• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2747-2756
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• 2023

Reinforced Concrete (RC) shear walls are one of the civil structures in nuclear power plants to resist lateral loads such as earthquakes and wind loads effectively. Risk-informed and performance-based regulation in the nuclear industry requires considering possible accidents and determining desirable performance on structures. As a result, rather than predicting only the ultimate capacity of structures, the prediction of performances on structures depending on different damage states or various accident scenarios have increasingly needed. This study aims to develop machine-learning models predicting drifts of the RC shear walls according to the damage limit states. The damage limit states are divided into four categories: the onset of cracking, yielding of rebars, crushing of concrete, and structural failure. The data on the drift of shear walls at each damage state are collected from the existing studies, and four regression machine-learning models are used to train the datasets. In addition, the bagging ensemble method is applied to improve the accuracy of the individual machine-learning models. The developed models are to predict the drifts of shear walls consisting of various cross-sections based on designated damage limit states in advance and help to determine the repairing methods according to damage levels to shear walls.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.177-184
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• 2023

In order to reserve frequency bands for stable operation of the Korean Positioning System (KPS), it must be demonstrated that the impact of interference caused by KPS on other services operating in the same bands is tolerable. The International Telecommunication Union (ITU) provides the radio regulations and a compatibility assessment methodology for the coexistence of different services in limited frequency resources. The purpose of this paper is to investigate the radio regulations regarding the compatibility issues between the KPS and other services sharing the same frequency bands. The results of the investigation show that the RNSS system can be operated in the L5-band under the condition that the Power Flux Density (PFD) and Aggregated Equivalent PFD (AEPFD) thresholds specified in the radio regulations are met. In addition, the ITU recommends that the interference-to-noise ratio (INR) protection criteria be met to prevent degradation of the performance of radar systems operating in the L2/L6-band. In the case of the S-band, coordination of allocations for RDSS space stations with respect to terrestrial services is not required if the PFD does not exceed regulated thresholds regulated by ITU.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4499-4513
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• 2022

Spent fuel behavior of dry storage was simulated in a continuous state from steady-state operation by modifying FRAPCON-4.0 to incorporate spent fuel-specific fuel behavior models. Spent fuel behavior of a typical PWR was compared with that of NuScale Power Module (NPM^TM). Current PWR discharge burnup (60 MWd/kgU) gives a sufficient margin to the hoop stress limit of 90 MPa. Most hydrogen precipitation occurs in the first 50 years of dry storage, thereby no extra phenomenological safety factor is identified for extended dry storage up to 100 years. Regulation for spent fuel management can be significantly alleviated for LWR-based SMRs. Hydride embrittlement safety criterion is irrelevant to NuScale spent fuels; they have sufficiently lower plenum pressure and hydrogen contents compared to those of PWRs. Cladding creep out during dry storage reduces the subchannel area with burnup. The most deformed cladding outer diameter after 100 years of dry storage is found to be 9.64 mm for discharge burnup of 70 MWd/kgU. It may deteriorate heat transfer of dry storage by increasing flow resistance and decreasing the view factor of radiative heat transfer. Self-regulated by decreasing rod internal pressure with opening gap, cladding creep out closely reaches the saturated point after ~50 years of dry storage.

• The Journal of Economics, Marketing and Management
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• v.5 no.3
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• pp.12-20
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• 2017

The study examined effects of psychological change of distribution environment upon commercial areas to investigate consumers' experience and theory and to suggest power of new management strategy for growth of retailers A The study investigated actual conditions of business transaction of hyper market by blind interview. In April, 2016, the author visited 6 manufacturers to do depth interview. The questionnaire between food manufacturers and hyper market investigated the Association of Food Industries in Korea, NH Nonghyup and large manufacturers in July 2012. Questionnaires of 25 companies were used after excluding questionnaire having poor and inadequate answers. The sales commission with large scaled distribution business decreased (0.3 ~ 0.7) to increase additional expenses such as number of salesmen, interior expenses and economic costs (0.7 ~ 40%). (source: Fair Trade Commission). Fair Trade Commission released types and notice of unfair trade of large scaled retail business based on monopoly regulation and fair trade (hereinafter called 'notice of large scaled retail) to prevent large scaled distribution business from doing unfair trade. The notice controled unfair trade at different position between large scaled distribution business and small vendors.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.18 no.1
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• pp.1-10
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• 2022

Currently, there is no technical standard and regulation for seismic analysis of non-nuclear safety piping. Accordingly, ASME Sec.III ND, a standards applied to safety class 3 piping, is applied. However, the technical standard applied for other than seismic analysis is ASME B31, which leads to controversy. In this study, the feasibility of applying ASME B31E was confirmed by reviewing rulescomparing technical standards, and evaluating piping allowable stress margins. The evaluation revealed that applying ASME B31.1 as a technical standard is too conservative compared to ASME Sec.III ND. On the other hand, ASME B31E (issued at the request of the industry) clearly presents the technical standards for seismic analysis of ASME B31 piping, and shows a similar level of conservatism compared to ASME Sec.III ND. It is expected to reduce the controversy over technical standards for seismic analysis of non-nuclear safety piping by applying ASME B31E.

• Journal of Radiation Industry
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• v.17 no.1
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• pp.111-118
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• 2023

The International Commission on Radiological Protection (ICRP) 103 recommends a cost-benefit analysis method as an auxiliary tool for scientific and rational decision-making for the principle of optimization of radiological protection. In order to conduct a cost-benefit analysis, the safety improvement of nuclear power by regulation must be measured and converted into monetary terms. The improvement of nuclear safety can be measured by reducing the radiation exposure dose of the people, and it is necessary to determine the coefficient to convert the radiation exposure dose into money. The monetary coefficient is calculated as the product of the statistical life value (VSL) and the nominal risk coefficient. In order to derive the monetary coefficient, the willingness to pay (WTP) can be estimated using the contingent valuation method (CVM), which quantifies the value of non-market goods by converting them into monetary units. WTP can be estimated based on the random utility model, which is the basic model for bivariate selection type conditional value measurement data. Statistical life value can be calculated using the estimated WTP and reduction in early mortality, and a monetary coefficient can be derived.

• The Korean Journal of Emergency Medical Services
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• v.28 no.2
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• pp.109-118
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• 2024

Purpose: This study attempted to identify correlation between communication skills, self-control, and adaptation to college life and identify how communication skills, self-control, and adaptation to college life influence factors influence clinical practice stress among health-related college students. Methods: Data for this study were collected through an online questionnaire for nine days from April 15, 2024, to April 23, 2024, targeting health-related college students nationwide who experienced clinical practice. Results: Clinical practice stress showed a significant negative correlation with communication skills(r=-.387, p<.001), self-regulation(r=-.355, p<.001), and adaptation to college life(r=-.433, p<.001). The factor that most influenced clinical practice stress was adaptation to college life, with an explanatory power of 20%. Conclusion: It is necessary to reduce stress in clinical practice by improving communication skills, self-control, and adaptation to college life through practical measures such as academic support services, psychological counseling, and major-related programs.

• 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.

• Journal of Legislation Research
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• no.41
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• pp.367-399
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• 2011

This Article examines the regulation of outsider trading under the Financial Investment Services and Capital Markets Act (the "Capital Markets Act"). Outsider trading occurs when a market participant who is not a traditional corporate insider trades securities based on either "inside" or "outside" nonpublic information. Unlike "inside" information, "outside" information is referred to as information not derived directly or indirectly from the issuer. "Outside" information includes both "corporate" and "market" information. "Corporate information" is information about events or circumstances which affect the company's assets or earning power. "Outside corporate information" is information about the company's assets or earning power not derived directly or indirectly from the issuer. "Market information" is information about events or circumstances which affect the market for a company's securities but which do not affect the company's assets or earning power. The Capital Markets Act prohibits both "temporary insiders" from using "corporate" information in trading securities and "outsiders" from using "market" information, such as (i) information regarding the initiation or discontinuance of a tender offer; or (ii) information regarding acquisition or disposition of stocks in bulk. However, the Act does not encompass circumstances (i) where an outsider trades securities based on confidential corporate information obtained through certain types of wrongful conduct; (ii) where an outsider trades securities based on corporate information obtained through eavesdropping; and (iii) where an outsider trades securities based on either outside corporate information or market information created by the outsider himself. In order to plug a few of the gaps left open in the law of outsider trading under the Capital Markets Act, this Article suggests that regulators adopt a relatively broad reading of the scope of ${\S}$ 178(1) of the Act, which is similar to SEC Rule 10b-5, to include outsiders with no relationship to the corporation that had issued the securities. Since ${\S}$ 178(1) of the Act does not require "deception" for liability, it would seem to evade the limitations imposed by the U.S. misappropriation theory. Key Words : Outsider Trading, Insider Trading, Material Nonpublic Information, the Capital Markets Act, Misappropriation Theory, Fiduciary Theory.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1383-1388
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• 2011

Due to many recent activities on enforcement of the intensified environmental regulation such as the policies of curbing the greenhouse gas and the Restriction of Hazardous Substances (RoHS), the usage of Light emitting diode (LED) has been rapidly increased and energy efficient management of LED light system is regarded as an important technology to enhance the energy efficiency. In this paper, we propose an energy-efficient control scheme of LED light, being composed of multiple light sources. The proposed scheme controls the intensity of LED light source to minimize the total intensity while providing the quality of lighting service. The intensity of light is assumed to be proportional to power consumption, thus the objective is to minimize the total power consumption. A linear programming problem is formulated to find the optimal intensity of each light source and procedure to apply the proposed scheme in the real system is suggested. The performance evaluation results elucidate that the proposed scheme achieves over 20% improvement in power consumption of light intensity in comparison with the conventional dimming control scheme.