Miracle-dz/UniFAR-FTUs huggingface dataset:
An x-ray extensional flow cell

We have designed an x-ray extensional flow cell based on the crossed-slot geometry that is compatible with x-ray diffraction. Extensional flow within the cell was both confirmed and characterized by examining the trajectories of small latex spheres suspended in water via video microscopy. The cell was then used to examine extensional-flow-induced structural changes in a well-known lamellar surfactant system, and the alignment of the surfactant domains was observed to increase with increasing extension rate.
Inverse Problems under Sarmanov dependence structure

Consider a sequence $\{(X_{i}, Y_{i})\}$ of independent and identically distributed random vectors, with joint distribution bivariate Sarmanov. This is a natural set-up for discrete time financial risk models with insurance risks. Of particular interest are the infinite time ruin probabilities $P\left[\sup_{n \geq 1}\sum_{i=1}^{n} X_i \prod_{j=1}^{i}Y_{j} > x\right]$. When the $Y_{i}$'s are assumed to have lighter tails than the $X_{i}$'s, we investigate sufficient conditions that ensure each $X_{i}$ has a regularly varying tail, given that the ruin probability is regularly varying. This is an inverse problem to the more traditional analysis of the ruin probabilities based on the tails of the $X_{i}$'s. We impose moment-conditions as well as non-vanishing Mellin transform assumptions on the $Y_{i}$'s in order to achieve the desired results. But our analysis departs from the more conventional assumption of independence between the sequences $\{X_{i}\}$ and $\{Y_{i}\}$, instead assuming each $(X_{i}, Y_{i})$ to be jointly distributed as bivariate Sarmanov, a fairly broad class of bivariate distributions.
Vector Valued Maximal Carleson Type Operators on the Weighted Lorentz Spaces

In this paper, by using the idea of linearizing maximal op-erators originated by Charles Fefferman and the TT* method of Stein-Wainger, we establish a weighted inequality for vector valued maximal Carleson type operators with singular kernels proposed by Andersen and John on the weighted Lorentz spaces with vector-valued functions.
Trace of broken integrability in stationary correlation properties

We show that the breaking of integrability in the fundamental one-dimensional model of bosons with contact interactions has consequences on the stationary correlation properties of the system. We calculate the energies and correlation functions of the integrable Lieb-Liniger case, comparing the exact Bethe-ansatz solution with a corresponding Jastrow ansatz. Then we examine the non-integrable case of different interaction strengths between each pair of atoms by means of a variationally optimized Jastrow ansatz, proposed in analogy to the Laughlin ansatz. We show that properties of the integrable state are more stable close to the Tonks-Girardeau regime than for weak interactions. All energies and correlation functions are given in terms of explicit analytical expressions enabled by the Jastrow ansatz. We finally compare the correlations of the integrable and non-integrable cases and show that apart from symmetry breaking the behavior changes dramatically, with additional and more pronounced maxima and minima interference peaks appearing.
Multiplicative Nambu structures on Lie groupoids

We study some properties of coisotropic submanifolds of a manifold with respect to a given multivector field. Using this notion, we generalize the results of Weinstein \cite{wein} from Poisson bivector field to Nambu-Poisson tensor or more generally to any multivector field. We also introduce the notion of Nambu-Lie groupoid generalizing the concepts of both Poisson-Lie groupoid and Nambu-Lie group. We show that the infinitesimal version of Nambu-Lie groupoid is the notion of weak Lie-Filippov bialgebroid as introduced in \cite{bas-bas-das-muk}. Next we introduce coisotropic subgroupoids of a Nambu-Lie groupoid and these subgroupoids corresponds to, so called coisotropic subalgebroids of the corresponding weak Lie-Filippov bialgebroid.
Spectral analysis of a selected non self-adjoint Hamiltonian in an infinite dimensional Hilbert space

The so-called equation of motion method is useful to obtain the explicit form of the eigenvectors and eigenvalues of certain non self-adjoint bosonic Hamiltonians with real eigenvalues. These operators can be diagonalized when they are expressed in terms of pseudo-bosons, which do not behave as ordinary bosons under the adjoint transformation, but obey the Weil-Heisenberg commutation relations.
A Unified Framework for Multiscale Modeling using the Mori-Zwanzig Formalism and the Variational Multiscale Method

We describe a paradigm for multiscale modeling that combines the Mori-Zwanzig (MZ) formalism of Statistical Mechanics with the Variational Multiscale (VMS) method. The MZ-VMS approach leverages both VMS scale-separation projectors as well as phase-space projectors to provide a systematic modeling approach that is applicable to non-linear partial differential equations. Spectral as well as continuous and discontinuous finite element methods are considered. The framework leads to a formally closed equation in which the effect of the unresolved scales on the resolved scales is non-local in time and appears as a convolution or memory integral. The resulting non-Markovian system is used as a starting point for model development. We discover that unresolved scales lead to memory effects that are driven by an orthogonal projection of the coarse-scale residual and inter-element jumps. It is further shown that an MZ-based finite memory model is a variant of the well-known adjoint-stabilization method. For hyperbolic equations, this stabilization is shown to have the form of an artificial viscosity term. We further establish connections between the memory kernel and approximate Riemann solvers. It is demonstrated that, in the case of one-dimensional linear advection, the assumption of a finite memory and a linear quadrature leads to a closure term that is formally equivalent to an upwind flux correction.
Convergence of incremental adaptive systems

In this paper, incremental adaptive mechanisms are presented and characterized, to provide design hints for the development of continuous-time adaptive systems. The comparison with the conventional integral adaptive systems indicates that the suggested design methodology will be a supplement to the existing ones. With the aid of a Barbalat-like lemma, convergence results of the incremental adaptive systems are established. It is shown that the proposed adaptive mechanisms are able to work well in handling parametric uncertainties in systems undertaken.
The topological trees with extremal Matula numbers

Denote by $p_m$ the $m$-th prime number ($p_1=2,~p_2=3,~p_3=5,~ p_4=7,~\ldots$). Let $T$ be a rooted tree with branches $T_1,T_2,\ldots,T_r$. The Matula number $M(T)$ of $T$ is $p_{M(T_1)}\cdot p_{M(T_2)}\cdot \ldots \cdot p_{M(T_r)}$, starting with $M(K_1)=1$. This number was put forward half a century ago by the American mathematician David Matula. In this paper, we prove that the star (consisting of a root and leaves attached to it) and the binary caterpillar (a binary tree whose internal vertices form a path starting at the root) have the smallest and greatest Matula number, respectively, over all topological trees (rooted trees without vertices of outdegree $1$) with a prescribed number of leaves -- the extreme values are also derived.
A Note on Minimal Senders

In this paper we prove that if a pair of graphs G,H have senders, then they necessarily have connected minimal senders; we also prove that given two fixed graphs that are either 3-connected or triangles there are minimal (G,H)-senders with arbitrarily distant signal edges and (G,H)-minimal graphs with arbitrarily large cycles, thus showing there is no upper bound for the diameters of (G,H)-minimal graphs.
Feedforward control using the higher‐harmonic, time‐averaged gradient descent algorithm

A unique approach to adaptive feedforward control, namely the higher‐harmonic time‐averaged gradient descent algorithm (H‐TAG), is presented. As opposed to the more common adaptive feedforward control method based on the filtered‐x LMS algorithm, H‐TAG does not require a measure of the control to error sensor transfer function for the system. Thus if the system dynamics change during the control process, H‐TAG will simply adapt to the new optimal control configuration, rendering the approach model insensitive. Until now, work presented on the H‐TAG algorithm has been limited to a single‐input, single‐output theoretical simulation. This paper describes the additional considerations involved in implementing the algorithm on an actual complex laboratory model (a de Havilland Dash 7 turbo‐prop fuselage) that has multiple inputs and multiple outputs. Results from this preliminary experimental study suggest that the H‐TAG algorithm is a viable alternative for adaptive feedforward control of systems with slowly .
Compact forms of homogeneous spaces and higher-rank semisimple group actions

This paper proves that there are no compact forms for a large class of homogeneous spaces admitting actions by higher-rank semisimple Lie groups. It builds on Zimmer's approach for studying such spaces using cocycle superrigidity. The proof involves cocycle superrigidity, measure rigidity for unipotent flows, techniques from partially hyperbolic dynamics, and the geometry and pseudo-Riemannian structure of the homogeneous space.
Feature tracking from an image sequence using affine invariance and Hough transform

Feature point tracking from an image sequence is an important step in many methods of image understanding including shape from motion and mobile robot navigation. Assuming an affine camera model, this paper proposed a new tracking method using affine invariance. Any 3D feature point can have unique coordinates with reference to an affine basis and the affine coordinates are invariant to affine transformation: camera rotations and translations. The images of a set of 4 control points defining an affine basis are tracked in an image sequence using a conventional method. Under this assumption, given a feature point in any image, its locus in the first image is a straight line. The straight lines of the corresponding features from the image sequence will intersect at a point, the corresponding feature point, in the first image. A Hough transform technique is designed to detect this intersection point and track the corresponding feature points in the image sequence. This technique is suitable for tracking a large number of feature points. Its performance is practically unaffected by missing features in some images and large motion steps. Accurate and reliable results had been obtained in real experiments using the method.
Arithmetic differential equations on $GL_n$, II: arithmetic Lie theory

Motivated by the search of a concept of linearity in the theory of arithmetic differential equations we introduce here an arithmetic analogue of Lie algebras and a concept of skew arithmetic differential cocycles. We will then construct such skew cocycles, based on certain remarkable lifts of Frobenius for the classical groups $GL_n, SL_n, SO_n, Sp_{n}$. The theory for $GL_n$, especially on the Galois side, will be further developed in a sequel to this paper.
Coherent states for a polynomial su(1, 1) algebra and a conditionally solvable system

In a previous paper (2007 J. Phys. A: Math. Theor. 40 11105), we constructed a class of coherent states for a polynomially deformed su(2) algebra. In this paper, we first prepare the discrete representations of the nonlinearly deformed su(1, 1) algebra. Then we extend the previous procedure to construct a discrete class of coherent states for a polynomial su(1, 1) algebra which contains the Barut–Girardello set and the Perelomov set of the SU(1, 1) coherent states as special cases. We also construct coherent states for the cubic algebra related to the conditionally solvable radial oscillator problem.
Influence of flexoelectric effects on multiferroic nanocomposite thin bilayer films

The flexoelectric effect, which describes the induction of polarization from strain gradient, is negligible in bulk but not nanometer scale ferroelectrics. The influence of flexoelectric effects on magnetic field induced electric polarizations in multiferroic nanocomposite thin bilayer films has been investigated. It has been found that with flexoelectric effects taken into consideration, the polarization would not be reduced to zero even if the film was ultra-thin. Under an applied magnetic field, polarizations were induced from two effects, i.e., the conventional electrostrictive and flexoelectric effects. In the case where the film thickness was relatively large, the former factor was the main one influencing the magnetic field induced polarization. By decreasing the film thickness, the flexoelectric induced polarization became more and more dominant and it finally overcame the electrostrictive induced polarization and changed the value of magnetic field induced polarization from negative to positive.
Coherent noise-free ophthalmic imaging by spectral optical coherence tomography

In this contribution we examine a methodology to avoid parasitic cross-correlation terms in spectral optical coherence tomography (SOCT) images. The optimal conditions of optical power and exposure time are found theoretically and confirmed experimentally to ensure that parasitic images are hidden under the shot noise. An upper limit on useful exposures may then be estimated. In a case of SOCT imaging of the retina this limit is below the ANSI safety limit.
Norms in motivic homotopy theory

If $f : S' \to S$ is a finite locally free morphism of schemes, we construct a symmetric monoidal "norm" functor $f_\otimes : \mathcal{H}_{\bullet}(S')\to \mathcal{H}_{\bullet}(S)$, where $\mathcal{H}_\bullet(S)$ is the pointed unstable motivic homotopy category over $S$. If $f$ is finite étale, we show that it stabilizes to a functor $f_\otimes : \mathcal{S}\mathcal{H}(S') \to \mathcal{S}\mathcal{H}(S)$, where $\mathcal{S}\mathcal{H}(S)$ is the $\mathbb{P}^1$-stable motivic homotopy category over $S$. Using these norm functors, we define the notion of a normed motivic spectrum, which is an enhancement of a motivic $E_\infty$-ring spectrum. The main content of this text is a detailed study of the norm functors and of normed motivic spectra, and the construction of examples. In particular: we investigate the interaction of norms with Grothendieck's Galois theory, with Betti realization, and with Voevodsky's slice filtration; we prove that the norm functors categorify Rost's multiplicative transfers on Grothendieck-Witt rings; and we construct normed spectrum structures on the motivic cohomology spectrum $H\mathbb{Z}$, the homotopy $K$-theory spectrum $KGL$, and the algebraic cobordism spectrum $MGL$. The normed spectrum structure on $H\mathbb{Z}$ is a common refinement of Fulton and MacPherson's mutliplicative transfers on Chow groups and of Voevodsky's power operations in motivic cohomology.
Solitons and polarons in polyacetylene: Self-consistent-field calculations of the effect of neutral and charged defects on molecular geometry

Semiempirical self-consistent-field calculations are carried out on various polyenes with emphasis on defect configurations designed to simulate soliton and polaron excitations in polyacetylene. For 0 defect-free polyenes, the calculated bond-length alternation (Dr=0.106 A) is in close agreement with generally accepted values for polyacetylene. Solitons and polarons are simulated on polyene radicals, ions, and radical ions by the introduction of appropriate symmetries and by charging; these are viewed as neutral (radical) and charged (cation and anion) defects in the polyene structure. The equilibrium geometries and charge distributions of varying-length polyenes and defect-containing polyenes are calculated. The extent of disruption of the bond-length alternation pattern of the carbon backbone is predicted to be about half as large as previously thought for neutral defects (solitons) and even smaller for anionic defects. Positively charged solitons are of larger extent. These results are consistent with known conductivity —doping-level relationships. A spatially damped charge-density wave is associated with the charged solitons and a spin-density wave with the neutrals; in both cases the wave extends farther than the lattice kink itself. Polarons and bipolarons, studied as soliton-antisoliton pairs (radical cations and radical anions) on the same model molecule, are also found to exhibit charge-density-wave solutions. The bipolaron is shown to be unstable to the formation of a like-charge soliton-antisoliton pair. Strong interchain coupling is expected as a result of the large dipole moments associated with the unique form of the lattice polarization due to the damped charge-density wave in charged solitons and polarons.
Control of unstable mechanical system Control of pendulum

This paper relates to the design of a control system for a mechanical system which contains an unstable mode and to an experiment for demonstrating that the control theory may be applied to practical real systems. In this paper the object treated is the control of the pendulum-cart system, which has been studied by many control theorists and engineers as an inverted pendulum problem, and a composite control system is designed not only to stabilize the inverted pendulum but to swing the pendulum from the natural pendent position up to the inverted position, which is actually made. The experimental results are presented.
Nodal area distribution for arithmetic random waves

We obtain the limiting distribution of the nodal area of random Gaussian Laplace eigenfunctions on $\mathbb{T}^3= \mathbb{R}^3/ \mathbb{Z}^3$ ($3$-dimensional 'arithmetic random waves'). We prove that, as the multiplicity of the eigenspace goes to infinity, the nodal area converges to a universal, non-Gaussian, distribution. Universality follows from the equidistribution of lattice points on the sphere. Our arguments rely on the Wiener chaos expansion of the nodal area: we show that, analogous to (Marinucci, Peccati, Rossi and Wigman, 2016), the fluctuations are dominated by the fourth-order chaotic component. The proof builds upon recent results in (Benatar and Maffiucci, 2017) that establish an upper bound for the number of non-degenerate correlations of lattice points on the sphere. We finally discuss higher-dimensional extensions of our result.
Ulysses observations of short‐period (≤30 Days) modulation of the galactic cosmic rays

A frequency analysis of the short‐period modulation of the GCR as seen by instruments aboard Ulysses shows interesting temporal variations. In particular, during an approximate five‐month period from December 1993 to May 1994, the modulation was not the usual 26 days but more than 29 days. The CIR‐associated MeV ions did not exhibit this period shift.
Blur identification in super-resolution restoration with Arnoldi process

The point spread function (PSF) parameters of the imaging system are not often known a prior in super-resolution enhancement applications. In our super-resolution algorithm, we identify the PSF and regularization parameters from the raw data using the generalized cross-validation method (GCV). Motivated by the success of GCV in identifying optimal smoothing parameters for image restoration, we have extended the method to the problem of estimating blur parameters. To reduce the computational complexity of GCV, we propose efficient approximation techniques based on the Arnoldi process. The Arnoldi process can yield a small and condensed Hessenberg matrix which is orthogonal bases of the Krylov subspaces. Experiments are presented which demonstrate the effectiveness and robustness of our method.
Magnetic reconnection in the disc and halo

This paper presents some new ideas about magnetic fields in the interstellar medium. Movements due to the galactic fountain are analysed and interpreted in terms of their implications for a frozen-in interstellar magnetic field. We find that magnetic field lines will be drawn up into the halo (or thick disc) by expanding hot gas and, in falling back to a different position, there will be tangling and reconnecting effects. Also, under certain circumstances, a new sort of field amplification may occur in parts of the interstellar medium
Measuring the exciton diffusion length of C60 in organic planar heterojunction solar cells

Planar copper phthalocyanine (CuPc)/C60 heterojunction solar cells with a 2 nm layer of bathocuproine (BCP) inserted into the C60 layer were fabricated and characterized. The 2 nm BCP layer in the devices was used as an electronically selective sieve allowing the electron current through but blocking the excitons in the C60 layer. By combining the experimental results with the optical modeling, the effective triplet exciton diffusion length in C60 was confirmed to be 30–35 nm under the device working condition. We demonstrate a simple, useful method to determine the exciton diffusion lengths of organic electron acceptors.
Heegaard gradient of Seifert fibered 3-manifold

The infimal Heegaard gradient of a compact 3-manifold was defined and studied by Marc Lackenby in an approach toward the well-known virtually Haken conjecture. As instructive examples, we consider Seifert fibered 3-manifolds, and show that a Seifert fibered 3-manifold has zero infimal Heegaard gradient if and only if it virtually fibers over the circle or over a surface other than the 2-sphere. For a collection of finite coverings of a Seifert fibered 3-manifold, a necessary and sufficient condition to have zero infimal Heegaard gradient is also given.
The Application of the Moment in the Human Recognition

The important method of the human recognition is to use the moment of the target. This paper is mainly dedicated to the method of human recognition use for Hu moment and Zernike moment, and separates some sports target using the minimum distance classifier. Comparing characteristic of these moments in specific application, have provided the certain basis for the choice of the invariant moments in the human recognition algorithm.
: Leveraging Facial Action Units Activation Knowledge for Emotion Recognition on Faces

People naturally understand emotions, thus permitting a machine to do the same could open new paths for human-computer interaction. Facial expressions can be very useful for emotion recognition techniques, as these are the biggest transmitters of non-verbal cues capable of being correlated with emotions. Several techniques are based on Convolutional Neural Networks (CNNs) to extract information in a machine learning process. However, simple CNNs are not always sufficient to locate points of interest on the face that can be correlated with emotions. In this work, we intend to expand the capacity of emotion recognition techniques by proposing the usage of Facial Action Units (AUs) recognition techniques to recognize emotions. This recognition will be based on the Facial Action Coding System (FACS) and computed by a machine learning system. In particular, our method expands over EmotiRAM, an approach for multi-cue emotion recognition, in which we improve over their facial encoding module.
Observational constraints on solar nebula nitrogen chemistry: N2/NH3

Observations of N2(+) and NH2 in Comet Halley and N2H(+) and NH3 in nine Galactic star-forming regions are used to determine the average N2/NH3 abundance ratio in these objects. For Comet Halley, N2/NH3 of about 0.1 is found, and for the quiescent gas in a sample of star-forming regions, N2/NH3 of about 170 +/- 100. The cometary N2/NH3 ratio corrected for gas-phase elemental nitrogen depletion in Comet Halley indicates that the gas component in the comet-forming region of the solar nebula was N2/NH3 of about 4. It is concluded that more realistic models which include condensation fractionation effects are required before the N2 and NH3 abundances in comet volatiles can be related to star-forming regions.