• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.98-104
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• 2018

Macroscopic accident analyses have been conducted to incorporate transportation safety into long-term transportation planning. In macro-level accident prediction model, exposure variable(e.g. a settled population) have been used as fundamental explanatory variable under the concept that each trip will be subjected to a probable risk of accident. However, a settled population may be embedded error by exclusion of active population concept. The objective of this research study is to develop macro-level accident prediction model using floating population variable(concept of including a settled population and active population) collected from mobile phone data. The concept of accident prediction models is introduced utilizing exposure variable as explanatory variable in a generalized linear regression with assumption of a negative binomial error structure. The goodness of fit of model using floating population variable is compared with that of the each models using population and the number of household variables. Also, log transformation models are additionally developed to improve the goodness of fit. The results show that the log transformation model using floating population variable is useful for capturing the relationships between accident and exposure variable and generally perform better than the models using other existing exposure variables. The developed model using floating population variable can be used to guide transportation safety policy decision makers to allocate resources more efficiently for the regions(or zones) with higher risk and improve urban transportation safety in transportation planning step.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.1
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• pp.57-68
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• 2019

Objective: The purpose of this study is to propose the benefits of reduction measures according to the occupational radon reference level in order to present basic data for radon management guidelines considering domestic circumstances. Methods: This study uses radon data measured in the subway stations from 2015 to 2016. Of the total of 4,643 cases, 4,231 cases were analyzed excluding the 412 cases where the values were below $300Bq/m^3$. Results: Cost-Benefit analysis was done on the results of the field survey on subway work sites. At the exposure level of $400Bq/m^3$, the ratio between the cost and the benefit was highest at 1 : 1.81(the cost was KRW 1,398,568,032, while the benefit KRW 2,5248,772,841). At the exposure level of $600Bq/m^3$, the ratio of cost and benefit was 1: 1.80, at $300Bq/m^3$ it was 1.72, at $800Bq/m^3$ it was 1.71, at $200Bq/m^3$ it was 1.54, and at $100Bq/m^3$ it was 1.40. Conclusions: Radon management in the workplace provides economic benefits and appropriate reduction strategies are needed. In addition, it is necessary to establish and distribute radon exposure assessment procedures and guidelines for the safety and health of employees when exceeding the exposure standard, and guidelines for radon management in the workplace should be established.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.219-228
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• 2014

Objectives: The major objective of this study was to develop a tier 2 exposure model combining tier 1 exposure model estimates and worker monitoring data and suggesting narrower exposure ranges than tier 1 results. Methods: Bayesian statistics were used to develop a tier 2 exposure model as was done for the European Union (EU) tier 2 exposure models, for example Advanced REACH Tools (ART) and Stoffenmanager. Bayesian statistics required a prior and data to calculate the posterior results. In this model, tier 1 estimated serving as a prior and worker exposure monitoring data at the worksite of interest were entered as data. The calculation of Bayesian statistics requires integration over a range, which were performed using a Riemann sum algorithm. From the calculated exposure estimates, 95% range was extracted. These algorithm have been realized on Excel spreadsheet for convenience and easy access. Some fail-proof features such as locking the spreadsheet were added in order to prevent errors or miscalculations derived from careless usage of the file. Results: The tier 2 exposure model was successfully built on a separate Excel spreadsheet in the same file containing tier 1 exposure model. To utilize the model, exposure range needs to be estimated from tier 1 model and worker monitoring data, at least one input are required. Conclusions: The developed tier 2 exposure model can help industrial hygienists obtain a narrow range of worker exposure level to a chemical by reflecting a certain set of job characteristics.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.3
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• pp.139-144
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• 2011

The purpose of this report is recommending a standard indicator which reflects the radiation exposure that is incident on a detector after every exposure event and that reflects the noise levels present in the image data. The experiment was performed with mobile digital X-ray unit and used a acrylic phantom for exposure index measurement. Exposure modality was kVp, mAs, SID. After every exposure, make a data sheet for characteristic curve of detector response. The equipment performed Mobile digital X-ray unit provide the user with values ralated to the incident exposure(air kerma)to the digital detector. They are showed as a logarithmic function shaped. As a result, DEI means a relative measure of exposure to the detector, as compared to the expected exposure for a particular anatomical view. Radiographic technique is the combination of factors used to exposure an anatomical part to produce a high quality radiography and technique charts used most commonly by radiographers to produce consistently exposure level which patient dose can be kept acceptably low.

• Safety and Health at Work
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• v.12 no.4
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• pp.439-444
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• 2021

Background: In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. Methods: Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. Results: A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. Conclusion: Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.41-48
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• 2014

This paper provides the design of system software for the management of radiation dose that is generated by using computerized tomography(CT). Recently, the radiation leakage incident of Japanese nuclear power plant was in the news internationally and there is a growing interest not only in nuclear power plant but in medical radiation exposure. In spite of the fact that currently safety management of radiation is under control only the workers of the radiation involved, now the exposure management of patients have been required. As surgery and inspections using the radiation have increased, this medical radiation exposure is increasing too. But it is a real situation that medical institutions don't know the level of radiation exposure applied to the patient. Therefore, a system for managing the radiation exposure of a patient from the medical institution is required. This paper proposes a design of a software program that manages the radiation exposure of CT which is a typical imaging tool to use the radiation in the medical institution. By check the amount of radiation dose and set the limit of dose, we would be of help to optimize the medical exposure of the patient.

• Journal of the Korean Society of Costume
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• v.61 no.6
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• pp.146-160
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• 2011

The purpose of this study is to examine the aesthetic view towards exposure in the Korean society through the means of analyzing the characteristics of exposure and figuring out the implications expressed in the red carpet fashion of Korean female movie stars. The concept of exposure in fashion was reviewed through previous studies and related publications. The pictures of actresses wearing red carpet evening gowns in Korea's major film festival were collected and analyzed. The results indicated that the meaning of exposure expressed in the red carpet fashion of Korean female movie stars are as follows: First, this leads the trend reflecting the contemporary aesthetic view of exposure as an effective way to show the beauty of the female body. Second, this emphasizes the femininity and expresses eroticism by exposing certain body parts which symbolize the female gender. Third, this shows the narcissistic self conspicuousness as well as the self confidence and self satisfaction. Forth, this displays the playfulness through exposing the body in a unique way. Lastly, the way and level of exposure can be used to maintain or change the public's view upon the celebrity.

• Research in Community and Public Health Nursing
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• v.17 no.3
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• pp.376-386
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• 2006

Purpose: This study was conducted to analyze the exposure of female high school students to Internet pornography and its related factors. Methods: A total of 392 female high school students were selected through convenience sampling. Data were collected using self-reported questionnaires from June 27 to July 8, 2005. Results: 1. As for exposure to Internet pornography, 61.0% of the respondents had been exposed to Internet pornography and 29.7% had their first exposure to Internet pornography when they were in the 3rd grade of middle school. In addition, 87.9% of the respondents spent less than 30 minutes each time to view Internet pornography. In 41.8% of the respondents, the reason for seeing Internet pornography was curiosity about sexuality. 2. Both the level of sexual knowledge (t=3.174, p=.002) and attitude (t=2.567, p=.011) were significantly different between the exposure group and the non-exposure group. 3. Grade, daily mean time to use computer, and sexual knowledge had statistically significant effects on exposure to Internet pornography. Conclusion: It is necessary to make repeated study to find other variables that affect students' exposure to Internet pornography and to develop education programs to enhance students' coping ability against Internet pornography. Also, parents' concern over youth is necessary to prevent them from being exposed to Internet pornography.

• Journal of Aquaculture
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• v.17 no.3
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• pp.161-166
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• 2004

The influence of TBTO (Tributyltin-Oxide) at a series of concentrations (0.52, 1.41 and 3.05 $\mu$g/L) for a period of 3 weeks on estradiol-17$\beta$, testosterone and cortisol levels in male Korean rockfish, Sebastes schlegeli was investigated. Compared to the stable concentration of estradiol-17$\beta$, plasma testosterone level was decreased significantly at the 3rd week after TBTO exposure in plasma of fish (＞1.41 $\mu$g/L). The most profound physiological variation in TBTO exposed fish was a dramatic increase in plasma cortisol level at 3rd week. Conclusively, TBTO exposure caused increase level of cortisol as well as alteration of testosterone in the Korean rockfish. These results suggest that TBTO at environmentally relevant (nanomolar) concentrations disrupt endocrine secretions.

• KIEAE Journal
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• v.9 no.1
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• pp.61-68
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• 2009

In this study, computer simulation program was using to identify the effects of road traffic noise propagation depending on the road types which are very variable in dense city. To achieve this goal, the roads should adjacent to housing complex were categorized into 7 types and propagation noise level should predicted then after simulation of noise exposure population calculation are carried out. Followings the results. First, the road types producing the higher noise level are R1, R2, R3 and R7. The lowest one is R6. And R4, R5 showed that some amount of noise level reduction. Second. the R6 road type which is tunnel shaped showed the highest noise level reduction in vertical distance gap. Last, the order of noise exposure population ratio is R1>R2>R7 and R6 showed the lowest.