Miracle-dz/UniFAR-FTUs huggingface dataset:
NUMERICAL SIMULATIONS OF SUPERNOVA DUST DESTRUCTION. I. CLOUD-CRUSHING AND POST-PROCESSED GRAIN SPUTTERING

We investigate through hydrodynamic simulations the destruction of newly formed dust grains by sputtering in the reverse shocks of supernova (SN) remnants. Using an idealized setup of a planar shock impacting a dense, spherical clump, we implant a population of Lagrangian particles into the clump to represent a distribution of dust grains in size and composition. We then post-process the simulation output to calculate the grain sputtering for a variety of species and size distributions. We explore the parameter space appropriate for this problem by altering the overdensity of the ejecta clumps and the speed of the reverse shocks. Since radiative cooling could lower the temperature of the medium in which the dust is embedded and potentially protect the dust by slowing or halting grain sputtering, we study the effects of different cooling methods over the timescale of the simulations. In general, our results indicate that grains with radii less than 0.1 μm are sputtered to much smaller radii and often destroyed completely, while larger grains survive their interaction with the reverse shock. We also find that, for high ejecta densities, the percentage of dust that survives is strongly dependent on the relative velocity between the clump and the reverse shock, causing up to 50% more destruction for the highest velocity shocks. The fraction of dust destroyed varies widely across grain species, ranging from total destruction of Al2O3 grains to minimal destruction of Fe grains (only 20% destruction in the most extreme cases). C and SiO2 grains show moderate to strong sputtering as well, with 38% and 80% mass loss. The survival rate of grains formed by early SNe is crucial in determining whether or not they can act as the “dust factories” needed to explain high-redshift dust.
Multi-field inflation with random potentials: field dimension, feature scale and non-Gaussianity

We explore the super-horizon evolution of the two-point and three-point correlation functions of the primordial density perturbation in randomly-generated multi-field potentials. We use the Transport method to evolve perturbations and give full evolutionary histories for observables. Identifying the separate universe assumption as being analogous to a geometrical description of light rays, we give an expression for the width of the bundle, thereby allowing us to monitor evolution towards the adiabatic limit, as well as providing a useful means of understanding the behaviour in fNL. Finally, viewing our random potential as a toy model of inflation in the string landscape, we build distributions for observables by evolving trajectories for a large number of realisations of the potential and comment on the prospects for testing such models. We find the distributions for observables to be insensitive to the number of fields over the range 2 to 6, but that these distributions are highly sensitive to the scale of features in the potential. Most sensitive to the scale of features is the spectral index, with more than an order of magnitude increase in the dispersion of predictions over the range of feature scales investigated. Least sensitive was the non-Gaussianity parameter fNL, which was consistently small; we found no examples of realisations whose non-Gaussianity is capable of being observed by any planned experiment.
Early days following Grover's quantum search algorithm

This is a note accompanying "CS 410/510: INTRO TO QUANTUM COMPUTING" I taught at Portland State University in Spring 2017. It is a review and summary of some early results related to Grover's quantum search algorithm in a consistent way. I had to go back and forth among several books, notes and original papers to sort out various details when preparing the lectures, which was a pain. This is the motivation behind this note. I would like to thank Peter H{\o}yer for valuable feedback on this note.
THE CHANDRA SURVEY OF THE COSMOS FIELD. II. SOURCE DETECTION AND PHOTOMETRY

The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra program that covers the central contiguous ∼0.92 deg2 of the COSMOS field. C-COSMOS is the result of a complex tiling, with every position being observed in up to six overlapping pointings (four overlapping pointings in most of the central ∼0.45 deg2 area with the best exposure, and two overlapping pointings in most of the surrounding area, covering an additional ∼0.47 deg2). Therefore, the full exploitation of the C-COSMOS data requires a dedicated and accurate analysis focused on three main issues: (1) maximizing the sensitivity when the point-spread function (PSF) changes strongly among different observations of the same source (from ∼1 arcsec up to ∼10 arcsec half-power radius); (2) resolving close pairs; and (3) obtaining the best source localization and count rate. We present here our treatment of four key analysis items: source detection, localization, photometry, and survey sensitivity. Our final procedure consists of a two step procedure: (1) a wavelet detection algorithm to find source candidates and (2) a maximum likelihood PSF fitting algorithm to evaluate the source count rates and the probability that each source candidate is a fluctuation of the background. We discuss the main characteristics of this procedure, which was the result of detailed comparisons between different detection algorithms and photometry tools, calibrated with extensive and dedicated simulations.
The Implementation of a Fast-folding Pipeline for Long-period Pulsar Searching in the PALFA Survey

The Pulsar Arecibo L-Band Feed Array (PALFA) survey, the most sensitive blind search for radio pulsars yet conducted, is ongoing at the Arecibo Observatory in Puerto Rico. The vast majority of the 180 pulsars discovered by PALFA have spin periods shorter than 2 s. Pulsar surveys may miss long-period radio pulsars owing to the summing of a finite number of harmonic components in conventional Fourier analyses (typically ∼16), or as a result of the strong effect of red noise at low modulation frequencies. We address this reduction in sensitivity by using a time-domain search technique: the fast-folding algorithm (FFA). We designed a program that implements an FFA-based search in the PALFA processing pipeline and tested the efficiency of the algorithm by performing tests under both ideal, white-noise conditions, as well as with real PALFA observational data. In the two scenarios, we show that the time-domain algorithm has the ability to outperform the FFT-based periodicity search implemented in the survey. We perform simulations to compare the previously reported PALFA sensitivity with that obtained using our new FFA implementation. These simulations show that for a pulsar having a pulse duty cycle of roughly 3%, the performance of our FFA pipeline exceeds that of our FFT pipeline for pulses with dispersion measure ≲ 40 pc cm−3 and for periods as short as ∼500 ms, and that the survey sensitivity is improved by at least a factor of two for periods ≳ 6 s. Early results from the implementation of the algorithm in PALFA, including discoveries, are also presented in this paper.
Shock–Cloud Interaction in the Solar Corona

Flare-associated coronal shock waves sometimes interact with solar prominences, leading to large-amplitude prominence oscillations (LAPOs). Such prominence activation gives us a unique opportunity to track the time evolution of shock–cloud interaction in cosmic plasmas. Although the dynamics of interstellar shock–cloud interaction has been extensively studied, coronal shock–solar prominence interaction is rarely studied in the context of shock–cloud interaction. Associated with the X5.4 class solar flare that occurred on 2012 March 7, a globally propagated coronal shock wave interacted with a polar prominence, leading to LAPO. In this paper, we studied bulk acceleration and excitation of the internal flow of the shocked prominence using three-dimensional magnetohydrodynamic (MHD) simulations. We studied eight MHD simulation runs, each with different mass density structure of the prominence, and one hydrodynamic simulation run, and we compared the result. In order to compare the observed motion of activated prominence with the corresponding simulation, we also studied prominence activation by injection of a triangular-shaped coronal shock. We found that the prominence is first accelerated mainly by magnetic tension force as well as direct transmission of the shock, and later decelerated mainly by magnetic tension force. The internal flow, on the other hand, is excited during the shock front sweeps through the prominence and damps almost exponentially. We construct a phenomenological model of bulk momentum transfer from the shock to the prominence, which agreed quantitatively with all the simulation results. Based on the phenomenological prominence activation model, we diagnosed physical parameters of the coronal shock wave. The estimated energy of the coronal shock is several percent of the total energy released during the X5.4 flare.
Gravitational wave emission from a magnetically deformed non-barotropic neutron star

A strong candidate for a source of gravitational waves is a highly magnetized, rapidly rotating neutron star (magnetar) deformed by internal magnetic stresses. We calculate the mass quadrupole moment by perturbing a zeroth-order hydrostatic equilibrium by an axisymmetric magnetic field with a linked poloidal–toroidal structure. In this work, we do not require the model star to obey a barotropic equation of state (as a realistic neutron star is not barotropic), allowing us to explore the hydromagnetic equilibria with fewer constraints. We derive the relation between the ratio of poloidal to total field energy Λ and ellipticity e, and briefly compare our results to those obtained using the barotropic assumption. Then, we present some examples of how our results can be applied to astrophysical contexts. First, we show how our formulae, in conjunction with current gravitational wave (non-)detections of the Crab pulsar and the Cassiopeia A central compact object (Cas A CCO), can be used to constrain the strength of the internal toroidal fields of those objects. We find that, for the Crab pulsar (whose canonical equatorial dipole field strength, inferred from spin-down, is 4 × 108 T) to emit detectable gravitational radiation, the neutron star must have a strong toroidal field component, with maximum internal toroidal field strength Btm= 7 × 1012 T; for gravitational waves to be detected from the Cas A CCO at 300 Hz, Btm∼ 1013 T, whereas detection at 100 Hz would require Btm∼ 1014 T. Using our results, we also show how the gravitational wave signal emitted by a magnetar immediately after its birth (assuming it is born rapidly rotating, with Λ≲ 0.2) makes such a newborn magnetar a stronger candidate for gravitational wave detection than, for example, an SGR giant flare.
Phase diagram and multicritical behaviors of mixtures of three-dimensional bosonic gases

We investigate the Bose-Einstein condensation (BEC) patterns, the critical and multicritical behaviors of three-dimensional mixtures of bosonic gases with density-density interactions, characterized by a global U(1)circle plus U(1) symmetry [one U(1) transformation for each species]. In particular, we consider the three-dimensional Bose-Hubbard model for two lattice bosonic gases coupled by an on-site interspecies density-density interaction. We study the phase diagram and the critical behaviors along the transition lines of the BEC of one or both species. We present mean-field calculations and finite-size scaling analyses of quantum Monte Carlo data. We also investigate the nature of the multicritical points where the BEC transition lines of the two species meet. The corresponding universality classes are inferred from a renormalization-group analysis of the corresponding multicritical U(1)circle plus U(1) Landau-Ginzburg-Wilson Phi(4) theory. We find two distinct critical behaviors, associated with bicritical and tetracritical points, respectively, depending on the relative strength of the interspecies and intraspecies interactions.
THE BLACK HOLE MASS–STELLAR VELOCITY DISPERSION RELATION OF NARROW-LINE SEYFERT 1 GALAXIES

Narrow-line Seyfert 1 galaxies (NLS1s) are arguably one of the key active galactic nucleus (AGN) subclasses in investigating the origin of the black hole mass–stellar velocity dispersion ( M BH − &sgr; * ? > ) relation because of their high accretion rate and significantly low M BH ? > . Currently, it is under discussion whether present-day NLS1s offset from the M BH − &sgr; * ? > relation. Using the directly measured stellar velocity dispersion of 93 NLS1s at z < 0.1, and M BH ? > estimates based on the updated mass estimators, we investigate the M BH − &sgr; * ? > relation of NLS1s in comparison with broad-line AGNs. We find no strong evidence that the NLS1s deviates from the M BH − &sgr; * ? > relation, which is defined by reverberation-mapped type 1 AGNs and quiescent galaxies. However, there is a clear trend of the offset with the host galaxy morphology, i.e., galaxies that are more inclined toward the LOS have higher stellar velocity dispersions, suggesting that the rotational broadening plays a role in measuring stellar velocity dispersion based on the single-aperture spectra from the Sloan Digital Sky Survey. In addition, we provide the virial factor log f = 0.05 ± 0.12 ? > (f = 1.12), for M BH ? > estimators based on the FWHM of Hβ, by jointly fitting the M BH − &sgr; * ? > relation using quiescent galaxies and reverberation-mapped AGNs.
The Cosmic History of Black Hole Growth from Deep Multiwavelength Surveys

Significant progress has been made in the last few years on understanding how supermassive black holes form and grow. In this paper, we begin by reviewing the spectral signatures of active galactic nuclei (AGN) ranging from radio to hard X-ray wavelengths. We then describe the most commonly used methods to find these sources, including optical/UV, radio, infrared, and X-ray emission, and optical emission lines. We then describe the main observational properties of the obscured and unobscured AGN population. Finally, we summarize the cosmic history of black hole accretion, that is, when in the history of the universe supermassive black holes were getting most of their mass. We finish with a summary of open questions and a description of planned and future observatories that are going to help answer them.
TIME SEQUENCE SPECTROSCOPY OF AW UMa. THE 518 nm Mg I TRIPLET REGION ANALYZED WITH BROADENING FUNCTIONS

High-resolution spectroscopic observations of AW UMa, obtained on three consecutive nights with a median time resolution of 2.1 minutes, have been analyzed using the broadening function method in the spectral window of 22.75 nm around the 518 nm Mg i triplet region. Doppler images of the system reveal the presence of vigorous mass motions within the binary system; their presence puts into question the solid-body rotation assumption of the contact binary model. AW UMa appears to be a very tight, semi-detached binary; the mass transfer takes place from the more massive to the less massive component. The primary, a fast-rotating star with V sin i = 181.4 ± 2.5 ? > km s−1, is covered with inhomogeneities: very slowly drifting spots and a dense network of ripples more closely participating in its rotation. The spectral lines of the primary show an additional broadening component (called the “pedestal”) that originates either in the equatorial regions, which rotate faster than the rest of the star by about 50 km s−1, or in an external disk-like structure. The secondary component appears to be smaller than predicted by the contact model. The radial velocity field around the secondary is dominated by accretion of matter transferred from (and possibly partly returned to) the primary component. The parameters of the binary are A sin i = 2.73 ± 0.11 R ⊙ ? > and M 1 sin 3 i = 1.29 ± 0.15 M ⊙ ? > , M 2 sin 3 i = 0.128 ± 0.016 M ⊙ ? > . The mass ratio, q sp = M 2 / M 1 = 0.099 ± 0.003 ? > , while still the most uncertain among the spectroscopic elements, is substantially different from the previous numerous and mutually consistent photometric investigations which were based on the contact model. It should be studied why photometry and spectroscopy give such discrepant results and whether AW UMa is an unusual object or if only very high-quality spectroscopy can reveal the true nature of W UMa-type binaries.
WITTGENSTEIN’S IDEALISM: FROM KANT THROUGH HEGEL

: The following contribution aims at presenting a reading of Wittgenstein’s later philosophy as a kind of idealism within the Kantian and post-Kantian tradition. The goal is to argue that Wittgenstein’s position shares substantial theoretical and methodological grounds with Hegel’s idealism. The main concepts pertaining to the later Wittgenstein’s position are analyzed and understood as a form of idealism. After defending the reading against anti-idealist interpretations we argue that the kind of idealism presented clashes with central tenets of the Kantian position. These points of departure are then shown to cover in substantial manner the same kind of criticism Hegel raised against Kant. In the last section, an interpretation of central concepts of the Hegelian position is offered in order to dissolve any fundamental incompatibility with Wittgenstein’s idealism.
Edge of Medical Things Implementation for Deep Learning-Based Cognitive Task Recognition

The emergence of edge devices for the Internet of Medical Things (IoMT) has enabled the integration of low-power resource-limited hardware units with communication technologies for smart healthcare applications including, brain-computer interface (BCI) and mental health management. Implementation of BCI systems on edge devices can provide high clinical decision accuracy with low latency and power consumption while reducing cloud-based training and communication. Hence, this article presents the edge of medical things (EoMT) implementation for cognitive task recognition (CTR) from electroencephalogram (EEG) signals in portable BCI systems. The proposed implementation exploits deep learning-based CTR on different computing platforms for edge devices including Arduino Due and Portenta H7 micro-controllers, Intel Movidius Neural Compute Stick 2 (NCS2), and Mimas v2 Spartan 6 field-programmable gate array (FPGA) board, along with IoMT communication technologies toward transmission of CTR information to caregivers. The real-time CTR performance results on different public and self-recorded databases indicate that the EoMT implementation scheme achieves high accuracies of 99.30 percent and 99.02 percent for public databases, and 96 percent and 89.50 percent for self-recorded databases, with low power consumption and latency, which makes it suitable for the IoMT context.
A 13-bit 1-MS/s SAR ADC With Rotation-Based Mismatch Error Cancellation

This paper presents a mismatch error cancellation technique for high-resolution successive approximation register (SAR) analog-to-digital converter (ADC). The proposed technique that combines residue voltage oversampling and capacitors rotation significantly diminishes the impact of capacitor mismatch without calibration. A VCO-based comparator is adopted to achieve good noise performance with high energy efficiency. A 13-bit 1-MS/s SAR ADC is designed in a 180-nm CMOS technology to prove this technique. The post-layout simulated SAR ADC consumes $154.45 \mu \mathrm{W}$, achieves SNDR of 75.25 dB and SFDR of 90.34 dB at Nyquist input, resulting in a Schreier Figure of merit (FoM) of 170.35 dB.
Robust Recovery of Sparse Signal from Compressed Measurements for Wireless Sensor Networks

In this paper, we present two robust, thresholding based distributed algorithms for recovering a sparse signal from compressed measurements. These algorithms use Lorentzian norm as the cost function which has been observed to give robustness against heavy tailed noise, e.g., impulsive noise. The first algorithm named Diffusion based Lorentzian Iterative Hard Thresholding (DLIHT) requires only gradient information whereas the second algorithm named Diffusion based Lorentzian Hard Thresholding Pursuit(DLHTP) requires solving a linear system, on top of the gradient based update. It is observed through simulations that for moderate corruptions, DLHTP converges faster than DLIHT to similar steady state error value. However, for higher levels of corruptions, DLIHT leads to much less steady state error than offered by DLHTP.
Compressive Sensing based Low Complexity Terahertz Receiver

Terahertz (THz) communication is recognized as a promising technology that could help meet the growing demand of wireless system for the forthcoming 6G wireless technology. However, sampling rate required for signal processing in the THz system is very high and difficult to realize in practical systems. To combat this need for sampling at THz rates, the THz signal detection and demodulation at sub-Nyquist rate is carried out at the receiver. In this paper, we propose a signal-matched (SM) measurement matrix for THz system for sub-Nyquist rate sampling. The proposed SM matrix senses signal containing higher energy more efficiently as compared with the commonly used Gaussian and discrete cosine transform (DCT) matrices in the compressed sensing (CS) framework. Theoretical analysis and simulation results show that the bit error rate (BER) performance of a CS-based $T$ Hz receiver utilizing the proposed SM measurement matrix is better than the popular Gaussian and DCT measurement matrices, and is close to a conventional system sampled at Nyquist rate albeit with much lower system complexity.
Development of Cyber Attack Model for Private Network

Cyber Attack is the most challenging issue all over the world. Nowadays, Cyber-attacks are increasing on digital systems and organizations. Innovation and utilization of new digital technology, infrastructure, connectivity, and dependency on digital strategies are transforming day by day. The cyber threat scope has extended significantly. Currently, attackers are becoming more sophisticated, well-organized, and professional in generating malware programs in Python, C Programming, C++ Programming, Java, SQL, PHP, JavaScript, Ruby etc. Accurate attack modeling techniques provide cyber-attack planning, which can be applied quickly during a different ongoing cyber-attack. This paper aims to create a new cyber-attack model that will extend the existing model, which provides a better understanding of the network’s vulnerabilities.Moreover, It helps protect the company or private network infrastructure from future cyber-attacks. The final goal is to handle cyber-attacks efficacious manner using attack modeling techniques. Nowadays, many organizations, companies, authorities, industries, and individuals have faced cybercrime. To execute attacks using our model where honeypot, the firewall, DMZ and any other security are available in any environment.
Safety Assurance System for Electric Vehicles Based on Infrared LiDAR

With the development of electric vehicles, more and more people choose electric vehicles as their means of transportation. Microwave radar and terahertz radar can be used to build safety assurance system for electric vehicles. However, both of the two technologies have the disadvantage of low stability. Infrared LiDAR has the advantages of high resolution, low cost and high reliability, but it has not yet been widely applied in the safety assurance system for electric vehicles. In this paper, we propose a safety assurance system for electric vehicles based on infrared LiDAR. In the design, infrared sensors are used for obstacle detection, and an MCU (microprogrammed control unit) is used for control. The excellent performance of the electric vehicle equipped with the safety assurance system in avoiding obstacles proves the high efficiency and high reliability of the system proposed in this paper. This experiment can deepen students’ understanding of the circuit system and cultivate their ability to construct the system independently, which can be of important meaning in their education.