PACE: Simple Multi-hop Scheduling for Single-radio 802.11-based Stub Wireless Mesh Networks

IEEE 802.11-based Stub Wireless Mesh Networks (WMNs) are a cost-effective and flexible solution to extend wired network infrastructures. Yet, they suffer from two major problems: inefficiency and unfairness. A number of approaches have been proposed to tackle these problems, but they are too restrictive, highly complex, or require time synchronization and modifications to the IEEE 802.11 MAC. PACE is a simple multi-hop scheduling mechanism for Stub WMNs overlaid on the IEEE 802.11 MAC that jointly addresses the inefficiency and unfairness problems. It limits transmissions to a single mesh node at each time and ensures that each node has the opportunity to transmit a packet in each network-wide transmission round. Simulation results demonstrate that PACE can achieve optimal network capacity utilization and greatly outperforms state of the art CSMA/CA-based solutions as far as goodput, delay, and fairness are concerned

The Road Ahead for State Assessments

The adoption of the Common Core State Standards offers an opportunity to make significant improvements to the large-scale statewide student assessments that exist today, and the two US DOE-funded assessment consortia -- the Partnership for the Assessment of Readiness for College and Careers (PARCC) and the SMARTER Balanced Assessment Consortium (SBAC) -- are making big strides forward. But to take full advantage of this opportunity the states must focus squarely on making assessments both fair and accurate.A new report commissioned by the Rennie Center for Education Research & Policy and Policy Analysis for California Education (PACE), The Road Ahead for State Assessments, offers a blueprint for strengthening assessment policy, pointing out how new technologies are opening up new possibilities for fairer, more accurate evaluations of what students know and are able to do. Not all of the promises can yet be delivered, but the report provides a clear set of assessment-policy recommendations. The Road Ahead for State Assessments includes three papers on assessment policy.The first, by Mark Reckase of Michigan State University, provides an overview of computer adaptive assessment. Computer adaptive assessment is an established technology that offers detailed information on where students are on a learning continuum rather than a summary judgment about whether or not they have reached an arbitrary standard of "proficiency" or "readiness." Computer adaptivity will support the fair and accurate assessment of English learners (ELs) and lead to a serious engagement with the multiple dimensions of "readiness" for college and careers.The second and third papers give specific attention to two areas in which we know that current assessments are inadequate: assessments in science and assessments for English learners.In science, paper-and-pencil, multiple choice tests provide only weak and superficial information about students' knowledge and skills -- most specifically about their abilities to think scientifically and actually do science. In their paper, Chris Dede and Jody Clarke-Midura of Harvard University illustrate the potential for richer, more authentic assessments of students' scientific understanding with a case study of a virtual performance assessment now under development at Harvard. With regard to English learners, administering tests in English to students who are learning the language, or to speakers of non-standard dialects, inevitably confounds students' content knowledge with their fluency in Standard English, to the detriment of many students. In his paper, Robert Linquanti of WestEd reviews key problems in the assessment of ELs, and identifies the essential features of an assessment system equipped to provide fair and accurate measures of their academic performance.The report's contributors offer deeply informed recommendations for assessment policy, but three are especially urgent.Build a system that ensures continued development and increased reliance on computer adaptive testing. Computer adaptive assessment provides the essential foundation for a system that can produce fair and accurate measurement of English learners' knowledge and of all students' knowledge and skills in science and other subjects. Developing computer adaptive assessments is a necessary intermediate step toward a system that makes assessment more authentic by tightly linking its tasks and instructional activities and ultimately embedding assessment in instruction. It is vital for both consortia to keep these goals in mind, even in light of current technological and resource constraints.Integrate the development of new assessments with assessments of English language proficiency (ELP). The next generation of ELP assessments should take into consideration an English learners' specific level of proficiency in English. They will need to be based on ELP standards that sufficiently specify the target academic language competencies that English learners need to progress in and gain mastery of the Common Core Standards. One of the report's authors, Robert Linquanti, states: "Acknowledging and overcoming the challenges involved in fairly and accurately assessing ELs is integral and not peripheral to the task of developing an assessment system that serves all students well. Treating the assessment of ELs as a separate problem -- or, worse yet, as one that can be left for later -- calls into question the basic legitimacy of assessment systems that drive high-stakes decisions about students, teachers, and schools." Include virtual performance assessments as part of comprehensive state assessment systems. Virtual performance assessments have considerable promise for measuring students' inquiry and problem-solving skills in science and in other subject areas, because authentic assessment can be closely tied to or even embedded in instruction. The simulation of authentic practices in settings similar to the real world opens the way to assessment of students' deeper learning and their mastery of 21st century skills across the curriculum. We are just setting out on the road toward assessments that ensure fair and accurate measurement of performance for all students, and support for sustained improvements in teaching and learning. Developing assessments that realize these goals will take time, resources and long-term policy commitment. PARCC and SBAC are taking the essential first steps down a long road, and new technologies have begun to illuminate what's possible. This report seeks to keep policymakers' attention focused on the road ahead, to ensure that the choices they make now move us further toward the goal of college and career success for all students. This publication was released at an event on May 16, 2011

Local Land Use: Decision Expands Federal Government\u27s Role

The United States Environmental Protection Agency (EPA), pursuant to its authority under the Clean Water Act, has promulgated regulations creating the Storm Water Management Program. Contrary to the overall Clean Water Act scheme, which focuses on reducing pollution from point sources, the program has the objective of reducing non-point source water pollution. However, this program is not without controversy as heavy burdens are placed upon local governments, who themselves lack the financial resources, manpower, or technology to implement a complex federal system without federal or state assistance

The ecology of wisdom

This is the first of two papers concerning wisdom as an ecosystem appearing in sequential editions of Management & Marketing journal. The notion of wisdom as an ecosystem, or “the wisdom ecology,” builds on work by Hays (2007) who first identified wisdom as an organisational construct and proposed a dynamic model of it. The centrepiece of this paper and the companion part to follow is a relationship map of the wisdom ecosystem (the Causal Loop Diagram at Figure 1). This first instalment provides background on wisdom and complex adaptive systems, and introduces the wisdom ecosystem model. The second instalment, “Mapping Wisdom as a Complex Adaptive System,” appearing in the next edition of Management & Marketing, explains systems dynamics modelling and discusses the wisdom ecosystem model in detail. It covers the four domains, or subsystems, of the wisdom ecosystem, Dialogue, Communal Mind, Collective Intelligence, and Wisdom, and walks readers through the model, exploring each of its 24 elements in turn. That second paper examines the relationships amongst system elements and illuminates important aspects of systems function.causal loop diagramming, complexity, dialogue, organisational learning, systems dynamics, wisdom.

Understanding the type and pace of organisational change in the Maltese budgetary framework

Purpose: This paper analyses the type and pace of organisational change expected in the Maltese budgetary framework. Drawing on the Greenwood and Hinings’ (1996) model, the paper provides an examination of the internal dynamics surrounding the budgetary framework in Malta, including stakeholders’ dissatisfaction, value commitments, power dependencies and capacity for action. The paper explores the different categories of performance budgeting systems (presentational, performance-informed and direct) and their bearing on the different levels of change. Design/methodology/approach: The study follows a qualitative approach using data gathered from documentary sources, corroborated with empirical evidence collected from in-depth, semi-structured interviews. The interviews comprised open-ended questions and they were conducted with senior politicians from the government and the opposition, including former ministers and Prime Ministers, and with senior civil servants. Findings: The findings indicate that a radical change to the existing Maltese budgeting system could be problematic, as the current system is an institutionalised practice and change could be resisted by the parties affected by the reform. The findings suggest that, within the Maltese scenario, the political ability required to make reforms happen is a further enabler of radical change. Originality/value: The paper provides an analysis of the expected change in the budgetary framework of a small EU country, identifying the enabling elements of such a change. The method of analysis could be extended to other countries which intend to embark on budgetary reforms. The study also assesses the relevant issues from a policy-making perspective, through access to senior politicians as policy makers, and senior civil servants who influence policy makers and are responsible for implementing policy.peer-reviewe

Latent Replay for Real-Time Continual Learning

Training deep neural networks at the edge on light computational devices, embedded systems and robotic platforms is nowadays very challenging. Continual learning techniques, where complex models are incrementally trained on small batches of new data, can make the learning problem tractable even for CPU-only embedded devices enabling remarkable levels of adaptiveness and autonomy. However, a number of practical problems need to be solved: catastrophic forgetting before anything else. In this paper we introduce an original technique named "Latent Replay" where, instead of storing a portion of past data in the input space, we store activations volumes at some intermediate layer. This can significantly reduce the computation and storage required by native rehearsal. To keep the representation stable and the stored activations valid we propose to slow-down learning at all the layers below the latent replay one, leaving the layers above free to learn at full pace. In our experiments we show that Latent Replay, combined with existing continual learning techniques, achieves state-of-the-art performance on complex video benchmarks such as CORe50 NICv2 (with nearly 400 small and highly non-i.i.d. batches) and OpenLORIS. Finally, we demonstrate the feasibility of nearly real-time continual learning on the edge through the deployment of the proposed technique on a smartphone device.Comment: Pre-print v3: 13 pages, 9 figures, 10 tables, 1 algorith