• Journal of Korean Society of Transportation
• /
• v.21 no.3
• /
• pp.15-22
• /
• 2003

In general, the linear regression model has been used to estimate trip generation in the travel demand forecasting procedure. However, the model suffers from several methodological limitations. First, trips as a dependent variable with non-negative integer show discrete distribution but the model assumes that the dependent variable is continuously distributed between -$\infty$ and +$\infty$. Second, the model may produce negative estimates. Third, even if estimated trips are within the valid range, the model offers only forecasted trips without discrete probability distribution of them. To overcome these limitations, a poisson model with a assumption of equidispersion has frequently been used to analyze count data such as trip frequencies. However, if the variance of data is greater than the mean. the poisson model tends to underestimate errors, resulting in unreliable estimates. Using overdispersion test, this study proved that the poisson model is not appropriate and by using Vuong test, zero inflated negative binomial model is optimal. Model reliability was checked by likelihood test and the accuracy of model by Theil inequality coefficient as well. Finally, marginal effect of the change of socio-demographic characteristics of households on trips was analyzed.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.6D
• /
• pp.577-585
• /
• 2010

Traffic accidents are caused by several factors such as drivers, vehicles, and road environment. It is necessary to investigate and analyze them in advance to prevent similar and repetitive traffic accidents. Especially, the human factor is most significant element and traffic accidents by drinking-driving caused from human factor have become social problem to be paid attention to. The study analyzes traffic accidents resulting from drinking-driving and the effects of driver's attributes and environmental factors on them. The study is composed as two parts. First, the log-linear model is applied to analyze that accidents by drinking or non-drinking driving associate with road geometry, weather condition and personal characteristics. Probability is tested for drinking-driving accidents relative to non-drinking drive accidents. The study analyzes probability differences between genders, between ages, and between kinds of vehicles through odds multipliers. Second, traffic accidents related to drinking are classified into property damage, minor injury, heavy injury, and death according to their severity. Heavy injury is more serious than minor one and death is more serious than heavy injury. The ordinal regression models are established to find effecting factors on traffic accident severity.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.12
• /
• pp.5786-5799
• /
• 2012

In this era of the knowledge-based economy, the most important issue that we faced is the management of the knowledge workers who is the main source of enterprise. There has been a big issue on the organizational commitment recently which is the idea of how much employees have a positive affection to the enterprise they work for and also how much time, knowledge and energy employees are willing to invest for their company success. Improving this concept would provide a meaningful implication in managing the knowledge workers. This research which is based on previous studies, it aims to control the effect on the organizational commitment by Shared Leadership which puts the job characteristics of knowledge workers into a dominant factor. As a result of the study, among the several job characteristics, autonomy and a feedback had a positive effect on the organizational commitment. Shared Leadership as a moderating variable, has shown an affirmative effect on autonomy, a feedback, and problem solving as an independent variable and on the organizational commitment as a dependent variable. However, related to the job complexity, it did not show a notable influence. Also, the Shared Leadership has shown a favorable impact on the feedback and problem solving, but barely effected on autonomy or job complexity.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.38 no.6
• /
• pp.887-894
• /
• 2018

An electric vehicle is emerging as an alternative to the response of global climate change and sustainability. However, an Electric vehicle has not been popular due to the constraints such as its price or technical limitations. In order to analyze the effect of purchasing electric vehicles, this study conducted a binary logistic regression model that demonstrates the relation between purchasing and influencing variables. Variables which have high correlation were excluded from the model through the correlation analysis to prevent multicollinearity. Socio-economic variables such as the number of owned vehicles, sex, ages are not significant. On the other hand, Variables related to prices, charging and policy are found to have a significant to effect on the purchase of electric vehicles. In accordance with the model estimated result, it seems to be necessary to improve the charging incentives, or to provide electric car information and to expand opportunities for experience electric vehicles. The result is also expected to be helpful for spreading electric vehicles and formulating policies.

• Journal of Digital Convergence
• /
• v.14 no.5
• /
• pp.527-539
• /
• 2016

The purpose of this study is to examine the structural relationship among professionalism of sport instructors, job burnout and turnover intention. Independent variable was professionalism of sport instructors, mediating variable was job burnout. Finally, dependent variable was turnover intention. The data were collected from 253 sport instructors of elementary school by the convenience sampling method. This study used IBM SPSS Ver. 20.0 and AMOS 18.0 for frequency analysis, reliability, correlation analysis, confirmatory factor analysis and structural equation model. After confirming the test of goodness of fit of a model, individual hypotheses was verified. The results were as follows; First, Professionalism had a significant influence on job burnout. Second, Job burnout had a significant influence on turnover intention. Third, Professionalism did not have a significant influence on turnover intention.

• The Journal of the Korea Contents Association
• /
• v.17 no.6
• /
• pp.250-260
• /
• 2017

This study analyzed the impacts of programming characteristics perceived by the consumers of entertainment programs on general programming channels on watching intention and the data of a survey with 360 adult viewers in the capital area. Research questions were verified as follows: First, as a result of multiple regression to analyze the impacts of the factors of programming characteristics perceived by the consumers on their watching intention, setting personal characteristics as a control variable, programming characteristics as an independent variable and watching intention as a dependent variable, the regression model was significant. Thus, the more positive the perceived factors of programming characteristics, the more significant their watching intention improved. Second, the factors of programming characteristics significantly affecting watching intention had greater positive(+) impacts in the following order: Adjacency > substantiality > weight of genre > social evidence > relative advantage > ease of access.

• The Journal of the Korea Contents Association
• /
• v.15 no.12
• /
• pp.247-256
• /
• 2015

This study begins with the importance of customer satisfaction in public sector, social welfare and job enthusiasm and how authentic leadership impacts the job engagement and customer orientation. To analyze and to verify the hypothesis, a Structural Equation Model was constructed, with the genuine leadership as an independent variable, the job engagement as a parameter, customer orientation as a dependent variable. Sample data was collected from 230 employees of social welfare organizations located in Yong-in city. Strong association between authentic leadership perception and costomer oreintation was identified from structural equation model, where job engagement plays significant intermediating role. In conclusion, positive perception toward leadership characteristic influence the job performance through desirable attitude formulation. Job engagement as a mediating variable strengthens the influence of autheneic leadership on the improvement in customer orientation which overcame the opposition, the exhaustion due to emotional labor and job burnout from those who are engaged in welfare facilities.

• Journal of Digital Convergence
• /
• v.11 no.1
• /
• pp.129-138
• /
• 2013

As the use of smartphones becomes widespread, the negative aspects of smartphone are under controversy. The cutting-edge technologies, such as smartphone, lead to technostress, and the digital addiction causes a social problem, where users cannot properly work without smartphone in their hands, causing anxiety or embarrassment to them. The digital detox intended to solve such digital addiction and the technostress caused by cutting-edge technologies are currently under controversy. This paper investigated the negative factors from smartphone as internal factors affecting the use of smartphone and found their relationship. In this study, a theoretical study model was presented on the satisfaction of smartphone users, in which technostress was selected as an independent variable affecting the satisfaction of smartphone users and user satisfaction as an dependent variable, and digital detox, perceived usefulness and flow were set as parameters. This paper, investigated the effects of technostress and digital detox on the satisfaction of smartphone users with questionnaires data.

• Journal of Digital Convergence
• /
• v.18 no.4
• /
• pp.177-191
• /
• 2020

This study examines the effect of the self-overviewing attributes derived from agency problem on the cost behavior in franchise industry. To solve the research problem, we developed the proxies for self-overviewing attributes of domestic franchise CEO and used Anderson et al. (2003)'s cost behavior model to test hypothesis. Moreover, we grouped the self-overviewing variables for additional test. We find that operating costs are more sticky for firms which present higher CEO's self-overviewing attributes in franchise industry. Second, we find that the greater the self-overviewing tendency, more strengthened cost stickiness when sales decrease. This study is meaningful in that we developed proxies for self-overviewing propensity, such as the hypodermic behaviors of franchise CEO, which have not been performed in previous studies, to enhance future studies of franchise CEO. Futhermore, we empirically provide the effects of CEO's self-overviewing attributes on the operating costs behaviors, suggesting useful information to franchise stakeholders such as prospective start-ups, franchisee and investors.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.7
• /
• pp.57-65
• /
• 2023

Various studies to enhance the accuracy of rice production forecasting are focused on improving the accuracy of the models. In contrast, there is a relative lack of research regarding the data itself, which the prediction models are applied to. When applying the same dependent variable and prediction model to two different sets of rice production data composed of distinct features, discrepancies in results can occur. It is challenging to determine which dataset yields superior results under such circumstances. To address this issue, by identifying potential influential features within the data before applying the prediction model and centering the modeling around these, it is possible to achieve stable prediction results regardless of the composition of the data. In this study, we propose a method to adjust the composition of the data's features in order to select optimal base variables, aiding in achieving stable and consistent predictions for rice production. This method makes use of the Korea Meteorological Administration's ASOS data. The findings of this study are expected to make a substantial contribution towards enhancing the utility of performance evaluations in future research endeavors.