• 산업경영시스템학회지
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• 제17권32호
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• pp.227-232
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• 1994

In the performance domain, physical performance is a measure that represents some degree of system, subsystem, component or device success in a continuous sense, as opposed to a classical binomial sense (success or failure). If applicable sensing and monitoring means exist, physical performance can be observed over time, along with explanatory variables or covariables. Performance-based reliability represents the probability that performance will remain satisfactory over a finite period of time or usage cycles in the future when a performance critical limit (which represents an appropriate definition of failure in terms of performance) is set at a fixed level, based on application requirements. In the case of inadequate knowledge of the failure mechanics, this physical based empirical modeling concept along with performance degradation knowledge can serve as an important analysis tool in reliability work in product and process improvement.

• KCI Concrete Journal
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• 제12권2호
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• pp.31-43
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• 2000

The extensive usage of pretensioned prestressed concrete component in modem construe- tion as structural members mandates precise understanding of its mechanism. Especially, an adequate transfer of prestressing force from steel tendons to concrete around the end regions of the member is a critical issue. Due to the importance of the topic, several investigators have formulated equations modeling the transfer bond length based on various bonding mechanism between steel and concrete. However, the existing models are still inadequate in predicting the bond development in pretensioned prestressed concrete members. Therefore, this study presents a model of transfer bond length based on rational theory that can simulate experimental results. The model is developed into solid mechanics based structural analysis computer program. The program is validated by comparing the analysis results with experimental results of bond stress distribution, concrete strain profiles, and transfer length in pretensioned prestressed concrete members. The proposed analytical procedure in this study can be utilized as a useful tool for realistic evaluation of transfer length in pretensioned prestressed concrete members.

• 한국공작기계학회논문집
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• 제13권1호
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• pp.88-93
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• 2004

In general, a fundamental structural design consideration for an automobile is the overall dynamic behavior in bending and torsion. Dynamic behavior of the automobile are mainly influenced by the structural stiffness of B.I.W.(body-in-white) and the physical property of trim components. In this paper, the modeling techniques for various trim components of middle-sized bus are presented, and the dynamic effects of the trim components on the vibration characteristics of the bus are investigated. The $1^{st}$ torsional frequency is decreased by attaching windshield and backlite to the B.I.W., but the $1^{st}$ vertical bending frequency and the $1^{st}$ lateral bending frequency are increased. The natural frequencies of the bus are decreased by attaching doors and windows. And also, the natural frequencies of the bus are large decreased by attaching seats, instrument panel etc. The study shows that the dynamic characteristics of the bus can be effectively predicted in the initial design stage.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.164-170
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• 2008

A typical clutch system for automotive manual transmissions transfers hydraulic pressure generated by driver's pedal manipulation to the clutch diaphragm spring. The foot effort history during the period of push is different than the period of the clutch pedal's return. The effort or load difference is called clutch foot effort hysteresis. It is known that the hysteresis is caused by friction. The frictional force and moment are produced between various component contact points such as between the rubber seal and the inner wall inside the hydraulic cylinder and between the diaphragm spring and the pressure plate, etc. Understanding the clutch pedal foot effort hysteresis is essential for a clutch release system design and analysis. The dynamic model for a clutch release system is developed for the foot effort hysteresis prediction and a simulation analysis is performed to propose a tool for analysing a clutch system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.323-324
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• 2007

For the efficient and accurate development of a biped humanoid robot, systematic humanoid development platform is a necessary component in building the development environment. The simulator is a significant tool to develop a biped humanoid robot. In this paper, we first present a method for constructing a humanoid simulator that can be easily applied to an actual humanoid. Easy transplantation into an actual humanoid increases the efficiency of simulator and the development speed. Systematic structure, closely modeling and prediction of an actual humanoid is a significant part of the simulator to set a goal. Using the simulator, we can predict the motion of an actual humanoid. The functions and the effectiveness of the developed simulator were evaluated through simulated motions and walks.

• Steel and Composite Structures
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• 제33권2호
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• pp.277-298
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• 2019

Concrete filled steel tubular (CFST) column joints with composite beams have been widely used as lateral loading resisting elements in civil infrastructure. To better utilize these innovative joints for the application of structural seismic design and analysis, it is of great importance to investigate the dynamic behavior of the joint under cyclic loading. With this aim in mind, a novel phenomenal model has been put forward in this paper, in which a Bouc-Wen hysteresis component is employed to portray the strength and stiffness deterioration phenomenon caused by increment of loading cycle. Then, a modified chicken swarm optimization algorithm was used to estimate the optimal model parameters via solving a global minimum optimization problem. Finally, the experimental data tested from five specimens subjected to cyclic loadings were used to validate the performance of the proposed model. The results effectively demonstrate that the proposed model is an easy and more realistic tool that can be used for the pre-design of CFST column joints with reduced beam section (RBS) composite beams.

• 한국정보처리학회논문지
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• 제4권3호
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• pp.731-746
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• 1997

객체 지향 패러다임의 확산으로 인하여 소프트웨어 개발을 위한 객체 모델의 사용이 일반화되고 있다. 소프트웨어 요구사항의 분석 및 설계 결과로 생성되는 객체 모델은 소프트웨어의 구현 시에 많은 도움이 된다. 특히 작성된 객체 모델이 구체적인 경우에는 자동적인 원시 코드의 생성도 가능하다. 따라서 시스템 분석기나 설계자는 분석 단계 단계 초반기의 추상적인 객체 모델을 정제함으로써 구체적인 객체 모델을 유도하기 위해 많은 시간을 투입해야 한다. 그러나 추상적 객체 모델을 구체적 모델로 정제하는 과정은주 로 설계자의 비정형적인 경험에 의하여 이루어지는 것이 현실이다. 본 논문에서는 OMT(Object Modeling Technique)의 객체 모델을 대상으로 추상적 모델의 구체화 기법을 논한다. 따라서 본문에서 제시되는 주된 내용은 객체 모델의 추상화 정도에 대한 정희와 모델 의 변환 규칙에 대한 것이다. 이 변환 규칙은 정보 통신 서비스 개발 프로세스 모형화 개발 지원 도구의 일부분은 프로세스 모델러(Process Moedeler)의 설계시에 적용되고 있 으며 그 결과로 C++ 코드로 변환하기 쉬운 구체적 객체 모델을 얻을 수 있었다.

• 한국멀티미디어학회논문지
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• 제15권9호
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• pp.1156-1164
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• 2012

한옥은 단순히 전통건축의 의미를 넘어서 우리 선조들의 삶에 대한 양식과 인식을 담고 있는 지금도 살아 숨 쉬는 문화유산이다. 최근 한옥이 자연친화적 건축으로 주목을 받게 되면서 한옥의 전통적 방식을 훼손하지 않으면서도 건축과정에 효율을 꾀할 수 있는 방안이 모색될 필요가 대두되었다. 이에, 본 논문에서는 건축정보모델링을 기반으로 하는 설계 지원도구를 개발하여 한옥의 설계에서 검증, 생산 공정에 이르는 전 과정을 지원하는 것을 목표로 한다. 이를 위해 먼저, 전통건축의 통시대적 고찰과 한옥의 목구조 방식에 대한 체계적인 분석을 통해 전통건축 설계에 필요한 부재들에 대한 효율적 설계 방식을 제시한다. 논문에서 제안하는 방식은 특성이 비슷한 부재들을 모아서 하나의 템플릿으로 설계하고 다양한 형태의 유사부재들을 속성 값에 따라 자유롭게 생성할 수 있도록 객체지향 방식의 표현기법을 사용하는 것이다. 이 방식은 객체지향 방식의 부재를 표현함에 있어서 연결 부재간의 상관관계를 부재와 부재간의 관련 파라미터들 사이의 결합규칙을 적용함으로써 설계의 오류를 최소화 하도록 지원할 수 있다. 또한 개발된 시스템은 서양건축 설계 위주의 CAD프로그램에 플러그 인 형태로 수행할 수 있기 때문에 전통적인 방식의 한옥설계는 물론 한옥 건축문화를 현대적 생활공간에 쉽게 접목할 있도록 고안되었다.

• 한국지역지리학회지
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• 제17권4호
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• pp.432-442
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• 2011

기온, 강수와 같은 기후관측 자료들은 공간과 더불어 시간적인 변이를 동시에 나타낸다. 따라서 신뢰성 높은 시계열 분포도 작성을 위해 공간적 자기상관성만을 고려하는 기존 공간 내삽 기법에 시공간적 자기상관성 정보를 반영할 필요가 있다. 이 연구에서는 시계열 기온 분포도 제작을 위해 1개월 동안 1시간 간격으로 획득된 기온 관측소 자료를 대상으로 시공간 크리깅을 적용하였다. 우선 기온자료를 결정론적 경향 성분과 확률론적 잔차 성분으로 분해한 후에, 경향 성분 모델링 과정에 기온과 연관성이 높은 고도 자료를 부가 자료로 통합하여 지형 효과를 반영하는 경향 성분을 모델링하였다. 잔차 성분에 대한 시공간 베리오그램 모델링에는 곱-합 모델을 적용하여 시간과 공간 베리오그램의 상호 연관성을 반영하도록 하였다. 이러한 시공간 베리오그램 모델을 이용하여 시공간 정규 크리깅을 적용한 결과, 기존 공간적 자기상관성만을 고려하는 정규 크리깅과 고도 자료를 부가 자료로 이용하는 회귀분석 크리깅에 비해 상대적으로 높은 예측 능력을 보였다. 이러한 결과는 고도 자료와 더불어 시공간 자기상관성 정보의 이용이 중요함을 지시한다. 따라서 공간적으로 가용할 수 있는 자료의 수가 한계가 있지만 시계열적으로 자료 획득이 가능한 변수를 분석할 때, 시공간 크리깅이 유용한 내삽 방법론으로 적용될 수 있을 것으로 기대된다.

• 한국농공학회논문집
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• 제49권2호
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• pp.49-60
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• 2007

The alpine agricultural activities are usually performed at higher and steep areas in nature. Thus, significant amounts of soil erosion are occurring compared with those from other areas. Thus, the soil erosion induced environmental impacts in these areas are getting greater. The Doam watershed is located at alpine areas and it has been well known that the agricultural activities in the watershed are causing accelerated soil erosion and water quality degradations. Many modeling approaches were employed to solve soil erosion and water quality issues. In this study, the Soil and Water Assessment Tool (SWAT) model was utilized to simulate the hydrologic and sediment behaviors in the Doam watershed. In many previous modeling studies, the digital soil map and its corresponding soil properties were used without modification to reflect soil conditioning at many agricultural fields of the Doam watershed. Thus, the soil sample was taken at the agricultural field within the Doam watershed and analyzed for its physical properties. In this study, the digital topsoil properties in the agricultural fields within the Doam watershed were replaced with the soil properties for reconditioned soil analyzed in this study to simulate the impacts of using soil properties for reconditioned soil in hydrologic and sediment modeling at the Doam watershed using the SWAT model. The hydrologic component of the SWAT model was calibrated and validated for measured flow data from 2002 to 2003. The $R^2$ value was 0.79 and the EI value was 0.53 for weekly simulated data. The calibrated model parameters were used for hydrologic component validation and the $R^2$ value was 0.86 and the EI value was 0.74 for weekly data. For sediment comparison, the $R^2$ value was 0.67 and the EI value was 0.59. These statistics improved with the use of soil properties of the reconditioned soil in the field compared with the results obtained without considering soil reconditioning. The simulated sediment amounts with and without considering the soil properties of the reconditioned soil were 284,813 ton and 158,369 ton, respectively. This result indicates that there could be approximately 79% of errors in estimated sediment yield at the Doam watershed, although the model comparison with the measured data gave similar satisfactory statistics with and without considering soil properties from the reconditioned soil.