• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.267-275
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• 2023

Occupational exposure records are subject of global interest, and analysis of radiation workers in work categories is being conducted. In Rep. of Korea, according to relevant ministries, the MOHW(Ministry of Health and Welfare), the MAFRA(Ministry of Agriculture, Food and Rural Affairs), and the NSSC(Nuclear Safety and Security Commission) collect and analyze records of occupational exposure by dividing them into 11 work categories. However, this classification system lacks consistency with the systems of major countries, including the UNSCEAR(United Nations Scientific Committee on the Effects of Atomic Radiation). The domestic radiation work field classification system does not have clear classification criteria and does not reflect the characteristics of the radiation work field. Through the analysis of the classification system of the UNSCEAR, we suggested the five main categories(nuclear cycle, medical, industrial, others(education/research, military/public) field and several sub-categories according to each radiation work field.

• Journal of Environmental Impact Assessment
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• v.14 no.5
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• pp.347-353
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• 2005

The risk assessment is the qualitative or quantitative evaluation of the risk posed to human health and the environment by the actual or potential presence or release of hazardous substances, pollutants or contaminants. The environmental impact assessment (EIA) is assessed by the environmental criteria, and risk assessment is assessed by the risk rate. Risk rate based on dose-response values may not be easy to apply on regulatory basis like EIA for uncertainty. Internationally there is an example of OECD program. Risk assessment of High Production Volume (HPV) Chemicals has started since the OECD Program with the 1990 Council Act on the Co-operative Investigation and Risk Reduction of Existing Chemicals. These HPV chemicals include all chemicals produced or imported at levels greater than 1,000 tonnes per year in at least one Member country or in the European Union region. The SIDS called the Screening Information Data Set is regarded as the minimum information needed to assess an HPV chemical to determine whether any further work should be carried out or not. All the data elements of SIDS including assessment for environment and health are prepared as three formats of the full SIDS Dossier, the SIDS Initial Assessment Report (SIAR), and the SIDS Initial Assessment Profile (SIAP) of an HPV chemical. In 1998 the global chemical industry through the International Council of Chemical Associations (ICCA) has joined to work with OECD. The OECD has assessed approximately 1,000 chemicals from 1991 through 2004 with ICCA. Till the February of 2005, 592 chemicals of those chemicals completed SIDS reports. Member countries have been targeted the goal of 1,000 new chemicals from 2005 to 2010 and Korea shared 36 chemicals from the 1,000 new chemicals. Currently Korea has completed SIDS reports of 7 chemicals among sponsored 24 chemicals. In conclusion SIDS project will be linked to national program for outputs application with more reliable production. Both the OECD and industry will carry out their commitment to complete assessments for more and the remaining chemicals assessment. The major outputs will contribute to cope with international chemical management.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.35-48
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• 2021

This study is an attempt to establish a model and identify the relationship between the individual characteristics of college students, Internet usage characteristics, exposure to pornography, and anti-social sexual perception. The subjects of the study were 360 college students aged 18 or older in B city, and the collected data were analyzed using the IBM SPSS 21.0 and AMOS 22.0 programs. The goodness-of-fit index of the modified model met the acceptance criteria (𝛘²/df=2.786, GFI=.95, AGFI=.92, SRMR=.06, RMSEA=.07, NFI=.89, CFI=.93, TLI=.90). According to the results of path analysis, the variables that directly affect anti-social sexual perceptions of college students were personal characteristics and exposure to pornography, and the variable with indirect effect was the Internet usage characteristics. The biggest direct effect on anti-social sexual perception was exposure to pornography, and it was confirmed that exposure to pornography was directly affected by personal characteristics and Internet usage characteristics. Therefore, in order to reduce anti-social sexual perceptions among college students, measures should be taken to control personal characteristics and Internet usage characteristics that directly affect the level of exposure to pornography.

• Journal of Preventive Medicine and Public Health
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• v.26 no.3 s.43
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• pp.371-386
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• 1993

This study was carried out to evaluate diagnostic criteria of noise-induced hearing loss (NIHL) among-workers in an iron foundry. Of 1,093 workers under the observation of noise-specific health examination, 184 workers were selected by way of first and second screening audiometric examination. A questionnaire survey, otological examinations, Rinne test and audiometric test were performed and the results were as follows ; The degree of hearing impairment in the left ear was more severe than in the right ear (p<0.05). The difference between hearing threshold of the first and the second hearing test at 1,000 Hz was about 5 dB with a narrow range of deviations while the difference at 4,000 Hz was about -7 dB with a wide range. Of the total study workers, 84.8% were tested within 15 hours away from noise exposure, and the rest after 16 hours. This study has identified that mean hearing loss at 4,000 Hz showed a significant statistical difference among the two study groups while mean hearing loss by 4-divided classification did not. The same phenomena were observed between the group with and without tinnitus and between the group with and without difficulty in hearing (p<0.05). Among 184 workers, 10 workers (5.4%) diagnosed as NIHL by old diagnostic criteria in contrast to 150 workers diagnosed as NIHL by the new diagnostic criteria. There was a significant difference between the two groups in the average hearing loss at 4,000 Hz and 4-divided classification (p<0.01), but there were no significant differences in age, the duration of employment, blood pressure and the duration wearing the personal hearing protector (p>0.05). If we apply Early Loss Index (ELI) method, some workers in younger age group diagnosed as NIHL by the new diagnostic criteria were fallen into within the normal range. In the mean time older age group show reverse results in contrast to the above finding. It is too early to confirm the value of the usage of the new diagnostic criteria in hearing examination. Further study is called for to verify the value of this criteria.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.7-12
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• 2014

It has good features for social networking with friends SNS is maintained. However, various enterprises, individuals invading the inconvenience spammers have exposure to a number of users to tweet spam. The study was conducted in the existing research on these spam tweets. However, the results showed a more accurate classification and detection is difficult because of the lack of precision and different causes. In this paper, we describe how to classify the characteristics of spammers, classification criteria. Also has a link rate and difference between followers and following, these features were present classification criteria for spammers account. This experiment was performed according to the criteria. Randomized trial of spam and non-spam accounts were selected and account type was conducted according to the criteria 68% of the link ratio of spam accounts. Followers / Following ratio was 27581.5. Non-spam accounts was 6.12%. Followers / Following ratio was 1.26.

• Journal of Climate Change Research
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• v.1 no.1
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• pp.21-30
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• 2010

In this study, vulnerability of water resources to climate change was assessed in terms of flood, drought and water management. Criteria and indicators were employed for assessing the vulnerability. The criteria used to assess the vulnerability was sensitivity of the study area, the exposure to climate and the adaptability to climate change. These criteria were quantified and standardized using corresponding indicators. Vulnerability of water resources to climate change is assessed to be generally increasing over time. The appropriate watershed scales are the large drainage basin for national level vulnerability assessment and the small drainage basin for local one.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.75-83
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• 2000

Recently, many landfills are constructed by using geosynthetics with earth materials. Geotextiles in geosynthetics are applied for the various purposes such as filters of the leachate collection and removal system and protectors of geomembrane liner. However geotextiles can be exposed to direct sunlight during the construction of landfill for several months. As you know the exposure of polymers to sunlight can be a major source of degradation of them. This study is to suggest a criteria on the installation of heavy weight geotextiles at the landfill. For this purpose, several different geotextiles were evaluated by outdoor exposure at two different locations and under the different seasons for one and half years. As the results of outdoor exposure, polypropylene geotextiles with 500g/$m^2$ and 700g/$\textrm{m}^2$were maintained around 40% of the initial strength during for one and half years. However, the polypropylene geotextile of 1000g/$\textrm{m}^2$showed 65% of the retained strength for the same duration of exposure. The retained strength of all polypropylene geotextile reduced dramatically with the cumulative sunshine radiation on a horizontal surface of around 1500MJ/$\textrm{m}^2$.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.11.1-11.19
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• 2015

Objectives The objective of this study was to conduct a systematic review to provide summarized evidence on the association between maternal exposure to particulate air pollution and birth weight (BW) and preterm birth (PTB) after taking into consideration the potential confounding effect of maternal smoking. Methods We systematically searched all published cohort and case-control studies examining BW and PTB association with particulate matter (PM, less than or equal to $2.5{\mu}m$ and $10.0{\mu}m$ in diameter, $PM_{2.5}$ and $PM_{10}$, respectively) from PubMed and Web of Science, from January 1980 to April 2015. We extracted coefficients for continuous BW and odds ratio (OR) for PTB from each individual study, and meta-analysis was used to combine the coefficient and OR of individual studies. The methodological quality of individual study was assessed using a standard protocol proposed by Downs and Black. Forty-four studies met the inclusion criteria. Results In random effects meta-analyses, BW as a continuous outcome was negatively associated with $10{\mu}g/m^3$ increase in $PM_{10}$ (-10.31 g; 95% confidence interval [CI], -13.57 to -3.13 g; I-squared=0%, p=0.947) and $PM_{2.5}$ (-22.17 g; 95% CI, -37.93 to -6.41 g; Isquared=92.3%, p<0.001) exposure during entire pregnancy, adjusted for maternal smoking. A significantly increased risk of PTB per $10{\mu}g/m^3$ increase in $PM_{10}$ (OR, 1.23; 95% CI, 1.04 to 1.41; I-squared=0%, p=0.977) and $PM_{2.5}$ (OR, 1.14; 95% CI, 1.06 to 1.22; I-squared=92.5%, p<0.001) exposure during entire pregnancy was observed. Effect size of change in BW per $10{\mu}g/m^3$ increase in PM tended to report stronger associations after adjustment for maternal smoking. Conclusions While this systematic review supports an adverse impact of maternal exposure to particulate air pollution on birth outcomes, variation in effects by exposure period and sources of heterogeneity between studies should be further explored.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.4
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• pp.296-303
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• 2003

A personal portable type electronic dosimeter using silicon PIN photodiode and small GM tube is recently attracting much attention due to its advantages such as an immediate indication function of dose and dose rate, alerting function, and efficient management of radiation exposure history and dose data. We designed and manufactured a semiconductor radiation detector aimed to directly measure X-ray and v-ray irradiated in silicon PIN photodiode, without using high-priced scintillation materials. Using this semiconductor radiation detector, we developed an active electronic dosimeter, which measures the exposure dose using pulse counting method. In this case, it has a shortcoming of over-evaluating the dose that shows the difference between the dose measured with electronic dosimeter and the dose exposed to the human body in a low energy area. We proposed an energy compensation filter and developed a dose conversion algorithm to make both doses indicated on the detector and exposed to the human body proportional to each other, thus enabling a high-precision dose measurement. In order to prove its reliability in conducting personal dose measurement, crucial for protecting against radiation, the implemented electronic dosimeter was evaluated to successfully meet the IEC's criteria, as the KAERI (Korea Atomic Energy Research Institute) conducted test on dose indication accuracy, and linearity, energy and angular dependences.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.2
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• pp.131-138
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• 2010

This technical report was developed to suggest the guideline to assess the safe use and handling metalworking fluids (MWFs) in machining operation. The basis of this method developed in this study was based on self assessment procedure recommended by Organization Resources Counselors (ORC) of the United States (US). In addition, various MWF management elements obtained from the review on various articles, reports and author's experience regarding MWF were newly added to the evaluation guideline. A total of four areas were finally selected in order to control exposure to MWF used in machining operations. They are all related to the presence and efficiency of the control measures, exposure assessment, management on tank and sump, and safe treatment of chips and metal fines generated during machining operations. Each area is consisted of several related elements. Several evaluation areas and elements used in this study could be revised, replaced, added and deleted according to the process environment, evaluation objectives and evaluator's (manager) criteria etc. This evaluation guide manual could be used for safe management of MWF in metalworking operation. In addition, industrial hygienists can use this evaluation method for auditing and evaluating the management status on MWF.