Search results for "binary"
showing 10 items of 833 documents
Radio detection of the young binary HD 160934
2013
Precise determination of dynamical masses of pre-main-sequence (PMS) stars is essential to calibrate stellar evolution models that are widely used to derive theoretical masses of young low-mass objects. Binary stars in young, nearby loose associations are particularly good candidates for this calibration since all members share a common age. Interestingly, some of these young binaries present a persistent and compact radio emission, which makes them excellent targets for astrometric VLBI studies. We aim to monitor the orbital motion of the binary system HD 160934, a member of the AB Doradus moving group. We observed HD 160934 with the Very Large Array and the European VLBI Network at 8.4 an…
A relativistically smeared spectrum in the neutron star X-ray binary 4U 1705−44: looking at the inner accretion disc with X-ray spectroscopy
2009
Iron emission lines at 6.4-6.97 keV, identified with fluorescent Kalpha transitions, are among the strongest discrete features in the X-ray band. These are therefore one of the most powerful probes to infer the properties of the plasma in the innermost part of the accretion disc around a compact object. In this paper we present a recent XMM observation of the X-ray burster 4U 1705-44, where we clearly detect a relativistically smeared iron line at about 6.7 keV, testifying with high statistical significance that the line profile is distorted by high velocity motion in the accretion disc. As expected from disc reflection models, we also find a significant absorption edge at about 8.3 keV; th…
Shear influences on the solubility of LDPE in ethene
1998
Abstract The influence of shear on the demixing pressures of the binary system ethene/polyethene was determined viscometrically in the temperature range 147–195°C up to pressures of 1400 bar at polymer concentrations of 18.4, 22.5 and 27.4 wt%, respectively. Autoclaves were used to prepare the solutions and to measure cloud points for the stagnant system. A high-pressure viscometer was used to perform experiments at shear rates γ up to 1500 s −1 . Under all conditions investigated here the two-phase area grows as γ becomes larger and the demixing pressures increase up to 23 bar. This observation is in contrast to theoretical expectation according to which it should be the one-phase region w…
Models and Astrophysical Parameters of High Mass X-ray Binaries
1996
The objective of this work is the High Mass X-ray Binaries. These systems consist of a neutron star orbiting around a star of spectral type OB. According to the luminosity class of the optical companion they split into Supergiant X-ray binaries and Be/X-ray systems. In both systems the high energy radiation is due to the accretion phenomenum, but in the first case the accreted metter comes from the strong stellar wind of the primary and in the second case it comes from the circumstellar envelope surrounding the Be star equator. In this work I concentrate on the optical and infrared bands of the electromagnetic spectrum although a discussion of the X-ray characteristics for some systems is a…
Surface effects on spinodal decomposition in binary mixtures: The case with long-ranged surface fields
1997
We present detailed numerical results for phase-separation kinetics of critical binary mixtures in the vicinity of a surface that exerts a long-ranged attractive force on one of the components of the mixture. We consider surface potentials of the form $V(Z)\ensuremath{\sim}{Z}^{\ensuremath{-}n}$, where $Z$ is the distance from the surface and $n=1,2,3$. In particular, we investigate the interplay of the surface wetting layer with the dynamics of domain growth. We find that the wetting layer at the surface exhibits power-law growth with an exponent that depends on $n$, in contrast to the case with a short-ranged surface potential, where the growth is presumably logarithmic. From correlation …
The regression Tsetlin machine: a novel approach to interpretable nonlinear regression
2019
Relying simply on bitwise operators, the recently introduced Tsetlin machine (TM) has provided competitive pattern classification accuracy in several benchmarks, including text understanding. In this paper, we introduce the regression Tsetlin machine (RTM), a new class of TMs designed for continuous input and output, targeting nonlinear regression problems. In all brevity, we convert continuous input into a binary representation based on thresholding, and transform the propositional formula formed by the TM into an aggregated continuous output. Our empirical comparison of the RTM with state-of-the-art regression techniques reveals either superior or on par performance on five datasets. Thi…
Unmet care needs are common among community-dwelling older people with memory problems in Finland
2019
Aims: Ageing in place has become a policy priority. Consequently, residential care has been reduced, and more older people with multiple care needs reside at home with the help of informal care and home care services. An increasing share of these people has memory disorders. We examined the extent to which memory problems, in addition to other individual characteristics, are associated with unmet care needs among community-dwelling older people. Methods: The study employed cross-sectional survey data from community-dwelling people aged 75+ collected in 2010 and 2015, analysed using binary logistic regression analysis. The study population consisted of people who had long-term illnesses or …
A distance metric on binary trees using lattice-theoretic measures
1990
A so called height function which is a strictly antitone supervaluation is defined on binary trees. Via lattice-theoretic results and using the height function, we can define a distance metric on binary trees of size n which can be computed in expected time O(n 3/2 )
Proof of a Conjecture on Contextuality in Cyclic Systems with Binary Variables
2015
We present a proof for a conjecture previously formulated by Dzhafarov, Kujala, and Larsson (Foundations of Physics, in press, arXiv:1411.2244). The conjecture specifies a measure for the degree of contextuality and a criterion (necessary and sufficient condition) for contextuality in a broad class of quantum systems. This class includes Leggett-Garg, EPR/Bell, and Klyachko-Can-Binicioglu-Shumovsky type systems as special cases. In a system of this class certain physical properties $q_{1},...,q_{n}$ are measured in pairs $(q_{i},q_{j})$; every property enters in precisely two such pairs; and each measurement outcome is a binary random variable. Denoting the measurement outcomes for a proper…
CONTRIBUTION OF PSEUDO-FOCUSED SOFT PROTONS TO THE BACKGROUND OF ATHENA
2021
This PhD thesis explores the role of low energy protons, the so-called ‘soft protons', as a component of the background in view of the future ESA's X-ray mission Athena. As a matter of fact, a high level of soft proton flux at the focal plane of Athena can adversely affect the scientific goals of the mission. To prevent this, a correct estimate of the soft proton flux expected at the focal plane of the satellite is fundamental. Such an estimate can be achieved only if the reflectivity of soft protons from the optics is well understood, with efforts on both the experimental and the theoretical sides. To this aim, I applied the model of reflectivity of particles at grazing incidence proposed …