Uncertainty in fish location using a split beam sonar

Thesis (M.S.) University of Alaska Fairbanks, 2000The enumeration of fish is of critical importance to the management of both commercial and sport fisheries in Alaska and worldwide. Current methods for riverine fish enumeration are inaccurate and unreliable. Improved fish counting accuracy in Alaskan rivers by acoustic methods is required. A split beam sonar system in the presence of noise is modeled. The sonar system including the received sonar pulse, receiver system, transducer beam pattern, propagation losses, and noise are modeled. An analysis of the effects of noise, pulse duration and sampling frequency on the uncertainty in fish location is presented. Signal to noise ratios less than 5 dB can cause significant errors in the calculation of received signal phase. A stationary fish with a signal to noise ratio of 15 dB has approximately plus-minus 0.001 degrees of uncertainty in the angles of arrival. Reducing the SNR to 3 dB the uncertainty increases to plus-minus 3.6 degrees in the angles of arrival

State of Alaska Election Security Project Phase 2 Report

A laska’s election system is among the most secure in the country, and it has a number of safeguards other states are now adopting. But the technology Alaska uses to record and count votes could be improved— and the state’s huge size, limited road system, and scattered communities also create special challenges for insuring the integrity of the vote. In this second phase of an ongoing study of Alaska’s election security, we recommend ways of strengthening the system—not only the technology but also the election procedures. The lieutenant governor and the Division of Elections asked the University of Alaska Anchorage to do this evaluation, which began in September 2007.Lieutenant Governor Sean Parnell. State of Alaska Division of Elections.List of Appendices / Glossary / Study Team / Acknowledgments / Introduction / Summary of Recommendations / Part 1 Defense in Depth / Part 2 Fortification of Systems / Part 3 Confidence in Outcomes / Conclusions / Proposed Statement of Work for Phase 3: Implementation / Reference

Leading Self-Help Groups: Report on Workshop for Leaders of Childhood Cancer Support Group

http://deepblue.lib.umich.edu/bitstream/2027.42/51119/1/351.pd

Work in progress: a novel method of creating an academic content repository

This paper outlines a project aimed at addressing the issue of the scalability of online academic support. This project is being run during the Autumn semester at the University of Southern Queensland (USQ) Toowoomba Australia, in conjunction with the Australian Digital Futures Institute. The study attached to the project will use Design-Based Research to evaluate the effectiveness of a simple, but innovative academic content and metadata creation tool referred to as Academic Assist. Academic Assist has been recently developed at USQ as a plug-in block for the moodle-based Learning Management System employed at USQ for its several hundred online subjects. The pilot project and associated study now extends over nine subjects, including three consecutive subjects in computer engineering; and covers faculties of Engineering, Education, Business, Science and Arts. Some preliminary results are presented here. Complete results of the study including acceptance surveys, expert reviews and usage statistics will be presented at FIE 2009

Complete Atrioventricular Heart Block From an Epilepsy Treatment

Atrioventricular (AV) heart block without adequate escape rhythm can result in sudden cardiac arrest and death. We report complete (third degree) AV block in a 16 year-old boy as a late effect of vagus nerve stimulation (VNS). He experienced brief, daily, complex partial seizures, treated with lamotrigine, levetiracetam, and the placement of Model 102 VNS at age 4. Electroencephalography (EEG) showed generalized slow spike-and-wave discharges consistent with Lennox-Gastaut syndrome. At age 12, his VNS was changed to Model 303 PereniaDURA/Model 103 Demipulse generator, set at an output current of 2.25 mA on a standard 30 seconds on, 5 minutes off paradigm. At age 16, he experienced episodes of sudden collapse followed by unconsciousness. Holter monitor showed 15 second symptomatic complete AV block without escape (Figure 1). The patient was taking psychotropic medication with potential cardiac side effects: methylphenidate (tachycardia), guanfacine (first degree AV block), and haloperidol (prolonged QT interval, Torsades de Pointes). Haloperidol, methylphenidate, and VNS were stopped without further symptoms. Off these medications, the VNS was resumed at reduced current (1.25 mA), with re-occurrence of symptomatic AV block. Again, the VNS was stopped and symptoms/heart block ceased. Psychotropic medication was resumed without any side effects

What Search Data Shows About Americans and Guns During the COVID-19 Crisis

With millions of Americans staying at home across the country during a crisis of intense emotional and economic stress, gun safety advocates have raised concerns about increased risks of unintentional shootings, domestic violence shootings, gun suicides, and city gun violence. Unprecedented spikes in background checks, meanwhile, reflect a dramatic increase in gun purchasing that compounds these risks.Federal background check data, however, fails to capture the full spectrum of ways that people acquire guns, as well as the number of people who are removing guns from gun lockers or other storage. In an effort to cast additional light on issues of firearm access during this stage of the COVID-19 crisis, we used real-time Google search data to gauge interest in buying and cleaning guns across the country