• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.49-55
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• 2003

When a body with slant angle after its shoulder is moving at high speed, the turbulent motion around the afterbody is generally associated with the flaw separation and determines the normal component of the drag. By changing the slant angle of afterbody, there exists a critical angle at which the drag coefficients change drastically. Understanding and control of the turbulent separated flows are of significant importance for the design of optimal configuration of the moving bodies. In the present paper, a new Large Eddy Simulation technique has been developed to investigate turbulent vortical motions around the afterbodies with slant angle. By basis of understanding the structure of turbulent flaw around the body, the new configuration of afterbodies are designed to reduce the drag of body and the nonlinear effects due to the interaction between the body configuration and the turbulent separated flows are investigated by use of the developed LES technique.

• Advances in Computational Design
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• v.8 no.4
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• pp.273-293
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• 2023

This study evaluated the acoustic performance of two configurations of serial HR arrays and lined HR arrays in the presence of grazing flow using a 3D numerical simulation. The dual, triple, and quad HR arrays were compared to the conventional HR array. The simulation results showed that the number of resonant frequencies increased with the number of serial HR arrays. The C_TL did not significantly change with the number of serial HR arrays. The acoustic performance of the two, three, and four-lined HR arrays was compared to the conventional HR array. The results showed that the resonant frequency and TLmax increased with the number of lined HR arrays. The C_TL also increased with the number of lined HR arrays. The effect of the grazing flow Mach number (M_a) was investigated on the four-lined HR array configuration and compared to the conventional HR configuration. TLmax and C_TL decreased for both configurations with increasing M_a. The four-lined HR array configuration had significantly better acoustic performance than the conventional HR configuration. The TLmax and C_TL increased by more than 300% when the configuration was changed from the conventional HR to the four-lined HR array at M_a = 0.The increment percentage decreased with increasing M_a.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.146-153
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• 2005

In this paper, a multi-step optimization using genetic algorithm with variable penalty function is introduced to the structural design optimization of a grinding machine. The design problem, in this study, is to find out the optimum configuration and dimensions of structural members which minimize the static compliance, the dynamic compliance, and the weight of the machine structure simultaneously under several design constraints such as dimensional constraints, maximum deflection limit, safety criterion, and maximum vibration amplitude limit. The first step is shape optimization, in which the best structural configuration is found by getting rid of structural members that have no contributions to the design objectives from the given initial design configuration. The second and third steps are sizing optimization. The second design step gives a set of good design solutions having higher fitness for lightweight and minimum static compliance. Finally the best solution, which has minimum dynamic compliance and weight, is extracted from the good solution set. The proposed design optimization method was successfully applied to the structural design optimization of a grinding machine. After optimization, both static and dynamic compliances are reduced more than 58.4% compared with the initial design, which was designed empirically by experienced engineers. Moreover the weight of the optimized structure are also slightly reduced than before.

• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.34-45
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• 2018

Nuclear power plant(NPP) is a large-sacle national infrastructure with total project cost of 77 billion dollars and period of 10 years or more. Moreover, since it is operated over 60 years, NPP is a facility closely related to national economy and public safety. Therefore, accurate information and consistent physical configuration should be maintained to enable accurate and economical decision making in NPP project process such as design, construction, operation, and decommission. Since NPP industry is more complicate and regulated than other industries, the importance of configuration management(CM) has been widely recognized in the early days. However, there were limitations in implementing systematic CM due to unclear purpose and subject. Therefore, this paper suggests a room-based database for CM in NPP reflects design requirements and facility configuration information.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1095-1096
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• 2006

Configuration management plays a key role in systems engineering process for any project from earlier stage of development. It consists of five major activities, ie., configuration management planing, configuration identification, configuration control, configuration status accounting and configuration verification and audit, and is essential to control system design development and operation throughout entire life cycle of the system development. And it is directly associated with other part of systems engineering management, ie., technical data management which provides traceability of important decisions and changes during development. In this paper, we describe how to apply CASE(Computer-aided Systems Engineering) tool-Cradle for the configuration management to achieve effectiveness of City Train Standard Specification Management process.

• 한국전산유체공학회:학술대회논문집
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• 2007.10a
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• pp.100-110
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• 2007

A new design approach for a delicate treatment of complex geometries such as a wing/body configuration is arranged using overset mesh technique under large scale computing environment for turbulent viscous flow. Various pre- and post-processing techniques which are required of overset flow analysis and sensitivity analysis codes are discussed for design optimization problems based on gradient based optimization method (GBOM). The overset flow analysis code is validated by comparing with the experimental data of a wing/body configuration (DLR-F4) from the 1st Drag Prediction Workshop (DPW-I). In order to examine the applicability of the present design tools, careful design works for the drag minimization problem of a wing/body configuration are carried out by using the developed aerodynamic shape optimization tools for the viscous flow over multiple-body aircraft geometries.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.184-192
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• 2009

There are total eight degrees of freedom in designing a three-mirror system. If we correct four kinds of third order aberrations and the system should have the specified effective focal length, the remaining three degrees of freedom can be used for selecting a suitable configuration for a specific application. We suggest an analytic design procedure for a three-mirror telescope system which has a suitably sized secondary mirror and proper separations between mirrors, and is corrected for four kinds of third order aberrations, spherical aberration, coma, astigmatism, and field curvature. Two design examples are shown. One has a compact configuration with off-axial field, the other has relatively long configuration with annular ring field.

• Journal of Ship and Ocean Technology
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• v.5 no.3
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• pp.14-26
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• 2001

The shape of an industrial product has to be determined within the constrained conditions of keeping firmly many kinds of functional and performance requirements. On the other hand, the configuration of artistic work would be created desirably using the sense of aesthetics, even if conflicting slightly with these requirements. The development of a methodology for an aesthetic design founded on human sensitivity is becoming highly desirable in recent years. In this paper, a method of measuring beauty quantitatively for an artistic evaluation if proposed using the aesthetic cognitive theory and the optimum configuration could be found by a search using the genetic algorithm. Furthermore, an expression of optimum ship appearance can be gained as graphics.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.27-34
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• 2005

One of the most famous designers of our age, Philippe Starck designed eight hotels among fan Schrager's of which hotels are not so big but have huge popularity all around the world located in major cities such as New York, London, Miami, L.A., and San Francisco. These hotels have brought significant influence particularly to the aspects of their recent fashion and strategies in Boutique hotels. Therefore, this paper intends to examine the space composition and design methods by analyzing the eight hotel projects by him. The research started with reviewing his design background first and analyzed the characteristic of his designs of above hotels. The analysis results were arranged from the aspects of narrative spatial configuration and dramatic presentation. From the aspect of narrative spatial configuration, the hotels by Philippe Starck mainly consisted of 1) boundaries and gateways, 2) spaces of passage, 3) center spaces, and 4) the spaces surrounding the center spaces. For the latter's aspects, it was found that various design methods such as 1) objectification, 2) intended ambiguity, 3) depaysement 4) eclectic hybrid, 5) distortions of scale, and 6) sensuous clues were employed. A study on the hotels by tan Schrager, which owe their big success to the emotional design of Philippe Starck's, not only widens the understanding of his design world, but also serves to the appreciation of today's hotel marketing strategies and design.

• Korean Journal of Computational Design and Engineering
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• v.11 no.1
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• pp.57-66
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• 2006

Modeling product configurations needs large amounts of knowledge about technical and marketing restrictions on the product. Previous attempts to automate product configurations concentrate on representations and management of the knowledge for specific domains in fixed and isolated computing environments. Since the knowledge about product configurations is subject to continuous change and hard to express, these attempts often failed to efficiently manage and exchange the knowledge in collaborative product development. In this paper, XML Topic Map (XTM) is introduced to represent and exchange the knowledge about product configurations in collaborative product development. A product configuration model based on XTM along with its merger and inference facilities enables configuration engineers In collaborative product development to manage and exchange their knowledge efficiently. An implementation of the proposed product configuration model is presented to demonstrate that the proposed approach enables enterprises to exchange the knowledge about product configurations during their collaborative product development.