• 제목/요약/키워드: life-time use

검색결과 1,785건 처리시간 0.025초

절단된 자료가 있는 병렬형 시스템의 단계적 충격수명검사 (The Step Stress Life Testing for the Parallel System with Censored Data)

  • 박희창;이석훈
    • 품질경영학회지
    • /
    • 제23권1호
    • /
    • pp.15-28
    • /
    • 1995
  • We consider a step-stress life testing which is devised for a two-component parallel system with considerably long life time. To describe such a system, we use an exponential distribution as the survival function. The lift distribution is assumed between the log mean life time and the stress with the cumulative exposure model. The criterion for optimality is to minimize the sum of the variances of the maximum likelihood estimators of the mean life times of each part under the normal stress.

  • PDF

어머니의 취업에 따른 영유아기 아동의 생활시간 양태 (Young Children's Time-Use According to Employment Status of Mothers)

  • 진미정;이윤주
    • 대한가정학회지
    • /
    • 제48권6호
    • /
    • pp.43-56
    • /
    • 2010
  • This study explored time-use patterns of young children and compared the patterns according to mother's employment status. Using 6718 time diaries of 3359 children under age 5, as reported by their mothers, this study examined (1) the proportion of children who spent time on certain activities and the amount of time they spent on each activity for a weekday and a weekend day and (2) the proportion and the amount of time that children spent with certain adults. Compared to children with unemployed mothers, children with employed mothers spent more time during weekdays in child care centers and less time sleeping. These children also spent more time on education during weekends. The proportionate and actual times children spent with various adults also differed by the mother's employment status. Those with employed mothers spent less time with their mothers and more time with other relatives or teachers on weekdays. These results indicate that maternal employment corresponds with differing timeuse patterns from children's early life stages.

보건계열학과 대학생의 인터넷 중독 영향요인에 관한 연구 (Study on Factors affecting to Internet Addiction of Students in Department of Public Health)

  • 권수진;김혜숙;박재성
    • 보건의료산업학회지
    • /
    • 제1권1호
    • /
    • pp.45-58
    • /
    • 2007
  • The study is designed to compare differences between male and female Internet users in present Internet use conditions, Internet addition, self-respect, and deviation from a health life and analyze and understand factors causing compulsive Internet use. The research is aimed at suggesting basic information to guide a desirable direction for healthy and effective Internet use. The survey of 456 students majoring in public health at some universities in the Pusan-Kyungnam areas was made in November, 2006. The results are as follows: As for general information on those surveyed the number of the males was 50(11.0%) and that of the females was 406(89.0%), which shows an absolute higher ratio of the female respondents. On a question of Internet use frequency 62% of the male students and 44.6% of the female students answered they use the Internet everyday. Also the male respondents' Internet use time was longer. 64.0% of the male students use the Internet for games and entertainment, which were the highest ranked reason. 64.4% of the female students said they use the Internet to check e-mails. To all the questions assessing Internet addiction, the male users' answers implied higher addiction levels, but there wasn't statistically significant difference. However, the statistically outstanding distinction between the two sexes on deviation from a health life is shown in smoking, cheating in a test, obscene video/books, and conflicts with parents. The most answered deviations among the male respondents are smoking, cheating in a test, and obscene video/books, while conflicting with parents is for the female students. On self-respect the survey has found statistical differences in five questionnaire items and the female showed higher levels in all those questions. The male students answered cheating in a test(0.399), conflicts with parents(0.391), and Internet use time(0.242) have significant plus(+) influences on their compulsive internet use, while alcohol(-0.308) has a minus(-) influence. The female students answered self-respect(0.114), alcohol(0.097), obscene video/book (0.218), conflicts with parents (0.243), and Internet use time (0.284) factors have plus(+) effects.

  • PDF

The Effect of Computer and Internet Use on the Happiness, Hopes and Optimisim in Past and Future Encounters of Various Age Groups : The Turkish Experience

  • Gurol, Mehmet Ali
    • Journal of Information Technology Applications and Management
    • /
    • 제18권3호
    • /
    • pp.31-39
    • /
    • 2011
  • The weakening of the traditional cultures is becoming more evident from the final quarter of the last century, a period of time where the world starts to look like a "small village" in all means. A substantial cause of cultural deterioration shows to be the growing use of information and communication technologies widening the views, mentalities, and perspectives of people. Today the adolescent groups frequently owning, utilizing and consequently being charmed by the electronic equipment such like computers, internet and cellular phones have developed a unique tradition/practice in sensing and meaning life triggering larger generation gap and fading of established cultures. The main focusing of the paper is on the correlation between computer and internet use and life satisfaction, level of hope, personal development assessments and expectations of the adolescent groups in Turkey. Interpretation of the survey findings indicates that this group grading highest in use of that shows to be the happiest, most hopeful and optimistic ones among other groups. Methodologically, the study is based on data analysis and a review of recent key literature. For more dependable results a further study comparing similar tendencies of the similar groups of other nationalities is recommended.

Pattern and process in MAEUL, a traditional Korean rural landscape

  • Kim, Jae-Eun;Hong, Sun-Kee
    • Journal of Ecology and Environment
    • /
    • 제34권2호
    • /
    • pp.237-249
    • /
    • 2011
  • Land-use changes due to the socio-economic environment influence landscape patterns and processes, which affect habitats and biodiversity. This study considers the effects of such land-use changes, particularly on the traditional rural "Maeul" forested landscape, by analyzing landscape structure and vegetation changes. Three study areas were examined that have seen their populations decrease and age over the last few decades. Five types of plant life-forms (Raunkier life-forms) were distinguished to investigate ecosystem function. Principle component analysis was used to understand vegetation dynamics and community characteristics based on a vegetation similarity index. Ordination analysis transformed species-coverage data was introduced to clarify vegetation dynamics. Landscape indices, such as area metrics, edge metrics, and shape metrics, showed that spatial heterogeneity has increased over time in all areas. Pinus densiflora was the main land-use plant type in all study areas but decreased over time, whereas Quercus spp. increased. Over a decade, P. densiflora communities shifted to deciduous oak and plantation. These findings indicate that the impact of human activities on the Maeul landscape is twofold. While forestry activities caused heavy disturbances, the abandonment of traditional human activities has led to natural succession. Furthermore, it can be concluded that the type and intensity of these human impacts on landscape heterogeneity relate differently to vegetation succession. This reflects the cause and consequence of patch dynamics. We discuss an approach for sustainable landscape planning and management of the Maeul landscape based on traditional management.

시간의존성 균열 패턴을 고려한 탄산화에 노출된 콘크리트의 확률론적 내구수명 평가 (Service Life Evaluation of RC Column Exposed to Carbonation Considering Time-dependent Crack Pattern)

  • 권성준
    • 한국건설순환자원학회논문집
    • /
    • 제4권1호
    • /
    • pp.10-18
    • /
    • 2016
  • 대도시의 콘크리트 구조물은 탄산화에 노출되며 사용기간의 증가로 인해 내구성 저하를 나타내며 콘크리트에 발생하는 균열은 국부적인 탄산화 증가를 야기한다. 본 연구에서는 실태조사를 통하여 균열부의 탄산화속도를 분석하였으며, 이를 시간의존성균열과 초기재령균열로 구분하여 탄산화에 노출된 RC교각의 내구수명을 분석하였다. 실태조사 결과를 기본으로 균열이 최대 0.3mm까지 진전하고 여기에 최대 균열폭에 이르는 시간을 변수로 하여 내구성 파괴확률, 신뢰성 지수, 내구수명 등이 평가되었다. 시간의존성균열 패턴은 초기재령부터 발생한 균열보다 낮은 내구성파괴확률과 높은 내구수명을 나타내었는데, 이는 지나치게 보수적인 해석기법보다 합리적이다. 또한 피복두께가 100mm보다 클 경우, 균열에 대한 시간효과는 내구성 파괴확률 및 내구수명에 큰 영향을 미치지 못하였다. 고정 균열이 아닌 시간의존적균열을 고려한 확률론적 내구수명 해석기법은 운용 중 발생하여 균열이 발생한 구조물에 효과적으로 사용될 것이다.

Predicting Shelf-life of Ice Cream by Accelerated Conditions

  • Park, Jung-Min;Koh, Jong-Ho;Kim, Jin-Man
    • 한국축산식품학회지
    • /
    • 제38권6호
    • /
    • pp.1216-1225
    • /
    • 2018
  • Shelf-life is defined as the amount of time during which a food product retains its desired sensory, chemical, and physical characteristics while remaining safe for consumption. The food industry needs to rapidly obtain the necessary information for determining the shelf life of its products. Here we studied the approaches available for conducting accelerated shelf-life tests. Accelerated shelf-life testing is applied to a variety of products to rapidly estimate change in characteristics with time. The aim of this work was to use accelerated shelf-life testing to study the changes in pH, microbiology, and sensory characteristics of ice cream by the application of a kinetic approach and, based on the observations, to estimate its shelf life. As per the current law, there is no shelf life on ice cream. Our results suggest that the shelf life of an ice cream sample was 24.27 months at $-18^{\circ}C$, 2.29 months at $-6^{\circ}C$, 0.39 months at $-1^{\circ}C$, and 0.15 months at $4^{\circ}C$. Results of this study suggest that a set expiration date on ice cream might also contribute to effective management of ice cream characteristics in the retail chilled chain.

서울시 아파트 거주 중년기 가정의 생활 실태와 문제(IV): 가족관계를 중심으로 (Family Life of Middle-Aged Apartment-Residents in Seoul: Focused on Family Relations)

  • 이연숙
    • 대한가정학회지
    • /
    • 제33권6호
    • /
    • pp.164-177
    • /
    • 1995
  • The purpose of this research was to analyze the family relationships of the middle aged women residing in an apartment house in Seoul as a part of a collaborative study on their family life issues. the sampling area was divided into Kangnam and Kangbuk according to the residential location and upper middle group and lower middle group according to the size of the apartment unit. The data were collected from 307 fulltime housewives with at least one child in a junior or senior high school. the self-identity scores of middle-aged wives were found generally somewhat higher and were explained by satisfaction with time use and leisure activities, husband's help with raising children, and feeling after quarrel with husband. most wives felt very comfortable and intimate about their husbands. the relationship between wife and husband was influenced by feeling after quarrel with husband, husband's help with raising children, and satisfaction with leisure activities. Most wives reported stresses in raising children. Help from husband, satisfaction with time use, and financial debt were influencing the level of stress perceived by the wives in raising children.

  • PDF

영적간호중재가 말기암환자의 삶의 의미와 영적고통에 미치는 효과

  • 윤매옥
    • 호스피스학술지
    • /
    • 제5권2호
    • /
    • pp.64-74
    • /
    • 2005
  • Purpose : This study is non-equivalent control group pre-post design attempted to see 'The effect of spiritual nursing intervention on the meaning of life and spiritual distress of the terminal cancer patients.' Method : The data collection was performed from June to October, 2004. The subjects were 41 terminal cancer patients of one general hospital in Jeon Ju city. They are formed two groups, 20 experimental group and 21 control group. Experimental treatment provided spiritual nursing intervention 3 times per a week, the mean 45 minutes each, for 4 weeks for experimental group with the contents of therapeutical use of oneself, use of bible, use of hymn, use of prayer, depend on the priest in the spiritual need assessment of 6 kinds. Study tools was used the thing which Kim(1990) developed about purpose inspection of life which Crumbaugh(1968) developed to measure the meaning of life. The measure of spiritual distress was used the tool which Kim(1990) developed, spiritual nursing intervention was developed by researcher of this thesis. Data was analyzed by descriptive statistics of real number, percentage, the mean etc. and x2-test, t-test, ANCOVA. Result: The 1st hypothesis, 'spiritual the meaning of life score in the experimental group, who received the spiritual nursing intervention, will be higher than the control group who did not receive it' was supported(F=157.09, P=0.000) The 2nd hypothesis, 'spiritual distress score in the experimental group, who received the spiritual nursing intervention, will be lower than the control group who did not receive it' was supported(F=36.48, P=0.000) Conclusion: Spiritual nursing intervention was verified as an effective program to improve the meaning of life and decrease spiritual distress for the terminal cancer patients. Thus, it was confirmed with an effective nursing intervention which helps them in order to spend the rest time of life meaningfully and meet the peaceful death.

  • PDF

국민연금 수급액 차이에 따른 삶의 만족도와 성공적 노후의 차이 분석 (Difference Analysis of Life Satisfaction and Successful Aging on Difference in National Pension Receipt)

  • 유지연
    • 한국콘텐츠학회논문지
    • /
    • 제16권4호
    • /
    • pp.170-178
    • /
    • 2016
  • 본 연구는 60세 이상을 대상으로 하여 국민연금 수급액 차이에 따라 삶의 만족도와 성공적 노후가 어느 정도 차이가 있는지 분석하고, 그 후 삶의 만족도와 성공적 노후에 영향을 미치는 요인을 분석하였다. 그 결과 수급액의 차이에 따라 삶의 만족도와 성공적 노후에 차이가 나는 것으로 나타나 수급액이 많을수록 삶의 만족도가 향상되고, 성공적 노후를 보내고 있다는 인식이 높은 것으로 나타났다. 영향을 미치는지 알아보기 위해 회귀분석을 한 결과, 수급액의 차이는 삶의 만족도에선 유의미하였으나, 성공적 노후에는 유의미하지 않은 것으로 나타났다. 이로 볼 때, 국민연금 수급이 경제적 안정감을 주어 삶의 만족도를 증가시키는 기반이 될 수는 있으나 성공적 노후로 이어지려면 여가선용과 같은 사회적 지지도 필요하다는 것을 파악할 수 있었다. 또한 현재 국민연금의 수급액의 만족도는 낮은 편이며, 수급액만으론 생활이 불안정하고 느끼고 있기 때문에 차후에 수급액의 만족도를 높이며, 여가선용 확대를 통해 안정적인 생활을 영위할 수 있는 정책적 방안이 필요하다.