• 한국CDE학회논문집
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• 제15권4호
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• pp.289-296
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• 2010

Energy consumption by buildings accounts for a large part of the world‘s energy consumption. Methods to analyze building energy consumption before construction have been studied for decades. With BIM (Building Information Modeling) technology, architects can easily export building information to data models in order to analyze the design‘s effect on building energy efficiency. Although several BIM-based energy simulation applications are currently available, utilizing these applications for energy efficiency simulation is difficult. In this paper, by comparing existing BIM-based energy applications, the authors test the building energy efficiencies estimated by some BIM models, offer ideas and solutions to problems that appeared during the test process and propose new methods for BIM-based energy evaluation based on quantitative factors.

• Computers and Concrete
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• 제9권1호
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• pp.63-79
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• 2012

The purpose of this study is to evaluate the behavior and strength of prestressed concrete deep beams using nonlinear analysis. By using a sophisticated nonlinear finite element analysis program, the accuracy and objectivity of the assessment process can be enhanced. A computer program, the RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), was used for the analysis of reinforced concrete structures. Tensile, compressive and shear models of cracked concrete and models of reinforcing and prestressing steel were used to account for the material nonlinearity of prestressed concrete. The smeared crack approach was incorporated. A bonded or unbonded prestressing bar element is used based on the finite element method, which can represent the interaction between the prestressing bars and concrete of a prestressed concrete member. The proposed numerical method for the evaluation of behavior and strength of prestressed concrete deep beams is verified by comparing its results with reliable experimental results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.383-384
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• 2009

콘크리트의 건조수축과 크리프는 노출환경, 물성치 및 하중조건 등의 여러 변수에 따라 결정되어 그 예측이 어렵다. 본 연구에서는 국내 8개 FCM 교량 적용 고성능 콘크리트의 실험 데이터를 활용하여 대표적인 5개 건조수축 및 크리프 제안식의 신뢰성를 평가하였다. 예측 모델과 실측 데이터의 합리적인 평가를 위해 5가지 통계학적 평가방법이 이용되었다.

• 대한임베디드공학회논문지
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• 제5권2호
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• pp.67-76
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• 2010

Although both functional verification and performance evaluation are necessary for the development of effective and reliable communication systems, they have been often performed independently; by functional modeling with formal language tools and by performance modeling with professional network performance evaluation tools, respectively. Separate and repeated modeling of one system, however, would often result in cost increase and inconsistency between the models. This paper proposes an integrated model design approach in order to overcome this problem that evaluates the performance of a communication protocol designed in SDL with SDL-OPNET model conversion. The proposed technique generates OPNET skeleton code from Tau-generated C code of the SDL model by analyzing the relations between SDL and OPNET models. IEEE 802.2 LLC protocol was used as an example of model conversion to show the applicability and effectiveness of the proposed technique.

• 대한기계학회논문집A
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• 제30권12호
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• pp.1534-1542
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• 2006

In this paper, the concept of accelerated life test, which is a popular research field nowadays, is applied to the shot peened material. To predict the efficient and exact room temperature fatigue characteristics from the high temperature fatigue data, the adequate accelerated model is investigated. Ono type rotary bending fatigue tester and high temperature chamber were used for the experiment. Room temperature fatigue lives were predicted by applying accelerated models and doing reliability evaluation. Room temperature fatigue tests were accomplished to check the effectiveness of predicted data and the adequate accelerated life test models were presented by considering errors. Experimental result using Arrhenius model, fatigue limit obtain almost 5.45% of error, inverse power law has about 1.36% of error, so we found that inverse power law is applied well to temperature-life relative of shot peened material.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.686-691
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• 1994

For evaluating the response fluctuation of the actual environmental acoustic system excited by arbitrary random inputs, it is important to predict a whole probability distribution form closely connected with evaluation indexes Lx, Leq and so on. In this paper, a new type evaluation method is proposed by introducing three functional models matched to the prediction of the response probability distribution from a problem-oriented viewpoint. Because of the positive variable of the sound intensity, the response probability density function can be reasonably expressed theoretically by a statistical Laguerre expansion series form. The relationship between input and output is described by the regression relationship between the distribution parameters(containing expansion coefficients of this expression) and the stochastic input. These regression functions are expressed in terms of the orthogonal series expansion and their parameters are determined based on the least-squares error criterion and the measure of statistical independency.

• 대한교통학회지
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• 제34권3호
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• pp.234-247
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• 2016

교통운영전략의 친환경성 평가의 필요성이 대두되고 있는 가운데, 정확한 평가를 위해서는 분석에 사용되는 차량연료소모 예측모형에 대한 이해가 선행되어야 한다. 이를 위해 본 연구에서는 국내에서 사용되고 있는 3개 모형과 외국에서 사용되고 있는 모형들 중 광범위하게 사용되는 동시에 비교적 취득이 용이한 3개 모형을 선정하여 모형의 특성을 응용측면에서 비교하였다. 구체적으로, 국립환경연구원의 차량주행기록인 NIER 차속모드와 미시교통류시뮬레이션 소프트웨어인 VISSIM을 이용하여 차량의 운행패턴을 모델링하였으며, 이를 차량연료소모 예측모형에 입력하여 연료소모량을 예측하였다. 본 연구를 통해 정속주행의 경우 국내외의 모든 모형이 유사한 결과를 보이는 것으로 분석되었으나, NIER 차속모드와 VISSIM 모형을 이용한 분석결과 국내모형 중 KR-1, KR-2 모형은 순간적인 차량의 비출력에 민감하지 못하여 미시적인 분석을 요하는 경우에는 사용에 주의를 기울여야 하는 것으로 분석되었다.

• 한국산림과학회지
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• 제97권4호
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• pp.368-373
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• 2008

본 연구는 전북부안 지역의 소나무와 진안 지역 낙엽송림을 대상으로 개발된 생장모형을 지역적으로 독립된 데이터를 이용하여 검증하고 기존에 개발된 생장모형이 다른 지역에도 적용 할 수 있는지의 효율성을 측정하는데 그 목적을 두었다. 기존에 개발된 소나무의 직경생장 모형은 새로운 데이터에 우수한 적합성을 보였으나, 흉고단면적 및 수고 생장 모형은 적합도가 떨어지는 것으로 나타났다. 반면에 낙엽송의 직경, 흉고단면적 및 수고 생장 모형은 지역적으로 독립된 데이터에 우수한 적합성을 보였다. 따라서 기존에 개발된 소나무의 직경생장 모형을 제외한 흉고단면적 및 수고 생장 모형의 적용은 개발된 지역에서만 사용 할 수 있는 효율성의 한계가 있는 것으로 보인다. 그러나 낙엽송의 직경, 흉고단면적 및 수고 생장 모형은 다른 지역에도 적용 할 수 있는 우수한 효율성을 보여 산림 자원이 풍부한 전라북도 동부 산악권 지역의 낙엽송 생장 모형으로 이용 될 수 있는 것으로 판단된다.

• 소성∙가공
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• 제24권1호
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• pp.52-61
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• 2015

Evaluation of the elevated temperature flow stress for thermoplastic fiber metal laminates(TFMLs) sheet, comprised of two aluminum sheets in the exterior layers and a self-reinforced polypropylene(SRPP) in the interior layer, was conducted. The flow stress as a function of temperature should be evaluated prior to the actual forming of these materials. The flow stress can be obtained experimentally by uniaxial tensile tests or analytically by deriving a flow stress model. However, the flow stress curve of TFMLs cannot be predicted properly by existing flow stress models because the deformation with temperature of these types of materials is different from that of a generic pure metallic material. Therefore, the flow stress model, which includes the effect of the temperature, should be carefully identified. In the current study, the flow stress of TFMLs were first predicted by using existing flow stress models such as Hollomon, Ludwik, and Johnson-Cook models. It is noted that these existing models could not effectively predict the flow stress. Flow stress models such as the modified Hollomon and modified Ludwik model were proposed with respect to temperatures of $23^{\circ}C$, $60^{\circ}C$, $90^{\circ}C$, $120^{\circ}C$. Then the stress-strain curves, which were predicted using the proposed flow stress models, were compared to the stress-strain curves obtained from experiments. It is confirmed that the proposed flow stress models can predict properly the temperature dependent flow stress of TFMLs.

• 한국IT서비스학회지
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• 제10권2호
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• pp.141-162
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• 2011

The controls of Information Systems (IS) have been an more critical issue controls as the sophistication and integration of IS is more proceeded. ITGI (The Information Technology Governance Institute) of ISACA (Information Systems Audit and Control Association) has suggested COBIT (Control Objectives for Information and related Technology) and this has been widely recognized the evaluation model of IS controls. In COBIT, IS was evaluated in terms of process, information quality, and IT resources. This study used COBIT in order to suggest and empirically test an evaluation model of IS service. The data was collated from one major Chinese SI (Systems Integration) company in four domains of processes : planning and organization, acquisition and implementation, delivery and support, and monitoring. Seven factors are extracted using an exploratory factor analysis as follows : Overall IT planning process, technological assessment process in IT planning of IT, cost-benefit assessment process in IT planning, implementation process, support process, monitoring process, post-implementation evaluation process. The results of confirmatory analysis of three alternative measurement models indicated that the measurement model with one inherent or conceptual variable has greater model fitness than the other models. This study suggests the logical and general way to test and apply COBIT in evaluating IS services.