scholarly journals Simulation of radioelectronic means non-stationary bounce flow and its intensity estimation procedure

2019 ◽  
pp. 18-25
Author(s):  
A. T. Kurilyak ◽  
S. S. Sokolov
Keyword(s):  
Random Process ◽  
Estimation Procedure ◽  
Linear Filter ◽  
Filter Parameter ◽  
Practical Applications ◽  
Optimal Value ◽  
Radio Electronics ◽  
Transcendental Functions ◽  
Physical Phenomena ◽  
Theoretical Results

Unsteady bounce flow is a Poisson flow modulated in intensity by a stationery random process. Flows of this class, known as double stochastic flows, are found in application for describing in addition to the unsteady flow of failures of radio electronics means, a number of physical phenomena in the Earth’s magnetosphere, meteorology and medicine. The problem of registration is the choice of the optimal value of the linear filter parameter, which provides the minimum total root-mean-square error of estimating the flow rate. The obtained theoretical results, based on solving the Wiener-Hopf education, confirmed the presence of the optimal value of the filter parameter for a wide class of random process modulating the flow in intensity. However, when performing mathematical transformations, several approximations of transcendental functions were used, which influenced the accuracy of the results, but allowed to obtain solutions important for practical applications. As part of the study, an algorithm and a computer program for stimulating the implementation of a nonstationary flow and the procedure for forming the relative error of estimating its intensity have been developed. The simulation results combined with the theoretical results, obtained for the exponential autocorrelation function of the modulating random process are presented.

scholarly journals Double Hopf Bifurcation in Microbubble Oscillators with Delay Coupling

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jinbin Wang ◽  
Rui Zhang ◽  
Lifenq Ma
Keyword(s):  
Hopf Bifurcation ◽  
Center Manifold ◽  
Two Dimensional ◽  
Main Attention ◽  
Dimensional Parameter ◽  
Center Manifold Reduction ◽  
Double Hopf Bifurcation ◽  
Physical Phenomena ◽  
Manifold Reduction ◽  
Theoretical Results

Using center manifold reduction methodswe investigate the double Hopf bifurcation in the dynamics of microbubble with delay couplingwith main attention focused on nonresonant double Hopf bifurcation. We obtain the normal form of the system in the vicinity of the double Hopf point and classify the bifurcations in a two-dimensional parameter space near the critical point. Some numerical simulations support the applicability of the theoretical results. In particularwe give the explanation for some physical phenomena of the system using the obtained mathematical results.

scholarly journals A New Flexible Bathtub-Shaped Modification of the Weibull Model: Properties and Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Qinghu Liao ◽  
Zubair Ahmad ◽  
Eisa Mahmoudi ◽  
G. G. Hamedani
Keyword(s):  
Weibull Distribution ◽  
Hazard Rate ◽  
Likelihood Estimation ◽  
Estimation Procedure ◽  
Weibull Model ◽  
Rate Function ◽  
Model Parameters ◽  
Hazard Functions ◽  
Practical Applications ◽  
Nonnested Models

Many studies have suggested the modifications and generalizations of the Weibull distribution to model the nonmonotone hazards. In this paper, we combine the logarithms of two cumulative hazard rate functions and propose a new modified form of the Weibull distribution. The newly proposed distribution may be called a new flexible extended Weibull distribution. Corresponding hazard rate function of the proposed distribution shows flexible (monotone and nonmonotone) shapes. Three different characterizations along with some mathematical properties are provided. We also consider the maximum likelihood estimation procedure to estimate the model parameters. For the illustrative purposes, two real applications from reliability engineering with bathtub-shaped hazard functions are analyzed. The practical applications show that the proposed model provides better fits than the other nonnested models.

scholarly journals Every Local Minimum Value Is the Global Minimum Value of Induced Model in Nonconvex Machine Learning

2019 ◽  
Vol 31 (12) ◽  
pp. 2293-2323 ◽  
Author(s):  
Kenji Kawaguchi ◽  
Jiaoyang Huang ◽  
Leslie Pack Kaelbling
Keyword(s):  
Machine Learning ◽  
Neural Networks ◽  
Local Minimum ◽  
Deep Neural Networks ◽  
Representation Learning ◽  
Minimum Value ◽  
Special Cases ◽  
Optimal Value ◽  
Special Case ◽  
Theoretical Results

For nonconvex optimization in machine learning, this article proves that every local minimum achieves the globally optimal value of the perturbable gradient basis model at any differentiable point. As a result, nonconvex machine learning is theoretically as supported as convex machine learning with a handcrafted basis in terms of the loss at differentiable local minima, except in the case when a preference is given to the handcrafted basis over the perturbable gradient basis. The proofs of these results are derived under mild assumptions. Accordingly, the proven results are directly applicable to many machine learning models, including practical deep neural networks, without any modification of practical methods. Furthermore, as special cases of our general results, this article improves or complements several state-of-the-art theoretical results on deep neural networks, deep residual networks, and overparameterized deep neural networks with a unified proof technique and novel geometric insights. A special case of our results also contributes to the theoretical foundation of representation learning.

scholarly journals The Optimal Dividend Payout Model with Terminal Values and Its Application

2017 ◽  
Vol 2017 ◽  
pp. 1-15
Author(s):  
Xiankang Luo ◽  
Peimin Chen ◽  
Jiangming Ma
Keyword(s):  
Value Function ◽  
Analytic Solution ◽  
Important Application ◽  
Stochastic Dynamic ◽  
Optimal Dividend ◽  
Optimal Value ◽  
The Status ◽  
Optimal Dividend Policy ◽  
The Relationship ◽  
Theoretical Results

For some firms with large nonliquid assets, preferred shareholders can still get back a little bit of money when the firms finish disbursement of loans at the status of bankruptcy. For such a situation, to investigate the optimal dividend policy, a stochastic dynamic dividend model with nonzero terminal bankruptcy values is put forward in this paper. Moreover, an analytic solution for the optimal objective function of the discounted dividends is provided and verified. An important application of this result is that it can be employed to construct the solution for the optimal value function on the dividend problem with bailouts at bankruptcy. Further, the relationship for the solutions of these two different problems is demonstrated. In the end, some numerical examples are provided to support our theoretical results and the corresponding economic interpretations are illustrated.

Strip Width Model in Hot Strip Rolling

2014 ◽  
Vol 926-930 ◽  
pp. 856-859
Author(s):  
Kai Wu ◽  
Xiang Rong Song ◽  
Zi Ying Liu
Keyword(s):  
Calculation Model ◽  
Strip Width ◽  
Good Effect ◽  
Hot Strip Mill ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Practical Applications ◽  
Hot Strip ◽  
Flat Rolling ◽  
Physical Phenomena

This paper has researched strip width model in hot strip rolling. Analyzed physical phenomena influencing strip width, established calculation model in production including width spread during flat rolling, width change induced by bending, width changed by high temperature creep and thermal expansion and contraction during rolling. Practical applications in domestic 1500 hot strip mill show that the width model achieved good effect and enhanced the calculation precision.

scholarly journals Bernoulli multi-armed bandit problem under delayed feedback

2021 ◽  
pp. 20-26
Author(s):  
A. S. Dzhoha
Keyword(s):  
Clinical Trials ◽  
Online Learning ◽  
Numerical Experiments ◽  
Upper Bounds ◽  
Delayed Feedback ◽  
Software Framework ◽  
Bernoulli Distribution ◽  
Bandit Problem ◽  
Practical Applications ◽  
Theoretical Results

Online learning under delayed feedback has been recently gaining increasing attention. Learning with delays is more natural in most practical applications since the feedback from the environment is not immediate. For example, the response to a drug in clinical trials could take a while. In this paper, we study the multi-armed bandit problem with Bernoulli distribution in the environment with delays by evaluating the Explore-First algorithm. We obtain the upper bounds of the algorithm, the theoretical results are applied to develop the software framework for conducting numerical experiments.

scholarly journals Deviating Features of Protons, Neutrons and Electrons on a Nano Scale

2019 ◽  
Vol 3 (1) ◽  
Keyword(s):  
Gravitational Waves ◽  
Theoretical Background ◽  
Elementary Particles ◽  
Quantum Mechanical ◽  
Nano Scale ◽  
Physical Phenomena ◽  
Theoretical Results

In the previous fourteen years twin physics has been developed to reconcile descriptions of phenomena on quantum mechanical and astronomical scale, by considering them in a complementary way. After having identified several theoretical results as basic physical phenomena, elementary particles and gravitational waves, this model seems to be ready for exploring the region between the extremes of phenomena. In twin physics it is possible to describe two types of protons, three types of neutrons and four of electrons. The expected appearances of these types in nano structured material and the consequences for their features are considered in general. Because these descriptions can be presented in a geometrical way, they are relatively easily accessible. As assistance to workers in this field, the results focus less on the theoretical background and more on first steps towards experimental applications.

scholarly journals Semi-analytical approaches to vibrations induced by moving loads

2018 ◽  
Vol 211 ◽  
pp. 11005 ◽  
Author(s):  
Zuzana Dimitrovová
Keyword(s):  
Analytical Solutions ◽  
High Speed ◽  
Moving Object ◽  
Moving Loads ◽  
Numerical Convergence ◽  
Practical Applications ◽  
Tight Contact ◽  
Harmonic Components ◽  
Physical Phenomena ◽  
Analytical Approaches

With the evolution of the computational power, there is a tendency to overlook analytical and semi-analytical solutions, despite their inherent obvious advantages. One should, however, be aware of the fact, that these solutions provide the necessary insight into the relevant physical phenomena and are accompanied by highly precise results, quickly obtainable without the necessity of additional numerical convergence tests. The objective of this contribution is to fill the gap in available semi-analytical solutions related to wave propagation induced by moving loads, with practical applications of high-speed rails. The structures that will be considered are composed of a beam and a supporting medium. The beam represents the interface between the structure and the moving object and will be simplified in conformity with the Euler-Bernoulli theory. In this paper the supporting structure will be considered as a two-parameter viscoelastic foundation and the moving object will be simplified by masses carrying constant forces with harmonic components, under assumption of tight contact. Special attention is paid to the proximity of moving masses.

Physical basis of laser technology

2017 ◽  
Author(s):  
Пойзнер ◽  
Boris Poizner
Keyword(s):  
Nonlinear Dynamics ◽  
Active Medium ◽  
Population Inversion ◽  
Laser Light ◽  
Theoretical Models ◽  
Optical Technology ◽  
Laser Technology ◽  
Radio Electronics ◽  
Laser Devices ◽  
Physical Phenomena

The basic implementation conditions of a population inversion, pumping methods, physical phenomena in the active medium and optical resonator, their influence on the properties of laser light are systematized. The processes in lasers are described, proximities concerning their theoretical models are given and analysis of models is performed. The concepts of nonlinear dynamics in the context of laser physics are determined. For students of physics, radio-electronics, optical technology, radio engineering specialties, postgraduates, professionals who develop new active medium and laser devices and apply laser technology.

Percolation Effects on Electrical Resistivity and Electron Mobility

2012 ◽  
Vol 5 (1) ◽  
Author(s):  
J. Weddell ◽  
A. Feinerman
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Aspect Ratio ◽  
Porous Material ◽  
Percolation Threshold ◽  
Electron Mobility ◽  
Past Research ◽  
Practical Applications ◽  
Percolation Thresholds ◽  
Theoretical Results

Percolation, defined as the study of transport across a porous material, can be used to determine transport quantities of a material such as electrical and thermal conductivity. Observing the way electrons flow across a porous conductive sheet is a common way that percolation studies are performed, and has many practical applications in electronics. This study determines how elliptical pores cut into a conductive sheet affect the percolation threshold; the remaining area of the conductive sheet when the current across it first becomes zero. Past research has been performed on this topic which yielded theoretical results of the percolation thresholds, and this study aims to verify those results experimentally. This study shows that as the aspect ratio of an ellipse approaches zero, the percolation threshold approaches one. This report also establishes a novel experimental method of studying percolating networks.

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