• 한국안전학회지
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• 제27권5호
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• pp.64-69
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• 2012

The concept of SIL is applied in the most of all standards relating to functional system safety. However there are problems for the people to apply SIL to their plants. as these standards don't include sufficient informations. In this regards, this paper will suggest the direction of SIL application and concept based on IEC 61508 and IEC 61511. A Safety Integrity Level(SIL) is the discrete level(one out of possible fours), corresponding to a range of the probability of an E/E/PE (Electric/Electrical/Programmable Electrical) safety-related system satisfactorily performing the specific safety functions under all the stated conditions within a stated period of time. SIL can be divided into the target SIL(or required SIL) and the result SIL. The target SIL is determined by the risk analysis at the analysis phase of safety lifecycle and the result SIL is calculated during SIL verification at the realization phase of safety lifecycle. The target SIL is determined by the risk analysis like LOPA(Layer Of Protection Analysis), Risk Graph, Risk Matrix and the result SIL is calculated by HFT(Hardware Fault Tolerance), SFF(Safe Failure Fraction) and PFDavg(average Probability of dangerous Failure on Demand). SIL is applied to various areas such as process safety, machinery(road vehicles, railway application, rotating equipment, etc), nuclear sector which functional safety is applied. The functional safety is the part of the overall safety relating to the EUC and the EUC control system that depends on the correct functioning of the E/E/PE safety-related systems and other risk reduction measures. SIL is applied only to the functional safety of SIS(Safety Instrumented System) in safety. EUC is the abbreviation of Equipment Under Control and is the equipment, machinery, apparatus or plant used for manufacturing, process, transportation, medical or other activities.

• Journal of Korean Society for Atmospheric Environment
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• 제9권E호
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• pp.397-400
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• 1993

The possible air pollution problems in a proposed underground highway are discussed using carbon monoxide (CO) as an indicator. Carbon monoxide concentrations in the underground highway depend on several factors, including the size of tunnel, the number of automobiles, the CO emission rate, and the tunnel ventilation rate. Using the estimated values, CO concentrations in the underground highway can be predicted. Without proper ventilation system, CO concentration in the underground highway can be dangerous level. However, the cost of operating the mandatory mechanical ventilation system may be tremendouslyy high and may be technically unrealistic to implement. If the underground highway is constructed with proper ventilation system, a continuous air pollution monitoring system with alarming function must be installed to alert personnel of serious air pollution built up in the underground highway. Traffic must be restricted, whenever the inside air pollution levels exceed agreed values. Short distances between evacuation exits are necessary for emergency situations or malfunction of ventilation system.

• 한국환경보건학회지
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• 제23권2호
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• pp.24-27
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• 1997

This study has been designed to check the removal effect of contaminated water by various water treatmemt processes using sediment filter, activated carbon, reverse osmosis membrane, ultra vilolet sterilizer and ultra filtration and then to analyze the change of pH, the concentration of chlorides, bacteria and E. coli. after 24 hours. pH has increased as much as 0.15-0.32 by activated carbon but decreased sharply by reverse osmosis treatment after 24 hours. The removal effect of chloride was low by activated carbon and ultra filter but high in reverse osmosis. The removal effect of bacteria and E. coli was low by activated carbon and membrane filter system using activated carbon. Ultra filtration process was effective for purify agricultural water containg bacteria and E.coli.

• Journal of Preventive Medicine and Public Health
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• 제22권3호
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• pp.398-405
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• 1989

A change in the consumer's surplus was measured in order to evaluate the social benefit to be derived from expanding health insurance to the entire population. The most refined and correct way to measure a project's net benefit to society is to determine a change in the consumer's surplus. Benefits from introducing the health insurance program to the uninsured people can be classified into two elements. The first is the pricing-down effect(E1) which results from applying the insurance price system, which is lower than the actual price, to the uninsured patients. The second effect(E2) is a decrease in actual payment because an insured patient pays only a portion of the total medical bill(copayment). We collected medical price information from the data banks of 93 hospitals, and obtained information of medical utilization by referring to the results of other research and from data published by the Korean Medical Insurance Societies. The total net benefit was estimated as \214 billion, comprising the first effect(E1) of \57 billion and the second effect(E2) of \157 billion. The price elasticity of physician visits is less than that of hospital admissions: however, benefits from the increase in physician visits are greater than those from hospital admissions because there are considerably more of physician visits than hospital admissions. The sensitivity analysis also shows the conclusion that expansion of the health insurance program to the entire population would result in a positive net benefit. Therfore, we conclude that the National Health Insurance Program is socially desirable.

• 한국보건간호학회지
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• 제34권3호
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• pp.405-415
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• 2020

Purpose: This study was undertaken to identify the mediating effect of family strengths in the relationship between e-learning readiness and learning management system-based online education learning outcomes. Our results provide basic data for proposing strategies to increase online education learning outcomes of nursing students. Methods: A self-report questionnaire was surveyed by 133 nursing students who took online education using a learning management system at three nursing colleges in Daejeon, Jeonbuk, and Gyeongbuk. The mediating effect of family strengths in the relationship between the e-learning readiness of the subject and online education learning outcomes, were analyzed by hierarchical multiple regression. Sobel test was performed to verify effectiveness of the pathway. Results: In the relationship between e-learning readiness and online education learning outcomes of nursing students, family strengths were determined to exert absolute mediating effect. Conclusions: Our results indicate that in order to improve e-learning readiness, the basic curriculum for nursing students should include web-based communication, cooperation, and the use of information technology, including interaction for online education. Improvements in family strengths can be achieved through home study activities, such as frequent conversations with members, monitoring achievements of the students, and sharing family leisure activities.

• 한국환경과학회지
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• 제21권9호
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• pp.1069-1078
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• 2012

This study was performed to evaluate the asbestos exposure levels and to calculate excess lifetime cacer risks(ELCRs) in asbestos-containing buildings for maintenance and management. The range of airborne asbestos concentration of 33 buildings was 0.0018 ~ 0.0126 f/cc and one site exceeded indoor air-quality recommended limit 0.01 f/cc. And ELCRs based on US EPA IRIS(Integrated risk information system) model are 1.5E-06 ~ 3.9E-05 levels, and there was no site showed 1.0E-04 (one person per million) level or more, and 11 sites showed 1.0E-05 (one person per 100,000 people) level or more. To prevent the release of asbestos fibers, it needs operation and maintenance of asbestos-containing building materials, and there are some methods such as removal, repairment, enclosure and encapsulation. In conclusion, a risk-based air action level for asbestos in air is an appropriate metric for asbestos-containing building management.

• Healthcare Informatics Research
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• 제24권4호
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• pp.371-375
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• 2018

Objectives: To successfully introduce an Internet of Things (IoT) system in the hospital environment, this study aimed to identify issues that should be considered while implementing an IoT based on a user demand survey and practical experiences in implementing IoT environment monitoring systems. Methods: In a field test, two types of IoT monitoring systems (on-premises and cloud) were used in Department of Laboratory Medicine and tested for approximately 10 months from June 16, 2016 to April 30, 2017. Information was collected regarding the issues that arose during the implementation process. Results: A total of five issues were identified: sensing and measuring, transmission method, power supply, sensor module shape, and accessibility. Conclusions: It is expected that, with sufficient consideration of the various issues derived from this study, IoT monitoring systems can be applied to other areas, such as device interconnection, remote patient monitoring, and equipment/environmental monitoring.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 추계학술발표대회
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• pp.101-103
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• 2011

E-Health is one of the most promising applications of wireless sensor networks. This paper describes a prototype for e-Health systems. Based on the system, we propose the energy-balanced location-aided routing protocol. The location and energy information of the neighbor Coordinators is collected and stored in the neighbor discovery procedure. And then the Coordinator selects the most suitable neighbor to forward the data. The simulation results show that the proposed protocol has better performance than the three other routing protocols.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.407-410
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• 1997

In this paper, we have designed a portable patient monitor that monitors both ECG and NIBP(Non-Invasive Blood Pressure) for a patient who is bring moved around inside a hospital. System hardware consists of the one-chip microcomputer(80c251), A/D converter, ROM, RAM, LCD diplsy, two channel ECG module and NIBP module. NIBP module was calibrated to the values found in NIBP analyzer. ECG module detects QRS complex and compute heart rate. NIBP module measures the blood pressure by oscilometric method.

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1689-1692
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• 2013

Food is a common source of chromium (Cr) exposure. However, it is difficult to analyze Cr in complex food matrices by using inductively coupled plasma mass spectrometry (ICP-MS) because the major isotope, $^{52}Cr$, is masked by interference generated by the sample matrix and the plasma gas. Among the systems available to minimize interference, the recently developed collision-reaction interface (CRI) has a different structure relative to that of other systems (e.g., collision cell technology, octopole reaction system, and dynamic reaction cell) that were designed as a chamber between the skimmer cone and quadrupole. The CRI system introduces collision or reaction gas directly into the plasma region through a modified hole of skimmer cone. We evaluated the use of an CRI ICP-MS system to minimize polyatomic interference of $^{52}Cr$ and $^{53}Cr$ in various foodstuffs. The $^{52}Cr$ concentrations measured in the standard mode were 2-3 times higher than the certified values. This analytical method based on an ICP-MS system equipped with a CRI of helium gas was effective for Cr analysis in complex food matrices.