• Journal of Advanced Marine Engineering and Technology
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• v.40 no.10
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• pp.899-905
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• 2016

Wireless access in vehicle environment (WAVE) communication is currently being researched as core wireless communication technologies for cooperative intelligent transport systems (C-ITS). WAVE consists of both vehicle to vehicle (V2V) communication, which refers to communication between vehicles, and vehicle to infrastructure (V2I) communication, which refers to the communication between vehicles and road-side stations. V2I has a longer communication range than V2V, and its communication range and reception rate are heavily influenced by various factors such as structures on the road, the density of vehicles, and topography. Therefore, domestic environments in which there are many non-lines of sight (NLOS), such as mountains and urban areas, require optimized communication channel modeling based on research of V2I propagation characteristics. In the present study, the received signal strength indicator (RSSI) was measured on both an experience road and a test road, and the large-scale characteristics of the WAVE communication were analyzed using the data collected to assess the propagation environment of the WAVE-based V2I that is actually implemented on highways. Based on the results of this analysis, this paper proposes a WAVE communication channel model for domestic public roads by deriving the parameters of a dual-slope logarithmic distance implementing a two-ray ground-reflection model.

• Journal of the Korean Society for Railway
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• v.18 no.2
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• pp.94-104
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• 2015

Trams are rail vehicles that run on tracks along public, urban streets; they also sometimes run on separate rights of way. Tram vehicles run more efficiently and their overall operating costs are lower than those of similar vehicles. In general, trams provide a higher capacity service than buses. However, when tram stops in the middle of the road do not have pedestrian refuges, trams can cause speed reductions for other transport modes (buses, cars), as in such configurations other traffic cannot pass whilst passengers are alighting from or boarding the tram. In this study we examined the qualifications of overseas tram operation. The Railway Safety Act, sub-laws, and other relevant laws were examined to determine complementary measures.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.4
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• pp.464-476
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• 2019

Objectives: This study aimed to assess the exposure levels of tollbooth workers to diesel particulate matter using black carbon (BC) and to find the correlations among variables associated with BC using the motor vehicle management act regulated by the Ministry of Land, Infrastructure and Transport. Methods: This study was performed over 14 days at a university in Seoul. BC levels were monitored using an aethalometer and were conducted around the breathing zones of the workers. There were three sampling locations: inside the tollbooth (front gate and rear gate) and an office as a control group. T-test, correlation, and multiple linear regression analysis were performed using SPSS. Results: The geometric mean (GM) of BC_30min concentrations in the exposure group was 2.44 ㎍/㎥, approximately 1.4 times higher than the control group (1.75 ㎍/㎥). The GM of BC_30min concentrations was 2.75 ㎍/㎥ during the heavy traffic time (9-10 am) and 2.30 ㎍/㎥ during non-heavy traffic times (p<0.001). The multiple linear regression analysis shows that the number of all types of vehicles and PM_2.5 concentrations in the atmosphere were factors increasing the GM of BC(ln(BC_30min)) concentrations (adjusted R²=0.42, p<0.001). The workers were constantly exposed to low concentrations (GM of BC_30min=2.44 ㎍/㎥), but they were exposed to peak concentrations instantly (BC_10sec=3545.04 ㎍/㎥). When the GM of BC_30min concentrations was momentarily represented as high, it was identified that a vehicle mainly using diesel fuel or an aging vehicle had passed. Conclusions: A ventilation system should be installed in the closed tollbooth or aging vehicles should be controlled so as not to pass tollbooths.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.1
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• pp.71-82
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• 2020

The existing transportation system, which is based on internal combustion engines, is rapidly being converted to electrification. Thus, eco-friendly public transportation with high transportation efficiency will continue to spread throughout the market in the near future. The purpose of this study is to compare and analyze the cognitive characteristics of passengers redgarding the technical and social factors of various public transportation means to help a successful introduction of eco-friendly public transit. Through a survey questionnaire (N=485), seven factors of seven transportation modes were evaluated and analyzed using principal component analysis. As a result, it is confirmed that potential passengers have high expectations for the eco-friendliness and city image of the eco-friendly buses. Also, it is confirmed that eco-friendly buses are superior in cleanliness and ride comfort than diesel buses. Given the study's results, this study identifies the cognitive characteristics of passengers regarding eco-friendly public transportation. We hope that these results will be used as basic information for image positioning and improved service with the use of eco-friendly transportation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.1
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• pp.57-65
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• 2022

Gyeongsangnam-do has been operating Bravo-taxi, a Gyeongnam-type DRT using taxi vehicles, since 2017 to guarantee the right of mobility for residents who live in areas lacking public transportation. This research investigated and analyzed changes in users' awareness over two years from beginning of Bravo-taxi operation in Gyeongsangnam-do, which started operating Bravo-taxis in 2017, targeting sites lacking public transportation. Through this study, the positive effects of taxi-type DRT were confirmed, such as improving the mobility of residents in areas underprivileged by public transportation, reducing required time for trips, and increasing preference for Bravo-taxis compared to existing buses. On the other hand, problems with the current Bravo-taxi system were also identified. In some areas, it was found that there were not enough coupons for Bravo-taxis, or in the case of Bravo-taxis operating at fixed times, the user's desired time and operating time did not match, resulting in lower satisfaction. The results of this research are expected to be utilized as basic data for service continuity of taxi-type DRT in operation by other local governments.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.241-249
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• 2013

Since the enactment of "Mobility Promotion Law for Transportation Vulnerable", each municipality has been various efforts to improve the transportation vulnerable's the right of movement. However, the effectiveness of mobility promotion policy for the transportation vulnerable is awfully inadequate because circumstances which associated with operation of transportation of the handicapped such as local conditions and transport characteristics have not been considered. Thus, in this study investigated traffic characteristics of the transportation vulnerable through the data of regional slope, non-step buses and handicap vehicles operating conditions and so on in Busan Metropolitan. Also, we proposed to introduction of the 'mobility index' which is based on local condition analysis of Busan. And we suggested that how to improve the convenience of transportation vulnerable's movement.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.341-346
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• 2015

This study was conducted to investigate the awareness tendency of the government employees who manage forest roads about problems of forest road use and how to improve them in the future using surveys. The results show there are more silvicultural operations than harvesting operations using forest roads. The main purpose of using forest roads is to transport workers; however, the road will be used more for harvesting operations in the future. The respondents wanted to be accessibility for forest operations within 200 m from road in both present and future. For silvicultural operations 1-ton vehicle is used at present, and 5-ton vehicles are expected to be used in the future. For harvesting operations 5-ton vehicle is used at present, and 10-ton vehicles are will be used in the future. The roadway width is 3 - 4 m at present, but should be 4 - 4.5 m in the future. The longitudinal gradient of roads is 7 - 10% at present, and will be below 10% in the future. The minimum curve radius of roads is 12 - 15 m at present, and will be 15 - 20 m in the future. The results provide basic data for making future forest road policies.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.4
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• pp.161-169
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• 2011

There is a consensus in the field of vehicular network security that public key cryptography should be used to secure communications. A certificate revocation list (CRL) should be distributed quickly to all the vehicles in the network to protect them from malicious users and malfunctioning equipment as well as to increase the overall security and safety of vehicular networks. Thus, a major challenge in vehicular networks is how to efficiently distribute CRLs. This paper proposes a CRL distribution method aided by terrestrial digital multimedia broadcasting (T-DMB). By using T-DMB data broadcasting channels as alternative communication channels, the proposed method can broaden the network coverage, achieve real-time delivery, and enhance transmission reliability. Even if roadside units are not deployed or only sparsely deployed, vehicles can obtain recent CRLs from the T-DMB infrastructure. A new transport protocol expert group (TPEG) CRL application was also designed for the purpose of broadcasting CRLs over the T-DMB infrastructure.

• Journal of Preventive Medicine and Public Health
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• v.1 no.1
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• pp.1-8
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• 1968

This paper describes the incidence of transport accident for the period, 1955-1965. Transport accidents were classified into three categories, viz. railway(WHO Classification of Diseases, E-802), watercraft (E 550-E 858) and motor vehicle accidents(E810-E835, E840-E841, E844-E845). Crude data on the subject were collected from the various souces of Government Statistical Books including Statistical Year Books edited by the Central Office of Economic Planning Board, Annual Police Reports by the Ministry of Home Affairs, and the national and local associations for road traffic safety. From the data incidence and mortality rates by year, month and local province were computed and other variables relevant to the epidemiology of accidents were observed. The following summary could be drawn: 1. Death rates due to transport accidents per 100,000 population were 12.3 for 1955 and 9.7 for 1965. The incidence of injury due to the same cause were 34.0 for 1955 and 35.9 for 1965. 2. Death rates by transportation vehicle showed 9.0 due to motor vehicle accidents, 1.7 due to water-crafts, and 1.6 due to railway trains for 1955. In 1965 death rates were 6.0 due to motor vehicles, 1.2 to water-crafts and 2.4 to railway. 3. Seasonal distribution of transport accidents revealed that car accidents occur more frequently in spring and fall fall seasons while ship accidents do in winter and train accidents more in summer. 4. Both car and ship accidents slightly decreased during the past decade, 1955-1965, whereas the accidents of railway trains showed a tendency of increase. 5. Although the survey on railway accidents excluded the injuries of passengers or railway employees corresponding to WHO classification of diseases, E 801, due to inaccuracy of data, it is roughly estimated that the same number of casualities as the incidence among pedestrians or any other than passengers or employees assumed to be at work(E 802).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.182-199
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• 2023

Since 2021, government departments have been promoting Automated Driving Technology Development and Innovation Project as national research and development(R&D) project. The automated vehicles and service technologies developed as part of these projects are planned to be subsequently provided to the public at the selected Living Lab City. Therefore, it is important to determine a spatial area and operation section that enables safe and stable automated driving, depending on the purpose and characteristics of the target service. In this study, the static Operational Design Domain(ODD) elements for Level 4 automated driving services were reclassified by reviewing previously published papers and related literature surveys and investigating field data. Spatial analysis techniques were used to consider the reclassified ODD elements for level 4 in the real area of level 3 automated driving services because it is important to reflect the spatial factors affecting safety related to real automated driving technologies and services. Consequently, a total of six driving mode changes(disengagement) were derived through spatial information analysis techniques, and the factors affecting the safety of automated driving were crosswalk, traffic light, intersection, bicycle road, pocket lane, caution sign, and median strip. This spatial factor analysis method is expected to be useful for determining special areas for the automated driving service.