3,449 research outputs found

    Generalizing Amdahl’s Law for Power and Energy

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    Extending Amdahl\u27s law to identify optimal power-performance configurations requires considering the interactive effects of power, performance, and parallel overhead

    Assessing Devolution in the Canadian North: A Case Study of the Yukon Territory

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    Despite a rich literature on the political and constitutional development of the Canadian territorial North, few scholars have examined the post-devolution environment in Yukon. This lacuna is surprising since devolution is frequently cited as being crucial to the well-being of Northerners, leading both the Government of Nunavut and the Government of the Northwest Territories to lobby the federal government to devolve lands and resources to them. This paper provides an updated historical account of devolution in Yukon and assesses its impact on the territory since 2003. Relying mainly on written resources and 16 interviews with Aboriginal, government, and industry officials in the territory, it highlights some broad effects of devolution and specifically analyzes the processes of obtaining permits for land use and mining. Our findings suggest that devolution has generally had a positive effect on the territory, and in particular has led to more efficient and responsive land use and mining permit processes

    Resolving Conflict between Canada’s Indigenous Peoples and the Crown through Modern Treaties: Yukon Case History

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    This article presents an example of how modern treaties with Yukon First Nations have created a foundation for co-relational involvement in the direction and control of land and resource management throughout Canada’s subnational region of Yukon, approximately 470,000 square kilometers in size. The modern treaties with eleven of the fourteen Yukon First Nations create assessment and management structures where appointment to these bodies are nominations not only from the territorial and federal governments but from the Yukon First Nations. The rights captured in the treaties are protected under Canada’s supreme law, the Constitution Act, 1982. The treaty relationship has effectively changed conflict. No longer is the Indigenous population (approximately 25 percent of the territory) alienated from government powers that control land and resources. The structures set out under the modern treaties provide shared ownership of the institutions that either control or have extensive influence over critical aspects of governing the territory: land, water, surface and subsurface resources, heritage, wildlife, fish, and the environment

    Empirical and Statistical Application Modeling Using on -Chip Performance Monitors.

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    To analyze the performance of applications and architectures, both programmers and architects desire formal methods to explain anomalous behavior. To this end, we present various methods that utilize non-intrusive, performance-monitoring hardware only recently available on microprocessors to provide further explanations of observed behavior. All the methods attempt to characterize and explain the instruction-level parallelism achieved by codes on different architectures. We also present a prototype tool automating the analysis process to exploit the advantages of the empirical and statistical methods proposed. The empirical, statistical and hybrid methods are discussed and explained with case study results provided. The given methods further the wealth of tools available to programmer\u27s and architects for generally understanding the performance of scientific applications. Specifically, the models and tools presented provide new methods for evaluating and categorizing application performance. The empirical memory model serves to quantify the hierarchical memory performance of applications by inferring the incurred latencies of codes after the effect of latency hiding techniques are realized. The instruction-level model and its extensions model on-chip performance analytically giving insight into inherent performance bottlenecks in superscalar architectures. The statistical model and its hybrid extension provide other methods of categorizing codes via their statistical variations. The PTERA performance tool automates the use of performance counters for use by these methods across platforms making the modeling process easier still. These unique methods provide alternatives to performance modeling and categorizing not available previously in an attempt to utilize the inherent modeling capabilities of performance monitors on commodity processors for scientific applications

    Iso-energy-efficiency: An approach to power-constrained parallel computation

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    Future large scale high performance supercomputer systems require high energy efficiency to achieve exaflops computational power and beyond. Despite the need to understand energy efficiency in high-performance systems, there are few techniques to evaluate energy efficiency at scale. In this paper, we propose a system-level iso-energy-efficiency model to analyze, evaluate and predict energy-performance of data intensive parallel applications with various execution patterns running on large scale power-aware clusters. Our analytical model can help users explore the effects of machine and application dependent characteristics on system energy efficiency and isolate efficient ways to scale system parameters (e.g. processor count, CPU power/frequency, workload size and network bandwidth) to balance energy use and performance. We derive our iso-energy-efficiency model and apply it to the NAS Parallel Benchmarks on two power-aware clusters. Our results indicate that the model accurately predicts total system energy consumption within 5% error on average for parallel applications with various execution and communication patterns. We demonstrate effective use of the model for various application contexts and in scalability decision-making

    PowerPack: Energy Profiling and Analysis of High-Performance Systems and Applications

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    Energy efficiency is a major concern in modern high-performance computing system design. In the past few years, there has been mounting evidence that power usage limits system scale and computing density, and thus, ultimately system performance. However, despite the impact of power and energy on the computer systems community, few studies provide insight to where and how power is consumed on high-performance systems and applications. In previous work, we designed a framework called PowerPack that was the first tool to isolate the power consumption of devices including disks, memory, NICs, and processors in a high-performance cluster and correlate these measurements to application functions. In this work, we extend our framework to support systems with multicore, multiprocessor-based nodes, and then provide in-depth analyses of the energy consumption of parallel applications on clusters of these systems. These analyses include the impacts of chip multiprocessing on power and energy efficiency, and its interaction with application executions. In addition, we use PowerPack to study the power dynamics and energy efficiencies of dynamic voltage and frequency scaling (DVFS) techniques on clusters. Our experiments reveal conclusively how intelligent DVFS scheduling can enhance system energy efficiency while maintaining performance

    The origin of isomerization of aniline revealed by high kinetic energy ion mobility spectrometry (HiKE-IMS)

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    Although aniline is a relatively simple small molecule, the origin of its two peaks observed in ion mobility spectrometry (IMS) has remained under debate for at least 30 years. First hypothesized as a difference in protonation site (amine vs. benzene ring), each ion mobility peak differs by one Dalton when coupled with mass spectrometry where the faster mobility peak is the molecular ion peak, and the slower mobility peak is protonated. To complicate the deconvolution of structures, some previous literature shows the peaks as unresolved and thus proposes these species exist in equilibrium. In this work, we show that when measured with high kinetic energy ion mobility spectrometry (HiKE-IMS), the two peaks observed in spectra of both aniline and all n-fluoroanilines are fully separated (chromatographic resolution from 2-7, Rp > 110) and therefore not in equilibrium. The HiKE-IMS is capable of changing ionization conditions independently of drift region conditions, and our results agree with previous literature showing that ionization source settings (including possible fragmentation at this stage) are the only influence determining the speciation of the two aniline peaks. Finally, when the drift and reactant gas are changed to nitrogen, a third peak appears at high E/N for 2-fluoroaniline and 4-fluoroaniline for the first time in reported literature. As observed by HiKE-IMS-MS, the new third peak is also protonated showing that the para-protonated aniline and resulting fragment ion, molecular ion aniline, can be fully separated in the mobility domain for the first time. The appearance of the third peak is only possible due to the increased separation of the other two peaks within the HiKE-IMS

    Do Not Diagonalize

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    Speakers assert in order to communicate information. It is natural, therefore, to hold that the content of an assertion is whatever information it communicates to its audience. In cases involving uncertainty about the semantic values of context-sensitive lexical items, moreover, it is natural to hold that the information an assertion communicates to its audience is whatever information audience members are in a position to recover from it by assuming that the proposition it semantically determines is true. This sort of picture corresponds to an influential and widely endorsed theory of assertoric content: diagonalism. I begin by arguing that, despite its intuitive appeal, diagonalism should be rejected because it conflicts with our intuitive judgments about the circumstances in which the contents of speakers’ assertions would be true or false. I then show that the failure of diagonalism requires us to either abandon a familiar way of thinking about information and rational assertion or hold that the content of an assertion is not always the information it communicates. I suggest that we choose the latter horn of this dilemma — assertoric content is better characterized in terms of the commitments speakers undertake than in terms of the information they communicate

    Dilemmatic Gaslighting

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    Existing work on gaslighting ties it constitutively to facts about the intentions or prejudices of the gaslighter and/or his victim’s prior experience of epistemic injustice. I argue that the concept of gaslighting is more broadly applicable than has been appreciated: what is distinctive about gaslighting, on my account, is simply that a gaslighter confronts his victim with a certain kind of choice between rejecting his testimony and doubting her own basic epistemic competence in some domain. I thus hold that gaslighting is a purely epistemic phenomenon — not requiring any particular set of intentions or prejudices on the part of the gaslighter — and also that it can occur even in the absence of any prior experience of epistemic injustice. Appreciating the dilemmatic character of gaslighting allows us to understand its connection with a characteristic sort of epistemic harm, makes it easier to apply the concept of gaslighting in practice, and raises the possibility that we might discover its structure and the associated harm in surprising places
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