• 제목/요약/키워드: control flow intensive

검색결과 30건 처리시간 0.022초

전자산업 청정실의 작업환경 및 유해물질농도 평가 (Assessment of hazardous substances and workenvironment for cleanrooms of microelectronic industry)

  • 정은교;박현희;신정아;장재길
    • 한국산업보건학회지
    • /
    • 제19권3호
    • /
    • pp.280-287
    • /
    • 2009
  • High-tech microelectronics industry is known as one of the most chemical-intensive industries. In Korea, Microelectronics industry occupied 38% of export and 16% of working employees work in microelectronics industry. But, chemical information and health hazards of high-tech microelectronics manufacturing are poorly understood because of rapid development and its penchant for secrecy. We need to investigate on chemical use and exposure control. We Site-visits to 6 high-tech microelectronics manufacturing company which have cleanroom work using over 1,000kg organic solvents (5 semi-conductor chips and its related parts company, 1 liquid crystal display (LCD)). We reviewed their data on chemical use and ventilation system, and measured TVOCs (Total Volatile Organic Compounds) and carbon dioxide concentration. All cleanroom air passed through hepa filters to acheive low particle levels and only 1 cleanroom uses carbon filters to minimize the organic solvents exposures In TVOC screening test, Cleanroom for semi-conductor chips and its related parts company with laminar down flow system (e.g. class 1~100) showed nondetectable level of TVOCs concentration, but Cleanroom for liquid crystal display (LCD) with conventional flow system (e.g. class 1,000~10,000) showed 327 ppm as TVOCs. Acetone concentration in cleanroom for Jig cleaning, LC Injection, Sealing processes were 18.488ppm (n=14), 49.762 ppm (n=15), 8.656 ppm (n=14) as arithmetric mean. Acetone concentration in cleanroom for LCD inspection process was 40ppm (n=55) as geometric mean, where the range was 7.8~128.7ppm and weakly correlated with ventilation rate efficiency(r=0.44, p<0.05). To control organic solvents in cleanrooms, chemical and carbon filters should be installed with hepa filters. Even though their volatile organic compounds concentration was not exceed to occupational exposure limits, considering of entrance limited cleanroom environment, long-term period exposure effects and adverse health effects of cleanroom worker need further reseach.

반도체 FAB 공정에서의 효율적 흐름제어를 위한 시뮬레이션 (Simulation of Efficient Flow Control for FAB of Semiconductor Manufacturing)

  • 한영신;전동훈
    • 한국멀티미디어학회논문지
    • /
    • 제3권4호
    • /
    • pp.407-415
    • /
    • 2000
  • 설비 집약적이며 복잡한 생산 시스템중의 하나인 반도체 FAB 공정은 제품의 흐름시간과 대기시간, 공정 중 재고를 줄이는 것이 흐름제어의 가장 중요한 목표이다. 이에 본 연구에서는 소품종 다랑 생산 시스템에서 발생하는 비경제성을 줄이고 생산성을 향상시키기 위하여 현재 반도체 양산 회사에서 주로 채택하고 있는 In-Line Layout을 분석하고 새로운 제안 방식인 그룹테크놀로지를 이용한 Job Shop 형태의 Stand Alone Layout과 함께 각각의 모델로 구축하고 시뮬레이션 함으로써 일별 생산 계획상의 회수 변화에 따른 각Layout의 특성을 비교, 분석하였다. 이 때 사용한 시뮬레이션 툴은 모델 구축 및 시뮬레이션이 용이하고 범용적인 (이산형 제조 시스템용) ProSys를 사용하였다. 연구 결과로는 일별 생산 계획상의 회수 초기에는 In-Line Layout이 Stand Alone Layout보다 대체로 생산량 측면에서 우세하지만 일별 생산계획상의 회수가 증가된 14회부터는 Stand Alone Layout이 더 우세한 것으로 나타났다

  • PDF

하도 층구조 이력조사를 통한 하도내 국지퇴적 특성 분석 (Study on Characteristics for Local Deposit of Sediment by Surveying River Bed's Layer History in High Berm of River Channel)

  • 류영훈;이삼희;안원식
    • 한국수자원학회논문집
    • /
    • 제43권10호
    • /
    • pp.883-891
    • /
    • 2010
  • 최근 기후변화에 기인하는 유출특성 변화와 유역 및 하도 환경 변화에 따라 하도형태가 바뀌는 경향을 보이고 있다. 특히 지속적인 성장세를 보이고 있는 하도내 국지퇴적이 전국에 걸쳐 중 대하천에서 야기되고 있다. 이 가운데 고수부지 형태로 나타나는 복단면 하도에서 홍수터가 일방향적 성장과 저수로의 저하현상이 현저한 것으로 나타나고 있다. 이와 같은 현상은홍수량 관리는 물론 하천생태관리에도 영향을 미치고 있는것으로 평가되고 있다. 본 연구에서 우리나라에서의 하도내 국지퇴적에 대해 조사한 결과, 국지퇴적 현상이 사실로 확인되었으며, 하천관리상 현실적인 당면 문제인 것으로 드러났다. 그동안 하상변동특성에 관한 주된 관심사는 저수로에 분급된 하상재료를 토대로 저수로 하상변화에 초점이 맞추어져 왔다. 그러나 본 연구의 결과에서 고수부지(홍수터)의 표층 퇴적이 지피상황 변화와 상호연관성이 높으며, 결국 하도전체의 하상변동에도 영향을 미치고 있음이 입증되었다. 하도내 국지퇴적의 대표적인 장소인 한강하구 고수부지에서의 집중조사 결과에 의하면, 고수부지에 퇴적하는 미세립토가 하천 식생의 정착 및 성장의 결정적인 원인이 되었으며, 이를 계기로 수림화를 동반하는 육역화가 진행되어 홍수 소통에 장애 요소는 물론 건전한 하천생태계에도 영향을 끼치는 것으로 확인되었다.

소하천의 오염부하량이 수질에 미치는 영향에 관한 연구 (A Study about the Influence of Pollutant Load on Water Quality in a Small Stream Watershed)

  • 이상훈;조욱상
    • 환경영향평가
    • /
    • 제10권1호
    • /
    • pp.9-19
    • /
    • 2001
  • An intensive watershed survey including water quality measurement of 6 times was carried out in order to find out the relationship between pollutant load and water quality in a small stream watershed where livestock wastewater is the main source of water pollution. The findings from the survey are as follows. 1) The number of livestock showed large disagreement among county office, myon, and insite survey. It is vital to check the data at the beginning of watershed survey. 2) The fluctuation of streamflow and water quality was so large depending on the day of measurement that it is essential to set up continuous telemetering system to get reliable data about delivery ratio of pollutants. 3) It was helpful for setting the priority of investigation to check water quality and quantity at several points along the stream after dividing the watershed into 5 drainage areas. 4) To control the livestock wastewater, especially in case of cows, it is necessary to have roof system and prevent overland flow from the ground. In case of pig farms, it is recommended to have public treatment system instead of private treatment system. The exact emission load of livestock wastewater was difficult to estimate, and requires more study.

  • PDF

농촌 소유역 유출수에서의 영양염류의 거동 (Behavior of Nutrients in Runoff Water from a Small Rural Watershed)

  • 오광영;김진수;오승영
    • 한국농공학회논문집
    • /
    • 제51권2호
    • /
    • pp.51-57
    • /
    • 2009
  • The purpose of this study was to investigate characteristics of behavior of nutrients such as TN (Total nitrogen), TDN (Total dissolved nitrogen), TP (Total phosphorus) TDP (Total dissolved phosphorous) in runoff water from a nonpoint source dominated watershed ($6.67\;km^2$). Regular and intensive flow measurement and water sampling were taken during two years (February 2002 to January 2004) in the Ingyeong River, a tributary of the Han River. The mean concentrations of nutrients during rainy days were significantly (p < 0.05) higher than those during dry days. The mean TDN/TN ratio in rainy days (95%) is almost identical to that in dry days (96%), but mean TDP/TP ratio in rainy days (24%) significantly decreased compared with that in dry days (66%), suggesting that dominant form of TP is shifted from dissolved form to particulate form. Accordingly, the measures (.eg. filter strips, cover crops) to reduce soil erosion for fallow upland in the rainy season should be taken to control particulate phosphorous.

공간구문론을 이용한 국내권역외상센터 공간구성에 관한 연구 (A Study on the Spatial Configuration for Regional Trauma Center in Korea by Using Space Syntax)

  • 박수로;박재승
    • 한국실내디자인학회논문집
    • /
    • 제26권6호
    • /
    • pp.172-179
    • /
    • 2017
  • The regional trauma center should be a trauma treatment center equipped with facilities, equipments, and manpower capable of providing optimal treatment from emergency surgery to a severely traumatized patient upon arrival at the hospital. In order to establish a medical system for effective severe diseases, it is necessary to prepare architectural planning guidelines for the regional trauma centers. This study analyzes the connectivity, control, integration, and mean depth of current trauma centers using the convex map of space syntax, And to provide basic data for building for more efficient regional trauma center. The major areas that must be included in the regional trauma center are trauma resuscitation room, trauma operating room, trauma intensive care unit, and trauma general ward. It is necessary to carry out the architectural planning to increase the interconnection of the four areas. Also, the elevator plan for trauma patients should be emphasized. In addition, a regional trauma center should be separated from the existing facility for independent operation. According to the case analysis of the space configuration of the regional trauma center, the location of the operating room is most important considering the connection with each department of the hospital and the treatment flow of the severe trauma patients.

Implementation of Remote Monitoring Scenario using CDMA Short Message Service for Protected Crop Production Environment

  • Bae, Keun-Soo;Chung, Sun-Ok;Kim, Ki-Dae;Hur, Seung-Oh;Kim, Hak-Jin
    • Journal of Biosystems Engineering
    • /
    • 제36권4호
    • /
    • pp.279-284
    • /
    • 2011
  • Protected vegetable production area is greater than 26% of the total vegetable production area in Korea, and portion of protected production area is increasing for flowers and fruits. To secure stable productivity and profitability, continuous and intensive monitoring and control of protected crop production environment is critical, which is labor- and time-consuming. Failure to maintain proper environmental conditions (e.g., light, temperature, humidity) leads to significant damage to crop growth and quality, therefore farmers should visit or be present close to the production area. To overcome these problems, application of remote monitoring and control of crop production environment has been increasing. Wireless monitoring and control systems have used CDMA, internet, and smart phone communications. Levels of technology adoption are different for farmers' needs for their cropping systems. In this paper, potential of wireless remote monitoring of protected agricultural environment using CDMA SMS text messages was reported. Monitoring variables were outside weather (precipitation, wind direction and velocity, temperature, and humidity), inside ambient condition (temperature, humidity, $CO_2$ level, and light intensity), irrigation status (irrigation flow rate and pressure), and soil condition (volumetric water content and matric potential). Scenarios and data formats for environment monitoring were devised, tested, and compared. Results of this study would provide useful information for adoption of wireless remote monitoring techniques by farmers.

Machine learning application for predicting the strawberry harvesting time

  • Yang, Mi-Hye;Nam, Won-Ho;Kim, Taegon;Lee, Kwanho;Kim, Younghwa
    • 농업과학연구
    • /
    • 제46권2호
    • /
    • pp.381-393
    • /
    • 2019
  • A smart farm is a system that combines information and communication technology (ICT), internet of things (IoT), and agricultural technology that enable a farm to operate with minimal labor and to automatically control of a greenhouse environment. Machine learning based on recently data-driven techniques has emerged with big data technologies and high-performance computing to create opportunities to quantify data intensive processes in agricultural operational environments. This paper presents research on the application of machine learning technology to diagnose the growth status of crops and predicting the harvest time of strawberries in a greenhouse according to image processing techniques. To classify the growth stages of the strawberries, we used object inference and detection with machine learning model based on deep learning neural networks and TensorFlow. The classification accuracy was compared based on the training data volume and training epoch. As a result, it was able to classify with an accuracy of over 90% with 200 training images and 8,000 training steps. The detection and classification of the strawberry maturities could be identified with an accuracy of over 90% at the mature and over mature stages of the strawberries. Concurrently, the experimental results are promising, and they show that this approach can be applied to develop a machine learning model for predicting the strawberry harvesting time and can be used to provide key decision support information to both farmers and policy makers about optimal harvest times and harvest planning.

심장수술 받은 영아의 영양중재프로그램 개발 및 적용 (Development and Application of a Feeding Program for Infants Postoperatively following Cardiac Surgery)

  • 문주령;조용애;민선인;양지혁;허준;정연이
    • 대한간호학회지
    • /
    • 제39권4호
    • /
    • pp.508-517
    • /
    • 2009
  • Purpose: Despite recent advances in the surgical and postoperative management of infants with congenital heart disease, nutritional support for this population is often suboptimal. The purpose of this study was to develop a nutritional program for the postoperative period for infants who have had cardiac surgery and to evaluate effects of the program. Methods: A quasi-experimental design with pretest and posttest measures was used. A newly developed nutritional program including a feeding protocol and feeding flow was provided to the study group (n=19) and usual feeding care to the control group (n=19). The effects of the feeding program were analyzed in terms of total feed intake, total calorie intake, gastric residual volume, and frequency of diarrhea. Results: Calorie intake and feeding amount in the study group were significantly increased compared to the control group. However, the two groups showed no significant differences in gastric residual volume and frequency of diarrhea. Conclusion: The results indicate that the nutritional program used in the study is an effective nursing intervention program in increasing feeding amount and calorie intake in infants postoperative to cardiac surgery and does not cause feeding-related complications.

VM(Virtual Machine) 을 이용한 분리된 가상화 침해유형 학습 데이터베이스 관리와 보안방안 (The Management and Security Plans of a Separated Virtualization Infringement Type Learning Database Using VM (Virtual Machine))

  • 서우석;전문석
    • 한국통신학회논문지
    • /
    • 제36권8B호
    • /
    • pp.947-953
    • /
    • 2011
  • 최근 지속적이고 치명적인 데이터베이스에 대한 공격성향은 보안 정책과 유사한 발전형태를 가지고 비례적으로 진보하고 있다. 폐쇄적 네트워크에서 생성된 정보에 대한 접근제어 기반의 방어기법과 제한된 접근경로에 대한 공격을 과거 축적되고 학습되어진 공격패턴을 기반으로 많은 시스템과 데이터베이스가 침해당하는 사례가 늘고 있다. 따라서 본 논문 연구를 통하여 제한된 인증과 접근권한에 대한 안정성 확보를 위해 이원화된 VM(Virtual Machine)을 탑재한 가상 침해 패턴 시스템 기반으로 공격정보와 형태를 분리하고 공격 네트워크에 대한 침해 패턴 집중관리를 통해 침해를 차단하는 시스템을 제안하고 최종 데이터베이스를 방어하는 실험과 최적의 방어 기법 및 보안 정책을 구현하기 위한 메커니즘을 개선코자 한다