Special Parameters Research Articles

Higgs Boson Searches at the LHC Beyond the Standard Model

The latest results of Higgs boson searches beyond the Standard Model from the ATLAS and CMS experiments are reviewed. This includes searches for additional neutral, charged, and double charged Higgs-like bosons, searches for dark matter produced in association with a Higgs boson, and searches for new physics in Higgs boson production and decay processes. Interpretations are given within the hMSSM, a special parameterization of the Minimal Supersymmetric extension of the Standard Model, in which the mass of the lightest Higgs boson is set to the value of 125 GeV measured at the LHC.

A parametric modeling method for 2.5D warp-reinforced woven composites considering the extruded distortion of yarns

2.5D warp-reinforced woven composites (2.5DWRWC) are widely used in various industries, but it is currently difficult to model parametrically considering the molding effects due to their complex structure. Accordingly, two special parameters (ψ and φ) are introduced to regulate the degree of yarn extrusion, where ψ is used to characterize the extrusion degree of the binder yarn on the weft yarn in the thickness direction, and φ is used to characterize the twisting degree of the warp yarn. On this basis, a parametric modeling method for 2.5DWRWC is constructed by uniting the essential weaving parameters, and the modeling code is written in TexGen software using Python language. Subsequently, the established model is verified experimentally, and the results show that the average comparison error of the geometric parameters is only 5.07 %, the maximum prediction error of the mechanical properties is only 4.78 %, validating the reasonableness of the proposed modeling method. Finally, the effects of the two special parameters on the mechanical properties are emphasized, and the results show that the mechanical properties in weft direction are enhanced with the increase of ψ, and the mechanical properties in warp direction are weakened with the increase of φ. This work can provide guidance for the molding process and mechanical design of 2.5DWRWC, which has significant theoretical value and engineering significance.

Experimental investigation of friction stir welding with special spherical ball shoulder different probe tools and parameters for enhanced material properties of AA2219 aluminium alloy

This research investigates the impact of unique spherical ball shoulder enhancement tool pin configurations on the friction stir welding (FSW) of AA2219 aluminum alloy under various parameters. FSW was performed using three different pin shapes: square, hexagonal, and octagonal. Testing samples were prepared using an L9 orthogonal array layout with varying welding parameters. The material behavior in the three distinct weld zones was evaluated for each pin configuration. Results indicated superior microhardness values in the heat-affected zone (HAZ) and thermo-mechanically affected zone (TMAZ) compared to the weld nugget zone. Elemental composition analysis of the TMAZ revealed significant differences, highlighting the influence of thermal stress and material behavior due to the tool pin and shoulder configuration. The square-headed tool demonstrated improved tensile strength and microhardness. Optimal welding performance was achieved with a spindle speed of 1000 RPM, a travel speed of 25 mm/min, and a tilt angle of 3°. Variations in Cu content in the TMAZ and HAZ underscored localized modifications within the material structure, driven by the spherical ball spinning effects on the shoulder. Tensile tests showed that welds made with the square pin consistently exhibited higher tensile strength compared to those made with hexagonal and octagonal pins.

Flat bands in three-dimensional lattice models with non-trivial Hopf index

We report the presence of exactly and nearly flat bands with non-trivial topology in three-dimensional (3D) lattice models. We first show that an exactly flat band can be realized in a 3D lattice model characterized by a 3D topological invariant, namely Hopf invariant. In contrast, we find another distinct 3D model, exhibiting both 2D Chern and 3D Hopf invariant, namely Hopf-Chern insulator, that can host nearly or perfect flat bands across different 2D planes. Such a Hopf-Chern model can be constructed by introducing specific hopping along the orthogonal direction of a simple two-orbital 2D Chern insulator in the presence of in-plane nearest-neighbor and next-nearest hopping among different orbitals. While the Chern planes host nearly perfect flat bands, the orthogonal planes can host both perfect or nearly perfect flat bands with zero Chern number at some special parameter values. Interestingly, such a 3D lattice construction from 2D allows finite Hopf invariant too. Finally, we show that higher Chern models can also be constructed in the same lattice setup with only nearest and next-nearest hopping, but the appearance of flat bands along high-symmetric path in the Brillouin zone requires longer-range hopping. We close with a discussion on possible experimental platforms to realize the models.

A locking-free numerical method for the quasi-static linear thermo-poroelasticity model

In this paper, we propose a locking-free numerical method to solve the quasi-static linear thermo-poroelasticity model, which exhibits two types of locking phenomena: Poisson locking and nonphysical oscillations. By analyzing the regularity of solution of the original model, we find that the Poisson locking is caused by divu≈0 as λ→+∞. Moreover, when discretizing the diffusion equations using backward Euler method for time, one can see that divu1≈0 for some special parameters. If we directly use the continuous Galerkin mixed finite element method (FEM) to solve the original model, the pressure and temperature fields exhibit numerical oscillations at early times. To overcome these two locking phenomena, we introduce a new variable ξ=αp+βT−λdivu to reformulate the original problem into a new one. This new problem includes a built-in mechanism to maintain stability for the continuous Galerkin mixed FEM. We further prove the existence and uniqueness of the weak solution by using the standard Galerkin method in conjunction with regularity estimates. We also design a fully discrete time-stepping scheme that employs mixed FEM with P2−P1−P1−P1 element pairs for the space variables and the backward Euler method for the time variable. Optimal convergence is demonstrated in both space and time. Finally, numerical examples are provided to demonstrate the optimal convergence rates of the variables and the robustness of the proposed method with respect to ν, and to verify the absence of the locking phenomenon.

Intramedullary pediatric low-grade glioma of the spine.

Pediatric intramedullary spinal cord low-grade gliomas (pLGGs) are rare diagnoses among central nervous system (CNS) tumors in the pediatric population. The classic presentation of the patients includes some degree of neurologic deficit, although many times the symptoms are vague which leads to delayed diagnosis. The first step in the diagnosis includes special parameters in spinal imaging, particularly magnetic resonance imaging (MRI), and surgical resection remains the cornerstone for both diagnosis and treatment. Yet, recent years advancement in molecular and genetic understanding of CNS tumors allows for better adjustment of the treatment and follow-up regimens. Based on postoperative status, adjuvant therapy may provide additional therapeutic advantage for some types of tumors. Ultimately, patients have a very promising prognosis when treated appropriately in most of the cases of pediatric spinal cord LGG with continued advances arising. This manuscript summarizes the most contemporary evidence regarding clinical and treatment features of intramedullary pLGGs.

Riemann-Hilbert approach and multi-soliton solutions of nonlocal Newell-type long wave-short wave equation

This article’s purpose is to investigate the inverse scattering transform of the nonlocal long wave-short wave (LW-SW) equation and its multi-soliton solutions via Riemann-Hilbert (RH) approach. By using spectral analysis to the Lax pair of LW-SW equation, the RH problem can be constructed. However, we consider spectral analysis from the time part rather than the usual space part, since it is hard to obtain the analyticity of the space part. Then the RH problem can be solved and the formula of the soliton solutions can be given. We provide several special soliton solutions including Y-shaped solitons, V-shaped solitons, bound-state solitons and mixed four-soliton solutions. Compared with the local case, the solutions of nonlocal LW-SW equation exhibit distinct characteristics that (i) these soliton solutions are strictly symmetric with respect to x = 0 under special parameter conditions, (ii) the mixed four-soliton solution, which combines Y-type and bound-state solitons, is novel.

COMPARATIVE ANALYSIS OF PHYTOCHEMICALS IN ACACIA CATECHU BARK EXTRACTS FROM GUNA DISTRICT, MADHYA PRADESH

Objective: Current study aims to discover novel sources of physiologically active natural chemicals with diverse applications. In this study, four types of specific phytochemical in different extracts of Acacia catechu bark samples were investigated, which were collected from. Additionally, bibliographic analysis was conducted using dimensions research database. Methods: For this phytochemical screening, some common and standard test methods were done. Qualitative test for Phenols was done using Lead acetate test method; proteins were quantified by biuret and ninhydrin method, carbohydrates by Molish test, benedict’s test and Fehling’s test, and starch by using Iodine test method. Results: Phytochemical screening showed the phenolic compounds (different colour intensity in different samples) and soluble carbohydrates (almost same colour intensity in all test samples) are present and both proteins and insoluble carbohydrate (starch) are completely absent in all test extracts. Conclusion: The bibliographic analysis indicated the therapeutic values as well as the unavailability of published studies with these special parameters. This preliminary study provide base to find out the possible medicinal significance of Acacia catechu of Guna district and also serve as the base for further investigations.

Generalizations of the Jacobi identity to the case of the Lauricella function F D ( N )

ABSTRACT The paper considers the issue of constructing differential relations for the Lauricella hypergeometric function F D ( N ) . The formulas found give explicit expressions for the derivative of the product of the function F D ( N ) and some binomials through the product of other binomials and a combination of adjacent Lauricella functions whose parameters differ by 1 or − 1 . The derived differential relations generalize the Jacobi identity and other differential formulas known in the theory of the Gauss hypergeometric function on the multidimensional case. With special parameter values F D ( N ) , the right-hand side of such Jacobi-type formulas are simplified and have the form of a product of binomials and a polynomial. Such formulas can be used to transform a Cauchy-type integral to the form of the Schwartz–Christoffel integral and have an application to the Riemann–Hilbert problem with piecewise constant coefficients.

Iris Recognition based on Statistically Bound Spatial Domain Zero Crossing and Neural Networks

Purpose The iris pattern is an important biological feature of the human body. The recognition of an individual based on an iris pattern is gaining more popularity due to the uniqueness of the pattern among the people. Iris recognition systems have received attention very much due to their rich iris texture which gives robust standards for identifying individuals. Notwithstanding this, there are several challenges in unrestricted recognition environments. Methods This article discusses a highly error-resistant technique to implement a biometric recognition system based on the iris portion of the human eye. All iris recognition algorithms of the current day face a major problem of localization errors and the enormous time involved in this localization process. Spatial domain zero crossing may be the simplest and least complex method for localization. Yet, it has not been used due to its high sensitivity to erroneous edges, as a consequence of which more complex and time-consuming algorithms have taken its place. Appropriate statistical bounds imposed on this process help this method to be the least erroneous and time-consuming. Errors were reduced to 0.022% using this approach on the CASIA v1 & v2 datasets. Time consumption in this stage was the least compared to other algorithms. At the comparison stage, most algorithms use multiple comparisons to account for translation and rotation errors. This is time-consuming and very resource-hungry. Results The current approach discusses a robust method based on a single comparison, which works with a correct recognition of over 99.78% which is clearly demonstrated by tests. Conclusions The technique is to use a neural network trained to recognize special statistical and regional parameters unique to every person’s iris. The algorithm also gives sufficient attention to consider illumination errors, elliptical pupils, excess eyelash errors and bad contrast.

Transfer Matrix Method for the Analysis of Multiple Natural Frequencies

Multiple natural frequencies may be encountered when analyzing the essential natural vibration of a symmetric mechanical system or sub-structure system or a system with special parameters. The transfer matrix method (TMM) is a useful tool for analyzing the natural vibration characteristics of mechanical or structural systems. It derives a nonlinear eigen-problem (NEP) in general, even a transcendental eigen-problem. This investigation addresses the NEP in TMM and proposes a novel method, called the determinant-differentiation-based method, for calculating multiple natural frequencies and determining their multiplicities. Firstly, the characteristic determinant is differentiated with respect to frequency, transforming the even multiple natural frequencies into the odd multiple zeros of the differentiation of the characteristic determinant. The odd multiple zeros of the first derivative of the characteristic determinant and the odd multiple natural frequencies can be obtained using the bisection method. Among the odd multiple zeros, the even multiple natural frequencies are picked out by the proposed judgment criteria. Then, the natural frequency multiplicities are determined by the higher-order derivatives of the characteristic determinant. Finally, several numerical simulations including the multiple natural frequencies show that the proposed method can effectively calculate the multiple natural frequencies and determine their multiplicities.

High-order rogue wave and mixed interaction patterns for the three-component Gross-Pitaevskii equationsin F=1 spinor Bose-Einstein condensates.

Under investigation are the three-component Gross-Pitaevskii equationsin F=1 spinor Bose-Einstein condensates. Various localized waves' generation mechanisms have been derived from plane wave solutions using modulation instability. The perturbed continuous waves produce a large number of rogue wave structures through the split-step Fourier numerical method. Based on the known Lax pair, we construct the generalized iterative (n,N-n)-fold Darboux transformation to generate various high-order solutions, including the bright-dark-bright structure of rogue waves, periodic waves, and their mixed interaction structures. Numerical simulations show that rogue waves with a two-peaked structure have robust noise resistance and stable dynamical behavior. The asymptotic states of high-order rogue waves as the parameter approaches infinity are also predicted using the large parameter asymptotic technique. In addition, the position of these localized wave patterns can be controlled by some special parameters. These results may help us understand the dynamic behavior of spinor condensates for the mean-field approximation.

Wave solutions in (3 + 1)-dimensional generalized fractional mKdV-ZK equation utilizing jacobi elliptic functions

In this research, we investigate the effects of fractional order on the (3 + 1)-dimensional generalized space-time fractional modified KdV-Zakharov-Kuznetsov (mKdV-ZK) equation. We approach the problem by utilizing the conformable fractional derivative. By reducing the mKdV-ZK equation to an integer order nonlinear ordinary differential equation, we apply the Jacobi elliptic function method to find exact solutions. These solutions are specifically tailored for the fractional order of the (3 + 1)-dimensional generalized mKdV-ZK equation, encompassing solitary waves, shock waves, and periodic waves. We also compare these exact solutions with fractional solutions to gain further insights. Notably, our approach demonstrates the feasibility of solving nonlinear time-fractional differential equations with conformable derivatives. Several diagrams have been included to visually depict the behavior of the solutions under fractional order when certain special parameter values are employed.

Neural network analysis of neutron and X-ray reflectivity data incorporating prior knowledge.

Due to the ambiguity related to the lack of phase information, determining the physical parameters of multilayer thin films from measured neutron and X-ray reflectivity curves is, on a fundamental level, an underdetermined inverse problem. This ambiguity poses limitations on standard neural networks, constraining the range and number of considered parameters in previous machine learning solutions. To overcome this challenge, a novel training procedure has been designed which incorporates dynamic prior boundaries for each physical parameter as additional inputs to the neural network. In this manner, the neural network can be trained simultaneously on all well-posed subintervals of a larger parameter space in which the inverse problem is underdetermined. During inference, users can flexibly input their own prior knowledge about the physical system to constrain the neural network prediction to distinct target subintervals in the parameter space. The effectiveness of the method is demonstrated in various scenarios, including multilayer structures with a box model parameterization and a physics-inspired special parameterization of the scattering length density profile for a multilayer structure. In contrast to previous methods, this approach scales favourably when increasing the complexity of the inverse problem, working properly even for a five-layer multilayer model and a periodic multilayer model with up to 17 open parameters.

Riemann–Hilbert approach for the inhomogeneous discrete nonlinear Schrödinger equation with nonzero boundary conditions

In this paper, we systematically investigate the Riemann–Hilbert (RH) approach and obtain the soliton solutions for the inhomogeneous discrete nonlinear Schrödinger (NLS) equation with nonzero boundary conditions (NZBCs). Starting from the spectral problem and introducing the uniformization variable κ to avoid the complexity of double-valued function and Riemann surface, we deduce the analyticity, asymptotics and symmetries of the eigenfunctions and scattering coefficients, then the RH problem and reconstruction formula for the potential are successfully constructed. Under reflectionless condition and combining the time evolution of the scattering coefficients and eigenfunctions, we obtain various first-order soliton solutions with different direction of propagation caused by the change of the coefficients. Based on the analytic solution and the choice of special parameter values, we obtain the collision mechanism of two soliton solutions. Furthermore, the important advantage of the RH problem is that it can be further used to study the soliton resolution and the long-time asymptotic behavior of the solutions.

Study on the influence of base shear distribution on the seismic response of base-isolated split-foundation structures

ABSTRACT Split-foundation structures with base isolation have multiple isolation layers due to their uneven foundation heights. This complexity adds challenges to the seismic isolation design of split-foundation structures. In this paper, two special parameters, namely the shear non-uniformity factor Φ and the ratio of shear non-uniformity factor Γ, were proposed. Response spectrum analysis and time history analysis on base-isolated split-foundation structures with varying Φ and Γ were conducted to investigate their seismic response and damping effect. The results indicate that Φ primarily affects the seismic response in the lower stories and the upper embedding story. When Φ is too small or too large, it results in an uneven isolation effect. Moreover, when the base shear ratio β z exceeds 0.5, the distribution of plastic hinges is significantly affected by the variations in Φ. Additionally, the story shear and story drift ratio of lower stories in the along-slope direction are generally greater than that of the corresponding story of the non-isolated structure. Therefore, in the seismic isolation design of the split-foundation structure, the base shear at different embedding ends should be reasonably assigned. Special attention should also be given to the adverse effects in the along-slope direction.

Simplified expression for transverse mode instability threshold in high power fiber lasers.

In this work, we propose an analytical expression for calculating the transverse mode instability (TMI) threshold power, which clearly shows the role of various fiber parameters and system parameters. The TMI threshold expression is obtained by solving the heat conduction equation and the nonlinear coupling equation using the fundamental mode fitted by Gaussian functions. The calculation results of the proposed TMI threshold expression are consistent with the experimental phenomena and simulation results from the well-recognized theoretical model. The influence of some special parameters on the TMI threshold and the power scaling is also investigated. This work will be helpful for fiber design and TMI mitigation of high-power fiber lasers.

DETERMINATION OF THE OPTIMAL TRAJECTORY OF THE MOVEMENT OF AIRCRAFT IN AREAS WITH COMPLEX TERRAIN UNDER THE CONTROL OF THE ENEMY

One of the main issues in the controlling of aircraft in difficult terrain during wartime is to ensure normal movement, but also to fulfill the requirements of evading enemy control. This paper proposes an improved ant swarm algorithm that makes it possible to pre-determine and optimize the trajectory of aircraft in such areas. When applying this method, a special parameter is included in the probability of choosing a movement trajectory – the height of the terrain above sea level, so that each ant does not enter territory controlled by the enemy. Using a 2D-H digital elevation map, the rectangular area under study is divided into 90 m × 90 m squares. To take into account the variability of the terrain, the heuristic function of the ant swarm algorithm takes into account the parameters of distance, height and smooth surface. Additionally, to reduce the number of iterations and computations, the ants are divided in half by number and released from the start and end points simultaneously. As a result, it allows you to choose the shortest and minimum trajectory among various calculated trajectories. To verify the effectiveness of the proposed scheme, a number of computational experiments were conducted. Experimental results on various simulated and real terrain maps show that this algorithm can be used to select an initial reference trajectory in difficult terrain.

Heterogeneous multistability and antimonotonicity for a new 3D system with a triple well nonlinearity: theoretical study, control and microcontroller implementation

We propose a new 3D autonomous multistable jerk-like system with a nonlinear term consisting of a six-order triple well function. The presence of six equilibrium points with symmetrical locations along the x-axis represents one of the main distinguishing properties of the new system. Strikingly, the stability analysis of equilibria reveals a cascade of Hopf bifurcations at three specific values of a single control parameter, which results in several forms of complexity. Accordingly, various forms of coexisting attractors such as stable fixed points, limit cycles of diverse periodicities, and chaotic attractors are depicted for some special parameter values. Moreover, It is found that the new jerk-like system with six order triple well polynomial function exhibit extremely complex nonlinear behaviors such as anti-monotone bifurcations, hysteresis and parallel bifurcation branches. These latter aspects explain the presence of multiple (i.e. up to four) coexisting asymmetric attractors for some special rank of parameters. In the presence of multiple competing dynamics, we resort to basins of attraction in order to highlight the how the state space is magnetized. The combination of dynamic features discussed in the new jerk-like system with triple well polynomials nonlinearity introduced in this article is unique and rarely reported. An electronic version of the new system with triple well polynomial nonlinearity is implemented in PSpice. Moreover, a hardware digital implementation of the system is also carried out using an Arduino microcontroller. A very good agreement is captured between PSpice simulation results, the laboratory measurements and the theoretical predictions.

New stability results for discrete-time switched systems under admissible edge-dependent average persistent dwell-time or admissible edge-dependent persistent dwell-time switching

This paper is devoted to the stability analysis of a class of discrete-time switched systems under newly designed switching regularities. The utilized switching is extended from the primitive mode-dependent persistent dwell-time switching. By integrating the existing admissible edge-dependent average dwell-time switching into the mode-dependent persistent dwell-time regime, a novel admissible edge-dependent average persistent dwell-time strategy involving the notion of admissible transition edges is proposed. The integrated admissible edge-dependent average dwell-time switching has been confirmed to be superior to mode-dependent average dwell-time switching. This superiority makes the proposed switching more general than the relaxed mode-dependent persistent dwell-time switching in the literature. Even if the embedded admissible edge-dependent average dwell-time restrictions degrade to admissible edge-dependent dwell-time ones under special parameter settings, the resulting admissible edge-dependent persistent dwell-time switching retains the advantage of admissible transition edges to generalize the original mode-dependent persistent dwell-time switching. Meanwhile, to remove the switching information reliance in the existing multiple convex Lyapunov functions, an improved multiple convex Lyapunov function method is devised. The designed Lyapunov function can be used to implement broader feasible ranges and tighter lower bounds of admissible edge-dependent average persistent dwell-time (or admissible edge-dependent persistent dwell-time). Finally, the validity and efficiency of the presented approaches are illustrated by a three-phase inverter and a numerical example.