bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase transitions in the anisotropic XY ferromagnet with quenched nonmagnetic impurity
Authors: Mallick Olivia , Acharyya Muktish
Published: December 2023

The equilibrium behaviors of the anisotropic XY ferromagnet, with nonmagnetic impurity, have been investigated in three dimensions by Monte Carlo simulation using Metropolis algorithm. Two different types of anisotropy, namely, the bilinear exchange type and single-site anisotropy are considered here. The thermodynamic behaviors of the components of the magnetizations (M), susceptibility ([Formula: see text]) and the specific heat (C) have been studied systematically through extensive Monte Carlo simulations. The ferro–para phase transition has been observed to take place at a lower temperature for impure anisotropic XY ferromagnet. The pseudocritical temperature ([Formula: see text]) has been found to decrease as the system gets more and more impure (impurity concentration p increases). In the case of bilinear exchange type of anisotropy ([Formula: see text]), the pseudocritical temperature ([Formula: see text]) increases linearly with [Formula: see text] for any given concentration of nonmagnetic impurity (p). The slope of this linear function has been found to depend on the impurity concentration (p). The slope decreases linearly with the impurity concentration (p). In the case of the single-site anisotropy (D), the pseudocritical temperature ([Formula: see text]) has been found to decrease linearly with p for fixed D. The critical temperature (for a fixed set of parameter values) has been estimated from the temperature variation of fourth-order Binder cumulants ([Formula: see text]) for different system sizes (L). The critical magnetization ([Formula: see text]) and the maximum value of the susceptibility ([Formula: see text]) are calculated for different system sizes (L). The critical exponents for the assumed scaling laws, [Formula: see text] and [Formula: see text], are estimated through the finite size analysis. We have estimated, [Formula: see text], equals [Formula: see text] and [Formula: see text] for bilinear exchange and single-site anisotropy, respectively. We have also estimated, [Formula: see text] equals [Formula: see text] and [Formula: see text] for bilinear exchange and single-site anisotropy, respectively.
Random Matrix Theory and Nested Clustered Optimization on high-dimensional portfolios
Authors: García-Medina Andrés , Rodríguez-Camejo Benito
Published: December 2023

This work aims to address the optimal allocation instability problem of Markowitz’s modern portfolio theory in high dimensionality. We propose a combined strategy that considers covariance matrix estimators from Random Matrix Theory (RMT) and the machine learning allocation methodology known as Nested Clustered Optimization (NCO). The latter methodology is modified and reformulated in terms of the spectral clustering algorithm and Minimum Spanning Tree (MST) to solve internal problems inherent in the original proposal. Markowitz’s classical mean-variance allocation and the modified NCO machine learning approach are tested on the financial instruments that compose the S&P 500 index listed on the New York Stock Exchange (NYSE) from 2012 to 2021. The modified NCO algorithm achieves stable allocations by incorporating RMT covariance estimators. A particular combination of covariance estimators, known as two-step estimators involving a hierarchical clustering technique, achieves the best portfolio performance. Surprisingly, a common pattern suggests that the improvement in performance is agnostic to the allocation strategy and, in fact, relies heavily on the covariance estimator selection. Our results suggest that the amount of leverage can be drastically reduced in investment strategies through RMT inference and statistical learning techniques.
Relativistic quantum oscillator under rainbow gravity’s effects in traversable wormhole with disclination
Authors: Guvendi Abdullah , Ahmed Faizuddin
Published: December 2023

In this paper, our principal objective is to investigate the impact of disclination and throat radius of a three-dimensional traversable wormhole on quantum oscillator fields. Specifically, we focus on Perry–Mann-type wormhole with disclination while also considering the influence of rainbow gravity’s. We derive the radial equation of the relativistic Klein–Gordon oscillator within this wormhole background under the effects of gravity’s rainbow and the analytical eigenvalue solution is obtained using the confluent Heun function. In fact, we show that the behavior of the oscillator fields is significantly influenced not only by the presence of disclination and the throat radius but also by the parameter of rainbow gravity’s. We choose various such rainbow functions to present and analyze the eigenvalue solutions of the quantum oscillator fields.
P-v criticality of charged Reissner–Nordström-de Sitter black hole under the influence of Lorentz violation theory
Authors: Laxmi Y. Onika , Media Ningthoujam , Singh T. Ibungochouba
Published: December 2023

In this paper, the modified Hawking radiation and the P-v criticality of Reissner–Nordström-de Sitter (RNdS) black hole are investigated by using Dirac equation with Lorentz violation theory in curved space–time. Taking cosmological constant as the thermodynamic pressure and its conjugate quantity as thermodynamic volume, the analogy between the RNdS black hole in the ensemble with fixed charge and van der Waals liquid-gas system is derived. We also study the equation of state, critical exponents, critical point, heat capacity, entropy correction, Gibbs free energy. It is worth mentioning that the critical temperature, entropy, Gibbs free energy and Helmholtz free energy are modified but the critical exponents are found to be unchanged due to the influence of Lorentz violation theory. We observe that the number of Hawking–Page critical point increases due to Lorentz violation theory.
Realizations of the Yang–Poisson model on canonical phase space
Authors: Meljanac S. , Mignemi S.
Published: December 2023

In this paper, we discuss exact realizations of the Yang–Poisson model on canonical phase space. The Yang model is an example of noncommutative geometry on a background space–time of constant curvature and is notable for its duality between position and momentum manifolds. We call Yang–Poisson model its classical limit, with commutators replaced by Poisson brackets. The structure is simpler in the classical case, and exact realizations can be found.
NAND/NOR Polar Logic Circuits Using a Single Current Conveyor
Authors: Maheshwari Sudhanshu
Published: December 2023

This paper presents a new polar logic circuit using a single current conveyor, two MOS switches and two resistors in each case. Thus, polar NAND and NOR circuits are proposed. The circuits’ operation details and simulation results are given in support of the proposed theory. The circuits are designed using CMOS CCII[Formula: see text] with ±2 V supply voltage. The polar logic levels at the output are −1 and 1 V for logic 0 and 1, respectively. The gates’ functioning for capacitive loading is also tested. The new circuits are expected to be useful in digital and communication systems.
Compact K-Band Current Mode Tunable Active Only Bandpass Filter Using 32 nm CNTFET-Based MOCCCII
Authors: Mirnezami Shabnam , Dousti Massoud , Dolatshahi Mehdi
Published: December 2023

A low-power and compact carbon nanotube field-effect transistor (CNTFET)-based [Formula: see text]-band electronically tunable band-pass filter (BPF) is presented. The filter is designed using second-generation multiple-output current-controlled current conveyor (MOCCCII). The presented active only current-mode BPF employs three MOCCCIIs and two CNTFETs as capacitors. This BPF can be tuned by varying the parasitic resistance of MOCCCIIs via the control current. The designed current-mode tunable BPF is simulated in an advanced design system (ADS) using the Stanford CNTFET model with the extension of noise and manufacturing process variation. The filter achieves a 21–23 GHz tuning frequency range, with a minimum noise figure of about 11.09 dB. The 1-dB compression point and input-referenced third-order intercept point are −19.28 and −8.4 dBm, respectively. This compact filter consumes only 145.7 [Formula: see text] W power at ± 0.5 V supply voltage at room temperature. The temperature analysis shows good thermal stability. The Monte Carlo analysis demonstrates the good process variation stability of the filter. The suggested BPF can be thought of as the first fully active BPF that is a candidate for [Formula: see text]-band communication applications with future advances in the fabrication process for CNTFET.
The Dynamics and Theoretical Analysis Underlying Periodic Bursting in the Nonsmooth Murali–Lakshmanan–Chua Circuit
Authors: Song Jinchen , Ma Nan , Zhang Zhengdi , Yu Yue
Published: December 2023

Motivated by the study of multiple time scale system dynamics, we analyze the Murali–Lakshmanan–Chua (MLC) dissipative circuit exhibiting periodic bursting with different types of oscillations in this paper. Such patterns can be analyzed by treating the slow variable as a parameter of the nonsmooth fast subsystem. The discontinuous bifurcation structure of the subsystem can be described by the generalized differential of Clarke and the Jacobian matrix of the system. Bursting patterns as well as the oscillation mechanisms can be clarified by the discontinuous bifurcations, time series and phase portraits. For the chosen circuit parameter values, this designed circuit admits both MLC type bursting attractors and Duffing–van der Pol circuit type bursting attractors. It is found that not only the features combined with the circuit parameters of the system, but also the two switching boundaries may have an important impact on the origin of the bursting behaviors. In particular, the explicit analytic solutions of the proposed circuit are investigated in detail. We also show that the bursting can arise from either discontinuous saddle-node bifurcation or slow passage through a discontinuous Hopf bifurcation. Finally, the validity of the theoretical analysis has been well verified by the numerical simulations.
Monitoring Rubbish on Roads in Real Time by Deep Neural Network
Authors: Fu Yan , Xiao Tiaozong , Xu Zichen
Published: December 2023

Monitoring and managing litter on the roadways is important not only for preserving the cleanliness and esthetic appeal of our cities but also for safeguarding the overall health and sanitary environment of citizens. With the development of artificial intelligence, it is now possible to design algorithms capable of autonomously assessing the sanitation status of roadways. In this paper, we propose a method for detecting garbage on roads as our solution to tackle the issue. The proposed model is a deep learning model with an attention mechanism introduced to detect garbage in real-time scenarios. Furthermore, the object recognition capability of the model is enhanced through transfer learning to mitigate the influence of irrelevant content during training. The refined network can detect rubbish on roads with higher efficiency than the existing models. Also, compared with other methods, it consumes less amount of data for training. The experimental results demonstrate the efficiency of our proposed model, with a performance boost of 7.62% over the state-of-the-art methods.
A Low-Cost Triple-Node-Upset Self-Recovery Latch Design
Authors: Xu Hui , Xia Yu , Ma Ruijun , Liang Huaguo , Huang Zhenfeng
Published: December 2023

As the CMOS process continues to decrease in size, the latch becomes increasingly vulnerable to the triple-node-upset (TNU), leading to a decrease in circuit reliability in harsh radiation environments. In this paper, a low-cost TNU self-recovery latch (LCTR) is proposed, which is based on one PMOS and two NMOS (1P2N) inverters and C-elements (CEs) forming a multi-level feedback loop. Due to the error interception function of these fundamental elements, the proposed latch completely realizes TNU self-recovery capability. Then the simulated tests are used for comparing the overhead of the LCTR latch and the other two typical TNU self-recoverable latches. The results reveal that the LCTR latch decreases power consumption by 56.98%, delay by 30.08%, area by 21.25% and PDP by 70.77%, respectively. Moreover, the LCTR latch is moderately sensitive to the variation of process, voltage and temperature (PVT).
Realization of nth Order Wave Active Low-Pass Filter Using Differential Difference Current Conveyor
Authors: Kumari Sweta , Nand Deva
Published: December 2023

A wave active filter (WAF) based on a differential difference current conveyor (DDCC) is presented in this paper. An active filter formation depends entirely on wave quantity processing. The wave method is demonstrated for the basic wave active elements (WAEs) of active filters such as a series inductor and a shunt capacitor. The novelty of the proposed work is that the mathematical operations required to implement the wave active components, such as lossy integration-subtraction; subtraction; summation and inverter, are performed using the DDCC as an analog building block (ABB). Designing WAFs of lower to higher-order is extremely challenging, i.e., great motivation to propose a WFA using a CMOS-based DDCC for lower and higher-order low-pass Butterworth filter topologies. Additionally, the filter performances are verified through noise analysis, percentage total harmonic distortion (%THD) and Monte Carlo analysis. The proposed WFA is theoretically verified for [Formula: see text]th order low-pass Butterworth filter designs ([Formula: see text]) using DDCC-based WAEs and validated using SPICE simulations with [Formula: see text]m TSMC CMOS technology parameters for DDCC, operating on [Formula: see text][Formula: see text]V.
Exploring the Impact of Vocabulary Techniques on Code Completion: A Comparative Approach
Authors: Hussain Yasir , Huang Zhiqiu , Zhou Yu , Khan Izhar Ahmed
Published: December 2023

Integrated Development Environments (IDEs) are pivotal in enhancing productivity with features like code completion in modern software development. Recent advancements in Natural Language Processing (NLP) have empowered neural language models for code completion. In this study, we present an extensive investigation of the impact of open and closed vocabulary systems on the task of code completion. Specifically, we compare open and closed vocabulary systems with various vocabulary sizes to observe their impact on code completion performance. We experiment with three different open vocabulary systems: byte pair encoding (BPE), WordPiece and Unigram to compare them with closed-vocabulary systems to analyze their modeling performance. We also conduct experiments with different context sizes to study their impact on code completion performance. We have experimented using various prominent language models, including one from recurrent neural networks and five from transformers. Our results indicate that vocabulary size significantly impacts modeling performance and can artificially boost the accuracy of code completion models, especially in the case of a closed-vocabulary system. Moreover, we find that different vocabulary systems have varying impacts on token coverage, whereas open-vocabulary systems exhibit better token coverage. Our findings offer valuable insights for building effective code completion models, aiding researchers and practitioners in this field.
Distinguishing surface-links described by 4-charts with two crossings and eight black vertices
Authors: Nagase Teruo , Shima Akiko
Published: December 2023

Charts are oriented labeled graphs in a disk. Any simple surface braid (2-dimensional braid) can be described by using a chart. Also, a chart represents an oriented closed surface (called a surface-link) embedded in 4-space. In this paper, we investigate surface-links by using charts. In [T. Nagase and A. Shima, The structure of a minimal [Formula: see text]-chart with two crossings I: Complementary domains of [Formula: see text], J. Knot Theory Ramifactions 27(14) (2018) 1850078; T. Nagase and A. Shima, The structure of a minimal [Formula: see text]-chart with two crossings II: Neighbourhoods of [Formula: see text], Revista de la Real Academia de Ciencias Exactas, Fiskcas y Natrales. Serie A. Math. 113 (2019) 1693–1738, arXiv:1709.08827v2 ] we gave an enumeration of the charts with two crossings. In particular, there are two classes for 4-charts with two crossings and eight black vertices. The first class represents surface-links each of which is connected. The second class represents surface-links each of which is exactly two connected components. In this paper, by using quandle colorings, we shall show that the charts in the second class represent different surface-links.
Nonlinear electrodynamical lensing of electromagnetic waves on the dipole magnetic field of the magnetar
Authors: Beissen Nurzada , Abishev Medeu , Toktarbay Saken , Yernazarov Tursynbek , Aimuratov Yerlan , Khassanov Manas
Published: December 2023

We study numerically a combined gravitational and nonlinear magnetic lensing effect on electromagnetic flux. A magnetar with a dipole magnetic field and background gravitational field is considered to deflect the light rays which passed through its magnetosphere. We assume a square wave front with sides [Formula: see text][Formula: see text]m as a grid with the [Formula: see text][Formula: see text]m dynamic step. At the nodes of this grid, the rays enter perpendicularly into the cubic area, which covers the main magnetic lensing region with a magnetar at the center. On the basis of general relativity (GR) and nonlinear vacuum electrodynamics, the distribution of rays by the deflection angle in the combined field of the magnetar was obtained. On the basis of the analysis of the obtained data, it is possible to assert that the magnetic field distorts the result of gravitational lensing. Therefore, the magnetar is regarded as a gravitational-magnetic lensing object, wherein the magnetic field induces axial distortion within [Formula: see text]. These results are expected to be detectable by modern instruments.
A comparative study of wormhole models in f(R,T) gravity
Authors: Chawla Chanchal , Dixit Archana , Pradhan Anirudh , Krishnannair S.
Published: December 2023

We have conducted research on the presence of wormholes characterized by a logarithmic shape function within the framework of exponential [Formula: see text] gravity. This gravity model is defined as [Formula: see text], with [Formula: see text] representing an arbitrary constant. We find that the logarithmic shape function serves as expected, providing all the necessary conditions for traversable and asymptotically flat wormholes. We have examined the solutions with three distinct sets of physical constraints placed on [Formula: see text], [Formula: see text] and [Formula: see text]. viz. Model-I: [Formula: see text] with k being variable dependent on r and [Formula: see text] with [Formula: see text] being EoS parameter, Model-II: [Formula: see text] and [Formula: see text] with [Formula: see text] and [Formula: see text] being EoS parameters, Model-III: Trace is zero i.e. [Formula: see text] or [Formula: see text] i.e. [Formula: see text] gravity model. From Model-I, we have obtained a new parametrization for EoS parameter [Formula: see text] and from Model-III, we have obtained a new form of shape function [Formula: see text] in [Formula: see text] gravity theory.
Diffeomorphism invariance and quantum mechanical paradoxes
Authors: Dukehart Adam , Mattingly David
Published: December 2023

Paradoxes in gravitational physics, such as grandfather paradoxes with closed timelike curves or the AMPS paradox, are often constructed in a weak gravity regime but upon further examination engender strong gravitational responses such as unstable Cauchy horizons or firewalls. In contrast, some proposed paradoxes in nonrelativistic quantum mechanics ignore gravity completely. Such nonrelativistic proposed paradoxes are often not gauge invariant — they use local operators which should be forbidden by diffeomorphism-invariant quantum gravity. Ignoring this complication is reasonable if there is a consistent weak gravity regime where the paradox can be formulated with gauge invariant observables up to some order in Newton’s constant. We show that this approach remains inconsistent due to a lack of analyticity of the necessary solutions. As a consequence, there is no consistent weak gravity, diffeomorphism invariant embedding of such paradoxes—just as in other gravitational paradoxes they generate a strong gravitational response and are in principle sensitive to quantum gravity.
Thermal fluctuations of (non)linearly charged BTZ black hole in massive gravity
Authors: Pourhassan Behnam , Hendi Seyed Hossein , Upadhyay Sudhaker , Sakallı İzzet , Saridakis Emmanuel N.
Published: December 2023

In this paper, we consider a charged BTZ black hole in asymptotically AdS spacetime of massive gravity to study the effect of the thermal fluctuations on the black hole thermodynamics. We consider the Einstein–Born–Infeld solution and investigate critical points and stability. We also compare the results with the case of Einstein–Maxwell solutions. Besides, we find that thermal fluctuations, which appear as a logarithmic term in the entropy, affect the stability of the black hole and change the phase transition point. Moreover, we study the geometrical thermodynamics and find that the behavior of the linear Maxwell solution is the same as the nonlinear one.
Dissipative dynamics for infinite lattice systems
Authors: Mehta Shreya , Zegarlinski Boguslaw
Published: December 2023

We study dissipative dynamics constructed by means of non-commutative Dirichlet forms for various lattice systems with multiparticle interactions associated to CCR algebras. We give a number of explicit examples of such models. Using an idea of quasi-invariance of a state, we show how one can construct unitary representations of various groups. Moreover in models with locally conserved quantities associated to an infinite lattice we show that there is no spectral gap and the corresponding dissipative dynamics decay to equilibrium polynomially in time.
Subgame-Consistent Cooperative Equilibria of Multi-Objective Dynamic Games
Authors: Yeung David W. K. , Petrosyan Leon A.
Published: December 2023

This paper develops subgame consistent cooperative equilibria of multi-objective dynamic games. The presence of multiple objectives in decision-making is prevalent and inherent. Given that the set of objectives of each player will be affected by the actions of other players, non-coordinated maximization by individual players could lead to the case where some prominent objectives may reach an undesirably level. Cooperation is the best way to alleviate the problem and enhance the participants’ payoffs. This paper presents the techniques for solving subgame consistent cooperative equilibria of multi-objective dynamic games with utility-based players. In such an equilibrium, individual rationality, group efficiency, and subgame consistency are realized. An application of collaboration between Australia and New Zealand is provided. This is the first time that subgame consistent cooperative equilibria are applied in multi-objective dynamic games with utility-based players, ample applications in various fields are expected.
The Marriage Game Revisited: New Insights About Domestic Labor, Divorces and Men’s Expectations About Marriage
Authors: Benati Stefano
Published: December 2023

In the Marriage Game, women decide whether to get married and afterward men decide whether to cooperate in the domestic tasks. Then, if a husband is not cooperative, a wife can divorce or remain married. The sequence of decisions can be formalized as a game in extensive form, in which the strategic interaction between partners turns out evident. A husband may deceive, hoping that the divorce threat is not realistic, and a woman may decide not to get married from the beginning. If players had perfect knowledge about partners’ attitude, then divorce would not exist. Unfortunately, partners’ type is revealed only after the wedding. So, it is assumed that the game is played by different type of players, both men and women, and they interact with incomplete information. The model is solved by calculating all the perfect Bayes–Nash equilibria and it is shown that they depend on a complex interaction between model parameters, as multiple or mixed strategy equilibria can be found same parameters configuration. Comparing equilibria, we argue that the model can describe the marriage evolution that has been experienced by contemporary society. Following the increasing women’s participation in the job market, the number of marriages started to decline, but surprisingly, we are observing its resurgence in the most advanced societies. Our solution to the Marriage Game points to both the active role of autonomous women and the men’s expectations about marriage. As the number of autonomous women increases, men realize that divorce is credible and they change their expectations on women.
Numerical Prediction of Ballistic Performance of Thin Concrete Plate
Authors: Kamran  , Asif Mohd , Iqbal M. A.
Published: December 2023

This research explores the ability of 60[Formula: see text]mm thick reinforced concrete (RC) plates to resist impacts from ogive-nosed hard steel projectiles. The projectiles used in the present study have a diameter of 19[Formula: see text]mm, a length of 200[Formula: see text]mm, and a mass of 0.4[Formula: see text]kg impacted on the RC plates with incident velocities ranging from 92[Formula: see text]m/s to 161[Formula: see text]m/s. Numerical simulations were conducted using ABAQUS/Explicit finite element software to validate the experimental results. The Holmquist–Johnson–Cook (HJC) material model was employed to simulate the constitutive behavior of concrete, while the Johnson–Cook (JC) material model was used to simulate the material response of reinforcing steel bars. The residual velocities obtained from the simulations closely matched the actual experimental results, showing a polynomial correlation with the incidence velocities of the projectiles. Moreover, the experimentally and numerically determined ballistic limit for the 60[Formula: see text]mm thick RC plate was found to be 108[Formula: see text]m/s and 109.5[Formula: see text]m/s, respectively. In contrast, the ballistic limit calculated using empirical mathematical expressions was 107.4[Formula: see text]m/s. This alignment between predicted, calculated, and actual ballistic limits underscores the reliability and accuracy of both numerical and empirical approaches.
Stochastic Optimization of Electromagnetic Inertial Mass Dampers in Nonlinear Hybrid Base Isolation Systems Under Seismic Excitations
Authors: Lei Ying , Yang Xiongjun
Published: December 2023

Recently developed inerter-based dampers have been installed at the base layer to reduce base displacement and simultaneously improve the superstructure’s performance. However, in the existing research on optimizing damper parameters, the nonlinear property of base isolation is simplified and stochastic linearization technique is introduced to approximate such nonlinearity, which would inevitably introduce errors. In this paper, an improved method is proposed for stochastic optimization of electromagnetic inertial mass dampers (EIMD) in nonlinear hybrid isolation systems subject to seismic excitations. First, a stochastic seismic excitation is represented by one elementary random variable adopting the dimension-reduction spectral representation method. Then, statistical moments of nonlinear base-isolated structural responses are estimated using two-point estimation method (2PEM). Finally, the EIMD optimal parameters are obtained via the modified directional bat algorithm (MDBA) recently proposed by the authors through minimizing base layer response moments. This proposed improved method could fully consider the base isolation nonlinearity compared with the previous stochastic linearization technique. Moreover, the proposed stochastic optimization of the EIMD only requires two dynamic analyses to achieve its efficiency. A seven-story base-isolated frame building equipped with an EIMD is investigated in the numerical simulation, and results indicate that EIMD optimized by this proposed method obviously outperforms the results by the stochastic linearization technique and the conventional viscous damper (VD) in the base layer displacement reduction.
Global Displacement Reconstruction of Lattice Tower Using Limited Acceleration and Strain Sensors
Authors: Fu Xing , Zhang Qing , Ren Liang , Li Hong-Nan
Published: December 2023

Displacement is an important parameter for evaluating structural performance. However, the accurate measurement of global dynamic displacement remains a challenging task. To solve this problem, this paper proposes a global dynamic displacement reconstruction method for lattice tower structures, fusing limited acceleration and strain data. First, the strain-displacement mapping method for cantilever beams with variable cross-sections is presented and then extended to lattice towers. Thereafter, a modified multi-rate data fusion algorithm incorporating Kalman filtering and the proposed strain-displacement mapping methods is developed to fuse the acceleration and strain data to reconstruct the global dynamic displacement of the tower. The numerical simulation, model test and full-scale test demonstrate that the reconstructed dynamic displacements using the proposed method agree well with the reference values in both the time and frequency domains, and the parametric analysis has also been carried out, exhibiting great robustness and high reconstruction accuracy.
Active Control of Quasi-Zero-Stiffness Vibration Isolator with Variable Load
Authors: Sun Ke , Tang Jie , Yang Yukang , Jiang Bolong , Li Yinghui , Cao Dengqing
Published: December 2023

Quasi-zero-stiffness (QZS) isolator has great application potential in the field of low-frequency vibration isolation due to its high-static and low-dynamic (HSLD) nonlinear stiffness characteristic, but it is precisely this characteristic that makes it very sensitive to load changes. Once the load changes, causing it to deviate from the equilibrium position, it no longer qualifies zero-stiffness characteristic, and the vibration isolation capacity will be significantly decrease. To make the QZS isolator possess variable load capacity and be more suitable for engineering practice, an active QZS vibration isolator based on electromagnetic actuator is designed in this paper, which eliminates the influence of load changes through the active force of the electromagnetic actuator. First, the dynamic equation of the isolator is established by Newton–Euler method, and the dynamic characteristic of the isolator under standard load and load variations are analyzed through improved incremental harmonic balance (IHB) method based on discrete Fourier transform (DFT). Next, the improved particle swarm optimization (PSO) algorithm are employed to optimize the Proportion Integration Differentiation (PID) controller parameters. Then, the vibration isolation performance of QZS isolator in controlled and uncontrolled and linear systems in the same control state are compared in frequency domain and time domain, respectively. Finally, the performance of active QZS isolator under load variation is discussed. The results indicate that the isolation performance of the QZS isolator under active control is significantly better than in uncontrolled conditions and the controlled linear system. When the load changes, real-time compensation through the actuator output control force can also enable the QZS isolator to achieve a better vibration isolation performance.
Metro Monolithic Track Bed Vibration Characterization
Authors: Lei Kaiyun , Miao Linchang , Zheng Haizhong , Xiao Peng , Wang Qian
Published: December 2023

With the rapid development of cities, metro transportation has also developed rapidly to solve the congestion problems caused by urban development. However, with the continuous development of metro transportation, the vibration problems caused by it have become increasingly obvious. Based on the phonon crystal theory, this paper investigates the vibration characteristics of the metro track structure. It analyzes the influence of the track structure parameters on the band gap characteristics to regulate the metro vibration band gap range. To study the band gap characteristics of metro monolithic bed track structure, establish the double-layer Euler beam model and use the plane wave expansion method (PWE) to calculate its energy band structure; use the finite element method (FEM) to calculate to get its band structure, frequency response function, and time domain analysis. The calculation of PWE shows that there is a band gap in the range of 0–300[Formula: see text]Hz for the metro monolithic track bed, which is 0–194.5[Formula: see text]Hz; the calculation of FEM shows that the range of band gap is 0–193.7[Formula: see text]Hz. Fastening spacing, stiffness, and sub-slab support stiffness will have an impact on the band gap, so appropriate fastening and spacing need to be selected for effective vibration damping of the track structure. The results show that the band gap characteristics of the metro monolithic track bed can be calculated effectively and accurately by using the phononic crystal theory.
Approach Advancing Stock Market Forecasting with Joint RMSE Loss LSTM-CNN Model
Authors: Kiran Kumar Mungara , Chandra Patni Jagdish , Raparthi Mohan , Sherkuziyeva Nasiba , Abdullah Bilal Muhammad , Aurangzeb Khursheed
Published: December 2023

The intricacies and dynamism of financial markets pose challenges to models seeking to comprehensively capture the multitude of factors influencing stock price movements. As such, there remains room for improvement in forecasting accuracy. In response, we introduce a novel approach that unifies the Root Mean Square Error (RMSE), loss functions of Long Short-Term Memory (LSTM) and Convolutional Neural Networks (CNN). By concurrently optimizing their RMSE loss functions, our novel approach takes use of the capabilities of LSTM for learning long-term time series relationships and CNN for extracting deep features from data. To maximize the efficacy of each model branch within this unified framework, we split the training set into two different representations, one consisting of standard time series data and the other of standard picture data. We compare our proposed model to others in the field to demonstrate its viability, particularly Backpropagation (BP), LSTM, CNN, and a fusion LSTM-CNN model. Experimental evaluations conducted on three diverse datasets—Development Bank, Stock Connect Index (SCI), and Composite Index (CI)—validate the robust predictive performance and applicability of our joint RMSE loss LSTM-CNN model, thus showcasing its potential in financial forecasting.
Tree Seed Algorithm-based Feature Selection with Optimal Deep Learning Model for Supply Chain Management
Authors: Alzahrani Jaber S. , Maashi Mashael , Alshahrani Haya Mesfer , Hassan Abdulkhaleq Q. A. , Khan Jahangir , Dutta Ashit Kumar , Eltahir Yasir A. M. , Saad Hussam Eldin Hussein , Gilkaramenthi Rafiulla
Published: December 2023

In recent days, supply chain and logistic industries have been going through a transformational wave of automation and digitization. Supply chain management (SCM) can involve machine learning (ML) abilities and prediction models to ensure that the demands are satisfied at a minimum cost. Intelligent models can be developed to determine whether adequate inventory is accessible to encounter the predictable rise in demands, and if not, the system spontaneously begins to adjust the orders with suppliers to source the raw materials for resolving the predicted future high demand. The conventional ways of SCM can be replaced by the design of recent artificial intelligence (AI) and deep learning (DL) techniques. By this motivation, this research presents a tree seed algorithm-based feature selection with optimum DL technique for supply chain management (TSA-ODLSCM). The proposed TSA-ODLSCM model involves the design of a feature subset selection approach using a tree search algorithm (TSA) algorithm. Besides, a new convolutional neural network with fuzzy cognitive maps (CNN-FCM) technique is designed for the classification process. Moreover, optimal parameter tuning of the CNN-FCM model was performed using the Henry gas solubility optimization (HGSO) technique. To exhibit the improved performance of the TSA-ODLSCM approach, a huge range of simulations were executed and outcomes were examined below several aspects. The experimental validation reported an enhanced 96.52% outcome of the TSA-ODLSCM approach over other methods.
Enhancing Economic Stability with Innovative Crude Oil Price Prediction and Policy Uncertainty Mitigation in USD Energy Stock Markets
Authors: Islam Umar , Awwad Emad Mahrous , Sarhan Nadia Mohamed , Fattah Sharaf Mohamed Abdel , Ali Ijaz , Khan Inayat , Ahmad Shehzad , Khan Faheem
Published: December 2023

In today’s globalized economic landscape, the assurance of economic stability is of paramount importance, necessitating precise financial decision-making and policy formulation. This assurance is significantly augmented by innovative approaches to predicting crude oil prices, particularly in the context of energy stock markets denominated in USD. This paper delves into the transformative effect of accurate crude oil price prediction on economic policy stability. It underscores the challenges and limitations posed by policy uncertainties and emphasizes the pivotal role of innovative solutions in mitigating these challenges. Moreover, it recognizes the imperative need for secure data storage to facilitate the application of machine learning in this domain. Furthermore, effective management and regulation of power grid systems are explored as indispensable strategies for tempering the volatility introduced by fluctuations in energy stock markets. As we work to address these gaps in knowledge, the potential for sustainable power systems to supersede fossil fuels emerges as a driving force behind the maintenance of stable economic policies.
Stock Price Forecasting Based on Dynamic Factor Augmented Model Averaging Approach
Authors: Li Fangfei
Published: December 2023

Accurate forecasting of stock prices not only guides investor behavior but also assesses financial risk and promotes balanced economic and social development. This paper uses a dynamic factor-enhanced model averaging method to forecast the daily closing price of the Shanghai Composite Index, maximizing the use of valid information by weighting the forecast values of different models. Firstly, the common factor is extracted from the smoothed original explanatory variables; then the dynamic factor augmented model selection method and the model averaging method based on different criteria are used to predict different lag orders of the common factor and the explanatory variables, and the effectiveness of the dynamic factor augmented censored group cross-validation model averaging method is verified using multiple predictor error indicators as well as the DM test. The experimental results show that the dynamic factor augmented censored group cross-validation model averaging method has better prediction results and is more robust.
Stock Market Volatility Prediction Based on Robust GBM-GRU Model
Authors: Liao Chuyue , Chen Guoqing , Cai Siyang
Published: December 2023

In this study, a corrective learning technique is proposed to enhance the time series forecasting accuracy of traditional intelligent algorithms and address issues with engineering data adaptability. The financial world makes substantial use of volatility, and forecasting stock market volatility has great significance. Because stock price time series are nonstationary and nonlinear, predicting stock market volatility is a significant difficulty. In this study, a simulation experiment using an approach for corrective learning is carried out. Over a 3-year period, a LightGBM-GRU model is created to predict the volatility of 126 equities from diverse industries over the length of the subsequent 10 min, utilizing LightGBM and GRU as base models and correctors, respectively. Even traditional and effective ensemble learning models can benefit from the corrective learning technique, which simultaneously improves accuracy and generalization, according to performance metrics like RMSPE, MAE, MSE, and RMSE. The research emphasizes how the contradiction within intelligent algorithms has changed from one of restricted generality to different engineering difficulties in the era of algorithm enrichment and large data. The corrective learning strategy offers a fresh method for simulating data.
Weak Hopf algebras, smash products and applications to adjoint-stable algebras
Authors: Liu Zhimin , Zhu Shenglin
Published: December 2023

For a semisimple quasi-triangular Hopf algebra [Formula: see text] over a field [Formula: see text] of characteristic zero, and a strongly separable quantum commutative [Formula: see text]-module algebra [Formula: see text], we show that [Formula: see text] is a weak Hopf algebra, and it can be embedded into a weak Hopf algebra [Formula: see text]. With these structures, [Formula: see text] is the monoidal category introduced by Cohen and Westreich, and [Formula: see text] is tensor equivalent to [Formula: see text]. If [Formula: see text] is in the Müger center of [Formula: see text], then the embedding is a quasi-triangular weak Hopf algebra morphism. This explains the presence of a subgroup inclusion in the characterization of irreducible Yetter–Drinfeld modules for a finite group algebra.
Cohomology of modified Rota–Baxter Leibniz algebra of weight λ
Authors: Mondal Bibhash , Saha Ripan
Published: December 2023

Rota–Baxter operators have been paid much attention in the last few decades as they have many applications in mathematics and physics. In this paper, our object of study is modified Rota–Baxter operators on Leibniz algebras. We investigate modified Rota–Baxter Leibniz algebras from the cohomological point of view. We study a one-parameter formal deformation theory of modified Rota–Baxter Leibniz algebras and define the associated deformation cohomology that controls the deformation. Finally, as an application, we characterize equivalence classes of abelian extensions in terms of second cohomology groups.
Two results on character codegrees
Authors: Liu Yang , Yang Yong
Published: December 2023

Let [Formula: see text] be a finite group and [Formula: see text] be the set of irreducible characters of [Formula: see text]. The codegree of an irreducible character [Formula: see text] of the group [Formula: see text] is defined as [Formula: see text]. In this paper, we study two topics related to the character codegrees. The first result is related to the prime graph of character codegrees and we show that the codegree prime graphs of several classes of groups can be characterized only by graph theoretical terms. The second result is about the [Formula: see text]-parts of the codegrees and character degrees.
Partial actions of Sweedler Hopf algebra on generalized quaternion algebra
Authors: Deng Yong , Chen Quanguo , Wang Dingguo
Published: December 2023

In the paper, we discuss the partial actions of Sweedler Hopf algebra on the generalized quaternion algebra, and give the sufficient and necessary conditions to make the actions be the partial actions. As an application, we give a complete description of all partial actions of Sweedler Hopf algebra on the generalized quaternion algebra.
A look at FPF rings
Authors: Ghashghaei E. , Koşan M. Tamer , Quynh T. Cong , Thuyet L. Van
Published: December 2023

An error in Corollary 9.32 of [C. Faith, Rings and Things and a Fine Array of Twentieth Century Associative Algebra, Mathematical Surveys and Monographs, Vol. 65 (American Mathematical Society, Providence, RI, 2004)], motivated us to consider again FPF rings which were initiated by Faith in the 1970s. In this paper, it is shown that a commutative ring [Formula: see text] is reduced FPF if and only if it is [Formula: see text]-semihereditary. We show that when a semiperfect ring with a strongly right bounded basic ring with right and left Ore conditions, is an FPF ring. After some general results, the article focuses on rings of continuous functions. We give some algebraic characterizations for a [Formula: see text] to be FPF and retrieve a result of Jorge Martinez. Also, we show that a space [Formula: see text] is fraction-dense if and only if [Formula: see text] is a continuous ring.
A type C study of Braverman–Gaitsgory–Ginzburg’s construction of sln representations
Authors: Dong Zhijie , Ma Haitao
Published: December 2023

In [Z. Fan, H. Ma and H. Xiao, Equivariant K-theory approach to [Formula: see text]-quantum groups, Publ. Res. Inst. Math. Sci. 58 (2022), no.3, 635–668], it is proved that the convolution algebra of the top Borel–Moore homology on the Steinberg variety of type [Formula: see text] realizes [Formula: see text], where [Formula: see text] is the fixed point subalgebra of involution on [Formula: see text]. So, the top Borel–Moore homology of the partial Springer fibers gives the representations of [Formula: see text]. In this paper, we study these representations using Schur–Weyl duality and Springer theory.
Arithmetic of semisubtractive semidomains
Authors: Fox Hannah , Goel Agastya , Liao Sophia
Published: December 2023

A subset [Formula: see text] of an integral domain is called a semidomain if the pairs [Formula: see text] and [Formula: see text] are commutative and cancellative semigroups with identities. The multiplication of [Formula: see text] extends to the group of differences [Formula: see text], turning [Formula: see text] into an integral domain. In this paper, we study the arithmetic of semisubtractive semidomains (i.e. semidomains [Formula: see text] for which either [Formula: see text] or [Formula: see text] for every [Formula: see text]). Specifically, we provide necessary and sufficient conditions for a semisubtractive semidomain to be atomic, to satisfy the ascending chain condition on principals ideals, to be a bounded factorization semidomain, and to be a finite factorization semidomain, which are subsequent relaxations of the property of having unique factorizations. In addition, we present a characterization of factorial and half-factorial semisubtractive semidomains. Throughout the paper, we present examples to provide insight into the arithmetic aspects of semisubtractive semidomains.
Nonlinear Jordan triple ∗-derivations on prime ∗-algebras
Authors: Taghavi Ali
Published: December 2023

Let [Formula: see text] be a unital prime ∗-algebra containing a nontrivial projection [Formula: see text]. In this paper, it is shown that if a mapping [Formula: see text] satisfies [Formula: see text] or [Formula: see text] for all [Formula: see text], where [Formula: see text] and [Formula: see text], then [Formula: see text] preserves self-adjoint elements. Therefore, the two relations (0.1) and (0.2) will be equivalent for every [Formula: see text] and [Formula: see text]. This result makes possible to unify the conclusions in a single statement which implies the above two results. In fact, it is shown that if a map [Formula: see text] satisfies the conditions in (0.1) or (0.2) for every [Formula: see text] and [Formula: see text], then [Formula: see text] is an additive ∗-derivation.