Miracle-dz/UniFAR-FTUs huggingface dataset:
Young Binaries as a Test for Pre-Main Sequence Evolutionary Tracks

Abstract Observations of young low-mass binaries (t ≲ 107 yr, M ≲ 3 M_⊙) can be used to calibrate pre-Main Sequence (pre-MS) evolutionary tracks. Recent high angular resolution HST/FGS, speckle, and long-baseline interferometry have resolved the astrometric orbits of a few SB2 pre-MS binaries and have provided the individual dynamical masses of their components as well as the system orbital parallaxes. Spectroscopic fits and filter photometry have permitted to determine SpT (temperatures) and a good estimate of the absolute magnitude (bolometric luminosity) of the components, which in turn allows one to place the components on a theoretical HR-diagram. In this way, one can check (a) whether the measured dynamical masses agree with the predicted masses on the tracks and (b) whether both components lie on an isochrone, as they should for a coeval physical pair of stars. With a sufficiently large sample of different masses and ages of resolved SB2 systems, most of the parameter space of pre-MS tracks can be tested, even for very low stellar masses (M < 0.5 M_⊙) and very young ages (< 2 Myr). This is a prerequisite in order to derive the IMF and star formation history in very young clusters and associations.
Mathematical Modeling of a Solid–Liquid Mixture with Mass Exchange Between Constituents

The mechanical behavior of a mixture composed by an elastic solid and a fluid that exchange mass is investigated. Both the liquid flow and the solid deformation depend on how the solid phase has increased (diminished) its mass, i.e. on the mass conversion between constituents. The model is developed introducing a decomposition of the solid phase deformation gradient. In particular, exploiting the criterion of maximization of the rate of entropy production, we determine an explicit evolution equation for the so-called growth tensor which involves directly the solid stress tensor. An example of a possible choice of the constitutive functions is also presented.
Multi-parameter polynomial order reduction of linear finite element models

In this paper we present a numerically stable method for the model order reduction of finite element (FE) approximations to passive microwave structures parameterized by polynomials in several variables. The proposed method is a projection-based approach using Krylov subspaces and extends the works of Gunupudi etal. (P. Gunupudi, R. Khazaka and M. Nakhla, Analysis of transmission line circuits using multidimensional model reduction techniques, IEEE Trans. Adv. Packaging 25 (2002), pp. 174–180) and Slone etal. (R.D. Slone, R. Lee and J.-F. Lee, Broadband model order reduction of polynomial matrix equations using single-point well-conditioned asymptotic waveform evaluation: derivations and theory, Int. J. Numer. Meth. Eng. 58 (2003), pp. 2325–2342). First, we present the multivariate Krylov space of higher order associated with a parameter-dependent right-hand-side vector and derive a general recursion for generating its basis. Next, we propose an advanced algorithm to compute such basis in a numerically stable way. Finally, we apply the Krylov basis to construct a reduced order model of the moment-matching type. The resulting single-point method requires one matrix factorization only. Numerical examples demonstrate the efficiency and reliability of our approach.
Symmetry-adapted ab initio no-core shell model calculations for 12C

Symmetry-adapted no-core shell-model calculations reveal dominant symmetry patterns in the structure of light nuclei, independent of whether the system Hamiltonian is phenomenological in nature or derived from realistic interactions. We show results of large-scale nuclear structure computations based on the ab initio symmetry-adapted no-core shell model that use only a fraction of the model space. In addition, the symmetry patterns unveiled in these results are employed to explore ultra-large model spaces for 12C. The outcome suggests a possible path forward for realizing collective theories that target correlated highly-deformed and alpha-cluster structures in terms of microscopic degrees of freedom that build forward from the nucleon-nucleon interaction itself.
Systematics of laser operation in GaAs/AlGaAs multiquantum well heterostructures

Important laser parameters of GaAs/AlGaAs MQWH's were measured by means of optical gain spectroscopy. Unsaturated optical net gain spectra are carefully analyzed using a model for band-to-band transitions including momentum conservation and an energy-and density-dependent lifetime broadening. The calculated dependence of the peak gain on the carrier density agrees well with experimental data. The description of energetic positions of the peak gain has to include a bandgap shrinkage with carrier density, present at laser threshold. Temperature-dependent measurements of the onset of optical net gain reveal a pure thermodynamic behavior of the absolute threshold values as a function of L z and of the characteristic temperature T 0 .
On the Liapunov-Krasovskii functionals for stability analysis of linear delay systems

This paper focuses on 'mixed' delay-independent/delay-dependent asymptotic stability problems of a class of linear systems described by delay-differential equations involving several constant but unknown delays. We give some sufficient conditions for characterizing unbounded stability regions in the delays parameter space. The proposed approach makes use of some appropriate Liapunov-Krasovskii functionals, and the results obtained are expressed in terms of matrix inequalities. We also discuss several ways to construct such analytic functionals. These results allow us to recover (or to improve) as limit cases previous delay-independent or/and delay-dependent conditions from the control literature.
Mahan excitons in degenerate wurtzite InN: Photoluminescence spectroscopy and reflectivity measurements

Unintentionally degenerately doped $n$-type hexagonal wurtzite InN samples were studied by using Fourier-transform photoluminescence spectroscopy and reflectivity measurements. We found in luminescence overlapping band acceptor $(e,{A}^{0})$ transitions related to two different acceptors with a strong enhancement of their intensities close to the Fermi energy of the electrons recombining with the localized holes. Our explanation is in terms of a Fermi-edge singularity of the electrons due to strongly increased electron-hole scattering. Electron-hole pairs with such resonantly enhanced oscillator strengths have been referred to as Mahan excitons. Temperature-dependent reflectivity measurements confirm this interpretation.
Discussion on “Optimal Sequential Surveillance for Finance, Public Health, and Other Areas” by Marianne Frisén

Abstract In the stimulating article by Marianne Frisén, a general overview about sequential surveillance is presented. Many applications of sequential surveillance in various fields of science are given. Although sequential surveillance has been successfully applied in engineering for more than 70 years, the extension to areas such as finance and medicine is not straightforward because completely new problems arise in practice. In our discussion of the article, we want to focus on this aspect and we will describe some of these points.
A simulation and theoretical study of energy transport in the event of MHD Kelvin‐Helmholtz instability

[1] Surface waves developed from the Kelvin-Helmholtz (K-H) instability perturb the ambient plasma and radiate waves that extract surface-wave energy. In magnetohydrodynamic (MHD) plasma, the fast-mode waves can propagate across the magnetic field lines. The fast-mode waves emitted from the surface perturbations should play an important role in transporting the surface-wave energy away from the velocity shear layer. Thus, the energy transported by the K-H instability should not be confined near the velocity shear layer. In this study, energy transport in the events of K-H instabilities is studied by the two-dimensional MHD simulation. Our simulation results indicate that most of the energy flux is confined in the vicinity of the velocity shear layer when the fast-mode Mach number of the surface wave is less than one. However, a small amount of the surface-wave energy is transported away from the velocity shear layer by the fast-mode waves. A considerable amount of the surface-wave energy is transported away from the velocity shear layer with the expanding of the fast-mode Mach-cone-like plane waves when the fast-mode Mach number of the surface wave is greater than one. It is shown that the fast-mode Mach-cone-like plane waves can transport the surface-wave energy away from the velocity shear layer efficiently. In this study, we also find that the energy transport velocity obtained from our simulation results is approximately equal to the group velocity of the fast-mode wave. Applications of our simulation results to the magnetosphere are also discussed.
Remote Consultations for People With Parkinson Disease and Cognitive Impairment: Interview Study With Patients, Caregivers, and Health Care Professionals

The COVID-19 pandemic led to many consultations being conducted remotely. Cognitive impairment is recognized as a potential barrier to remote health care interactions and is common and heterogeneous in Parkinson disease. Studies have shown remote consultations in Parkinson disease to be feasible, but little is known about real-life experience, especially for those with cognitive impairment. We explored the experiences and perceptions of remote consultations for people with Parkinson disease and cognitive impairment. This study aimed to explore the experiences of remote consultations for people with Parkinson disease and cognitive impairment from the perspective of service users and professionals and investigate considerations for future service delivery. Semistructured interviews were conducted remotely with 11 people with Parkinson disease and cognitive impairment, 10 family caregivers, and 24 health care professionals (HCPs) between 2020 and 2021. Purposive sampling was used. Interviews were audio-recorded, transcribed, and analyzed using reflexive thematic analysis. Overall, four themes were identified: “the nature of remote interactions,” “challenges exacerbated by being remote,” “expectation versus reality,” and “optimizing for the future. ” Remote consultations were considered as “transactional” and less personal, with difficulties in building rapport, and considered to play a different role from that of in-person consultations. The loss of nonverbal communication and ability of HCPs to sense led to remote consultations being perceived as riskier by all groups. Issues arising from communication and cognitive impairment, balancing the voices of the person with Parkinson disease and the caregiver, and discussions of the future affect this population specifically. Remote consultations were reported to have been more successful than anticipated in all 3 groups. Obstacles were not always as expected; for example, age was less of a barrier than predicted. Video consultations were perceived as being preferable to telephone consultations by many participants, but not accessible to all people with Parkinson disease. With widespread expectation of ongoing remote consultations, potential improvements for these 3 groups and health care services were identified, including practice, preparation, increased awareness of issues, expectation management by HCPs, and more time and flexibility for consultations. Advantages and challenges of remote consultations for this population are identified. Consultations could be improved with increased support, practice, preparation, awareness of issues, and more time and flexibility within services.
Particle detector prototype based on a discrete cell sensitive to the latchup effect

The paper describes an innovative idea for an ionizing particle detector. The principle is based on a latchup effect that is common in to-date CMOS technologies working in a radiation environment. In principle the detector can operate at room temperature, does not require a high voltage power supply and is intrinsically more tolerant to radiation effects than the common solid-state detectors. A latchup-based detector can be constructed using state-of-the-art technologies and could be applied for beam monitoring or as a heavy-ion selector. A prototype made up of discrete components is described and its rough sensitivity is exploited. Tests with daylight, electrons, via a current pulse generator and with a laser beam have proved that charge sensitivity of the order of 1 pC can be easily achieved.
Rotation Curve of the Galaxy

Reanalyzing the galactic Hi survey data with two methods which make use of the geometry of the galactic disk, we explore the outer rotation curve. In addition to the derivation of the outer rotation curve, we investigate their uncertainties, which have not been established previously. Comparing with those obtained previously based on various methods, we find that the rotation curve obtained by the method of Merrifield has the smallest error and the largest coverage of galacto-centric radius among the existing rotation curves. Combining with the inner rotation curve obtained previously by the HI tangential velocity, we present the overall rotation curve of the Galaxy, which ranges from 0.3Ro to 2.5i? o- The rotation curve is gradually rising with the galacto-centric radius if the IAU standard galactic constants, Ro = 8.5 kpc and Go = 220 km s -1 , are assumed. However, the shape of the rotation curve is fairly sensitive to the adopted values of the galactic constants, and the outer rotation curve could be declining if Go is smaller than 200 km s _1 .
The discrete hungry Lotka–Volterra system and a new algorithm for computing matrix eigenvalues

The discrete hungry Lotka–Volterra (dhLV) system is a generalization of the discrete Lotka–Volterra (dLV) system which stands for a prey–predator model in mathematical biology. In this paper, we show that (1) some invariants exist which are expressed by dhLV variables and are independent from the discrete time and (2) a dhLV variable converges to some positive constant or zero as the discrete time becomes sufficiently large. Some characteristic polynomial is then factorized with the help of the dhLV system. The asymptotic behaviour of the dhLV system enables us to design an algorithm for computing complex eigenvalues of a certain band matrix.
Low afterpulsing and narrow timing response InGaAs/InP Single-Photon Avalanche Diode

We designed, fabricated and tested a new planar InGaAs/InP Single-Photon Avalanche Diode (SPAD). By optimizing design and fabrication processes, we obtained low afterpulsing and very good timing jitter, with very fast tail. The detector has a separate absorption, charge and multiplication structure, with double p-type Zn diffusion into n-type InP for defining the p-n high-field avalanching junction. The SPAD can be operated at temperatures achievable with thermoelectric coolers mounted in compact packages (like TO-8). When operated in gated mode with 5 V excess bias, the 25 μm active area diameter InGaAs/InP SPAD reaches good performance at 225 K: i) photon detection efficiency of 40% at 1 μm and 25% at 1.55 μm; ii) dark count rate below 100 kcps (counts per second); iii) low afterpulsing allowing to set a hold-off time as short as 1 μs, corresponding to 1 Mcps; iv) timing jitter less than 90 ps (full width at half maximum) and time constant of decaying tail of just 30 ps. Overall this new planar InGaAs/InP SPAD can be exploited in many near-infrared (up to 1.7 μm) applications where low light, wide dynamic range waveforms have to be acquired, e.g. in Time-Correlated Single-Photon Counting (TCSPC) measurements or Time-of-Flight LIDAR applications for eye-safe 3D ranging.
Triple‐goal estimates in two‐stage hierarchical models

The beauty of the Bayesian approach is its ability to structure complicated models, inferential goals and analyses. To take full advantage of it, methods should be linked to an inferential goal via a loss function. For example, in the two‐stage, compound sampling model the posterior means are optimal under squared error loss. However, they can perform poorly in estimating the histogram of the parameters or in ranking them. ‘Triple‐goal’ estimates are motivated by the desire to have a set of estimates that produce good ranks, a good parameter histogram and good co‐ordinate‐specific estimates. No set of estimates can simultaneously optimize these three goals and we seek a set that strikes an effective trade‐off. We evaluate and compare three candidate approaches: the posterior means, the constrained Bayes estimates of Louis and Ghosh, and a new approach that optimizes estimation of the histogram and the ranks. Mathematical and simulation‐based analyses support the superiority of the new approach and document its excellent performance for the three inferential goals.
Commensurate-incommensurate transition with frozen impurities

2014 A model of commensurate-incommensurate transition with frozen impurities is discussed. In D = 3 dimensions the Bragg peak shift varies linearly with the chemical potential or temperature near the transition. At the lower critical dimension D, = 2, the commensurate phase is, strictly speaking, always instable. There is some analogy with an Ising model in random fields, where Dl is claimed to be 3 according to recent work. The replica trick is shown to be difficult to apply.
Diagnosed Characteristics of Precipitation Systems over Taiwan during the May–June 1987 TAMEX

Abstract Characteristics of Mei-Yu precipitating cloud systems over Taiwan during the May–June 1987 Taiwan Area Mesoscale Experiment (TAMEX) have been studied using sounding, surface precipitation, and radar data. Vertical motion has been computed over the island at 6-h intervals from 13 May to 15 June using a modification of the kinematic method that takes into account the mountainous lower boundary within a four-station sounding polygon. Two primary characteristics of the precipitation have been found. First, the major rainfall event were linked to the passage of midlatitude disturbances and typically consisted of both deep convective and stratiform components. Deep convection was primarily prefrontal or frontal, while the stratiform precipitation was postfrontal, presumably in association with overrunning and orographic lifting. Second, there was a pronounced diurnal variability in the rainfall. Vertical motion, heating (Q1), and moistening (Q2) profiles have been used to define the character of the pr.
Simple principal components

We introduce an algorithm for producing simple approximate principal components directly from a variance–covariance matrix. At the heart of the algorithm is a series of ‘simplicity preserving’ linear transformations. Each transformation seeks a direction within a two‐dimensional subspace that has maximum variance. However, the choice of directions is limited so that the direction can be represented by a vector of integers whenever the subspace can also be represented by vector if integers. The resulting approximate components can therefore always be represented by integers. Furthermore the elements of these integer vectors are often small, particularly for the first few components. We demonstrate the performance of this algorithm on two data sets and show that good approximations to the principal components that are also clearly simple and interpretable can result.
High-temperature Yang-Mills theories and three-dimensional quantum chromodynamics

We demonstrate that for sufficiently high temperature T the behavior of any four-dimensional gauge theory with small coupling constant a, at distances beyond the electrical Debye screening length j/sub D/approx.1/. sqrt.a-barT, is determined precisely by the corresponding three-dimensional theory. This is the magnetic sector of the original theory, and in the non-Abelian case it is a Yang-Mills theory like three-dimensional quantum chromodynamics (QCD/sub 3/). We study QCD/sub 3/ in the loop expansion, which is only valid for distances or approx. =1/aT cannot be directly probed in the loop expansion, however. We present a simpler model which is calculable in this infrared limit, and which might serve as a prototype for QCD/sub 3/. more » The model is massless scalar QED/sub 3/, which with N charged scalars is soluble in a 1/N expansion as N. -->. infinity. Using the 1/N expansion, we demonstrate that infrared softening occurs: the long-range behavior of the photon propagator in massless scalar QED/sub 3/ is less singular than that of free fields. Infrared softening might also occur in QCD/sub 3/, although it cannot be demonstrated to finite order in the loop expansion. The implications of an assumed infrared softening in QCD/sub 3/ for the magnetic sector of Yang-Mills theories at high temperatures are also discussed. « less
Free subalgebras of enveloping fields

Let K be a field of characteristic zero and L a nonabelian Lie algebra over K. We show that the skew field of fractions of the enveloping algebra of L over K contains a free noncommutative A"-algebra when L is solvable or finite-dimensional. The first author has announced a belief (M-L) that all reasonable skew fields (i.e., those not locally finite-dimensional over their centers) contain free non- commutative algebras. We pursue this by showing that the skew field of fractions of an enveloping algebra of a Lie algebra contains a free algebra when the Lie algebra is solvable or finite-dimensional over a field of characteristic zero. Here the main tool is the result of the first author that the skew field of quotients of the Weyl algebra contains a free algebra. For a Lie algebra L over a (commutative) field K, the enveloping algebra UL is the (universal) associative A"-algebra such that the Lie operation on (a copy of) L coincides with the additive commutator (x, y) = x y - yx in UL. Thus we will use the notation (x, y) for both of these without confusion. The enveloping algebra UL is always a domain; in some cases it is an Ore domain and thus has a skew field of fractions QUL, called the enveloping field of L. We reproduce a fairly general result of Lichtman on the existence of QUL.
A Novel hybrid Quantum Protocol to enhance secured dual party Computation over Cloud Networks

Enhancing the security of the dual party computation is considered as primitive to establish a secured multiparty computation in the geographically distributed networks. With the advent of variously distributed paradigms like Cloud computing, IoT and Fog computing, securing ubiquitous computation that involves multiparty collaboration is considered an open research area that attains the attention of the researchers to develop novel protocols. Addressing the problem of secured computation over the network this paper presents a novel and hybrid quantum protocol in with Quantum key distribution is integrated with 3DES to enhance the secure computations through a quantum channel within the cloud infrastructure. Simulation results of the proposed protocol show that it outperforms many security protocols developed based on quantum resources.