• Title/Summary/Keyword: poisson regression analysis

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Analysis of Disaster Occurrences in Mongolia Based on Climatic Variables (기후변수를 기반으로 한 몽골 재해발생 분석)

  • Da Hye Lee;Onon-Ujin Otgonbayar;In Hong Chang
    • Journal of Integrative Natural Science
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    • v.17 no.3
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    • pp.93-103
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    • 2024
  • Mongolia's diverse geographical landscape and harsh climate make it particularly susceptible to various natural disasters, including forest fires, heavy rains, dust storms, and heavy snow. This study aims to explore the relationships between key climatic variables and the frequency of these disasters. We collected monthly data from January 2022 to April 2024, encompassing average temperature, temperature variability (absolute temperature difference), average humidity, and precipitation across the capitals of Mongolia's 21 provinces and the capital city Ulaanbaatar. The data were analyzed using multiple statistical models: Linear Regression, Poisson Regression, and Negative Binomial Regression. Descriptive statistics provided initial insights into the variability and distribution of the climatic variables and disaster occurrences. The models aimed to identify significant predictors and quantify their impact on disaster frequencies. Our approach involved standardizing the predictor variables to ensure comparability and interpretability of the regression coefficients. Our findings indicate that climatic variables significantly affect the frequency of natural disasters. The Negative Binomial Regression model was particularly suitable for our data, which exhibited overdispersion common characteristic in count data such as disaster occurrences. Understanding these relationships is crucial for developing targeted disaster management strategies and policies to mitigate the adverse effects of climate change on Mongolian communities. This research provides valuable insights into how climatic changes impact disaster occurrences, offering a foundation for informed decision-making and policy development to enhance community resilience.

Developing the Accident Models of Cheongju Arterial Link Sections Using ZAM Model (ZAM 모형을 이용한 청주시 간선가로 구간의 사고모형 개발)

  • Park, Byung-Ho;Kim, Jun-Yong
    • International Journal of Highway Engineering
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    • v.12 no.2
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    • pp.43-49
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    • 2010
  • This study deals with the traffic accident of the Cheongju arterial link sections. The purpose of the study is to develop the traffic accident model. In pursuing the above, this study gives particular attentions to developing the ZAM(zero-altered model) model using the accident data of arterial roads devided by 322 small link sections. The main results analyzed by ZIP(zero inflated Poisson model) and ZINB(zero inflated negative binomial model) which are the methods of ZAM, are as follows. First, the evaluation of various developed models by the Vuong statistic and t statistic for overdispersion parameter ${\alpha}$ shows that ZINB is analyzed to be optimal among Poisson, NB, ZIP(zero-inflated Poisson) and ZINB regression models. Second, ZINB is evaluated to be statistically significant in view of t, ${\rho}$ and ${\rho}^2$ (0.63) values compared to other models. Finally, the accident factors of ZINB models are developed to be the traffic volume(ADT), number of entry/exit and length of median. The traffic volume(ADT) and the number of entry/exit are evaluated to be the '+' factors and the length of median to be '-' factor of the accident.

A Study on the Influence of the Space Syntax and the Urban Characteristics on the Incidence of Crime Using Negative Binomial Regression (음이항 회귀모형을 이용한 공간구문론 및 도시특성요소가 범죄발생에 미치는 영향 연구)

  • Kim, Hyeong Jun;Choi, Yeol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.2
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    • pp.333-340
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    • 2016
  • The aim of this study is to specifically understand the characteristics of the crime by empirical analysis for the determining factors that affect determining the crime through the space syntax in Busan. In this study, poisson regression and negative binomial regression were used for accurate analysis. 8 variables that were significant of the total 13 variables. The summary if this study based on the results is as follow. Statistically significant variables are female ratio, over 65 population ratio, administration are and commercial area ratio in characteristics. And the more CCTVs a region has, the lower crime rate it shows. As a results of examing whether space syntax variables can predict crime occurrence places. Space with low connectivity come to be a crime causal factor because they have few other related spaces and thereby have low possibility of sudden appearance of interrupters, which results in low surveillance levels of foot passengers. It will provide the basic data that can contribute to urban planning and implementation of crime prevention aspects.

Rear-end Accident Models of Rural Area Signalized Intersections in the Cases of Cheongju and Cheongwon (청주.청원 지방부 신호교차로의 후미추돌 사고모형)

  • Park, Byoung-Ho;In, Byung-Chul
    • International Journal of Highway Engineering
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    • v.11 no.2
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    • pp.151-158
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    • 2009
  • This study deals with the rear-end collisions in the rural aiea. The objectives of this study are 1) to analyze the characteristics of rear-end accidents of signalized intersections, and 2) to develop the accident models for Cheongju-Cheongwon. In pursing the above, this study gives the particular attentions to comparing the characters of urban and rural area. In this study, the dependent variables are the number of accidents and value of EPDO(equivalent property damage only), and independent variables are the traffic volumes and geometric elements. The main results analyzed are the followings. First, the statistical analyses show that the Poisson accident model using the number of accident as a dependant variable are statistically significant and the negative binomial accident model using the value of EPDO are statistically significant. Second, the independent variables of Poisson model are analyzed to be the ratio of high-occupancy vehicles, total traffic volume and the sum of exit/entry, and those of negative binomial regression are the main road width, total traffic volume and the ratio of high-occupancy vehicles. Finally, the specific independent variables to the rural area are the main road width, the ratio of high occupancy vehicle, and the sum exit/entry.

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A Study of Bicycle Crash Analysis at Urban Signalized Intersections (도시부 신호교차로에서의 자전거사고 분석)

  • Oh, Ju-Taek;Kim, Eung-Cheol;Ji, Min-Kyung
    • International Journal of Highway Engineering
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    • v.9 no.2 s.32
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    • pp.1-11
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    • 2007
  • The rapid growths of economy and automobiles since the 1970's have caused serious traffic jams and environmental disruption in urban areas. To relieve these problems caused by urbanization, there should be considered alternative means of transportation modes. Many developed countries have accepted bicycles as a so called "Green Mode" for environmentally oriented strategies to increase the qualities of urban lives. Korea have also attempted various means to raise bicycle usages. In this research, significant factors affecting bicycle crashes at signalized intersections in urban areas were studied. The model results showed that Poisson regression is the best fit methodology for data modeling and revealed that traffic volume, a number of driveways, configuration of the ground, presence of bicycle path, school, and bus stop, residential area, size of intersection are significant factors affecting the bicycle crashes.

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The Effect of Pornography Use Among Adolescents on Violent Sexual Behavior and the Moderating Effect of Family Support (청소년의 음란물 이용이 성폭력 가해행동에 미치는 영향 : 가족지지의 조절효과를 중심으로)

  • Kim, Jae Yop;Choi, Sunah;Lim, Jeong Su
    • Human Ecology Research
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    • v.59 no.4
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    • pp.489-500
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    • 2021
  • The purpose of this study was to identify the impact of pornography use among adolescents on their subsequent violent sexual behavior, and to ascertain the moderating effect of family support. The study was conducted with a sample of 2,087 Korean middle and high-school students. To analyze the data, a descriptive analysis, a correlation analysis, and a Poisson regression were conducted using SPSS 24.0. A Poisson regression was performed because the dependent variable, violent sexual behavior, was measured by the frequency of occurrence, and most responses were distributed at '0', indicating a non-normal distribution. The results indicated that 8.1% of adolescents admitted to having sexually violent experiences over the past year, with a relatively high rate of sexual harassment. Secondly, 53.3% of adolescents had used pornography over the past couple of years, with the highest percentage of use occurring via the Internet. Finally, pornography use among adolescents had a significant and direct impact on their sexually violent behavior, with family support playing a moderating role. This indicated that, for adolescents with a high level of family support, the impact of pornography usage on sexually violent behavior decreased. Based on these results, we discuss practical and policy interventions to prevent sexually violent behavior by adolescents.

Application of a Geographically Weighted Poisson Regression Analysis to Explore Spatial Varying Relationship Between Highly Pathogenic Avian Influenza Incidence and Associated Determinants (공간가중 포아송 회귀모형을 이용한 고병원성 조류인플루엔자 발생에 영향을 미치는 결정인자의 공간이질성 분석)

  • Choi, Sung-Hyun;Pak, Son-Il
    • Journal of Veterinary Clinics
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    • v.36 no.1
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    • pp.7-14
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    • 2019
  • In South Korea, six large outbreaks of highly pathogenic avian influenza (HPAI) have occurred since the first confirmation in 2003 from chickens. For the past 15 years, HPAI outbreaks have become an annual phenomenon throughout the country and has extended to wider regions, across rural and urban environments. An understanding of the spatial epidemiology of HPAI occurrence is essential in assessing and managing the risk of the infection; however, local spatial variations of relationship between HPAI incidences in Korea and related risk factors have rarely been derived. This study examined whether spatial heterogeneity exists in this relationship, using a geographically weighted Poisson regression (GWPR) model. The outcome variable was the number of HPAI-positive farms at 252 Si-Gun-Gu (administrative boundaries in Korea) level notified to government authority during the period from January 2014 to April 2016. This response variable was regressed to a set of sociodemographic and topographic predictors, including the number of wild birds infected with HPAI virus, the number of wintering birds and their species migrated into Korea, the movement frequency of vehicles carrying animals, the volume of manure treated per day, the number of livestock farms, and mean elevation. Both global and local modeling techniques were employed to fit the model. From 2014 to 2016, a total of 403 HPAI-positive farms were reported with high incidence especially in western coastal regions, ranging from 0 to 74. The results of this study show that local model (adjusted R-square = 0.801, AIC = 954.5) has great advantages over corresponding global model (adjusted R-square = 0.408, AIC = 2323.1) in terms of model fitting and performance. The relationship between HPAI incidence in Korea and seven predictors under consideration were significantly spatially non-stationary, contrary to assumptions in the global model. The comparison between global Poisson and GWPR results indicated that a place-specific spatial analysis not only fit the data better, but also provided insights into understanding the non-stationarity of the associations between the HPAI and associated determinants. We demonstrated that an empirically derived GWPR model has the potential to serve as a useful tool for assessing spatially varying characteristics of HPAI incidences for a given local area and predicting the risk area of HPAI occurrence. Considering the prominent burden of HPAI this study provides more insights into spatial targeting of enhanced surveillance and control strategies in high-risk regions against HPAI outbreaks.

Ensemble variable selection using genetic algorithm

  • Seogyoung, Lee;Martin Seunghwan, Yang;Jongkyeong, Kang;Seung Jun, Shin
    • Communications for Statistical Applications and Methods
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    • v.29 no.6
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    • pp.629-640
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    • 2022
  • Variable selection is one of the most crucial tasks in supervised learning, such as regression and classification. The best subset selection is straightforward and optimal but not practically applicable unless the number of predictors is small. In this article, we propose directly solving the best subset selection via the genetic algorithm (GA), a popular stochastic optimization algorithm based on the principle of Darwinian evolution. To further improve the variable selection performance, we propose to run multiple GA to solve the best subset selection and then synthesize the results, which we call ensemble GA (EGA). The EGA significantly improves variable selection performance. In addition, the proposed method is essentially the best subset selection and hence applicable to a variety of models with different selection criteria. We compare the proposed EGA to existing variable selection methods under various models, including linear regression, Poisson regression, and Cox regression for survival data. Both simulation and real data analysis demonstrate the promising performance of the proposed method.

Traffic Accident Models of 3-Legged Signalized Intersections in the Case of Cheongju (3지 신호교차로의 교통사고 발생모형 - 청주시를 사례로 -)

  • Park, Byung-Ho;Han, Sang-Uk;Kim, Tae-Young
    • Journal of the Korean Society of Safety
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    • v.24 no.2
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    • pp.94-99
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    • 2009
  • This study deals with the traffic accidents at the 3-legged signalized intersections in Cheongu. The goals are to analyze the geometric, traffic and operational conditions of intersections and to develop a various functional forms that predict the accidents. The models are developed through the correlation analysis, the multiple linear, the multiple nonlinear, Poisson and negative binomial regression analysis. In this study, two multiple linear, two multiple nonlinear and two negative binomial regression models were calibrated. These models were all analyzed to be statistically significant. All the models include 2 common variables(traffic volume and lane width) and model-specific variables. These variables are, therefore, evaluated to be critical to the accident reduction of Cheongju.

A Study on the Statistical Analysis of Korea Patent Information (한국특허정보의 통계분석에 관한 연구)

  • Uhm, Dai-Ho;Chang, Young-Bae;Jeong, Eui-Seop
    • Journal of Information Management
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    • v.41 no.3
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    • pp.27-44
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    • 2010
  • Most research about patent data analyzes the trend of technologies using a Patent Map(PM), and suggests the frequencies and trend of patents in a certain topic using tables or graphs in Excel. However, more advanced analysis tools are recently needed to compare the trends among national and international industries. This research discussed why statistical analysis is needed to improve the reliability in PM analysis, and the research compares the trends of patents in Korea between 1990 and 2004 by years, International Patent Classification(IPC) sections, and countries using the frequencies and Poisson regression model. The statistical analysis is also suggested and applied to R&D studies.