• Title/Summary/Keyword: Technology Principle

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Operation Principle and Topology Structures of Axial Flux-Switching Hybrid Excitation Synchronous Machine

  • Liu, Xiping;Wang, Chen;Zheng, Aihua
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.3
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    • pp.312-319
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    • 2012
  • The operation principle of an axial flux-switching hybrid excitation synchronous machine (AFHESM) is analyzed and its topology structures are proposed in this paper. After some comprehensive analysis of the operation principle to axial flux electrical machine, flux-switching electrical machine and hybrid excitation electrical machine, the operation principle of AFHESM is given. Combined with some typical topological structures of hybrid excitation electrical machine, some possible topological structures are proposed and some comprehensive comparisons are carried out. The analysis results show that the stator-separated AFHESM has some advantages such as less AM turns, less impact on the demagnetization of PM, less magnetic flux-leakage and higher efficiency compared to other topologies.

OBSERVABILITY-IN-DEPTH: AN ESSENTIAL COMPLEMENT TO THE DEFENSE-IN-DEPTH SAFETY STRATEGY IN THE NUCLEAR INDUSTRY

  • Favaro, Francesca M.;Saleh, Joseph H.
    • Nuclear Engineering and Technology
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    • v.46 no.6
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    • pp.803-816
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    • 2014
  • Defense-in-depth is a fundamental safety principle for the design and operation of nuclear power plants. Despite its general appeal, defense-in-depth is not without its drawbacks, which include its potential for concealing the occurrence of hazardous states in a system, and more generally rendering the latter more opaque for its operators and managers, thus resulting in safety blind spots. This in turn translates into a shrinking of the time window available for operators to identify an unfolding hazardous condition or situation and intervene to abate it. To prevent this drawback from materializing, we propose in this work a novel safety principle termed "observability-in-depth". We characterize it as the set of provisions technical, operational, and organizational designed to enable the monitoring and identification of emerging hazardous conditions and accident pathogens in real-time and over different time-scales. Observability-in-depth also requires the monitoring of conditions of all safety barriers that implement defense-in-depth; and in so doing it supports sensemaking of identified hazardous conditions, and the understanding of potential accident sequences that might follow (how they can propagate). Observability-in-depth is thus an information-centric principle, and its importance in accident prevention is in the value of the information it provides and actions or safety interventions it spurs. We examine several "event reports" from the U.S. Nuclear Regulatory Commission database, which illustrate specific instances of violation of the observability-in-depth safety principle and the consequences that followed (e.g., unmonitored releases and loss of containments). We also revisit the Three Mile Island accident in light of the proposed principle, and identify causes and consequences of the lack of observability-in-depth related to this accident sequence. We illustrate both the benefits of adopting the observability-in-depth safety principle and the adverse consequences when this principle is violated or not implemented. This work constitutes a first step in the development of the observability-in-depth safety principle, and we hope this effort invites other researchers and safety professionals to further explore and develop this principle and its implementation.

Is the Precautionary Principle Unscientific?: 'Rationality' of the Precautionary Principle and its Conflicts with Risk Analysis Framework (사전주의의 원칙은 비과학적인가?: 위험 분석과의 논쟁을 통해 본 사전주의 원칙의 '합리성')

  • Ha, Dae-Cheong
    • Journal of Science and Technology Studies
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    • v.10 no.2
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    • pp.143-174
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    • 2010
  • How can a regulatory policy to address potential hazards be made legitimate in the face of scientific uncertainty? The precautionary principle has been gradually regarded as the most persuasive answer to this intricate question in Europe since the 1970s and generally recognized as a guiding principle in international environmental law. This principle, however, has often been subject to diverse concerns and criticisms due to its vague definition. This article tries to elaborate the precautionary principle while reviewing both the validity and unreasonableness of these criticisms over this principle. Then, this article explores the policy relevance of this principle by applying this elaborated definition to the concrete case of risk governance such as the risk assesment of food safety. In the end, this paper emphasizes the fact that the precautionary principle can be applied in the field of risk governance, refuting the argument that the precautionary principle is only a moral attitude or a political position.

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Investigation on $SF_6$ Hybrid Interrupter using Thermal Expansion and Arc Rotation Principle (자력팽창 및 아크 회전에 의한 배전급 $SF_6$ 복합소호부 개발 연구)

  • Lee, B.W.;Sohn, J.M.;Kang, J.S.;Choe, W.J.;Kim, Y.K.;Seo, J.M.
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.919-921
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    • 2000
  • This paper considers the research of the hybrid interrupter which adopts both rotating arc and thermal expansion technology. The operating principle of this device depends on rapid arc rotation due to the magnetic field created by the fault current through a coil which is mounted on contacts and also relies on the principle of thermal expansion created by arc energy in extinguishing chamber and finally causes pressure rise in expansion volume. In this research, the principle of the interrupting techniques are given and experimental results of hybrid interrupter which is developed by new technology is introduced.

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A Study on the Improvement for Problems of ICT-related laws system in Korea

  • Lee, Hie-Houn
    • International Journal of Advanced Culture Technology
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    • v.7 no.2
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    • pp.7-12
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    • 2019
  • Korea's laws regarding ICT must follow the Void for vagueness doctrine, the Principle of forbidden general delegation, the Principle of justification of system and the Principle of balancing test in the Constitution. The Act for the Promotion and Convergence and so on of Information and Communication in the Future should be improved as follows. It is desirable to improve the part where the principle of system justification of the Constitution is problematic in relation to existing laws. It is desirable to improve the ICT's policies on industry and convergence technologies so that they are well balanced between promotion and regulation of ICT's industries. It is desirable to improve the information service policy and legislative makeup relationship between various government agencies related to ICT. It is therefore desirable to improve the institutional complement to the post-regulatory framework for the protection of users of ICT in the future. It is desirable to create a device to replace the functions of the Information Service Budget Council in the special law of ICT.

A Study on the Convergency Property of the Auxiliary Problem Principle

  • Kim, Balho-H.
    • Journal of Electrical Engineering and Technology
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    • v.1 no.4
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    • pp.455-460
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    • 2006
  • This paper presents the convergency property of the Auxiliary Problem Principle when it is applied to large-scale Optimal Power Flow problems with Distributed or Parallel computation features. The key features and factors affecting the convergence ratio and solution stability of APP are also analyzed.

Development of Medium Voltage $SF_6$ Interrupter for RMU ($SF_6$ 가스를 이용한 배전급 RMU용 소호부 개발)

  • Lee, B.W.;Sohn, J.M.;Seo, J.M.;Choe, J.W.
    • Proceedings of the KIEE Conference
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    • 2001.05a
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    • pp.301-304
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    • 2001
  • This paper considers the research of the hybrid interrupter which adopts both rotating arc and thermal expansion technology. The operating principle of this device defends on rapid arc rotation due to the magnetic field created by the fault current through a coil which is mounted on contacts and also relies on the principle of thermal expansion created by arc energy in extinguishing chamber and finally causes pressure rise in expansion volume. In this research, the principle of the interrupting techniques are given and experimental results of hybrid interrupter which is developed by new technology is introduced.

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A Modeling Based MIS Education (모델링 기반의 경영정보학 교육 방안)

  • Kang, Shin Cheol
    • Journal of Information Technology Applications and Management
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    • v.19 no.4
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    • pp.153-169
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    • 2012
  • In the rapidly changing field of Management Information Systems, the definition and educational programs must be continually reevaluated and revised. A study was conducted to find a way to which the modeling principle is applied for redefining the identity of Management Information Systems as an independent academic field and to develop a plausible MIS curriculum based on the modeling principle. Previous researches on the MIS frameworks, knowledge and technology requirements for IS professionals, and standard MIS curriculums were reviewed thoroughly. For this study, the Kantian cognitive model was adopted as a basis of modeling principle. The result shows that modeling ability has been the core competence of IS people in the field of MIS. The applicability of a modeling principle is also verified in establishing the identity of MIS and developing a normative MIS curriculum. For the MIS field to thrive as an independent academic field and research discipline, it is believed to be imperative for the discipline to have a unique educational goals distinguished from both other management areas, and sub-fields of computer science.

Need for Reinforcement of Safety Assessment on Genetically Modified Organisms (GMO 안전성평가제도의 고찰)

  • Kim Eun-Jin;Choi Dong-Keun
    • Korean Journal of Organic Agriculture
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    • v.14 no.2
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    • pp.139-157
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    • 2006
  • Biotechnology has reached the level of giving birth to new forms of life and with this is a growing controversy in the conflict between science and ethics. Especially, GMOs are closely linked to the food products we consume and thus, the majority of the public shows a very sensitive reaction to the safety of GMO food products. Many perspectives arose surrounding the issues of safety on the human body and the ecology. This outlines diverse structural mechanisms to be set up to ensure safety such as risk assessment, risk management etc. Despite the precautionary principle guaranteed in many ways, the problem arises whether and how this principle can be taken in the safety assessment. GMOs due to its uniqueness do not end with just the possession of the technology involved but must also be considered with the prerequisite that they could be cultured again. Therefore the reinforcement of safety assessment system is necessary. That is, the reinforcement of risk assessment including field tests, the consideration of socio-economic effects, the coordinated system of relevant authorities, the development of technology for safety assessment.

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