Duty-cycled Wake-up Schemes for Ultra-low Power Wireless Communications

In sensor network applications with low traffic intensity, idle channel listening is one of the main sources of energy waste.The use of a dedicated low-power wake-up receiver (WRx) which utilizes duty-cycled channel listening can significantlyreduce idle listening energy cost. In this thesis such a scheme is introduced and it is called DCW-MAC, an acronym forduty-cycled wake-up receiver based medium access control.We develop the concept in several steps, starting with an investigation into the properties of these schemes under idealizedconditions. This analysis show that DCW-MAC has the potential to significantly reduce energy costs, compared to twoestablished reference schemes based only on low-power wake up receivers or duty-cycled listening. Findings motivatefurther investigations and more detailed analysis of energy consumption. We do this in two separate steps, first concentratingon the energy required to transmit wake-up beacons and later include all energy costs in the analysis. The more completeanalysis makes it possible to optimize wake-up beacons and other DCW-MAC parameters, such as sleep and listen intervals,for minimal energy consumption. This shows how characteristics of the wake-up receiver influence how much, and if, energycan be saved and what the resulting average communication delays are. Being an analysis based on closed form expressions,rather than simulations, we can derive and verify good approximations of optimal energy consumption and resulting averagedelays, making it possible to quickly evaluate how a different wake-up receiver characteristic influences what is possible toachieve in different scenarios.In addition to the direct optimizations of the DCW-MAC scheme, we also provide a proof-of-concept in 65 nm CMOS,showing that the digital base-band needed to implement DCW-MAC has negligible energy consumption compared to manylow-power analog front-ends in literature. We also propose a a simple frame-work for comparing the relative merits ofanalog front-ends for wake-up receivers, where we use the experiences gained about DCW-MAC energy consumption toprovide a simple relation between wake-up receiver/analog front-end properties and energy consumption for wide ranges ofscenario parameters. Using this tool it is possible to compare analog front-ends used in duty-cycled wake-up schemes, evenif they are originally designed for different scenarios.In all, the thesis presents a new wake-up receiver scheme for low-power wireless sensor networks and provide a comprehensiveanalysis of many of its important properties

Becoming Prospective Medicine Students. A Case Study of Access to Medicine Students’ Descriptions of Their Experiences of a Further Education Course in the UK as Determined Through Narrative Enquiry and Poststructuralist Discourse Analysis

‘Becoming prospective medicine students' is about how ‘Access to medicine’ students at a college of Further Education (FE) in England describe their experiences of the course and how they become positioned through discourses as they prepare to progress from an ‘Access’ course to medical schools. The research explores students’ descriptions of their experiences of an ‘Access to medicine’ course and discusses whether the course is promoting equity and inclusion for socially and educationally disadvantaged students. The thesis contributes to the literature on widening participation in Higher Education (HE), mainly widening participation in medicine. Only the second educational research report into an ‘Access to medicine’ course, the thesis extends understandings of the same course at the same FE college eighteen years later. The novel contribution is that this is the first report to investigate the students' experiences of an ‘Access to medicine’ course using Foucauldian discourse analysis. I argue that the dominant ‘learning market’ approach to FE undermines the aims of ‘Access to HE’ courses which are designed to widen participation in HE and promote equity and inclusion of students. Policymakers and OFSTED need to wake up and recognise that dominating discourses based around the hard work ethic and vocational biases towards the purposes of FE promote capitalism and reproduce the social and educational inequalities which consecutive governments since 1979 have claimed to aim to reduce. ‘Becoming prospective medicine students' offers an alternative to existing research into widening participation in medicine through reporting the students’ subjective experiences of an ‘Access to medicine’ course while exploring whether and how the course actually widens participation in medicine. It is hoped that ‘Becoming prospective medicine students’ will prove useful to anyone interested in students' experiences of FE courses, anyone questioning the political motives of policymakers and exposing them or anyone wondering what it is like to aspire to study medicine at university

LEVERAGING WI-FI INFRASTRUCTURE FOR INCREASED POWER SAVINGS IN IOT DEVICES

Mining is one of the oldest industries known to man, and it continues to remain essential for the prosperity of modern civilization. Compared to surface mining, a large number of disasters are likely to occur during underground mining. To ensure the safety and security of an underground working environment, it is critical for underground mining operations to employ a robust and efficient monitoring infrastructure. To address that need, techniques are presented herein that support an increase in power savings in Internet of things (IoT) devices by leveraging a Wi-Fi infrastructure to determine when, and how frequently, such devices should wake up to send or receive data. Aspects of the presented techniques employ an access point’s (AP\u27s) channel state information (CSI) data, in conjunction with data from an AP’s on-board sensors (for metrics such as air quality, altimeter, temperature, and humidity), to detect indoor occupancy which, in turn, may drive the Target Wakeup Time (TWT) for selected IoT devices

Confronting the Biased Algorithm: The Danger of Admitting Facial Recognition Technology Results in the Courtroom

From unlocking an iPhone to Facebook “tags,” facial recognition technology has become increasingly commonplace in modern society. In the wake of the Black Lives Matter movement and call for police reform in the United States, it is important now more than ever to consider the implications of law enforcement’s use of facial recognition technology. A study from the National Institute of Standards and Technology found that facial recognition algorithms generated higher rates of false positives for Black faces—sometimes up to one hundred times more false identifications—than white faces. Given the embedded bias of this technology and its increased prevalence, the lack of federal regulation of facial recognition technology and its uses by law enforcement are alarming. This Note explores issues that arise with law enforcement’s use of facial recognition technology and how results from the technology should be treated in the criminal justice system. This Note cautions against admitting results from facial recognition technology into evidence in criminal trials based on the current state of the industry and the technology. Further, if facial recognition evidence is admitted, this Note argues that defendants should have access to the software’s source code to meaningfully challenge the evidence presented against them under the confrontation clause of the US Constitution. While this Note recognizes developers’ interest in protecting trade secrets, it nevertheless recommends that judges balance these interests with those of defendants and make case-by-case decisions about how to protect developers’ information without blocking defendants’ access to the software

School Finance Toolkit: How to Create a Community Guide to Your School District's Budget

If your community-based organization would like to launch a school finance initiative in your community, you can use this toolkit as a starting point. The toolkit walks through the major steps organizations have gone through in their own initiatives, offering advice and examples of tools you can adapt for your own use. The toolkit explores the major challenges organizations have faced in this work, and how they have addressed those challenges. And the toolkit points you toward other resources that can help you find and analyze information about school finance. This toolkit is not itself a primer on school finance. Except in passing, it does not explain how school funding works in school districts. You will have to obtain this kind of background information from other resources (some listed in this toolkit) and as you go along.The toolkit contains five major sections:Get Started. This section helps you set a mission for your school finance initiative, organize your people to get the job done, and find the resources to get the job done.Engage the Public. This section discusses strategies for engaging the public up-front, finding out what citizens want to know about school finance -- and why.Crunch the Numbers. This section addresses the nitty-gritty work of creating a community guide to the school budget, offering helpful tips on finding, analyzing, and presenting information effectively.Put the Numbers to Work. This section talks about ways you can use the information you have gathered as a catalyst for community-wide discussions of school finance and its impact on school quality.Resources. This section contains a variety of tools used by community-based organizations in their school finance initiatives, everything from town meeting agendas to focus group questions to budget analysis spreadsheets. This section also contains references to many sources of data about school finance, many of them just a mouse-click or toll-free call away

Aero-optical characterization of aircraft optical turrets by holography, interferometry and shadowgraph

Density variations in the aircraft boundary layer, turret wakes and shock waves create distortion of an optical wavefront through associated refractive index variations. Such effects can be observed directly through optical flow visualization. The application of holographic interferometry, wave shearing interferometry, and laser shadowgraph to observe and quantify such effects is described. Examples of the results from five different wind tunnel tests are presented. The examples show that diagnostics have provided valuable qualitiative and quantitiative data. These include (1) wake dimensions, (2) optical strength of the flow field, (3) turbulence characterization, (4) shock location, and (5) direct observation of areo-optical effects

Special Libraries, August 1980

Volume 71, Issue 8https://scholarworks.sjsu.edu/sla_sl_1980/1006/thumbnail.jp

New Forms of Judicial Review and the Persistence of Rights - And Democracy-Based Worries

Recent developments in judicial review have raised the possibility that the debate over judicial supremacy versus legislative supremacy might be transformed into one about differing institutions to implement judicial review. Rather than posing judicial review against legislative supremacy, the terms of the debate might be over having institutions designed to exercise forms of judicial review that accommodate both legislative supremacy and judicial implementation of constitutional limits. After examining some of these institutional developments in Canada, South Africa, and Great Britain, this Article asks whether these accommodations, which attempt to pursue a middle course, have characteristic instabilities that will in the long run lead constitutional systems back to wither judicial or legislative supremacy