• 대한수학회지
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• 제54권1호
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• pp.117-139
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• 2017

This paper presents a systematic study for theoretical aspects of a unified approach to the abstract relative Fourier transforms over canonical homogeneous spaces of semi-direct product groups with Abelian normal factor. Let H be a locally compact group, K be a locally compact Abelian (LCA) group, and ${\theta}:H{\rightarrow}Aut(K)$ be a continuous homomorphism. Let $G_{\theta}=H{\ltimes}_{\theta}K$ be the semi-direct product of H and K with respect to ${\theta}$ and $G_{\theta}/H$ be the canonical homogeneous space (left coset space) of $G_{\theta}$. We introduce the notions of relative dual homogeneous space and also abstract relative Fourier transform over $G_{\theta}/H$. Then we study theoretical properties of this approach.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.177-180
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• 2001

This paper describes the calibration method and the evaluation method of relative expanded uncertainty for a multi-axis force/moment sensor. This sensor should be calibrated to be use in the industry. Now, the confidence of the calibration result is expressed with interference error. But it is no inaccurate, because an interference error, besides, a reproducibility error of the sensor, a error of this six-axis force/moment sensor calibrator, and so on. Thus, in order to accurately evaluate the relative expanded uncertainty of it, the concept of the uncertainty should be induced, and these errors must be contained in the relative expanded uncertainty. In this paper, the calibration method is exhibited and the evaluation method of the relative expanded uncertainty is also exhibited. And, a six-axis force/moment sensor was calibrated and the relative expanded uncertainty was evaluated.

• 한국세라믹학회지
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• 제34권11호
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• pp.1139-1150
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• 1997

A model for predicting the relative density and the compressive strength of open-cell ceramics with three-dimensional network structure was proposed through the interpretation of their macrostructure and fracture mechanics. The equation predicting the relative density was derived under the assumption that the open-cell structure was a periodic array of the tetrakaidecahedron unit cell consisting of cylindrical struts containing the internal hollow with the shape of a triangular prism. The model for compressive strength of open-cell ceramics with the hollow strut was also developed by modifying conventional model which based on fracture behavior of them subjected to the compressive stress. Both the relative density and the compressive strength were expressed in terms of the ratio of the strut diameter to the length together with the ratio of the hollow size to the strut diameter. The proposed model for the relative density and the compressive strength of the alumina-zirconia composite with open-cell structure were accorded well with the experimental values, whereas Gibson-Ashby and Zhang's model did not show such a good agreement.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년 춘계학술발표대회 논문집
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• pp.288-293
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• 2009

The evaluation of the quality of residential environment may be different according to the experts' characteristics. This study aimed at estimating the relative weights of the constituents of a residential environment by AHP(Analytic Hierarchy Process) through experts' evaluation. The respondent group was composed of 72 experts in the fields of architectural design, housing design, urban design, and urban planning. The findings are as follows(:) 1) the relative weights of residential constituents were different between detailed fields ; 2) the relative weights of residential constituents were not different according to institute in which experts are engaged ; and 3) for the practical application of estimation results of the relative weights, the relation between residential performance constituents and physical design elements should be considered in future.

• 한국생활과학회지
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• 제24권2호
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• pp.237-253
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• 2015

The purpose of this study was to examine the relative deprivation of the households in poverty, comparing with the households in non-poverty, and to find out the characteristics of household groups by the level of relative deprivation. The data for this study was from the 6th Korea Welfare Panel Survey(KOWEPS), consisting of total 5,552 households. The results are as follows: There were statistically significant differences in the objective cost of living, the subjective minimum cost of living, and the subjective adequate cost of living between households in poverty and households in non-poverty. There was statistically significant difference in the relative deprivation between households in poverty and households in non-poverty. Poverty was the factor for the relative deprivation of households.

• 소성∙가공
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• 제6권6호
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• pp.508-516
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• 1997

Forging process on sintered powder metals has been applied to produce automotive parts which require a high level of strength. In those parts, the measurement of relative density is very important because a low relative density density causes deterioration of strength. In the present study, an indentation force equation was proposed by which the result obtained from the hardness measurement is used to evaluate the relative density. This equation was applied to the prediction of the relative density in cylindrical specimens which were first sintered and then forged at the room temperature and at an elevated temperature. The experimental results were compared with predictions with and without consideration of the workhardening effect on the powder.

• 한국의류산업학회지
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• 제2권5호
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• pp.443-449
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• 2000

An investigation of the relative velocity of friction surface for the newly developed cone drum twister texturing mechanism is reported. The cone drum twister is one of the outer surface contacting friction-twisting devices in false-twist texturing. In this cone drum twister, a filament yam passes over the surface of the cone drum that rotates by passing the yarn without a special driving device. This research is theoretically composed of the analysis of the false twisting mechanism. The equations were derived by using the conical angle of the cone drum, projected wrapping angle, and yarn helix angle. Theoretical values of the relative velocity of friction surface were calculated and discussed. It is shown that, as the projected wrapping angle increased, the relative velocity of friction surface decreased. But as the conical angle increased the relative velocity of friction surface also increased.

• 대한수의학회지
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• 제36권1호
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• pp.131-142
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• 1996

The effect of relative humidity in swine house on swin pleuropneumonia was examined in piglets experimentally infected with Actinobacillus pleuropneumoniae serotype 5. A total of 20 piglet were grown under 30~40%, 41~50%, 51~64% and 65~80% relative humidity chambers after intratracheal inoculation of A pleuropneumoniae. Characteristic fibrinous pleuropneumonia was observed in the pigs grown at the low relative humidity groups. The detailed results were as follows : 1. Growth performance and environment conditions were lower than high relative humidity groups. 2. Characteristic histopathological findings were fibrinous pleuritis and pneumonia accompanied congestion, hemorrhage, thrombosis and edematous change. 3. Antigenic distribution of inoculated bacterium was found mainly in alveolar macrophages or accumulated foci of macrophages adjacent to necrotic area. 4. Characteristic electron microscopic findings were proliferation of type II pneumocyte with increased lamella bodies and activated alveolar macrophages with pseudopods and widening of interstitium.

• 한국항공운항학회지
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• 제21권4호
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• pp.1-10
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• 2013

This paper addresses the derivation of 6-DOF equation of Tanker and Receiver's aircraft for aerial refueling. The new set of nonlinear equations are derived in terms of the relative translational and rotational motion of receiver aircraft respect to the tanker aircraft body frame. Further the wind effect terms due to the tanker's turbulence are included. The derivation of absolute dynamic equation for tanker aircraft written in the inertial frame is calculated from the relative dynamics equations of receiver. The derived relative and absolute equations are implemented the simulation in the same flight conditions to verify the relative motion and compare the trim results by using the MATLAB/SIMULINK program.

• 한국식품저장유통학회지
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• 제7권1호
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• pp.63-67
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• 2000

Changes in the compressive strength of four typical corrugating mediums (K$_2$A, AS and S) as affected by relative humidity conditions were compared and their relative cost effectiveness was analysed. All mediums lost their compressive strength as relative humidity increased. at the relative humidity of 93% , As medium lost 58% of its initial strength while S medium did about 40%. Calculations of compress factor and compress factor by price indicated that $K_2$ medium was the most cost effective and maintained the highest compressive strength among the mediums tested. It was recommended that $K_2$ medium could be effectively used to make corrugated fiberboard especially for fresh agricultural product packaging .