• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1350-1353
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• 1993

A fuzzy control system typically requires“tuning,”or adjuctment of the parameters defining its linguistic variables. Automating this process amounts to applying a second“metacontrol”layer to drive the controller and plant to desired performance levels. Current methods of automated tuning rely on a single crisp numeric functional to evaluate control system performance. A generalization of Box's complex algorithm allows more realistic tuning based on lexicographic aggregation of multiple ordinal scales of performance, such as effectiveness and efficiency. The method is presented and illustrated using a simple inverted pendulum control system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1993년도 추계학술대회논문집; 반도아카데미, 26 Nov. 1993
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• pp.49-54
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• 1993

The nonlinear dynamic characteristics of a two-degree-of-freedom beam-mass structure is investigated. The flexible L-shaped structure with a two-to-one internal resonance is subject to a primary resonance and the resulting planar dynamic responses are examined. A quadratic damping, which has been avoided to use because of the difficulties in the analysis, is considered to take into account the effect of viscous damping due to the surrounding fluid. The method of multiple scales is used to determine first-order approximations to the solutions. Force-response and frequency-response curves are generated.

• 한국의류학회지
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• 제27권5호
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• pp.496-504
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• 2003

The purpose of this study was (1) to identify the experimental bias which could appear person perception as results of presentation methods (2) to find out the most desirable method in presentation of stimulus. The research was a quasi experiment and the subjects were 773 male and female undergraduate students. The experimental instruments consisted of a set of stimulus and semantic differential scales of 7- point hi-polar adjectives. The collected data were analyzed by Factor Analysis, ANOVA(analysis of variance), Scheffe＇s multiple range test. The independent variables were presentation orders and presentation time of stimulus. The results were as follows: First, five factors which were potency, sociality, appearance, evaluation, activity impression dimensions emerged to account for the methods of development of stimulus. Second, the presentation order of stimulus in the combination of four stimuli sets had significant effects on the 3 impressional factors(sociality, appearance, evaluation). The presentation order of stimuli in the combination of eight stimuli set had significant effects on the 3 impressional factors(potency, sociality, appearance) and the presentation order of stimuli in the combination of eight stimuli set showed a significant effect on memorization of stimulus and the results support the recency effect. Third, the presentation time of stimuli had significant effects on the 2 impressional factors(potency, activity). 30 seconds presentation as well as free duration time resulted less experimental bias than 3 seconds presentation.

• Structural Engineering and Mechanics
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• 제84권6호
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• pp.767-782
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• 2022

In this paper, the nonlinear vibration behavior of the spiral stiffened multilayer functionally graded (SSMFG) cylindrical shells exposed to the thermal environment and a uniformly distributed harmonic loading using a semi-analytical method is investigated. The cylindrical shell is surrounded by a nonlinear viscoelastic foundation consisting of a two-parameter Winkler-Pasternak foundation augmented by a Kelvin-Voigt viscoelastic model with a nonlinear cubic stiffness. The distribution of temperature and material constitutive of the stiffeners are continuously changed through the thickness direction. The cylindrical shell has three layers consisting of metal, FGM, and ceramic. The interior layer of the cylindrical shell is rich in metal, while the exterior layer is rich in ceramic, and the FG material is located between two layers. The nonlinear vibration problem utilizing the smeared stiffeners technique, the von Kármán equations, and the Galerkin method has been solved. The multiple scales method is utilized to examine the nonlinear vibration behavior of SSMFG cylindrical shells. The considered resonant case is 1:3:9 internal resonance and subharmonic resonance of order 1/3. The influences of different material and geometrical parameters on the vibration behavior of SSMFG cylindrical shells are examined. The results show that the angles of stiffeners, temperature, and elastic foundation parameters have a strong effect on the vibration behaviors of the SSMFG cylindrical shells.

• Journal of Multimedia Information System
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• 제5권4호
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• pp.235-244
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• 2018

Potential maximum soil moisture retention (S) is a dominant parameter in the Soil Conservation Service (SCS; now called the USDA Natural Resources Conservation Service (NRCS)) runoff Curve Number (CN) method commonly used in hydrologic modeling for event-based flood forecasting (SCS, 1985). Physically, S represents the depth [L] soil could store water through infiltration. The depth of soil moisture retention will vary depending on infiltration from previous rainfall events; an adjustment is usually made using a factor for Antecedent Moisture Conditions (AMCs). Application of the method for continuous simulation of multiple storms has typically involved updating the AMC and S. However, these studies have focused on a time step where S is allowed to vary at daily or longer time scales. While useful for hydrologic events that span multiple days, this temporal resolution is too coarse for short-term applications such as flash flood events. In this study, an approach for deriving a time-variable potential maximum soil moisture retention curve (S-curve) at hourly time-scales is presented. The methodology is applied to the Napa River basin, California. Rainfall events from 2011 to 2012 are used for estimating the event-based S. As a result, we derive an S-curve which is classified into three sections depending on the recovery rate of S for soil moisture conditions ranging from 1) dry, 2) transitional from dry to wet, and 3) wet. The first section is described as gradually increasing recovering S (0.97 mm/hr or 23.28 mm/day), the second section is described as steeply recovering S (2.11 mm/hr or 50.64 mm/day) and the third section is described as gradually decreasing recovery (0.34 mm/hr or 8.16 mm/day). Using the S-curve, we can estimate the hourly change of soil moisture content according to the time duration after rainfall cessation, which is then used to estimate direct runoff for a continuous simulation for flood forecasting.

• 한국산학기술학회논문지
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• 제17권3호
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• pp.544-553
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• 2016

본 연구는 중학생의 각성추구성향이 체육수업내적동기 및 체육교과태도에 미치는 영향을 규명하고자 하였다. 이 연구에 참여한 연구대상은 중학생을 대상으로 표집하였다. 표집된 설문자료 중에서 335명의 자료를 토대로 분석하였다. 연구도구는 각성추구검사지, 체육수업내적동기 검사지, 체육교과태도 검사지를 이용하였다. 자료처리는 빈도분석, 상관분석, 신뢰도분석, 탐색적 요인분석, 중다회귀분석을 이용하여 분석하였다. 결과는 다음과 같다. 각성추구성향 중 신기함 추구만이 체육수업내적동기의 재미-노력과 유능감에 정적 영향을 주는 것으로 나타났다. 그리고 각성추구성향 중 신기함 추구는 체육교과태도에 정적 영향을 주는 반면에, 스릴 추구는 건강과 체력에만 부적 영향을 주는 것으로 나타났다. 또 체육수업내적동기의 재미-노력은 체육교과태도에 정적 영향을 주는 반면에, 유능감과 긴장은 부분적으로 영향을 주는 것으로 나타났다. 따라서 체육교과태도와 내적동기를 증진시키기 위해서는 학생들의 각성추구성향 중 신기함 추구를 높여 줄 수 있는 교수학습방안이 요구된다.

• 한국의류학회지
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• 제22권5호
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• pp.597-606
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• 1998

The purposes of the study were 1) to evaluate the visual image of colored Korean traditional dress for woman 2) to analyze the colors and, color combinations effect on the image perception using gestalt theory. The research method was a quasi-experimental with a between subjects design. The experimental materials developed for the study were a set of stimuli and a response scale. The stimuli was consisted of 17 drawings of females wearing Korean tradinational dress, by using CAD simulation. A response scale consisted of semantic differential scales. The subjects were 1138 undergraduate students of Taejon city, Chungnam province and Chungbuk province. Their responses to the semantic differential scales were analyzed using factor analysis, one-way ANOVA, Duncan's multiple range test, 1-test. Results were as follows; 1) The image of the stimulus was consisted of the 4 different dimensions.(sociability, evaluation, visibility, attractiveness) 2) Clothing colors had significant effects on image perception of the evaluation dimension, visibility dimension and attractiveness dimension in the mono-color set. The blue showed the most positive image on the evaluation dimension, and the yellow and the gray showed negative image on the same dimension. The yellow showed the most salient image and the gray showed the least salient image on the visibility dimension. The red showed the most attractive image and the green showed the least attractive image on the attractiveness dimension. 3) In hi-color set stimulus, the perceived image was influenced by color combinations. The yellow blouse-the red skirt set showed the most sociable image on the sociability dimension. The blue blouse-the green skirt set showed the most positive image on the evaluation dimension. The yellow blouse-the red skirt set showed the most salient image and the blue blouse-the green skirt set showed the least salient image on the visibility dimension. And the red blouse-the yellow skirt set showed the most attractive image on the attractiveness dimension. On conclusion the visual image of Korean traditional dress wearer was affected by dress colors and color combinations.

• 천문학회보
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• 제39권2호
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• pp.57.1-57.1
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• 2014

We present results of our investigation of intrinsic brightness temperatures of compact radio jets at radio frequencies. The intrinsic brightness temperatures of about 100 compact radio jets at 2, 5, 8, 15, and 86 GHz are estimated based on large VLBI surveys conducted in 2001-2003 (or in 1996 for the 5 GHz sample). The multi-freqeuncy intrinsic brightness temperatures of the sample of the jets are determined with a statistical method relating the observed brightness temperatures with the maximal apparent jet speed, assuming one representative intrinsic brightness temperature for the sample at each observing frequency. With investigating the observed brightness temperatures at 15 GHz in multiple epochs, we found that the determination of the intrinsc brightness temperature for our sample is affected by variability of individual jets in flux density at the time scales of a few years. This implies an importance of contemporaneity of the multi-frequency VLBI observations for the statistical method. Since our analysis is based on the VLBI observations conducted in 2001-2003, the results are less affected by the flux density variability. We found that the intrinsic brightness temperature $T_0$ increases as $T_0{\propto}{\nu}^{\epsilon}$ with ${\epsilon}{\approx}0.7$ below a critical frequency ${\nu}_c{\approx}10GHz$ where energy losses begin to dominate the emission, and above the critical frequency, $T_0$ decreases with ${\epsilon}{\approx}-1.2$ supporting for the decelerating jet model.

• 복식문화연구
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• 제12권1호
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• pp.28-40
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• 2004

The purpose of this study was (1) to identify the experimental bias which could appear person perception as results of development methods (2) to find out the most desirable method in developments of stimulus. The research was a quasi experiment and the subjects were 358 male and female undergraduate students by convenient sampling. The experimental instruments consisted of a set of stimulus and semantic differential scales of 7-point bi-polar adjectives. The collected data were analyzed by Principle Component Analysis, ANOVA(analysis of variance), Scheffe's multiple range test. The independent variables were developing methods of stimulus(live person, photography of real person, 2 kinds of black and white line drawing, 2 kinds of color drawing). The results were as follows. First, five factors which were potency, sociality, appearance, evaluation, activity impressional dimensions emerged to account for the methods of development of stimulus. Second, the methods of development of stimulus had significant effects on potency, sociality, appearance, activity factors. In sociality factors, the impression of photographic stimulus was the closest to the live person's impression. However in the appearance and activity impressions, significant difference existed between live person and other developing stimulus. In the potency impression, black and white line-drawing gave the highest impressional bias. In the sociability and appearance impressions, color-drawing stimulus gave the highest impressional bias. Result: On conclusion the developments of stimulus can effect on stimulus person's impressions and these effects can produce experimental biases, the photographic stimulus gave the least impressional bias. The study shows that photography of real person will produce minimize measurement error.

• 산업공학
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• 제13권4호
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• pp.619-626
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• 2000

In this paper, we place the focus on suggesting a method of forecasting demand for PCS resale service with survey data in Korea. It is important for the service provider to forecast the diffusion process when designing marketing strategies and analyzing the costs and benefits. For the reason, we conduct a survey of three groups composed of non-subscribers, cellular subscribers, and PCS subscribers in order to forecast the demand according to several possible scenarios and business strategies. We consider the survey item that is measured by multiple point scales in response to a question if he would subscribe to the mobile telephone service in the future. We propose a method to forecast the size of market potential by classifying each individual into the two extreme groups, that is, yes or no. Then, by integrating survey data and historical data, we forecast the demand for PCS resale service that varies according to scenarios and strategies. From the results, we can find several implications for the provider of PCS resale service.