scholarly journals A New Approach to Analysis of the Properties of Disordered Structures in Hydrodynamic Acoustics as Supplement to Technology and Detection Theory

2021 ◽  
pp. 306-315
Author(s):  
Pavel A. Starodubtsev ◽  
Evgeny P. Starodubtsev ◽  
Roman N. Alifanov ◽  
Grigory V. Dorofeev
Keyword(s):  
Sound Field ◽  
Principle Of Superposition ◽  
New Approach ◽  
Disordered Structures ◽  
Complex Interactions ◽  
Rotation Of The Earth ◽  
The Fourier Transform ◽  
Fundamental Equations ◽  
Physical Phenomena ◽  
Special Case

The article presents the results of the analysis of the properties of disordered structures in hydrodynamic acoustics, associated with the process of detecting physical phenomena and marine objects based on the results of their mechanical impact on the marine environment, in which acoustic vibrations propagate. If vortices, attractors, fractals arise as a result of complex interactions of forces of nature (upwellings, seiches, Coriolis forces, currents, convection flows, rotation of the Earth) and are essentially mechanical effects on the environment of formation and propagation of an acoustic field, then mechanical sources of sound introduced into the hydrosphere (water) should repeat fractal iterations on a smaller scale at the sound field level. Recognizing the equations of hydrodynamics (the equation of motion, the equation of continuity, and the equation of state) as the fundamental equations of hydroacoustics, the nonlinearity of these equations is proposed to be considered the theory of the hydroacoustic field as nonlinear, and the linearity of the processes in this study is considered a special case. The principle of superposition also becomes a special case, and the Fourier transform, remaining necessary, loses its sufficiency. Fractal analysis in combination with wavelet analysis should be involved to help him

scholarly journals Neuroimmune Response Mediated by Cytokines in Natural Scrapie after Chronic Dexamethasone Treatment

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 204
Author(s):  
Isabel M. Guijarro ◽  
Moisés Garcés ◽  
Pol Andrés-Benito ◽  
Belén Marín ◽  
Alicia Otero ◽  
...  
Keyword(s):  
Prion Diseases ◽  
Global Approach ◽  
Profile Data ◽  
Dexamethasone Treatment ◽  
New Approach ◽  
Complex Interactions ◽  
Natural Scrapie ◽  
Anti Inflammatory

The actual role of prion protein-induced glial activation and subsequent cytokine secretion during prion diseases is still incompletely understood. The overall aim of this study is to assess the effect of an anti-inflammatory treatment with dexamethasone on different cytokines released by neuroglial cells that are potentially related to neuroinflammation in natural scrapie. This study emphasizes the complex interactions existent among several pleiotropic neuromodulator peptides and provides a global approach to clarify neuroinflammatory processes in prion diseases. Additionally, an impairment of communication between microglial and astroglial populations mediated by cytokines, mainly IL-1, is suggested. The main novelty of this study is that it is the first one assessing in situ neuroinflammatory activity in relation to chronic anti-inflammatory therapy, gaining relevance because it is based on a natural model. The cytokine profile data would suggest the activation of some neurotoxicity-associated route. Consequently, targeting such a pathway might be a new approach to modify the damaging effects of neuroinflammation.

scholarly journals A New Approach for Approximate Solution of ADE: Physical-Based Modeling of Carriers in Doping Region

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 458
Author(s):  
Leobardo Hernandez-Gonzalez ◽  
Jazmin Ramirez-Hernandez ◽  
Oswaldo Ulises Juarez-Sandoval ◽  
Miguel Angel Olivares-Robles ◽  
Ramon Blanco Sanchez ◽  
...  
Keyword(s):  
Differential Equation ◽  
Approximate Solution ◽  
Analytic Solution ◽  
Order Differential Equation ◽  
Electric Circuit ◽  
New Approach ◽  
In Doping ◽  
Electric Behavior ◽  
Spatio Temporal ◽  
Physical Phenomena

The electric behavior in semiconductor devices is the result of the electric carriers’ injection and evacuation in the low doping region, N-. The carrier’s dynamic is determined by the ambipolar diffusion equation (ADE), which involves the main physical phenomena in the low doping region. The ADE does not have a direct analytic solution since it is a spatio-temporal second-order differential equation. The numerical solution is the most used, but is inadequate to be integrated into commercial electric circuit simulators. In this paper, an empiric approximation is proposed as the solution of the ADE. The proposed solution was validated using the final equations that were implemented in a simulator; the results were compared with the experimental results in each phase, obtaining a similarity in the current waveforms. Finally, an advantage of the proposed methodology is that the final expressions obtained can be easily implemented in commercial simulators.

The Physics of Music

2012 ◽  
pp. 29-47
Author(s):  
Jyri Pakarinen
Keyword(s):  
Sound Transmission ◽  
Sound Field ◽  
Room Acoustics ◽  
Human Observer ◽  
Sound Sources ◽  
Acoustic Effect ◽  
Musical Sound ◽  
Transmission Parameters ◽  
Definition Of ◽  
Physical Phenomena

This chapter discusses the central physical phenomena involved in music. The aim is to provide an explanation of the related issues in an understandable level, without delving unnecessarily deep in the underlying mathematics. The chapter is divided in two main sections: musical sound sources and sound transmission to the observer. The first section starts from the definition of sound as wave motion, and then guides the reader through the vibration of strings, bars, membranes, plates, and air columns, that is, the oscillating sources that create the sound for most of the musical instruments. Resonating structures, such as instrument bodies are also reviewed, and the section ends with a discussion on the potential physical markup parameters for musical sound sources. The second section starts with an introduction to the basics of room acoustics, and then explains the acoustic effect that the human observer causes in the sound field. The end of the second section provides a discussion on which sound transmission parameters could be used in a general music markup language. Finally, a concluding section is presented.

The Special Case of Anesthesia

2019 ◽  
pp. 49-56
Author(s):  
Robert L. Wears ◽  
Kathleen M. Sutcliffe
Keyword(s):  
Medical Specialty ◽  
Clinical Safety ◽  
Complex Interactions ◽  
State Of Affairs ◽  
Special Case ◽  
Over Time

Anesthesia became the only medical specialty to undertake systematic and dramatic improvements in safety over time. Evidence suggests that this process began through the fortuitous engagement of engineers in anesthesia work, supported by respected leaders in the field. The goal was not simply to solve a problem. The aims were too deeply understand the nature of the technology, the work, and the complex interactions that take place in work as carried out. Oddly, healthcare more generally failed to emulate these efforts. This state of affairs may be attributed to the substantive influence of non-clinical safety scientists in anesthesia, and also to differences in widely accepted methodological and investigative research approaches.

scholarly journals A New Application Methodology of the Fourier Transform for Rational Approximation of the Complex Error Function

2016 ◽  
Vol 8 (1) ◽  
pp. 14 ◽  
Author(s):  
S. M. Abrarov ◽  
B. M. Quine
Keyword(s):  
Fourier Transform ◽  
Rational Approximation ◽  
Error Function ◽  
Practical Importance ◽  
Exponential Functions ◽  
New Approach ◽  
Practical Applications ◽  
Input Parameters ◽  
The Fourier Transform

<p>This paper presents a new approach in application of the Fourier transform to the complex error function resulting in an efficient rational approximation. Specifically, the computational test shows that with only $17$ summation terms the obtained rational approximation of the complex error function provides accuracy ${10^{ - 15}}$ over the most domain of practical importance $0 \le x \le 40,000$ and ${10^{ - 4}} \le y \le {10^2}$ required for the HITRAN-based spectroscopic applications. Since the rational approximation does not contain trigonometric or exponential functions dependent upon the input parameters $x$ and $y$, it is rapid in computation. Such an example demonstrates that the considered methodology of the Fourier transform may be advantageous in practical applications.</p>

The Evolution of Complex Systems

1988 ◽  
Vol 43 (1) ◽  
pp. 73-77
Author(s):  
G. L. Hofacker ◽  
R. D. Levine
Keyword(s):  
Complex Systems ◽  
Maximum Entropy ◽  
Transition Probabilities ◽  
Maximum Entropy Principle ◽  
Average Energy ◽  
Entropy Principle ◽  
Fundamental Equations ◽  
Special Case ◽  
Extremal Properties

Abstract A principle of evolution of highly complex systems is proposed. It is based on extremal properties of the information I (X, Y) characterizing two states X and Y with respect to each other, I(X, Y) = H(Y) -H(Y/X), where H(Y) is the entropy of state Y,H (Y/X) the entropy in state Y given the probability distribu­tion P(X) and transition probabilities P(Y/X).As I(X, Y) is maximal in P(Y) but minimal in P(Y/X), the extremal properties of I(X, Y) con­stitute a principle superior to the maximum entropy principle while containing the latter as a special case. The principle applies to complex systems evolving with time where fundamental equations are unknown or too difficult to solve. For the case of a system evolving from X to Y it is shown that the principle predicts a canonic distribution for a state Y with a fixed average energy .

scholarly journals Parabolic Sandwiches for Functions on a Compact Interval and an Application to Projectile Motion

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Robert Kantrowitz ◽  
Michael M. Neumann
Keyword(s):  
Present Article ◽  
Decisive Role ◽  
Valid Argument ◽  
Quadratic Polynomials ◽  
New Approach ◽  
Projectile Motion ◽  
Full Result ◽  
Air Resistance ◽  
Special Case ◽  
Natural Way

About a century ago, the French artillery commandant Charbonnier envisioned an intriguing result on the trajectory of a projectile that is moving under the forces of gravity and air resistance. In 2000, Groetsch discovered a significant gap in Charbonnier’s work and provided a valid argument for a certain special case. The goal of the present article is to establish a rigorous new approach to the full result. For this, we develop a theory of those functions which can be sandwiched, in a natural way, by a pair of quadratic polynomials. It turns out that the convexity or concavity of the derivative plays a decisive role in this context.

A Generalized von Mises Criterion for Yield and Fracture

1980 ◽  
Vol 47 (2) ◽  
pp. 297-300 ◽  
Author(s):  
W. H. Yang
Keyword(s):  
Bauschinger Effect ◽  
Hydrostatic Stress ◽  
Fracture Criteria ◽  
Deformation History ◽  
Von Mises Criterion ◽  
Effect On Yield ◽  
Von Mises ◽  
New Criterion ◽  
Physical Phenomena ◽  
Special Case

Yield and fracture criteria for real materials are to a varying degree affected by a state of hydrostatic stress. Some materials, after certain deformation history, exhibit different yield point when the direction of the stress is reversed, a behavior known as the Bauschinger effect. These physical phenomena are not represented by the von Mises criterion. Based on a convexity theorem of matrices, a generalization of the von Mises criterion is presented. The new criterion satisfies the convexity requirement of plasticity theory and, with two scalar functions of deformation history α and β, produces a class of hardening behavior. The current values of α and β account for the effect of hydrostatic stress and an aspect of the Bauschinger effect on yield and fracture. The generalized criterion reduces to the form of the von Mises criterion as a special case.

scholarly journals IDENTIFICATION OF BINARY CELLULAR AUTOMATA FROM SPATIO-TEMPORAL BINARY PATTERNS USING A FOURIER REPRESENTATION

2007 ◽  
Vol 17 (06) ◽  
pp. 1985-1996 ◽  
Author(s):  
L. Z. GUO ◽  
S. A. BILLINGS
Keyword(s):  
Fourier Transform ◽  
Cellular Automata ◽  
Least Squares ◽  
Boolean Functions ◽  
Multilinear Polynomial ◽  
Polynomial Representation ◽  
New Approach ◽  
Spatio Temporal ◽  
The Fourier Transform ◽  
Robust To Noise

The identification of binary cellular automata from spatio-temporal binary patterns is investigated in this paper. Instead of using the usual Boolean or multilinear polynomial representation, the Fourier transform representation of Boolean functions is employed in terms of a Fourier basis. In this way, the orthogonal forward regression least-squares algorithm can be applied directly to detect the significant terms and to estimate the associated parameters. Compared with conventional methods, the new approach is much more robust to noise. Examples are provided to illustrate the effectiveness of the proposed approach.

From direct-space discrepancy functions to crystallographic least squares

2015 ◽  
Vol 71 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Carmelo Giacovazzo
Keyword(s):  
Least Squares ◽  
Crystal Structure Analysis ◽  
Scaling Factor ◽  
Mathematical Approach ◽  
New Approach ◽  
Density Maps ◽  
Scattering Contribution ◽  
Special Case ◽  
Degree Of Similarity

Crystallographic least squares are a fundamental tool for crystal structure analysis. In this paper their properties are derived from functions estimating the degree of similarity between two electron-density maps. The new approach leads also to modifications of the standard least-squares procedures, potentially able to improve their efficiency. The role of the scaling factor between observed and model amplitudes is analysed: the concept ofunlocated modelis discussed and its scattering contribution is combined with that arising from thelocated model. Also, the possible use of an ancillary parameter, to be associated with the classical weight related to the variance of the observed amplitudes, is studied. The crystallographic discrepancy factors, basic tools often combined with least-squares procedures in phasing approaches, are analysed. The mathematical approach here described includes, as a special case, the so-called vector refinement, used when accurate estimates of the target phases are available.

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