Miracle-dz/UniFAR-FTUs huggingface dataset:
Evaluations of the predistortion technique by neural network algorithm in MIMO-OFDM system using USRP

MIMO OFDM is the key technology of 4G network system. MIMO-OFDM system enhances the spectrum efficiency and increases the capacity of the system. The implementation of USRP hardware to MIMO OFDM system has been attracted some researchers to conduct the experiments. So we conduct the experiments in a MIMO OFDM system that applies the predistortion technique. In this experiment, we evaluate performances of the predistortion technique by using the artificial neural network. USRP 2920 hardware which is supported by LabVIEW and Phyton software are used in this experiment. OFDM system uses 128 subcarriers to produce an OFDM symbol, and MIMO system uses 2 antennas at transmitter and receiver side. And no obstacles between Tx and Rx, or line of sight transmission scenarios. The performances of the predistortion technique using the artificial neural network algorithm are shown in symbol constellations or Error Vector Magnitude (EVM) at the receiver. And the texts or characters are used as the input of the system. From the experiment results can be seen that the distance between Tx and Rx affects the Error Vector Magnitude (EVM) and predistortion technique produces the Error vector magnitude (EVM) improvement. More shorter the distance between Tx and Rx can decrease distortions of the received signal, At the transmitter side, the performance of predistortion technique is shown as the linearization improvement of the non-linearity power amplifier. Therefore more wider the linear region of power amplifier results the decreasing in band distortion of transmitted signal, and can be seen as the Error Vector Magnitude (EVM) improvement.
A deep probe of the galaxy stellar mass functions at z ∼ 1―3 with the GOODS NICMOS Survey

We use a sample of 8298 galaxies observed as part of the Hubble Space Telescope (HST) H 160 -band GOODS NICMOS Survey (GNS) to construct the galaxy stellar mass function both as a function of redshift and as stellar mass up to z = 3.5. Our mass functions are constructed within the redshift range z = 1-3.5 and consist of galaxies with stellar masses of M * = 10 12 M ⊙ down to nearly dwarf galaxy masses of M * = 10 8.5 M ⊙ in the lowest redshift bin. We discover that a significant fraction of all massive M * > 10 11 M ⊙ galaxies are in place up to the highest redshifts we probe, with a decreasing fraction of lower mass galaxies present at all redshifts. This is an example of 'galaxy mass downsizing', and is the result of massive galaxies forming before lower mass ones, and not just simply ending their star formation earlier as in traditional downsizing scenarios, whose effect is seen at z 2. We furthermore show that, although there is a downsizing such that high-mass galaxies are nearer their z = 0 values at high redshift, this turns over at masses M * ∼ 10 10 M ⊙ , such that the lowest mass galaxies are more common than galaxies at slight higher masses, creating a 'dip' in the observed galaxy mass function. We argue that the galaxy assembly process may be driven by different mechanisms at low and high masses, and that the efficiency of the galaxy formation process is lowest at masses M * ~ 10 10 M ⊙ at 1 < z < 3. Finally, we calculate the integrated stellar mass density for the total, blue and red populations. We find the integrated stellar mass density of the total and blue galaxy population is consistent with being constant over z = 1-2, while the red population shows an increase in integrated stellar mass density over the same redshift range.
Eternal traversable wormhole

We construct a nearly-$AdS_2$ solution describing an eternal traversable wormhole. The solution contains negative null energy generated by quantum fields under the influence of an external coupling between the two boundaries. In parallel, we discuss two SYK systems coupled by a relevant interaction. The physics of the two cases is very similar. They both share a "gravitational" subsector which is identical. The solution within this subsector sets the stage for dynamics which is almost conformal invariant. We study this system in detail, both in gravity and in the SYK model. The coupled SYK models have an interesting phase diagram at finite temperature, displaying the usual Hawking-Page transition between the thermal AdS phase at low temperature and the black hole phase at high temperature. Interestingly, these two phases are continuously connected in the microcannonical ensemble.
The 2.35 year itch of Cygnus OB2 #9. I. Optical and X-ray monitoring

Context. Nonthermal radio emission in massive stars is expected to arise in wind-wind collisions occurring inside a binary system. One such case, the O-type star Cyg OB2 #9, was proven to be a binary only four years ago, but the orbital parameters remained uncertain. The periastron passage of 2011 was the first one to be observable under good conditions since the discovery of binarity. Aims. In this context, we have organized a large monitoring campaign to refine the orbital solution and to study the wind-wind collision. Methods. This paper presents the analysis of optical spectroscopic data, as well as of a dedicated X-ray monitoring performed with Swift and XMM-Newton. Results. In light of our refined orbital solution, Cyg OB2 #9 appears as a massive O+O binary with a long period and high eccentricity; its components (O5-5.5I for the primary and O3-4III for the secondary) have similar masses and similar luminosities. The new data also provide the first evidence that a wind-wind collision is present in the system. In the optical domain, the broad Hα line varies, displaying enhanced absorption and emission components at periastron. X-ray observations yield the unambiguous signature of an adiabatic collision, because as the stars approach periastron, the X-ray luminosity closely follows the 1/D variation expected in that case. The X-ray spectrum appears, however, slightly softer at periastron, which is probably related to winds colliding at slightly lower speeds at that time. Conclusions. It is the first time that such a variation has been detected in O+O systems, and the first case where the wind-wind collision is found to remain adiabatic even at periastron passage.
The central dynamics of M3, M13, and M92: stringent limits on the masses of intermediate-mass black holes

We used the PMAS integral field spectrograph to obtain large sets of radial velocities in the central regions of three northern Galactic globular clusters: M3, M13, and M92. By applying the novel technique of crowded field 3D spectroscopy, we measured radial velocities for about 80 stars within the central ~ 10 arcsec of each cluster. These are by far the largest spectroscopic datasets obtained in the innermost parts of these clusters up to now. To obtain kinematical data across the whole extent of the clusters, we complement our data with measurements available in the literature. We combine our velocity measurements with surface brightness profiles to analyse the internal dynamics of each cluster using spherical Jeans models, and investigate whether our data provide evidence for an intermediate-mass black hole in any of the clusters. The surface brightness profiles reveal that all three clusters are consistent with a core profile, although shallow cusps cannot be excluded. We find that spherical Jeans models with a constant mass-to-light ratio provide a good overall representation of the kinematical data. A massive black hole is required in none of the three clusters to explain the observed kinematics. Our 1sigma (3sigma) upper limits are 5300 M_sun (12000 M_sun) for M3, 8600 M_sun (13000 M_sun) for M13, and 980 M_sun (2700 M_sun) for M92. A puzzling circumstance is the existence of several potential high velocity stars in M3 and M13, as their presence can account for the majority of the discrepancies that we find in our mass limits compared to M92.
Signatures of topological phase transitions in Josephson current-phase discontinuities

Topological superconductors differ from topologically trivial ones for the presence of topologically protected zero-energy modes. To date, experimental evidence of topological superconductivity in nanostructures has been mainly obtained by measuring the zero-bias conductance peak via tunneling spectroscopy. Here, we propose an alternative and complementary experimental recipe to detect topological phase transitions in these systems. We show in fact that, for a finite-sized system with broken time-reversal symmetry, discontinuities in the Josephson current-phase relation correspond to the presence of zero-energy modes and to a change in the fermion parity of the groundstate. Such discontinuities can be experimentally revealed by a characteristic temperature dependence of the current, and can be related to a finite anomalous current at zero phase in systems with broken phase-inversion symmetry.
Grain alignment by radiative torques in special conditions and implications

Grain alignment by radiative torques (RATs) has been extensively studied for various environment conditions, including interstellar medium, dense molecular clouds, and accretion disks, thanks to significant progress in observational, theoretical and numerical studies. In this paper, we explore the alignment by RATs and provide quantitative predictions of dust polarization for a set of astrophysical environments that can be tested observationally. We first consider the alignment of grains in the local interstellar medium and compare predictions for linear polarization by aligned grains with recent observational data for nearby stars. We then revisit the problem of grain alignment in accretions disks by taking into account the dependence of RAT alignment efficiency on the anisotropic direction of radiation fields relative to magnetic fields. Moreover, we study the grain alignment in interplanetary medium, including diffuse Zodiacal cloud and cometary comae, and calculate the degree of circular polarization (CP) of scattered light arising from single scattering by aligned grains. We also discuss a new type of grain alignment, namely the alignment with respect to the ambient electric field instead of the alignment with the magnetic field. We show that this type of alignment can allow us to reproduce the systematic features of CP observed across a cometary coma. Our findings suggest that polarized Zodiacal dust emission may be an important polarized foreground component, which should be treated carefully in cosmic microwave background experiments.
Witnessing causal nonseparability

Our common understanding of the physical world deeply relies on the notion that events are ordered with respect to some time parameter, with past events serving as causes for future ones. Nonetheless, it was recently found that it is possible to formulate quantum mechanics without any reference to a global time or causal structure. The resulting framework includes new kinds of quantum resources that allow performing tasks—in particular, the violation of causal inequalities—which are impossible for events ordered according to a global causal order. However, no physical implementation of such resources is known. Here we show that a recently demonstrated resource for quantum computation—the quantum switch—is a genuine example of ‘indefinite causal order’. We do this by introducing a new tool—the causal witness—which can detect the causal nonseparability of any quantum resource that is incompatible with a definite causal order. We show however that the quantum switch does not violate any causal inequality.
The young nuclear stellar disc in the SB0 galaxy NGC 1023

Small kinematically-decoupled stellar discs with scalelengths of a few tens of parsec are known to reside in the centre of galaxies. Different mechanisms have been proposed to explain how they form, including gas dissipation and merging of globular clusters. Using archival Hubble Space Telescope imaging and ground-based integral-field spectroscopy, we investigated the structure and stellar populations of the nuclear stellar disc hosted in the interacting SB0 galaxy NGC 1023. The stars of the nuclear disc are remarkably younger and more metal rich with respect to the host bulge. These findings support a scenario in which the nuclear disc is the end result of star formation in metal enriched gas piled up in the galaxy centre. The gas can be of either internal or external origin, i.e. from either the main disc of NGC 1023 or the nearby satellite galaxy NGC 1023A. The dissipationless formation of the nuclear disc from already formed stars, through the migration and accretion of star clusters into the galactic centre is rejected.
STAR FORMATION RELATIONS IN THE MILKY WAY

The relations between star formation and properties of molecular clouds (MCs) are studied based on a sample of star-forming regions in the Galactic Plane. Sources were selected by having radio recombination lines to provide identification of associated MCs and dense clumps. Radio continuum emission and mid-infrared emission were used to determine star formation rates (SFRs), while 13CO and submillimeter dust continuum emission were used to obtain the masses of molecular and dense gas, respectively. We test whether total molecular gas or dense gas provides the best predictor of SFR. We also test two specific theoretical models, one relying on the molecular mass divided by the free-fall time, the other using the free-fall time divided by the crossing time. Neither is supported by the data. The data are also compared to those from nearby star-forming regions and extragalactic data. The star formation “efficiency,” defined as SFR divided by mass, spreads over a large range when the mass refers to molecular gas; the standard deviation of the log of the efficiency decreases by a factor of three when the mass of relatively dense molecular gas is used rather than the mass of all of the molecular gas.
Can stellar activity make a planet seem misaligned

Several studies have shown that the occultation of stellar active regions by the transiting planet can generate anomalies in the high-precision transit light curves, and these anomalies may lead to an inaccurate estimate of the planetary parameters (e.g., the planet radius). Since the physics and geometry behind the transit light curve and the Rossiter- McLaughlin effect (spectroscopic transit) are the same, the Rossiter-McLaughlin observations are expected to be affected by the occultation of stellar active regions in a similar way. In this paper we perform a fundamental test on the spin-orbit angles as derived by Rossiter-McLaughlin measurements, and we examine the impact of the occultation of stellar active regions by the transiting planet on the spin-orbit angle estimations. Our results show that the inaccurate estimation on the spin-orbit angle due to stellar activity can be quite significant (up to 30 degrees), particularly for the edge-on, aligned, and small transiting planets. Therefore, our results suggest that the aligned transiting planets are the ones that can be easily misinterpreted as misaligned owing to the stellar activity. In other words, the biases introduced by ignoring stellar activity are unlikely to be the culprit for the highly misaligned systems.
NGC628 with SITELLE: I. Imaging spectroscopy of 4285 H ii region candidates

This is the first paper of a series dedicated to nebular physics and the chemical evolution of nearby galaxies by investigating large samples of HII regions with the CFHT imaging spectrograph SITELLE. We present a technique adapted to imaging spectroscopy to identify and extract parameters from 4285 HII region candidates found in the disc of NGC628. Using both the spatial and spectral capabilities of SITELLE, our technique enables the extraction of the position, dust extinction, velocity, Halpha profile, diffuse ionised gas (DIG) background, luminosity, size, morphological type, and the emission line fluxes for individual spaxels and the integrated spectrum for each region. We have produced a well-sampled HII region luminosity function and studied its variation with galactocentric radius and level of the DIG background. We found a slope of 1.12+/-0.03 with no evidence of a break at high luminosity. Based on the width of the region profile, bright regions are rather compact, while faint regions are seen over a wide range of sizes. The radius function reveals a slope of 1.81+/-0.02. BPT diagrams of the individual spaxels and integrated line ratios confirm that most detections are HII regions. Also, maps of the line ratios show complex variations of the ionisation conditions within HII regions. All this information is compiled in a new catalogue for HII regions. The objective of this database is to provide a complete sample which will be used to study the whole parameter space covered by the physical conditions in active star-forming regions.
Ground-state g factor of middle-Z boronlike ions

Theoretical calculations of the interelectronic-interaction and QED corrections to the g factor of the ground state of boronlike ions are presented. The first-order interelectronic-interaction and the self-energy corrections are evaluated within the rigorous QED approach in the effective screening potential. The second-order interelectronic interaction is considered within the Breit approximation. The nuclear recoil effect is also taken into account. The results for the ground-state g factor of boronlike ions in the range Z = 10-20 are presented and compared to the previous calculations.
Appearance of a 
Td*
 phase across the 
Td−1T′
 phase boundary in the Weyl semimetal 
MoTe2

Using elastic neutron scattering on single crystals of ${\mathrm{MoTe}}_{2}$ and ${\mathrm{Mo}}_{1\ensuremath{-}x}{\mathrm{W}}_{x}{\mathrm{Te}}_{2}$ ($x\ensuremath{\lesssim}0.01$), the temperature dependence of the recently discovered ${T}_{d}^{*}$ phase, present between the low-temperature orthorhombic ${T}_{d}$ phase and high-temperature monoclinic $1{T}^{\ensuremath{'}}$ phase, is explored. The ${T}_{d}^{*}$ phase appears only on warming from ${T}_{d}$ and is observed in the hysteresis region prior to the $1{T}^{\ensuremath{'}}$ transition. This phase consists of four layers in its unit cell, and is constructed by an ``AABB'' sequence of layer stacking operations rather than the ``AB'' and ``AA'' sequences of the $1{T}^{\ensuremath{'}}$ and ${T}_{d}$ phases, respectively. Though the ${T}_{d}^{*}$ phase emerges without disorder on warming from ${T}_{d}$, on cooling from $1{T}^{\ensuremath{'}}$ diffuse scattering is observed that suggests a frustrated tendency toward the ``AABB'' stacking.
The Effect of Active Stretching Training in Patients with Chronic Venous Insufficiency Monitored by Raster-Stereography

(1) Background: Musculoskeletal disorders can be associated with advanced clinical stages of chronic venous insufficiency (CVI). The aim of the study is to investigate the effect of active stretching (AS) training on lower limb venous function and quality of life in patients affected by CVI. (2) Methods: A prospective two-armed pilot randomized controlled was conducted. Twenty (20) CVI patients were randomly assigned to an AS training or to a control group (C) who did not receive any exercise indication. At baseline and after three months all the participants were tested for leg volumetry (LV), air plethysmography (APG), and quality of life (QoL) measured by a disease specific validated questionnaire (VVSymQ), ankle range of motion (ROM), and postural deformities using an optoelectronic body posture machine. (3) Results: At the end of the training in the AS group a significant leg volume reduction was detected (from 2340 ± 239 mL to 2239 ± 237 mL (4.3%); p < 0.0001), whereas in the C group no significant volume changes were found. The ejection fraction rate (EF%) increased significantly from 49.3 ± 9.3 to 61.1 ± 14.5, p < 0.005. A moderate-strong linear correlation with EF% and ankle ROM variation was found (R2 = 0.6790; p < 0.0034). Several postural outcomes such as pelvic tilt, pelvic torsion, and lordotic angle significantly improved in the AS group (p < 0.01, p < 0.04, p < 0.01 respectively). (4) Conclusion: The AS training impacts on the APG parameters related to the musculoskeletal pump efficiency, opening a further possibility in the management of CVI patients by means of an appropriate adapted physical exercise program.
Field-induced magnetic phases and electric polarization in LiNiPO4

Neutron diffraction is used to probe the (H,T) phase diagram of magnetoelectric (ME) LiNiPO4 for magnetic fields along the c axis. At zero field the Ni spins order in two antiferromagnetic phases. One has commensurate (C) structures and general ordering vectors k(C)=(0,0,0); the other one is incommensurate (IC) with k(IC)=(0,q,0). At low temperatures the C order collapses above mu H-0=12 T and adopts an IC structure with modulation vector parallel to k(IC). We show that C order is required for the ME effect and establish how electric polarization results from a field-induced reduction in the total magnetoelastic energy.
Reproductive Potential and Embryonic Lethality of The Blowfly, Chrysomya albiceps (Wiedemann 1819)Influenced by Gamma Radiation

Chrysomya albiceps play a major role as a mechanical vector for plentiful pathogens to humans and animals such as bacteria, viruses, and helminths, as well as causing myiasis in animals. The present study aimed at investigating the effect of gamma radiation on the reproductive potential and embryonic lethality of C. albiceps. Results showed that the number of eggs laid by C. albiceps females resulted from pupae irradiated with different doses of gamma radiation decreased as the dose increased. Also, the non-hatching eggs %was found to be dose-dependent i.e., increased as the dose of the gamma irradiation used increased.The highest reduction in the number of eggs occurred at high doses (10 and 15 Gy) when irradiated females were crossed with non-irradiated males. Non-hatching egg % increased to record 76.6 and 66.8 at 15 and 10 Gy when irradiated females crossed with irradiated males. Gamma radiation resulted in a progressive increase in the sterility % of C. albiceps females as compared with the untreated group. Complete sterility (100.0%) was attained by 20 Gy for all groups. The sterility index was recorded at 96.3% when irradiated females crossed with non-irradiated males.In addition, gamma radiation-induced a progressive increase in egg lethality giving an estimated LD 50 value of 9.3598 Gy when non-irradiated females mated with irradiated males, compared with 10.6257 Gy for egg-lethality laid by irradiated females mated with non-irradiated males. However, the LD 50 value was 3.603 Gy when both males and females were irradiated, respectively. Generally, C. albiceps females were more radiosensitive than their male counterparts.
Resonant exchange interaction in semiconductors

We present a non-perturbative calculation of indirect exchange interaction between two paramagnetic impurities via 2D free carriers gas separated by a tunnel barrier. The new method accounts for the impurity attractive potential producing a bound state. The calculations show that for if the bound impurity state energy lies within the energy range occupied by the free 2D carriers the indirect exchange interaction is strongly enhanced due to resonant tunneling and exceeds by a few orders of magnitude what one would expect from the conventional RKKY approach.