• Journal of Bio-Environment Control
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• v.7 no.2
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• pp.91-108
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• 1998

This study was carried out to survey basic information of swine farms on the machine holdings. facility type. management of manure by farm scale and operation, and then to develop the mechanization model. Manual feeding was common for sows and nursing sows. but automation feeding was normally furnished for weaners. growing pigs and castrated male pigs. Water supplies was completely automated for all of the surveyed swine farms. Fully mechanized and automated system would not be feasible and affordable for the small scale farms breeding less than 500 heads. Because the environmental control for the nursing sows and weaner was important, some swine houses were constructed with the windowless type. However, the furnished rates ranged from 22.2% to 44.4% of the surveyed nursing sow and weaner houses at the farm scales. In the future, a computerized ventilation system would be commended for the efficient use of heat energy and to maintain the desirable temperature of swine buildings. Over-investment for large scale farm and over-crowded pigpen of small farm would cause wasting construction expenses and spreading epidermic diseases Hence, the size of swine building should follow the recommended scale. The fermentation drier was recommended for the manure management. Urine could be recycled or discharged after treating by the activated sludge process.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.202-210
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• 2015

Objectives: The purpose of this study was to examine clean room(C/R) structure, air conditioning and contamination control systems and to provide basic information for identifying a correlation between the semiconductor work environment and workers' disease. Methods: This study was conducted at 200 mm and 300 mm semiconductor wafer fabrication facilities. The C/R structure and air conditioning method were investigated using basic engineering data from documentation for C/R construction. Furthermore, contamination parameters such as airborne particles, temperature, humidity, acids, ammonia, organic compounds, and vibration in the C/R were based on the International Technology Roadmap for Semiconductors(ITRS). The properties of contamination control systems and the current status of monitoring of various contaminants in the C/R were investigated. Results: 200 mm and 300 mm wafer fabrication facilities were divided into fab(C/R) and sub fab(Plenum), and fab, clean sub fab and facility sub fab, respectively. Fresh air(FA) is supplied in the plenum or clean sub fab by the outdoor air handling unit system which purifies outdoor air. FA supply or contaminated indoor air ventilation rates in the 200 mm and 300 mm wafer fabrication facilities are approximately 10-25%. Furthermore, semiconductor clean rooms strictly controlled airborne particles(${\leq}1,000{\sharp}/ft^3$), temperature($23{\pm}0.5^{\circ}C$), humidity($45{\pm}5%$), air velocity(0.4 m/s), air change(60-80 cycles/hr), vibration(${\leq}1cm/s^2$), and differential pressure(atmospheric pressure$+1.0-2.5mmH_2O$) through air handling and contamination control systems. In addition, acids, alkali and ozone are managed at less than internal criteria by chemical filters. Conclusions: Semiconductor clean rooms can be a pleasant environment for workers as well as semiconductor devices. However, based on the precautionary principle, it may be necessary to continuously improve semiconductor processes and the work environment.

• Korean Journal of Community Nutrition
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• v.25 no.5
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• pp.374-385
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• 2020

Objectives: This study was conducted to examine the status of foodservice management, with special interest on sanitary and nutritional food service in elderly day care centers. Methods: A total of 79 employees who managed foodservice facilities in elderly day care centers were included in the survey. The contents of the questionnaire consisted of general characteristics, importance and performance of sanitary and nutrition management, the reasons for poor performance, factors necessary for improvement, and the employee's demand for support. Data analysis was conducted using the SPSS v25.0. Results: Sanitary management showed an average importance score of 4.84 ± 0.40 and a performance score of 4.70 ± 0.61 (t-value: 8.260). The item with the lowest performance score was personal sanitary management (4.58 ± 0.71). In nutrition management, the average importance score was 4.52 ± 0.68, and the performance score was 4.20 ± 1.00 (t-value: 9.609). There were significant differences between the average score of importance and performance in both areas. As a result of an Importance-Performance Analysis, items that were recognized as important but had relatively low performance was "personal hygiene", "ventilation" and "food storage". Also in the nutritional management area, "menu planning for disease management" and "checking the saltiness in the soup" etc. had very low performance with low importance recognition. The items shown in the "low priority" quadrant were those that required professional management skills. In the areas that demanded support in foodservice management, education about sanitary and safe institutional food service had the highest score (4.42 ± 0.74), and all other items showed a demand of 4 points or more. Conclusions: Foodservice managers recognize the importance of foodservice facility management but performance is relatively low. Institutional support is, therefore, needed to improve performance. For items with low importance, it seems necessary to improve awareness of the necessity of these items and to provide education in this regard. To gradually improve foodservice management, continuous provision of education and training in these areas are of great importance.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.439-444
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• 2012

We studied the characteristics of odor emitted from 40 swine facilities across the country under various conditions like rearing densities, management style, ventilation system and swine manure handling characteristics, based on the olfactory and analytical evaluation. Odor concentrations (D/T) measured from swine facilities were respectively an average 4,055 D/T at liquid manure storage tanks on aeration, an average 913 D/T at slurry manure storage, an average 506 D/T at finishing swine facilities and an average 201 D/T at composting facilities. The higher rearing densities and slurry accumulation volume in finishing swine house, the more odor concentration (D/T) was increased. But The odor concentration (D/T) in finishing swine house did not show significant difference according to application of microbial additives. 9 odor compounds ($NH_3$, $H_2S$, MM, DMS, DMDS, PA, n-BA, n-VA, i-VA) were detected at swine facilities and the main odor compounds were volatile sulfur compounds such as $H_2S$, MM and volatile fatty acids compounds such as n-BA, n-VA, i-VA. 97.5% of swine farms surveyed in this study is located within 300 m of residential area and it is easy to bring odor complaints.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.410-424
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• 2021

Background: Subway stations have the characteristics of being located underground and are a representative public-use facility used by an unspecified number of people. As concerns about indoor air quality (IAQ) increase, various management measures are being implemented. However, there are few systematic studies and cases of long-term continuous measurement of underground station air quality. Objectives: The purpose of this study is to analyze changes and factors influencing IAQ in subway stations through real-time continuous long-term measurement using IoT-based IAQ sensing equipment, and to evaluate the IAQ improvement effect of a bio-filter system. Methods: The IAQ of a subway station in Seoul was measured using IoT-based sensing equipment. A bio-filter system was installed after collecting the background concentrations for about five months. Based on the data collected over about 21 months, changes in indoor air quality and influencing factors were analyzed and the reduction effect of the bio-filter system was evaluated. Results: As a result of the analysis, PM₁₀, PM_2.5, and CO₂ increased during rush hour according to the change in the number of passengers, and PM₁₀ and PM_2.5 concentrations were high when a PM warning/watch was issued. There was an effect of improving IAQ with the installation of the bio-filter system. The reduction rate of a new-bio-filter system with improved efficiency was higher than that of the existing bio-filter system. Factors affecting PM_2.5 in the subway station were the outdoor PM_2.5, platform PM_2.5, and the number of passengers. Conclusions: The IAQ in a subway station is affected by passengers, ventilation through the air supply and exhaust, and the spread of particulate matter generated by train operation. Based on these results, it is expected that IAQ can be efficiently improved if a bio-filter system with improved efficiency is developed in consideration of the factors affecting IAQ and proper placement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.456-463
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• 2019

Micro climatic conditions within the livestock facility are affected by various factors such as ventilation, cooling, heating, insulation and latent and sensible heat generation from animals. In this study, numerical BES method was used to simulate energy flow inside the poultry house. Based on the BES method and THI concept, degree of thermal stress of poultry was evaluated according to the locations in South Korea. Comparison of THI values within the poultry house was also carried out according to the stocking densities to reflect recent animal-welfare issue. Significant decrease in thermal stress of poultry was observed when the stocking density of $30kg/m^2$ was applied in the change of the seasons(p<0.05) however, there was no statistically significant difference in summer season(p>0.05). It meant that installation of proper cooling system is urgently needed. For Iksan city of Jeollabuk-do province, total 252 hours of profit for thermal stress was found according to decrease in the stocking density.

• Journal of the Korean Society of Food Culture
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• v.23 no.5
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• pp.582-594
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• 2008

This study aimed at evaluating current sanitation management performances in Korean-Food restaurants by their operation types and to develop sanitary training posters based on the risk factors, in an attempt to improve the level of sanitation management in Korean food service facilities. Eighteen Korean-food restaurants that are managed by franchisor, franchisees as well as self-managed with large-scale and small-scale restaurants in Seoul and Gyeonggi-Do, were evaluated by on-the-spot inspectors with an auditing tool consisting of three dimensions, nine categories and thirty four items. Data were analyzed using SPSS. The total score of each group showed that restaurants managed by franchisees ranked the highest (59 out of 100 points), while self-managed, small-scale restaurants ranked the lowest (44 out of 100 points). In the categorization of sanitation management compliance, the dimensions of food hygiene during production recorded the lowest compliance rate of 47.7% (22.89/48.0 points) followed by the dimension of environmental hygiene 59.3% (20.17/34.0 points) and personal hygiene 60.5% (10.89/18.0 points). This indicated the need for urgent improvement. The items which showed the lowest compliance rates were 'proper thawing of frozen foods' (0%), 'notifying and observing heating/reheating temperature' (6%), 'using of hand-washing facility and proper hand-washing' (33%), 'monitoring temperature of frozen-foods and cold-foods' (35%), and 'prevention of cross-contamination' (36%) among thirty four items. Self-managed, small-scale restaurants, in particular, needed to improve sanitary practices such as 'sanitation education for employee', 'verifying the employee health inspection reports', 'storing food on the shelves 15 cm distance away from the wall', 'suitability of ventilation capacity of hoods' and 'cleanliness of drainage'. On the basis of the findings of this study, we developed sanitary training posters, especially for small-scale restaurant operators. This could be an effective tool to educate food service employees on sanitary knowledge and principles and could be used to improve the existing sanitary conditions in Korean food service facilities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.1
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• pp.173-185
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• 2015

This study aims to investigate the characteristics and types of car accidents and establish a prediction model by analyzing 456 car accidents having occurred in the 11 tunnels in Busan, through statistical analysis techniques. The results of this study can be summarized as below. As a result of analyzing the characteristics of car accidents, it was found that 64.9% of all the car accidents took place in the tunnels between 08:00 and 18:00, which was higher than 45.8 to 46.1% of the car accidents in common roads. As a result of analyzing the types of car accidents, the car-to-car accident type was the majority, and the sole-car accident type in the tunnels was relatively high, compared to that in common roads. Besides, people at the age between 21 and 40 were most involved in car accidents, and in the vehicle type of the first party to car accidents, trucks showed a high proportion, and in the cloud cover, rainy days or cloudy days showed a high proportion unlike clear days. As a result of analyzing the principal components of car accident influence factors, it was found that the first principal components were road, tunnel structure and traffic flow-related factors, the second principal components lighting facility and road structure-related factors, the third principal factors stand-by and lighting facility-related factors, the fourth principal components human and time series-related factors, the fifth principal components human-related factors, the sixth principal components vehicle and traffic flow-related factors, and the seventh principal components meteorological factors. As a result of classifying car accident spots, there were 5 optimized groups classified, and as a result of analyzing each group based on Quantification Theory Type I, it was found that the first group showed low explanation power for the prediction model, while the fourth group showed a middle explanation power and the second, third and fifth groups showed high explanation power for the prediction model. Out of all the items(principal components) over 0.2(a weak correlation) in the partial correlation coefficient absolute value of the prediction model, this study analyzed variables including road environment variables. As a result, main examination items were summarized as proper traffic flow processing, cross-section composition(the width of a road), tunnel structure(the length of a tunnel), the lineal of a road, ventilation facilities and lighting facilities.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.28-34
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• 2010

Purpose: According to increment of thyroid cancer recently, patients of high dose radioiodine therapy were accumulated. Taking into consideration the acceptance capability in the current facility, this study is to calculate the maximum value of high dose radioiodine therapy in patients for treatment. Materials and Methods: The amount and radioactivity of waste water discharged from high dose radioiodine therapy in patients admitted at present hospital as well as the radiation density of the air released into the atmosphere from the high dose radioiodine therapy ward were measured. When the calculated waste water's radiation and its density in the released air satisfies the standard (management standard for discharge into water supply 30 Bq/L, management standard for release into air 3 $Bq/m^3$) set by the Ministry of Education, Science and Technology, the maximum value of treatable high dose radioiodine therapy in patients was calculated. Results: When we calculated in a conservative view, the average density of radiation of waste water discharged from treating high dose radioiodine therapy one patient was 8 MBq/L and after 117 days of diminution in the water-purifier tank, it was 29.5 Bq/L. Also, the average density of radiation of waste water discharged from treating high dose radioiodine therapy two patients was 16 MBq/L and after 70 days of diminution in the water-purifier tank, it was 29.7 Bq/L. Under the same conditions, the density of radiation released into air through RI Ventilation Filter from the radioiodine therapy ward was 0.38 $Bq/m^3$. Conclusion: The maximum value of high dose radioiodine therapy in patients that can be treated within the acceptance capability was calculated and applied to the current facility, and if double rooms are managed by improving the ward structure, it would be possible to reduce the accumulated treatment waiting period for radioiodine therapy in patients.

• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.77-81
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• 2010

The effects of $CO_2$ concentration on fruit-body formation and yield of Pleurotus ferulae (KME65003) mushroom were examined in the growing facilities for bottle cultivation. The $CO_2$ concentration levels in the growing facilities were 500 ppm, 1000 ppm, 1500 ppm and 2000 ppm of $CO_2$, controlled by different ventilation amount. Yield of fruit body was highest of 102.4 g/bottle at 1000 ppm treatment and lowest of 75.1 g/bottle at 2000 ppm. As the $CO_2$ concentration increased up to 2000 ppm, the first pinhead formation and fruit-body growing period took longer, so total growing period took 16 days at 500 ppm, but 23 days at 2000 ppm. The number of pinhead formation was highest of 12.2/bottle at 1500 ppm and valid stipes was highest of 2.8/bottle at 1000 ppm. Fruit body characteristics such as pileus and stipe diameter, and stipe length were not significant at different $CO_2$ concentration. The fruit body ratio of 20~50 g range among the whole fruit body which was classified by weight was highest of 60.3% at 1000 ppm. As a result, the suitable $CO_2$ concentration of growth and yield of Pleurotus ferulae was showed as 1000 ppm.