• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3D
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• pp.213-222
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• 2012

After enforcing 2007 semi-public management system of intra-city bus, Busan city has tried to promote the bus utilization through bus service improvements. As an effort for this, we attempted to clarify the main factors affecting to bus service satisfaction targeting intra-city bus users. In this study, 20 subcategories of intra-city bus service were assorted into 6 factors: Basic Service, Safe Driving, Route Information, Comfort, Cleanliness and Facilities, then the preference for each detailed bus service were analyzed. And the effects for bus service satisfaction were shown under the various conditions according to the general characteristics of intra-city bus users (gender, age), behavioral traffic characteristics (frequency of use, boarding time) and transportation environments (temperature, rainfall). These results would be important basic data for decision-making in bus policy for climate change and establishment of operating plan for bus utilization.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.154-163
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• 2015

This study is based on deductions from analysis of historical changes in hydrographic surveys, the problems with the existing system in Korea and analysis of the literature, including foreign cases. Using these criteria, we created and administered a survey of marine professionals of Korea, and based on the results, established an order of priority for hydrographic surveys, as follows: changes in the seabed, quantities of marine traffic, existing performance data from hydrographic survey, consumer's demand, marine accidents, conservation of oceanic environment, and natural resources. The study also deduced, based on a survey of experts, the relative importance ranking of the major ports in South Korea and suggests policy implications and a priority decision model to conduct future hydrographic surveys in a more scientific and systematic way.

• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.1-12
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• 2018

The purpose of this study is to establish a methodology for evaluating quantitative effects of transportation GHG (greenhouse gas) reduction-related policies that were implemented based on the reduction goals of transportation GHG and effective implementation plans. This study uses a modal utility function and demand estimation models as well as a GHG emission basic unit estimation model by each transportation mode based on actual traffic and emission data. The results showed that the effects of GHG reduction policies such as electric vary from region to region, and from vehicle to vehicle. It is also confirmed that an eco-drive promotion policy, one of the lowest budget policies, is expected to contribute to high reduction in GHG. In addition, not only automobile emission improvement policies but also the promotion policies of public transportation are expected to highly reduce GHG as confirmed quantitatively in this study. The results of this study are expected to be useful for national and local governments' evaluation of GHG reduction policies to cope with the post 2020.

• Journal of the Korean Data and Information Science Society
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• v.25 no.2
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• pp.327-336
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• 2014

Recurrent event data occurs when a subject experiences same type of event repeatedly and is found in various areas such as the social sciences, Economics, medicine and public health. To analyze recurrent event data either a total time or a gap time is adopted according to research interest. In this paper, we analyze recurrent event data with incomplete observation gap using a gap time scale. That is, some subjects leave temporarily from a study and return after a while. But it is not available when the observation gaps terminate. We adopt an interval censoring mechanism for estimating the termination time. Furthermore, to model the association among gap times of a subject, a frailty effect is incorporated into a model. Programs included in Survival package of R program are implemented to estimate the covariate effect as well as the variance of frailty effect. YTOP (Young Traffic Offenders Program) data is analyzed with both proportional hazard model and a weibull regression model.

• Journal of Digital Convergence
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• v.15 no.5
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• pp.161-172
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• 2017

The purpose of this research is to take a look at what are research autonomy's factors of the government-supported research institutes with a new angle and how these factors influence on organizational effectiveness at the same time. ultimately, this research will suggest what government should guarantee and support researcher of the government-supported research institutes. In the groundwork, this research divides the level of research autonomy individual and organizational level, and divides the type of research autonomy intrinsic and extrinsic autonomy and also organizational commitment, and measure job satisfaction for organizational effectiveness. consequently, intrinsic autonomy which is associated with 'selection of research project', 'freely and lively traffic in ideas', 'choice of research methodology', 'utilization of research's result' is much more important than extrinsic autonomy for researchers to improve organizational effectiveness.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.6
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• pp.92-101
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• 2023

The increasing use of personal mobility has led to a rise in traffic accidents and social issues. Consequently, the government is continually revising laws and regulations to address the problems associated with personal mobility. This study conducted a survey that reflects user characteristics and public perceptions based on the law revised in May 2021. The personal characteristics, legal awareness, usage patterns, risk characteristics, and risk factors were analyzed. The analysis indicated that driving on roads without separate sidewalks, speeding, and carrying passengers are hazardous practices. Moreover, Poor awareness of the legal framework governing personal mobility results in law violations. These results are significant as they highlight the need for policy measures regarding institutional and legal improvements, and they underscore the importance of enhancing social awareness about safety as personal mobility become more widespread.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.3
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• pp.94-104
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• 2016

In this study, factor and cluster analysis are used to classify characteristics of the administrative basic unit, "Dong", of the Incheon Metropolitan City. Travel characteristics of the classified groups are then analyzed through databases to provide directions of urban transportation planning. First, industrially developed administrative-dong show a high commuting volume by using cars. Thus the analysis indicated the need to staggering work-hour system and signal operating system policy. Second, commercially developed administrative-dong show heavy use of public transportation and long distance commute as well as high volume of shoppers. The analysis indicated the need to improve road infrastructure. Third, densely populated administrative-dong show a high rate of commute to work and school as well as long hours of commuting. Thus the analysis indicated the need to improve road transportation policies during rush hours. Fourth, administrative-dong with multiple characteristics feature heavy pedestrian traffic thus the study analyzed the need to improve pedestrian environment policies. Lastly, administrative-dong in close proximity to train stations feature extensive use of biking as well as high volume of shoppers and students commuting. Thus the study analyzed the necessity to have plans to enhance accessibility.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.39-46
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• 2010

In 2007, Iowa department of transportation (DOT) initiated to run the falling weight deflectometer (FWD) network-level testing along Iowa highway and road systems and to build a comprehensive database of deflection data and subsequent structural analysis, which are used for detecting pavement structure failure, estimating expected life, and calculating overlay requirements over a desired design life. Iowa's current FWD networklevel testing protocol requires that pavements are tested at three-drop level with 8-deflection basin collected at each drop level. The test point is determined by the length of the tested pavement section. However, the current FWD network-level program could cover about 20% of Iowa's highway and road systems annually. Therefore, the current FWD network-level test protocol should be simplified to test more than 20% of Iowa's highway and road systems for the network-level test annually. The main objective of this research is to investigate if the minimum number of drop levels and test points could be reduced to increase the testing production rate and reduce the cost of testing and traffic control without sacrificing the quality of the FWD data. Based upon the limited FWD network-level test data of eighty-three composite pavement sections, there was no significant difference between the mean values of three different response parameters when the number of drop levels and test points were reduced from the current FWD network-level testing protocol. As a result, the production rate of FWD tests would increase and the cost of testing and traffic control would be decreased without sacrificing the quality of the FWD data.

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.9-16
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• 2010

Roughness is the most important factor to maintain the road performance, and affects greatly on the design life in Jointed Plain Concrete pavements. Also, the factors the evaluate pavement‘s commonality is the three method such as functionality, safety and structural performance. In evaluating function of road, representative factors is the roughness, which has been used to determine maintenance time as key standard. As research for roughness is absence in pavement design. Applied roughness-model had a low-reliability in Korea. Therefore, it is needed to develop reliable model in road roughness. In this research, uniform specific is applied to distribute them after selecting the concrete pavements. Concrete pavement is divided by sections of 238. Total length of this sections has 281km and account for 16% of total road length in korean concrete pavements for selected sections. Considering the korean roughness-model, the evaluation of roughness is performed for the freezing index, average annual rainfall, condition for the base, the amount of traffic as well as spalling(%), cracking(%), age(year) at the selected section at the selected section. Also, additional sections is selected to evaluate various age which affects on the roughness. As a result of the analysis, it showed that spalling(%), cracking(%), age(year), and the condition of the base affected road roughness. When the correlation with the road roughness was analyzed, the reliable model for road roughness was proposed, and the ratio that can explain road roughness was R2-68.8% and P value-0 which is statistically meaningful.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.202-217
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• 2022

Purpose: The recent increased use of Personal Mobility (PM) has been accompanied by a rise in the annual number of accidents. Accordingly, the safety requirements for PM use are being strengthened, but the laws/systems, infrastructure, and management systems remain insufficient for fostering a safe environment. Therefore, this study comprehensively searches the main problems and improvement methods through a review of previous studies that are related to PM. Then the priorities according to the importance of the improvement methods are presented through the Delphi survey. Method: The research method is mainly composed of a literature study and an expert survey (Delphi survey). Prior research and improvement cases (local governments, government departments, companies, etc.) are reviewed to derive problems and improvements, and a problem/improvement classification table is created based on keywords. Based on the classification contents, an expert survey is conducted to derive a priority improvement plan. Result: The PM-related problems were in 'non-compliance with traffic laws, lack of knowledge, inexperienced operation, and lack of safety awareness' in relation to human factors, and 'device characteristics, road-drivable space, road facilities, parking facilities' in relation to physical factors. 'Management/supervision, product management, user management, education/training' as administrative factors and legal factors are divided into 'absence/sufficiency of law, confusion/duplication, reduced effectiveness'. Improvement tasks related to this include 'PM education/public relations, parking/return, road improvement, PM registration/management, insurance, safety standards, traffic standards, PM device safety, PM supplementary facilities, enforcement/management, dedicated organization, service providers, management system, and related laws/institutional improvement', and 42 detailed tasks are derived for these 14 core tasks. The results for the importance evaluation of detailed tasks show that the tasks with a high overall average for the evaluation items of cost, time, effect, urgency, and feasibility were 'strengthening crackdown/instruction activities, education publicity/campaign, truancy PM management, and clarification of traffic rules'. Conclusion: The PM market is experiencing gradual growth based on shared services and a safe environment for PM use must be ensured along with industrial revitalization. In this respect, this study seeks out the major problems and improvement plans related to PM from a comprehensive point of view and prioritizes the necessary improvement measures. Therefore, it can serve as a basis of data for future policy establishment. In the future, in-depth data supplementation will be required for each key improvement area for practical policy application.