2,281 research outputs found

    New Solution to the Midas Touch Problem: Identification of Visual Commands Via Extraction of Focal Fixations

    Get PDF
    AbstractReliable identification of intentional visual commands is a major problem in the development of eye-movements based user interfaces. This work suggests that the presence of focal visual fixations is indicative of visual commands. Two experiments are described which assessed the effectiveness of this approach in a simple gaze-control interface. Identification accuracy was shown to match that of the commonly used dwell time method. Using focal fixations led to less visual fatigue and higher speed of work. Perspectives of using focal fixations for identification of visual commands in various kinds of eye-movements based interfaces are discussed

    Electric Switching of the Charge-Density-Wave and Normal Metallic Phases in Tantalum Disulfide Thin-Film Devices

    Full text link
    We report on switching among three charge-density-wave phases - commensurate, nearly commensurate, incommensurate - and the high-temperature normal metallic phase in thin-film 1T-TaS2 devices induced by application of an in-plane electric field. The electric switching among all phases has been achieved over a wide temperature range, from 77 K to 400 K. The low-frequency electronic noise spectroscopy has been used as an effective tool for monitoring the transitions, particularly the switching from the incommensurate charge-density-wave phase to the normal metal phase. The noise spectral density exhibits sharp increases at the phase transition points, which correspond to the step-like changes in resistivity. Assignment of the phases is consistent with low-field resistivity measurements over the temperature range from 77 K to 600 K. Analysis of the experimental data and calculations of heat dissipation suggest that Joule heating plays a dominant role in the electric-field induced transitions in the tested 1T-TaS2 devices on Si/SiO2 substrates. The possibility of electrical switching among four different phases of 1T-TaS2 is a promising step toward nanoscale device applications. The results also demonstrate the potential of noise spectroscopy for investigating and identifying phase transitions in materials.Comment: 32 pages, 7 figure

    SANC integrator in the progress: QCD and EW contributions

    Full text link
    Modules and packages for the one-loop calculations at partonic level represent the first level of SANC output computer product. The next level represents Monte Carlo integrator mcsanc, realizing fully differential hadron level calculations (convolution with PDF) for the HEP processes at LHC. In this paper we describe the implementation into the framework mcsanc first set of processes: DY NC, DY CC, ff->HW(Z) and single top production. Both EW and QCD NLO corrections are taken into account. A comparison of SANC results with those existing in the world literature is given

    Electroweak radiative corrections to the three channels of the process f_1 bar-f_1 ZA --> 0

    Full text link
    We have calculated the electroweak radiative corrections at the O(alpha) level to the three channels of the process f_1 bar-f_1 Z A --> 0 and implemented them into the SANC system. Here A stands for the photon and f_1 for a first generation fermion whose mass is neglected everywhere except in arguments of logarithmic functions. The symbol --> 0 means that 4-momenta of all the external particles flow inwards. We present the complete analytical results for the covariant and helicity amplitudes for three cross channels: f_1 + bar-f_1 --> Z + gamma, Z --> f_1 + bar-f_1 + gamma and f_1 + gamma --> f_1 + Z. The one-loop scalar form factors of these channels are simply related by an appropriate permutation of their arguments s,t,u. To check the correctness of our results we first of all observe the independence of the scalar form factors on the gauge parameters and the validity of the Ward identity, i.e. external photon transversality, and, secondly, compare our numerical results with the other independent calculations available to us.Comment: 19 pages, 6 figures, 10 table

    The central engine of GRB 130831A and the energy breakdown of a relativistic explosion

    Full text link
    Gamma-ray bursts (GRBs) are the most luminous explosions in the universe, yet the nature and physical properties of their energy sources are far from understood. Very important clues, however, can be inferred by studying the afterglows of these events. We present optical and X-ray observations of GRB 130831A obtained by Swift, Chandra, Skynet, RATIR, Maidanak, ISON, NOT, LT and GTC. This burst shows a steep drop in the X-ray light-curve at 105\simeq 10^5 s after the trigger, with a power-law decay index of α6\alpha \sim 6. Such a rare behaviour cannot be explained by the standard forward shock (FS) model and indicates that the emission, up to the fast decay at 10510^5 s, must be of "internal origin", produced by a dissipation process within an ultrarelativistic outflow. We propose that the source of such an outflow, which must produce the X-ray flux for 1\simeq 1 day in the cosmological rest frame, is a newly born magnetar or black hole. After the drop, the faint X-ray afterglow continues with a much shallower decay. The optical emission, on the other hand, shows no break across the X-ray steep decrease, and the late-time decays of both the X-ray and optical are consistent. Using both the X-ray and optical data, we show that the emission after 105\simeq 10^5 s can be explained well by the FS model. We model our data to derive the kinetic energy of the ejecta and thus measure the efficiency of the central engine of a GRB with emission of internal origin visible for a long time. Furthermore, we break down the energy budget of this GRB into the prompt emission, the late internal dissipation, the kinetic energy of the relativistic ejecta, and compare it with the energy of the associated supernova, SN 2013fu.Comment: Accepted for publication by MNRAS. 21 pages, 3 figures, 8 tables. Extra table with magnitudes in the sourc

    Transition from Fireball to Poynting-flux-dominated Outflow in Three-Episode GRB 160625B

    Full text link
    The ejecta composition is an open question in gamma-ray bursts (GRB) physics. Some GRBs possess a quasi-thermal spectral component in the time-resolved spectral analysis, suggesting a hot fireball origin. Others show a featureless non-thermal spectrum known as the "Band" function, consistent with a synchrotron radiation origin and suggesting that the jet is Poynting-flux-dominated at the central engine and likely in the emission region as well. There are also bursts showing a sub-dominant thermal component and a dominant synchrotron component suggesting a likely hybrid jet composition. Here we report an extraordinarily bright GRB 160625B, simultaneously observed in gamma-rays and optical wavelengths, whose prompt emission consists of three isolated episodes separated by long quiescent intervals, with the durations of each "sub-burst" being \sim 0.8 s, 35 s, and 212 s, respectively. Its high brightness (with isotropic peak luminosity Lp,iso4×1053_{\rm p, iso}\sim 4\times 10^{53} erg/s) allows us to conduct detailed time-resolved spectral analysis in each episode, from precursor to main burst and to extended emission. The spectral properties of the first two sub-bursts are distinctly different, allowing us to observe the transition from thermal to non-thermal radiation between well-separated emission episodes within a single GRB. Such a transition is a clear indication of the change of jet composition from a fireball to a Poynting-flux-dominated jet.Comment: Revised version reflecting the referees' comments. 27 pages, 11 figures, 5 tables. The final edited version will appear in Nature Astronom

    A choice of legal act during law-making process

    Get PDF
    There is a problem of legal act choice during the law-making process considered in the paper. A method for step-by-step choice algorithm is advanced. The algorithm is associated with public relationship assessment. The public relationships to be regulated must have a certain social valu

    La opinión del pueblo y del poder supremo: sobre la naturaleza de la relación entre el soberano y sus ciudadanos en Rusia a mediados del siglo XVI

    Get PDF
    According to the authors, the effectiveness of the work of the Moscow state machine was largely determined by the extent of feedback channels within the supreme power. In the summer of 1547, the passivity of the supreme power in investigating the facts of abuse of governors, eliminating the consequences of the fire, coupled with the growth of taxes and crop failures and subsequent rise in the price of bread led to the rebellion of citizens in Moscow and forcing Ivan IV to dialogue and satisfy their demand

    The modern law-making process: structure and main problems

    Get PDF
    Tlirough the dialectical method the objective of the articlewas to analyze the process of the elaboration of modern laws, considering their structure and main problems. There is a major stracture and problems inherent in the modern law-making process described in the articl

    Forming and development of law-making principles system and its meaning for legal enforcement of suitable legal regulation model

    Get PDF
    There is a law-making principles system worked out in the paper. It plays the great role in creation or choice of legal regulation model. When elaborating the latter, the deep interaction between law-making and law principles takes place. The deeper interaction is put by a legislator into model background the better public regulation is carried ou
    corecore