Using GPS Receiver 1PPS Output to Verify Time Stamp Accuracy and Measure Propagation Delay

A simple pulse overlay circuit using a logic OR gate was developed to overlay a precise leading edge 1 pulse per second time reference marker from a global positioning system receiver onto a non-return -to- zero-level pulse code modulation telemetry data stream to validate time stamp accuracy and measure propagation delay in telemetry equipment. A pulse overlay (PO) circuit was designed to produce a time reference marker within a pulse code modulation (PCM) telemetry data stream that was recorded and analyzed to validate an IRIG Standard 106-17 Chapter 10 recorders time stamp accuracy [1]. A manufacturer of a newly purchased Chapter 10 recorder claimed the time stamp accuracy to be better than 10 microseconds (s) with only IRIG-B120 (IRIG-B) input and better than 1 s with IRIG-B and one pulse per second (1PPS) inputs. The PO circuit and a Chapter 10 recorder test setup were used to verify the vendors data-time synchronization claims and to justify infrastructure upgrade costs to connect additional cables to each purchased recorder. The circuit was also used to measure the propagation delay (PD) of a long distance Telemetry multiplexer/demultiplexer telecommunication system which the manufacturer did not provide a PD specification. Using the one pulse per second time reference marker of the global positioning system receiver and the pulse overlay circuit to overlay the one pulse per second variable pulse width signal into a pulse code modulation telemetry stream provided an excellent means to validate time stamp accuracy within a Chapter 10 recorder and to measure propagation delays within a normal telemetry operating environment. The positive results from the Chapter 10 recorder tests validated the vendors claims and justified the implementation to add the one pulse per second signal to the range Chapter 10 recorders. The pulse overlay circuit and test setups defined in this paper can easily be used to measure other telemetry equipment

Using GPS Receiver 1PPS Output to Verify Time Stamp Accuracy and Measure Propagation Delay

A simple pulse overlay circuit using a logic OR gate was developed to overlay a precise leading edge 1 pulse per second time reference marker from a global positioning system receiver onto a non-return -to- zero-level pulse code modulation telemetry data stream to validate time stamp accuracy and measure propagation delay in telemetry equipment

Conceptual mechanization studies for a horizon definition spacecraft attitude control subsystem, phase A, part II, 10 October 1966 - 29 May 1967

Attitude control subsystem for spin stabilized spacecraft for mapping earths infrared horizon radiance profiles in 15 micron carbon dioxide absorption ban

Profiling of micrometer sized laser beams in restricted volumes

We present a method for determining the 3D intensity distribution of directed laser radiation with micrometer resolution in restricted volumes. Our method is based on in-coupling and guiding properties of optical fibers, with the current version requiring only few hundred micrometers. We characterize the performance of the method and experimentally demonstrate profiling of micrometer sized laser beams. We discuss the limiting factors and routes towards a further increase of the resolution and beam profiling in even more restricted volumes. Finally, as an application example, we present profiling of laser beams inside a micro ion trap with integrated optical fibers

Absence of bias against smokers in access to coronary revascularization after cardiac catheterization

Objective. Many consider smoking to be a personal choice for which individuals should be held accountable. We assessed whether there is any evidence of bias against smokers in cardiac care decision-making by determining whether smokers were as likely as non-smokers to undergo revascularization procedures after cardiac catheterization. Design. Prospective cohort study. Subjects and setting. All patients undergoing cardiac catheterization in Alberta, Canada. Main measures. Patients were categorized as current smokers, former smokers, or never smokers, and then compared for their risk-adjusted likelihood of undergoing revascularization procedures (percutaneous coronary intervention or coronary artery bypass grafting) after cardiac catheterization. Results. Among 20406 patients undergoing catheterization, 25.4% were current smokers at the time of catheterization, 36.6% were former smokers, and 38.0% had never smoked. When compared with never smokers (reference group), the hazard ratio for undergoing any revascularization procedure after catheterization was 0.98 (95% CI 0.93-1.03) for current smokers and 0.98 (0.94-1.03) for former smokers. The hazard ratio for undergoing coronary artery bypass grafting was 1.09 (1.00-1.19) for current smokers and 1.00 (0.93-1.08) for former smokers. For percutaneous coronary intervention, the hazard ratios were 0.93 (0.87-0.99) for current smokers and 1.00 (0.94-1.06) for former smokers. Conclusion. Despite potential for discrimination on the basis of smoking status, current and former smokers undergoing cardiac catheterization in Alberta, Canada were as likely to undergo revascularization procedures as catheterization patients who had never smoke

Computer recommendations for an automatic approach and landing system for V/STOL aircraft. Volume 1 - Computer recommendations

Evaluation of digital computer for V/STOL aircraft automatic approach and landing syste

Complete Genome Sequences of Mycobacterium smegmatis Phages NihilNomen and Carlyle, Isolated in Las Vegas, Nevada

We present the complete genomes of the Mycobacterium smegmatis phages Carlyle and NihilNomen, isolated from soil in Las Vegas, Nevada. The phages were isolated and annotated by undergraduate students enrolled in the Phage Discovery course offered by the School of Life Sciences at the University of Nevada Las Vegas

Towards Standardization of Retinal Vascular Measurements:On the Effect of Image Centering

Within the general framework of consistent and reproducible morphometric measurements of the retinal vasculature in fundus images, we present a quantitative pilot study of the changes in measurements commonly used in retinal biomarker studies (e.g. caliber-related, tortuosity and fractal dimension of the vascular network) induced by centering fundus image acquisition on either the optic disc or on the macula. To our best knowledge, no such study has been reported so far. Analyzing 149 parameters computed from 80 retinal images (20 subjects, right and left eye, optic-disc and macula centered), we find strong variations and limited concordance in images of the two types. Although analysis of larger cohorts is obviously necessary, our results strengthen the need for a structured investigation into the uncertainty of retinal vasculature measurements, ideally in the framework of an international debate on standardization.</p

Reflections in Time: Budget Crisis and Presidential Decisions

Significant budget deficits pressure university presidents to make changes that will transform higher education in the United States. Because many institutions are facing deficits, it is important to understand why presidents are making the decisions they do to help resolve these budget gaps. Staff reductions, program closures, and school closures will change their institution, thus impacting the communities and regions they serve. Understanding the why behind their decision is important so everyone can acknowledge how presidents got to their decision. My research aimed to identify patterns of why presidents chose their shifts and if one or more reasons influenced them more. Using Bolman and Deal’s four-frame change model, I interviewed a dozen presidents across the Midwest to identify these themes, influences, and reasons why they made their decisions in the structural, human resources, political, and symbolic frames. The results of this study help university leaders identify common reasons why leaders make their decisions and what affects their choices. Through the four frames of change, leaders have several common influences and reasons why they made their specific decisions. Knowing their reasons why they chose to do what they did during a budget crisis is important for higher education leaders to recognize. It is important for community stakeholders to be aware of this. It may also be helpful to everyone who is interested in leadership decision making