• International Journal of Railway
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• v.1 no.1
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• pp.1-5
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• 2008

The railway system requires safety and reliability of service of all railway vehicles. Suitable technical systems and working methods adapted to it, which meet the requirements on safety and good order of traffic, should be maintained. For detection of defects, non-destructive testing methods-which should be quick, reliable and cost-effective - are most often used. Since failure in railway wheelset can cause a disaster, regular inspection of defects in wheels and axles are mandatory. Ultrasonic testing, acoustic emission and eddy current testing method and so on regularly check railway wheelset in service. However, it is difficult to detect a crack initiation clearly with ultrasonic testing due to noise echoes. It is necessary to develop a non-destructive technique that is superior to conventional NDT techniques in order to ensure the safety of railway wheelset. In the present paper, the new NDT technique is applied to the detection of surface defects for railway wheelset. To detect the defects for railway wheelset, the sensor for defect detection is optimized and the tests are carried out with respect to surface and internal defects each other. The results show that the surface crack depth of 1.5 mm in press fitted axle and internal crack in wheel could be detected by using the new method. The ICFPD method is useful to detect the defect that initiated in railway wheelset.

• The Korean Journal of Food And Nutrition
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• v.32 no.6
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• pp.730-737
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• 2019

The purpose of this study was to derive practical improvement measures for the food traceability system that could improve food reliability and secure food safety. To this, in our survey May-June, 2019, 567 adult males and females were analyzed for recognition and experience of the food traceability system, measures to improve the system, and intention to make additional payments to improve the system. In the case of a food safety accident, 2.54 of 5 points were given on if the food was recalled or not. Approximately 77.4 percent of the respondents had never seen indication of a food traceability system, and approximately 93.8 percent had no access to, or experience with, using the system. Most respondents said that the food traceability system should be applied to items that need to be applied. As the volume of data that is recorded and managed by the government is recognized as high, improvement is needed. Finally, it was analyzed that the company intends to pay an additional 1.34% on average to expand its food traceability system. A more sophisticated cost analysis is needed to apply the improvements proposed to complement the plans that are acceptable to consumers and the industry.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.4
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• pp.189-199
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• 2002

This study is intended to propose a systematic procedure for the development of the conditional assessment based on the safety of structures and the cost effective performance criteria for designing and upgrading of bridge structures. As a result, a set of cost function models for a life cycle cost analysis of bridge structures is proposed and thus the expected total life cycle costs (ETLCC) including initial (design, testing and construction) costs and direct/indirect damage costs considering repair and replacement costs, human losses and property damage costs, road user costs, and indirect regional economic losses costs. Also, the optimum safety indices are presented based on the expected total cost minimization function using only three parameters of the failure cost to the initial cost (${\tau}$), the extent of increased initial cost by improvement of safety (${\nu}$) and the order of an initial cost function (n). Through the enough numerical invetigations, we can positively conclude that the proposed optimum design procedure for bridge structures based on the ETLCC will lead to more rational, economical and safer design.

• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.7-12
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• 2015

CFRP composites are used as primary structural members in various industrial fields because their specific strength and specific stiffness are excellent in comparison to conventional metals. Their usage is expanding to high added-value industrial fields because they are more than 50% lighter than metals, and have excellent heat resistance and wear resistance. However, when CFRP composites suffer impact damage, destruction of fiber and interface delamination occur. This causes an unexpected deterioration of strength, and for this reason it is very difficult to ensure the reliability of the excellent mechanical properties. Therefore, for the destruction mechanism in bending with impact damage, this study investigated the reinforcement data regarding various external loads by identifying the consequential strength deterioration. Specimens were damaged by impact with a steel ball propelled by air pressure. Decrease in bending strength caused by the tension and compression of the impact side, and depending on the lamination direction of fiber and interface inside the specimen. From the bending test it was found that the bending strength reduced when the impact energy increased. Especially in the case of compression on the impact side, as tensile stress occurred at the damage starting point, causing rapid failure and a substantially reduced failure strength.

• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.2
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• pp.93-104
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• 2021

The worldwide coronavirus pandemic has brought to light the importance of having a reliable supply of masks for each person. This study aims to understand the effect of personal awareness (including community, others', and safety awareness) on consumption conformity and the repurchase intention of masks. The research method used the SPSS 22.0 and AMOS 22.0 statistical systems to analyze descriptive statistics in terms of reliability, validity, structural equation modeling, and moderated regression analysis. A total of 272 Chinese participants were recruited via an online survey website (www.sojump.com) from May 1 to May 14, 2020. Findings indicated that mask users' awareness can be categorized into three distinct types: community, others', and safety awareness. The more community and safety awareness is perceived, the higher the level of consumption conformity. In contrast, others' has no statistical effect on consumption conformity or repurchase intention. The positive influence of consumption conformity on the repurchase intention of masks is also weaker than price perception. However, another moderating variable, mask quality, has no moderating effect. The results of this study can help mask manufacturers and distributors retain their customers, resulting in reasonable protective measures while maintaining market order. Theoretical and managerial implications for mask suppliers are also provided.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.477-480
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• 2003

The objective procedure and criterion needs to efficiently perform the safety assessment and improve reliability for results of the cost analysis. There are many studies about cost analysis of safety assessment, but the these studies have problems such as non-quantification of criterions and methods. The purpose of this study to suggest the procedure and criterion for successful cost analysis and quantify cost factors. First, in the cost analysis of the housing reconstruction that is presented this study, determinate the life-cycle and the discount rate, then estimate reconstruction cost and remodeling cost. Finally, compare the annual equivalent LCC of two costs for decision malting to reconstruction or remodeling.

• Nuclear Engineering and Technology
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• v.47 no.2
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• pp.187-195
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• 2015

Human-induced initiating events, also called Category B actions in human reliability analysis, are operator actions that may lead directly to initiating events. Most conventional probabilistic safety analyses typically assume that the frequency of initiating events also includes the probability of human-induced initiating events. However, some regulatory documents require Category B actions to be specifically analyzed and quantified in probabilistic safety analysis. An explicit modeling of Category B actions could also potentially lead to important insights into human performance in terms of safety. However, there is no standard procedure to identify Category B actions. This paper describes a systematic procedure to identify Category B actions for low power and shutdown conditions. The procedure includes several steps to determine operator actions that may lead to initiating events in the low power and shutdown stages. These steps are the selection of initiating events, the selection of systems or components, the screening of unlikely operating actions, and the quantification of initiating events. The procedure also provides the detailed instruction for each step, such as operator's action, information required, screening rules, and the outputs. Finally, the applicability of the suggested approach is also investigated by application to a plant example.

• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.642-649
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• 2016

Important safety parameters such as the fuel temperature coefficient (FTC) and the power coefficient of reactivity (PCR) of the CANada Deuterium Uranium (CANDU-6) reactor have been evaluated using the Monte Carlo method. For accurate analysis of the parameters, the Doppler broadening rejection correction scheme was implemented in the MCNPX code to account for the thermal motion of the heavy uranium-238 nucleus in the neutron-U scattering reactions. In this work, a standard fuel lattice has been modeled and the fuel is depleted using MCNPX. The FTC value is evaluated for several burnup points including the mid-burnup representing a near-equilibrium core. The Doppler effect has been evaluated using several cross-section libraries such as ENDF/B-VI.8, ENDF/B-VII.0, JEFF-3.1.1, and JENDL-4.0. The PCR value is also evaluated at mid-burnup conditions to characterize the safety features of an equilibrium CANDU-6 reactor. To improve the reliability of the Monte Carlo calculations, we considered a huge number of neutron histories in this work and the standard deviation of the k-infinity values is only 0.5-1 pcm.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.6
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• pp.689-694
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• 2014

An SPLC (Safety Programmable Logic Controller) must be designed to meet the highest safety standards, IEEE 1E, and should guarantee a level of fault-tolerance and high-reliability that ensures complete error-free operation. In order to satisfy these criteria, I/O modules, communication modules, processor modules and bus modules of the SPLC have been configured in triple or dual modular redundancy. The redundant modules receive the same data to determine the final data by the voting logic. Currently, the processor of each rx module performs the voting by deciding on the final data. It is the intent of this paper to prove the improvement on the current system, and develop a voting system for multiple data on a system bus level. The new system bus protocol is implemented based on a TCN-MVB that is a deterministic network consisting of a master-slave structure. The test result shows that the suggested system is better than the present system in view of its high utilization and improved performance of data exchange and voting.

• The Research Journal of the Costume Culture
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• v.14 no.6
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• pp.1027-1041
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• 2006

The purpose of this study was to identify the differences of internet shopping attitude, shopping behavior, and shopping satisfaction according to purchasing frequency of internet shoppers for children's clothing. Data were collected from 170 female internet users who had purchasing experiences of children's clothing. For data analysis, factor analysis, one-way ANOVA, Duncan test, cross tabulation, regression analysis, t-test, frequency and multi- response analysis were conducted. The results are as follows: The internet shoppers for children's clothing were classified by purchasing frequency. Factors of internet shopping attitude were convenience, reliability, and safety. Significant differences were found on internet usages, internet attitudes, and shopping behaviors between two groups. Heavy purchasers used internet longer, had more positive attitude toward convenience and safety, and paid more money than light purchasers. Significant differences were found on internet attitudes according to age and internet usage. Convenience and safety factors had impact on internet shopping satisfaction.