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Designs and Comparison of Step and Constant-Stress ALTs for Acceleration Factor and Lognormal Lifetime Distributions

  • Sang Wook Chung;Seong-Woog Lee
    • Journal of Korean Society for Quality Management
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    • v.25 no.1
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    • pp.80-99
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    • 1997
  • This paper considers designing the simple (2-level) constant-and step-stress ALTs minimizing the asymptotic variance of the maximum likelihood estimator of the accelaeration factor, which is defined as the ratio of the 100qth percentile at use stress to that a specified stress, for items having lognormally-distributed lives. It is assumed that (i) the log-linear relationship exists between the stress and the mean log life, (ii) the standard deviation of the log life is constant, and (iii) the cumulative exposure model holds for the effect of changing stress. For the constant-stress ALT the low stress and the sample proportion allocated to low stress are determined and for two modes of stress loading of step-stress ALTs, the low-to-high and high-to-low, the low stress and the stress change time are determined. For selected values of the design parameters the optimum plans are figured, two modes of step-stress ALTs and the constant-stress ALT are compared to each other, and the effects of the incorrect pre-estimates of the design parameters are investigated.

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Computation of Extreme Food Consumption by Korean Adults in 1990s (한국성인을 위한 식품 극단소비량(1990년대)의 산정)

  • 이미경;이서래
    • Journal of Food Hygiene and Safety
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    • v.15 no.2
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    • pp.79-87
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    • 2000
  • In order to obtain the data for extreme food intake by Koream adults, the data of adult dietary survey undertaken in 1995 were used through statistical treatment, taking into account of dietary habits. Various food commodities amounting to 159 items were classified into 14 food groups and fractiles of 90th and 95th percentile of individual food items were computed on the assumption that the food consumption pattern exhibits a normal distribution. Most of the food items showed the ratio of fractiles to mean intake in the range of 2.0∼3.0 while the ratio greatly deviated from these values in items such as seasonings, spices, nuts, seeds and favorite beverages as well as most commonly-eaten or rarely-eaten foods.

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A Study on Nursing students' Learned helplessness and Helplessness behavior (간호대학생의 학습된 무기력과 무기력 행동)

  • Yoon, Heun-Keung
    • Journal of Korean Public Health Nursing
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    • v.29 no.2
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    • pp.244-256
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    • 2015
  • Purpose: The current study is a descriptive survey study conducted in order to investigate degree and properties of learned helplessness and lethargic behaviors in students of the college of nursing. Methods: A total of 332 nursing students were enrolled and responded for data collection from October $1^{st}$ through October $20^{th}$, 2013. Frequency, percentile, means and standard deviations of collected data were analyzed using t-test, one-way ANOVA, and Pearson correlation coefficient. Results: The mean score of learned helplessness in nursing students was 2.46, which was statistically significant in relation to friendship (F=13.45, p<.001) and academic achievement (F=3.67, p<.013). On the other hand, the average score of lethargic behaviors was 2.52 and it showed significant association with grade (F=6.49, p<.001), current residence (F=3.26, p<.022), friendship (F=4.81, p<.009), and academic achievement (F=5.34, p<.001), indicating a positive association between these variables. Conclusion: Based on the study results herein, effective counseling, as well as continuous attention to students by school, and professors are needed in order to alleviate sense of learned helplessness, which is a psychological variables often shown in nursing patients. Further, additional studies with regards to various variables impacting the nursing student might be warranted.

Establishing a Standard Definition for East Asian Adolescent's Obesity (동아시아 청소년의 비만 기준 설정)

  • Kim, Ha-Rim;Kim, Soo-Nam;Kim, Hong-Baek;Kim, She-Whan
    • Korean Journal of Health Education and Promotion
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    • v.27 no.1
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    • pp.105-113
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    • 2010
  • Objcetive: The purpose of this study was to establish body mass index percentiles and cutoffs for overweight and obesity in East Asian Adolescent. Methods: Based on one's age and gender, subjects were selected and measured their weight and height in order to calculate BMI. For BMI cut off points, data were analyzed and percentile curves were established by the modified LMS method. Results were followed by comparing BMI cut off points and percentiles with one's nationality, age and gender. Results: The prevalence of male's overweight and obesity among East Asian adolescent were as follows: Taiwan (15.4%, 9.0%), Korean (14.5%, 8.5%), Chinese (13.3%, 6.6%), and Japanese (6.0%, 2.1%). And for female, Korean (13.1%, 3.7%), Taiwan (12.6%, 5.1%), Chinese (8.3%, 2.3%) and Japanese (7.9%, 3.1%) were in the order. Conclusion: Corresponded to the whole subjects, 11.0% of men were overweight, 4.7 were obesity and that appeared in women with 9.0% in overweight, 3.5% were obese.

A Study on the Problems in the Consumption Life of Household Over Family Life Cycle (가족생활주기에 따른 가계의 소비생활문제에 관한 연구)

  • 홍향숙;이기춘
    • Journal of Families and Better Life
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    • v.7 no.1
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    • pp.1-14
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    • 1989
  • The purpose of this study was to identify the problems in the consumption life of household over the family life cycle so that they would support to select the consumer education subjects and the establish the long-term household plan. For these purposes, a survey was conducted using questionnaire. The data used in this study included 562 homemakers living in Seoul. Statistics used for data analysis were frequency distribution, Mean, Percentile, One-way Anova, Scheffie-test, Multiple Classification Analysis. Major findings were as follows; 1) In the level of the problems in the consumption life of household, housing problem, durable goods problem, healthy-medical problem and child education problem area were in the low level. Leisure problem and properties management problem area were in the high level. 2) The problems in the consumption life of household differed significantly over the family life cycle. 3) When controlling family monthly income and education level of husband was compared with not-controlling them, the influences of family life cycle on the problems in the consumption life were as follows. (1)At housing problem area, the effect of the FLC was higher in controlling them than not-controlling them. (2) At other problems the effects of the FLC was lower or same in controlling them than not-controlling them.

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A Comparative Study on Value Orientation about Family Life between the Older Generations and College Students. (기성세대와 대학생의 가족생활에 대한 가치의식 비교연구)

  • 김일명
    • Journal of Families and Better Life
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    • v.7 no.1
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    • pp.59-78
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    • 1989
  • The purpose of this study is to clarify the value orientation about family life between the older generations and college student. For this purpose, questionnaire were distributed to the older generations and college students in Seoul. Among them 920 data were obtained To obtain the family value scale, item analysis through pearson's correlation and factor analysis were used in pretest, frequency distribution, percentile, mean , t-test , and step-wise multiple were used for data analysis. The results are summarized as follows. 1) Male college students show traditional tendency and female college students show modern tendency especially sex-role attitude, ancestor worship attitude, patriarchy attitude. 2) Male and female of the older generations how traditional tendency. 3) The older generations show traditional tendency, college students show modern tendency, especially sex-role attitude and kinship attitude. 4) Male adults and male college students show traditional tendency. 5) Female adults show traditional tendency , female college students show modern tendency. In female, generation gap is more serious than males. 6) the most influencial socio-demographic variables on family value consciousness of the older generations are the religion and education, In case of college students, sex, major, religion, family income grown-up area effect on their value consciousness about family life, Based on the above findings , we should develop school education and many social programs to reduce the generation gap.

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A Study on Rent burden and Family Economic Problem Perception - Focus on Seoul City's Rental Households - (서울시 임차가계의 임대료부담과 가계경제문제지각)

  • Lee, Kee-Choon;Bae, Soon-Young
    • Journal of Families and Better Life
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    • v.9 no.1 s.17
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    • pp.241-257
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    • 1991
  • The objectives of this study are : to measure the level of rent burden. to examine the independent influences of the variables related to rent burden. to measure the level of family economic problem perception. to examine the differences in the level of family economic problem perception due to rent burden, household characteristics, housing characteristics and rent incresing. For these purpose, a survey is conducted using questionaires. The data used in this study included 369 renters living in Seoul. Statistics uses for data analysis were Frequency Distribution. Percentile, men, Pearson's Correlation, Partial Correlation, One-way ANOVA, Breakdown and Multiple Regression Analysis. Major findings are as follows : The average score of rent burden was 35.87, Therefore rent burden of large cities, rental households is very heavy. Family income, housing facility quality, rent type, and rent incresing have independent influences on rent burden. The average of family economic problem perception is above the mid-point of the scale. The level of family economic problem perception differs due to rent burden, family income, family life cycle, family size, occupation of household head, education leval of household head and homemaker, rent type, housing type, housing size, housing facility quality and rent increases. If the level of rent burden is below 25, family economic problem perception is adequate.

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A Study on the Consumer Consciousness and Behavior on environmental problems -A survey of college Women Students in Kwangyu- (환경문제에 대한 소비자의 의식과 행동에 관한 연구-광주시여대생을 중심으로-)

  • 노채영;신효식;조혜정
    • Journal of Families and Better Life
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    • v.9 no.2
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    • pp.49-62
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    • 1991
  • The purpose of this study is to measure the overall level of consumer consciousness and behavior environmental problems of college women students and to analyze influencial factors. Five hundred and sixteen college women students were selected randomly, in Kwangju area. The methods of data analysis were Frequency Distribution, Mean , Percentile, one-Way ANOVA , Scheffe-test . Pearson's Correlation, and Stepwise Multiple Regression Analysis. Major finding are as follows; 1) The consumer consciousness and behavior an environmental problems of college women student showed significant differences according to the grade, age, major, socio-economic status, consumer education experience environmental problems, and frequencies of contacting mass media. 2) The consumer behavior on environmental problems of college women students had a positive relationship with consumer consciousness on environmental problems. Based on the above findings , this study suggests the followings; first the consumer education as a formal program is needed for the improvement of the consumer consciousness and behavior of college women student. Second. The content of the consumer education must emphasize more clearly the consumer rights in order to improve consumer's consciousness and behavior of environmental problems. Third. mass media of TV, radio, newspaper, magazine must be more active publicity and instruction in order to improve consumer's consciousness and behavior on environmental problems.

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A Study On Housewives' Purchasing Behavior by Brand Image and Brand Preference (도시주부의 상표이미지 및 상표선호도에 따른 구매행동에 관한 연구)

  • Kang, Ki-Jeoung;Kye, Sun-Ja
    • Journal of Families and Better Life
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    • v.9 no.1 s.17
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    • pp.145-160
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    • 1991
  • The purpose of this study is to suggest some fundamental data for the welfare of consumers by investigation some characteristics of the housewives and their attitudes toward a famous brand. For the purpose of this study, the samples were distributed to houswives who lived in Seoul. The 493 data obtained were analyzed by frequency distribution, percentile, $X^2$-test, t-test, F-test, Pearson's correlation, Duncan's multiple range test and Stepwise multiple regression analysis. The major finding were follows ; The major finding were follows ; 1) In general the score for the brand preference of the housewives was somewhat high. There were significant differences between the brand preference of the housewives and the socio-demographic, reference group variables. 2) There were significant differences between the brand image of housewives and the socio-demographic, reference group variables 3) In general the score for the dissatisfaction of the housewives was somewhat low. There were significant differences between the dissatisfaction the housewives and the socio-demographic variables. 4) The brand preference of the housewives had a positive relationship with the level of their dissatisfaction. 5) The most influential variables for the brand preference of the housewives was in the rank of reference group, income, education level.

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The Subjective Financial Well-Being Among Urban Households Based on a System's Approach (체계론적 관점에서 본 가정의 주관적 재정복지에 관한 연구)

  • 김연정;김순미
    • Journal of Families and Better Life
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    • v.9 no.2
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    • pp.103-117
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    • 1991
  • The purpose of this study was to investigate causal relations of resources and demands, family financial management and subjective financial wee-being among urban households by applying a system's approach. The data were collected through the questionnaire whose respondent were 455 housewives in Seoul. The data were analyzed by various statistical methods such as Frequency. Percentile, ANOVA , F-test, T-test, Pearson's correlation analysis, Multiple Regression Analysis. Path Analysis. The results of this research were as follows. 1) The level of subjective financial wee-being among urban households exceeded the middle level. It had significant differences according to resource variables such as age of housewife. education level of housewife, housewife's occupation, househead's occupation. per capita income, debt/net asset ratio, and according to demand variables such as aspiration, expectancy, perception of financial progress, relative deprivation. 2) The level of subjective financial well-being among urban households according to level of family financial management capability has significant differences. Therefore, the higher family financial management capability, the higher level of subjective financial well-being. 3) Among all variables affecting the subjective financial well-being among urban households. aspiration had the highest relative influence on the subjective financial well-being and per capita income, occupation of househead and family financial management variables were in this order. 4) Among all variables affecting the subjective financial well-being among urban households aspiration, occupation of househead, per capita income and finacial management variables had direct effect on subjective financial well-being . Besides housewife's education level, aspiration and per capita income had indirect effect on it through family financial management.

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