• 조명전기설비학회논문지
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• 제28권2호
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• pp.9-18
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• 2014

This paper proposes the fuzzy PI controller for maximum power point tracking(MPPT) control of photovoltaic system. The output characteristics of the solar cell are a nonlinear and affected by a temperature, the solar radiation. The MPPT control is a very important technique in order to increase an output and efficiency of the photovoltaic system. The conventional perturbation and observation(PO) and incremental conductance(IC) are the method which finding maximum power point(MPP) by the continued self-excitation vibration, and uses the fixed step size. If the fixed step size is a large, the tracking speed of maximum power point is faster, but the tracking accuracy in the steady state is decreased. On the contrary, when the fixed step size is a small, the tracking accuracy is increased and the tracking speed is slower. Therefore, this paper proposes the MPPT control using the fuzzy PI controller that can be improve a MPPT control performance. The fuzzy PI controller is adjusted a input of PI controller by fuzzy control and compensated a cumulative error of fuzzy control by PI controller. The fuzzy PI MPPT control is compared to conventional PO and IC MPPT method for various temperature and radiation condition. This paper proves the validity of the fuzzy PI controller using these results.

• 복식
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• 제54권6호
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• pp.77-90
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• 2004

The purpose of this study was to provide basic information requisite in the new sizing system for gloves. KS glove standards' size dimensions, size designation and labeling systems were analyzed. Also, KS glove standards' control sizes were compared to the anthropometric data of 824 Korean adults taken in the previous study. As well, the ISO hand size system was also compared to the anthropometric data of the previous study according to frequency tables of hand length and hand circumference. The size dimensions showed differences among KS standards and there was no size designation and labeling systems existed in KS standards. Among KS glove size systems, protective rubber gloves for radioactive contamination and surgical rubber gloves' size which followed ISO system were accurately indicate the hand size of the person a glove is intended to fit. ISO glove sizing system comprised the control dimensions of hand length and hand circumference. The coverage of ISO size A was 84.8% which was highest among ISO size A. B, C. And in hand circumference 178, 191, 203, 216mm showed the frequencies above 3% and in hand length 167, 175. 183, 191, 199mm showed the frequencies above 3%.

• Advances in nano research
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• 제14권2호
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• pp.155-164
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• 2023

Grain size in sheet metals in one of the main parameters in determining formability. Grain size control in industry requires delicate process control and equipment. In the present study, effects of grain size on the formability of steel sheets is investigated. Experimental investigation of effect of grain size is a cumbersome method which due to existence of many other effective parameters are not conclusive in some cases. On the other hand, since the average grain size of a crystalline material is a statistical parameter, using traditional methods are not sufficient for find the optimum grain size to maximize formability. Therefore, design of experiment (DoE) and artificial intelligence (AI) methods are coupled together in this study to find the optimum conditions for formability in terms of grain size and to predict forming limits of sheet metals under bi-stretch loading conditions. In this regard, a set of experiment is conducted to provide initial data for training and testing DoE and AI. Afterwards, the using response surface method (RSM) optimum grain size is calculated. Moreover, trained neural network is used to predict formability in the calculated optimum condition and the results compared to the experimental results. The findings of the present study show that DoE and AI could be a great aid in the design, determination and prediction of optimum grain size for maximizing sheet formability.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.22-24
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• 1996

Small size DC motor control method for portable drug delivery system has been developed to be used for the actuator of insulins pump. The control method gives the controllabilities both in high speed(40-50 revolution per second(rps)) DC motor drive and also in low speed(0.5-1rps). In low speed mode DC motor is controlled to act like stepping motor and in high speed to optimize power consumption. To control both mode modified bang bang control is suggested. Using this method small size DC motor(spec.) speed is controlled from 0.2 rps to 50 rps. Experimental setup is developed using micro-processor(PIC16C73, Micro Chips co., USA), motor turns checking circuitry, small size DC motor for pager(SM1012, Samhong co., Korea) and gear box. Results from experiment meet need for vailable load condition which is require for portable drug delivery system.

• 한국의류학회지
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• 제23권8호
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• pp.1240-1247
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• 1999

The purpose of this study was to classify size specifications of Korean adult male for the men's ready-made garments especially jacket and dress shirts By the stratified sampling method data were collected by the real anthropometric measurement. Sample size was 263 subjects as the sample and their age range was from 36 to 43 years old 66 variables from the direct anthropometric data were applied to analyze. ANOVA is SPSSWIN 8.0 package was applied to the data and the expected frequency distribution of 10.000 men was calculated by the extraction of density function. This study was performed to classify size specificatios by the control dimensions. The drop values of 9,12 and 6 have the high coverage rate of 28.52% 23.44% respectively Obese body type ; H type HD type and HE type are composed of the majority of 55.47% of the subjects. According to the drop values size specifications and distribution of control dimensions are predicted About 69.82% of the expected frequency distribution were covered by 19 size specifications.

• 한국의류학회지
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• 제21권7호
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• pp.1247-1257
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• 1997

The purpose of this study was to classify size specifications of Korean adult male for the men's ready·made garments, especially jacket and dress shirts. Concept of the comfort and fitness has become a major concern in the basic function of the ready-made garments. Data were collected by the real anthropometric measurement and by the photographic sources. Sample size was 1.290 subjects as the sample and their age range was from 19 to 54 pean old by the stratified sampling method. 66 variables from the direct anthropometric data in total were applied to analyze. ANOVA in SAS package was applied to the data and the expected frequency distribution of 10.000 men was calculated by the extraction of density function. Control dimensions for jacket and dress shirts has been designated by Bcorean Apparel Sizing System (KS-K). Therefore this study was performed to classify size specifications by the control dimensions and at the same interval of KS-K. The drop values of 15, 12 and 9 has the high coverage rate of 22.1%, 21.0% and 18.8% respectively and are composed of the majority of 61.9% of the subjects. According to the drop values, size specifications and distribution of control and reference dimensions are predicted. About 65.75% of the expected frequency distribution without stature were covered by 19 size specification.

• 한국관개배수논문집
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• 제17권2호
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• pp.57-70
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• 2010

This study was performed to analyze the affect of water supply capacity followed by allocating flood control volume in heightening reservoir, of which Baekgog reservoir was selected as a case study in here. Baekgog reservoir is located in Jincheon county, Chungbuk province, of which full water level will be heightened from EL. 100. 1m to EL. 102.1m, and total storage from 21.75M $m^3$ to 26.67M $m^3$. Flood inflow with 200year frequency was estimated to 997 $m^3$/s in peak flow and 22.54M $m^3$ in total volume. Reservoir flood routing was conducted to determine flood limited water levels, which was determined to have scenarios such as EL 97-98-99m in periods of 6.21.-7.20., 7.21.-8.20., and 8.21.-9.20., respectively, EL 97-97-97m, EL 98-98-98m in present reservoir, and EL 99-100-101m, EL 99-99-99m, and EL 100-100-100m in heightened reservoir. Reservoir inflow was simulated by DAWAST model. Annual paddy irrigation requirement was estimated to 33.19M $m^3$ to 2,975ha. Instream flow was allocated to 0.14mm/d from October to April. Operation rule curve was drawn using inflow, irrigation and instream flow requirements data. In case of withdrawal limit reservoir operation using operation rule curve, reduction rates of annual irrigation supply before and after flood control by reservoir were 2.0~4.3% in present size and 1.5~3.6% in heightened size. Reliability on water supply was decreased from 77.3% to 63.6~68.2% in present size and from 81.6% to 72.7~79.5% in heightened size. And reduction rates of water storage at the end of year before and after flood control by reservoir were 7.3~16.5% in present size and 7.7~16.9% in heightened size. But water supplies were done without any water deficiency through withdrawal limit reservoir operation in spite of low flood regulating water level.

• 품질경영학회지
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• 제35권2호
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• pp.106-112
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• 2007

In statistical process control, it is assumed that the process data are independent. However, most of chemical processes such as semi-conduct processes do not satisfy the assumption because of presence of autocorrelation between process data. It causes abnormal out of control signal in the process control and misleading estimation in process capability. In this study, we adopted Shore's method to solve the problem and propose an optimal subgroup size to estimate the variance correctly for AR(1) processes. Especially, we focus on finding an actual subgroup size for small samples based on simulation study.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권3호
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• pp.390-395
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• 1994

The author evaluated the nasal asymmetry after primary operations in the patients with unilateral cleft lip using full face photographs. The results are as follows : 1. Nasal deviation angle is average 2.98+3.01 degree(ranged from 0 to 10 degree), significantly different from control group(p<0.05). 2. Nasal deviation angle is average 5.1% when inter-medial canthal distance is 100%, significantly different from control group(p<0.05). 3. Difference in nostril size between cleft and noncleft side is 2.1% when inter-medial canthal distance is 100%, significantly different from control group(p<0.05). 4. Nasal attractiveness analysis shows higher points in difference in nostril size, nasal deviation, nasal form in that order. 5. Nasal asymmetry after primary operations in the patients with unilateral cleft lip using full face photographs is related with Nasal deviation angle, Nasal deviation distance and Difference in nostril size between cleft and noncleft side.

• Korean Membrane Journal
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• 제7권1호
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• pp.42-50
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• 2005

Among ceramic membranes developed to date, amorphous silica membranes are attractive for gas separation at elevated temperatures. Most of the silica membranes can be formed on a porous support by sol-gel or chemical vapor deposition (CVD) process. To improve gas permselectivity of the membrane, well-controlled pores having desired size and chemical affinity between permeates and membrane become important factors in the preparation of membranes. In this article, we review the literature and introduce our technologies on the microstructure to be solved and pore size control of silica membranes using sol-gel and CVD methods.