Miracle-dz/UniFAR-FTUs huggingface dataset:
Simplified Chromatic Dispersion Model Applied to Ultrawide Optical Spectra for 60 GHz Radio-Over-Fiber Systems

Radio-over-fiber systems can be harnessed to generate millimeter-wave (mm-wave) frequencies, but the optical impairments such as optical noise, chromatic dispersion, and nonlinearity can degrade the quality of the generated heterodyne signals. When optical frequency comb sources are employed, chromatic dispersion has a main importance since it causes a phase shift and phase decorrelation between optical lines. These both effects subsequently induce power fading and also optical noise on the beat note carrier. With utilizing ultrawide optical spectra, higher order dispersion coefficients must be considered during the propagation across optical fiber, which introduces a high level of complexity in the analytic model. In this paper, we present a simple and convenient model to analyze the impact of chromatic dispersion on the power of the mm-wave heterodyne carrier. The proposed model manipulates and integrates the higher order dispersion terms into an equivalent second-order dispersion term. This allows to perform the easiest way to calculate the propagation constant. Simulation and experimental results are conducted for fiber distance up to 30 km in order to validate the suggested model in terms of the carrier power. Through the results obtained, the well-known behavior between the signal power and chromatic dispersion can be modified. Optical phase shift results in a diverse power fading and intensity noise while optical phase de-correlation manifests phase noise. Therefore, data transmission over 25 km fiber is carried out to show the impact of chromatic dispersion on optical noise of the beating carrier. RF power and error vector magnitude reveal that the chromatic dispersion can overcome power fading and increase the tolerance to fiber length with limiting the optical noise in the optical heterodyning system.
Enhanced Receiver Based on FEC Code Constraints for Uplink NOMA With Imperfect CSI

Non-orthogonal multiple access (NOMA) has been envisioned as a useful component of fifth generation (5G) mobile networks. As imperfect channel state information (CSI) due to channel estimation errors poses problems for most wireless receivers, it presents even greater challenges in successive interference cancellation (SIC) reception of NOMA signals. We present a novel approach to the multi-user detection problem by exploiting the important constraints of forward error correction (FEC) code word. We devise our new receiver based on the minimum output energy (MOE) criterion while preserving a distortionless response to the user equipment (UE) of interest. In particular, we efficiently adopt the UE signatures presented by the FEC channel codes under distinct permutations to separate desired signals of interest from interfering UEs. We formulate our receiver optimization into a quadratic-programming problem anchored with a set of code constraints. Our simulations demonstrate that the proposed code-anchored quadratic programming (CQP) receiver can accurately improve SIC performance and provide robustness to CSI errors better than other legacy schemes.
Model reference resilient control for the helicopter with time‐varying disturbance

In this paper, the problem of model reference resilient control is investigated for the helicopter system with the time‐varying disturbance and unmeasurable states. Firstly, a disturbance observer and a state observer are built to estimate the time‐varying disturbance and unmeasurable states. Then, combining the methods of model reference control and disturbance observer–based control, the state feedback robust resilient control scheme and the dynamic output feedback robust resilient control method are proposed, respectively. Under the two developed robust resilient control schemes, sufficient conditions are obtained to guarantee that the helicopter system asymptotically tracks the reference model with H∞ performance. Finally, simulation results are presented to show the effectiveness of the model reference resilient control method.
OPTICAL SMOKE DETECTOR: AN APPROACH TO SEMICONDUCTORS FIELD FOR HIGH LEVEL EDUCATION STUDENTS

Nowadays, it is undeniable that the amount of technological devices is having a sharp increase all around us, with important benefits and repercussions for the society. Despite this, students are not used to knowing the basic principles of its operations. Hence, it is of utmost importance to approach undergraduate students to a practical example of a device they can find in their daily life. It is a fact that science is interconnected with multiple disciplines, such as Physics and Solid State Chemistry, Materials Science and Engineering. A good example of it is a smoke detector because it combines both optical and electrical behaviour. Such a device contains a chamber inside which there is an infrared LED (light-emitting diode) and a photodiode (light detector). According to the principle of light scattering, when the smoke interrupts the path of light, it will scatter a fraction of light into the photodiode, activating the detector. Thus, detecting low levels of smoke is vital for preventing the fire expansion and occupants can get more time to escape from the premises. The main purpose of this work is to help students to understand the work mechanism of the LED and photodiode in basis of their material composition. In order to do that, a smoke detector is disassembled and its different parts are observed. After that, the microstructure and composition of them are fully analysed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) techniques. With these experiments, students have gained knowledge about semiconductors materials and got a more accurate understanding of their role in these devices. This experience has allowed them to keep in contact during the whole study with three main concepts of Materials Science: composition, structure and properties. This fact make the work interesting not only from the point of view of students, but also for teachers of Inorganic Chemistry and Materials Science owing to its pedagogical character employing a Problem-Based Learning (PBL).
Roadmap on photonic, electronic and atomic collision physics: II. Electron and antimatter interactions

We publish three Roadmaps on photonic, electronic and atomic collision physics in order to celebrate the 60th anniversary of the ICPEAC conference. In Roadmap II we focus on electron and antimatter interactions. Modern theoretical and experimental approaches provide detailed insight into the many body quantum dynamics of leptonic collisions with targets of varying complexity ranging from neutral and charged atoms to large biomolecules and clusters. These developments have been driven by technological progress and by the needs of adjacent areas of science such as astrophysics, plasma physics and radiation biophysics. This Roadmap aims at looking back along the road, explaining the evolution of the field, and looking forward, collecting contributions from eighteen leading groups from the field.
Time Dependent Modeling of Electron Acceleration and Cooling During Blazar Flares

We present a new time-dependent leptonic code that we developed to model the varying multiwavelength (MWL) emission during blazar flares. In our modeling, we assume that the blazar emission originates from a plasma blob located in the jet, and that relativistic electrons are injected into the blob and may undergo stochastic (Fermi II) or shock (Fermi I) acceleration. We numerically solve the kinetic equation for electron evolution in the blob, taking into account particle injection, escape, acceleration and radiative cooling. In order to calculate the spectral energy distribution (SED) of the blob emission we assume a synchrotron self-Compton (SSC) scenario, including also synchrotron self absorption and gamma-gamma absorption processes. Our code computes the evolution of the electron spectrum and of the associated broad-band SED. As a first application, we attempt to connect the continuous, steady-state emission from the blazar Mrk 421 with a flare observed in February 2010, using a minimal number of free parameters in a two-zone scenario in which a turbulent region is present around the emitting zone. Mrk 421 is a high-synchrotron-peaked (HSP) BL Lac, and one of the brightest extragalactic γ-ray sources in the Very High Energy (VHE) γ-ray band. It is also the closest TeV emitting blazar to the Earth (redshift z=0.031).
A volume of fluid method algorithm for simulation of surface tension dominant two-phase flows

Abstract In this article, a two-phase flow algorithm that uses an explicit Adams–Bashforth scheme coupled with volume of fluid (VOF) method in a uniform staggered Cartesian grid for surface tension dominant simulation is presented. The interface reconstruction procedure is implemented using the Weighed Linear Interface Calculation (WLIC) algorithm. The level set (LS) function instead of VOF function is adopted for calculation of not only the interface normal vectors in the WLIC algorithm but also the surface tension terms in the Navier–Stokes equations. This VOF method is compared with LS method and other experiment results in the literature for vortex deforming, milk crown, droplet impacting into deep liquid pool and bubble bursting at a free surface problems to show whether mass can be well conserved and breaking and merging phenomena can be accurately simulated.
Mobile Monitoring System for Gas Sampling Based on Zigbee, 4G and Web GIS

For the realization of the real-time collection, upload, visualization and intelligent management of air quality data, mobile management system of gas sampling was designed based on the technologies including Web GIS, ZigBee wireless sensor network, the 4G (4th generation) communication system and so on. The ZigBee module is mainly used for wireless communication between PDA and mobile sensor nodes. The 4G module is used to upload data uploaded by ZigBee terminal nodes to the remote server through TCP/IP protocol, to realize remote monitoring of spatio-temporal variation of gas information. The real-time tracking of gas sampling can be realized through Digital Map, with the combination of GPS information and Web GIS technique. The spatial distribution figure of gas sampling can be generated automatically by calling data stored in database. It can guide the the follow-up of manual decision effectively.
Effect of sintering temperature on the growth of (K0.5Na0.5)NbO3 single crystals fabricated by the solid-state crystal growth method

The effect of sintering temperature on the growth of (K0.5Na0.5)NbO3 (KNN) single crystals fabricated by a solid-state crystal growth method with a sintering aid of 2 wt%Co3O4 and the seed crystals of (110) and (100) KTaO3 was investigated. For the KNN single crystals fabricated with the (110) KTaO3 seed crystal, crystal growth length was gradually increased with increasing sintering temperature at the temperatures of 1020 °C–1120 °C. At the temperatures of 1130 °C–1200 °C, rapid growth was observed and a grown single crystal reached the surfaces of the ceramic compact containing the seed crystal. The length of the KNN crystal sintered at 1140 °C for 24 h was 690 μm. On the other hand, such rapid growth was not observed for the KNN single crystals fabricated with the (100) KTaO3 seed crystal. The length of the KNN crystal sintered at 1140 °C for 24 h was 160 μm. The dielectric, ferroelectric, and piezoelectric properties of the KNN single crystal fabricated with the (110) KTaO3 seed crystal at a sintering temperature of 1140 °C were reported.
A Search for Analogs of KIC 8462852 (Boyajian’s Star): A Proof of Concept and the First Candidates

The seemingly normal F dwarf, KIC 8462852 (a.k.a. Boyajian’s Star), has been observed to exhibit two types of behavior unique among known variable stars: infrequent episodes of small brightness dips and a long-term decline in brightness between the dips. No satisfactory mechanism has been found for this behavior, at least in part, because there is only one known example. To begin to rectify this, we have searched for other stars exhibiting similar dipping behavior using the Northern Sky Variability Survey and have used data from the All Sky Automated Survey for Supernovae to further investigate the behavior. Twenty-one stars are identified as possible dippers. Fifteen may be similar to Boyajian’s star and the other six are likely to be more extreme examples of the same phenomenon. Using data from the Gaia Second Data Release we show that the dipper candidates are located in two restricted regions of the H-R diagram, near the main sequence with masses near 1 solar mass and in the red giant region near the evolutionary track for 2 solar mass stars. Stars in the former group are considered to be likely analogs to Boyajian’s star and should be studied in more detail to gain insights into the dipping phenomenon.
A Multi-Factorial Assessment of the 3-Minute Burpee Test

Body composition parameters may be associated with motor fitness. The aim of the study wasto evaluate the relationship between strength endurance, anthropometric features, body composition and physiological parameters in individuals with low or moderate levels of physical activity performing extreme exercise. The study involved 45 female and 51 male participants (20.05±1.81 and 20.20±2.71 y, respectively). The participants’ physical activity levels were evaluated before the study with the International Physical Activity Questionnaire. Physiological parameters were measured using a heart rate monitor. The correlations between the evaluated parameters were determined using Spearman’s rank correlation test. The analyzed physiological parameters were most significantly correlated with physical exertion values within the maximum effort range. In both female and male participants, the number of cycles was significantly and negatively correlated with body mass (r=-0.78 and r=-0.67), degree of obesity (r=-0.87 and r = -0.74), BMI (r=-0.85 and r = -0.76), BFM (r=0.81 and r=-0.58) and VFL (r=-0.81 and r=-0.59). Physiological parameters (PTE, energy expenditure, VO2avg, max, EPOC avg, peak, and RR avg, max) were significantly and positively correlated with maximum physical effort. Somatic features and body composition parameters are significantly correlated with strength endurance in females and males aged 18-29 years.
Remote Sensing Image Reconstruction Using Tensor Ring Completion and Total Variation

Time-series remote sensing (RS) images are often corrupted by various types of missing information such as dead pixels, clouds, and cloud shadows that significantly influence the subsequent applications. In this paper, we introduce a new low-rank tensor decomposition model, termed tensor ring (TR) decomposition, to the analysis of RS data sets and propose a TR completion method for the missing information reconstruction. The proposed TR completion model has the ability to utilize the low-rank property of time-series RS images from different dimensions. To further explore the smoothness of the RS image spatial information, total-variation regularization is also incorporated into the TR completion model. The proposed model is efficiently solved using two algorithms, the augmented Lagrange multiplier (ALM) and the alternating least square (ALS) methods. The simulated and real-data experiments show superior performance compared to other state-of-the-art low-rank related algorithms.
On the bootstrap methodology for the estimation of the tail sample fraction

In statistics of extremes we are usually interested in the estimation of parameters of extreme events. Such estimation is usually based on the largest k + 1 order statistics or on the excesses over a high level u. In this paper, we consider the adaptive estimation of either k or u through the nonparametric bootstrap methodology. We shall introduce an improved version of Hall’s bootstrap methodology and compare it with the double bootstrap methodology. The comparison of such methodologies is performed for simulated data sets.
Hard x-ray photoelectron spectroscopy study of copper formation by metal salt inclusion in a polymer film

In this work we present the results of a hard x-ray photoelectron spectroscopy (HAXPES) study on the creation of metallic copper layers via metal-salt infiltration into a poly-2-vinylpyridine (P2VP) film. Metal salt inclusion is a wet chemistry process which allows for the fabrication of both metal and metal oxide films by means of infiltrating a receptive polymer thin film with metal salt precursors. A copper infiltrated P2VP film was subject to UV/Ozone treatment to form copper oxide and annealed in-vacuo to reduce the film to metallic copper. HAXPES and transmission electron microscope measurements were used to study the polymer film before and after metal salt infiltration, along with analysis of the copper oxide created after UV/Ozone treatment. The results show successful infiltration of the metal salt into the polymer film, as well as complete conversion to copper oxide following UV/Ozone treatment and reduction to metallic copper with a subsequent in situ anneal, which demonstrates the ability of the technique for the creation of several key integrated circuit features.
Controlled Graphene Synthesis from Solid Carbon Sources

Here the authors present the investigation of controllable growth of large area high quality graphene from different solid carbon sources. A home‐made cold‐wall chamber is used for chemical vapor deposition realization to grow graphene on copper foils. It is supplied with tools for in situ monitoring the temperature along the entire sample. Monolayer graphene films are synthesized using solid poly(methyl methacrylate) (PMMA) and paraffin precursors at a growth temperature of about 850 °C and under low pressure conditions. The area of 1 × 1 cm2 appears to be covered by graphene. Raman spectroscopy and scanning electron microscopy are used to estimate the quality of graphene films fabricated and the graphene layer number.
Unifying the Landscape of Cell-Probe Lower Bounds

We show that a large fraction of the data-structure lower bounds known today in fact follow by reduction from the communication complexity of lopsided (asymmetric) set disjointness. This includes lower bounds for (i) high-dimensional problems, where the goal is to show large space lower bounds; (ii) constant-dimensional geometric problems, where the goal is to bound the query time for space $O(n\cdot\mathrm{polylog}n)$; and (iii) dynamic problems, where we are looking for a trade-off between query and update time. (In the last case, our bounds are slightly weaker than the originals, losing a $\lg\lg n$ factor.) Our reductions also imply the following new results: (i) an $\Omega(\lg n/\lg\lg n)$ bound for four-dimensional range reporting, given space $O(n\cdot\mathrm{polylog}n)$ (this is quite timely, since a recent result [Y. Nekrich, in Proceedings of the 23rd ACM Symposium on Computational Geometry (SoCG), 2007, pp. 344-353] solved three-dimensional reporting in $O(\lg^2\lg n)$ time, raising the prospect that higher dimensions could also be easy); (ii) a tight space lower bound for the partial match problem, for constant query time; and (iii) the first lower bound for reachability oracles. In the process, we prove optimal randomized lower bounds for lopsided set disjointness.
Status of cosmic-ray antinuclei searches

The precise measurement of cosmic-ray antiparticles and antinuclei serves as important means for identifying the nature of dark matter and other beyond-standard-model physics. Recent years showed that identifying the nature of dark matter with cosmic-ray positrons and antiprotons is difficult, and has lead to a significantly increased interest in cosmic-ray antideuteron and antihelium searches. Antideuterons and antihelium nuclei may also be generated in dark matter annihilations or decays, offering a potential breakthrough in unexplored phase space for dark matter. Low-energy antinuclei are an important approach because the flux from dark matter interactions exceeds the background flux by orders of magnitude in the low-energy range for a wide variety of models without relying on any boosting mechanisms. This talk summarizes the results of the ``2nd Cosmic-ray Antideuteron Workshop" that was held in March 2019 and brought together theorists and experimentalists in the field to discuss the current status, perspectives, and challenges for cosmic-ray antinuclei searches. It will review the motivation for antinuclei searches, the experimental status and its interpretation, as well as discuss some of the theoretical and experimental uncertainties of antinuclei production and propagation in our Galaxy.
H.E.S.S. searches for TeV gamma-rays associated to high-energy neutrinos

The detection of an astrophysical flux of high-energy neutrinos by IceCube is a major step forward in the search for the origin of cosmic rays, as this emission is expected to originate in hadronic interactions taking place in or near cosmic-ray accelerators. No neutrino point sources, or significant correlation with known astrophysical objects, have been identified in the IceCube data so far. The hadronic interactions responsible for the neutrino emission should also lead to the production of high-energy gamma rays. The search for neutrino sources can then be performed by studying the spatial and temporal correlations between neutrino events and very high energy (VHE, E > 100 GeV) gamma rays. We report here on the search for VHE gamma-ray emission with the H.E. S.S. imaging air Cherenkov telescopes (IACTs) at the reconstructed position of muon neutrino events detected by IceCube. We will provide an up-to-date summary of the extensive program to perform prompt IACT observations of realtime IceCube neutrino event positions. A recent highlight of this program are the H.E. S.S. observations during the broad multi-wavelength campaign that followed the detection of the neutrino event IceCube-170922A arriving from a direction consistent with the location of a flaring gamma-ray blazar TXS 0506+056 in September 2017. We'll present the H.E. S.S. observations obtained within ~4h hours of the neutrino detection as well as a complementary search for gamma-ray emission at longer timescales and put them into the multi-wavelength and multi-messenger context.
Ensemble of fast learning stochastic gradient boosting

Abstract Boosting is one of the most popular and powerful learning algorithms. However, due to its sequential nature in model fitting, the computational time of boosting algorithm can be prohibitive for big data analysis. In this paper, we proposed a parallel framework for boosting algorithm, called Ensemble of Fast Learning Stochastic Gradient Boosting (EFLSGB). The proposed EFLSGB is well suited for parallel execution, and therefore, can substantially reduce the computational time. Analysis of simulated and real datasets demonstrates that EFLSGB achieves highly competitive prediction accuracy in comparison with gradient tree boosting.