the HAVEGE algorithm [1] [2] generates unpredictable random numbers by gathering entropy from internal processor states that are inheritably volatile and impossible to tamper with in a controlled fashion by any applic...
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ISBN:
(纸本)9783642144028
the HAVEGE algorithm [1] [2] generates unpredictable random numbers by gathering entropy from internal processor states that are inheritably volatile and impossible to tamper with in a controlled fashion by any application running on the target system the method used to gather the entropy implies that its main loop will almost monopolize the CPU, the output depends on the operating system and other running applications, as well as some internal mechanisms that stn the processor states to generate an enormous amount of entropy the algorithm was designed withthe idea of single-core CPUs in mind, and no parallelization, however the recent market explosion of multi-core CPUs and the lack of results in increasing the CPU frequency justifies the need to research a multithreaded parallel version of HAVEGE, capable of running the same algorithm loop on each core independently and transparently combine the results in one single output bitstream this paper will demonstrate how such a parallelization is possible and benchmark the output speed of its implementation
Gradual patterns highlight complex order correlations of the form "the more/less X. the more/less Y". Only recently algorithms have appeared to mine efficiently gradual rules. However, due to the complexity ...
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ISBN:
(纸本)9783642120251
Gradual patterns highlight complex order correlations of the form "the more/less X. the more/less Y". Only recently algorithms have appeared to mine efficiently gradual rules. However, due to the complexity of milling gradual rules, these algorithms cannot yet scale on huge real world datasets. hi this paper, we propose to exploit parallelism in order to enhance the performances of the fastest existing one (GRITE). through a detailed experimental study, we show that our parallel algorithm scales very well withthe number of cores available.
In this paper, we claim that Lindenmayer systems (L systems) –more precisely, ET0L systems– can be considered as bio-inspired multi-agent systems that, because of its inherent features, can be usefully applied to th...
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the modeling of the electrical activity of the heart is of great medical and scientific interest, because it provides a way to get a better understanding of the related biophysical phenomena, allows the development of...
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ISBN:
(纸本)9783642143892
the modeling of the electrical activity of the heart is of great medical and scientific interest, because it provides a way to get a better understanding of the related biophysical phenomena, allows the development of new techniques for diagnoses and serves as a platform for drug tests. the cardiac electrophysiology may be simulated by solving a partial differential equation (PDE) coupled to a system of ordinary differential equations (ODEs) describing the electrical behavior of the cell membrane. the numerical solution is, however, computationally demanding because of the fine temporal and spatial sampling required. the demand for real time high definition 3D graphics made the new graphic processing units (GPUs) a highly parallel, multithreaded, many-core processor with tremendous computational horsepower. It makes the use of GPUs a promising alternative to simulate the electrical activity in the heart. the aim of this work is to study the performance of the use of GPUs to solve the equations underlying the electrical activity in a simple cardiac tissue.
Currently existing monitoring services for Grid infrastructures typically collect information from local agents and store it as data sets in global repositories However, for some scenarios querying real-time streams o...
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ISBN:
(纸本)9783642144028
Currently existing monitoring services for Grid infrastructures typically collect information from local agents and store it as data sets in global repositories However, for some scenarios querying real-time streams of monitoring information would be extremely useful In this paper, we evaluate Complex Event processing technologies applied to real-time Grid monitoring. We present a monitoring system which uses CEP technologies to expose monitoring information as queryable data streams We study an example use case - monitoring for job rescheduling We also employ CEP technologies for data reduction, measure the overhead of monitoring, and conclude that teal-tune Grid monitoring is possible without excessive intrusiveness for resources and network
the processing and integration of data for direct assessment (DA) and in-line inspection (ILI) comparisons is critical to making sound integrity-based decisions. While geographic information systems (GIS) are now comm...
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ISBN:
(纸本)9780791844205
the processing and integration of data for direct assessment (DA) and in-line inspection (ILI) comparisons is critical to making sound integrity-based decisions. While geographic information systems (GIS) are now commonly used to model pipeline systems, most day-to-day data processing and integration occurs outside of the GIS, for example in Microsoft Excel(TM). As such, Det Norske Veritas (DNV) developed a data integration tool within Excel(TM) as part of a large scale stress corrosion cracking direct assessment (SCCDA) program for a major pipeline operator. Linear based data provided by the client (e.g., in-line inspections, girth welds, previous excavations, close interval survey, coating, grade and wall thickness, pressure history, road and water crossings, risk assessments, landowner information, etc.) is processed, analyzed and incorporated into the overlay. this tool provides the ability to integrate any linear based data in a graphical representation of the pipeline along continuous and parallel chainage. the overlay allows for identifying similar locations using criteria that are difficult to program into an algorithm and helps engineers to relate complex factors during the decision making process. the overlay also provides the ability to easily extract data relevant to sites selected for assessment along the pipeline. the data integration tool has already found many applications beyond SCCDA since it provides a robust process to integrate and analyze data in parallel with GIS systems. the overlay provides engineers with a method to make decisions without learning complex GIS programs and has the added ability to feed the results back into GIS systems. Such decision making processes and applications include direct assessment programs, cathodic protection enhancements, risk reduction programs, in-line inspection comparisons, and maintenance activities.
How to develop efficient and scalable parallel applications is the key challenge for emerging many-core architectures. We investigate this question by implementing and comparing two parallel H.264 decoders on the Cell...
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Pathway analysis is a powerful tool to study metabolic reaction networks under steady state conditions An Elementary pathway constitutes a minimal set of reactions that can operate at steady state such that each react...
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ISBN:
(纸本)9783642144028
Pathway analysis is a powerful tool to study metabolic reaction networks under steady state conditions An Elementary pathway constitutes a minimal set of reactions that can operate at steady state such that each reaction also proceeds in the appropriate direction In mathematical terms, elementary pathways are the extreme rays of a polyhedral cone-the solution set of homogeneous equality and inequality constraints Enumerating all extreme rays-given the constraints-is difficult especially if the problem is degenerate and high dimensional We present and compare two approaches for the parallel enumeration of extreme rays, both based on the double description method this iterative algorithm has proven efficient especially for degenerate problems, but is difficult to parallelize due to its sequential operation the first approach parallelizes single iteration steps individually in the second approach, we introduce a born/die matrix to store intermediary results, allowing for parallelization across several iteration steps We test our multi-core implementations on a 16 core machine using large examples from combinatories and biology
Extracting complex geometric primitives from 2-D imagery is a long-standing problem that researchers have had to deal with. Various approaches were tried from Hough transform based methods to stochastic algorithms. Ho...
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ISBN:
(纸本)9788086943886
Extracting complex geometric primitives from 2-D imagery is a long-standing problem that researchers have had to deal with. Various approaches were tried from Hough transform based methods to stochastic algorithms. However, serial implementations lack sufficient scalability on high resolution imagery. As sequential computing power cannot pace up withthe increase in size of datasets, researchers are compelled to exploit parallel computational resources and algorithms. In this study, we have merged parallelization capability of GPUs with inherent parallelism on genetic algorithms to cope withthe problem of detecting complex geometric primitives on high resolution imagery. We have implemented ellipse detection on commodity graphics processing unit and showed that our GPU implementation achieve high speed-up relative to state of the art CPU by experimental results.
the proceedings contain 125 papers. the topics discussed include: schedule swapping: a technique for temperature management of distributed embedded systems;user-level network protocol stacks for automotive infotainmen...
ISBN:
(纸本)9780769543222
the proceedings contain 125 papers. the topics discussed include: schedule swapping: a technique for temperature management of distributed embedded systems;user-level network protocol stacks for automotive infotainment systems;replay debugging for multi-threaded embedded software;optimizing runtime reconfiguration decisions;architectural support for reducing parallelprocessing overhead in an embedded multiprocessor;trading conditional execution for more registers on ARM processors;co-simulation of self-adaptive automotive embedded systems;empirical evaluation of content-based pub/sub systems over cloud infrastructure;a reflective service gateway for integrating evolvable sensor-actuator networks with pervasive infrastructure;handling mobility on a QoS-aware service-based framework for mobile systems;trust measurement methods in organic computing systems by direct observation;and rule-based approach for context inconsistency management scheme in ubiquitous computing.
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