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991.
Miguel Vivas-Cortez Muhammad Aamir Ali Hüseyin Budak Humaira Kalsoom Praveen Agarwal 《Entropy (Basel, Switzerland)》2021,23(7)
In this investigation, for convex functions, some new –Hermite–Hadamard-type inequalities using the notions of derivative and integral are obtained. Furthermore, for -differentiable convex functions, some new () estimates for midpoint and trapezoidal-type inequalities using the notions of integral are offered. It is also shown that the newly proved results for and can be converted into some existing results. Finally, we discuss how the special means can be used to address newly discovered inequalities. 相似文献
992.
This paper discusses the use of probabilistic or randomized algorithms for solving vehicle routing problems with non-smooth objective functions. Our approach employs non-uniform probability distributions to add a biased random behavior to the well-known savings heuristic. By doing so, a large set of alternative good solutions can be quickly obtained in a natural way and without complex configuration processes. Since the solution-generation process is based on the criterion of maximizing the savings, it does not need to assume any particular property of the objective function. Therefore, the procedure can be especially useful in problems where properties such as non-smoothness or non-convexity lead to a highly irregular solution space, for which the traditional optimization methods—both of exact and approximate nature—may fail to reach their full potential. The results obtained so far are promising enough to suggest that the idea of using biased probability distributions to randomize classical heuristics is a powerful one that can be successfully applied in a variety of cases. 相似文献
993.
We consider two types of trajectories found in a wide range of mechanical systems, viz. box orbits and loop orbits. We elucidate the dynamics of these orbits in the simple context of a perturbed harmonic oscillator in two dimensions. We then examine the small-amplitude motion of a rigid body, the rock’n’roller, a sphere with eccentric distribution of mass. The equations of motion are expressed in quaternionic form and a complete analytical solution is obtained. Both types of orbit, boxes and loops, are found, the particular form depending on the initial conditions. We interpret the motion in terms of epi-elliptic orbits. The phenomenon of recession, or reversal of precession, is associated with box orbits. The small-amplitude solutions for the symmetric case, or Routh sphere, are expressed explicitly in terms of epicycles; there is no recession in this case. 相似文献
994.
ABSTRACTIn this article we study the behavior of left QI-rings under perfect localizations. We show that a perfect localization of a left QI-ring is a left QI-ring. We prove that Boyle’s conjecture is true for left QI-rings with finite Gabriel dimension such that every hereditary torsion theory in the Gabriel filtration is perfect. As corollary, we get that Boyle’s conjecture is true for left QI-rings which satisfy the restricted left socle condition, a result proved by Faith in [6]. 相似文献
995.
996.
Alvar Daza Alexandre Wagemakers Shanmuganathan Rajasekar Miguel A.F. Sanjuán 《Communications in Nonlinear Science & Numerical Simulation》2013,18(2):411-416
Biological oscillators can respond in a surprising way when they are perturbed by two external periodic forcing signals of very different frequencies. The response of the system to a low-frequency signal can be enhanced or depressed when a high-frequency signal is acting. This is what is known as vibrational resonance (VR). Here we study this phenomenon in a simple time-delayed genetic toggle switch, which is a synthetic gene-regulatory network. We have found out how the low-frequency signal changes the range of the response, while the high-frequency signal influences the amplitude at which the resonance occurs. The delay of the toggle switch has also a strong effect on the resonance since it can also induce autonomous oscillations. 相似文献
997.
Mattia Coccolo Jesús M. Seoane Miguel A.F. Sanjuán 《Communications in Nonlinear Science & Numerical Simulation》2013,18(12):3449-3457
Noisy scattering dynamics in the randomly driven Hénon–Heiles system is investigated in the range of initial energies where the motion is unbounded. In this paper we study, with the help of the exit basins and the escape time distributions, how an external perturbation, be it dissipation or periodic forcing with a random phase, can enhance or mitigate the unpredictability of a system that exhibit chaotic scattering. In fact, if basin boundaries have the Wada property, predictability becomes very complicated, since the basin boundaries start to intermingle, what means that there are points of different basins close to each other. The main responsible of this unpredictability is the external forcing with random phase, while the dissipation can recompose the basin boundaries and turn the system more predictable. Therefore, we do the necessary simulations to find out the values of dissipation and external forcing for which the exit basins present the Wada property. Through these numerical simulations, we show that the presence of the Wada basins have a specific relation with the damping, the forcing amplitude and the energy value. Our approach consists on investigating the dynamics of the system in order to gain knowledge able to control the unpredictability due to the Wada basins. 相似文献
998.
999.
Abstract Two vibrational spectrometry–based methodologies were developed for procymidone determination in wettable powdered pesticide formulations. The Fourier‐transform infrared (FTIR) procedure was based on the selective extraction of procymidone by chloroform and determination by peak area measurement between 1451 and 1441 cm?1, using a baseline correction established between 1490 and 1410 cm?1, and a precision of 0.4% and a limit of detection of 0.01% w/w procymidone for a sample mass of 25 mg were obtained. For FT‐Raman determination, the selected conditions were peak area measurement between 1005 and 995 cm?1 Raman shift, with a baseline correction fixed between 1030 and 947 cm?1, and a relative standard deviation of 1% and a limit of detection of 0.8% procymidone in the original sample were obtained. The sample frequency for FTIR determination was 30 hr?1, lower than that for Raman with 40 hr?1. FT‐Raman reduces to the minimum the reagent consumption and waste generation, also avoiding the sample handling and contact of the operator with the pesticide. It can be concluded that the proposed methods are appropriate for quality control in commercial pesticide formulations. 相似文献
1000.
How fast do stock prices adjust to market efficiency? Evidence from a detrended fluctuation analysis
In this paper we analyse price fluctuations with the aim of measuring how long the market takes to adjust prices to weak-form efficiency, i.e., how long it takes for prices to adjust to a fractional Brownian motion with a Hurst exponent of 0.5. The Hurst exponent is estimated for different time horizons using detrended fluctuation analysis–a method suitable for non-stationary series with trends–in order to identify at which time scale the Hurst exponent is consistent with the efficient market hypothesis. Using high-frequency share price, exchange rate and stock data, we show how price dynamics exhibited important deviations from efficiency for time periods of up to 15 min; thereafter, price dynamics was consistent with a geometric Brownian motion. The intraday behaviour of the series also indicated that price dynamics at trade opening and close was hardly consistent with efficiency, which would enable investors to exploit price deviations from fundamental values. This result is consistent with intraday volume, volatility and transaction time duration patterns. 相似文献