• 한국잠사곤충학회지
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• 11호
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• pp.73-80
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• 1970

This study was carried out in order to investigate the correlation among test items of export raw silk. The results obtained from the study are summarized as follows. 1. The highest correlation was between evenness and low evenness in case of the filaments made of autumn cocoons and the coefficient of correlation was 0.854. 2. Among following items, viz.; evenness and cleanness, neatness and low neatness and elongation and cohesion, the correlation phisically was not acknowledged, but the coefficients of correlation were high figures. 3. Poor correlation existed between following items, viz.; size deviation and maximum deviation, evenness and low evenness, neatness and low neatness, cleanness and low neatness. 4. It is considered that the high correlation exists between tenacity and elongation, but in this study the correlation existed among some items. 5. In this study it is a new fact that the correlation between neatness and cohesion as well as low neatness and tenacity existed enough highly. 6. As a conclusion the independence of ten items tested at present was acknowledged.

• 품질경영학회지
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• 제28권2호
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• pp.70-88
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• 2000

Short runs where it is neither possible nor practical to obtain sufficient subgroups to estimate accurately the control limit are common in modem business environments. In this study, the standardized control chart, Hillier's exact method, Q chart, EWMA(Exponentially Weighted Moving Average) chart for Q statistics and EWMA chart for mean and absolute deviation among many SPC(Statistical Process Control) techniques for short runs have been reviewed and advantages and disadvantages of these techniques are discussed. The simulation experiments to compare performances of these variable charts for process mean and variations are conducted for combination of subgroup size, scale and timing of shifts of process mean an/or standard deviation. Based upon simulation results, some guidelines for practitioners to choose short run SPC techniques are recommended.

• 품질경영학회지
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• 제34권4호
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• pp.125-132
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• 2006

An adjusted control limit of the $\overline{X}$ chart is proposed for monitoring the continually improving processes. The continual improvement of the process implies the decrease of the process variance, which is represented by a logistic curve. The process standard deviation is estimated by the exponentially weighted moving average of the sample standard deviations from the past to the current times. The control limits are adjusted by the estimated standard deviation at every sampling time. The performance of the adjusted control limit is compared with that of the standard control limits for various cases of the decreasing speed and size of the variance. The results show that the $\overline{X}$ chart with the adjusted control limits provides better performances for monitoring the small and moderate shifts in continually improving processes.

• Journal of Biosystems Engineering
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• 제22권2호
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• pp.217-226
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• 1997

This study was to develop a machine vision system to detect and to discriminate 5 kinds of apple surface defectbruise, decay. fleck, worm hole and scar. To detect the defects from an image of apple, thresholding technique was applied to images on various frames (R, G, B, H, S and I) of the color machine vision and an image of near infrared (NIR). To discriminate the detected region of defect, various features of the 5 kind defect regions were extracted from the 4 kinds of images selected above. The features were size of area, roundness, axes length ratio, mean and valiance of pixel values, standard deviation of real part of amplitude spectrum in frequency domain obtained by Fourier transform of pixel data and mean and standard deviation of power spectrum obtained by the same transform of pixel data. Routines to discriminate the defects from the features of image were developed and tested to prove their validity. The test resulted that I-frame and NIR images were the most desirable. Accuracies of the two images to discriminate the defects were noted as 76% and 77%, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.229-231
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• 1988

In this paper, we design adaptive DPCM by the two dimensional linear prediction using the covariance method and propose adaptive algorithm which determines analysis frame size by the compassion of the local standard deviation and the global standard deviation of images.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.892-894
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• 1995

This paper deals with developmeant and application of coating thickness control system in hot dip galvanizing process. According to the line conditions, such as line speed, strip size and target coating weight, a predictive preset model sets the initial oprating conditions. Referring the zine coating informations from the gauge, mean coating value controller adjusts the chamber pressure and horizontal distance between strip and air knife, while coating deviation controller adjusts the lip gap profile of the air knife. All adaptive gains are interactively calculated by numeric models based on the theoretical analysis. The operating result with this system effectively reduces the coating deviation in transverse direction as well as in longitudinal direction.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권2호
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• pp.69-75
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• 2004

In this paper, we propose the shape of extremely small thrust VCM for application of the Nanoindenter, which enables control of very small force and displacement. We performed optimization of the VCM shape using conjugated gradient method. And the purposes of optimization are the minimization of the permanent magnet size for the efficient systems, minimization of deviation of flux density from the air gap for operate on regular thrust and a linearization of thrust for a good control characteristic. The finite element method is used for characteristic analysis. The node moving method is used to redundant changes of design variables. As a result, the VCM produces a yew small force by the difference of flux density of lower part from higher one. Also, in a wide range of current (0［A］-1［A］), the VCM produces linear driving thrust by saturating the magnetic circuit path and operate on regular thrust by minimizing deviation of flux density of the air gap.

• 소성∙가공
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• 제27권6호
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• pp.356-362
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• 2018

A liner is a crucial component that directly affects the penetration performance of the shaped charge warhead. If the material of the liner has fine grain size and high strength, then the penetration performance can be further improved. There have been attempts to use a preform obtained by a severe plastic deformation (SPD) process. In this study, the process of minimizing the strain deviation to maintain the characteristics of material obtained by the severe plastic deformation process was investigated. The FE analysis of liner forging process was performed using the design of experiments (DOE), to optimize various shape parameters of the forming process such as shape of preform and forging die. As a result, the combination of design variables with the minimum effective strain deviation in the liner forging process were obtained.

• 복식
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• 제57권10호
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• pp.50-59
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• 2007

This study has been conducted to classify elderly men's feet with the three-dimensional body scanner data of Size Korea. It was intended to assist the manufacturing of the shoes that can appropriately perform the functions of feet, by providing the specific information about the shapes of elderly men's feet that are altered as a result of aging and shoe-wearing for a long time. The findings are as follows. 1. The investigations into the average and standard deviation of the measurements and index values for the elderly men's feet showed a large personal difference in the items of length and circumference. 2. The factors constituting the elderly men's feet were observed to be the size of foot width(Factor 1), the central angle of feet and the extension of toes(Factor 2), the size of ankle(Factor 3), the positions of lateral malleolus and pternion(Factor 4), and the position and size of medial malleolus(Factor 5). 3. The cluster analysis for the classification of elderly men's feet produced three types of them.

• 한국의류산업학회지
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• 제18권5호
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• pp.647-657
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• 2016

This study investigated domestic and foreign cycle wear sizing systems for the domestic market and provided basic data for development of a high functional cycle wear with excellent fitness qualities. Each brand was found to have different dimension items and different sizes as well as size deviation and range according to each item. Therefore, a size selected by referring to the dimension items would be expected to have confusion when selecting a size. Domestic brands are able to selects sizes relatively easily because they suggest sizes mainly by height and weight (which are a universal size). However, the development of a sizing system for domestic cycle wear brands is needed because each brand have different sizes according to its dimension items. Foreign brands are also different from domestic brands in size marking items and sizes according to items. Therefore, the establishment of a sizing system standard for foreign brands is necessary because there could be a problem with fitness in the same sizes selected for domestic brands. Cycle wear is also able to cover various body types due to the elasticity of its material; however, and evaluation of fitness and a follow-up study will be necessary to develop cycle wear with a fitness that is proper for a Korean body type.