• Journal of Information Technology Applications and Management
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• v.30 no.6
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• pp.81-90
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• 2023

In aviation, with the rapid transformation of the mobility industry, UAMs are emerging to operate green low-altitude airspace in urban environments. In order for UAM aircraft to fly safely transporting passengers and cargo in low-altitude urban airspace, a traffic control system that supports the safe operation of the aircraft is essential. In particular, traffic control systems that reflect the characteristics of the flight environment, such as operating at low altitude in urban environments for a short period of time, are required. In this study, we define the definition of UATM and its main services that perform traffic control for the safe operation of UAMs. In addition, we analyzed the development trends of UATM systems based on domestic and overseas cases. Based on these analyses, we present the results of the concept design of the UATM system. After analyzing UATM development cases, we found that there is no commercialized UATM system, but overseas development is focused on systems that can integrate ATM and UTM. And we identified key stakeholders and interface data, and performed UATM system architecture and functional design based on the identified data. Finally, as a necessary element for the future development of UATM systems, we propose the establishment and advancement of UAM traffic flow management systems, the establishment of integrated control systems, and the development of interface with aircraft operation systems in preparation for the unmanned UAM aircraft.

• Journal of Korean Society of Transportation
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• v.31 no.4
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• pp.3-17
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• 2013

The purpose of this study is to develop a traffic assignment model where the variable of signal intersection delay is taken into account in assigning traffic in large-scale network settings. Indeed, despite the fact that the majority of the increase in travel time or cost involving congested urban network or interrupted flow are accounted for by stop delays or congested delays at signal intersections, the existing traffic assignment models did not reflect this. The traffic assignment model considering intersection delays presented in this study was built based on the existing traffic assignment models, which were added to by the analysis technique for the computation of intersection delay provided in Korea Highway Capacity Manual. We can conclude that a multiple variety of simulation tests prove that this model can be applied to real network settings. Accordingly, this model shows the possibility of utilizing a model considering intersection delay for traffic policy decisions through analysis of effects of changes in traffic facilities on large urban areas.

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.25-36
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• 2017

The purpose of this study is to analyze traffic accident reduction effect of the introduction of motorcycle safety inspection. To analyze the effect of motorcycle inspection, we first estimate the number of defective motorcycles, and calculate the probability of accident occurrences caused by the defect using four year traffic accident data. Finally, we estimate the number of reduced accidents due to the introduction of the inspection and the total reduced accident cost. In this study, we analyzed three scenarios. It is analyzed that when the safety inspection system is applied to all motorcycles, 642 cases of traffic accidents and 325 million won per year of traffic accident costs are reduced. It is approximately 0.1% of 2014 total traffic accident cost of 26.5725 trillion won per year. It suggests that the cost of traffic accidents and traffic accidents due to vehicle factors are reduced when the safety inspection system is introduced.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.2
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• pp.100-109
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• 2022

Large-scale urban concentration of population and vehicles due to economic growth in Korea has been causing serious urban transport problems. Although the collection of congestion pricing has been evaluated as the most effective transportation policy to alleviate traffic demand, its effectiveness is very limited as it was just executed around congested points or along main arterial roads. This study derived dynamic congestion zones with the average travel speed of 206 traffic analysis zones in Busan Metropolitan City to propose a dynamic congestion pricing collection system by employing Space-Time Cube Analysis and Emerging Hot Spot Analysis. As a result, dynamic hot spots were formed from 7h to 24h and particularly, traffic congestion was severely deteriorated from 18h to 20h around Seomyeon and Gwangbok-dong. Therefore, it is expected that the effect of dynamic congestion pricing will be maximized in managing traffic demand in the city center.

• Journal of Advanced Navigation Technology
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• v.28 no.1
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• pp.21-26
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• 2024

Urban air mobility (UAM) is being considered as an alternative to transportation in urban areas where traffic congestion is increasing. It is judged that it will be difficult to manage the complex UAM operation environment with the existing Air Traffic Service, which is a person-centered service. Therefore, an advanced information processing-based traffic management system for UAM (UATM) is needed. Airspace management is essential to establish a systematic UAM traffic management (UATM) environment. In particular, the establishment of exclusive corridors where UAM aircraft can operate safely can provide opportunities to operate UAM aircraft without violating the minimum flight altitude regulations. This study conducted an empirical analysis using a helicopter of similar size to UAM to establish the cross-track dimension of the corridor for UAM operation. The research results can be used as a guideline when designing UAM corridors.

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.204-214
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• 2014

Objectives: Vehicular emissions are one of the main sources of air pollution in urban areas. Correlation analysis was conducted between air pollutants and traffic volume in order to identify causes of air pollution in Gwangju. Methods: Using traffic volumes and air quality monitoring data from 2002 to 2012 from nine stations (seven urban areas, two roadside areas), especially at three sites where traffic volumes were high, the correlation coefficients were obtained between air pollutants as PM-10 (particulate matter), $NO_2$, $SO_2$, CO and $O_3$ at the stations and traffic volumes near the air monitoring stations. Results: Due to traffic volume and distance between the station and the traffic road, concentrations of pollutants at roadside areas were higher than at urban areas, with the exception of $O_3$. The concentration of $O_3$ showed statistically significance with those of other gas materials as $NO_2$, $SO_2$, and CO in winter (p<0.001) and spring (p<0.05). During the period of October 7 to 20, 2012, excluding periods of yellow dust, smog and rainy season, the ratio of $NO/(NO+NO_2)$ showed the highest value 0.57 and 0.40 at Unam and Chipyeong of two roadside stations, followed by 0.35 at Nongseong with vehicular effects. The correlation coefficient between traffic volume and $O_3$, CO, $NO_2$ became higher when the data on mist and haze days were excluded, than when all hourly data were used in that period, at the three sites of Unam, Chipyeong, and Nongseong. Conclusions: Air quality showed a considerable effect from vehicles at roadside areas compared to in urban areas. Air pollutant diminishment strategies need to be aggressively adopted in order to protect atmospheric environment.

• Journal of Environmental Impact Assessment
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• v.7 no.1
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• pp.109-116
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• 1998

As of July 1997, the registered number of automobiles exceeded 10 million and Korean auto industry produced 2,850,000 cars. Many environmentalists warn that the passenger cars are not sustainable urban transportation system in large cities. The cars produce about 80% of air pollutants, and consume 30% of petroleum imported. For the past 30 years the administration increased the road system, but the length of road per car is decreased from 813m in 1965 to 9m in 1995. The cost of traffic congestion was estimated to be \14.7 trillion in 1996, and is feared to increase without changing the present transportation system. The undesirable impact of cars include the casualties from traffic accidents, insurance loss, and separation of human relatioships. To construct sustainable urban transportation system, three principles should be followed. The first principle is to make the urban streets walkable for the people. The second principle is to encourage bicycling. Roads and traffic systems should be designed to let bicylces travel safely. The third principle is to supply more buses and construct integrated transportation system based on buses. The subway system is too expensive to construct and without the support of a well-organized bus system it may not work efficiently. The Brazilian city of Curitiba has constructed a very efficient bus system only with 1/80 of the estimated cost of subway system. The car-oriented transportation system does not seem to be an envrironmentally sustainable transportation system in most of the Korean cities.

• Journal of the Korea Computer Industry Society
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• v.2 no.11
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• pp.1373-1382
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• 2001

Traditionally, Mobile Teletraffic model consists of two sub-models, i.e. the network traffic model and the traffic source model. In this paper, we present the traffic source model by developing MobCall(Mobile Call Simulator) which analyses various mobile wireless environments based on regional characteristics that the base stations are located. User mobility is presented by regional average vehicle speeds and the transportation share rate. Moreover, the user mobility on subway, which is increasing in urban area, is considered in MobCall. Using MobCall, the accumulated number of calls in residential and commercial regions, the handoff rate with respect to traffic sources of Seoul, the handoff rate on highway, and the handoff rate according to the call duration are presented. MobCall enables the simulation of dynamic handoff buffering and functional entity control of one base station according to the changes in user's calling pattern at the design phase.

• Journal of the Korean Society of Safety
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• v.33 no.3
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• pp.77-82
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• 2018

This paper aims to analyze the accident based on changing patterns of traffic culture index. For this purpose, this paper particularly focuses on classifying the traffic culture patterns and developing the traffic accidents using panel count data model. The main results are as follows. First, the traffic culture patterns are divided into 'increasing', 'decreasing' and 'other' patterns. The null hypotheses that the number of accident are the same over patterns are rejected. Second, 4 fixed effect negative binomial models which are all statistically significant are developed. Third, the regions with 'increasing' pattern are analyzed to be mostly the counties, and to demand the traffic law enforcement. Fourth, the regions with 'decreasing' pattern are evaluated to be mainly the districts and to require such the traffic culture as turn signal usage. Finally, the regions with 'other' pattern are analyzed to be mostly the cities and to ask for enhancing the level of traffic culture.

• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.163-171
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• 2024

In the existing air traffic management (ATM) system, various types of safety alert features are provided based on trajectory data to ensure the safety of aircraft operations, along with aircraft position and detailed flight information. The urban air traffic management (UATM) system for urban air mobility (UAM) should also provide safety alert features to ensure the safety of UAM operations. Considering the operational environment of UAM, it is necessary that the safety alert features provided at least match or exceed those available in the existing ATM system. This study aims to present the safety alert features of the new UATM system that differ from those provided by the existing ATM system before introduction and commercialization of UAM. The study was conducted focusing on the safety alert features that should be provided in the event of a deviation from the UAM's path, and the establishment of the safety alert features was carried out in two parts: approach path monitor (APM), which is applied during the approach phase, and route adherence monitoring (RAM), which is applied during the cruise phase.