• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.692-700
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• 2007

A trial run of locally-developed tilting train has been in process on Chungbuk line since the test vehicle was first produced. For the system stabilization, interface verification among the systems including track, structure, catenary and signaling system, not to mention the rolling stock, is very crucial. In the area of wayside structure, the stability of track structure and train run shall be evaluated through the review of impact by increased speed by developed train on track structure. The study thus was intended to evaluate the impact on track while a tilting train is running the curve section, which is vulnerable to accelerated train speed. The analysis of tilting train test running the part of Chungbuk line and Honam line was conducted to identify the impact on existing track performance by tilting train. To identify the movement behavior of each part of track while tilting train, high speed train and traditional train (Mugunghwa and freight train) were running the existing line, wheel load, lateral wheel load, rail bending stress, vertical and lateral displacement of rail and vertical displacement of sleeper were compared and analyzed so as to evaluate the expected impact by tilting train for improving the train speed.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.439-448
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• 2016

The population over 65 years old is 12.7% of total population in 2014 and Korea is going to be an aged society in the near future. The transportation vulnerable including the aged should be guaranteed in walking mobility under safe and comfortable environment for their socio-economic activities. For the era of fusion and convergence this paper investigated the characteristics of walking accidents related to the aged pedestrians and analyzed the aged-oriented walking factors with a reaction time and a walking speed at crosswalks in Yeosu. In the results, the crashes for the aged occur at 9.9% of total crashes and the fatalities of the aged are 40.3% of total fatalities in 2014. The 47.4% of the aged fatalities is also attributed to vehicle-to-pedestrian accidents. The 49.3% of all pedestrian fatalities occurs at the aged pedestrians with a very high proportion. The reaction time and walking speed for the aged were determined as the values located at the lower 15%-tile of the elderly physical ability. It is shown that the reaction time is 4.56 seconds and the walking speed is 0.76 m/s in the case of Yeosu. From two factors' standpoint, the walking environment at crosswalks in Yeosu is inappropriate for the aged.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.560-569
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• 2019

Purpose: Greenhouse gases are one of the major causes of global warming, a global disaster. This study aims to calculate road sector greenhouse gas emissions more precisely than conventional methods. Method: Currently, the average speed of a vehicle is used to calculate greenhouse gas emissions. In this study, GHG emissions are calculated using the speed of individual vehicles and compared with current methods. Result: It was confirmed that the existing emission estimation method underestimated about 15% in the case of carbon dioxide, about 1% in the case of nitrous oxide, and about 1% in the case of methane. Conclusion: Current methods of estimating greenhouse gas emissions were developed before 2000 and were developed to meet the limits of available data. However, with the advancement of technology, the quality of available data is now high, and new emissions estimation methods are needed. Therefore, in this study, we propose a method for estimating the velocity-based greenhouse gas emissions of individual vehicles as a more accurate method for calculating greenhouse gas emissions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.85-94
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• 2016

Lane Designation is defined as reasonable road management to ensure the road safety and enhance road efficiency. While the lane designation system was abolished in 1999, it was redefined because of the increasing number of large vehicles in the passing lane, violent on driving and traffic accidents in 2000. The needs of improvement on operating the lane designation has been increasing more in recent due to the low ratio of compliance with the system and difficulties to keep the right lane due to need of turning and demand of widening of designates lane for two-wheeled vehicles and truck. In this study, we presented the improvement plan through the question survey, simulation analysis, safety evaluation. It found a problem that the low-speed vehicle is to use the upper level roadway, difficulties of supervision, the imbalance in the lane use, imbalance traffic and does not match the international standards. This study suggested five different alternatives through the survey. micro simulation has used in order to examine each alternative by management effectiveness and feasibility. It analyzed the traffic speed, efficiency, traffic balance of alternatives. Also, safety evaluation conducted in terms of the range of field-of-view to ensure the easiness of field of view by various configurational difference between the vehicles. By the analysis results of such indicators, This study presents proposals for improvement in operating designated lane that low-speed-big-sized vehicles keep to the right lane, and high-speed-small sized vehicles keep to the left lane.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.8
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• pp.939-944
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• 2014

Traffic accidents caused by the attention dispersion are increasing and the behavior of the attention dispersion affects the front-observing rate, road keeping ability, and reaction time for a dangerous situation. Many drivers listen to a radio broadcast and they have to change the frequency for continuously listening a radio broadcast of the specific broadcasting station in case of crossing a boundary of the particular area. In this situation, the possibility of a car accident increases, because the attention dispersion of a driver might be occurred. Especially, the risk of a car accident caused by changing the frequency of a radio is more serious in the highway, due to the high speed of a vehicle. In order to reduce the risk of a car accident caused by handling a radio during driving car, in this paper, we propose an automatic frequency conversion algorithm for vehicle radio, which saves normal system frequencies of primary broadcasting stations in a database and determines new frequency of the changed area using the location information obtained from a navigation system in a boundary of the specific area. After determining new frequency, the proposed algorithm selects a frequency with better receiving rate comparing signal-to-noise ratios (SNRs) of two signals corresponding previous and new frequencies.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.107-116
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• 2005

The information on travel time in providing the information of traffic to drivers is one of the most important data to control a traffic congestion efficiently. Especially, this information is the major element of route choice of drivers, and based on the premise that it has the high degree of confidence in real situation. This study developed a vehicle arrival time prediction algorithm called as "VAT-DV" for 6 corridors in total 6.1Km of "Nam-san area trffic information system" in order to give an information of congestion to drivers using VMS, ARS, and WEB. The spatial scope of this study is 2.5km~3km sections of each corridor, but there are various situations of traffic flow in a short period because they have signalized intersections in a departure point and an arrival point of each corridor, so they have almost characteristics of interrupted and uninterrupted traffic flow. The algorithm uses the information on a demand volume and a queue length. The demand volume is estimated from density of each points based on the Greenburg model, and the queue length is from the density and speed of each point. In order to settle the variation of the unit time, the result of this algorithm is strategically regulated by importing the AVI(Automatic Vehicle Identification), one of the number plate matching methods. In this study, the AVI travel time information is composed by Hybrid Model in order to use it as the basic parameter to make one travel time in a day using ILD to classify the characteristics of the traffic flow along the queue length. According to the result of this study, in congestion situation, this algorithm has about more than 84% degree of accuracy. Specially, the result of providing the information of "Nam-san area traffic information system" shows that 72.6% of drivers are available.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.733-746
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• 2021

Purpose: This study was conducted for the purpose of selecting important events from among various events that may pose a risk to railway passengers. For this purpose, opinions of various railroad vehicle passengers and railway operator workers were investigated and analyzed. Method: The survey was conducted on 1,000 men and women in their 20s and 60s and 429 workers at 11 company across the country. A survey was conducted on the dangerous situations that may occur in subways, general railroads and high-speed rail vehicles targeting passengers. For railway operator workers, the questionnaire is limited to subway vehicles. Result: Among the passenger risk factors(abnormal behavior and dangerous situations) selected based on the frequency and importance of occurrence of passenger risk factors, the main risk factors are selected 'car door jamming', 'sexual harassment', 'intoxicating behavior', 'fighting' /assault', 'wandering around', and 'not wearing a mask'. Conclusion: The major risk factors affecting passengers were selected by surveying passengers and railway operators. we plan to develop a CCTV detection system with AI technology that can quickly and continuously detect the major risk factors of railway vehicles selected as a result of this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.568-573
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• 2018

UAV(Unmanned Aerial Vehicle) is widely used in space information construction, agriculture, fisheries, weather observation, communication, and entertainment fields because they are cheaper and easier to operate than manned aircraft. In particular, UAV have attracted much attention due to the speed and cost of data acquisition in the field of spatial information construction. However, ortho image images produced using UAVs are distorted in buildings and forests. It is necessary to solve these problems in order to utilize the geospatial information field. In this study, fixed wing, rotary wing, vertical take off and landing type UAV were used to detect distortions of ortho image of UAV under various conditions, and various object areas such as construction site, urban area, and forest area were captured and analysed. Through the research, it was found that the redundancy of the unmanned aerial vehicle image is the biggest factor of the distortion phenomenon, and the higher the flight altitude, the less the distortion phenomenon. We also proposed a method to reduce distortion of orthoimage by lowering the resolution of original image using DTM (Digital Terrain Model) to improve distortion. Future high-quality unmanned aerial vehicles without distortions will contribute greatly to the application of UAV in the field of precision surveying.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.4
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• pp.305-316
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• 2022

Hydrogen energy is emerging as an alternative to the depletion of fossil fuels and environmental problems, and the use of hydrogen vehicles is increasing in the automobile industry as well. However, since hydrogen has a wide flammability limit of 4 to 75%, there is a high concern about safety in case of a hydrogen car accident. In particular, in semi-enclosed spaces such as tunnels and underground parking lots, a fire or explosion accompanied by hydrogen leakage is highly likely to cause a major accident. Therefore, it is necessary to review hydrogen safety through analysis of flammability areas caused by hydrogen leakage. Therefore, in this study, the effect of the air velocity in the tunnel on the flammability area was investigated by analyzing the hydrogen concentration according to the hydrogen leakage conditions of hydrogen vehicles and the air velocity in the tunnel in a road tunnel with standard section. Hydrogen leakage conditions were set as one tank leaking and three tanks leaking through the TPRD at the same time and a condition in which a large crack occurred and leaked. And the air velocity in the tunnel were considered 0, 1, 2.5, and 4.0 m/s. As a result of the analysis of the flammability area, it is shown that when the air velocity of 1 m/s or more exists, it is reduced by up to 25% compared to the case of air velocity of 0 m/s. But there is little effect of reducing the flammability area according to the increase of the wind speed. In particular, when a large crack occurs and completely leaks in about 2.5 seconds, the flammability area slightly increases as the air velocity increases. It was found that in the case of downward ejection, hydrogen gas remains under the vehicle for a considerably long time.

• Journal of Broadcast Engineering
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• v.27 no.6
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• pp.936-939
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• 2022

As air combat system technologies developed in recent years, the development of air defense systems is required. In the operating concept of the anti-aircraft defense system, selecting an appropriate armament for the target is one of the system's capabilities in efficiently responding to threats using limited anti-aircraft power. Much of the flying threat identification relies on the operator's visual identification. However, there are many limitations in visually discriminating a flying object maneuvering high speed from a distance. In addition, as the demand for unmanned and intelligent weapon systems on the modern battlefield increases, it is essential to develop a technology that automatically identifies and classifies the aircraft instead of the operator's visual identification. Although some examples of weapon system identification with deep learning-based models by collecting video data for tanks and warships have been presented, aerial vehicle identification is still lacking. Therefore, in this paper, we present a model for classifying fighters, helicopters, and drones using a convolutional neural network model and analyze the performance of the presented model.