Miracle-dz/UniFAR-FTUs huggingface dataset:
System for projectively invariant recognition of planar objects

This paper describes a complete recognition system for planar objects, using semi-local projectively invariant information on the contours to be identified. The system combines two different canonical descriptions of these segments. Using semi-local information makes it possible to recognize objects which are only partially visible. This allows for realistic imaging situations. By doing recognition up to only a projective transformation, nothing has to be known about the camera position or focal length, which makes the system applicable in a wide range of applications. Classification of training data is done by BUCA, a new supervised classification algorithm which is both fast and reliable. BUCA incorporates the idea of the `minimal description length' principle by the use of splitting entropy. The final assembling of recognized segments tries to avoid polynomial running time by first combining the most certain matches, and subsequently eliminating all segments that are compatible with such a match.
Mismatch-Induced Electric Field as Reason of Self-Polarization Phenomenon and Electret State Appearance in the Strained Ultrathin Ferroelectric Films

For the first time we proved, that built-in electric field originated from film-substrate misfit strain suppresses the size-driven transition from ferroelectric to paraelectric phase in the strained ultrathin ferroelectric films. Instead of paraelectric phase built-in field induces electret-like polar state with irreversible spontaneous polarization, pyroelectric and piezoelectric response at film thickness below the critical one. This normal to the film surface field increases when the film thickness decreases. Built-in field makes spontaneous polarization orientations energetically non-equivalent, in particular spontaneous poling becomes the most probable for the thin enough film when it exceeds thermodynamic coercive field. So, mismatch-induced electric field is the most probable reason of self-polarization phenomenon and electret state appearance in ultrathin films.
Improved confidence estimators for Fieller's confidence sets

Fieller's confidence set CF for ratios of location parameters, although of great importance in practice, is often cited as an example to criticize frequentist theory. The reason is that the set can consist of the whole parameter space and yet the confidence is γ = 1 – α in any case. In this paper, we study the problem of constructing data‐dependent estimators better than γ+, A reasonable estimator appears to be γ+, which is one if CF is the whole parameter space and γ otherwise. By using an estimated confidence approach and a squared‐error loss, it is shown that γ+ dominates γ. The risk improvement of γ+ over γ can be sizable. Also, by numerically comparing γ+ with a generalized Bayes estimator γL, which is shown to be admissible when one or two ratios are concerned, it is shown that γ+ is nearly admissible. We also conclude that the common practice of reporting 1 – α only when CF is not the whole parameter space is nearly admissible.
Puzzling Asteroid Families

Abstract The analysis of recent observational data has clarified several general properties of the collisional processes originating the asteroid dynamical families. However, a few puzzling physical problems remain open. According to the observations, the fragments are usually ejected at high velocities; the available theoretical models of catastrophic fragmentation, based on hydrodynamical simulations, do not reproduce this kind of result. Whenever high velocities are obtained in the models, the family is formed by very small—and thus unobservable—fragments. In this paper we discuss the general features of the problem, and we focus on the action of self-gravity, which may cause a later reaccumulation of originally small fragments. We have performed several N -body simulations, showing that the self-gravitational reaccumulation is unable to act for more than one—or few—selected fragments. Thus an original deep shattering of the parent body, followed by a significant recollection driven by self-gravity, cannot reproduce the size distribution observed in various real families, in which the large-size end includes several fragments of almost the same size. Moreover the ejection velocities required by the model to form, at least, a reaccumulated largest remnant as massive as that observed are usually too small in comparison to those estimated from the observations. We propose possible alternative explanations for this puzzling inconsistency between model outcomes and real world.
A new approximate mathematical model for global convergence for a coefficient inverse problem with backscattering data

An approximately globally convergent numerical method for a 3d Coefficient Inverse Problem for a hyperbolic equation with backscattering data is presented. A new approximate mathematical model is presented. An approximation is used only on the first iteration and amounts to the truncation of a certain asymptotic series. A significantly new element of the convergence analysis is that the so-called "tail functions" are estimated. Numerical results in 2d and 3d cases are presented, including the one for a quite heterogeneous medium.
On an anisotropic Minkowski problem

In this paper, we study the anisotropic Minkowski problem. It is a problem of prescribing the anisotropic Gauss-Kronecker curvature for a closed strongly convex hypersurface in Euclidean space as a function on its anisotropic normals in relative or Minkowski geometry. We first formulate such problem to a Monge-Amp\'ere type equation on the anisotropic support function and then prove the existence and uniqueness of the admissible solution to such equation. In conclusion, we give an affirmative answer to the anisotropic Minkowski problem.
Empty-Car Routing in Ridesharing Systems

This paper considers a closed queueing network model of ridesharing systems such as Didi Chuxing, Lyft, and Uber. We focus on empty-car routing, a mechanism by which we control car flow in the network to optimize system-wide utility functions, e.g. the availability of empty cars when a passenger arrives. We establish both process-level and steady-state convergence of the queueing network to a fluid limit in a large market regime where demand for rides and supply of cars tend to infinity, and use this limit to study a fluid-based optimization problem. We prove that the optimal network utility obtained from the fluid-based optimization is an upper bound on the utility in the finite car system for any routing policy, both static and dynamic, under which the closed queueing network has a stationary distribution. This upper bound is achieved asymptotically under the fluid-based optimal routing policy. Simulation results with real-world data released by Didi Chuxing demonstrate the benefit of using the fluid-based optimal routing policy compared to various other policies.
Concavity of some entropies

It is well-known that the Shannon entropies of some parameterized probability distributions are concave functions with respect to the parameter. In this paper we consider a family of such distributions (including the binomial, Poisson, and negative binomial distributions) and investigate the concavity of the Shannon, R\'enyi, and Tsallis entropies of them.
Locality Sensitive Semi-Supervised Dimensionality Reduction on Multimodal Data

A special kind of data is considered in this paper called multimodal data. It has the property that samples in a class are from several separate clusters. Locality Preserving Projection (LPP) can work well with multimodal data due to its locality preserving property. However, the label information is not used to improve the learning performance due to the unsupervised character of LPP. In this paper, we propose a method called Locality Sensitive Semi-Supervised Dimensionality Reduction (semi-LSDR). It takes both the discriminant information and geometry structure into account. Specifically, we construct a between-class graph on labeled samples and a nearest neighbor graph both from the perspective of locality. A directly mapping can be achieved by solving a generalized eigenvalue problem. Effectiveness of the proposed method is showed through simulations with benchmark data sets.
A variational reconstruction method for undersampled dynamic x-ray tomography based on physical motion models

In this paper we study the reconstruction of moving object densities from undersampled dynamic x-ray tomography in two dimensions. A particular motivation of this study is to use realistic measurement protocols for practical applications, i.e. we do not assume to have a full Radon transform in each time step, but only projections in few angular directions. This restriction enforces a space-time reconstruction, which we perform by incorporating physical motion models and regularization of motion vectors in a variational framework. The methodology of optical flow, which is one of the most common methods to estimate motion between two images, is utilized to formulate a joint variational model for reconstruction and motion estimation. We provide a basic mathematical analysis of the forward model and the variational model for the image reconstruction. Moreover, we discuss the efficient numerical minimization based on alternating minimizations between images and motion vectors. A variety of results are presented for simulated and real measurement data with different sampling strategy. A key observation is that random sampling combined with our model allows reconstructions of similar amount of measurements and quality as a single static reconstruction.
Diffusive stability of spatially periodic patterns with a conservation law

Applying the Lyapunov-Schmidt reduction approach introduced by Mielke and Schneider in their analysis of the fourth-order scalar Swift-Hohenberg equation, we carry out a rigorous small-amplitude stability analysis of Turing patterns for the model introduced by Matthews and Cox for pattern formation with a conservation law. Our results confirm that stability is accurately predicted in the small-amplitude limit by the formal modified Ginzburg-Lanadau system (mGL) consisting of a coupled Ginzburg-Landau equation and mean mode equation derived by Matthews and Cox, rigorously validating the standard weakly unstable approximation.
Calculation of Parameters of Crop Water Production Function of Jensen Model Based on Stochastic Particle Swarm Optimization Algorithm

In this paper, Stochastic Particle Swarm Optimization Algorithm (SPSO) is introduced to calculate parameters of crop water production function directly. SPSO is an improvement of the standard PSO, compared with which, it can be guaranteed to converge to the global optimization solution with probability one in theory, and speed up the convergence. The dimension of space of a particulate is determined by the phases of crop growth and development period in SPSO, and the sensitive index , an important parameter of crop water production function, is regarded as optimized variable to be calculated directly. This method can eliminate some problems existing in linear regression method, such as biased estimate and distortion of result and it can search the global optimization value more easily than the PSO. Through example analysis, we can see that the SPSO is better than PSO in accuracy and calculation speed.
A note on the overlap region in turbulent boundary layers

Two independent experimental investigations of the behavior of turbulent boundary layers with increasing Reynolds number were recently completed. The experiments were performed in two facilities, the Minimum Turbulence Level (MTL) wind tunnel at Royal Institute of Technology (KTH) and the National Diagnostic Facility (NDF) wind tunnel at Illinois Institute of Technology (IIT). Both experiments utilized oil-film interferometry to obtain an independent measure of the wall-shear stress. A collaborative study by the principals of the two experiments, aimed at understanding the characteristics of the overlap region between the inner and outer parts of the boundary layer, has just been completed. The results are summarized here, utilizing the profiles of the mean velocity, for Reynolds numbers based on the momentum thickness ranging from 2500 to 27 000. Contrary to the conclusions of some earlier publications, careful analysis of the data reveals no significant Reynolds number dependence for the parameters desc.
Matrix factorizations and link homology II

For each positive integer n the HOMFLY polynomial of links specializes to a one-variable polynomial that can be recovered from the representation theory of quantum sl(n). For each such n we build a doubly-graded homology theory of links with this polynomial as the Euler characteristic. The core of our construction utilizes the theory of matrix factorizations, which provide a linear algebra description of maximal Cohen-Macaulay modules on isolated hypersurface singularities.
Horizontal velocity structure functions in the upper troposphere and lower stratosphere: 2. Theoretical considerations

The Kolmogorov equation for the third-order velocity structure function is derived for atmospheric mesoscale motions on an f plane. A possible solution is a negative third-order structure function, varying linearly with separation distance and mean dissipation, just as in three-dimensional turbulence, but with another scaling constant. On the basis of the analysis and the observed stratospheric third-order structure function, it is argued that there is a forward energy cascade in the mesoscale range of atmospheric motions. The off-diagonal part of the general tensor equation is also studied. In this equation there is an explicit Coriolis term that may be crucial for the understanding of the kinetic energy spectrum at scales larger than 100 km.
Carbon-to-nitrogen ratios along the evolutionary sequence of M67

A low-resolution spectroscopic study of the C and N abundances of stars in the old open cluster M67 was conducted in order to find the first dredge-up in the H-R diagram, when the surface C/N ratio is altered during evolution up the giant branch. The C/N ratio is found to change abruptly at the base of the giant branch. If probable systematic errors are allowed for, the C/N ratio does not change elsewhere on the cluster evolutionary sequence. The location in the H-R diagram of the onset of this change is in accordance with theoretical predictions of stellar evolution, but the composition change is complete at a substantially lower luminosity in the cluster than in standard models of red giant evolution, and the amount of the change in C/N is greater than that predicted by standard evolution calculations. 67 references.
Spin-transfer-induced magnetization switching in magnetic tunnel junctions

Micromagnetic simulations for spin-transfer-induced magnetization dynamics in nanoscale low-resistance magnetic tunnel junctions (MTJs) are performed by using the modified Landau-Lifshitz equation in which a spin-transfer model for MTJs is included. Calculations show that critical switching current density (Jc) is about (4–8)×106A∕cm2, consistent with the experimental data, lower than the values found in metallic spin-valve nanopillars (typically in the order of ∼107A∕cm2). A slight asymmetry of the critical current is observed in the magnetization switching loop, due to the asymmetry of the spin-torque factor. The switching time is related to the applied current, and our calculation results show that a longer switching time, 10–15ns, is needed when the applied current density J is close to Jc, and it decreases down to 1ns for J>2×107A∕cm2.
A conserved energy for axially symmetric Newman–Penrose–Maxwell scalars on Kerr black holes

We show that there exists a 1-parameter family of positive-definite and conserved energy functionals for axially symmetric Newman–Penrose–Maxwell scalars on the maximal space-like hypersurfaces in the exterior of Kerr black holes. It is also shown that the Poisson bracket within this 1-parameter family of energies vanishes on the maximal hypersurfaces.
Global Torelli Theorem for Projective Manifolds of Calabi-Yau Type

We prove that the period maps from the Torelli space and the moduli space with level $m$ structure of Calabi-Yau type manifolds to the corresponding period domain of polarized Hodge structures are injective. The proof is based on the construction of holomorphic affine structure on the Teichm\"uller space and the construction of the completion space of the Torelli space with respect to the Hodge metric.
The MiniBooNE detector technical design report

The MiniBooNE experiment [1] is motivated by the LSND observation, [2] which has been interpreted as {nu}{sub {mu}} {yields} {nu}{sub e} oscillations, and by the atmospheric neutrino deficit, [3,4,5] which may be ascribed to {nu}{sub {mu}} oscillations into another type of neutrino. MiniBooNE is a single-detector experiment designed to: obtain {approx} 1000 {nu}{sub {mu}} {yields} {nu}{sub e} events if the LSND signal is due to {nu}{sub {mu}} {yields} {nu}{sub e} oscillations, establishing the oscillation signal at the > 5{sigma} level as shown in Fig. 1.1; extend the search for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations significantly beyond what has been studied previously if no signal is observed; search for {nu}{sub {mu}} disappearance to address the atmospheric neutrino deficit with a signal that is a suppression of the rate of {nu}{sub {mu}}C {yields} {mu}N events from the expected 600,000 per year; measure the oscillation parameters as shown in Fig. 1.2 if oscillations are observed; and test CP conservation in the lepton sector if oscillations are observed by running with separate {nu}{sub {mu}} and {bar {nu}}{sub {mu}} beams. The detector will consist of a spherical tank 6.1 m (20 feet) in radius, as shown in Fig. 1.3, that stands in a 45-foot diameter cylindrical vault. An inner tank structure at 5.75 m radius will support 1280 8-inch phototubes (10% coverage) pointed inward and optically isolated from the outer region of the tank. The tank will be filled with 807 t of mineral oil, resulting in a 445 t fiducial volume. The outer tank volume will serve as a veto shield for identifying particles both entering and leaving the detector with 240 phototubes mounted on the tank wall. Above the detector tank will be an electronics enclosure that houses the fast electronics and data acquisition system and a utilities enclosure that houses the plumbing, overflow tank, and calibration laser. The detector will be located {approx} 550 m from the Booster neutrino source. The neutrino beam, produced using 8 GeV protons from the Booster at FNAL, will consist of a target within a focusing system, followed by a {approx}50 m long pion decay volume. The low energy, high intensity and 1 {micro}s time-structure of a neutrino beam produced from the Booster beam are ideal for this experiment. We assume that the Booster can reliably deliver protons for a typical run which is two-thirds of a calendar year. The sensitivities discussed above assume the experiment receives 5 x 10{sup 20} protons per year. This Booster experiment is compatible with the Fermilab collider and MI programs. The Booster must run at 7.5 Hz to accommodate the MiniBooNE and collider programs simultaneously. The current schedule calls for data-taking to begin by the end of calendar year 2001.
Optimization of the Trajectory, Transmit Power, and Power Splitting Ratio for Maximizing the Available Energy of a UAV-Aided SWIPT System

In this study, we investigate the maximization of the available energy for an unmanned aerial vehicle (UAV)-aided simultaneous wireless information and power transfer (SWIPT) system, in which the ground terminals (GTs) decode information and collect energy simultaneously from the downlink signal sent by the UAV based on a power splitting (PS) policy. To guarantee that each GT has a fair amount of available energy, our aim is to optimize the trajectory and transmit power of the UAV and the PS ratio of the GTs to maximize the minimum average available energy among all GTs while ensuring the average spectral efficiency requirement. To address the nonconvexity of the formulated optimization problem, we apply a successive convex optimization technique and propose an iterative algorithm to derive the optimal strategies of the UAV and GTs. Through performance evaluations, we show that the proposed scheme outperforms the existing baseline schemes in terms of the max–min available energy by adaptively controlling the optimization variables according to the situation.
AESTHETIC OPTIMIZATION OF A BASIC SHAPE

An important aspect in nowadays industries is to obtain end products that are optimal with respect to several criteria. The aesthetic criterion is an essential one and it has been studied since Antiquity by several artists and scientists. In this paper we propose two aesthetic optimization models of a basic shape using evolutionary algorithms. The objective functions are formulated using the Golden Ratio as an aesthetic standard . Key words: aesthetic standards, mathematical mean, Golden Ratio, optimization, evolutionary algorithms.
DISCRETE CONDITIONS FOR THE HOLONOMY GROUP OF A PAIR OF PANTS

A pair of pants Σ(0, 3) is a building block of oriented surfaces. The purpose of this paper is to determine the discrete conditions for the holonomy group π of hyperbolic structure of a pair of pants. For this goal, we classify the relations between the locations of principal lines and entries of hyperbolic matrices in PSL(2,R). In the level of the matrix group SL(2,R), we will show that the signs of traces of hyperbolic elements play a very important role to determine the discreteness of holonomy group of a pair of pants.
Air-to-Ground Large-Scale Channel Characterization by Ray Tracing

Through ray tracing simulation on three-dimensional (3D) urban environments, we characterize air-to-ground (A2G) channels for 5G and beyond wireless communications. In this study, we review four types of elevation angle-dependent probability of line-of-sight (LoS) expressions according to building distribution types. With channel characterization data extracted from the ray tracing (RT) simulation, LoS probability versus elevation angle agrees better with the elevation angle-dependent probability expressions of LoS that assumes the buildings are randomly distributed. Furthermore, we provide a more accurate LoS probability expression that enables better curve-fitting for the LoS probability data obtained from RT simulations. In addition, the A2G channel parameters such as LoS and non-line-of-sight (NLoS) channel path loss exponents (PLEs) and the shadow fading with UAV altitudes are obtained in four typical and realistic urban environments. The LoS PLEs increase slowly with the height of the UAV, while the NLoS one decreases significantly with the increase of the UAV height.
A Type B Analogue to Ribbon Tableaux

We introduce a shifted analogue of the ribbon tableaux defined by James and Kerber. For any positive integer $k$, we give a bijection between the $k$-ribbon fillings of a shifted shape and regular fillings of a $\lfloor k/2\rfloor$-tuple of shapes called its $k$-quotient. We also define the corresponding generating functions, and prove that they are symmetric, Schur positive and Schur $Q$-positive.