• Title/Summary/Keyword: Sampling Strategy

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The Study of the Process of Smoking Cessation in Adults (성인의 금연과정에 관한 연구)

  • 김애경
    • Journal of Korean Academy of Nursing
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    • v.28 no.2
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    • pp.319-328
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    • 1998
  • The purpose of this study was to explore the process of smoking cessation behavior in adults with a history of smoking cessation. The subject were 17 adults selected by theoretical sampling. The data were collected by in-depth interviews using audiotape recording over a period of six months. The data were analyzed simultaneously by a constant comparative method in which new data were continuously coded in categories and properties according to Strauss and Corbin' methodology. Analysis of the data resulted in the identification of 12 categories. The result of this study are as follows : 1. Smoking cessation in adults is caused by fear about health, environmental pressure of smoking cessation, and intention of smoking cessation. 2. Smoking cessation occurs in connection with situations of limited smoking 3. Maintenence of smoking cessation is related to psychological stress, and environmental cues to smoking. 4. In the smoking cessation process, adults experienced either health promotion or relapse. It is suggested that the result of this study may contributed to the development of a strategy for decreasing smoking behavior among adults.

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A Study on Digital control of Inverter for UPS based on Disturbance Observer (외란관측기를 가지는 UPS용 인버터의 디지탈제어에 관한 연구)

  • Lee, C.D.;Kim, J.S.;Choi, S.Y.;Lee, J.C.;Woo, J.I.
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.606-608
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    • 1996
  • In this paper, a new control scheme based on deadbeat control with disturbance observer for voltage controlled Inverter system is proposed. The inverter system is modelled as the 4th-order system treating R load current variation caused by disturbance. So the disturbance observer exists in the state observer. By using the pole placement strategy, the observer estimates the state and disturbance variable of the next sampling instant. Simulation results so show that The proposed scheme has robust feature against disturbance.

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A study on the torque ripple reduction of PMSM in direct torque control by using dither signal (Dithering기법에 의한 직접 토크 제어 방식의 토크리플 개선에 관한 연구)

  • Lee H.H.;Kim J.H.
    • Proceedings of the KIPE Conference
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    • 2003.07a
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    • pp.415-419
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    • 2003
  • This paper focuses on a simple technique to reduced torque ripple in the direct torque control inverter for PMSM drive. It is actually impossible to raise the inverter switching frequency in the conventional system, although the hysterisis bandwidths for the stator flux and torque control are sufficiently diminished, because of the sampling Interval and the delay in estimating the flux and the torque In order to overcome the problem, the proposed method introduces a dithering technique into the conventional system by superposing triangular waves with high frequency and minute amplitude on the torque error. And the programable 3- stage lowpass filter is added instead of pure Integrator. Simulation results prove the feasibility of proposed strategy compared with conventional method.

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Influence of Correlation Functions on Maximum Entropy Experimental Design (최대엔트로피 실험계획에서 상관함수의 영향)

  • Lee Tae-Hee;Kim Seung-Won;Jung Jae-Jun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.7 s.250
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    • pp.787-793
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    • 2006
  • Recently kriging model has been widely used in the DACE (Design and Analysis of Computer Experiment) because of prominent predictability of nonlinear response. Since DACE has no random or measurement errors contrast to physical experiment, space filling experimental design that distributes uniformly design points over whole design space should be employed as a sampling method. In this paper, we examine the maximum entropy experimental design that reveals the space filling strategy in which defines the maximum entropy based on Gaussian or exponential. The influence of these two correlation functions on space filling design and their model parameters are investigated. Based on the exploration of numerous numerical tests, enhanced maximum entropy design based on exponential correlation function is suggested.

A Characteristic analysis of Slot Shape Variation for 6MW BLDC Motor by using Latin Hypercube Sampling Strategy (LHS를 이용한 6MW급 BLDC MOTOR의 슬롯형상 변화에 따른 특성해석 연구)

  • Kim, Yong-Bae;Woo, Sung-Hyun;Jang, Hyeong-Taek;Shin, Pan-Seok;Oh, Jin-Seok;Kong, Yeong-Kyong
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.640_641
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    • 2009
  • 본 논문에서는 6MW급 BLDC Motor의 슬롯형상을 변화시켜 코깅토그와 공극에서의 자속밀도, 저장 에너지를 해석하고, 슬롯형상의 중앙에 설계변수를 주어 공극에 흐르는 자속의 변화를 계산하여 분석 하였다. 폭길이는 최소화에 기준을 두었으며 Parameter는 LHS를 이용한 샘플링 포인트 기법을 사용하여 최적의 조건에 가장 알맞은 최적점를 찾아내어 특성해석을 하였다. 최종적으로 고용량에서의 슬롯형상변화에 따라 코깅토크를 최소화하는 최적화 설계를 위하여 이번 특성해석 연구를 하였다.

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A Study of Cogging Torque Minimization for a Outer-Rotor Type Small BLDC Motor by using Latin Hypercube Sampling strategy (II) (LHS를 이용한 소형 다상 외전형 BLDC 전동기의 코깅토크 최소화 연구 (II))

  • Woo, Sung-Hyun;Chung, Hyun-Koo;Kim, Yong-Bae;Shin, Pan-Seok;Oh, Jin-Seok;Kong, Yeong-Kyung
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.646_647
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    • 2009
  • 소형 다상 외전형 BLDC 전동기의 코깅토크를 최소화하기 위해 코깅토크의 발생원인 중 하나인 영구자석의 형상에 샘플링 포인트 기법인 LHS를 이용한 최적화 알고리즘을 적용하여 코깅토크를 최소화하는 최적 설계를 수행 하였다. 총 3번의 반복계산을 하여 코깅토크가 최소화 되는 최적점을 계산한 결과,최대 코깅토크가 0.20 [N.m]에서 0.15 [N.m]로, 초기 형상의 약 75%로 감소되었다

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Comparison and Analysis of Competition Strategies in Competitive Coevolutionary Algorithms (경쟁 공진화 알고리듬에서 경쟁전략들의 비교 분석)

  • Kim, Yeo Keun;Kim, Jae Yun
    • Journal of Korean Institute of Industrial Engineers
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    • v.28 no.1
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    • pp.87-98
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    • 2002
  • A competitive coevolutionary algorithm is a probabilistic search method that imitates coevolution process through evolutionary arms race. The algorithm has been used to solve adversarial problems. In the algorithms, the selection of competitors is needed to evaluate the fitness of an individual. The goal of this study is to compare and analyze several competition strategies in terms of solution quality, convergence speed, balance between competitive coevolving species, population diversity, etc. With two types of test-bed problems, game problems and solution-test problems, extensive experiments are carried out. In the game problems, sampling strategies based on fitness have a risk of providing bad solutions due to evolutionary unbalance between species. On the other hand, in the solution-test problems, evolutionary unbalance does not appear in any strategies and the strategies using information about competition results are efficient in solution quality. The experimental results indicate that the tournament competition can progress an evolutionary arms race and then is successful from the viewpoint of evolutionary computation.

A Study on Brand Image Preference and Fashion Advertising Strategy (상표이미지 선호도와 패션 광고 전략에 관한 연구 - 여대생을 중심으로 -)

  • Kim Moon Jin;Rim Sook Ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.13 no.3 s.31
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    • pp.197-206
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    • 1989
  • This study was to investigate brand images of ladies wear and the effects of fashion advertisements, and to determine the difference of brand image preference and the effects of fashion advertising by clothing life style. 421 subjects were gathered through stratified sampling method and, for data analysis, frequency distribution, $x^2-test$, Cronbach'$\alpha$, ANOVA, Duncan's multiple Range test, Multiple Dimentional Scaling (M.D.S.), Factor analysis, Cluster analysis, were conducted. The results are as follows; 1. In image formation process, feminine as formal image, manish as casual image, were recognized. 2. Four factors were determined for analysis of clothing life styles and with these factors five different clothing life style groups were classified. 3. There was a meaningful difference between clothing life style and brand image preference, and also between clothing life style and the effects of fashion advertisement. From these findings, general and specific fashion advertising strategies are proposed.

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Development of Health Behavior Assessment Tool of the Korean Adults (성인의 건강행위 측정도구 개발연구)

  • 김애경
    • Journal of Korean Academy of Nursing
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    • v.28 no.3
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    • pp.540-549
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    • 1998
  • This study has been designed to develop a health behavior scale. Data were collected through a survey over a period of two month period. Subjects who participated in the study were 298 Korean adults. The author used a convenience sampling method. The analysis of the data was done with SPSS PC for descriptive statistics and factor analysis. Initially 34 items were generated from the interview data of twenty one adults and from literature review and survey. This preliminary scale was analyzed for a reliability and validity. The results are as follow : 1. Crombach Coefficient alpha for the 30 items was .7907. 2. Factor analysis was done in order to confirm construct validity and nine factor were extracted from the results. These contributed 54.4% of the variance in the total score. 3. Nine factor label were 'exercise' 'stress management' 'energy conservation' 'limit in liking' 'selection of food' 'ingestion of natural food' 'health examination' 'relaxation' and 'nutrition'. The author suggests that this scale could be adequately applied in assessing the health behavior of Korean adults. The results of using this scale in a study can contribute to designing an appropriate health promotion strategy.

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Conflict Levels in Indian IT and Manufacturing Sectors: A Comparative Study

  • Bhat, Aruna B.;Rangnekar, Santosh;Barua, Mukesh Kumar
    • Journal of Information Technology Applications and Management
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    • v.19 no.3
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    • pp.1-18
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    • 2012
  • The present study highlights the conflict management levels in Indian manufacturing and Information Technology (IT) sectors. Nearly 110 samples from different organizations of manufacturing and IT have been collected using convenient sampling technique. Standardised scale on Organisational Conflict developed by Dhar U. and Dhar S. [2003] has been used which consists of twenty items on a four point scale. The study has shown that miscommunication at organizational level has been a reason for conflict in manufacturing organizations whereas intrinsic motivation at organizational as well as individual level has been found a reason for conflict in IT sector. The study bears implications for HR managers to develop policies and conflict management strategies so as to deal with the situations constructively at a particular level of conflict.