• Journal of The Korea Institute of Healthcare Architecture
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• v.28 no.4
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• pp.89-97
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• 2022

Purpose: Because of the recent COVID-19 pandemic, there have been many cases of using portable negative pressure unit to convert general wards into temporary negative pressure isolation wards. The purpose of this study is to analyze the indoor environment of the switching type wards. Methods: Field measurements and experiments were conducted in a medical facility. Air volume, wind speed and pressure difference were measured in non-occupant state. Dispersion tests were performed with gas and particle matter. Results: The pressure difference between the wards and the corridor was higher than -2.5 Pa in normal situation. However, in the gas and particle dispersion tests, it was found that there were concerns about the spread through leakages in low-airtight walls or ceilings. In addition, it was confirmed that the pressure imbalance in ducts through the non-sealed diffusers could cause back flow during portable unit operation. Furthermore, when there was a pressure difference between adjacent wards planned to be at same pressure level, the possibility of the spread through the leakages was found. Implications: When using portable units for making switching type wards, it is necessary to create airtight space and seal the non-operation diffusers. In case of operating the air handling unit, T.A.B must be performed to adjust the duct balancing.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.2
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• pp.47-59
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• 2022

Liquid hydrogen/liquid oxygen rocket engines with highest specific impulse have been developed since the 1950s and used until now to maximize the capability of space launch vehicles. Domestic liquid hydrogen infrastructures for the production, transportation and distribution are being expanded at world-class level with the rise of hydrogen economy, which is a great opportunity for the performance enhancement for indigenous space launch vehicles. In this paper, feasibility of applying liquid hydrogen as a propellant is investigated in various aspects. The status of domestic liquid hydrogen infrastructure, the technologies required for liquid hydrogen engines, and operational aspects for safe handling of hydrogen are reviewed. In addition, test facilities for developing hydrogen engines are introduced briefly.

• Journal of Environmental Health Sciences
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• v.49 no.2
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• pp.78-88
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• 2023

Background: Exposure to volatile organic compounds (VOCs) can have acute and chronic health effects on human beings in general and in working environments. In particular, VOCs are often emitted in large quantities in industrial settings. In such circumstances, there is a need to improve the indoor air quality at workplaces. Objectives: The purposes of this study were to verify the effectiveness of air cleaning devices in workplaces and provide alternative solutions for improving working environments. Methods: Personal exposure and area level of VOCs for workers were evaluated in a car-part adhesive process before and after installing an air cleaning device with a TiO₂-coated filter. Passive samplers and direct reading instruments were used to collect and analyze the VOCs, and the removal efficiency and improvement of air quality were evaluated. We also calculated the exposure index (EI) to assess the risk level in the workplace. Results: The removal efficiency for VOCs through the installation of the air cleaning device was approximately 26.9~69.0% as determined by the concentration levels before and after installation. The measured substances did not exceed the exposure limits for the work environment and the EI was less than 1. However, carcinogenic substances such as benzene, formaldehyde, carbon tetrachloride, and trichloroethylene were detected. Conclusions: The application of an air cleaning device can be a solution for controlling the indoor air quality in a workplace, particularly in cases where ventilation systems cannot be installed due to process limitations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.944-954
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• 2007

The Purpose of this study was to investigate overall sanitation levels of restaurants in Korea by examining sanitation management. Sanitation inspections were carried out in 200 large Korean, Western, Chinese, and Japanese restaurants and in buffet-style restaurants of over 100 pyeong in size located in Daegu and Gyeongbuk province. This survey of sanitation management practices found that in large restaurants employing many workers, sanitation management was good in the areas of the kitchen environment, equipment and utensils, food handling, and worker's personal hygiene. Restaurants having relatively large kitchens showed significantly high scores in these sanitation areas. Furthermore, open-kitchen-type restaurants showed significantly higher scores in kitchen sanitation compared with closed-kitchen-type restaurants. Survey results of sanitation management show that, in all restaurants surveyed, sanitation management was good in dining hall sanitation and in providing a safe drinking water supply, but poor in food handling sanitation. Kitchen environment sanitation was poor in Korean, Chinese, and Japanese restaurants. Equipment and utensils sanitation was unsatisfactory in Western and buffet-style restaurants. In the food handling area, especially food sanitation and temperature, checks were rarely made, and pasteurization and temperature records were not kept. Therefore, it is recommended that, in planning a kitchen facility in the future, the floor area should be as large as Possible and open. In terms of management, more attention should be paid to food pasteurization, sanitation of cooking equipment and utensils, and checking of food temperature.

• Journal of Environmental Health Sciences
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• v.43 no.1
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• pp.42-54
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• 2017

Objectives: The present study was conducted to investigate farm work environments among farmers and examine the level of management of safety and health, and to subsequently produce study result to serve as foundational data for the development of guidelines on safety and health as part of the improvement of farming work environments among farmers raising Korean native cattle. Methods: The present study conducted a survey on farm work environments and the management of safety and health with 407 farmers engaged in Korean native cattle farming in selected regions in eight provinces. It also visited 10 farmers to verify the current status of farm work. Results: The survey results showed that 16.4% of the respondents experienced safety-related accidents due to farm work. The locations of the accidents were inside the cattle shed (71.4%) and facilities outside the cattle shed (19.6%). The types of accident showed collision with animals (35.7%), collision or contact with obstacles (27.1%), and musculoskeletal accidents due to heavy object handling (12.9%). The causes of the accidents were cattle (38.3%), cultivators and tractors (25.4%), facility tools in cattle sheds (9.0%), and slippery floors (6.0%). The damaged areas were hand (21.0%), spine (19.8%), lower limb (18.5%), and foot (17.3%). A self-diagnostic survey on respiratory diseases showed that 11.5% of the respondents experienced respiratory-related symptoms. The survey on safety and health during farm work showed that wearing personal protective equipment and response to emergency situations, which were needed to prevent safety-related accidents, were relatively low compared to the level of recognition of the need and awareness of safety issues. Furthermore, the field survey identified the current status of safety and health issues such as prevention management of collision accidents with cattle, how to handle heavy objects, and wearing of personal protective equipment. Conclusions: The present study identified safety-related accidents and problems in the management of safety and health among Korean native cattle farmers. In order to address the problem, it is necessary to not only provide guidelines on safety and health management which are appropriate to the characteristics of Korean native cattle farming work, but also to study the development of personal protective equipment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.365-372
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• 2004

The purpose of this study was to implement HACCP system to foodservice of W and D elementary schools with joint-lunch management system in Kyungsan area. Steamed rice with squid was selected and Control Action, Monitoring Procedure and Control measure were identified based on HACCP flowchart to produce safe and healthy food. It was suggested that frozen squid must be thawed under the cold running city water and kept temperature below 1$0^{\circ}C$ and receiving/thawing procedure has to be done within 30 min. Raw vegetables must be washed under three-tube wash stand and whole prepreparation procedures should be done in 20 minutes. Clean and sanitize all the equipment and utensils before and after handling squid. Knives and cutting boards for vegetable and squid should be classified. Sauce for steamed rice with squid should be heated about 21 minutes to reach the temperature of 94$^{\circ}C$ before serving and internal temperature of food must be kept above 84.4$^{\circ}C$ during serving. The ideal temperature of kitchen should be remained 15∼18$^{\circ}C$. The underground water has to be excluded to minimize the risk of contamination in the foodservice facility and the prepreparation place must be separated with cooking place. Also, Personal hygiene Practice should be check in each stage. Further, additional research needs to be conducted to determine models for HACCP implementation for different menu.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.274-282
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• 2011

The purpose of this study was to investigate factory workers' knowledge of sanitation management of school foodstuffs and sanitation practices. A questionnaire that identified employees' food safety sanitation management knowledge and practices was developed based on a review of literature. Subjects consisted of 221 factory workers employed at 34 factories in the Daegu and Gyeongbuk areas. Almost half of the factory workers were 40~49 years of age (45.7%), 34.8% had 1~3 years of work experience, 62.4% of the respondents received food safety education 1~2 times a month and 75.1% of the respondents were satisfied with sanitation education. However, the total score for factory worker sanitation knowledge was low: 4.63/9. Sanitation performance was self-evaluated using a Likert 5-point scale. The total mean score for the factory workers' sanitation performance was 4.63/5. Satisfaction level and the amount of sanitation education, application of sanitation knowledge, attitude regarding sanitation management, and sanitation management performance level were significantly high among workers employed in a HACCP certification facility (p<0.05). The difficulties were found to be sanitation management and the time to deliver food to schools. To instill a sense of duty and pride among workers and to ensure that the food suppliers provide best-quality school foodstuffs safely, school dietitians and factory managers must actively educate workers in safe food handling and sanitation.

• Journal of Animal Environmental Science
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• v.12 no.1
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• pp.7-12
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• 2006

Ammonia emission from swine production process originates from three major sources: manure storage facility, swine housing, and land application of manure. Most of the ammonia gas that are emitted from swine production operations is the by-product of aerobic or anaerobic decomposition of swine waste by microorganism. Knowing the ammonia emission rate is necessary to understand how management practices or alternative manure handling process could reduce impacts of this emission on the environment and neighbors. Ammonia gas emission from pig slurry is very difficult to predict because it is affected by many factors including wind speed of slurry surface, temperature or pH of the swine slurry, sort breed differences and classes, and diets. This study was carried out to effects of pH and temperature on ammonia gas emission from growing-finishing pig slurry. Treated far slurry in this study were pH and temperature. Results showed that pH of slurry variable changes 5, 6, 7, 8 upon an addition of NaOH and $HNO_3$, respectively. The temperature of the slurry which was contained in a water bath maintained at increasing levels ranging from 10 to $35^{\circ}C$. Ammonia emission rate of influenced pH and temperature such that the increase in pH or temperature resulted to an increase in ammonia emission. The ammonia gas was not detected at pH 5 and 6. Moreover, at a slurry of pH 8, the ammonia ranged from 28 to 60ppm and 8-29 ppm at slurry pH of 7 while temperature was 13 to $33^{\circ}C$. When slurry pH was>6, the ammonia emission was significantly increased according to rise in temperature in contrast to acid treatment of the pH. There was also a significantly increase in ammonia emission relative to slurry pH of 7 to 8. The above findings showed that to effectively reduce ammonia emission from slurry of growing-finishing pigs, the pH and temperature should be maintained a low levels.

• Journal of Distribution Science
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• v.10 no.10
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• pp.25-33
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• 2012

Purpose - The Garak agricultural wholesale market ('Garak Market') plays a central role in the distribution of agricultural products in Korea and is important in connecting consumers with producers. However, problems regarding inefficiencies and the high-cost structure of the wholesale market's distribution/logistical system are being raised in relation to severe competition among retailers. Furthermore, the service needs of retailers and market users are not being fulfilled due to the inconsistency of the wholesale market's functions and facilities, thus reducing the competitiveness of the market. In this regard, innovative changes are being requested of the agricultural wholesale market according to changes in the agricultural product distribution environment. In particular, the lack of unloading facilities and the outdated unloading system of the wholesale market must be improved to enhance system efficiency. Research design, data, and methodology - This study observed the problems of the unloading system of the agricultural wholesale market in order to present relevant measures for improvement. The need for unloading auctions was also researched in this study. The survey of 70 forwarders belonging to the producing district distributor association of the Garak market was conducted by post. Additionally, 20 auction dealers and 59 shippers and transporters were individually interviewed. The survey on the need for unloading auctions used five-point Likert Scales. The statistical analysis was conducted with SPSS WIN 12.0 software. Results - First, the wholesale market must employ members of the unloading labor union to allow these employees to directly manage the unloading process. Second, it is crucial to revise regulations to ensure that the principal agent pays the unloading cost according to the standard unloading cost system. Third, the vehicle auction carried out for certain vegetable products must be converted to the unloaded auction system. According to the related interviews with the wholesale market's distribution agents, whereas shippers and transporters recognized the need for unloaded auctions, auction dealers tend to have a negative view of this system. Furthermore, the stated reasons in favor of unloaded cabbage, radish, and other vegetable auctions were prevention of constraint, creation of transparent trade conditions, and reduction of corrected seller tickets. Many of the respondents answered that the transport cost reduction rate in unloaded auctions must be below 20%. Fourth, the unloading system must be mechanized and a detailed, reasonable plan must be provided to settle the existing conflict with the unloading labor union. Conclusions - The proposals in this study are expected to play an important role in improving the cargo handling system of the wholesale agricultural product market in the future. Improving the system is expected to help shore up the competitiveness of the industry. If all the related bodies closely cooperate with each other and work harder, taking advantage of the synergies created by the facility modernization project, the Garak market will play a pivotal role in the distribution of agricultural products.

• Journal of Korea Port Economic Association
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• v.29 no.2
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• pp.39-61
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• 2013

China, a leader of regional economies in North-East Asia, helps to integrate a single shipping market and affects diversely main ports in the region through affecting the flows of container transshipment, strategies of shipping companies for port calling and shipping networks. This study examines competition and cooperation among the hub ports in the region through studying examples of the three Chinese hub ports -Hong Kong, Shanghai, and Tianjin- and concludes some implications of status change of hub ports in the region after scrutinising development process of the Chinese main hub ports and the historic interaction of port development among these ports. The characteristics of growth pattern of three ports are as follows. The port of Hong Kong constructs step by step the container facilities in accordance with demand growth and prefers stabilisation of operation and management through scale enlargement of port facilities. Even though demand grows continually, the port of Shanghai continued its defensive attitude towards facility expansion till the 1990s and has tried to get economies of scale in enlargement of port facilities. The port of Tianjin, similarly as the two other ports, expands serially its facilities and utilizes the capacity concentration and functional specialisation of facilities. The analysis of panel data and panel regression of three hub ports implicates that each port has its own specific demand and shows that the interaction of container handling among three ports was weak in 1980s and has become stricter and stronger since 1990.