Improvement of indoor VLC network downlink scheduling and resource allocation

Indoor visible light communications (VLC) combines illumination and communication by utilizing the high-modulation-speed of LEDs. VLC is anticipated to be complementary to radio frequency communications and an important part of next generation heterogeneous networks. In order to make the maximum use of VLC technology in a networking environment, we need to expand existing research from studies of traditional point-to-point links to encompass scheduling and resource allocation related to multi-user scenarios. This work aims to maximize the downlink throughput of an indoor VLC network, while taking both user fairness and time latency into consideration. Inter-user interference is eliminated by appropriately allocating LEDs to users with the aid of graph theory. A three-term priority factor model is derived and is shown to improve the throughput performance of the network scheduling scheme over those previously reported. Simulations of VLC downlink scheduling have been performed under proportional fairness scheduling principles where our newly formulated priority factor model has been applied. The downlink throughput is improved by 19.6% compared to previous two-term priority models, while achieving similar fairness and latency performance. When the number of users grows larger, the three-term priority model indicates an improvement in Fairness performance compared to two-term priority model scheduling

A Moral Debate at the Invisible Rainbow: Thoughts about Best Practices in Servicing LGBTQ Students in Special Education

Instead of occupying a marginal space within teacher preparation programs, special education courses and training should promote diversity in servicing marginalized groups such as lesbian, gay, bisexual, transgender, and questioning (LGBTQ) students. Within these programs, issues related to LGBTQ students should occupy a meaningful and formative space in the training of future teachers in special education. Often, special education teachers are at a loss about how to educate LGBTQ students with disabilities. Rethinking the role of special education and LGBTQ students with special needs within teacher education programs enables pre-service teachers to cultivate new values and attitudes that can enrich the student/teacher relationship within public schools. As such, this article proposes to explore best practices for servicing LGTBQ students in special education by promoting better ways to train future teachers

A colimit decomposition for homotopy algebras in Cat

Badzioch showed that in the category of simplicial sets each homotopy algebra of a Lawvere theory is weakly equivalent to a strict algebra. In seeking to extend this result to other contexts Rosicky observed a key point to be that each homotopy colimit in simplicial sets admits a decomposition into a homotopy sifted colimit of finite coproducts, and asked the author whether a similar decomposition holds in the 2-category of categories Cat. Our purpose in the present paper is to show that this is the case.Comment: Some notation changed; small amount of exposition added in intr

Designing the future of primary and secondary-level learning environments in knowmad society

In an era consumed with accelerating technological and social change, coupled with rapidly evolving organizational needs and missions, primary and secondary-level schools need to reframe why, how, and for whom they exist and explore new pathways to realize these functions. This article explores a strategic framework for learners to develop skills to navigate a society in constant flux, disentangling information, knowledge, and innovation. We plot a pathway for maximizing creativity and innovation capital for schools in knowledge-based societies, together with the communities they serve

American Pie: The Politics of Food in the 21st Century

American Pie: The Politics of Food in the 21st Century In light of the increasing interest in food studies at Penn and in Philadelphia, Penn Libraries is sponsoring the Muriel Pfaelzer Bodek Public Affairs Lecture Series focusing on food policy in the 21st century. The speakers, experts in their fields, address issues relating to global food security, sustainable agriculture, and food waste in America. Wednesday, April 11, 2012: Jonathan Bloom, The Food Not Eaten : Jonathan Bloom, journalist and author of American Wasteland: How America Throws Away Nearly Half of Its Food (and What We Can Do About It) (2010), speaks on how much food we waste, where and why we squander so much, the ethical, environmental, and economic impact of our actions, and, most importantly, how we can minimize waste. Thursday, April 19, 2012: Alan M. Kelly, Global Food Security: A 21st Century Challenge Dr. Alan M. Kelly, Dean Emeritus and Professor of Veterinary Medicine, University of Pennsylvania, speaks on the challenges faced by agriculture as it expands production to meet society\u27s growing needs while conserving the environment, controlling the spread of infectious diseases, and accommodating to the vagaries of climate change. Tuesday, April 24, 2012: John E. Ikerd, The Future of Food: Sustainable Agriculture is not Optional Dr. John E. Ikerd, Professor Emeritus of Agricultural Economics, University of Missouri, and author of Sustainable Capitalism: A Matter of Common Sense and Small Farms are Real Farms: Sustaining People Through Agriculture, will speak on the need for sustainable agriculture, the challenges facing the movement, and the development of a new and better paradigm. To download podcasts of these lectures, choose one of the additional files below. Lectures by Jonathan Bloom and Alan Kelly are available for download in audio-only (.mp3) and as audio with image (.m4v) versions. To view the event announcement, select Download button at upper right

An experimental evaluation of software redundancy as a strategy for improving reliability

The strategy of using multiple versions of independently developed software as a means to tolerate residual software design faults is suggested by the success of hardware redundancy for tolerating hardware failures. Although, as generally accepted, the independence of hardware failures resulting from physical wearout can lead to substantial increases in reliability for redundant hardware structures, a similar conclusion is not immediate for software. The degree to which design faults are manifested as independent failures determines the effectiveness of redundancy as a method for improving software reliability. Interest in multi-version software centers on whether it provides an adequate measure of increased reliability to warrant its use in critical applications. The effectiveness of multi-version software is studied by comparing estimates of the failure probabilities of these systems with the failure probabilities of single versions. The estimates are obtained under a model of dependent failures and compared with estimates obtained when failures are assumed to be independent. The experimental results are based on twenty versions of an aerospace application developed and certified by sixty programmers from four universities. Descriptions of the application, development and certification processes, and operational evaluation are given together with an analysis of the twenty versions

L'invasion du Canada en 1775, d'après les historiens canadiens-français

Québec Université Laval, Bibliothèque 201