• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.215-229
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• 2023

Objectives: To validate the effectiveness of a real-time chemical exposure monitoring system developed by KOSHA (Korea Occupational Safety and Health Agency), we applied the system to a workplace in the electronics industry for 153 days. Methods: The monitoring system consisted of a PID chemical sensor, a LTE communication equipment, and a web-based platform. To monitor chemical exposure, four sets of sensors were placed in two manufacturing tasks - inspection and jig cleaning - which used TCE as a degreasing agent. We reviewed previous reports of work environment measurements and conducted a new work environment measurement on one day during the period. The PID sensor systems detected the chemical exposure levels in the workplace every second and transmitted it to the platform. Daily average and maximum chemical exposure levels were also recorded. Results: We compared the results from the real-time monitoring system and the work environment measurement by traditional methods. Generally, the data from the real-time monitoring system showed a higher level because the sensors were closer to the chemical source. We found that 28% of jig cleaning task data exceeded the STEL. Peak exposure levels of sensor data were useful for understanding the characteristics of the task's chemical use. Limitations and implications were reviewed for the adoption of the system for preventing poisoning caused by chemical substances. Conclusions: We found that the real-time chemical exposure monitoring system was an efficient tool for preventing occupational diseases caused by chemical exposure, such as acute poisoning. Further research is needed to improve the reliability and applicability of the system. We also believe that forming a social consensus around the system is essential.

• Journal of Environmental Health Sciences
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• v.46 no.3
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• pp.285-296
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• 2020

Objective: The objective of this study was to describe the characteristics of exposure to humidifier disinfectants (HDs) and their association with the presence of a person who experienced the adverse health effects in general households in Korea. Methods: During the month of December 2016, a nationwide online survey was conducted on adults over 20 years of age who had experience of using HDs. It provided information on exposure characteristics and the experience of health effects. The final survey respondents consisted of 1,555 people who provided information on themselves and their household members during the use of HD. Exposure characteristics at the household level included average days of HD use per week, average hours of HD use per day, the duration within which one bottle of HD was emptied, average input frequency of HD, amount of HD (cc) per one time used, and active ingredients of HD products (PHMG, CMIT/MIT, PGH, or others). The risk of the presence of a person who experienced adverse health effects in the household was evaluated by estimating odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for monthly income and region using a multiple logistic regression model. Subgroup analyses were conducted for households with a child (≤7 years) and households with a newborn infant during HD use. Results: The level of exposure to HD tended to be higher for households with a child or newborn infant for several variables including average days of HD use per week (P<0.0001) and average hours of HD use per day (P<0.0001). The proportion of households in which there was at least one person who experienced adverse health effects such as rhinitis, asthma, pneumonia, atopy/skin disease, etc. was 20.6% for all households, 25.3% for households with children, and 29.9% for households with newborn infants. The presence of a person who experienced adverse health effects in the household was significantly associated with average hours of HD use per day (P_trend<0.001), duration within which one bottle of HD was emptied (P_trend<0.001), average input frequency of HD (P_trend<0.001), amount of HD per one use (P_trend=0.01), and use of HDs containing PHMG (OR=2.23, 95% CI=1.45-3.43). Similar results were observed in subgroup analyses. Conclusion: Our results suggest that level of exposure to HD tended to be higher for households with a child or newborn infant and that exposure to HD is significantly associated with the presence of a person who experienced adverse health effects in the household.

• Safety and Health at Work
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• v.11 no.3
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• pp.335-346
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• 2020

Background: Nursing service is a nonroutine work with an excessive physical load and diverse tasks. This study derived representative common tasks based on the frequently occurring tasks with a high physical load in the nursing workers' daily work and developed indicators to evaluate the work risk by reflecting the characteristics of nonroutine work. Methods: Common tasks were classified through the following stages: literature review, first focus group interview (FGI) with experts, first classification of common tasks, second FGI with hospital health managers, a survey of nursing service workers, and the final classification of common tasks for each task type. To develop an objective risk index for physical load assessment, we investigated the frequency and duration of the derived common tasks via survey. Results: Nursing common tasks were categorized into six task types and 56 subtasks. To evaluate the risks of various tasks in nonroutine works, three frequencies and three working time levels were defined by examining the task frequency and working hours. Exposure time was defined to reflect the characteristics of a nonroutine job. The final risk assessment was the product of the exposure time level and job intensity level. From this, four risk action levels were derived. Conclusion: This study has the advantage of solving the problem of focusing on some tasks in evaluating the physical load. It was meaningful in that a new risk assessment index based on exposure time was proposed based on the development of an evaluation scale for frequency and time by reflecting the characteristics of nonroutine work.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.10
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• pp.1100-1106
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• 2004

In this paper, we intend to make fringe-field switching (FFS) mode cell by the ion beam (IB) alignment method on the a-C：H thin film, to analyze electro-optical characteristics in this cell. We studied on the suitable inorganic thin film for fringe-field switching (FFS) cell and the aligning capabilities of nematic liquid crystal (NLC) using the alignment material of a-C：H thin film as working gas at 30 W rf bias condition. A high pretilt angle of about 5 $^{\circ}C$ by ion beam (IB) exposure on the a-C：H thin film surface was measured. Consequently, the high pretilt angle and the good thermal stability of LC alignment by the IB alignment method on the a-C：H thin film surface as working gas at 30 W rf bias condition can be achieved. An excellent voltage-transmittance (V -T) and response time curve of the IE-aligned FFS-LCD was observed with oblique IB exposure on the a-C：H thin films. Also, AC V-T hysteresis characteristics of the IB-aligned FFS-LCD with IE exposure on the a-C：H thin films is almost the same as that of the rubbing-aligned FFS cell on a polyimide (PI) surface.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.8
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• pp.1076-1087
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• 2004

The purpose of the study is to give new aesthetic values of black dress one of the important items in contemporary women＇s fashion. Through the work, to give the new aesthetic characteristics that women really needed can be found. This study was processed by fashion books and articles, literal material with fashion photos which were related fashion trend from 1920 to the present. The results are as follows: In early 20th century, the black dress, which had simple form pursuing function like little black dress. In the middle of the 20th century, elegance and minimalism was represented by black dress, expressed erotic images together with see-through fabrics. In the end of the 20th century, body conscious style of black dress expressed sensual images of women. Modem black dress has design characteristics of the form: simple, close, exposure type and of the materials: matte, transparent and dazzling etc. Simple type emphasizes feminine elegance, while close type and exposure type disclose woman body curve to express erotic images. Matte materials made black dress express feminine elegance while transparent materials and dazzling materials made black dress express erotic and sensual beauty. The aesthetic characteristics of black dress were as followings: Sensualism expresses sexual attractiveness of women-close type and exposure type black dress and see-through materials and dazzling materials made black dress. Simplicity of extreme decoration effects are expressed through black dress having temperate and simple form. Femineity expresses traditional femineity to emphasize chaste, modest and elegant women images-the black dress, which is made of simple form, velvet and satin materials. Modernism combines black colour, which is called modem colour, with simplicity and function factors and pursues simple form. Ascetic practice controls mental and physical desire of the individuals, simple form without decoration covering up woman body and box type silhouette of black dress. Therefore, the study on image of the black dress, which have made appearance at modern fashion, is thought to help develop fashion trends and design, through which modern women express themselves and their beauty.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.1
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• pp.29-34
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• 2016

In this study, development of multichannel filter module and characteristic evaluation for bio imaging were studied. The filter module was fabricated in order to realize near infrared fluorescence imaging of 700 nm and 800 nm wavelength ranges, and contrast imaging analysis for characteristic evaluation of the filter module was studied through signal to back ground ratio (SBR), controlled by parameters such as magnification, exposure, gain. Furthermore, phantoms, which are biomimetic tissue with equal optical properties of kidney and liver, were fabricated to study characteristics of both filter module depending on thickness and exposure amount of light source for bio imaging analysis. The fabricated filter module has more than 4 of SBR difference despite changes of magnification, exposure, gain, and in the case of the kidney phantom and the liver phantom, contrast imaging of more than 4 of SBR was confirmed on 50 mA, 60 mA exposure amount of light source respectively.

• Analytical Science and Technology
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• v.25 no.6
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• pp.416-420
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• 2012

The increasing use of recycling products results in the need for assessing the risk to human health. In this study heavy metals's contents of playground flooring were compared with rubber powder which is row material. And it is reviewed characteristics of heavy metals's exposure from absorption of skin, checking amount of dermal uptake for each heavy metal. Despite its high content, Zn had a very low migration rate with 0.1 $mg/cm^2$. This indicates that Zn is not easily released by surface contact. However, the contents of Fe and Al in flooring were 12 times higher than that of Zn and Fe, and Al showed migration rate 5 times higher than that of Zn. This implies that Fe and Al were derived from pigment in flooring. The measurement of dermal exposure to heavy metals at 6 playgrounds found higher level of exposure in Ba than in other heavy metals. It is assumed that despite high content of Zn, Ba had a higher exposure rate because five times as much Ba as Zn was darmal absorptionactor ($AF_{darmal}$).

• Journal of The Korean Society of Clinical Toxicology
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• v.5 no.1
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• pp.1-7
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• 2007

Purpose: The aim of this study was to evaluate the characteristics and the prognostic factors of carbamate poisoned patients who visited emergency departments. Methods: From August 2005 to July 2006, we investigated the demographic feature, dose of exposure, time of exposure, alcohol intake, route of exposure, reason of exposure, site of exposure, pre-existing medical condition, time from exposure to emergency department (ED), transfer from other hospitals, vital sign at ED arrival, symptom or sign at ED arrival, and result of care of the patients who visited the ED of thirty-eight hospitals in Korea. According to the result of care, we divided the patients into two groups, the survival and the dead. To evaluated the prognostic factors, we calculated the odds ratio of each factor for the survival. Results: Among the sixty-eight patients, fifty-five patients (80.9%) were survival and thirteen patients (19.1%) were dead. The patients in the dead were older than the patients in the survival. The Glasgow coma scale (GCS) of the patients in the dead was lower than the GCS in the survival. The odds ratio of the GCS at ED arrival for the survival was 1.58 (95% CI; 1.23-2.05). Other factors showed no statistical significances. Conclusion: The GCS at emergency department arrival was the prognosis factor of the carbamate poisoned patients who visited emergency departments. If the carbamate poisoned patients showed altered mentalities, they should be provided intensive care, immediately.

• Restorative Dentistry and Endodontics
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• v.28 no.3
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• pp.195-202
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• 2003

The purpose of this study was to evaluate the color changes of the composite resin resulting from xenon lamp exposure in different environments. Composite resin (Z 250 ; shade Al, A2, A3, A3.5, and A4) were applied in a cylindrical metal mold. Seventy five specimens according to environments of exposure were made as follows; Group I aluminum foiling of the specimens in the air at $37^{\circ}C$ for 1 day and 7 days. Group II : exposure of xenon lamp to the specimens in the air at $37^{\circ}C$ for 1 day and 7 days. Group III: exposure of xenon lamp to the specimens in distilled water at $37^{\circ}C$ for 1 day and 7 days. The color characteristics ($L^{*},a^{*},b^{*}$) of the specimens before and after exposure of xenon lamp were measured by spectrophotometer and the total color differences (${\Delta}E^{*}$) were computed. The results obtained were as follows : 1. In all groups except A1 shade of group III, the ${\Delta}E^{*}$ values presented below 2.0, and group III showed the highest ${\Delta}E^{*}$ values followed by group II and group I in a decreasing order(p<0.05). 2 In all shades and groups, the more the exposure time of xenon lamp and the lighter the shade were, the higher the tendency for discoloration (p<0.05). 3. The composite resins which was exposed to xenon lamp in the distilled water was more discolored than those in the air (p<0.05). 4. The major changes of composite resins which were exposed to xenon lamp in the air were an increase in yellowness through a positive shift of the $b^{*}$ value, and those in the distilled water were an increase in darkness and yellowness through a negative shift of the $L^{*}$ value and a positive shift of the $b^{*}$ value.

• International Journal of High-Rise Buildings
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• v.10 no.4
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• pp.345-364
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• 2021

Developments in the understanding of fire behaviour for large open-plan spaces typical of tall buildings have been greatly outpaced by the rate at which these buildings are being constructed and their characteristics changed. Numerous high-profile fire-induced failures have highlighted the inadequacy of existing tools and standards for fire engineering when applied to highly-optimised modern tall buildings. With the continued increase in height and complexity of tall buildings, the risk to the occupants from fire-induced structural collapse increases, thus understanding the performance of complex structural systems under fire exposure is imperative. Therefore, an accurate representation of the design fire for open-plan compartments is required for the purposes of design. This will allow for knowledge-driven, quantifiable factors of safety to be used in the design of highly optimised modern tall buildings. In this paper, we review the state-of-the-art experimental research on large open-plan compartment fires from the past three decades. We have assimilated results collected from 37 large-scale compartment fire experiments of the open-plan type conducted from 1993 to 2019, covering a range of compartment and fuel characteristics. Spatial and temporal distributions of the heat fluxes imposed on compartment ceilings are estimated from the data. The complexity of the compartment fire dynamics is highlighted by the large differences in the data collected, which currently complicates the development of engineering tools based on physical models. Despite the large variability, this analysis shows that the orders of magnitude of the thermal exposure are defined by the ratio of flame spread and burnout front velocities (V_S / V_BO), which enables the grouping of open-plan compartment fires into three distinct modes of fire spread. Each mode is found to exhibit a characteristic order of magnitude and temporal distribution of thermal exposure. The results show that the magnitude of the thermal exposure for each mode are not consistent with existing performance-based design models, nevertheless, our analysis offers a new pathway for defining thermal exposure from realistic fire scenarios in large open-plan compartments.