• Journal of Korean Neurosurgical Society
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• v.57 no.5
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• pp.379-385
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• 2015

Chronic subdural hematomas mainly occur amongst elderly people and usually develop after minor head injuries. In younger patients, subdural collections may be related to hypertension, coagulopathies, vascular abnormalities, and substance abuse. Different techniques can be used for the surgical treatment of symptomatic chronic subdural hematomas : single or double burr-hole evacuation, with or without subdural drainage, twist-drill craniostomies and classical craniotomies. Failure of the brain to re-expand, pneumocephalus, incomplete evacuation, and recurrence of the fluid collection are common complications following these procedures. Acute subdural hematomas may also occur. Rarely reported hemorrhagic complications include subarachnoid, intracerebral, intraventricular, and remote cerebellar hemorrhages. The causes of such uncommon complications are difficult to explain and remain poorly understood. Overdrainage and intracranial hypotension, rapid brain decompression and shift of the intracranial contents, cerebrospinal fluid loss, vascular dysregulation and impairment of venous outflow are the main mechanisms discussed in the literature. In this article we report three cases of different post-operative intracranial bleeding and review the related literature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5646-5653
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• 2015

This study focused on the architectural, interior and management guidelines in rehabilitation center for visually impaired persons. For these purposes, we reviewed the movement behaviors and the characteristics of fire drill in rehabilitation center for visually impaired persons. The results are as follows. : First, the liner circulation paths and interior landmarks are recommended, and dwelling units and program rooms should be located in ground floor for barrier free evacuation. Second, It is important to establish continuous handrail, variations of paving patterns and materials, good color definition, tactile informations and directional sound. Third, it is necessary to serve more specified architectural, interior, and management guidelines according to impaired prototypes.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.2
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• pp.200-208
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• 2024

The occurrence a fire on a training ship with a large number of people on board can lead to severe casualties. Hence the Seafarers' Act and Safety Life At Sea(SOLAS) emphasizes the importance of the abandon ship drill. Therefore, in this study, the training ship of Mokpo National Maritime University, Segero, which has a large number of people on board, was selected as the target ship and the likelihood and severity of fire accidents on each deck were predicted through the preliminary hazard analysis(PHA) qualitative risk assessment. Additionally, assuming a fire in a high-risk area, a simulation of evacuation time and population density was performed to quantitatively predict the risk. The the total evacuation time was predicted to be the longest at 501s in the meal time scenario, in which the population distribution was concentrated in one area. Depending on the scenario, some decks had relatively high population densities of over 1.4pers/m², preventing stagnation in the number of evacuees. The results of this study are expected to be used as basic data to develop training scenarios for training ships by quantifying evacuation time and population density according to various evacuation scenarios, and the research can be expanded in the future through comparison of mathematical models and experimental values.

• Fire Science and Engineering
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• v.2 no.2
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• pp.9-16
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• 1988

This study is intended to suggest some ideal measures available in the course of construction from the viewpoint of an architect to reduce damage of human lives and Properties caused by fire accidents in buildings. For this study, 7 buildings burnt by conflaguration in Seoul during the years of 1985 and 1987 are picked up, and 105 withnesses, who were present in one of them at them at fire, are traced for personal interview and respones to the written questionaire about 5 main issues; their perceptional behaviour, their emotional state at that time, their reactions to avoid danger, their escape routes, and their usual awareness to prevent fire. Some desirable measures suggested here are ;making Provisions to install fire centers in large buildings and underground structures in the fire fighting law, and requlating to compose fire units appropriate to the quantity of combustibles inside, limit the length of a blind corridor, furnish balustrade, and limit the width of the landing of the stairs in building code and regulations. Such measures should be considered from the time of planning to construct a building, and some drill and education in fire prevention is demanded for the occupants of the buildings too.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.899-904
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• 2001

The impact of PVD coatings can be summed up in practical terms: this technology historically complements the best designed tool substrates to enhance cutting performance. PVD coatings are now incorporated in 25% of all HSS tools. The functionality is to extend the machining speed range, improve wear resistance at the cutting edge, and reduce friction at chip/tool contact areas to allow easier chip evacuation. These translate to a larger safe zone, as discussed in the failure mode diagram, for better productivity and higher reliability in machining operations of the customer. PVD coatings therefore represent an enabling technology that extends the application range of cutting tools in response to modern industrial needs. PVD coatings prolong the product life cycle of HSS tools and help this "mature" material to hold its territory against the advent of the newer hardmetal and ceramic tool materials. There is a lot of competitive life left particularly in PVD coated HSS endmills, drills, threading/tapping tools. PM HSS technology further increases the possibilities.ibilities.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.533-537
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• 2003

Compared to sintered polycrystalline diamond (PCD), the deposited thin film diamond has a great advantage on the fabrication of cutting tools with complex geometries such as drills. Because of high performance in high speed machining non-ferrous difficult-to-cut materials in the field of automobiles industry, aeronautics and astronautics industry, diamond-coated drills find large potentialities in commercial applications. However, the poor adhesion of the diamond film on the substrate and high surface roughness of the drill flute adversely affect the tool lift and machining quality and they become the main technical barriers for the successful development and commercialization of diamond-coated drills. In this paper, diamond thin films were deposited on the commercial WC-Co based drills by the electron aided hot filament chemical vapor deposition (EACVD). A new multiple coating technology based on changing gas pressure in different process stages was developed. The large triangular faceted diamond grains may have great contribution to the adhesive strength between the film and the substrate, and the overlapping ball like blocks consisted of nanometer sized diamond crystals may contribute much to the very low roughness of diamond film. Adhesive strength and quality of diamond film were evaluated by scanning electron microscope (SEM), atomic force microscope (AFM), Raman spectrum and drilling experiments. The ring-block tribological experiments were also conducted and the results revealed that the friction coefficient increased with the surface roughness of the diamond film. From a practical viewpoint, the cutting performances of diamond-coated drills were studied by drilling the SiC particles reinforced aluminum-matrix composite. The good adhesive strength and low surface roughness of flute were proved to be beneficial to the good chip evacuation and the decrease of thrust and consequently led to a prolonged tool lift and an improved machining quality. The wear mechanism of diamond-coated drills is the abrasive mechanical attrition.

• Fire Science and Engineering
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• v.31 no.1
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• pp.116-123
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• 2017

The purpose of this paper is to improve the evacuation stability of residents in apartment fire. For this purpose, the actual condition survey about the obstacles was conducted on 3,056 escape stairs in the 183 apartments. In addition, the questionnaire investigation was carried out a survey targeting the residents of apartments about their experience of fire safety education, perception on safety management of escape stairs, and perception on fire safety. As a result of investigation, we confirmed that the obstacles were formed in the 1,916 escape stairs among the 3,056 escape stairs of the 183 apartments (percent of barricades in escape stairs: 62.70%). Furthermore, it showed that fire safety education experience was found to be 83.10% of subject. The perception on safety management of the subjects in the escape step and the perception on fire safety were $3.84{\pm}0.75%$, and $3.49{\pm}0.61$, respectively. In the results, most of the subjects had a fire safety education and knew how to safety management the escape stairs but, the practice of the safety management action was low. Based on the results in the paper, the policy proposal is that the fire safety education is emphasized to change from the perception to action.

• The Journal of the Korea Contents Association
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• v.17 no.3
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• pp.222-230
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• 2017

The Ministry of Public Safety and Security plans to expand fire safety education infrastructure to provide customized fire safety education, spread fire safety culture and develop a tailored fire safety education system as a part of the 2016 Citizens' Safety Improvement Policy. This study has also been designed to improve safety problems in the Republic of Korea. Even though safety education has been given, citizens aren't still able to experience a close-to-real situation. In addition, their understanding and satisfaction with the curriculum are very low. Therefore, this study offers VR fire-extinguishing experience education contents as an effective alternative. With a goal of having the participants experience fire extinguishing and evacuation drill in a virtual space, this program has the following advantages: i) safe fire-extinguishing experience; ii) UI to create fun ; iii) useful in fire-extinguishing education; iv) budget saving. we configure the VR fire experience system structure and hardware by applying UX design methodology. We also develop for VR-specific motion recognition plug-in and controller that can be feeling in HMD environment.

• Journal of Environmental Health Sciences
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• v.37 no.3
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• pp.226-233
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• 2011

Exactly 25 years after the Chernobyl nuclear disaster, 11th of March 2011 the Fukushima nuclear accident occurred in Japan and was ranked at level 7 same to the Chernobyl. A Korean and Japanese joint civil survey was conducted around Fukushima on April 13-17. The radiation survey data clearly shows a large hotspot area between 20 km and 50 km radius north and west direction from the accident reactors, with the highest radiation recorded being 55.64 ${\mu}Sv/hr$ in the air, 99.89 ${\mu}Sv/hr$ in the surface air, and 36.16 ${\mu}Sv/hr$ in a car, respectively. 3.65 ${\mu}Sv/hr$ in the air and 6.89 ${\mu}Sv/hr$ in the surface air were detected at the playground of an elementary school in Fukushima City. Spring came with full cherry blossoms in Fukushima, but it was silent spring of radiation contamination. Interviews with Fukushima nuclear refugees reveal serious problems about Japanese nuclear safety systems, such as there was no practical evacuation drill within 1-10 km and no plan at all for 10-30 km areas. Several reforms items for Korean nuclear safety system can be suggested: minimization of accident damage, clear separation of regulatory and safety bureaus with a new and independent administrating agency, community participation and agreement regarding the safety system and levels, which is the major concern of 80% Korean. To tackle threats of nuclear disaster in neighboring nations like China, a new position entitled 'Ambassador for nuclear safety diplomacy' is highly necessary. The nuclear safety of Korea should no longer be the monopoly of those nuclear engineers and limited technocrats criticized as a 'nuclear mafia'.

• The Journal of the Convergence on Culture Technology
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• v.4 no.1
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• pp.299-306
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• 2018

As recent Jecheon and Milyang fire cases show, the need for fire disaster training to prepare for a fire disaster continues to grow. In the event of a disaster, people become mentally confused and are called disaster personalities. In order to survive in a disaster, it is necessary to develop the power to overcome the disaster personality by experiencing the disaster situation in advance. Therefore, training to overcome disaster personality is needed, and virtual reality can be a good training means in that it can experience without physical space. In addition, periodic actual disaster evacuation drills should be carried out to compensate for the shortcomings of virtual reality. In order to introduce fire disaster drill using virtual reality and to spread it to the public, the Korea National VR project should be introduced which benchmarked national PC project which succeeded in the past informatization project. Besides, the Korea National Safety Point system should be integrated to cover disaster preparedness training and building reinforcement. If the national VR project and the national safety point system are introduced successfully, Korea will be the basis for escaping the disgraceful nickname of 'disaster republic'.