• Title/Summary/Keyword: Negative binomial regression

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Study on Shared E-scooter Usage Characteristics and Influencing Factors (공유 전동킥보드 이용 특성 및 영향요인에 관한 연구)

  • Kim, Su jae;Lee, Gyeong jae;Choo, Sangho;Kim, Sang hun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.1
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    • pp.40-53
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    • 2021
  • Recently, shared dockless e-scooter usage has rapidly increased, rather than the station-based shared mobility service, because of convenience. This transition leads to new social problems in urban areas such as increased traffic accidents and hindrance of pedestrian environments. In this study, we analyze the usage characteristics of shared e-scooters in Seoul, and identify factors influencing demand for shared e-scooters by developing a negative binomial regression model. As a result, the usage characteristics show that the average trip distance, the average trip duration, and the average trip speed were 1.5km, 9.4min, and 10.3km/h, respectively. Demographic factor, transport facility factors, land use factors, and weather factors have statistically significant impacts on demand for shared e-scooters. The results of this study will be used as basic data for suggesting effective operation strategies for areas with higher shared e-scooter demand and for establishing transport policies for facilitating shared e-scooter usage.

Development of a Pedestrian Accident Exposure Estimation Modelconsidering Walking Conflicts (보행상충을 고려한 보행사고 노출 추정 모형 개발)

  • Iljoon Chang;Nam ju Kwon;Se-young Ahn
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.22 no.2
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    • pp.54-63
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    • 2023
  • Pedestrian traffic needs to be accurately quantified to predict effectively pedestrian traffic accidents, however, pedestrian traffic is more difficult to measure than vehicle traffic. In this study, we suggest the time-and cost-effective application of mobile closed-circuit television (CCTV) using a smartphone as an alternative that can collect and analyze real-time data with little. In the present investigation, the pedestrian-vehicle conflict that can develop into an accident was defined as the pedestrian accident exposure. After installing mobile CCTV in 40 sections of Dongseong-ro, Daegu, the pedestrian accident exposure was estimated through negative binomial regression analysis using the collected data. The results of the analysis showed statistically significant changes in the pedestrian accident exposure variables. Based on the present results, a pedestrian accident exposure estimation model was developed which can be used in sections where pedestrian accidents may occur.

Are More Followers Always Better? The Non-Linear Relationship between the Number of Followers and User Engagement on Seeded Marketing Campaigns in Instagram

  • Moon, Suyoung;Yoo, Shijin
    • Asia Marketing Journal
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    • v.24 no.2
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    • pp.62-77
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    • 2022
  • Seeded marketing campaign (SMC) is a newly created type of marketing activities with the widespread use of social media. Previous research has examined to find out the optimal seeding strategy that yields the best outcome from the campaign. This research explores the relationships between the characteristics of the seeded influencer and user engagement. The data consists of information from 1062 seeded Instagram posts posted in September 2020 in Korea and 778 seeded influencers who posted those contents. Analyzed by negative binomial regression, our quadratic model suggests that the relationship between user engagement and the number of followers of the seeded influencer draws an inverted U-shape, indicating influencers with greater number of followers may not always be the best choice for the marketers. Moreover, this research shows that the negative marginal impact coming from the huge number of followers can be attenuated when the influencer is an expert of the seeded product.

Developing the Traffic Accident Severity Models by Vehicle Type (차량유형에 따른 교통사고심각도 분석모형 개발)

  • Kim, Kyung-Hwan;Park, Byung-Ho
    • Journal of the Korean Society of Safety
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    • v.25 no.3
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    • pp.131-136
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    • 2010
  • This study deals with the accident models of arterial link sections by vehicle type. The objectives are to analyze the characteristics of accidents, and to develop the models by type. In pursuing the above, this study uses the data of 414 accidents occurred on 24 major arterial links in 2007. The main results analyzed are as follows. First, the number of accidents is analyzed to account for about 47% in passenger car, 15% in SUV and 10% in trucks. Second, 3 Poisson regression models which are all statistically significant are developed using passenger car, SUV and truck as dependant variables. Finally, AADT and the number of traffic islands as common variables, and the number of pedestrian crossings, lanes, connecting roads, intersections(4-Leg), rate of medians and the number of bus stops as specific variables of the models are selected.

Developing the Traffic Accident Severity Models by Accident Type (사고유형에 따른 교통사고 심각도 모형 개발)

  • Kim, Kyung-Hwan;Park, Byung-Ho
    • Journal of the Korean Society of Safety
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    • v.26 no.6
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    • pp.118-123
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    • 2011
  • This study deals with the traffic accidents of the arterial link sections. The purpose is to comparatively analyze the characteristics and models by accident type using the data of 24 arterial links in Cheongju. In pursuing the above, this study gives particular emphasis to modeling such the accidents as the side-right-angle collision, rear-end collision and side-swipe collision. The main results are the followings. First, six accident models are developed, which are all analyzed to be statistically significant. Second, the models are comparatively evaluated using the common and specific variables by accident type.

Motorcycle Accident Model at Roundabout in Korea using ZAM (ZAM을 이용한 국내 회전교차로 오토바이 사고모형)

  • Park, Byung Ho;Lim, Jin Kang;Na, Hee
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.107-113
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    • 2014
  • The goal of this study is to develop the accident models of motorcycle at roundabouts. In the pursuing the above, this study gives particular attentions to developing the appropriate models using ZAM. The main results are as follows. First, the evaluation of various developed models by the Vuong statistic and over-dispersion parameter shows that ZINB is analyzed to be optimal among Poisson, NB, ZIP(zero-inflated Poisson) and ZINB regression models. Second, the traffic volume, width of central island and width of approach are evaluated to be important variables to the accidents. Finally, the common variables that affect to the accident are selected to be traffic volume and width of approach. This study might be expected to give some implications to the accident research on the roundabout by motorcycle.

Count Data Model for The Estimation of Bus Ridership (Focusing on Commuters and Students in Seoul) (가산자료모형(Count Data Model)을 이용한 버스이용횟수추정에 관한 연구 (서울시 통근.통학자를 대상으로))

  • 문진수;김순관;임강원
    • Journal of Korean Society of Transportation
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    • v.17 no.5
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    • pp.123-135
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    • 1999
  • The rapid increase of Passenger cars which is caused by the discomfort of Public transit and the Preference of automobiles is the major factor of increasing traffic congestions in Seoul With the point that leading the automobilists to the Public transit can be the most important Policy to ease these traffic congestions, this study focuses on the behavioral aspects of company employees and university students and investigates factors influencing bus ridership. To be brief, by estimating bus ridership through count models, this study investigates factors which influence bus ridership and elicits Political suggestions which lead automobilists to Public transit. The Purpose in this study is the application of appropriate count data model. The count data models have been widely applied to the economic area from the middle of the 1980s and to transportation aspect mainly in the foreign countries from the latter half of the 1980s. Even though a few studies in this country employed count data model to count data. all of them were Poisson regression models without suitable tests for the importance of the model specification. In the end, as the result of statistical test, negative binomial regression model which is suitable for overdispersed data was found to be appropriate for the data of weekly bus ridership. To emphasize the importance of model specification, both of poisson regression model and negative binomial regression model were estimated and the results were compared.

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Accident Models of 4-Legged Signalized Intersections by Vehicle Type in the Case of Cheongju (4지 신호교차로 차종별 사고모형 -청주시를 사례로-)

  • Park, Byung-Ho;Park, Gil-Soo;In, Byung-Chul
    • International Journal of Highway Engineering
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    • v.10 no.4
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    • pp.161-170
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    • 2008
  • This study deals with the accident models by vehicle type. The goal is to develop the accident models by vehicle type using the data of 143 4-legged signalized intersections in Cheongju. In pursuing the above, this study gives the particular attentions to explaining the relationships between the values of EPDO(equivalent property damage only) and the traffic and geometric elements. The main results analyzed are the followings. First, 6 negative binomial models are developed, which are all significant at the 90% confidence level. Second, the values of ${\rho}^2$ by vehicle type are 0.14307(auto), 0.35556(large van), 0.21684(small van), 0.205152(motocycle), 0.32338(light-duty truck) and 0.29046(heavy-duty truck), that are all analyzed to be statistically significant. Finally, the common variable included in all models is ADT(average daily traffic), and the specific variable(SV) of auto is analyzed to be the sum of lane width of main road, SV of large van is the average yellow time, and SV of small van is the difference in the number of lane between main and minor road.

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Factors Related Smoking Cessation Attempts among Teenage Smokers (청소년 흡연자의 금연시도 관련 요인)

  • Park, Hye-rin;Wang, Yeon-ju;Kim, Kyoung-Beom;Kim, Bomgyeol;Kwon, Ohwi;Noh, Jin-won
    • The Journal of the Korea Contents Association
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    • v.20 no.7
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    • pp.118-126
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    • 2020
  • The purpose of the study is to analyze the relationship between the warning picture on a cigarette pack and non-smoking attempt, which is expected to contribute to the negative perception of smoking as a research subject about smoking adolescents. An online survey data of the Youth Health Behavior in 2018 has been used, and 3,722 adolescents who are currently smokers were selected for the study. For the measurement of variables, demographic sociology, health-related, and smoking-related factors have been revised, and multivariate binomial logistic regression analysis has been performed. The perception rate of cigarette warning pictures among adolescents who smoke currently is 84.7%, and among them, the attempt rate to quit smoking is 72.8%. As a result of the multivariate binomial logistic regression analysis, there is a meaningful relationship between adolescent smokers' attempts to quit smoking and whether they perceived cigarette pack warning pictures, and school grade year, academic performance, stress perception, and ease of purchasing cigarettes have been also expressed as meaningful variables. To be based on the result, it is necessary to manufacture to design a cigarette pack warning picture that can be easily recognized by smoking adolescents in the future.

The Determinants of Korean Manufacturing Firms' Innovative Activity: Do Firm Size and Appropriabilities Matter? (한국 제조업체의 혁신활동 결정요인: 기업규모와 전유성의 역할)

  • Song, Ji-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.565-577
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    • 2020
  • This study empirically examined how a firm size affects the determinants of innovative activities using the data of the Korean Innovation Survey (KIS) 2016. With data from 2,003 firms in the manufacturing sector, we performed logistic regression analysis and zero-inflated negative binomial regression analysis. R&D expenditure and patent applications were used as proxies for innovative activity. The independent variables included the firm's characteristics variables such as the firm's age, tech-level industry, RDemp (R&D employee ratio), venture, export, and industrial characteristics variables such as networking, appropriability, and spillovers. The empirical findings are that there are some differences in firms' innovative activity determinants among the firms' size groups. Next, strategic appropriability has negative impacts on small firms' R&D expenditure and medium-firms' patents. Networking is an important determinant of innovative activity for all firms, except for large firms. Furthermore, in deciding R&D activities, small and medium-sized firms were significantly influenced by industrial characteristics as compared to that of large firms. Our findings suggest some R&D promotion policies. Policies fostering firms' technological interaction would allow firms to take advantage of technological spillovers and thus raise the probability of investing in R&D.