• 한국의류산업학회지
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• 제12권5호
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• pp.642-649
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• 2010

This study was designed to generate briefs pattern for women in their twenties using 3D parametric body model. 151 women in their 20's were random sampled and measured using Martine's anthropometry. And one subject was chosen as the representative subject for 3D scanning. Parametric model was generated of using CATIA P3, Unigraphics NX4.0, Rapidform 2006. And the 3D surface of parametric body model was flattened onto the 2D plane. 3 downscale ratios(0%, 10%, 15%) were applied to generated pattern to figure out what downscale ratio was suitable to make briefs with stretch fabric. 4 kinds of experimental briefs were made with stretch fabrics(0%, 10%, 15% downscale) and worn on the dressform. Subjective evaluation on the appearance was done and the data was analyzed by ANOVA with post-hoc test. Briefs pattern was generated through the process of flattening the parametric surface and arranging the patches to make briefs pattern by dart manipulation. The different ration of outline and area between 3D surface and 2D pattern were 0.22% and 0.09% respectively. It showed that a parametric model could provide a desirable pattern with minute size error. The results of subjective evaluation on the appearance of 4 experimental briefs showed that stretch briefs with 15% downscale ratio was evaluated most highly in most items. Findings imply that it is feasible to apply 3D parametric model to generate patterns for various items considering various fabric properties.

• 한국음향학회지
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• 제28권8호
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• pp.768-773
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• 2009

본 논문에서는 파라메트릭 어레이를 이용한 공기 중 디지털 통신의 특성을 측정해 보았다. 2차 오더의 비선형 현상인 파라메트릭 어레이를 구현하기 위하여, 고출력, 고효율의 음파 발생이 가능한 요철 트랜스듀서가 사용되었다. 1차 음파 (primary wave)의 주파수는 트랜스듀서 공진 주파수에 맞추어 83 kHz, 122 kHz 로 결정하였고, 이를 통해 발생되는 39 kHz의 차음 (difference frequency wave)을 통신 신호로 이용하였다. 통신 변조방법으로 On-Off Keying 방식을 이용하였다. 실험은 파라메트릭 어레이를 이용한 디지털 통신의 특성을 측정하기 위하여 파형 분석을 하였고, 거리, 각도에 따른 SNR을 측정해 보았다. 실험 결과 파라메트릭 어레이를 이용한 디지털 통신은 3m이내의 근거리 영역에서 적합함을 알 수 있었고, 빔폭 (-3 dB)은 $14^{\circ}$로 측정되어 고지향성 통신이 가능함을 확인하였다. 위의 실험 결과를 통해 파라메트릭 어레이를 이용한 공기 중 음향 통신에 대한 가능성을 확인하였고, 고지향성 통신 특성은 다중경로 문제나 보안 문제에 강점이 있을 것으로 판단된다.

• 대한조선학회논문집
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• 제44권5호
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• pp.542-550
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• 2007

A geometry modification is one of main keys in achieving a successful optimization. The optimized hull form generated from the geometry modification should be a realistic, faired form from the ship manufacturing point of view. This paper presents a practical hull optimization procedure using a parametric modification function. In the parametric modification function method, the initial ship geometry was easily deformed according to the variations of design parameters. For example, bulbous bow can be modified with several parameters such as bulb area, bulb length, bulb height etc. Design parameters are considered as design variables to modify hull form, which can reduce the number of design variables in optimization process and hence reduce its time cost. To verify the use of the parametric modification function, optimization for KCS was performed at its design speed (FN=0.26) and the wave making resistance is calculated using a well proven potential code with fully nonlinear free surface conditions. The design variables used are key design parameters such as Cp curve, section shape and bulb shape. This study shows that the hull form optimized by the parametric modification function brings 7.6% reduction in wave making resistance. In addition, for verification and comparison purpose, a direct geometry variation method using a bell-shape modification function is used. It is shown that the optimal hull form generated by the bell-shaped modification function is very similar to that produced by the parametric modification function. However, the total running time of the parametric optimization is six times shorter than that of the bell shape modification method, showing the effectiveness and practicalness from a designer point of view in ship yards.

• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1504-1514
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• 2018

The objective of this study is to compare the suitability of a non-parametric and 3 parametric distributions in the characterization of prediction intervals of photovoltaic power forecasts with high confidence levels. The prediction intervals of the forecasts are calculated using a method based on recent past data similar to the target forecast input data, and on a distribution assumption for the forecast error. To compare the suitability of the distributions, prediction intervals were calculated using the proposed method and each of the 4 distributions. The calculations were done for one year of day-ahead forecasts of hourly power generation of 432 PV systems. The systems have different sizes and specifications, and are installed in different locations in Japan. The results show that, in general, the non-parametric distribution assumption for the forecast error yielded the best prediction intervals. For example, with a confidence level of 85% the use of the non-parametric distribution assumption yielded a median annual forecast error coverage of 86.9%. This result was close to the one obtained with the Laplacian distribution assumption (87.8% of coverage for the same confidence level). Contrasting with that, using a Gaussian and Hyperbolic distributions yielded median annual forecast error coverage of 89.5% and 90.5%.

• Journal of the Korean Data and Information Science Society
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• 제17권2호
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• pp.401-409
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• 2006

We consider a generalized partly-parametric additive risk model which generalizes the partly parametric additive risk model suggested by McKeague and Sasieni (1994). As an estimation method of this model, we propose to use the weighted least square estimation, suggested by Huffer and McKeague (1991), for Aalen's additive risk model by a piecewise constant risk. We provide an illustrative example as well as a simulation study that compares the performance of our method with the ordinary least squares method.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1987년도 학술발표회 논문집
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• pp.17-19
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• 1987

In this paper an ultrasonic loud speaker (ie,. parametric speaker) driving technic was proposed. The study was focused on reduction of distortion in self-demodulated sound using a sound source deriven by MDSB(Modified Double Side Band) signal. And, the esperiment was performed in acoustic wave guide usin the developed MDSB unit according to the variation of distance from the source. In the result, prposed MDSB method was found to decrease second harnonic distortion in -3 to -6 dB compared to conventional DSB method.

• 품질경영학회지
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• 제23권3호
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• pp.93-101
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• 1995

We present a brief survey concerning the relations between mean residual life and failure rate. Change points of mean residual life and failure rate are known to be different in general and we explore such situations in this paper. A few parametric models which show bathtub-shaped failure rate are examined in details, including the shape of its corresponding mean residual life function. We give some graphical comparisons of trend changes of mean residual life and failure rate for various choices of parameters for each parametric model.

• Journal of applied mathematics & informatics
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• 제19권1_2호
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• pp.493-506
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• 2005

In this paper, we study the behavior and sensitivity analysis of the solution set for a system of parametric generalized nonlinear mixed quasi-variational inclusions in Banach spaces. By using some new and innovative technique, existence theorem for the system of parametric generalized nonlinear mixed quasi-variational inclusions in $L_p(p\ge2$ spaces is established. Our results improve the known result of Agarwal et al.[1].

• Journal of the Korean Data and Information Science Society
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• 제10권1호
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• pp.155-162
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• 1999

This paper is concerned with the empirical Bayes estimation of one of the two shape parameters(${\theta}$) in the Burr(${\beta},\;{\theta}$) type XII failure model based on type-II censored data. We obtain the bootstrap empirical Bayes confidence intervals of ${\theta}$ by the parametric bootstrap introduced by Laird and Louis(1987). The comparisons among the bootstrap and the naive empirical Bayes confidence intervals through Monte Carlo study are also presented.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.625-630
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• 2010

Parametric study was performed using the SCW numerical model for evaluating the performance of the SCW. The five ground related parameters, which are porosity, hydraulic conductivity, thermal conductivity, specific heat, geothermal gradient, and five SCW design parameters, which are pumping rate, well depth well diameter, dip tube diameter, bleeding rate, were used in the study. Numerical simulations were performed for short-term (24-hour) simulation. The study results indicate that the parameters that have important influence on the performance of SCW were hydraulic conductivity, thermal conductivity, geothermal gradient, pumping rate, and bleeding rate. Overall, this study showed that various factors had a cumulative influence on the performance of the SCW, and a numerical simulation can be used to accurately predict the performance of the SCW.