Cycle-time properties of the timed token medium access control protocol

We investigate the timing properties of the timed token protocol that are necessary to guarantee synchronous message deadlines. A tighter upper bound on the elapse time between the token's lth arrival at any node i and its (l + v)th arrival at any node k is found. A formal proof to this generalized bound is presented

Experimental and analytical tools for evaluation of Stirling engine rod seal behavior

The first year of a two year experimental and analytical program is reported. The program is directed at the elastohydrodynamic behavior of sliding elastomeric rod seals for the Stirling engine. During the year, experimental and analytical tools were developed for evaluating seal leakage, seal friction, and the fluid film thickness at the seal/cylinder interface

Haar expectations of ratios of random characteristic polynomials

We compute Haar ensemble averages of ratios of random characteristic polynomials for the classical Lie groups K = O(N), SO(N), and USp(N). To that end, we start from the Clifford-Weyl algebera in its canonical realization on the complex of holomorphic differential forms for a C-vector space V. From it we construct the Fock representation of an orthosymplectic Lie superalgebra osp associated to V. Particular attention is paid to defining Howe's oscillator semigroup and the representation that partially exponentiates the Lie algebra representation of sp in osp. In the process, by pushing the semigroup representation to its boundary and arguing by continuity, we provide a construction of the Shale-Weil-Segal representation of the metaplectic group. To deal with a product of n ratios of characteristic polynomials, we let V = C^n \otimes C^N where C^N is equipped with its standard K-representation, and focus on the subspace of K-equivariant forms. By Howe duality, this is a highest-weight irreducible representation of the centralizer g of Lie(K) in osp. We identify the K-Haar expectation of n ratios with the character of this g-representation, which we show to be uniquely determined by analyticity, Weyl group invariance, certain weight constraints and a system of differential equations coming from the Laplace-Casimir invariants of g. We find an explicit solution to the problem posed by all these conditions. In this way we prove that the said Haar expectations are expressed by a Weyl-type character formula for all integers N \ge 1. This completes earlier work by Conrey, Farmer, and Zirnbauer for the case of U(N).Comment: LaTeX, 70 pages, Complex Analysis and its Synergies (2016) 2:

Impact of random dopant induced fluctuations on sub-15nm UTB SOI 6T SRAM cells

The CMOS scaling increases the impact of intrinsic parameter fluctuation on the yield and functionality of SRAM. A statistical circuit simulation framework which can fully capture intrinsic parameter fluctuation information into the compact model has been developed. The impact of discrete random dopants in the source and drain regions on 6T SRAM cells has been investigated for well scaled ultra thin body (UTB) SOI MOSFETs with physical channel length in the range of 10nm to 5nm

Electronic Interface Reconstruction at Polar-Nonpolar Mott Insulator Heterojunctions

We report on a theoretical study of the electronic interface reconstruction (EIR) induced by polarity discontinuity at a heterojunction between a polar and a nonpolar Mott insulators, and of the two-dimensional strongly-correlated electron systems (2DSCESs) which accompany the reconstruction. We derive an expression for the minimum number of polar layers required to drive the EIR, and discuss key parameters of the heterojunction system which control 2DSCES properties. The role of strong correlations in enhancing confinement at the interface is emphasized.Comment: 7 pages, 6 figures, some typos correcte

A design study for an optimal non-linear receiver/demodulator Final report

Design study for optimal nonlinear receiver demodulato

Modeling soil system:complexity under your feet

This is an introductory articl

Matter-wave localization in a random potential

By numerical and variational solution of the Gross-Pitaevskii equation, we studied the localization of a noninteracting and weakly-interacting Bose-Einstein condensate (BEC) in a disordered cold atom lattice and a speckle potential. In the case of a single BEC fragment, the variational analysis produced good results. For a weakly disordered potential, the localized BECs are found to have an exponential tail as in weak Anderson localization. We also investigated the expansion of a noninteracting BEC in these potential. We find that the BEC will be locked in an appropriate localized state after an initial expansion and will execute breathing oscillation around a mean shape when a BEC at equilibrium in a harmonic trap is suddenly released into a disorder potential

Formation and kinetics of transient metastable states in mixtures under coupled phase ordering and chemical demixing

We present theory and simulation of simultaneous chemical demixing and phase ordering in a polymer-liquid crystal mixture in conditions where isotropic- isotropic phase separation is metastable with respect to isotropic-nematic phase transition. It is found that mesophase formation proceeds by a transient metastable phase that surround the ordered phase, and whose lifetime is a function of the ratio of diffusional to orientational mobilities. It is shown that kinetic phase ordering in polymer-mesogen mixtures is analogous to kinetic crystallization in polymer solutions.Comment: 17 pages, 5 figures accepted for publication in EP

Probing High Redshift Radiation Fields with Gamma-Ray Absorption

The next generation of gamma-ray telescopes may be able to observe gamma-ray blazars at high redshift, possibly out to the epoch of reionization. The spectrum of such sources should exhibit an absorption edge due to pair-production against UV photons along the line of sight. One expects a sharp drop in the number density of UV photons at the Lyman edge E_{L}. This implies that the universe becomes transparent after gamma-ray photons redshift below E (m_{e}c^2)^{2}/E_{L} 18 GeV. Thus, there is only a limited redshift interval over which GeV photons can pair produce. This implies that any observed absorption will probe radiation fields in the very early universe, regardless of the subsequent star formation history of the universe. Furthermore, measurements of differential absorption between blazars at different redshifts can cleanly isolate the opacity due to UV emissivity at high redshift. An observable absorption edge should be present for most reasonable radiation fields with sufficient energy to reionize the universe. Ly-alpha photons may provide an important component of the pair-production opacity. Observations of a number of blazars at different redshifts will thus allow us to probe the rise in comoving UV emissivity with time.Comment: ApJ accepted version, minor changes. 19 pages, 5 figure