• Title/Summary/Keyword: partially linear regression

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A Study on the Relationship between Influential Range and Cognition Factor of Landmark (랜드마크의 영향력 범위와 인지요인과의 관계)

  • 김종호;변재상;임승빈
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.4
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    • pp.9-18
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    • 2002
  • This study investigated the influential range of landmarks and the relationship between landmarks and cognition factor so as to offer basic data to be used for the effective use and the management of landmarks. In this study, eighteen famous landmark in Seoul were selected and analyzed. The result of this study can be summarized as follows : 1) First, eighteen determining elements of cognition factors were selected via documents survey. Second, general cognition factors of landmarks were analysed using these elements through questionnaires to specialists. As a result of factor analysis, historic cultural factor, scale factor, visual form factor, locational factor and uniqueness factor were revealed. 2) According to revealed cognition factor, eighteen landmarks are categorized into four types using MDS method via questionnaire to resident in Seoul city. These four types of landmarks are: type I that are recognized by historic cultural factor; type II that are recognized by scale factor; type III that are recognized by uniqueness factor; and type IV that are recognized by visual form factor. 3) As the result of regression, the influential range of landmarks were revealed at about a 10km radius(type I : 12km type II : whole area of Seoul city≒15km, typeIII : 8.7km, typeIV : 8.5km). 4) As a result of analysing the correlation between the influential range and the cognition factor through multiple linear regression analysis, the locational factor is the main factor affecting the influential range of landmarks in every type. The uniqueness factor comes next, which affects influential range partially. 5) Except type 1, as a result of analysing the correlation between influential range and the physical heights of landmarks, a quadratic equation is revealed, showing that the influential range of landmarks over 200 meters in height shows a radical change. Landmarks can be used as reinforcement tools of legibility, effective tools for landscape management and for the improvement of a community's image. This study on the influential range of landmarks and main cognition factor can be utilized as a landmark management plan and in urban planning, such as a new town plan.

Strengthening of prestressed girder-deck system with partially debonding strand by the use of CFRP or steel plates: Analytical investigation

  • Haoran Ni;Riliang Li;Riyad S. Aboutaha
    • Computers and Concrete
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    • v.31 no.4
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    • pp.349-358
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    • 2023
  • This paper describes an in-depth analysis on flexural strength of a girder-deck system experiencing a strand debonding damage with various strengthening systems, based on finite element software ABAQUS. A detailed finite element analysis (FEA) model was developed and verified against the relevant experimental data performed by other researchers. The proposed analytical model showed a good agreement with experimental data. Based on the verified FE model, over a hundred girder-deck systems were investigated with the consideration of following variables: 1) debonding level, 2) span-to-depth ratio (L/d), 3) strengthening type, 4) strengthening material thickness. Based on the data above, a new detailed analytical model was developed and proposed for estimating residual flexural strength of the strand-debonding damaged girder-deck system with strengthening systems. It was demonstrated that both finite element model and analysis model could be used to predict flexural behaviors for debonding damaged prestressed girder-deck systems. Since the strands are debonding from surrounding concrete over a certain zone over the length of the beam, the increase of strain in strands can be linked with a ratio ψ, which is Lp/c. The analytical model was proposed and developed regarding the ratio ψ. By conducting procedure of calculating ψ, the ψ value varies from 9.3 to 70.1. Multiple nonlinear regression analysis was performed in Software IBM SPSS Statistics 27.0.1 to derive equation of ψ. ψ equation was curved to be an exponential function, and the independent variable (X) is a linear function in terms of three variables of debonding level (λ), span length (L), and amount of strengthening material (As). The coefficient of determinate (R2) for curve fitting in nonlinear regression analysis is 0.8768. The developed analytical model was compared to the ultimate capacities computed by FEA model.

Prediction of Ground Thermal Properties from Thermal Response Test (현장 열응답 시험을 통한 지중 열물성 추정)

  • Yoon, Seok;Lee, Seung-Rae;Kim, Young-Sang;Kim, Geon-Young;Kim, Kyungsu
    • Journal of the Korean Geotechnical Society
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    • v.32 no.7
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    • pp.5-14
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    • 2016
  • The use of geothermal energy has increased for economically and environmentally friendly utilization, and a geothermal heat pump (GSHP) system for space heating and cooling is being used widely. As ground thermal properties such as ground thermal conductivity and ground thermal diffusivity are substantial parameters in the design of geothermal heat pump system, ground thermal conductivity should be obtained from in-situ thermal response test (TRT). This paper presents an experimental study of ground thermal properties of U and 2U type ground heat exchangers (GHEs) measured by TRTs. The U and 2U type GHEs were installed in a partially saturated dredged soil deposit, and TRTs were conducted for 48 hours. A method to derive the thermal diffusivity as well as thermal conductivity was proposed from a non-linear regression analysis. In addition, remolded soil samples from different layers were collected from the field, and soil specimens were reconstructed according to the field ground condition. Then equivalent ground thermal conductivity and ground thermal diffusivity were calculated from the lab test results and they were compared with the in-situ TRT results.

Relationship Between Urinary Melatonin Levels and Extremely Low Frequency Magnetic Fields for the Selected Primary Schoolchildren Living Nearby and Away from Overhead Transmission Power Line (송전선로 주변과 비주변 초등학생을 대상으로 극저주파 자기장 노출과 뇨중 멜라토닌 분비량간의 상관성 연구)

  • Cho, Yong-Sung;Kim, Yoon-Shin;Lee, Jong-Tae;Hong, Seung-Cheol;Jang, Seong-Ki
    • Journal of Environmental Health Sciences
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    • v.30 no.3
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    • pp.191-206
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    • 2004
  • The present study investigated the hypothesis that a extremely low frequency magnetic field partially suppresses the synthesis of melatonin in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 ${\mu}$T, whereas the value for the primary schoolchildren living away from overhead transmission power line 0.05 mT. From simple analyses, the mean melatonin levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, but not statistically significant differences in the levels of the melatonin (p=0.2421), whereas the statistically significant differences in the levels of the melatonin related to the distance from residence to power line less and more than 100 m by cut-off point (p=0.0139). In multiple linear regression analyses, distance from residence to power line (p=0.0146) and dietary habit about burned meat (p=0.0170) proved to be significant risk factors in the mean nocturnal melatonin levels in the primary schoolchildren. In conclusion, these results demonstrate that urinary levels of nocturnal melatonin are not altered in primary schoolchildren exposed to extremely low frequency magnetic field(ELF-MF) at overhead transmission power line.

Mediating Effect of Illness Perception on the Relationship between Family Function and Health Behavior in Patients with Risk Factors for Metabolic Syndrome (대사증후군 위험군의 가족기능과 건강행위의 관계에서 질병인식의 매개효과)

  • Yeom, Hyun-E;Shin, Jee-Won;Kim, Se Hyeon;Shin, Sunui
    • Journal of East-West Nursing Research
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    • v.25 no.2
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    • pp.183-192
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    • 2019
  • Purpose: This study aimed to examine the mediating effect of illness perception on the relationship between family function and health behavior of patients with risk factors for metabolic syndrome. Methods: This is a cross-sectional correlational study. Data were collected from 160 patients using self-administered questionnaires including the Illness Perception Questionnaire-Revised, Family APGAR, and the Health Behavior Scale. The data were analyzed using Pearson's correlation coefficients, independent t-test and multiple linear regression analysis by the SPSS 23.0 program. Results: Health behavior was significantly correlated with family function (r=.30, p<.001) and illness perception of controllability by treatment (r=-.21, p=.007). Family function was a significant predictor of health behavior and illness perception, and the influence of family function on health behavior was partially mediated by illness perception of controllability by treatment. Conclusion: The findings of this study indicate that family function is a critical factor affecting health behavior and illness perception, and illness perception of controllability by treatment mediates the influence of family function on health behavior. It is necessary to develop a psycho-cognitive intervention program for enhancing supportive family function and for modifying negative illness perceptions to improve health behavior in patients with risk factors for metabolic syndrome.

Effects of Academic Relationships on Academic Burnout in Health Professions Students (보건의료계 학생에서 학업적 대인관계가 학업소진에 미치는 영향)

  • Jang, Junhwan;Bae, Seonhwan;Kim, Gyungjae;Kim, Doyoung;Park, Junseong;Lee, Seunghyeon;Park, Mira;Kim, Do-Hwan
    • Korean Medical Education Review
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    • v.21 no.2
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    • pp.100-111
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    • 2019
  • There are several dimensions of academic burnout experienced by medical and health science college students. The purpose of this study was to examine the effects of academic relationships on academic burnout. Data was collected from 476 Eulji University students using an online survey over 4 days in April of 2018. Of the 264 respondents, 111 studied medicine (42.0%), 105 studied nursing (39.8%), and 48 studied clinical pathology (18.1%). The questionnaire was composed of the following sections: demographics (four questions), general life characteristics (seven questions), academic enthusiasm (eight questions), academic relationships (15 questions), and academic burnout sub-dimensions (partially revised Maslach Burnout Inventory-Student Survey Scale) (11 questions). T-tests and one-way analysis of variance were performed to illustrate the differences among the three departments. The effects of academic relationships and academic enthusiasm on academic burnout were analyzed using linear regression. Comparing the three departments, academic burnout was not found to be statistically significant (p=0.296). However, medical students' academic enthusiasm was significantly lower (p<0.001) and academic relationships were significantly higher (p<0.001) than nursing and clinical pathology students. The difference in academic burnout among the three departments was not significant. However, medical students have stronger academic relationships, while nursing and clinical pathology students were more focused on academics. Relationships and academic enthusiasm contribute to reducing academic burnout. Therefore, strategies need to be developed to deal with academic burnout considering relationship factors.

Structural relationship of dental hygienist image, major satisfaction, and dropout intention (치과위생사 이미지, 전공만족도 및 중도탈락의도의 구조적 관계)

  • Kim, Chang-Hee;Kim, Jung-Hee;Kim, Hyeong-Mi
    • Journal of Korean society of Dental Hygiene
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    • v.22 no.2
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    • pp.143-151
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    • 2022
  • Objectives: This study investigates dropout intention and the structural relationship between the dental hygienist role and satisfaction with the study major perceived by dental hygiene students. Methods: A survey was conducted on 269 dental hygiene students. The survey items covered general characteristics, department choice motivation, the desirability of dental hygienist career, practice clinical experience, perception of dental hygienist role, satisfaction with study major, and dropout intention. Independent sample t-test, one-way ANOVA, Mann-Whitney U test, multiple linear regression analysis, and structural equation modeling were used for statistical analysis. Results: The dropout intention level of dental hygiene students was 2.4 out of 5.0. Satisfaction with study major partially mediates perception of dental hygienist role and dropout intention (direct effect=0.182, p=0.024, indirect effect=-0.437, p=0.010). Perception of dental hygienist role (β=-0.255, p=0.010) and satisfaction with study major (β=-0.661, p=0.010) showed a negative relationship with dropout intention. The factor most affecting dropout intention was satisfaction with study major. Dropout intention was high when selecting a major based on external motivations (β=-0.448, p<0.001). Conclusions: Perception of dental hygienist role and satisfaction with study major directly or indirectly affect dropout intention. Therefore, improving satisfaction with study major and improving the perception of dental hygienists will help reduce dropout intention.

The Distribution of Tax Collectability, Quality of Tax Services Efforts to Tax Coverage Ratio

  • Muh.RUM;Muryani ARSAL;Ansyarif KHALID;Murtiadi AWALUDDIN
    • Journal of Distribution Science
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    • v.21 no.6
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    • pp.107-117
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    • 2023
  • Purpose: To know the existence of tax services, it is seen as a redistribution of income to ensure the implementation of national development and social welfare carried out by the state to the community and determine the effect of the quality of tax services, tax audits and tax collection against either simultaneously or partially against the tax ratio in the area of the Primary Tax Service Office of West Makassar. Research Design Data and Methodology: The tax revenue rate is too low based on the Revenue Statistics in Asian and Pacific report, released by the OECD at the end of July 2017. Tax revenue growth is also difficult to increase because of typical inelastic tax revenues. Consequently, tax growth cannot exceed GDP growth. The government boosted the tax ratio by minimizing tax payment irregularities and optimizing tax data utilization as well as distribution income for national social welfare. Transforming all sectors in the real economy so that it is affordable to tax, diversification of taxation is directed towards new sources of economic growth. The data analysis method used is multiple linear regression. Results: The results showed that the quality of tax services and tax audits were dominant in determining tax ratios, whereas Tax collection offers a significant but lower value.Conclusion: The existence of tax services, it is seen as a redistribution of income to ensure the implementation of national development and social welfare carried out by the state to the community.Quality and service in taxation services to create and maintain trust and cooperation relationships between tax officials and taxpayers.

Association between Korean Healthy Eating Index and abdominal obesity in Korean adults: the mediating effect of high-sensitivity C-reactive protein (한국 성인의 식생활평가지수 및 복부비만의 관계: 고감도 C-반응 단백질의 매개효과)

  • Jina Yoon;Dayeon Shin
    • Journal of Nutrition and Health
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    • v.57 no.1
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    • pp.88-104
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    • 2024
  • Purpose: High-sensitivity C-reactive protein (hs-CRP) is primarily synthesized in the liver upon stimulation of infectious disease cytokines, such as interleukin-6 (IL-6), and is used as a biological marker of systemic inflammation. Previous studies reported that hs-CRP is closely related to diet and abdominal obesity. Furthermore, a dietary score favoring the consumption of vegetables, fruits, and whole grains over meat and saturated fat reduced inflammation and decreased the prevalence of obesity and abdominal obesity. Nevertheless, no studies have examined whether hs-CRP mediates the relationship between dietary scores and abdominal obesity, and research on the Korean Healthy Eating Index (KHEI) is lacking. Therefore, the present study examined the association between the KHEI and abdominal obesity and the mediating effect of hs-CRP. Methods: In total, 17,770 adults aged ≥19 years were included in the study using the Korea National Health and Nutrition Examination Survey 2015-2018. KHEI was developed to assess the overall diet quality of Korean adults. Multivariable linear and logistic regression analyses assessed the relationship between KHEI, hs-CRP, and abdominal obesity. The mediation analysis with the bootstrapping method was performed using SAS MACRO. Results: Among women, the odds ratio (OR) of abdominal obesity prevalence was lower in the highest KHEI compared to the lowest KHEI after adjusting for age, body mass index, educational level, income level, occupational status, marital status, household type, region type, alcohol consumption, smoking status, physical activity, total energy intake, and hsCRP (OR 0.744, 95% confidence interval 0.598-0.926). The association between KHEI and abdominal obesity was partially mediated via hs-CRP, and the mediated proportion was 68.7% in men and 38.1% in women. Conclusion: A substantial relationship was observed between the KHEI and abdominal obesity among females. Moreover, according to the KHEI, abdominal obesity may be mediated partially by hs-CRP.

Extraction Conditions and Green Index of Green Pigments from Discolored Garlic (녹변된 마늘의 색소 추출 조건과 Green Index)

  • Hwang, Jin-Bong;Ha, Jae-Ho;Shin, Dong-Bin;Park, Wan-Soo;Nahmgung, Bae;Lee, Young-Chun
    • Korean Journal of Food Science and Technology
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    • v.37 no.4
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    • pp.678-684
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    • 2005
  • Extraction conditions, spectrometric, and sensory properties of pigment extracts from green discolored garlic (GDG) were studied for development of green index to evaluate degree of green discoloration of garlic. GDG pigments were extracted using polar solvents, such as methanol, ethanol, and water. Methanol with 1% HCl resulted in highest extraction of green pigments. Extraction of pigments was affected by temperature, and extracted pigments were partially destroyed at high temperatures. Optimum conditions for extraction of green pigments were $20^{\circ}C$ for 30 min. Because green pigments are unstable at room temperature, and no method has been reported to evaluate degree of green discoloration of garlic, color chart was designed by mixing varying amounts of control and GDG. High correlation was observed between sensory scores and "a" value of color chart samples (y=-3.465x - 11.676) with $R^2$ of 0.993. Green index (GI) was developed based on linear regression equation between sensory scores and "a" values. Sensory panel recognized green discoloration of garlic at $GI{\geq}3.0$. GI developed in this study could be utilized to evaluate degree of green discoloration of garlic during cold storage and distribution of garlic.