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

• Fire Science and Engineering
• /
• v.19 no.2 s.58
• /
• pp.63-68
• /
• 2005

In this study, the arc dispersion properties were analyzed according to switching of high sensitive type Residual Current Protective Device(RCD) contacts. Arc dispersion and ignition process was taken by high speed imaging system(HSIS). In this experiment, electric lamps(60 W) and heaters(950 W) were connected in parallel as loads. In case of normal RCD, it took about 2.3(ms) from the generation of arc to the extinction of uc. When arc was dispersed in normal RCD, it did not ignite cotton. Whereas, in case of RCD deteriorated by NaCl solution, the range of arc dispersion was wider and the arc lasted for 3.3[ms] more compared to normal RCD. And the arc ignited cotton. In order to prevent accidents caused by RCD, we should be careful of environmental factors, such as dust and humidity, and the parts of RCD should be used as incombustible materials.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.6
• /
• pp.39-45
• /
• 2012

More than 80 percent of traffic accidents related with lane departure believed to be the result of crossing the lane due to either negligence or drowsiness of the driver. Lane-departure related accident in the highway usually involve high fatality. Even though LDWS is believed to prevent accident 25% and reduce fatalities by 15% respectively, its effectiveness in performance is yet to be confirmed in many aspects. In this study, the vehicle lateral locations relative to warning zone envelop (earliest and latest warning zone) defined in ISO standard, ECE and NHTSA regulations are compared with respect to various factors including delays, vehicle speed and vehicle heading angle with respect to the lane. Since LDWS is designed to be activated at the speed over 60 km/h, vehicle speed range for the study is set to be from 60 to 100 km/h. The vehicle heading angle (yaw angle) is set to be up to 5 degree away from the lane (abrupt lane change) considering standard for lane change test using double lane-change test specification. The TLC is calculated using factors like vehicle speed, yaw angle and reaction time. In addition, the effect of vehicle type has been considered to assess LDWS safety.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.1336-1341
• /
• 2011

The pantograph-overhead contact line system is an interface that supplies power to high-speed trains used in many countries including Korea. Due to the fact that power is supplied through direct contact between contact wires and contact strips, wear may occur, increasing the possibility of accidents over periods of time. Therefore, there is a need to establish methods of effectively extracting safety related parameters. In this paper, an image processing based method that calculates and draws graphs of a pantograph's dynamic stagger is proposed. To assess reliability, the results were compared with data collected from conventional maintenance vehicles.

• Journal of the Korean Society of Safety
• /
• v.25 no.3
• /
• pp.1-6
• /
• 2010

Ball bearings are one of main components that support the rotational shaft in high speed rotary machinery. So, it is very important to detect the incipient faults and fault growth of bearing since the damage and failure of bearing can cause a critical failures or accidents of machinery system. In the past, many researchers mainly performed to detect the bearing fault using traditional method such as wavelet, statistics, envelope etc in vibration signals. But study on the detection technique for bearing fault growth has a little been performed. In this paper, we verified the possibility for monitoring of fault growth and detection of fault size in bearing outer-race by using the envelope powerspectrum and probabilistic density function from measured vibration signals.

• Journal of Navigation and Port Research
• /
• v.27 no.6
• /
• pp.645-652
• /
• 2003

A virtual vessel traffic control system is introduced to contribute to prevent a marine accident such as collision and stranding from happening. Existing VTS has its limit. The virtual vessel traffic control system consists of both data acquisition by satellite remote sensing and a simulation of traffic environment stress based on the satellite data, remotely sensed data And it could be used to provide timely and detailed information about the marine safety, including the location, speed and direction of ships, and help us operate vessels safely and efficiently. If environmental stress values are simulated for the ship information derived from satellite data, proper actions can be taken to prevent accidents. Since optical sensor has a high spatial resolution, JERS satellite data are used to track ships and extract their information. We present an algorithm of automatic identification of ship size and velocity. It lastly is shown that based on ship information extracted from JERS data, a qualitative evaluation method of environmental stress is introduced.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1465-1467
• /
• 2004

Compared with other transport means, safety and timeliness are the merits of railways. Unexpectedly when accident happens, much time and human strength are required to cope with the accident. And for swift recovery, systematic rehabilitation is needed. Recently using MTS(Moving picture Transmission System), we can perform accident rehabilitation and recording work efficiently. MTS is the device that transmits continuous picture information from accident field to control center. e are developing the appropriate system to railway situation to make use of the existing information communication technology, processing technology of video-tex, super high speed transmission technology through fiber-optic, copper cable and network description of information Technology, etc. If these communication-based can technologies are applied to railway system, railway managers can control the accident by inspecting the picture of accident field and can contribute to the safe train operation and the improvement of railway management. In this paper, we investigate the connecting methods when optical fiber is used for moving picture data transmission of train accidents, and its problems. And, we validate MTS's performance through about 28km section of field test.

• Corrosion Science and Technology
• /
• v.6 no.6
• /
• pp.308-310
• /
• 2007

The owner of underground metallic structures (gas pipeline, oil pipeline, water pipeline, etc) has a burden of responsibility for the corrosion protection in order to prevent big accidents like gas explosion, soil pollution, leakage and so on. So far, Cathodic Protection(CP) technology have been implemented for protection of underground systems. The stray current from DC subway system in Korea has affected the cathodic protection (CP) design of the buried pipelines adjacent to the railroads. In this aspect, KERI has developed a various mitigation method, drainage system through steel bar under the rail, a stray current gathering mesh system, insulation method between yard and main line, distributed ICCP(Impressed Current Cathodic System), High speed response rectifier, restrictive drainage system, Boding ICCP system. We installed the mitigation system at the real field and test of its efficiency in Busan and Seoul, Korea. In this paper, the results of field test, especially, distributed ICCP are described.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1817-1823
• /
• 2007

In this study, we have studied rail infrastructure related to emergency action to manage the risk when emergency caused by faults of facility or rail vehicle during operation happens. Especially we have compared the effect of emergency action with examining the structure of vehicle, tunnel, bridge and access road, etc which are related to emergency action. Also, we have tried to analyze effects of radio and communication equipment, lifesaving and refuge which could be used for rolling stock, station, control room, tunnel, bridge and etc, and we have presented the way of reporting the emergency to the train driver or crew, control room, outside networks which could be used by passengers in vehicle, station, railroad line. Based on these, we have analyzed the conduct of emergency action in length of time when emergency happens in railway and high-speed railway, and studied the method of which passengers could be guided safely and escape from the scene of the accident.

• Fire Science and Engineering
• /
• v.10 no.1
• /
• pp.3-9
• /
• 1996

Electrostatic charge is generated in large scale or high speed processes dealing with materials with large resistance, or under complicated condition. Fire and explosion often occur due to electrostatic charge accumulated in flammable gases, vapor, liquids and powder. It is usually very difficult to verify the cause of accidents as well as the prevention. In this study, it is shown that the needle electrode needs the electrode gap from 1.8mm to 3.8mm, sphere electrode and plate electrodes need the electrode gap of 1.9mmfor the minimum ignition energy. The sphere electrode and the plate electrode requires 12.8mJ and 3.2mJ of minimum ignition energy respectively with the electrode gap of 1.1mm. The ignition voltage rises to very large value as the ground resistance increases.