Modeling Sound in Ancient Maya Cities: Moving Towards a Synesthetic Experience using GIS & 3D Simulation

Digital technologies enable modeling of the potential role of sound in past environments. While digital approaches have limitations in objectively rendering reality, they provide an expanded platform that potentially increases our understanding of experience in the past and enhances the investigation of ancient landscapes. Digital technologies enable new experiences in ways that are multi-sensual and move us closer toward reconstructing holistic views of past landscapes. Archaeologists have successfully employed 2D and 3D tools to measure vision and movement within cityscapes. However, built environments are often designed to invoke synesthetic experiences that also include sound and other senses. Geographic Information Systems (GIS) and Virtual Reality (VR) allow archaeologists to measure and explore the acoustics of ancient spaces. I employ GIS and 3D modeling o measure sound propagation and reverberation using the main civic-ceremonial complex in ancient Copán as a case study. The goal is to create a synesthetic experience to enrich our and understanding of the role sight and sound played in ancient Maya cities. For the ancient Maya, sight and sound worked in concert to create ritually charged atmospheres and architecture served to shape these experiences. I use an immersive VR headset (Oculus Rift) to integrate vision with spatial sound and sight to facilitate an embodied experience in order to: (1) examine potential locations of ritual performance and (2) determine spatial placement and capacity of participants in these events. Advisor: Heather Richards-Rissett

Modelling Acoustics in Ancient Maya Cities: Moving Towards a Synesthetic Experience Using GIS & 3D Simulation

Archaeological analyses have successfully employed 2D and 3D tools to measure vision and movement within cityscapes; however, built environments are often designed to invoke synesthetic experiences. GIS and Virtual Reality (VR) now enable archaeologists to also measure the acoustics of ancient spaces. To move toward an understanding of synesthetic experience in ancient Maya cities, we employ GIS and 3D modelling to measure sound propagation and reverberation using the main civic-ceremonial complex in ancient Copán as a case study. For the ancient Maya, sight and sound worked in concert to create ritually-charged atmospheres and architecture served to shape these experiences. Together with archaeological, iconographic, and epigraphic data, acoustic measures help us to (1) examine potential locations of ritual performance and (2) determine spatial placement and capacity of participants in these events. We use an immersive VR headset (Oculus Rift) to integrate vision with spatial sound and sight to facilitate an embodied experience

A Nonlinear Dynamic Boiler Model accounting for Highly Variable Load Conditions

This paper describes a new nonlinear dynamic model for a natural circulation boiler. The model is based on physical principles, i.e. mass, energy and momentum balances. A systematic approach is followed leading to new insights into the physics of drum water level and downcomer mass flow. The final model captures fast dynamic responses that are necessary to describe the operation of a boiler under highly variable load conditions. New features of the model include (i) a multi-compartment model for the risers, (ii) a new model for drum water level, and (iii) a new dynamic model for the flow of water in the downcomers. Implications of the model for control system design are also explored.Comment: 25 pages, 5 figures. Submitted to Automatic

Trapped-ion quantum error-correcting protocols using only global operations

Quantum error-correcting codes are many-body entangled states that are prepared and measured using complex sequences of entangling operations. Each element of such an entangling sequence introduces noise to delicate quantum information during the encoding or reading out of the code. It is important therefore to find efficient entangling protocols to avoid the loss of information. Here we propose an experiment that uses only global entangling operations to encode an arbitrary logical qubit to either the five-qubit repetition code or the five-qubit code, with a six-ion Coulomb crystal architecture in a Penning trap. We show that the use of global operations enables us to prepare and read out these codes using only six and ten global entangling pulses, respectively. The proposed experiment also allows the acquisition of syndrome information during readout. We provide a noise analysis for the presented protocols, estimating that we can achieve a six-fold improvement in coherence time with noise as high as $\sim 1\%$ on each entangling operation.Comment: 7 pages, 4 figures, published version, comments are welcom

Stochastic Adaptive Control for Exponentially Convergent Time-Varying Systems

This paper shows that the standard stochastic adaptive control algorithms for time-invariant systems have an inherent robustness property which renders them applicable, without modification, to time-varying systems whose parameters converge exponentially. One class of systems satisfying this requirement is those having non-steady-state Kalman filter or innovation representations. This allows the usual assumption of a stationary ARMAX representation to be replaced by a more general state space model.published_or_final_versio

Kinematic Masses of Super Star Clusters in M82 from High-Resolution Near-Infrared Spectroscopy

Using high-resolution (R~22,000) near-infrared (1.51 -- 1.75 microns) spectra from Keck Observatory, we measure the kinematic masses of two super star clusters in M82. Cross-correlation of the spectra with template spectra of cool evolved stars gives stellar velocity dispersions of sigma_r=15.9 +/- 0.8 km/s for MGG-9 and sigma_r=11.4 +/- 0.8 km/s for MGG-11. The cluster spectra are dominated by the light of red supergiants, and correlate most closely with template supergiants of spectral types M0 and M4.5. We fit King models to the observed profiles of the clusters in archival HST/NICMOS images to measure the half-light radii. Applying the virial theorem, we determine masses of 1.5 +/- 0.3 x 10^6 M_sun for MGG-9 and 3.5 +/- 0.7 x 10^5 M_sun for MGG-11. Population synthesis modelling suggests that MGG-9 is consistent with a standard initial mass function, whereas MGG-11 appears to be deficient in low-mass stars relative to a standard IMF. There is, however, evidence of mass segregation in the clusters, in which case the virial mass estimates would represent lower limits.Comment: 16 pages, 8 figures; ApJ, in pres

The Quadratic Gaussian Rate-Distortion Function for Source Uncorrelated Distortions

We characterize the rate-distortion function for zero-mean stationary Gaussian sources under the MSE fidelity criterion and subject to the additional constraint that the distortion is uncorrelated to the input. The solution is given by two equations coupled through a single scalar parameter. This has a structure similar to the well known water-filling solution obtained without the uncorrelated distortion restriction. Our results fully characterize the unique statistics of the optimal distortion. We also show that, for all positive distortions, the minimum achievable rate subject to the uncorrelation constraint is strictly larger than that given by the un-constrained rate-distortion function. This gap increases with the distortion and tends to infinity and zero, respectively, as the distortion tends to zero and infinity.Comment: Revised version, to be presented at the Data Compression Conference 200