• 한국물환경학회지
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• 제25권5호
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• pp.651-660
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• 2009

Detailed flow analysis in river is essential to increase the accuracy of water quality simulation since flow variation depends on many factors such as cross sections, channel slopes, and bed materials. In the QUAL2E stream water quality simulation model, the hydraulic coefficients are assigned to the reach that is collection of computational element using the hydraulic coefficient. This study developed a module that can incorporate the results of non-uniform flow analysis and assign such information to each individual element. Model application focused on the upstream of the Hoengseong reservoir including the reservoir where significant flow change is expected. Comparing with original QUAL2E model the developed module improved the result of water quality simulation without considering the relation of flow velocity and flow depth in terms of flow rates.

• The Journal of Advanced Prosthodontics
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• 제3권1호
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• pp.10-15
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• 2011

PURPOSE. This study investigated the influence of bone quality and surgical technique on the implant stability quotient (ISQ) value. In addition, the influence of interfacial bone quality, directly surrounding the implant fixture, on the resonance frequency of the structure was also evaluated by the finite element analysis. MATERIALS AND METHODS. Two different types of bone (type 1 and type 2) were extracted and trimmed from pig rib bone. In each type of bone, the same implants were installed in three different ways: (1) Compaction, (2) Self-tapping, and (3) Tapping. The ISQ value was measured and analyzed to evaluate the influence of bone quality and surgical technique on the implant primary stability. For finite element analysis, a three dimensional implant fixture-bone structure was designed and the fundamental resonance frequency of the structure was measured with three different density of interfacial bone surrounding the implant fixture. RESULTS. In each group, the ISQ values were higher in type 1 bone than those in type 2 bone. Among three different insertion methods, the Tapping group showed the lowest ISQ value in both type 1 and type 2 bones. In both bone types, the Compaction groups showed slightly higher mean ISQ values than the Self-tapping groups, but the differences were not statistically significant. Increased interfacial bone density raised the resonance frequency value in the finite element analysis. CONCLUSION. Both bone quality and surgical technique have influence on the implant primary stability, and resonance frequency has a positive relation with the density of implant fixture-surrounding bone.

• 복식
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• 제66권2호
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• pp.1-14
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• 2016

This study was intended to investigate the influences that consumer's price sensitivity, bundle discount type, and price level of the male cosmetics have on consumer attitude. The design of this research was comprised of $2{\times}2{\times}2$ mixed design studies. The first element was high price sensitivity vs. low sensitivity, the second element was the bundle discount type (mixed leader vs. mixed-joint), and the third element was the price level of male cosmetics (high-price brand vs. low-price brand). The results of this study showed that price sensitivity, bundle discount type and price level of male cosmetic had a statistically significant interaction effect on the consumer's quality perception. The quality perception of low-cost brands for high price sensitivity/mixed-joint bundle group was low. The quality perception of low-cost brands for mixed-leader bundled groups did not change significantly even when the price sensitivity became higher. However, it can be seen as the same result that the overall value is higher when suggested the price information in Mixed-leader bundle than Mixed-joint bundle. In particular, this study suggests that price information should be presented in mixed-leader bundles for high price sensitivity and low cast brands.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.238-241
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• 2007

A roller straightening process is a metal forming technique to improve the geometric quality of products such as straightness and flatness. The geometrical quality can be enhanced by eliminating unnecessary deformations produced during upstream manufacturing processes and minimizing any detrimental internal stress during the roller straightening process. The quality of steel cords can be achieved by the roller straightening depends the process parameters. Such process parameters are the roll intermesh, the roll pitch, the diameter of rolls, the number of rolls and the applied tension. This paper is concerned with the design optimization of the roller straightening process for steel cords with the aid of elasto-plastic finite element analysis. Effects of the process parameters on the straightness of the steel cord are investigated by the finite element analysis. Based on the analysis results, the optimization of the roller straightening process is performed by the response surface method. The roller straightening process using optimum design parameters is carried out in order to confirm the quality of the final products.

• 소음진동
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• 제5권3호
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• pp.353-360
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• 1995

A new automatic diagnostic system for predicting multiple defects in rolling element bearings is developed by taking probbability into account. A database is constructed from the frequency characteristics of tested bearings with various types of defects. The proposed algorithms for the automatic diagnosis of bearing defects are shown to be satisfactory through the experiments. This method can be effectively used for quality control of the rolling bearing in plants.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.855-859
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• 2004

We develop a new four-node flat shell element which is accurate, efficient, and suitable to be used on general purpose. The new element has a hybrid Trefftz element with drilling degrees of freedom as a membrane part. We define the two independent displacement field: the internal displacement field that satisfies governing equations in the domain a priori and the boundary displacement field that is usually used as a conventional finite element method. The hybrid Trefftz variational formulation connects these two displacement fields on the boundary of the domain. To add drilling degrees of freedom, we introduce the Allman's quadratic displacement field to the boundary displacement field. As a result, our flat shell element has 6 degrees of freedom per a node. We also use the well-known DKMQ plate bending element for the plate part of the proposed element. The DKMQ element satisfies Mindlin-Reissner‘s plate theory along the edge of the element and gives proper behavior regardless of the thickness. A series of numerical experiments shows that the performance of the new element such as accuracy, rate of convergence, robustness to mesh quality, and so on.

• 한국환경과학회지
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• 제8권3호
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• pp.355-361
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• 1999

The aim of this study is to develop the water quality simulation model (BAYQUAL) that deal with the physical, chemical and biological aspects of fate/behavior of pollutants in the bay. BAYQUAL is a two dimensional, time-variable finite element water quality model based on the flow simulation model in bay(BAYFLOW). The algorithm is composed of a hydrodynamic module which solves the equations of motion and continuity, a pollutnat dispersion module which solves the dispersion-advection equation. The applicability and feasibility of the model are discussed by applications of the model to the Kwangyang bay of south coastal waters of Korea. Based on the field data, the BAYQUAL model was calibrated and verified. The results were in good agreement with measured value within relative error of 14% for COD, T-N, T-P. Numerical simulations of velocity components and tide amplitude(M2) were agreed closely with the actual data.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.130-136
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• 2003

A FQI(fatigue quality index) analysis using the concept of SF(severity factor) is performed to various shape of elliptical hole. FQI is fatigue quality index to estimate the dynamic SF from static SF by finite element analysis. Since the SF is affected by the location of cutout in plate and radius ratio, static SF is analyzed with finite element method and forms the equation of FQI for predicting a dynamic SF. To examine the validity, dynamic SF is measured by photoelastics and thermalelastics for an epoxy resin plate with various elliptical holes under dynamic load.

• 건축역사연구
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• 제8권3호
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• pp.39-51
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• 1999

The purpose of this study is to establish the theory of the spatial composition that is 'The Structure of Relation' in Korean traditional houses. This study has been focused on the spatial composition of Hyangdan. The form composition is an element defining primitive functions and space and producing aesthetical effects, where 'quality as a substance' is not important but 'quality as a relation' is essential. Quality as a meaningful relationship comes from realization and regulation of visual attributes among form elements. Each form compositional element establishes the hierarchical structure logically with the entire order, In order for the quality of all form compositional elements to be clarified as a meaningful relationship logically, 'compositional concept' which combines a series of form elements into the grammatical dependence to a specific direction, has to be assumed. If the intrinsic relationship among a series of form compositional elements fails to confront with the 'contextual concept' which eventually indicates unique conditions for a place according to the refined compositional concept, the result of form composition never leads to a specific solution

• 한국의류학회지
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• 제32권1호
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• pp.35-44
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• 2008

The research is purposed to help obese children to recover their physical, spiritual inferiority complex and it give them to affirmative self formation by developing training-suit which has slender effect. In order to accomplish a research problem, this research examined the effect of wearer's outward appearance with the principle and element of design and the characteristics of obesity. In order to apply consumer's demand to developing goods, this research used 'House of quality' theory. The design ten suits(the half are made for boys) development is based on the result of 'House of quality', parents and obese children's interview, design element, slender effect. The design which is developed is evaluated by five specialists in order to prove it's quality though the 'Quad' analysis which is a subjective evaluation method.