• 국제초고층학회논문집
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• 제2권2호
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• pp.115-121
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• 2013

The ventilation performance of a street in Bangkok, Thailand, was investigated by performing measurements and conducting a CFD analysis. We focused on a street that was covered by an elevated train station. It was shown that the ventilation efficiency varied drastically depending on the angle between the street and the wind direction. When the wind direction was parallel to the street, the elevated structure had a negative influence, which created higher pollutant concentrations than in locations without elevated structures. However, when the wind direction was perpendicular to the street, the pollutant concentrations in the two situations were similar. Using a CFD analysis and ventilation performance indexes, it was shown that the elevated structure directed the wind flow and enhanced the ventilation efficiency, which positively affected ventilation performance. These kinds of knowledge can lead us to optimize city planning including high-rise buildings with high ventilation efficiency.

• Wind and Structures
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• 제9권1호
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• pp.37-58
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• 2006

The paper describes a study about effects of upstream hills on design wind loads using two mathematical approaches: Computational Fluid Dynamics (CFD) and Artificial Neural Network (NN for short). For this purpose CFD and NN tools have been developed using an object-oriented approach and C++ programming language. The CFD tool consists of solving the Reynolds time-averaged Navier-Stokes equations and $k-{\varepsilon}$ turbulence model using body-fitted nearly-orthogonal coordinate system. Subsequently, design wind load parameters such as speed-up ratio values have been generated for a wide spectrum of two-dimensional hill geometries that includes isolated and multiple steep and shallow hills. Ground roughness effect has also been considered. Such CFD solutions, however, normally require among other things ample computational time, background knowledge and high-capacity hardware. To assist the enduser, an easier, faster and more inexpensive NN model trained with the CFD-generated data is proposed in this paper. Prior to using the CFD data for training purposes, extensive validation work has been carried out by comparing with boundary layer wind tunnel (BLWT) data. The CFD trained NN (CFD-NN) has produced speed-up ratio values for cases such as multiple hills that are not covered by wind design standards such as the Commentaries of the National Building Code of Canada (1995). The CFD-NN results compare well with BLWT data available in literature and the proposed approach requires fewer resources compared to running BLWT experiments.

• Steel and Composite Structures
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• 제18권3호
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• pp.673-691
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• 2015

In this paper we are particularly focusing on the dynamic crack fatigue life of a 25 m length wind turbine blade. The blade consists of composite materiel (glass/epoxy). This work consisted initially to make a theoretical study, the turbine blade is modeled as a Timoshenko rotating beam and the analytical formulation is obtained. After applying boundary condition and loads, we have studied the stress, strain and displacement in order to determine the critical zone, also show the six first modes shapes to the wind turbine blade. Secondly was addressed to study the crack initiation in critical zone which based to finite element to give the results, then follow the evolution of the displacement, strain, stress and first six naturals frequencies a function as crack growth. In the experimental part the laminate plate specimen with two layers is tested under cyclic load in fully reversible tensile at ratio test (R = 0), the fast fracture occur phenomenon and the fatigue life are presented, the fatigue testing exerted in INSTRON 8801 machine. Finally which allows the knowledge their effect on the fatigue life, this residual change of dynamic behavior parameters can be used to predicted a crack size and diagnostic of blade.

• 한국컴퓨터정보학회논문지
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• 제3권4호
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• pp.110-119
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• 1998

본 논문은 개방형 분산 Computing system에서 여러 분산 어플리케이션 프로그래머들에게 범용 암호 서비스 제공을 위한 C-API(Cryptographic-Application Program Interface) Mechanism개발에 대하여 설명한다. C-API Mechanism는 응용 프로그래머에게 공통적으로 사용 할 수 있는 암호 알고리즘 및 인터페이스를 제공함으로써 프로그래머가 암호 알고리즘을 알지 못하여도 분산 어플리케이션이 보안 서비스를 제공할 수 있다. 따라서,본 논문에서는 다양한 응용 환경 또는 시스템 하부구조에 독립적으로 사용될 수 있는 공용암호 서비스 구조를 설계하여 공통적으로 이용할 수 있도록 하였다. 이러한 구조는 응용 프로그래머에게 각종 암호화 관련서비스 및 키관리 서비스를 응용 프로그램과 운영체제의 제약없이 사용할 수 있는 장점이다.

• 대한족부족관절학회지
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• 제6권2호
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• pp.178-180
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• 2002

Authors report one patient of concurrent fracture of medial malleolus and rupture of deltoid ligament. To the author's knowledge, combined failure of both structures has not been previously reported in Korea. Injury mechanism was classified into pronation -abduction type according to Lauge-Hansen classification. Plain radiograph revealed trimalleolar fracture and posterior ankle dislocation. MRI showed complete rupture of both deep and superficial layer of the deltoid ligament. In conclusion, therefore, concurrent rupture of deltoid ligament should be considered for the surgical treatment in trimalleolar ankle fracture with posterior ankle dislocation resulted from pronation-adduction injury.

• Smart Structures and Systems
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• 제14권2호
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• pp.191-207
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• 2014

In this research, an internal model based method is proposed to estimate the structural displacements and velocities under ambient excitation using only acceleration measurements. The structural response is assumed to be within the linear range. The excitation is assumed to be with zero mean and relatively broad bandwidth such that at least one of the fundamental modes of the structure is excited and dominates in the response. Using the structural modal parameters and partial knowledge of the bandwidth of the excitation, the internal models of the structure and the excitation can be respectively established, which can be used to form an autonomous state-space representation of the system. It is shown that structural displacements, velocities, and accelerations are the states of such a system, and it is fully observable when the measured output contains structural accelerations only. Reliable estimates of structural displacements and velocities are obtained using the standard Kalman filtering technique. The effectiveness and robustness of the proposed method has been demonstrated and evaluated via numerical simulations on an eight-story lumped mass model and experimental data of a three-story frame excited by the ground accelerations of actual earthquake records.

• 대한산업공학회지
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• 제39권3호
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• pp.204-211
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• 2013

In this article, we propose a typology of industry convergences which encourages to invent new types of products and services through combining technologies across industries and identifying success factors of convergence industries which were resulted by industry convergences. In detail, the proposed typology of industry convergences is analyzed based on three viewpoints such as academic areas that provide the knowledge of convergence technologies, industry structures for the existing markets, and user experiences used for improving user friendliness. Such viewpoints can not only be considered as the sources for convergence industries but also be closely related with success factors of convergence industries. Based on the typology and the success factors of convergence industries, we suggest the implications about policies for the domestic industry convergence. It is expected that the results of this article can be widely applied to further activate industry convergences to overcome the recent global economic downturn.

• 한국문헌정보학회지
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• 제31권2호
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• pp.79-93
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• 1997

동일 분류항목 내에 분류되는 저작들을 개별화하여 배열과 검색을 용이하게 하기 위해 사용되는 도서기호는 크게 입수순기호, 저자기호, 그리고 연대순기호로 나누어 볼 수 있다. 현대의 매우 빠른 학문 발전속도는 최신의 정보가 최상의 가치를 갖도록 만들었고, 이용자들의 이용행태 또한 최신의 자료에 집중되고 있다. 이러한 정보의 가치기준과 이용행태의 변화에 따라 도서관에서는 최신의 자료를 오래된 것과 구분하여 모아줄 필요가 발생하였다. 본고에서는 이러한 요구를 반영하여 고안된 「새 연대순 도서기호법」이 널리 채용되게 하고자 하는 목적으로 그 특징과 기호구성을 살펴보았고, 일부 자모순 도서기호를 적용토록 지시된 항목의 성격에 대해 규명하였다.

• 한국멀티미디어학회논문지
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• 제5권1호
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• pp.59-67
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• 2002

이 논문에서는 XML을 이용하여 웹 기반 적응적 하이퍼미디어 시스템을 설계한다. 설계한 적응적 하이퍼미디어 시스템은 학습자 각각의 동적 이해 과정을 통해 하이퍼미디어 컨텐츠를 프리젠테이션 할 수 있는 기능을 포함하고 있다. 학습자 프로필은 학습자 모델 안에 포함되어 있고, 하이퍼미디어 컨텐츠인 영역 지식은 개념 기반의 영역 모델 형태로 설계되었다. 따라서 이 논문에서는 XML을 이용해서 영역 모델과 학습자 모델을 구조화하기 위한 두 가지의 다른 마크업 언어를 정의한다. 이러한 마크업 언어는 웹 기반 교육용 적응적 하이퍼미디어 분야에서 자료를 구조화하기 위한 간단한 방법론을 가지고 쉽게 확장될 수 있고 저작될 수 있다.

• Journal of Yeungnam Medical Science
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• 제35권1호
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• pp.89-93
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• 2018

Idiopathic non-cirrhotic portal hypertension (INCPH) is a disease with an uncertain etiology consisting of non-cirrhotic portal hypertension and portal pressure increase in the absence of liver cirrhosis. In INCPH, patients exhibit normal liver functions and structures. The factors associated with INCPH include the following: Umbilical/portal pyremia, bacterial diseases, prothrombic states, chronic exposure to arsenic, vinyl chloride monomers, genetic disorders, and autoimmune diseases. Approximately 70% of patients present a history of major variceal bleeding, and treatment relies on the prevention of complications related to portal hypertension. Autoimmune disorders associated with INCPH are mainly systemic sclerosis, systemic lupus erythematosus and rheumatoid arthritis. To the best of our knowledge, a case of ankylosing spondylitis (AS) associated with INCPH has not been reported thus far. Therfore, we report our experience of a patient with AS accompanied by INCPH, who showed perisplenic varices with patent spleno-portal axis and hepatic veins along with no evidence of cirrhosis on liver biopsy, and provide a brief literature review.