Patterns in the Chaos - a Study of Performance Variation and Predictability in Public IaaS Clouds

Benchmarking the performance of public cloud providers is a common research topic. Previous research has already extensively evaluated the performance of different cloud platforms for different use cases, and under different constraints and experiment setups. In this paper, we present a principled, large-scale literature review to collect and codify existing research regarding the predictability of performance in public Infrastructure-as-a-Service (IaaS) clouds. We formulate 15 hypotheses relating to the nature of performance variations in IaaS systems, to the factors of influence of performance variations, and how to compare different instance types. In a second step, we conduct extensive real-life experimentation on Amazon EC2 and Google Compute Engine to empirically validate those hypotheses. At the time of our research, performance in EC2 was substantially less predictable than in GCE. Further, we show that hardware heterogeneity is in practice less prevalent than anticipated by earlier research, while multi-tenancy has a dramatic impact on performance and predictability

Einfluss von Stoppelhobel als Alternative zum Grubber auf Beikrautentwicklung und Dinkelertrag

Der modifizierte Schälpflug oder "Stoppelhobel" schützt den Boden durch seine flach wendende Arbeitsweise, unterdrückt Beikräuter durch das ganzflächige Unterschneiden des Bodens, reduziert den Energieverbrauch und ermöglicht höhere Arbeitsgeschwindigkeiten. Im Jahr 2016/17 wurde auf einem Biobauernhof im Waldviertel im nördlichen Niederösterreich ein Praxis-Feldversuch durchgeführt. Zwei Bodenbearbeitungsverfahren vor dem Dinkelanbau - Var. A: 3x Stoppelhobel, Var. B: 2x Grubber / 1x Stoppelhobel - wurden hinsichtlich Bodeneigenschaften, Beikrautdruck und Ertragsmerkmalen untersucht. Es wurden keine signifikanten Unterschiede zwischen dem Dinkel-Kornertrag (Var. A 17,2 dt TM ha-1 / Var. B 18,3 dt TM ha-1), den pflanzenverfügbaren Nährstoffen im Boden, Humusgehalt und der Beikrautdichte festgestellt. Die Versuchsergebnisse bestätigten den Stoppelhobel als Alternative zum Grubber, da die gleichen Ergebnisse mit einer geringeren Arbeitstiefe erzielt werden konnten

Towards vision-based deep reinforcement learning for robotic motion control

This paper introduces a machine learning based system for controlling a robotic manipulator with visual perception only. The capability to autonomously learn robot controllers solely from raw-pixel images and without any prior knowledge of configuration is shown for the first time. We build upon the success of recent deep reinforcement learning and develop a system for learning target reaching with a three-joint robot manipulator using external visual observation. A Deep Q Network (DQN) was demonstrated to perform target reaching after training in simulation. Transferring the network to real hardware and real observation in a naive approach failed, but experiments show that the network works when replacing camera images with synthetic images

ALife in humanoids: Developing a framework to employ artificial life techniques for high-level perception and cognition tasks on humanoid robots

We describe our recent research and advances in building a framework enabling artifical life (ALife) systems on real robotic hardware. Our framework allows our iCub humanoid to build better visual perception, improve its motion capabilities and even provide a sense of proprioception. This paper presents how we can use various techniques, such as, e.g., genetic programming, to build subsystems for these specific areas. Our framework runs in parallel with the hardware system and is updated with new information from the real robot. We plan to use this framework in the future for developing higher cognitive tasks, such as, scene understanding, prediction of action outcomes, and reasoning on our robot

Federating structural models and data:Outcomes from a workshop on archiving integrative structures

Structures of biomolecular systems are increasingly computed by integrative modeling. In this approach, a structural model is constructed by combining information from multiple sources, including varied experimental methods and prior models. In 2019, a Workshop was held as a Biophysical Society Satellite Meeting to assess progress and discuss further requirements for archiving integrative structures. The primary goal of the Workshop was to build consensus for addressing the challenges involved in creating common data standards, building methods for federated data exchange, and developing mechanisms for validating integrative structures. The summary of the Workshop and the recommendations that emerged are presented here

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements