• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.185-188
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• 2008

Fiber reinforced polymer(FRP) bars are proving to be a valuable solution in the corrosion problem of steel reinforced concrete structures. As such, a number of guidelines for their use have been developed. These guidelines are primarily based on modifications to existing codes of practice for steel reinforced concrete structures. These guidelines are also similar in that though the design equations are presented in the partial factor formats that are often used in probability based design, they are not true probabilistic codes. Instead, they typically make use of already existing design factors for loads and resistances. Thus, when concrete structures reinforced FRP bars are designed, the structural reliability levels are not known. This paper investigates uncertainties of concrete beams reinforced with GFRP bars. Also, the structural reliability levels are evaluated for the flexural failure mode.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.215-229
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• 2023

Objectives: To validate the effectiveness of a real-time chemical exposure monitoring system developed by KOSHA (Korea Occupational Safety and Health Agency), we applied the system to a workplace in the electronics industry for 153 days. Methods: The monitoring system consisted of a PID chemical sensor, a LTE communication equipment, and a web-based platform. To monitor chemical exposure, four sets of sensors were placed in two manufacturing tasks - inspection and jig cleaning - which used TCE as a degreasing agent. We reviewed previous reports of work environment measurements and conducted a new work environment measurement on one day during the period. The PID sensor systems detected the chemical exposure levels in the workplace every second and transmitted it to the platform. Daily average and maximum chemical exposure levels were also recorded. Results: We compared the results from the real-time monitoring system and the work environment measurement by traditional methods. Generally, the data from the real-time monitoring system showed a higher level because the sensors were closer to the chemical source. We found that 28% of jig cleaning task data exceeded the STEL. Peak exposure levels of sensor data were useful for understanding the characteristics of the task's chemical use. Limitations and implications were reviewed for the adoption of the system for preventing poisoning caused by chemical substances. Conclusions: We found that the real-time chemical exposure monitoring system was an efficient tool for preventing occupational diseases caused by chemical exposure, such as acute poisoning. Further research is needed to improve the reliability and applicability of the system. We also believe that forming a social consensus around the system is essential.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.910-917
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• 2011

CBTC(Communication Based Train Control) car-borne equipment, a part of the communication based train control system, mainly consists of automatic train protection(ATP) functions, automatic train operation(ATO) functions as well as the interface functions with other equipment including CBTC wayside equipment and train control management system etc. The CBTC car-borne software implementing ATP/ATO functions is a real-time embedded software requiring a high level of safety and reliability. To satisfy the requirements of the CBTC car-borne software, the model-based design techniques are applied with SCADE(Safety-Critical Application Development Environment) to the development of the CBTC car-borne software. In this paper, we illustrate the process modeling the car-borne ATP/ATO functions satisfying system requirement specification with system requirement management, modeling and document generation tools etc. supported by SCADE. In addition, the developed models corresponding to the ATP/ATO functions are applied to the train with CBTC car-borne equipment through its corresponding EN-50128 standards-compliant C code generated by the code generator. It is shown from the test result that the ATP/ATO models developed by SCADE work well while the trains are running in driverless operation mode.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.6
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• pp.637-647
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• 2012

Bridges are ones of fundamental facilities for roads which become social overhead capital facilities and they are designed to get safety in their life cycles. However as time passes, bridge can be damaged by changes of external force and traffic environments. Therefore, a bridge should be repaired and maintained for extending its life cycle. The working load on a bridge is one of the most important factors for safety, it should be calculated accurately. The most important load among working loads is live load by a vehicle. Thus, the travel characteristics and weight of vehicle can be useful for bridge maintenance if they were estimated with high reliability. In this study, a B-WIM system in which the bridge is used for a scale have been developed for measuring the vehicle loads without the vehicle stop. The vehicle loads can be estimated by the developed B-WIM system with the reaction responses from the supporting points. The algorithm of developed B-WIM system have been verified by numerical analysis.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.2
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• pp.243-250
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• 2013

We have entered into an era of smart software system where the many kinds of embedded software, especially SCADA and Automotive software not only require high reliability and safety but also high-security. Removing software weakness during the software development lifecycle is very important because hackers exploit weaknesses which are source of software vulnerabilities when attacking a system. Therefore the coding rule as like core functions of MISRA-C should expand their coding focus on security. In this paper, we used CERT-C secure coding rules for nuclear-related software being developed to demonstrate high-safety software, and proposed how to remove software weakness during development.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.6
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• pp.1107-1113
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• 2015

The number of phishing/pharming attacks occurring has increased and consequently, the number of studies on anti-phishing/pharming has also increased. The target sites of phishing/pharming are financial sites, and these have a low connection rate compared to those of portal sites. In this paper, we propose an anti-phishing/pharming method that uses a portal site as a stopover. The proposed method is based on the reliability of portal sites. This method is intended for general users rather than for professional users or developers. We also analyze the safety of the proposed method by separating the method into sub components of module safety assumption.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.163-167
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• 2014

From Korea Elevator Safety Institute's report, the major accident factor of elevator is user's mistake, 60%. It means that the necessity of simple monitoring system. In this paper, we explain the standard of elevator safety check and the rate of accidents, then compare with old elevator managing system and new elevator managing system based on IOT technology. Also, we explain the reliability statistics of smart managing system based on expert's decision. Finally, we propose the smart managing system as the alternative method for decreasing the accident factor of elevator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2828-2836
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• 2015

Evaluation items were deducted by based on literature materials to supplement the evaluation system of rock cut-slope in national road. Delphi survey of experts were conducted to review the final evaluation items. As a result of reviewing the significance through stepwise multiple linear regression, all of deducted items were statistically significant because these had lower P-value than 0.05. And It was confirmed that the items were selected appropriately as they had relatively similar levels of the weight. In consideration of CVR and reliability both suggested items and existing items, the exclusible items was selected and new items can complement existing evaluation system were added. Finally 18 rock cut-slope evaluation items was deducted.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.287-294
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• 2013

This study were proposed for the promotion policy on public confidence in nuclear power recovery schemes. To this end, the existing survey and secondary data review and public distrust of nuclear power plant safety issues were raised. In addition, the meta-analysis data were analyzed by using. Promote public confidence in nuclear power plants recovered three major policy presented. First, the nuclear power plant for the economical / safety communication strategy, short term / long term in terms proposed. Second, strengthen the nuclear power plant reliability and short-term communication strategy / long term in terms proposed. Finally, Korea Hydro & Nuclear Power's long-term image building measures proposed. The results of this study Korea's nuclear power plants to increase confidence in the effect is expected to be presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.236-240
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• 2013

Due to difficulty of considering dynamic load in side of a computer resource and computing time, it is common that external load is assumed as ideal static load. However, structural analysis under static load cannot guarantee the safety of structural design. Recently, the systematic method to construct equivalent static load from the given dynamic load has been proposed. Previous study has calculated equivalent static load through the optimization procedure under displacement constraints. And previously reported works to distribute equivalent static load were based on ad hoc methods. However, it is appropriate to take into account the stress constraint for the safety design. Moreover, the improper selection of loading position may results in unreliable structural design. The present study proposes the methodology to optimize an equivalent static which distributed on the primary DOFs, DOFs of the constraint elements, DOF of an external load as positions. In conclusion, the reliability of proposed method is demonstrated through a global optimization.