A Novel Technique for Fingerprint Classification based on Fuzzy C-Means and Naive Bayes Classifier

Fingerprint classification is a key issue in automatic fingerprint identification systems. One of the main goals is to reduce the item search time within the fingerprint database without affecting the accuracy rate. In this paper, a novel technique, based on topological information, for efficient fingerprint classification is described. The proposed system is composed of two independent modules: the former module, based on Fuzzy C-Means, extracts the best set of training images; the latter module, based on Fuzzy C-Means and Naive Bayes classifier, assigns a class to each processed fingerprint using only directional image information. The proposed approach does not require any image enhancement phase. Experimental trials, conducted on a subset of the free downloadable PolyU database, show a classification rate of 91% over a 100 images test database using only 12 training examples

Modular Middleware for Gestural Data and Devices Management

In the last few years, the use of gestural data has become a key enabler for human-computer interaction (HCI) applications. The growing diffusion of low-cost acquisition devices has thus led to the development of a class of middleware aimed at ensuring a fast and easy integration of such devices within the actual HCI applications. The purpose of this paper is to present a modular middleware for gestural data and devices management. First, we describe a brief review of the state of the art of similar middleware. Then, we discuss the proposed architecture and the motivation behind its design choices. Finally, we present a use case aimed at demonstrating the potential uses as well as the limitations of our middleware

VisIVOWeb: A WWW Environment for Large-Scale Astrophysical Visualization

This article presents a newly developed Web portal called VisIVOWeb that aims to provide the astrophysical community with powerful visualization tools for large-scale data sets in the context of Web 2.0. VisIVOWeb can effectively handle modern numerical simulations and real-world observations. Our open-source software is based on established visualization toolkits offering high-quality rendering algorithms. The underlying data management is discussed with the supported visualization interfaces and movie-making functionality. We introduce VisIVOWeb Network, a robust network of customized Web portals for visual discovery, and VisIVOWeb Connect, a lightweight and efficient solution for seamlessly connecting to existing astrophysical archives. A significant effort has been devoted for ensuring interoperability with existing tools by adhering to IVOA standards. We conclude with a summary of our work and a discussion on future developments

Dynamics of Line-Driven Winds from Disks in Cataclysmic Variables. II. Mass Loss Rates and Velocity Laws

We analyze the dynamics of 2D stationary line-driven winds from accretion disks in cataclysmic variables (CVs), by generalizing the Castor, Abbott and Klein theory. In paper 1, we have solved the wind Euler equation, derived its two eigenvalues, and addressed the solution topology and wind geometry. Here, we focus on mass loss and velocity laws. We find that disk winds, even in luminous novalike variables, have low optical depth, even in the strongest driving lines. This suggests that thick-to-thin transitions in these lines occur. For disks with a realistic radial temperature, the mass loss is dominated by gas emanating from the inner decade in r. The total mass loss rate associated with a luminosity 10 Lsun is 10^{-12} Msun/yr, or 10^{-4} of the mass accretion rate. This is one order of magnitude below the lower limit obtained from P Cygni lines, when the ionizing flux shortwards of the Lyman edge is supressed. The difficulties with such small mass loss rates in CVs are principal, and confirm our previous work. We conjecture that this issue may be resolved by detailed nonLTE calculations of the line force within the context of CV disk winds, and/or better accounting for the disk energy distribution and wind ionization structure. We find that the wind velocity profile is well approximated by the empirical law used in kinematical modeling. The acceleration length scale is given by the footpoint radius of the wind streamline in the disk. This suggests an upper limit of 10 Rwd to the acceleration scale, which is smaller by factors of a few as compared to values derived from line fitting.Comment: 14 pages, 3 Postscript figures, also from http://www.pa.uky.edu/~shlosman/publ.html. Astrophysical Journal, submitte

B cell immunosenescence: different features of naive and memory B cells in elderly

Elderly people show a reduced protection against new infections and a decreased response to vaccines as a consequence of impairment of both cellular and humoral immunity. In this paper we have studied memory/na\uefve B cells in the elderly, evaluating surface immunoglobulin expression, production of the pro- and anti-inflammatory cytokines, tumor necrosis factor (TNF)-\u3b1 and interleukin (IL)-10, and presence of somatic hypermutation, focusing on the IgG(+)IgD(-)CD27(-) double negative (DN) B cells that are expanded in the elderly. Our results show that na\uefve B cells from young donors need a sufficiently strong stimulus to be activated "in vitro", while na\uefve B cells from old subjects are able to produce IL-10 and TNF-\u3b1 when stimulated "physiologically" (\u3b1-CD40/IL-4), suggesting that these cells might play a role in the control of the immuno-inflammatory environment in the elderly. In addition, in the elderly there is an accumulation of DN B cells with a reduced rate of somatic hypermutation. Thus, DN B lymphocytes may be exhausted cells that are expanded and accumulate as a by-product of persistent stimulation or impaired germinal center formatio

Streamer Propagation as a Pattern Formation Problem: Planar Fronts

Streamers often constitute the first stage of dielectric breakdown in strong electric fields: a nonlinear ionization wave transforms a non-ionized medium into a weakly ionized nonequilibrium plasma. New understanding of this old phenomenon can be gained through modern concepts of (interfacial) pattern formation. As a first step towards an effective interface description, we determine the front width, solve the selection problem for planar fronts and calculate their properties. Our results are in good agreement with many features of recent three-dimensional numerical simulations.Comment: 4 pages, revtex, 3 ps file

Blob Ejection from Advection-dominated Accretion Flow II: the Multiwavelength Properties of Light Curves

It has been argued that blobs ejected from advection-dominated accretion flow through the accretion-ejection instability undergo expansion due to their high internal energy density. The expanding blobs interact with their surroundings and form strong shock, which accelerates a group of electrons to be relativistic. Then flares are formed. This model has advances in two aspects: shock acceleration and self-consistent injection. We derive an analytical formula of the injection function of relativistic electrons based on the Sedov's law. We calculate the time-dependent spectrum of relativistic electrons in such an expanding blob. The light-travel effect, the evolution of the electron spectrum due to energy loss, and the escape of relativistic electrons from the radiating region are considered, as well as the expansion (at sub-relativistic speed) of the coasting blob. A large number of light curves spanning wide spaces of parameters have been given in this paper. Regarding the symmetry, relative amplitude, duration of a flare, and the time lag between peak fluxes, we find four basic kinds of light curves for the non-expanding blob, and seven basic kinds of light curves for the expanding blob. We also calculate the evolution of the photon spectrum from both non-expanding and expanding blobs. Different shapes in the phase of decreasing luminosity are then obtained for different parameter values. The photon index, $\alpha_{\rm ph}$, keeps constant for non-expanding blobs when luminosity decreases, whereas $\alpha_{\rm ph}$ continues to decrease after the luminosity reaches its maximum for expanding blobs. It is expected that we can extract the information of ejected blobs from the observed light curves based on the present model.Comment: 23 pages in emulatapj.sty, accepted by the Astrophysical Journa

Chemistry Resolved Kinetic Flow Modeling of TATB Based Explosives

Detonation waves in insensitive, TATB based explosives are believed to have multi-time scale regimes. The initial burn rate of such explosives has a sub-microsecond time scale. However, significant late-time slow release in energy is believed to occur due to diffusion limited growth of carbon. In the intermediate time scale concentrations of product species likely change from being in equilibrium to being kinetic rate controlled. They use the thermo-chemical code CHEETAH linked to an ALE hydrodynamics code to model detonations. They term their model chemistry resolved kinetic flow as CHEETAH tracks the time dependent concentrations of individual species in the detonation wave and calculates EOS values based on the concentrations. A HE-validation suite of model simulations compared to experiments at ambient, hot, and cold temperatures has been developed. They present here a new rate model and comparison with experimental data