In this paper, we study the problem of stream reasoning and propose a reasoning approach over large amounts of RDF data, which uses graphics processing units (GPU) to improve the performance. First, we show how the problem of stream reasoning can be reduced to a temporal reasoning problem. Then, we

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Fluorine gas is produced industrially by electrolysing hydrogen fluoride in a potassium acid fluoride electrolyte. Fluorine is produced at the carbon anode, while hydrogen is produced at the mild-steel cathode. The fluorine produced has a wide range of uses, most notably in the nuclear industry where it is used to separate 235U and 238U. The South African Nuclear Energy Corporation (Necsa) is a producer of fluorine and requested an investigation into the hydrodynamics of their electrolysis cells as part of a larger national initiative to beneficiate more of South Africa’s large fluorspar deposits. Due to the extremely corrosive and toxic environment inside a typical fluorine electrolysis reactor, the fluid dynamics in the reactor are not understood well enough. The harsh conditions make detailed experimental investigation of the reactors extremely dangerous. The objective of this project is to construct a model that can accurately predict the physical processes involved in the production of fluorine gas. The results of the simulation will be compared to experimental results from tests done on a lab-scale reactor. A good correlation

[1] There is an ongoing debate concerning the distribution of eddy stirring across the Antarctic Circumpolar Current (ACC) and the nature of its controlling processes. The problem is addressed here by estimating the isentropic eddy diffusivity from a collection of hydrographic and altimetric observations, analyzed in a mixing length theoretical framework. It is shown that, typically, is suppressed by an order of magnitude in the upper kilometer of the ACC frontal jets relative to their surroundings, primarily as a result of a local reduction of the mixing length. This observation is reproduced by a quasi‐geostrophic theory of eddy stirring across a broad barotropic jet based on the scaling law derived by Ferrari and Nikurashin (2010). The theory interprets the observed widespread suppression of the mixing length and in the upper layers of frontal jets as the kinematic consequence of eddy propagation relative to the mean flow within jet cores. Deviations from the prevalent regime of mixing suppression in the core of upper‐ocean jets are encountered in a few special sites. Such ‘leaky jet ’ segments appear to be associated with sharp stationary meanders of the mean flow that are generated by the interaction of the ACC with major topographic features. It is contended that the characteristic thermohaline structure of the Southern Ocean, consisting of multiple upper‐ocean thermohaline fronts separated and underlaid by regions of homogenized properties, is largely a result of the widespread suppression of eddy stirring by parallel jets.

Massively multiplayer online games (MMOGs) have become increasingly popular in the recent years, particularly in the form of online role-playing games (MMORPGs). These games support up to several ten thousand players interacting in a virtual game world. The current commercially successful games are client-server based, which is feasible for relatively slow role-playing games. Those have modest bandwidth and latency requirements and are paid for by their customers. For MMOGs with higher realtime requirements and/or a smaller number of customers willing to pay, peer-to-peer networking seems to be a serious alternative. This work analyzes the implementation of both a client-server and a peer-to-peer networking model for the prototype shooter game Planet π4. Initially, a survey introduces recent academic approaches to peer-to-peer systems specifically designed for games. Of those, one system is selected for implementation with Planet π4. Planet π4 is improved in several aspects for the purpose of analyzing various network implementations. First, its architecture is restructured and cleaned to allow for an easy replacement of the networking component. Second, its core is modified to work in a completely event-based mode, supporting the execution of the game in an discrete-event-based network simulator. Third, a simple artificial intelligence player is developed for workload generation in large (and possibly simulated) networks. Furthermore, the newly developed transport protocol CUSP is applied for the network implementation, thus the game is the first real application using CUSP. Finally the game Planet π4 is integrated with the CUSP network simulator, allowing to run the whole game in a simulated network without the need for modification of its core components. Kurzfassung Massen-Mehrspieler-Onlinespiele (Massively multiplayer online games; MMOGs) wurden in den vergangenen Jahren zunehmend populär, insbesondere in Form von Online-Rollenspielen (MMORPGs). In

Abstract: Online learning initia-tives over the past decade have become increasingly comprehen-sive in their selection of courses and sophisticated in their presen-tation, culminating in the recent announcement of a number of consortium and startup activities that promise to make a university education on the internet, free of charge, a real possibility. At this pivotal moment it is appropriate to explore the potential for obtaining comprehensive bioinformatics training with currently existing free video resources. This article pre-sents such a bioinformatics curric-ulum in the form of a virtual course catalog, together with editorial commentary, and an assessment of strengths, weaknesses, and likely future directions for open online learning in this field. Online Learning Comes of Age Online academic ‘‘courseware’ ’ at the university level has now been available to the public for a decade, the earliest concerted effort having originated in 2002 with the Massachusetts Institute of Technology (MIT) and their OpenCour-seWare initiative

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Hiermit versichere ich, die vorliegende Master-Thesis ohne Hilfe Dritter nur mit den angegebenen Quellen und Hilfsmitteln angefertigt zu haben. Alle Stellen, die aus Quellen entnommen wurden, sind als solche kenntlich gemacht. Diese Arbeit hat in gleicher oder ähnlicher Form noch keiner Prüfungsbehörde vorgelegen. Darmstadt, den 17. Mai 2011 (Marcel Lucas) The popularity of Networked Virtual Environments (NVE) increased remarkably in recent years where a plethora of players participate concurrently. Traditional approaches applying the Client/Server pattern swiftly reach their limit in terms of scalability and maintainability. Hence, different approaches are based on Peer-to-Peer (P2P) technology. In particular, fast-paced NVEs stress these systems and most likely cause high overlay maintenance overhead. This Master’s Thesis presents a novel approach to spatial Publish/Subscribe (Pub/Sub) in P2P NVEs. The unstructured P2P system BubbleStorm offers flexible and scalable means and is therefore used as a fundamental base for the developed Pub/Sub system. As the evaluation of the subscription is performed

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Diese Dissertation wurde vom Cuvillier Verlag Göttingen als Buch unter ISBN 978-3-95404-019-3 veröffentlicht (www.cuvillier.de). iContents