Extended Non Linear Conformal Symmetry and DSR Velocities on the Physical Surface

The relation between Conformal generators and Magueijo Smolin Deformed Special Relativity term, added to Lorentz boosts, is achieved. The same is performed for Fock Lorentz transformations. Through a dimensional reduction procedure, it is demonstrated that a massless relativistic particle living in a $d$ dimensional space, is isomorphic to one living in a $d+2$ space with pure Lorentz invariance and to a particle living in a $AdS_{d+1}$ space. To accomplish these identifications, the Conformal Group is extended and a nonlinear algebra arises. Finally, because the relation between momenta and velocities is known, the problem of position space dynamics is solved.Comment: totally renewe

GpsTunes: controlling navigation via audio feedback

We combine the functionality of a mobile Global Positioning System (GPS) with that of an MP3 player, implemented on a PocketPC, to produce a handheld system capable of guiding a user to their desired target location via continuously adapted music feedback. We illustrate how the approach to presentation of the audio display can benefit from insights from control theory, such as predictive 'browsing' elements to the display, and the appropriate representation of uncertainty or ambiguity in the display. The probabilistic interpretation of the navigation task can be generalised to other context-dependent mobile applications. This is the first example of a completely handheld location- aware music player. We discuss scenarios for use of such systems

Extraction of an Overlapped Second Harmonic Chirp Component using the Fractional Fourier Transform

In ultrasound harmonic imaging with chirp coded excitation, the axial resolution can be improved by increasing the excitation signal bandwidth. However, increasing the bandwidth will cause overlapping between the received nonlinear second harmonic chirp component (SHCC) and the fundamental component. For the spectrally overlapping harmonics, signal decoding using the second harmonic matched filter (SHMF) typically produces higher range sidelobes level (RSLL), which reduces the image contrast. A multi-pulse detection scheme such as pulse inversion can be used to extract the overlapped SHCC; however it is susceptible to motion artifacts and reduced system frame-rate. In this study, the fractional Fourier transform (FrFT) is proposed with chirp coded excitation for the extraction of the overlapped SHCC. The experimental results indicate at least a 13 dB improvement in the RSLL of the FrFT filtered compressed SHCC when compared with the unfiltered compressed SHCC

A note on fragmentability and weak-G_delta sets

In terms of fragmentability, we describe a new class of Banach spaces which do not contain weak-G_delta open bounded subsets. In particular, none of these spaces is isomorphic to a separable polyhedral space

Comprehension of familiar and unfamiliar native accents under adverse listening conditions

This study aimed to determine the relative processing cost associated with comprehension of an unfamiliar native accent under adverse listening conditions. Two sentence verification experiments were conducted in which listeners heard sentences at various signal-to-noise ratios. In Experiment 1, these sentences were spoken in a familiar or an unfamiliar native accent or in two familiar native accents. In Experiment 2, they were spoken in a familiar or unfamiliar native accent or in a nonnative accent. The results indicated that the differences between the native accents influenced the speed of language processing under adverse listening conditions and that this processing speed was modulated by the relative familiarity of the listener with the native accent. Furthermore, the results showed that the processing cost associated with the nonnative accent was larger than for the unfamiliar native accent

QCD: Challenges for the Future

Despite many experimental verifications of the correctness of our basic understanding of QCD, there remain numerous open questions in strong interaction physics and we focus on the role of future colliders in addressing these questions. We discuss possible advances in the measurement of $\alpha_s$, in the study of parton distribution functions, and in the understanding of low $x$ physics at present colliders and potential new facilities. We also touch briefly on the role of spin physics in advancing our understanding of QCD.Comment: 12 pages, LATEX2e with snow2e, epsfig and 2 figures. Also available at http://penguin.phy.bnl.gov/~dawson/qcdsnow.ps . QCD working group summary at DPF/DPB Summer Study on New Directions for High Energy Physics, Snowmass, CO, June 25- July 12, 199