• Title/Summary/Keyword: Stable laws

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Graphical Estimation of the Parameters of the Stable Laws

  • Paulson, Albert-S.;Won, Hyung-Gyoo
    • Management Science and Financial Engineering
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    • v.2 no.1
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    • pp.103-122
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    • 1996
  • This paper presents an easily used graphical procedure for simultaneous estimation of the index, skewness, scale, and location parameters of the stable laws. First, the index $\alpha$ and skewness $\beta$ are estimated through the joint use of a tail length statistic $\widetilde{K_t}$ and a skewness statistic $\widetilde{K_s}$, both of which are functions of order statistics. Next, the function of order statistics needed for estimation of scale $\sigma$ and location $\mu$ are determined from a nomogram indexed on the estimates of $\alpha$ and $\beta$. Some applications and examples are provided.

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Comparative Legal Study on the Arbitral Award under Arbitration Laws in Northeast Asian Nations (동북아국가들의 중재법상 중재판정의 비교법적 고찰)

  • Choi, Seok-Beom
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.27
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    • pp.29-65
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    • 2005
  • Northeast Asian economies have achieved high levels of growth due to a stable economic environments and economic policy reforms for free trade. As Northeast Asia has been risen as big bloc in the world and in the future in case free trade agreement could be concluded, trade volume could be increased dramatically. And it is evident that disputes will be increased in Northeast Asian economic bloc. Arbitration must be popular in resolving international commercial disputes in Northeast Asian bloc in order to increase the volume of intra-trade in the bloc. Through arbitration, the parties can have full autonomy and can resolve disputes independently, impartially and without delay. But in order for the parties to make use of arbitration in the bloc, they must be fully aware of the arbitration laws of Northeast Asian nations in view of the similarity and difference of the laws. Therefore, this paper deals with arbitral award in Northeast Asian Nations' arbitration laws in view of comparative law.

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Neural Network Controller with Dynamic Structure for nonaffine Nonlinear System (불확실한 비선형 계통에 대한 동적인 구조를 가지는 강인한 신경망 제어기 설계)

  • 박장현;서호준;박귀태
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.384-384
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    • 2000
  • In adaptive neuro-control, neural networks are used to approximate the unknown plant nonlinearities. Until now, most of the papers in the field of controller design fur nonlinear system using neural networks considers the affine system with fixed number of neurons. This paper considers nonaffne nonlinear systems and dynamic variation of the number of neurons. Control laws and adaptive laws for weights are established so that the whole system is stable in the sense of Lyapunov.

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Feedback stabilization of linear systems with delay in control by receding horizon (지연요소를 갖는 시스템의 안정화 방법)

  • 권욱현
    • 전기의세계
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    • v.28 no.5
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    • pp.44-48
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    • 1979
  • For ordinary systems the receding horizon method has beer proved by the author as a very useful and easy tool to find stable feedback controls. In this paper an open-loop optimal control which minimizes the control energy with a suitable upper limit and terminal control and state constraints is derived and then transformed to the closed-loop control. The stable feedback control law is obtained from the closed-loop control. The stable feedback control law is obtained from the closed-loop control by the receding horizon concept. It is shown by the Lyapunov method that the control law derived from the receding, horizon concept is asymtotically stable under the complete controllability condition. The stable feedback control which is similar to but more general than the receding horizon control is presented in this paper To the author's knowledge the control laws in this paper are easiest to stabilize systems with delay in control.

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A Design of Stable Adaptive Composite Control Systems (안정한 적응 이중 제어시스템의 설계)

  • Zhang, Jeong-Il;Yang, Hai-Won
    • Proceedings of the KIEE Conference
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    • 1994.11a
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    • pp.370-372
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    • 1994
  • In this paper, a stable adaptive composite control system consisting of a PID and a fuzzy controllers is designed to control nonlinear systems. In the fuzzy controller, parameters of membership functions characterizing the linguistic terms change according to some adaptive law. Also, parameters of PID controller change according to some adaptive law. These adaptive laws are based on the Lyapunov synthesis approach. Then, it is proved that the closed-loop system using such an adaptive composite control system is globally stable in the sense that all signals involved are bounded and the tracking error converges to zero. We apply this adaptive composite control system to control a nonlinear system.

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Stabilizing Control Law of Underactuateted Spacecraft (작동기 수가 부족한 위성체의 자세안정화기법)

  • 김성필;김유단
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.102-102
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    • 2000
  • In this paper, attitude control laws are proposed for an underactuated spacecraft. The stabilization problem of the complete system including the kinematics as well as the dynamics of the spacecraft is addressed. The quaternion parameterization is used. The key idea is that the angular velocity of a uncontrolled axis is first regulated and then, the other states are regulated. Based on numerical simulations, it is conjectured that the closed-loop nonlinear system of a spacecraft with the proposed control laws is globally asymptotically stable. The control law for the stabilization problem around the origin as well as the command following problem are proposed. The numerical examples indicate that the stabilization of an underactuated asymmetric spacecraft can be achieved successfully.

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Delay-dependent Stabilization of Singular Systems with Multiple Internal and External Incommensurate Constant Point Delays

  • Xie, Yong-Fang;Gui, Wei-Hua;Jiang, Zhao-Hui
    • International Journal of Control, Automation, and Systems
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    • v.6 no.4
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    • pp.515-525
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    • 2008
  • In this paper, the problem of delay-dependent stabilization for singular systems with multiple internal and external incommensurate constant point delays is investigated. The condition when a singular system subject to point delays is regular independent of time delays is given and it can be easily test with numerical or algebraic methods. Based on Lyapunov-Krasovskii functional approach and the descriptor integral-inequality lemma, a sufficient condition for delay-dependent stability is obtained. The main idea is to design multiple memoryless state feedback control laws such that the resulting closed-loop system is regular independent of time delays, impulse free, and asymptotically stable via solving a strict linear matrix inequality (LMI) problem. An explicit expression for the desired memoryless state feedback control laws is also given. Finally, a numerical example illustrates the effectiveness and the availability for the proposed method.

A Study on the Supply and Demand of Fishmeal and Stable Securing Strategies (양어용 어분의 수급 실태 및 안정적 확보 방안)

  • Kim, Dae-Young;Lee, Jung-Sam;Lee, Heon-Dong
    • The Journal of Fisheries Business Administration
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    • v.44 no.3
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    • pp.61-76
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    • 2013
  • This study is aimed to present measures for stable supply of fishmeal and to develop fish farming into a food industry and an export industry. The study analyzed current domestic and international supply and demand for fishmeal and suggested future prospects. The results of the study suggested the basic directions for the stable supply of fishmeal in Korea as follows: first, stable securing of fishmeal importers and establishment of the supply and demand monitoring system; second, policies to boost using of compound feeds and expansion of relevant fishmeal use; third, higher competitiveness of fishmeal and compound feeds through selective and intensive R&D investments. Based on the basic directions, the paper suggested implementation measures such as strengthening of cooperations with fishmeal suppliers abroad, expansion of overseas local market entrance, diversification of fishmeal trading countries, revision of relevant laws and polices on the fishmeal and feeds, organization of domestic fishmeal, promotion of group purchase, improvement of domestic fish meal quality, development of fish meal alternatives, etc.

Analysis of Stable Walking Pattern of Biped Humanoid Robot: Fuzzy Modeling Approach (이족 휴머노이드 로봇의 안정적인 보행패턴 분석: 퍼지 모델링 접근방법)

  • Kim Dongwon;Park Gwi-Tae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.6
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    • pp.376-382
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    • 2005
  • In this paper, practical biped humanoid robot is presented, designed, and modeled by fuzzy system. The humanoid robot is a popular research area in robotics because of the high adaptability of a walking robot in an unstructured environment. But owing to the lots of circumstances which have to be taken into account it is difficult to generate stable and natural walking motion in various environments. As a significant criterion for the stability of the walk, ZMP (zero moment point) has been used. If the ZMP during walking can be measured, it is possible for a biped humanoid robot to realize stable walking by a control method that makes use of the measured ZMP. In this study, measuring the ZMP trajectories in real time situations throughout the whole walking phase on the flat floor and slope are conducted. And the obtained ZMP data are modeled by fuzzy system to explain empirical laws of the humanoid robot. By the simulation results, the fuzzy system can be effectively used to model practical humanoid robot and the acquired trajectories will be applied to the humanoid robot for the human-like walking motions.

The Strategy of Russia's Political Elites to Maintain Dominance Through the Overhaul of Electoral System (선거제도 개편을 통한 러시아 정치 엘리트의 지배력 유지 전략)

  • Siheon Kim;Seho Jang
    • Analyses & Alternatives
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    • v.7 no.1
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    • pp.7-43
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    • 2023
  • This study examines and identified a series of strategies of Russia's political elites to maintain and strengthen their dominance by reviewing the case of revisions in the election laws of Russia in 2014. At that time, a mixed-member electoral system was newly introduced, and on the surface, it seemed that the new system was a step toward meeting the demands of the people for "enhanced democracy". However, in 2016 and 2021, the ruling party of Russia won the general elections by making the most of the factors that could distort the election results inherent in the mixed-member electoral system. Therefore, this study aimed to analyze whether the revision of election laws was a mere vehicle used by the ruling party, United Russia, to maintain its political power, or whether it was a leap forward to achieve democracy. The study result indicate that the revision of election laws in 2014 was part of the policy responses to the internal conflicts in the circle of Russia's political elites, which had been rising since 2008, as well as to the public resistance. In other words, it was confirmed that the revision of election laws was one of the measures taken to "minimize competition" and "reproduce political power on a stable basis".