• Journal of Korea Water Resources Association
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• v.42 no.8
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• pp.591-605
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• 2009

In this study the risk integrated erosion and seepage failure factor and combined risk of the levee embankment were assessed. For the research of the reliability, the risk assessment of erosion, seepage and both of them combined for the levee embankment were conducted using discharge curve and stage hydrograph generated by stochastic rainfall variation method during typhoon and monsoon season. The risk of erosion was evaluated using tractive force and the seepage analysis was performed by selecting representative cross sections for SEEP/W model analysis. And the probability of seepage failure was assessed with MFOSM analysis using critical hydraulic gradient method. Unlike deterministic analysis method, quantitative risk could be obtained and the characteristics of realistic rainfall variation patterns as well as a variety of factors contributing to levee failure could be reflected in this research. The results of this study show significantly enhanced applicability for the combined risk. As this model can be employed to determine dangerous spots for levee failure and to establish flood insurance linked with flood risk map, it will dramatically contribute to the establishment of both efficient and systematic measures for integrated flood management on a watershed.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.2
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• pp.142-150
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• 2024

Objective: Diminished ovarian reserve (DOR) is a disorder characterized by impaired ovarian function. Sleep disorders are disruptions of the circadian rhythm, which appears to be closely linked to reproductive systems. This study aimed to investigate the impact of poor sleep quality on the ovarian reserve of childbearing-age women. Methods: A cross-sectional study was conducted in China from June 2021 to March 2023. In total, 102 participants diagnosed with chronic insomnia disorder were included in the study. Questionnaires were administered to assess participants' menstrual patterns, insomnia severity, anxiety, and depression. The anti-Müllerian hormone level and the basal antral follicle count were measured for ovarian reserve evaluation. Correlation analysis and ordinal logistic regression analysis were conducted. Results: The women with insomnia presented high percentages of hypomenorrhea, premenstrual syndrome, and dysmenorrhea (78.4%, 74.5%, and 46.1%, respectively). Severe sleep disorder in the past month was identified as an independent risk factor for hypomenorrhea and premenstrual syndrome (odds ratio [OR], 2.64 and OR, 2.688; p<0.05). The prevalence of DOR among women with insomnia (33.3%) was significantly higher than the average reported in previous studies for young women. Insomnia duration exceeding 1 year was determined to be an independent risk factor for DOR in women aged 36 to 40 years (OR, 4.5; p=0.033). Conclusion: This study highlights the association between sleep disorders and menstrual problems. Prolonged poor sleep quality in women aged 36 to 40 years was identified as a significant risk factor for DOR. We should pay more attention to improving sleep quality in order to maintain normal ovarian function.

• Nuclear Engineering and Technology
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• v.56 no.10
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• pp.4031-4041
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• 2024

The PSA (Probabilistic Safety Assessment) is presented as a method of comprehensively evaluating the types of accidents that can occur at nuclear power plants. One of the key components to obtain technical success was the introduction of event tree analysis, and its strength and weakness has been reviewed and enhanced with the term, for instance, Integrated Deterministic-Probabilistic Safety Assessment (IDPSA) since 1980s. However, the technical and policy maturity of IDPSA appears to have room for improvement: the terminologies need to be arranged internationally, and there are no official standards or guidelines for the method itself. Due to a misperception of IDPSA, there are even concerns that appropriate contribution in risk assessment cannot be made. For this reason, surveys and focus group interviews, sharing development experiences, and the direction of regulation and R&D on IDPSA were conducted targeting PSA experts in Korea. In order to support such process, authors have structured an overview of the development history and technical features of IDPSA. Finally, we will explore the ways to achieve synergy between the deterministic safety analysis and PSA, which may the origin of motivation how to deal with dynamic variability more properly such that an undue risk can be minimized.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.338-343
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• 2013

Integrated Project Delivery (IPD) as a delivery method fully capitalizes on an integrated project team that takes advantage of the knowledge of all team members to maximize project outcomes. IPD is currently the highest form of collaboration available because all three core project stakeholders, owner, designer and contractor, are aligned to the same purpose. Compared with traditional project delivery approaches such as Design-Bid-Build (DBB), Design-Build (DB), and CM at-Risk, IPD is distinguished in that it eliminates the adversarial nature of the business by encouraging transparency, open communication, honesty and collaboration among all project stakeholders. The team appropriately shares the project risk and reward. Sharing reward is easy, while it is hard to fairly share a failure. So the compensation structure and the contingency in IPD are very different from those in traditional delivery methods and they are expected to encourage motivation, inspiration and creativity of all project stakeholders to achieve project success. This paper investigates the compensation structure in IPD and provides a method to determine the proper level of contingency allocation to reduce the risk of cost overrun. It also proposes a method in which contingency could be used as a functional monetary incentive when established to produce the desired level of collaboration in IPD. Based on the compensation structure scenario discovered, a probabilistic contingency calculation model was created by evaluating the random nature of changes and various risk drivers. The model can be used by the IPD team to forecast the probability of the cost overrun and equip the IPD team with confidence to really enjoy the benefits of collaborative team work.

• Fire Science and Engineering
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• v.17 no.4
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• pp.20-27
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• 2003

Hazard Analysis is one of the basic tasks to ensure the safety of chemical plants. However, it is an arduous, tedious, time-consuming work and requires multidisciplinary knowledge and demands considerable cognitive load from the analysts. To overcome these problems, there have been attempts to automate this work by utilizing computer technology, particularly in the area of knowledge-based technique. There is two methods in the risk assessment of Chemical plant; quantitative and qualitative risk assessment. Both of them have been applied respectively, but if the integrated method of quantitative and qualitative risk assessments is used, all of the advantage of two methods can be applied. It is difficult to carry out integrated risk management of chemical plant. Therefore, automated integration system of risk management is necessary. We developed S/W Automated System for Hazard Screening & Analysis(ASCA) and applied to practical plant. By applying ASCA to case study, we can get the information about relative ranks of equipments, variable deviation, and consequence of potential accident. In this study, we applied ASCA to the H.T.U(Hydrotreating Unit) of the process to produce aromatic material. We could know relative ranks of equipments, variable deviation of malfunction in storage tank, D-101, and consequence of potential accident using ASCA. If integrated risk management in the chemical plant is applied, we can develop the emergency plan and prevent the accident.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.34-42
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• 2023

This study aims to analyze safety reports received through the recently added SMS safety self-report in the Air Force's "integrated air control management" system, identify hazards, present improvements by region (base), and lay the foundation for future data-based safety management. To identify risk factors, it was first classified by base based on data classified into 16 groups in the autonomous reporting system, and second classified in detail based on the type and description. Risk factors were analyzed for the most reported control cooperation (306) items, and improvements were derived by dividing risk factors into information sharing, regulations, procedures, education, training, and equipment items based on the analysis results. It was confirmed that risk factors and specific improvements vary by base (12), which is important data that can present statistical analysis and the direction of safety management in the flight control field by base (region). In addition, since there is no data-based risk factor analysis study for each specific base (region), it can be used in the future as basic research data for data-oriented safety management.

• Journal of Environmental Health Sciences
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• v.43 no.4
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• pp.307-313
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• 2017

Objectives: Chemicals derived from various environment media contaminates food across the food supply chain. In Korea, levels of contaminants in food have been sporadically measured by monitoring programs of different government agencies. There is difficulty with data compilation and integrated analysis across media. Therefore, the aim of this study was to propose an overall integrated database and analytical platform design for the 'ECO-FOOD NET (Environmental COntaminant reduction platform for FOOD through an interagency collaboration NETwork)', a tool to support the reduction of environmental contaminants in food. Methods: We developed a new data structure and standardized protocols for the compilation of integrated data. In addition, we conducted subject-oriented logical and physical relational database modeling and created the architecture design of the platform. Results: We established a standardized code system related to exposure media and route, analysis method and food matrix. In addition, we designed the seven software modules of 'About the System', 'Introduction to Interagency Work', 'Media-Chemicals Profiles', 'Method Bank', 'Monitoring Data Base', 'Integrated Media Analysis', and 'Risk-Benefit Analysis'. Conclusions: This study will contribute to decision-making as a tool for executing risk management, such as sustainable reduction policies of contaminants in food.

• Nuclear Engineering and Technology
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• v.39 no.2
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• pp.123-128
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• 2007

In order to apply a static fault-tree (FT) method to a system or a plant whose configuration changes dynamically, condition gates and a post processing method are used to effectively accommodate these changes. An operator's performance change, which can be caused by these configuration changes, should also be considered to assess the risk to a plant in a more realistic manner. This study aims to develop an integrated framework to accommodate various configuration changes and their effect on an operator’s performance by using the FT model. We applied a condition-based human reliability assessment (CBHRA) method to consider various conditions endured by an operator. That is, we integrated the CBHRA method with the conventional post processing method for modeling the system configuration changes. The effect of the condition monitoring systems installed in a plant is also considered. In this study, we show an example application of the integrated framework to a probabilistic safety assessment for the shutdown phase of a nuclear power plant.

• Nuclear Engineering and Technology
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• v.49 no.2
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• pp.426-433
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• 2017

This paper describes the development process, the innovative techniques used and insights gained from the latest integrated, full scope, multistate Level 2 PSA analysis conducted at the Leibstadt Nuclear Power Plant (KKL), Switzerland. KKL is a modern single-unit General Electric Boiling Water Reactor (BWR/6) with Mark III Containment, and a power output of $3600MW_{th}/1200MW_e$, the highest among the five operating reactors in Switzerland. A Level 2 Probabilistic Safety Assessment (PSA) analyses accident phenomena in nuclear power plants, identifies ways in which radioactive releases from plants can occur and estimates release pathways, magnitude and frequency. This paper attempts to give an overview of the advanced modeling techniques that have been developed and implemented for the recent KKL Level 2 PSA update, with the aim of systematizing the analysis and modeling processes, as well as complying with the relatively prescriptive Swiss requirements for PSA. The analysis provides significant insights into the absolute and relative importances of risk contributors and accident prevention and mitigation measures. Thanks to several newly developed techniques and an integrated approach, the KKL Level 2 PSA report exhibits a high degree of reviewability and maintainability, and transparently highlights the most important risk contributors to Large Early Release Frequency (LERF) with respect to initiating events, components, operator actions or seismic component failure probabilities (fragilities).

• Journal of the Korea Institute of Building Construction
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• v.7 no.3
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• pp.91-98
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• 2007

Recently a construction industry introduces information that brings about many advantages in the early planning phase, design phase and construction phase. Especially it replaces 2D, 3D systems(usually using explanation of drawing information) ai 4D CAD(offering a sort of 4D-having relation of construction schedule and 3D drawing information). Nevertheless a 4D has these benefits, it has limits which are not only usually using 3D modeling but also limit of making full use of practical affairs because of a lack of connecting varietals of progress of work. To solve these uppermost limits, this research is presenting unified systems to use in risk management which are efficient management of space and non-space information, space analysis, making full use of data base, introducing GIS system of easy interaction.