• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.300-308
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• 2024

Urban air mobility (UAM) is emerging as a revolutionary transportation solution to urban congestion and environmental issues. Especially, electric vertical take-off and landing (eVTOL) aircraft are expected to enhance urban mobility, reduce traffic congestion, and decrease environmental pollution. However, the successful implementation and operation of UAM systems heavily rely on advanced technological infrastructure, particularly in sensor technology. Among these, 3D light detection and ranging (LiDAR) systems are essential for detecting obstacles and generating pathways in complex urban environments. This paper focuses on the challenges of developing LiDAR-based perception solutions, emphasizing the importance and performance of object detection capabilities using 3D LiDAR. It integrates LiDAR data processing algorithms and object detection methodologies to experimentally validate the effectiveness of perception solutions that contribute to the safe navigation of aircraft. This research significantly enhances the ability of aircraft to recognize and avoid obstacles effectively within urban settings.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.131-137
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• 2011

The development of underground space essentially leads to increase in construction cost and installation of a large structure also acts as a factor deteriorating fine sight of the city. Accordingly, there recently is a trend to make city center structures light and small if possible. In this study, for efficient development of underground space, we analyzed the change in the average delay time in comparison to the existing underpass and the influence thereof using a microscopic simulation software VISSIM 5.20 after controlling heavy vehicles not to use the underpass and to detour using the intersection above the underpass, and gradually increasing the ratio of heavy vehicles in accordance with v/c of the access road in order to examine efficiency of introducing an underpass exclusive to small cars at an underground road installed and being operated in a city road area, and presented installation standard for underpass exclusive to small vehicles adequate to the traffic characteristics. Considering the findings of the study, introduction of underpass exclusive to small cars judged to be beneficial in the aspects of reduction in the economic loss resulting from land purchase, environmental damage due to construction of large traffic structures and environment-friendly green traffic.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.273-286
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• 2013

Recently, due to problems with subway and bus operations, a need has emerged for a solution such as the introduction of an Advanced Transit System. In several municipalities, systems have been introduced using light rail as AGT urban aesthetics construction. There is high inhibition and civil cases are delayed by more environmentally friendly and accessible remedies. For the purpose of this study, Changwon city would be transformed to have an environmentally friendly transportation system such as a tram with an overview. Features, advantages, and disadvantages are analyzed, and systems are established the existing public transport routes by transfer system. Changwon city's tram plan is first step in open in year 2018, and second step with the opening goal of the year 2021, and the total line length of 33.9 km, the station will be built in the 38 locations. and also in 2011 a feasibility study, evaluated a low economic as B/C to 0.88, but it evaluated the high value of the policy analysis as AHP to 0.502. However, introduction of a tram project that should precede the as following condition. The first step in Changwon city's tram plan would be as follows : The introduction of the tram system would demand traffic management along with a restructuring of the bus system, and the tram system would be selected for domestic realities. Secondly, the introduction of trams would comprehend the advanced traffic composition in accordance with the consensus of the citizenship, and a legal system should be established for the introduction of the trams.

• Journal of the Korean Institute of Gas
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• v.20 no.5
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• pp.64-71
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• 2016

According to the urban gas business law, electrical corrosion prevention measures shall be installed to the buried gas pipelines and the pipe-to-soil potentials should be measured at the test box at least once a year. Most of the test boxes installed in urban area are usually located on the road where the vehicle travels, therefore, it is difficult to measure the CP potentials at the test boxes. That is, we need traffic control when carrying out the measurement of the CP potentials on daytime when the traffic is heavy, or we have to measure the potentials in the late night when the traffic is light. To solve these difficulties, we have studied remotely CP potential measuring method by using the patrol car. We have installed solid reference electrodes and data loggers under the test boxes on the site and received the CP potentials from the data loggers when the vehicle moves. It was difficult to send and receive the data because the data logger was located under the ground. We have applied 3 different method including 2 antenna systems to achieve best effective way in receiving the data. We have found the remote CP measuring method by using a car can save more 20 times of measuring time than conventional measuring methods.

• The Transactions of the Korea Information Processing Society
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• v.7 no.9
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• pp.3037-3047
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• 2000

This paper describes a method of tracking a close leading vehicle by color image processing using the pairs of tail and brake lights. which emit red light and are housed on the rear of the vehicle in stop-and-go traffic condition. In the color image converted as an HSV color model. candidate regions of rear lights are identified using the color features of a pair of lights. Then. the pair of tailor brake lights are detected by means of the geometrical features and location features for the pattern of the tail and brake lights. The location of the leading vehicle can be estimated by the location of the detected lights and the vehicle can be tracked continuously. It is also possible to detect the braking status of the leading vehicle by measuring the change in HSV color components of the pair of lights detected. In the experiment. this method tracked a leading vehicle successfully from urban road images and was more useful at night than in the daylight. The KAV-Ill (Korea Autonomous Vehicle- Ill) equipped with a color vision system implementing this algorithm was able to follow a leading vehicle autonomously at speeds of up to 15km!h on a paved road at night. This method might be useful for developing an LSA (Low Speed Automation) system that can relieve driver's stress in the stop-and-go traffic conditions encountered on urban roads.

• Journal of Korean Society of Transportation
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• v.21 no.5
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• pp.41-48
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• 2003

Korea Claim Adjustor Association(KCAA) defines the near pedestrian crossing accidents as those accidents that occurred in the area within 25m from pedestrian crossing on the arterial road and within 15m from pedestrian crossing on other classes of road. Accidents between pedestrian crossing and stop line are classified as the accident near pedestrian crossing. Reviewing of current statute and court precedent, three kinds of traffic accidents which are accidents occurred in the pedestrian crossing. near pedestrian crossing and the area between pedestrian crossing and stop line. should be distinguished by different pedestrian contributory negligence. To find out how different they are. we surveyed transportation society members about the contributory negligence of traffic accidents between pedestrian crossing and stop line and the results are as follows : (1) The current two classification of pedestrian crossing accidents and near pedestrian crossing accidents should be changed to three classification of pedestrian crossing accidents that includes accidents on pedestrian crossing, near pedestrian crossing and between pedestrian crossing and the stop line. (2) For the pedestrian's contributory negligence, the least reasonability to pedestrian is accident on the pedestrian crossing. The next one is the accident between pedestrian crossing and stop line and the last is the accident near pedestrian crossing. (3) Pedestrian contributory negligence for accident by space is recommended as 〈table 8〉, 〈table 9〉, 〈table 10〉. (4) Contributory negligence rate of the accident on the pedestrian crossing during red light should be modified to be less than that of near pedestrian crossing.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.8
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• pp.592-597
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• 2013

It is widely known that the sound insulation of soundproof panel is highly correlated to two factors, surface density of material and the frequency of noise. Accordingly, the character of traffic noise released in actual situation is important requisite for determining thickness to determine surface density and material of soundproof panel. This present study selected polymer panel with advantage of light weight and workability and evaluates according to frequency of traffic noise. Polypropylene (PP) and high-density polyethylene (HDPE) were selected as subjects based on economic valuation and efficiency. The sound transmission loss of selected polymer panels were compared with the currently used panels such as polycarbonate (PC) and polymethyl methacrylate (PMMA) depending on thickness and materials. As a result, PC showed the highest sound transmission loss followed by PMMA, HDPE, and PP in range of mass law. In terms of acoustic performance on thickness, the transmission loss increased with thickness of soundproof panel meanwhile coincidence dip was observed in lower frequency where had reduced transmission loss. Therefore, it is suggested that after determining target frequency, the kind of materials and thickness of soundproof panel need to be designed so that traffic noise can be more efficiently reduced.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.1
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• pp.85-91
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• 2021

In contrast to standard train tracks, tramlines are often set along public roads, with trams running among pedestrians and other vehicles. In some cities and towns, trams and buses share the same routes and stations. Under the current investment appraisal system, trams are classified into light rail when predicting traffic demand and calculating benefits, but in the case of non-capital areas, it is notable that the origin-destination and transit lines of buses are not provided in the Korea Transport Database distribution data. Due to this problem, it is difficult to reflect proper mode changing behaviors between route buses and trams. This study examines the impact on tramlines of bus routes that are not currently considered in non-capital areas. Following an analysis of the effect of tram projects according to whether bus routes are considered or not, an improvement in methodology is proposed. Through this study, it is expected that the investment appraisal system for the planning of new tramlines will be improved in the future.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.53-62
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• 2016

This paper is shown the new method using LED Light, which the light environment is upgraded the natural LED light in the area of Disaster Prevention and Safety Management (PDSD), which the events of deaths is reduced on the Suicide, the Infectious diseases, the safety accidents, the Traffic Accident, the crime, the fire, the Nature Disaster, and which the health and the environment and the safety is implemented using the value of the color LED Light. Research findings include,during 3 weeks in the November 2016, in the ten residents (average living 28.7 years, age 67.5 years) with depressive symptoms in the northern part of Seoul, according to the request of the user, the PDSD natural light LED lighting was installed in the home bedroom or the living room, expectations for the ability to restore physical and mental stability were high (88%), in the same way, after 1 week and 3 weeks, the physical and mental changes were compared and the results,84% in the first week and 90% in the third week and thereafter, the effect of relieving depression was high. We conclude that patients with depression have a good sleep, an uneasy feeling, a sense of security, a good night's sleep, and a good feeling. The PDSD LED Light is expected to contribute in the various areas, which reduced the suicides, which give increased immunity from infectious diseases, which give a crash to reduce accidents caused by negligence, which improve the safe operation of heavy vehicles in which a traffics accident incidence installed on the highest point, which improve the safety function on the 'safety way home' for the safety of the community, which due to fire gives alleviate the emotional anxiety of firefighters, which improve the environment for long-term control room working during decision making caused by natural disasters.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.177-184
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• 2004

Orthotropic steel deck bridge has much advantages such as the light deadweight, so the construction of orthotropic steel deck is profitable for the long-span bridges Although the system has a lot of merits, it happens some damages by the traffic density and the fatigue cracks of welding. The cross-connection of longitudinal rib and transversal rib is one of the weakest at the fatigue. The secondary stresses which are from the out-plane deformation of transversal rib and the torsion of longitudinal rib make the topical stress concentration phenomenon. The Bulkhead Plate for prevention of this stress concentration phenomenon was applied by changing the orthotropic steel deck of Williamsburg bridge in USA. But, it is principle that a Bulkhead Plate is not established in the domestic design standard. Therefore, it is estimated that the study for installation of Bulkhead Plate is needed. This study with considering these circumstances proves efficiency of Bulkhead Plate and will be presented optimal design details through finite element analysis according to change the geometrical of Bulkhead Plate and the cross-connection area of longitudinal and transversal rib