• 제목/요약/키워드: time trends

검색결과 2,318건 처리시간 0.03초

A Study on the Change of Non-Working Days of Incheon Metropolitan through BCP Analysis (BCP분석을 통한 인천지역 작업불능일 변화 연구)

  • Ko, Kyujin;Lee, Chansik
    • Korean Journal of Construction Engineering and Management
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    • 제16권4호
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    • pp.80-88
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    • 2015
  • In the case of those types of work that are performed outdoor construction work, many non-working days occur due to climatic elements such as low temperature, rainfall, and high wind velocity. In particular, damage incurred construction delays hardly decreases because weather forecasting has become difficult due to global warming. In the present study, time points of drastic changes in annual average temperatures, annual average maximum temperatures, and annual average minimum temperatures were identified through BCP analysis and increasing/decreasing trends of non-working days in summer and winter were compared and analyzed on the basis of the change points. According to the results of the study, annual average temperatures drastically changed in 1988 and 1998. After the two time points, non-working days in summer and winter clearly showed increasing trends and decreasing trends respectively.

A Study on the Research Trend of Surveying in Korea (국내 측량분야의 연구동향에 관한 연구)

  • Kim, Youn-Hee;Choi, Yun Soo;Kang, Moon Kwon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • 제26권5호
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    • pp.475-483
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    • 2008
  • The purpose of this study is to figure out the research trend of surveying in Korea through the analyses of research field and the published year of surveying related papers in journals and theses of master and Ph. D. The papers and theses published since 1957 were collected and analyzed to find out the major research topics and trends with time. The analyses of research trends in terms of time showed certain correlation between research areas, for example, remote sensing is highly correlated with GIS (98%), GPS correlated with GIS(95%). Through the regression analysis, it was found that the trends of the most fields were well-fitted with a third-order polynomial except the field of Geodesy. Furthermore, it was predicted that the number of studies in general surveying, photogrammetry, remote sensing and land information will be increasing while those in GPS, GIS, digital map and Geodesy will be decreasing.

Trends in Sexual Intercourse, Sex Education Experience, and Contraception among Adolescents in Korea: Based on Korea Youth Risk Behavior Web-based Survey from 2006 to 2019 (청소년 성관계, 성교육 경험 및 피임실천의 추이: 2006년에서 2019년까지 청소년 건강행태 온라인 자료)

  • Jang, Insun;Choi, Eun-Hi
    • Journal of the Korean Society of School Health
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    • 제33권2호
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    • pp.79-88
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    • 2020
  • Purpose: The purpose of this study was to identify 14 years of trends in sexual intercourse and sex education experiences among Korean adolescents from 2006 to 2019, based on online data. Methods: The study was a secondary analysis using the raw data of the 2nd (2006) through 15th (2019) Youth Risk Behavior Web-based Survey. The data of 504,105 male adolescents and 473,053 female adolescents were used for the analysis. A complex-sample cross-analysis (Rao-Scott χ2 test) was performed to identify differences in sexual intercourse, sex education experience, and contraception over time, and logistic regression was performed to identify factors affecting adolescent sexual intercourse. Results: Sexual intercourse was found to increase as the year progressed. More high school students had sexual experiences than middle school students. Students who had ever smoked or drunk were more likely to have had sexual intercourse than the ones who had not. Students living with relatives or living in boarding houses or dormitories showed a higher rate of sexual intercourse than those living with family members. Students who never received sex education also showed a high rate of sexual intercourse. Conclusion: It is significant to grasp the trends in sexual intercourse, sex education experience, and contraception among adolescents over time. Providing adolescents with healthy sex education is becoming more and more important every year and health-related education including sex education that meets the need of teenagers should be incorporated into the regular curriculum.

A Bibliometric Analysis of Research Trends on Disaster in Korea (국내 재난 관련 연구 동향에 대한 계량정보학적 분석)

  • Lee, Jae Yun;Kim, Soojung
    • Journal of the Korean Society for information Management
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    • 제33권4호
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    • pp.103-124
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    • 2016
  • This study aims to investigate the research trends of disaster in Korea through a bibliometric analysis. To do that, it analyzed 772 scholarly articles published from 2002 to 2016, retrieved from KCI (Korean Citation Index) database. For analysis, discipline profiling analysis, journal profiling analysis, and co-word analysis methods were used. The study found that the number of scholarly articles on disaster has increased, especially after Sewol ferry disaster occurred in 2004. The major discipline areas were identified as 'policy sciences/public administration' area, 'engineering' area, 'GIS/telecommunication' area, and 'medical/humanities/social sciences' area. In terms of time series, the proportion of scholarly articles published in 'policy sciences/public administration' area has decreased since 2014 and at the same time, discipline areas have been diversified including law, medical, and journalism.

A Study of the Kinds and Frequency Characteristics of Descriptors in the Articles Related to Scientific Literacy (과학적 소양 관련 논문에서 서술자의 종류와 빈도 특성 연구)

  • Lee, Myeong-Je
    • Journal of Korean Elementary Science Education
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    • 제29권4호
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    • pp.401-413
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    • 2010
  • This study analyzed the kinds and frequencies of descriptors in 154 articles in ERIC data base on the 4th day of January in 2010. The titles of the articles includes the words, 'scientific literacy'. As each descriptor is constituted of two words and over, in this study the first word in the descriptor was defined as 'restrictive word' and the rest word(s) as 'target word(s)'. The results are as follows. First, the descriptors which show high frequencies of target words are the traditionally important themes of scientific literacy education. Target words which show relatively high frequency are 'education', 'literacy', 'instruction' and 'countries'. Low frequency word is 'curriculum', which has various restrictive words and represents wide differentiation. Second, among the descriptors which show low frequencies of target words, relatively high frequency descriptors are '(and)society', 'change', 'secondary education', 'concepts', and 'biology', which have been given more attention in scientific literacy research than the rest descriptors. Third, the number of the descriptors that shows largely distributed pattern A, which happens over 15 years continuously, is over the half of all analyzed descriptors, which shows that they have been the major objectives in researches about scientific literacy. Most descriptors of pattern A shows normal distribution of frequency or the trends of increasing frequency as the time is nearer. Fourth, The descriptors are divided into four groups according to the time span. Each research trends are as follows. In later 80s, the research which emphasizes the importance of the sociality and technology in all level school science curriculum. In later 90s the research for educational change of inquiry-centered science curriculum which considers technological literacy in social contexts. In earlier 2000s the research that scientists and science teachers develop science curricula mostly related to scientific principles and thinking in chemistry and biology especially. In later 2000s case studies which relates teaching methods and science process activities to students' attitudes, scientific concepts and curricula.

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Accounting for Trends in Income Inequality Among the Elderly (노인 소득불평등 추이의 영향요인)

  • Lee, Won Jin
    • Korean Journal of Social Welfare
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    • 제64권4호
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    • pp.163-188
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    • 2012
  • This study examines recent trends in income inequality among the elderly in Korea. Aggregate income inequality trends are explained by examining evidence from inequality index decomposition by population subgroup and by income source. Data come from Korean Labor and Income Panel Study(KLIPS). The results are as follows. First, elderly income inequality increased from 1999 to 2002, and then decreased until 2008. Second, household composition changes appear to have disequalizing influence. The proportion of elderly people who are economically dependent on non-elderly family member or living with adult children has declined. Equalizing influence of private transfers also decreased between 2002 and 2008. These results indicate that the redistributive role of family has weakened over time. Third, the improvement of education level and changing occupational structure among the elderly household head contributed to increase in elderly income inequality. Fourth, earning's factor share has declined steadily, and the diminishing role of earnings provides equalizing influence on elderly income inequality from 2002 to 2008. Fifth, the impact of recent expansion of social insurance has changed over time. Inequality contribution of social insurance income increased from 1999 to 2002, and then decreased from 2002 to 2008.

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Evaluation of Delhi Population Based Cancer Registry and Trends of Tobacco Related Cancers

  • Yadav, Rajesh;Garg, Renu;Manoharan, N;Swasticharan, L;Julka, PK;Rath, GK
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권6호
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    • pp.2841-2846
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    • 2016
  • Background: Tobacco use is the single most important preventable risk factor for cancer. Surveillance of tobacco-related cancers (TRC) is critical for monitoring trends and evaluating tobacco control programmes. We analysed the trends of TRC and evaluated the population-based cancer registry (PBCR) in Delhi for simplicity, comparability, validity, timeliness and representativeness. Materials and Methods: We interviewed key informants, observed registry processes and analysed the PBCR dataset for the period 1988-2009 using the 2009 TRC definition of the International Agency for Research on Cancer. We calculated the percentages of morphologically verified cancers, death certificate-only (DCO) cases, missing values of key variables and the time between cancer diagnosis and registration or publication for the year 2009. Results: The number of new cancer cases increased from 5,854 to 15,244 (160%) during 1988-2009. TRC constituted 58% of all cancers among men and 47% among women in 2009. The age-adjusted incidence rates of TRC per 100,000 population increased from 64.2 to 97.3 among men, and from 66.2 to 69.2 among women during 1988-2009. Data on all cancer cases presenting at all major government and private health facilities are actively collected by the PBCR staff using standard paper-based forms. Data abstraction and coding is conducted manually following ICD-10 classifications. Eighty per cent of cases were morphologically verified and 1% were identified by death certificate only. Less than 1% of key variables had missing values. The median time to registration and publishing was 13 and 32 months, respectively. Conclusions: The burden of TRC in Delhi is high and increasing. The Delhi PBCR is well organized and generates high-quality, representative data. However, data could be published earlier if paper-based data are replaced by electronic data abstraction.

Research trends in the field of multicultural education Network analysis:Focusing on Time series analysis of Co-word (다문화교육 분야의 연구동향에 대한 네트워크 분석: 동시출현단어의 시계열 분석중심으로)

  • Bae, Kyungim
    • Journal of Convergence for Information Technology
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    • 제11권10호
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    • pp.159-170
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    • 2021
  • The purpose of this study was to understand the knowledge structure through keyword network analysis for the purpose of identifying research trends in the research field of multicultural education. To this end, the research trends and intellectual structure of multicultural education were identified through network analysis of words that appeared more than 6 times in the keywords of the papers registered in the KCI (Korean Journal of Citation Index) from 2002 to 2020. Study changes were analyzed by analysis. As a result of the analysis, the first period (2002-2010) focused on multicultural society and multiculturalism, while the second period (2011-2015) additionally introduced multicultural families, globalization, and teacher education, and the third period (2016-2020), multicultural receptivity, multicultural sensitivity, and multicultural efficacy were newly revealed. The research trend of multicultural education in Korean society over the past 19 years has been confirmed that the research topic has changed from theoretical research to empirical research, and the content of multicultural education has also been specified and expanded by field and subject.

Trend Analysis of Convergence Research based on Social Big Data (소셜 빅데이터 기반 융합연구 동향 분석)

  • Noh, Younghee;Kim, Taeyoun;Jeong, Dae-Keun;Lee, Kwang Hee
    • The Journal of the Korea Contents Association
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    • 제19권2호
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    • pp.135-146
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    • 2019
  • This study was designed to analyze trends in the entire convergence research beyond academic research through social media big data analysis at a time when interdisciplinary convergence research is emphasized along with the fourth industrial revolution. For this purpose, about 150,000 cases of texts and titles were acquired for about 10 years from January 2009 to September 2018 in connection with the convergence research in social media, and word cloud and network analysis were conducted. As a results, the research fields that were actively conducted for each period were eco-tech in 2009 and 2010, smart technology in 2011 and 2012, information and communication in 2013 and 2014, robots in 2015 and 2016, and artificial intelligence in 2017 and 2018. Also, the research areas that have been consistently conducted for about 10 years are culture, design, chemistry, nanotechnology, biotechnology, robot, IT, and information and communication. Since this study identifies trends in convergence research over time, it can be helpful to researchers who are planning convergence research direction by understanding the trends of convergence research.

Analysis of Water Quality Trends Using the LOADEST Model: Focusing on the Youngsan River Basin (LOADEST 모형을 활용한 수질 경향성 분석: 영산강 수계를 중심으로)

  • Gi-Soon, Lee;Jonghun, Baek;Ji Yeon, Choi;Youngjea, Lee;Dong Seok, Shin;Don-Woo, Ha
    • Journal of Korean Society on Water Environment
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    • 제38권6호
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    • pp.306-315
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    • 2022
  • In this study, long-term measurement data were applied to the LOADEST model and used as an analysis tool to identify and interpret trends in pollution load. The LOADEST model is a regression equation-based pollution load estimation program developed by the United States Geological Survey (USGS) to estimate the change in the pollution load of rivers according to flow rate and time and provides 11 regression equations for pollution load evaluation. As a result of simulating the Gwangjuchen2, Pungyeongjeongchen, and Pyeongdongchen in the Yeongbon B unit basin in the middle and upper reaches of the Yeongsan River with the LOADEST model using water quality and flow measurement data, lower values were observed for the Gwangjuchen2 and Pyeongdongchen, whereas the Pungyeongjeongchen had higher values. This was judged to be due to the characteristics of the LOADEST model related to data continuity. According to the parameters estimated by the LOADEST model, pollutant trends were affected by increases in the flow. In addition, variability increased with time, and BOD and T-P were affected by the season. Thus, the LOADEST model can contribute to water quality management as an analytical tool for long-term data monitoring.