Research on the Detection of Vehicle Vibration and Noise Signal Based On Negative Entropy Detection Algorithm

As an important part of vehicle noise signal detection and processing, negative entropy detection algorithm can accurately reduce the number of speech coding bits, ameliorate the recognition accuracy, and establish the noise model in the process of noise reduction. Based on this, this paper first analyses the source and control of vehicle vibration and noise, then studies the principle of negative entropy detection algorithm of vehicle vibration and noise signal, and finally gives the vehicle vibration and noise signal detection method based on negative entropy detection algorithm.

Dynamics of tax revenues in the budget of Ukraine and their forecast during the crisis period

It is extremely important for the budget process to obtain accurate forecasts of potential tax revenues, especially in periods of disruption and crisis. The paper is devoted to the study of dynamics of tax revenues’ volumes in the budget of Ukraine and the forecast of their values during the crisis.The dynamics of tax revenues in the Consolidated Budget of Ukraine, studied by using randomized R|S-analysis, fractal and probabilistic analyses as well as entropy calculation based on the data on monthly tax revenues for the period 2011–2021, is anti-persistent, fractal-like and unpredictable based on parametric dependencies, simple and complex trends. The topological dimension of the lines of dynamics for tax revenues of all types of taxes is much higher than 1, and the Hirst index indicates either fractal similarity of dynamics or its chaos. The map of dissipation periods of tax revenues in Ukraine, determined on the basis of entropy calculation and periods of negative entropy production according to the dynamics of tax revenues, coincided with the periods of maximum reduction in their volumes. The most crisis periods in the formation of tax revenues are 2019–2020, for certain types of taxes – 2016–2020, but the dissipation of tax revenues is projected for 2021–2022.The comparison of the level of fractal similarity in dynamics of the volume of tax revenues and peculiarities of the dynamics of entropy and entropy production, allowed to substantiate the division of taxes into nine types, of which five were found in Ukraine.

Perchlorate salts confer psychrophilic characteristics in α-chymotrypsin

Studies of salt effects on enzyme activity have typically been conducted at standard temperatures and pressures, thus missing effects which only become apparent under non-standard conditions. Here we show that perchlorate salts, which are found pervasively on Mars, increase the activity of α-chymotrypsin at low temperatures. The low temperature activation is facilitated by a reduced enthalpy of activation owing to the destabilising effects of perchlorate salts. By destabilising α-chymotrypsin, the perchlorate salts also cause an increasingly negative entropy of activation, which drives the reduction of enzyme activity at higher temperatures. We have also shown that α-chymotrypsin activity appears to exhibit an altered pressure response at low temperatures while also maintaining stability at high pressures and sub-zero temperatures. As the effects of perchlorate salts on the thermodynamics of α-chymotrypsin’s activity closely resemble those of psychrophilic adaptations, it suggests that the presence of chaotropic molecules may be beneficial to life operating in low temperature environments.

The Carbon-Based Evolutionary Theory (CBET)

To establish a comprehensive and comprehensible evolutionary theory, and to use this theory to bridge physics, biology, and social sciences, we employ the concept carbon-based entities (CBEs), which include methane, glucose, proteins, organisms, and other entities chemically containing carbon atoms. We deduce the steps, driving forces, and mechanisms of evolution of CBEs through integration of geology, physics, chemistry, and biology. We hence establish the Carbon-Based Evolutionary Theory (CBET), which suggests that evolution is the increase in the amount, diversity, and fitness of higher-hierarchy CBEs under natural selection and driven by the organic synthesis tendency on the Earth from the thermodynamic features of the Earth. It provides better explanations for various evolutionary issues and social issues (e.g. life origin, natural selection, neutral mutation, diversity importance, and altruism) than previous theories. It refutes some incorrect views (e.g. negative entropy) in thermodynamics on evolution. The CBET could have great significance in various sciences.

Global Sensitivity Analysis Based on Entropy: From Differential Entropy to Alternative Measures

Differential entropy can be negative, while discrete entropy is always non-negative. This article shows that negative entropy is a significant flaw when entropy is used as a sensitivity measure in global sensitivity analysis. Global sensitivity analysis based on differential entropy cannot have negative entropy, just as Sobol sensitivity analysis does not have negative variance. Entropy is similar to variance but does not have the same properties. An alternative sensitivity measure based on the approximation of the differential entropy using dome-shaped functionals with non-negative values is proposed in the article. Case studies have shown that new sensitivity measures lead to a rational structure of sensitivity indices with a significantly lower proportion of higher-order sensitivity indices compared to other types of distributional sensitivity analysis. In terms of the concept of sensitivity analysis, a decrease in variance to zero means a transition from the differential to discrete entropy. The form of this transition is an open question, which can be studied using other scientific disciplines. The search for new functionals for distributional sensitivity analysis is not closed, and other suitable sensitivity measures may be found.

Research on Segmentation Experience of Music Signal Improved Based on Maximization of Negative Entropy

With the rapid growth of digital music today, due to the complexity of the music itself, the ambiguity of the definition of music category, and the limited understanding of the characteristics of human auditory perception, the research on topics related to automatic segmentation of music is still in its infancy, while automatic music is still in its infancy. Segmentation is a prerequisite for fast and effective retrieval of music resources, and its potential application needs are huge. Therefore, topics related to automatic music segmentation have important research value. This paper studies an improved algorithm based on negative entropy maximization for well-posed speech and music separation. Aiming at the problem that the separation performance of the negative entropy maximization method depends on the selection of the initial matrix, the Newton downhill method is used instead of the Newton iteration method as the optimization algorithm to find the optimal matrix. By changing the descending factor, the objective function shows a downward trend, and the dependence of the algorithm on the initial value is reduced. The simulation experimental results show that the algorithm can separate the source signal well under different initial values. The average iteration time of the improved algorithm is reduced by 26.2%, the number of iterations is reduced by 69.4%, and the iteration time and the number of iterations are both small. Fluctuations within the range better solve the problem of sensitivity to the initial value. Experiments have proved that the new objective function can significantly improve the separation performance of neural networks. Compared with the existing music separation methods, the method in this paper shows excellent performance in both accompaniment and singing in separated music.

pH Dependent Mechanisms of Hydrolysis of 4-Nitrophenyl β-D-Glucoside

<p>1,2-<i>trans</i>-Glycosides hydrolyze through a range of mechanisms under conditions of different pH, but systematic studies are lacking. Here we report the pH-rate constant profile for the hydrolysis of<i> </i>4-nitrophenyl β-D-glucoside. An inverse kinetic isotope effect (<i>k</i>(H₃O⁺)/<i>k</i>(D₃O⁺) = 0.63) in the acidic region indicates that the mechanism requires the formation of the conjugate acid of the substrate for the reaction to proceed, with heterolytic cleavage of the glycosidic C-O bond. Reactions in the pH-independent region extrapolated to zero buffer concentration show a small inverse solvent isotope effect <i>k</i>(H₂O)/<i>k</i>(D₂O) = 1.1 and a positive entropy of activation (D<i>S</i>^‡ = 3.07 cal mol^–1 K^–1), which is consistent with water attack through a dissociative mechanism. In the basic region, solvolysis in ¹⁸O-labelled water and H₂O/MeOH mixtures allowed detection of bimolecular hydrolysis and neighboring group participation, and to a minor degree, nucleophilic aromatic substitution. Under mildly basic conditions, a bimolecular dissociative mechanism is implicated through a solvent isotope effect of <i>k</i>(HO^-)/<i>k</i>(DO^-) = 0.5 and a strongly negative entropy of activation (D<i>S</i>^‡ = –13.6 cal mol^–1 K^–1). Finally, at high pH, an inverse solvent isotope effect of <i>k</i>(HO^-)/<i>k</i>(DO^-) = 0.6 and a weakly negative entropy of activation (D<i>S</i>^‡ = –5.5 cal mol^–1 K^–1) indicates that the formation of 1,2-anhydrosugar is the rate determining step. <b></b></p>