Purpose: To examine the relationship between working in a very dry clean room (relative humidity less than 1%) and dry eye, and its progress by lapse of time. Methods: Targeting 352 employees working in a clean room of onesecondary cell production plant, it performed a dry eye examination in 2011, 2012, and 2013, totally three times. It performed the TFBUT, Schirmer’s test,slit lamp microscope examination, and Mac Morning survey. dry eye stages were classified based on the DEWS criteria. The annual examination results were analyzed through the Anova test and the post-mortem was conducted with Tukey, and in order to learn the effect of working time on dry eye, anunivariate logistic regression analysis was conducted having dry eye examination results as a dependent variable and working time as an independent variable. Results: According to TFBUT and Mac Morning survey, dry eye degenerated as time passed. There was no change in the Schirmer’s test. Considering that as a result of the univariate logistic regression analysis having dry eye examination results as a dependent variable and working time as an independent variable, in the Mac Morning survey, the cross ratio increased up to 1.127(95%CI 1.033~1.230)by lapse of time, it could be found that as working time is elongated, the complaining rate of dry eye increases. Conclusion: It is thought that a clean room with a relative humidity less than 1% affects causing dry eye. Working time limitation, job rotation, and health care such as prescription of artificial tear solution without preserved agent are necessary.
Since korea must get 5.2% reduction of green gas emission and insecurity of economic impact is on the increase due to unstable oil market, the demands of energy saving techniques are increasing. In this paper, we investigate necessity of development of enormous energy used cleanroom energy saving techniques furthermore we also investigate the adoption of dependability management system to develop the energy saving cleanroom development process.
In this report, we provide the focus on suggesting a method of estimating and measurement of CBM(Customer Behavior Model). Through the use of internet, a new trend of business for e-CRM on B2C Web Site known as EC has emerged. The purpose of this study is to identify the relationship between the customers of a shopping mall and CBM characteristics. It can be used to gain a better understanding of customers. From this we can determine trends, and so refine business toward customer's needs and target new products to particular customer groups. Result shows that there is a significant relationship between the customers pattern of shopping mall and CBM, CVM(Customer Visit Model).
This research analyzes clean room major fire prevention standard of clean Room(FM, IRI, and NFPA Code), the structure of Performance-Based Fire Safety Design(PBD) applied the korean fire industry situation. Performance-Based Fire Safety can operate effectively the performance of fire protection equipment & building design, so the fitness of fire safety system can be embodied by operating this. moreover, cost to be consume fire safety of real building can reduce and Performance-Based Fire Safety is considered to important technique in fire protection field. A fire in a clean room may cause a serious loss by spreading smoke particles. We will be investigated by using a computational fluid dynamics, for loss prevention by smoke spreading from one fire area to another for clean room and compared the Performance-Based Fire Safety Design with the prescriptive code design. The methodology of fire safety performance-based fire safety design and guarantee of many kinds design skill of fire system and developing design procedure will be very serious one in order to improve efficiency of domestic system. Therefore, This research will be contributing to secure safety of clean room and to set up the performance-based fire safety design in Korea by regulation for the performance-based fire safety design effectively.
Numerical analysis was conducted to characterize particle deposition on a heated rotating semiconductor wafer with respect to wafer diameter. The particle transport mechanisms considered in this study were convection, Brownian diffusion, gravitational settling, and thermophoresis. The averaged particle deposition velocities and their radial distributions on the upper surface of the wafer were calculated from the particle concentration equation in an Eulerian frame of reference at rotating speeds of 0 and 1000 rpm, wafer diameters of 100, 300 mm and wafer heating of =0 and 5K. It was observed from the numerical results that the averaged deposition velocities on the upper surface increase, when the wafer diameter confirms increase. The comparison of the present numerical results with the available experimental results showed relatively good agreement between different studies.
건축물에서 사용되고 있는 건축 재료의 연소 특성 예측 및 성능 분류는 국내의 경우, 콘칼로리미터 시험 방법 등을 적용하여 건축법에서 불연/준불연/난연으로 구분하고 있다. 하지만 반도체 공정에서 사용되고 있는 고분자 재료 등에서는 이러한 열량 측정과 가스유해성 평가로는 정확한 연소 특성을 판단하기 어렵다. 건축물에서 화재위험성을 예측하고 대비하기 위해서는 사용되고 있는 재료에 대한 연소 특성 분석이 선행되어야 하며, 이를 위해서 재료가 연소되면서 발생되는 열량의 크기를 기본으로 하여 재료에 대한 연소 특성 예측 및 연소 성능 분류를 실시하고 있다. 하지만 점차 건축물에서는 다양한 재료가 사용되고 있고 이러한 재료에 대한 화재위험성은 열량 크기의 측정만으로는 한계를 가진다. 특히 플라스틱 재품은 발생되는 열량은 작지만 재료가 녹으면서 발생되는 가스 및 인접 재료에 대한 화재전파의 위험성을 높게 나타나고 있지만 현재 국내에서는 이러한 위험성을 예측할 수 있는 기준 및 시험방법이 미비한 실정이다. 따라서 본 연구에서는 FM 4910 시험 기준에 의해서 클린룸에서 사용되는 재료에 대한 연소특성을 예측하고 이를 토대로 하여 제시될 수 있는 연소 성능 기준에 대해 분석해 보고자 하였다.