Involutions and Trivolutions in Algebras Related to Second Duals of Group Algebras

We define a trivolution on a complex algebra $A$ as a non-zero conjugate-linear, anti-homomorphism $\tau$ on $A$, which is a generalized inverse of itself, that is, $\tau^3=\tau$. We give several characterizations of trivolutions and show with examples that they appear naturally on many Banach algebras, particularly those arising from group algebras. We give several results on the existence or non-existence of involutions on the dual of a topologically introverted space. We investigate conditions under which the dual of a topologically introverted space admits trivolutions

Qualitative and Quantitative Estimation of Pedestrian Level of Service at Signalized Intersections

Pedestrians form the largest single road user group and also are the most vulnerable road users. Pedestrian’s movements are not restricted to lanes or specific routes however they are restricted by the physical boundaries around them such as the presence of walkways or pedestrian ways. The main objective of this study is to identify the various factors affecting pedestrian level of service (PLOS) at signalized intersections and to propose a suitable methodology for estimation of pedestrian level of service. The study carried out to develop a model for pedestrian level of service of signalized intersections in Vijayawada city and Bhubaneswar city based on pedestrian’s perception on safety and comfort. The main factors considered for the development of the model were through traffic, left turning traffic, right turning traffic, number of pedestrians, number of lanes and pedestrian delay. Pedestrian delay was one of the key performance indicators for pedestrian level of service. Total twelve crosswalks from two cities were considered for study purpose. Video graphic method was used for collection of field data. Questionnaire survey was conducted to know the perceived level of service of pedestrians. The various factors required to develop the model extracted from video graphic data. Pearson correlation analysis was done to identify the various significant factors influencing pedestrian level of service. By considering perceived LOS as dependent variable and significant factors as independent variables stepwise regression analysis was done to develop a model which suitable for urban Indian conditions. The study revealed that various factors affecting level of service under heterogeneous traffic condition were turning traffic, through traffic, number of lanes, and number of pedestrian and pedestrian delay

Effective permittivity of random plasmonic composites

An effective-medium theory (EMT) is developed to predict the effective permittivity \epsilon_eff of dense random dispersions of high optical-conductivity metals such as Ag, Au and Cu. Dependence of \epsilon_eff on the volume fraction \phi, a microstructure parameter \kappa related to the static structure factor and particle radius a is studied. In the electrostatic limit, the upper and lower bounds of \kappa correspond to Maxwell-Garnett and Bruggeman EMTs respectively. Finite size effects are significant when |\beta^2(ka/n)^3| becomes O(1) where \beta, k, and n denote the nanoparticle polarizability, wavenumber and matrix refractive index respectively. The coupling between the particle and effective medium results in a red-shift in the resonance peak, a non-linear dependence of \epsilon_eff on \phi, and Fano resonance in \epsilon_eff.Comment: Manuscript submitted to J. Opt. Soc. Am. B. 33 page

Steady Stokes flow with long-range correlations, fractal Fourier spectrum, and anomalous transport

We consider viscous two-dimensional steady flows of incompressible fluids past doubly periodic arrays of solid obstacles. In a class of such flows, the autocorrelations for the Lagrangian observables decay in accordance with the power law, and the Fourier spectrum is neither discrete nor absolutely continuous. We demonstrate that spreading of the droplet of tracers in such flows is anomalously fast. Since the flow is equivalent to the integrable Hamiltonian system with 1 degree of freedom, this provides an example of integrable dynamics with long-range correlations, fractal power spectrum, and anomalous transport properties.Comment: 4 pages, 4 figures, published in Physical Review Letter

Far-field approximation for hydrodynamic interactions in parallel-wall geometry

A complete analysis is presented for the far-field creeping flow produced by a multipolar force distribution in a fluid confined between two parallel planar walls. We show that at distances larger than several wall separations the flow field assumes the Hele-Shaw form, i.e., it is parallel to the walls and varies quadratically in the transverse direction. The associated pressure field is a two-dimensional harmonic function that is characterized by the same multipolar number m as the original force multipole. Using these results we derive asymptotic expressions for the Green's matrix that represents Stokes flow in the wall-bounded fluid in terms of a multipolar spherical basis. This Green's matrix plays a central role in our recently proposed algorithm [Physica A xx, {\bf xxx} (2005)] for evaluating many-body hydrodynamic interactions in a suspension of spherical particles in the parallel-wall geometry. Implementation of our asymptotic expressions in this algorithm increases its efficiency substantially because the numerically expensive evaluation of the exact matrix elements is needed only for the neighboring particles. Our asymptotic analysis will also be useful in developing hydrodynamic algorithms for wall-bounded periodic systems and implementing acceleration methods by using corresponding results for the two-dimensional scalar potential.Comment: 28 pages 5 figure

A characteristic frequency of two mutually interacting gas bubbles in an acoustic field

Transition frequencies of two spherical gas bubbles interacting in an acoustic field are discussed theoretically. In the present study, transition frequency is defined as the frequency of external sound for which the phase difference between a bubble's pulsation and the external sound is $\pi / 2$. It is shown by a linear theory that a bubble interacting with a neighboring bubble has three (or fewer) transition frequencies but only two natural frequencies. This result means that the bubble has a characteristic frequency besides the natural frequencies.Comment: 14 pages, 5 figures, elsart, "Eigenfrequency" replaced with "transition frequency" and a reference added, accepted for publication in Phys. Lett.

Many-particle hydrodynamic interactions in parallel-wall geometry: Cartesian-representation method

This paper describes the results of our theoretical and numerical studies of hydrodynamic interactions in a suspension of spherical particles confined between two parallel planar walls, under creeping-flow conditions. We propose a novel algorithm for accurate evaluation of the many-particle friction matrix in this system--no such algorithm has been available so far. Our approach involves expanding the fluid velocity field into spherical and Cartesian fundamental sets of Stokes flows. The interaction of the fluid with the particles is described using the spherical basis fields; the flow scattered with the walls is expressed in terms of the Cartesian fundamental solutions. At the core of our method are transformation relations between the spherical and Cartesian basis sets. These transformations allow us to describe the flow field in a system that involves both the walls and particles. We used our accurate numerical results to test the single-wall superposition approximation for the hydrodynamic friction matrix. The approximation yields fair results for quantities dominated by single particle contributions, but it fails to describe collective phenomena, such as a large transverse resistance coefficient for linear arrays of spheres

Fecal microbiota transplant rescues mice from human pathogen mediated sepsis by restoring systemic immunity.

Death due to sepsis remains a persistent threat to critically ill patients confined to the intensive care unit and is characterized by colonization with multi-drug-resistant healthcare-associated pathogens. Here we report that sepsis in mice caused by a defined four-member pathogen community isolated from a patient with lethal sepsis is associated with the systemic suppression of key elements of the host transcriptome required for pathogen clearance and decreased butyrate expression. More specifically, these pathogens directly suppress interferon regulatory factor 3. Fecal microbiota transplant (FMT) reverses the course of otherwise lethal sepsis by enhancing pathogen clearance via the restoration of host immunity in an interferon regulatory factor 3-dependent manner. This protective effect is linked to the expansion of butyrate-producing Bacteroidetes. Taken together these results suggest that fecal microbiota transplantation may be a treatment option in sepsis associated with immunosuppression

Scheduling Algorithms in Map Reduce

Data generated in the past few years cannot be efficiently manipulated with the traditional way of storing techniques as it is a large-scale dataset, and it can be structured, semi-structured, or unstructured. To deal with this kind of enormous dataset Hadoop framework is used, which supports the processing of large dataset in a distributed computing environment. Hadoop uses a technique named as MapReduce for processing and generating a large dataset with a parallel distributed algorithm on a cluster. It automatically handles failures and data loss due to its fault-tolerance property. The scheduler is a pluggable component of the MapReduce framework. Hadoop MapReduce framework uses various scheduler as per the requirements of the task. FIFO (First In First Out) is a default algorithm used by Hadoop, in which the jobs are executed in the order of their arrival. This paper will discuss myriad of schedulers such as FIFO, Capacity Scheduler, LATE Scheduler, Fair Scheduler, Delay Scheduler, Deadline Constraint Scheduler, and Resource Aware Scheduler. Besides these schedulers, we also conducted study of comparison of schedulers like Round Robin, Weighted Round Robin, Self-adaptive Reduce Scheduling (SARS), Self-adaptive MapReduce Scheduling (SAMR), Dynamic Priority Scheduling, Learning Scheduling, Classification & Optimization-based Scheduler (COSHH), Network-Aware, Match-matching, and Energy-Aware Scheduler. Hopefully, this study will enhance the understanding of the specific schedulers and stimulate other developers and consumers to make accurate decisions for their specific research interests