Method For Calculation Of Integrals Research Articles

Multiple stochastic and inverse stochastic resonances with transition phenomena in complex corporate financial systems.

This study examines the role of periodic information, the mechanism of influence, stochastic resonance, and its controllable analysis in complex corporate financial systems. A stochastic predator-prey complex corporate financial system model driven by periodic information is proposed. Additionally, we introduce signal power amplification to quantify the stochastic resonance phenomenon and develop a method for analyzing stochastic resonance in financial predator-prey dynamics within complex corporate financial systems. We optimize a simplified integral calculation method to enhance the proposed model's performance, which demonstrates superiority over benchmark models based on empirical evidence. Based on stochastic simulations and numerical calculations, we can observe multiple stochastic and multiple inverse stochastic resonances. Furthermore, variations in initial financial information, periodic information frequency, and corporate growth capacity induced stochastic resonance and inverse stochastic resonance. These variations also led to state transitions between the two resonance behaviors, indicating transition phenomena. These findings suggest the potential for regulating and controlling stochastic and inverse stochastic resonance in complex corporate finance, enabling controllable stochastic resonance behaviors.

A multipole fast asymptotic algorithm for a class of equations based on the flow function method with fractional order Laplace transform

As a mature and reliable method, this study is based on the flow function method for mathematical modeling and establishes a class of mathematical models that are approximately realistic, flexible, and easy to calculate. According to the characteristics of fractional order calculus, the initial boundary conditions are modified and optimized to reduce the model error of this class of equations. According to the minimum energy principle and linearized integral calculation method, the multi-field multi-parameter non-linear coupling problem in the calculation process is solved, and the rapid calculation of the initial boundary model is realized. The accuracy of the model is tested by numerical simulation and simulation validation of different processes. A reliable theoretical and technical support is provided for the calculation of this type of equations.

Shallow stability of soil slope with frame protection considering rainwater seepage: A calculation method

This paper introduces an integrated calculation method for analyzing the impact of frame protection engineering on the safety factor of shallow stability for soil slopes. The calculation method is based on the infinite long slope model, but it produces superior results by comprehensively taking into account the anti-sliding effect of the shallow slope sliding body. It combines the tension zone at the upper edge, the main sliding zone in the middle section, and the compression zone at the lower edge, while considering the anti-sliding force system of the frame protection structure and its contact surface with the soil. By converting the three-dimensional force system into a two-dimensional plane problem, an approximate calculation method for the shallow stability analysis of soil slopes with frame protection under rainfall seepage was established and numerically verified using the finite element method. The analysis indicates that the safety factor of the slope decreases significantly when seepage force is considered. As the length of the main sliding zone increases, the safety factor gradually decreases and approaches the result of the infinite long slope model. When the length decreases to zero, the safety factor gradually increases and approaches the result of the circular slip model. The use of frame protection significantly improves slope stability under rainfall seepage, and the safety factor increases with the number and embedded depth of the frame structure.

ЭКОЛОГИЧЕСКАЯ ОЦЕНКА СОСТОЯНИЯ ПОЧВ МЕТОДАМИ БИОИНДИКАЦИИ

Biotesting of soils in various districts of Bishkek was carried out. The sections of the western, eastern and southern parts of the city, characterized by different traffic congestion, were surveyed. Test cultures of freshwater crustaceans Daphnia magna and ciliates Paramecium caudatum were used to determine soil toxicity. Cultivation water was taken for control. The experiments were carried out in triplicate. The cultures were placed in a climatostat for 120 hours. The survival rate and sensitivity of test cultures were determined. Mathematical integral calculation methods were used to determine the degree of toxicity in the soil. Survival of bioindicator organisms varies from less toxic to acutely toxic to test systems. The cleanest area is the territory of the southern part of the city, in which there is a park area. The methods of bioindication of the state of soils used in this study make it possible to obtain preliminary reliable information on the state of soil ecosystems and are one of the aspects of the Triad approach in assessing environmental pollution.

Method and computer library for calculation of the Boltzmann collision integrals on discrete momentum lattice.

We present a general and numerically efficient method for calculation of collision integrals for interacting quantum gases on a discrete momentum lattice. Here we employ the original analytical approach based on Fourier transform covering a wide spectrum of solid-state problems with various particle statistics and arbitrary interaction models, including the case of momentum-dependent interaction. The comprehensive set of the transformation principles is given in detail and realized as a computer Fortran 90 library FLBE (Fast Library for Boltzmann Equation).

Risk management as a factor of adaptation of tourism and hotel business enterprises to crisis conditions

Introduction. The analysis of the situation in the field of development of the tourism industry allows us to conclude that the most acute problem that enterprise managers often face is the uncertainty and variability of the external environment and its threats, especially in the context of crisis phenomena. Both the level of prosperity of enterprises and the development of tourism in the country as a whole depend on the solution of this problem. Despite a significant number of publications devoted to the issue of risks, the specifics of the development of a risk management program in the tourism industry in the system of enterprise management strategy, as well as the issue of the methodology of their diagnosis and means of their minimization, have not been adequately covered in the literature. The purpose of the article is to study the specifics of risk management as a factor in the strategy of adaptation in the context of crisis phenomena and to develop recommendations for improving the tools of risk management at enterprises of the tourism industry. The method (methodology) of research includes a number of general scientific research methods, namely: the method of theoretical generalization, the abstract-logical method, and the method of grouping; the expert method and the integral calculation method were used in the implementation of empirical research. The results. As a result of the conducted research, elements of scientific novelty were obtained, which are as follows: a list of the main threats in the activities of tourism and hotel business enterprises was formed by spheres of occurrence, taking into account the factor of physical danger that exists during military operations; the risk management system is presented in a general form, which contributes to the prevention, identification and minimization of risks in the enterprise, and is a sequence of interconnected blocks; it is substantiated that one of the main elements in the risk management system is the block of risk diagnostics; the expediency of using expert risk diagnostics for tourism industry enterprises has been proven; an expert diagnosis of the risks of the tourist enterprise was carried out, which includes the assessment of individual criteria and the calculation of an integrated risk assessment. Taking into account the above, it is proposed to develop a risk management program using the specified toolkit with elements of its adaptation to today's crisis conditions in Ukrainian realities, for more effective monitoring of the results of the program implementation, it is proposed to divide it into two stages: preliminary selection of risks and final formation of the risk management program. Given the relevance and complexity of the problem, further in-depth research is needed to find means of early prediction and prevention of risks in order to minimize their negative impact on the financial results and market position of tourism industry enterprises. It is the reduction of the threat of risks to the operation of the enterprise that will contribute to the sustainability of the development of the tourism industry in general.

Метод пересчета результатов модельных испытаний гребного винта на натурные условия

Object and purpose of research. This paper discusses numerical method for simulation of propeller parameters in model and full-scale conditions. The purpose is to develop a similar methods for extrapolation of propeller model test data to the full-scale. Materials and methods. Propeller parameters are simulated as per the improved numerical method of E. Papmel. The flow around cylindrical section profiles of blades and hub is simulated as per the methods of boundary integral equations and integral calculation methods for the boundary layer with consideration of laminary-to-turbulent transition. Main results. Development of the method taking into account scale effect for propellers. The method has been applied to extrapolate model test data to the full scale. Conclusion. The method is of practical value for modern propeller design.

Multi-view imaging simulation of a space born TDI CCD camera and a 3D geometric reconstruction estimate

This paper proposes a multi-view imaging simulation method for a space-born TDI CCD camera, focusing on the integral time and satellite attitude calculation method of a TDI CCD camera when the imaging target is far away from the nadir point. The accuracy of the calculation method was verified by a target imaging simulation. Furthermore, a multiview stereo imaging simulation of a single camera was realized. Based on the high-precision three-dimensional (3D) building model and the simulation method, the simulation image was generated under various side swing angles and 3D angles. The generated building point cloud data was based on the belief propagation and graph-cuts stereo matching methods. Finally, we evaluated the impact of the side-view angle and stereo angle on the 3D reconstruction effects of the overall area and building façade based on the effective point percentage, root mean square, NMAD, and LE90.

An integral method for calculation of capillary pressure based on centrifuge data of tight sandstone

The traditional Hassler-Brunner (HB) interpretation method of centrifuge capillary pressure is widely used in materials, soil, biotechnology, and especially in the petroleum industry. However, the assumptions of the traditional method cannot be simultaneously satisfied, the traditional method has been known to lead significant errors in some cases. In this paper, a new double integral method is proposed to evaluate the centrifuge capillary pressure of long tight sandstone samples. Both the changes of capillary length and interface of wetting phase and non-wetting phase fluids are considered by the new integral method, thus the average pressure and saturation derived from the proposed double integral method is more sufficient in theoretic foundation and clearer on physical meaning. By comparing with the measured capillary pressure of long tight sandstone core samples from porous plate, the capillary pressure calculated from traditional HB method is obviously smaller than the measured value, and the discrepancy increases with the decreasing core porosity. However, the average capillary pressure obtained by the proposed double integral method is remarkably consistent with the measured value. The findings of this study can help for better understanding of distribution of wetting phase fluid and average centrifuge capillary pressure in the core during centrifugal process.

Performance Assessment of Thermoelectric Generators with Application on Aerodynamic Heat Recovery.

Based on thermoelectric generators (TEGs), an aerodynamic heat energy recovery system for vehicle is proposed. A mathematical model describing the energy conversion law of the system is established, and the integrated calculation method which combined aerodynamic heating and thermoelectric (TE) conversion is given. Furthermore, the influences of the typical flight Mach number, flight altitudes and the length of TE legs on the energy conversion behavior of energy recovery systems are investigated. The performance of the energy recovery system is analyzed and evaluated. The results show that, the decrease of flight altitude and the increase of Mach number will obviously improve the performance of the heat energy recovery system with TEGs. The increase of leg length will increase the temperature of the hot end of TEGs and reduce the heat absorbed at the hot end. When the external load, Mach number and flight altitude is fixed, there exists an optimal length of legs corresponding to the maximum output power and maximum conversion efficiency of the system. The results will have significant positive impact on thermal protection and management of supersonic/hypersonic vehicles.

Dissipation of energy analysis approach for vehicle plane motion stability

This paper proposes the dissipation of the energy analysis approach for vehicle plane motion stability analysis. The vehicle uses a three-degree-of-freedom vehicle model, and a unified tire-sideslip-angle model suitable for large tire-sideslip-angle and wheel reverse rotation conditions. Two calculation methods of total dissipation of energy are proposed: the integral calculation method and the energy difference calculation method. This paper analyses the system stability of the vehicle model, using the total dissipation of the energy indicator and compares the results with the Lyapunov exponent indicator. It shows that the dissipation of the energy analysis approach has a fast calculation speed, strong interpretability and high calculation accuracy, which can intuitively and quantitatively reveal the global stability characteristics of vehicle plane motion.

The comparison between integral and local calculation methods on the simulation of crystallization fouling

A local calculation method, based on the crystallization fouling model, is proposed to simulate the fouling process. Calcium carbonate crystallization fouling process occurring in a rectangular channel, with and without a vortex generator, is simulated by the integral and local calculation methods. The local calculation method is verified against the experimental data from the relevant literature. Fouling resistance obtained via local calculation method has shown stronger correlation with the experimental data as opposed to the integral calculation method. With an increase in the complexity of the channel structure, a greater distinction between the results obtained by the two methods is observed. The local calculation method has shown an advantage by providing the local fouling information, whereas the integral calculation method was unable to do so.

Speech as Noise Interference During a Mass Event

Participants of mass events are noise sources for surrounding area and perception of information. To rate the intelligibility of the signals of sound amplification systems and to design the instruments of the noise insolation, the methods of calculating the propagation of sound energy from distributed noise sources such as people are developed. Methods take into account features of the emission of sound energy by such sources. The features include time-varying acoustic and spatial characteristics of noise sources. They are associated with the random nature of the position and direction of noise emission from event visitors. The method of calculating the energy parameters of direct sound depends on the parameters of the noise source. The low density of people location implies to use the method of mathematical modeling, including the random position, orientation and duration of speech of noise sources. The increase in the mass character of events and the increase in the density of point noise sources are rational to use the integral calculation method. The numerical solution of the integral equation is implemented in a computer program and used for calculating the noise from fans of a football match at the stadium and adjacent urban development. The methods for calculating direct sound from distributed sources in the form of a circle, a circular sector and a rectangle are suggested on the basis of an analytical solution of integral expressions. Comparison of calculation results by developed methods and experimental data is performed. The discrepancy between the results in the most difficult situations doesn’t exceed ± 3 dB.

CuRCD: Region covariance descriptor CUDA implementation

Abstract Region covariance is a robust feature descriptor that allows the use of even the simplest image features like intensity and gradient combined to form a well-performing descriptor for regions on the image. Beyond its robustness, it requires many identical heavy computations on different parts of input data which makes it a good candidate for parallel execution. In this manuscript, we present a real-time parallel implementation of the region covariance which, to our best knowledge, is the first in the literature. We experimented against existing implementations and achieved 6 times faster execution time over vectorized CPU parallel implementation that provides necessary speed up for real-time processing. Additionally, we improved the existing integral image calculation method on CUDA, reducing memory usage by 50%, achieving the fastest computation speed compared to exist- ing solutions, and improved the covariance matrix comparison metric by using a distance metric that is lightweight to compute and easy to implement.

Performance Analysis of Non-uniform Sparse Segmentation Integral Method Based on Gauss Integral in EM Forward of Electrical Antenna Under Stratified Ocean

In order to solve the problem that it is difficult to take into account the computational efficiency and accuracy of electromagnetic field froward modeling of electrical antenna under the stratified ocean, evaluate the performance of two non-uniform sparse segmentation integral calculation methods based on Gauss integrals and improve the efficiency and accuracy of data interpretation in engineering applications, firstly two non-uniform sparse segmentation calculation methods based on Gauss integral nodes (Gauss-Legendre integral nodes and Gauss-Chebyshev integral nodes) are introduced. Then, two fast numerical integration methods corresponding of the time and frequency domain of the electrical antenna electromagnetic field under stratified ocean is established. Finally, by comparing and analyzing the results of the traditional uniform dense segmentation numerical integral calculation from the two aspects of computational accuracy and efficiency, the results show that two non-uniform sparse segmentation integral methods can improve the computational efficiency under the condition that the calculation accuracy is comparable, and the non-uniform sparse integral calculation method based on the Gauss-Chebyshev integral nodes is more significant than the calculation efficiency performance of the method based on the Gauss-Legendre integral node. At the same time, the general parameter setting of the non-uniform sparse segmentation integral method is given in this paper.

3D stem model construction with geometry consistency using terrestrial laser scanning data

ABSTRACT The traditional stem model is inconsistent with the real geometry of the stem. Terrestrial laser scanning (TLS) provides a possibility of constructing a realistic stem model. In this study, we present a 3D stem model, which includes the stem axis curve and stem cross-sectional profile curve, with geometrical consistency and stem parameter retrieval methods using TLS data. The 3D stem axis curve is interpolated based on the geometric central points, which are calculated from stem slices formed by stem cross-sections. From the 3D stem axis curve, the stem shape characteristic is clearly depicted in 3D space. Stem parameters, such as the location of a stem cross-section, stem diameter, height, length, curvature and torsion at any position along the stem, are calculated. The stem cross-sectional profile curve is interpolated based on the stem cross-sectional profile points, which are calculated from stem cross-sectional points by angle simplification. Then, the convex-concave characteristic of the stem cross-section is represented by the stem cross-sectional profile curve, and from this, the integral method for basal area calculation is presented. The presented methods were tested on stem points from different tree species with different shape properties. The feasibility and validity of the 3D stem model was demonstrated by 3D stem model visualization. The root mean square error (RMSE) of the presented stem diameter method was 0.129 cm. Compared with the basal area calculated from the cross-sectional profile curve, the mean absolute percentage error (MAPE) and RMSE values of the traditional method were 8.921% and 49.926 cm2, respectively. The stem parameter retrieval experiment demonstrated the accuracy and practicability of the 3D stem model. Compared with the traditional stem model, the 3D stem model can accurately represent the geometric structure of the stem and provide accurate calculations of stem parameters. It will help improve the applications of TLS in forestry inventories.

Criteria for Assessing Optimal Distribution of Ore/Coke Ratio Along Blast Furnace Radius

The distribution of the ore/coke ratio along the radius of a furnace is currently estimated by a change in two criteria, i.e., the proportion of CO used and the temperature of the blast furnace gas. Although this approach provides only a qualitative representation, changes are made to the load programs on this basis, which may result in less than optimal decision-making and deterioration in performance. To determine the optimal distribution of the ore/coke ratio, in this study, we selected additional known criteria that characterize the reduction and thermal energy processes of the gas stream, which more accurately reflect the influence of changes in the ore/coke (O/C) ratio on the course of blast-furnace smelting. Several easily calculated criteria are adopted to characterize the thermal and reduction processes, namely the carbon consumed to meet thermal needs Ct, the change in the ratio of the water equivalents Wg/Wb along the throat radius, the proportion of CO used (ηCO), and the temperature of the blast furnace gas (Tbfg). As a result, we obtained a single integrated calculation method for assessing the optimal distribution of O/C that includes these four criteria. Based on the analysis of these criteria, we make recommendations regarding the optimal distribution of O/C along the radius of the blast furnace.

Analytical evaluation of relativistic molecular integrals: III. Computation and results for molecular auxiliary functions

This work describes the fully analytical method for calculation of the molecular integrals over Slater-type orbitals with non-integer principal quantum numbers. These integrals are expressed through relativistic molecular auxiliary functions derived in our previous paper [Phys. Rev. E 91, 023303 (2015)]. The procedure for computation of the molecular auxiliary functions is detailed. It applies both in relativistic and non-relativistic electronic structure theory. It is capable of yielding highly accurate molecular integrals for all ranges of orbital parameters and quantum numbers.

Analysis of effects of boundary conditions on CFD calculation results -From the viewpoint of wake integral drag calculation method

Analysis of effects of boundary conditions on CFD calculation results -From the viewpoint of wake integral drag calculation method

Numerical Determination of the Secondary Acoustic Radiation Force on a Small Sphere in a Plane Standing Wave Field.

Two numerical methods based on the Finite Element Method are presented for calculating the secondary acoustic radiation force between interacting spherical particles. The first model only considers the acoustic waves scattering off a single particle, while the second model includes re-scattering effects between the two interacting spheres. The 2D axisymmetric simplified model combines the Gor’kov potential approach with acoustic simulations to find the interacting forces between two small compressible spheres in an inviscid fluid. The second model is based on 3D simulations of the acoustic field and uses the tensor integral method for direct calculation of the force. The results obtained by both models are compared with analytical equations, showing good agreement between them. The 2D and 3D models take, respectively, seconds and tens of seconds to achieve a convergence error of less than 1%. In comparison with previous models, the numerical methods presented herein can be easily implemented in commercial Finite Element software packages, where surface integrals are available, making it a suitable tool for investigating interparticle forces in acoustic manipulation devices.