• Journal of applied mathematics & informatics
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• 제28권3_4호
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• pp.723-737
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• 2010

In this paper, we investigate the sampling theorem for frame in multiwavelet subspaces. By the frame satisfying some special conditions, we obtain its dual frame with explicit expression. Then, we give an equivalent condition for the sampling theorem to hold in multiwavelet subspaces. Finally, a sufficient condition under which the sampling theorem holds is established. Some typical examples illustrate our results.

• 수산해양기술연구
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• 제28권3호
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• pp.274-285
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• 1992

Among various Power converters, a variable voltage variable frequency (VVVF) three-phase PWM inverter is regarded as most promising power converter due to its capabilities, which permits the control of voltage, frequency and harmonic contents in a single power stage employing only on DC source. As a modulating technique of the PWM inverter, the regular sampling technique has rendered possible the on-line computation and generation of PWM control waveforms with a reasonably high switching frequencies. In this paper, microprocessor based three-phase regular samping PWM inverter with real-time control algorithm and control circuits for driving three phase AC motor has been developed. Harmocic components of PWM waveform were analized theoretically in terms of Bessel function series and then calculated by digital computer and observed with spectrum analyzer.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.86-89
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• 2003

To model a numerical problem space under the limitation of available data, we need to extract sparse but key points from the space and to efficiently approximate the space with them. This study proposes a sampling method based on the search process of genetic algorithm and a space modeling method based on least-squares approximation using the summation of Gaussian functions. We conducted simulations to evaluate them for several kinds of problem spaces: DeJong's, Schaffer's, and our original one. We then compared the performance between our sampling method and sampling at regular intervals and that between our modeling method and modeling using a polynomial. The results showed that the error between a problem space and its model was the smallest for the combination of our sampling and modeling methods for many problem spaces when the number of samples was considerably small.

• 한국수산과학회지
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• 제50권5호
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• pp.594-604
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• 2017

The Korean National Institute of Fisheries Science (NIFS) has biannually (spring and fall, respectively) deployed a bottom trawl survey along the coastal areas for last decade, taking samples on a regular basis (i.e., a systematic sampling). Despite the availability of the survey data, NIFS has not yet officially reported the estimates of the groundfish population sizes as well as has not evaluated uncertainty of the estimates. The objectives of our study were to infer the relative size of a fish population, applying two different sampling techniques (namely simple and stratified sampling) with different observation units to the NIFS survey data, and to compare those two techniques in bias and precision. For demonstration purposes, we used data on Pacific cod (Gadus macrocephalus) collected by the 2011-2015 surveys, and the results of simple and stratified sampling showed that the point estimates and precision varied by observation unit as well as the sampling technique.

• Journal of the Korean Statistical Society
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• 제8권2호
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• pp.165-168
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• 1979

For crops that are planted in a lattice layout, sampling designs can be made to take advantage of this regular arrangement. In order to select which tobacco plants to be examined in a survey to estimate disease loss in tobacco a method of, so called, bent plots was devised based on the regularity of plantings in the tobacco fields. We will first describe this sample selection and measurement method and then provide estimators and their bias and variance properties.

• 산업경영시스템학회지
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• 제14권24호
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• pp.187-192
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• 1991

We consider a filling process problem on a production line. Up to present this problem have examined by 100% inspection. Thus a target value is determined which takes into account the regular selling prices, the reprocess cost, the excess quality cost and the process variability and so on. However, in this paper we propose a solution under specified sampling plan when the inspection is nondestructive.

• 한국보건간호학회지
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• 제33권2호
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• pp.270-283
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• 2019

Purpose: The aim of this study was to identify the job insecurity, job satisfaction, and organizational commitment of non-regular visiting nurses working at public health centers, and evaluate the effects of job insecurity on the job satisfaction and organizational commitment. Methods: This study was a descriptive survey study. One hundred forty-three visiting nurses, who were non-regular hired by 16 public health centers in B city, were selected using a convenient sampling method. Results: The results were analyzed using SPSS/Win 21.0. A feeling of helplessness (among job insecurity factors) and retention intention significantly affected the job satisfaction of non-regular visiting nurses, and their explanation power was 20%. Retention intention, a feeling of helplessness, and age significantly influenced the organizational commitment, and their explanation power was 26%. Conclusion: Therefore, it would be necessary to stabilize the employment type, provide appropriate promotion and compensation for nurses according to their work performance, and reduce the number of non-regular employees to increase the job satisfaction and organizational commitment of non-regular visiting nurses.

• 대한인간공학회지
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• 제27권3호
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• pp.53-60
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• 2008

The work-related musculoskeletal disorders have constantly increased since it became an issue in 1996. In 2002, the Government established the risk factors analysis system in order to prevent musculoskeletal disorders. The proclamation by the Ministry of Labor defined eleven spheres of work associated with musculoskeletal disorders. As a result, business proprietors, who have workers engaged in tasks associated with musculoskeletal disorders, are required to conduct the risk factor analysis on a regular basis every three years. However, numerous issues have been raised while carrying out the risk factor analysis in various industries. One of the issues is that even though work sampling is an ideal method in risk factor analysis, most cases have selected extreme task postures, which is judged by an expert, due to limited time. This study will propose the desired direction of the risk factor analysis by comparing task assessment results between work sampling scenes and extreme task scenes.

• 대한지역사회영양학회지
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• 제24권5호
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• pp.408-421
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• 2019

Objectives: This study compared the dietary behaviors of single-person households when eating alone according to the employment pattern and age. Methods: A total of 566 people aged 20~59 years old were collected from the status of workers and classified into three groups according to their employment pattern (regular, non-regular workers and business owner). The subjects were collected by purposive quota sampling on a Gallup panel from June to November in 2017. The dietary behavior and perception of eating alone of the subjects were surveyed via online and self-reported questionnaires. Results: The frequency of eating alone was significantly higher in the regular group than the non-regular group and business group (p<0.01). The place of eating alone was significantly higher in the regular and non-regular group in the convenience store, and business group in the office (p<0.001). Ramen, the menu when eating alone, was significantly higher in the non-regular group than the other groups (p<0.01). The preference for eating alone was lower in the older age group (p<0.05). The young aged group (aged 20~30) ate more fast food and felt more convenience than the older aged group aged 40~50 years (p<0.05). Conclusions: Single-person households with a non-regular job have poorer dietary behavior in eating alone than those who had regular employment. In a situation of an increasing number of non-regular workers aged in their 20s and 30s, there is a high likelihood of social problems, such as health and poverty. This study highlights the need for a healthy food selection environment to improve the dietary life of single-person households with non-regular jobs for the diverse types of single-person households.

• 한국노년학
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• 제28권4호
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• pp.953-968
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• 2008

본 연구는 노인들을 대상으로 노후불안 수준이 어떠한지 알아보며, 규칙적인 체육활동을 실시하기 전과 후의 노후불안 수준을 파악할 것이며, 구체적으로 노후불안 수준이 체육활동을 통해 얼마큼 감소되는지 밝혀내는데 본 연구의 목적이 있다. 본 연구의 대상은 서울, 경기 지역에 위치한 L노인대학, S노인대학, J노인대학, Y(a)노인대학, Y(b) 노인대학, D노인대학에 체육활동 강좌(건강체조, 게이트볼, 스포츠댄스) 수강생을 모집단으로 선정하였으며, 비확률표집방법(nonprobability)의 편의표본추출법(convenience sampling)을 이용하여 총 200명을 연구대상자로 선정하였다. 조사대상자의 연령을 고려하여, 직접 기입방법과 일대일 면접법을 병행하여 총 200부의 자료를 수집하였다. 자료처리는 SPSS 12.0 Version통계 패키지를 이용하였으며, 모든 통계치의 유의 수준은 .05로 정하였다. 분석방법은 빈도분석(Frequency Analysis), 대응표본 t-test (Paired t-test), 독립표본 t-test(Independent t-test)를 실시하였다. 노인들이 규칙적인 체육활동을 실시하기 전과 후의 노후불안 인식수준의 차이를 분석한 결과, 노후불안은 4가지 요인으로 구분된다. 첫째, 체육활동 실시 전 상실에 대한 두려움은 (M=3.756), 실시 후에는 (M=1.942)으로 나타났다. 둘째, 노인에 대한 두려움은 체육활동 실시 전 (M=3.443), 실시 후 (M=2.243)으로 나타났다. 셋째, 신체적 외모에 대한 걱정에서는 체육활동 실시 전 (M=3.253), 실시 후 (M=2.310)으로 나타났다. 마지막 요인인 심리적 불안정 요인에서는 체육활동 실시 전 (M=3.060), 실시 후 (M=1.666)으로 나타났으며, 모든 요인이 유의수준 .001에서 통계적으로 유의한 차이가 나타났으며, 전체적인 요인 모두 사전테스트 전 보다 노후불안점수가 낮게 나타나 체육활동이 노인의 불안수준을 낮추는 것으로 나타났다.