Major League Baseball: America’s Recession-Proof Pastime

This project is a study which examines how attendance levels in Major League Baseball stadiums have been impacted by the current recession in the United States which began in October 2007. Research on attendance during past recessions has shown a strong relationship that during downtrends in the economy, baseball attendance levels generally do not suffer. Using an ordinary least squares regression, independent variables including; percent change in ticket price from previous season, distance to closest competitor, percent change in ticket price of the closest competitor, winning percentage during previous year, winning percentage during current year, unemployment rate during current year, per capita income during current year, and a dummy variable were run against the dependent variable of season attendance totals for 29 of the 30 MLB teams (Those located within the US). The data used is from the years 2008 and 2009, the first and second years of the current recession. Results were analyzed to find if there were any relationships that proved to be significant, with a t-Stat score \u3e 2 or a P-value \u3c .10. The variables of team’s current year winning percentage and presence of a new stadium are the only variables that prove to be significant during both seasons, with a positive correlation for both years. Unemployment becomes significant during the 2009 season, and also changes from being negatively correlated to positively correlated with attendance levels from one year to the next. Overall, the league as a whole had a drop in attendance of 1.09% and 6.59% during the 2008 and 2009 seasons, which were the first and second seasons following the start of the recession. Based on the trend of attendance during past recessions, one would expect that for the upcoming year attendance numbers would jump back up to their 2007 levels. However, due to the length and severity of the recent recession, as well as the growing amount of substitutes available, attendance may suffer more and for longer than it ever has before

OH Masers and Supernova Remnants

OH(1720 MHz) masers are created by the interaction of supernova remnants with molecular clouds. These masers are pumped by collisions in warm, shocked molecular gas with OH column densities in the range 10^{16}--10^{17} cm^{-2}. Excitation calculations suggest that inversion of the 6049 MHz OH line may occur at the higher column densities that have been inferred from main-line absorption studies of supernova remnants with the Green Bank Telescope. OH(6049 MHz) masers have therefore been proposed as a complementary indicator of remnant-cloud interaction. This motivated searches for 6049 MHz maser emission from supernova remnants using the Parkes 63 m and Effelsberg 100 m telescopes, and the Australia Telescope Compact Array. A total of forty-one remnants have been examined by one or more of these surveys, but without success. To check the accuracy of the OH column densities inferred from the single-dish observations we modelled OH absorption at 1667 MHz observed with the Very Large Array towards three supernova remnants, IC 443, W44 and 3C 391. The results are mixed -- the OH column is revised upwards in IC443, downwards in 3C391, and is somewhat reduced in W44. We conclude that OH columns exceeding 10^{17} cm^{-2} are indeed present in some supernova remnants and so the lack of any detections is not explained by low OH column density. We discuss the possibility that non-local line overlap is responsible for suppressing the inversion of the 6049 MHz line.Comment: 8pages, to appear in Proc IAU 287, Cosmic Masers: from OH to H_0, R. Booth, E. Humphries and W. Vlemmings, ed

Channel noise induced stochastic facilitation in an auditory brainstem neuron model

Neuronal membrane potentials fluctuate stochastically due to conductance changes caused by random transitions between the open and close states of ion channels. Although it has previously been shown that channel noise can nontrivially affect neuronal dynamics, it is unknown whether ion-channel noise is strong enough to act as a noise source for hypothesised noise-enhanced information processing in real neuronal systems, i.e. 'stochastic facilitation.' Here, we demonstrate that biophysical models of channel noise can give rise to two kinds of recently discovered stochastic facilitation effects in a Hodgkin-Huxley-like model of auditory brainstem neurons. The first, known as slope-based stochastic resonance (SBSR), enables phasic neurons to emit action potentials that can encode the slope of inputs that vary slowly relative to key time-constants in the model. The second, known as inverse stochastic resonance (ISR), occurs in tonically firing neurons when small levels of noise inhibit tonic firing and replace it with burst-like dynamics. Consistent with previous work, we conclude that channel noise can provide significant variability in firing dynamics, even for large numbers of channels. Moreover, our results show that possible associated computational benefits may occur due to channel noise in neurons of the auditory brainstem. This holds whether the firing dynamics in the model are phasic (SBSR can occur due to channel noise) or tonic (ISR can occur due to channel noise).Comment: Published by Physical Review E, November 2013 (this version 17 pages total - 10 text, 1 refs, 6 figures/tables); Associated matlab code is available online in the ModelDB repository at http://senselab.med.yale.edu/ModelDB/ShowModel.asp?model=15148

Signal acquisition via polarization modulation in single photon sources

A simple model system is introduced for demonstrating how a single photon source might be used to transduce classical analog information. The theoretical scheme results in measurements of analog source samples that are (i) quantized in the sense of analog-to-digital conversion and (ii) corrupted by random noise that is solely due to the quantum uncertainty in detecting the polarization state of each photon. This noise is unavoidable if more than one bit per sample is to be transmitted, and we show how it may be exploited in a manner inspired by suprathreshold stochastic resonance. The system is analyzed information theoretically, as it can be modeled as a noisy optical communication channel, although unlike classical Poisson channels, the detector's photon statistics are binomial. Previous results on binomial channels are adapted to demonstrate numerically that the classical information capacity, and thus the accuracy of the transduction, increases logarithmically with the square root of the number of photons, N. Although the capacity is shown to be reduced when an additional detector nonideality is present, the logarithmic increase with N remains.Comment: 7 pages, 2 figures, accepted by Physical Review E. This version adds a referenc

Distance Distributions for Real Cellular Networks

This paper presents the general distribution for the distance between a mobile user and any base station (BS). We show that a random variable proportional to the distance squared is Gamma distributed. In the case of the nearest BS, it can be reduced to the well established result of the distance being Rayleigh distributed. We validate our results using a random node simulation and real Vodafone 3G network data, and go on to show how the distribution is tractable by deriving the average aggregate interference power.Comment: 2 pages, 1 figure, IEEE Conference on Computer Communications (INFOCOM