• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.425-432
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• 2001

Fluidic valve is adopted in APR1400 to control passively the flow rate of cooling water from the safety injection tank. It is necessary to establish independent evaluation guideline for the flow characteristics of fluidic valve in order to secure safety. Three dimensional numerical model for fluidic valve is developed and numerical results are compared with experimental data obtained at KAERI in order to verify numerical simulation. Also influence of the grid number and the turbulence model were investigated. In addition, variation of flow rate is investigated at various elapsed times after valve operating, and flow characteristics are analyzed at low and high flow rate conditions, respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.236-237
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• 2013

The fire safety design of performance is fire behavior inside buildings must be scientifically described and systemized as a theory, thereby allowing application to fire safety design of buildings. In this study, experiment of fire behavior according to disposition of combustibles were performed for correlation analysis between flashover and smoke production rate in building structure. As a result, smoke production rates is happened more than 80 m2/s in compartment(ISO 9705). Also, even if the fire load for flashover to if occur smoke did not, which confirmed that the delay time of occurrence.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.122-128
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• 2017

Korean government announced long-term railway safety investment plan for the safety improvement by 2020. But no research have been done about differential analysis on railroad safety investment and safety improvement. In this study, recent 10 year data on safety investments and accident data are analysed for the differential analysis. Three main safety investments are analysed on regard to accident rate and accident fatalities. Three safety measures include level crossing accident, platform fatalities, and track trespass fatalities. About 90% of railway accident fatalities are caused by these three kind of accidents. Differential analysis shows about 4 to 6 years delay after railroad safety investment and safety improvement. This result can be utilized for the decision making on safety measures and safety target. Which required long term approach.

• Journal of the Korean Society for Railway
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• v.7 no.3
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• pp.251-258
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• 2004

A systematic methodology to determine safety requirements for railway signalling system and safety requirement allocation into system are presented. THR concept is used for as an interface between Risk Analysis to be performed by railway operator and System Design Analysis by the supplier. This approach is based on Signalling Safety Standard EN50129 by CENELEC.

• Journal of the Korea Safety Management & Science
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• v.20 no.1
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• pp.11-21
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• 2018

Safety accidents, which are called industrial accidents in construction work, are often caused by unstable physical and personal conditions combined during preparation and execution of work. It is difficult to manage all the construction works, but especially in the field of apartment construction work, complex and many kinds of works are being carried out at the same time. In the current construction, safety regulations such as safety management guidelines are generally well maintained, but the execution of manpower resources that can fulfill them is limited, and it is difficult to reduce the accident rate and loss cost. Therefore, in this study, it is a reality that most of the types of construction work are under contruction by subcontracting contract, so they are limit by methods of manual maintenance and safety education. Currently, the subcontractor is also allowed to perform safety management through the composition of the safety management review body, but it is operated formally. So alternatives to this were studied. As a result, safety accidents occur in the subcontractor's worker due to vertical integration, which is characteristic of the construction industry, together to the contractor, the safety management system is based on a safety construction system in which a worker who has a certain qualification condition such as career experience of the work type, work understanding of the work type, and management experience of the work type among the subcontractor, when we manage based on mutual personality which is the personality of interpersonal relationship that can communicate with each other by work type, process and grouping, it is concluded that effective and practical safety management can be achieved to reduce the accident rate and loss cost.

• Journal of Korean Academy of Nursing Administration
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• v.19 no.2
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• pp.315-327
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• 2013

Purpose: The purpose of this study was to investigate the patient safety culture in Korean nursing homes using the Nursing Home Survey Patient Safety Culture (NHS-PC), a valid tool, provided by the Agency for Healthcare Research and Quality (AHRQ) and to compare the results with AHRQ data. Methods: Administrators and staff (N=151) of six nursing homes in Seoul, Busan, Kyeonggi Province and Gyeongsangnam Province completed the survey in July, 2010. The data were analyzed using descriptive statistics, positive response rate, t-test, ANOVA, DUNCAN, Cronbach's ${\alpha}$. Results: The total mean (SD) positive response rate for patient safety culture was not significantly different from the AHRQ data. For composite levels, the results of 'handoffs' were significantly higher, and the results of 'feedback and communication about incidents' and 'nonpunitive responses to mistakes' were significantly lower than the AHRQ data. Conclusion: More effective strategies related to nonpunitive responses to mistakes and management activities for patient safety are needed to improve patient safety culture in nursing homes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.240-241
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• 2019

Construction disasters have more distinctive characteristics than other industrial disasters. Since it is likely that construction disasters will spread to severe accidents, the accident mortality rate is very high compared to the disaster incidence rate. Therefore, the purpose of this study is to compare and analyze the operation status of construction risk assessment by domestic large and medium sized construction companies to prepare improvement direction of risk assessment system. The survey results for safety management experts of construction companies are as follows: Large companies have developed and utilized risk assessment systems in their respective companies, while small and medium construction companies have developed and evaluated risk factors through the Excel program. Rather than performing risk assessment tasks based on historical safety accident data, construction companies have limitations in developing risk factors and preparing solutions with suppliers for each major construction. Therefore, it is necessary to prepare a risk assessment system in the future by analyzing the types of safety accidents, such as the safety accident data of each company as well as the safety accident data.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.32-39
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• 2022

This study analyzed the relationship between occupational accidents in the construction industry and business cycle factors. Multiple regression analyses were conducted to achieve the research purpose; additionally, time-varying parameter estimations were performed to interpret the results. The results obtained for the construction industry revealed a statistically significant relationship between occupational accidents and wage increase rate, unemployment, construction starts, and other factors. The wage increase rate plays a role in reducing occupational accidents because efforts are made to prevent accidents owing to the increase in income loss due to accidents and the demand for increased safety levels. The number of construction starts affects occupational accidents with a time lag of 1 to 2 or 4 months; therefore, it is likely to be used as a leading indicator for estimating fatal accidents in the construction industry. This study highlighted the importance of monitoring socioeconomic changes that could affect the working conditions of workers and workplaces, and production activities in the workplace for the effective prevention of occupational accidents. This study also reveals the necessity of developing a method to operate prevention projects flexibly and the seasonality of industrial characteristics, particularly those of the construction industry where the highest number of fatal occupational injuries occur.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.692-698
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• 2022

With the expansion of domestic hydrogen fuelling station infrastructure, it is necessary to secure reliability among hydrogen traders, and for this, technology to accurately measure hydrogen is important. In this study, 4 types of hydrogen trading volume calculation models (model 1-4) were presented to improve the accuracy of the hydrogen trading volume. In order to obtain the reference value of model 4, and experiment was conducted using a flow rate measurement equipment, and the error rate of the calculated value for each model was compared and analyzed. As a result, model 1 had the lowest metering accuracy, model 2 had the second highest metering accuracy and model 3 had the highest metering accuracy until a certain point. But after the point, model 2 had the highest metering accuracy and model 3 had the second metering accuracy.

• Journal of Radiation Protection and Research
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• v.44 no.2
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• pp.64-71
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• 2019

Background: It is very difficult to distinguish between a radioactive contamination source and background radiation from natural radionuclides in the marine environment by means of online monitoring system. The objective of this study was to investigate a statistical process for triggering abnormal level of count rate data measured from our on-line seawater radioactivity monitoring. Materials and Methods: Count rate data sets in time series were collected from 9 monitoring posts. All of the count rate data were measured every 15 minutes from the region of interest (ROI) for $^{137}Cs$ ($E_{\gamma}=661.6keV$) on the gamma-ray energy spectrum. The Shewhart ($3{\sigma}$), CUSUM, and Bayesian S-R control chart methods were evaluated and the comparative analysis of determination methods for count rate data was carried out in terms of the false positive incidence rate. All statistical algorithms were developed using R Programming by the authors. Results and Discussion: The $3{\sigma}$, CUSUM, and S-R analyses resulted in the average false positive incidence rate of $0.164{\pm}0.047%$, $0.064{\pm}0.0367%$, and $0.030{\pm}0.018%$, respectively. The S-R method has a lower value than that of the $3{\sigma}$ and CUSUM method, because the Bayesian S-R method use the information to evaluate a posterior distribution, even though the CUSUM control chart accumulate information from recent data points. As the result of comparison between net count rate and gross count rate measured in time series all the year at a monitoring post using the $3{\sigma}$ control charts, the two methods resulted in the false positive incidence rate of 0.142% and 0.219%, respectively. Conclusion: Bayesian S-R and CUSUM control charts are better suited for on-line seawater radioactivity monitoring with an count rate data in time series than $3{\sigma}$ control chart. However, it requires a continuous increasing trend to differentiate between a false positive and actual radioactive contamination. For the determination of count rate, the net count method is better than the gross count method because of relatively a small variation in the data points.