• 대한기계학회논문집A
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• 제21권9호
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• pp.1357-1363
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• 1997

Currently it is increasing to use th bonded dissimilar materials in the various field of advanced engineering such as the highly rigid and lighter vehicle, plastic molding LSI package and metal/ceramic bonded joint. In spite of such a wide application of the bonded dissimilar materials, the evaluation method of the bonding strength has not been established yet. Therefore in this paper we analyze the interface crack problem by introducing fracture mechanics parameters as the basic research about estimating of the strength of adhesive joints. The variation of stress intensity factor according to the elastic modulus of adherend and thickness of bonded layer are investigated. Numerical results are based on the results of boundary element analysis of four different type butt joints subjected to uniaxial tension loading.

• 대한기계학회논문집A
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• 제22권1호
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• pp.148-159
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• 1998

Spot welding palys a key role in increasing productivity and weight reduction of the final products. This paper proposes a systematic approach on the design of spot weld configuration, dealing with the requried number and location of spot weld joints under the given design parameters, such as the applied loads, lap area, and individual spot weld strength. The optimal design of a spot-welded joint is postulated as a state when the safety factors of all spot weld points (i) are evenly distributed and (ii) reach maximum value. A CAD program is developed to arrange the optimal location of each spot weld based on the derived objective function and constraints. The CAD tool integrates the optimization procedure with Finite Element Analysis (FEA) code through an interface. The interface automatically provides geometrical data and mesh configuration for different spot weld locations to FEA model. It also extracts the transmitted load of each spot weld from the FEA code, and allows the optimization code predict an improved arrangement of spot weld locations. The feasibility of the developed approach is demonstrated by the selected examples.

• Asian-Australasian Journal of Animal Sciences
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• 제12권4호
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• pp.633-641
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• 1999

Reaction by neighbours to odours is increasingly affecting operations of existing animal farming operations and may adversely constrain the further development of the animal production industry in some parts of Australia. It is critical that the scale of such odour impact on the rural-urban interface be estimated to provide useful information both for environmental protection and animal farming operations. Furthermore, the information can be used to modify odour reduction strategies as economic conditions change. The Centre for Water and Waste Technology at The University of New South Wales has developed a comprehensive set of odour control techniques in the course of its research and development effort over the past eight years. Techniques have been developed for odour sampling at point, area and volume sources, monitoring environmental parameters such as ventilation rate, shed temperature, shed humidity, litter water content and ambient meteorological condition, olfactometry and odour dispersion modelling. The work has paved the way for the establishment of odour reduction strategies based on best environmental management practice and advanced odour abatement technologies.

• 한국농공학회지
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• 제39권2호
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• pp.53-61
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• 1997

The interface system, GIS-AGNPS was to be validated with field data from six tested small watersheds ranging from 0.7 to 4.7$km^2$ in size which have steep topography and complex landuses. The model validation involved the calibration of input parameters and component modifications, in efforts to develop a model applicable to general uses for identifying and controlling nonpoint source pollution loads from agricultural watersheds. The simulated direct runoff from AGNPS was in good agreement with the field data for the averaged antecedent moisture conditions or AMC- II. The results differed, however, from the observed for AMC- I or III. A simple empirical relationship was proposed to estimate the curve number for AMC- I or m from AMC- II, which was found to result in simulated runoff close to the observed. The peak runoff relationship at AGNPS was also modified to reflect the watershed conditions and tested satisfactorily with the field data. The simulated sediment yields from the watersheds were fair as compared to the observed. Nutrient loads simulated from the model were different from the observed data. It appeared that the model was incapable of adequate depicting nutrient transport processes at paddy field and other landuses of the tested watersheds. Some modifications may be needed for the accurate representing the processes at paddy field.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.300-304
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• 2007

The reactor head structure assembly(RHSA) is the structure located on the reactor assembly. The purpose of the assembly is providing interface location for cables, preventing pipe whips, prohibiting instruments from becoming missiles, and restraining CEDMs' horizontal motion. On the RHSA, reactor disconnect panels(RDP) are installed. The installation location of RDP is to be decided to minimize the geometric interface with other components. Since the neighborhood of RHSA is crowded due to many connectors and cables, it is necessary to find the good design of RHSA to make an intricate situation attenuated and the required function maintained. The geometric shape and overall configuration of RHSA are determined by axiomatic design approach. The FRs of RHSA are specified and the corresponding DPs are found to satisfy FRs in sequence. The finite element analysis is carried out based on the result of the axiomatic design to evaluate the structural integrity.

• Structural Engineering and Mechanics
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• 제49권1호
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• pp.1-22
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• 2014

A seismic evaluation is made of the response to horizontal ground shaking of cantilever retaining walls using the finite element model in three dimensional space whose verification is provided analytically through the modal analysis technique in case of the assumptions of fixed base, complete bonding behavior at the wall-soil interface, and elastic behavior of soil. Thanks to the versatility of the finite element model, the retained medium is then idealized as a uniform, elastoplastic stratum of constant thickness and semi-infinite extent in the horizontal direction considering debonding behavior at the interface in order to perform comprehensive soil-structure interaction (SSI) analyses. The parameters varied include the flexibility of the wall, the properties of the soil medium, and the characteristics of the ground motion. Two different finite element models corresponding with flexible and rigid wall configurations are studied for six different soil types under the effects of two different ground motions. The response quantities examined incorporate the lateral displacements of the wall relative to the moving base and the stresses in the wall in all directions. The results show that the wall flexibility and soil properties have a major effect on seismic behavior of cantilever retaining walls and should be considered in design criteria of cantilever walls. Furthermore, the results of the numerical investigations are expected to be useful for the better understanding and the optimization of seismic design of this particular type of retaining structure.

• 한국콘텐츠학회논문지
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• 제5권1호
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• pp.19-26
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• 2005

본 논문은 생체신호(EEG/EOG)를 이용한 기계 작동 시스템을 구현하는 방법을 소개한다. 더 나아가서는 EEG/EOG 반응 컴퓨터 시스템이나 일반 바이오피드백(biofeedback) 시스템과 접목시키는 목적도 포함하고 있다. 이를 위해서 선정된 뇌파 대역의 스펙트럼 특성이나 EEG 리듬 요소, 그리고 그것들의 조합지수 및 EOG파라미터에 반응하여 기능을 수행하는 무선 완구 원격조종 시스템을 구현하고자 한다. 이러한 생체신호 처리 모듈 전체를 헤드셋에 내장 시켜서 사용자의 편의성을 제공하고 기존의 BCI 시스템과는 새로운 차원의 시스템 구현 방법을 제시한다.

• 정보처리학회논문지B
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• 제9B권2호
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• pp.163-172
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• 2002

기존의 에이전트 기반 협상 모델이 갖는 특징 중의 하나는 협상에 필요한 사용자의 요구 조건 및 관련 정보들을 일괄적으로 입력해야 한다는 점이다. 이것은 B2B 고유의 속성인 모호성, 불완전성 및 동적 성질 등을 감안 할 때, 지나치게 무리한 요구가 될 수 있다. 본 논문에서는 이 문제에 초점을 맞춘 B2B 협상용 사용자 인터페이스 모델을 제안하였다. 제안된 모델은 2차원 협상 공간, 다양한 협상 모드, 감성 기반 제어 도구 등을 지원한다. 우리는 본 논문에서 이런 세 가지 기능이 기존의 에이전트 기반 협상 모델의 유용성을 어떻게 개선시킬 수 있는지를 입증해 보인다.

• 접착 및 계면
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• 제4권2호
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• pp.1-9
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• 2003

Epoxy-amine liquid prepolymers are extensively applied onto metallic substrates and cured to obtain painted materials or bonded joint structures. Overall performances of such systems depend on the created interphase between the organic layer and the substrate. When epoxy-amine liquid mixtures are applied onto more or less hydrated metallic oxide layer, concomitant amine chemical sorption and hydroxide dissolution appear lending to the chelate formation. As soon as the chelate concentration is higher than the solubility product, these species crystallize as sharp needles. Moreover, intrinsic and thermal residual stresses are developed within painted or bonded systems. When residual stresses are higher than the organic layer/substrate adhesion, buckling, blistering, debonding may occur leading to a catastrophic drop of system performances. Practical adhesion can be evaluated with either ultimate parameters (Fmax or Dmax) or the critical strain energy release rate, using the three point flexure test (ISO 14679-1997). We observe that, for the same system, the ultimate load decreases while residual stresses increase when the liquid/solid time increases. Ultimate loads and residual stresses depend on the metallic surface treatment. For these systems, the critical strain energy release rate which takes into account the residual stress profile and the Young's modulus gradient remains quite constant whatever the metallic surface treatment was. These variations will be discussed and correlate to the formation mechanisms of the interphase.

• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1293-1302
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• 1999

In this paper, an on-line process scheme is presented for implementation of a intelligent on-line modeling of nonlinear complex system. The proposed on-line process scheme is composed of FNN-based model algorithm and PLC-based simulator, Here, an adaptive fuzzy-neural networks and HCM(Hard C-Means) clustering method are used as an intelligent identification algorithm for on-line modeling. The adaptive fuzzy-neural networks consists of two distinct modifiable sturctures such as the premise and the consequence part. The parameters of two structures are adapted by a combined hybrid learning algorithm of gradient decent method and least square method. Also we design an interface S/W between PLC(Proguammable Logic Controller) and main PC computer, and construct a monitoring and control simulator for real process system. Accordingly the on-line identification algorithm and interface S/W are used to obtain the on-line FNN model structure and to accomplish the on-line modeling. And using some I/O data gathered partly in the field(plant), computer simulation is carried out to evaluate the performance of FNN model structure generated by the on-line identification algorithm. This simulation results show that the proposed technique can produce the optimal fuzzy model with higher accuracy and feasibility than other works achieved previously.