Generalized Super-Cerenkov Radiations in Nuclear and Hadronic Media

Generalized Super-Cerenkov Radiations (SCR), as well as their SCR-signatures are investigated and classified. Two general SCR- coherence conditions are found as two natural extremes of the same spontaneous particles decay in (dielectric, nuclear or hadronic) media The main results on the quantum theory of the SCR-phenomena as well as the results of the first experimental test of the super-coherence conditions, obtained by using the experimental data from BNL are presented. The new concepts such as: SCR-gluons, SCR-W-bosons and SCR-Z-bosons, all three suggested by elementary particle classification, are introduced. The gluonic Super-Cerenkov-like radiation, first introduced here, is schematically described. The interpretation of some recent RHIC results as signature of the SCR-gluons is suggested.Comment: 16 pages, v2 corrected typo

Properties which normal operators share with normal derivations and related operators

Let $S$ and $T$ be (bounded) scalar operators on a Banach space \scr X and let $C(T,S)$ be the map on \scr B(\scr X), the bounded linear operators on \scr X, defined by $C(T,S)(X)=TX-XS$ for $X$ in \scr B(\scr X). This paper was motivated by the question: to what extent does $C(T,S)$ behave like a normal operator on Hilbert space? It will be shown that $C(T,S)$ does share many of the special properties enjoyed by normal operators. For example, it is shown that the range of $C(T,S)$ meets its null space at a positive angle and that $C(T,S)$ is Hermitian if $T$ and $S$ are Hermitian. However, if \scr X is a Hilbert space then $C(T,S)$ is a spectral operator if and only if the spectrum of $T$ and the spectrum of $S$ are both finite

The very nearby M/T dwarf binary SCR 1845-6357

The recently discovered star SCR 1845-6357 is the first late M/T dwarf binary discovered. SCR 1845 is a particular object due to its tight orbit (currently around 4 AU) and its proximity to the Sun (3.85 pc). We present spatially resolved VLT/NACO images and low resolution spectra of SCR 1845 in the J, H and K near-infrared bands. Since the T dwarf companion, SCR 1845B, is so close to the primary SCR 1845A, orbital motion is evident even within a year. Following the orbital motion, the binary's mass can be measured accurately within a decade, making SCR 1845B a key T-dwarf mass-luminosity calibrator. The NIR spectra allow for accurate determination of spectral type and also for rough estimates of the object's physical parameters. The spectral type of SCR 1845B is determined by direct comparison of the flux calibrated JHK spectra with T dwarf standard template spectra and also by NIR spectral indices obtained from synthetic photometry. Constrained values for surface gravity, effective temperature and metallicity are derived by comparison with model spectra. Our data prove that SCR 1845B is a brown dwarf of spectral type T6 that is co-moving with and therefore gravitationally bound to the M8.5 primary. Fitting the NIR spectrum of SCR 1845B to model spectra yields an effective temperature of about 950K and a surface gravity log(g)=5.1 (cgs) assuming solar metallicity. Mass and age of SCR 1845B are in the range 40 to 50 Jupiter masses and 1.8 to 3.1 Gyr.Comment: 5 pages, 4 figures, accepted for publication in Astronomy & Astrophysic

Limb-Bone Scaling Indicates Diverse Stance and Gait in Quadrupedal Ornithischian Dinosaurs

Background The most primitive ornithischian dinosaurs were small bipeds, but quadrupedality evolved three times independently in the clade. The transition to quadrupedality from bipedal ancestors is rare in the history of terrestrial vertebrate evolution, and extant analogues do not exist. Constraints imposed on quadrupedal ornithischians by their ancestral bipedal bauplan remain unexplored, and consequently, debate continues about their stance and gait. For example, it has been proposed that some ornithischians could run, while others consider that none were cursorial. Methodology/Principal Findings Drawing on biomechanical concepts of limb bone scaling and locomotor theory developed for extant taxa, we use the largest dataset of ornithischian postcranial measurements so far compiled to examine stance and gait in quadrupedal ornithischians. Differences in femoral midshaft eccentricity in hadrosaurs and ceratopsids may indicate that hadrosaurs placed their feet on the midline during locomotion, while ceratopsids placed their feet more laterally, under the hips. More robust humeri in the largest ceratopsids relative to smaller taxa may be due to positive allometry in skull size with body mass in ceratopsids, while slender humeri in the largest stegosaurs may be the result of differences in dermal armor distribution within the clade. Hadrosaurs are found to display the most cursorial morphologies of the quadrupedal ornithischian cades, indicating higher locomotor performance than in ceratopsids and thyreophorans. Conclusions/Significance Limb bone scaling indicates that a previously unrealised diversity of stances and gaits were employed by quadrupedal ornithischians despite apparent convergence in limb morphology. Grouping quadrupedal ornithischians together as a single functional group hides this disparity. Differences in limb proportions and scaling are likely due to the possession of display structures such as horns, frills and dermal armor that may have affected the center of mass of the animal, and differences in locomotor behaviour such as migration, predator escape or home range size

MODEL RISK AND DETERMINATION OF SOLVENCY CAPITAL IN THE SOLVENCY 2 FRAMEWORK

This paper investigates the robustness of the Solvency Capital Requirement (SCR) when a log-normal reference model is slightly disturbed by the heaviness of its tail distribution. It is shown that situations with "almost" lognormal data and a rather important variation between the "disturbed" SCR and the reference SCR can be built. The consequences of the estimation errors on the level of the SCR are studied too.Solvency; extreme values

Spoken content retrieval: A survey of techniques and technologies

Speech media, that is, digital audio and video containing spoken content, has blossomed in recent years. Large collections are accruing on the Internet as well as in private and enterprise settings. This growth has motivated extensive research on techniques and technologies that facilitate reliable indexing and retrieval. Spoken content retrieval (SCR) requires the combination of audio and speech processing technologies with methods from information retrieval (IR). SCR research initially investigated planned speech structured in document-like units, but has subsequently shifted focus to more informal spoken content produced spontaneously, outside of the studio and in conversational settings. This survey provides an overview of the field of SCR encompassing component technologies, the relationship of SCR to text IR and automatic speech recognition and user interaction issues. It is aimed at researchers with backgrounds in speech technology or IR who are seeking deeper insight on how these fields are integrated to support research and development, thus addressing the core challenges of SCR