• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.360-366
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• 2012

In the power distribution panel installed in airport or industrial facilities, MCCB has been used for main switch and ELCB for branch switch to perform human body and leakage-inducing fire protection as well as overcurrent and short circuit protection. Especially for the airport panel, increase in accident protection is needed for stable power supply due to rapid modernization with fast-growing users, higer capacity and diversification of equipment, the increase of power capacity and the breaker made slim is a main issue for now because the issue for installation space is standing out by making panel with two-row arrangement connection method, etc. due to a many use of branch ELCBs. In this thesis, we designed arc extinguishing mechanism, considered movement direction change of contact in mechanism design. Also, we designed the breaker to work stably in case of miniaturization of leakage detection circuit and reverse connection. We conducted short circuit test to verify its function and developed the breaker that can be improved protection against accidental current with slim size operating leakage function when reverse connection to help solve the problem in using space that is increasing in the airport distribution panel.

• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.56-69
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• 2016

Flame resistant treatment has been applied since 1973 for fire prevention in historical wooden buildings, but several problems, such as whitening and discoloration are constantly occurring in some Dancheong, in spite of evaluation criteria. It is supposed that these phenomena are caused by the stability issue of flame retardant, Dancheong production methods, the residue of chemicals, which were applied in the past, building location environments, etc., but no evaluation and cause inspection has been performed. Therefore, this study aims to verify the effect of flame retardant on Dancheong by producing Pseudo-samples and setting spatial and temporal environment conditions. Pseudo-samples of Dancheong were produced using three methods; the method specified in the Standard Specification of Properties; the method, which is generally used in the site and the traditional method. For different environment conditions of pseudo-samples, the areas were classified into a coastal area and an inland area and the places were classified into a sunny place and a wetland. After applying a flame retardant, annual variations were inspected for 12 months and change aspects were observed through scan and regular observation. In annual variation inspection, various variations like whitening, decolorization, dissolution and exfoliation were found and especially, whitening was most dominant. When the effect of flame retardant depending on the production methods was analyzed, whitening occurred in all the three production methods. It is supposed that this is because calcium(Ca) was contained in the coloring material of each production method and it reacted with phosphorous(P) of flame retardant. When the effect of flame retardant depending on the environment conditions was analyzed, whitening occurred more in the coastal area than in the inland area and it reduced in the building in a sunny place, which was constructed using the traditional method. It is supposed that this results from the humidity change and the difference of glue used in each production method. In conclusion, for using a flame retardant containing phosphorous(P), there is a need to check if calcium components including Oyster Shell White were used in Dancheong in advance and to conduct various preliminary studies on place conditions and Dancheong construction conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.53-61
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• 2013

This study was conducted to determine the proper mixing ratio of multigrains-added cooked rice for adolescent and aged people and analyze the nutritional and functional properties. As a result of sensory evaluation according to mixing ratio of polish rice and grains, the palatable grain mixing ratio of mixed grain rice for adolescent and aged people was 40% and 30%, respectively. The ratio of general grains to specialized grains was 9:1 in mixed grain rice for adolescent (MGA) and 8:2 in multigrain rice for aged people (MGAP). The ratio of mung bean to BacTae was 2:1 in MGA, and the ratio of adlay to buckwheat was 1:1 in MGAP. MGA contained the highest amount of crude protein, crude fat and minerals among the samples. In contrast, MGAP showed higher amounts of polyphenols and antioxidant activity compared to polished rice and MGA.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.707-716
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• 2009

The levels of psychosocial stresses and fatigue of firemen were analyzed to reveal the various factors related to them. The self-administered questionnaires were performed to 262 firemen ill Cheonsju City. In terms of various levels of psychosocial stresses, 12.2% were under potential stresses, 87.8% were under high-level of stress, but healthy group was not found. The levels of fatigue symptoms divided by the median of total scores was 51.1% of low levels, and 48.9% of high levels. Multiple stepwise analysis revealed that the factors or influence on psychosocial stresses with explanatory powers of 11.5% included subjective health status, job satisfaction, job demand and alcohol drinking habits. The factors of influence on fatigue symptoms with explanatory powers of 9.0% included subjective health and regular exercises. The study results indicate that the level of stress or fatigue is so complicatedly influenced by variable factors. Thus the effective strategy for stress and fatigue reduction among firemen should include additional programs focusing on health promotion.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.34-37
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• 2017

In recent emerging industry, Display field becomes bigger and bigger, and also semiconductor technology becomes high density integration. In Flat Panel Display, there is an issue that electrostatic phenomenon results in fine dust adsorption as electrostatic capacity increases due to bigger size. Destruction of high integrated circuit and pattern deterioration occur in semiconductor and this causes the problem of weakening of thermal resistance. In order to solve this sort of electrostatic failure in this process, Soft X-ray ionizer is mainly used. Soft X-ray Ionizer does not only generate electrical noise and minute particle but also is efficient to remove electrostatic as it has a wide range of ionization. X-ray Generating efficiency has an effect on soft X-ray Ionizer affects neutralizing performance. There exist variable factors such as type of anode, thickness, tube voltage etc., and it takes a lot of time and financial resource to find optimal performance by manufacturing with actual X-ray tube source. MCNPX (Monte Carlo N-Particle Extended) is used for simulation to solve this kind of problem, and optimum efficiency of X-ray generation is anticipated. In this study, X-ray generation efficiency was measured according to target material thickness using MCNPX under the conditions that tube voltage is 5 keV, 10 keV, 15 keV and the target Material is Tungsten(W), Gold(Au), Silver(Ag). At the result, Gold(Au) shows optimum efficiency. In Tube voltage 5 keV, optimal target thickness is $0.05{\mu}m$ and Largest energy of Light flux appears $2.22{\times}10^8$ x-ray flux. In Tube voltage 10 keV, optimal target Thickness is $0.18{\mu}m$ and Largest energy of Light flux appears $1.97{\times}10^9$ x-ray flux. In Tube voltage 15 keV, optimal target Thickness is $0.29{\mu}m$ and Largest energy of Light flux appears $4.59{\times}10^9$ x-ray flux.

• Journal of Preventive Medicine and Public Health
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• v.38 no.2
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• pp.125-131
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• 2005

Injury has recently become a major world-wide health problem. Injury related deaths occur in many actively working young people and produce major social and economical losses. However health related specialists do not recognize the importance of injury and there have not been many studies related to this problem. This research studied the trends of injury related research in Korea, mortality rate and prevalence rate, socio-economical losses and control in Korea and out of the country, based on literature from Korea and without such as statistical yearly reports on causes of deaths and OECD health reports, as well as WHO web sites. Studies in Korea about injury were very few, with 9 in the 1960's, 5 in the 1980's, 4 in the 1990's and 5 in 2000's. Mortality rate of injury was higher in Korea than in England, USA or Japan, especially in car accidents, suicide and falls. In Korea, the yearly trends in mortality rates were highest in car accidents but those rates are falling, suicide is steadily rising, with highest rate in 2003. Falls is in second rank with no change in rates. In 2003, the ten causes of death in Korea were suicide in 5th rank, transport accidents in 7th rank, and falls in 10th rank. Considering age groups, in the teens, transport accidents were 1st rank, in the 20's and 30's, suicide was 1st rank, and although there were some differences, falls, drowning, assault, fire were in the top 10. Prevalence rates of injury could not be known, but in 2001, according to the National Health and Nutrition Survey, lifelong injury was 10%, and yearly major injury was 1.3%, major injury for two weeks was 0.1%, and minor injury was 10%. In other foreign countries, injury has become to be recognized as a major health related problem, and much programs are being set up to reduce injury related deaths and injuries. WHO is putting much effort in prevention of violence and transport accidents, and in the USA, Canada and Europe, there are injury surveillance systems. Recently, as suicide is increasing rapidly and providing much problems, each country are managing suicide prevention programs. In Korea, Ministry of Construction and Transportation is managing and guiding the policies for prevention of transport accidents. In September of 2004, the Ministry of Health and Welfare has set up a 5 year plan of suicide prevention.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.4
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• pp.94-104
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• 2014

This contribution studied knowledges, informations and main project issues for systematic conservation management utilize of Joseon Royal Tombs guaranteeing their Outstanding Universal Value, Authenticity and Integrity, and the outcomes are as follows. The first, regarding the tomb's system, it should be planned to enhance authenticity and integrity of Joseon Royal Tombs through historical facts, measurement, diagnosis and intervention according to international and national charters, statements and general standards. The second, regarding prevention against disasters, the anti-fire system including construction of GIS materials and the Risk Map following investigation the present condition, premising improvement of relevant laws and regulations, should be planned. The third, we should consider, regarding utilize, educational application by the each tomb's story and royal ancestral rite, tourism by the local area of each tomb and industrial application by science and IT technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.539-547
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• 2017

This study examined the perception of disasters and post-traumatic stress disorder in occupational therapy majors to provide the basic data necessary for future occupational therapy. A questionnaire survey was conducted on 545 students in occupational therapy departments of three year and four year universities. The frequency of the questionnaire was calculated by frequency analysis using the SPSS 19.0 win program. A chi-squared test was conducted to verify the analyzed questionnaire data. The reliability of the questionnaire in this study showed a Cronbach' alpha value of 0.891. According to the survey results, approximately 20% of learners who majored in occupational therapy were unaware of the symptoms, developmental mechanism, and diagnostic criteria of post-traumatic stress disorder(PTSD). Knowledge of the underlying causes of psychological symptoms, such as post-traumatic stress disorder as well as physical damage through industrial accidents, was found to be 2.92 on the Likert 5-point scale. To be effective in rehabilitation treatment, the degree of the approach to education from the viewpoint of occupational therapy is important enough to be recognized as 3.90 on the Likert 5-point scale. The Pearson correlation coefficient for the need for education on disasters was higher than the correlation with the awareness of disasters.

• Journal of Korean Society of Forest Science
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• v.96 no.5
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• pp.520-527
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• 2007

Biomass and species diversity of understory vegetation after fertilization were studied for 28-year-old Quercus acutissima plantation (MQA), 29-year-old Pinus densiflora plantation (MPD), 8-year-old Betula platyphylla var. japonica plantation after coal reclamation (YBP), and 4-year-old Pinus densiflora plantation after forest fire (YPD) in central Korea. Nitrogen + phosphorus + potassium (6:4:1) fertilizer was applied for 3 years from 2004. Thereafter photosynthetically active radiation (PAR) and understory species richness and diversity were measured in late July-early August 2006. PAR (${\mu}mol\;m^{-2}S^{-1}$) was higher at the fertilization treatment (100.9) than at the control (67.0) for MQA while was lower at the fertilization treatment (156.5) than at the control (268.7) for MPD. Total understory biomass (t $ha^{-1}$) was lower at the fertilization plot (1.8) than at the control plot (3.0) for YPD, however, there were no differences in biomass between fertilization and control plots for MQA, MPD and YBP. Total species number of understory vegetation was higher for fertilization than for control at MPD (47 vs. 45) and YPD (21 vs. 13), and was higher for mature plantations (33 vs. 37 for MQA and 47 vs. 45 for MPD) than for young plantations (16 vs. 16 for YBP and 21 vs. 13 for YPD). Species richness and diversity were higher at the fertilization treatment than at the control for MQA, YBP, and YPD while were lower at the fertilization treatment than at the control for MPD, however, the differences were not statistically significant. Our results indicate that there were no consistent patterns in light conditions, biomass and species richness and diversity of understory vegetation following fertilization. More detailed long-term studies with different fertilizer applications would be necessary to conclude the influence of fertilization on understory vegetation in the region.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.714-722
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• 2014

In the previous study, a variety of wood-based panels was thermally decomposed to manufacture carbonized boards that had been proved to be high abilities of insect and fungi repellence, corrosion and fire resistant, electronic shielding, and formaldehyde adsorption as well as sound absorption performance. Based on the previous study, carbonized medium density fiberboard (c-MDF) was chosen to improve sound absorption performance by holing and sanding process. Three different types of holes (cross shape, square shape, and line) with three different sanding thickness (1, 2, and 3 mm) were applied on c-MDF and then determined sound absorption coefficient (SAC). The control c-MDF without holes had 14% of SAC, however, those c-MDFs with holes had 16.01% (square shape), 15.68% (cross shape), and 14.25% (line) of SAC. Therefore, making holes on the c-MDF did not significantly affect on the SAC. As the degree of sanding increased, the SAC of c-MDF increased approximately 65% on sanding treated c-MDFs (21.5, 21.83, and 19.37%, respectively) compared to the control c-MDF (13%). Based on these results, composite sound absorbing panel was developed with c-MDF and MDF (11 mm). The noise reduction coefficient of composite sound absorbing panel was 0.45 which was high enough to certify as sound absorbing material.