bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exact densities of loops in O(1) dense loop model and of clusters in critical percolation on a cylinder: II. Rotated lattice
Authors: Povolotsky A M 
Published: March 2023

Abstract
This work continues the study started in Povolotsky (2021 J. Phys. A: Math. Theor.
54 22LT01), where the exact densities of loops in the O(1) dense loop model on an infinite strip of the square lattice with periodic boundary conditions were obtained. These densities are also equal to the densities of critical percolation clusters on the 45∘ rotated square lattice rolled into a cylinder. Here, we extend those results to the square lattice with a tilt. This in particular allows us to obtain the densities of critical percolation clusters on the cylinder of the square lattice of standard orientation extensively studied before. We obtain exact densities of contractible and non-contractible loops or equivalently the densities of critical percolation clusters, which do not and do wrap around the cylinder, respectively. The solution uses the mapping of O(1) dense loop model to the six-vertex model in the Razumov–Stroganov point, while the effective tilt is introduced via the inhomogeneous transfer matrix proposed by Fujimoto. The further solution is based on the Bethe ansatz and Fridkin–Stroganov–Zagier’s solution of Baxter’s T–Q equation. The results are represented in terms of the solution of two explicit systems of linear algebraic equations, which can be performed either analytically for small circumferences of the cylinder or numerically for larger ones. We present exact rational values of the densities on the cylinders of small circumferences and several lattice orientations and use the results of high precision numerical calculations to study the finite-size corrections to the densities, in particular their dependence on the tilt of the lattice.
Superfluid dynamics, equilibrium conditions, and centripetal forces
Authors: Liu Mario 
Published: March 2023

Abstract
Thermodynamics of superfluids is revisited, clarifying two points. First, the density and pressure distribution for given normal and superfluid velocities is obtained, with the finding that counter heat currents give rise to a pressure depression and a centripetal force. Second, it is shown that the ideal two-fluid hydrodynamics is simply an assembly of equilibrium conditions—expressions of entropy being maximal.
Strain fields and critical phenomena in manganites II: spin-lattice-energy Hamiltonians
Authors: Singh Rohit , Puri Sanjay 
Published: March 2023

Abstract
The dynamic critical behavior at the paramagnetic-antiferromagnetic (PM-AFM) transition in manganites has recently been studied experimentally (Niermann et al 2015 Phys. Rev. Lett.
114 037204). We extend the Hamiltonian of paper I by incorporating an energy field, and study the corresponding Model C of critical dynamics. We use the dynamic renormalization group approach and calculate the dynamic critical exponents z,

ν
z

and the line-width exponent Δ to leading order in the small expansion parameters

ϵ
=
4
−
d
+
2
σ

and

ϵ

′

=
4
−
d

. Here, d is the space dimension and σ is the long-range exponent. Using σ as an adjustable parameter, the theory gives us a good match to the experimentally available static and dynamic critical exponents at the PM-AFM transition.
An Inverse Source Problem for A One-dimensional Time-Space Fractional Diffusion Equation
Authors: Lin Rixin , Li Yushan , Nong Linshuzhen 
Published: March 2023

AbstractFor the fractional diffusion equation, it has received extensive study from various angles on the inverse problem. This paper is dedicated to determining a source term with time-dependence of the time-space fractional diffusion equation with additional observation data. First, the implicit difference scheme and the matrix transfer technique are used to solve an initial boundary value direct problem, in which the time-space fractional diffusion equation for the homogeneous Dirichlet boundary condition is considered. For the conclusive solution of the given inverse source problem, a numerical method is proposed based on the optimal perturbation algorithm with optimized Tikhonov regularization. The numerical examples illustrate that our proposed numerical method is highly effective and relatively stable.
Fast Numerical Solution of a Kind of Nonlinear Integral Equations—Dyson-Schwinger Equations for Quark Propagator in Hadron Physics
Authors: Huang Jinghui , Hu Xiangyun , Chen Huan , Duan Xueying , Wang Guangjun 
Published: March 2023

Abstract
The nonlinear integral equation has been widely studied and has become the heart of the matter in many scientific and engineering fields, such as seismology, optical fiber evolution, radio astronomy, and hadron physics with Quantum Chromodynamics. The Dyson-Schwinger Equations (DSEs) approach provides an essential nonperturbative approach to investigating the properties of hadrons and hot/dense quark matter. Mathematically, the Dyson-Schwinger Equations are a group of coupled nonlinear integral equations of quark propagators, gluon propagators, ghost propagators, and various vertices. On account of the non-linearity and singularity of the coupled equations, it is almost impossible to solve the DSEs analytically. One has to resort to the numerical solution of the equations, in which efficient fast algorithms are key points in practice. In this work, two improvements for numerically solving the nonlinear and singular integral equation for quark propagator in a vacuum are proposed. One is a modified interpolation method for unknown functions in the integral with high degrees of freedom. The other is the parallelization on CPUs with OpenMP in GCC Comparing the CPU times with different algorithms, our results indicate that our proposed methods can greatly improve the efficiency and reduce the computation time of the CPU.
Fractals and Finite Distributions of Power Sets
Authors: Zheng Haosen , Li Xiaopei 
Published: March 2023

Abstract
In this paper, we are committed to investigating the fractal decomposition of power sets. Our main result is that every power set can be decomposed into a sum of a power set and an isomorphic set that does not intersect with it. For the finite power set, this property can be drawn on the ordinal line by constructing the fractal number axis of the ordinal line, and the fractal distribution and fractal graph of the finite power set can be obtained by using the parallel translation drawing method. Moreover, the distributions do not overlap or cross. The results in this paper provide a new perspective for further investigation of the fractal distribution of power sets.
Research on Applicability and Efficient Construction with Typical Surrogate Models
Authors: Wang Puyi , Fan Tianfeng , Wang Liguo , Zhou Jiayong , Ning Yanping 
Published: March 2023

Abstract
Surrogate models (SMs) are generally employed in expensive engineering optimization and uncertainty quantification. At present, it is still one of the hot topics for researchers to construct high-performance SMs with limited resources. By comparing the predicted errors of the typical functions, this work intends to obtain the applicability of typical SMs and the count of the necessary experimental samples for efficiently constructing SMs. In detail, representative test functions such as Branin-Hoo, Camelback, Godlstein-Price, Hartman, ZDT3 and ZDT4 are approximated by the models such as PRS, RBF, GP, NN and SVR. The predicted indicators such as R2, RMSE and MAE under multiple groups of experimental samples are discussed by cross-validation. Finally, the applicability of typical SMs and the count of experimental samples in DOE are given, and the conclusion might be a reference for constructing high-performance SMs and an ensemble of SMs.
Smooth Transition of Safety Controllers Filtered by Control Barrier Functions
Authors: Li Shilei , Yuan Zhimin , Ye Qing , Sun Yuhui , Wang Dong , Li Meng 
Published: March 2023

Abstract
Recently, control barrier functions (CBFs), are becoming popular and widely used as a safety-filter of the controller through quadratic programming(QP) optimization framework to ensure the forward invariance of the dynamic systems. However, for sequential safety tasks, the transitions of CBFs are required. To avoid control input discontinuities, firstly, a smooth and speed adjustable transition mechanism by adding a time-varying coefficient of different CBFs is proposed. Moreover, the value of the previous CBF constraint is fixed to reduce the change of the combined CBF constraint. Secondly, a method to integrate different sequential CBFs into a synthetic new one is presented. Through these methods, the smoothness of optimized control inputs can be ensured compared with existing formulations. Simulation results demonstrate that our algorithm provides a smoother transition mechanism to switch different CBFs, and improves the control performance consequently.
A New Method of Solving Fuzzy Linear Systems
Authors: Chen Fanhong , Han Yuanliang , Shao Zejun 
Published: March 2023

AbstractIn this text, our work focuses on fuzzy linear systems where the number of rows and columns of the left correlation coefficient matrix are not equal. A method to handle a wider range of these systems is introduced by our selected more general definition of fuzzy values. Different expressions for the result are obtained based on generalized inverses for different types of the left-hand side expanded matrix. Finally, we verified our method with five cases where the fuzzy values were defined in a more general range. These cases show that the method is simple and effective whether the equations are consistent or not.
A Novel Method of Efficient Max-min Metric for Classification
Authors: Du Mo , Li Shu , Li Qiang 
Published: March 2023

Abstract
Distance metric learning is an important method to study distance metrics that reflect the interaction between features and labels. Because of the high computational complexity and the fact that existing studies on algorithms that measure the similarities with Euclidean distances cannot reflect the real correlations between pairs of samples, learning a suitable distance metric is quite demanding for many data mining tasks. This paper innovatively proposes an extended efficient max-min metric (EMM) that maximizes the total distance between different pairs and minimizes the total distance between similar pairs as much as possible. Simultaneously, the adoption of the local preserving projection framework changes the solution process of the algorithm and improves the speed of the algorithm without losing accuracy. Because traditional EMM only considers pairwise constraints and ignores sample distribution, this study extends EMM based on sample distribution and successfully solves the multi-manifold problem. In the process of data realization, compared with the vector representation method, the use of high-order tensors will make the image representation more accurate and natural. To maintain the structure of higher-order tensors, a tensor-efficient max-min metric (TEMM) is proposed. In order to prove the accuracy and superiority of the research method in this paper, a large number of experiments have been carried out on image processing. The experimental results show that the method proposed in this paper has a good effect.
Global Topology Concept Neighborhood Graph and Its Application in Topological Similarity Measurement
Authors: Cheng Mianmian , Sun Qun , Chen Huanxin , Yang Na , Xing Zhibin , Meng Yao 
Published: March 2023

Abstract
A topological relationship is a key factor in the spatial data processing. Aiming at the problem of topological similarity measurement when the dimension of spatial objects changes in the process of map generalization, this paper proposes a topological similarity measurement method based on the global topological concept neighborhood graph. Firstly, all the topological relationships that can be described by the nine intersection model are abstracted, generalized, and classified, and the classified point/point, point/line, point/polygon, line/line, line/polygon, and polygon/polygon local topological concept neighborhood graphs are established. Then, according to the map generalization rules, the mapping between different types of topological concept neighborhood graphs is established, and the global topological concept neighborhood graph is obtained, Finally, the similarity of the topological relationship between different morphological objects is measured. The experimental results show that the proposed method can better meet the topological similarity measurement when the shape of spatial objects changes.
Study on Vibration Characteristics of Hydraulic Pipes in Case of Internal Pulsating Fluid Excitation
Authors: Zhou Zhi-jin , Liu Ai-jun , Zhou Li-ying 
Published: March 2023

Abstract
The influence of transverse external periodic force on the fluid-structure interaction vibration of hydraulic pipe was researched. Through stress analysis on the pipe under the effect of internal flow, the Bernoulli-beam model in the paper was selected. The equation of fluid-structure interaction vibration was established. By comparing the simulation results of load and no load the transverse external periodic force, a length of hydraulic pipe was analyzed using ansys cfx. The results were shown that the transverse external periodic force strengthened the hydraulic oil’s pressure fluctuation of the pipe internal and the fluid-structure interaction vibration.
Numerical Method of Propulsion Concept: Partially Cut Multiaperture Stick Propellant
Authors: Xue Shao , Wang Hao , Cheng Shenshen 
Published: March 2023

Abstract
The partially cut Multiaperture stick propellant is a new concept charging structure. In this paper, in order to accurately obtain the change and development process of the two-phase flow field in different stages of the whole interior ballistic process in this propulsion concept system, a coupled calculation model of computational interior ballistic is established, which converts the Euler-Lagrange method to the Euler-Euler method. Firstly, at the initial stage of ignition, the Euler-Lagrange method is used to describe the flow field. During this period, the gas phase is based on Euler coordinates, while the solid phase is based on Lagrangian coordinates. After the projectile starts, the partially cut Multiaperture stick propellant is fractured into granular propellant. The flow field is converted to describe by the Euler-Euler method by using the initial mapping method. Finally, by comparing the calculated results with the experimental results, the maximum pressure error is only 0.54%, which verifies the accuracy and effectiveness of the coupling calculation method. It effectively captures the distribution of the physical parameters in the combustion chamber, providing a new research method for the computational interior ballistic of the propulsion concept. Based on this method, the pressure distribution in the propulsion concept system is obtained, and no obvious shock waves and expansion waves are seen, indicating that the charge scheme of partially cut Multiaperture stick propellant can improve launch safety.
Simulation of an Adaptive Model Based on AIC and BIC ARIMA Predictions
Authors: Zhang Ying , Meng Gong 
Published: March 2023

Abstract
ARIMA model forecasting algorithm is a commonly used time series forecasting algorithm, this paper first obtains a stable sequence through differential operation, and then obtains a stable sequence from the AR model, as the MA model, and even the ARIMA model. Select the appropriate model for prediction and use it for adaptive mode model design. In the field of machine learning, the complexity of the model is likely to increase, while the accuracy of the model improves, and the models with a complex structure usually cause the following overfitting problem. In order to balance the complexity and the accuracy of the model reasonably, using appropriate indicators AIC (Akaike Information Criterion), as well as BIC (Bayesian information criterion), to make the judgments, which is achieved by eliciting penalty terms in the paper, and the established ARIMA (1,1,2) model meets the requirements.
Mathematical Modeling of GM (1, 1) Polymorphic Management Based on Dormant System
Authors: Zhang Ying , Peng Di 
Published: March 2023

Abstract
In this paper, a GM(1, 1) polymorphic management prediction algorithm based on a dormant system is proposed, which first obtains the optimal data quantity m through simulation, and then the data used is forecasted only once, and the input data will be updated to the latest data immediately after the prediction is completed, and then the parameter estimates will be recalculated for the next prediction. The simulation results show that the MRE value of the optimized GM (1, 1) is 0.090, which has much better MRE values for GM (1, 1) algorithms that are not optimized. At the same time, other commonly used algorithms in the industry are compared horizontally. In contrast, the optimized GM (1, 1) algorithm responds quickly, has high prediction accuracy, short prediction time, and consumes fewer resources.
Unsupervised Abnormal Transaction Order Detection Method Based on Deep Learning Time Factor
Authors: Wang Cheng , Jin Cheng 
Published: March 2023

Abstract
Abnormal transaction order detection plays an important role in identifying transaction data changes and abnormal transaction behaviors of users. The existing abnormal order detection methods have low generalization ability in different transaction time series, and the exception itself has a variety of patterns. In addition, the positive sample points with a large proportion carry much more information than the abnormal sample points, which will cause the classifier to be disturbed in the learning process and inaccurate classification. The research proposes an unsupervised abnormal transaction order detection method based on the depth learning time factor. By processing the original data column, the first feature sequence is obtained, and then the later feature sequence is trained through the depth learning model. The abnormal order is detected by comparing the differences between the two feature sequences. The results show that the research effectively solves the practical problem of too few abnormal transaction samples, can be applied to the transaction process of different modes, reduces the noise in the original transaction data, and has obvious improvement in each evaluation index compared with the traditional method.
A Study of the Purely Azimuthal Passive Positioning Problem of UAVs
Authors: Zhao Jianqiang , Hu Wei , Dong Zirui , Kang Liwen 
Published: March 2023

Abstract
In order to maintain electromagnetic silence and avoid external interference, UAV clusters usually use purely azimuthal passive positioning methods to adjust the position of UAVs when attempting formation flights. However, due to the large number of UAVs flying in formation, it is difficult to perform effective localization, although they can keep flying at an altitude based on their own sensors. Therefore, this paper establishes a passive positioning model based on the triangulation method under the condition of pure azimuthal passive positioning, solves the coordinates of the UAV position of the received signal by using the least squares problem, and designs the UAV position adjustment scheme by using the optimal scheduling model based on the immune-genetic algorithm, so as to improve the positioning accuracy and survivability of the UAV.
Multi-objective Optimization Design of Solar UAV Overall Parameters
Authors: Hou Yingyu , Ji Chen , Liu Ziqiang 
Published: March 2023

Abstract
Based on the design background of solar UAV, this paper introduces the characteristics of this kind of UAV, such as high flying height, large wingspan, large structural deformation and low wing load. The mathematical model of multi-objective optimization for this type of UAV is established, and the multi-objective genetic algorithm is used to optimize the design. The optimization results of the aircraft design are obtained by computer. Finally, the summary parameters and basic design drawings of this kind of aircraft are given. The results show that multi-objective optimization can be used in the design of solar UAV, and the optimal combination of the overall parameters of this kind of UAV can be obtained to avoid design defects and improve design efficiency. After the optimization design, the overall performance of the aircraft has been improved. This method has a certain reference value for the design of new aircraft.
Simulation and Majorization of Multi-source Relatively Complemented Heating System Based on TRNSYS
Authors: Lv Haotian , Liu Jingxia , Yang Peihong , Li Baoli 
Published: March 2023

Abstract
In order to make up for the shortcomings of solar energy, ground source heat pump as well as air source heat pump during heating, a new multi-complementary heating system with three heat sources is proposed. Take the Tumeteyouqi item as the object of study for program devise and load simulation on the basis of the set scheme, and TRNSYS hybrid heating system is established. The main parameters of the air source heat pump and the solar collector are optimized, and the hooke-Jeewes and Coordinate descent optimization algorithms are used to optimize the annual value of system costs, and the two algorithms are compared. Results are included the Collector area of 80m2, the Collector of 42.1875 ° inclination, Azimuth Angle of 10°. The unit area is homologous and the volume of the water box is 0.10125. The capacity of the water tank is 8.1 m3, and the heat quantity of the air source heat pump is 286200kj/h. The system reaches the optimum, and the annual value of the heating cost is reduced by 3.8%. Then the supply heating cost is reduced by 4.96%. The Hooke-Jeewes algorithm is superior to the Coordinate descent algorithm.
Design of an Airborne γ-ray Spectrometry System Based on Unmanned Aerial Vehicle
Authors: Jia Xu , Qin Guoxiu , Li Fan , Zhao Guozhi 
Published: March 2023

Abstract
An airborne γ-ray spectrometry system that can be installed on an unmanned aerial vehicle (UAV) was designed to satisfy the requirements of radioactive mineral exploration and environmental radiation monitoring. The system consists of an airborne measurement device and a ground control platform. The airborne measurement device includes a γ-ray spectrum survey instrument, the main controller, data and graph transmission module. The ground control platform integrates the data and graph transmission module, industrial computer, energy spectrum analysis and processing software. Field flight tests showed that the data collected by the system were stable and reliable, and the survey results were consistent with existing data. The designed system can be applied to small-scale radioactive geological surveys, environmental surveys, and radioactive pollution monitoring.