Miracle-dz/UniFAR-FTUs huggingface dataset:
Network depth: identifying median and contours in complex networks

Centrality descriptors are widely used to rank nodes according to specific concept(s) of importance. Despite the large number of centrality measures available nowadays, it is still poorly understood how to identify the node which can be considered as the ‘centre’ of a complex network. In fact, this problem corresponds to finding the median of a complex network. The median is a non-parametric—or better, distribution-free—and robust estimator of the location parameter of a probability distribution. In this work, we present the statistical and most natural generalization of the concept of median to the realm of complex networks, discussing its advantages for defining the centre of the system and percentiles around that centre. To this aim, we introduce a new statistical data depth and we apply it to networks embedded in a geometric space induced by different metrics. The application of our framework to empirical networks allows us to identify central nodes which are socially or biologically relevant.
Automated Discovery of Jet Substructure Analyses

The study of the substructure of collimated particles from quarks and gluons, or jets, has the promise to reveal the details how color charges interact with the QCD plasma medium created in colliders such as RHIC and the LHC. Traditional jet substructure observables have been constructed using expert knowledge, and are largely transplanted, unmodified, from the high-energy physics, where the goal is primarily the study of boosted hadronic decays. A novel neural network architecture is described that is capable of examining theoretical models, and constructs, on its own, an analysis procedure that is sensitive to the internal model features. This architecture, in combination with symbolic regression, further allows the extraction of closed-form algebraic expressions from the learned result -- enabling the automatically constructed jet substructure analysis to be subsequently understood and reproduced by humans. This system is then tasked to construct an analysis that infers the plasma temperature from observing jets, which is demonstrated using both JEWEL and the Linearized Boltzmann Transport model, and at the presence of a realistic remnant of the plasma, or underlying event, that the measurement has to overcome. In a demonstration how algorithms can produce original research in direct competition to human experts, the resulting jet substructure variables and analyses are capable of determining the initial temperature of the plasma medium from analyzing 1200--2500 jets, a performance not seen in existing, manually designed analyses. Comparison of an incidentally discovered observable with the existing literature further indicates that the system described is capable of examining the model phase spaces to a detail at least comparable to the current field of human experts.
Noise calculation model and analysis of high-gain readout circuits for CMOS image sensors

A thermal noise calculation model of high-gain switched-capacitor column noise cancellers for CMOS image sensors is presented. In the high-gain noise canceller with a single noise cancelling stage, the reset noise of the readout circuits dominates the noise at high gain. Using the double-stage architecture using a switched-capacitor gain stage and a sample-and-hold stage using two sampling capacitors, the reset noise of the gain stage can be cancelled. The resulting input referred thermal noise power of high-gain double-stage switched-capacitor noise canceller is revealed to be proportional to (g_a/g_s)/GC_L where g_a, G and C_L are the transconductance, gain and output capacitance of the amplifier, respectively, and g_s is the output conductance of an in-pixel source follower. An important contribution of the proposed noise calculation formula is the inclusion of the influence of the transconductance ratio of the amplifier to that of the source follower. For low-noise design, it is important that the transconductance of the amplifier used in the noise canceller is minimized under the condition of meeting the required response time of the switched capacitor amplifier which is inversely proportional to the cutoff angular frequency.
Deep reinforcement learning for quantum gate control

How to implement multi-qubit gates efficiently with high precision is essential for realizing universal fault-tolerant computing. For a physical system with some external controllable parameters, it is a great challenge to control the time dependence of these parameters to achieve a target multi-qubit gate efficiently and precisely. Here we construct a dueling double deep Q-learning neural network (DDDQN) to find out the optimized time dependence of controllable parameters to implement two typical quantum gates: a single-qubit Hadamard gate and a two-qubit CNOT gate. Compared with traditional optimal control methods, this deep reinforcement learning method can realize efficient and precise gate control without requiring any gradient information during the learning process. This work attempts to pave the way to investigate more quantum control problems with deep reinforcement learning techniques.
Realization of "Time Crystal" Lagrangians and Emergent Sisyphus Dynamics

We demonstrate how non-convex "time crystal" Lagrangians arise in the effective description of conventional, realizable physical systems. Such embeddings allow for the resolution of dynamical singularities that arise in the reduced description. Sisyphus dynamics, featuring intervals of forward motion interrupted by quick resets, is a generic consequence. Near the would-be singularity of the time crystal, we find striking microstructure.
The Hubble Space Telescope Survey of BL Lacertae Objects. I. Surface Brightness Profiles, Magnitudes, and Radii of Host Galaxies

We report on a large Hubble Space Telescope imaging survey of BL Lac objects, at spatial resolution ≳10 times better than previous ground-based surveys. We focus on data reduction and analysis, describing the procedures used to model the host galaxy surface brightness radial profiles. A total of 69 host galaxies were resolved out of 110 objects observed, including almost all sources at z ≲ 0.5. We classify them morphologically by fitting with either an exponential disk or a de Vaucouleurs profile; when one fit is preferred over the other, in 58 of 69 cases, it is invariably the elliptical morphology. This is a very strong result given the large number of BL Lac objects, the unprecedented spatial resolution, and the homogeneity of the data set. With the present reclassification of the host galaxy of 1418+546 as an elliptical, there remain no undisputed examples of a disk galaxy hosting a BL Lac nucleus. This implies that, at 99% confidence, fewer than 7% of BL Lac objects can be in disk galaxies. The apparent magnitude of the host galaxies varies with distance as expected if the absolute magnitudes are approximately the same, with a spread of ±1 mag, out to redshift z ~ 0.5. At larger redshifts, only six of 23 BL Lac objects are resolved so the present data do not constrain possible luminosity evolution of the host galaxies. The collective Hubble diagram for BL Lac host galaxies and radio galaxies strongly supports their unification.
An optimised gravitational wave follow-up strategy with the Australian Square Kilometre Array Pathfinder

Abstract The detection of a neutron star merger by the Advanced Laser Interferometer Gravitational-Wave Observatory and Advanced Virgo gravitational wave detectors, and the subsequent detection of an electromagnetic counterpart have opened a new era of transient astronomy. With upgrades to the Advanced Laser Interferometer Gravitational-Wave Observatory and Advanced Virgo detectors and new detectors coming online in Japan and India, neutron star mergers will be detected at a higher rate in the future, starting with the O3 observing run which will begin in early 2019. The detection of electromagnetic emission from these mergers provides vital information about merger parameters and allows independent measurement of the Hubble constant. The Australian Square Kilometre Array Pathfinder is expected to become fully operational in early 2019, and its 30 deg2 field of view will enable us to rapidly survey large areas of sky. In this work we explore prospects for detecting both prompt and long-term radio emission from neutron star mergers with Australian Square Kilometre Array Pathfinder and determine an observing strategy that optimises the use of telescope time. We investigate different strategies to tile the sky with telescope pointings in order to detect radio counterparts with limited observing time, using 475 simulated gravitational wave events. Our results show a significant improvement in observing efficiency when compared with a naïve strategy of covering the entire localisation above some confidence threshold, even when achieving the same total probability covered.
Impurity-impurity pair correlation function and paramagnetic-ferromagnetic phase transition in the random Ising model

In this Monte Carlo study we concentrated on the influence of non-magnetic impurities arranged as the lines with random orientation on paramagnetic-to-ferromagnetic phase transition in the 3D Ising model. Special emphasize is given to the long-distance decay of the impurity-impurity pair correlation function. It is shown that for the lattice sizes considered ( L =10-96) and for the two different impurity distributions (purely random and mutually avoiding lines) the function is governed by the power law of 1/r a with an universal exponent a » 2. This result supports our findings about the numerical values of the critical exponents governing magnetic phase transition in the 3D Ising model with long-range-correlated disorder. The ferromagnetic phase transition in the three-dimensional ( 3D ) Ising model with quenched long-range-correlated impurities is governed by the critical exponents that are different of both those for the pure 3D Ising model and for the 3D Ising model with uncorrelated impurities
The nature and structure of the emission line nebula K 3‐35: a very young planetary nebula with precessing bipolar jet‐like outflows?

We present Hα, [N II]6583 and 6-cm continuum images of the emission line nebula K 3-35. The optical images reveal an extended nebula (size ≃ 11 × 9 arcsec2 in [N II]) in which most of the emission originates in a very narrow (width 0.7–1.3 arcsec) S-shaped region which extends almost all along the nebula (≃ 7 arcsec). The 6-cm continuum emission also arises in this narrow region, which is characterized by an exceedingly high point-symmetry and systematic and continuous changes of the orientation with respect to the nebular centre. The properties of the narrow region suggest that it represents a system of precessing bipolar jet-like components. Two low-excitation, compact bipolar knots near the tips of the jet-like components are observed in the deduced [N II]/Hα image ratio. These knots may be generated by the interaction of the collimated outflows with surrounding material. A comparison of the optical and radio images shows the existence of differential extinction within the nebula. Maximum extinction is observed in a disc-like region which traces the equator of the elliptical shell previously observed at 20-cm continuum. All available data strongly suggest that K 3-35 is a very young planetary nebula in which we could be observing the first stages of the formation of collimated outflows and point-symmetric structures typically observed in planetary nebulae. The properties of the jet-like components in K 3-35 are in good agreement with models of binary central stars in which highly collimated outflows originate either from a precessing accretion disc or via magnetic collimation in a precessing star.
Horizontal Line-of-Sight Turbulence Over Near-Ground Paths and Implications for Adaptive Optics Corrections in Laser Communications.

Atmospheric turbulence over long horizontal paths perturbs phase and can also cause severe intensity scintillation in the pupil of an optical communications receiver, which limits the data rate over which intensity-based modulation schemes can operate. The feasibility of using low-order adaptive optics by applying phase-only corrections over horizontal propagation paths is investigated. A Shack–Hartmann wave-front sensor was built and data were gathered on paths 1 m above ground and between a 1- and 2.5-km range. Both intensity fluctuations and optical path fluctuation statistics were gathered within a single frame, and the wave-front reconstructor was modified to allow for scintillated data. The temporal power spectral density for various Zernike polynomial modes was used to determine the effects of the expected corrections by adaptive optics. The slopes of the inertial subrange of turbulence were found to be less than predicted by Kolmogorov theory with an infinite outer scale, and the distribution of variance explained by increasing order was also found to be different. Statistical analysis of these data in the 1-km range indicates that at communications wavelengths of 1.3 μm, a significant improvement in transmitted beam quality could be expected most of the time, to a performance of 10% Strehl ratio or better.
Ensemble method: Community detection based on game theory

Timely and cost-effective analytics over social network has emerged as a key ingredient for success in many businesses and government endeavors. Community detection is an active research area of relevance to analyze online social network. The problem of selecting a particular community detection algorithm is crucial if the aim is to unveil the community structure of a network. The choice of a given methodology could affect the outcome of the experiments because different algorithms have different advantages and depend on tuning specific parameters. In this paper, we propose a community division model based on the notion of game theory, which can combine advantages of previous algorithms effectively to get a better community classification result. By making experiments on some standard dataset, it verifies that our community detection model based on game theory is valid and better.
The low mass stellar population of the Orion OB1 association and implications for the formation of low mass stars

The OB associations, which are fossil star formation regions, retain the end-products of the star formation process in an open, unobscured environment. Observations of the low mass stars in OB associations provide a far clearer picture of the results of the star formation process than do observations of embedded, on-going star formation regions. We review the X-ray and optical surveys of the fossil star formation regions in the Orion OB1 association. Low mass pre-main sequence stars abound not only in the known regions of recent star formation, but are also distributed over a much larger volume. The pre-main sequence stars have a narrow age spread, and the mass function extends down to substellar masses. The clustering of pre-main sequence stars around sigma Ori may represent an evolved version of the Orion Nebula Cluster. We speculate about the effect of the OB environment on the initial mass function and the formation of planetary systems like the Solar System.
Test of fit and model selection based on likelihood function

Notre travail port sur l'inf´erence au sujet de l'AIC (un cas de vraisemblance p`enalis´ee) d'Akaike (1973), o`u comme estimateur de divergence de Kullback-Leibler est intimement reli´ee `a l'estimateur de maximum de vraisemblance. Comme une partie de la statistique inf´erentielle, dans le contexte de test d'hypoth`ese, la divergence de Kullback-Leibler et le lemme de Neyman-Pearson sont deux concepts fondamentaux. Tous les deux sont au sujet du rapports de 11 vraisemblance. Neyman-Pearson est au sujet du taux d'erreur du test du rapport de vraisemblance et la divergence de Kullback-Leibler est l'esp´erance du rapport de log-vraisemblance.
Chaoticity analysis of the current through pure, hydrogenated and hydrophobically modified PEG-Si thin films under varying relative humidity

Polyethylene Glycol has an irregular current characteristic under constant voltage and slowly varying relative humidity. The current through a thin film of Gamma-isocyanatopropyltriethoxysilane added Polyethylene glycol (PEG-Si), its hydrogenated and hydrophobically modified forms, as a function of increasing relative humidity at equal time steps is analyzed for chaoticity. We suggest that the irregular behavior of current through PEG-Si thin films as a function of increasing relative humidity could best be analyzed for chaoticity using both time series analysis and detrended uctuation analysis; the relative humidity is kept as a slowly varying parameter. The presence of more then one regime is suggested by the calculation of the maximal Lyapunov exponents. Furthermore, the maximal Lyapunov exponent in each of the regimes was positive, thus confirming the presence of low dimensional chaos. DFA also confirms the presence of at least two different regimes, in agreement with the behavior of the maximal Lyapunov exponent in the time series analysis. We also suggest that the irregular behavior of the current through PEG-Si can be reduced by hydrogenating and hydrophobically modifying PEG-Si and the improvement in stability can be confirmed by our study.
ON LOCALLY DIVIDED RINGS AND GOING-DOWN RINGS

All rings considered below are commutative with 1. As in [B2], if R is a ring, P 2 SpecðRÞ is a divided prime ideal in R if P is comparable under inclusion to each ideal of R; and R is a divided ring if each P 2 SpecðRÞ is divided in R. Divided rings generalize the divided domains introduced in [D2]. Our main goal is to generalize another class of domains introduced in [D2], the locally divided domains. We say that a ring R is a locally divided ring if RP is a divided ring for each P 2 SpecðRÞ. Each divided ring is locally divided [B2, Proposition 4]. Since the literature on locally divided domains ([D2], [D4], [DF]) is tied to studies of going-down domains (in the sense of [D1]), it is natural to pursue connections between locally divided rings and the recently introduced going-down rings [D5]. Section 3 develops several such connections, some with the flavor of domain-theoretic studies and others differing from such phenomena in the presence of zero-divisors. First, Section 2 develops more information about divided rings and initiates the theory of locally divided rings.
A white-and-blue mixed LED backlight for airplane display

As LCDs are not self-luminance, a backlight unit (BLU) is necessary for LCDs. For a display installed on an airplane, the brightness of a BLU is required to be very high and the color temperature should be able to change to higher in order to guarantee the pilot can clearly and accurately read the information on the display. This paper presents a LED BLU consisting of high-luminous-efficiency white LEDs and blue LEDs. White LEDs with the luminous efficiency as high as 120lm/W provide the most of luminance. When an airplane flies to higher altitude, the pilot can push a button to lighten the blue LEDs to change the color temperature. The paper presents a theoretical model for luminous flux estimation. The simulation results show that the white-and-blue-LED-mixed BLU presents the merits of high brightness, various color temperatures, high uniformity, and less complicated control.
Alignment of DNA Sequence Using the Features of Global and Local Algorithms along with Matrices

The algorithm generated is based on designing matrices in such a way that score matrix contains the maximum scores for alignment of the DNA sequences and the aligned sequences are generated by trace matrix generated based on the score matrix. The score matrix is initialized by using Smith – Waterman algorithm and the scores used for filling up the score matrix are calculated using Needleman –Wunsch algorithm.
Solution of the dark energy and its coincidence problem based on local antigravity sources without fine-tuning or new scales

A novel idea is proposed for a natural solution of the dark energy and its cosmic coincidence problem. The existence of local antigravity sources, associated with astrophysical matter configurations distributed throughout the universe, can lead to a recent cosmic acceleration effect. Various physical theories can be compatible with this idea, but here, in order to test our proposal, we focus on quantum originated spherically symmetric metrics matched with the cosmological evolution through the simplest Swiss cheese model. In the context of asymptotically safe gravity, we have explained the observed amount of dark energy using Newton's constant, the galaxy or cluster length scales, and dimensionless order one parameters predicted by the theory, without fine-tuning or extra unproven energy scales. The interior modified Schwarzschild-de Sitter metric allows us to approximately interpret this result as that the standard cosmological constant is a composite quantity made of the above parameters, instead of a fundamental one.
Controlled electron injection into the wake wave using plasma density inhomogeneity

The electron injection, for the laser wake field accelerator, controlled through the plasma density inhomogeneity is studied on a basis of analytical estimates and two- and three-dimensional particle-in-cell simulations. The injection scheme requires a concordance of the density scale length and laser intensity. It is shown that at a sloping inhomogeneity of plasma the wave breaking produces stronger singularity of the electron density than at a density discontinuity, but develops slower. With the help of simulations for a moderate laser intensity, we demonstrate the optimal plasma density gradient, where the electron injection into the wake wave forms the electron beam with low divergence, small energy spread and high energy.
Photon migration within the P3 approximation

The diffusion approximation to the photon transport equation is the simplest model for photon migration. The applicability of the diffusion approximation, however, is limited. For example, it is strictly valid only when the absorption coefficient is small compared to the scattering coefficient and the source modulation frequency is small compared to the scattering rate. In this contribution we establish the theoretical range of validity of the diffusion approximation, review a frequency-dependent solution of the transport equation within the P3 approximation, and establish the significance of the P3 solution using Monte Carlo computer simulations. We find that the P3 approximation, in most cases, permits a more accurate determination of the optical properties of highly absorbing media as well as from data obtained at modulation frequencies greater than 3 GHz. Interestingly, for highly anisotropic scattering (g equals 0.9), we find that diffusion theory and the P3 approximation predict approximately the same values for the reduced scattering coefficient.
Identification of Mitochondrial species-Chiromantes boulengeri in Arvand River, Persian Gulf

In this study, Identification of Chiromantes boulengeri was carried out in 2014 in two parts of the Arvand River in Minoo Island (Minoo City Bridge and Omm ol Ejaj region) based on the characteristics of its mtDNA gene. In order to investigate the molecular analyzes of this species with the species close to the NCBI gene bank, DNA was extracted from the phenol-chloroform method and the 16S rRNA mitochondrial genes were amplified by PCR and finally sequenced. Based on the polymorphism analysis, two mutation regions were observed in Chiromantes boulengeri species, which indicated its evolution and adaptation for better survival in different ecological and atmospheric conditions in the study area.