• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.1
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• pp.1-8
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• 2012

Objectives: The aim of this study is to review occupational hygiene activities, including work environment measurement as required by the industrial safety and health laws of Korea, and suggest improvements required to establish an effective exposure surveillance system. Methods: The controversial limitations of exposure surveillance examining the work-association of several types of cancers in semiconductor workers were reviewed. Results: The bulk of the exposure surveillance system was found to focus purely on work environment measurements without providing other important exposure surrogates, such as job title, operation, exposure duration, etc. The current work environment measurement system is limited in terms of the efficient assessment of the exposure status of workers due to a lack of exposure information. Conclusion: The introduction of a national standard classification of occupations and job titles into the exposure and health effect surveillance system should be discussed in order to retrospectively assess exposure characteristics.

• Journal of Environmental Health Sciences
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• v.45 no.4
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• pp.358-369
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• 2019

Objective: This study aimed to introduce cases of exposure to humidifier disinfectant (HD) in hospitals and to present their exposure characteristics. Methods: We used data from 4,393 subjects who participated in the fourth assessment survey of environmental exposure to HD conducted by the Korea Environmental Industry & Technology Institute. In this study, we selected 301 subjects who reported their place of use of HD as a hospital. Then, we classified cases as 'Hospital-provided'. 'Probably hospital-provided', 'Individual purchased', and 'Unknown' according to the supply sources of HD. Also, we introduced detailed exposure characteristics for the selected cases. Results: Of the 4,393 subjects, 301 (6.9%) reported the use of HD in 392 hospitals (including duplicate answers for the use in ${\geq}2$ hospitals). The 301 hospital-user subjects included 139 survivors and 162 non-survivors. When we classified the 392 cases by supply sources, 'Hospital-provided' was 12.2% (48 cases), 'Probably hospital-provided' was 25.5% (100 cases), 'Individual purchased' was 59.7% (234 cases), and 'Unknown' was 2.6% (10 cases). Among the 'Hospital-provided' cases, we selected six cases and provided a detailed description of the HD use in this study. Additionally, we reported details for six cases that had purchased HD upon a doctor or nurse's recommendation and for three cases that had purchased it at hospital stores. Conclusion: This study presents various cases of HD exposure in hospitals. Because there may be a considerable burden of HD exposure in public spaces, including hospitals, further studies are necessary to assess HD exposure in hospitals and public places.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.1
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• pp.19-33
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• 2023

Objectives: The purpose of this study is to systematically identify situations where exposure levels are expected to be high by structuring domestic lead measurement data according to exposure processes and activities. Methods: Occupational exposure data on lead was collected from the results of the Evaluation of Reliability of Working Environment Measurement conducted by the government from 2019 to 2020. Lead exposure characteristics were analyzed by PROC (process category) and activity. The Risk Characterization Ratios (RCRs) of five PROCs according to ventilation type and lead content were evaluated using the MEASE (Metal's EASE) model. Results: The exposure data on lead (n=250) was classified into 12 PROCs and 12 activities, with an average concentration of 0.040 mg/m³ and about 14% exceeding the occupational exposure limit of 0.05 mg/m³. Processes with high exposure levels were PROC 7 (industrial spraying), 23 (open processing and transfer operations of molten metal), 24 (mechanical treatment), 25 (welding), and 26 (handling of powder containing lead). The results of evaluating RCR for the five PROCs were greater than 1 or close to 1 even if local exhaust ventilation was used. Conclusions: There is a possibility that the concentration of exposure is high in the casting and tapping of molten metal containing lead, mechanical treatment such as fracturing and abrasion, handling of powder, spraying, battery manufacturing, and waste battery recycling processes. It is necessary to implement chemical management policies for workplaces with such processes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.835-838
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• 2000

A new photo-alignment material, copoly (PM4Ch-ChMA), copoly (poly (4-methacryloyloxy) chalcone-cholesterol methacrylate) was synthesized and the electro-optical (EO) characteristics for the photo-aligned vertical-aligned (VA)-LC display (LCD) were studied. Good voltage-transmittance (V-T) and response time characteristics for the photo-aligned VA-LCD with polarized UV exposure on the copolymer-1 (2%) surfaces for 1 min. were observed. EO performance for the photo-aligned VA-LCD decreased with increasing UV exposure time on a copolymer surface. Also, excellent V-T and response time characteristics for the photo-aligned VA-LCD with UV exposure on copolymer-2 and copolymer-3 surfaces for 3min. can be achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.181-184
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• 2000

A new photo-alignment material, copoly (PM4Ch-ChMA), copoly (poly (4-methacryloyloxy) chalcone-chalconemethacryl) was synthesized and the electro-optical (EO) characteristics for the photo-aligned vertically aligned (VA)-LC display (LCD) were investigated. The monodomain alignment of the NLC for the photo-aligned VA-LCD by linearly polarized UV exposure on the photo-dimerized copoly (PM4Ch-ChMA) surfaces was observed. Excellent voltage-transmittance characteristics for the photo-aligned VA-LCD by UV exposure for 1 min. on the copoly (PM4Ch-ChMA) surfaces were achieved. The response time of the photo-aligned VA-LCD by UV exposure on for 1 min. the copoly (PM4Ch-ChMA) surfaces was about 39.3 ms. The response time for the photo-aligned VA-LCD decreased with increasing UV exposure time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2160-2174
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• 2011

In this paper, a new technique for color reproduction based on color variation characteristics of digital camera under a dim light condition is proposed. Generally, photographers should adjust a camera exposure properly for obtaining an image with real color tone of subjects. Thus, in case of taking a picture under a dim light condition, the exposure time of a camera has to be relatively longer than the one under a bright light condition. Although images with real color tone of the subject are obtained, the images may get blurred due to the shaky hands of photographer holding the camera. In order to avoid the blur effect, an input image is captured from a camera set as a short exposure time under a dim light condition. Then we propose a method to reproduce color tone of the dim input image. To this end, color variation characteristics which represent color variations of a digital camera are first extracted by analyzing the Macbeth color checker images taken under various exposure values. Then, a color reproduction is performed by an estimation based on the color variation characteristics. Experimental results have shown that the proposed method has achieved better performance of color reproduction, compared with existing methods.

• Nuclear Engineering and Technology
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• v.38 no.5
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• pp.449-454
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• 2006

Neutron imaging technique was used to investigate the water distribution and movement in Polymer Electrolyte Membrane Fuel Cell (PEMFC) at HANARO, KAERI. The Feasibility tests were performed in the first and second exposure rooms at the neutron radiography facility (NRF) at HANARO in order to check the ability of each exposure room, respectively. The feasibility test apparatus was composed of water and pressurized air before making up the actual test apparatus. Due to the low neutron intensity in the second exposure room, the exposure time was too long to investigate the transient phenomena of PEMFC. Although the exposure time was improved to 0.1 sec in the first exposure room, it was difficult to discriminate detail water movement at the channel due to the high noise level. Therefore, the experimental setup must be optimized according to the test conditions. Water discharge characteristics were investigated under different flow field geometries by using feasibility test apparatus and the neutron imaging technique. The water discharge characteristics of a 3-parallel serpentine are superior to those of a 1-parallel serpentine, but water at Membrane Electrode Assembly (MEA) was not removed, regardless of the flow field type.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.61 no.12
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• pp.669-673
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• 2018

Background and Objectives Tinnitus, a common complaint of workers who are exposed to noise, can cause substantial negative effects on the quality of life of these workers. The aim of this study was to analyze the characteristics of tinnitus in patients with noise-induced hearing loss and the relationship between tinnitus and the duration of noise exposure. Subjects and Method Thirty-three patients with subjective tinnitus and noise-induced hearing loss were included in this study. Tinnitus questionnaire, Tinnitus Handicap Inventory (THI) and audiological examinations were investigated according to the duration of noise exposure. Results There was a significant correlation between the tinnitus loudness and the duration of noise exposure. Patients who had longer periods of noise exposure had a louder tinnitus and higher THI score. However, there is no significant correlation between the characteristics of tinnitus and aging process. Conclusion The duration of noise exposure influences the loudness and distress of tinnitus. An awareness of tinnitus should be considered as part of hearing conservation program.

• Journal of the Korea Society of Computer and Information
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• v.22 no.3
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• pp.123-129
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• 2017

This study intends examine the relevance of factors with negative influences on anti-social sexual awareness formation in adolescents as per the concern of the parents of families with adolescents, as internet pornography exposure in adolescents lead to excessive indulgence in pornographic photographs, cartoons, videos, or fictions, or in video chatting with exposure of one's own body parts. For this, the factors of internet pornography exposure in the study subjects of adolescents were constructed into a multilateral model, and the structural equation model was analyzed. As the result of the study, the following conclusion were drawn. First, the most powerful factor influencing the anti-social sexual awareness in adolescents was, contrary to the concern of many, not the exposure to pornography through internet media, but personal characteristics such as sensation-seeking tendency and socio-environmental characteristic of differential association. Second, it is worth noting that the most major factor influencing intentional internet pornography exposure by adolescents is another form of pornography exposure. Third, whether intentional or unintentional, the internet-related variable influencing the internet pornography exposure was found to be the amount of internet usage. Fourth, the unintended internet pornography exposure was found to have no direct influence on the sexual awareness of adolescents, but it did have an indirect influence on sexual awareness mediated by intentional internet pornography exposure and existing-media pornography exposure. Based on these study results, the conclusion was drawn regarding the influence of internet pornography on sexual awareness in adolescents.

• Journal of Environmental Health Sciences
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• v.41 no.1
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• pp.1-10
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• 2015

Objectives: The purpose of this study was to propose an indirect exposure assessment method using a questionnaire survey at a time when direct exposure assessment would be impossible after a chemical accident. Methods: About two weeks after an accident, a questionnaire survey was performed with 1,264 persons from the local community. Variables related to exposure were extracted from the survey contents, weighted and then graded for comparison with subjective symptoms in order to evaluate the extent of exposure. Survey items suitable for reflecting the previous exposure level during the accident were extracted, weighted and divided into quartile ranges. Subjective symptoms showed an increasing tendency with higher exposure level when compared with final exposure level (p<0.01). Results: For the relationship between the final exposure grade and subjective symptoms, as the exposure grade was increasing the rates complaining of symptom also showed an increasing tendency. However, when adjusted for demographic characteristics, there was a tendency for the eye irritation symptom to appear higher in women, and respiratory organ irritation appeared higher in smokers. Conclusions: When the problem of recall bias is considered, this study may not have completely unraveled exposure and the characteristics of the participants can affect subjective symptoms. Nevertheless, the exposure rating method of using a questionnaire showed a significant relationship with symptom level. It can be deemed that assessment of past exposure may be successfully evaluated by questionnaire in cases such as chemical accidents.