• 한국식품조리과학회지
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• 제19권4호
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• pp.403-412
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• 2003

The purpose of this study was to develop methods for foodservice employees to perform by measuring their levels of sanitation and hygiene practices. The employees' sanitation and hygiene competency list for school foodservice was developed on the basis of the job standardization. The competency list was divided into three parts; (1) before starting the work, (2) during the work and (3) after the work. The levels of the employees' sanitation and hygiene practices were evaluated by dietitians and by the employees themselves. Most schools had conventional foodservice systems (83.4%), which were operated by contract management (94.8%). It was found that the highest practice level related to sanitation and hygiene before starting work, with the lowest levels observed after work. The item related to the cleaning and sanitizing of dishes had the lowest practice level score. Employees perceived their sanitation and hygiene practice after work to be worse than before starting and during work. The items of ″Clean and sanitize all large stationary equipment after every use, and record equipment monitoring chart″ and ″Do not clean dishes and utensils in production area″ had the lowest scores by employees. The scores of the employees were similar to the perception of the dietitians.

• 한국기계가공학회지
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• 제18권10호
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• pp.99-103
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• 2019

Recently, as the high-precision machinery industry has developed rapidly, peripheral equipment has been developed to improve machining efficiency. Peripheral equipment for machining includes cooling units, housings, oil separators, and much more. Oil, such as cleaning and cutting fluids, is used for machining. When waste oil is reused, the contamination of the workpieces and reduction in machining accuracy are generated by the waste oil, including sludge. Therefore, the development of an oil separator is necessary for efficiently separating oil, water, and sludge. The purpose of this study is to analyze the oil separation efficiency and flow characteristics of a high-speed centrifugal separator according to the rotation velocity and diffusion plate. The oil separation efficiency and flow characteristics were analyzed using hydrodynamic theory and computational fluid dynamics (CFD). The results of this study will be used as basic data for the development of a high-speed centrifugal separator.

• 한국기계가공학회지
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• 제18권5호
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• pp.1-8
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• 2019

Breath analysis using a portable device is better than the classical breath analysis system in terms of installation and operation. There is an increasing need to develop cost-effective equipment for testing gas sensors from the viewpoint of functionalities that can be applied applicable to portable devices. In the present study, an economical gas chamber for in-situ gas measurement is implemented with a single gas chamber without using expensive gas storage and control equipment; the gas response characteristics are analyzed using the above-described chamber. The main features of the implemented gas chamber are simple injection procedure, improved gas diffusion, easy measurement and cleaning, support for low-power mode measurement function for portable devices, and open source platform. Moreover, an analysis of gas response characteristics based on changes in sensor voltage show that the sensitivity and 90% response time are affected by the sensor voltage. Furthermore, the sensitivity graph has an inflection point in a specific range. The gas sensor applied in this study showed fast response speed and high sensitivity for sensor voltages of 3.0-3.5 V, regardless of the concentration of acetone gas, the target gas used in this study.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.837-847
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• 2007

The study focused on the evaluation of maintenance management strategies used in public hospital buildings in Lagos state. It also assessed the labour composition for maintenance operations. In achieving these objectives, opinions of maintenance officers of ten (10) different hospitals in different local government areas of the state were sampled through well structured questionnaires. The data collected were analyzed using descriptive and inferential statistics. From the analysis, the study revealed that majority of those public hospitals do not have specific budget for maintenance programmes, maintenance policies, maintenance log book and maintenance manual to guide the operatives. About 98% of them do not understand the type of maintenance strategy being used for their maintenance operations. 78% of the maintenance work are only executed when there is a breakdown or in response to user's request. For labour composition, the cleaning of interior and exterior of the building, inspection of building elements, repairs and replacements of building elements are mainly carried out by in-house staff, while the repair and replacement of equipment is by outsourcing. The study also revealed that using in- house staff, reduces costs and provides a higher security while outsourcing provides more flexibility in staffing reduces equipment expenditures and provide better access to special skills. The study recommended proactive measures to provide necessary training and support for maintenance staff and users of these facilities and a means of securing sufficient funds for maintenance programmes.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.800-803
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• 2008

도로시설은 교통을 위한 가장 기본적인 인프라 시설로, 원활한 교통흐름을 위해 다양한 정보가 노면에 표시되어 있다. 이러한 정보는 도로를 유지 관리하는 과정에서 지속적으로 제거되고 다시 표시하게 된다. 노면표시를 제거하는데 있어서 기존의 방법은 토치와 그라인더를 이용한 반복 작업으로 위험성과 함께 작업자가 운행 중인 차량에 직접 노출되는 문제점을 갖고 있었다. 또한 노면표시 중 일부인 차선을 효과적으로 제거하기 위한 개선방안으로 자동화 장비의 도입과 워터젯을 이용한 차선제거 장비가 개발되어 활용되고 있으나 몇 가지 문제점을 갖고 있다. 이에 본 연구는 친환경 세척기술의 하나인 드라이아이스 블래스터 장비 도입을 통하여 자동화 차선제거 장비개발의 가능성을 검토하고자 하였다. 기본 연구 수행 결과 드라이아이스 블래스터를 차선제거에 적용하는 것은 가능할 것으로 판단되며, 향후 구체적인 장비 개발을 위한 경제성 및 타당성 분석하는데 추가적인 연구가 요구될 것으로 판단된다.

• 반도체디스플레이기술학회지
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• 제12권3호
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• pp.19-22
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• 2013

The purpose of this study is to develop a system that can monitor the amounts of energy consumption during CVD and etching process for semiconductor manufacturing. Specifically, this system is designed to measure the $CO_2$ emission amounts quantitatively by measuring the flow rate of gas used and amount of power consumed during the processes. The processes of CVD equipment can be classified generally into processing step and cleaning step and all the two steps were monitored. In CVD and etcher equipments, various gases including Ar and $O_2$ are used, but Ar, $O_2$ and He were monitored with the use of the LCI data of Korea Environmental Industry & Technology Institute and carbon emission coefficients of EcoInvent. As a result, it was found that the carbon emission amounts of CVD equipment for Ar, $O_2$ and He were $0.030kgCO_2/min$, $4.580{\times}10^{-3}kgCO_2/min$ and $6.817{\times}10^{-4}kgCO_2/min$, respectively and those of etcher equipment for Ar and $O_2$ are $5.111{\times}10^{-3}kgCO_2/min$ and $7.172kgCO_2/min$, respectively.

• 한국물환경학회지
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• 제36권6호
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• pp.535-545
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• 2020

This study aims to conserve and monitor energy use in public sewage treatment plants by utilizing data from the SCADA system and by controlling the aeration rate required for maintaining effluent water quality. Power consumption in the sewage treatment process was predicted using the equipment's uptime, efficiency, and inherent power consumption. The predicted energy consumption was calibrated by measured data. Additionally, energy efficiency indicators were proposed based on statistical data for energy use, capacity, and effluent quality. In one case study, a sewage treatment plant operated via the SBR process used ~30% of energy consumed in maintaining the bioreactors and treated water tanks (included decanting pump and cleaning systems). Energy consumption analysis with the K-ECO Tool-kit was conducted for unit processing. The results showed that about 58.7% of total energy consumed was used in the preliminary and biological treatment rotating equipment such as the blower and pump. In addition, the energy consumption rate was higher to the order of 19.2% in the phosphorus removal process, 16.0% during sludge treatment, and 6.1% during disinfection and discharge. In terms of equipment energy usage, feeding and decanting pumps accounted for 40% of total energy consumed following 27% for blowers. By controlling the aeration rate based on the proposed feedback control system, the DO concentration was reduced by 56% compared pre-controls and the aeration amount decreased by 28%. The overall power consumption of the plant was reduced by 6% via aeration control.

• 한국산업보건학회지
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• 제4권2호
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• pp.224-239
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• 1994

본 연구는 1993년 10월부터 1994년 3월 사이에 PCE를 세정제로 사용하는 세탁소중 충청권에 있는 23개소의 세탁소 작업자 30명을 폭로군으로, 모대학교 사무직원 42명을 비폭로군으로 하여 자각증상을 조사하였고, 세탁소 작업자의 PCE 폭로농도 및 작업장 기중농도를 측정하였다. 혈액과 뇨를 채취하여 혈액학적, 임상화학적 검사 및 뇨단백, 뇨당을 검사함으로써 PCE 폭로정도에 따른 관련성을 분석하여 다음과 같이 결과를 요약하고, 세탁소의 작업장 환경을 양호하게 관리하기 위한 몇가지 방안을 제안하고자 한다. 1. 폭로군이 비폭로군에 비해 조사항목 대부분에서 높은 자각증상 호소율을 나타냈으며, 특히 호흡기계, 심혈관계, 소화기계, 신경정신계에서 높은 자각증상을 호소했다. 개인폭로농도와 자각증상 호소율은 상호 관련성이 없었다. 2. 1일 8시간 작업시 PCE의 허용농도는 우리나라의 경우 50.0ppm, ACGIH에서는 25.0ppm으로 권장하고 있다. 조사대상 세탁소 형태별로 작업자의 PCE폭로농도는 체인본부가 16.85ppm, 일반 세탁소가 8.83ppm, 셀프-서비스점이 3.07ppm으로 나타났다. 전체적으로 세탁소 작업자의 PCE 폭로농도는 25.0ppm 이하가 19개소(82.6%)였으며, 25.0ppm 이상 측정된 세탁소는 4개소(17.4%)였고, 50.0ppm을 넘는 세탁소는 한 곳도 없었다. 이상의 결과에서 측정대상 세탁소의 작업환경 관리가 비교적 양호함을 알 수 있다. 3. PCE 기기의 가동횟수가 증가할수록 또한 작업량(세탁량)이 많아질수록 PCE 폭로정도는 증가하였다. 또 개방형 PCE 기기를 사용하는 작업자의 폭로농도는 6.18ppm, 밀폐형은 11.48ppm으로 나타났으나, 밀폐형을 사용하는 세탁소의 경우 개방형보다 작업량이 2-3배 정도 많았으며, 이 결과는 기기의 형태보다 작업량과 관계가 있는 것으로 나타났다. 4. 혈액학적 검사에서는 WBC, RBC, Hgb, Hct, MCV, MCH, MCHC, PLT 모두 정상으로 나타났으며, 혈액의 임상화학적 검사에서도 간기능, 신장기능 진단에 이용되는 GOT, GPT, ALP, U-A 및 LDH가 정상으로 나타났다. 5. 뇨단백 및 뇨당 검사에서는 대부분 정상이었고, 3명의 뇨단백이 30mg/dl 이하로 약간 배출되었으며, 뇨당은 3명이 100mg/dl 이하, 2명이 100-250mg/dl로 약간 높게 배출하였다. 이상의 결과에서 PCE 폭로군은 비폭로군보다 신체의 여러부분에 대해 높은 자각증상 호소율을 나타냈다. 조사대상 세탁소의 작업환경은 비교적 양호하게 관리되고 있었으며, 혈액학적 및 임상화학적 검사는 직업성으로 인해 이상이 유발되었다고 평가할만한 사실은 관찰되지 않았다. 그러나 세탁소에서는 PCE뿐만 아니라 얼룩을 제거하기 위하여 여러 종류의 유기용제를 사용하기 때문에 작업자들은 항상 위해한 환경 인자에 노출되고 있다고 사료되므로, 작업장 환경을 보다 쾌적하게 관리하기 위해서는 PCE의 기계적 누출을 조사하고, 의류의 충분한 건조, 적절하고 합리적인 환풍기의 가동 및 개인보호구 착용 등에 관심을 기울여야 할 것이다.

• 한국연소학회지
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• 제17권3호
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• pp.30-45
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• 2012

An existing unit of power plant is considered to refurbish it for possible application of carbon capture and storage(CCS). Conceptual design of the plant includes basic considerations on the national and international situation of energy use, environmental concerns, required budget, and time schedule as well as the engineering concept of the plant. While major equipment of the recently upgraded power plant is going to be reused, a new boiler for air-oxy fired dual mode operation is to be designed. Cryogenic air separation unit is considered for optimized capacity, and combustion system accommodates flue gas recirculation with multiple cleaning and humidity removal units. The flue gas is purified for carbon dioxide separation and treatment. This paper presents the background of the project, participants, and industrial background. Proposed concept of the plant operation is discussed for the possible considerations on the engineering designs.

• International Journal of Contents
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• 제12권3호
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• pp.17-21
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• 2016

The purpose of this study was to obtain qualitative data on Korean-American dry cleaners' concerns about work-related health and safety and their attitudes toward the use of PPE(Personal Protective Equipment). Two focus group discussions were conducted with convenient samples of Korean-American drycleaners in middle-eastern state. A total of 13 individuals participated in two focus groups. Participants had concerns as both owners and workers. As owners, they were concerned mostly about compliance of environmental regulation and economic depression. The participants knew very little about the hazards of chemical exposure and expressed vague concerns about chemical exposure and health. Majority of participants do not use PPE and had no intention of using it in the future because of their limited knowledge about the hazardous nature of chemical exposure. The findings from this study would guide the development of intervention to increase drycleaners knowledge of chemical exposure and use of PPE.