November 2008 arXiv papers — page 49

Ruslan Prozorov

This thesis describes experimental and theoretical study of static and dynamic aspects of the irreversible magnetic behavior of high-Tc superconductors. Experimentally, conventional magnetometry and novel Hall-probe array techniques are employed. Using both techniques extends significantly the experimental possibilities and yields a wealth of new experimenta

Zoe M. Leinhardt, Sarah T. Stewart

The outcome of collisions between small icy bodies, such as Kuiper belt objects, is poorly understood and yet a critical component of the evolution of the trans-Neptunian region. The expected physical properties of outer solar system materials (high porosity, mixed ice-rock composition, and low material strength) pose significant computational challenges. We

Yaming Yu

The data augmentation (DA) algorithm is a simple and powerful tool in statistical computing. In this note basic information theory is used to prove a nontrivial convergence theorem for the DA algorithm.

G. Siracusano, G. Finocchio, I. N. Krivorotov, L. Torres

We perform 3D micromagnetic simulations of current-driven magnetization dynamics in nanoscale exchange biased spin-valves that take account of (i) back action of spin-transfer torque on the pinned layer, (ii) non-linear damping and (iii) random thermal torques. Our simulations demonstrate that all these factors significantly impact the current-driven dynamic

Daniel J. Majaess, David Higgins, Larry A. Molnar, Melissa J. Haegert

In their study Bottke et al. (2007) suggest that a member of the Baptistina asteroid family was the probable source of the K/T impactor which ended the reign of the Dinosaurs 65 Myr ago. Knowledge of the physical and material properties pertaining to the Baptistina asteroid family are, however, not well constrained. In an effort to begin addressing the situa

Ivo Saviane, Katrina Exter, Yiannis Tsamis, Carmen Gallart

Context: A planetary nebula (PN) candidate was discovered during FORS imaging of the Local Group dwarf galaxy Phoenix. Aims: Use this PN to complement abundances from red-giant stars. Methods: FORS spectroscopy was used to confirm the PN classification. Empirical methods and photoionization modeling were used to derive elemental abundances from the emission

Dinh-V-Trung

Circumbinary disks have been hypothesized to exist around a number of binary post-AGB stars. Although most of the circumbinary disks have been inferred through the near IR excess, a few of them are strong emitters of molecular emission. Here we present high angular resolution observations of the emission of $^{12}$CO and its isotopomer $^{13}$CO J=2--1 line

Andriy V. Bondarenko, Maryna S. Viazovska

Let N(n, t) be the minimal number of points in a spherical t-design on the unit sphere S^n in R^{n+1}. For each n >= 3, we prove a new asymptotic upper bound N(n, t) <= C(n)t^{a_n}, where C(n) is a constant depending only on n, a_3 <= 4, a_4 <= 7, a_5 <= 9, a_6 <= 11, a_7 <= 12, a_8 <= 16, a_9 <= 19, a_10 <= 22, and a_n < n/2*log_2(2n), n > 10.

K. D. Borne, J. Becla, I. Davidson, A. Szalay

We describe features of the LSST science database that are amenable to scientific data mining, object classification, outlier identification, anomaly detection, image quality assurance, and survey science validation. The data mining research agenda includes: scalability (at petabytes scales) of existing machine learning and data mining algorithms; developmen

David Monniaux

We propose a method for automatically generating abstract transformers for static analysis by abstract interpretation. The method focuses on linear constraints on programs operating on rational, real or floating-point variables and containing linear assignments and tests. In addition to loop-free code, the same method also applies for obtaining least fixed p

Cornelia Drutu

We explain how the Transference Principles from Diophantine approximation can be interpreted in terms of geometry of the locally symmetric spaces $T_n=SO(n) \backslash SL(n,R) /SL(n,Z)$ with $n>1$, and how, via this dictionary, they become transparent geometric remarks and can be easily proved. Indeed, a finite family of linear forms is naturally identified

Matthew Bate

We report the statistical properties of stars, brown dwarfs and multiple systems obtained from the largest hydrodynamical simulation of star cluster formation to date that resolves masses down to the opacity limit for fragmentation (a few Jupiter masses). The simulation is essentially identical to that of Bate, Bonnell & Bromm except that the initial molecul

Chhaya Ravikant, P. Arun, Savita Roy, M. P. Srivastava

Diamond Like Carbon (DLC) films were deposited on quartz substrates using Dense Plasma Focus (DPF) method. The formation of ${\rm sp^3}$ bonds as is it&#39;s content in the film strongly depends on the substrate and it seems quartz is not a suitable substrate. However, we report here the formation of DLC films on quartz substrates that were maintained at ele

Jing Zhang, Chenguang Ye, Feng Gao, Min Xiao

Squeezed vacuum field can be amplified or deamplified when it is injected, as the signal beam, into a phase-sensitive optical parametric amplifier (OPA) inside an optical cavity. The spectral features of the reflected quantized signal field are controlled by the relative phase between the injected squeezed vacuum field and the pump field for the OPA. The exp

A. Skopal, T. Pribulla, J. Budaj, A. A. Vittone

We present development of the collimated bipolar jets from the symbiotic prototype Z And that appeared and disappeared during its 2006 outburst. In 2006 July Z And reached its historical maximum at U ~ 8.0. During this period, rapid photometric variations with Dm ~ 0.06 mag on the timescale of hours developed. Simultaneously, high-velocity satellite componen

D. Raabe, B. Sander, M. Friak, D. Ma

In this progress report we present a new approach to the ab-initio guided bottom up design of beta-Ti alloys for biomedical applications using a quantum mechanical simulation method in conjunction with experiments. Parameter-free density functional theory calculations are used to provide theoretical guidance in selecting and optimizing Ti-based alloys with r

Miguel-Ángel García-March, Albert Ferrando, Mario Zacarés, Sarira Sahu

We determine the functional behavior near the discrete rotational symmetry axis of discrete vortices of the nonlinear Schrödinger equation. We show that these solutions present a central phase singularity whose charge is restricted by symmetry arguments. Consequently, we demonstrate that the existence of high-charged discrete vortices is related to the prese

Vadim Kavera

The author suggests an approach based on the separation of total energy of multielectron systems into the semi-classical Coulomb part and the non-classical additional part. This approach allows on the one hand to simplify calculations and on the other hand to see very simple and very interesting relations. These relations were not obvious when using more com

Lianlin Li, Yin Xiang, Fang Li

In this paper, the theoretical analysis of compressive sensing via random filter, firstly outlined by J. Romberg [compressive sensing by random convolution, submitted to SIAM Journal on Imaging Science on July 9, 2008], has been refined or generalized to the design of general random filter used for compressive sensing. This universal CS measurement consists

Astrid Jourdan

Experimental designs are tools which can dramatically reduce the number of simulations required by time-consuming computer codes. Because we don&#39;t know the true relation between the response and inputs, designs should allow one to fit a variety of models and should provide information about all portions of the experimental region. One strategy for select

Ilja Gerhardt, Gert Wrigge, Gert Zumofen, Jaesuk Hwang

We report on the excitation of single molecules via narrow zero-phonon transitions using short laser pulses. By monitoring the Stokes-shifted fluorescence, we studied the excited state population as a function of the delay time, laser intensity, and frequency detuning. A pi-pulse excitation was demonstrated with merely 500 photons, and 5 Rabi cycles were ach

Garcia de Andrade

Earlier Arnold, Zeldovich, Ruzmaikin and Sokoloff [\textbf{JETP (1982)}] have computed the eigenvalue of a uniform stretching torus transformation which result on the first Riemann metric solution of the dynamo action problem. Recently some other attempts to obtain Riemann metrics representing dynamo action through conformal maps have been undertaken [{\text

Burglind Joricke

The envelope of holomorphy of an arbitrary domain in a two-dimensional Stein manifold is identified with a connected component of the set of equivalence classes of analytic discs immersed into the Stein manifold with boundary in the domain. This implies, in particular, that for each of its points the envelope of holomorphy contains an embedded (non-singular)

Stefan Jaeger

In this paper, I expand Shannon&#39;s definition of entropy into a new form of entropy that allows integration of information from different random events. Shannon&#39;s notion of entropy is a special case of my more general definition of entropy. I define probability using a so-called performance function, which is de facto an exponential distribution. Assu

Deepyaman Maiti, Mithun Chakraborty, Amit Konar

This contribution deals with identification of fractional-order dynamical systems. System identification, which refers to estimation of process parameters, is a necessity in control theory. Real processes are usually of fractional order as opposed to the ideal integral order models. A simple and elegant scheme of estimating the parameters for such a fraction

Ayan Acharya, Deepyaman Maiti, Aritra Banerjee, R. Janarthanan

The paper presents an exponential pheromone deposition approach to improve the performance of classical Ant System algorithm which employs uniform deposition rule. A simplified analysis using differential equations is carried out to study the stability of basic ant system dynamics with both exponential and constant deposition rules. A roadmap of connected ci

Deepyaman Maiti, Ayan Acharya, R. Janarthanan, Amit Konar

This contribution deals with identification of fractional-order dynamical systems. System identification, which refers to estimation of process parameters, is a necessity in control theory. Real processes are usually of fractional order as opposed to the ideal integral order models. A simple and elegant scheme of estimating the parameters for such a fraction

Deepyaman Maiti, Ayan Acharya, Amit Konar, Janarthanan Ramadoss

This article presents a unique design for a parser using the Ant Colony Optimization algorithm. The paper implements the intuitive thought process of human mind through the activities of artificial ants. The scheme presented here uses a bottom-up approach and the parsing program can directly use ambiguous or redundant grammars. We allocate a node correspondi

Mithun Chakraborty, Deepyaman Maiti, Amit Konar, Ramadoss Janarthanan

Of the many definitions for fractional order differintegral, the Grunwald-Letnikov definition is arguably the most important one. The necessity of this definition for the description and analysis of fractional order systems cannot be overstated. Unfortunately, the Fractional Order Differential Equation (FODE) describing such a systems, in its original form,

Ayan Acharya, Deepyaman Maiti, Aritra Banerjee, Amit Konar

The paper presents an exponential pheromone deposition rule to modify the basic ant system algorithm which employs constant deposition rule. A stability analysis using differential equation is carried out to find out the values of parameters that make the ant system dynamics stable for both kinds of deposition rule. A roadmap of connected cities is chosen as

Nan Jiang, Ailing Ji, Zexian Cao

Atmospheric pressure plasma jet can protrude some 5.0 cm into air. It holds promise for multivarious innovative applications, but its formation mechanism remains unsettled. We show that the plasma jet is essentially a streamer corona totally independent of, but obscured by, dielectric barrier discharge. Consequently, the jets can be equally successfully gene

Arif A. Akhundov

A numerical study of QED radiative corrections for the SMC experiment at SPS is been performed. The semi-analytical program POLRAD is been used to get the size of the radiative corrections for the proton to get the size of the radiative corrections for the measurements of the proton spin dependent structure functions $g_1^p(x)$ and $g_2^p(x)$. A brief descri

Otto E. Rossler, Ramis Movassagh

Sinai chaos is characterized by exponential divergence between neighboring trajectories of a point billiard. If the repulsive potential of the finite-diameter fixed particle in the middle of the table is made smooth, the Sinai divergence persists with finite measure. So it does if the smooth potential is made attractive. So it still does if the potential is

Akhilesh Singh, Karol G. Grycznski, Bibhu Rout, Jianyou Li

Study of light emitting silicon fabricated by ion implantation.

Ann B. Lee, Larry Wasserman

Spectral kernel methods are techniques for transforming data into a coordinate system that efficiently reveals the geometric structure - in particular, the &#34;connectivity&#34; - of the data. These methods depend on certain tuning parameters. We analyze the dependence of the method on these tuning parameters. We focus on one particular technique - diffusio

R. Alicki, M. Horodecki, P. Horodecki, R. Horodecki

We analyse stability of the four-dimensional Kitaev model - a candidate for scalable quantum memory - in finite temperature within the weak coupling Markovian limit. It is shown that, below a critical temperature, certain topological qubit observables X and Z possess relaxation times exponentially long in the size of the system. Their construction involves p

M. Khodas, M. G. Vavilov

We study transport properties of a two-dimensional electron gas, placed in a classically strong perpendicular magnetic field and in constant and oscillating in-plane electric fields. The analysis is based on a quantum Boltzmann equation derived for a weakly disordered two-dimensional electron gas. We consider disordered potential with both long and short ran

Raseong Kim, Xufeng Wang, Mark Lundstrom

Fermi-Dirac integrals appear frequently in semiconductor problems, so a basic understanding of their properties is essential. The purpose of these notes is to collect in one place, some basic information about Fermi-Dirac integrals and their properties. We also present Matlab scripts that calculate Fermi-Dirac integrals (the "script F" defined by Dingle (195

Joseph Andrew Spencer, James T. Wheeler

Of those gauge theories of gravity known to be equivalent to general relativity, only the biconformal gauging introduces new structures - the quotient of the conformal group of any pseudo-Euclidean space by its Weyl subgroup always has natural symplectic and metric structures. Using this metric and symplectic form, we show that there exist canonically conjug

Andre C. R. Martins

Opinion Dynamics lacks a theoretical basis. In this article, I propose to use a decision-theoretic framework, based on the updating of subjective probabilities, as that basis. We will see we get a basic tool for a better understanding of the interaction between the agents in Opinion Dynamics problems and for creating new models. I will review the few existin

Aristophanes Dimakis, Folkert Müller-Hoissen

Via a Cole-Hopf transformation, the multicomponent linear heat hierarchy leads to a multicomponent Burgers hierarchy. We show in particular that any solution of the latter also solves a corresponding multicomponent (potential) KP hierarchy. A generalization of the Cole-Hopf transformation leads to a more general relation between the multicomponent linear hea

S. H. Pereira, J. F. Jesus

We analyze the interaction between Dark Energy and Dark Matter from a thermodynamical perspective. By assuming they have different temperatures, we study the possibility of occurring a decay from Dark Matter into Dark Energy, characterized by a negative parameter $Q$. We find that, if at least one of the fluids has non vanishing chemical potential, for insta

G. Botelho, D. Diniz, D. Pellegrino

In this note we solve, except for extremely pathological cases, a question posed by Puglisi and Seoane-Sepulveda on the lineability of the set of bounded non-absolutely summing linear operators. We also show how the idea of the proof can be adapted to several related situations.

Charlotte Wahl

We define generalized Atiyah-Patodi-Singer boundary conditions of product type for Dirac operators associated to C*-vector bundles on the product of a compact manifold with boundary and a closed manifold. We prove a product formula for the K-theoretic index classes, which we use to generalize the product formula for the topological signature to higher signat

K. Inami

We have studied hadronic tau decay modes involving an eta meson using 490 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The following branching fractions have been measured: B(tau- -> K- eta nu)=(1.58 +- 0.05 +- 0.09)x 10^{-4}, B(tau- -> K- pi0 eta nu)=(4.6 +- 1.1 +- 0.4)x 10^{-5}, B(tau- -> pi- pi0 eta nu)=(1

Wei Wei, J. W. Zhang, Tian Liu, Hong Guo

We propose an approach to realize a quantum random number generator (QRNG) based on the photon number decision of weak laser pulses. This type of QRNG can generate true random numbers at a high speed and can be adjusted to zero bias conveniently, thus is suitable for the applications in quantum cryptography.

Dov Gabbay, Karl Schlechta

We give a unified approach to various results and problems of nonclassical logics

Pierre Alquier, Mohamed Hebiri

We focus on the high dimensional linear regression $Y\sim\mathcal{N}(Xβ^{*},σ^{2}I_{n})$, where $β^{*}\in\mathds{R}^{p}$ is the parameter of interest. In this setting, several estimators such as the LASSO and the Dantzig Selector are known to satisfy interesting properties whenever the vector $β^{*}$ is sparse. Interestingly both of the LASSO and the Dantzig

I. Radinschi, F. Rahaman, M. Kalam, K. Chakraborty

We provide a new electromagnetic mass model admitting Chaplygin gas equation of state. We investigate three specializations, the first characterized by a vanishing effective pressure, the second provided with a constant effective density and the third is described by a constant effective pressure. For these specializations two particular cases are discussed.

Akito Futaki, Hajime Ono

In this expository article we review the problem of finding Einstein metrics on compact Kähler manifolds and Sasaki manifolds. In the former half of this article we see that, in the Kähler case, the problem fits better with the notion of stability in Geometric Invariant Theory if we extend the problem to that of finding extremal Kähler metrics or constant sc

Zihua Weng

The paper discusses some scalar invariants in the gravitational field and electromagnetic field by means of the characteristics of the quaternions. When we emphasize some definitions of quaternion physical quantities, the speed of light, mass density, energy density, power density, charge density, and spin magnetic moment density etc. will remain the same re

Andrej Dujella

Wiener's attack is a well-known polynomial-time attack on a RSA cryptosystem with small secret decryption exponent d, which works if d<n^{0.25}, where n=pq is the modulus of the cryptosystem. Namely, in that case, d is the denominator of some convergent p_m/q_m of the continued fraction expansion of e/n, and therefore d can be computed efficiently from the p

Tathagata Basak

Let $D$ be the incidence graph of the projective plane over $\FF_3$. The Artin group of the graph $D$ maps onto the bimonster and a complex hyperbolic reflection group $Γ$ acting on 13 dimensional complex hyperbolic space $Y$. The generators of the Artin group are mapped to elements of order 2 (resp. 3) in the bimonster (resp. $Γ$). Let $Y^{\circ} \subseteq

Christopher L. Henley

How might systematic left-right (L/R) asymmetry of the body plan originate in multicellular animals (and plants)? Somehow, the microscopic handedness of biological molecules must be brought up to macroscopic scales. Basic symmetry principles suggest that the usual &#34;biological&#34; mechanisms -- diffusion and gene regulation -- are insufficient to impleme

T. Aaltonen

We present a search for high-mass neutral resonances using dimuon data corresponding to an integrated luminosity of 2.3 fb$^{-1}$ collected in {$p\bar p$} collisions at {$\sqrt{s}$ = 1.96 TeV} by the CDF II detector at the Fermilab Tevatron. No significant excess above the standard model expectation is observed in the dimuon invariant-mass spectrum. We set 9

J. R. A. Pitcairn, D. Roberge, A. Gorelov, D. Ashery

We have measured the angular distribution of recoiling daughter nuclei emitted from the Gamow-Teller $β$ decay of spin-polarized $^{80}$Rb. The asymmetry of this distribution vanishes to lowest order in the Standard Model (SM) in pure Gamow-Teller decays, producing an observable very sensitive to new interactions. We measure the non-SM contribution to the as

Yu-Bo Sheng, Fu-Guo Deng, Hong-Yu Zhou

We present an entanglement concentration protocol for electrons based on their spins and their charges. The combination of an electronic polarizing beam splitter and a charge detector functions as a parity check device for two electrons, with which the parties can reconstruct maximally entangled electron pairs from those in a less-entanglement state nonlocal

Dave Witte Morris

This expository paper describes the various methods that have yielded partial results on the conjecture that if n > 2, then no lattice in SL(n,R) has a faithful action on the circle (by homeomorphisms). Topics include amenability, Kazhdan&#39;s property (T), bounded cohomology, bounded generation, and the Reeb-Thurston Stability Theorem.

Matthew G. Walker, Mario Mateo, Edward Olszewski

We present spectroscopic data for individual stars observed from 2004 March through 2008 August as part of our Michigan/MIKE Fiber System (MMFS) survey of four dwarf spheroidal (dSph) galaxies: Carina, Fornax, Sculptor and Sextans. Using MMFS at the Magellan/Clay Telescope at Las Campanas Observatory, we have acquired 8855 spectra from 7103 red giant candida

Winfried Just, German Enciso

It is an increasingly important problem to study conditions on the structure of a network that guarantee a given behavior for its underlying dynamical system. In this paper we report that a Boolean network may fall within the chaotic regime, even under the simultaneous assumption of several conditions which in randomized studies have been separately shown to

Florentin Smarandache

In this article we construct a family of expressions $\varepsilon(n)$. For each element E(n) from $\varepsilon(n)$, the convergence of the series $\sum_{n \ge n_E}{E(n)}$ can be determined in accordance to the theorems of this article. Some applications are also presented.

Emory F. Bunn

In future microwave background polarization experiments, particularly those that aim to characterize the B component, careful attention will have to be paid to the mixing of E and B components due to finite sky coverage and pixelization. Any polarization map can be decomposed into &#34;pure E,&#34; &#34;pure B,&#34; and &#34;ambiguous&#34; components. In pra

Sinisa Slijepcevic

We generalize various notions of stability of invariant sets of dynamical systems to invariant measures, by defining a topology on the set of measures. The defined topology is similar, but not topologically equivalent to weak* topology, and it also differs from topologies induced by the Riesz Representation Theorem. It turns out that the constructed topology

M. A. Rodriguez-Meza, J. L. Carrillo

The kinetics of ultra-fast processes which leads to the thermalization condition of a photo-excited plasma in semiconductor systems is studied theoretically. We analyze the time evolution of a carrier population generated by a finite optical pulse, from the beginning of the pulse until the time in which the carrier population reaches a quasi-equilibrium cond

Philip R. Schiff, Adam C. Durst

Given the experimental evidence of charge order in the underdoped cuprate superconductors, we consider the effect of coexisting charge order on low-temperature thermal transport in a d-wave superconductor. Using a phenomenological Hamiltonian that describes a two-dimensional system in the presence of a Q=(π,0) charge density wave and d-wave superconducting o

G. Mauceri, S. Meda, M. Vallarino

In this paper we consider a complete connected noncompact Riemannian manifold M with Ricci curvature bounded from below and positive injectivity radius. Denote by L the Laplace-Beltrami operator on M. We assume that the kernel associated to the heat semigroup generated by L satisfies a mild decay condition at infinity. We prove that if m is a bounded holomor

U. Chandni, Arindam Ghosh, H. S. Vijaya, S. Mohan

We experimentally address the importance of tuning in athermal phase transitions, which are triggered only by a slowly varying external field acting as tuning parameter. Using higher order statistics of fluctuations, a singular critical instability is detected for the first time in spite of an apparent universal self-similar kinetics over a broad range of dr

Chandni. U, Arindam Ghosh, H. S. Vijaya, S. Mohan

Slow time-dependent fluctuations, or noise, in the electrical resistance of dc magnetron sputtered thin films of Nickel Titanium shape memory alloys have been measured. Even in equilibrium, the noise was several orders of magnitude larger than that of simple diffusive metallic films, and was found to be non-monotonic around the martensitic transformation reg

A. Carbonaro, G. Mauceri, S. Meda

In a previous paper the authors developed a H^1-BMO theory for unbounded metric measure spaces $(M,ρ,m)$ of infinite measure that are locally doubling and satisfy two geometric properties, called &#34;approximate midpoint&#34; property and &#34;isoperimetric&#34; property. In this paper we develop a similar theory for spaces of finite measure. We prove that

D. W. Longcope, C. E. Parnell

The coronal magnetic field above a particular photospheric region will vanish at a certain number of points, called null points. These points can be found directly in a potential field extrapolation or their density can be estimated from Fourier spectrum of the magnetogram. The spectral estimate, which assumes that the extrapolated field is random, homogeneo

R. A. Treumann, C. H. Jaroschek, R. Pottelette

We present auroral evidence for multiple and, most probably, small scale reconnection in the near Earth magnetospheric plasma sheet current layer during auroral activity. Hall currents as the source of upward and downward field-aligned currents require generation of the corresponding electron fluxes. The auroral spatial ordering in a multiple sequence of the

Chandra Shekhar, Sonal Singh, P K Siwach, H K Singh

We report on the synthesis and structural/ microstructural studies of iron based fluorine doped LaOFeAs superconductors. We have successfully synthesized fluorine doped superconducting LaO1-xFxFeAs materials by choosing lower temperature (1150^0C) and longer synthesis duration (60 hours) as compared to the standard values of these employed in the pioneering

A. Hoffman, J. Mallet-Paret

We study traveling waves for reaction diffusion equations on the spatially discrete domain $\Z^2$. The phenomenon of crystallographic pinning occurs when traveling waves become pinned in certain directions despite moving with non-zero wave speed in nearby directions. Mallet-Paret has shown that crystallographic pinning occurs for all rational directions, so

Ehud Hrushovski, Ya&#39;acov Peterzil, Anand Pillay

We prove several structural results on definably compact groups G in o-minimal expansions of real closed fields, such as (i) G is definably an almost direct product of a semisimple group and a commutative group, and (ii) the group (G, .) is elementarily equivalent to (G/G^00, .). We also prove results on the internality of finite covers of G in an o-minimal

Bob Olivier

The Liquid Argon Jet Trigger, installed in the H1 experiment at HERA, implements in 800 ns a real-time cluster algorithm by finding local energy maxima, summing their immediate neighbors, sorting the resulting &#34;jets&#34; by energy, and applying topological conditions. It operated since the year 2006 and drastically reduced the thresholds for triggering o

Ioannis G. Karafyllidis

Studies of quantum computer implementations suggest cellular quantum computer architectures. These architectures can simulate the evolution of quantum cellular automata, which can possibly simulate both quantum and classical physical systems and processes. It is however known that except for the trivial case, unitary evolution of one-dimensional homogeneous

S. I. Maslovski, D. K. Morits, S. A. Tretyakov

Symmetry and reciprocity constraints on polarization state of the field diffracted by gratings of quasi-planar particles are considered. It is shown that the optical activity effects observed recently in arrays of quasi-planar plasmonic particles on a dielectric substrate are due to the reflection of the field at the air-dielectric slab interface and are pro

Deepyaman Maiti, Ayan Acharya, Mithun Chakraborty, Amit Konar

Particle swarm optimization (PSO) is extensively used for real parameter optimization in diverse fields of study. This paper describes an application of PSO to the problem of designing a fractional-order proportional-integral-derivative (FOPID) controller whose parameters comprise proportionality constant, integral constant, derivative constant, integral ord

Slavik Jablan

Using computer calculations and working with representatives of pretzel tangles we established general adequacy criteria for different classes of knots and links. Based on adequate graphs obtained from all Kauffman states of an alternating link we defined a new numerical invariant: adequacy number, and computed adequacy polynomial which is the invariant of a

Ayan Acharya, Deepyaman Maiti, Amit Konar, Ramadoss Janarthanan

Ant Colony Optimization (ACO) is a metaheuristic for solving difficult discrete optimization problems. This paper presents a deterministic model based on differential equation to analyze the dynamics of basic Ant System algorithm. Traditionally, the deposition of pheromone on different parts of the tour of a particular ant is always kept unvarying. Thus the

Mithun Chakraborty, Deepyaman Maiti, Amit Konar

The Proportional-Integral-Derivative Controller is widely used in industries for process control applications. Fractional-order PID controllers are known to outperform their integer-order counterparts. In this paper, we propose a new technique of fractional-order PID controller synthesis based on peak overshoot and rise-time specifications. Our approach is t

Deepyaman Maiti, Ayan Acharya, Amit Konar

System identification refers to estimation of process parameters and is a necessity in control theory. Physical systems usually have varying parameters. For such processes, accurate identification is particularly important. Online identification schemes are also needed for designing adaptive controllers. Real processes are usually of fractional order as oppo

Deepyaman Maiti, Amit Konar

System identification is a necessity in control theory. Classical control theory usually considers processes with integer order transfer functions. Real processes are usually of fractional order as opposed to the ideal integral order models. A simple and elegant scheme is presented for approximation of such a real world fractional order process by an ideal i

Dov Gabbay, Karl Schlechta

We give an analysis of defeasible inheritance diagrams, also from the perspective of reactive diagrams.

Takashi Yamasaki, Tomoteru Fukumura, Masaki Nakano, Kazunori Ueno

Room temperature ferromagnetic semiconductor rutile Ti1-xCoxO2-δ(101) epitaxial thin films were grown on r-sapphire substrates by a dc sputtering method. Ferromagnetic magnetization, magnetic circular dichroism, and anomalous Hall effect were clearly observed at room temperature in sputter-grown films for the first time. The magnetization value is nearly as

Al. A. Ivanov

We embed a countably categorical group G into a locally compact group c(G) with a non-trivial topology and study how topological properties of c(G) are connected with the structure of definable subgroups of G.

A. Cherepashchuk, K. Postnov, E. Antokhina, S. Molkov

The analysis of INTEGRAL observations (2003-2008) of superaccreting galactic microquasar SS433 at precessional phases with the maximum disk opening angle is carried out. The shape and width of the primary X-ray eclipse is found to be strongly variable suggesting additional absorption in dense stellar wind and gas outflows from the optical A7I-component. The

Tamoghna Das, Surajit Sengupta, Subhasis Sinha

We study structural transitions in a system of interacting particles arranged as a crystalline bilayer, as a function of the density $ρ$ and the distance $d$ between the layers. As $d$ is decreased a sequence of transitions involving triangular, rhombic, square and centered rectangular lattices is observed. The sequence of phases and the order of transitions

A. R. Hayotov

In this paper in the space $W_2^{(2,1)}(0,1)$ square of the norm of the error functional of a optimal quadrature formula is calculated.

Iasson Karafyllis, Lars Grune

In this work we study the problem of step size selection for numerical schemes, which guarantees that the numerical solution presents the same qualitative behavior as the original system of ordinary differential equations, by means of tools from nonlinear control theory. Lyapunov-based and Small-Gain feedback stabilization methods are exploited and numerous

G. C. Anupama, D. K. Sahu, U. K. Gurugubelli, T. P. Prabhu

We present optical UBVRI photometric and spectroscopic data of the type Ibn supernova SN 2006jc, until the onset of the dust forming phase. The optical spectrum shows a blue continuum and is dominated by the presence of moderately narrow (velocity ~2500 km/s) He I emission lines superimposed over a relatively weak supernova spectrum. The helium lines are pro

M. V. Entin, L. I. Magarill

Curvature of quantum wire results in intrasubband absorption of IR radiation that induces stationary photovoltage in presence of circular polarization. This effect is studied in ballistic (collisionless) and kinetic regimes. The consideration is concentrated on quantum wires with curved central part. It is shown, that if mean free path is shorter than length

Michael Anshelevich

In math/0702157, arXiv:0712.4185, we investigated monic multivariate non-commutative orthogonal polynomials, their recursions, states of orthogonality, and corresponding continued fraction expansions. In this note, we collect a number of examples, demonstrating what these general results look like for the most important states on non-commutative polynomials,

E. Lenc, S. J. Tingay

Wide-field VLBI observations of the nearby starburst galaxy NGC 4945, obtained with the Australian LBA, have produced 2.3 GHz images over two epochs with a maximum spatial resolution of 0.3 pc. 15 sources were detected, 13 of which correspond to sources identified in higher frequency (3 cm and 12 mm) ATCA images. Four of the sources are resolved into shell-l

Toke Meier Carlsen, Sergei Silvestrov

For dynamical systems defined by a covering map of a compact Hausdorff space and the corresponding transfer operator, the associated crossed product $C^*$-algebras $\cros$ introduced by Exel and Vershik are considered. An important property for homeomorphism dynamical systems is topological freeness. It can be extended in a natural way to in general non-inve

Jing Li, A. A. van Ballegooijen, Don Mickey

First, we describe a general procedure to produce high quality vector magnetograms using the Imaging Vector Magnetograph (IVM) at Mees Solar Observatory. At the spatial resolution 2&#34;x2&#34;, the Stokes Q,U,V uncertainty reaches 0.001-0.0005 in time-averaged data over 1-hour in the quiet Sun. When vector magnetic fields are inferred from the time-averaged

E. Bozzo, L. Stella, M. Vietri, P. Ghosh

In this paper we review some aspects of the theory of magnetic threaded disks. We discuss in particular the equations that determine the position of the inner disk boundary by using different prescriptions for the neutron star-accretion disk interaction. We apply the results to several accretion powered X-ray pulsars that showed both quasi-periodic oscillati

Nicholas E. Dowdall, Thomas W. Mattman, Kevin Meek, Pablo R. Solis

The m,n Turk&#39;s Head Knot, THK(m,n), is an &#34;alternating (m,n) torus knot.&#34; We prove the Harary-Kauffman conjecture for all THK(m,n) except for the case where m \geq 5 is odd and n \geq 3 is relatively prime to m. We also give evidence in support of the conjecture in that case. Our proof rests on the observation that none of these knots have prime

M. Avrigeanu, V. Avrigeanu

$(α,γ)$ and $(α$,n) reaction cross sections recently measured close to the reaction thresholds are rather well described by a previously developed regional optical potential. Thus, particular features of the $α$-particle optical potential at energies below the Coulomb barrier, besides parameters describing $α$-particle elastic scattering at higher energies a