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Structure of the earth's magnetosheath at small fluctuations in the interplanetary magnetic field direction

COSMIC RESEARCH 2011年第4期49卷 281-291页

作者： Chugunova, O. M. Pilipenko, V. A. Zastenker, G. N. Shevyrev, N. N. Russian Acad Sci Space Res Inst Moscow 117810 Russia Russian Acad Sci Schmidt Joint Inst Phys Earth Moscow 123810 Russia

Spatial structure of the magnetosheath of the Earth was studied under the conditions when no sharp (more than 40A degrees during 5 min) changes in the interplanetary magnetic field direction were observed. On the basis of 24 flights of the Interball-1 satellite through the magnetosheath, it is found that three regions differing from each other by parameters of the field and plasma can be observed in the magnetosheath under the above-indicated conditions. These regions also differ from the solar wind region before front of the Earth's magnetospheric bow shock. Empirical distributions of parameters were studied in each region. Taking into account the influence of the interplanetary magnetic field direction on the processes in the magnetosheath, the cases of quasi-perpendicular and quasi-parallel shock waves were considered separately. The study showed that the distribution of parameters in the selected regions (in the solar wind before front of the bow shock, in the magnetosheath behind the bow shock (post-shock), in the region of the magnetosheath with minimal fluctuations in the field, and in the inner magnetosheath) differ from each other at any interplanetary magnetic field direction.

关键词： INTERPLANETARY MAGNETIC FIELDS solar wind magnetosheath field direction distributed parameter

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Controller design of a distributed slewing flexible structure - A frequency domain approach

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME 1997年第4期119卷 809-814页

作者： Yang, SM Jeng, JA Liu, YC Natl Cheng Kung Univ Inst Aeronaut & Astronaut Tainan 70101 Taiwan Kaohsiung Polyteech Inst Dept Engn Mech Kaohsiung Taiwan

The vibration control of a slewing flexible structure by collocated and noncollocated feedback is presented in this paper. A stability criterion derived from the root locus method in frequency domain is applied to predict the closed-loop system stability of the distributed parameter model whose analytical transfer functions are formulated It is shown that the control law design requires neither distributed state sensing/estimation nor functional feedback gain;moreover, the spillover problem associated with discrete parameter model can be prevented. Implementation of the noncollocated feedback in a slewing beam experiment validates that the control law is effective in pointing accuracy while suppressing the tip vibration.

关键词： POINTING ACCURACY Distribute Flexible structures controller design Stability criteria distributed parameter root-locus technique vibration control TRANSFER FUNCTIONS control law

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A new extension of the infinite-dimensional KYP lemma in the coercive case

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IFAC-PapersOnLine 2015年第11 11期48卷 246-251页

作者： Proskurnikov, Anton V. ENTEG Institute at the University of Groningen Netherlands St.-Petersburg State University Institute for Problems of Mechanical Engineering RAS ITMO University Russia

The Kalman-Yakubovich-Popov (KYP) Lemma, giving the frequency-domain criteria for solvability of LQR problems and feasibility of related LMIs and Lur'e-Riccati equations, is undoubtedly one of the cornerstone results in modern control theory. Numerous applications of the KYP lemma in nonlinear and robust control motivated its extension to systems with distributed parameters. Unlike the finite-dimensional case, where the KYP lemma admits elegant proofs by means of algebraic techniques and methods from convex analysis, a prerequisite for its infinite-dimensional extensions is feasibility of the corresponding LQR problem, resulting on assumptions of exponential or L2-stabilizability. This property is restrictive and not easily verifiable for general infinite-dimensional systems. Being quite natural in the problems of absolute stability, it seems unnecessary in other applications of the KYP lemma which require only solvability of the operator inequality, but not positivity of its solution, such as e.g. instability or dichotomy criteria. In the present paper we show, that in the “strict” or coercive case the KYP lemma retains its validity, replacing stabilizability assumption with some technical assumption which holds, for instance, whenever the linear system is exponentially dichotomic. © 2015

关键词： Riccati equations Algebra Frequency domain analysis Linear systems Robust control Stability criteria Dissipation inequality distributed parameter Infinite dimensional Infinite dimensional system Kalman Yakubovich Popov lemma KYP lemma Modern control theory Operator inequalities

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Flatness-Based Model Predictive Control with Linear Programming for a Single Mast Stacker Crane

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IFAC-PapersOnLine 2018年第2期51卷 31-36页

作者： Galkina, A. Schlacher, K. Institute of Automatic Control and Control Systems Technology Johannes Kepler University Linz Altenberger Strasse 69 Linz4040 Austria

This paper deals with a trajectory tracking model predictive control for a single mast stacker crane, which is used for automatic storage or retrieval of payloads in automated warehouses. The mathematical model of the plant is a distributed parameter one, but it admits an excellent approximation by a flat lumped parameter system. The approximate nonlinear system is simplified further and the resulting linear time-varying system is implemented to design a model predictive controller. To provide an efficient formulation of an optimization task for the controller, the LTV-model is parametrized by a special flat output. Then, the model predictive control is formulated in the form of a linear program. For solving the derived linear program, an open-source optimal solver LP_SOLVE is chosen. To reduce a mechanical stress at clamping of a mast and an overall accessibility time, a special optimal trajectory calculated offline is chosen for the tracking by the designed controller. Finally, the simulation results of the nonlinear approximate model, subjected to model uncertainties and external disturbances, with the designed model predictive controller are presented. © 2018

关键词： Model predictive control Controllers Cranes Linear programming Open source software Time varying control systems Uncertainty analysis distributed parameter Efficient formulation External disturbances Flatness Flexible construction Linear time varying systems Lumped parameter systems Model predictive controllers

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A Monte Carlo method for calculating Bayesian uncertainties in internal dosimetry

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RADIATION PROTECTION DOSIMETRY 2008年第1期132卷 1-12页

作者： Puncher, M. Birchall, A. HPA Ctr Radiat Chem & Environm Hazards Radiat Protect Div Didcot OX11 0RQ Oxon England

This paper presents a novel Monte Carlo method (WeLMoS, Weighted Likelihood Monte-Carlo sampling method) that has been developed to perform Bayesian analyses of monitoring data. The WeLMoS method randomly samples parameters from continuous prior probability distributions and then weights each vector by its likelihood (i.e. its goodness of fit to the measurement data). Furthermore, in order to quality assure the method, and assess its strengths and weaknesses, a second method (MCMC, Markov chain Monte Carlo) has also been developed. The MCMC method uses the Metropolis algorithm to sample directly from the posterior distribution of parameters. The methods are evaluated and compared using an artificially generated case involving an exposure to a plutonium nitrate aerosol. In addition to calculating the uncertainty on internal dose, the methods can also calculate the probability distribution of model parameter values given the observed data. In other words, the techniques provide a powerful tool to obtain the estimates of parameter values that best fit the data and the associated uncertainty on these estimates. Current applications of the methodology, including the determination of lung solubility parameters, from volunteer and cohort data, are also discussed.

关键词： Probability distribution Posterior distribution Monte Carlo technique Dosimetry PLUTONIUM NITRATES Volunteers measurement data distributed parameter goodness of fit Markov chain monte carlo methods

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Delays. Nonlinearity. Synchronization

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IFAC-PapersOnLine 2016年第10期49卷 200-205页

作者： Danciu, Daniela Rsvan, Vladimir Department of Automation and Electronics University of Craiova A.I. Cuza 13 CraiovaRO-200585 Romania

A rather common model of the synchronization is represented by several local oscillators coupled to some (possibly distributed) transmission environment. This model goes back to Huygens. If the transmission environment is represented by a one dimensional distributed parameter structure (vibrating string in the mechanical case or an electric transmission line for electrical systems) then some functional differential equations may be associated by integration along the characteristics. Consequently, the synchronization of the two local oscillators can be analyzed as a problem of forced oscillations for functional differential equations. In this paper two LC local nonlinear oscillators are viewed as connected to a lossless LC transmission line of infinite length. This is the electrical analogue of the Huygens like case where two nonlinear pendula are coupled to a vibrating string. © 2016

关键词： Electric lines Control nonlinearities Differential equations Oscillators (mechanical) Synchronization Time delay distributed parameter Electrical systems Forced oscillations Functional differential equations Local oscillators Non linear oscillators Popov criteria Transmission environment

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ELASTIC-SCATTERING OF POLARIZED ELECTRONS FROM MERCURY AND XENON

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JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 1986年第21期19卷 3539-3557页

作者： BERGER, O KESSLER, J Phys. Inst. Munster Univ. West Germany

Polarised electrons have been scattered elastically from mercury and xenon. The angular distribution of the parameters that describe the change in the electron polarisation caused by the scattering process has been measured in the energy range from 25 to 150 eV for mercury and from 40 to 350 eV for xenon. With these parameters, in conjunction with the absolute differential cross section, a complete analysis of the scattering amplitudes with respect to their magnitudes and their relative phase is performed for xenon.

关键词： Scattering elastic scattering ENERGY RANGE Electrons Xenon electron polarization distributed parameter mercury

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Conformational transitions of DNA induced by changing water content of the sample: A theoretical study

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JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS 2000年第5期17卷 913-920页

作者： Tolstorukov, MY Maleev, VY Kharkov State Univ Chair Mol & Appl Biophys UA-310077 Kharkov Ukraine

A semi-phenomenological model with spatially distributed parameters is suggested to describe the processes of conformational transitions induced with change of water content of wet DNA samples. It allows describing conformational dynamics of DNA molecules with heterogeneous primary structures. It has been shown that the process of cooperative conformational transition can be simulated as propagating front of a new conformation. The evolution of a conformational perturbation of DNA molecule has been described. It can collapse for finite time or occupy the whole molecule depending on the water content of the sample.

关键词： DNA Nucleic Acid Conformation Water 核酸构象水 Nucleic Acid Conformation conformational transition moisture content Theoretical Study distributed parameter DNA

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New Interpretation of Signals and In-Reactor Detector Calibration

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ATOMIC ENERGY 2013年第6期114卷 399-403页

作者： Postnikov, V. V. Evdokimov, A. M. Yakunin, I. S. Volkov, A. E. Zhukov, O. E. Petrov, V. V. Dollezhal Res & Dev Inst Power Engn NIKIET Moscow Russia Natl Res Ctr Kurchatov Inst Moscow Russia

One way to increase the accuracy of monitoring general and distributed parameters of the core of a nuclear reactor is to calibrate the in-reactor neutron and gamma-ray detectors. The calibration can be performed before the detectors are placed in the core as well as periodically during operation. The approaches used to calibrate detectors for different types of modern nuclear reactors are examined and the accuracy of some methods of calibration is presented.

关键词： Nuclear reactors Gamma-ray detectors CALIBRATION METHODS signals distributed parameter

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ASSESSING THE INVERSE GAUSSIAN DISTRIBUTION ASSUMPTION

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IEEE TRANSACTIONS ON RELIABILITY 1990年第3期39卷 352-355页

作者： EDGEMAN, RL Colorado State University Fort Collins USA

Two easily applied goodness-of-fit tests for the inverse Gaussian distribution are discussed. One of these tests is the familiar Kolmogorov-Smirnov one-sample test that is applied when the form of a probability distribution is completely specified. When the parameters of the distribution are unknown, as is more typical, the Kolmogorov-Smirnov test cannot be directly applied. In this instance, a transformation that uses a distributional result relating the Student-t distribution to the inverse Gaussian distribution allows the Lilliefors test of normality to be adapted to test the inverse Gaussian distribution assumption.

关键词： Inverse Student's t-distribution Gaussian distribution Probability distribution distributed parameter

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