• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.344-346
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• 2006

In this paper, a novel algorithm for increasing the steady state efficiency during light load operation of the induction generator that integrated with a wind power generation system is presented. The proposed algorithm based on the flux level reduction, where the flux level is estimated using Support-Vector -Machines for regression (SVR) for the optimum d-axis current of the generator. SVR is trained off-line to estimate the unknown mapping between the system's inputs and outputs, and then is used online to calculate the optimum d-axis current for minimizing generator loss. The experimental results show that SVR can define the flux-power loss accurately and determine the optimum d-axis current value precisely. The loss minimization process is more effective at low wind speed and the percent of power saving can approach to 40%.

• 한국통신학회논문지
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• 제19권2호
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• pp.373-380
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• 1994

본 논문에서는 음성신호를 일정한 크기로 적응시켜 최적의 특징을 추출할 수 있는 방법을 제안하였다. 음성신호의 특징을 추출하기 위하여 고속선형예측 알고리즘인 FRLS 적용할 때 음성신호를 일정한 크기로 분할한 후 각 프레임 마다 제안한 균등사기상관함수를 가지고 최적특징을 추출하였다.

• 한국환경과학회지
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• 제20권1호
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• pp.71-79
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• 2011

In this study, a series of soil concrete mixtures were tested for the compressive strength according to ratio of aggregate to binder, compaction energy, maximum aggregate size, ratio of silica fume to cement, and ratio of water to binder. The optimum mixing ratio of soil concrete mixtures composed of volcaniclastic, cement, silica fume, concrete polymer and water were analysed. The test results for optimum proportion were as follows ; (1)ratio of aggregate to binder was 4 : 1, (2)compaction energy level was level 2, (3)maximum aggregate size was 13 mm, (4)ratio of silica fume to cement was 10%, (5)ratio of water to binder was 25%. Also, dry type construction techniques were applied using the optimum soil concrete mixture. From the results of this study, the compressive strength of soil concrete and construction techniques were suitable for making eco-friendly soil pavement.

• 한국조리학회지
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• 제23권5호
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• pp.87-91
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• 2017

This study was conducted to investigate the quality characteristics of sun-dried salt prepared with added Cheongyang hot pepper juice(CPJ). The moisture, crude protein, crude lipid, and crude ash contents of the CPJ were 84.36%, 2.27%, 1.41%, and 0.67% respectively. The moisture content, yellowness, capsaicin, and dihydrocapsaicin of sun-dried salt increased according to the level of added CPJ, whereas the NaCl, pH, lightness, and redness value increased. The sensory evaluation results showed that preferences for the sun-dried salt increased as CPJ, approached their optimum value and decreased as they exceeded optimum levels. Consequently, the proposed optimum level in the ingredient formulation for manufacture of the standard sun-dried salt was 30% CPJ, as based on analyses. Ultimately, this study was expected to contribute to the commercialization of sun-dried salt of high quality.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.211-214
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• 2005

This research studied robust design of composite structure under combined loading of bending and torsion. DOE (Design of Experiment) technique was used to find important design factors. The results show that the beam height, beam width, layer thickness and stack angle of outer-layer are important design parameter. The $2^{nd}$ DOE and RSM (Response Surface Model) were conducted to obtain optimum design. Multi-island genetic algorithm was used to optimum design. An approximate value of 6.65 mm in deflection was expected under optimum condition. Six sigma robust design was conducted to find out guideline for control range of design parameter. To acquire six sigma level reliability, the sigma level reliability, the standard deviation of design parameter should be controlled within 2.5 % of average design value.

• 한국기계가공학회지
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• 제7권4호
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• pp.37-43
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• 2008

Working condition is one of the most important factors in precision working. In this study, we optimized the vibration acceleration level(VAL) of Al 2024 alloy to select optimum working condition of side wall end-milling using RSM(Response Surface Methodology). RSM was well adapted to make analytic model for minimizing vibration acceleration, created the objective function and saved a great deal of computational time. Therefore, it is expected that the proposed optimization procedure using RSM can be easily utilized to solve the optimization problem of working condition. The experimental results of the surface roughness and VAL showed the validity of the proposed working condition of side wall end-milling as it can be observed.

• 가족자원경영과 정책
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• 제5권1호
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• pp.1-13
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• 2001

The purpose of this study was not only to identify real-life conditions of Korean-Chinese in Korea(clothing habits, eating habits, housing habits, economic life and leisure activities) but also to reveal the related variables that shall affect life quality. The subjects were selected from Korean-Chinese in Korea related to ‘Compatriots House’. The survey was conducted from June 20th to July 5th, 2000. A total of 225 questionnaires out of 350 were used as the final data analysis. All data were analyzed using the SAS/PC for frequency, percentage, F-test and Regression analysis. The study revealed the following results. 1. Significant differences were found in life quality of Korean-Chinese in Korea according to age(p<.05), optimum income (p<.001), health condition(p<.001), education level(p<.005), and entry motivation(p<.05). 2. Variable such as optimum income(β=.334) education level(β=-.190), monthly income(β=.170), health condition(β=.151), and self-esteem(β=.133) affected life quality of Korean-Chinese in Korea. Korean-Chinese’s life quality was explained by these variable(35%). The optimum income variable was the primary influential factor.

• Journal of the Korean Data and Information Science Society
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• 제17권3호
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• pp.945-952
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• 2006

Several accelerated life test plans use tests at only two levels of stress and thus, have practical limitations. They highly depend upon the assumption of a linear relationship between stress and time-to-failure and use only two extreme stresses that can cause irrelevant failure modes. Thus 3-level stress plans are preferable. When the lifetime distribution of test unit is exponential with mean lifetime $\theta_i$ at stress $x_i$, i=0, 1, 2, 3, we derive the optimum quadratic plan under the assumption that a quadratic relationship exists between stress and log(mean lifetime), and propose the compound linear plans, as an alternative to the optimum quadratic plan. The proposed compound linear plan is better than two other compromise plans for constant stress testing and nearly as good as the optimum quadratic plan, and has the advantage of simplicity.

• 품질경영학회지
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• 제23권1호
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• pp.29-40
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• 1995

This paper considers the problem of optimally designing accelerated degradation tests in which the performance value of a specimen is measured only at one of three test conditions for a given exposure time. For the product having lognormally distributed performance, the optimum plan-low stress level and sample proportion allocated to each test condition - is obtained, which minimize the asymptotic variance of maximum likelihood estimator of a stated quantile at design stress. An illustrative example for the optimum plan is given.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1418-1421
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• 1987

An important problem in edge detection is to select a proper threshold that transforms the gradient picture to e two level picture containing optimum edges between regions, Such a threshold is determined depending on some measures of errors in tresholding. In this paper, an error criterion on extracting edges by thresholding the block gradient image is presented. Based on the error measure, the optimum threshold is chosen for the detection of acceptable edges.