Fission barriers heights in A∼\sim 200 mass region

Statistical model analysis has been carried out for $p$ and $\alpha$ induced fission reactions using a consistent description for fission barrier and level density in A $\sim$ 200 mass region. A continuous damping of shell correction with excitation energy have been considered. Extracted fission barriers agree well with the recent microscopic-macroscopic model. The shell corrections at the saddle point were found to be not significant.Comment: Pramana - J. Phys. (In press

Gaussian information matrix for Wiener model identification

We present a closed form expression for the information matrix associated with the Wiener model identification problem under the assumption that the input signal is a stationary Gaussian process. This expression holds under quite generic assumptions. We allow the linear sub-system to have a rational transfer function of arbitrary order, and the static nonlinearity to be a polynomial of arbitrary degree. We also present a simple expression for the determinant of the information matrix. The expressions presented herein has been used for optimal experiment design for Wiener model identification.Comment: 16 page

Dynamical system analysis for DBI dark energy interacting with dark matter

A dynamical system analysis related to Dirac Born Infeld (DBI) cosmological model has been investigated in this present work. For spatially flat FRW space time, the Einstein field equation for DBI scenario has been used to study the dynamics of DBI dark energy interacting with dark matter. The DBI dark energy model is considered as a scalar field with a nonstandard kinetic energy term. An interaction between the DBI dark energy and dark matter is considered through a phenomenological interaction between DBI scalar field and the dark matter fluid. The field equations are reduced to an autonomous dynamical system by a suitable redefinition of the basic variables. The potential of the DBI scalar field is assumed to be exponential. Finally, critical points are determined, their nature have been analyzed and corresponding cosmological scenario has been discussed.Comment: 12 pages, 9 figure

A Dynamical System Analysis of Holographic Dark Energy Models with Different IR Cutoff

The paper deals with a dynamical system analysis of the cosmological evolution of an holographic dark energy (HDE) model interacting with dark matter (DM) which is chosen in the form of dust. The infrared cut-off of the holographic model is chosen as future event horizon or Ricci length scale. The interaction term between dark energy and dark matter is chosen of following three types i) proportional to the sum of the energy densities of the two dark components ii) proportional to the product of the matter energy densities and iii) proportional to dark energy density. The dynamical equations are reduced to an autonomous system for the three cases and corresponding phase space is analyzed.Comment: 13 pages, 9 figure

Dilatonic Scalar Field: A Dynamical System Analysis

The work deals with homogeneous and isotropic, flat FRW model of the universe which is filled up with non-interacting dark matter and dark energy to compatible with recent observational evidences. By choosing the dark energy in the form of a dilatonic scalar field, the evolution equations are reduced to an autonomous system. A phase space analysis is done around the critical points and stability criteria is examined. Finally, cosmological implications of the nature of the critical points are discussed.Comment: 8 pages, 4 figure

Dynamical System Analysis for a phantom model

The paper deals with a dynamical system analysis related to phantom cosmological model . Here gravity is coupled to phantom scalar field having scalar coupling function and a potential. The field equations are reduced to an autonomous dynamical system by a suitable redefinition of the basic variables and assuming some suitable form of the potential function. Finally, critical points are evaluated, their nature have been analyzed and corresponding cosmological scenario has been discussed.Comment: 15 pages, 3 figure

A Dynamical System Analysis of Three Fluid cosmological Model

In Friedman-Robertson-Walker flat spacetime, we consider a three fluid cosmological model which contains dark matter, dark energy and baryonic matter in the form of perfect fluid with a barotropic equation of state. Dark matter is taken in form of dust and dark energy is described by a scalar field with a potential $V(\phi)$. Einstein's field equations are reduced to an autonomous dynamical system by suitable redefinition of basic variables. Considering exponential potential for the scalar field, critical points are obtained for the autonomous system. Finally stability of the critical points and cosmological implications are analyzed.Comment: 10 pages, 7 figure

Zadoff-Chu sequence design for random access initial uplink synchronization

The autocorrelation of a Zadoff-Chu (ZC) sequence with a non-zero cyclically shifted version of itself is zero. Due to the interesting property, ZC sequences are widely used in the LTE air interface in the primary synchronization signal (PSS), random access preamble (PRACH), uplink control channel (PUCCH) etc. However, this interesting property of ZC sequence is not useful in the random access initial uplink synchronization problem due to some specific structures of the underlying problem. In particular, the state of the art uplink synchronization algorithms do not perform equally for all ZC sequences. In this work, we show a systematic procedure to choose the ZC sequences that yield the optimum performance of the uplink synchronization algorithms. At first, we show that the uplink synchronization is a sparse signal recovery problem on an overcomplete basis. Next, we use the theory of sparse recovery algorithms and identify a factor that controls performance of the algorithms. We then suggest a ZC sequence design procedure to optimally choose this factor. The simulation results show that the performance of most of the state of the art uplink synchronization algorithms improve significantly when the ZC sequences are chosen by using the proposed technique.Comment: 13 pages, 7 figure

InfyNLP at SMM4H Task 2: Stacked Ensemble of Shallow Convolutional Neural Networks for Identifying Personal Medication Intake from Twitter

This paper describes Infosys's participation in the "2nd Social Media Mining for Health Applications Shared Task at AMIA, 2017, Task 2". Mining social media messages for health and drug related information has received significant interest in pharmacovigilance research. This task targets at developing automated classification models for identifying tweets containing descriptions of personal intake of medicines. Towards this objective we train a stacked ensemble of shallow convolutional neural network (CNN) models on an annotated dataset provided by the organizers. We use random search for tuning the hyper-parameters of the CNN and submit an ensemble of best models for the prediction task. Our system secured first place among 9 teams, with a micro-averaged F-score of 0.693.Comment: 2nd Workshop on Social Media Mining for Healt

Synchronization, phase slips and coherent structures in area-preserving maps

The problem of synchronization of coupled Hamiltonian systems exhibits interesting features due to the non-uniform or mixed nature (regular and chaotic) of the phase space. We study these features by investigating the synchronization of unidirectionally coupled area-preserving maps coupled by the Pecora-Carroll method. We find that coupled standard maps show complete synchronization for values of the nonlinearity parameter at which regular structures are still present in phase space. The distribution of synchronization times has a power law tail indicating long synchronization times for at least some of the synchronizing trajectories. With the introduction of coherent structures using parameter perturbation in the system, this distribution crosses over to exponential behavior, indicating shorter synchronization times, and the number of initial conditions which synchronize increases significantly, indicating an enhancement in the basin of synchronization. On the other hand, coupled blinking vortex maps display both phase synchronization and phase slips, depending on the location of the initial conditions. We discuss the implication of our results.Comment: 15 pages, 10 figures, Perspectives in Nonlinear Dynamics 2016 (24th - 29th July 2016), Berlin, Germany. The paper is a part of the proceedings to appear in Pramana - Journal of Physics (Indian Academy of Sciences); distributed in print outside India and online worldwide by Springe