Redefining a Gamma-Ray Burst Pulse

by Eric Hofesmann, 14 December 2016, Physics

NASA’s Burst And Transient Source Experiment (BATSE) Gamma-Ray Burst catalog was used to analyze complex Gamma-Ray Burst pulses. Complex GRB pulses are selected based off of the condition that there is an unknown number of pulses due to high variability in the structures intensity or due to non standard residual structures. Once the sample is selected, the pulses are scaled based off of their amplitude, asymmetry, and duration. The pulse intensities of the scaled pulses were interpolated to allow the pulses to be added together. The summed pulses were then binned to run through an existing pulse fitting algorithm. The pulse fit was removed from the data and the residuals were examined using another algorithm. Complex pulses were found to have similar characteristics within subgroups of bursts.

Software Engineering Blog

by Eric Hofesmann, 30 August 2016, Physics

My site where I will be posting my responses to the homework assignments of CSCI 362, Software Engineering, at the College of Charleston.

Physical Random Number Generators

by Eric Hofesmann, 2 May 2016, Physics

Methods for creating true random numbers include the emission of radioactive particles, audio noise, and photocell noise. The most basic random number generator creates only ones and zeros. Radiation was collected with a Geiger counter and an even or odd value represented a zero or one. The audio and photocell noise were both attached to an amplifier and the voltage was read off of the oscilloscope data. The voltage being even or odd represented a zero or a one. The randomness of the numbers was tested by the percentage of time that a specific bit string appears in each sample. The data was also unbiased through the Von Neumann approach. The biased data showed that the photocell and 50 ms speaker noise are more random than the radiation and 5 ms speaker data. The unbiased data showed an improvement in all samples except radiation and the control.

Redefining a Gamma-Ray Burst Pulse

by Eric Hofesmann, 30 April 2016, Physics

A catalog of Gamma-Ray Burst pulses is being compiled using data collected by NASAs Burst And Transient Source Experiment. Pulses are the smallest units of gamma-ray burst prompt emission, and have been found to undergo hard to soft evolution while exhibiting recognizable substructures. The catalog is being upgraded and improved to redefine pulses on the basis of their spectrotemporal characteristics: bursts that were previously thought to contain multiple pulses have been determined to contain single pulses having prominent substructures.

Impedance to Frequency Relationship of a Speaker

by Eric Hofesmann, 28 March 2016, Physics

The impedance of two dual driver speakers, of nominal impedance 6 Ohm and 8 Ohm , was determined on the range of frequencies of human hearing, from 10 Hz to 14 kHz. Ohm's Law was used to calculate the impedance, ranging from 5 Ohm to 40 Ohm , of the speakers by measuring the voltage drop and current. Two impedance peaks were found in a closed case speaker while a third, 60 Hz peak was found in an open, ported speaker. Using an oscilloscope, a phase shift was measured which reached zero during the impedance peaks and troughs. An equivalent circuit was simulated which showed a phase shift similar to the experimental data. A 6 Ohm impedance was measured for the 6 Ohm speaker but a 5 Ohm impedance was measured for the 8 Ohm speaker.