• Title/Summary/Keyword: protection design

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A Safety Assessment Methodology for a Digital Reactor Protection System

  • Lee Dong-Young;Choi Jong-Gyun;Lyou Joon
    • International Journal of Control, Automation, and Systems
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    • v.4 no.1
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    • pp.105-112
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    • 2006
  • The main function of a reactor protection system is to maintain the reactor core integrity and the reactor coolant system pressure boundary. Generally, the reactor protection system adopts the 2-out-of-m redundant architecture to assure a reliable operation. This paper describes the safety assessment of a digital reactor protection system using the fault tree analysis technique. The fault tree technique can be expressed in terms of combinations of the basic event failures such as the random hardware failures, common cause failures, operator errors, and the fault tolerance mechanisms implemented in the reactor protection system. In this paper, a prediction method of the hardware failure rate is suggested for a digital reactor protection system, and applied to the reactor protection system being developed in Korea to identify design weak points from a safety point of view.

Improving Motor Protection Using Thermal Model (열 모델을 이용한 전동기 보호성능 개선)

  • Chang, Choong-Koo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.3
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    • pp.473-479
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    • 2015
  • Thermal relays are sometimes used instead of long time overcurrent relays for motor protection. But, it is difficult for any relay design engineer to adequately approximate motor heating curves which represent the average of a difficult-to-define thermal zone. Thermal relays frequently may not provide sufficient protection on heavy overloads. Digital multifunction relays are microprocessor-based devices. These relays offer highly reliable and advanced protection of motors. If a situation can be mathematically described, the microprocessor in a digital relay can be programmed to tackle that problem. Today's motor protection is accomplished with digital protective relays. Digital relays offer additional, highly important features to complement protection. The best way to prevent short in motor is to not overheat and degrade the insulation.

A Study of the Possibility of Legal Protection of Fashion Designs under the Copyright Law - Based on the Review of the Requisites of Works of Authorship and their types - (패션디자인의 저작권법상 보호 가능성에 대한 고찰 - 저작물의 성립요건과 보호대상 저작물의 유형 검토를 중심으로 -)

  • Cho, Kyeong Sook
    • Journal of the Korean Society of Costume
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    • v.64 no.1
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    • pp.123-135
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    • 2014
  • The author has explored whether legal protection of fashion designs is possible under the current Korean Copyright Act with the purpose of promoting the understanding of the legal principles of the copyright law among fashion professionals. It examined the general provisions of the copyright law as well as the requisites for establishment of "works of authorship" and the types of protection stipulated by the copyright law, which are needed to understand the possibilities of legal protection for fashion designs under the law. It then analyzed several leading cases in the fashion designs sector for the interpretation of related legal principles. The Copyright Act defines "works of authorship" for protection as the creative works that express human ideas or emotions. Works to be legally protected under the law include artistic works that are equipped with the prerequisites for establishment of "works of authorship", or fashion designs that are equipped with the prerequisites for establishment of an independent applied artistic works whose originality is distinguishable from articles.

Measurements and Assessments on Shielding Performance of FCTC10 60Co Transport Container

  • Zhuang, Dajie;Zhang, Guoqing;Li, Guoqiang;Wang, Renze
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.310-314
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    • 2016
  • Background: FCTC10 container is designed to transport $^{60}Co$ radioactive sources used in irradiation industry. It belongs to Type B(U) Category III (yellow) package when being loaded with a $^{60}Co$ source of $1.8{\times}10^5$ Ci. Materials and Methods: The container is constituted of shielding container, basket, protective cover and bracket. Shielding ability is provided mainly by stainless steel shells, tungsten alloy and lead among steel shells. Radiation level around the container has been calculated with both Monte Carlo simulations and measurements. Results and Discussion: It is proven that the shielding performance of the container fulfills the requirements in GB11806-2004 (Regulations for the safe transport of radioactive material, China Standard Press). Exposure doses to workers and to critical groups of public were calculated based on hypothetical exposure scene according to transport practice experience. Conclusion: The results show that doses to workers and public are less than the constraint dose considered in design, and the radiation level would be increased less than a factor of 2 under design basis accidents.

The study of method local scour protection to the existing piers bridge (기존 교각주변의 국부세굴 방지공법에 관한 연구)

  • Park, Sang-Kil;Chang, Tae-Rae;Park, Byung-Yul
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.598-602
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    • 2006
  • Local scour is associate with particular local types of vortex around bridge piers. This paper is method of protection local scour for the existing Busan City subway 3 Line bridge piers and Gupo large bridge piers. In order to take design of protection of local scour this bridge piers, We calculate the local scour hole of depth , scour width, riprap construction , filter construction by formulas. We had experimental hydraulic model test for this bridge piers in order to take proof for the calculation of local scour. We knew that the vortex intensifies the local flow velocities and acts to erode sediment from the scour hole and transport it downstream. As the result of hydraulic model test, we could suggest three types method of protection local scour this bridges. We knew that FHWA HEC-18(Richardson et al. 2001: Modified CSU) Formula is useful to checking calculation as application of field. One is pier protection using the sheet piles and riprap, the others are pier protection using the riprap with filter and to make renew Wall-caisson. The best method of protection for the existing Busan City subway 3 Line bridge piers and Gupo large bridge piers is pier protection using the sheet piles and riprap.

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Study on Social Network Service(SNS) Users' Privacy Protection Behavior : Focusing on the protection motivation theory (소셜 네트워크 서비스(SNS) 이용자들의 개인정보보호 행동에 관한 연구: 보호동기이론을 중심으로)

  • Kim, Jung-Eun;Kim, Seong-Jun;Kwon, Do-Soon
    • The Journal of Information Systems
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    • v.25 no.3
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    • pp.1-30
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    • 2016
  • Purpose The purpose of this study is to grasp the factors influencing domestic SNS users' privacy protection behavior and verify their relationship through self-efficacy and responsiveness. Thus, this study tries to suggest efficient and effective measures for SNS personal information protection. Design/methodology/approach To this end, with main variables of the protection motivation theory based on the assumption that when users are exposed to the threat to their health, they would have protection motivation and change their behavior of protecting their health, a research model was suggested. In addition, in order to empirically verify the research model, a survey was performed targeting general college students having the experience of using SNS. Findings As a result of the analysis, first, perceived effectiveness and self-efficacy had a positive effect on responsiveness. Second, perceived barrier had a positive effect on self-efficacy. Third, self-efficacy and responsiveness had a positive effect on privacy protection behavior. This study is expected to contribute to establishing an effective guideline for measures that could induce SNS users' privacy protection behavior.

A Study on Fire Hazard Analysis and Smoke Flowing for the Semiconductor Manufacturing Process (반도체 제조공정의 연기유동에 관한 연구)

  • Han, Soo-Jin;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.9 no.1
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    • pp.197-211
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    • 2007
  • The power of semiconductor, Korea is continuously constructing semiconductor production line for keeping a front-runner status. however, studies and data about potential risks in semiconductor factory are still short. If fire does not initially suppressed, the fire causes a great damage. To decrease fire risk factors, in addition to fire fighting safety equipment, more important thing is how to design and construct fire protection system. The current fire protection codes about semiconductor factory come under functional law, and this law is short of consideration about particularity of factory. The existing prescriptive fire codes depending on experience compose without evident engineering verifications, thus equipments which is created by the current prescriptive fire code may bring about a variety of problems. For example, the design under the current regulation can not cope with the excessive investments, low efficiencies, and the diversifying construction designs and be applied to the quick changes of new technologies. Ergo, an optimal design for fire protection is to equip fire protection arrangements with condition and environment of production field. Manufacturing factory of semiconductors is a windowless airtight space. And for cleanliness, there exists strong flow of cooperation. Therefore, there is a need for fire safety design that meets the characteristic of a clean room. Accordingly, we are to derive smoke flow according to cooperation process within a clean room and construction plan of an optimal sensor system. In this study, in order to confirm the performance of proposed smoke-exhaust equipment and suggest efficient smoke exhaust device when there is a fire of 1MW of methane in the clean room of company H, we have implemented fire simulation using fluid dynamics computation.

A Case Study on the Protection of Endangered Species Campaign in Domestic and Foreign Companies (국내외 기업의 멸종 위기 동물 보호 캠페인 사례 연구)

  • Lee, Suzy;Kim, Seung-In
    • Journal of Digital Convergence
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    • v.18 no.8
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    • pp.385-390
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    • 2020
  • The purpose of this study is to analyze the cases of endangered species protection campaigns of domestic and foreign enterprises and to present improvement points and direction. Therefore, this study analyzed the cases and characteristics of the campaign by setting above small and medium sized domestic and foreign companies as subjects for research. The study found that there were mainly campaigns conducted in cooperation with large environmental organizations in Korea, and as an IT powerhouse, there were examples of such campaigns. Foreign companies independently participated in environmental protection, and cases of fashion and cosmetic brand campaigns were easily found. Based on these characteristics, this study aims to present improvements and directions for animal protection campaigns in the future.

Demonstration of the Effectiveness of Monte Carlo-Based Data Sets with the Simplified Approach for Shielding Design of a Laboratory with the Therapeutic Level Proton Beam

  • Lai, Bo-Lun;Chang, Szu-Li;Sheu, Rong-Jiun
    • Journal of Radiation Protection and Research
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    • v.47 no.1
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    • pp.50-57
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    • 2022
  • Background: There are several proton therapy facilities in operation or planned in Taiwan, and these facilities are anticipated to not only treat cancer but also provide beam services to the industry or academia. The simplified approach based on the Monte Carlo-based data sets (source terms and attenuation lengths) with the point-source line-of-sight approximation is friendly in the design stage of the proton therapy facilities because it is intuitive and easy to use. The purpose of this study is to expand the Monte Carlo-based data sets to allow the simplified approach to cover the application of proton beams more widely. Materials and Methods: In this work, the MCNP6 Monte Carlo code was used in three simulations to achieve the purpose, including the neutron yield calculation, Monte Carlo-based data sets generation, and dose assessment in simple cases to demonstrate the effectiveness of the generated data sets. Results and Discussion: The consistent comparison of the simplified approach and Monte Carlo simulation results show the effectiveness and advantage of applying the data set to a quick shielding design and conservative dose assessment for proton therapy facilities. Conclusion: This study has expanded the existing Monte Carlo-based data set to allow the simplified approach method to be used for dose assessment or shielding design for beam services in proton therapy facilities. It should be noted that the default model of the MCNP6 is no longer the Bertini model but the CEM (cascade-exciton model), therefore, the results of the simplified approach will be more conservative when it was used to do the double confirmation of the final shielding design.