• Journal of radiological science and technology
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• v.33 no.3
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• pp.185-192
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• 2010

Platelets originating from Megakaryocyte are sensitive to radiation along with white blood cells, and thus these platelets are used as an index of radiation hazard as they decrease in advance. Thus, when there is a scarcity of platelets, dot hemorrhage occurs and it leads to decrease of blood corpuscle and a decline in immunity. In particular, when 4~6 Gy whole body irradiation is received, after three weeks, the platelets will decrease to the lowest level, which can be a cause of death by bleeding and anemia. Therefore, this study tried to identify the mechanism of platelet damage and protection effect. The protection substance used in the experiment is Alliin, which is a component of garlic, and it was observed by an Transmission Electron Microscope(TEM) after its injection to the rat's tail vein. In the study, it was found that the cell membrane was severely damaged in a 10-day progressed platelet organ after receiving 5 Gy irradiation. It billowed as balloon-like figure and the glycocalyx became hyperplasia. The minute organ was damaged to the point that it was beyond recognition in a 20-day progressed platelet organ after receiving irradiation, and the cytoplasmic contents were exposed to epilepsy parts and outrageously damaged. Furthermore, the form of granules could also not be observed. A hole was formed in the middle, and the damaged organ was found in a 30-day progressed platelet. However, the form of granules was consistently maintained in the experiment group injecting Alliin, as with the control group, and there was no damage to the cell membrane recognized. Thus, it was possible to verify the effectiveness of radiation protection of the platelet when Alliin was injected to the blood vessel.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.490-499
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• 2002

Recently, gamma radiographic equipments have been used about 1,000 sets manually and operated by about 2,500 persons in Korea. In order for a radiography to work effectively with avoiding any hazard of the high level radiation from the source, many field workers have expected developing a wireless automatic remote exposure controller. The KlTCO research team has developed an automatic remote exposure controller that can regulate the speed of $0.4{\sim}1.2m/s$ by BLDC motor of 24V 200W which has output of $54kgf{\cdot}cm$, suitable torque and safety factor for the work. And the developed automatic remote exposure controller can control rpm of motor, pigtail position by photo-sensor and exposure time by timer to RF sensor. Thus, the developed equipment is expected that the unit can be used in many practical applications with benefits in economical advantage to combine the use of both automatic and manual type because attachment is possible existent manual remote exposure controller, AC and DC combined use.

• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.94-101
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• 1977

Noise pollution, both in the environment and in the workplace, has been recognized as a major health hazard -one that can impair not only a person's hearing but also his physical and mental well-being. As industrialization progresses, the prevalence rate of occupational diseases is increasing, especially hearing loss, which has the highest prevalence rate among the occupational diseases. The major cause of noise is the construction of various large industries without any regulation of noise sources. Therefor, we must establish an enactment to control mechanical noise sources. as soon as possible. For the purpose of controlling the noise source, we must have exact data about such things as the sound level, the frequency of the peak sound and the revolutions per minute (r.p.m.) of the machine (a measure of the power of its motor). This study was undertaken in order to define the noise characteristics, the power of the machine's motor, the change of the sound level and the peak sound as the r.p.m. increases, and the permissible exposure time. The sample size of this study was 74 machines at 11 plants in 6 industries. The results are as follows; 1. The breakdown of the types of mechanical noise noted was : 63.6% continuous normal sound, 26.9% intermittent sound, 4.7% continuous repeating sound and 4.6% impulsive sound. 2. With respect to the type of industry, the overall sound level was the highest in the mechanical industry, with $103.8{\pm}2.8dB(A)$, and lowest in the textile industry, with $89.2{\pm}1.43dB(A)$. 3. With respect to the type of machine, the highest sound level was 124 dB(A) caused by Gauzing(II), in the mechanical industry, and the lowest was 76 dB(A) caused by Attachment (Jup Chack) (I) in the timber industry. 4. The shortest permissible exposure time to Gauzing(II) in the mechanical industry was less than 15 minutes. 5. Among 74 machines, 68.2% of the peak sound was situated in the high frequency range (52.7% at 2 KHz, 4.1% at 4 KHz and 1.4% at 8 KHz). 41.8% of the peak sound was in the middle frequency range (4.1% at 250Hz, 14.8% at 500Hz and 22.9% at 1KHz). 6. If one machine had two motors or more, the peak sound was shifted to the low frequency range. 7. As the r.p.m. increased, the overall and peak sound levels were increased without any change of the frequency of the peak sound. 8. Whenever the machines had the same kind and the same r.p.m., the overall and peak sounds were changed by the physicochemical characteristics of the raw materials and the management.

• Journal of Chest Surgery
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• v.50 no.2
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• pp.78-85
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• 2017

Background: Closure of a secundum atrial septal defect (ASD) is possible through surgical intervention or device placement. During surgical intervention, concomitant pathologies are corrected. The present study was conducted to investigate the outcomes of surgical ASD closure, to determine the risk factors of mortality, and establish the effects of concomitant disease correction. Methods: Between October 1989 and October 2009, 693 adults underwent surgery for secundum ASD. Their mean age was $40.9{\pm}13.1years$, and 199 (28.7%) were male. Preoperatively, atrial fibrillation was noted in 39 patients (5.6%) and significant tricuspid regurgitation (TR) in 137 patients (19.8%). The mean follow-up duration was $12.4{\pm}4.7years$. Results: There was no 30-day mortality. The 1-, 5-, 10-, and 20-year survival rates were 99.4%, 96.8%, 94.5%, and 81.6%, respectively. In multivariate analysis, significant preoperative TR (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.09 to 3.16; p=0.023) and preoperative age (HR, 1.04; 95% CI, 1.01 to 1.06; p=0.001) were independent risk factors for late mortality. The TR grade significantly decreased after ASD closure with tricuspid repair. However, in patients with more than mild TR, repair was not associated with improved long-term survival (p=0.518). Conclusion: Surgical ASD closure is safe. Significant preoperative TR and age showed a strong negative correlation with survival. Our data showed that tricuspid valve repair improved the TR grade effectively. However, no effect on long-term survival was found. Therefore, early surgery before the development of significant TR mat be beneficial for improving postoperative survival.

• Journal of Food Hygiene and Safety
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• v.19 no.2
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• pp.74-83
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• 2004

Raw-fish food contains a lot of moisture and is a high-protein food. It is a first-stage processed food taking a lot of manual work. Therefore, it is classified as a PHF food, very liable to cause a bacterial food-poisoning. But its manufacturers are usually small-sized and a systematic sanitation management is difficult to expect. But the manufacturer participating in this study produces chilled fresh raw-fish food. Fish are sliced into two fillets, which are packaged under vacuum, kept and distributed in refrigerators, and sold within a day. It is a newly-developed kind of raw-fish food, and a more improved kind of raw-fish food making possible a systematic sanitation management. The HACCP (Hazard Analysis and Critical Control Point) is a systematic and continuous process-control method which is very efficient for controling food sanitation and reducing the expenses. A new HACCP model has been developed to be applied to a large-sized chilled fresh raw-fish food manufacturer. To ascertain its efficiency, the baterial examination was done to its workplace and products. The significance test was done on its data by "SPSS 12.0 for Window" and "Mann-Whitney U Test". The numbers of bacteria on its final products were significantly different in flatfish and porgy. The number of bacteria tended to decrease in each time-differential sampling (P＜.00l). The final food products showed no food-poisoning bacteria in all the time-differential tests and in all the samplings, which proves that the CCP of the HACCP system is under control. After the SSOP program was applied, no pathogenic bacteria were found in the work-place, and the kinds and numbers of bacteria decreased. The numbers of general bacteria and colon bacilli also showed a significant difference from those before the SSOP program in the filleting board (P＜.05), in the skinning board (P＜.0l), in the neck-removing knife (P＜.05), and in the filleting knife (P＜.01). The working equipments, periodically disinfected, also showed a significant difference in sanitary conditions (in the dehydrator, P＜.05). The number of bacteria found on the food-touching surface was within the standard (below 500/l00 cm$^2$) After the SSOP program was applied, the general bacteria and colon bacilli were not found. The quality of water used in the food processing was also within the standard. The numbers of bacteria falling from the air in the work-place were negligible in all the samplings (＜30CFU/l000ι). The staphylococci and fungi were not found.

• Journal of the Korean Institute of Gas
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• v.16 no.1
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• pp.39-45
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• 2012

While the natural gas supply industry has continuously been growing, its potential hazard has also risen since the natural gas facilities essentially require installations that carry highly flammable and pressurized gas close to the populated areas, posing a serious consequence of significant property damage as well as human casualties in the event of accident. Therefore Quantitative Risk Assessment (QAR) has been recognized as a appropriate method to reduce the risk as far as possible, considering the reality of unachievable zero-risk. However, it is hard to perform effective QRA on hundreds of gas facilities because of insufficient number of expert and long-term analysis. In this paper, we suggest a conceptual QRA system framework to support more efficient risk analysis in gas supply facilities. In this system, the experts make questionnaires and internal calculation formula needed in accident frequency/consequence analysis of the facility through pre-analysis on the point of analysis, called incident point, and general users locate the point on the map and input the value required by the questionnaire to obtain the risk. Ultimately, this is suggested based on the idea that the specialization is available in QRA analysis process and the validity of the system is verified through actual system construction and application.

• Journal of Gastric Cancer
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• v.18 no.1
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• pp.58-68
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• 2018

Purpose: Generally, adjuvant chemotherapy (AC) should be initiated as soon as possible after surgery to eradicate microscopic cancer cells. In this study, we investigated the effect of early AC on the survival of stage II/III gastric cancer patients. Materials and Methods: Four hundred sixty patients who received AC (S-1 or XELOX) for pathologic stage II/III gastric cancer at Seoul National University Bundang Hospital between January 2008 and December 2014 were included. Patients were divided into 2 groups: early AC administration (within 4 weeks) and late AC administration (more than 4 weeks). Patients in the early AC group (n=174) were matched 1:1 with patients in the late AC group (n=174) by propensity scoring to adjust for clinical differences. Three-year relapse-free survival (RFS) was evaluated according to the timing of AC. Results: Three-year RFS was 98.1% in stage IIA (n=109), 85.0% in stage IIB (n=83), 87.4% in stage IIIA (n=96), 83.5% in stage IIIB (n=91), and 62.5% in stage IIIC (n=81). After propensity score matching, RFS was similar between early and late AC groups (hazard ratio [HR],1.04; 95% confidence interval [CI], 0.62-1.74; P=0.889). Pathologic stage and histological type were independent prognostic factors of RFS (HR, 2.05; 95% CI, 1.06-3.96; P=0.033 and HR, 2.61; 95% CI, 1.42-4.80; P=0.002, respectively). Conclusions: Early initiation of AC within 4 weeks does not affect survival rates in stage II/III gastric cancer.

• Korean Journal of Organic Agriculture
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• v.27 no.4
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• pp.437-452
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• 2019

The HACCP evaluation standards for the meat packaging plant are divided into general scale HACCP evaluation standard and small scale HACCP evaluation standard. There are 69 evaluation items in the general scale HACCP evaluation criteria, of which 54 items in the prerequisite management and 15 items in the HACCP management are included. The number of small scale HACCP evaluation items are 20 and about 29% of the general scale HACCP evaluation items. This may not be enough to produce a safety livestock products for the purpose of implementing the HACCP system due to the nature of the meat packaging plant, which does not show much difference in the production process or method of product depending on the scale. To improve the small scale HACCP evaluation standard, the importance of each item was compared with the small scale HACCP evaluation based on the rate of non-compliance and the severity levels in the general scale HACCP evaluation items. As a result of the study, 8 items were derived from the prerequisites management, 2 items were derived from the HACCP management, and some similar evaluation items were grouped together. Finally, 10 items were added to the 20 items of the existing small scale HACCP evaluation items. In this study, study on the safety management of domestic livestock products are continuously carried out, so that it is possible to provide safety livestock products to consumers and contributes to securing competitiveness of domestic livestock industry.

• The Korean Journal of Quaternary Research
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• v.20 no.2
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• pp.1-10
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• 2006

Flooding hazard caused by natural and artificial environmental changes is closely associated with change in river bed configuration. This study is aimed at explaining a river-bed change related to soil erosion in the Keum river basin using GIS and RS. The USLE was used to compute soil erosion rate on the basis of GIS. River-bed profiles stretching from Kongju to Ippo were measured to construct a 3D-geomorphological map. The river-bed change was also detected by remote sensing images using Landsat TM during the period of 1982 to 2000 for the Keum river. The result shows that USLE indicates a mean soil erosion rate of $1.8\;kg/m^2/year$, and a net increase of a river-bed change at a rate of $+5\;cm/m^2$/year in the Kangkyeong area. The change in river-bed is interpreted to have been caused by soil erosion in the downstream of the Keum river basin. In addition river-bed change mainly occurred on the downstream of the confluence where tributaries and the main channel meet. Other possible river-bed change is caused by a removal of fluvial sand aggregates, which might have resulted in a net decrease of exposed area of sediment distribution between 1991 and 1995, while a construction of underwater structures, including a bridge, a reclamation of sand bars for rice fields and dikes, resulted in an increase of the exposed area of river-bed due to sediment accumulation.

• Journal of Korean Society for Geospatial Information Science
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• v.9 no.2 s.18
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• pp.29-36
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• 2001

The purpose of this paper is to describe the Disaster Management System Development of Enterprise GIS at the Kangwon Province in Korea. This project is included into 'the Kangwon Enterprise GIS 21 plan'. The Division of Disaster Management is in the middle of the 2-year project of the Disaster Management System development, appropriate for business performed at the Departments of Forestry, Culture, Environment, Tourism, etc. At the 1st phase of CIS implementation, for more than half a year we focused on the necessity of management of disasters. In the planning process, we needed long-term information on the whole area of Kangwon. In the assessment and response processes, we needed real-time data from Korean Meteorological Administration and other agencies. All the above information was carefully studied and referred to. ESRI's new GIS technologies solve the natural hazard/disaster problems. For example, hazardous materials routing often needs to be found the least expensive path through a roadway network. In the circumstances given, we can choose the departure point and destination of the vehicle, which carries the materials. It's also possible to minimize overall risk and costs of disaster problems by making a plan of people and possessions evacuation from the disaster area in short time limits. We can meet all the above goals using the latest ESRI's technologies.