• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.32-38
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• 2020

This study examined the problems of existing vehicles to propose alternatives to improve the crashworthiness of railway freight cars through collision acceleration analysis using a one-dimensional collision analysis method. A collision scenario of railway shunting and crash accidents was selected from the collision accident cases and international standards. A one-dimensional collision simulation using LS-DYNA was performed according to those scenarios. As a result, the acceleration level of the freight wagon was calculated to be under 2g and was predicted to meet the EN 12663 standard in the shunting situation. On the other hand, the result of crash simulation with an impact velocity between 10 and 15 km/h revealed the shock absorber capacity of the railway coupler to be insufficient in a crash situation, resulting in increased acceleration, and carbody deformation could be predicted. As a method of improving the crashworthiness, a deformation tube-type energy absorber was applied to the coupler system, and collision analysis was performed again with new energy absorption strategy. Overall, the simulation showed that the acceleration level was decreased by 12% of the conventional freight-car energy absorption system.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.112-128
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• 2018

We are implementing pedestrian priority zone policy to certain districts to reduce greenhouse gas and to develop eco-friendly city which has more focus on pedestrians' walking environment. This policy has contributed to citizens' satisfaction level with improved public transportation service as well as more spacious streets for walk. Despite highly positive influence of pedestrian priority zone policy to the walking environment, we need to anticipate the impact of this to traffic environment as it may have bad effect to the overall traffic flow around the zone where the policy is implemented. This research has analyzed the change of characteristics of traffic accidents around the eco-traffic area of Hang-Gung dong, Suwon city, to understand impact of the pedestrian priority zone policy to the traffic surroundings, with pre-post analysis methodology. As a result, number of accidents related to pedestrians showed decrease as pedestrian priority zone is designed operated with focus to pedestrians. But accidents related illegal U-turn and violation of the traffic signal showed (significant) increase as there was a restriction of turns and decrease of overall traffic speed. To prevent the accidents above, we need to notice drivers to pay special attention before the pedestrian priority zone event, and information from this research should be given to the drivers through safety signs and mobile application at the place near to the event.

• Journal of the Society of Disaster Information
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• v.7 no.4
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• pp.266-272
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• 2011

This study is focused on guard major collegians who are composed of factor in medical emergency system. In the case of cardiac failure, it is to make its basic data develop its education program of CPR which can increase the patient's survival rate before his hospitalization. The subject of study is composed of 120 persons who are 94 boy-collegians(78.3%) and 26 girl-collegians(21.7%) in sex and 66 first-grade collegians(55.0%) and 54 second-grade collegians(45.0%) in a school year. There is significant difference in the practices of artificial respiration and the thorax pressure after the education of basic CPR in sex(p<0.01). The practices of artificial respiration in boy-collegians($93.72{\pm}4.21$) is higher than in girl-collegians($82.31{\pm}6.36$) and the practices of thorax pressure in boy-collegians($92.45{\pm}4.44$) is higher than in girl-collegians($88.08{\pm}6.49$). The satisfaction degree of boy-collegians($4.33{\pm}0.59$) is higher than that of girl-collegians($3.73{\pm}0.67$) after theory & practice education of basic CPR(p<0.01). It is necessary to develop the education program and educate its knowledge & technology in proportion to collegians characteristics of sex and school year. Also, education authorities should develop a subject of the accident provided the practical education of CPR for guard major collegians.

• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.133-138
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• 2003

The data on outbreaks of puffer fish poisoning during 1991 to 2002 in Korea were gathered from press reports, and characterized information collected. During the period, a total of 32 outbreaks of puffer fish poisoning was reported. These outbreaks caused 111 persons to become poisoning, among the cases 30 persons were fatal. The mean case fatality rate was 27.0%, and most of deaths (93.3%) were the male of above 29 years old. Patient number of below 4 persons per a poisoning accident occupied 75.0% of total outbreaks; 65.8% of total cases; and 66.7% of total deaths) was occurred in the months, November through January. Most of puffer fish poisoning (75.0% of total outbreaks; 68.5% of total cases; and 73.3% of total deaths) were found along the south coastal area of Korea, including Busan, Gyeongsangnam-do, Jeollanam-do and Jeju-do. Over than 80% of puffer fish poisoning outbreaks occurred at fishing boat and home where privately made food was cause, and outbreaks in restaurants accounted for 15.6%. Most commonly implicated foods were Guk, boiled soup with puffer fish meat and spices.

• Nuclear Engineering and Technology
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• v.45 no.5
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• pp.605-612
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• 2013

Removal of decay heat from an operating reactor during a prolonged station blackout condition is a big concern for reactor designers, especially after the recent Fukushima accident. In the case of a prolonged station blackout condition, heat removal is possible only by passive means since no pumps or active systems are available. Keeping this in mind, the AHWR has been designed with many passive safety features. One of them is a passive means of removing decay heat with the help of Isolation Condensers (ICs) which are submerged in a big water pool called the Gravity Driven Water Pool (GDWP). The ICs have many tubes in which the steam, generated by the reactor core due to the decay heat, flows and condenses by rejecting the heat into the water pool. After condensation, the condensate falls back into the steam drum of the reactor. The GDWP tank holds a large amount of water, about 8000 $m^3$, which is located at a higher elevation than the steam drum of the reactor in order to promote natural circulation. Due to the recent Fukushima type accidents, it has been a concern to understand and evaluate the capability of the ICs to remove decay heat for a prolonged period without escalating fuel sheath temperature. In view of this, an analysis has been performed for decay heat removal characteristics over several days of an AHWR by ICs. The computer code RELAP5/MOD3.2 was used for this purpose. Results indicate that the ICs can remove the decay heat for more than 10 days without causing any bulk boiling in the GDWP. After that, decay heat can be removed for more than 40 days by boiling off the pool inventory. The pressure inside the containment does not exceed the design pressure even after 10 days by condensation of steam generated from the GDWP on the walls of containment and on the Passive Containment Cooling System (PCCS) tubes. If venting is carried out after this period, the decay heat can be removed for more than 50 days without exceeding the design limits.

• Korean Journal of Acupuncture
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• v.22 no.3
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• pp.63-81
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• 2005

Herbal acupuncture has been used to prevent and treat the cerebrovascular accident, such as a stroke, and many studies of acupuncture and moxibustion concerning to the stroke have been undertaken in the human and various animals. The main characteristics of herbal acupuncture are a combination of acupuncture and herbal medicine. It was not well known the therapeutic effect and the mechanism of herbal acupuncture on transient forebrain ischemic injury, although it has been used frequently in clinics. In this study, neuroprotective effects of folium artemisiae argyi (艾葉)' herbal acupuncture on the $LR_3$ (Taechung) on the transient forebrain ischemia were investigated in Sprague-Dawely rats. Expressions of cFos, FosB and BDNF protein in the hippocampus and cortex were observed at 2 hrs and 48 hrs after transient forebrain ischemia by immunohistochemistry and ELISA technique. Expression of cFos protein was increased slightly in the hippocampus and cortex at 2 hrs after transient forebrain ischemia, but FosB protein was increased highly comparing to cFos protein. However, pretreatment with folium artemisiae argyi' herbal acupuncture on $LR_3$ significantly increased expression of cFos protein and significantly decreased expression of FosB protein compared to control group. These features were observed in the motor cortex and retrosplenial granular cortex as well as the hippocampus. Also, pretreatment with folium artemisiae argyi' herbal acupuncture on $LR_3$ significantly increased the expression of BDNF protein in the hippocampus ($263.26{\pm}44.56pg/ml$ extracted by water, $275.35{\pm}51.47pg/ml$ extracted by moxa tar)and the cortex ($102.33{\pm}13.65pg/ml$ extracted by water, $109.54{\pm}9.37pg/ml$ extracted by moxa tar) compared to the hippocampus $(134.07{\pm}2.96pg/ml)$ and the cortex $(61.16{\pm}4.11pg/ml)$ in control group at 48 hrs after transient forebrain ischemia. These results suggest that pretreatment with folium artemisiae argyi'herbal acupuncture on $LR_3$ has neuroprotective effect on transient forebrain ischemia and the herbal acupunture on $LR_3$ may be related to antioxidative function of folium artemisiae argyi.

• Fire Science and Engineering
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• v.29 no.2
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• pp.79-83
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• 2015

The fire accident is a representative type of disaster that can largely impact on business. Therefore, precautionary measures and rapid initial response is very important when a disaster occurs. The storage of porous combustibles is inevitable in coal yard, plywood processing industry, and others that are currently operating. Initial fire fighting of fire and identifying the ignition point in such a porous combustible storage space are so difficult that if the initial response is failed, being led to deep-seated fire, surface fire is likely to result in secondary damage. In addition, deep-seated fire can cause personal injuries and property damage due to a large amount of toxic gases and reignition. Therefore damage reduction measures is required around the storage space to handle a porous flammable. Improving the penetration performance of the concentration of the surfactant is carried out as underlying study, which is about an deep-seated fire extinguishing efficiency augmentation when using wetting agents. The porous materials used in the experiments is radiata pine wood flour, which occupies more than 75% of the domestic wood market. Fire fighting water is selected as Butyl Di Glycol (BDG), which is being used for infiltration extinguishing agent, and the experiment was carried out by producing a standard solution. The experiment was carried out on the basis of the Deep-Seated Fire Test of NFPA 18. The amount of watering, porous material to the internal amount of penetration, and runoff measurement out of the porous material was conducted. According to experimental results, as the surface tension is reduced, the surfactant concentration macroscopic penetration rate decreases, but infiltration to a porous material is shown to have growth characteristics.

• Journal of Radiation Protection and Research
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• v.27 no.3
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• pp.189-198
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• 2002

The time for evacuation of residents in emergency planning zone(EPZ) of Uljin nuclear site in case of a radiological emergency was estimated with traffic analysis. Evacuees were classified into 4 groups by considering population density, local jurisdictions, and whether they ate residents or transients. The survey to investigate the behavioral characteristics of the residents was made for 200 households and included a hypothetical scenario explaining the accident situation and questions such as dwelling place, time demand for evacuation preparation transportation means for evacuation, sheltering place, and evacuation direction. The microscopic traffic simulation model, CORSIM, was used to simulate the behavior of evacuating vehicles on networks. The results showed that the evacuation time required for total vehicles to move out from EPZ took longer in the daytime than at night in spite that the delay times at intersections were longer at night than in the daytime. This was analyzed due to the differences of the trip generation time distribution. To validate whether the CORSIM model fan appropriately simulate the congested traffic phenomena assumable in case of emergency, a benchmark study was conducted at an intersection without an actuated traffic signal near Uljin site during the traffic peak-time in the morning. This study indicated that the predicted output by the CORSIM model was in good agreement with the observed data. satisfying the purpose of this study.

• Journal of Digital Contents Society
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• v.19 no.1
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• pp.93-102
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• 2018

This study aims to present policy implications by analyzing information security behavior factors of internet users. The research model, based on PMT and UTAUT2, consists of perceived threat, severity, social influence, self-efficacy, experience and habits, PC and privacy behaviors, security behaviors on new services and set demographic characteristics, use places of internet, use of paid products, and experiences of accident as moderate variables to analyze the effect on security behavior. The results showed that perceived severity, self-efficacy significantly influenced on experience and habits, and experience and habits and self-efficacy had a high influence on PC and privacy behavior. Also, PC and privacy behaviors have a high impact on security behavior of new services. Age, income, use of paid products, and experience of accidents have a moderating effects on security behaviors. The results of this study are expected to help policy decision making to improve the level of information security of internet users.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.4
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• pp.743-755
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• 2018

Tunnel is a semi-closed structure similar to underground space where the smoke generated from fire fills the space fast while escaping from the space slow. Because of such characteristics, when the fire breaks out by traffic accident, the vehicles are jammed making it difficult for the people to evacuate from the scene as well as for the fire engine to gain access to the scene. For such reasons, tunnels are globally categorized into some disaster classes for differentiated facilities and operation approaches. In Korea, less than a 1 km-long tunnel accounts for 80.0% and such a short tunnel which is categorized into Class III is not required to have smoke control system. In this study, a full-scale fire test was conducted in a bid to apply air curtain system using heat-resistant sirocco fan to a less than 1 km-long tunnel. To that end, heat resistance test to verify the normal operation at $250^{\circ}C$ for 60 minutes was conducted. Consequently, despite of rapid rising-temperature and increasing-carbon dioxide inside the air curtain (direction of fire in tunnel), initial condition was found to have been sustained outside the air curtain (opposite direction of fire in tunnel).