• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.191-202
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• 2006

Computer programs for a structure design help the optimum design that considers each condition. however, the findings can not explain accurately a behavior of the real-living structure because each condition of a structure is simplified and generalized. The smart structure is introduced to overcome these problems, and we can understand a behavior of the real-living structure by means of Health Monitoring System. In this study, we compare a behavior by means of the existing structure design with a behavior of the living structure by means of an experiment. As a result, we examine adequacy of a measuring system and developing possibility in the future.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.101-107
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• 2011

In view of the importance of material reduction because of the jump in oil and steel prices, structural design studies for lifting lugs were performed. Hundreds of thousands of such lifting lug structures are needed every year for ship construction. A direct design study was reviewed using the developed design system to increase the design efficiency and provide a way of directly inserting a designer's decisions into the design system process. In order to understand the design efficiency and convenience of a lug structure, parametric studies for prototype lug shapes were performed using the developed design system. From these design studies, various patterns of design parameters for the lug structure according to changes in the main plate length were examined. Based on these parametric study results, design guides were developed for more efficiently suggesting structural data for enormous lug structures. Additionally, a more detailed structural analysis through local strength evaluations will be performed to verify the efficiency of the optimum structural design for a lug structure.

• Journal of Ocean Engineering and Technology
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• v.28 no.3
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• pp.218-226
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• 2014

Since the support structure of an offshore wind turbine has to withstand severe environmental loads such as wind, wave, and seismic loads during its entire service life, the need for a robust and reliable design increases, along with the need for a cost effective design. In addition, a robust and reliable support structure contributes to the high availability of a wind turbine and low maintenance costs. From this point of view, this paper presents a design process that includes design optimization and reliability analysis. First, the jacket structure of the NREL 5-MW offshore wind turbine is optimized to minimize the weight and stresses, while satisfying the design requirements. Second, the reliability of the optimum design is evaluated and compared with that of the initial design. Although the present study results in a new optimum shape for a jacket support structure with reduced weight and increased reliability, the authors suggest that the optimum design has to be accompanied by a reliability analysis during the design process, as well as reliability based design optimization if needed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.243-246
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• 2001

Thyristor devices have 3-dimensional complicated structure and were sensitive to temperature characteristics. Therefore, it was difficult to optimize thyristor devices design. We have to consider many design parameter to characterize, and trade-off relations. The important parameters to design thyristor devices are cathode structure, effective line width, cathode-emitter shunt structure, gate structure, doping profile and carrier lifetime. So, we must consider that these design parameters were not acted separately. However, there are many difficulties to determine optimized design parameters by experiment. So, We used specific design software to design thyristor devices, and estimated the thyristor devices characteristics.

• Korean Journal of Computational Design and Engineering
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• v.5 no.2
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• pp.136-143
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• 2000

The appearance of new machine tools with higher flexibility is in need of a basic structure design system for establishing the systematic and rationalized design and manufacturing procedures. In this study. the basic structure design system for machine tools is realized based on the modular construction method. Machine tools are represented as a whole and modular complex with the directed graph, and all possible structural configurations and codes of machine tools for satisfying the machining requirement are derived from the DNA data and connecting patterns of basic structural elements. Especially the structural configurations of machine tools are visualized by the solid modeling techniques and 3-D graphics techniques.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.05a
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• pp.302-305
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• 2005

To comply to demand for a development requirement of aircraft design part, the expert system builds up standard knowledge-base based on presently maintained expert knowledge and experience in aircraft structure material selection. It also builds up database based on aircraft design open data, and standard calculation module used for present design and analysis method. This system is developed using Visual Basic language. The expert system standardize aircraft structure material selection and can be applied to all type of elementary stage of aircraft structure design. It is working on Windows, which has a friendly interface and is convenient for debugging, maintenance and transplanting. Explanation of the structure and the function of the system was given in this paper.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.867-872
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• 2002

The seismic design from the underground structures with the ground structures differently relative acceleration of ground and structure for, that period ci it was a condition where the recognition against the seismic design of the underground structure is insufficient because the decease damage does not very to that extent. Analysis result, earthquake hour section power increase one that price smiles from one part and when it applies a regular design hour safety rate 20%, seismic efficiency level satisfaction is it becomes feed with the fact that it will be able to augment the efficient characteristic of design.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.444-451
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• 1999

The purpose of this study is to Propose data models for central database in integrated system for structural design building. In order to efficiently express data related to structure, I analyzed the structure design process and classified data considering design step. 1 used an object-oriented modeling methodology for logical data model and relational modeling for physical data model. Based on this model, we will develop an integration system with several applications for structure design. Each application will communicate through the central database.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.57-64
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• 2012

For the vibration control of earthquake-excited buildings, an optimal design method of integrated control system considering soil-structure interaction is studied in this paper. Interaction between soils and the base of the building is simply modeled as lumped parameters and equations of motion are derived. The equations of motion are transformed into the state space equations and the probabilistic excitations such as Kanai-Tajumi power spectral density function is introduced. Then an optimization problem is formulated as finding hybrid or integrated control systems which minimizes the stochastic responses of the building structure for given constraints. In order to investigate the feasibility of the optimization method, an example design and numerical simulations are performed with tenstory building. Finally, numerical results are compared with a conventional design case that soil-structure interaction is not considered.

• Journal of Power System Engineering
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• v.7 no.4
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• pp.38-43
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• 2003

This paper proposes an optimum design problem of structural and control systems. taking a 3-D truss structure as an example. The structure is supposed to be subjected to initial static loads and time-varying disturbances. The structure is controlled by a state feedback $H_{\infty}$ controller to suppress the effect of the disturbances. The design variables are the cross sectional areas of truss members. The structural objective function is the structural weight. As the control objective, we consider two types of performance indices. The first function represents the effect of the initial loads. The second one is the norm of the feedback gain. These objective functions are in conflict with each other. Then, first, two control objective functions are transformed into one control objective by the weighting method. Next, the structural objective is treated as the constraint. By introducing the second control objective which considers the magnitude of the feedback gain, we can per limn the design which is robust in modeling errors.