• International Journal of Highway Engineering
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• v.18 no.4
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• pp.77-82
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• 2016

PURPOSES : This paper proposes a reliability index for the safety evaluation of freeway sections. It establishes a reliability index as a safety surrogate on freeways considering speeds and speed dispersions. METHODS : We collated values of design elements including radii, curve lengths, vertical slopes (absolute values), superelevations, and vertical slopes from seven freeway sections in Korea. We also collected data about driving speeds, traffic accidents, and their deviations. We established a reliability index using these variables. RESULTS : The average radii, curve lengths, and superelevations are highly correlated with the incidence of traffic accidents. Deviations in radius and curve lengths show an especially high correlation. The reliability index, derived from speed and speed dispersions of the seven freeway sections, also correlated highly with accidents with a correlation index of 0.63. CONCLUSIONS : Since the reliability index obtained from speed and speed dispersions are highly correlated with traffic accidents, we conclude that a reliability index can be a safety surrogate on freeways considering speeds and speed dispersions together in terms of design and operational levels.

• Journal of Korean Society of Transportation
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• v.12 no.1
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• pp.137-149
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• 1994

The objective of study is to evaluate the effect of speed control hump on traffic operation and accidents. Three sites were investigated for the change of traffic accidents before and after the hump installation. Vehicle speeds approaching the hump were also analyzed. The study revealed that not only the number of traffic accidents but also the accident severity were significantly reduced by the installation of hump. Further, different types of traffic accidents with lower severity were observed after the hump installation. For the effect of speed reduction by hump, it was found that the speeds observed at 15m upstream of hump were in the range of 36~50 percent of approaching speeds which were not affected by (ie, without) the hump. Economic analysis of hump installation showed the benefit-cost ratio of 4.3 and 11.2 at two sites. Further analysis revealed that the benefit by the accident reduction exceeds the cost by speed reduction and installation capital if AADT is below 43,150 vehicles on two lane highways. It is recommended from the study that humps should be considered on two lane highways of high accident locations for excessive speeds to reduce traffic accidents and severity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.18-20
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• 2019

In this paper, in order to prevent accidents when deviating from the lane during high-speed self-driving, we are going to design a warning system that will sound an alarm after recognizing the surrounding situation with a $360^{\circ}$ camera. Accidents often occur while driving on self-driving cars because they try to change lanes excessively or fail to recognize people, animals and objects that appear suddenly when driving at high speeds. The government wants to identify the surrounding situation with cameras when driving off a lane during high-speed autonomous driving, and to create a car that sounds a warning system through a lane departure sensor on the underside of the vehicle to reduce various accidents that occur during self-driving and to have a safer driving system.

• Wind and Structures
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• v.6 no.5
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• pp.325-346
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• 2003

High-sided road vehicles are susceptible to a sharp-edged crosswind gust, which may cause vehicle accidents such as overturning, excessive sideslip, or exaggerated rotation. This paper thus investigates the dynamic behaviour and possible accidents of high-sided road vehicles entering a sharp-edged crosswind gust with road surface roughness and vehicle suspension included. The high-sided road vehicle is modelled as a combination of several rigid bodies connected by a series of springs and dampers in both vertical and lateral directions. The random roughness of road surface is generated from power spectral density functions for various road conditions. The empirical formulae derived from wind tunnel test results are employed to determine aerodynamic forces and moments acting on the vehicle. After the governing equations of motion are established, an extensive computation work is performed to examine the effects of road surface roughness and vehicle suspension on the dynamic behaviour and vehicle accidents. It is demonstrated that for the high-sided road vehicle and wind forces specified in the computation, the accident vehicle speed of the road vehicle running on the road of average condition is relatively smaller than that running on the road of very good condition for a given crosswind gust. The vehicle suspension system should be taken into consideration, and the accident vehicle speed becomes smaller if the vehicle suspension system has softer springs and lighter dampers.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.278-283
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• 2013

With the increasing power demands, size of the fault current in electrical grids is steadily increasing, and it exceeds the breaking capacity of circuit breakers. To effectively cope with these problems, a high-speed interrupter was suggested. The high-speed interrupter provides fault current with a bypass to a fault current limiter in case of accidents and consequently, fault current can be restricted. In this study, behavioral characteristics of high-speed interrupter were analyzed by accident types occurred in a distribution system. When accidents occurred, a and b contact of the high-speed interrupter were turned-off and then, turned-on. Accordingly, fault current flowed to the circuit connected to a current limiting element, and the fault current limiter restricted fault current to within a half-cycle. Nevertheless, the behavior of the high-speed interrupter was slowed down by a switching surge. As a result, fault current was confirmed to be restricted not to within the anticipated half-cycle, but to after a half-cycle. Moreover, the behavioral characteristics of the high-speed interrupter changed not only by accident types, but by behaviors of R, S, and T phases. This was due to the errors in stroke lengths of the high-speed interrupters, which resulted in a slight time discrepancy among three interrupters. In addition, the switching behaviors of the b and a contact were confirmed not to have coincided due to the switching surge; b contact behaved first and a contact followed. because of this, accuracy of stroke length and switching surges through the solenoid suction increases may be necessary to resolve.

• International Journal of Automotive Technology
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• v.5 no.3
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• pp.173-180
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• 2004

An intensive study was conducted for the crash worthy structural design of the recently developed Korean High Speed Train (KHST). Two main design concepts were set up to protect both crews and passengers from serious injury in heavy collision accidents, and to reduce damage to the train itself in light collision accidents. A collision against a movable 15-ton rigid obstacle at 110 kph was selected from train accident investigations as the accident scenario for the heavy collisions. A train-to-train collision at the relative velocity of 16 kph was used for the light collision. The crashworthiness behaviors of KHST were numerically evaluated using FEM. Analysis results using 1-D collision dynamics model of the full rake consist and 3-D shell element model of the front end structure showed good crashworthy responses in a viewpoint of structural design. Occupant analyses and sled tests demonstrated that KHST performed well enough to protect occupants under the considered accident scenarios. Finally our numerical approaches were evaluated by a real scale collision test.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.4
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• pp.47-54
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• 2019

In the worldwide, The issue comes up which is the danger of car accidents from climate-change effects. We are considering about various types of speed limit signs for setting restricts to high-speed vehicles. South Korea has 4 seasons in the land. At Summer or Winter seasons have heavy rains and fogs or snow, In these seasons need to enforce speed limit laws or methods to prevent car collision. But South korea is using stationary speed limiters that is not enough to proof against rear-end car accidents in these climates. In this paper shows the necessity of independent LED speed limits display to reduce car accidents. And explaining the prototype model which is a combination of rain sensor and wiper systems. This model is independently changed the speed limits to 50%, 80%, 100% of standards by raindrops and snowflake. Also it is freely setting speed limits on each places anywhere it settled in. Visual effects of the model as being speed-down of vehicles helps to prevent rear-ending car accidents and traffic beforehand.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.17-23
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• 2000

In Korea, the number of railroad accidents is decreasing, but the scale of railroad accidents tend to be growing large. On considering the opening of the high speed railway in 2004, the problem of railroad safety is very important. The purpose of this study is to make plans for improving railroad safety of Korea. To make this plan, we generally analyzed the future railway traffic, and reviewed annual statistics of railroad accidents trend and case studies of foreign railway accidents.

• Explosives and Blasting
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• v.12 no.3
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• pp.32-41
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• 1994

The specific characters in recent Chemical processing and industrial plants are the handling of severe limit conditions such as high pressure, high and low temperature, high speed production and transportation plant automation and appearance of many new hazardous materials in numbers and quantity. The possibilities of these characters causing the accident and environmental pollution in industrial activities become very high. This paper describes the concrete policy In prevent the explosion accident out of the many accidents which are the safety of the safety engineering.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.357-366
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• 2002

In this paper the cases on accidents/incidents and the reporting/responding procedures of high-speed rail operating countries will be reviewed and what these suggest us will be identified, and those countries' efforts to secure the prompt rescue system will be reviewed and the plan to secure the more customized rescue and rehabilitation system taking account into circumstances of our high-speed railway accident/incident will be presented.