• Title/Summary/Keyword: 환기 시설

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Study on the Fire Risk Prediction Assessment due to Deterioration contact of combustible cables in Underground Common Utility Tunnels (지하공동구내 가연성케이블의 열화접촉으로 인한 화재위험성 예측평가)

  • Ko, Jaesun
    • Journal of the Society of Disaster Information
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    • v.11 no.1
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    • pp.135-147
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    • 2015
  • Recent underground common utility tunnels are underground facilities for jointly accommodating more than 2 kinds of air-conditioning and heating facilities, vacuum dust collector, information processing cables as well as electricity, telecommunications, waterworks, city gas, sewerage system required when citizens live their daily lives and facilities responsible for the central function of the country but it is difficult to cope with fire accidents quickly and hard to enter into common utility tunnels to extinguish a fire due to toxic gases and smoke generated when various cables are burnt. Thus, in the event of a fire, not only the nerve center of the country is paralyzed such as significant property damage and loss of communication etc. but citizen inconveniences are caused. Therefore, noticing that most fires break out by a short circuit due to electrical works and degradation contact due to combustible cables as the main causes of fires in domestic and foreign common utility tunnels fire cases that have occurred so far, the purpose of this paper is to scientifically analyze the behavior of a fire by producing the model of actual common utility tunnels and reproducing the fire. A fire experiment was conducted in a state that line type fixed temperature detector, fire door, connection deluge set and ventilation equipment are installed in underground common utility tunnels and transmission power distribution cables are coated with fire proof paints in a certain section and heating pipes are fire proof covered. As a result, in the case of Type II, the maximum temperature was measured as $932^{\circ}C$ and line type fixed temperature detector displayed the fire location exactly in the receiver at a constant temperature. And transmission power distribution cables painted with fire proof paints in a certain section, the case of Type III, were found not to be fire resistant and fire proof covered heating pipes to be fire resistant for about 30 minutes. Also, fire simulation was carried out by entering fire load during a real fire test and as a result, the maximum temperature is $943^{\circ}C$, almost identical with $932^{\circ}C$ during a real fire test. Therefore, it is considered that fire behaviour can be predicted by conducting fire simulation only with common utility tunnels fire load and result values of heat release rate, height of the smoke layer, concentration of O2, CO, CO2 etc. obtained by simulation are determined to be applied as the values during a real fire experiment. In the future, it is expected that more reliable information on domestic underground common utility tunnels fire accidents can be provided and it will contribute to construction and maintenance repair effectively and systematically by analyzing and accumulating experimental data on domestic underground common utility tunnels fire accidents built in this study and fire cases continuously every year and complementing laws and regulations and administration manuals etc.

Study on PM10, PM2.5 Reduction Effects and Measurement Method of Vegetation Bio-Filters System in Multi-Use Facility (다중이용시설 내 식생바이오필터 시스템의 PM10, PM2.5 저감효과 및 측정방법에 대한 연구)

  • Kim, Tae-Han;Choi, Boo-Hun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.5
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    • pp.80-88
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    • 2020
  • With the issuance of one-week fine dust emergency reduction measures in March 2019, the public's anxiety about fine dust is increasingly growing. In order to assess the application of air purifying plant-based bio-filters to public facilities, this study presented a method for measuring pollutant reduction effects by creating an indoor environment for continuous discharge of particle pollutants and conducted basic studies to verify whether indoor air quality has improved through the system. In this study conducted in a lecture room in spring, the background concentration was created by using mosquito repellent incense as a pollutant one hour before monitoring. Then, according to the schedule, the fine dust reduction capacity was monitored by irrigating for two hours and venting air for one hour. PM10, PM2.5, and temperature & humidity sensors were installed two meters front of the bio-filters, and velocity probes were installed at the center of the three air vents to conduct time-series monitoring. The average face velocity of three air vents set up in the bio-filter was 0.38±0.16 m/s. Total air-conditioning air volume was calculated at 776.89±320.16㎥/h by applying an air vent area of 0.29m×0.65m after deducing damper area. With the system in operation, average temperature and average relative humidity were maintained at 21.5-22.3℃, and 63.79-73.6%, respectively, which indicates that it satisfies temperature and humidity range of various conditions of preceding studies. When the effects of raising relatively humidity rapidly by operating system's air-conditioning function are used efficiently, it would be possible to reduce indoor fine dust and maintain appropriate relative humidity seasonally. Concentration of fine dust increased the same in all cycles before operating the bio-filter system. After operating the system, in cycle 1 blast section (C-1, β=-3.83, β=-2.45), particulate matters (PM10) were lowered by up to 28.8% or 560.3㎍/㎥ and fine particulate matters (PM2.5) were reduced by up to 28.0% or 350.0㎍/㎥. Then, the concentration of find dust (PM10, PM2.5) was reduced by up to 32.6% or 647.0㎍/㎥ and 32.4% or 401.3㎍/㎥ respectively through reduction in cycle 2 blast section (C-2, β=-5.50, β=-3.30) and up to 30.8% or 732.7㎍/㎥ and 31.0% or 459.3㎍/㎥ respectively through reduction in cycle 3 blast section (C-3, β=5.48, β=-3.51). By referring to standards and regulations related to the installation of vegetation bio-filters in public facilities, this study provided plans on how to set up objective performance evaluation environment. By doing so, it was possible to create monitoring infrastructure more objective than a regular lecture room environment and secure relatively reliable data.

Actual Conditions and Perception of Safety Accidents by School Foodservice Employees in Chungbuk (충북지역 학교급식 조리종사원의 안전사고 실태 및 인식)

  • Cho, Hyun A;Lee, Young Eun;Park, Eun Hye
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.10
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    • pp.1594-1606
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    • 2014
  • The purpose of this study was to examine safety accidents related to school foodservice, working and operating environments of school foodservice, status and awareness of safety education, educational needs, and information on qualitative improvement of school foodservice. The subjects in this study were 234 cooks in charge of cooking at elementary and secondary schools in Chungbuk. A survey was conducted from July 30 to August 8, 2012, and among 202 questionnaires gathered, 194 completed questionnaires were analyzed. Statistical analyses were performed on data utilizing the SPSS version 19.0. The main results of this study were as follows: 44.3% of workers experienced safety accidents. The most frequent safety accident was 'once' (60.5%), and most safety accidents took place between June and August (31.4%). The time at which most safety accidents happened was between 8 and 11 am. Most safety accidents happened during cooking (52.3%) and while using a soup pot or frying pot (52.4%). The most common accidents were 'burns', 'wrist and arm pain', and 'slips and falls'. Respondents who experienced safety accidents replied that 57.6% of employees dealt with injuries at their own expense, and only 35.3% utilized industrial accident insurance. In terms of the operating environment, the score for 'offering information and application' was highest (3.76 points), whereas that for 'security of budget' was lowest (1.77 points). As for accident education, employees received safety education approximately 3.45 times and 5.10 hours per year. Improving the working environment of school foodservice cooks requires administrative and financial support. Furthermore, educational materials and guidelines based on the working environment and safety accident status of school foodservice cooks are required in order to minimize potential risk factors and control safety accidents in school foodservice.

Comparative analysis of status of safety accidents and importance-performance analysis (IPA) about precautions of safety accidents by employment type of industry foodservices in Jeonbuk area (전북지역 산업체급식소 조리종사자의 고용형태에 따른 안전사고 실태 및 안전사고 예방관리에 대한 중요도와 수행도 분석)

  • So, Hee;Rho, Jeong Ok
    • Journal of Nutrition and Health
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    • v.50 no.4
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    • pp.402-414
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    • 2017
  • Purpose: The purpose of the study was to evaluate the status of safety accidents and importance-performance analysis (IPA) between regular and non-regular employees in industry foodservices. Methods: The participants were regular employees (n = 119) and non-regular employees (n = 163) in industry foodservices in the Jeonbuk area. Demographic characteristics, status of safety accidents, safety education, and importance and performance status were assessed using a self-administered questionnaire. Results: Approximately 66.4% of regular employees and 53.4% of non-regular employees experienced safety accidents (p < 0.05). Types of safety accidents of regular and non-regular employees were mostly burns, and causes were mostly from their own negligence. Approximately 98.3% of regular employees and 95.1% of non-regular employees experienced safety education. Approximately 88.9% of regular employees and 96.8% of non-regular employees received safety education from dietitians. Approximately 41.9% of regular employees and 50.0% of non-regular employees had difficulty applying the contents of safety education due to lack of time during work. As a result of IPA, regular and non-regular employees were aware of the importance of the following and performed them well: 'Clean the floor of the work place', 'Arrange in the work area', 'Wear safety shoes', 'Check for heater cord', and 'Safety cooking when using oil'. On the other hand, they were not aware of the importance of the following and performed them insufficiently: 'Check for the MSDS', 'Aware of chemical signs', 'Wear protection gloves etc.', 'Do stretching exercise', and 'Using ancillary tools'. Conclusion: Therefore, it is necessary to improve the consciousness of dietitians for effective application of safety education contents, development of contents, especially MSDS, and related things.

Evaluation of Oven Utilization Effects at School Foodservice Facilities in Daegu and Gyeongbuk Province (대구·경북지역 학교급식소 오븐 사용 효과 평가)

  • Lee, Jung-A;Lee, Jin-Hyang;Bae, Hyun-Joo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.7
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    • pp.1064-1072
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    • 2010
  • The objectives of this study were to gain an overview of practices and effect evaluation of oven utilization at school foodservice facilities in Daegu and Gyeongbuk province. Out of 147 dieticians, who responded for questionnaires, 44 dieticians used the oven and 103 dieticians did not use the oven. All statistical analyses were conducted with the SPSS 14.0 statistical software program. With regard to the style of foodservice system, 74.4% were urban, 23.3% were rural, and 2.3% were remote country. Also, 23.3% of school foodservices produced meals by batch cooking. According to the results of the expected effect and using effect analysis for 27 items, the average of evaluation score about expected effect was 1.64 points and that of using effect was 1.61 points. Both expected effect and using effect had higher scores than average points in 13 items out of 27 items. Using effect had higher scores than expected effect in 4 items. In conclusion, using ovens could help to increase foodservice satisfaction of students at school foodservice, because it can improve the various cooking methods and the food safety management. Therefore, it is important to modernize and automate cooking equipment for quality improvement of school foodservice operations.

Seasonal Dust Concentration and Characteristics of Windowless Broiler Building (무창 육계사의 계절별 먼지 농도와 특성 연구)

  • Choi H. C.;Yeon G. Y.;Song J. I.;Kang H. S.;Kwon D. J.;Yoo Y. H.;Barroga A. J.;Yang C. B.;Chun S. S.;Kim Y. K.
    • Journal of Animal Environmental Science
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    • v.11 no.3
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    • pp.197-206
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    • 2005
  • This study was carried out to investigate the concentration and characteristics of dust originating from windowless broiler building in each season. 12.0m width and 46m tenth with side wall height of 3.0m was investigated and capacity was 12,800 birds at a stock density of 23.2 birds per square meter. Dust concentrations in terms of total suspended particles (TSP), and particulate matter of sizes $10{\mu}m(PM10),\;2.5{\mu}m (PM2.5),\;and\;1{\mu}m(PM1)$ were measured at 30-minute intervals. On the basis of broiler age, the average dust concentration in summer in TSP as follows: 1,229 904.5 558.8 and $1,053{\mu}g/m^3$ on the broilers' first to fourth week of age, respectively. But during winter, the average dust concentration showed an increasing pattern, as follows: 465.4, 1,401, 4,497, 5,097 and $6,873{\mu}g/m^3$ on the broilers' first to fifth week of age, respectively. The maximum dust concentration of $11,132{\mu}g/m^3$ was observed on the fifth week. On a daily basis, the maximum dust concentration during summer was detected in early morning, and the minimum in the afternoon. The aerial dust particle size of $0.05\~0.35{\mu}m$ was the highest in number. But on volume basis, particle size of 16~99 un had the largest percentage in the broiler house. Crude protein of the dust $(42.8\~65.2\%)$, on dry matter basis, was higher than that $(20.5\~24.5\%)$ fed to the broilers. Heavy metal concentration of the dust also had high levels compared with that of the feed.

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Effect of Modified Cyclone Dust Collector in Windowless Broiler Building (변형된 사이클론 먼지포집기의 이용이 무창계사의 먼지농도에 미치는 영향)

  • Choi, H.C.;Yeong, G.Y.;Song, J.I.;Kang, H.S.;Kwon, D.J.;Yoo, Y.H.;Yang, C.B.;Chun, S.S.;Kim, Y.K.
    • Journal of Animal Environmental Science
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    • v.13 no.2
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    • pp.97-104
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    • 2007
  • This study was carried out to develop the modified cyclone dust collector in windowless broiler building measuring 12 m wide, 46 m long, with a side wall height of 3 m and a capacity of 12,800 birds. Ventilation rate in windowless broiler building was $0.014{\sim}0.015\;and\;0.158{\sim}0.181cmm$ in second weeks and fifth weeks of age, respectively. Ammonia concentration was $13{\sim}16\;and\;20{\sim}24\;ppm$ in first and second weeks of age, respectively. Amount of dust collected in dust collector each week was 104.1, 274.7 and 388.6g in first, second and third weeks of age. But it was decreased from fourth weeks of age because of the increased ventilation rate. Total suspended particulate(TSP) of polluted air was $3,111.7{\sim}8,745.2{\mu}g/m^3$, but it was decreased to $530.8{\sim}2,264.4{\mu}g/m^3$ when it passed through the dust collector. Collecting efficiency was $54.2{\sim}82.9%$ in TSP. But collecting efficiency of Particulate matter smaller than $1{\mu}g$ (PM1.0) was $7.6{\sim}33.8%$, and lower than TSP. TSP concentration in control broiler house was 1,387.6 and $4,210.1{\mu}g/m^3$ in first and fourth weeks of age, respectively. But it was decreased to 876.3 and $2,535.3{\mu}g/m^3$ in broiler house operated dust collector in first and fourth weeks of age, respectively. Dust collecting efficiency for TSP was $36.8{\sim}39.8%$, and it was decreased to $11.4{\sim}39.8%$ in smaller dust size.

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Effect of Stocking Density on Chicken Meat Grades and PSE Incidence in Broiler House with or without Window (유창 및 무창계사의 사육 밀도에 따른 닭고기 등급 및 PSE육 출현에 미치는 영향)

  • Chae, H.S.;Kang, H.S.;Yoo, Y.M.;Jang, A.;Jeong, S.G.;Ham, J.S.;Ahn, C.N.
    • Korean Journal of Poultry Science
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    • v.36 no.1
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    • pp.1-7
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    • 2009
  • This study was performed to evaluate the effect of the level of stocking density of housing with or without window on chicken meat quality. The incidence of $1^+$ grade of whole chicken housed with window significantly influenced by stocking density. The incidence of $1^+$ grade chicken at high stocking density ($0.050\;m^2$/head), standard stocking density ($0.066\;m^2$/head), and low stocking density ($0.083\;m^2$/head) was 26, 52, and 66%, respectively. Breast muscle of chicken housed with window and with low stocking density showed higher incidence of $1^+$ grade than high stocking density. Also minor and severe PSE (pale, soft, extractive) incidence of chicken meat were showed 4% each, while the $1^+$ grade chicken was not appeared at low density. In chicken thigh, the incidence rate was not affected by stocking density. In chicken housed without window, the incidence of $1^+$ grade chicken in high, standard, and low stocking density was 18, 8, and 46%, respectively. Also, the incidence of $1^+$ grade chicken breast was 2.6 times higher than the chicken in low stocking density. However, incidence of $1^+$ grade thigh was not affected by the stocking density. These results suggest that high stocking density significantly reduced the incidence of $1^+$ grade chicken meat regardless of housing with or without window.

Analysis of Actual State of Facilities for Pleurotus eryngii Cultivation - Based on Western Gyeongnam Area - (큰느타리버섯 재배사의 실태분석 - 서부경남지역을 중심으로 -)

  • Yoon Yong Cheol;Suh Won Myung;Yu Chan
    • Journal of Bio-Environment Control
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    • v.13 no.4
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    • pp.217-225
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    • 2004
  • This study was performed to provide the basic knowledge about the mushroom cultivation facilities. Classified current status of cultivation facilities in Gyeongnam province was investigated by questionnaire. The structure of Pleurotus eryngii cultivation facilities can be classified into the simple and permanent frame type. The simple frame structures were mostly single-span type, on the other hand, the permanent frame structures were more multi-span than simple structures. And the scale of cultivation facilities was very different regardless of structural type. But as a whole, the length, width and ridge height were prevailing approximately 20.0 m, $6.6\~7.0m$ and $4.6\~5.0m$ range, respectively. The floor area was about $132\~160\;m^2$, and floor was built with concrete to protect mushrooms from various harmful infection. The roof slope of the simple and permanent type showed about $41.5^{\circ}\;and\;18.6\~28.6^{\circ}$, respectively. The width and layer number of growing bed for mushroom cultivation were around $1.2\~1.6m$, 4 layers in common, respectively. Most of year round cultivation facilities were equipped with cooler, heater, humidifier, and ventilating fan. Hot water boiler was the most commonly used heating system, the next was electric heater and then steam boiler. The industrial air conditioner has been widely used for cooling. And humidity was controlled mostly by ultra-wave or centrifuging humidifier. But some farmers has been using nozzle system for auxiliary purpose. More then $90\%$ of the mushroom house had the independent environment control system. The inside temperature was usually controlled by sensor, but humidity and $CO_2$ concentration was controlled by timer for each growing stage. The capacity of medium bottle was generally 850 cc and 1100cc, some farms used 800 cc, 950 co and 1,250 cc. Most of mushroom producted has been usually shipped to both circulating company and joint market.

Present Condition of Fortress of Silla Capital and Research Direction on Landscape Architecture (신라왕경 성곽의 현황과 조경학적 차원의 연구방향)

  • Kim, Hyung-Suk;Sim, Woo-Kyung;Lee, Won-Ho;Ahn, Gye-Bog
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.1
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    • pp.1-11
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    • 2015
  • Gyeongju, Silla capital, hasn't paid much attention to a value of fortress as advanced frame of landscape all the while. All have done until now were maintaining lots of fortress including Gyeongju and setting night landscape lighting for them or building a trail in mountain fortress. Hereupon, this study tried to take a look at historical and scenic value of fortress, landscape frame of Gyeongju-Silla capital, based on Wolseong and Myeonghwalseong and find the way to contribute to it on landscape architectural level. As Wolseong(月城) and Myeonghwalseong(明活城) functioned as royal palace in Silla Dynasty, they need some research and study on fortress inside in detail rather than restoring them by simply maintaining the shapes. While Wolseong has overall excavation investigation going on, Myeonghwalseong representing mountain fortress area is losing its value due to unbefitting management to a title of world heritage. If conducting close research and study on these remains, it seems like it could contribute a lot to landscape architectural research of Silla royal palace through tracks, which will be used as royal palace. Here I suggest research direction on landscape architectural level about fortress remains in Gyeongju area as followings. Firstly, away from all research focusing on fortress shape, consecration way, etc, we need to conduct a research comprisable of inner space of fortress. As Wolseong and Myeonghwalseong functioned as royal palace in Silla Dynasty, it'll be possible to research about ponds, Nu-Jeong(樓亭), drainage facilities, oddly shaped stones, moundings, pavements, circulation systems, planting traces, etc. For this, we need to research and study through comparison with cases of China, Japan and Goguryeo of the same age. Secondly, applying garden archaeological way is possible to translate objectively regarding research of ancient garden with low literature record. But attainable achievement and information will be limited if implementing excavation based on archaeology as excavations so far regarding excavation investigation of Wolseong. The alternative to such problem is participation plan of landscaping field through the foundation of garden archaeology. We might be able to attain many results on landscape architectural level from research, if conducting research and study about Silla capital including Wolseong by applying garden archaeology such as collection of environmental sample and discovery and analysis of remains through aerial photograph, archaeological research, analysis of historical building, surface exploration, excavation technique, analysis of soil and flowerpot, etc. For this, many people majored in landscape architecture need to try and acquire archaeological knowledge. Also, we need to call attention to internal garden archaeology through international academic symposium by inviting global experts in garden archaeology field. I've suggested the study of location of Wolseong and Silla fortress in Gyeongju area, plan research on using and treating trees about the space in and out of fortress and landscape architectural research direction of Wolseong fortress.