• Journal of the Society of Disaster Information
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• v.9 no.4
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• pp.449-461
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• 2013

As the hydrofluoric acid leak in Gumi-si, Gyeongsangbuk-do or hydrochloric acid leak in Ulsan, Gyeongsangnam-do demonstrated, chemical related accidents are mostly caused by large amounts of volatile toxic substances leaking due to the damages of storage tank or pipe lines of transporter. Safety assessment is the most important concern because such toxic material accidents cause human and material damages to the environment and atmosphere of the surrounding area. Therefore, in this study, a hydrofluoric acid leaked from a storage tank was selected as the study example to simulate the leaked substance diffusing into the atmosphere and result analysis was performed through the numerical Analysis and diffusion simulation of ALOHA(Areal Location of Hazardous Atmospheres). the results of a qualitative evaluation of HAZOP (Hazard Operability)was looked at to find that the flange leak, operation delay due to leakage of the valve and the hose, and toxic gas leak were danger factors. Possibility of fire from temperature, pressure and corrosion, nitrogen supply overpressure and toxic leak from internal corrosion of tank or pipe joints were also found to be high. ALOHA resulting effects were a little different depending on the input data of Dense Gas Model, however, the wind direction and speed, rather than atmospheric stability, played bigger role. Higher wind speed affected the diffusion of contaminant. In term of the diffusion concentration, both liquid and gas leaks resulted in almost the same $LC_{50}$ and ALOHA AEGL-3(Acute Exposure Guidline Level) values. Each scenarios showed almost identical results in ALOHA model. Therefore, a buffer distance of toxic gas can be determined by comparing the numerical analysis and the diffusion concentration to the IDLH(Immediately Dangerous to Life and Health). Such study will help perform the risk assessment of toxic leak more efficiently and be utilized in establishing community emergency response system properly.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.415-426
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• 2021

Purpose: The purpose of this study is to create the deveopment plan for promotion of advanced disaster-safety awareness, which is noted as a major factor in the large disaster. Method: This study is to conduct theoretical review with regard to disaster management and safety awareness. Consciousness surveys on safety awareness and previous disaster case was analyzed to derive the cause of the disaster, and the development plan for promotion of advanced disaster-safety awareness was suggested. Result: In the survey on the public's sense of safety on the disaster management evaluation, 'Response' stage was well performed, but the 'Recovery' stage was not. Especially, it was found that disaster safety education at the 'Prevention' stage was very lacking. In the survey on the public's safety awareness, the awareness level of the evacuation facility was very low, information on infectious diseases and collapse accident was insufficient. Especially, it has been found that the awareness on safety regulation in daily life is very insufficient. Through the case study on previous disaster(COVID-19, Fire in Miryang Sejong Hospital, Forest fire in the east coas at 2004'), it was derived that the lack of safety awareness(such as safety insensitivity) was the main factor of the expansion of the damage scale. Conclusion: The development plan for promotion of advanced disaster-safety awareness are as follow. First, it is necessary to spread the safety culture movement through the expansion of safety education and safety promotion. Second, disaster confrontation training for the public should be implemented to improve the effectiveness of disaster response. Finally, it is necessary to change the individual awareness on safety. When these factors are implemented systematically, advanced disaster-safety awareness can be promoted. Ultimately, disaster accidents in our society can be reduced.

• Journal of Chest Surgery
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• v.13 no.3
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• pp.212-218
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• 1980

A severe crushing injury of the chest produce a very striking syndrome referred to as traumatic asphyxia. This syndrome is characterized by bluish-red discoloration of the skin which is limited to the distribution of the valveless veins of the head and neck. And also if it is characterized by bilateral subconjunctival hemorrhages and neurological manifestations. But these clinical entities faded away progressively in a few weeks. Apporximately 90% of the patients who live for more than a few hours will recover from traumatic asphyxia when it occurs as a single entity. And so, death results from either severe associated injuries of from subsequent infection, rather than from pulmonary or cardiac insufficiency in traumatic asphyxia. We have experienced 4 cases of traumatic asphyxia with severe crushing thoracic injuries at department of the chest surgery, Captial Armed forces General Hospital during about 3 years from April 1977 to Aug. 1980. The 1st 22 year-old male was struct 2$\frac{1}{2}$ ton truck on the road and was transferred to this hospital immediately. He had taken tracheostomy due to severe dyspnea with contusion pneumonia and for removal of a large amount of bronchial secretion. The 2nd case was 23 year-old male who was got buried in a chasm. In this case, the heavy metal post tumbled over him back while at work. The 3rd case was 39 year-old male who leapt out of a window in 5th story while fire broke out in living room by oil stove heating. He had multiple rib fracture with right hemothor x and right colle's fracture and pelvic bone fracture. The last 22 year-old male was run over by a gun carriage. The wheel of this gun carriage passed over his thorax and right chin. He was brought to this hospital by helicopter. when he was first examined at emergency room, he was in semicomatose state and has pneurmomediastinum with multiple rib fracture and severe subcutaneous emphysema. As soon as he arrived, bilateral closed thoracostomy was performed and cardiopulmonary resuscitation was done. In hospital 8th weeks, chest series showed fibrothorax in right side even if chest wall stabilized. All 4 cases had multiple petechiae over their facees and chest and bilateral subconjunctival hemorrhages referred to as traumatic asphyxia. 3 cases except one case who received splenectomy, had been suffered from contusion pneumonia and had been treated with respiratory care. In these 3 cases, they had warning of impending injury before accident, and took a deep breath hold it and braces himself. And also, even if he had not impending fear in remaining one case, he had taken a deep breath and had got valsalva maneuver for pulling off the heavy metal post. Intrathoracic pressure rose suddenly and resulted to traumatic asphyxia in this situation. All these cases were recovered completely without sequelae except one fibrothorax, right.

• Journal of the Korea Concrete Institute
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• v.24 no.6
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• pp.761-768
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• 2012

The purpose of this study is to investigate bond properties of GFRP used in SFRC (Steel fiber reinforced concrete) and normal concrete. The experimental variables were rebar diameter (D13, D16), steel fiber volume fraction (0~2%) and cover thickness ($1.5d_b$, $5.4d_b$). The experimental results showed a different failure mode depending on the cover thickness. Through the tested specimens, splitting failure occurred for the specimens with small cover thickness and pull out failure occurred in the specimens with large cover thickness. Introduction of steel fiber caused the specimens to have more ductile behavior of bond stresss-lip after peak stress, but they did not increase the bond strength significantly. These failure modes were shown in both steel reinforcement and GFRP. However, from the difference of micro structure of bond failure mechanism between steel rebar and GFRP rebar, more ductile behavior was observed in GFRP-specimens after maximum bond strength was reached.

• International Journal of Highway Engineering
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• v.18 no.6
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• pp.145-152
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• 2016

OBJECTIVES : Visibility at night can be improved by using retroreflection for short distances and phosphorescent line markings for long distances. In this study, we analyzed the characteristics of the phosphorescent line marking through a laboratory luminance test. Field performance analysis was performed through tests conducted on the road. We also examined the luminance measurement methods using the digital image obtained during the phosphorescent visibility evaluation. METHODS : In this study, the laboratory luminance test of the phosphorescent line marking was conducted using seven specimens to characterize the luminance changes according to the type of the glass beads, the thickness of the phosphorescent line marking, and the brightness and irradiation time of the light source. Phosphorescent and general line markings were made at 150 m to investigate the field luminance performance. A preliminary review of the luminance measurement methods was made using a digital image from a digital single-lens reflex (DSLR) camera. The measured luminance ratio of the general and the phosphorescent line markings was compared with the calculated luminance ratio using luminance analysis. RESULTS : Through the laboratory luminance test, it was seen that the change in luminance, which corresponds to the brightness of the light source, appears large but the influence of the thickness and irradiation time is low. The field performance test of the phosphorescent line marking conducted on the road involved measuring the luminance on the day the marking was made and 7 days after the marking was made. The luminance was found to be $190mcd/m^2$ at 30 min after sunset and approximately $10-12mcd/m^2$ 4h after sunset. The results of the luminance test were captured using a digital image for each time group. The luminance ratio of the phosphorescent line marking, when compared to that of the general line marking, showed a similar trend within a 13% maximum error. Additionally, when this luminance ratio is compared to the direct field measurement, it could be confirmed that the luminance ratio, as captured in the digital image, showed a similar tendency. CONCLUSIONS : 1) The change in luminance corresponding to the brightness of the light source is significant in comparison with that corresponding to the thickness and the irradiation time. In addition, the results of the field test for the phosphorescent line marking satisfied the phosphorescent fire protection standard. 2) We examined the validity of the luminance measurement method using a digital image and we concluded that the change in the luminance ratio shows a similar tendency in both the cases. The results can form the basis for luminance measurement methodology for the construction and maintenance of phosphorescent line markings.

• Journal of the Korean Institute of Gas
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• v.21 no.4
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• pp.47-61
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• 2017

The preconditions of the usefulness of an operator safety training model in large plants are the versatility and accuracy of operational procedures, obtained by detailed analysis of the various types of risks associated with the operation, and the systematic representation of knowledge. In this study, we consider the artificial intelligence planning method for the generation of operation procedures; classify them into general actions, actions and technical terms of the operator; and take into account the sharing and reuse of knowledge, defining a knowledge expression ontology. In order to expand and extend the general operations of the operation, we apply a Hierarchical Task Network (HTN). Actual boiler plant case studies are classified according to operating conditions, states and operating objectives between the units, and general emergency shutdown procedures are created to confirm the applicability of the proposed method. These results based on systematic knowledge representation can be easily applied to general plant operation procedures and operator safety training scenarios and will be used for automatic generation of safety training scenarios.

• The Korean Journal of Quaternary Research
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• v.14 no.1
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• pp.33-48
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• 2000

Vegetation disturbance history of the Korean Peninsula from the Palaeolithic Age to the Koryo Dynasty (1392) has reconstructed by the use of various data sources. Active vegetation disturbance, which has begun during the Neolithic Age, seems to be more widespread on lowland and coastal areas in the early stages, but later expanded into inland areas. The ploughing of a field and the selective cutting of certain trees, such as oak trees, nettle trees and pine trees are noticeable, and eventually caused deforestation during the Bronze Age. The use of iron tools of the Iron Age has enabled the forest clearing to develope the dry fields. During the Three Kingdoms period (BC 57∼AD 918) extensive deforestation has maintained for the development of cultivated fields, as well as other activities, such as timber, lumbering, production of iron farm implement, ploughing by cattle. The encouragement of disafforestation on mountain slope and creation of terraced field during the Koryo Dynasty (918∼1392) has caused the deforestation over the country, along with the consumption of large amount of wood and timber for fire-wood, ship-building, mining, xylography and so on.

• Journal of Cadastre & Land InformatiX
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• v.46 no.2
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• pp.27-42
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• 2016

Forest accounts for almost 64 percents of total land cover in South Korea. For inventorying, monitoring, and managing such large area of forest, application of remote sensing and geographic information system (RS/GIS) technology is essential. On the basis of spectral characteristics of satellite imagery, forest cover and tree species can be classified, and forest cover map can be prepared. Using three dimensional data of LiDAR(Light Detection and Ranging), tree location and tree height can be measured, and biomass and carbon stocks can be also estimated. In addition, many indices can be extracted using reflection characteristics of land cover. For example, the level of vegetation vitality and forest degradation can be analyzed with VI (vegetation Index) and TGSI (Top Grain Soil Index), respectively. Also, pine wilt disease and o ak w ilt d isease c an b e e arly detected and controled through understanding of change in vegetation indices. RS and GIS take an important role in assessing carbon storage in climate change related projects such as A/R CDM, REDD+ as well. In the field of climate change adaptation, impact and vulnerability can be spatio-temporally assessed for national and local level with the help of spatio-temporal data of GIS. Forest growth, tree mortality, land slide, forest fire can be spatio-temporally estimated using the models in which spatio-temporal data of GIS are added as influence variables.

• Journal of the Korean association of regional geographers
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• v.12 no.6
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• pp.645-655
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• 2006

Apsan, as part of the main ecosystem of Daegu city, plays an important role for maintaining the environmental sustainability of the large city. Especially varieties of valuable resources, which are cultural, historical, biological, geomorphological and geological, are distributed around Apsan. Therefore the positive preservation plan is required. This paper aims to examine the environmental characteristics of Apsan and then suggests the following ideas for the environmental preservation and sustainable use of Apsan. 1) 'The New Map of Apsan' that includes more exact information needs to be produced. 2) The Apsan ecosystem management plan should be made under the precision natural ecology investigation. 3) For the protection of inanimate object resources, such as geographical feature and geology, the Geotourism Department needs to be established within Daegu metropolitan office of education or the tourism division of Daegu city government. 4) An effective environmental-impact-assessment system should be officially established. 5) the positive administrative and financial support system led by local NGOs is required for the Apsan environmental protection activities and education. 6) It is necessary to bring out into the open prayer sites to prevent forest fire. 7) 'The nature rest year system' enforcement is required to restore the damaged ecological space of Apsan.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.105-111
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• 2018

This study aims to evaluate the safety for cable stayed bridge due to damages on the cable system. Many cable supported bridges, including cable stayed bridge and suspension bridge, have been built in the Korean peninsula. This requires efficient maintenance and management since this structure has complex structural components and system. This large structure also often faces risks either from manmade or natural phenomenon. In 2015 one cable-stayed bridge in South Korea had been struck by a bolt of lightning on the cables. This event had led to fire on cables. These cables had been damaged and putting the bridge at risk. This bridge was back in used after a few weeks of investigations and replacements of the cables. However, enormous social and economic expense were paid for recovery. After this event risk based management for infra structures is required by public demands. Therefore, this study was initiated and aimed to evaluate risks on the cable system due to potential damages. In this paper one cable-stayed bridge in South Korea was selected and investigated its safety based on the damage scenarios of cable system for efficient and prompt management, and for supporting decision making. FEM analysis was conducted to evaluate the safety of the bridges due to damages on the cable system.