• Advances in Computational Design
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• 제1권3호
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• pp.265-274
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• 2016

The present paper describes the results of numerical modeling of a dam founded on loose liquefiable deposit using PLAXIS-3D finite element software. Effect of a different dam water level on parameters like displacements, Excess Pore water pressures, Liquefaction potential and Accelerations is studied. El- Centro earthquake motion is applied as input earthquake motion. The results of this study show that different upstream dam water level greatly affects the displacements, excess pore pressure and displacement tendency of the underlying foundation soils and the dam.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.509-514
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• 2005

In recent years, use of the web technologies and on-line process has immensely swapped single-user platform practice. This study attempted to develop preliminary cost estimating program by means of Web technologies based on statistical modeling results. A prototype Web-based Preliminary Item-Level Cost Estimating System (WBPILCES) using open source software was developed as an on-line estimating tool in this research. The primary objective is to study the possible flexibility of implementing a centralized information system that will be maintained by the Texas Department of Transportation (TxDOT) IT division. The full-scale deployment of proposed information architecture is expected to seamlessly integrate with legacy database system currently used by TxDOT so as to streamline data storage, cost growth tracking and estimates documentation.

• Structural Engineering and Mechanics
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• 제91권4호
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• pp.357-368
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• 2024

In this study, a finite-element surface wave simulation using an effective elastic constant (EEC) was developed to calculate the Rayleigh wave velocity change and polarization change in aluminum, steel, and concrete under uniaxial stress. Under stress, an isotropic medium behaves like an anisotropic material during the wave propagation. The EEC is an equivalent anisotropic stiffness matrix which was derived to simulate the acoustoelastic effect using classical finite-element software. The vertical and horizontal surface displacements located 8-mm from a 1-㎲ excitation load were used to find the acoustoelastic coefficients k^v and k^p and compared to an analytical scheme. It was found that k^v for aluminum and concrete matched within 4% of the analytical solution. The finite-element simulation showed that the Rayleigh wave arrival time for concrete and aluminum was greatly influenced by the stress level. Thus, predicting the stress level using concrete and aluminum's acoustoelastic effect is applicable.

• 서비스연구
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• 제8권1호
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• pp.59-72
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• 2018

서비스 관점에서 국제표준기구가 요구하는 수준의 인증 서비스를 SW 개발과정에 도입하는 것은 매우 중요하다. 그 이유는 우리 산업에서 ICT가 차지하는 비중이 매우 높을 뿐만 아니라, ICT 관련 SW에 대한 국제적인 수준의 인증은 필수적이기 때문이다. 그리고 이를 위해서 ADONIS와 같은 과학적이며 체계적인 도구를 기반으로 한 인증 서비스가 절대적으로 요구된다. 본 논문에서는 이러한 시대적, 사회적 요구에 부응할 수 있는 하나의 새로운 방법 체계를 제시하였다. 이 체계는 우리 산업에 국제적인 수준에서 요구되는 SW의 안전성에 대한 인증 서비스를 제공하였고, 이러한 서비스는 다른 영역에도 적용될 수 있다. 이러한 체계를 설명하기 위해 EU우주항공국의 표준안 중 ECSS-E-40의 인증을 위한 서비스의 설계와 이에 대한 보증이 어떻게 이루어지는지 서비스 공학 측면에서 살펴보고, ADONIS를 통해서 보여주고자 한다. 본 논문은 E-40 표준안의 항목 중 SW의 명세와 검증에 관해 집중하며, 검증의 대상은 안전성(Safety)을 우선으로 한다.

• 정보처리학회논문지D
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• 제8D권6호
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• pp.681-690
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• 2001

본 논문에서는 컴포넌트에 기반한 소프트웨어 개발(CBSD) 환경의 전반적인 활성화 개념을 제시한다. 컴포넌트 기술에 대한 연구가 컴포넌트를 시스템 구축에 효율적으로 적용하려는 쪽으로 집중되어, 컴포넌트 시장의 활성화 방안이나 컴포넌트 자체의 개발 방식 등에 대해서는 지속적인 연구가 필요한 상태이다. 우선 CBSD 활성화로의 장애요소를 진단하고 이를 해결하기 위한 방안으로 중개개념 고려의 필요성을 강조한다. 그러나 단순한 사전적 의미로의 중개개념으로는 CBSD 활성화를 도모할 수 없으므로 중개개념에 부가적인 서비스를 추가한 “부가가치 중개 개념”이 요구된다. 부가가치 중개 개념에는 크게 1) 도메인 아키텍쳐 지향의 컴포넌트 생산 촉진, 2) 지능형 컴포넌트 검색 서비스, 3) 화이트 박스 서비스의 세 가지 기능을 수행한다. 도메인 아키텍쳐 지향의 컴포넌트 생산 촉진은, 균형 잡힌 컴포넌트 생산과 아키텍쳐 중심의 대단위 재사용을 꾀할 수 있다. 지능형 컴포넌트 검색 서비스는, 컴포넌트 생산자와 소비자 간의 1：1 거래의 한계를 해결해주고 마지막으로 화이트 박스 서비스는 컴포넌트 도입의 가장 큰 걸림돌인 유지보수 문제를 보장해준다. 특히 이 개념은 국내 컴포넌트 개발의 특수 상황에 적용하여 큰 효과를 얻을 수 있을 것으로 기대된다.

• 한국소음진동공학회논문집
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• 제27권2호
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• pp.139-147
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• 2017

Acoustic performance of splitter silencers was investigated by using 3-dimensional commercial software and experiments. Flow resistivity of sound absorbing material was indirectly estimated by using an impedance tube setup and a curve fitting method. In addition the acoustic impedance of perforated plate was determined by an empirical formulation. Such properties have been used as input parameters in the commercial software. The prediction for a splitter silencer with 1000 mm length was compared with the experimental result. The numerical method is then applied to identify the effects of number of splitters, length of splitters, absorptive material density, and porosity of a perforated plate on the performance of the splitter silencers. As the number and length of splitter increases, the acoustic performance significantly increases. Although the increase of density of absorptive material also increase the acoustic performance, a change in the density over a certain level hardly affect it. The increase of porosity will enhance the performance especially at higher frequencies.

• 대한안전경영과학회지
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• 제16권3호
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• pp.35-44
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• 2014

This study empirically examines how much effect levels of fatigue and stress of a construction worker have on disaster risks from the perspective of human factors concerning construction disaster risks. To achieve the purpose of this study, a survey was conducted with respect to construction workers working at large construction sites within the metropolitan area. The retrieved survey data were analyzed by using the statistical software programs, SPSS 18.0 and AMOS 8.0. The results of this study do not definitively lead to the conclusion that the level of fatigue or stress of construction workers result in disaster risks. However, it does show that the results vary depending upon the individual approach and treatment of stress and fatigue. In particular, this study revealed that disaster risk levels could increase through unsafe behavior intentions which were established as a mediator variable. Also, with respect to unsafe behavior intentions of construction workers leading to disaster risks, when examining the results that the level of mental fatigue, occupational stress and social-psychological stress of construction workers had a greater significant effect than the level of physical fatigue, this study demonstrates the importance of psychological and mental issues that could be easily overlooked with respect manual labor workers.

• International journal of advanced smart convergence
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• 제8권4호
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• pp.169-178
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• 2019

Due to the characteristics of an ad hoc network without a control center, self-organization, and flexible topology, the trust evaluation of the nodes in the network is extremely difficult. Based on the analysis of ad hoc networks and the blockchain technology, a blockchain-based node-level trust evaluation model is proposed. The concepts of the node trust degree of the HASH list on the blockchain and the perfect reward and punishment mechanism are adopted to construct the node trust evaluation model of the ad hoc network. According to the needs of different applications the network security level can be dynamically adjusted through changes in the trust threshold. The simulation experiments demonstrate that ad-hoc on-demand distance vector(AODV) Routing protocol based on this model of multicast-AODV(MAODV) routing protocol shows a significant improvement in security compared with the traditional AODV and on-demand multipath distance vector(AOMDV) routing protocols.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권9호
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• pp.4624-4644
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• 2019

With the development of films, games and animation industry, analysis and reuse of human motion capture data become more and more important. Human motion segmentation, which divides a long motion sequence into different types of fragments, is a key part of mocap-based techniques. However, most of the segmentation methods only take into account low-level physical information (motion characteristics) or high-level data information (statistical characteristics) of motion data. They cannot use the data information fully. In this paper, we propose an unsupervised framework using both low-level physical information and high-level data information of human motion data to solve the human segmentation problem. First, we introduce the algorithm of CFSFDP and optimize it to carry out initial segmentation and obtain a good result quickly. Second, we use the ACA method to perform optimized segmentation for improving the result of segmentation. The experiments demonstrate that our framework has an excellent performance.

• 한국정보과학회논문지:소프트웨어및응용
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• 제29권12호
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• pp.873-882
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• 2002

소프트웨어 개발 초기에 개발비용, 소요인력과 기간을 추정하는 것은 소프트웨어공학 분야에서 어렵고도 중요한 문제이다. 이 정보들은 소프트웨어 요구사항 명세서로부터 측정된 소프트웨어 규모인 기능점수를 이용하여 추정한다. 측정된 소프트웨어 규모를 개발하기 위해서는 개발팀을 몇 명으로 구성할 것인가가 문제로 제기된다. 본 논문은 소프트웨어 개발팀의 규모를 추정할 수 있는 모델을 제시한다. 모델을 유도하기 위해 301개 소프트웨어 프로젝트들이 사용되었다. 먼저, 통계적 알고리즘 모델인 회귀모델을 연구하였다. 다양한 데이타 변환과 회귀분석 결과 좋은 성능의 모델을 얻지 못하였다. 따라서, 비알고리즘 모델인 RBF망을 적용하여 잔차가 랜덤하게 분포하고 우수한 성능을 가진 모델을 제안하였다. 본 모델은 소프트웨어 개발에 필요한 개발팀 규모에 대한 기준을 제공함으로써 인력관리 정보로 활용할 수 있다.