Miracle-dz/UniFAR-FTUs huggingface dataset:
Deadbeat-Direct Torque and Flux Control of a Brushless Axial-Flux Magnetic-Geared Double-Rotor Machine for Power-Splitting HEVs

A deadbeat-direct torque and flux control (DB-DTFC) for brushless axial-flux magnetic-geared double-rotor machines (AMGDRMs) is presented in this article. The AMGDRM is employed as a power-splitting component in hybrid electric vehicles to enable speed decoupling between the internal combustion engine (ICE) and load. Since the rigid connection between the ICE and the drive train is replaced by the AMGDRM, fast torque control of the AMGDRM is required for the ICE speed regulation. Furthermore, the ICE torque contains abundant harmonics, inevitable sinusoidal components are introduced to the modulating rotor torque for torque balance, and further to the PM rotor torque owing to the magnetic-gear effect. Since both the PM rotor of the AMGDRM and the traction motor contribute to the hybrid electric system total torque output (i.e., torque coupling), the cascaded traction motor should compensate the PM rotor torque ripple actively to guarantee smooth total output torque. However, proportional-integral (PI) regulator suffers from limited bandwidth and thus could not realize accurate torque decoupling. Therefore, DB-DTFC, where torque and flux linkage are decoupled and respectively achieve their reference commands within two sampling periods, i.e., deadbeat responses, is proposed to enable a faster and more robust ICE speed control and accurate torque decoupling. The DB-DTFC law is derived and discrete-time close-loop current and flux linkage observers of the AMGDRM are developed. The proposed scheme and its superiorities are experimentally validated on an AMGDRM prototype test bench.
Some classification results for generalized q-gaussian algebras

To any trace preserving action $\sigma: G \curvearrowright A$ of a countable discrete group on a finite von Neumann algebra $A$ and any orthogonal representation $\pi:G \to \mathcal O(\ell^2_{\mathbb{R}}(G))$, we associate the generalized q-gaussian von Neumann algebra $A \rtimes_{\sigma} \Gamma_q^{\pi}(G,K)$, where $K$ is an infinite dimensional separable Hilbert space. Specializing to the cases of $\pi$ being trivial or given by conjugation, we then prove that if $G \curvearrowright A = L^{\infty}(X)$, $G' \curvearrowright B = L^{\infty}(Y)$ are p.m. p. free ergodic rigid actions, the commutator subgroups $[G,G]$, $[G',G']$ are ICC, and $G, G'$ belong to a fairly large class of groups (including all non-amenable groups having the Haagerup property), then $A \rtimes \Gamma_q(G,K) = B \rtimes \Gamma_q(G',K')$ implies that $\mathcal R(G \curvearrowright A)$ is stably isomorphic to $\mathcal R(G' \curvearrowright B)$, where $\mathcal R(G \curvearrowright A), \mathcal R(G' \curvearrowright B)$ are the countable, p.m. p. equivalence relations implemented by the actions of $G$ and $G'$ on $A$ and $B$, respectively. Using results of D. Gaboriau and S. Popa we construct continuously many pair-wise non-isomorphic von Neumann algebras of the form $L^{\infty}(X) \rtimes \Gamma_q(\mathbb{F}_n,K)$, for suitable free ergodic rigid p.m. p. actions $\mathbb{F}_n \curvearrowright X$.
Skew-monoidal reflection and lifting theorems

The Day Reflection Theorem gives conditions under which a reflective subcategory of a closed monoidal category can be equipped with a closed monoidal structure in such a way that the reflection adjunction becomes a monoidal adjunction. We adapt this result to skew monoidal categories. The beauty of this variant is further evidence that the direction choices involved in the skew notion are important for organizing, and adding depth to, certain mathematical phenomena. We also provide conditions under which a skew monoidal structure can be lifted to the category of Eilenberg-Moore algebras for a comonad.
Stabilization of fractional-evolution systems

This paper is devoted to the analysis of the problem of stabilization of fractional (in time) partial differential equations. We consider the following equation $$ \partial^{\alpha,\eta}_{t} u(t)=\mathcal{A}u(t)-\frac{\eta}{\Gamma (1-\alpha)}\int_{0}^{t}(t-s)^{-\alpha} \, e^{-\eta(t-s)}u(s)\, ds,\; t > 0, $$ with the initial data $u(0)=u^{0}$, where $\mathcal{A}$ is a unbounded operator in Hilbert space and $\partial_{t}^{\alpha,\eta}$ stands for the fractional derivative. We provide two main results concerning the behavior of the solutions when $t\longrightarrow+\infty$. We look first to the case $\eta>0$ where we prove that the solution of this problem is exponential stable then we consider the case $\eta=0$ when we prove under some consideration on the resolvent that the energy of the solution goes to $0$ as $t$ goes to the infinity as $1/t^\alpha$.
The twisted Kahler-Ricci flow

In this paper we study a generalization of the Kahler-Ricci flow, in which the Ricci form is twisted by a closed, non-negative (1,1)-form. We show that when a twisted Kahler-Einstein metric exists, then this twisted flow converges exponentially. This generalizes a result of Perelman on the convergence of the Kahler-Ricci flow, and it builds on work of Tian-Zhu.
Effect of Eggshell Powder and Nano-Hydroxyapatite on the Surface Roughness and Microhardness of Bleached Enamel

Background: The aim of the study was to evaluate the remineralizing potential of prepared solutions of eggshell powder (ESP) and nano-hydroxyapatite (nHA) on the surface roughness and microhardness of bleached enamel. Materials and Methods: Fifty bovine anterior teeth were selected and cleaned then bleached using a chemically activated in-office bleaching agent then the teeth were randomly allocated into five groups (n = 10) according to the tested remineralizing agents (10% ESP solution, 10% nHA solution, and MI Paste Plus) into; control, bleached, bleached + ESP solution, bleached + nHA solution, and bleached + MI Paste Plus groups. Then, the teeth were tested for surface roughness and microhardness of the bleached enamel, respectively. Results: There was a statistically significant difference in the surface roughness and microhardness values of the tested groups. The highest surface roughness mean value was found in bleached enamel group, while the least mean value was found in the control group. The highest mean microhardness value was found in the bleached enamel + ESP solution group, while the least mean value was found in the bleached enamel group. Conclusions: The application of the tested remineralizing agents following the bleaching procedure had improved the surface roughness and microhardness of the bleached enamel. ESP and nHA present promising and potent remineralizing agents.
Managing the quality of seeds from cereal conditioned with effective microorganisms (EM) and red light (RL)

The study pertained to environmentally-friendly methods in the cultivation of cereal, and aimed to manage the quality of rye and triticale seeds and determine the impact of seed conditioning using effective microorganisms (EM), red light (RL), and a combination of the two (RL × EM) on the yield of grain and straw. Moreover, the seeds were sown into soil with and without EM conditioning, designated as 0 and PEM. The yield fluctuations depended mostly on the studied rye and triticale cultivars. The best effects we observed in soil without EM conditioning for Dańkowskie Złote rye and Moderato triticale. The increase in grain and straw yields was, respectively: 26% (RL), 31% (RL × EM), 40% (EM), and 17% (RL × EM), 23% (RL), 32% (EM) – Dańkowskie Złote, 27% (RL × EM), 44% (EM), 46% (RL), and 17% (RL × EM), 51% (EM), 78% (RL) – Moderato. In turn, seeds exposed to the experimental treatment and sown into soil containing EM produced reduced yields in both of the above cultivars. It is noteworthy that the conditioning methods employed in the field experiment can facilitate increased yields but most importantly contribute to the resilience of agrosystems and can therefore have environmental benefits. It is noteworthy that the conditioning methods employed in the field experiment can facilitate increased yields but most importantly contribute to the resilience of agrosystems and can therefore have environmental benefits.
Dynamical degrees of birational transformations of projective surfaces

The dynamical degree lambda( f ) of a birational transformation f measures the exponential growth rate of the degree of the formulae that define the n -th iterate of f . We study the set of all dynamical degrees of all birational transformations of projective surfaces, and the relationship between the value of lambda( f ) and the structure of the conjugacy class of f . For instance, the set of all dynamical degrees of birational transformations of the complex projective plane is a closed and well ordered set of algebraic numbers.
The Impact of Active and Post-Labor Human Capital on the Value of Brazilian Companies

1. Autor de contato: SQNW 309, BLOCO K, APT. 621; SETOR NOROESTE; Brasília DISTRITO FEDERAL; CEP 70687155; Brasil A pesquisa teve como objetivo investigar os impactos das Despesas de Pessoal e de Benefícios Definidos (BD) no valor das empresas brasileiras. O estudo foi focado nas 29 companhias listadas no IBrX-100 com divulgações relativas a BD, entre 2013 e 2019 e utilizados dados em painel. Os achados apontam para relação positiva entre valor de mercado e Despesas de Pessoal possivelmente porque geram criação de valor para as entidades e relação negativa com os BD, provavelmente pelos riscos identificados levando os gestores ao congelamento ou substituição destes planos. autores
A Comprehensive Analysis of Metamaterial-Coupled WPT Systems for Low Electromagnetic Field Leakage

In this article, electromagnetic metamaterials with mu-near-zero (MNZ-MM) have been presented to explain the shielding effect in the wireless power transfer systems. First, the optimized design of the metamaterials unit cell has been carried on to achieve the near-zero permeability at the working frequency of 13.56 MHz. The equivalent circuit model of the MNZ-MM unit cell has been derived, which illustrates metamaterials with near-zero permeability have the great electromagnetic field (EMF) shielding effect. Additionally, the self- and mutual inductances associated with the resonance coils and MNZ-MM unit cells are deduced in detail. Moreover, the simplified human head model is established to investigate the magnetic field cancellation by MNZ-MM on the coil side. To evaluate the performance of the proposed MNZ-MM, the magnetic field strengths of the receiving terminal with different shielding materials have been compared in simulation. Finally, a series of experiments in real-environment are implemented to discuss the shielding effect of the MNZ-MM. The measurement results show the MNZ-MM has better performance in the swine brain sample than the ferrite and aluminum plate on the whole. With the proposed MNZ-MM, we demonstrate a maximum reduction of 17.52 dB in the leakage EMF and basically no effect on transfer efficiency.
Harmonic Current Control of OW-PMSM for Low-Voltage Traction by Nonlinear Disturbance Rejection With Improved Modulation Scheme

The open-winding permanent magnet synchronous motor (OW-PMSM) has been developed, mostly potential for low-voltage traction in electric vehicles. Yet, both the disturbance from vehicle system under driving and the motor with low-reactance (LR) feature expose the limits of traditional controllers that are prone to great current harmonics. Therefore, the current control for LR OW-PMSM becomes challenging. The main objective of this research is to provide a current harmonic control strategy for LR OW-PMSM by the nonlinear lumped disturbance observer (NLDO) combined with improved space vector modulation (SVM) scheme. The existence of nonlinear, unknown, unmodeled factors has been confirmed by current measurement and harmonic analysis in full operation range, and thus is considered in proposed controllers. The NLDO is designed for all the three axes under the dq0 frame. The SVM algorithm is adjusted to two switching patterns in order to get widened linear voltage modulation range. In addition, in the 3-D voltage space is the possible modulation area investigated. Ultimately, the target LR OW-PMSM has been designed, prototyped, and tested. The proposed NLDO, juxtaposed with ordinary PI and deadbeat controllers, reduces current harmonics on both the motor and inverter sides, possesses high robustness, and is practical for LR motors, according to experimental results.
First-order phase transitions in classical lattice gas spin models

The present paper considers some classical ferromagnetic lattice-gas models, consisting of particles that carry $n$-component spins $(n=2,3)$ and associated with a $D$-dimensional lattice $(D=2,3)$; each site can host one particle at most, thus implicitly allowing for hard-core repulsion; the pair interaction, restricted to nearest neighbors, is ferromagnetic, and site occupation is also controlled by the chemical potential $\ensuremath{\mu}$. The models had previously been investigated by mean field and two-site cluster treatments (when $D=3$), as well as grand-canonical Monte Carlo simulation in the case $\ensuremath{\mu}=0$, for both $D=2$ and $D=3$; the obtained results showed the same kind of critical behavior as the one known for their saturated lattice counterparts, corresponding to one particle per site. Here we addressed by grand-canonical Monte Carlo simulation the case where the chemical potential is negative and sufficiently large in magnitude; the value $\ensuremath{\mu}=\ensuremath{-}D∕2$ was chosen for each of the four previously investigated counterparts, together with $\ensuremath{\mu}=\ensuremath{-}3D∕4$ in an additional instance. We mostly found evidence of first-order transitions, both for $D=2$ and $D=3$, and quantitatively characterized their behavior. Comparisons are also made with recent experimental results.
Asymptotic analysis of the Ginzburg–Landau functional on point clouds

Abstract The Ginzburg–Landau functional is a phase transition model which is suitable for classification type problems. We study the asymptotics of a sequence of Ginzburg–Landau functionals with anisotropic interaction potentials on point clouds Ψn where n denotes the number data points. In particular, we show the limiting problem, in the sense of Γ-convergence, is related to the total variation norm restricted to functions taking binary values, which can be understood as a surface energy. We generalize the result known for isotropic interaction potentials to the anisotropic case and add a result concerning the rate of convergence.
A Crowd-Aided Vehicular Hybrid Sensing Framework for Intelligent Transportation Systems

In traditional practices of transportation system's constructions, traffic-related information is collected based on dedicated sensor networks, which are not only coverage-limited but also cost-consuming. With the enrichment of the concepts concerning “social sensors” and “social transportation”, Sparse Mobile Crowdsensing (MCS) is proposed to collect data from only a few subareas by recruiting participants with portable devices and to infer the data in unsensed subareas with acceptable errors. However, in real-world sensing campaigns, the Sparse MCS systems often fail to collect data from any subareas of interest since the assumption about sufficient participants is not always realistic. To be specific, the recruitment of participants is often limited by interest deficiency, privacy awareness, and distribution biases. To handle this problem, we introduce the dedicated sensing vehicles (DSVs) into traditional Sparse MCS to improve subarea coverage and inference performance. To achieve effective collaboration among DSVs and mobile users, we first design a crowd-aided vehicular hybrid sensing framework, which defines the order of task assignment for different participants as well as the budget allocation. In terms of DSVs route planning, we propose a three-step strategy, including optimal route searching, fused route selection, and final route determination. Moreover, mobile users are selected based on a novel selection strategy. Experimental findings on two real-world datasets validate the effectiveness (with less inference error) of the hybrid sensing framework, in comparison with the user-only/DSV-only framework and five baselines. Results reveal important implications of applying the hybrid sensing paradigm in intelligent transportation systems to enhance data collection
Twinlike models with identical linear fluctuation spectra

Recently, the possibility of so-called twinlike field theories has been demonstrated, that is, of different field theories which share the same topological defect solution with the same energy density. Further, purely algebraic conditions have been derived which the corresponding Lagrangians have to obey in order that the field theories be twins of each other. A further diagnostical tool which, in general, allows to distinguish the topological defects of a given theory from the corresponding defects of its twins is the spectrum of linear fluctuations about these defects. Very recently, however, explicit examples of twin theories have been constructed such that not only their shapes and energy densities coincide, but also their linear fluctuation spectra are the same. Here we show that, again, there exist purely algebraic conditions for the Lagrangian densities which imply that the corresponding field theories are twins and that the fluctuation spectra about their defects coincide. These algebraic conditions allow to construct an infinite number of twins with coinciding fluctuation spectra for a given theory, and we provide some explicit examples. The importance of this result is related to the fact that coinciding defects with coinciding energy densities and identical fluctuation spectra are almost indistinguishable physically, that is, indistinguishable in a linear or semiclassical approximation. This implies that the measurable physical properties of a kink, in general, do not allow to determine the theory which provides the kink uniquely. Instead, in principle an infinite number of possible theories has to be considered.
Vortices and Vermas

In three-dimensional gauge theories, monopole operators create and destroy vortices. We explore this idea in the context of 3d N=4 gauge theories in the presence of an Omega-background. In this case, monopole operators generate a non-commutative algebra that quantizes the Coulomb-branch chiral ring. The monopole operators act naturally on a Hilbert space, which is realized concretely as the equivariant cohomology of a moduli space of vortices. The action furnishes the space with the structure of a Verma module for the Coulomb-branch algebra. This leads to a new mathematical definition of the Coulomb-branch algebra itself, related to that of Braverman-Finkelberg-Nakajima. By introducing additional boundary conditions, we find a construction of vortex partition functions of 2d N=(2,2) theories as overlaps of coherent states (Whittaker vectors) for Coulomb-branch algebras, generalizing work of Braverman-Feigin-Finkelberg-Rybnikov on a finite version of the AGT correspondence. In the case of 3d linear quiver gauge theories, we use brane constructions to exhibit vortex moduli spaces as handsaw quiver varieties, and realize monopole operators as interfaces between handsaw-quiver quantum mechanics, generalizing work of Nakajima.
MEASURING TECHNOLOGICAL CAPABILITY AND BUSINESS PERFORMANCE POST-COVID ERA: EVIDENCE FROM SMALL AND MEDIUM-SIZED ENTERPRISES(SMEs) IN NIGERIA

The coronavirus pandemic has resulted in a significant shock to businesses, with negative implications on present production capacity. Simultaneously, technology is being increasingly recommended as a significant means of minimising economic losses caused by the pandemic. Survival and lack of performance of small and medium-sized businesses continue to generate public discourse, intellectual interest, and attention. Though relationship between technological capabilities and business performance is more intricate than is often assumed. Inadequate technological capability is one of the primary factors contributing to business situation. Therefore, relationship between technological capability (TC) and business performance was examined amongst selected small and medium-sized businesses in Lagos State. This study used a survey research methodology with a sample size of 742 owner-managers of chosen SMEs in Lagos State. A questionnaire that was adopted and validated for the study was used to collect data. The questionnaire questions' Cronbach's alpha coefficients range from 0.77 to 0.88. The response rate to the survey was 94.5 percent. Using descriptive and inferential statistics, the acquired data was analysed (Pearson product moment correlation and regression analysis). The examination of the data demonstrated a significant association between technological capacity and small company performance (= 0.090, t = 3.029, F= 245.45 p.05). The conclusion of this research is that technical aptitude is a resource that enhances the performance of small businesses, with theoretical and practical consequences for businesses. It is recommended that the managers of small and medium-sized enterprises (SMEs) in Lagos State use their technology capability as a business resource, since this could help them generate new ideas or enhance existing goods.
More Than 20 W, High Signal-to-Noise Ratio Single-Frequency All-Polarization-Maintaining Hybrid Brillouin/Ytterbium Fiber Laser

A high-power all-polarization-maintaining (PM) hybrid Brillouin/ytterbium fiber laser (BYFL) at 1064 nm is demonstrated by adopting large-mode-area fiber with core/cladding diameter of 20/400 µm as the hybrid gain medium. Single-frequency laser output with a record output power of 23 W and an excellent optical signal-to-noise ratio of 72 dB is achieved. The BYFL also presents linear-polarized operation with a polarization extinction ratio of over 16.5 dB, excellent output beam profile and long-term stability. Meanwhile, the relative intensity noise of the Brillouin pump laser is significantly reduced with a maximum factor of 36 dB by the BYFL at the high frequency range, while the corresponding frequency noise is reduced by 15–30 dB across the whole examined frequency range. In addition, the estimated laser linewidth was compressed by 7.8 times from 260 kHz to 33 kHz. To the best of our knowledge, this is the highest output power that emitted from any kind of single-frequency fiber lasers and Brillouin lasers. It is believed that the combination of the hybrid gains and larger mode area fiber provides a promising scheme for realizing further power scaling of a single-frequency laser with all-fiber configuration.
Fault-Tolerant Control of Autonomous Surface Vessels Subject to Steer Jamming for Harbor Returning

Steering jam is a common fault of autonomous surface vessels (ASVs) frequently encountered in practical operations. In such a scenario, the allowable ASV moving direction is confined to a narrow zone, which inevitably induces technical challenges for harbor-returning operations of ASVs. As a remedy, we propose a moving-direction fault-tolerant control method for steering jammed ASVs to return to harbors autonomously. We derive sufficient conditions to guarantee the asymptotical stability of the closed-loop ASV system. We elaborate on experimental results on a HUSTER-16 platform established by us to substantiate the effectiveness of the proposed method.