• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.525-538
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• 2014

Safety of reactive systems is one of the most important research areas in the field of weapon development. A NoGo response or at least a low-order explosion should be ensured to prevent unexpected accidents when the reactive system is impacted by high-velocity projectile. We investigated the shock-induced detonation of cased reactive systems subject to a normal projectile impact to the cylindrical surface based on two-dimensional hydrodynamic simulations using the I&G chemical rate law. Two types of energetic materials, namely LX-17 and AP-based solid propellant, were considered to compare the dynamic responses of the reactive system when subjected to the threshold impact velocity. It was found that shock-to-detonation transition phenomena occurred in the cased LX-17, whereas no full reaction occurred in the propellant.

• Journal of Korean Academy of Nursing Administration
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• v.12 no.1
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• pp.76-93
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• 2006

Purpose: The purpose of this study was to define the core components required of nurses to provide quality nursing care to patients and analyze the significance of these components in the hospital's various units to maintain a high level of competence among nurses. Method: The study evaluated 3 categories included 35 subcategories with 148 core components that were derived from literature review and interviews of nursing professionals. The nursing professional category included 18 subcategories with 98 components, the organizational culture category included 4 subcategories with 16 components, and the temperament-attitude category included 13 subcategories with 34 components. The study included 335 nurses with more than one year of hospital experience and measured disparities among different hospital units. The data was analyzed with SPSS-Win 10.0, differing perceptions of the importance of general traits among the participants were measured using standard deviation, and differing perceptions of the importance of professional traits among the participants were assessed using ANOVA and subsequently with the Bonferroni Test. The reliability of the aforementioned research tools were evaluated using the Cronbach's ${\alpha}$. Result: The results of the study were as follows: 1. Among the three categories, temperament-attitude category was perceived to be the most important, followed by nursing professional category and organizational culture category. Among the ten most important subcategories within the three categories, safety and infection prevention as well as responsibility were perceived to be the most important, followed by promotion of physiologic adaptation, document management and presentation, self-control, ethics, observance law, coping with emergency, humanity, and medication. 2. The relative importance of category associated with the core competencies within the hospital unit were as follows : 1) The units that rated nursing professional category as being the most significant were: internal medicine, surgical unit, mother-child unit, emergency room, intensive care unit, and operating room, in that order. 2) The units that rated the organizational culture competencies as being the most significant were: mother-child unit, internal medicine, surgical unit, emergency room, operating room, and intensive care unit, in that order. 3) The units that rated temperament-attitude category as being the most significant were: internal medicine, surgical unit, emergency room, mother-child unit, operating room, and intensive care unit, in that order.

• Journal of Environmental Health Sciences
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• v.46 no.5
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• pp.565-575
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• 2020

Objective: South Korea still lacks systematic national poisoning data collection or a poison control center (PC). The objectives of this study are to provide estimates of poisoning incidents in South Korea and to stress the necessity of a national poisoning surveillance framework managed by a national PC. Method: The number of poisoning incidents was estimated based on the 2018 annual report of the American Association of Poison Control Centers' National Poison Data System (NPDS). Our estimation of poisoning data was classified according to age group, reason for poison exposure, and case management site. Results: Total poisoning cases estimated numbered 326,636, which is tantamount to 631 cases per 100 thousand. Poisoning cases among those younger than five years old accounted for 71.7% in the United States. Fatal poisoning cases were estimated to be 210.63 (95% CI: 199.70-222.15). Non-intentional poisoning cases (250,378 cases, 95% CI: 249,992-250,764, 76.7%) were estimated to be far higher than intentional cases (62,399 cases, 95% CI: 62,207-62,593, 19.1%). Conclusion: Our results can be used to suggest the necessity of producing national poisoning data and establishing a PC despite the uncertainty of estimation.

• Journal of Internet Computing and Services
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• v.16 no.6
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• pp.97-107
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• 2015

Up until recently, Korea has ranked the first place in UN e-Government Survey for three consecutive years. In keeping with such accomplishment, the size of budget execution has been consistently growing in accordance with Korea's Government 3.0 policy and vision, leading to increase in big-sized informatization projects in the business. Especially in mission critical public sector's infrastructure where it affects many people, growing demand for establishing high-quality information system with new technologies being brought to attention in order to meet the complex needs of citizens. National defense information system, being one of representative domains examples in the concerned area, established high military competency by applying breakthrough technology. Network-oriented national defense knowledge informatization was set as the vision in order to implement core roles in making efficient national defense management; and effort has been made to materialize the vision by making advancement in national defense's information system and its informatization implementation system. This research studies new quality index relevant to test and evaluation (T&E)of informatization business in national defense which is the representative example of mission critical public sector's infrastructure. We studied international standards and guidelines, analyzed actual T&E cases, and applied them to the inspection items that are currently in use, complying with the e-government law (Act No. 12346, Official Announcement Date 2014. 1.28., Enforcement Date 2014. 7.29.) As a result of productivity analysis, based on hypothesis in which suggested model was applied to T&E of the national defense informatization business, we confirmed the possibility of enhancement in the T&E productivity by assessing reliability, expertise, and safety as evaluation factors.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.461-468
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• 2001

The effectiveness and safety of Enzyme Food, a group of dietary supplements designated by Korean Food Law, were evaluated and the possibility of HACCP (Hazard Analysis Critical Control Point) application was investigated. Chemical composition, enzyme activities and the degree of bacterial contamination in 12 samples of different brands sold in Korean market were measured. The chemical composition of the selected products varied and inconsistent to those claimed in the label description. It is known that effectiveness of Enzyme Food depends on enzyme activity, but enzyme activities of ${\alpha}-amylase$ varied from $1,793\;{\mu}g/min$ g to $159\;{\mu}g/min$ g and those of ${\beta}-amylase$ ranged from $171\;{\mu}g/min$ g to $11\;{\mu}g/min$ g. The protease activities varied from $27.57\;{\mu}g/min$ g to $0.18\;{\mu}g/min$ g. In coli-form bacterial test, positive reactions were appeared in the 50 % of the samples. Numbers of bacteria ranged from $1.3\;{\times}\;10^5\;to\;1.2\;{\times}\;10^9$. Five CCPs were identified; heating, inoculation, cultivation, drying and granulation. Consideration of HACCP system indicated that the pretreatment of raw material, checking of bacterial contamination and stability of enzyme activity during fermentation process were important factors for the quality of Enzyme Foods.

• Journal of Korean Society for Quality Management
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• v.46 no.2
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• pp.301-310
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• 2018

Purpose: The purpose of this study is to investigate the effect of work intensity on fit factor and affective quality of the dustproof Background: Among the victims who suffer pneumoconiosis due to the inhalation of toxic substances or the lack of oxygen during the work, the proportion of the victims is larger than the other causes. Wearing a respirator may prevent pneumoconiosis, but it can be hazardous to workers because of the leakage through filters, cartridges, exhaust valves, broken parts, and face-to-face contact. Despite leakage through the contact area between the mask and the face has various causes such as the wearer's activity, sweat accumulation, facial shape, etc., There is a lack of relevant research and regulation compared to developed countries that have already institutionalized the law 30 years ago and give the right to sell through a test Method: The work intensity was adjusted by walking or running at 6km/h and 11km/h on the treadmill, and tasks were defined with reference to the test procedure and the exercise sequence applied in the face leakage test of the dustproof mask. And fit factor was measured objectively using 'Respirator Fit Tester 8038' which measures fit factor calculated by dividing the number of dust present outside the mask by inside the mask. In addition, affective quality was classified by the ease of use, ease of breathing, and ease of wearing, and was measured using the 5-point likert scale questionnaire. Results: There was a significant difference in fit factor, ease of breathing, and wearing convenience according to work intensity and no significant difference in ease of use(${\alpha}=0.01$). And when the work intensity was high, fit factor, ease of breathing, and wearing convenience were all lower than when the work intensity was low. Conclusion: In Korea, it is necessary to consider consideration of the work intensity when testing the leakage rate of the face part for safety certification of the respiratory protective equipment, When developing a mask, it should be possible to maintain high adhesion even under intense, active situation and high temperature conditions by selecting materials, improving the wearing style, and expanding the adjustable range.

• Tunnel and Underground Space
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• v.22 no.3
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• pp.163-172
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• 2012

As more diesel engines have been employed in underground limestone mines with large cross section, underground space environment is worsened by diesel exhausts and heat flow. This paper aims for the ultimate goal to optimize the work place environment through assuring the optimal required ventilation rate based on the analysis of the airflow, diesel exhaust gas concentrations and the effects of mechanization and deepening working face on temperature and humidity. Due to the insufficient capacity of the main exhaust fan and poor airway management, stagnant airflows were observed at various locations, while the flow direction was reversed instantly with passing diesel equipment and the flow reversal was also made by the seasonal variation of the outside surface weather. During the loading operation, CO concentration measurements were found to be frequently higher than the threshold limit of 50 ppm, and most of the $NO_2$ measurements during drilling and loading operations shows even more serious levels surpassing the permissible limit of 3 ppm. The actual ventilation quantity was considerably less than the required quantity estimated by the mine health and safety law, and this shortage problem was less serious in colder winter showing more effectiveness of the natural ventilation.

• Journal of the Korean Institute of Rural Architecture
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• v.17 no.4
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• pp.17-24
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• 2015

Vacant houses are increasing across the country, but the appropriate measures have not been set up yet. Accordingly, vacant houses are left unattended for a long time, and become deserted to degrade the residential environment. They are often used as the space for the deviation of youth or even for crimes, threatening the safety of rural society. Vacant houses are not only personal properties but also public assets that form the residential environment of a town. Therefore, the problem should be better taken care of with appropriate policies. In this study, the present situation of vacant houses in Korea, the causes of the vacant house and the limits and lessons of the improvement projects were reviewed, along with the vacant house improvement systems in the UK and Japan. The most significant difference between the cases in Korea and other countries are the method of vacant house improvement. In terms of policies and support, Korea focuses on demolition, whereas other countries focus on reuse. In addition, the vacant house improvement projects in Korea are performed mostly by government agencies, whereas local governments and private organizations in other countries cooperate to improve vacant houses and go beyond mere residential environment improvement towards the local revitalization. Based on the study results, the following are proposed to efficiently improve and use the rural vacant houses. First, the Rearrangement of Agricultural and Fishing Villages Act, which allows the vacant houses to be left unattended and not improved, should be revised. Second, the intermediate support organizations that connect the demand and supply should be fostered and supported so that the use of vacant houses can be vitalized and privately led. Third, the best practices of using the vacant houses should be found and promoted, and the vacant house remodeling technique should be developed and propagated. Fourth, a special law should be enacted to comprehensively plan, support and execute the vacant house improvement, as in Japan. Finally, the value of the vacant houses as public properties should be shared in public so that all citizens can participate in addressing the vacant house issue to derive the detailed plans to solve the problem.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.1-8
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• 2017

Currently gas safety management in the industrial field has been done by LDAR as contact method or methane leak detector as non-contact method. But LDAR method requires a lot of man-power and methane leak detector have the limitation of methane only. Therefore the Research on the OGI(optical gas image) has big attention by industry. This research was undertaken to see the effect of background temperature difference of gas cloud on the clarity of OGI. The background temperature control panel was constructed to cool down the background temperature. OGI was taken at the various methane gas ejection rate and the designed temperature difference. The experimental results showed that the OGI(when the temperature difference is $-6^{\circ}C$) is more clear thane the OGI(when the temperature difference is zero). To quantify the clarity difference, MATLAB's RGB analysis method was employed. The RGB value of the OGI at ${\Delta}T-6^{\circ}C$ was 20% lower than the OGI at ${\Delta}T0^{\circ}C$. The clarity difference by T difference can be explained by the total radiation law. When the background temperature of the gas is lower than the air temperature, the radiation energy coming into the OGI lens is increasing. As the energy is increasing, the OGI image becomes clear.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.10
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• pp.1093-1100
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• 2014

The purpose of this paper is to suggest a weight-reduction design method for the hybrid carbody of a high-speed maglev train that uses aluminum extrusion profiles and sandwich composites. A sandwich composite was used on the roof as a secondary member to minimize the weight. In order to assemble the sandwich composite roof and aluminum extrusion side frame of the carbody using welding, a guide aluminum frame located at the four sides of the sandwich composite roof was introduced in this study. The clamping force of this guide aluminum frame was verified by three-point bending test. The structural integrity and crashworthiness of the hybrid carbody of a high-speed maglev train were evaluated and verified according to the Korean Railway Safety Law using a commercial finite element analysis program. The results showed that the hybrid carbody composed of aluminum extrusion frames and a sandwich composite roof was lighter in weight than a carbody made only of aluminum extrusion profiles and had better structural performance.