• International Journal of Precision Engineering and Manufacturing
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• v.7 no.1
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• pp.9-12
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• 2006

A spectral analysis and numerical simulation are employed to assess the effects of the stylus tip radius on measuring surface profiles. Original profiles with fractal spectral densities are generated and then are numerically traced with circular tipped stylus. Instead of their spectral densities, the accumulative power spectrums of traced profiles are analyzed. It is shown that the minimum wavelength of traced profile relates directly to the radius r of the stylus tip and the root-mean-square (rms) roughness ${\sigma}_o$ of original profile. From this accumulation spectral analysis, a formula is developed to estimate the minimum wavelength of traced profile. By using the concept of the minimum wavelength, an appropriate stylus tip radius can be chosen for the given rms roughness ${\sigma}_o$ of the profile.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.240-249
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• 2000

An improved global optimization algorithm is developed by extending the domain elimination method. The concept of triangular patch consists of two or more trajectories of local minimizations is introduced to widen the attraction region of the domain elimination method. Using the an-]c between each of three vertices of the patch and a design point, we measure the proximity, between the design point and the patch. With the Gram-Schimidt orthonormalization, this method can be extended to general n-dimensional problems. We code the original domain elimination algorithm and a patch-based algorithm. Then we compare the performance of two algorithms. Through the well-known example problems. the algorithm using patch is shown to be superior to the original domain elimination algorithm in view of computational efficiency.

• Journal of KSNVE
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• v.10 no.3
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• pp.437-443
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• 2000

The optimal design problem for increasing dynamic stiffness using hybrid model which composed of original detailed BIW(body in white) and impinged beam elements is investigated. Using the characteristics of the beam elements and design sensitivity analysis this approach utilizes an optimization technique to determine the optimal section properties of beam elements. The constraint is to increase the first natural frequency by five percent compared with original one. The results show that the first torsion and bending natural frequencies are increased by five percent using hybrid model and optimization. These results indicate that this optimization method can be employed to enhance the dynamic stiffness of vehicle body structure in design concept stage.

• Proceedings of the Safety Management and Science Conference
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• 2007.11a
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• pp.275-298
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• 2007

Recently, all kind of 21C-typed electronic goods show the tendency of hightechnology and digital convergence rapidly. Also, failure mechanism which differs from original goods concept presents. Today, failure mechanism which differs from one that was happened by restricted harmful environment material before adapted the raw of environment material is changing the paradigm of reliability engineering. Thus, when applied the environment matter of original and secondary material at the electronic goods were removed, reliability assessment method and prediction stay into low level. This study suggests as solution to overcome these phenomenon. The study on the management method of environmental restriction substances which is recognized as important element in the reliability assessment about environment material of electronic goods and the study on reliability assessment method of PWB without environment material are progressed.

• Journal of the Korean Society of Costume
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• v.42
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• pp.137-162
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• 1999

The purpose of this thesis was twofold. First it explains the emergence of street styles and their inner meanings from its origin subculture group practices. Recent developments in cultural studies which approach cultural practices in a holistic way by incorporating socio-economic background offers us the concept of 'hegemonic relation' it explains why subcultural practices and street style in particular has weakened from 19080s as well as why in the post-subculture period we observe the 'superma-rketization' of styles and plethora of eclecticism instead of original ones. Street styles as a magical expression or resolution of socio-economic frustrations are anticipated to weaken significantly if not totally disappear in the post-modern era although it has become the original texts of high fashion.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.5
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• pp.121-128
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• 2000

Simple design methods were developed to control the coolant flow rates through cylinder head gasket holes. Applying the concept of flow through an obstruction the ratio of intake to exhaust side flow rates could be easily controlled while maintaining the flow rates per cylinder of the original model. Flow distribution in the coolant passage of the original model was calculated by CFD and the flow rates at the gasket holes were modified based on the calculation results. The calculated flow rated of the modified gasket holes were reasonably close to target values. For more accurate control of the flow rate distribution, a design method with iterative CFD calculations was also suggested. The final size of gasket holes for the target flow rates were obtained just after a few optimization iterations. These methods can be very useful for the optimization of heat transfer characteristics in engine cylinder head and block.

• Journal of the Korea Safety Management & Science
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• v.9 no.6
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• pp.55-68
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• 2007

Recently, all kind of 21C-typed electronic goods show the tendency of hightechnology and digital convergence rapidly. Also, failure mechanism which differs from original goods concept presents. Today, failure mechanism which differs from one that was happened by restricted harmful environment material before adapted the raw of environment material is changing the paradigm of reliability engineering. Thus, when applied the environment matter of original and secondary material at the electronic goods were removed, reliability assessment method and prediction stay into low level. This study suggests as solution to overcome these phenomenon. The study on the management method of environmental restriction substances which is recognized as important element in the reliability assessment about environment material of electronic goods and the study on reliability assessment method of PWB without environment material are progressed.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.524-530
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• 2009

We scrutinized the Korean taxonomic literature, with special focus on some nomenclatural points and four different cases were listed categorically. Several naked names (nomen nudum), invalidly published names, typographical and orthographical errors, incorrect use of hybrid names and authorship, and errors in the citation of the bibliographic references have appeared in newly published literature in Korea, due to misapplications of ICBN (International Code of Botanical Nomenclature). Although literature review and synonyms are imperative and essential elements of taxonomic study, many author citations tend to be copied from one publication to another without any confirmation of the original source. It is strongly recommended that scientists who have previously published careless work should be more careful, and they should be instructed to read original descriptions and to learn current practices in the code.

• Structural Engineering and Mechanics
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• v.8 no.3
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• pp.299-310
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• 1999

One problem with base isolators of the sliding type is that their dynamic responses are nonlinear, which cannot be solved in an easy manner, as distinction must be made between the sliding and non-sliding phases. The lack of a simple method for analyzing structures installed with base isolators is one of the obstacles encountered in application of these devices. As an initial effort toward simplification of the analysis procedure for base-isolated structures, an approach will be proposed in this paper for computing the equivalent damping for the resilient-friction base isolators (R-FBI), based on the condition that the sum of the least squares of errors of the linearized response with reference to the original nonlinear one is a minimum. With the aid of equivalent damping, the original nonlinear system can be replaced by a linear one, which can then be solved by methods readily available. In this paper, equivalent damping curves are established for all ranges of the parameters that characterize the R-FBI for some design spectra.

• Tribology and Lubricants
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• v.19 no.1
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• pp.36-42
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• 2003

Nowadays the importance of equipment reliability and efficiency is increasing and the concept of Total Fluid Management is introduced to make production cost down and improve equipment reliability. In this paper, basic survey on the current status of lubricants application and equipment maintenance is made. Lubrication point of the factory was 233 and 60 percent of the point was lubricated by hydraulic oils. Lubricants used at 87 points were different from those of original equipment manufacturers' recommendation. And 40 percent of the points are heavily contaminated. Exchange of oils, use of filter, computerization and so on were recommended. And introduction of Total Fluid Management concept is required.