• Title/Summary/Keyword: variable importance

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Estimation of the Effects of Daily Walking Hours and Days on the Mental Health of Urban Residents - The Case in Seoul - (주거지역 가로환경 및 일상 걷기가 정신 건강에 미치는 영향 - 서울시 대상으로 -)

  • Koo, Bonyu;Baek, Seungjoo;Yoon, Heeyeun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.52 no.1
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    • pp.87-100
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    • 2024
  • This study aimed to investigate the impact of the quality of the street environment in residential areas on the mental health of urban residents, considering the frequency of street use. Using a zero-inflated negative binomial regression model, the study analyzed the influence of walking frequency and the street environment on depressive symptoms of urban residents. The research focused on Seoul, South Korea, in 2017, with depressive symptoms as the dependent variable and street environment variables, walking variables, and individual characteristics as independent variables. Additionally, the study explores the interaction effect of street greenery and walking frequency to analyze the synergistic impacts of walking in green spaces on mental health. The findings indicate that a higher ratio of street green areas is associated with fewer depressive symptoms. Increased walking frequency is linked to a reduction in depressive symptoms or a weaker manifestation of such symptoms. The interaction effect confirms that more frequent walking in green spaces is associated with weaker depressive symptoms. Lower ratios of visual complexity are correlated with reduced depressive symptoms. This study contributes to addressing urban residents' mental health issues at the community level by emphasizing the importance of the street green environment in residential areas.

Study of the Derive of Core Habitats for Kirengeshoma koreana Nakai Using HSI and MaxEnt (HSI와 MaxEnt를 통한 나도승마 핵심서식지 발굴 연구)

  • Sun-Ryoung Kim;Rae-Ha Jang;Jae-Hwa Tho;Min-Han Kim;Seung-Woon Choi;Young-Jun Yoon
    • Korean Journal of Environment and Ecology
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    • v.37 no.6
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    • pp.450-463
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    • 2023
  • The objective of this study is to derive the core habitat of the Kirengeshoma koreana Nakai utilizing Habitat Suitability Index (HSI) and Maximum Entropy (MaxEnt) models. Expert-based models have been criticized for their subjective criteria, while statistical models face difficulties in on-site validation and integration of expert opinions. To address these limitations, both models were employed, and their outcomes were overlaid to derive the core habitat. Five variables were identified through a comprehensive literature review and spatial analysis based on appearance coordinates. The environmental variables encompass vegetation zone, forest type, crown density, annual precipitation, and effective soil depth. Through surveys involving six experts, importance rankings and SI (Suitability Index) scores were established for each variable, subsequently facilitating the creation of an HSI map. Using the same variables, the MaxEnt model was also executed, resulting in a corresponding map, which was merged to construct the definitive core habitat map. Out of 16 observed locations of K. koreana, 15 were situated within the identified core habitat. Furthermore, an area historically known to host K. koreana but not verified in the present, Mt. Yeongchwi, was found to lack a core habitat. These findings suggest that the developed models exhibit a high degree of accuracy and effectively reflect the current ecological landscape.

Effects of Experiential Fishing Village Authenticity on Experience Value and Subjective Well-being (어촌체험휴양마을의 고유성이 체험가치와 주관적 행복감에 미치는 영향)

  • Sung-Dae Cho;Chang-Soo Kim
    • The Journal of Fisheries Business Administration
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    • v.55 no.1
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    • pp.55-76
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    • 2024
  • The purpose of this study is to elucidate the impact of authenticity on experience value and subjective well-being among visitors who have participated in direct experiential activities in experiential fishing villages. The research method used literature research methods and empirical research methods using questionnaires, and this questionnaire was composed by determining three major variables and seven constituent factors for each variable through factor analysis and conducting prior research and preliminary surveys. The survey was conducted from February 5, 2023 to April 5, 2023 among experimental fishing villages with excellent ratings for scenery (environment), service, experience, accommodation, and food, and four villages that can experience tidal flats and manage customers online. The survey was conducted from February 5, 2023 to April 5, 2023, among experimental fishing villages with excellent ratings for scenery (environment), service, experience, accommodation, and food, and four villages that can experience tidal flats and manage customers online. The results of this study are as follows. First, the factors of authenticity in experiential fishing villages include three sub-factors: objective authenticity, constructive authenticity, and existential authenticity. The factors of experience value include two sub-factors: emotional values and functional values. Subjective well-being is derived from positive emotion and life satisfaction. Second, upon examining the importance of authenticity in experiential fishing villages, it was found that existential authenticity and objective authenticity, in that order, have a significant impact on emotional values. However, constructive authenticity did not have a significant impact on emotional values. Third, in terms of functional values, constructive authenticity, existential authenticity, and objective authenticity, in that order, had a significant impact. Fourth, experience value, in the order of emotional values and functional values, had a significant impact on positive emotion and life satisfaction of subjective well-being. Therefore, it was confirmed that the authenticity of experiential fishing villages is important as a strategy to enhance experience value and subjective well-being. Especially, considering that the majority of visitors to experiential fishing villages are family-centered (86.5%), applying marketing management strategies to develop programs that enhance existential authenticity and improve emotional values could elevate the subjective well-being of experiential visitors.

Effects of High-Speed Train on Regional Population In-Migration - Focusing on Shrinking City and Demographic Structure - (고속철도가 지역 인구 이동에 미치는 영향 -지방소멸 위험과 인구 구조를 중심으로-)

  • Eunji Kim;Heeyeun Yoon
    • Journal of the Korean Regional Science Association
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    • v.40 no.2
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    • pp.91-106
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    • 2024
  • Around the world, many countries experiencing the issue of shrinking cities are continually expanding high-speed rail networks to enhance regional accessibility and address imbalances. This study analyzed the effects of high-speed train operations on the age-specific population migration in South Korean municipalities from 2012 to 2019, taking into account the risk levels of shrinking cities. For this purpose, an analysis was conducted using age-specific net in-migration population as the dependent variable, employing the spatial panel autoregressive model. The research results indicated that the influence of high-speed rail on regional population inflow varies depending on the risk level of shrinking city. In other words, high-speed railway operations had positive effects on population inflow in the capital areas and some major cities, while explained population outflow in the other regions. High-speed railways particularly exerted a significant impact on the inflow of the young and middle-aged population, representing the working age, but this effect was also limited to regions with a low risk of shrinkage. The findings of this study emphasize the importance of considering planned population and industrial attraction when installing high-speed rail with the goal of achieving regional balanced development and mitigating shrinkage. The results of this study also suggest the need for subsequent research to explore factors that positively influence population structure and inflow based on the level of shrinkage risk in each region, as well as the introduction of new policies tailored to the specific situations of each local government.

Influence of College Students' and Parents' Interest of Entrepreneurship on Intention (대학생과 부모의 창업관심이 창업의도에 미치는 영향)

  • HyeJin An;SeungHa Lee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.19 no.1
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    • pp.33-53
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    • 2024
  • By identifying the relationship between Interest of Entrepreneurship and intention, this study clarifies the entire lifecycle process leading up to a college student's decision to start a business. We explore whether an individual's Interest of Entrepreneurship stemming from start-up activities and the interest of parents toward their children's start-up affect start-up intention. For this purpose, attitude toward start-up, subjective norms, and perceived behavioral control, which are components of the Theory of Planned Behavior (TPB), were set as parameters. Furthermore, start-up self-efficacy was established as a moderating variable to examine the relationships between factors and their importance. In addition, survey questionnaires were collected from 300 college students in Korea, and after excluding 18 insincere responses, a total of 282 were analyzed using SPSS 26 and AMOS 26. The main findings are as follows. First, an individual's Interest of Entrepreneurship has a significant impact on start-up intention, mediated by attitude toward start-up, subjective norms, and perceived behavioral control. Therefore, future college start-up education should apply the components of TPB to enhance its effectiveness, and various start-up activities should be provided to foster students' interest. Secondly, parents' interest in start-up has a significant impact on subjective norms and perceived behavioral control. Therefore, even if parents are interested in their children's start-up activities, such interest does not necessarily lead to favorable attitude. However, as it significantly impacts subjective norms and perceived behavioral control, start-up education targeting parents linked to these parameters could increase college students' Interest of Entrepreneurship and intentions.

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Estimation of Cerchar abrasivity index based on rock strength and petrological characteristics using linear regression and machine learning (선형회귀분석과 머신러닝을 이용한 암석의 강도 및 암석학적 특징 기반 세르샤 마모지수 추정)

  • Ju-Pyo Hong;Yun Seong Kang;Tae Young Ko
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.26 no.1
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    • pp.39-58
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    • 2024
  • Tunnel Boring Machines (TBM) use multiple disc cutters to excavate tunnels through rock. These cutters wear out due to continuous contact and friction with the rock, leading to decreased cutting efficiency and reduced excavation performance. The rock's abrasivity significantly affects cutter wear, with highly abrasive rocks causing more wear and reducing the cutter's lifespan. The Cerchar Abrasivity Index (CAI) is a key indicator for assessing rock abrasivity, essential for predicting disc cutter life and performance. This study aims to develop a new method for effectively estimating CAI using rock strength, petrological characteristics, linear regression, and machine learning. A database including CAI, uniaxial compressive strength, Brazilian tensile strength, and equivalent quartz content was created, with additional derived variables. Variables for multiple linear regression were selected considering statistical significance and multicollinearity, while machine learning model inputs were chosen based on variable importance. Among the machine learning prediction models, the Gradient Boosting model showed the highest predictive performance. Finally, the predictive performance of the multiple linear regression analysis and the Gradient Boosting model derived in this study were compared with the CAI prediction models of previous studies to validate the results of this research.

Evaluation of the operational efficiency of major coastal ports in China based on the PCA-DEA model (PCA-DEA 모델을 기반으로 한 중국 주요연안 항만의 운영 효율성 평가)

  • Haiqing Zhang;Hyangsook Lee
    • Journal of Korea Port Economic Association
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    • v.40 no.1
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    • pp.87-118
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    • 2024
  • Coastal ports play an essential role in developing a country and a city. Port efficiency is an important factor affecting port trade, and the importance of port efficiency for port performance has been recognized in previous literature. DEA (Data Envelopment Analysis) and SFA (Stochastic Frontier Analysis) are widely used in this field of research. However, these two methods are limited in selecting input and output variables. In addition, the literature studies on Chinese coastal ports mainly focus on the study of port clusters in local areas, which lacks a holistic approach and generally lacks up-to-date data. Therefore, to fill the gap in this area of research, this paper introduces a model combining principal component analysis and data envelopment analysis to analyze the operational efficiency of the top 17 coastal ports in China in terms of throughput based on the most recent data available in 2021. This paper identifies container throughput as the output variable, and 13 second indicators are selected as input variables from four primary indicators: land, capital, labor, and infrastructure. Four principal components were selected from 13 second indicators using PCA.After that, DEA (BBC) and DEA (CCR) were used to analyze the 17 ports, among which five were Shanghai, Ningbo-Zhoushan, Guangzhou, Xiamen, and Dongguan, respectively, DEA efficient, and the remaining 12 ports were non-DEA efficient. Finally, improvement directions for each port are derived, and brief suggestions are made. This paper provides some reference value for developing and constructing coastal ports in China.

Discussion on Detection of Sediment Moisture Content at Different Altitudes Employing UAV Hyperspectral Images (무인항공 초분광 영상을 기반으로 한 고도에 따른 퇴적물 함수율 탐지 고찰)

  • Kyoungeun Lee;Jaehyung Yu;Chanhyeok Park;Trung Hieu Pham
    • Economic and Environmental Geology
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    • v.57 no.4
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    • pp.353-362
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    • 2024
  • This study examined the spectral characteristics of sediments according to moisture content using an unmanned aerial vehicle (UAV)-based hyperspectral sensor and evaluated the efficiency of moisture content detection at different flight altitudes. For this purpose, hyperspectral images in the 400-1000nm wavelength range were acquired and analyzed at altitudes of 40m and 80m for sediment samples with various moisture contents. The reflectance of the sediments generally showed a decreasing trend as the moisture content increased. Correlation analysis between moisture content and reflectance showed a strong negative correlation (r < -0.8) across the entire 400-900nm range. The moisture content detection model constructed using the Random Forest technique showed detection accuracies of RMSE 2.6%, R2 0.92 at 40m altitude and RMSE 2.2%, R2 0.95 at 80m altitude, confirming that the difference in accuracy between altitudes was minimal. Variable importance analysis revealed that the 600-700nm band played a crucial role in moisture content detection. This study is expected to be utilized in efficient sediment moisture management and natural disaster prediction in the field of environmental monitoring in the future.

Characteristics of posteroanterior cephalometric analysis in children with skeletal Class I malocclusion (성장기 골격성 I 급 부정교합 환자의 정모두부방사선 계측의 특징)

  • Moon, Yoon-Shik;Kim, Jung-Kook;Jung, Hyun-Sung;Sung, Sang-Jin
    • The korean journal of orthodontics
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    • v.31 no.2 s.85
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    • pp.159-172
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    • 2001
  • Three dimensional analysis of malocclusion and craniofacial deformation is essential for the successful orthodontic treatment. But the orthodontists are not familiar with diagnosis and treatment plane based on lateral cephalometric analysis. Since orthodontists do not posses a sufficient knowledge in standard value of posteroanterior cephalometric anaysis and of clinical importance for transverse jaw growth. In this study male(n=130) and female(n=171) aged from 6 to 16 and diagnosed as Class I malocclusion were selected to analysis width of cranium, maxilla and mandible on the posteroanterior cephalogram. The changes as a function of chronologic age and cervical vertebrae maturity index(CVXI) were examined. The Proper regression model was selected by sex with polynominal regression models and method of variable selection. Mean of each measurements and 70% confidence interval of individual measurement according to age was assesed and a graphs were made. Results are as follows :1. All the measurements for the width are gradually incresed as increase in chronologic age and CVMI. From the total amount of change between age 6 and 16, there is a tendency that mandibular width is broader than maxillary width and the width of male is broader than female. 2. There is no statistically significant sexual difference in Mx-Mn difference, Mx-Mn width differential, Mx/Mn ratio according to age and CVMI. 3. Mean of each measurement and 70% confidence interval of individual measurement according to age and sex were assessed and graphs were made for maxillary width, mandibular width, Mx-Mn difference, Mx/Mn ratio. 4. The width of maxilla and mandible in Korean children are broader than Western children during growth period.

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Effect of Residential Environment on the Health Status in Apartment Inhabitants (아파트 주민의 건강상태에 거주 환경이 미치는 영향)

  • Kang, Ki-Won;Kim, Hwa-Joon;Kwon, Geun-Yong;Jung, Min-Soo
    • Journal of agricultural medicine and community health
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    • v.34 no.3
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    • pp.279-290
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    • 2009
  • Objectives: WHO insisted on that we should study about association between residential environment and health status and make 'health city' concept as practical motto. This study analyzed about that how community environment affected their health. Methods: We surveyed residential environment satisfaction and health status of a apartment complex residents. We transformed Chun's index about housing environment study and social capital index of WHO and used as community health survey. We analyzed the association between health status and related factor by using principal compound analysis and logistic regression analysis. Results: We found out that the perceived health status 1 years ago was highly related to the residential environment and also extracted five residential environment component (APT maintenance, House, APT complex, Neighbor, APT building) by principal component analysis. After residential environment component, demographic and socioeconomic variable were controlled, the high satisfaction group of APT complex and neighbor relationship was in lower risk of perceived health status 1 years ago than the low satisfaction group. Conclusions: Recently, the importance of residential environment and neighborhood is shaped as community capacity. Therefore, social relationship and residential environment should be the core variable for health promotion of community. After all, we should know the relationship of residential environment and perceived health status 1 years ago. This helps the concept of health city clearly.