• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.119-120
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• 2002

The aim is to urge the need of elaborate commissioning of 3D RTP system from the firsthand experience. A 3D RTP system requires so much data such as beam data and patient data. Most data of radiation beam are directly transferred from a 3D dose scanning system, and some other data are input by editing. In the process inputting parameters and/or data, no error should occur. For RTP system using algorithm-bas ed-on beam-modeling, careless beam-data processing could also cause the treatment error. Beam data of 3 different qualities of photon from two linear accelerators, patient data and calculated results were commissioned. For PDD, the doses by Clarkson, convolution, superposition and fast superposition methods at 10 cm for 10${\times}$10 cm field, 100 cm SSD were compared with the measured. An error in the SCD for one quality was input by the service engineer. Whole SCD defined by a physicist is SAD plus d$\sub$max/, the value was just SAD. That resulted in increase of MU by 100${\times}$((1_d$\sub$max//SAD)$^2$-1)%. For 10${\times}$10 cm open field, 1 m SSD and at 10 cm depth in uniform medium of relative electron density (RED) 1, PDDs for 4 algorithms of dose calculation, Clarkson, convolution, superposition and fast-superposition, were compared with the measured. The calculated PDD were similar to the measured. For 10${\times}$10 cm open field, 1 m SSD and at 10 cm depth with 5 cm thick inhomogeneity of RED 0.2 under 2 cm thick RED 1 medium, PDDs for 4 algorithms were compared. PDDs ranged from 72.2% to 77.0% for 4 MV X-ray and from 90.9% to 95.6% for 6 MV X-ray. PDDs were of maximum for convolution and of minimum for superposition. For 15${\times}$15 cm symmetric wedged field, wedge factor was not constant for calculation mode, even though same geometry. The reason is that their wedge factor is considering beam hardness and ray path. Their definition requires their users to change the concept of wedge factor. RTP user should elaborately review beam data and calculation algorithm in commissioning.

• Journal of Gifted/Talented Education
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• v.11 no.3
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• pp.85-97
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• 2001

This study was to gain a suggestion how to educate the science gifted student and manage the science gifted education center by analyzing the science gifted student's perception of the science, scientist and vocation. One seventy and eight science gifted students were involved in the questionnaire to investigating the perception of science, scientist and vocation. As the results, many of science gifted students thought the convenience as the positive aspect of science and the environmental pollution as the negative aspect of science. Science gifted students considered most scientists a diligent person, researcher and what's more, they are careless about home. They suggested much more of foreign scientists like Einstein, Edison, etc. than Korean ones as respectable scientists. Scientist is a major vocation that they want and know in the science area, while some students want to be a doctor, occurred to science singer. The mystery, difficulty, complexity, scientist, etc. occurred to science gifted students when they heard the ‘science’. According to the results, there are in need of the new educational programs for the science gifted students and science gifted education center. One of the aims of the science gifted education center is the judgment and cultivation of the science gifted student. Therefore, the science gifted student to be educated to improve positively the images of science and scientist. In addition to, they should get a concern about the vocation in science area and to be a famous scientist.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.185-185
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• 2007

Starting at the beginning q the 20th century, increasing amounts of tetrach1oroethene (PCE) and trichloroethene (TCE)were manufactured due to the extensive use of these compounds in industry, in the military, and in private households, mainly as nonflammable solvents. This widespread use, along with careless handling and storage, are among the most serious contaminants of soil, sediment and groundwater. Highly chlorinated ethenes are typically not degraded through oxygenation by aerobic bacteria Since complete reductive dechlorination of PCE and TCE to ethene (ETH) has been observed in anaerobic enrichment culture, anaerobic dehalorespiring bacteria have received increased attention in the last decade. Under anaerobic conditions, these compounds con be reductively dehalogenated to less-chlorinated ethenes or innocuous ethene by microorganism through dehalorespiration. We have been studying anaerobic enrichment culture which used lactate as the electron donor for reductive dechlorination of PCE to ETH the anaerobic mixed microbial culture was enriched from the sediment sample taken from site contaminated with PCE. PCE was consistently and completely converted to ethene. In addition, the accumulation of intermediate products such as 1,2-ds-dichloroethene (cis-DCE) and vinyl chloride (VC) was observed in the anaerobic mixed microbial culture. the established dechlorinating enrichment culture was analyzed by DGGE using primers specific to DefrJ1ococcoides 16S rRNA gene sequences. In conclusion, we established the PCE dechlorinating enrichment culture and confirmed the existence of Dehalococcoides in an enrichment culture.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.11-17
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• 1996

Trichloroethylene(TCE) is the organic compound which is used variously at the industrial areas. It contaminates soils and groundwater by leaked storage tank, careless treatment in field and the effluent from waste landfills. This study was carried out to identify adsorptive behavior of TCE by soil. Batch experiments were conducted at different soil-organic matter content and lime treatment to determine Freundlich isothermal adsorption equation constant, k and n, for TCE. Sewage sludge cake was applied to make different soil-organic matter content with the level of Oton/ha(S1), 50ton/ha(S2), 100ton/ha(S3). Lime(calcium hydroxide) was treated with the level of 2ton/ha, 4ton/ha, 6ton/ha, 10ton/ha. Freundlich isothermal adsorption equations obtained from experiment with sewage sludge cake were as follows (on condition that the level of TCE applied to soil ranged from 0.5ng/g soil to 2.5 ng/g soil.) : S1 :x/m = 0.393 $C^2$, S2 : x/m = 0.436 $C^2$, S3 : x/m = 0.636 $C^2$Value of k was increased in higher order of 51, 52, 53 with increased level of sewage sludge cake application. From this results, soil which was applied higher level of sewage sludge cake had a good ability on TCE adsorption. With increased the level of lime application, pH of the soil was increased and the ability of the soil in TCE adsorption was decreased.

• Journal of Soil and Groundwater Environment
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• v.12 no.6
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• pp.38-45
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• 2007

Trichloroethylene (TCE) is a representative dense non-aqueous phase liquid (DNAPL) and has contaminated substance environments including soil and groundwater due to leakage and careless. DNPAL, has been treated by surfactant-enhanced aquifer remediation (SEAR). After application of SEAR, groundwater contains still surfactant as well as little amount of residual TCE. Permeable reactive barrier using zero-valent iron (ZW) is a very effective technology to treat the residual TCE in groundwater. In this study, the effect of the residual surfactant on the reductive dechlorination of residual TCE was investigated using ZVI. Mixed surfactant composed of nonioinic surfactant and cationic surfactant was used as a residual surfactant because of toxicity and enhancement of dechlorination rate. Structure of surfactant affected significantly the decrhlorination rate of TCE. Mixed surfactant system with relatively short polyethylene oxide (PEO) chain in nonionic surfactant, cationic surfactant did not affect TCE dechlorination rate. However, mixed surfactant system with relatively long PEO chain in nonionic surfactant shows that TCE dechlorination rate was significantly dependent on fraction of cationic surfactant and HLB of nonionic surfactant. Cationic surfactant with trimethyl ammonium group enhanced reductive dechlorination rate compared to that surfactant with pyridinium group.

• The Journal of Korean Society for School & Community Health Education
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• v.5
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• pp.43-70
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• 2004

This research was conducted to provide basic document on efficient health promotion behavior program that elementary school students can use from elementary school course to enhance health promotion behavior for healthy life by checking out the degree of the most influential factor for health promotion behavior about elementary school students who establish lifelong health habit, and by checking out the relation between the degree of self-efficacy and health promotion behavior. The number of subjects of this research was 598. They were all elementary school students from the sixth grade students of the 5 cities of the Kyeong Nam province. We conducted questionnaires and did statistical analyses by using 592 papers which were suitable for date analyses with SPSS. The conclusions were as follows; A. The degree of self-efficacy The degree of self-efficacy of elementary school students was more than average. The degree of self-efficacy on physical activity was the highest and the degree of self-efficacy on self-fulfillment was the lowest. The degree of self-efficacy of girl students was comparatively higher than that of boy students. When their parents got higher education, made a lot of money and kept harmony with their children, the degree of self-efficacy became high. Furthermore, when their parents or themselves have a lot of interest in health, they feel that they are healthy, and they feel that they are satisfied with their bodies, the degree of self-efficacy was high too. B. The degree of health promotion behavior Although the degree of health promotion behavior of elementary school students was a bit lower than the degree of self-efficacy, it was higher than average. The degree of health promotion behavior on physical activity was the highest. But the degree of health promotion behavior on health of their own was the lowest. The degree of health promotion behavior between girl students and boy students was the same. When their parents got higher education, made a lot of money and kept harmony with their children, the degree of self-efficacy became high. Furthermore, when their parents or themselves have a lot of interest In health, they feel that they are healthy, and they feel that they are satisfied with their bodies, the degree of self-efficacy was high too. C. The relation between self-efficacy and health promotion behavior When the degree of self-efficacy was high, the degree of health promotion behavior was high too. So there was high positive relationship between self-efficacy and health promotion behavior. Physical activity showed the highest relationship. The order of strong relationship run as follows. Relationship with others, self-fulfillment, management of stress. The higher self-efficacy which was a recognizable factor on health behavior, the higher the degree of health promotion behavior. It is being revealed that many modem chronic diseases are cause by accumulated careless attitude on harmful health habit and lack of self-control. The behavior of keeping healthy and enhancing health is more firm when they have high self-efficacy which is believing their own conviction. So, When we teach elementary school students health promotion education at school, we should try to enhance their own self-efficacy rather than just instill simple information about health. By doing so, we can help them change their attitude on health. Then, they could enjoy life-long healthy life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.488-496
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• 2020

This study was based on nitrate chemical accidents at home and abroad. Toxic gases due to adverse reactions are generated in the workplace, laboratory, hospital, container damage, and chemical misinjection. Through a case review of possible situations and safety, this study analyzed various cases of accidents, accident status, accident type, cause of the accident, location of the accidents, etc. from 2014 to 2018. The plans for improvement in education and nitrate accidents were reviewed. As a result, 36 nitrate chemical accidents were investigated, including 16 careless worker accidents, eight transportation accidents, and 12 facilities shortages. Nitrate chemical accidents are occurring continuously. Based on this, the range of toxic effects using CARIS was calculated at the worst-case scenario, and the effective response range was measured through the damage impact range. For this purpose, the impact range was predicted based on the strengthening of safety education, emergency action plan and correlation, and the quantified data was identified. In addition, the reliability of the scope of impact was reviewed based on the correlation formula that could facilitate the evacuation of residents, and it was applied to actual accident scenarios of the workplace to present the effects of the accident response and preventive measures.

• Journal of Preventive Medicine and Public Health
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• v.1 no.1
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• pp.79-86
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• 1968

This paper describes the incidence and some epidemiological features of drowning accident out of a series of our study on the epidemiology of various accidents in Korea. By the daily press it is apparent from the frequent reporting of swimming accidents that the incidence would be high. In the rural areas, there are, at present, about 1,250 artificial lakes and farm ponds to be utlized for rice production. The reservoirs, irrigation ditches and riversides are also used for recreation. In most places facilities for aquatic activities is meager, and safety measures for the prevention of drowning is not sufficiently enforced. In the survey crude data on drownings were collected from the concerned governmental statistic books for the period 1955 to 1967 which were compiled not in a uniform way. Drownings were classfied into two categories, one is accidental drowning, E 929 and the other is due to cataclysm, E 934, according to the WHO international classification of diseases. Epidemiological variables in relation to drowning accident were obtained through qualitative analysis of informations from the popular news papers. The following summary may be drawn; 1. The average number of deaths due to accidental drowning totaled 1,088 annually and the mortality rate per 100,000 population was 3.4, The 42.0% of all drownings were rescued and the remaining were not saved. 2. The sex ratio (M/F) of the victims for all ages was 5 to 1, which had a wide range of difference among the age groups. The young ages less than 20 years occupied 68.0% of all deaths. 3. The percentage distribution of the causes of accidents revealed 31.9% for careless swimming, 45.5% for unskilled, 10.6% for swimmer's cramp and 6.0% for drunked. The distribution of places where accidents occurred showed 88.0% for rivers, water reservoirs, irrigation ditches and 12.0% for regular swimming pools. The seasonal distribution of cases indicated 85.0% of the total were seen during the summer months, June-August, and 50.0% of them occurred on Sundays, 4. The average annual deaths due to cataclysm were 402 and mortality rate per 100,000 population was 1.6, but the number of victims due to cataclysm varied greatly each year. 5. The accident cases due to cataclysm were classified into 60.0% for injuries, 40.0% for deaths. The 26.8% of all deaths were missing cases. 6. The deaths due to either accidental drowning or cataclysm totaled 1,490, and the death rate per 100,000 for the whole country was 5.0.

• Journal of Preventive Medicine and Public Health
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• v.1 no.1
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• pp.43-49
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• 1968

Epidemiological and statistical observations were made of fire hazards that occurred during the past 18 years, 1948 to 1965. Injury and mortality rates for all ages were computed chronologically. For the years of 1955, 1961 and 1965, all fire accidents were epidemiologically analysed to draw characteristic patterns in relation to the seasonal and 24 hour distribution, causes and sites of accidents etc.. Fire hazards observed herein are the categorys E 916 of the International Classification of Causes of Death, 1955, and includes all accidents caused by fire and explosion of combustible materials. The following conclusion was made: 1. The average number of annual deaths due to fire was 183 and the number of the in jured due to the same cause was 335. The mortality rate per 100,000 population was 0.8 and the ratio of injuries per death was 1.83. 2. The casually rate including both the dead and injured was 5.0 per 100,000 in Seoul, the highest among the provinces and followed by 3.4 in Cheju -Do, 2.1 in Kangwon-Do, 1.7 in Kyunggi-Do accordingly. The other provinces had a range of 0.6 to 1.2. 3. The monthly distribution of fro accidents showed that the winter months, December through February, had more frequent accidents, while the summer season, June through August had less. The 24 hour distribution of accidents showed more cases from 12:00 to 18:00 and less from 4:00 to 10:00 hours. 4. The per cent distribution of causes of accidents showed; 90.0% for careless, 10.0% for arson. The cause of carelessness was further breakdown into; 15.0% for kitchen fire places, 13.8% for fire playing, 9,4% for electrical heating and wires, 8.3% for fuels, 6.3% for matches, 5.2% for ash dumps and the remaining for others. 5. The accidents as classified by place revealed that 56.8% of the total occurred at the common dwelling houses, 11.3 at various industrial workshops, 9.3% at the street shops and the remaining at the miscellaneous places.

• Fire Science and Engineering
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• v.30 no.4
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• pp.111-120
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• 2016

This is an experimental study to analyze the explosion and fire hazards of mobile phone batteries. Using the lithium-ion batteries currently used on smart phone as the experiment samples, the experiments were conducted by overcharging, internal and external short circuit, and thermal shock with the potential of explosion and fire caused by careless use or abnormal conditions. The experiment results showed that, in the case of overcharging and external short circuit, there was no explosion and fire hazard in the normal operation of the protection circuit module (PCM), but there were big risks when the PCM faulted conditions were assumed. In the case of the experiments by internal short circuit and thermal shock, such risks varied depending on a battery charge state. In other words, it could be verified that there were low risks of explosion and fire in a full discharge state, but there were high risks in a full charge state. These experiment results suggest that to minimize the explosion and fire hazards of mobile phone batteries, an alarm device is necessary when the PCM fault occurs. In addition, a solid battery case should be made and safety equipment, such as a cooling device to avoid high temperature, is needed.