• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.731-740
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• 1999

Autocorrelation function is widely used as a tool measuring linear dependence of hydrologic time series. However, it may not be appropriate for choosing decorrelation time or delay time ${\tau}_d$ which is essential in nonlinear dynamics domain and the mutual information have recommended for measuring nonlinear dependence of time series. Furthermore, some researchers have suggested that one should not choose a fixed delay time ${\tau}_d$ but, rather, one should choose an appropriate value for the delay time window ${\tau}_d={\tau}(m-1)$, which is the total time spanned by the components of each embedded point for the analysis of chaotic dynamics. Unfortunately, the delay time window cannot be estimated using the autocorrelation function or the mutual information. Basically, the delay time window is the optimal time for independence of time series and the delay time is the first locally optimal time. In this study, we estimate general dependence of hydrologic time series using the C-C method which can estimate both the delay time and the delay time window and the results may give us whether hydrologic time series depends on its linear or nonlinear characteristics which are very important for modeling and forecasting of underlying system.

• The Journal of the Acoustical Society of Korea
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• v.19 no.1
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• pp.48-53
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• 2000

To analyze a room reverberation, many objective parameters have been suggested as measures of subjective perception in concert hall acoustics. However, it is difficult to understand the relationship among the individual parameters and to have a whole image of them. In this paper five primary objective parameters were selected and a reverberation model based on them was established by the reverberation decay curve. The proposed model was interpreted geometrically in terms of subjective characteristics. And finally we discuss the usefulness and the limitation of the model when it is applied to the analysis and.

• Journal of the korean Society of Automotive Engineers
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• v.9 no.5
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• pp.19-24
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• 1987

본 문에서는 선회의 정도를 나타내는 선회도가 크고 작은 대표적인 두가지 경우에 대하여 시간평균 구조와 난류혼합 특성을 나타내는 시간변동치의 상관관계를 실험적으로 구한 예를 제시함으로써 선회운동에 의한 난류혼합특성을 설명하고자 한다.

• Cross-Cultural Studies
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• v.46
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• pp.465-495
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• 2017

The purpose of this study is to verify whether the concept of time conveys meanings similar to nonverbal communicative elements in foreign language education. This study surveys cultural traits of time from the French cultural education perspective. Anthropologist Edward T. Hall points out that each cultural community has developed a different perception of time and experience, and that time conveys the meaningful message nonverbally similar to the nonverbal elements such as space, gesture, eye movement, and facial expression. I investigated the time experiences of a drinking party in France and in Korea, from a cultural relativistic point of view. The subject of a drinking party was chosen on the ground that a drinking party is highly related to most people's daily lives and it also indicates how they have a relationship with others. I sought a new direction in foreign language cultural education by analyzing how cultural differences between the two communities, especially the relationships between individuals and organisations, ways to separate leisure and labor, and the nonverbal elements, are presented in the two drinking parties.

• Spatial Information Research
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• v.16 no.2
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• pp.219-236
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• 2008

Data stream collected from sensors contain a large amount of useful information including causality relationships. The causality join query for data stream is to retrieve a set of pairs (cause, effect) from streams of data. A part of causality pairs may however be lost from the query result, due to the delay from sensors to a data stream management system, and the limited size of sliding windows. In this paper, we first investigate spatial, temporal, and spatio-temporal aspects of the causality join query for data stream. Second, we propose several strategies for sliding window management based on these observations. The accuracy of the proposed strategies is studied by intensive experiments, and the result shows that we improve the accuracy of causality join query in data stream from simple FIFO strategy.

• Journal of Labour Economics
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• v.39 no.1
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• pp.57-79
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• 2016

This study analyses determinant factors of time allocation within married couple using 2014 Time-use survey. Findings show that husbands spend less time on child care and housework than wives do. When wives have high income and young kids, husbands' time spending on child care and housework increases. Wives' time allocation is associated with husbands' income- wives' working time is negatively associated, but wives' housework time is positively associated with husbands' income. However, both wives' and husbands' income is not related to child care time. When wives' income increases, while, husbands' time spent on housework and child care increases. There are complementary relations within time allocation, but substitute relationships between wives' and husbands' housework time. In other words, if a wife works long hours, husband spends more time on housework, but if a wife or a husband spends on housework, her husband or his wife does not spends on it. However, findings of married couple time allocation for weekend shows different patterns from weekday time use.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.05a
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• pp.106-117
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• 1999

본 논문에서는 쉽고 융통성 있는 저작 시스템 개발을 목표로 다음과 같은 특징을 갖는 시스템을 설계하고 구현하였다. 첫째, 사용자가 멀티미디어 문서를 쉽게 저작하고 프리젠테이션 할 수 있는 시각 환경을 제공한다. 둘째, 실행중에 발생되는 미디어 실행시간 변경을 효과적으로 처리할 수 있는 인과성 시간 관계를 정의한다. 셋째, 저작 내용을 트리 형태의 내부 구조로 저장함으로써 효과적인 문서 파싱을 수행한다. 네째, 실행 시간의 효과적인 프리젠테이션과 사용자 상호 작용을 지원하기 위한 프리젠테이션 엔진을 개발한다. 본 시스템은 미디어간의 시간 관계를 인과성 관계에 기초하고 참조점 방식을 추가하여 정의함으로서, 수행시간이 변경되거나 사용자 상호 작용이 발생하더라도 융통성있는 프리젠테이션을 지원한다.

• 한국노년학
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• v.41 no.1
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• pp.49-68
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• 2021

The present study aims to examine the mediating role of life satisfaction in the relationship between productive activities and future time perspective in later life. Drawn from the 7^th wave of the Korea Longitudinal Study of Aging, our sample consists of a total of 6,756 older adults aged 55 and over. Complex samples analyses were conducted the relationship between productive activities, life satisfaction and future time perspective measured in two dimensions (i. e., life expectancy and job expectation). Results from complex samples analysis showed that productive activities were associated with life satisfaction and future time perspective. Employed older adults including unpaid family workers tended to have higher levels of life satisfaction and future time perspective (i.e., life expectancy and job expectation) than their counterparts. The relationship between productive activities and future time perspective was mediated by life satisfaction. Findings suggest that engaging in productive activities influences better satisfaction with life among older adults, which is eventually linked to an expansive view of the future. Policy implications were discussed that promoting productive activities in later life and age-friendly working environment should be encouraged.

• Journal of Convergence for Information Technology
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• v.8 no.4
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• pp.27-35
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• 2018

This study aimed to analyze the association among dental care consumers' responses to waiting time, hospital image, and patient satisfaction and provide basic data that could help qualitative waiting conditions management related to health care service. A survey was conducted from May 18 to June 20, 2016 in adults who had spent waiting time at dental hospitals or clinics, and the following conclusion was drawn: Hospital image was associated with the changes in reliance on dental care centers in case of long wait, the changes in reuse intentions, and the reservation system, and patient satisfaction was associated with gender, explanation of expected waiting time, the changes in reliance on dental care centers in case of long wait, the changes in reuse intentions, and the reservation system. The positive responses to waiting time was positively correlated with hospital image and patient satisfaction; the negative reaction to waiting time was negatively correlated with hospital image and patient satisfaction; and hospital image was positively correlated with patient satisfaction.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.146-150
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• 2010

무선센서네트워크 기술은 유비쿼터스 컴퓨팅에서 정보전달을 위한 중요한 매개체가 되는 등 그 중요성이 점점 더 커지고 있다. 그런 무선센서네트워크에 이미지처리능력을 추가하면 사용자가 이용할 수 있는 좀 더 다양한 서비스를 제공할 수 있다. 그 중 재산 보호를 위한 감시시스템의 관심이 커지고 있고 이에 관련된 몇몇 연구들이 진행되어오고 있다. 몇몇 연구에서 카메라 네트워크 망에서 발견된 객체를 연속적으로 추적을 하지만 카메라와 서버간 직접적인 통신을 통해 다량의 정보를 주고 받기에 Ad-hoc 무선망을 사용하는 방식에서는 적합하지 않다. 또 다른 방면으로는 타겟 추적에 time critical한 방법들을 쓰고 있기에 시간 동기화를 위한 추가적인 프로토콜의 사용이 필요해진다. 본 연구에서는 다중 카메라에서 관계자와 비관계자를 명확히 구분해서 관계자를 제대로 추적함으로써 비관계자 인원이 감시구역에 접근하는 행동을 방지하고 노드간의 시간 동기화 의존도를 줄이기 위한 방법을 제시한다.