Miracle-dz/UniFAR-FTUs huggingface dataset:
FDD Massive MIMO Channel Training Optimal Rate Distortion Bounds and the Efficiency of one-shot Schemes

We study the problem of providing channel state information (CSI) at the transmitter in multi-user “massive” MIMO systems operating in frequency division duplexing (FDD). The wideband MIMO channel is a vector-valued random process correlated in time, space (antennas), and frequency (subcar-riers). The base station (BS) broadcasts periodically β tr pilot symbols from its M antenna ports to K single-antenna users (UEs). Correspondingly, the K UEs send feedback messages about their channel state using β fb symbols in the uplink (UL). Using results from remote rate-distortion theory, we show that, as snr Ñ 8 , the optimal feedback strategy achieves a channel state estimation mean squared error (MSE) that behaves as Θ p 1 q if β tr ă r and as Θ p snr ´ α q when β tr ě r , where α “ min p β fb { r, 1 q , where r is the rank of the channel covariance matrix. The MSE-optimal rate-distortion strategy implies encoding of long sequences of channel states, which would yield completely stale CSI and therefore poor multiuser precoding performance. Hence, we consider three practical “one-shot” CSI strategies with minimum one-slot delay and analyze their large-SNR channel estimation MSE behavior. These are: (1) digital feedback via entropy-coded scalar quantization (ECSQ), (2) analog feedback (AF), and (3) local channel estimation at the UEs and digital feedback. These schemes have different requirements in terms of knowledge of the channel statistics at the UE and at the BS. In particular, the latter strategy requires no statistical knowledge and is closely inspired by a CSI feedback scheme currently proposed in 3GPP standardization. It is shown that ECSQ achieves optimal MSE at the price of a slight increase in feedback rate which vanishes for large SNR. AF achieves the optimal MSE decay rate of Θ p snr ´ 1 q whenever β tr , β fb ě r but is sub-optimal if β ě r and β fb ă r . The 3GPP-inspired scheme is shown, via numerical simulations, to achieves performance similar to ECSQ and AF when the multipath channel is sufﬁciently sparse in the angle-delay domain, but suffers from a large performance gap if this requirement is not met.
Spurious minimizers in non uniform Fourier sampling optimization

A recent trend in the signal/image processing literature is the optimization of Fourier sampling schemes for specific datasets of signals. In this paper, we explain why choosing optimal non Cartesian Fourier sampling patterns is a difficult nonconvex problem by bringing to light two optimization issues. The first one is the existence of a combinatorial number of spurious minimizers for a generic class of signals. The second one is a vanishing gradient effect for the high frequencies. We conclude the paper by showing how using large datasets can mitigate the first effect and illustrate experimentally the benefits of using stochastic gradient algorithms with a variable metric.
Sequence Models for Drone vs Bird Classification

Drone detection has become an essential task in object detection as drone costs have decreased and drone technology has improved. It is, however, difficult to detect distant drones when there is weak contrast, long range, and low visibility. In this work, we propose several sequence classification architectures to reduce the detected false-positive ratio of drone tracks. Moreover, we propose a new drone vs. bird sequence classification dataset to train and evaluate the proposed architectures. 3D CNN, LSTM, and Transformer based sequence classification architectures have been trained on the proposed dataset to show the effectiveness of the proposed idea. As experiments show, using sequence information, bird classification and overall F1 scores can be increased by up to 73% and 35%, respectively. Among all sequence classification models, R(2+1)D-based fully convolutional model yields the best transfer learning and fine-tuning results.
w algebras, conformal mechanics and black holes

We discuss BPS solitons in gauged = 2, D = 4 supergravity. The solitons represent extremal black holes interpolating between different vacua of anti-de Sitter spaces. The isometry superalgebras are determined and the motion of a superparticle in the extremal black hole background is studied and confronted with superconformal mechanics. We show that the Virasoro symmetry of conformal mechanics, which describes the dynamics of the superparticle near the horizon of the extremal black hole under consideration, extends to a symmetry under the w algebra of area-preserving diffeomorphisms. We find that a Virasoro subalgebra of w can be associated with the Virasoro algebra of the asymptotic symmetries of AdS 2 . In this way spacetime diffeomorphisms of AdS 2 translate into diffeomorphisms in phase space: our system offers an explicit realization of the AdS 2 /CFT 1 correspondence. Using the dimensionally reduced action, the central charge is computed. Finally, we also present generalizations of superconformal mechanics which are invariant under = 1 and = 2 superextensions of w .
OIMNet++: Prototypical Normalization and Localization-aware Learning for Person Search

We address the task of person search, that is, localizing and re-identifying query persons from a set of raw scene images. Recent approaches are typically built upon OIMNet, a pioneer work on person search, that learns joint person representations for performing both detection and person re-identification (reID) tasks. To obtain the representations, they extract features from pedestrian proposals, and then project them on a unit hypersphere with L2 normalization. These methods also incorporate all positive proposals, that sufficiently overlap with the ground truth, equally to learn person representations for reID. We have found that 1) the L2 normalization without considering feature distributions degenerates the discriminative power of person representations, and 2) positive proposals often also depict background clutter and person overlaps, which could encode noisy features to person representations. In this paper, we introduce OIMNet++ that addresses the aforementioned limitations. To this end, we introduce a novel normalization layer, dubbed ProtoNorm, that calibrates features from pedestrian proposals, while considering a long-tail distribution of person IDs, enabling L2 normalized person representations to be discriminative. We also propose a localization-aware feature learning scheme that encourages better-aligned proposals to contribute more in learning discriminative representations. Experimental results and analysis on standard person search benchmarks demonstrate the effectiveness of OIMNet++.
The miniJPAS survey. Galaxy populations in the most massive cluster in miniJPAS: mJPC2470-1771

The miniJPAS is a 1 deg$^2$ survey that uses the Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) filter system (54 narrow-band filters) with the Pathfinder camera. We study mJPC2470-1771, the most massive cluster detected in miniJPAS. We study the stellar population properties of the members, their star formation rates (SFR), star formation histories (SFH), the emission line galaxy (ELG) population, their spatial distribution, and the effect of the environment on them, showing the power of J-PAS to study the role of environment in galaxy evolution. We use a spectral energy distribution (SED) fitting code to derive the stellar population properties of the galaxy members: stellar mass, extinction, metallicity, colours, ages, SFH (a delayed-$\tau$ model), and SFRs. Artificial Neural Networks are used for the identification of the ELG population through the detection of H$\alpha$, [NII], H$\beta$, and [OIII] nebular emission. We use the WHAN and BPT diagrams to separate them into star-forming galaxies and AGNs. We find that the fraction of red galaxies increases with the cluster-centric radius. We select 49 ELG, 65.3\% of the them are probably star forming galaxies, and they are dominated by blue galaxies. 24% are likely to host an AGN (Seyfert or LINER galaxies). The rest are difficult to classify and are most likely composite galaxies. Our results are compatible with an scenario where galaxy members were formed roughly at the same epoch, but blue galaxies have had more recent star formation episodes, and they are quenching from inside-out of the cluster centre. The spatial distribution of red galaxies and their properties suggest that they were quenched prior to the cluster accretion or an earlier cluster accretion epoch. AGN feedback and/or mass might also be intervening in the quenching of these galaxies.
Online Localisation and Colored Mesh Reconstruction Architecture for 3D Visual Feedback in Robotic Exploration Missions

This paper introduces an Online Localisation and Colored Mesh Reconstruction (OLCMR) ROS perception architecture for ground exploration robots aiming to perform robust Simultaneous Localisation And Mapping (SLAM) in challenging unknown environments and provide an associated colored 3D mesh representation in real time. It is intended to be used by a remote human operator to easily visualise the mapped environment during or after the mission or as a development base for further researches in the field of exploration robotics. The architecture is mainly composed of carefully-selected open-source ROS implementations of a LiDAR-based SLAM algorithm alongside a colored surface reconstruction procedure using a point cloud and RGB camera images projected into the 3D space. The overall performances are evaluated on the Newer College handheld LiDAR-Vision reference dataset and on two experimental trajectories gathered on board of representative wheeled robots in respectively urban and countryside outdoor environments.
Effet de l'instruction sur la régulation de la raideur des membres inférieurs lors de sauts de contre-haut The effect of instruction on leg stiffness regulation in drop jump

Goal. – We tested in this study the possibility of influencing leg stiffness through instructions on the knee flexion in drop jump (30 and 60 cm). Method. – Twelve basket players were instructed to jump with three different instructions: 1) “jump as high as you can”; 2) jump high with a larger knee flexion at touch-down and 3) jump high with a smaller knee flexion at touch-down. The ground reaction force were measured with an AMTI force plate (500 Hz). The kinematics of the jump was recorded using two digital cameras (50 Hz). Results. – The results show that the ground reaction force pattern depended more on the instruction than on the height of the box. The active peak decreased from 6 times the body weight (BW) to 2.9 times BW. Bending the knee appears to be an efficient strategy to increase the leg stiffness [R =0.86; P <0.05]. Conclusion. – The instructions high knee flexion decreases the leg stiffness. The same vertical jump performance could be achieved with different values of stiffness. The maximum knee flexion does not modify the vertical performance. © 2005 Elsevier SAS. Tous droits reserves. Mots cles : Flexion de genoux ; Extension ; Cinetique ; Patron de force ; Basket-ball
Solution-generating transformations and the string effective action

We study exhaustively the solution-generating transformations (dualities) that occur in the context of the low-energy effective action of superstring theory. We first consider target-space duality (`T duality') transformations in the absence of vector fields. We find that for one isometry the full duality group is , the discrete part being non-Abelian. We then include non-Abelian Yang - Mills fields and find the corresponding generalization of the T duality transformations. We study the corrections to these transformations and show that the T duality rules are considerably simplified if the gauge group is embedded in the holonomy group. Next, in the case in which there are Abelian vector fields, we consider the duality group that includes the transformation, introduced by Sen, that rotates among themselves the components of the metric, axion and vector field. Finally we list the duality symmetries of the type II theories with one isometry.
Teoria de la respuesta al item

La preocupacion con las medidas de los rasgos psicologicos es antigua y muchos estudios y propuestas de metodos fueron desarrollados para lograr este objetivo. Entre estas propuestas de trabajo se incluye la Teoria de la Respuesta al Item (TRI) que, en principio, vino a completar las limitaciones de la Teoria Clasica de los Tests, ampliamente utilizada hasta hoy en la medida de los rasgos psicologicos. El punto principal de la TRI es que se tiene en cuenta el punto concreto, sin relevar las puntuaciones totales; por lo tanto, los resultados no solo dependen de la prueba o cuestionario, sino que de cada item que lo compone. En este articulo se propone presentar la Teoria que revoluciono la teoria de medidas.
ANTIMICROBIAL SCREENING OF THE ETHANOLIC LEAVES EXTRACT OF FICUS CARICA L. ( MORACEAE ) — AN ANCIENT FRUIT PLANT

In the present study, ethanolic extracts of Ficus carica L. leaves were tested for their antibacterial activity against Gram-negative bacteria Klebsiella pneumoniae (ATCC 700603), Pseudomonas aeruginosa (ATCC 27853), and Escherichia coli (ATCC 25922), Gram-positive bacteria Staphylococcus aureus (ATCC 25923), methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae (ATCC 49619) as well as fungus Candida albicans. The leaves of F. carica were collected in M.M. Gryshko National Botanical Garden (Kyiv, Ukraine). Antimicrobial activity was determined using the agar diffusion method. Crude extracts of Ficus carica leaves have shown a wide spectrum of antimicrobial activities. The ethanolic extract of F. carica leaves exhibited mild antimicrobial activity against the Gram-positive bacteria (10.4 mm of inhibition zone diameter for methicillin-re sistant Staphylococcus aureus and 14.28 mm for Staphylococcus aureus), and the Gram-negative bacteria (13.25 mm for Escherichia coli). Klebsiella pneumoniae, Pseudomonas aeruginosa and Streptococcus pneumoniae appeared to be less sensitive to the extract, the inhibition zones were 9.75 mm, 8.69 mm and 8.56 mm, respectively. The antimicrobial activity of leaves extract is possibly could be explained by the presence of flavonoids, steroid, saponins and/or tannins. These plants have great medicinal potential for the therapy of infection. Further investigation is necessary to identify those bioactive compounds, which will be a platform for clinical applications. These findings are important in order to evaluate the significance of collections of tropical plants maintained under glass house conditions at botanical gardens of Ukraine and to plan the conservation strategy by establishment of national collections of plants with valuable characteristics with the prospects of their use as sources of antimicrobial agents.
Microfabrication of channels using an embedded mask in negative resist

A technique has been developed which allows the fabrication of channels within the body of multiple layers of negative resist. Previously this was only possible in the positive resist system but with the transfer to negative resist, higher and more clearly defined channels are now possible. Thick negative resists are also easier to process than their positive counterparts, allowing multiple crossing channels. The physical structure of a full height W-band waveguide with an integrated E-plane filter has been fabricated with this technique. The fabrication procedure presented in this paper is quick, reproducible and easily implemented using standard photolithography equipment.
Theory for a gas composition sensor based on acoustic properties

Sound travelling through a gas propagates at different speeds and its intensity attenuates to different degrees depending upon the composition of the gas. Theoretically, a real-time gaseous composition sensor could be based on measuring the sound speed and the acoustic attenuation. To this end, the speed of sound was modelled using standard relations, and the acoustic attenuation was modelled using the theory for vibrational relaxation of gas molecules. The concept for a gas composition sensor is demonstrated theoretically for nitrogen–methane–water and hydrogen–oxygen–water mixtures. For a three-component gas mixture, the measured sound speed and acoustic attenuation each define separate lines in the composition plane of two of the gases. The intersection of the two lines defines the gas composition. It should also be possible to use the concept for mixtures of more than three components, if the nature of the gas composition is known to some extent.
An integrated omics analysis of eicosanoid biology.

Eicosanoids have been implicated in a vast number of devastating inflammatory conditions, including arthritis, atherosclerosis, pain, and cancer. Currently, over a hundred different eicosanoids have been identified, with many having potent bioactive signaling capacity. These lipid metabolites are synthesized de novo by at least 50 unique enzymes, many of which have been cloned and characterized. Due to the extensive characterization of eicosanoid biosynthetic pathways, this field provides a unique framework for integrating genomics, proteomics, and metabolomics toward the investigation of disease pathology. To facilitate a concerted systems biology approach, this review outlines the proteins implicated in eicosanoid biosynthesis and signaling in human, mouse, and rat. Applications of the extensive genomic and lipidomic research to date illustrate the questions in eicosanoid signaling that could be uniquely addressed by a thorough analysis of the entire eicosanoid proteome. — Buczynski, M. W. , D. S. Dumlao, and E. A. Dennis. An integrated omics analysis of eicosanoid biology. J. Lipid Res. 2009. 50: 1015 – 1038.
Distributed Variable Droop Curve Control Strategies in Smart Microgrid

In micro grid (MG), active/reactive power sharing for all dis-patchable units is an important issue. To meet fluctuating loads’ active and reactive power demands, the units generally adopt primary P-f and Q-U droop control methods. However, at different state of charge (SOC) values, the capability of Lead Acid Battery Bank (LABB) based units to take loads varies in a large range; active power should not be shared according to the units P capacities in a constant ratio. Besides, influenced by the output and line impedance between units, reactive power is not able to be shared in proportion to the units Q capacities. Another problem, after MG power balance requirement is satisfied, frequency and voltage are deviating from their rated values thus power quality is reduced. This paper presents a new smart MG which is based on the multi agent system. To solve the problems mentioned above, P-f and Q-U droop curves are adjusted dynamically and autonomously in local agents. To improve the power quality, secondary restoration function is realized in a decentralized way, the computation tasks are assigned to local, the computation capability and communication reliability requirements for central PC are low, and operation reliability is high. Simulation results back the proposed methods.
Studies on the flora of Yemen: Flora of Kharab AlMarashi, AlJawf, Republic of Yemen

The present study deals with the floristic analysis of Karab AlMarashi, Al Jawf, Yemen. Eighty six species belong to 67 genera and 36 families of the vascular plants have been recorded. The dicots are represented by 81 species, while the monocots are represented by 5 species. The family Asteraceae had the highest contributions followed by Asclepiadaceae, Solanaceae, Malvaceae, Apiaceae, Zygophyllaceae, Euphorbiaceae and Lamiaceae. Life form spectra are highly represented by chamaephytes followed by phanerophytes, therophytes, hemicryptophytes and cryptophytes. The pluri-regionals species are the highest, followed by the mono-regionals species, while the bi-regionals species were the lowest. The present results proved that the flora of Kharab AlMarashi is species rich and diverse. The generic index is 1.3. Acacia is the largest recorded genus in Kharab AlMarashi.
Efficacy of annual mugwort ( Artemisia annua ) powder on gastrointestinal nematodes in cattle

Parasitism remains a challenge in the effective and efficient management of ruminant livestock. Among the different approaches proposed for a better management of these different ruminant parasites, the present work carried out on the farm of the Faculty of Agronomic Sciences (FSA) located in Sékou, focused on the effectiveness of the annual mugwort powder ( Artemisia annua ) on gastrointestinal nematodes (Nematoda) of cattle. The coprological analyses were made at the Laboratory of Ethno pharmacology and Animal Health (LESA) in a population of eighteen (18) animals, divided in 2 groups with treatment and one without treatment. The result after treatment showed that the Artemisia annua powder significantly reduced the excretion of nematode eggs. It is noted that the more the animals are infested the faster there is a decrease in egg excretion.
The Movement of Foot and the Shift of Ground Reaction Force in Batters according to the Ball Speed Increase

The batting performance in baseball is a repetitive movement. In order to make the stabilization of posture and the efficient shift of body weight, both the range of stance and stride are important. The previous studies explained that the consistent stride which included the amount of time, stance, and direction were needed. However, the batting performance is frequently changed according to the several speed of ball. Therefore, this study was to analyze the reaction time, the range of stance, the change of stride, and the change of GRF during the batting movement in three kinds of ball speed (120km/h, 130km/h, & 140km/h). Seven elite players are participated in this study. 1. The reaction time of the stride phase was short whereas the time of the swing phase was long according to the increasing ball speed. 2. The range of the stance was wide and the mediolateral direction of the stride was decreased according to the increasing ball speed. 3. In the three kinds of ball speed, the change of body weight was transferred to the center, the rear foot, and the front foot directions. The ball speed of 130km/h showed the high frequency of the suitable batting. At this ball speed, the movement of the body weight was shifted smoothly and the value of the Ground Reaction Force was large enough.