorillonite based on the methyl methacrylate monomer was chosen as 30 wt.%. 2,2-azobis(isobuthylamidine hydrochloride) and n-dodecyltrimethylammonium chloride were used as an initiator and a surfactant in cationic emulsion system. Potassium persulfate and sodium lauryl sulfate were used as an initiator and a surfactant in anionic emulsion system. The evidence of intercalated /exfoliated structure of montmorillonite in the nanocomposite prepared in our experiment was confirmed by wide angle x-ray diffraction patterns of $d_{001}$ plane. Thermal behavior of nanocomposite was traced using DSC and TGA. It was found that the nanocomposite particle prepared by cationic emulsion system showed intercalated structured. We also found that the nanocomposite particle obtained from anionic emulsion system resulted in the fully exfoliated structure.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.456-460
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• 2009

Biofilm is a structured community of microorganism encapsulated within a self-developed polymeric matrix and adherent to a living or a solid surface. In this study, we investigated the effects of various substrates on the formation of biofilm in Vibrio parahaemolyticus. We found that biofilm formation profoundly increased in a substrate, that consisted of calcium chloride, calcium nitrate, and calcium sulfate in 1% peptone water. On the other hand, a dramatic reduction in biofilm formation was observed in a substrate, that consisted of glucose and ferric chloride in LB broth. These results suggest that V. parahaemolyticus prefer to form a biofilm on the surface of a crustacean or a clam, where calcium ion is rich, and also where seawater temperature is relatively lower. In contrast, high levels of glucose in a crustacean or a clam body resulting from increased seawater temperature, can make V. parahaemolyticus detach from it and lead to free floating.

• Korean Journal of Human Ecology
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• v.21 no.5
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• pp.889-901
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• 2012

This study examined acculturation stress resulting from socio-demographic characteristics and psychological and social status of married immigrant women residing in the Jeonbuk region. Data were gathered from married immigrant women who were participating in non-profit agencies offering multi-cultural services and those who worked for business offices and stores in the Jeonbuk area. A structured self-administered questionnaire was used. A total of 280 questionnaires were distributed, and 210 were returned. Twenty three questionnaires were excluded from the study because of invalid responses, providing a final data pool of 187 responses. Hierarchical multiple regression analyses revealed that Korean language ability and levels of depression were significantly associated with acculturation stress among married immigrant women. Based on the findings of this study, interventions for reducing acculturation stress among married immigrant women and implications for future studies are discussed.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.199-204
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• 2001

SECOS는 분리개발 된 객체 컴포넌트를 통합함으로써 새로운 응용 시스템을 작성할 수 있는 CBSE(Component Based Software Engineering)기법을 바탕으로 한, 웹 기반 정보 저장/검색의 전형적 모델을 제공하는 소프트웨어 시스템이다. 현재 본 연구팀은 SECOS 시스템의 적용 사례로서 e-business를 위한 쇼핑몰을 구축하고자 검색, 지불, 응용분야의 모듈들을 S/W 컴포넌트로 개발 중에 있다. 본 논문에서는 그 중, SECOS의 검색분야에서 상품정보를 보다 효율적으로 수집하고 사용자에게 양질의 정보를 제공하기 위해 필수적으로 요구되는 정보 수집 서비스의 구조에 대하여 설명하고, 특히 비 정형화 된 XML 웹 소스에서의 정보수집 방법에 있어 현재 진행중인 연구에 대하여 설명하고자 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.324-327
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• 2011

스마트폰과 무선인터넷 상에서 멀티미디어 사용이 일반화되면서, 스마트폰 환경에서 멀티미디어 관련 취약점을 악용한 공격이 급증하고 있다. 이러한 취약점을 악용한 공격을 예방하기 위해, 퍼징(Fuzzing)을 적용하여 취약점을 미리 발견하려는 연구들이 진행되고 있다. 본 논문에서는 '임의 생성 기반 퍼징'(단순랜덤, simple random) 방법과 '구조적 변이 기반 퍼징'(구조적 변이, structured mutation) 방법을, 안드로이드 스마트폰용 멀티미디어 플레이어에 적용하는 실험을 수행하였다. 또한 PC 환경의 멀티미디어 플레이어들에서 발생했던 기존 취약점을 악용한 공격파일(exploit)을 안드로이드 스마트폰 환경의 멀티미디어 플레이어들에 적용하고 그 결과를 분석하였다. 실험 결과, PC 환경에서는 구조적 변이 퍼징이 효과적인데 비해, 안드로이드 스마트폰 환경에서는 단순 랜덤 퍼징이 효과적임을 알 수 있었다.

• Wind and Structures
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• v.18 no.5
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• pp.529-548
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• 2014

This article presents the unsteady aerodynamic performance of crosswind stability obtained numerically for the ATM train. Results of numerical investigations of airflow past a train under different yawing conditions are summarized. Variations of occurrence flow angle from parallel to normal with respect to the direction of forward train motion resulted in the development of different flow patterns. The numerical simulation addresses the ability to resolve the flow field around the train subjected to relatively large yaw angles with three-dimensional Reynolds-averaged Navier-Stokes equations (RANS). ${\kappa}-{\varepsilon}$ turbulence model solved on a multi-block structured grid using a finite volume method. The massively separated flow for the higher yaw angles on the leeward side of the train justifies the use of RANS, where the results show good agreement with verification results. A method of solution is presented that can predict all aerodynamic coefficients and the wind characteristic curve at variety of angles at different speed.