• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.236-248
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• 2020

Objectives: The purpose of this study was to evaluate the concentrations of particulate matter generated during coffee roasting and to study various factors affecting the concentrations. Methods: Differences in concentration levels were investigated based on various factors to understand the emission rates of particulate matter over time and to compare the mass and number concentrations according to their size. Sampling was performed in closed laboratories without the operation of air conditioning or ventilation. Optical Particle Sizer(OPS) was used as a measuring device. An OPS measures using a light-scattering method. Sampling was performed for sixty minutes at one-minute intervals. The background concentration was measured for about 30 minutes before starting of coffee roasting. The concentrations of particulate matter generated during coffee roasting were monitored until roasted coffee beans were removed from the roaster and cooled down. Several factors affecting the concentrations of particulate matter were investigated, which includes the origins of green beans, the roasting level, and the input amount of green beans. Results: The results of this study may be summarized as follows: 1) There was no difference in particulate matter concentration levels by the origin of the green beans, but a statistically significant difference in concentration levels by roasting level and the input amount of green beans; The higher the roasting level, the higher was the particulate matter concentration. The more green beans we put in the roaster, the higher were the concentrations; 2) The PM10 mass concentrations increased over time. The average concentration after roasting was higher than the average concentration during roasting; 3) In the distribution of mass and number concentration by particle diameter, the majority of particles was below 2.5 ㎛. Conclusions: Persons who work in roastery cafes can be exposed to high concentrations of particulate matter. Therefore, personal exposure and risk assessment should be conducted for roastery cafe workers.

• Journal of Korean society of Dental Hygiene
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• v.2 no.2
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• pp.215-225
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• 2002

Objectives: Dental personnels have high chances of exposure to various infections during many dental procedures. This study was performed to investigate the state of infection control in the private dental clinics and prevention state of hepatitis B virus infection among the dental hygiene students in Kwanju city, Korea. Methods: Questionnaires were obtained from 94 dental hygiene students who participated in dental practice in private dental clinics for more than five weeks. Results: 83.9% of dentists and 17.2% of dental hygienists routinely used the mask for treating all patients, 32.3% of dentists and 6.5% of dental hygienists routinely used the rubber gloves. The use of protective eyeware was much lower in each group. Disinfectant was used in 52.7% for sanitization of dental instruments before cleansing. The prevalence of HBsAg and anti-HBs were 3.8% and 67.1% respectively, 52.7% of dental hygiene students had history of accidental needle stick. Conclusion: Routine use of personal barrier techniques by dental personnels should be emphasized. Dental hygiene students were not properly immunized against hepatitis B virus and had high incidence of accidental needle stick. It is necessary to establish specific regulations or recommendations for cross infection control in dental practice and to performed scheduled vaccination program for hepatitis B virus for dental hygiene students.

• Journal of Radiation Protection and Research
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• v.34 no.3
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• pp.95-101
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• 2009

Protective behavior of radiological technologists against radiation exposure is important to achieve reduction of the patient doses without compromising medical achievements. This study attempts to provide a basic model for the sophisticated intervention strategy that increases the level of the protective behavior of the technologists. The model was applied to real situations in Korea to demonstrate its utility. The results of this study are summarized as follows: First, the protective environment showed the highest relationship in the factors considered, r=0.637 (p<0.01). Secondly, the important factors were protective environment in environment characteristics, expectation for the protective behavior 0.228 (p<0.001), self-efficacy 0.142 (p<0.001), and attitude for the protective behavior 0.178 (p<0.001) in personal characteristics, and daily patient -0.112 (p<0.001) and number of the participation in the education session for the protective behavior 0.074 (p<0.05). Thirdly, the final protective behavior model by a path analysis method had direct influence on the attitude 0.171 (p<0.01) and environment 0.405 (p<0.01) for the protective behavior, self efficacy 0.122 (p<0.01), expectation for the protective behavior 0.16 (p<0.01), and self-efficacy in the specialty of projects 0.154 (p<0.01). The acceptance of the model determined by the absolute fit index (GFI), 0.969, and by the incremental fit index (CFI), 0.943, showed very significant levels. Value of $x^2$/df that is a factor applied to verify the acceptance of the model was 37, which implies that the result can be accepted in the desirable range. In addition, the parsimonious fit index configured by AGFI (0.890) and TLI (0.852) was also considered as a scale that accepts the model in practical applications. In case of the establishment of some specific intervention strategies based on the protective behavior model against harmful radiation effects proposed in this study, the strategy will provide an effective way to prevent medical harmful radiation effects that could cause severe injuries to people.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.305-310
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• 2013

To provide medical services to patients who have a terminal illness, recent hospital patients to monitor the state of the device attached to the body, the body insertion device is. U-Healthcare Environment and hospital officials indiscriminately exploited by the patient's vital information, however, could threaten the patient's life problems are appearing. In this paper, depending on the level of authority, hospital officials, Union of ID-based authentication model is proposed to use a patient's vital information. Union proposed model identify different authentication system is used in hospitals that exist in various forms in a number of ID information, health / medical information sharing between hospitals without exposure to unnecessary personal information, you can be assured of the anonymity. In particular, with easy access to patient information, hospital officials about the malicious act to protect patient information to access level for the rights granted by third parties to prevent easy access.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.191-206
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• 2004

The present study investigated the hypothesis that a extremely low frequency magnetic field partially suppresses the synthesis of melatonin in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 ${\mu}$T, whereas the value for the primary schoolchildren living away from overhead transmission power line 0.05 mT. From simple analyses, the mean melatonin levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, but not statistically significant differences in the levels of the melatonin (p=0.2421), whereas the statistically significant differences in the levels of the melatonin related to the distance from residence to power line less and more than 100 m by cut-off point (p=0.0139). In multiple linear regression analyses, distance from residence to power line (p=0.0146) and dietary habit about burned meat (p=0.0170) proved to be significant risk factors in the mean nocturnal melatonin levels in the primary schoolchildren. In conclusion, these results demonstrate that urinary levels of nocturnal melatonin are not altered in primary schoolchildren exposed to extremely low frequency magnetic field(ELF-MF) at overhead transmission power line.

• Tuberculosis and Respiratory Diseases
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• v.50 no.5
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• pp.615-623
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• 2001

Background : Pneumoconiosis is a parenchymal lung disease that results from the accumulation of coal dust in the lungs and the consequent tissue reaction. To evaluate the role of various personal factors in pneumoconiosis and the significance of some serologic markers for assessing the disease activity related to pneumoconiosis, the Rheumatoid Factor(RF), ${\alpha}_1$-AT, C-Reactive Protein(CRP), ceruloplasmin and fibrinogen levels were measured. Method : All the patients were males, 45-76 years old, and the mean duration of coal dust exposure was 23.2 years. 51 patients were classified as having Simple Pneumoconiosis (SP), 59 had Progressive Massive Fibrosis (PMF). Fifty eight men with ages ranging from 26-70 years were used as normal controls. The serum RF and CRP were titrated using an Autochemistry analyzer (HITACHI 7150 : Japan) and the ${\alpha}_1$-AT and ceruloplasmin levels were measured using a Nephelometer (Behring Nephelometer : Germany) and the fibrinogen levels were estimated by using an Autoanalyzer for hematologic coagulation. Result : There was a higher RF level in the SP, and PMF groups than in the control groups but there was no statistical difference. The CRP, ${\alpha}_1$-AT, and ceruloplasmin levels were also higher in the SP, and PMF groups. However, the fibrinogen concentration was within the normal ranges in both the SP and PMF groups. Conclusion : The CWP (Ed note : Define CWP) patients had significantly higher CRP, ${\alpha}_1$-AT, and ceruloplasmin levels compared to the control group. It is believed that these serologic changes could be used as a marker of the disease activity.

• Journal of Environmental Health Sciences
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• v.40 no.5
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• pp.367-375
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• 2014

Objectives: The main purpose of this study is to produce background data which can be compared with several large-scale industrial complex regions. Methods: The framework of this study was designed to evaluate and monitor health effects associated with low-level and long-term exposure to environmental pollutants. In this study, 1,009 local residents were recruited in the city of Chungju using personal questionnaires, medical check-ups, and allergen skin-prick tests for 12 common allergens. The prevalence rate of skin allergens was reviewed together with that from large-scale industrial areas. Results: The diagnosis prevalence and medical treatment prevalence of asthma was 5.6% and 1.7%, respectively. Allergic rhinitis was 25.4% and 16.7%, allergic dermatitis was 16.6% and 9.9% and allergic conjunctivitis was 18.7% and 7.9%, respectively. These results were similar with those of industrial complexes. The prevalence of allergen skin-prick test was 16.4% and the most common allergen was dust mites (27.9-31.6%). This result was lower than those of the industrial complexes (22.5-39.9%) and Gangneung (18.2-24.7%). Conclusion: Further study is required to find the cause of the regional differences in skin prick prevalence.

• Journal of radiological science and technology
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• v.43 no.2
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• pp.71-77
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• 2020

This study aims to explain the process of providing important medical images for the diagnosis of pneumonia caused by coronavirus disease 2019 (COVID-19) through the only mobile hospital computed tomography (CT) in Korea. Since January 28, 2020, medical imaging examinations have been provided to confirmed and suspected COVID-19 patients, and the quality of images was evaluated based on the objective and subjective indicators. In order to prevent the transmission in the hospital that may occur due to exposure to medical staff and general patients, personal protective equipment was worn and the separate route was used blocking human infection factors. For 11 weeks, a total of 185 tests were performed for 98 confirmed patients and 72 suspected patients. The average time to complete the test was 33 minutes. In the course of the test, no cross-infection cases were examined. During the outbreak of the COVID-19, the only mobile hospital CT room of Korea provided medical imaging examinations without infection among medical staff and patients and also provided adequate medical images without significant difference (p >0.05) in determining the degree of pneumonia progression compared to a stationary in-hospital CT.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.821-826
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• 2011

Synthetic musk compounds are widely used as fragrances in a variety of personal care products like soaps, sampoos, cosmetics and perfumes. The occurrence of synthetic musk compounds in municipal sewage effluent and other environmental samples could negatively impact the health of the ecosystem and humans, due to persistent and long-term chronic exposure of aquatic organisms. Fifteen synthetic musk compounds (musk ketone, musk xylene, musk ambrette, musk moskene, musk tibetene, HHCB, AHTN, ADBI, AHDI, DPMI, ATII, ethylenebrasssylate, ambretettolide, cyclopentadecanolide, OTNE) were analysed in surface waters and sewage treatment plants (STP) influents/effluents in Korea by GC/MS. Method detection limits were $0.005{\sim}0.398{\mu}g/L$. HHCB and AHTN were most frequently observed in both surface waters and STP influents/effluents.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1409-1415
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• 2013

With the development of Internet communication and the use of a variety of online services has been greatly expanded. Therefore, the importance of authentication techniques for users of online services has increased. The most commonly used methods for user authentication is a technique that utilizes a prearranged password. However, the existing password scheme for authentication must use the same password every time. Therefore, the password being leaked by attackers, it can be used maliciously. In this paper, we proposed the Variable Password Generation Method in Internet Authentication System that generates a new password using information such as the access date, time, and IP address when user logs in. The method proposed in this paper prevents disclosure of personal information due to password exposure and improves the reliability and competitiveness in the field of security systems.