scholarly journals Separation of edge effects in highly non-dipole radiation spectra

2018 ◽  
Vol 33 (07n08) ◽  
pp. 1850035 ◽  
Author(s):  
M. V. Bondarenco
Keyword(s):  
Time Delay ◽  
Edge Effects ◽  
Spectral Decomposition ◽  
Point Of View ◽  
Relativistic Electrons ◽  
Double Scattering ◽  
Decomposition Property ◽  
Dipole Radiation ◽  
Radiation Spectra

Edge effects in spectra of non-dipole radiation from ultra-relativistic electrons passing through various finite targets are analyzed from a unified point of view. Examples include radiation in a finite magnet, bremsstrahlung at double scattering, and bremsstrahlung in an amorphous plate. A generalization of the encountered spectral decomposition property is proposed. The relevance of phenomena of jet–inter-jet radiation interference and electron time delay in the target is emphasized. Features produced by them in the radiation spectra are discussed.

scholarly journals The Dynamic Complexity of a Holling Type-IV Predator-Prey System with Stage Structure and Double Delays

2011 ◽  
Vol 2011 ◽  
pp. 1-19 ◽  
Author(s):  
Yakui Xue ◽  
Xiafeng Duan
Keyword(s):  
Time Delay ◽  
Equilibrium Point ◽  
Dynamical Behavior ◽  
Stage Structure ◽  
Point Of View ◽  
Maturation Time ◽  
Dynamic Complexity ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Type Iv

We invest a predator-prey model of Holling type-IV functional response with stage structure and double delays due to maturation time for both prey and predator. The dynamical behavior of the system is investigated from the point of view of stability switches aspects. We assume that the immature and mature individuals of each species are divided by a fixed age, and the mature predator only attacks the mature prey. Based on some comparison arguments, sharp threshold conditions which are both necessary and sufficient for the global stability of the equilibrium point of predator extinction are obtained. The most important outcome of this paper is that the variation of predator stage structure can affect the existence of the interior equilibrium point and drive the predator into extinction by changing the maturation (through-stage) time delay. Our linear stability work and numerical results show that if the resource is dynamic, as in nature, there is a window in maturation time delay parameters that generate sustainable oscillatory dynamics.

scholarly journals Transfer of Energy to the Crab Nebula Following the Spin-Up of the Pulsar

1971 ◽  
Vol 46 ◽  
pp. 296-307 ◽  
Author(s):  
D. B. Melrose
Keyword(s):  
Energy Flux ◽  
Central Region ◽  
Crab Nebula ◽  
Point Of View ◽  
Relativistic Electrons ◽  
Synchrotron Emission ◽  
X Ray ◽  
Enhanced Activity ◽  
The Crab Nebula

Observed enhanced activity in the central region of the Crab Nebula following the spin-up of the pulsar is discussed from the point of view of the transfer of energy to relativistic electrons. It is argued that a rapid deposition of energy associated with the spin-up of the pulsar causes a radial energy flux which becomes a flux in hydromagnetic activity at about the regions where enhanced synchrotron emission is observed. It is shown that such hydromagnetic activity is rapidly damped by the relativistic electrons with energy being transferred to the relativistic electrons. This acceleration can account for the short synchrotron halflifetimes observed. The model predicts highly enhanced X-ray emission from the central region of the Nebula following a spin-up.

scholarly journals Very High Energy γ-Ray Generation Near The Light Cylinder of an Axisymmetric Rotator: Cos-B Like γ-Ray Sources

1992 ◽  
Vol 128 ◽  
pp. 207-208
Author(s):  
S. V. Bogovalov ◽  
YU. D. Kotov
Keyword(s):  
High Energy ◽  
Relativistic Electrons ◽  
X Rays ◽  
Inverse Compton Scattering ◽  
Light Cylinder ◽  
Radiation Spectra ◽  
Inverse Compton ◽  
Very High Energy ◽  
Γ Ray ◽  
Very High

AbstractSuper-hard γ-ray radiation spectra have been calculated. This radiation is generated near the velocity-of-light cylinder through the process of inverse-Compton scattering of relativistic electrons by thermal photons radiated by a neutron star. These calculations have been compared with observations of the Crab and Vela pulsars at 1000-GeV γ-ray energies. A correlation between γ-ray flares and those in soft (Ex ≃ lkeV) X-rays are predicted.

scholarly journals Time-Delay Identification in a Chaotic Semiconductor Laser With Optical Feedback: A Dynamical Point of View

2009 ◽  
Vol 45 (7) ◽  
pp. 879-1891 ◽  
Author(s):  
Damien Rontani ◽  
Alexandre Locquet ◽  
Marc Sciamanna ◽  
David S. Citrin ◽  
Silvia Ortin
Keyword(s):  
Time Delay ◽  
Semiconductor Laser ◽  
Optical Feedback ◽  
Point Of View

scholarly journals Parameter Estimation for Dynamic Model of the Financial System

2015 ◽  
Vol 63 (6) ◽  
pp. 2051-2055
Author(s):  
Veronika Novotná ◽  
Vladěna Štěpánková
Keyword(s):  
Time Delay ◽  
Dynamic Model ◽  
Dynamic Models ◽  
Financial System ◽  
Point Of View ◽  
Investment Demand ◽  
History Of ◽  
New Perspective ◽  
The Interest Rate

Economy can be considered a large, open system which is influenced by fluctuations, both internal and external. Based on non-linear dynamics theory, the dynamic models of a financial system try to provide a new perspective by explaining the complicated behaviour of the system not as a result of external influences or random behaviour, but as a result of the behaviour and trends of the system’s internal structures. The present article analyses a chaotic financial system from the point of view of determining the time delay of the model variables – the interest rate, investment demand, and price index. The theory is briefly explained in the first chapters of the paper and serves as a basis for formulating the relations. This article aims to determine the appropriate length of time delay variables in a dynamic model of the financial system in order to express the real economic situation and respect the effect of the history of factors under consideration. The determination of the delay length is carried out for the time series representing Euro area. The methodology for the determination of the time delay is illustrated by a concrete example.

scholarly journals Identifying The Effective Factors for Cost Overrun and Time Delay in Water Construction Projects

2016 ◽  
Vol 6 (4) ◽  
pp. 1062-1066 ◽  
Author(s):  
D. Mirzai Matin
Keyword(s):  
Time Delay ◽  
Construction Projects ◽  
Point Of View ◽  
Relative Importance ◽  
Cost Overrun ◽  
Weighting Method ◽  
Additional Information ◽  
Financial Difficulties ◽  
Questionnaire Form ◽  
The Government

Water construction projects in Iran frequently face problems which cause cost overrun and time delay, the two most common issues in construction projects in general. The objective of this survey is to identify and quantify these problems and thus help in avoiding them. This survey represents a collection of the most significant problems found in the literature, classified into 11 groups according to their source. The questionnaire form used contains 84 questions which were answered by random engineers who work in water construction projects. The Relative Importance Weight (RIW) method is used to weight the importance of each one of the 84 problems. The focus of this survey is on overall top ten issues which are: bureaucracy in bidding method, inflation, economical condition of the government, not enough information gathered and surveys done before design, monthly payment difficulties, material cost changes, law changes by the government, financial difficulties, mode of financing and payment for completed work and changes made by the owner. A section for each of these issues provides additional information about them. In the full text of this survey the same weighting method is used to classify the main groups, and the results show that issues related to the groups of government, owner and consultant has the most significant impact. The last part of this survey describes the point of view of the engineers who took part in this survey and the recommendations they made.

The Gaseous Squeeze-Film at Moderately Large Squeeze Numbers

1970 ◽  
Vol 92 (4) ◽  
pp. 766-781 ◽  
Author(s):  
C. H. T. Pan
Keyword(s):  
Edge Effects ◽  
Lubrication Theory ◽  
Point Of View ◽  
Squeeze Film ◽  
Universal Functions ◽  
Inertia Effects ◽  
Gas Lubrication ◽  
Spherical Bearing ◽  
Squeeze Number ◽  
Isothermal Gas

The asymptotic analysis of the gaseous squeeze-film bearing has been extended to obtain 0 {σ−1/2} effects in accordance with the isothermal gas lubrication theory and the method of singular perturbation. 0 {σ−1/2} corrections are identified to contain not only edge effects (inner problem) but also edge-interior interactions which are analogous to the boundary layer displacement effects in aerodynamics. The latter features can further be recognized to be related to mean-gap taper, squeeze taper, and cross-edge sliding. These results are discussed from the point of view of “global bearing properties” including the temporal mean as well as the in-phase and quadrature synchronous components of the fluid film force and moment. The edge effects are presented in terms of universal functions which can be used directly as corrections in the global properties. The edge-interior interactions must be determined by solving the asymptotic p.d.e. with boundary condition also expressed in terms of universal functions. Formulations applicable to cylindrical, conical, and spherical bearing geometries are outlined. Illustrative numerical examples are provided. Conditions affecting the validity of the isothermal gas lubrication theory (neglecting inertia effects) as related to the magnitude of the squeeze number are discussed.

2DOF Controller Tuning

2015 ◽  
Vol 18 ◽  
pp. 57-64
Author(s):  
Miluse Viteckova ◽  
Antonin Vitecek
Keyword(s):  
Time Delay ◽  
Analytical Method ◽  
Degrees Of Freedom ◽  
Point Of View ◽  
Pid Controllers ◽  
Two Degrees Of Freedom ◽  
First Order ◽  
Quality Of Control ◽  
Dominant Pole

At present the two degrees of freedom (2DOF) controllers are more often available. These controllers enable to tune both from point of view of the desired variable and the disturbance variable as well. It allows increase the overall quality of control. For the tuning of the 2DOF controllers to date there are only a few suitable methods. This paper is devoted to the tuning of the 2DOF PI and PID controllers by the multiple dominant pole method (MDPM) for first order plants and integrating plants with time delay. It is an analytical method and it is shown that by the corresponding tuning of the 2DOF controllers it is possible to obtain the non-oscillatory servo and regulatory step responses without overshoots. The use is demonstrated in the example.

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