The effect and compensation of time-base perturbations in analog recording systems

The mean square error between recorded and reproduced signals is used as an error measure to determine the effects of time-base perturbations on an analog singal. The mean square error caused by time-base perturbations is shown to be proportional to the product of the square of the signal bandwidth and the time-base error variance for the case of low pass signal. When the signal is band pass, there is shown to be an additional error term which is proportional to the square of the signal center frequency and the time-base error variance. Calculations are also carried out to determine the relative effects of pre-recorder and post-recorder external additive noise. It is found that this external noise adds a term to the mean square error which is approximately equal to the noise power. An analysis is made to determine the error reduction which is possible by the use of the optimum linear filter. It is shown that a significant improvement is possible for the case where the signal bandwidth is less than the time-base error bandwidth. Practical approximations to the optimum linear filter are also considered and, in some cases, they are found to give a reduction in the mean square error which is approximately the same as that given by the optimum filter --Abstract, pages ii-iii

A content review of precision agriculture courses across the United States

Knowledge of what Precision Agriculture (PA) content is currently taught across the U.S. will help build a better understanding for what PA instructors should incorporate into their classes in the future. For this assessment, the University of Missouri (MU) partnered with several universities throughout the nation on a United States Department of Agriculture (USDA) challenge grant. A survey was conducted with PA instructors from 44 institutions from across the U.S. participating. Each institution was assessed to determine amount of time they spent teaching on 59 different PA topics in their PA-related courses. Results were obtained from 56 PA courses. Scope of PA, Global Positioning System (GPS), Differential GPS, Yield Monitoring, and Yield Map were all topics that were frequently discussed in PA courses, whether they were entryor advanced-level or two-year or four-year institutions. Review of the content showed a need for a more standardized curriculum.Dr. Leon Schumacher, Thesis Supervisor.Includes bibliographical references (pages 69-72)

Next Generation Social Networks:Elicitation of User Requirements

Abstract—When it comes to discussing the future of electronic communication, social networking is the buzzword. The Internet has become a platform where new social networks emerge and the Internet it itself support the more traditional computer supported communication. The way users build and verifies different online networks for communities of people who share interests or individuals who presents themselves through user produced content is what makes up the social networking of today. The purpose of this paper is to discuss perceived user requirements to the next generation social networks. The paper is based on a survey of users working within the ICT field as well as user requirement categorizations developed within the WWRF. Index Terms—Computer supported communication, social networks, user requirements, Web-applications. I