• International Journal of Fluid Machinery and Systems
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• v.10 no.3
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• pp.296-306
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• 2017

Hydropower is now changing its role from the energy generator into the most powerful and reliable tool for stabilizing the electrical network, especially under the increase of intermittent power sources like wind-power and solar-power. Although the hydropower plants are the most robust generating facilities, they are not immune from unexpected severe incidents having long downtime, considerable restoration cost and sometimes fatalities. The present paper provides some study results about severe incidents in the conventional hydropower plants, mainly about the flood, fire and electro-mechanical troubles, except for the incidents of civil facilities. It also provides some possible scenarios which may lead some measures how to avoid such incidents. Finally, it provides some comprehensible recommendations to avoid severe incidents based on experiences.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.65-73
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• 2009

The terrestrial laser scanner measures the signal delay time of electronic circuit in EDM(Electronic Distance Measurement) Module for distance measurement. To measure signal delay time precisely, transmitting laser beam of terrestrial laser scanner is divided optically. Therefore, 10% of the laser beam power is entered into the electronic circuit and the others go out through lens. But, measure of delay time is severe in the laser scanner system that the laser beam power is changed dynamically by reflectance of a object, because characters like gain of electronic circuit involving APD(Avalanche Photo Diode) and so on are changed by incident laser beam. Therefore, we adapt ND(Neutral Density) filter that has grid pattern to the laser scanner system to keep constant the incident laser beam power. In this paper, we propose the simulation program for efficient design of ND filter pattern. Finally, to affirm simulation program, we conduct the experimental test of simulated ND filter that has linearly transmittance change, and we consider the experiment result.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.15.1-15.6
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• 2016

A number of absurdities surrounding the humidifier disinfectant (HD) incident may have occurred because 1) a judicial system operates on the underlying false assumption that the involved parties are equals in knowledge, information and resource mobilization capabilities, regardless of respective real status as company or individual; 2) there is a lack of a system that mandates a company to prevent and actively manage possible catastrophes; 3) the regulatory scheme makes companies believe that as long as they are complying with the existing regulations, they have satisfied all of their responsibilities. I believe that this issue is an opportunity to bring about changes in the judicial redress system, the system of internal management of manufacturers, and the regulatory system of the government. The following regulation amendments are needed to move towards the changes stated above. First, legislation relating to victim relief that is applicable to the HD incident must be established. Second, a risk management system must be formed within the manufacturing company and to this end an institutional environment for the system must be established within regulatory framework. Furthermore, legislation must be passed that could punish companies themselves that have caused severe damage to individuals because they had failed to take necessary actions to avoid foreseeable harm. Finally, the framework of regulation must be changed so that the company, who has the necessary information regarding the product and the component chemicals used in the product, must self-directed experiment and assessment of the safety of their own products.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.205-211
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• 2012

According to the Hebei Spirit incident, 12,547kl of crude oil was spilled into the sea and a total of approximately 40,000 households was damaged. Also, eleven cities and counties including "Taean" were designated as a Special Disaster District by government. Large oil pollution incidents cause severe impact on the change of the surrounding environment as well as destruction of the natural environment of damaged areas. This study analyzes the impacts on the surrounding environment of damaged areas caused by Hebei Spirit oil pollution incident, focusing on the largest damaged county called Taean. Survey was performed with items which are changes in population and local economy, effects on public health, social conflicts and etc. The result of analysis can be used as an important factor to forecast the impact on a damaged area in case of future oil pollution incidents and to establish effective policy of government.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.1
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• pp.118-123
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• 1987

In relation to the dust detonatians which have imposed severe damages on the industry, the ignitability of various dusts has been investigated on a horizontal shock tube in this study. By using a newly designed air injector, very well-distributed clouds could be obtained. The proper reflected shock conditions have been generated by placing a reflector 1.5cm behind the air injector, which reflected the incident shock wave. The incident shock waves in the range of Mach number 2.8-3.3 created the postreflected shock temperature of 1200-1600K. Experimentally the ignition delay was defined as the time interval between the arrival of a reflected shock wave at dusts and the detection of visible light. Measured ignition delays of dusts investigated were located lower than 1msec under the above conditions. These values are one-order higher than those in the incident shock wave condition. In this type of ignitiion process the following three processes are considered to play important roles; heating of a particle, generation of volatile gas by endothermic devolatilization process, and its diffusion from the particle surface and the formation of stoichiometric mixture with oxidizer.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.4
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• pp.590-602
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• 2019

Objectives: This study was conducted to prevent asphyxiation of firefighters during confined space rescue. The specific purpose was to identify the magnitude of the problem, identify the cause of the accidents, and suggest measures to ensure safety of confined space rescues. Methods: We collected data from National Fallen Firefighters Memorial, press releases, and other sources In order to identify the current situation of asphyxiation incidents among firefighters from 1945 to 2019. In addition, an incident investigation was conducted for each case, and the processes, causes, and control measures of the incidents were described as a narrative data entry. Results: Over the past 73 years, eight incidents involving firefighter in Korea have occurred. In these incidents, five firefighters were killed, and eight were injured. The confined spaces incidents occurred were water supply tanks, wastewater treatment tanks, pickling pits, septic tanks, and more. The causes were three cases of hydrogen sulfide poisoning, one of oxygen deficiency, one of carbon monoxide poisoning, and three unclassifiable asphyxiations. The people in need were all workers in various industries. Conclusions: The number of firefighters' deaths and injuries during rescues in confined spaces was severe and the risks have not been completely eliminated. By establishing and implementing a precise incident investigation system, according control measures should be initiatedin order to prevent a recurrence of the same type of disaster and reflected in the SOP. In particular, due to the high risk of occurrence at workplaces, cooperation between fire and rescue authority and relevant agencies such as the Ministry of Employment and Labor and the KOSHA should be strengthened.

• Journal of Ocean Engineering and Technology
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• v.14 no.3
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• pp.1-10
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• 2000

In order to effective manage the construction, disaster prevention plan and the harbor tranquility control, meteorological and sea-state characteristics around Cheju Island have been analyzed. Using results and damage examples of the port facilities under severe sea conditions, a reasonable construction control plan considering the regional characteristics of the sea-state and winds was proposed. That is, in northern part of Cheju Island, the construction work is affected mainly by the winter storms, while the typhoon mainly affects the southern part port facilities during summer to Autumn. Considering their typical characteristics, it is strongly suggested that the main construction work should be carried out during April to July in the northern part, and it should be made during October to next July in the southern part of the island. A permeable TTP mounded breakwater was constructed to protect severe waves as a temporal structure under the long-term development plan in Sogipo port. The transmission characteristics of the structure was discussed using the experimental results. The results show that the transmission coefficient $K_{t}$ is over 20% of incident waves, which cause many problems in the cargo handling in relation to harbor tranquility. In conclusion, this kind of permeable structure can be used only as a temporal structure for the disaster prevention under the construction process. It causes many problems in harbor tranquility if it is used as a permanent harbor structures.s.

• Journal of Trauma and Injury
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• v.25 no.4
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• pp.278-282
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• 2012

An esophageal perforation following anterior cervical fusion is rare. Early development of an esophageal perforation after anterior cervical fusion is usually due to iatrogenic injury from retraction, injury associated with the original traumatic incident, improperly placed instruments or a bone graft. A 31-year-old man had a cervical dislocation and spinal cord injury because of severe cervical trauma after a traffic accident. He was quadriplegic and had no feeling below T4 dermatome. Anterior decompression of the cervical spine and anterior fusion with mesh with autobone were performed. An esophagocutaneous fistula occurred 7 days after anterior cervical surgery. A second anterior surgery was done because of pus drainage. The mesh was changed with an iliac bone graft, and the esophagocutaneous fistula site was primary repaired, but pus continued to drain. Conservative treatment, which consisted of wound drainage and intravenous administration of antibiotics, was tried, but was unsuccessful. After all, we removed the plate and screws, but did not removed the iliac bone graft, We closed the esophageal fistula, and transposed the sternocleidomastoid muscle flap to the interspace between the esophagus and the cervical spine. The wound to the esophagus was well repaired. In conclusion, precautionary measures are needed to avoid the complication, and adequate treatment is necessary to resolve those complications when they occur.

• Journal of Oriental Neuropsychiatry
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• v.14 no.2
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• pp.191-198
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• 2003

Dissociative amnesia is a psychiatric disorder charicterized by a sudden loss of memory, but which has no organic disease or explanation, It usually occurs after severe psychosocial stress or traumatic experience. As for medical treatment, medicine, psychotherapy and hypnosis are used. This case describes a 35-years-old woman who developed amnesia and depression following severe troublesome events. So she suited without expression and appealed against headache, dizziness, chest discomfort and weakness. Psychoanalytic psychotherapy was enforced for three days with hypnosis. She expressed the felling over the incident which she dose not like, and canceled in the past. She became reconciled with the family and left the husband by the heart. Then she recovered memory completely and body condition also improved. Recovery and growth of self were helped using supportive expression in order to prevent a recurrence. The prognosis is good with complete recovery, and there was no relapse.

• Geomechanics and Engineering
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• v.16 no.2
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• pp.177-185
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• 2018

The subsidence mechanism of ground surface is a complex phenomenon when multiple seam coal mining operations are carried out. Particularly, the coal mining beneath karstic formations causes a very special form of subsidence. The subsidence causes elasto-plastic deformation of the karstic layers and the collapse of cavities leads to dolinization and/or sinkhole formation. In this study, a sinkhole with a depth of 90 m and a width of 25 m formed in Gelik district within the coal-basin of Zonguldak (NW, Turkey) induced by multiple seam coal mining operations in the past has been presented as a case-history together with two-dimensional numerical simulations and InSAR monitoring. The computational results proved that the sinkhole was formed as a result of severe yielding in the close vicinity of the faults in contact with karstic formation due to multiple seam longwall mining at different levels.