A Survey of Techniques For Improving Energy Efficiency in Embedded Computing Systems

Recent technological advances have greatly improved the performance and features of embedded systems. With the number of just mobile devices now reaching nearly equal to the population of earth, embedded systems have truly become ubiquitous. These trends, however, have also made the task of managing their power consumption extremely challenging. In recent years, several techniques have been proposed to address this issue. In this paper, we survey the techniques for managing power consumption of embedded systems. We discuss the need of power management and provide a classification of the techniques on several important parameters to highlight their similarities and differences. This paper is intended to help the researchers and application-developers in gaining insights into the working of power management techniques and designing even more efficient high-performance embedded systems of tomorrow

Lessons From New York City's Universal Pre-K Expansion: How a focus on diversity could make it even better

This brief is divided into two parts. The first provides background on how universal pre-K programs fit into the national landscape of early childhood policy, outlines the main features of New York City's current Universal Prekindergarten Program (UPK) expansion efforts, and draws lessons for other cities and states interested in expanding their programs. The second part provides an in-depth look at the issue of preschool classroom diversity in UPK, highlighting the opportunities and obstacles for integration embedded in current policies and recommending policy changes to address this issue in New York City and beyond

On the Complexity of Spill Everywhere under SSA Form

Compilation for embedded processors can be either aggressive (time consuming cross-compilation) or just in time (embedded and usually dynamic). The heuristics used in dynamic compilation are highly constrained by limited resources, time and memory in particular. Recent results on the SSA form open promising directions for the design of new register allocation heuristics for embedded systems and especially for embedded compilation. In particular, heuristics based on tree scan with two separated phases -- one for spilling, then one for coloring/coalescing -- seem good candidates for designing memory-friendly, fast, and competitive register allocators. Still, also because of the side effect on power consumption, the minimization of loads and stores overhead (spilling problem) is an important issue. This paper provides an exhaustive study of the complexity of the ``spill everywhere'' problem in the context of the SSA form. Unfortunately, conversely to our initial hopes, many of the questions we raised lead to NP-completeness results. We identify some polynomial cases but that are impractical in JIT context. Nevertheless, they can give hints to simplify formulations for the design of aggressive allocators.Comment: 10 page

Definition, implementation and validation of energy code smells: an exploratory study on an embedded system

Optimizing software in terms of energy efficiency is one of the challenges that both research and industry will have to face in the next few years.We consider energy efficiency as a software product quality characteristic, to be improved through the refactoring of appropriate code pattern: the aim of this work is identifying those code patterns, hereby defined as Energy Code Smells, that might increase the impact of software over power consumption. For our purposes, we perform an experiment consisting in the execution of several code patterns on an embedded system. These code patterns are executed in two versions: the first one contains a code issue that could negatively impact power consumption, the other one is refactored removing the issue. We measure the power consumption of the embedded device during the execution of each code pattern. We also track the execution time to investigate whether Energy Code Smells are also Performance Smells. Our results show that some Energy Code Smells actually have an impact over power consumption in the magnitude order of micro Watts. Moreover, those Smells did not introduce a performance decreas

Extraterritorial Application and Customary Norm Assessment of Non-Refoulement: The Legality of Australia\u27s \u27Turn-Back\u27 Policy

This article considers whether the Commonwealth Government’s border protection policy of turning back asylum seeker boats breaches its international obligation not to refoule refugees, as imposed under the Refugee Convention art 33(1). In addressing this issue the article examines whether art 33(1) applies extraterritorially, and whether a similar obligation has become embedded in customary international law. The conclusions reached are applied to specific situations where Australia has returned refugees

Preface : CAA 2010: Computer assisted assessment: supporting student learning

The Preface for the first special issue for the International Journal of e-Assessment highlights the role of the assessment for learning agenda. It also points to papers within the special issue which relate to: (a) Overcoming the barriers to supporting student learning with computer-assisted assessment; (b) Marking and computer-assisted assessment; (c) Harnessing the technology to improve efficiency and pedagogy. The papers in this issue stress the general recognition that times are changing and that assessment needs to become embedded in the teaching/learning cycle and not purely as a checking device for the awarding institution. These papers encourage us to rise to the challenge of developing more sophisticated computer-assisted assessment systems that support student learning and there is still a lot to do