Miracle-dz/UniFAR-FTUs huggingface dataset:
X-ray decline and rejuvenation of a recurrent nova

The dynamical evolution and nonequilibrium X-ray emission of recurrent-nova remnants have been investigated by using a spherically symmetric hydrodynamic code. It is assummed that the nova ejecta expand into a wind from a red-giant companion. The wind material is blast shocked, and emits copious X-rays. The blast shock soon breaks out of the wind region which has formed since the previous outburst, and the remnant undergoes nearly unimpeded expansion. The rarefaction and adiabatic cooling of the remnant result in a drastic decline in the X-ray emission. At this stage the recombination exceeds the ionization, and the X-ray spectrum is characterized by strong recombination lines and continua. The blast shock eventually catches up with the relatively slow ejecta of the previous outbursts. The X-ray emission may then be rejuvenated in both luminosity and spectral shape. Observations of such an X-ray decline and rejuvenation may provide a clue to the outburst mechanism of recurrent novae. 51 refs.
Evaluation of Health Literacy Levels and Associated Factors Among Patients with Acute Coronary Syndrome and Heart Failure in Qatar

Purpose To determine the prevalence of inadequate health literacy and its associated risk factors among patients with acute coronary syndrome (ACS) and/or heart failure (HF) in Qatar. Patients and Methods This cross-sectional observational study was conducted among patients with ACS and/or HF attending the national Heart Hospital in Qatar. Health literacy was assessed using the abbreviated version of the Test of Functional Health Literacy in Adults (S-TOFHLA) and the Three-item Brief Health Literacy Screen (3-item BHLS). Results Three hundred patients with ACS and/or HF, majority male (88%) and non-Qatari (94%), participated in the study. The median (IQR) age of the participants was 55 (11) years. The prevalence of inadequate to marginal health literacy ranged between 36% and 54%. There were statistically significant differences in health literacy level between patients based on their marital status (p=0.010), education (p≤0.001), ability to speak any of Arabic, English, Hindi, Urdu, Malayalam, or other languages (p-values ≤0.001 to 0.035), country of origin (p≤0.001), occupation (p≤0.001), and receiving information from a pharmacist (p=0.008), a physiotherapist (p≤0.001), or a nurse (p=0.004). Conclusion Inadequate health literacy is common among patients with ACS and/or HF. This study suggests a need for developing strategies to assist healthcare professionals in improving health literacy skills among patients with ACS and HF. A combination of interventions may be needed to improve patients’ understanding of their disease and medications, and ultimately overall health outcomes.
Impacts of ICT and digital finance on poverty and income inequality: a sub-national study from India

ABSTRACT The present paper explores both the direct and indirect impact of ICT diffusion through the channel of digital finance on two development indicators such as poverty and income inequality at the sub-national level in India. Ordered probit estimation confirms that ICT diffusion directly reduces the persistence of poverty in both urban and rural areas. The application of ICT in the banking sector in the form of digital finance has a positive role in rural-urban poverty reduction. ICT has no direct impact on income inequality, though financial inclusion has a positive influence on both rural and urban inequality. ICT diffusion in the banking sector dampens the positive impact of financial inclusion on urban inequality with no impact on rural inequality. Proposed policy prescription can be strengthening of ICT infrastructure with wider and uniform spread of digital finance among rural and urban population so that more people can take advantage of it.
Influence of stray fields on the switching-field distribution for bit-patterned media based on pre-patterned substrates

Using a direct imaging method, we experimentally investigate the reversal of magnetic islands in a bit-patterned media sample based on a pre-patterned substrate. Due to systematic variation of the island distances in the media, we are able to study the influence of the dipolar interaction on the switching-field distribution of the island ensemble. The experimental findings are explained by an analytical magnetostatic model that allows us to quantify the different components of the demagnetizing field in the system and to distinguish intrinsic and dipolar broadening of the switching-field distribution. Besides the well-known dipolar broadening due to stray fields from neighboring islands, we find strong influence from the magnetized trench material on the island switching.
The brightness variations and orbital period changes of RT Lacertae

The light curves of the chromospherically active eclipsing binary RT Lacertae obtained from 1993 to 1999 are analyzed here. The variation of the brightness at mid-eclipses and at maxima is carefully re-examined. The largest variation was obtained at mid-primary, where the more massive, hotter component occults the less massive cooler secondary star. Therefore, we suggest that the variation of the system's brightness mainly arises from the more massive star. The mean brightness of the system indicates a cyclic change. It showed at least two jumps during the last 22 years. The first occurred in 1984 and the second in 1994. Therefore, the length of the magnetic cycle appears to be about ten years. All the timings of the mid-eclipses obtained so far were collected and analyzed under the assumption of the third body hypothesis. A period of 94 yr was found for the third body orbit. The variation of the systemic velocity of the eclipsing pair seems to confirm this suggestion. The time delay and advance due to the orbit of the eclipsing pair around the third component were computed and subtracted from the original residuals obtained with the linear light elements. The remaining residuals also show a quasi-periodic change. The period of this change was calculated to be about 18 yr. This second O-C change may be related to the magnetic activity of the more massive component.
Development of a methodology of teaching to computer network technologies for studying the transmission of packet information

The role of packet switching technology for modern networks is analyzed. "Cisco Packet Tracer" software network emulator is considered to determine the functionality of configuring networks, as well as the formation of professional competencies of students in the field of network technologies. The positive and negative aspects of working with a network resource are given. The Cisco Virtual Academy is being analyzed. This allows to highlight the actual problems and features associated with the tasks of forming a student as a highly qualified specialist in the field of packet switching.
A Gill–Matsuno‐type mechanism explains the tropical Atlantic influence on African and Indian monsoon rainfall

Recent studies using coupled atmosphere–ocean models have shown that the tropical Atlantic has a significant impact on the Indian monsoon. In this article, the observational basis for this teleconnection is examined and the physical mechanism responsible for bridging sea‐surface temperatures (SSTs) in the Atlantic and precipitation over India is investigated with idealized atmospheric general circulation model (AGCM) experiments in which constant SST anomalies are prescribed and ‘switched on’ in the tropical Atlantic region. A simple Gill–Matsuno‐type quadrupole response is proposed to explain the teleconnection between the tropical Atlantic and the Indian basin, with an enforcement of the eastward response likely due to nonlinear interactions with the mean monsoon circulation. The simplicity of this mechanism suggests the reproducibility of this result with a broad range of AGCMs. Copyright © 2009 Royal Meteorological Society
Deep Metric Learning With Adaptively Composite Dynamic Constraints

In this paper, we propose a deep metric learning with adaptively composite dynamic constraints (DML-DC) method for image retrieval and clustering. Most existing deep metric learning methods impose pre-defined constraints on the training samples, which might not be optimal at all stages of training. To address this, we propose a learnable constraint generator to adaptively produce dynamic constraints to train the metric towards good generalization. We formulate the objective of deep metric learning under a proxy Collection, pair Sampling, tuple Construction, and tuple Weighting (CSCW) paradigm. For proxy collection, we progressively update a set of proxies using a cross-attention mechanism to integrate information from the current batch of samples. For pair sampling, we employ a graph neural network to model the structural relations between sample-proxy pairs to produce the preservation probabilities for each pair. Having constructed a set of tuples based on the sampled pairs, we further re-weight each training tuple to adaptively adjust its effect on the metric. We formulate the learning of the constraint generator as a meta-learning problem, where we employ an episode-based training scheme and update the generator at each iteration to adapt to the current model status. We construct each episode by sampling two subsets of disjoint labels to simulate the procedure of training and testing and use the performance of the one-gradient-updated metric on the validation subset as the meta-objective of the assessor. We conducted extensive experiments on five widely used benchmarks under two evaluation protocols to demonstrate the effectiveness of the proposed framework.
Novel Zero-Voltage Zero-Current Transition Buck Converter With Minimal Impact of Active Auxiliary Cell on Overall Dynamics

This paper presents a novel zero-voltage zero-current transition DC/DC buck converter, which uses an active auxiliary resonant network to achieve soft switching operation of semiconductor switches and soft-recovery of power diodes over wide output power range and offers high efficiency. The auxiliary cell in the proposed converter does not cause any additional current stress on the semiconductor switches and has minimal impact on overall dynamics of the converter. Steady-state performance of the converter has been presented with detailed theoretical analysis of all operating modes. The design of auxiliary cell components and development of small signal model of the converter have been carried out from the mathematical equations depicting its dynamic behaviour. A closed loop voltage mode controller with a type III compensator has been developed for the converter to achieve the desired transient response under the influence of external disturbances. Power loss analysis and superiority of the proposed converter over other conventional configurations are also presented here. Finally, soft-switching behaviour and step-input transient response of the converter are verified by hardware experimentation on a 150W, 100 kHz prototype model. The experimental measurements have successfully validated the theoretically predicted behaviour of the converter.
Structural Approximate Reanalysis for Topological Modifications of Finite Element Systems

Conclusions Aperturbationmethodusingacorrectionintransformationispresented to improve the condensation solution. The method proved to be effective and is recommended as a postprocessor of the condensation. Theoretically, the perturbation solution should approach the exact eigenvalue from above. In practice, however, truncation error in the linear equation causes the approximation to overshoot the exact solution. Inclusion of several of the lowest terms can provide excellent estimations for both the eigenvalue and mode shape changes. One of the most dife cult problems is the rate of convergence in the series expansion. The sequential terms in the ine nite series may indicate the convergence characteristics in an eigenvalue approximation. Some of the nonlinear terms may be included to get more accurate solutions. Rather than iterations with nonlinear perturbation equations, integrated reduction methodssuch as the hybrid dynamic condensation are preferable.
Image sharpness function based on edge feature

Autofocus technique has been widely used in optical tracking and measure system, but it has problem that when the autofocus device should to work. So, no-reference image sharpness assessment has become an important issue. A new Sharpness Function that can estimate current frame image be in focus or not is proposed in this paper. According to current image whether in focus or not and choose the time of auto focus automatism. The algorithm measures object typical edge and edge direction, and then get image local kurtosis information to determine the degree of image sharpness. It firstly select several grads points cross the edge line, secondly calculates edge sharpness value and get the cure of the kurtosis, according the measure precision of optical-equipment, a threshold value will be set beforehand. If edge kurtosis value is more than threshold, it can conclude current frame image is in focus. Otherwise, it is out of focus. If image is out of focus, optics system then takes autofocus program. This algorithm test several thousands of digital images captured from optical tracking and measure system. The results show high correlation with subjective sharpness assessment for s images of sky object.
Multiple equilibria in two-dimensional thermohaline circulation

As a model of the thermohaline circulation of the ocean we study the two-dimensional Boussinesq equations forced by prescribing the surface temperature and the surface salinity flux. We simplify the equations of motion using an expansion based on the small aspect ratio of the domain. The result is an amplitude equation governing the evolution of the depth averaged salinity field. This amplitude equation has multiple, linearly stable equilibria. The simplified dynamics has a Lyapunov functional and this variational structure permits a simple characterization of the relative stability of the alternative steady solutions. Even when the thermal and salinity surface forcing functions are symmetric about the equator there are asymmetric solutions, representing pole to pole circulations. These asymmetric solutions are stable to small perturbations and are always found in conjunction with symmetric solutions, also stable to small perturbations. Recent numerical solutions of the full two-dimensional equations have shown very similar flow patterns.
Inversion of electromagnetic geosoundings using coordinate descent optimization

A coordinate-descent inversion algorithm is tested for a non-separable regularization operator. The algorithm is based on a homotopy moving regularization operator from l2 to l1. Results are presented for both linear and nonlinear problems. The linear case corresponds to electromagnetic soundings typically used for prospecting down to a few tens of meters. The first nonlinear case corresponds to direct-current resistivity soundings, which are typically useful for prospecting down to hundreds of meters. The last application is to magnetotelluric soundings that can reach penetration depths of tens of kilometers. Developed models are comparable with the original for the synthetic cases and with those obtained by other researchers for field data.
Barrier crossing of a Lévy flight

We consider the barrier crossing in a bistable potential for a random-walk process that is driven by Levy noise of stable index α. It is shown that the survival probability decays exponentially, but with a power law dependence Tc(α,D) = C(α)D−μ(α) of the mean escape time on the noise intensity D. Here C is a constant, and the exponent μ varies slowly over a large range of the stable index α[1,2). For the Cauchy case, we explicitly calculate the escape rate.
Personalized Symmetrical and Asymmetrical Gait Generation of a Lower Limb Exoskeleton

Personal assistive devices for rehabilitation will be in increasing demand during the coming decades due to demographic change, i.e., an aging society. Among the elderly population, difficulty in walking is the most common problem. Even though there are commercially available lower limb exoskeleton systems, the coordination between user and device still needs to be improved to achieve versatile personalized gaits. To tackle this issue, an advanced EXOskeleton framework for Versatile personalized gaIt generation with a Seamless user–exo interface (called “EXOVIS”) is proposed in this study. The main control of the framework uses adaptive bio-inspired modular neural mechanisms. These mechanisms include decoupled central pattern generators (CPGs) with Hebbian-based synaptic plasticity and adaptive CPG postprocessing networks with error-based learning. The control method facilitates the rapid online learning of personalized walking gaits described by the walking frequency as well as hip, knee, and ankle joint patterns. The method is verified on a real lower limb exoskeleton system with six degrees of freedom (DOFs) on different subjects under static and dynamic conditions, such as flat terrain and a split-belt treadmill. The results show that the proposed method can not only automatically learn to generate personalized symmetrical gaits, but also asymmetrical gaits, which have not been explicitly shown by other approaches so far.
A Qualitative Study on Medication Taking Behaviour Among People With Diabetes in Australia

Background: Australia has a high proportion of migrants with an increasing migration rate from India. Type II diabetes is a long-term condition common amongst the Indian population. Aims: To investigate patients’ medication-taking behaviour and factors that influence adherence at the three phases of adherence. Methods: Semi-structured interviews were conducted with a convenience sample of 23 Indian migrants living in Sydney. All interviews were audio-recorded, transcribed verbatim and thematically analysed. Results: 1) Initiation: The majority of participants were initially prescribed oral antidiabetic medicine and only two were started on insulin. Most started taking their medicine immediately while some delayed initiating therapy due to fear of side-effects. 2) Implementation: Most participants reported taking their medicine as prescribed. However, some reported forgetting their medicine especially when they were in a hurry for work or were out for social events. 3) Discontinuation: A few participants discontinued taking their medicine. Those who discontinued did so to try Ayurvedic medicine. Their trial continued for a few weeks to a few years. Those who did not receive expected results from the Ayurvedic medicine restarted their prescribed conventional medicine. Conclusion: A range of medication-taking behaviours were observed, ranging from delays in initiation to long-term discontinuation, and swapping of prescribed medicine with Ayurvedic medicine. This study highlights the need for tailored interventions, including education, that focus on factors that impact medication adherence from initiation to discontinuation of therapy.
Co-registered 3-D ultrasound and photoacoustic imaging using a 1.75D 1280-channel ultrasound system

Photoacoustic imaging is a promising non-invasive imaging technology due to its ability to combine the enhanced contrast of optical absorption with the spatial resolution of acoustic imaging. Co-registered three-dimensional (3-D) ultrasound and photoacoustic imaging takes advantage of both modalities to allow visualization of tissue structures within a volume using simultaneous structural and functional information. 1.75D acoustic arrays are well-suited for this application due to their ability to scan in 3-D volumes rapidly and accurately while maintaining a reasonable system complexity and cost. We have designed, fabricated, and tested a 1.75D 1280-ch ultrasound system for co-registered 3-D ultrasound and photoacoustic imaging. The system features a 1.75D 1280-channel ultrasound array with a center frequency of 5MHz and 80% bandwidth. The electronics includes 1280 high-voltage pulsers, 40 32-to-1 multiplexers, amplification circuitry, and a 40-channel data acquisition circuit. The system is able to drive the entire array simultaneously, and each array element independently, to scan a 3-D volume within +/- 40 degrees in azimuth direction and +/- 10 degrees in elevation respectively. System performance including axial and lateral resolution has been characterized and compared with simulations. Co-registered 3-D ultrasound and photoacoustic imaging has been successfully performed on phantoms with different geometries and contrast.
Microring bio-chemical sensor with integrated low dark current Ge photodetector

An integrated Ge photodetector of very low dark current density is demonstrated in an optoelectronic integrated circuit label-free biosensing system. The sensor system consists of a microring for optical sensing and a monolithically integrated Ge detector. For point-of-care applications, integration of Ge detector increases the reliability of measurement by eliminating mechanical-optical alignment of output signals. Optimizing Ge detector performance will further enhance system signal-noise ratio and reliability. For homogeneous sensing, the system has a sensitivity of ∼18.8 nm/RIU and a detection limit of 3.50 × 10−5.
Nonlocal Polyakov-Nambu-Jona-Lasinio model with wave function renormalization at finite temperature and chemical potential

We study the phase diagram of strongly interacting matter in the framework of a nonlocal SU(2) chiral quark model which includes wave function renormalization and coupling to the Polyakov loop. Both nonlocal interactions based on the frequently used exponential form factor, and on fits to the quark mass and renormalization functions obtained in lattice calculations are considered. Special attention is paid to the determination of the critical points, both in the chiral limit and at finite quark mass. In particular, we study the position of the critical end point as well as the value of the associated critical exponents for different model parametrizations.
A Compact Passive Quad‐Band Negative Group Delay Circuit With Stepped Impedance Resonator and Defected Microstrip Structure

Based on two‐stage stepped impedance resonator (SIR) and defected microstrip structure (DMS) with an E‐shaped slot, a novel compact passive quad‐band negative group delay circuit (NGDC) is proposed whose resonation frequencies and group delay performance are mainly determined by the SIR and the DMS. In order to help reveal the working mechanism of the quad‐band NGDC, an equivalent circuit of the NGDC is developed. It is composed of the transmission lines and serial‐parallel LC networks, and its S‐parameters are derived by using the theory of transmission matrix. The theoretical and simulated results for the transmission characteristics of the NGDC agree well with each other. To validate the design concept, a prototype of the proposed quad‐band NGDC was fabricated and measured. The measured results show that at the frequencies of 2.64, 7.88, 13.08, and 18.18 GHz, the negative group delay values achieve −5.4, −3.1, −1.18, and −1.14 ns, with |S21| values of −17.2, −20.5, −12.8, and −18.1 dB, respectively. Compared with the recently reported works, the proposed NGDC exhibits the largest number of operation frequency bands. Furthermore, it does not use lumped resistors and has miniaturized dimension.