The collisional moments of the second, third, and fourth order in a granular binary mixture are examined using the Boltzmann equation for d-dimensional inelastic Maxwell models. Precisely evaluating collisional instances necessitates the utilization of the velocity moments from the distribution function for each species, a condition that is fulfilled when diffusion is absent, meaning that the mass flux of every substance is void. The corresponding associated eigenvalues and cross coefficients are expressible as functions of the coefficients of normal restitution and the mixture parameters (masses, diameters, and composition). Applying these results, the analysis of moments' time evolution, scaled by a thermal speed, is performed in two different non-equilibrium situations: the homogeneous cooling state (HCS) and the uniform shear flow (USF). Given particular parameter values, the temporal moments of the third and fourth degree in the HCS differ from those of simple granular gases, potentially diverging. A detailed study scrutinizes the influence of the mixture's parameter space on the time-dependent behavior of these moments. Selleckchem LY3009120 Within the USF, the time-dependent behavior of the second- and third-degree velocity moments is examined in the tracer limit, characterized by a negligible concentration of one component. It is unsurprising that, while second-degree moments consistently converge, the third-degree moments of the tracer species might diverge under prolonged conditions.
This paper focuses on achieving optimal containment control for nonlinear, multi-agent systems with incomplete dynamic information, employing an integral reinforcement learning algorithm. The requirement for precise drift dynamics is softened by the use of integral reinforcement learning. A proof of equivalence between model-based policy iteration and the integral reinforcement learning method is provided, ensuring the convergence of the control algorithm. To solve the Hamilton-Jacobi-Bellman equation for every follower, a single critic neural network, characterized by a modified updating law, guarantees the asymptotic stability of the weight error dynamic. Each follower's approximate optimal containment control protocol is obtained by the application of the critic neural network to input-output data. Under the proposed optimal containment control scheme, the closed-loop containment error system is guaranteed to maintain stability. The simulation outcomes unequivocally demonstrate the efficiency of the proposed control scheme.
Deep neural networks (DNNs) used in natural language processing (NLP) are prone to being compromised by backdoor attacks. Existing defensive methods against backdoor exploits are limited in their ability to fully cover all attack possibilities. We introduce a textual backdoor defense methodology relying on the classification of deep features. To carry out the method, deep feature extraction and classifier design are essential steps. The method differentiates deep features of malicious and uncorrupted data, thereby maximizing its efficacy. Backdoor defense is present within both online and offline environments. We performed defense experiments across two datasets and two models, targeting a diversity of backdoor attacks. The experimental findings reveal that this defense method performs better than the baseline, demonstrating its effectiveness.
Adding sentiment analysis data to the feature set is a usual strategy for enhancing the predictive abilities of financial time series models. In addition, the sophisticated architectures of deep learning and advanced techniques are used more extensively because of their operational efficiency. Employing sentiment analysis, this work contrasts the most advanced techniques in forecasting financial time series. 67 different feature setups, incorporating stock closing prices and sentiment scores, underwent a detailed experimental evaluation across multiple datasets and diverse metrics. Two case studies, one evaluating diverse methods and the other comparing input feature configurations, involved the deployment of a total of 30 state-of-the-art algorithmic approaches. Aggregated data demonstrate both the popularity of the proposed methodology and a conditional uplift in model speed after incorporating sentiment factors during particular prediction windows.
A short review of quantum mechanics' probabilistic representation is given, exemplifying the probability distributions characterizing quantum oscillators at temperature T and demonstrating the time evolution of the quantum states of a charged particle under an electric capacitor's electric field. Explicitly time-dependent integral expressions of motion, linear in position and momentum, are employed to generate varied probability distributions that delineate the charged particle's evolving states. Discussions regarding the entropies associated with the probability distributions of initial coherent states in charged particles are presented. A link between the Feynman path integral and the probability framework in quantum mechanics has been ascertained.
Vehicular ad hoc networks (VANETs) have been of significant interest recently due to their considerable promise in promoting road safety improvements, traffic management enhancements, and providing support for infotainment services. The medium access control (MAC) and physical (PHY) layers of VANETs have been the subject of the IEEE 802.11p standard, which has been proposed for over a decade. Existing analytical procedures for performance assessment of the IEEE 802.11p MAC, while studied, demand significant improvement. In this paper, a 2-dimensional (2-D) Markov model is proposed to evaluate the saturated throughput and average packet delay of IEEE 802.11p MAC in VANETs, incorporating the capture effect within a Nakagami-m fading channel. The closed-form expressions for successful transmissions, transmission collisions, maximum achievable throughput, and the average time to deliver a packet are derived. Finally, the accuracy of the proposed analytical model is substantiated by simulation results, proving its superior precision in predicting saturated throughput and average packet delay when compared with existing models.
Using the quantizer-dequantizer formalism, the probability representation for quantum system states is devised. The probability representation of classical system states is compared, and the discussion is outlined. Presented are examples of probability distributions for systems of parametric and inverted oscillators.
We aim in this paper to provide a preliminary investigation into the thermodynamics of particles that comply with monotone statistics. For the purpose of creating realistic physical implementations, we suggest a revised method, block-monotone, derived from a partial order defined by the natural ordering within the spectrum of a positive Hamiltonian with a compact resolvent. Whenever all eigenvalues of the Hamiltonian are non-degenerate, the block-monotone scheme becomes equivalent to, and therefore, is not comparable to the weak monotone scheme, finally reducing to the standard monotone scheme. From a detailed analysis of the quantum harmonic oscillator model, we deduce that (a) the computation of the grand partition function is independent of the Gibbs correction factor n! (arising from particle indistinguishability) in its various terms of expansion concerning activity; and (b) a decimation of terms in the grand partition function yields an exclusion principle similar to the Pauli exclusion principle for Fermi particles, which is more prominent at high densities and less so at low densities, as predicted.
The importance of image-classification adversarial attacks in AI security cannot be overstated. Methods for adversarial attacks in image classification are often confined to white-box environments, which demand the target model's gradients and network structures. This constraint makes their utility less relevant in real-world scenarios. While the limitations presented above exist, black-box adversarial attacks, in combination with reinforcement learning (RL), appear to be a practical method for pursuing an optimized evasion policy exploration. Unfortunately, existing reinforcement learning-based attack strategies are less effective than predicted in terms of attack success rates. Selleckchem LY3009120 Facing these difficulties, our approach involves an ensemble-learning-based adversarial attack, ELAA, that strategically aggregates and enhances multiple reinforcement learning (RL) base learners, ultimately revealing the vulnerabilities in image classification models. Experimental studies have shown that the attack success rate for the ensemble model is approximately 35% higher in comparison to the success rate of a single model. The success rate of ELAA's attacks is 15% greater than that of the baseline methods.
This research delves into the shifting dynamical complexity and fractal properties of Bitcoin/US dollar (BTC/USD) and Euro/US dollar (EUR/USD) returns, analyzing the period both preceding and succeeding the COVID-19 outbreak. To be more precise, we employed the asymmetric multifractal detrended fluctuation analysis (A-MF-DFA) approach to examine the temporal development of the asymmetric multifractal spectrum's parameters. Our investigation included examining the temporal variation of Fuzzy entropy, non-extensive Tsallis entropy, Shannon entropy, and Fisher information. To ascertain the pandemic's consequences and resulting transformations in two key currencies central to the modern financial system, our study was designed. Selleckchem LY3009120 Our findings demonstrated a consistent trend in BTC/USD returns, both before and after the pandemic, contrasting with the anti-persistent behavior observed in EUR/USD returns. After the COVID-19 outbreak, a greater degree of multifractality, more pronounced large fluctuations in prices, and a marked decrease in the complexity (i.e., a gain in order and information content and a loss of randomness) were observed for the return patterns in both BTC/USD and EUR/USD. The World Health Organization's (WHO) announcement that COVID-19 was a global pandemic appears to be a key contributing factor in the rapid increase of complexities.