scholarly journals A Preemptive Fair Scheduler Policy for Disco MapReduce Framework

2020 ◽  
Author(s):  
Augusto Souza ◽  
Islene Garcia
Keyword(s):  
Open Source ◽  
Short Duration ◽  
Execution Time ◽  
Experimental Production ◽  
Mapreduce Framework ◽  
Small Impact ◽  
Long Duration ◽  
Fair Scheduler ◽  
Mapreduce Paradigm

Disco is an open source MapReduce framework and an alternative to Hadoop. Preemption of tasks is an important feature which helps organizations relying on the MapReduce paradigm to handle their heterogeneous workload usually constituted of research (long duration and with low priority) and production (short duration and with high priority) applications. The missing preemption in Disco affects the production jobs when these two kinds of jobs need to be executed in parallel: the high priority response is delayed because there aren’t resources to compute it. In this paper we describe the implementation of the Preemptive Fair Scheduler Policy which improved largely our experimental production job execution time with a small impact on the research job.

Optimal Energy Storage Portfolio for High and Ultrahigh Carbon-Free and Renewable Power Systems

2021 ◽  
Author(s):  
Omar J Guerra ◽  
Joshua Eichman ◽  
Paul Denholm
Keyword(s):  
Energy Storage ◽  
Power Systems ◽  
Short Duration ◽  
Current Literature ◽  
Optimal Energy ◽  
Renewable Power ◽  
Long Duration ◽  
Storage Technologies

Achieving 100% carbon-free or renewable power systems can be facilitated by the deployment of energy storage technologies at all timescales, including short-duration, long-duration, and seasonal scales; however, most current literature...

Intracellular analysis of trigeminal motoneuron rhythmical activity during stimulation of pontomedullary reticular formation in anesthetized guinea pig

1989 ◽  
Vol 62 (6) ◽  
pp. 1225-1236 ◽  
Author(s):  
S. M. Gurahian ◽  
S. H. Chandler ◽  
L. J. Goldberg
Keyword(s):  
Reticular Formation ◽  
Short Duration ◽  
Field Potential ◽  
Membrane Potentials ◽  
Repetitive Stimulation ◽  
Jaw Movements ◽  
Postsynaptic Potentials ◽  
Duration Stimulus ◽  
Long Duration ◽  
Stimulation Of

1. The effects of repetitive stimulation of the nucleus pontis caudalis and nucleus gigantocellularis (PnC-Gi) of the reticular formation on jaw opener and closer motoneurons were examined. The PnC-Gi was stimulated at 75 Hz at current intensities less than 90 microA. 2. Rhythmically occurring, long-duration, depolarizing membrane potentials in jaw opener motoneurons [excitatory masticatory drive potential (E-MDP)] and long-duration hyperpolarizing membrane potentials [inhibitory masticatory drive potentials (I-MDP)] in jaw closer motoneurons were evoked by 40-Hz repetitive masticatory cortex stimulation. These potentials were completely suppressed by PnC-Gi stimulation. PnC-Gi stimulation also suppressed the short-duration, stimulus-locked depolarizations [excitatory postsynaptic potentials (EPSPs)] in jaw opener motoneurons and short-duration, stimulus-locked hyperpolarizations [inhibitory postsynaptic potentials (IPSPs)] in jaw closer motoneurons, evoked by the same repetitive cortical stimulation. 3. Short pulse train (3 pulses; 500 Hz) stimulation of the masticatory area of the cortex in the absence of rhythmical jaw movements activated the short-latency paucisynaptic corticotrigeminal pathways and evoked short-duration EPSPs and IPSPs in jaw opener and closer motoneurons, respectively. The same PnC-Gi stimulation that completely suppressed rhythmical MDPs, and stimulus-locked PSPs evoked by repetitive stimulation to the masticatory area of the cortex, produced an average reduction in PSP amplitude of 22 and 17% in jaw closer and opener motoneurons, respectively. 4. PnC-Gi stimulation produced minimal effects on the amplitude of the antidromic digastric field potential or on the intracellularly recorded antidromic digastric action potential. Moreover, PnC-Gi stimulation had little effect on jaw opener or jaw closer motoneuron membrane resting potentials in the absence of rhythmical jaw movements (RJMs). PnC-Gi stimulation produced variable effects on conductance pulses elicited in jaw opener and closer motoneurons in the absence of RJMs. 5. These results indicate that the powerful suppression of cortically evoked MDPs in opener and closer motoneurons during PnC-Gi stimulation is most likely not a result of postsynaptic inhibition of trigeminal motoneurons. It is proposed that this suppression is a result of suppression of activity in neurons responsible for masticatory rhythm generation.

scholarly journals Intercropping Short and Long Duration Groundnut (Arachis Hypogaea) Genotypes to Increase Productivity in Environments Prone to End-of-season Droughts

1990 ◽  
Vol 26 (1) ◽  
pp. 63-72 ◽  
Author(s):  
R. C. Nageswara Rao ◽  
K. D. R. Wadia ◽  
J. H. Williams
Keyword(s):  
Arachis Hypogaea ◽  
Short Duration ◽  
Total Biomass ◽  
Season Length ◽  
Water Deficits ◽  
Pod Yield ◽  
Long Duration ◽  
Increase Productivity

SUMMARYThree short duration and one long duration groundnut genotypes, grown either ‘sole’ or as intercrops (in 1:1 ratios of the short duration with the long duration genotypes), were compared in four trials. The intercrop treatments resulted in Land Equivalent Ratios (LERs) of up to 1.25 for pod yield and total biomass despite moderate or severe water deficits at the end of the season. Specific combinations of genotypes were necessary to maximize the LER. The results indicate there is scope for achieving greater productivity in environments with a variable season length by growing late and early genotypes together in an intercrop system.

scholarly journals The training schedule affects the stability, not the magnitude, of the interlimb transfer of learned dynamics

2013 ◽  
Vol 110 (4) ◽  
pp. 984-998 ◽  
Author(s):  
Wilsaan M. Joiner ◽  
Jordan B. Brayanov ◽  
Maurice A. Smith
Keyword(s):  
Short Duration ◽  
Dynamic Environment ◽  
Internal Representation ◽  
Motor Adaptation ◽  
Training Period ◽  
Visually Guided ◽  
Brief Training ◽  
Long Duration ◽  
The Stability ◽  
The Right

The way that a motor adaptation is trained, for example, the manner in which it is introduced or the duration of the training period, can influence its internal representation. However, recent studies examining the gradual versus abrupt introduction of a novel environment have produced conflicting results. Here we examined how these effects determine the effector specificity of motor adaptation during visually guided reaching. After adaptation to velocity-dependent dynamics in the right arm, we estimated the amount of adaptation transferred to the left arm, using error-clamp measurement trials to directly measure changes in learned dynamics. We found that a small but significant amount of generalization to the untrained arm occurs under three different training schedules: a short-duration (15 trials) abrupt presentation, a long-duration (160 trials) abrupt presentation, and a long-duration gradual presentation of the novel dynamic environment. Remarkably, we found essentially no difference between the amount of interlimb generalization when comparing these schedules, with 9–12% transfer of the trained adaptation for all three. However, the duration of training had a pronounced effect on the stability of the interlimb transfer: The transfer elicited from short-duration training decayed rapidly, whereas the transfer from both long-duration training schedules was considerably more persistent (<50% vs. >90% retention over the first 20 trials). These results indicate that the amount of interlimb transfer is similar for gradual versus abrupt training and that interlimb transfer of learned dynamics can occur after even a brief training period but longer training is required for an enduring effect.

The Design, Building and Testing of a Trans-Atlantic Autonomous Sailboat

2015 ◽  
Author(s):  
Satchel B. Douglas ◽  
Nolan R. Conway ◽  
Matthew B. Weklar
Keyword(s):  
Open Source ◽  
Autonomous Vehicles ◽  
Low Cost ◽  
Design Decisions ◽  
Hull Form ◽  
Construction Methods ◽  
Autonomous Surface Vehicles ◽  
Marine Industry ◽  
Long Duration ◽  
Rotating Wing

The use of autonomous vehicles is growing in all industries. However, there are no open-source autonomous surface vehicles available in the marine industry. This paper details the design decisions made, construction methods used, and testing performed on a low-cost, open-source vessel. The vessel was designed to cross the Atlantic Ocean as a means of proving its ability to survive the harsh marine environment. A trimaran hull form and free rotating wing sail were used because the combination provided good righting characteristics, durability and low power consumption. The vessel has been shown to navigate autonomously. Total costs were less than $4000 dollars, excluding labor. Vessels of this type could be used for long duration missions recording data in the open ocean at extremely low cost.

Abstract 591: Can Waveform Characteristics Predict Defibrillation to a Perfusing Rhythm in Short Versus Prolonged Ventricular Fibrillation in a Swine Model?

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Julia H Indik ◽  
Mathias Zuercher ◽  
Karl B Kern ◽  
Ronald W Hilwig ◽  
Robert A Berg
Keyword(s):  
Logistic Regression ◽  
Ventricular Fibrillation ◽  
Short Duration ◽  
Important Determinant ◽  
Swine Model ◽  
Median Frequency ◽  
Chest Compressions ◽  
Long Duration ◽  
Spectral Area ◽  
Minute Duration

It is known that defibrillation of ventricular fibrillation (VF) to a perfusing rhythm (ROSC) is more likely to occur in VF of short duration. It is unknown whether ROSC can be predicted by waveform characteristics in VF of short compared to long duration, apart from a consideration of time alone. VF was untreated for 2 minutes (N=10) or 8 minutes (N=10) in normal swine, after which a defibrillation shock was applied. Chest compressions for two minutes were allowed following but not prior to the shock to achieve a perfusing rhythm (ROSC). VF was analyzed from needle electrodes prior to the shock for amplitude spectral area (AMSA), slope, median frequency and bandwidth. Predictors of ROSC were determined by logistic regression. In VF of 2 minute duration 7 out of 10 swine achieved ROSC compared to 2 out 10 swine with VF of 8 minutes (P=0.025) and time was a significant predictor of ROSC (P=0.033). AMSA was significantly higher at 2 minutes (75 ± 18 mV-Hz) compared to 8 minutes (56±11 mV-Hz, p=0.007) as was slope (3.5±1 vs 2.6±0.5 mV/s, p=0.015). Bandwidth was slightly increased from 2.2±0.6 Hz at 2 minutes to 2.8±0.8 Hz at 8 minutes,(p=0.048), while median frequency was similar. However, no waveform characteristic was a significant predictor of ROSC, with substantial overlap in distributions between animals with and without ROSC. Duration of VF is an important determinant of the likelihood of achieving ROSC with defibrillation. Particularly in VF of short duration, VF waveform characteristics do not add to the predictability of achieving ROSC even though they may demonstrate a significant time evolution.

Contraction duration affects metabolic energy cost and fatigue in skeletal muscle

1998 ◽  
Vol 274 (3) ◽  
pp. E397-E402 ◽  
Author(s):  
Michael C. Hogan ◽  
Erica Ingham ◽  
S. Sadi Kurdak
Keyword(s):  
Skeletal Muscle ◽  
Short Duration ◽  
Energy Cost ◽  
Lactate Concentration ◽  
Metabolic Energy ◽  
Muscle Lactate ◽  
Contracting Muscle ◽  
Contraction Duration ◽  
Long Duration ◽  
The Difference

It has been suggested that during a skeletal muscle contraction the metabolic energy cost at the onset may be greater than the energy cost related to holding steady-state force. The purpose of the present study was to investigate the effect of contraction duration on the metabolic energy cost and fatigue process in fully perfused contracting muscle in situ. Canine gastrocnemius muscle ( n = 6) was isolated, and two contractile periods (3 min of isometric, tetanic contractions with 45-min rest between) were conducted by each muscle in a balanced order design. The two contractile periods had stimulation patterns that resulted in a 1:3 contraction-to-rest ratio, with the difference in the two contractile periods being in the duration of each contraction: short duration 0.25-s stimulation/0.75-s rest vs. long duration 1-s stimulation/3-s rest. These stimulation patterns resulted in the same total time of stimulation, number of stimulation pulses, and total time in contraction for each 3-min period. Muscle O2 uptake, the fall in developed force (fatigue), the O2 cost of developed force, and the estimated total energy cost (ATP utilization) of developed force were significantly greater ( P < 0.05) with contractions of short duration. Lactate efflux from the working muscle and muscle lactate concentration were significantly greater with contractions of short duration, such that the calculated energy derived from glycolysis was three times greater in this condition. These results demonstrate that contraction duration can significantly affect both the aerobic and anaerobic metabolic energy cost and fatigue in contracting muscle. In addition, it is likely that the greater rate of fatigue with more rapid contractions was a result of elevated glycolytic production of lactic acid.

Sound-Localization Performance in the Cat: The Effect of Restraining the Head

2005 ◽  
Vol 93 (3) ◽  
pp. 1223-1234 ◽  
Author(s):  
Daniel J. Tollin ◽  
Luis C. Populin ◽  
Jordan M. Moore ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin
Keyword(s):  
Short Duration ◽  
Saccadic Eye Movements ◽  
Head Movements ◽  
Gaze Shifts ◽  
Localization Accuracy ◽  
Head Restraint ◽  
The Gaze ◽  
Long Duration ◽  
Localization Performance ◽  
Visual Targets

In oculomotor research, there are two common methods by which the apparent location of visual and/or auditory targets are measured, saccadic eye movements with the head restrained and gaze shifts (combined saccades and head movements) with the head unrestrained. Because cats have a small oculomotor range (approximately ±25°), head movements are necessary when orienting to targets at the extremes of or outside this range. Here we tested the hypothesis that the accuracy of localizing auditory and visual targets using more ethologically natural head-unrestrained gaze shifts would be superior to head-restrained eye saccades. The effect of stimulus duration on localization accuracy was also investigated. Three cats were trained using operant conditioning with their heads initially restrained to indicate the location of auditory and visual targets via eye position. Long-duration visual targets were localized accurately with little error, but the locations of short-duration visual and both long- and short-duration auditory targets were markedly underestimated. With the head unrestrained, localization accuracy improved substantially for all stimuli and all durations. While the improvement for long-duration stimuli with the head unrestrained might be expected given that dynamic sensory cues were available during the gaze shifts and the lack of a memory component, surprisingly, the improvement was greatest for the auditory and visual stimuli with the shortest durations, where the stimuli were extinguished prior to the onset of the eye or head movement. The underestimation of auditory targets with the head restrained is explained in terms of the unnatural sensorimotor conditions that likely result during head restraint.

Execution of Long-Duration Multi-Cloud Serverless Functions Using Selective Migration-Based Approach

2020 ◽  
Vol 10 (4) ◽  
pp. 70-97
Author(s):  
Boubaker Soltani ◽  
Afifa Ghenai ◽  
Nadia Zeghib
Keyword(s):  
Short Duration ◽  
Time Limit ◽  
Cloud Platform ◽  
New Paradigm ◽  
Selective Migration ◽  
Loosely Coupled ◽  
Software Deployment ◽  
Long Duration ◽  
Monolithic Approach ◽  
Multi Cloud

A relatively new paradigm for the Cloud-based software deployment is serverless computing. By adopting stateless loosely-coupled functions, the system can obtain many compositions for several purposes. Contrarily to monolithic approach, serverless computing facilitates the evolution of the applications, since the functions may be independently scheduled for reconstitution. Nevertheless, serverless computing dictates that function execution should be within a short duration (five minutes max in most Cloud platforms), after which the function is abruptly ended even if it has not completed its task. This leads to prevent functions requiring longer time from being adopted as Serverless functions. This paper deals with this drawback. It proposes a migration-based approach that promotes the execution of long-duration serverless functions: each running function that reaches the maximum time limit is repeatedly transferred to another cloud platform where it is carried on. At each migration step, the destination cloud is selected regarding the most relevant criteria.

Paraventricular nucleus efferents influence area postrema neurons

1996 ◽  
Vol 270 (2) ◽  
pp. R342-R347 ◽  
Author(s):  
P. M. Smith ◽  
A. V. Ferguson
Keyword(s):  
Short Duration ◽  
Paraventricular Nucleus ◽  
Area Postrema ◽  
Short Latency ◽  
Sprague Dawley ◽  
Potential Significance ◽  
Influence Area ◽  
Long Duration ◽  
Sprague Dawley Rats ◽  
Single Unit Recordings

Extracellular single-unit recordings were obtained from area postrema neurons (AP), and peristimulus histograms were used to determine the effects of paraventricular nucleus (PVN) stimulation on these cells from anesthetized Sprague-Dawley rats. Of 91 AP cells tested, 30.8% responded to PVN stimulation with a short-latency (28.2 +/- 3.3 ms, mean +/- SE), short-duration (49.3 +/- 8.0 ms) excitation, whereas 8.6% were inhibited. In animals that had stimulation sites outside of PVN (non-PVN), only 4 of the 72 AP cells tested (5.6%) were influenced by stimulation. These excitatory effects of PVN stimulation on AP neurons were unaffected by V1-receptor blockade. Of 93 nucleus of the solitary tract (NTS) cells tested, 38.9% responded to PVN stimulation with a short-latency (18.5 +/- 2.4 ms), short-duration (48.8 +/- 9.6 ms) excitation and 22.2% with short-latency (20.75 +/- 4.1 ms), long-duration (204.4 +/- 44.9 ms) inhibitions. In contrast, non-PVN stimulation sites influenced only 19% of NTS neurons tested, all of which were excited. These data demonstrate that activation of PVN neurons elicits excitatory effects on the majority of AP neurons influenced. They further emphasize the potential significance of descending hypothalamic inputs in controlling neuronal activity in this circumventricular organ.

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