• Asian Journal of Atmospheric Environment
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• v.2 no.1
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• pp.60-67
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• 2008

The spatial limitations of urban environments in general lead to invention and design of a wide range of underground transportation systems such as subways, underground roads and paths, etc. Among them, the application of subway systems in metropolitan cities is most commonly observed to ease those confronted difficulties on this purpose. It in turn leaves passengers and workers to be exposed to indoor air potentially polluted by various sources existing in this underground environment. Specifically when considering the IAQ in a subway station, there exist many IAQ-related parameters to be counted either as individual or as integrated exposures. In this study, a model system has been developed to manage the general IAQ in a subway station. Field survey and $CO_2$ measurements were initially conducted to analyze and understand the relationship between the indoor and outdoor air quality while considering the internal pollution sources such as passengers, subway trains, etc. The measurement data were then employed for the model development with other static information. For the model development, the algorithm of simple continuity was built and applied to model the subway IAQ concerned. In this paper, the recent updated draft version of model developed will be reported and demonstrated.

• Journal of Environmental Science International
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• v.28 no.2
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• pp.277-285
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• 2019

Heat watch warning systems are operating in Korea and several other countries (China, the United Kingdom, France, the United States, Germany, Australia, and Japan). The heat wave indices used in this system are the heat index, perceived temperature, the wet bulb globe temperature, and the daily maximum temperature. To improve the heat wave advisory and warning system, some suggestions have been made. The meteorological-health index (i.e., indirect index), has especially been proposed in previous studies. This information should be provided not only to vulnerable groups (seniors, infants, and children), but also to outdoor workers who may be particularly exposed to heat waves. In addition, to have sufficient preemptive response times, the need for an extension of the heat watch warning period was suggested. Finally, the subdivision of administrative units and risk stages was proposed.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.4
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• pp.113-118
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• 2022

Global warming has also increased the number of casualties caused by heat-related diseases caused by heat waves along with an increase in global temperature. The vulnerable groups from heat wave damage are outdoor workers and the elderly in particular, and it is necessary to respond the increasing heat wave damage. We propose a real-time control platform in order to reduce casualties of the vulnerable group from heatwaves, this research collects and analyzes user's vital signs data from wearable devices that generates alarms out of the suspected victims who are expected to be affected by heat-related illness and to respond quickly.

• Korean Journal of Construction Engineering and Management
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• v.11 no.3
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• pp.13-22
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• 2010

From now on, the aged apartment or house is expected to increase rapidly. So, we have to build a process of remodeling and develop the new technique. Demolition work is needed for systematic plan and management. However, contractors of the remodeling project established a rough plan and did not consider recycling wastes, safety of workers and structural stability of building. Therefore, we need a step to develop a assessment system, verify and make specified. This paper evaluated how much improve on construction speed, work efficiency, intensity of work and influence with another process comparing the existing method with the new demolition method. The qualitative and quantitative assessment system are developed with these output. The case study was carried out experimental group and control group, based on developed assessment system, which have the same condition. The existing method was made up of 3 steps- 1)Demolish windows, doors and iron goods, 2)Demolish indoor and outdoor walls, 3)Drop the waste. The new demolition method was made up of 5 steps- 1)Demolish windows, doors and iron goods, 2)Demolish the ceiling and wall's finishing materials, 3)Demolish the floor's finishing materials, 4)Demolish indoor and outdoor walls, 5)Drop the waste. Work time, idle time, the character of a work unit are analyzed by mock-up test. This study's output is expected to establish a systematic process of new demolition method and based on the maximizing waste recycling work in our construction industry.

• Journal of Environmental Health Sciences
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• v.27 no.3
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• pp.71-80
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• 2001

Blood and urine mercury level of three workers were monitored during 60~80 days after high exposure to mercury at the silver refining plant. Mercury was used to form silver-mercury amalgam from plating sludge. Workers were exposed to mercury about 70 days at the several processes, such as hand held weaving, vibration table, and heating from the furnace. mercury was analysed by atomic absorption spectroscopy-vapor generation technique. Recovery from the biological sample was 95.51% and pooled standard deviation was 0.033. At the time of study, there was no work at the workplace. So, airborne mercury concentration was measured with area sampling 5 days after the work, ranged from 0.1459 to 1.2351 mg/㎥(Arithmatic mean 0.4711 mg/㎥, Geometric mean 0.3566 mg/㎥) at the inside of the plant, that is far above the ACGIH's TLV(0.025 mg/㎥) and ranged from 0.0073 to 0.0330 mg/㎥ at the outdoor. Blood mercury levels at the beginning of the monitoring were 4~14 times greater than the American Conference of Governmental Industrial Hygienists Biological Exposure Index(ACGIH BEI, 15 ug/L). Blood mercury levels were decreased logarithmically, that is, rapidly at the high level and slowly at the low level but sustained above the level of the ACGIH BEI 60~80 days after the work. Urine mercury levels at the beginning of the monitoring were 8~16 times greater than the ACGIH BEI(35 ug/g creatinine). Urine mercury levels were decreased logarithmically, but correlation between urine level and off-days were lower than those of blood. Decreasing pattern of blood mercury levels were little affected than that of urine levels when the chelating agent, D-penicillamine, was administered. There was correlation between blood mercury level and urine mercury level(0.81~0.83) but it didn\`t mean that the highest blood mercury level corresponded the highest urine mercury level. In our study, Case 1 always shows the highest level in urine but case 3 always shows the highest level in blood. Creatinine correction represented better correlations between urine mercury levels and blood levels, and between urine levels and off-days rather than by urine volume. Spot urine sampling had a wide variation than that of whole day urine sampling. So, We recommend spot urine sampling for screening and whole day urine sampling for exact diagnosis.

• Journal of Korean Public Health Nursing
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• v.12 no.2
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• pp.1-11
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• 1998

This study was performed to analyze the occupational health nursing of support-project of health management skill for small-scale industries. The 2 subject centers were under the umbrella of Korean Industrial Health Association and data collection period was 2weeks from September 1 to 13. 1997 and time and motion study method was used. Data was handled by SPSS win 7.5 program. results were worked out number. percentage. F-value. (1) The weekly time spending of occupational health nurses was distributed into indoor service 46.9%, outdoor service 26.6%, movement 26.5%. The mean visiting times were 2-3 times per week. and spending time was about 1 hour per industry. (2) There are statistically significant difference among the distribution of time spending according to industrial works(F=23.08. p=.000). and the special education for occupational disease prevention takes the most mean time. (3) There were statistically significant difference among the spending time for the health coach of occupational health nurses(F=188.79. p=.000). and the activity time for workers (58.4%) was more than that of for monitors(41.6%). The frequency of health coachs were 155 times for monitors during two weeks. but health coach for worker was 87 times. As a results. the contents of health coach for workers was proved to take more time than that for monitors. Perhaps we think that monitors has limitation for health management. therefore we should be consider flexible management of visiting time and health coach guidelines for occupational health nurses. (4) There were statistically significant differences among the distribution of time spending according to health coach methods for industrial health nurses(F=66.31. p=.000). The most frequent method of all was guide transmission. 159 times(65.7%), and the mean spending time for instruction was 19.78 min. the longest time. Our suggestion for occupational health nursing of support-project of health management skill for small-scale industry is that the need of each industry is very complex because of various conditions. therefore need assessment for industries should be conducted professionally. And occupational health nurses should apply occupational health nursing process autonomously. and their activities be guaranted by the guideline

• Journal of the Korean Applied Science and Technology
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• v.39 no.2
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• pp.368-376
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• 2022

Spontaneous ignition occurs in industrial sites or anywhere in our lives, and is a phenomenon in which a substance ignites itself without an ignition source in the atmosphere. As the rate of chemical reaction increases, the heat generated increases, and the risk of spontaneous ignition increases. In this study, safe raw materials used for food and cosmetics were mixed to prepare coal spontaneous ignition prevention agents specifically among various spontaneous ignition phenomena. The effect of suppressing spontaneous combustion of coal was confirmed through lab and field tests with low-calorie, low-grade coal from Indonesia. As a result of the outdoor field test, the ignition prevention agent manufactured in this study compared with the control group(Fire after 90 days) showed excellent ignition inhibitors for more than 120 days. In addition, CO concentration control was confirmed by comparing the concentration of carbon monoxide for 50 days at the indoor coal yard. It was confirmed that the results were better than the comparative group coal and the existing anti-firing method. In addition, the possibility of coal fire prevention agents for indoor coal farms will be applied from 2024 was confirmed by studying the environment and safety of workers' working environments through official test such as soil and water quality test, MSDS of coal fire prevention agents in consideration of working workers, water quality, and eye irritation tests.

• Journal of Distribution Science
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• v.17 no.7
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• pp.65-76
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• 2019

Purpose - The purpose of this study is to investigate economical ventilation effectiveness to reduce hazardous materials exposure and damage of workers by analyzing exposure amount of noxious substances under various ventilation conditions of nail salon for indoor environments. Research design, data, and methodology - This study was carried out with cooperation of Nail shop located in SeongNam city to involve an analysis of the environmental impact indoor air quality, pollutant exposure and economical cost-effectiveness in the nail workplace. The hazardous substances were PM-10(Particulate Matter-10㎛), VOCs(Volatile Organic Compounds) and Formaldehyde, which are the major materials of nail workplace. Results - PM-10 is reduced by about 60% with air cleaner, forced artificial ventilation by 32%, and natural ventilation by about 12%. TVOCs and Formaldehyde showed similar efficiency (80~100%) after natural ventilation and ventilation after 60 minutes. The removal efficiencies of VOCs and formaldehyde were similar to those of natural ventilation and mechanical ventilation system. However, in case of dust, natural ventilation was reduced by artificial ventilation system due to inflow of external dust during natural ventilation. Conclusions - If the pollution degree of outdoor air is not high, air volume is high, and natural ventilation is performed when the air conditioning and heating system is not operated. Even at the end of the work, it keeps operating for 60 minutes to remove the pollutants generated. Results of this analysis demonstrated that the worker environment can be improved by adopting institutional legislation and guidelines for ventilation.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.112-121
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• 2006

The vertical displacement of a ship on the basis of the sea level is an important parameter for its stability and control. To indicate the displacement on operating conditions, "draft marks" are carved on the hull of the ship in various ways. One of the methods is welding. The position, shape and size of the marks are specified on the shipbuilding rules by classification societies to be checked by shipbuilders. In most cases, high-skilled workers do the welding along the drawing for the marks and welding bead becomes the marks. But the inaccuracies due to human errors and high labor cost increase the needs for automating the work process of the draft marks. In the preceding work, an indoor robot was developed for automatic marking system on flat surfaces and the work proved that the robot welding was more effective and accurate than manual welding. However, many parts of the hull structure constructed at the outdoor are cowed shapes, which is beyond the capability of the robot developed for the indoor works on the flat surface. The marking on the curved steel surface requiring the 25m elevations is one of the main challenges to the conventional robots. In the present paper, the robot capable of climbing vertical curved steel surfaces and performing the welding at the marked position by effectively solving the problems mentioned earlier is presented.

• Journal of Ocean Engineering and Technology
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• v.27 no.4
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• pp.1-8
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• 2013

Many PE (pre-erection) blocks are supported by wooden, concrete, or steel supports when they are stocked in the outdoor areas of a shipyard. Their positions and numbers are planned on the basis of the workers' experience. Recently, many shipyards have been making PE blocks with various shapes and weight distributions because of the variety of ships and building technologies. Therefore, it is now necessary to deal with blocks that they have no experience with. We propose a method to conveniently and quickly evaluate the structural safety of PE block supports, without the need for special knowledge and technology related to structural analysis. This method can reduce the large number of man hours (MH) normally needed for the analysis. The three-dimensional grillage analysis is performed for a simplified grillage model of a PE block. For efficiency, the grillage model of the PE block is automatically built from its three-dimensional CAD model, and its weight is also automatically distributed on the grillage model. The integrated system has been comprehensively implemented to perform the grillage analysis for the reaction forces on block supports. This paper describes how to make a grillage model of a PE block and estimate the weight distribution of the block on this grillage model. These steps are verified by comparing the supports reaction forces to those of the 3D finite element analysis for the PE blocks that are provided by a shipyard.