BibSonomy publications for /tag/heterogeneousThu Jan 19 16:06:12 CET 2012Wilhelmshöher Allee 73, 34121 Kassel, GermanydezInformation Exchange and Fusion in Dynamic and Heterogeneous Distributed Environments2010self-adaptive Heterogeneous computing ontology ubiquitous VENUS_VS mobile itegpub adaptation Context awareness, dynamic reconfiguration at runtime and heterogeneity are key characteristics of future distributed systems, particularly in ubiquitous and mobile computing scenarios. The main contributions of this dissertation are theoretical as well as architectural concepts facilitating information exchange and fusion in heterogeneous and dynamic distributed environments. Our main focus is on bridging the heterogeneity issues and, at the same time, considering uncertain, imprecise and unreliable sensor information in information fusion and reasoning approaches. A domain ontology is used to establish a common vocabulary for the exchanged information. We thereby explicitly support different representations for the same kind of information and provide Inter-Representation Operations that convert between them. Special account is taken of the conversion of associated meta-data that express uncertainty and impreciseness. The Unscented Transformation, for example, is applied to propagate Gaussian normal distributions across highly non-linear Inter-Representation Operations. Uncertain sensor information is fused using the Dempster-Shafer Theory of Evidence as it allows explicit modelling of partial and complete ignorance. We also show how to incorporate the Dempster-Shafer Theory of Evidence into probabilistic reasoning schemes such as Hidden Markov Models in order to be able to consider the uncertainty of sensor information when deriving high-level information from low-level data. For all these concepts we provide architectural support as a guideline for developers of innovative information exchange and fusion infrastructures that are particularly targeted at heterogeneous dynamic environments. Two case studies serve as proof of concept. The first case study focuses on heterogeneous autonomous robots that have to spontaneously form a cooperative team in order to achieve a common goal. The second case study is concerned with an approach for user activity recognition which serves as baseline for a context-aware adaptive application. Both case studies demonstrate the viability and strengths of the proposed solution and emphasize that the Dempster-Shafer Theory of Evidence should be preferred to pure probability theory in applications involving non-linear Inter-Representation Operations.Wed Jan 11 13:01:15 CET 2012Working Notes of the LWA 2011 - Learning, Knowledge, AdaptationVisual Analytics of Heterogeneous Data in Life Science Applications20112011 LWA LWA_2011 analytics applications heterogeneous science visual Sat Sep 03 13:18:16 CEST 2011Proceedings of the ECML/PKDD 2011Compact Coding for Hyperplane Classifiers in Heterogeneous Environment20112011 classification classifiers coding compact ecml_pkdd_2011 environment heterogeneous hyperplane prediction Wed Aug 10 21:31:20 CEST 2011New York, NY, USASIGOPS Oper. Syst. Rev.April66--75HASS: A Scheduler for Heterogeneous Multicore Systems432009Heterogeneous OperatingSystem Scheduling Threads Future heterogeneous single-ISA multicore processors will have an edge in potential performance per watt over comparable homogeneous processors. To fully tap into that potential, the OS scheduler needs to be heterogeneity-aware, so it can match jobs to cores according to characteristics of both. We propose a Heterogeneity-Aware Signature-Supported scheduling algorithm that does the matching using per-thread architectural signatures, which are compact summaries of threads' architectural properties collected offline. The resulting algorithm does not rely on dynamic profiling, and is comparatively simple and scalable. We implemented HASS in OpenSolaris, and achieved average workload speedups of up to 13%, matching best static assignment, achievable only by an oracle. We have also implemented a dynamic IPC-driven algorithm proposed earlier that relies on online profiling. We found that the complexity, load imbalance and associated performance degradation resulting from dynamic profiling are significant challenges to using this algorithm successfully. As a result it failed to deliver expected performance gains and to outperform HASS.Wed Aug 10 21:27:52 CEST 2011Beijing, ChinaProceedings of the Workshop on the Interaction between Operating Systems and Computer Architecture, in conjunction with ISCA-35Scheduling on Heterogeneous Multicore Processors Using Architectural Signatures2008OS OperatingSystem Scheduling heterogeneous multicore Wed Apr 27 15:05:39 CEST 2011New York, NY, USACommun. ACMmay67--77The Future of Microprocessors542011Design Hardware Heterogeneous Manycore Multicore Processor Energy efficiency is the new fundamental limiter of processor performance, way beyond numbers of processors.Thu Feb 17 17:41:57 CET 2011Ontology Learning from Text: Methods, Applications and Evaluation12359--73Frontiers in Artificial Intelligence and ApplLearning Taxonomic Relations from Heterogeneous Evidence2004evidence heterogeneous ol_web2.0 taxonomy_learning methods_concepthierarchy We present a novel approach to the automatic acquisition of taxonomic relations. The main difference to earlier approaches is that we do not only consider one single source of evidence, i.e. a specific algorithm or approach, but examine the possibility of learning taxonomic relations by considering various and heterogeneous forms of evidence. In particular, we derive these different evidences by using well-known NLP techniques and resources and combine them via two simple strategies. Our approach shows very promising results compared to other results from the literature. The main aim of the work presented in this paper is (i) to gain insight into the behaviour of different approaches to learn taxonomic relations, (ii) to provide a first step towards combining these different approaches, and (iii) to establish a baseline for further research.Wed Feb 16 10:53:04 CET 2011Los Alamitos, CA, USAIEEE Micro1The IBM Power Edge of NetworkTM processor: A wire-speed System-on-a-Chip with 16 Power(TM) cores / 64 threads and optimized HW acceleration995555Cache Core Crypto Hardware Heterogeneous Network Processor XML Mon Feb 14 16:52:54 CET 2011IEEE Trans. Communication (USA)aprIRIA/Lab., Rocquencourt, France4425--432{OSI} Reference Model-the {ISO} model of architecture for open systems interconnectionCOM-281980architecture computer heterogeneous interconnection model networks of open osi protocols reference standards systems Considering the urgency of the need for standards which would allow constitution of heterogeneous computer networks, iso created a new subcommittee for 'open systems interconnection' (ISO/TC97/SC16) in 1977. The first priority of subcommittee 16 was to develop an architecture for open systems interconnection which could serve as a framework for the definition of standard protocols. In july 1979 the specifications of this architecture, established by SC16, were passed under the name of 'osi reference model' to technical committee 97 'data processing'. This paper presents the model of architecture. Some indications are also given on the initial set of protocols which will likely be developed in this osi reference model.Wed Dec 22 13:56:32 CET 2010Wilhelmshöher Allee 73, 34121 Kassel, GermanydezInformation Exchange and Fusion in Dynamic and Heterogeneous Distributed Environments2010Heterogeneous VENUS_VS adaptation computing itegpub mobile ontology self-adaptive ubiquitous Context awareness, dynamic reconfiguration at runtime and heterogeneity are key characteristics of future distributed systems, particularly in ubiquitous and mobile computing scenarios. The main contributions of this dissertation are theoretical as well as architectural concepts facilitating information exchange and fusion in heterogeneous and dynamic distributed environments. Our main focus is on bridging the heterogeneity issues and, at the same time, considering uncertain, imprecise and unreliable sensor information in information fusion and reasoning approaches. A domain ontology is used to establish a common vocabulary for the exchanged information. We thereby explicitly support different representations for the same kind of information and provide Inter-Representation Operations that convert between them. Special account is taken of the conversion of associated meta-data that express uncertainty and impreciseness. The Unscented Transformation, for example, is applied to propagate Gaussian normal distributions across highly non-linear Inter-Representation Operations. Uncertain sensor information is fused using the Dempster-Shafer Theory of Evidence as it allows explicit modelling of partial and complete ignorance. We also show how to incorporate the Dempster-Shafer Theory of Evidence into probabilistic reasoning schemes such as Hidden Markov Models in order to be able to consider the uncertainty of sensor information when deriving high-level information from low-level data. For all these concepts we provide architectural support as a guideline for developers of innovative information exchange and fusion infrastructures that are particularly targeted at heterogeneous dynamic environments. Two case studies serve as proof of concept. The first case study focuses on heterogeneous autonomous robots that have to spontaneously form a cooperative team in order to achieve a common goal. The second case study is concerned with an approach for user activity recognition which serves as baseline for a context-aware adaptive application. Both case studies demonstrate the viability and strengths of the proposed solution and emphasize that the Dempster-Shafer Theory of Evidence should be preferred to pure probability theory in applications involving non-linear Inter-Representation Operations.Wed Oct 27 17:11:48 CEST 2010New York, NY, USAOOPSLA '10: Proceedings of the ACM international conference on Object oriented programming systems languages and applications205--222Hera-JVM: a runtime system for heterogeneous multi-core architectures2010Cell Hera Heterogeneous JVM ManyCore MultiCore Heterogeneous multi-core processors, such as the IBM Cell processor, can deliver high performance. However, these processors are notoriously difficult to program: different cores support different instruction set architectures, and the processor as a whole does not provide coherence between the different cores' local memories. We present Hera-JVM, an implementation of the Java Virtual Machine which operates over the Cell processor, thereby making this platforms more readily accessible to mainstream developers. Hera-JVM supports the full Java language; threads from an unmodified Java application can be simultaneously executed on both the main PowerPC-based core and on the additional SPE accelerator cores. Migration of threads between these cores is transparent from the point of view of the application, requiring no modification to Java source code or bytecode. Hera-JVM supports the existing Java Memory Model, even though the underlying hardware does not provide cache coherence between the different core types.Tue Jul 27 14:16:41 CEST 2010Los Alamitos, CA, USAComputer733-38Amdahl's Law in the Multicore Era412008Design Heterogeneous Homogeneous ManyCore Me:ToRead MultiCore PhD Processor Space Tue Jun 22 19:38:37 CEST 2010Aerosol Science and TechnologyJan2141--151Organic Aerosol Speciation: Intercomparison of Thermal Desorption Aerosol GC/MS (TAG) and Filter-Based Techniques442010Apportionment, Emissions, Factorization, Heterogeneous Instrument, Laboratory Makers, Mass, Matrix Measurements Molecular Oxidation, Particles, Positive Source Tracers, We compared measurements of organic molecular markers made using a novel Thermal Desorption Aerosol Gas Chromatograph/Mass Spectrometer (TAG) with two offline filter-based methods: solvent extraction GC/MS (SE-GC/MS) and thermal desorption GC/MS (TD-GC/MS). TAG is designed for automated, high time-resolved measurements of organic aerosol speciation. Laboratory and field measurements were performed to compare TAG and filter performance for n-alkanes, n-alkanoic acids, cholesterol, PAHs, and hopanes. Laboratory measurements of model organic aerosol mixtures of known composition were made in the Carnegie Mellon University smog chamber, and field measurements were made in downtown Pittsburgh. There was excellent agreement between techniques for hopanes and several PAHs, which are important markers for motor vehicle emissions. Agreement was also strong for moderately polar and nonpolar species in the high-concentration smog chamber experiments. Poorer agreement between filter and TAG observations was obtained for n-alkanes in ambient measurements. To further investigate the differences in n-alkane performance between these methods, potential matrix effects and internal consistency within the TAG and filter ambient air data sets were examined. We spiked a subset of ambient TAG samples with deuterated internal standards to examine potential matrix effects. Under typical conditions, there was little bias in recovery of deuterated standards. At extreme ambient aerosol levels, however, there were large biases in relative recovery, indicating matrix effects may be important under those conditions. Similar results were observed in laboratory experiments with engine lubricating oil. Applying internal standards in the TAG system would help track and correct for matrix effects influencing compound recovery.Tue Jun 22 19:38:37 CEST 2010International Journal of Mass SpectrometryJan1-395--103Reactions and mass spectra of complex particles using Aerosol CIMS2582006Acid, Aerosol, Alpha-Pinene, Alpha-Pinene/O-3 Biogenic Chemical Cigarette D-Limonene, Fatty-Acids, Heterogeneous Hydrocarbons, Initiated Ionization, Limonene, Oleic Oleic-Acid, Organic Oxidation, Reaction, Reaction-Kinetics, Secondary Smoke Smoke, Unsaturated Wood Aerosol chemical ionization mass spectrometry (CIMS) is used both on- and off-line for the analysis of complex laboratory-generated and ambient particles. One of the primary advantages of Aerosol CIMS is the low degree of ion fragmentation, making this technique well suited for investigating the reactivity of complex particles. To demonstrate the usefulness of this "soft" ionization, particles generated from meat cooking were reacted with ozone and the composition was monitored as a function of reaction time. Two distinct kinetic regimes were observed with most of the oleic acid in these particles reacting quickly but with 30% appearing to be trapped in the complex mixture. Additionally, detection limits are measured to be sufficiently low (100-200 ng/m(3)) to detect some of the more abundant constituents in ambient particles, including sulfate, which is measured in real-time at 1.2 mu g/m(3). To better characterize complex aerosols from a variety of sources, a novel off-line collection method was also developed in which non-volatile and semi-volatile organics are desorbed from particles and concentrated in a cold U-tube. Desorption from the U-tube followed by analysis with Aerosol CIMS revealed significant amounts of nicotine in cigarette smoke and levoglucosan in oak and pine smoke, suggesting that this may be a useful technique for monitoring particle tracer species. Additionally, secondary organic aerosol formed from the reaction of ozone with R-limonene and volatile organics from orange peel were analyzed off-line showing large molecular weight products (m/z > 300 amu) that may indicate the formation of oligomers. Finally, mass spectra of ambient aerosol collected offline reveal a complex mixture of what appears to be highly processed organics, some of which may contain nitrogen. (c) 2006 Elsevier B.V. All rights reserved.Tue Jun 22 19:38:37 CEST 2010Physical Chemistry Chemical PhysicsJan367931--7942Time-resolved molecular characterization of limonene/ozone aerosol using high-resolution electrospray ionization mass spectrometry112009Aerosol, Alpha-Pinene, Biogenic Chemical-Composition, Gaseous Heterogeneous Hno3, Hydrocarbons Oligomers, Organic Oxidation-Products, Ozonolysis, Particles, Reaction, Secondary Terpene Molecular composition of limonene/O-3 secondary organic aerosol (SOA) was investigated using high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) as a function of reaction time. SOA was generated by ozonation of D-limonene in a reaction chamber and sampled at different time intervals using a cascade impactor. The SOA samples were extracted into acetonitrile and analyzed using a HR-ESI-MS instrument with a resolving power of 100 000 (m/Delta m). The resulting mass spectra provided detailed information about the extent of oxidation inferred from the O : C ratios, double bond equivalency (DBE) factors, and aromaticity index (AI) values in hundreds of identified individual SOA species. The chemical composition of SOA was approximately the same for all size-fractionated samples studied in this experiment (0.05 to 0.5 mu m range). The SOA constituents quickly reached an average O : C ratio of 0.43, which grew to 0.46 after one hour of additional oxidation of particles by the excess ozone. The dominant mechanism of oligomerization, inferred from high resolution ESI-MS data, was reaction between Criegee intermediates and stable first-generation products of limonene ozonolysis. Although the SOA composition was dominated by various oxidized aliphatic compounds, a small fraction of products appeared to contain aromatic rings. SOA generation was also studied in the presence of UV radiation and at elevated relative humidity (RH). The presence of UV radiation had a negligible effect on the SOA composition. The presence of water vapor resulted in a slight redistribution of peak intensities in the mass spectrum likely arising from hydration of certain SOA constituents. The data are consistent with fast production of the first-generation SOA constituents, including oligomers, followed by very slow aging processes that have a relatively small effect on the average molecular composition on the timescale of our experiments.Tue Jun 22 19:38:37 CEST 2010Geophysical Research LettersJanL19803Direct observations of N2O5 reactivity on ambient aerosol particles362009Aerosol, Aerosols, Ammonium, Aqueous Gaseous Heterogeneous Hydrolysis, Impact Mass-Spectrometer, N2O5, Nitrate Phase, Size, Sulfate, N2O5 reactivity has been measured directly for the first time on ambient aerosol particles using an entrained aerosol flow reactor coupled to a custom-built chemical ionization mass spectrometer at two urban locations during summer. The observed N2O5 reactivity is a strong function of both relative humidity ( RH) and particle chemical composition. We show that particulate organic mass loadings, together with ambient relative humidity, play a leading role in determining the reaction rate of N2O5 with particles. Our observed reactivity values are both more variable and, at times, as much as a factor of ten lower than currently implemented large-scale model parameterizations would predict. Such discrepancies have likely consequences for predictions of NOx availability and ozone production, and the sensitivity of these quantities to aerosol particle loadings. Citation: Bertram, T. H., J. A. Thornton, T. P. Riedel, A. M. Middlebrook, R. Bahreini, T. S. Bates, P. K. Quinn, and D. J. Coffman ( 2009), Direct observations of N2O5 reactivity on ambient aerosol particles, Geophys. Res. Lett., 36, L19803, doi:10.1029/2009GL040248.Tue Jun 22 19:38:37 CEST 2010Environmental Science {\&} TechnologyJan238794--8800Effective Rate Constants and Uptake Coefficients for the Reactions of Organic Molecular Markers (n-Alkanes, Hopanes, and Steranes) in Motor Oil and Diesel Primary Organic Aerosols with Hydroxyl Radicals432009Diffusion, Emissions, Heterogeneous Hydrocarbons, Mass, Model Oh, Oxidation, Particle, Phase, Volatility, Hydroxyl radical (OH) uptake by organic aerosols, followed by heterogeneous oxidation, happens nearly at the collision frequency. Oxidation complicates the use of organic molecular markers such as hopanes for source apportionment since receptor models assume markers are stable during transport We report the oxidation kinetics of organic molecular markers (C-25-C-32 n-alkanes, hopanes and steranes) in motor oil and primary organic aerosol emitted from a diesel engine at atmospherically relevant conditions inside a smog chamber. A thermal desorption aerosol gas chromatograph/mass spectrometer (TAG) and Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) were used to measure the changes in molecular comosition and bulk primary organic aerosol. From the measured changes in molecular composition, we calculated effective OH rate constants, effective relative rate constants, and effective uptake coefficients for molecular markers. Oxidation rates varied with marker volatility, with more volatile markers being oxidized at rates much faster than could be explained from heterogeneous oxidation. This rapid oxidation can be explained by significant gas-phase OH oxidation that dominates heterogeneous oxidation, resulting in overall oxidation life times of 1 day or less. Based on our results, neglecting oxidation of molecular markers used for source apportionment could introduce significant error, since many common markers such as norhopane appear to be semivolatile under atmospheric conditions.Tue Jun 22 19:38:37 CEST 2010European Journal of Lipid Science and TechnologyJan11925--935Photoelectron resonance capture ionization mass spectrometry of fatty acids in olive oil1082006Acids, Beams, Capture Chromatographic Controlled Dimensions, Electrospray-Ionization, Fatty Generating Hazelnut Heterogeneous Ionization, Mass Methyl-Esters, Oil, Oleic-Acid, Olive Ozonolysis, Particle Photoelectron Reaction, Reactive Resonance Spectrometry, Techniques, Uptake Vegetable-Oils, Photoelectron resonance capture ionization (PERCI) mass spectrometry has been developed for the direct online analysis of organics, including lipids. Analysis is conducted without the need for sample preparation or chemical derivatization such as methylation, foregoing the use of harmful or toxic chemicals. PERCI is currently being adapted towards the analysis of edible oils. Herein, as a proof of principle of the simplicity and potential utility of this method towards the analysis of edible oils, we present the analysis of the prevalent fatty acids (FA) in Tuscan extra-virgin olive oil along with triolein and linolenic acid (LNA) standards. Ionization of olive oil results in little fragmentation of the prevalent FA, which are measured as their molecular ions, [FA-H](-). The relative concentrations of these FA determined by PERCI were in good agreement with established values. Further utility of PERCI was demonstrated by interrogation of ozonized LNA and olive oil, with 13 of the 18 anticipated products of the ozonolysis of LNA measured as their molecular anions, [M-H](-). Similarly, the PERCI mass spectrum of ozonized olive oil showed all the anticipated ions of the predominant FA, oleic acid, as well as many molecular ions arising from less abundant unsaturated FA.Tue Jun 22 19:38:37 CEST 2010Journal of Geophysical Research-AtmospheresJanD1721275--21285Water content and morphology of sodium chloride aerosol particles1041999Adsorption, Aerosols, Ambient Ammonium-Sulfate, Conditions, Heterogeneous Hno3, Nacl(100) Nacl, Optical-Constants, Reaction, Salt, Sulfuric-Acid Surface Sodium chloride droplets with a median diameter of similar to 0.4 mu m were generated in the laboratory by atomizing an aqueous solution of NaCl under ambient conditions. Infrared extinction spectra of the aerosols under controlled relative humidity (RH) ranging from 15 to 95% were obtained. The extinction spectra contained both scattering and absorption components. In order to obtain an absorption spectrum of the condensed phase H2O associated with the particulates, it was necessary to subtract from the extinction spectra the absorption by H2O vapor and the scattering by the particulates. H2O vapor subtraction was accomplished by a standard technique. A procedure using Mie theory to subtract the scattering component of the extinction spectrum is described. The absorption spectra were used to determine the water content and structure of the particulates. Above similar to 50% RH the aerosols contain aqueous droplets that have not reached equilibrium with the water vapor during the timescale of the experiments (similar to 10 s). There is a sharp transition in water content at around 50% RH which is consistent with other measures of the recrystallization point. Below 50% RH the NaCl particles contain an anomalously large amount of H2O. Several different particle models are considered to explain the H2O content. The model in which the NaCl particles contain pockets of aqueous NaCI solution was found to be most consistent with the spectroscopic observations. The relevance of salt particle morphology and water content to atmospheric aerosol chemistry is discussed.Tue Jun 22 19:38:37 CEST 2010Environmental Science {\&} TechnologyJan216674--6681Structural analysis of oligomeric molecules formed from the reaction products of oleic acid ozonolysis402006Aerosol-Particles, Aerosols, Atmospheric Fatty-Acids, Heterogeneous Mass-Spectrometry, Mechanisms, Organic Ozone, Particles, Reaction, Reaction-Kinetics, Transformation Unsaturated The products arising from the ozonolysis of oleic acid (cis-9-octadecenoic acid) in solution have been studied using negative ion mode electrospray ionization ion trap mass spectrometry. Oleic acid is an important component of atmospheric organic aerosol and is a key model species in predicting aerosol physical and chemical characteristics. The four predicted reaction products, 1-nonanal, nonanoic acid, 9-oxononanoic acid, and azelaic acid, were all observed in roughly equal yields. In addition to these products a large number of higher molecular weight compounds were detected with m/z ratios of up to 1000 Daltons. Tandem mass spectrometry of these larger ions revealed that they represented a complex mixture of linear alpha-acyloxyalkyl hydroperoxides, secondary ozonides, and cyclic diperoxides, formed by reactions between ozonolysis products and Criegee intermediates. These comprise the first directly elucidated structures of large oligomeric species from oleic acid ozonolysis. The degree of oligomerization and hence molecular weight distribution was observed to increase with reaction time in solution.heterogeneousCommunity for tag(s) heterogeneous