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We present a numerical method for learning the dynamics of slow components of unknown multiscale stochastic dynamical systems. While the governing equations of the systems are unknown, bursts of observation data of the slow variables are available. By utilizing the observation data, our proposed method is capable of constructing a generative stochastic model that can accurately capture the effective dynamics of the slow variables in distribution. We present a comprehensive set of numerical examples to demonstrate the performance of the proposed method. [ABSTRACT FROM AUTHOR]

The first-order input and output edge transfer matrix elements of the magnetic sector in a static mass spectrometer are derived based on the conservation law of the generalized momentum of ions in a magnetic field. The structure of the edge matrix is shown to be ambiguous and dependent on the effective model, which considers the displacement of ion trajectories in the edge field. A comparison of the results obtained with traditional methods, such as expanding the edge field components and trajectory equations into asymptotic series and integrating successive approximations, reveals significant differences in the first-order edge matrix elements in the effective model of the magnetic sector, where the ideal uniform field is bounded by Herzog boundaries, compared to the published data. Algorithms for matching the input and output axes of the magnetic sector, taking into account the action of the edge fields, are given. [ABSTRACT FROM AUTHOR]

Background: In Iran, the medical education system was integrated with the healthcare provision system in 1985 and finally, it led to the creation of a new ministry titled “Ministry of Health and Medical Education”. Regarding this integration has created some problems, the current study intended to provide an effective pattern for improvement of this integration. Methods: The present study is both fundamental and applied in terms of objective. The statistical population of the client study included all of the managers, faculty members and experts in the universities of medical sciences in Khuzestan Province, in southwestern Iran, who were chosen by the use of full census sampling. Finally, 103 people filled in the questionnaires. The data collection instrument was a researcher-devised questionnaire. The data analysis was done by SPSS Ver.24, the descriptive statistics (percentage, mean, and standard deviation), and the inferential statistics (Pearson Correlation Test). Results: In order to increase the effectiveness of this integration, four scenarios were suggested among which, finally “the separation of the medical education from the medical sciences universities and placing under direct supervision of the Minister of Health and Medical Education” with 3.84 (based on a maximum score of 4) achieved the highest score. Based on this score, a model based on the upstream laws of Iran was designed and suggested and in each province, instead of having a unit and independent institution under the title of the university of medical sciences and healthcare services, two separate institutions as “The Provincial University of Medical Sciences” and “The Provincial Health Service Organization” would be created and would work under the supervision of Minister of Health and Medical Education. Conclusion: The results of this study showed that medical education in the health ministry supervised universities is affected by the discussions of the provision of the health and medical care provision. Therefore, to realize it and improve the educational tasks, production of knowledge, and conducting of research in the universities, and protecting it from other departments, an effective pattern has been suggested.

We study the non-linear supersymmetric hyperbolic sigma model H2/2 on a complete graph with hierarchical interactions. For interactions which do not decrease too fast in the hierarchical distance, we prove tightness of certain spin variables in horospherical coordinates, uniformly in the pinning and in the size of the graph. The proof relies on a reduction to an effective H2/2-model; its size is logarithmic in the size of the original model. [ABSTRACT FROM AUTHOR]

The article is devoted to the «tomographic» approach to the interpretation of geopotential fields. A brief excursus into the history of the development of interpretational (pseudo-) tomography is given. General issues concerning the creation of «effective» tomographic models are considered. Transformations based on the equivalent source technique are proposed as a key part of the tomography. This type of transformations permits the usage of elevation data of magnetic survey as input. When constructing an analytical approximation, usually a system of linear algebraic equations (SLAE) with an approximated right part is solved. Using a model example, some issues concerning the conditionality of SLAE for different depths of equivalent sources are studied. Two iterative methods for the solving of systems, the Seidel method and the quickest gradient descent, are compared. It is shown that the latter method makes it possible to achieve the required accuracy of the field approximation with a smaller number of iterations. The advantage in the calculation speed, when the matrix of coefficients of the transform operator (source function) is sparce, is emphasized. An example of using this approach to interpret magnetic field anomalies above the submarine volcano 3.18 within the Kuril Iceland arc is presented.

This study aims to compare the Food and Agriculture Organization (FAO) framework as a common model and gene expression programming (GEP) model for predicting the irrigated wheat production by using land properties in Khajeh area, Iran. First, 80 representative soil profiles were described in wheat fields. Then, the soil samples were collected from each horizon, and soil properties were determined in the laboratory for obtaining the model input data. After that, wheat production models were developed by FAO and GEP models. Sensitivity analysis indicated that total N, available P, slope, coarse fragment, electrical conductivity, pH, and organic matter are important soil properties for wheat production. Based on the results, the value of predicted wheat production by GEP model (981–5382) is closer to the actual production (1000–5600) compared to the FAO models (1284–6123). The geometric mean error ratio (GMER), root mean square error (RMSE), and coefficient of determination (R2) between predicted and actual production for FAO and GEP models were calculated 1.24, 18.6, and 0.84 and 0.83, 15.4, and 0.91, respectively. The overall agreement was recognized between wheat predicted production by using FAO and GEP and actual production by composite operator. This agreement was 71.5 and 82.2% for FAO and GEP models, respectively. Therefore, gene expression programming model was introduced as an effective model for predicting the wheat production. This more accuracy was obtained due to good choosing and lack of interaction among land properties as input variables. [ABSTRACT FROM AUTHOR]

We study theoretically and numerically the occurrence of Fano resonances in a metagrating made of slits with some symmetry breaking resulting in a dual period. At low frequency, a grating composed of long enough slits supports Fabry-Pérot resonances on which Fano resonances superimpose when the grating acquires dual period. The resulting spectrum exhibits flat-banded peaks interrupted by sharp dips with successions of perfect and zero transmissions. To model these scattering properties, homogenization theory is used resulting in an effective problem governing the solutions in the two, non-identical, slits, which are coupled through jump conditions at the grating interfaces. These jumps efficiently encode the effect of the evanescent field able to resonate in the radiative region due to the folding of the spoof plasmon polaritons branches. The model is validated with direct numerics and a local analysis allows us to characterize the resonant mechanisms. [ABSTRACT FROM AUTHOR]

The article presents an analytical review of Russian and foreign approaches to understanding internal financial control. Different opinions of economists on the methods and tasks of internal financial control have been studied. As the main trend of the study of internal financial control, the strengthening of the role of the system approach is called. The article examines the main domestic models of internal control (indicative, effective, risk-oriented) and provides a comparative analysis of international models of internal control (COSO, COBIT, Ternbull Rewiev Group, KonTraG). The article concluded that it is necessary to increase the effectiveness of the internal control system through a risk-based model. The analysis of approaches to understanding this concept allowed to form a theoretical basis for studying the issues of practical formation of the internal control system.

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Background: In In, the medical education system was integrated with the healthcare provision system in 1985 and this was led to the creation of a new ministry titled "Ministry of Health and Medical Education". Regarding this integration, some problems were emerged. Therefore, the current study intended to provide an effective pattern for improvement of this integration. Methods: The present study is both fundamental and applied in terms of its objectives. The statistical population of the client study included all of the managers, feculty members, and experts in the universities of medical sciences in Khuzestan Province, in Southwest Inn, who were chosen by the use of foil census sampling. Finally, 103 participants filled in the questionnaires. The data collection instrtiment was a researcher-devised questionnaire. The data analysis was done by SPSS Ver. 24, the descriptive statistics (percentage, mean, and standard deviation), and the inferential statistics (Pearson Correlation Test). Results: In order to increase the effectiveness of this integration, four scenarios were suggested among which, finally "the separation of the medical education from the medical science universities and placing under direct supervision of the Ministry of Health and Medical Education" with 3.84 (based on a maximum score of 4) achieved the highest score. Based on this score, a model based on the upstream laws of Iran was designed and suggested and in each province, instead of having a tinit and independent instittition under the title of the university of medical sciences and healthcare services, two separate institutions as "The Provincial University of Medical Sciences" and "The Provincial Health Service Organization" would be created and would work under the supervision of Ministry of Health and Medical Education. Conclusion: The results of this sttidy showed that medical education defined by the Ministry of Health is affected by the discussions of medical care provisions. Therefore, to realize it and improve the educational tasks, producing knowledge, conducting research in the universities, and protecting it from other departments, were suggested as effective patterns. [ABSTRACT FROM AUTHOR]

A neuron's firing correlates are defined as the features of the external world to which its activity is correlated. In many parts of the brain, neurons have quite simple such firing correlates. A striking example are grid cells in the rodent medial entorhinal cortex: their activity correlates with the animal's position in space, defining 'grid fields' arranged with a remarkable periodicity. Here, we show that the organization and evolution of grid fields relate very simply to physical space. To do so, we use an effective model and consider grid fields as point objects (particles) moving around in space under the influence of forces. We reproduce several observations on the geometry of grid patterns. This particle-like behavior is particularly salient in a recent experiment in which two separate grid patterns merge. We discuss pattern formation in the light of known results from physics of two-dimensional colloidal systems. Notably, we study the limitations of the widely used 'gridness score' and show how physics of 2d systems could be a source of inspiration, both for data analysis and computational modeling. Finally, we draw the relationship between our 'macroscopic' model for grid fields and existing 'microscopic' models of grid cell activity and discuss how a description at the level of grid fields allows to put constraints on the underlying grid cell network. [ABSTRACT FROM AUTHOR]

In this paper we analyze for the first time the γN Δ excitation vertex from the point of view of the dynamics of the Δ field, Ψ μ. That is, we look for the value of the Z parameter, present in all contact invariant Δ-field interaction Lagrangians and usually regarded as redundant, and shift it to contact background non-Δ resonant amplitudes (in this sense it is called "redundant") by imposing that the Ψ 0 has no dynamics, instead of readjusting the background coupling constants. We do this within an unitarized model that comprises the Δ-direct amplitude plus background contributions including the Δ-cross term, nucleon Born and meson exchange ones, already implemented in previous works of πN scattering, photo-production and weak- π production. Also we analyze the use of a πN Δ decay vertex interaction containing both first (I 1) and second (I 2) order derivative contributions, as required by renormalization and power counting considerations, in building the γ N → Δ → π N amplitude, in contrast with other works where only I 1 or I 2 is adopted. It is shown that the description of the γ N → π N process, following these prescriptions, is improved. This is a first step: we plan to introduce final state interactions (FSI) in the future, following our previous work in which FCI were introduced using the I 1 interaction alone. [ABSTRACT FROM AUTHOR]

Due to advances in computer hardware and new algorithms, it is now possible to perform highly accurate many-body simulations of realistic materials with all their intrinsic complications. The success of these simulations leaves us with a conundrum: how do we extract useful physical models and insight from these simulations? In this article, we present a formal theory of downfolding–extracting an effective Hamiltonian from first-principles calculations. The theory maps the downfolding problem into fitting information derived from wave functions sampled from a low-energy subspace of the full Hilbert space. Since this fitting process most commonly uses reduced density matrices, we term it density matrix downfolding (DMD).

We clarify the two-channel Kondo effect in the seven-orbital Anderson model hybridized with Γ 8 conduction electrons by employing a numerical renormalization group method. From the numerical analysis for the case with two local f electrons, corresponding to Pr 3 + or U 4 + ion, we confirm that a residual entropy of 0.5 log 2 , a characteristic of two-channel Kondo phenomena, appears for the local Γ 3 non-Kramers doublet state. For further understanding on the Γ 3 state, the effective model is constructed on the basis of a j - j coupling scheme. Then, we rediscover the two-channel s - d model concerning quadrupole degrees of freedom. Finally, we briefly introduce our recent result on the two-channel Kondo effect for the case with three local f electrons. [ABSTRACT FROM AUTHOR]

Field models with extra spatial dimensions have a larger Lorentz symmetry which is broken down to the standard four-dimensional one by the compactification process. By considering Lorentz violating operators in a 5D supersymmetric Wess-Zumino model, which otherwise conserve the standard four-dimensional Poincaré invariance, we show that supersymmetry (SUSY) can be restored upon a simple deformation of the supersymmetric transformations. However, SUSY is not preserved in the effective 4D theory that arises after compactification when the 5D Lorentz violating operators do not preserve bulk parity. Our mechanism unveils a possible connection among Lorentz violation and the Scherk-Schwarz mechanism. We also show that parity preserving models, on the other hand, do provide well defined supersymmetric KK models. [ABSTRACT FROM AUTHOR]

Inspired by the construction of the Gribov–Zwanziger action in the Landau gauge, we introduce a quark model exhibiting both confinement and chiral symmetry aspects. An important feature is the incorporation of spontaneous chiral symmetry breaking in a renormalizable fashion. The quark propagator in the condensed vacuum turns out to be of a confining type. Besides a real pole, it exhibits complex conjugate poles. The resulting spectral form is explicitly shown to violate positivity, indicative of its unphysical character. Moreover, the ensuing quark mass function fits well to existing lattice data. To further validate the physical nature of the model, we identify a massless pseudoscalar (i.e. a pion) in the chiral limit and present estimates for the ρ meson mass and decay constant. [ABSTRACT FROM AUTHOR]

Cloud computing has increasingly been drawing attention these days. Each big company in IT hurries to get a chunk of meat that promises to be a whopping market in the future. At the same time, information is always associated with security and risk problems. Nowadays, the handling of these risks is no longer just a technology problem, with a good deal of literature focusing on risk or security management and framework in the information system. In this paper, we find the specific business meaning of the BMIS model and try to apply and leverage this model to cloud risk. Through a previous study, we select and determine the causal risk factors in cloud service, which are also known as CSFs (Critical Success Factors) in information management. Subsequently, we distribute all selected CSFs Into the BMIS model by mapping with ten principles in cloud risk. Finally, by using the leverage points, we try to leverage the model factors and aim to make a resource-optimized, dynamic, general risk control business model for cloud service providers. [ABSTRACT FROM AUTHOR]

We investigate the possibility of spatially inhomogeneous chiral and Cooper, or superconducting, pairing in the (1+1)-dimensional model by Chodos et al. [ Phys. Rev. D 61, 045011 (2000)] generalized to continuous chiral invariance. The consideration is performed at nonzero values of temperature T and quark number chemical potential μ. In the framework of the Fulde-Ferrel inhomogeneity ansatz for chiral and Cooper condensates, we show that if G1>G2, where G1 and G2 are the coupling constants in the quark-antiquark and diquark channels, then in the (μ, T)-phase diagram the superconducting phase is suppressed by spatially inhomogeneous chiral spiral phase with broken chiral symmetry. In contrast, in the above mentioned original Chodos et al. model, where only the opportunity for homogeneous condensates is taken into account, the superconducting phase is realized at sufficiently high values of μ at arbitrary values of G2>0, including the interval 0

With an effective chiral flavour SU(3) model we show the effect of hadronic resonances on the QCD phase diagram. We state that varying the resonance couplings to the scalar and vector fields affects the order and location of the phase transition, the possible existence of a critical end point (CEP), and the thermodynamic properties. We present (strange) quark number susceptibilities at zero baryochemical potential and at three different points at the phase transition. Comparing results to lattice QCD, we state that reasonable large vector couplings limit the phase transition to a smooth crossover ruling out a CEP. [ABSTRACT FROM AUTHOR]

Properties of the 1S0 superfluid phase are studied for symmetric nuclear matter at finite temperature. It is described within a covariant hadronic field model, of the σ-ω type, with addition of density dependent correlations simulating effects due to finite extension of nucleons. The model is solved in a self-consistent Hartree-Bogoliubov approach, assuming instantaneous interactions in the superfluid phase. A comparison with the results obtained from several hadronic field models is made. Main characteristics of our description of the superfluid gap are in qualitative agreement with some studies using microscopic potentials, although further refinements could improve its performance. [ABSTRACT FROM AUTHOR]

We study the consequences of the presence of a negative electric charge condensate of antikaons in neutron stars using an effective model with derivative couplings. In our formalism, nucleons interact through the exchange of σ, ω and ϱ mesons, in the presence of electrons and muons, to accomplish electric charge neutrality and beta equilibrium. The phase transition to the antikaon condensate was implemented through the Gibbs conditions combined with the mean-field approximation, giving rise to a mixed phase of coexistence between nucleon matter and the antikaon condensate. Assuming neutrino-free matter, we observe a rapid decrease of the electron chemical potential produced by the gradual substitution of electrons by kaons to accomplish electric charge neutrality. The exotic composition of matter in neutron star including antikaon condensation and nucleons can yield a maximum mass of about Mns ~ 1.76 M⊙. [ABSTRACT FROM AUTHOR]

We propose a new method for the homogenization of hysteresis models of plasticity. For the one-dimensional wave equation with an elasto-plastic stress-strain relation we derive averaged equations and perform the homogenization limit for stochastic material parameters. This generalizes results of the seminal paper by Franců and Krejčí. Our approach rests on energy methods for partial differential equations and provides short proofs without recurrence to hysteresis operator theory. [ABSTRACT FROM AUTHOR]

The effective behaviour of stationary micromagnetic phenomena is modelled by a convexified Landau–Lifshitz minimization problem for the limit of large and soft magnets Ω with no exchange energy. The numerical simulation of the resulting minimization problem has to overcome difficulties caused by the pointwise side-constraint $$|\bf{m}|\leq 1$$ and the stray-field energy on the unbounded domain $$\mathbb{R}^{d}$$ . A penalty method models the side-constraint and the exterior Maxwell equation is recast via a nonlocal integral operator $$\mathcal{L}$$ . This paper gives an overview of the available results and implementational details. [ABSTRACT FROM AUTHOR]

On-line educators and institutes are still trying to figure out how best to use web-based technology as a way of delivering courses and how web-based tools and learning activities, such as discussion boards, e-mail, group projects, virtual chats, and interaction with classmates and instructor, influence students' learning. The study proposed an effective model for designing instructional materials and measuring quality of web-based courses in the Industrial Management Master online program. The research data were gathered from 137 students in eleven online courses between 2003-2006. An online questionnaire was utilized in measuring students' satisfaction of instructor's performance, instructional material design, technology and activities used, and supported services. Key components that on-line course developers and educators can use in their pedagogical process of Internet-based environments to promote student satisfaction and learning effectiveness are instructional and design strategies, instructor's performance, use of web-based technology and activities, student participation, and supported services. [ABSTRACT FROM AUTHOR]

In the framework of an effective derivative-coupling model with scalar and vector mesons coupled to the octet of baryons and leptonic degrees of freedom, we have calculated in detail the nuclear property known as the compressibility function, using the mean-field theory formalism and taking into account chemical equilibrium, baryon number and electric charge conservation. The parameters of the model are chosen in order to reproduce phenomenology: an effective nucleon mass between 0.7–0.8 MN and a compression modulus between 200–300 MeV. [ABSTRACT FROM AUTHOR]

Abstract: The effective behaviour of stationary micromagnetic phenomena is modelled by a convexified Landau–Lifshitz minimization problem for the limit of large and soft magnets Ω without the exchange energy. The numerical simulation of the resulting minimization problem has to overcome difficulties caused by the pointwise side-restriction ∣m∣⩽1 and the stray field energy on the unbounded domain . A penalty method models the side-restriction and the exterior Maxwell equation is recast via a nonlocal integral operator . As shown in [Numer. Anal. Macrosc. Model Micromagnet, submitted for publication; Analysis, Numerik und Simulation eines Relaxierten Modellproblems zum Mikromagnetismus, doctoral thesis, Vienna University of Technology, 2003], the discretization leads to a nonlocal problem with piecewise constant ansatz and test functions and (dense) stiffness matrices with closed form formula for their entries. This paper addresses the numerical solution with Newton–Raphson schemes and the scientific computation of effective micromagnetic simulations. [Copyright &y& Elsevier]

The past decade has witnessed a surge of interest in exploring emergent particles in condensed matter systems. Novel particles, emerged as excitations around exotic band degeneracy points, continue to be reported in real materials and artificially engineered systems, but so far, we do not have a complete picture on all possible types of particles that can be achieved. Here, via systematic symmetry analysis and modeling, we accomplish a complete list of all possible particles in time-reversal-invariant systems. This includes both spinful particles such as electron quasiparticles in solids, and spinless particles such as phonons or even excitations in electric-circuit and mechanical networks. We establish detailed correspondence between the particle, the symmetry condition, the effective model, and the topological character. This obtained encyclopedia concludes the search for novel emergent particles and provides concrete guidance to achieve them in physical systems., (Copyright © 2021 Science China Press. Published by Elsevier B.V. All rights reserved.)