• Title/Summary/Keyword: Global State

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Adaptive Neural Control for Strict-feedback Nonlinear Systems without Backstepping (순궤환 비선형계통의 백스테핑 없는 적응 신경망 제어기)

  • Park, Jang-Hyun;Kim, Seong-Hwan;Park, Young-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.5
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    • pp.852-857
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    • 2008
  • A new adaptive neuro-control algorithm for a SISO strict-feedback nonlinear system is proposed. All the previous adaptive neural control algorithms for strict-feedback nonlinear systems are based on the backstepping scheme, which makes the control law and stability analysis very complicated. The main contribution of the proposed method is that it demonstrates that the state-feedback control of the strict-feedback system can be viewed as the output-feedback control problem of the system in the normal form. As a result, the proposed control algorithm is considerably simpler than the previous ones based on backstepping. Depending heavily on the universal approximation property of the neural network (NN), only one NN is employed to approximate the lumped uncertain system nonlinearity. The Lyapunov stability of the NN weights and filtered tracking error is guaranteed in the semi-global sense.

Transient State Analysis in Case of Lightning Arrester Deterioration due to Lightning Surge (뇌서지로 인한 피뢰기 열화시 과도상태 분석)

  • Lim, Sung-Yong;Kim, Kyu-Ho;Rhee, Sang-Bong;Kim, Soo-Bae
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.276-277
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    • 2015
  • As the effect of global warming continues, surge rates in Korea are also getting increased. Although there are devices to protect distribution line from the surge like lightning arrester, insulation of the lightning arrester can be destroyed if frequent surge occurs in distribution line. This paper assumed that the lightning surge hits the lightning arrester and make this device's insulation destroyed. This paper also simulated these processes utilizing EMTP/ATPDraw and verified voltage behavior when faults such as line to ground fault due to frequent lightning surge occur in lightning arrester.

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Optimal design using genetic algorithm with nonlinear inelastic analysis

  • Kim, Seung-Eock;Ma, Sang-Soo
    • Steel and Composite Structures
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    • v.7 no.6
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    • pp.421-440
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    • 2007
  • An optimal design method in cooperated with nonlinear inelastic analysis is presented. The proposed nonlinear inelastic method overcomes the difficulties due to incompatibility between the elastic global analysis and the limit state member design in the conventional LRFD method. The genetic algorithm used is a procedure based on Darwinian notions of survival of the fittest, where selection, crossover, and mutation operators are used to look for high performance ones among sections in the database. They are satisfied with the constraint functions and give the lightest weight to the structure. The objective function taken is the total weight of the steel structure and the constraint functions are load-carrying capacity, serviceability, and ductility requirement. Case studies of a planar portal frame, a space two-story frame, and a three-dimensional steel arch bridge are presented.

The Global Status of Ophthalmic Education and Legislation (검안 교육과 법률의 국제적 현상)

  • Penisten, Douglas K.;Di Stefano, Anthony F.;Kim, Douk Hoon
    • Journal of Korean Ophthalmic Optics Society
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    • v.8 no.1
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    • pp.73-84
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    • 2003
  • This paper reviews the current status of ophthalmic education and legislation worldwide. The impact of the profession of optometry in providing eye and vision care in different regions of the world and strategic directions for optometry in Korea are discussed. The role of the World Council of Optometry in advancing the access and delivery of eye and Vision care is emphasized.

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A Study on the Structure and Characteristics of Light-duty FC Hybrid Vehicle (경부하 FC 하이브리드 자동차의 구조와 특성에 관한 연구)

  • Bong, Tae-Keun
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.8
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    • pp.911-917
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    • 2007
  • Global primary energy demand is projected to increase by 1.7% per year from 2000 to 2030. Almost three-quaters of the increase in demand will come from the transportation sector. Fuel cell hybrid vehicle technology has the potential to significantly reduce energy and harmful emissions, as well as our dependence on foreign oil. In this paper, a systematic and logical methodology is developed and improved mainly to design light duty fuel cell hybrid electric vehicle. We investigated structure and characteristics of light duty FC hybrid vehicle carefully. It can easily be expanded to analyze vehicle-to-grid power connectable plug-in NeHEV. A fuel cell hybrid neighbourhood electric vehicle configuration has been studied in-depth utilizing the proposed methodology.

RECENT DEVELOPMENTS IN HYDROSYSTEMS

  • Larry-W.Mays
    • Proceedings of the Korea Water Resources Association Conference
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    • 1993.07a
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    • pp.3-26
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    • 1993
  • I have briefly described some of the important advances in hydrosystems and to remark on the important scientific research priorities in hydrological sciences. We have concentrated on data collection systems, real-time control of hydrosystems, global climate change and decision support systems and GIS. In summary, I would like to stress the following points: - the advances in data collection systems, advanced methodologies for interfacion hydrologic, hydraulic, and optimization models through optimal control approaches; and the advances in decision support systems and GIS will allow the interfacing of all these technologies into some sophisticated and much needed tools for operating hydrosystems; - the ability to better understand the hydrologic processes and their relationships to other earth processes is important to understanding and modelling of the hydrologic cycle and its interactions with the ocean-atmosphere system; - and the solution to a better understanding of hydrologic sciences needs to be an international effort such as the GEWEX program briefly discussed above. I would like to thamk each of you for listening to my lecture and to once again thank those responsible for me being here today. Thank you.

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IKEA and Corporate Social Responsibility: A Case Study

  • Hahn, Yoonah
    • Journal of Distribution Science
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    • v.13 no.10
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    • pp.45-50
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    • 2015
  • Purpose - The purpose of this paper is to examine IKEA in the context of corporate social responsibility to determine the reasons, if any, as to why IKEA has had more success in the implementation of its CSR policies and Code of Conduct where many other multinational companies seem to have failed. Research Design and Methodology - This is a case study, an analytical approach, which focuses on exploring and analyzing the CSR policies to measure IKEA's ethical behavior in a business environment. Results - IKEA stands out as a multinational company whose CSR policies are ingrained into the business itself as a part of its ethical operations, rather than a marketing event. Conclusion - Beyond profit, IKEA actively works together with its suppliers and the nation states to eradicate the harmful social causes of the various challenges it faces in the global business environment.

Country Analysis: Algeria

  • Mehyaoul, Quafaa
    • Asian Journal of Business Environment
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    • v.5 no.3
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    • pp.29-31
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    • 2015
  • Purpose - The purpose of this country analysis is to examine its current state: economically, politically, legally, and ethically, and look at small and medium Algerian businesses to identify any issues that could hinder economic and business performance and growth. Research Design, and Methodology - This is a case study, an analytical approach, which focuses on exploring and analyzing different aspects of Algeria. Results - Since 2008, the Algerian economy has experienced a relative slowdown due to falling oil and gas prices and the economic recessions of its main trading partners, in particular, European countries. Algeria has still not managed to diversify its economy or establish competitive industrialization at the international level; it has had difficulty shifting from its economic dependence on hydrocarbons. Algerian businesses continue to face obstacles and constraints, penalized in their performance and prevented from success in a dense and competitive global marketplace. Conclusion - The Algerian economy and Algerian businesses have shown positive performance and growth over the last few decades. However, issues exist that may hinder both business and economic progress in the future.

Study on key standardization Work Item derivation and strategies for IoT services (사물인터넷 서비스의 중점 표준화 항목 도출 및 전략에 관한 연구)

  • Kim, Jungsook
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.12 no.1
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    • pp.13-26
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    • 2016
  • Service and technology for the future hyper-connected society, which is every information receive through the mobile internet, will be an Internet of Things. Thus, it is mandatory to derive key standardization work item and establish strategy for the global business with the standardization of device and service platform by the application service. In this study, by analyzing the domestic and international market trends, state of technical development, and standardization of technology, we identified the open platform is the stepping stone for achieving the goal which is establishing the virtuous circulation of IoT ecosystem. Also, we defined emphasized key standardization work item for achieving the open platform are network, server, access authentication, billing system, and software platform. After that, we proposed future strategy direction of standardization. This research could be contribute to the IoT service diffusion by realizing IP communication among low power wireless terminals and implementing light-weight standard internet protocol.

A numerical study on the characteristics of flame propagation in small tubes under various boundary conditions (벽면조건에 의한 미소관내 화염 전파 특성 변화에 관한 수치해석)

  • Kim, Nam-Il;Maruta, Kaoru
    • 한국연소학회:학술대회논문집
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    • 2006.04a
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    • pp.32-38
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    • 2006
  • A premixed flame propagating in a tube suffers strong variation in its shape and structure depending on boundary conditions. The effects of thermal boundary conditions and flow fields on flame propagation are numerically investigated. Navier-Stokes equations and species equations are solved with a one-step irreversible global reaction model of methane-air mixture. Finite volume method using an adaptive grid method is applied to investigate the flame structure. In the case of an adiabatic wall, friction force on the wall significantly affected the flame structure while in the case of an isothermal wall, local quenching near the wall dominated flame shapes and propagation. In both cases, variations of flow fields occurred not only in the near field of the flame but also within the flame itself, which affected propagation velocities. This study provides an overview of the characteristics of flames in small tubes at a steady state.

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