Separating invariants for arbitrary linear actions of the additive group

We consider an arbitrary representation of the additive group G_a over a field of characteristic zero and give an explicit description of a finite separating set in the corresponding ring of invariants

Associative memory design using overlapping decompositions

Cataloged from PDF version of article.This paper discusses the use of decomposition techniques in the design of associative memories via arti"cial neural networks. In particular, a disjoint decomposition which allows an independent design of lower-dimensional subnetworks and an overlapping decomposition which allows subnetworks to share common parts, are analyzed. It is shown by a simple example that overlapping decompositions may help in certain cases where design by disjoint decompositions fails. With this motivation, an algorithm is provided to synthesize neural networks using the concept of overlapping decompositions. Applications of the proposed design procedure to a benchmark example from the literature and to a pattern recognition problem indicate that it may improve the e!ectiveness of the existing methods. ( 2001 Published by Elsevier Science Ltd

Searching for Overionized Plasma in the Gamma-ray Emitting Supernova Remnant G349.7++0.2

G349.7$+$0.2 is a supernova remnant (SNR) expanding in a dense medium of molecular clouds and interacting with clumps of molecular material emitting gamma rays. We analyzed the gamma-ray data of Large Area Telescope on board Fermi Gamma Ray Space Telescope and detected G349.7$+$0.2 in the energy range of 0.2$-$300 GeV with a significance of $\sim$13$\sigma$ showing no extended morphology. Modeling of the gamma-ray spectrum revealed that the GeV gamma-ray emission dominantly originates from the decay of neutral pions, where the protons follow a broken power-law distribution with a spectral break at $\sim$12 GeV. To search for features of radiative recombination continua in the eastern and western regions of the remnant, we analyzed the Suzaku data of G349.7$+$0.2 and found no evidence for overionized plasma. In this paper we discuss possible scenarios to explain the hadronic gamma-ray emission in G349.7$+$0.2 and the mixed morphology nature of this SNR.Comment: 10 pages, 7 figures; accepted by ApJ. arXiv admin note: text overlap with arXiv:1406.217

Robust adaptive sampled-data control of a class of systems under structured nonlinear perturbations

Cataloged from PDF version of article.A robust adaptive sampled-data feedback stabilization scheme is presented for a class of systems with nonlinear additive perturbations. The proposed controller generates a control input by using high-gain static or dynamic feedback from nonuniform sampled values of the output. A simple adaptation rule adjusts the gain and the sampling period of the controller

Recombining Plasma in the Gamma-ray Emitting Mixed-Morphology Supernova Remnant 3C 391

A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MC) has been discovered as strong GeV gamma-ray emitters by Large Area Telescope on board Fermi Gamma Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR interacting with MC. It was observed in GeV gamma rays by Fermi-LAT as well as in the 0.3 $-$ 10.0 keV X-ray band by Suzaku. In this work, 3C 391 was detected in GeV gamma rays with a significance of $\sim$ 18 $\sigma$ and we showed that the GeV emission is point-like in nature. The GeV gamma-ray spectrum was shown to be best explained by the decay of neutral pions assuming that the protons follow a broken power-law distribution. We revealed radiative recombination structures of silicon and sulfur from 3C 391 using Suzaku data. In this paper we discuss the possible origin of this type of radiative plasma and hadronic gamma rays.Comment: 10 pages, 7 figures; accepted by Ap

Genetic association between sexual maturity and weekly live-weights in laying-type Japanese quail

This study focused on the estimation of genetic relationships between weekly live weights and sexual maturity of male and female Japanese quail. The live body weight data of a laying-type quail line over time were collected from hatching to six weeks of age. Sexual maturity was determined as the day of production of cloacal gland foam for males, and the day of laying the first egg for females. (Co)Variance components and genetic parameters were estimated, using MTDFREML, a restricted maximum likelihood (REML) procedure using a model with direct and maternal genetic effects. Heritability estimates of weekly live weights ranged from moderate to high (0.20 - 0.60), and were higher for males than for females. The variance due to maternal effects disappeared gradually for males but rapidly for females as the chicks grew older. Heritability of age of sexual maturation was 0.24 ± 0.008 and 033 ± 0.136 for males and females, respectively. Genetic correlations between ages of reaching sexual maturity and live weights (except hatchling weight) were favourable for males (-0.16 to –0.45) and unfavourable for females (0.14 to 0.22). Genetic correlations between males and females ranged from moderate (0.46 ± 0.083) to high (0.98 ± 0.139) for weekly live weights, and were 0.71 ± 0.24 for age of reaching sexual maturity. Sexual size dimorphism can be explained by the differences in pattern of heritability and correlation estimates between reaching sexual maturity and live weights for males and females. South African Journal of Animal Science Vol. 36(2) 2006: 142-14

Robust stability of discrete time systems under parametric perturbations

Cataloged from PDF version of article.Stability robustness analysis of a system under parametric perturbations is concerned with characterizing a region in the parameter space in which the system remains stable. In this paper, two methods are presented to estimate the stability robustness region of a linear, time-invariant, discrete-time system under multiparameter additive perturbations. An inherent difficulty, which originates from the nonlinear appearance of the perturbation parameters in the inequalities defining the robustness region, is resolved by transforming the problem to stability of a higher order continuous-time system. This allows for application of the available results on stability robustness of continuous-time systems to discrete-time systems. The results are also applied to stability analysis of discrete-time interconnected systems, where the interconnections are treated as perturbations on decoupled stable subsystems