Miracle-dz/UniFAR-FTUs huggingface dataset:
ATesting for the Onset of Trend, Using Wavelets

This paper develops a test for the onset of a time trend, using a wavelet‐type estimator. The series level is a nonlinear function of time, with a slope that is zero initially, but non‐negative and non‐decreasing, or non‐positive and non‐increasing, beyond the onset point, permitting divergence. The series level is otherwise unspecified, and to estimate it we regress the data series on wavelet scaling functions of time, with a coefficient restriction that makes the fitted level constant until some point in the sample. Since the true onset point is unknown, we examine several such restrictions, yielding candidate onset points at equally spaced positions in the sample. We base our test on some F‐type statistics, which compare the performance of successive fitted levels. To exploit the asymmetry of the true level under the alternative, we use a weighted sum of F stastistics, with linearly increasing weight at points further in the sample. This test statistic has a nonstandard distribution, which we tabulate. Asymptotically, we show that linear weighting gives better local power than equal weighting. A simulation study confirms the power advantage of our test.
Image Quality Measure Based On A Human Visual System Model

A preliminary image quality measure that takes into account two major sensitivities of the human visual system (HVS) is described. The sensitivities considered are background illumination level and spatial frequency sensitivities. Given a digitized monochrome image, the algorithm produces, among some other figures of merit, a plot of the information content (IC) versus the resolution in units of pixels. The IC is defined here as the sum of the weighted spectral components at an arbitrary specified resolution. The HVS normalization is done by first intensity remapping the image by a monotonically increasing function representing the background illumination level sensitivity, followed by a spectral filtering to compensate for the spatial frequency sensitivity. The developed quality measure is conveniently parameterized and interactive. It allows experimentation with numerous parameters of the HVS model to determine the optimum set for which the highest correlation with subjective evaluations can be achieved. The preliminary results are promising.
Performance Variation of Gray Codes for Cropped Gaussian 16PAM Constellations

There are many ways to label symbols in a constellation. We investigate the performance impact of the Gray code choice both in the case of uniformly-spaced symbol constellations and cropped Gaussian constellations, with the BICM (bit-interleaved coded modulation) mutual information as a performance measure. We exhaustively search and find all 131 Gray codes, including cyclic and acyclic Gray codes, each representing a class of codes resulting in the same performance, that can be used with a symmetric 16PAM. Our results show that Gray codes having a bit position with only a single transition tend to outper-form codes where all bit positions have multiple transitions. The ranking of Gray code performance was similar when using both square PAM and optimized cropped Gaussian PAM, with only minor differences in the rankings of Gray codes. This indicates that joint selection of the cropped Gaussian constellation and the Gray code is not significantly important in designing a system. These results in the present paper can be applied to 256-symbol QAM constellations with in-phase/quadrature symmetry.
Simulating the interface morphology of silver thick film contacts on n-type Si-(100) and Si-(111)

Silver crystals at the interface of silver thick film contacts carry the current across such contacts and therefore govern the contact resistance. The crystals grow nearly exclusively in pits in the silicon surface, which form during contact formation before the crystals and hence determine the amount and size of crystals. We simulate the mechanism of pit formation at such contact interfaces by using a model based on the removal probability of silicon surface atoms. The model leads to good agreement between experimentally observed and simulated pits. The results enable the prediction of pit formation in dependence of contact processing parameters.
Induction Motor Failure Analysis using Machine Learning and Infrared Thermography

Induction motor are electrical machines used in a wide variety of industrial applications. However, due to their applications, are subjected to undesirable operating conditions. A complementary technique that aids in fault diagnosis in induction motors is infrared thermography. This paper proposes a methodology based on automatic learning and unsegmented infrared imaging for classifies and diagnosis failures on induction motor and their kinematic chain. The proposed methodology is analyzing the unsegmented infrared thermography, taking directly from the thermogram significant statistical features that describe the thermal behavior of the electromechanical system, to later reduce the set of characteristics and, through a machine learning algorithm, classify the fault condition. To demonstrate the efficiency of the proposed methodology, this paper presents the health condition analysis and three fault conditions in an induction motor: a broken rotor bar, bearing damage, and misalignment.
Pole assignment using dynamic output feedback compensators

ABSTRACT The design of dynamic output feedback compensators for the pole assignment of linear time-invariant multivariable systems is considered. A systematic procedure is developed for the synthesis of the transfer function matrix of the compensator. A certain number of poles can be arbitrarily assigned by the proposed compensator. Moreover, in order to assign more poles using a compensator of the same order as before, a new approximate assignment approach based on the least-square-error algorithm is proposed. A numerical example is given to demonstrate the effectiveness of the proposed approaches.
Controllable interaction of counterpropagating solitons in three-level media

We examine the dynamics of counterpropagating self-induced transparency solitons in three-level media. In a multilevel system, self-induced transparency gives rise to soliton solutions if the propagation is unidirectional, but the collision of counterpropagating pulses destroys the integrability of the underlying equations. We consider the collision of a rightward and a leftward moving self-induced transparency solitary wave by solving the full Maxwell-Bloch equations numerically using a finite-difference time-domain approach. Depending on pulse duration, amplitude and relative polarizations of the initial solitary waves we observe different regimes of interaction. For high group velocities and orthogonal polarizations, secondary solitary waves are born during the interaction, whereas the collision of solitary waves with the same polarization never produces secondary solitary waves but leaves behind a population grating in the interaction region. Because the crucial parameters can be controlled, an experimental confirmation of the predicted interaction regimes should be feasible.
A Machine Learning Based Automatic Hardware Trojan Attack Space Exploration and Benchmarking Framework

Due to the current horizontal business model that promotes increasing reliance on untrusted third-party Intellectual Properties (IPs), Computer-Aided-Design (CAD) tools, and design facilities, hidden malicious functionalities, also known as hardware Trojan attacks, have become a serious threat to the semiconductor industry. Development of effective countermeasures against hardware Trojan attacks require: (1) fast and reliable exploration of the viable Trojan attack space for a given design and (2) a suite of high-quality Trojan-inserted benchmarks that meet specific standards. The latter has become essential for the development and evaluation of design/verification solutions to achieve quantifiable assurance against Trojan attacks. While existing static benchmarks provide a baseline for comparing different countermeasures, they only enumerate a limited number of hand-crafted Trojans from the complete Trojan design space. To accomplish these dual objectives, in this paper, we present MIMIC, a novel machine learning guided framework for automatic Trojan insertion, which can create a large and targeted population of valid Trojans for a given design by mimicking the properties of a small set of known Trojans. While there exist tools to automatically insert Trojan instances using fixed Trojan templates, they cannot analyze known Trojan attacks for creating new instances that accurately capture the threat model. MIMIC works in two major steps: (1) it analyzes structural and functional features of existing Trojan populations in a multi-dimensional space to train machine learning models and generate a large number of “virtual Trojans” of the given design, (2) next, it binds them into the design by matching their functional/structural properties with suitable nets of the internal logic structure. We have developed a complete tool flow for MIMIC, evaluated the framework, and quantified its effectiveness to demonstrate highly promising results.
Joint Beam Management and Relay Selection Using Deep Reinforcement Learning for MmWave UAV Relay Networks

Unmanned aerial vehicle (UAV) relays are useful in tactical millimeter wave (mmWave) networks to overcome blockages and improve link resilience. Getting the most benefits from relays, though, requires efficient strategies for relay selection and for beam management. In this paper, we use deep reinforcement learning (DRL) to jointly select unblocked UAV relays and to perform beam management. The proposed DRL-based algorithm uses rate feedback from the receiver to learn a policy that adapts to the dynamic channel conditions. We show with numerical evaluation that the proposed method outperforms baselines without prior channel knowledge. Moreover, the DRL-based algorithm can maintain high spectral efficiency even under frequent blockages.
Progressive Series-Elastic Actuation with Magnet-based Non-linear Elastic Elements

We present the design and development of a non-linear series-elastic element based on repelling magnets. Progressive stiffness offers the transparency advantages of a low-stiffness elastic actuator at low load levels, and the high torque tracking bandwidth of a high-stiffness actuator at high loads. The design space of this magnet-based concept is thoroughly analysed, for both box- and arc-segment magnets. A proof-of-concept prototype is presented which is experimentally validated. A gain-scheduled torque controller is used to exploit its non-linear dynamics. Simulation and experimental results demonstrate the viability of the concept.
The structure of magnetic fields in dark clouds: Infrared polarimetry in B216-217

A near-infrared polarization map of background starlight seen through the B216-217 dark cloud in Taurus is presented. The mean direction and dispersion in direction of the polarization vectors observed in the near-infrared are indistinguishable from the direction and dispersion of optical polarization vectors around the periphery of the dark cloud. Measurements of J- and K-magnitudes of the stars observed in the near-infrared imply a range of extinctions 1 ≤ A V ≤ 10 mag, while the mean A V for the stars whose polarization has been measured optically is ≤1 mag
Digital Euclidean skeletons

The digitization of the skeleton is the source of many difficulties. The skeleton of a binary set can be defe12 as the set of crest points and their upstream on the distance function '' . The final result depends on the quality of the distance function which has been used. The result is particularly coarse with the hexagonal distance function. The use of an euclidean distance function yields a beautiful skeleton once some subtle interactions with the grid have been solved.
The Structure of Some Crystals as Indicated by Their Diffraction of X-rays

A new method of investigating the structure of a crystal has been afforded by the work of Laue* and his collaborators on the diffraction of X-rays by crystals. The phenomena which they were the first to investigate, and which have since been observed by many others, lend themselves readily to the explanation proposed by Laue, who supposed that electromagnetic waves of very short wave-lengths were diffracted by a set of small obstacles arranged on a regular point system in space. In analysing the interference pattern obtained with a zincblende crystal, Laue, in his original memoir, came to the conclusion that the primary radiation possessed a spectrum consisting of narrow bands, in fact, that it was composed of a series of six or seven approximately homogeneous wave trains. In a recent paper I tried to show that the need for assuming this complexity was avoided by the adoption of a point system for the cubic crystal of zincblende which differed from the system considered by Laue. I supposed the diffracting centres to be arranged in a simple cubic space lattice, the element of the pattern being a cube with a point at each corner, and one at the centre of each cube face. A simpler conception of the radiation then became possible. It might be looked on as continuous over a wide range of wave-lengths, or as a series of independent pulses, and there was no longer any need to assume the existence of lines or narrow bands in its spectrum.
Investigation of the effects of LIFT printing with a KrF-excimer laser on thermally sensitive electrically conductive adhesives

Laser induced forward transfer is an emerging material deposition technology. We investigated the feasibility of this technique for printing thermally sensitive, electrically conductive adhesives with and without using an intermediate dynamic release layer. A 248 nm KrF-excimer laser was used to print the epoxy-based conductive adhesives containing silver flakes down to 75 μm dot size. The process is particularly relevant for realizing electrical connections to surface mount devices in the microelectronics industry. Characterization of the printed materials was analyzed by Fourier transform infrared spectroscopy, four-point electrical measurements, die-shear testing and temperature shock testing, to establish that the properties of the adhesive were not affected by direct or indirect laser irradiation. The lack of degradation by the laser onto the adhesives confirms the potential of this technique for interconnection applications.
Dynamical masses for the nearest brown dwarf binary: ε Indi Ba,b

Binary brown dwarfs are important because their dynamical masses can be determined in a model-independent way. If a main sequence star is also involved, the age and metallicity for the system can be determined, making it possible to break the sub-stellar mass-age degeneracy. The most suitable benchmark system for intermediate age T dwarfs is ε Indi Ba,b, two T dwarfs (spectral types T1 and T6; McCaughrean et al. (2004)) orbiting a K4.5V star, ε Indi A, at a projected separation of 1460AU. At a distance of 3.6224pc (HIPPARCOS distance to ε Indi A; van Leeuwen (2007)), these are the closest brown dwarfs to the Earth, and thus both components are bright and the system is well-resolved. The system has been monitored astrometrically with NACO and FORS2 on the VLT since June 2004 and August 2005, respectively, in order to determine the system and individual masses independent of evolutionary models. We have obtained a preliminary system mass of 121±1MJup. We have also analysed optical/near-IR spectra (0.6-5.0μm at a resolution up to R~5000; King et al. (2009)) allowing us to determine bolometric luminosities, compare and calibrate evolutionary and atmospheric models of T dwarfs at an age of 4-8Gyr.
A Classical Mechanical Model of Brownian Motion with One Particle Coupled to a Random Wave Field

We consider the problem of deriving Brownian motions from classical mechanical systems. Specifically, we consider a system with one massive particle coupling to an ideal random wave field, evolved according to classical mechanical principles. We prove the almost sure existence and uniqueness of the solution of the considered dynamics, prove the convergence of the solution under a certain scaling limit and give the precise expression of the limiting process, a diffusion process.
Electric and magnetic responses in the multiple-split ring resonators by electric excitation

We experimentally demonstrate both the electric and magnetic responses from the multiple-split-ring resonators (MSRRs) via normal reflectance measurements. All the fabricated MSRRs exhibit electric resonances under electric couplings but the magnetic resonances are only excited in MSRRs with odd numbers of splits from the asymmetrically electric couplings. Furthermore, the dependence of split numbers on the resonant positions and strengths is also investigated. In addition, the coupling mechanism of correlated resonances in the MSRRs can be well elucidated by the concept of standing-wave plasmonic resonances. Such scalable MSRRs present the tailored electromagnetic responses at desired frequencies, paving ways toward integrated nanophotonic applications.
Kleinian signature change

We study the propagation of plane-waves in a fixed flat background spacetime whose metric changes from a Lorentzian signature to a Kleinian signature . When the change of signature is discontinuous there is an apparent difference in wave behaviour depending upon whether the wave describes matter with integer or half-integer spin. A more detailed study of the Dirac equation shows that, while it is possible to decrease this disparity, the two matter classes still do not behave identically. A more consistent picture finally emerges when the same problem is attempted with a metric which changes signature continuously. This leads to the prediction of some surprising physical phenomena.
Hypersonic flow over spiked cones

An investigation has been made of the flow over spiked cone-cylinders mainly at a Mach number of 10. Five distinct types of flow were discovered. The occurrence of each is defined in terms of spike length and cone angle. Following a discussion of the flow mechanism, a semi-empirical separation relation is derived. This can be used to predict the flow pattern for the most common type of separated flow.
A cubic‐spline technique to calculate nodal Darcian velocities in aquifers

A continuous and reliable velocity field is required for the simulation of mass and heat transport in an aquifer system. In this paper, a cubic-spline technique is proposed to calculate nodal Darcian velocities after the flow field is obtained. With this technique, a continuous velocity field is produced, and mass conservation is satisfied to an acceptable degree. Its requirements for computer storage are very small, and the calculation speed is very fast; it can be implemented in parallel. A synthetic diffusion problem is used to examine the accuracy of this technique. The results agree very well with the analytical solution. Application to another problem shows that this technique can be applied to any heterogeneous and anisotropic aquifer. The results of the two sample problems are also compared with the Galerkin finite element method [Yeh, 1981] and the dual mesh method [Batu, 1984]. It is observed that its agreement with the Galerkin method is much better than the dual mesh method.
THE PECULIARITY OF SELF-EXCITED OSCILLATIONS IN FRACTIONAL SYSTEMS

In this paper we show that the compensation of loss in the linear fractional oscillator by an active device can result in auto-oscillations. Due to the main feature of linear fractional oscillations, namely a finite number of zeros, the limit cycle in such a generator has a short life time depending on the order of fractional derivative. The electronic circuit, leading to such auto-oscillations, is studied as an example, and its differential equation is derived. The active device characteristic is represented in the piecewiselinear approximation. The features of electric elements are discussed.
Implicit Time Spectral Method for Periodic Incompressible Flows

This Ph.D work deals with the implementation and analysis of a Time Spectral Method (TSM) dedicated to the efficient calculation of time-periodic flows. The main interest of the formulation lies in the fact that the calculation of the flow transient is not needed anymore and, instead, the final periodic solution can be directly looked for. Besides, the use of large physical time step is made possible by the spectral accuracy of the TSM time deriva- tive operator. The Time Spectral Method converts a time-periodic flow computation into the solution of 2N + 1 coupled steady computations where N denotes the number of harmonics retained in the Fourier analysis of the flow. The TSM is implemented into a Navier-Stokes solver in the context of general moving unstructured grids using an ALE (Arbitary Lagrangian Eulerian) formulation. An implicit scheme is proposed to make the approach even more at- tractive in terms of computational cost. An original contribution of this thesis is the extension of the TSM to the computation of laminar incompressible flows using the artificial compress- ibility method. Numerical simulations of oscillating and heaving airfoils allow a fine analysis of the TSM and show that it can lead to substantial computational cost reduction.
Effects of unbalanced magnetic pull in spindle motors

This paper analyzes the effects of the unbalanced-magnetic-pull developed in spindle motors for hard disk drives. An analytical technique is used in the investigation which is based on magnetic circuit and field theory. Computational results show that the UMP development is closely related to the magnetic structure, armature winding and armature current of the spindle motors.
Causality in the Long Run

The definition of causation, discussed in Granger (1980) and elsewhere, has been widely applied in economics and in other disciplines. For this definition, a series yt is said to cause xt+l if it contains information about the forecastability for xt+l contained nowhere else in some large information set, which includes xt−j, j ≥ 0. However, it would be convenient to think of causality being different in extent or direction at seasonal or low frequencies, say, than at other frequencies. The fact that a stationary series is effectively the (uncountably infinite) sum of uncorrelated components, each of which is associated with a single frequency, or a narrow frequency band, introduces the possibility that the full causal relationship can be decomposed by frequency. This is known as the Wiener decomposition or the spectral decomposition of the series, as discussed by Hannan (1970). For any series generated by , where xt, and are both stationary, with finite variances and a(B) is a backward filter with B the backward operator, there is a simple, well-known relationship between the spectral decompositions of the two series.
Extracting grain-orientation-dependent data from in situ time-of-flight neutron diffraction. I. Inverse pole figures

The problem of calculating the inverse pole figure (IPF) is analyzed from the perspective of the application of time-of flight neutron diffraction toin situmonitoring of the thermomechanical behavior of engineering materials. On the basis of a quasi-Monte Carlo (QMC) method, a consistent set of grain orientations is generated and used to compute the weighting factors for IPF normalization. The weighting factors are instrument dependent and were calculated for the engineering materials diffractometer VULCAN (Spallation Neutron Source, Oak Ridge National Laboratory). The QMC method is applied to face-centered cubic structures and can be easily extended to other crystallographic symmetries. Examples include 316LN stainless steelin situloaded in tension at room temperature and an Al–2%Mg alloy, substantially deformed by cold rolling and in situannealed up to 653 K.