• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.883-886
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• 2002

A new exposure time scheduling scheme to implement the optimized photopolymer-based VHOE is proposed and using this method, the 8-view VHOE system is experimentally developed. The CGS dependence on the exposure energy is mathematically modeled using the fourth-order polynomial function and using this model optimized exposure-time schedule for recording the given multiple gratings in the photopolymer is calculated. In addition, basing on this suggested exposure-time schedule, 8-view VHOE is finally implemented and its performance is discussed.

• Korean Journal of Child Studies
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• v.26 no.4
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• pp.101-112
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• 2005

Subjects were 279 parents of 4- and 5-year-old day care children. Statistical techniques were factor analysis, t-test, ANOVA, Pearson's correlation, and multiple regression. Major findings were that parents with higher levels of education and income showed a higher level of attitudes and coping behavior toward preschoolers' exposure to secondhand smoke. Parents who were smokers had a higher level than non-smokers of knowledge and coping with preschoolers' secondhand smoke. Parents with higher levels of knowledge and more negative attitudes about secondhand smoke were more active in dealing with secondhand smoke. Parents' knowledge and attitudes were significant predictors of their coping behavior with preschoolers' secondhand smoke. Parents' knowledge was more predictive of parents' coping behavior than their attitudes.

• Transactions of the Society of Information Storage Systems
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• v.6 no.2
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• pp.63-67
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• 2010

Holographic data storage system is one of next generation high density optical memories. Thereby storing multiple data pages using multiplexing method in one spot, we can achieve high store density and fast access time. However, for uniform writing, we must control exposure time properly by the change of writing material characteristics. Many studies have been investigated about exposure time scheduling. However, once it is decided, we cannot change the scheduled time. Therefore, it is hard to obtain uniform data intensity. In this study, we propose exposure time control method using additional red beam as the monitoring signal. Through reconstructed red beam intensity in real time, we can adjust exposure time by the writing condition change. We construct compensation method mathematically and verify the feasibility of proposed method through the experiments.

• Safety and Health at Work
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• v.12 no.2
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• pp.230-237
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• 2021

Background: Noise-induced hearing loss is a well-known occupational disease that affects many fish harvesters from many fisheries worldwide, whose risk factor is prolonged exposure to hazardous noise levels. To date, academic research activities and regulatory bodies have not provided any comparative analysis among the existing methods to assess noise exposure levels of fish harvesters. This paper provides a comparison of four relevant assessment methods of noise exposure, examining the results of a measurement campaign performed onboard small fishing vessels from Newfoundland and Labrador. Methods: We traveled onboard 11 vessels engaged in multiple fisheries from Newfoundland and Labrador and performed extensive noise exposure surveys using the simplified International Maritime Organization method, the full-day measurement method, and the two methods provided by ISO 9612:2009, the task-based method and job-based method (JBM). Results: The results showed that the four methods yield similar values when the noise components are dominated by the engine and auxiliaries (steady-state sources); when noise components are dominated by the fishing gear, task-based method and the simplified International Maritime Organization method estimates are less accurate than JBM, using full-day measurements as baseline. Conclusion: The JBM better assesses noise exposure in small-scale fisheries, where noise exposure has significant variance and uncertainties on the exposure levels are higher.

• Journal of Information Science Theory and Practice
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• v.10 no.2
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• pp.86-101
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• 2022

This research aimed at studying the factors that influence new media exposure of political news by youths in Isan society in Thailand. The target group comprised 1,200 individuals, obtained from multi-stage sampling from undergraduate students in Isan's autonomous universities, governmental universities, and private institutions. The data collection tool was a questionnaire, the content of which was validated by experts. The reliability of the tool was tested by the formula for Cronbach's alpha coefficient, which yielded a reliability of 0.83. Multiple regression analysis was applied to analyze the data. The results, regarding factors influencing the channels for political news exposure, showed that channels for political news exposure were mostly influenced by inner drives, followed by importance in political news exposure, influence from social networks, and specific characteristics of the Internet. This could explain the variation of channels for political news exposure at 46.5%. In terms of factors influencing political news selection, it was found that political news selection was influenced mostly from social networks, followed by inner drives, benefits from political news exposure, specific characteristics of the Internet, and the field of study. The variation of the political news selection could be explained at 44.6%. These results elaborate on the current situation in Thailand, especially in Isan region, where youths in higher education are playing an increasing role in demonstrating their political stance through various political activities.

• Toxicological Research
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• v.32 no.1
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• pp.57-64
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• 2016

Recently several studies reported that the renal toxicity of lead (Pb) and cadmium (Cd) may exist in even a low level exposure. In terms of the deterioration of tubular function, it affects the loss of divalent metals and leads to other complications, so renal tubular effect of heavy metals should be well managed. Considering the exposure to heavy metals in reality, it is hard to find the case that human is exposed to only one heavy metal. We designed a cross-sectional study using Korean Research Project on the Integrated Exposure Assessment (KRIEFS) data to investigate the renal effects of multiple metal exposure in general population. We used blood Pb and urinary Cd as exposure measures, and urinary N-acetyl-${\beta}$-D-glucosaminidase (NAG) and ${\beta}_2$-microglobulin (${\beta}_2$-MG) as renal tubular impairment outcome. We conducted linear regression to identify the association between each heavy metal and urinary NAG and ${\beta}_2$-MG. And then, we conducted linear regression including the interaction term. Of 1953 adults in KRIEFS (2010~2011), the geometric mean of blood Pb and urinary Cd concentration was $2.21{\mu}g/dL$ (geometric $SD=1.49{\mu}g/dL$) and $1.08{\mu}g/g\;cr$ (geometric $SD=1.98{\mu}g/g\;cr$), respectively. In urinary Cd, the strength of the association was also high after adjusting (urinary NAG: ${\beta}=0.44$, p < 0.001; urinary ${\beta}_2$-MG: ${\beta}=0.13$, p = 0.002). Finally, we identified the positive interactions for the two renal biomarkers. The interaction effect of the two heavy metals of ${\beta}_2$-MG was greater than that of NAG. It is very important in public health perspective if the low level exposure to multiple heavy metals has an interaction effect on kidney. More epidemiological studies for the interaction and toxicological studies on the mechanism are needed.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.3
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• pp.251-258
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• 2001

Indoor and outdoor nitrogen dioxide(NO$_2$) concentrations of 122 houses were measured and compared with measurements of personal NO$_2$ exposure simultaneously . Time activity patterns were used to determine the impacts on NO$_2$ exposure assessment and time weighed average model to estimate the personal NO$_2$ exposure. Most people spent their times more than 80% of indoor and more than 50% in home, respectively. Personal NO$_2$ esposure was found to be significantly associated with both indoor NO$_2$ concentration(r=0.70) and outdoor NO$_2$ concentration (r=0.68). Using time weighted average model, personal NO$_2$ exposure was estimated with NO$_2$ measurements in indoor home, indoor workplace and outdoor home. The estimated NO$_2$ measurements were significantly correlated with measured personal exposures(r=0.69, N=122). For the difference between measured and estimated NO$_2$ exposures by multiple regression analysis showed that NO$_2$ concentrations in near workplace and other outdoors of no NO$_2$ measurements affected the personal NO$_2$ exposures(p=0.023).

• Korean Journal of Occupational Health Nursing
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• v.24 no.2
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• pp.67-75
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• 2015

Purpose: The objective of the present study was to evaluate the effects of occupational exposure to low dose organic solvents on the prevalence of cardiovascular risk factors. Methods: Study design was retrospective cohort study subjected on 191 exposures and 118 controls working in a petrochemical manufacture company. The eight indicators related to CVD risk were followed up for five years from 2008 to 2012. The risk level was compared during the follow up years and subject's characteristics, and the change of risk level were analyzed with repeated measures ANOVA and multiple logistic regression analysis. Results: At the start year 2008, the rate over cutoff value (ROCV) of BS (p<.001) and mean systolic BP (p=.017) were higher in organic solvent exposure group and the others showed no difference. And by the subject's characteristics, odds ratio of the ROCV of BS were higher in organic solvent exposure group and work shift group as 2.51 and 3.07. Comparing the results in 2012 to those of 2008, cardiovascular disease risk in organic solvent exposure group was about 1.5 times higher than that of in the control group. Conclusion: Gradual increase in the CVD risk was identified in organic solvent exposure group. However, the risk might be influenced by shift work and bad behaviors rather than organic solvent exposure.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.58-64
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• 2000

Indoor air quality tends to be the dominant contributor to personal exposure, because most people spend over 80% of their time indoors. In this study, indoor and outdoor NO$_2$ concentrations were measured and compared with simultaneously personal exposures of 21 university students in weekday and weekend. House characteristics and activity pattern were used to determine the impacts of these factors on personal exposure. Since university students spent most of their times in indoor, their NO$_2$ exposure was associated with indoor NO$_2$ level rather than outdoor NO$_2$ level both weekday and weekend in spite of different time activity. Using time-weighted average model, NO$_2$ exposures of university students were estimated by NO$_2$ measurements in indoor home, indoor school, and outdoor home levels. Estimated NO$_2$ personal exposures were significantly correlated with measured NO$_2$ personal exposures($r^2$=0.87). However, estimated personal NO$_2$ exposures by time-weighted average model were underestimated, comparing with the measured personal NO$_2$ exposure. Using multiple regression analysis, effect of personal NO$_2$ exposure for transportation was confirmed.

• Journal of East-West Nursing Research
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• v.28 no.1
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• pp.41-48
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• 2022

Purpose: The purpose of this study was to identify factors influencing prevention behaviors for particulate matter exposure in young adults. Methods: A convenience sample of 330 young adults was recruited from the community. Data were collected using a structured questionnaire and analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, and stepwise multiple regression analysis with the SPSS/WIN 26.0 program. Results: The factors affecting prevention behaviors of particulate matter exposure were self-efficacy (β=.54 p<.001), subjective norm (β=.18, p<.001) and using the air purifier (β=.-17, p<.001). These variables had a 46% variance to explain prevention behaviors for particulate matter exposure. Conclusion: Findings showed that 'self-efficacy' and 'subjective norm' were important factors influencing prevention behaviors of particulate matter exposure in young adults. Thus, we need to consider the positive impact of prevention behaviors of particulate matter exposure and increase the chances of prevention behaviors of particulate matter exposure program for young adults.