The NE2001 model for the free electron distribution of the Milky Way includes ad hoc electron “clumps” to reconcile line of sight observables with basic model predictions (Cordes et al. 2002). While MAGPIS (Multi-Array Galactic Plane Imaging Survey) is insensitive to emission from individual diffuse HII regions (ne ∼10 cm), by investigating the 20 cm maps we are able to verify their assumption ...

Information technology today is a complex area, in which new problems and challenges constantly arise and innovations emerge. The ability to incorporate an innovation in time or to solve a problem efficiently can mean competitive advantages for some firms. Being responsive in IT involves being alert, knowledgeable and prepared to face technical problems and to solve them in appropriate ways. In...

In this paper, we review the various tools in JPEG-2000 that allow the users to take advantages of the various properties of the human visual system such as spatial frequency sensitivity and the visual masking effect. We show that the visual tool sets in JPEG-2000 are much richer than what was available in JPEG, where only locally invariant frequency weighting can be exploited

Visual cognition is of significant importance in certain imaging applications, such as security and surveillance. In these applications, an important issue is to determine the cognition threshold, which is the maximum distortion level that can be applied to the images while still ensuring that enough information is conveyed to recognize the scene. The cognition task is usually studied with imag...

In this paper, we propose a generic hybrid oriented-transform and wavelet-based image representation for intra-band image coding. We instantiate for three popular directional transforms having similar powers of approximation but different redundancy factors. For each transform type, we design a compression scheme wherein we exploit intra-band coefficient dependencies. We show that our schemes o...

The LeGall 5/3 and Daubechies 9/7 filters have risen to special prominence because they were selected for inclusion in the JPEG2000 standard. We determine their key mathematical features: Riesz bounds, order of approximation, and regularity (Hölder and Sobolev). We give approximation theoretic quantities such as the asymptotic constant for the L2 error and the angle between the analysis and syn...

A pressure-induced crossover from normal Ferroelectic-to-Relaxer behavior has been observed in single crystal [Pb(Zn1BNb~)03]o.go5 (PbTi03)o.og5,or PZN 9.5% PT. Analogy with similar observations for other perovskites indicates that this crossover is a general feature of compositionally-disordered soft mode ferroelectrics. The Pressure-Temperature phase diagram has been also determined.

The species of the genus Brulleia Szépligeti, 1904 (Hymenoptera, Braconidae, Helconinae) from China are revised. Four new species, namely Brulleia fanjingensis YanandChen, sp. n., Brulleia longipalpis YanandChen, sp. n., Brulleia noncarinata YanandChen, sp. n. andBrulleia punctata Yan andChen, sp. n. are described and illustrated. A key to the Chinese species of the genus Brulleia is included.

Common compression systems treat color image channels similarly. Nonlinear color models like Hue-Saturation Value/ Brightness/ Luminance/ Intensity (HSV/ HSB/ HSL/ HSI) have special features for each channel. In this paper a new hybrid compression system is proposed for encoding color images in HSI color model. The proposed encoding system deals with each channel with a suitable compression tec...