Unit 8: major soils

1 online resource (PDF, 8 pages)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

An EDF-based restricted-migration scheduling algorithm for multiprocessor soft real-time systems

There has been much recent interest in the use of the earliest-deadline-first (EDF) algorithm for scheduling soft real-time sporadic task systems on identical multiprocessors. In hard real-time systems, a significant disparity exists between EDF-based schemes and Pfair scheduling: on M processors, the worst-case schedulable utilization for all known EDF variants is approximately M/2, whereas it is M for optimal Pfair algorithms. This is unfortunate because EDF-based algorithms entail lower scheduling and task-migration overheads. However, such a disparity in schedulability can be alleviated by easing the requirement that all deadlines be met, which may be sufficient for soft real-time systems. In particular, in recent work, we have shown that if task migrations are not restricted, then EDF (i.e., global EDF) can ensure bounded tardiness for a sporadic task system with no restrictions on total utilization. Unrestricted task migrations in global EDF may be unappealing for some systems, but if migrations are forbidden entirely, then bounded tardiness cannot be guaranteed. In this paper, we address the issue of striking a balance between task migrations and system utilization by proposing an algorithm called EDF-fm, which is based upon EDF and treads a middle path, by restricting, but not eliminating, task migrations. Specifically, under EDF-fm, the ability to migrate is required for at most M − 1 tasks, and it is sufficient that every such task migrate between two processors and at job boundaries only. EDF-fm, like global EDF, can ensure bounded tardiness to a sporadic task system as long as the available processing capacity is not exceeded, but, unlike global EDF, may require that per-task utilizations be capped. The required cap is quite liberal, hence, EDF-fm should enable a wide range of soft real-time applications to be scheduled with no constraints on total utilization

The Use of Genetics for the Management of a Recovering Population: Temporal Assessment of Migratory Peregrine Falcons in North America

Background: Our ability to monitor populations or species that were once threatened or endangered and in the process of recovery is enhanced by using genetic methods to assess overall population stability and size over time. This can be accomplished most directly by obtaining genetic measures from temporally-spaced samples that reflect the overall stability of the population as given by changes in genetic diversity levels (allelic richness and heterozygosity), degree of population differentiation (FST and DEST), and effective population size (Ne). The primary goal of any recovery effort is to produce a longterm self-sustaining population, and these genetic measures provide a metric by which we can gauge our progress and help make important management decisions. Methodology/Principal Findings: The peregrine falcon in North America (Falco peregrinus tundrius and anatum) was delisted in 1994 and 1999, respectively, and its abundance will be monitored by the species Recovery Team every three years until 2015. Although the United States Fish and Wildlife Service makes a distinction between tundrius and anatum subspecies, our genetic results based on eleven microsatellite loci suggest limited differentiation that can be attributed to an isolation by distance relationship and warrant no delineation of these two subspecies in its northern latitudinal distribution from Alaska through Canada into Greenland. Using temporal samples collected at Padre Island, Texas during migration (seven temporal time periods between 1985–2007), no significant differences in genetic diversity or significant population differentiation in allele frequencies between time periods were observed and were indistinguishable from those obtained from tundrius/anatum breeding locations throughout their northern distribution. Estimates of harmonic mean Ne were variable and imprecise, but always greater than 500 when employing multiple temporal genetic methods. Conclusions/Significance: These results, including those from simulations to assess the power of each method to estimate Ne, suggest a stable or growing population, which is consistent with ongoing field-based monitoring surveys. Therefore, historic and continuing efforts to prevent the extinction of the peregrine falcon in North America appear successful with no indication of recent decline, at least from the northern latitude range-wide perspective. The results also further highlight the importance of archiving samples and their use for continual assessment of population recovery and long-term viability

Current accounts of antimicrobial resistance: stabilisation, individualisation and antibiotics as infrastructure.

Antimicrobial resistance (AMR) is one of the latest issues to galvanise political and financial investment as an emerging global health threat. This paper explores the construction of AMR as a problem, following three lines of analysis. First, an examination of some of the ways in which AMR has become an object for action-through defining, counting and projecting it. Following Lakoff's work on emerging infectious diseases, the paper illustrates that while an 'actuarial' approach to AMR may be challenging to stabilise due to definitional and logistical issues, it has been successfully stabilised through a 'sentinel' approach that emphasises the threat of AMR. Second, the paper draws out a contrast between the way AMR is formulated in terms of a problem of connectedness-a 'One Health' issue-and the frequent solutions to AMR being focused on individual behaviour. The paper suggests that AMR presents an opportunity to take seriously connections, scale and systems but that this effort is undermined by the prevailing tendency to reduce health issues to matters for individual responsibility. Third, the paper takes AMR as a moment of infrastructural inversion (Bowker and Star) when antimicrobials and the work they do are rendered more visible. This leads to the proposal of antibiotics as infrastructure-part of the woodwork that we take for granted, and entangled with our ways of doing life, in particular modern life. These explorations render visible the ways social, economic and political frames continue to define AMR and how it may be acted upon, which opens up possibilities for reconfiguring AMR research and action

An EDF-based scheduling algorithm for multiprocessor soft real-time systems

We consider the use of the earliest-deadline-first (EDF) scheduling algorithm in soft real-time multiproces-sor systems. In hard real-time systems, a significant disparity exists between EDF-based schemes and Pfair scheduling (which is the only known way of optimally scheduling recurrent real-time tasks on multiprocessors): on M processors, all known EDF variants have utilization-based schedulability bounds of approximately M/2, while Pfair algorithms can fully utilize all processors. This is unfortunate because EDF-based algorithms entail lower scheduling and task-migration overheads. In work on hard real-time systems, it has been shown that this disparity in schedulability can be lessened by placing caps on per-task utilizations. In this paper, we show that it can also be lessened by easing the requirement that all deadlines be met. Our main contribution is a new EDF-based scheme that ensures bounded deadline tardiness. In this scheme, per-task utilizations must be capped, but overall utilization need not be restricted. The required cap is quite liberal. Hence, our scheme should enable a wide range of soft real-time applications to be scheduled with no constraints on total utilization. We also propose techniques and heuristics that can be used to reduce tardiness. To the best of our knowledge, this paper is the first to examine multiprocessor EDF scheduling in the context of soft real-time systems

Prospectus, November 2, 1976

BIG WALTER TO PLAY ON 9TH; Illinois mirrors voting patterns; Five star in \u27Twain\u27s Humor; Bus, dinner discussed; PC news in brief: Gun club forming, Turkeys!!!, Faculty Wives\u27 Auction, Hunting Symposium, Attention Bridge players; First of four: Wood sculptor Forbes will be Parkland guest; Letters to the editor: Nite students neglected; Does Parkland want a theatre department; WLS closer to home?; Only midterm echoes remain; Campaign year plea; Music-Makers tickets; Christians not spared from wants; Library cuts Saturday hrs.; Brazilian music: Pianist Prado plays Monday; Art Instit. trip planned; H.S. students to visit; Students to visit museum; Elevator breakdowns: Getting crops in - on time; Electronics mini-course given; Restorative Care workshop today; Local employers: Students work in advertising; PC hosts electronics, electricity educators; Theta Epsilon holds raffle; Speeders beware: Staying a S.T.E,.P. ahead; Performance is hypnotizing; Concert review: Prine: funny songs for scary things; Name needed; Concerts, plays: Krannert lists week\u27s events; Uncle Bob: Cycle gets mixed review; Julliard Quartet at Krannert Nov. 4; Classifieds; Parkland trainer: Blackie: I feel I have helped athletes; Duffers end best season; NADS misfits with potential; Wet track: Adams wins, Cobras 4th in state cross-country meet; 100 entries: Turner wins with 10 of 10; PC hosts volleyball tourney; Fast Freddy\u27s Football Forecast; Lincoln Land tonight: Spikers beat Milliken, now 14-3; Studs \u27took cocky\u27 in loss to Terrors; Games of November 6https://spark.parkland.edu/prospectus_1976/1005/thumbnail.jp