Waveguide physical modeling of vocal tract acoustics: flexible formant bandwidth control from increased model dimensionality

Digital waveguide physical modeling is often used as an efficient representation of acoustical resonators such as the human vocal tract. Building on the basic one-dimensional (1-D) Kelly-Lochbaum tract model, various speech synthesis techniques demonstrate improvements to the wave scattering mechanisms in order to better approximate wave propagation in the complex vocal system. Some of these techniques are discussed in this paper, with particular reference to an alternative approach in the form of a two-dimensional waveguide mesh model. Emphasis is placed on its ability to produce vowel spectra similar to that which would be present in natural speech, and how it improves upon the 1-D model. Tract area function is accommodated as model width, rather than translated into acoustic impedance, and as such offers extra control as an additional bounding limit to the model. Results show that the two-dimensional (2-D) model introduces approximately linear control over formant bandwidths leading to attainable realistic values across a range of vowels. Similarly, the 2-D model allows for application of theoretical reflection values within the tract, which when applied to the 1-D model result in small formant bandwidths, and, hence, unnatural sounding synthesized vowels

Galaxy Kinematics With Virus-P: The Dark Matter Halo Of M87

We present two-dimensional stellar kinematics of M87 out to R = 238 '' taken with the integral field spectrograph VIRUS-P. We run a large set of axisymmetric, orbit-based dynamical models and find clear evidence for a massive dark matter halo. While a logarithmic parameterization for the dark matter halo is preferred, we do not constrain the dark matter scale radius for a Navarro-Frenk-White (NFW) profile and therefore cannot rule it out. Our best-fit logarithmic models return an enclosed dark matter fraction of 17.2(-5.0)(+5.0)% within one effective radius (R-e congruent to 100 ''), rising to 49.4(-8.8)(+7.2)% within 2 R-e. Existing SAURON data (R <= 13 ''), and globular cluster (GC) kinematic data covering 145 '' <= R <= 554 '' complete the kinematic coverage to R = 47 kpc (similar to 5R(e)). At this radial distance, the logarithmic dark halo comprises 85.3(-2.4)(+2.5)% of the total enclosed mass of 5.7(-0.9)(+1.3) x 10(12) M-circle dot making M87 one of the most massive galaxies in the local universe. Our best-fit logarithmic dynamical models return a stellar mass-to-light ratio (M/L) of 9.1(-0.2)(+0.2) (V band), a dark halo circular velocity of 800(-25)(+75) km s(-1), and a dark halo scale radius of 36(-3)(+7) kpc. The stellar M/L, assuming an NFW dark halo, is well constrained to 8.20(-0.10)(+0.05) (V band). The stars in M87 are found to be radially anisotropic out to R congruent to 0.5 R-e, then isotropic or slightly tangentially anisotropic to our last stellar data point at R = 2.4 R-e where the anisotropy of the stars and GCs are in excellent agreement. The GCs then become radially anisotropic in the last two modeling bins at R = 3.4 R-e and R = 4.8 R-e. As one of the most massive galaxies in the local universe, constraints on both the mass distribution of M87 and anisotropy of its kinematic components strongly inform our theories of early-type galaxy formation and evolution in dense environments.Astronom

An evaluation of free-flight test data for aerodynamic heating from laminar, turbulent, and transitional boundary layers. Part II - The X-17 reentry body

Blunt body reentry vehicle aerodynamic heating determinatio

The relationship between visual memory and rider expertise in a show-jumping context

Individuals develop visual skills while participating in sport. The aim of this study was to assess the effect of reported riding expertise on the recall of visual information relating to show-jumps. We identified a relevant (F1) and irrelevant (F2) point of focus in 22 photographs of show-jumps. Participants were students (n = 40) with varying levels of horse riding ability. The task, having viewed each photograph for four seconds, was to identify F1s or F2s from four alternatives viewed for ten seconds. F1s were recalled significantly more than F2s (P<0.001). Riding expertise did not affect overall recall but only intermediate/advanced riders recalled F1s significantly better than F2s (P<0.05 and P<0.001 respectively). Recall of F1s but not of F2s was significantly correlated with riding expertise (P<0.05). Training riders in visual attention techniques might improve ridden performance and could reduce the number of accidents associated with lack of experience and/or rider error

The CHIME graduate programme in health informatics

In 1999 University College London inaugurated a programme of graduate part-time Health Informatics courses to support the UK National Health Service?s Information for Health strategy. The programme has attracted students from across the UK and abroad, with a diverse range of backgrounds and skills and has proved a challenging and rewarding experience for students and tutors alike. The modular programme aims to provide a thorough grounding in the theory and practice of Health Informatics and addresses important application areas. The guiding principle is that Health Informatics graduates need to understand computers and programming but that, since the majority are not going to become programmers, programming methods should not dominate the curriculum.In the taught phase of the programme students attend college for 3 days a month and complete an assignment each month, based on home study. Students may graduate with a certificate or diploma, or go on to tackle a dissertation leading to an MSc. Research projects have included a patient record system based on speech input, a mathematical model for illustrating to patients the risks associated with smoking, an analysis of Trust staff's preparedness for Information for Health and a patient information leaflet giving advice about drug related information on the Web. As we move towards our fifth intake of students, we are in the process of evaluating our programme and carrying out a follow up study of our graduates? subsequent career pathways

Boson Pairs in a One-dimensional Split Trap

We describe the properties of a pair of ultracold bosonic atoms in a one-dimensional harmonic trapping potential with a tunable zero-ranged barrier at the trap centre. The full characterisation of the ground state is done by calculating the reduced single-particle density, the momentum distribution and the two-particle entanglement. We derive several analytical expressions in the limit of infinite repulsion (Tonks-Girardeau limit) and extend the treatment to finite interparticle interactions by numerical solution. As pair interactions in double wells form a fundamental building block for many-body systems in periodic potentials, our results have implications for a wide range of problems.Comment: 9 pages, 8 figure