• Title/Summary/Keyword: T-test analysis

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Relationships between Topological Structures of Traffic Flows on the Subway Networks and Land Use Patterns in the Metropolitan Seoul (수도권 지하철망 상 통행흐름의 위상학적 구조와 토지이용의 관계)

  • Lee, Keum-Sook;Hong, Ji-Yeon;Min, Hee-Hwa;Park, Jong-Soo
    • Journal of the Economic Geographical Society of Korea
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    • v.10 no.4
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    • pp.427-443
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    • 2007
  • The purpose of this study is to investigate spacio-temporal structures of traffic flows on the subway network in the Metropolitan Seoul, and the relationships between topological structures of traffic flows and land use patterns. In particular we analyze in the topological structures of traffic flows on the subway network in time dimension as well as in spatial dimension. For the purpose, this study utilizes data mining techniques to the one day T-card transaction data of the last four years, which has developed for exploring the characteristics of traffic flows from large scale trip-transaction databases. The topological structures of traffic flows on the subway network has changed considerably during the last four years. The volumes of traffic flows, the travel time and stops per trip have increased until 2006 and decreased again in 2007. The results are visualized by utilizing GIS and analyzed, and thus the spatial patterns of traffic flows are analyzed. The spatial distribution patterns of trip origins and destinations show substantial differences among time zones during a day. We analyze the relationships between traffic flows at subway stops and the geographical variables reflecting land use around them. We obtain 6 log-linear functions from stepwise multiple regression analysis. We test multicollinearity among the variables and autocollelation for the residuals.

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Policy Directions to Build on Nature-Friendly Park Facilities - Based on an Evaluation on the Nature-Friendliness of Park Facilities in National Parks - (자연친화적인 공원시설 설치를 위한 정책방향 - 국립공원 공원시설의 자연친화성 평가를 근거로 -)

  • Park, Chang-Sug;Bae, Min-Ki;Kim, Tae-Jin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.5
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    • pp.1-12
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    • 2009
  • The purpose of this research was to propose policy directions for the design and construction of nature-friendly park facilities (PF) in national parks. In order to do that, nature-friendliness evaluation indicators(NEIs) used in green building rating systems and related articles were reviewed. After the initial literature review was complete, NEIs for park facilities based on location, design, construction, operation, and management sectors were developed. Data was obtained through a questionnaire completed by 79 managers at 19 national parks in Korea in 2008. The answers were analyzed using descriptive statistical methods, a t-test, a multi-dimensional analysis, and a factor analysis. This research found that: 1) The results indicated that based on relative weight calculation, the location condition was evaluated as the most important; 2) The evaluation results regarding the degree of nature-friendliness of park facilities showed that location condition was ranked higher than design and construction--in addition, the evaluated values of indicators related to energy efficiency were ranked the lowest; 3) the level of nature-friendliness of shelter was given the highest level, but resting facility was the lowest level; 4) Overall, park facilities at Mt. Seorak, Mt. Odae, and Taean Coast national parks showed high levels of nature-friendliness. But park facilities at Mt. Gyeongju and Mt. Songni national parks showed low levels of nature-friendliness. The results of this research shall contribute to the establishment of tailor-made management policies, the development of detailed guidelines for increased energy efficiency and visitor satisfaction, and the preservation of ecosystems and natural resources in Korea's national parks.

A Study on Estimation on Air Exchange Rate and Source Strength in Indoor Air Using Multiple Measurements of Nitrogen Dioxide (이산화질소 다중측정을 이용한 실내공기의 환기량 밀 발생량 추정에 관한 연구)

  • Yang, Won-Ho;Lee, Ki-Young;Chung, Moon-Ho;Zong, Moon-Shik
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.10 no.1
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    • pp.160-169
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    • 2000
  • Daily indoor and outdoor nitrogen dioxide ($NO_2$) concentration for 30 days were measured in 28 houses with questionnaire of housing characteristics in Brisbane, Australia. Using mass balance equation and regression analysis, penetration factors and source strength factors were calculated. The penetration factors of 27 houses except one house were between zero and 1, though penetration factor should be between zero and 1 by means of mass balance equation. Relationship between indoor and outdoor concentrations in each 27 house was calculated using regression analysis. According to the obtained linear regression equation, the slope means penetration factor and the intercept means source strength factor. Calculated mean and standard deviation of coefficients of determination ($R^2$) in electric and gas range houses were $0.70{\pm}0.13$ and $0.57{\pm}0.21$, respectively. The source strength factors were more than zero in 27 houses. Mean and standard deviation of slopes in electric and gas range houses were $0.65{\pm}0.18$ and $0.56{\pm}0.12$, respectively. Mean and standard deviation of intercepts in electric and gas range houses were $1.49{\pm}1.25$ and $5.77{\pm}3.55$, respectively. Air exchange rate and source strength were calculated from penetration factor and source strength factor, respectively. Geometric mean and standard deviation of calculated air exchange rates in 27 houses were $1.1/hr{\pm}1.5$. Presence of gas range was the most significant factor contributing to indoor $NO_2$ level in house characteristics (p=0.003). In gas range houses, source strengths ranged from 4.1 to $33.1cm^3/hr{\cdot}m^3$ with a mean $12.7cm^3/hr{\cdot}m^3$ and a standard deviation 9.8. The source strengths of gas range houses were significantly different from those of electric range houses by t-test (p<0.001)

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An Empirical Study of the Interrelationship Corporate Capability, Competitive Advantage and Business Performance in IT Enterprise (정보기술기업의 역량, 경쟁전략 및 성과의 관계)

  • Chung, Dong-Seop
    • Management & Information Systems Review
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    • v.29 no.4
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    • pp.287-304
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    • 2010
  • In spite of the variety of business environments around start-up firms, almost all existing studies on business strategy of new IT firms. The purpose of the present research is to examine the relationships of the corporate capability, competitive advantage and performance of IT enterprise. There was much research for IT enterprise in other lands, but there was a little in Korea. Through previous literature, we can't find differences between IT enterprise strategies and common corporation strategies. So this research treats new strategies of IT. This research is explanatory and three research questions. This research focuses on the determining factors(corporate capability, competitive advantage) and management performance of IT enterprise in Busan area. In order to test the established 3 hypothesis, several multi-variate analyses are used. Factor analysis is used to reduce the competitive advantage question to its underlying factors. Finally, multi-variate regression and analysis is used to determine whether performance differences The result of this study would be useful to practitioners on management and entrepreneurship. Finally, this study is expected to encourage entrepreneurs to create new possibility in IT enterprise and to assist more new operating business strategy.

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The Effects of Entrepreneurship of Real Estate Broker's on Performance: Moderating Effect of Entrepreneurship Education (소규모 부동산중개업 경영인의 창업가 특성이 경영성과에 미치는 영향: 창업교육의 조절효과를 중심으로)

  • Cho, Jun-Hee;Kim, Chul-Joong
    • The Journal of the Korea Contents Association
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    • v.12 no.10
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    • pp.408-417
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    • 2012
  • This study analyzed the effect of entrepreneurship of real estate broker's on subjective performance, and confirmed if a entrepreneurship education between them has moderating effects. The research results of the analysis are as follows. First, needs for achievement and risk taking of real estate brokerage were significant with subjective performance, which is the dependent variable, and it was shown as the positive (+) direction. This means entrepreneur factors of high needs for achievement or submitting to risk preference have a significant effect in subjective performance. Second, moderating effect of a business school was only shown in needs for achievement. As a result of analysis after classifying it into two groups according to completion status of a entrepreneurship education, it was shown the group that took a entrepreneurship education has higher beta(${\beta}$) than the group that did not take a entrepreneurship education. In other words, real estate brokerage who took a entrepreneurship education shows increase in needs for achievement, which is the entrepreneur factor. This signifies a business school has a positive effect in subjective performance. Third, as a result of t-test for completion status of a entrepreneurship education and financial performance, it was shown the group that took a entrepreneurship education showed higher average of sales and net income than the group that did not take a entrepreneurship education. The net income, in particular, showed about the double difference.

Determination of Genetic Diversity among Korean Hanwoo Cattle Based on Physical Characteristics

  • Choi, T.J.;Lee, S.S.;Yoon, D.H.;Kang, H.S.;Kim, C.D.;Hwang, I.H.;Kim, C.Y.;Jin, X.;Yang, C.G.;Seo, K.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.9
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    • pp.1205-1215
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    • 2012
  • This study was conducted to establish genetic criteria for phenotypic characteristics of Hanwoo cattle based on allele frequencies and genetic variance analysis using microsatellite markers. Analysis of the genetic diversity among 399 Hanwoo cattle classified according to nose pigmentation and coat color was carried out using 22 microsatellite markers. The results revealed that the INRA035 locus was associated with the highest $F_{is}$ (0.536). Given that the $F_{is}$ value for the Hanwoo INRA035 population ranged from 0.533 (white) to 1.000 (white spotted), this finding was consistent with the loci being fixed in Hanwoo cattle. Expected heterozygosities of the Hanwoo groups classified by coat colors and degree of nose pigmentation ranged from $0.689{\pm}0.023$ (Holstein) to $0.743{\pm}0.021$ (nose pigmentation level of d). Normal Hanwoo and animals with a mixed white coat showed the closest relationship because the lowest $D_A$ value was observed between these groups. However, a pair-wise differentiation test of $F_{st}$ showed no significant difference among the Hanwoo groups classified by coat color and degree of nose pigmentation (p<0.01). Moreover, results of the neighbor-joining tree based on a $D_A$ genetic distance matrix within 399 Hanwoo individuals and principal component analyses confirmed that different groups of cattle with mixed coat color and nose pigmentation formed other specific groups representing Hanwoo genetic and phenotypic characteristics. The results of this study support a relaxation of policies regulating bull selection or animal registration in an effort to minimize financial loss, and could provide basic information that can be used for establishing criteria to classify Hanwoo phenotypes.

Periodontal Status in Accordance with the Daily Stress and Coping and Control Effect of Oral Health Behavior (일상스트레스와 스트레스 대처방식에 따른 치주상태와 구강건강행위 통제효과)

  • Kim, Eun-Sol;Choi, Eun-Mi;Han, Gyeong-Soon
    • Journal of dental hygiene science
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    • v.16 no.6
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    • pp.472-480
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    • 2016
  • In this study, 110 adults aged 40 to 69 years were surveyed from April 28, 2016, to May 28, 2016 to analyze their periodontal status according to daily stress, coping methods, and oral health behavior. The collected data were analyzed using the t-test, one-way analysis of variance, and hierarchical multiple regression. Daily stress levels of all subjects were most frequent potential risk 64.5% of the subjects, the high risk 19.1% and 16.4% of the health group. Regarding stress coping methods, active methods recorded 2.46, passive methods recorded 2.32. Regarding oral health behaviors, subjects brushed an average of 2.45 times daily, for an average of 2 minutes. Futhermore, 69.1% of subjects brushed before bedtime and 89.1% practiced scaling. Regarding periodontal status, the O'Leary index was 73.45, gingivitis index was 1.30, an average of 2.83 quadrants possessed a periodontal pocket. The hierarchical multiple regression analysis identified, type of employment (${\beta}=-0.348$), scaling (${\beta}=-0.253$), and age (${\beta}=0.244$) as factors that influence the number of quadrants possessing a periodontal pocket. These results confirmed that the oral health behavior of scaling, but not stress levels of coping methods, strongly influenced periodontal status.

Changes in the Usage of Dental Technology CAD/CAM (치과기공 CAD/CAM 사용에 대한 실태변화)

  • Nah, Jung-Sook
    • Journal of Technologic Dentistry
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    • v.37 no.4
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    • pp.271-284
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    • 2015
  • Purpose: The purpose of this study was to examine the usage of CAD/CAM, which is one of dental technologist duties, in an effort to look for any possible changes in the usage of CAD/CAM. It's specifically meant to compare the results of this study with those of Lee Jong-do, Park Kwang-Sig(2011)'s study in March, 2011, to determine if there were any changes over the past four years. The selected variables that were investigated were the ownership of CAD/CAM, awareness of it, the route of acquiring the first information on it, the merits and demerits of its usage, usage experience and educational experience about it. Methods: An online survey was conducted on the dental technologists who worked in urban communities including metropolitan cities to find out the usage of CAD/CAM in 2015 from July 15 to 31, 2015, after existing questionnaire items were modified. The collected data were analyzed by IBM SPSS statistics 22.0, and statistical data on frequency, percentage, mean and standard deviation for each item were obtained. To figure out the characteristics of the subjects and the relationship between their occupational characteristics and the usage of CAD/CAM, crosstabs, independent-samples t-test and one-way ANOVA were utilized. As for the usage of CAD/CAM in 2011, the results of Lee Jong-do, Park Kwang-Sig(2011)'s study were selected, and then a comparative analysis was made. The level of significance was all set at .05. Total 250 questionnaires were distributed to them, and 190(76.0%) were returned. After excluding 23 whose answers were uncertain or seemed to lack reliability, total 167(66.8%) were used in final analysis. Results: As a result of analyzing the usage of CAD/CAM that was one of dental technologist duties, there was a great increase in the ownership of CAD/CAM in their workplaces from 2.4 percent in 2011 to 71.7 percent in 2015, and there was an improvement in awareness about it and the necessity of its usage as well. In 2011, the Internet and mass media were the most common route that they got to know about it. They had a strong tendency to acquire related knowledge through education in 2015, and there were some changes in the products that they used or preferred. In both years, the great merit of CAD/CAM was the simplified manufacturing process of restoration, and it had another great advantages in 2015 such as the improved quality of restoration or improved environments for dental technology. Concerning disadvantages, high price was a big problem in 2011. In 2015, not only price but the burden of material costs, frequent breakdown, poor demand among dental clinics and a lack of CAD/CAM professionals were pointed out a lot. In the future, this researcher intends to make research to seek ways of improving CAD/CAM professionals. Conclusion: There was more awareness of CAD/CAM in 2015 than in 2011 when the changes in awareness of it were analyzed, and the finding suggest the necessity of sustained education and concern.

A Study on Construction Condition of Modular System by Structural Analysis of Construction Stage (시공단계 구조해석을 통한 적층형 모듈러주택의 시공조건 검토)

  • Jo, Min-Joo;Kim, Jong-Sung;Yu, Seong-Yong;Choi, Ki-Bong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.2
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    • pp.143-150
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    • 2015
  • At present, the actual condition is that Korean modular structures are limited to a low rise detached house and military barracks. And there is no standardized structural design method of stacked modular structure. Accordingly, in general, they don't review impact force in the stage of stacking and installing a module, the effect which wind load has on a structure in the stage of lifting, and inertial force occurring in the stage of lifting or transporting a module in the process of constructing a structure. Therefore, this study investigated the construction method of modular system to be studied in stages, and decided on the position to which load was applied and boundary condition in structural analysis at each construction stage. Besides, inertial force according to each speed was calculated in the lifting and wheeled transport of module. And we calculated impact load according to lifting speed in module stacking and installation work and wind load due to instantaneous wind speed in the installation work by lifting. On the basis of the suggested method, in the modular system to be studied, it carried out review of structure by changing determining conditions of load being applied by construction stage, such as in the stage of lifting, in the stage of transport, and in the stage of installation, and drew construction conditions securing stability structurally.

Oral health care status and educational needs of care workers (요양보호사의 구강건강관리실태 및 구강건강관리교육 요구도 조사)

  • Kim, Hee-Kyoung;Kim, Kyung-Mi;Kim, Sun-Il;Kim, Eun-Ju;Namkoong, Eun-Jung;Bae, Soo-Myoung;Son, Jung-Hui;Shin, Bo-Mi;Shin, Sun-Jung;Eom, Mi-Ran;Lee, Min-Sun;Lee, Hye-Rin;Choi, Yong-Keum;Choi, Jin-Sun;Ryu, Da-Young
    • Journal of Korean Dental Hygiene Science
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    • v.2 no.2
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    • pp.41-51
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    • 2019
  • Introduction: This study intended to identify the current oral health care status and demand of care workers for oral health education. Methods: A survey was distributed to care workers working in 11 nursing homes for older people located in the Chungcheongdo Province. Of those distributed, 217 questionnaires were collected and analyzed. To analyze the collected data, a frequency analysis, t-test, and one-way analysis of variance(ANOVA) were performed using SPSS version 18.0. Results: The demand for an educational course on the 'Management of Oral Health Care for the Aged People' had a score of 4.22 points(full marks were 5.0 points), whereas the score for the necessity for control of oral health was 4.29 points. The control of oral health for the aged people suffering dysphagia scored 4.27 points, whereas the control of oral health for older people who have dementia was 4.27 points. The score for a course on the nutritional control for aged people having difficulties in masticating foods was 4.27. Conclusion: It is clear that the development of educational courses and standardized manuals for care workers on aspects of oral health care is necessary. Therefore, it would be desirable to develop institutional infrastructure for dental hygienists to educate care workers on oral health.