Miracle-dz/UniFAR-FTUs huggingface dataset:
Multi-User Orbital Angular Momentum Based Terahertz Communications

Terahertz (THz) wireless communications are commonly regarded as one of the key technologies of 6G communication. Combined with THz, the newly exploited physical layer transmission dimension orbital angular momentum (OAM) that multiplexes a set of orthogonal modes on the same frequency channel, can unleash its potential in achieving high spectrum efficiency. Currently, most of the research on radio OAM communications focus on the point-to-point scenario in microwave and millimeter-wave (mmWave) bands. In this paper, we propose a uniform circular array (UCA)-based THz multi-user OAM (MU-OAM) communication system including downlink and uplink transmission schemes that simplifies the signal detection to the despiralization and amplitude detection (AD). A salient feature of the proposed MU-OAM communication scheme is lower computational complexity than the traditional MU-MIMO scheme without sacrifacing bit error rate (BER) and achievable sum rate performances, which is validated by mathematical analysis and numerical simulations.
A 2‐D constitutive model for cyclic interface behaviour

The paper concerns a 2‐D constitutive model for interface behaviour between sand and solid inclusions under cyclic loading. The model is based on the experimental results obtained from laboratory direct shear interface tests conducted under both constant normal load (CNL) and constant normal stiffness (CNS) conditions. The model is formulated in terms of interface stresses and relative velocities and has been derived by extending an elastoplastic isotropic model previously formulated for monotonic loading to stress reversal paths. Such extension consists in adding to the isotropic hardening mechanism a kinematic rotational one defined by an inner conical surface rotating around the origin of the stress space. This allows one to store the memory of the previous stress and relative displacement history giving to the model the capability to analyse the interface behaviour under cyclic loading. After a brief description of the criteria governing the monotonic model, the paper describes in detail the features of the kinematic hardening. Finally, the predictions of the model are compared with the experimental results obtained from CNL and CNS interface tests. Copyright © 2002 John Wiley & Sons, Ltd.
Anxiety in pregnancy and stress responsiveness: An exploratory study of heart rate variability, cortisol, and alpha-amylase in the third trimester.

The present study aimed to explore the association between anxiety symptoms, including sleep, and physiological stress responsiveness in pregnant women with and without anxiety, as identified by psychiatric diagnosis. Fifty-four pregnant women with (n = 25) and without (n = 29) anxiety completed a laboratory cognitive stressor (the Stroop Color-Word Task) during the third trimester. Heart rate variability (HRV) (as the root mean square of successive differences, RMSSD) was recorded during baseline, stressor, and recovery periods. Salivary cortisol (sCORT) and alpha amylase (sAA) were measured at four timepoints surrounding the stressor task. Psychometric scales (Penn State Worry Questionnaire [PSWQ], Perceived Stress Scale [PSS], Spielberg Trait Anxiety Inventory Scale [STAI], and Pittsburgh Sleep Quality Index [PSQI]) were collected. Women in the anxiety group exhibited significantly less rebound in HRV (RMSSD, change of 4-ms difference, p = .025) from baseline to recovery following the Stroop than did those in the non-anxiety group. Neither neuroendocrine measure (sCORT, sAA) differed between groups at any measurement period. Across the recording period, lower reported sleep quality (PSQI, p = .0092) and higher subjective stress (PSS, p = .039) were associated with lower RMSSD. The findings suggest that women with and without anxiety in late pregnancy display differences in the degree of autonomic rebound as indicated by HRV following a stressor. In addition, levels of HRV over time were associated with subjective perceptions of increased stress and poor sleep. PREGNANCY AND ANXIOUS: The Role of the Immune and Endocrine Systems (NCT03664128).
Thermographic analysis of electromigration phenomena in aluminum metallization

Electromigration‐induced void growth in Al metallization was investigated by comparing it with the electrical resistance change and the thermographically measured change in temperature distribution. Constant current flowing through two different‐width interconnects in series consistently induced void growth at their junction so that it could be observed with high resolution in the fixed fields of an infrared microscope and an optical microscope. The electrical resistance change occurring as a result of an electromigration test was found to directly reflect a local temperature change resulting from the void growth: a pulse phenomenon in the electrical resistance corresponds to a temperature increase of more than 200 °C around the void‐growing area. This phenomenon can be attributed to a local melting induced by the void growth and to a void healing process after recrystallization of the adjacent Al grains.
Construction and Validation of a Nomogram Clinical Prediction Model for Predicting Osteoporosis in an Asymptomatic Elderly Population in Beijing

Background: Based on the high prevalence and occult-onset of osteoporosis, the development of novel early screening tools was imminent. Therefore, this study attempted to construct a nomogram clinical prediction model for predicting osteoporosis. Methods: Asymptomatic elderly residents in the training (n = 438) and validation groups (n = 146) were recruited. BMD examinations were performed and clinical data were collected for the participants. Logistic regression analyses were performed. A logistic nomogram clinical prediction model and an online dynamic nomogram clinical prediction model were constructed. The nomogram model was validated by means of ROC curves, calibration curves, DCA curves, and clinical impact curves. Results: The nomogram clinical prediction model constructed based on gender, education level, and body weight was well generalized and had moderate predictive value (AUC > 0.7), better calibration, and better clinical benefit. An online dynamic nomogram was constructed. Conclusions: The nomogram clinical prediction model was easy to generalize, and could help family physicians and primary community healthcare institutions to better screen for osteoporosis in the general elderly population and achieve early detection and diagnosis of the disease.
Results from the Martian Radiation Environment Experiment MARIE

One of the three science instruments aboard the 2001 Mars Odyssey spacecraft is the Martian Radiation Environment Experiment, MARIE. MARIE consists of a stack of silicon detectors, augmented by a Cerenkov detector. MARIE is designed to measure a portion of the particle spectrum of the Galactic Cosmic Rays (GCR), as well as the high fluxes of low-energy protons (energies less than about 100 MeV) that are intermittently produced by active regions on the sun in Solar Particle Events (SPE). MARIE is providing the first detailed information about the radiation environment near Mars.measurements. MARIE has been operating successfully for nearly a year. Solar particle events of considerable interest have been observed, and data have been obtained that will yield GCR spectra from a novel observation point in the solar system.
Development and Evaluation of a Novel One-Step RT-qPCR Targeting the Vero Gene for the Identification of False-Positive Results Caused by Inactivated Virus Vaccine Contamination

To identify false-positive SARS-CoV-2 test results caused by novel coronavirus inactivated vaccine contamination, a novel RT-qPCR targeting the ORF1ab and N genes of SARS-CoV-2 and Vero gene was developed. The amplification efficiency, precision, and lower limit of detection (LLOD) of the RT-qPCR assay were determined. A total of 346 clinical samples and 132 environmental samples were assessed, and the diagnostic performance was evaluated. The results showed that the amplification efficiency of the ORF1ab, N, and Vero genes was 95%, 97%, and 93%, respectively. The coefficients of variation of Ct values at a concentration of 3 × 104 copies/mL were lower than 5%. The LLOD for the ORF1ab, N, and Vero genes reached 8.0, 3.3, and 8.2 copies/reaction, respectively. For the 346 clinical samples, our RT-qPCR assay identified SARS-CoV-2-positive and SARS-CoV-2-negative samples with a sensitivity of 100.00% and a specificity of 99.30% and novel coronavirus inactivated vaccine-contaminated samples with a sensitivity of 100% and a specificity of 100%. For the environmental samples, our RT-qPCR assay identified novel coronavirus inactivated vaccine-contaminated samples with a sensitivity of 88.06% and a specificity of 95.38%. In conclusion, the RT-qPCR assay we established can be used to diagnose COVID-19 and, to a certain extent, false-positive results due to vaccine contamination.
Quantum Robust Optimal Control for Linear Complex Quantum Systems With Uncertainties

The aim of this note is to study the quantum robust optimal control problem for a class of linear quantum systems with uncertainties. It is shown that such problem can be converted into a mixed linear quadratic Gaussian and $H^{\infty }$ quantum control problem. A physical model described by complex quantum stochastic differential equations (CQSDEs) is presented for the quantum system with uncertainties. The quantum system described by CQSDEs is called a complex quantum system in terms of annihilation and creation operators (Maalouf and Petersen, 2011). For an uncertain quantum system, we build a connection with a scaled linear system without uncertainty. The desired quantum robust optimal control results are derived based on the connection. We provide one numerical procedure for quantum robust optimal controller synthesis and then provide an example. The resulting controller presents robustness and optimal performance.
The Amelioration of Grazing through Physiological Integration by a Clonal Dune Plant

Rhizomatous growth and associated physiological integration can allow a clonal dune species to potentially compensate for the selective removal of leaves associated with herbivory. Hydrocotyle bonariensis is a rhizomatous clonal plant species that is abundant in the coastal dune environments of the southeastern United States that are inhabited by large feral horse populations. H. bonariensis has been shown to integrate resources among ramets within extensive clones as an adaptation to resource heterogeneity in sandy soils. In this study, we hypothesized that clonal integration is a mechanism that promotes H. bonariensis persistence in these communities, despite high levels of herbivory by feral horses. In a field experiment, we used exclosures to test for herbivory in H. bonariensis over a four-month period. We found that feral horses utilized H. bonariensis as a food species, and that while grazing will suppress clonal biomass, H. bonariensis is able to maintain populations in a high grazing regime with and without competition present. We then conducted an experiment in which portions of H. bonariensis clones were clipped to simulate different levels of grazing. Half of the clones were severed to eliminate the possibility of integration. We found that after 12 weeks, the mean number of leaves and ramets increased as the grazing level increased, for integrated clones. Integrated clones had significantly increased biomass production compared to the severed equivalents. Our research suggests that rhizomatous growth and physiological integration are traits that allow clonal plant species to maintain populations and to tolerate grazing in coastal dune environments.
Young Stellar Nuclei in the Lenticular Galaxies. II. NGC 7280

We have undertaken bidimensional spectroscopy of the central part of the nearby lenticular galaxy NGC 7280 with the Multi-Pupil Fiber Spectrograph of the 6 m telescope of the Special Astrophysical Observatory. We find a rather young stellar nucleus, with a mean population age of 1.5 ± 0.5 Gyr, which is more metal-rich than the bulge at R ≈ 1 kpc by an order of magnitude. The chemically and age-decoupled nucleus seems to be spatially resolved: the circumnuclear absorption index isolines represent ellipses elongated in P.A. ≈ 100°–110°. The same orientation, P.A. = 103°, is found for the elongated circumnuclear stellar structure, revealed from the morphological analysis of the Hubble Space Telescope (HST) WFPC2 and NICMOS images of NGC 7280 and seen best of all at R = 1″. Taking into account the stellar kinematics inside R ≈ 2″, we conclude that this structure is a circumnuclear stellar disk inclined with respect to the global plane of the galaxy. Meanwhile, both photometric and kinematical data in the radius range 2″–8″ imply the existence of an intermediate-scale bar elongated in P.A. ≈ 60°. The circumnuclear ionized gas is distributed and rotates in the plane orthogonal to the plane of the circumnuclear stellar disk.
Novel Design Methodology for 3D-Printed Lenses for Travelling Wave Antennas

A novel methodology is introduced for designing bespoke homogeneous and graded index lenses for enhancing the gain of travelling wave antenna arrays (TWAs). 3D-printed lenses in the literature are majorly explored with standing wave antennas (SWAs) such as a microstrip or a horn antenna for gain enhancement. As there is progressively less power radiated from each slot in a TWA, as well as the successive phase delay between slots, the existing lens design approaches used for SWAs is not optimal for TWAs. Accordingly, we present a new approach of introducing a curvature to the lens that is derived from studying the power radiation profile of each slot of the TWA. This new methodology is demonstrated on a dielectric filled waveguide (DFW) slot array antenna operating at 26 – 30 GHz band. An optimized dielectric graded lens and an optimized homogeneous lens have both been designed, fabricated, and measured with the DFW slot array. The new lens demonstrated a gain enhancement of more than 7 dB compared to less than 4 dB with conventional dielectric lenses. The proposed lens theory has been further verified with a bespoke optimized lens for a periodic stub-loaded microstrip leaky-wave antenna with a beam-scanning of 65°. Design rules are included that can be applied for any TWA.
Inexact Subspace Iteration to Accelerate the Solution of Linear Systems with Multiple Right-Hand Sides

We propose a two-phase acceleration technique for the solution of Symmetric and Positive Definite (SPD) linear systems with multiple right-hand sides. In the first phase we compute some partial spectral information related to the ill conditioned part of the given coefficient matrix and, in the second phase, we use this information to improve the convergence of the Conjugate Gradient (CG) algorithm. This approach is adequate for large scale problems, like the simulation of time dependent differential equations, where it is necessary to solve consecutively several linear systems with the same coefficient matrix (or with matrices that present very close spectral properties) but with changing right-hand sides. To compute the spectral information, we combine the block Conjugate Gradient algorithm with the Subspace Iteration to build a purely iterative algorithm, that we call Block-CGSI. We analyze the convergence of the blockCG algorithm and exploit the possibility of reducing the total amount of computational work by controlling in a same appropriate manner the accuracy during the solution of linear systems at each subspace iteration. We also improve the global convergence of this algorithm by using Chebyshev polynomials as a spectral filtering tool when building the starting vectors. The concept of “sliding window” was also introduced as an algorithmic feature that enables the computation of a near-invariant subspace of any dimension. The spectral information computed by the BlockCGSI algorithm is then used to remove the effect of the smallest eigenvalues in two different ways: either by building a Spectral Low Rank Update (SLRU) preconditioner that basically adds the value 1 to the approximated eigenvalues, or by performing a deflation of the initial residual in order to remove part of the solution corresponding to the smallest eigenvalues. Both techniques yield important reductions of the total number of iterations and computational work in each subsequent runs of the Conjugate Gradient algorithm. We report on experiments on a 2D diffusion equation as well as on two applications coming from Computational Fluid Dynamics (CFD). The analysis of costs and benefits, in terms of floating point operations, helps to validate the strategy as a good way to speed up the solution of symmetric and positive definite linear systems
Recent advances in frequency domain techniques for electromagnetic scattering problems

Some recent applications of numerical techniques for the analysis of electromagnetic scattering problems involving several general classes of geometries are reviewed. The solution procedures are all formulated directly in the frequency domain, using the method of moments or the finite-element method, in terms of an integral equation and/or a partial differential equation. Geometrical configurations discussed include three-dimensional conducting scatterers and two- and three-dimensional homogeneous and inhomogeneous dielectric scatterers. >
Digital academic entrepreneurship: knowledge and public value from an Italian case study

ABSTRACT The paper investigates the impact of digital technologies in the academic entrepreneurship by enhancing the creation of public value and engaging with stakeholders in all the stages of the entrepreneurial process. We analyse the university of Bari as a pilot case to show emerging digital technologies in the academic environment. The research question is answered through a single case study approach based on Yin’s prescriptions.The analysis consists in a single case study and includes semi-structured interviews with student representatives, the Rector, the General Director, the IT coordinator and the academic delegate for innovation. The paper is novel because describes the impact of digital technologies, as forms of knowledge, on the entrepreneurial process of a public academic institution with the creation of public value. We show how digital technologies enhance the creation of public value for the stakeholders of the University of Bari. The results of this research are relevant for academic institutions seeking to implement digitalisation processes in their ecosystem.
Structure and dynamics of complex systems

A family of navigation algorithms for packet transport in complex networks is introduced. These algorithms use deterministic and probabilistic rules which depend, in di erent ways, on the degree of the node, packet ow and the temporal properties of packet delivery and distribution. On scale-free networks all our algorithms can handle a larger load than the random walk algorithm. I examined the uctuation properties of packet tra c on scale-free networks and random graphs using random di usion and a locally navigated di usive motion with preferred edges. I found that preferential behaviour in either the topology or in the dynamics leads to the scaling of uctuations of the number of packets passing nodes and the number of packets owing along edges, respectively. I showed that the absence of any preference results in the absence of scaling. Broad distributions of the return times at nodes and edges illustrate that the basis of the observed scaling is the cooperative behaviour between groups of nodes or edges. I presented an empirical study of the networks created by users within internet news groups and forums and showed that they organise themselves into scale-free trees. The structure of these trees depends on the topic under discussion; specialist topics have trees with a short shallow structure whereas more universal topics are discussed widely and have a deeper tree structure. The correlation function of activity shows long range correlations connected
NASA A COMPARISON OF RADIATIVE TRANSFER MODELS FOR PREDICTING THE MICROWAVE EMISSION FROM SOILS

Two general types of numerical models for predicting microwave emission from soils are com-pared—coherent and noncoherent. In the former, radiation in the soil is treated coherently, ai,d the boundary conditions on the electric fields across the layer boundaries are used to calculate the radiation intensity. In the latter, the radiation is assumed to be noncoherent, and the intensities of the radiation are considered directly. The results from the two approaches may be different because of the effects of interference, which can cause the transmitted intensity at the surface (i.e., emissivity) to be sometimes higher and sometimes lower for the coherent case than for the noncoherent case, depending on the relative phases of the reflected fields from the lower layers. This coupling between soil layers in the coherent models leads to greater soil moisture sampling depths observed with this type of model, and is the major difference that is found between the two types of models. In noncoherent models, the emissivity is determined by the dielectric contract at the air/soil interface. The subsequent differences in the results are functions of both the frequency of the radiation being considered and the steepness of the moisture gradient near the surface. The
All-Metal Monopulse Antenna Array in the Ka-Band With a Comparator Network Combining Ridge and Groove Gap Waveguides

This letter presents an all-metal three-layer monopulse antenna based on gap waveguide technology operating in <italic>Ka</italic>-band. (specifically from 29 to 31 GHz) for direction-finding applications. This contribution stands out mainly for the simplicity of its single-layer comparator network (layer 1) composed of a combination of ridge and groove gap waveguides. Also, the compactness of the feed network (layer 2) allows for a low-profile monopulse antenna comprising only three aluminum pieces. The antenna is bottom-fed through three ports connected, two of them to the comparator network, and one directly to the corporate-feed network, to achieve one sum (<inline-formula><tex-math notation="LaTeX">$\Sigma$</tex-math></inline-formula>) and two difference patterns (<inline-formula><tex-math notation="LaTeX">$\Delta _{H}$</tex-math></inline-formula>, <inline-formula><tex-math notation="LaTeX">$\Delta _{E}$</tex-math></inline-formula>). Experimental results validate the concept, showing a close agreement with simulations. The measured null depth is close to <inline-formula><tex-math notation="LaTeX">$-$</tex-math></inline-formula>30 dB in both difference patterns, and the sum pattern achieves 26.9 dBi directivity with a realized radiation efficiency greater than 80<inline-formula><tex-math notation="LaTeX">$\%$</tex-math></inline-formula>.
Thinking Functionally with Haskell: What is functional programming?

Preface 1. What is functional programming? 2. Expressions, types and values 3. Numbers 4. Lists 5. A simple Sudoku solver 6. Proofs 7. Efficiency 8. Pretty-printing 9. Infinite lists 10. Imperative functional programming 11. Parsing 12. A simple equational calculator Index.