Miracle-dz/UniFAR-FTUs huggingface dataset:
Finite precision implementation of LDPC decoders

Low-density parity-check (LDPC) codes are among the most powerful known error correcting codes and they have been shown to achieve performance very close to the Shannon bound. In practical hardware implementations of LDPC decoders, bit error rate performances are affected strongly by fixed-point representation of processed data and, although many papers have been published in recent years on the subject of LDPC codes, only a few of them report results on the effects of finite precision. In the paper two novel arithmetic approximations for the basic processing operations of the decoding algorithm are presented. The two proposed solutions are analysed in terms of bit error rate performance for different finite precision representations of both external and internal data; the estimated performance loss is comparable to that reported by previous works and limited to approximately 0.1 dB for cases of interests. However the proposed solutions support a reduced complexity formulation of the decoding algorithm, so enabling the implementation of flexible decoders that can be adapted to different LDPC codes, block sizes and code rates.
REDISCUSSION OF ECLIPSING BINARIES. XVIII. FAINT SECONDARIES IN THE SPECTRA OF EARLY B-TYPE SYSTEMS

Spectra of 3 early B-type eclipsing binaries, for which velocities of faint secondary components have been reportedly measured on photographic spectrograms, have been observed with high resolution and signal-to-noise ratio. The equipment employed is the echelle-CCD Hamilton spectrometer on the 3 m Shane telescope of the Lick Observatory. Very provisional orbits have been re-derived for the secondaries in two of the systems, VV Ori, a main-sequence system, and V380 Cyg, with a highly evolved BO primary, principally on the basis of velocities from the He I line, lambda-5876. Lines in the secondaries of these systems are considerably weaker than previously thought, the 5876 line have equivalent widths of 0.07 A and 0.024 A in VV Ori and V380 Cyg, respectively. No line of the secondary was detected unequivocally in the spectrum of the third system, V1765 Cyg, which also has an evolved early B-type primary. The 5876 line is weaker than 0.03 A. An unseen third body causes a variation of the velocity of the center of mass of the close binary in VV Ori, which is poorly determined. VV Ori would otherwise be a promising system for the determination of fundamental stellar properties, its masses being roughly 11 and 4.5 solar masses. V380 Cyg has the nearly unique potential of providing the mass and other properties of an evolved early B star, type B1.5 II-III. The principal difficulty in achieving this aim is in removing the indeterminacy of the solution of the light curve, with its shallow minima and eccentric orbit. Some discrepancies are found between theoretical and observed strengths of He lines in the spectra of early B-type stars of high luminosity.
Modelling the bar in the centre of the starburst galaxy M82

We present VLA A-array 21-cm atomic hydrogen (H i) absorption observed against the central region of the starburst galaxy M82 with an angular resolution of ∼1.3 arcsec (≃20 pc). These observations, together with MERLIN H i absorption measurements, are compared with the molecular (CO) and ionized ([Ne ii]) gas distributions and are used to constrain the dynamics and structure of the ionized, neutral and molecular gas in this starburst. A position–velocity diagram of the H i distribution reveals an unusual ‘hole’ feature which, when previously observed in CO, has been interpreted as an expanding superbubble contained within a ring of gas in solid body rotation. However, we interpret this feature as a signature of a nearly edge-on barred galaxy. In addition, we note that the CO, H i and [Ne ii] position–velocity diagrams reveal two main velocity gradients, and we interpret these as gas moving on x1- and x2-orbits within a bar potential. We find the best fit to the data to be produced using a bar potential with a flat rotation curve velocity vb=140 km s−1 and a total length of 1 kpc, a non-axisymmetry parameter q=0.9, an angular velocity of the bar Ωb=217 km s−1 arcsec−1, a core radius Rc=25 pc, an inclination angle i=80° and a projected angle between the bar and the major axis of the galaxy φ′=4°. We also discuss the orientation of the disc and bar in M82.
Magnetic properties of coupled ultrathin NiO/Fe 3 O 4 (001) films

A strong reduction in the magnetic spin and orbital moments as well as large magnetocrystalline anisotropies are observed in ultrathin $\mathrm{Ni}\mathrm{O}∕{\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ (001) films compared to ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ (001). Combining x-ray absorption spectroscopy, x-ray magnetic circular and linear dichroism (XMCD-XMLD), and high-resolution transmission electron microscopy (HRTEM) the magnetic anisotropy of ultrathin $\mathrm{Ni}\mathrm{O}∕{\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ (001) films was studied and compared to structural anisotropy at the interface. The evolution of the XMCD signal at the Fe octahedral sites allows a quantitative description of the interface. A simple model is proposed where uncompensated spins are located in a $1.5\text{\ensuremath{-}}\mathrm{nm}$-thick interfacial $\mathrm{Ni}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$ compound. Angular-dependent measurements of the effective spin and orbital magnetic moments at the Fe ${L}_{2,3}$ edges reveal the presence of a large magnetocrystalline anisotropy, appearing for a particular growth temperature of the films. The magnetocrystalline anisotropy measured at the Fe ${L}_{2,3}$ edges is attributed to the specific anisotropic structure developed at the interface and to crystalline ordering of a strained compound. HRTEM confirms the presence of an ordered anisotropic structure at the $\mathrm{Ni}\mathrm{O}∕{\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ (001) interface. The in-plane strained NiO(001) films promote antiferromagnetic order where the spins are oriented parallel to the ⟨100⟩ in-plane direction, collinear to the magnetization direction in the ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ (001) substrate.
Comparison of goodness of fit tests for the cox proportional hazards model

The proportional hazards regression model of Cox(1972) is widely used in analyzing survival data. We examine several goodness of fit tests for checking the proportionality of hazards in the Cox model with two-sample censored data, and compare the performance of these tests by a simulation study. The strengths and weaknesses of the tests are pointed out. The effects of the extent of random censoring on the size and power are also examined. Results of a simulation study demonstrate that Gill and Schumacher's test is most powerful against a broad range of monotone departures from the proportional hazards assumption, but it may not perform as well fail for alternatives of nonmonotone hazard ratio. For the latter kind of alternatives, Andersen's test may detect patterns of irregular changes in hazards.
Vortex Shedding and Noise Radiation from a Slat Trailing Edge

Vortex shedding and the associated noise radiation from a trailing edge were experimentally investigated for a leading-edge slat of a multi-element airfoil at stowed chord Reynolds number Re 2.1 x 10 5 , however, acoustic feedback becomes pronounced between the trailing-edge noise and the boundary-layer instability waves on the suction surface, so that multiple spectral peaks appear both in the velocity fluctuations and sound pressure. At and around the Reynolds number for the first appearance of tonal noise, Re = 1.9 x 10 5 , both of the instability modes coexist. Beyond Re = 2.1 x 10 5 , the boundary-layer instability waves excited by the acoustic feedback evolve into high-intensity vortices before reaching the trailing edge and suppress the absolute instability of the wake through diminishing the reversed-flow region in the wake.
Correlation between the radiation‐induced intrinsic 4.8 eV optical absorption and 1.9 eV photoluminescence bands in glassy SiO2

The controversial relationship between the intrinsic 1.9 eV photoluminescence (the R band), the 2.0 and 4.8 eV excitation/optical absorption bands is examined for 11 specimens with different OH, Cl, and O2 concentrations and with different irradiation histories. The direct relation is found between the intensities of the R‐band luminescence measured with the 4.0 eV (IUV) or resonance (1.94 eV) excitation (Ires), although it is slightly superlinear, Ires∝(IUV). The deviation from the exactly constant ratio between the band intensities in different glass samples is attributed mainly to the inhomogeneous broadening effects. Also, nonzero polarization degree, P=−1.5±0.5%, in the R‐band maximum region is reconfirmed upon linearly polarized 4.8 eV excitation, substantiating a close relation between the 4.8 eV absorption band and the R band. These results suggest strongly that both of the two absorption bands at 2.0 and 4.8 eV are originated from a single center, and quantitatively agree with the recently propos.
Measuring shapes by size functions

We define the concept of size functions. They are functions from the real plane to the natural numbers which describe the `shape of the objects' (seen as submanifolds of a Euclidean space). We give two different techniques of computation of size functions and some actual examples of computation. Moreover, we present the concept of deformation distance between manifolds (i.e., curves, surfaces, etc.). It is a distance which measures the `difference in shape' of two manifolds. Finally we point out the link between deformation distances and size functions.
Predictive Model for Detection of Depression Based on Uncertainty Analysis Methods

: Currently, advances in technology have permitted increases in the life expectancy of older adults. As a result, a large segment of the world population is 60’s years old, and over. Depression is an important disease in older adults is depression, which seriously affects the moods and behavior of elderly. Novel technologies for smart cities allow us to monitor people and prevent problematic situations related to this mental illness. In this paper, we propose a predictive model to automatically detect depression in older adults. The model is based on machine-learning techniques to analyze the data obtained by a sensor that monitores the daily activities of older adults. Also, the model was evaluated obtaining promising results.
Design and analysis of new fault-tolerant permanent magnet motors for four-wheel-driving electric vehicles

In this paper, a novel in-wheel permanent-magnet (PM) motor for four-wheel-driving electrical vehicles is proposed. It adopts an outer-rotor topology, which can help generate a large drive torque, in order to achieve prominent dynamic performance of the vehicle. Moreover, by adopting single-layer concentrated-windings, fault-tolerant teeth, and the optimal combination of slot and pole numbers, the proposed motor inherently offers negligible electromagnetic coupling between different phase windings, hence, it possesses a fault-tolerant characteristic. Meanwhile, the phase back electromotive force waveforms can be designed to be sinusoidal by employing PMs with a trapezoidal shape, eccentric armature teeth, and unequal tooth widths. The electromagnetic performance is comprehensively investigated and the optimal design is conducted by using the finite-element method.
The Supportive Roles of Adults in Designing with Young Deaf Children

Involving users in the research and design of new technologies is particularly relevant for groups affected by digital exclusion and lacking in cultural power, such as people with disabilities, people from cultural minorities, and children. Design with young Deaf children lies at the intersection of these three groups, as the medical community defines physical deafness as a disability; Deaf communities around the world identify as minority cultural groups with their own languages; and young children traditionally lack power in interactions with adults. Deaf children bring particular needs, abilities and experiences related to their youth, physical deafness and cultural Deafness to the technology design process, making their involvement in design vital. Their involvement presents a unique set of challenges and ethical considerations, including matters of consent and behaviour management. Adult involvement in supportive roles can facilitate young Deaf children’s involvement in design activities and address some of the challenges of designing with Deaf children. This article presents a case study that involved young Australian Deaf children as design partners, with their family members and Deaf and hearing education professionals in supportive roles, for the purpose of providing recommendations to researchers and designers who wish to undertake similar design activities with young Deaf children and supportive adults. The case study involved a series of 30-minute design sessions with four Deaf children (ages 3-5). Reflections on this case study will discuss the roles adult design team members took throughout the design sessions, the benefits and challenges of involving adults as members of design teams with young Deaf children, and ethical considerations to be addressed when designing with young Deaf children in design teams. The article concludes with recommendations for researchers and designers conducting design sessions with young Deaf children and adult supporters, so that young Deaf child designers are well-supported and have the freedom to explore their preferences, desires, requirements, and to contribute to design solutions.
Relationships between magnetization and dynamic stress for Galfenol rod alloy and its application in force sensor

Magnetization versus dynamic stress of Fe81.6Ga18. 4 is measured at 4.0 kA/m bias magnetic field and −7.0 MPa compressive pre-stress. The magnetization and stress curves show that magnetization decreases with increasing compressive stress. Magnetization increases with increasing stress frequency at −20 MPa compounded stress. The output voltage from the pickup coil of a Galfenol force sensor is measured when the frequency and amplitude of dynamic force vary. The measurements show that the output voltage increases proportionally with increasing force frequency and amplitude. When the bias magnetic field is 4.0 kA/m, a maximum output voltage of 57 mV is measured at −7.0 MPa compressive pre-stress.
Nanowire metal-oxide-semiconductor field effect transistor with doped epitaxial contacts for source and drain

The authors report the fabrication of a p-field effect transistor (FET) and an n-FET with a silicon nanowire channel and doped silicon source and drain regions. The silicon nanowires were synthesized by the vapor-liquid-solid method. For p-FETs the source and drain regions were formed by adding boron doped silicon to the unintentionally doped nanowire body at predefined locations using in situ doped silicon epitaxy. For n-FETs the epitaxial source and drain regions were grown undoped and were later implanted with P and As. The measured Id-Vg characteristics of the devices exhibited unipolar transport, while reference FETs made with nanowires from the same batch but with Schottky (metal) contacts exhibited ambipolar characteristics.
Anisotropy of optical absorption in birefringent porous silicon

Strong polarization-sensitive anisotropy of the optical absorption in the visible and infrared spectral range is observed in porous silicon (PSi) layers formed from bulk (110) Si wafers. It is shown that the anisotropy of the absorption via band-to-band and intraband (Drude-like) electronic transitions is consistent with the strong birefringence of these layers. Both phenomena are described by a model considering the form anisotropy in the (110) PSi layer assembled from nonspherical Si nanocrystals. We show that the anisotropic shape of the nanocrystals results in polarization-sensitive absorption by their surface silicon-hydrogen bonds. This allows an exact assignment of the stretching modes of silicon monohydride in the infrared absorption spectra of the PSi layers.
Optimization of Parametric Periodograms for the Study of Density Fluctuations in a Supersonic Jet

In our research on the density fluctuations of a supersonic jet we were confronted with a quite difficult problem. In the power spectrum obtained either with a spectrum analyzer, the peaks of the two of the modes that we wanted to identify overlapped. We needed to find a signal processing method that would resolve the two main frequencies. We made a thorough investigation of several methods and thought that parametric periodograms were the appropriate tool. The use of parametric periodograms in signal processing requires constant training. The proper application of this tool depends on the determination of the number of parameters that has to be used to best model a real signal. The methods generally used to determine this number are subjective, depending on trial and error and on the experience of the user. Some of these methods rely on the minimization of the estimated variance of the linear prediction error , as a function of the number of parameters n. In many cases, the graph vs n doesn’t have a minimum, and the methods cannot be used. In this paper, we show that there is a strong relationship between and the frequency resolution . That is, as we modify , we obtain graphs of vs n that present at least one minimum. The spectrum obtained with this optimal number of parameters, always reproduces the frequency information of the original signal. In this paper, we present basically the signal processing of the data obtained in a Rayleigh scattering experiment on a supersonic jet that has also been designed by the authors.
Magnetization reversal as a nonlinear multimode process

Dynamic magnetization reversal has been simulated in a single grain for an instantaneously applied reversal magnetic field. The grain was considered as a system of n(=2,4,8) subgrains with uniaxial anisotropy coupled by exchange interaction. The gyromagnetic equations of motion were solved without phenomenological damping terms. The evolution of the magnetization was found to exhibit nonlinear spin wave excitation on a short timescale. The average magnetization significantly decreases and demonstrates irregular oscillations at a well defined mean value. The final stage of reversal is the spin-lattice damping on a longer time scale. The magnetic moment is, thereby, reassembled in a new equilibrium direction.
Lattice-Boltzmann Method for Macroscopic Porous Media Modeling

An extension to the basic lattice-BGK algorithm is presented for modeling a simulation region as a porous medium. The method recovers flow through a resistance field with arbitrary values of the resistance tensor components. Corrections to a previous algorithm are identified. Simple validation tests are performed which verify the accuracy of the method, and demonstrate that inertial effects give a deviation from Darcy's law for nominal simulation velocities.
Adaptive design and characterization of features for SAR ATR

Synthetic aperture radar (SAR) is an essential sensor for military surface surveillance because of its unique ability to operate day or night through weather, smoke and dust. Of particular importance is the problem of automatic target recognition (ATR) which aims to identify targets of military significance within radar images. The Defence Evaluation and Research Agency of the UK has a substantial program of research into ATR algorithms for SAR battlefield surveillance. This covers both feature-based techniques which are the subject of this paper and model-based techniques. Feature-based ATR discriminates between target classes on the basis of the values taken by certain target features. The conventional approach is to select the best features for a particular task from a large set of features which have been pre-defined on the basis of physical intuition. A simple feature might be target area whilst a more sophisticated feature might be some measure of fractal dimension. ATR performance will be influenced by the type of features used and by the accuracy with which the statistical behavior of these features despite limited examples of target realizations. It also addresses the problem of feature choice by introducing a method for adaptive feature design which automatically recognizes the information not already contained in the existing feature set and develops a feature to represent this missing information. These ideas are illustrated by application to synthetic aperture radar images of vehicles.
Emerging liquid crystal waveguide technology for low SWaP active short-wave infrared imagers

Raytheon’s innovative active short wave infrared (SWIR) imager uses Vescent Photonic’s emerging liquid crystal waveguide (LCWG) technology to continuously steer the illumination laser beam over the imager field of view (FOV). This approach instantly illuminates a very small fraction of the FOV, which significantly reduces the laser power compared to flash illumination. This reduced laser power directly leads to a reduction in the size, weight and power (SWaP) of the laser. The reduction in laser power reduces the input power and thermal rejection, which leads to additional reduction in the SWaP of the power supplies and thermal control. The high-speed steering capability of the LCWG enables the imager’s SWaP reduction. The SWaP reduction is possible using either global or rolling shutter detectors. In both cases, the LCWG steers the laser beam over the entire FOV while the detector is integrating. For a rolling shutter detector, the LCWG synchronizes the steering with the rolling shutter to illuminate only regions currently integrating. Raytheon’s approach enables low SWaP active SWIR imagers without compromising image quality. This paper presents the results of Raytheon’s active SWIR imager demonstration including steering control and synchronization with the detector integration.
Prebreakdown and breakdown effects in AlGaN/GaN heterostructure field effect transistors

Prebreakdown and breakdown effects under high electric fields in AlGaN/GaN heterojunction field effect transistors were studied. In the subthreshold regime, at large drain-to-source voltages (>80 V), along with the gate leakage current, a significant source current was measured. For a wide range of gate-to-source bias voltages in OFF and ON regimes, the breakdown voltage was limited by a rapid buildup of the source current, rather than a process dominated by gate leakage.
LINE IDENTIFICATION IN THE SPECTRUM OF HD 213918.

Line identifications are presented for the spectrum of the peculiar star HD 213918, the only peculiar star found which is a probable member of the Lacerta OB1 association. Spectrograms on which the identifications are based were obtained with the coude feed system at Kitt Peak with a linear dispersion of 16.9 A/mm. Among the atomic species found with lines between 3700 and 4700 A are the first three ionization states of Fe, P II, P III, Cl II, Sr II and Hg II. THe U-B color index of -0.53 is used to derive an effective temperature of 14,800 K. Results suggest the relation of HD 213918 to the He-weak and silicon stars.
Filamentary superclustering in a universe dominated by cold dark matter

The relative orientations of neighboring clusters of galaxies in a universe dominated by cold dark matter (CDM) are examined using N-body simulations. A clear tendency is found for the major axes of neighboring clusters to be aligned for separations up to 10-15/sq h Mpc when all clusters pairs are included. When only those clusters which reside within superclusters are considered, alignments are found over even larger scales, up to about 30/sq h Mpc. The orientations of cluster minor axes also provide supporting evidence of the presence of filamentary rather than sheetlike features in the large-scale mass distributions. These findings agree well with observational results. The results indicate that a CDM-dominated universe can account for many of the observed features of the large-scale structure. 95 refs.