• Title/Summary/Keyword: period analysis

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The Appraisal of Female Jackets from the Period of $1890s{\sim}1960s$ (1890년${\sim}$1960년대 여자 저고리 감정)

  • Choi, Eun-Soo
    • Journal of the Korean Society of Costume
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    • v.58 no.5
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    • pp.178-197
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    • 2008
  • Due to the inflow of the western culture since the 19th century, female skirts and jackets have been changed considerably in detail though their basic composition was maintained. The analysis on female jackets from the start of the modern period to 1960s has been undertaken with artefacts as well as reports and research dissertations related to them. For period appraisal, analysis was divided into several periods which are from 1890s to 1910s, and every 10 years afterwards. As a result, aspects for the appraisal in each period was found. Aspects for period appraisal in modern jackets can be a change in total length and side length, a change in shape of the sleeves (from straight to round), a change in width, and a difference in closed shape of the collars. Material and color can be another aspect which shows fashionable material or new materials (man-made textile or nylon) of each period, color combination of surface and lining material as well as other parts of the jacket, use of a stiffener made with net or sheer textiles. Research using books and archives is important for the appraisal of the garment artifact. However, most of all, one should have the attitude of examining the artifacts frequently in order to achieve deeper understanding and an eye for accurate appraisal.

Effects of Smoking Behaviors on Maternal Conditions and Conditions Arising during the Perinatal Period among Women of Reproductive Age

  • Park, Hyun-Jung;Kim, Eun-Jung
    • Child Health Nursing Research
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    • v.24 no.3
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    • pp.329-336
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    • 2018
  • Purpose: This study analyzes the effects of smoking behaviors of women of reproductive ages in terms of maternal conditions and conditions arising during the perinatal period in Korea. Methods: We used the National Health Insurance Corporation's medical panel data. Subjects included 382 individuals suffering from maternal conditions and conditions arising during the perinatal period from 2013 to 2014. A t-test was used to analyze the individual differences between maternal conditions and conditions arising during the perinatal period-A hierarchical regression analysis was performed in two steps to measure the effects of smoking behaviors on diseases. Results: The amount and duration of smoking are significant factors causing maternal conditions and conditions arising during the perinatal period. In the regression analysis, the explanatory power of model was significantly increased by adding smoking behavior to the maternal conditions and conditions arising during the perinatal period. Smoking behavior during pregnancy displayed a significant influence on diseases. Conclusion: Results of this study showed that the effects of smoking behavior on maternal conditions and conditions arising during the perinatal period were significant. Therefore it is necessary to develop a smoking cessation education program for pregnant women in Korea.

Parameters affecting the fundamental period of infilled RC frame structures

  • Asteris, Panagiotis G.;Repapis, Constantinos C.;Tsaris, Athanasios K.;Di Trapani, Fabio;Cavaleri, Liborio
    • Earthquakes and Structures
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    • v.9 no.5
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    • pp.999-1028
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    • 2015
  • Despite the fact that the fundamental period appears to be one of the most critical parameters for the seismic design of structures according to the modal superposition method, the so far available in the literature proposals for its estimation are often conflicting with each other making their use uncertain. Furthermore, the majority of these proposals do not take into account the presence of infills walls into the structure despite the fact that infill walls increase the stiffness and mass of structure leading to significant changes in the fundamental period numerical value. Toward this end, this paper presents a detailed and indepth analytical investigation on the parameters that affect the fundamental period of reinforce concrete structure. The calculated values of the fundamental period are compared against those obtained from the seismic code and equations proposed by various researchers in the literature. From the analysis of the results it has been found that the number of storeys, the span length, the stiffness of the infill wall panels, the location of the soft storeys and the soil type are crucial parameters that influence the fundamental period of RC buildings.

Estimation of the Fundamental Period for Residential Buildings with Shear-Wall System

  • Chun, Young-Soo;Chang, Kug-Kwan;Lee, Li-Hyung
    • KCI Concrete Journal
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    • v.12 no.1
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    • pp.121-130
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    • 2000
  • This study focused on evaluating the reliability of code formulas such as those of the current Korean Building Code(KBC 1988). UBC 1997, NBCC 1995. and BSLJ 1994 for estimating the fundamental period of RC apartment buildings with shear-wall dominant systems, representative of typical residential buildings in Korea. For this purpose, full-scale measurements were carried out on fifty RC apartment buildings, and these results were compared to those obtained by code formulas and also by dynamic analysis. Although these code formulas are based on the measured periods of buildings during various earthquakes and building period varies with the amplitude of structural deflection or strain level, ambient surveys should provide an effective tool for experimentally verifying the design period to the completed building. This comparison shows that comparatively large errors are likely to occure when the code formula of KBC 1988 is used, and all the other code formulas are not sufficient to estimate the fundamental period of apartment buildings with shear-wall dominant systems. An improved formula is proposed by regression analysis on the basis of the measured period data. The proposal is for the servicebility stress level, but it can also be applied for seismic code in the regions of low seismicity similar to Korea.

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A Study for Maintenance Period Extension based on Reliability of Korea Trainer (국산훈련기 신뢰성기반 정비주기 연장방안 연구)

  • Jo, Intak;Park, Jong Hun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.4
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    • pp.123-132
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    • 2020
  • Currently, there are two types of trainer in Korea : basic and advanced. Both models have been in operation for more than 10 years, and compared to the early stage of operation, reliability has gradually improved and failure rates have also entered a trend of stabilization. Therefore, it is necessary to extend the maintenance period considering economic feasibility. This study investigates the three maintenance period calculation methods: NAVAIR 00-25-403 [17], DOD, U.S. [4], CERL and US Army [3], with intention to extend the maintenance period of the trainer from current 200 hours to 400 hours. In addition, the maintenance period was calculated by the three methods with actual operational data. Common standards and procedures were established to apply operational data to the existing maintenance period calculation methods, the required reliability indicators were derived, and the maintenance periods was calculated based on the results, additionally, a review on the field applicability of the three maintenance cycles was conducted. An on-site interviews were conducted with the calculation results, and 11 out of the 15 items were expected to be extended by 400 hours. It was suggested that the remaining 4 items could be extended to 400 hours by supplementing the inspection method through additional analysis such as functional analysis, inspection content verification, and site connection.

Sentiment analysis of nuclear energy-related articles and their comments on a portal site in Rep. of Korea in 2010-2019

  • Jeong, So Yun;Kim, Jae Wook;Kim, Young Seo;Joo, Han Young;Moon, Joo Hyun
    • Nuclear Engineering and Technology
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    • v.53 no.3
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    • pp.1013-1019
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    • 2021
  • This paper reviewed the temporal changes in the public opinions on nuclear energy in Korea with a big data analysis of nuclear energy-related articles and their comments posted on the portal site NAVER. All articles that included at least one of "nuclear energy," "nuclear power plant (NPP)," "nuclear power phase-out," or "anti-nuclear" in their titles or main text were extracted from those posted on NAVER in January 2010-December 2019. First, we performed annual word frequency analysis to identify what words had appeared most frequently in the articles. For that period, the most frequent words were "NPP," "nuclear energy," and "energy." In addition, "safety" has remained in the upper ranks since the Fukushima NPP accident. Then, we performed sentiment analysis of the pre-processed articles. The sentiment analysis showed that positive-tone articles have been reported more frequently than negativetone over the entire analysis period. Last, we performed sentiment analysis of the comments on the articles to examine the public's intention regarding nuclear issues. The analysis showed that the number of negative comments to articles each month-irrespective of positive or negative tone-was always larger than that of positive comments over the entire analysis period.

Statistical Analysis on Danger Period of Forest Fire by Regions in Korean (통계분석을 이용한 지역별 산불위험시기 구분)

  • Kim, Sun-Young;Lee, Si-Young;An, Sang-Hyun;Shin, Young-Chul;Oh, Jeong-Soo
    • Journal of the Korean Society of Hazard Mitigation
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    • v.2 no.1 s.4
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    • pp.161-167
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    • 2002
  • Forest fire danger period in nine Provinces (Gangwondo, Kyonggido, Gyeongsangnamdo, Gyeongsangbukdo, Jeollanamdo, Jeollabukdo, Jejudo, Chungcheongnamdo, Chungcheongbukdo) has turned out to be similar to recognize whether there are some differences between each Provinces, we used correlation analysis with number of occurrence and damage area by an interval of ten-day period. Based on this analysis, there was significant numbers of occurrence at all areas wish serious burns except Gyeongsangnamdo and Jejudo Provinces. Since persuasive power is insufficient as danger period of forest fire applies equally to nine Provinces, statistical analysis using number of forest fire occurrence and burned area are executed. And then, a analysis of variance(ANOVA) test of significance by an interval of ten day period is carried out. As a result of this analysis, there showed significant at 1% level for number of occurrence except Jejudo, and is also showed significant at 1% level for burned area except Gangwondo and Chejudo. Through regional correlation analysis for danger period, we classified three parts of Middle region (Gangwondo, Kyonggido, Gyeongsangnamdo, Gyeongsangbukdo, Jeollabukdo, Chungcheongnamdo, Chungcheongbukdo) Southern region (Gyongsangnamdo, Jeollanamdo) and Jejudo region. With respect to forest fire occurrence time, Middle region showed from the middle of February to first of May that amounts to 81% of entire occurrence in this region, and Southern region begins with at the last of January to the middle of April covering 71%. In terms of forest fire burned areas, it appears at the middle of February to the first of May, occupying 98% in Middle region, and Southern region showed burned areas from the last of January to the middle of April amounting to 82% of total occurrences.

A Study on the Perception of Pit and Fissure Sealant using Unstructured Big Data (비정형 빅데이터를 이용한 치면열구전색(치아홈메우기)에 대한 인식분석)

  • Han-A Cho
    • Journal of Korean Dental Hygiene Science
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    • v.6 no.2
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    • pp.101-114
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    • 2023
  • Background: This study aimed to explore the overall perception of pit and fissure sealants and suggest methods to revitalize their current stagnation. Methods: To determine the social perception of the change in coverage policy for pit and fissure sealants, we categorized them into five time periods. The first period (December 1, 2009 to November 30, 2010), the second period (December 1, 2010 to September 30, 2012), the third period (October 1, 2012 to May 5, 2013), the fourth period (May 6, 2013 to September 30, 2017), and the fifth period (October 1, 2017 to December 31, 2022). We utilized text mining, an unstructured big data analysis method. Keywords were collected and analyzed using Textom, and the frequency analysis of the top 30 keywords, structural features of the semantic network, centrality analysis, QAP correlation analysis, and co-occurrence analysis were conducted. Results: The frequency analysis showed that the top keywords for each time period were 'Cavities', 'Treatment', and 'Children'. In the structural features of the semantic network of pit and fissure sealants by time period, the density index was found to be around 1.00 for all time periods. The QAP correlation analysis showed the highest correlation between the first and second periods and the fourth and fifth periods with a correlation coefficient of 0.834. The co-occurrence analysis showed that 'cavities' and 'prevention were the top two words across all time periods. Conclusion: This study showed that pit and fissure sealants are well accepted by the society as a preventive treatment for caries. However, the awareness of health education related to these sealants was found to be low. Efforts to revitalize stagnant pit and fissure sealants need to be strengthened with effective education.

Circulation Trends of a Public Library during the Covid-19 Era: An Analysis of Circulation Statistics of A Public Library from 2019 to 2021 (코로나 시대의 공공도서관 대출 추이에 관한 연구 - A 공공도서관의 2019~2021 대출 통계 분석을 중심으로 -)

  • Soyeon, Park
    • Journal of the Korean Society for Library and Information Science
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    • v.56 no.4
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    • pp.357-376
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    • 2022
  • This study examines circulation status and trends of a public library during three year periods from January 2019 to December 2021. There was a statistically significant difference in the mean number of circulation between the pre-Covid-19 period and the Covid-19 period, and the Covid-19 period and the Covid-19 recovery period. However, no significant difference was found between the pre-Covid-19 period and the Covid-19 recovery period. Across three years, there was a significant difference in the distribution of circulation per month. Circulation distribution was also significantly different among different days of the week and different hours of the day. Monthly circulation distribution and hourly circulation distribution during the pre-Covid-19 period was similar to those of the Covid-19 recovery period, whereas those of the Covid-19 period differed from the pre-Covid-19 period and the Covid-19 recovery period. It is expected that the results of this study could contribute to the collection development, and the management and improvement of services of public libraries. It is also expected that the results of this study could contribute to the prediction of circulation patterns and information needs of public library users.

Response Modification Factors of Non-seismic School Buildings Considering Short Column Effects and Natural Period (단주효과 및 고유주기를 고려한 비내진 학교시설의 반응 수정계수)

  • Kim, Beom Seok;Park, Ji-Hun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.23 no.4
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    • pp.201-209
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    • 2019
  • Response modification factors of school facilities for non-seismic RC moment frames with partial masonry infills in 'Manual for Seismic Performance Evaluation and Retrofit of School Facilities' published in 2018 were investigated in the preceding study. However, since previous studies are based on 2D frame analysis and limited analysis conditions, additional verification needs to be performed to further apply various conditions including orthogonal effect of seismic load. Therefore, this study is to select appropriate response modification factors of school facilities for non-seismic RC moment frames with partial masonry infills by 3D frame analysis. The results are as follows. An appropriate response modification factor for non-seismic RC moment frames with partial masonry infills is proposed as 2.5 for all cases if the period is longer than 0.6 seconds. Also if the period is less than 0.4 seconds and the ratio of shear-controlled columns is less than 30%, 2.5 is chosen too. However, if the period is less than 0.4 seconds and the ratio of shear-controlled columns is higher than 30%, the response modification factor shall be reduced to 2.0. If the period is between 0.4 and 0.6 seconds, then linearly interpolates the response correction factor.