• Journal of Mechanical Science and Technology
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• 제14권2호
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• pp.197-206
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• 2000

A boundary integral equation method in the shape design sensitivity analysis is developed for the elasticity problems with axisymmetric non-homogeneous bodies. Functionals involving displacements and tractions at the zonal interface are considered. Sensitivity formula in terms of the interface shape variation is then derived by taking derivative of the boundary integral identity. Adjoint problem is defined such that displacement and traction discontinuity is imposed at the interface. Analytic example for a compound cylinder is taken to show the validity of the derived sensitivity formula. In the numerical implementation, solutions at the interface for the primal and adjoint system are used for the sensitivity. While the BEM is a natural tool for the solution, more generalization should be made since it should handle the jump conditions at the interface. Accuracy of the sensitivity is evaluated numerically by the same compound cylinder problem. The endosseous implant-bone interface problem is considered next as a practical application, in which the stress value is of great importance for successful osseointegration at the interface. As a preliminary step, a simple model with tapered cylinder is considered in this paper. Numerical accuracy is shown to be excellent which promises that the method can be used as an efficient and reliable tool in the optimization procedure for the implant design. Though only the axisymmetric problem is considered here, the method can be applied to general elasticity problems having interface.

• 대한기계학회논문집A
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• 제29권3호
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• pp.403-410
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• 2005

This study presents the benchmark results of several design frameworks for the purpose of developing an efficient design framework in view of Excel interface. For the benchmark, three optimum design problems are chosen and solved by using the design frameworks. In order to compare the frameworks with each other, the evaluation criteria are specified and modified to fit the problems with Excel interface. Three example cases are solved and compared. The evaluation report is summarized in terms of efficiency, ease of use, internal structure, API, etc. However, the optimization result itself is not focused because the specific optimization algorithm is not our concern. Finally, some suggestions of how to develop an efficient design framework with Excel interface are presented.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.78-86
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• 2020

The operation and monitoring (OM) interface is the digital medium between nuclear power system and operators. The cognitive load of OM interface has an important effect on the operation errors made by operator during OM task between operator and computer. The cognitive load model of OM interface is constructed for analysing the composition and influencing factors of OM interface cognitive load. And to study the coping strategies and methods for cognitive load of nuclear power system. An experiment method based on eye movement is proposed to measure the cognitive load of OM interface. Experiment case is carried out with 20 subjects and typical OM interface of a nuclear power system simulator. The OM interface is optimized based on the experiment results. And the results comparison between the original OM interface and the optimized OM interface shows that the cognitive load model and proposed method is valuable contributions in reducing the cognitive load and improving the interaction efficiency of OM tasks.

• 대한기계학회논문집A
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• 제26권1호
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• pp.83-94
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• 2002

Analysis technology is widely accepted and quite popular these days. Incorporation of the analysis result into design process is a key factor for the success of the analysis area. A few design software products have been commercialized. Generally, they are trying to make an interface between various design methods and analysis software. Optimization is a representative design method. The products are investigated and compared for the aspects of user convenience and algorithm performance. A few popular products are selected. Graphic user interface (GU) is compared for the function and efficiency. The performances of the optimization algorithms are tested by mathematical and engineering examples. The results are discussed.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.175-183
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• 2000

The internal residual stresses within the multilayered structure with shan interface induced by the difference in thermal expansion coefficient between the materials of adjacent layers often provide the source of failure such as delamination of interfaces and etc. Recent development of the multilayered structure with functionally graded interface would be the solution to prevent this kind of failure. However a systematic thermo-mechanical analysis is needed fur the customized structural design of multilayered structure. In this study, theoretical model for the thermo-mechanical analysis is developed for multilayered structures of the Al-$SiC_p$ functionally graded composite for electronic packaging. The evolution of curvature and internal stresses in response to temperature variations is presented for the different combinations of geometry. The resultant analytical solutions are used for the optimal design of the multilayered structures with functionally graded interface as well as with sharp interface.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.684-689
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• 2008

In this study, homogenization method combined with the effective interface model for the characterization of properties of the nanoparticulate composites is developed. In order to characterize particle size effect of nanocomposites, effective interface model has been developed. The application range of analytical micromechanics approach is limited because a simple analytical approach is valid only for simple and uniform geometry of fiber particles. Therefore this study focuses on the analysis of mechanical properties of the effect interface through the continuum homogenization method instead of using analytical micromechanics approach. Using the homogenization method, elastic stiffness properties of the effective interface are numerically evaluated and compared with the analytically obtained micromechanics solutions. The suggested homogenization method is expected to be applied to optimization problems for nanocomposite design.

• 한국항공우주학회지
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• 제32권7호
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• pp.117-125
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• 2004

기 수립한 열해석 모델을 바탕으로 접촉열전도가 있는 부위의 민감도 해석을 수행함으로서 향후 기계적 접속 부위 설계 변경시의 열설계에 대한 연구를 수행했다. 해석의 편의를 위해 비교적 간단한 열해석 모텔을 선택했다. 위성 버스 전압과 접촉열저항의 크기를 다양하게 변화시켜 해석을 수행했으며, 그 결과 향후 통일한 모듈에서 기계적 접속 조건 변경시 접촉열저항을 원래의 설계원용치를 기준 값으로 해 히터의 용량을 충분히 크게 설계할 경우 성공적인 열설계가 가능하리라 여겨진다.

• 항공우주기술
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• 제7권1호
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• pp.99-107
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• 2008

통신해양기상위성은 서로 다른 임무 수행을 위해 복수의 탑재체가 장착되는 정지궤도 복합위성이다. 탑재체중 두 장비는 지구관측임무를 수행하기위한 광학탑재체로, 용도에 따라 각각 기상과 해양탈재체로 구분된다 상이한 광학탑재 체를 위성체에 장착하여, 만족스러운 성능을 구현하기 위해서는 각각의 요구조건을 분석하고, 설계 변수에 대한 민감도 해석을 통한 일련의 최적화 과정이 필요하다. 따라서 여러 가지 종류의 설계 제한 조건에 대한 고려가 필수적이다. 본 논문에서는 통신해양기상위성의 기상 및 해양탑재체 장착을 위한 설계 시 기계 시스템 측면에서 고려된 여러 설계요건들을 제시하고, 위성체 설계에 미치는 영향을 최소화 하면서 기계 및 열적 요구조건을 충족시키기 위해 도입된 접속 구조물에 대해 설명할 것이다.

• Journal of Mechanical Science and Technology
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• 제19권10호
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• pp.1864-1874
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• 2005

This paper describes a wearable multi-modal user interface design and its implementation for a teleoperated field robot system. Recently some teleoperated field robots are employed for hazard environment applications (e.g. rescue, explosive ordnance disposal, security). To complete these missions in outdoor environment, the robot system must have appropriate functions, accuracy and reliability. However, the more functions it has, the more difficulties occur in operation of the functions. To cope up with this problem, an effective user interface should be developed. Furthermore, the user interface is needed to be wearable for portability and prompt action. This research starts at the question: how to teleoperate the complicated slave robot easily. The main challenge is to make a simple and intuitive user interface with a wearable shape and size. This research provides multi-modalities such as visual, auditory and haptic sense. It enables an operator to control every functions of a field robot more intuitively. As a result, an EOD (explosive ordnance disposal) demonstration is conducted to verify the validity of the proposed wearable multi-modal user interface.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권3호
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• pp.325-332
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• 2013

Diffuse interface model for numerical analysis was used to compute supercavitating flows around various cavitators. The ambient pressures of 2 atm permitted cavitation studies in a range of cavitation number, ${\sigma}=0.1$ to 1.0 on selected conical and disk-headed cavitors. The computed results were compared with relation by Reichardt. Drag coefficient obtained from pressure forces acting on the cavitator also compared well with those obtained from analytical relations.