• 제목/요약/키워드: 선형회귀 분석

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Association Metabolic Syndrome with Sarcopenia in Korean Stroke Patients : Korean National Health and Nutrition Examination Survey Data(2008-2011) (뇌졸중 유병자의 대사증후군과 근감소증의 관련성: 국민건강조사(2008년-2011년)자료를 근거로)

  • Choi, Sook-Hee;Kim, Yun-Hee
    • The Journal of the Korea Contents Association
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    • v.18 no.10
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    • pp.165-174
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    • 2018
  • The purpose of this study was to examine the association metabolic syndrome with sarcopenia in Korean stroke patients. We used the Korean National Health and Nutrition Examination Survey data from 2008 to 2011 and enrolled a total of 316 stroke patients older than 40 years. Data were analyzed by Rao-Scott ${\chi}^2-test$, generalized linear model and composite sample multiple logistic regression. The prevalence of sarcopenia was 47.3% in men and 46.3% in women. The prevalence of metabolic syndrome was 50.3% in men and 73.6% in women. After adjusting for age, smoking status, alcohol consumption, exercise, education, income, sroke sequla and stroke duration, men with sarcopenia had increased risk of metabolic syndrome (95% CI: 2.454-18.482, p<.001). This finding can be used to develop evidence-based health promotion program to prevent stroke reccurance for stroke patients.

Retention Time Prediction form Molecular Structure of Sulfur Compounds by Gas Chromatography (기체크로마토그래피에서 황화합물의 구조를 통한 용리시간 예측)

  • Kim, Young Gu;Kim, Won Ho;Pak, Hyung Suk
    • Journal of the Korean Chemical Society
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    • v.42 no.6
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    • pp.646-651
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    • 1998
  • The molecular structure of sulfur compounds and the retention relationship are studied by gas chromatography. Analyzed sulfur compounds are, hydrogen sulfide, sulfur dioxide, carbon disulfide, ethyl mercaptan, dimethyl sulfide, iso-propyl mercaptan, normal propyl mercaptan, ethyl methyl sulfide, tert-butyl mercaptan, tetrahydrothiophene, thiophene, and 2-chlorothiophene. Multiple linear regression explains the retention relationship of molecular descriptors. In GC the temperature program is 30$^{\circ}C$ held for 10.5 min, and then increased to 150$^{\circ}C$ at a rate 15$^{\circ}C$/min. Predicted equation for relative retention time (RRT) using SAS program is as follows; $RRT=0.121bp+14.39dp-8.94dp^2+0.0741sqmw-35.78\; (N=8,\; R^2=0.989, \;Variance=0.175,\;F=66.21)$. RRTs are function of boiling point, the square root of molecular weight, molecular dipole moment, and boiling point effects mostly on RRT. The RRT is maximized at the molecular dipole moment of 0.805D, when using nonpolar columns. The planar and highly symmetric compounds are eluted slowly. The square, of correlation coefficient $(R^2)$ using SAS program, is 0.989, and the variance is 0.175 in training sets. For three sulfur compounds, the variance between observed RRTs and predicted RRTs is 0.432 in testing sets.

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Proposal of Prediction Technique for Future Vegetation Information by Climate Change using Satellite Image (위성영상을 이용한 기후변화에 따른 미래 식생정보 예측 기법 제안)

  • Ha, Rim;Shin, Hyung-Jin;Kim, Seong-Joon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.3
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    • pp.58-69
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    • 2007
  • The vegetation area that occupies 76% in land surface of the earth can give a considerable impact on water resources, environment and ecological system by future climate change. The purpose of this study is to predict future vegetation cover information from NDVI (Normalized Difference Vegetation Index) extracted from satellite images. Current vegetation information was prepared from monthly NDVI (March to November) extracted from NOAA AVHRR (1994 - 2004) and Terra MODIS (2000 - 2004) satellite images. The NDVI values of MODIS for 5 years were 20% higher than those of NOAA. The interrelation between NDVIs and monthly averaged climate factors (daily mean, maximum and minimum temperature, rainfall, sunshine hour, wind velocity, and relative humidity) for 5 river basins of South Korea showed that the monthly NDVIs had high relationship with monthly averaged temperature. By linear regression, the future NDVIs were estimated using the future mean temperature of CCCma CGCM2 A2 and B2 climate change scenario. The future vegetation information by NOAA NDVI showed little difference in peak value of NDVI, but the peak time was shifted from July to August and maintained high NDVIs to October while the present NDVI decrease from September. The future MODIS NDVIs showed about 5% increase comparing with the present NDVIs from July to August.

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Size Effect on Flexural Compressive Strength of Reinforced Concrete Beams (철근콘크리트 보의 휨압축강도에 대한 크기효과)

  • 김민수;김진근;이성태;김장호
    • Journal of the Korea Concrete Institute
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    • v.14 no.6
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    • pp.934-941
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    • 2002
  • It is important to consider the effect of member size when estimating the ultimate strength of a concrete flexural member because the strength always decreases with an increase of member size. In this study, the size effect of a reinforced concrete (RC) beam was experimentally investigated. For this purpose, a series of beam specimens subjected to four-point loading were tested. More specifically, three different effective depth (d$\approx$15, 30, and 60 cm) reinforced concrete beams were tested to investigate the size effect. The shear-span to depth ratio (a/d=3) and thickness (20 cm) of the specimens were kept constant where the size effect in out-of-plane direction is not considered. The test results are curve fitted using least square method (LSM) to obtain parameters for the modified size effect law (MSEL). The analysis results show that the flexural compressive strength and the ultimate strain decrease as the specimen size increases. In the future study, since $\beta_1$ value suggested by design code and ultimate strain change with specimen size variation, a more detailed analysis should be performed. Finally, parameters for MSEL are also suggested.

Compression Lap Splice Length in Concrete of Compressive Strength from 40 to 70 MPa (40-70 MPa 콘크리트에서의 철근 압축이음 길이)

  • Chun, Sung-Chul;Lee, Sung-Ho;Oh, Bo-Hwan
    • Journal of the Korea Concrete Institute
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    • v.21 no.4
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    • pp.401-408
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    • 2009
  • A compression lap splice becomes an important issue due to development of ultra-high strength concrete. Current design codes regarding compression lap splice do not utilize merits of the improved strength of ultra-high strength concrete. Especially, a compression lap splice can be calculated longer than a tension lap splice according to the codes because they do not consider effects of compressive strength of concrete and transverse reinforcement. This anomaly confuses engineers in practice. Design equation is proposed for compression lap splice in 40 to 70 MPa of compressive strength of concrete. The proposed equation is based on 51 specimens conducted by authors. Basic form of the equation includes main parameters which are derived from investigating test results. Through two-variable non-linear regression analysis of measured splice strengths, a strength equation of compression lap splices is then derived. A specified splice strength is defined using a 5% fractile coefficient and a lap length equation is constructed. By the proposed equation, the anomaly of lap lengths in tension and compression is got rid of. In addition, the equation has a reliability equivalent to those of the specified strengths of materials.

Factors Influencing Subjective Well-Being of Immigrant Wives (이주여성의 주관적 안녕감에 영향을 미치는 요인)

  • Park, Hyeon-Woo;Kim, You-Young;Nam, Hyeon-Woo
    • Journal of Agricultural Extension & Community Development
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    • v.20 no.2
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    • pp.451-484
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    • 2013
  • This study investigated the factors that influence subjective well-being of immigrant wives in Korea. We initially grouped the factors into 3 categories: personal, domestic, and social. For personal factors, we included couple's age difference, reason for entry, religion, marital duration, employment status, economical status, acculturation to Korean culture, acquisition of Korean language, and ego-resiliency. For domestic factors we included marriage process, reason for marriage, husbands' understanding of wife's native language, husbands' understanding of wife's culture, marital satisfaction, existence of children, head of the household, and parenting efficacy. Finally for social factors, awareness of welfare services and systems, use of public institutions and civil organizations, and participation in social groups were included. We recruited 256 immigrant wives who live in Asan City, Chungnam Province and the data were analyzed by multiple linear regression. The factors that statistically significant were: ego-resiliency, marital duration, acculturation to Korean culture and economic status among personal factors; parenting efficacy, marital satisfaction and marriage process (married without a matchmaker) among domestic factors; participation in self-help group of women from the same mother country, awareness of welfare services and systems, participation in hobby club, and participation in fraternal/religious society among social factors. It is hoped that this paper will yield general insights into subjective well-being of immigrant wives and may help them to develop inner talent and strength.

Influence of transformational leadership of managers perceived by public health nurses and their social capital on empowerment (보건소장의 변혁적 리더십과 보건간호사의 사회적 자본이 임파워먼트에 미치는 영향)

  • Kim, Yeong Ae;Jun, Soo Young
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.3
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    • pp.585-596
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    • 2017
  • The purpose of this study was to elucidate public health nurses' empowerment to public health center managers' transformational leadership and public health nurses' social capital. From Feb. 29 to Apr. 8, 2016, a questionnaire survey was conducted with 303 public health nurses, the public nursing officials working at public health centers in Daegu and Gyeongsangbuk-do. Data were analyzed using SPSS 21.0 program and factors affecting the health-related quality of life were analyzed by t-test, ANOVA, Scheffe test, Pearson's correlation coefficient, and multiple regression analysis. Public health nurses' empowerment had a positive correlation with transformational leadership and social capital. The managers' transformational leadership perceived by the public health nurses and the social capital of the public health nurses were included in the factors affecting their empowerment. The results of the study indicate that these variables should be considered in developing nursing intervention programs to increase empowerment in public health nurses.

Mechanical Characteristics of Recycled PET Polymer Concrete with Demolished Concrete Aggregates (PET와 재생골재를 이용한 폴리머콘크리트의 역학적 특성)

  • Jo Byung-Wan;Lee Du-Wha;Park Seung-Kook
    • Journal of the Korea Concrete Institute
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    • v.17 no.3 s.87
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    • pp.335-342
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    • 2005
  • In this paper, fundamental properties of Polymer Concrete(PC), made from unsaturated polyester resin based on recycled PET and recycled aggregate were investigated. Mechanical properties include strength, modulus of elasticity, and chemical resistance. Resins based on recycled PET and recycled aggregate offer the possibility of low source cost for forming useful products, and would also help alleviate an environmental problem and save energy. The results of test for resin contents and recycled aggregate ratio we, first, the strength of Polymer Concrete made with resin based on recycled PET and recycled aggregate increases with resin contents relatively, however beyond a certain resin contents the strength does not change appreciably, Second, the relationship between the compressive strength and recycled aggregate ratio at resin $9\%$ has a close correlation linearly whereas there is no correlation between the compressive strength and the flexural strength of RPC with recycled aggregate ratio. Third, the effect of acid resistance at resin $9\%$ was found to be nearly unaffected by HCI, whereas the PC with $100\%$ recycled aggregate showed poor acid resistance. Unlike acid, alkali nearly does not seem to attack the RPC as is evident from the weight change and compressive strength. And last, In case of stress-strain curve of polymer concrete with $100\%$ of natural aggregate and $100\%$ recycled aggregate it is observed the exceptional behavior resulting in different failure mechanisms of the material under compression.

Effect of Calcium Hydroxide on the Microhardness of Root Dentin of Primary Tooth (수산화칼슘 근관충전제의 적용이 유치 치근상아질의 미세경도에 미치는 영향)

  • Jun, Saeromi;Kim, Jong-Bin;Yoo, Seung-Hoon
    • Journal of the korean academy of Pediatric Dentistry
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    • v.40 no.3
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    • pp.177-184
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    • 2013
  • Calcium hydroxide mixture medicaments can nearly be considered to be the ideal primary tooth filling material. However, long-term application of calcium hydroxide combinations as an intra canal medicament softens dentin. The aim of this study was to evaluate the effect of calcium hydroxide on the microhardness of root dentin of primary tooth. For the study, 60 extractedprimary incisors were divided into 3 groups (no medicament, calcium hydroxide/iodorform mixture, and calcium hydroxide/distilled water mixture). After the cleansing and shaping of canals, calcium hydroxide medicaments were applied and stored for different periods of time (1, 7, 30, 90 days). The root was horizontally sectioned into 2 mm thick specimens and the microhardness was measured using Vickers microhardness tester. The results were as follows : Root dentin microhardness of primary teeth decreased with long term exposure to calcium hydroxide medicaments according to the experimental period and showed statistically significance (p < 0.05). Root dentin microhardness of primary tooth filled with calcium hydroxide mixed with distilled water showed more decrease than filled with Vitapex and showed statistically significance (p < 0.05). Root dentin microhardness of a control group without exposure to calcium hydroxide decreased according to the experimental period and showed statistically significance (p < 0.05).

Effects of Urban Compactness and Residential Density on Trip Generation: Focusing on Work Trips in Seoul, Korea (도시 압축도와 주거밀도가 통행발생에 미치는 영향에 관한 연구: 서울시 출근 통행을 중심으로)

  • Mahriyar, Muhammad. Zia;RHO, Jeonghyun
    • Journal of Korean Society of Transportation
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    • v.35 no.1
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    • pp.1-10
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    • 2017
  • The compact city usually provides good accessibility of residents with multiple transportation modes. However, in a compact city, annual average of travel distance per household by car is relatively short due to more congested traffic condition and larger travel cost than disperse city. As a result, total travel demand is decreasing when the region becomes more compact. Therefore compact development is regarded as one of the sustainable choices for future urban planning in many countries. This study aims at an empirical analysis of the relationship between urban compactness and travel demand based upon land-use and travel data for city of Seoul. In this study, 424 sub-districts with the mixed land-use patterns are assessed in a hexagonal diagram. The measurement is based on the relative deviation of each sector's characteristics including numbers of residence, manufacture, and trade & service. Multiple linear regression models are developed to analyze the effects of urban compactness on zonal trip generations. As a result, the trip generation rate in the residence-intensive and mixed-use areas is found to be relatively low. Furthermore, residents in high-compact areas tend to use public transport more often than residents in less compact areas.