WorldWideScience

Sample records for heterogeneous systems impact

  1. Migration and Entrapment of DNAPLs in Heterogeneous Systems: Impact of Waste and Porous Medium Composition

    Energy Technology Data Exchange (ETDEWEB)

    Linda M. Abriola; Avery H. Demond

    2005-01-10

    Dense nonaqueous phase liquids (DNAPLs) pose a significant threat to soil and groundwater at Department of Energy (DOE) sites. Evidence suggests that subsurface wettability variations are present at many of these sites as a result of spatical and temporal variations in aqueous phase chemistry, contaminant aging, mineralogy and organic matter. The presence of such heterogeneity may significantly influence DNAPL migration and entrapment in the saturated zone.

  2. Impact of Land Surface Heterogeneity on Mesoscale Atmospheric Dispersion

    Science.gov (United States)

    Wu, Yuling; Nair, Udaysankar S.; Pielke, Roger A., Sr.; McNider, Richard T.; Christopher, Sundar A.; Anantharaj, Valentine G.

    2009-01-01

    Prior numerical modelling studies show that atmospheric dispersion is sensitive to surface heterogeneities, but past studies do not consider the impact of a realistic distribution of surface heterogeneities on mesoscale atmospheric dispersion. While these focussed on dispersion in the convective boundary layer, the present work also considers dispersion in the nocturnal boundary layer and above. Using a Lagrangian particle dispersion model (LPDM) coupled to the Eulerian Regional Atmospheric Modeling System (RAMS), the impact of topographic, vegetation, and soil moisture heterogeneities on daytime and nighttime atmospheric dispersion is examined. In addition, the sensitivity to the use of Moderate Resolution Imaging Spectroradiometer (MODIS)-derived spatial distributions of vegetation characteristics on atmospheric dispersion is also studied. The impact of vegetation and terrain heterogeneities on atmospheric dispersion is strongly modulated by soil moisture, with the nature of dispersion switching from non-Gaussian to near- Gaussian behaviour for wetter soils (fraction of saturation soil moisture content exceeding 40%). For drier soil moisture conditions, vegetation heterogeneity produces differential heating and the formation of mesoscale circulation patterns that are primarily responsible for non-Gaussian dispersion patterns. Nighttime dispersion is very sensitive to topographic, vegetation, soil moisture, and soil type heterogeneity and is distinctly non-Gaussian for heterogeneous land-surface conditions. Sensitivity studies show that soil type and vegetation heterogeneities have the most dramatic impact on atmospheric dispersion. To provide more skillful dispersion calculations, we recommend the utilisation of satellite-derived vegetation characteristics coupled with data assimilation techniques that constrain soil-vegetation-atmosphere transfer (SVAT) models to generate realistic spatial distributions of surface energy fluxes.

  3. Impacts of fluvial sedimentary heterogeneities on CO2 storage performance

    Science.gov (United States)

    Issautier, B. H.; Viseur, S.; Audigane, P. D.

    2011-12-01

    The heterogeneity of fluvial systems is a key parameter in sedimentology due to the associated impacts on flow performance. In a broader context, fluvial reservoirs are now targets for CO2 storage projects in several sedimentary basins (Paris Basin, North German Basin), thus calling for detailed characterization of reservoir behaviour and capacity. Fluvial reservoirs are a complex layout of highly heterogeneous sedimentary bodies with varying connectivity, depending on the sedimentary history of the system. Reservoir characterization must determine (a) the nature and dimension of the sedimentary bodies, and (b) the connectivity drivers and their evolution throughout the stratigraphic succession. Based on reservoir characterization, geological modelling must account for this information and can be used as a predictive tool for capacity estimation. Flow simulation, however, describes the reservoir behaviour with respect to CO2 injection. The present work focuses on fluvial reservoir performance and was carried out as part of a PhD (2008-2011) dedicated to the impact of sedimentary heterogeneity on CO2 storage performance. The work comprises three steps: ? Reservoir characterization based on detailed fieldwork (sedimentology and sequence stratigraphy) carried out in Central Arabia on the Minjur Sandstone. Twelve depositional environments and their associated heterogeneity are identified, and their layout is presented in a high-resolution sequence stratigraphy analysis. This step is summed up in a 3D geological model. ? Conceptual modelling based on this field data, using gOcad software and an in-house python code. The purpose was to study, for a given architecture, the impact of sedimentary heterogeneity on storage capacity estimations using two models: one with heterogeneity within the sedimentary fill (model A); the other without heterogeneity within the sedimentary fill (model B). A workflow was designed to estimate and compare the storage capacities for a series

  4. Design Technology for Heterogeneous Embedded Systems

    CERN Document Server

    O'Connor, Ian; Piguet, Christian

    2012-01-01

    Designing technology to address the problem of heterogeneous embedded systems, while remaining compatible with standard “More Moore” flows, i.e. capable of handling simultaneously both silicon complexity and system complexity, represents one of the most important challenges facing the semiconductor industry today. While the micro-electronics industry has built its own specific design methods to focus mainly on the management of complexity through the establishment of abstraction levels, the emergence of device heterogeneity requires new approaches enabling the satisfactory design of physically heterogeneous embedded systems for the widespread deployment of such systems. This book, compiled largely from a set of contributions from participants of past editions of the Winter School on Heterogeneous Embedded Systems Design Technology (FETCH), proposes a broad and holistic overview of design techniques used to tackle the various facets of heterogeneity in terms of technology and opportunities at the physical ...

  5. Languages as semiotically heterogenous systems.

    Science.gov (United States)

    Kendon, Adam

    2017-01-01

    The target article is consistent with seeing languages as semiotically heterogenous, using categorial, depictive, and analogic semiotic signs. "Gesture," used in the target article, is shown to be vague and not useful. Kendon's view, criticised in the target, is restated. His proposal for comparative semiotic analyses of how visible bodily action is used in utterance production is reexplained.

  6. Information flow in heterogeneously interacting systems.

    Science.gov (United States)

    Yamaguti, Yutaka; Tsuda, Ichiro; Takahashi, Yoichiro

    2014-02-01

    Motivated by studies on the dynamics of heterogeneously interacting systems in neocortical neural networks, we studied heterogeneously-coupled chaotic systems. We used information-theoretic measures to investigate directions of information flow in heterogeneously coupled Rössler systems, which we selected as a typical chaotic system. In bi-directionally coupled systems, spontaneous and irregular switchings of the phase difference between two chaotic oscillators were observed. The direction of information transmission spontaneously switched in an intermittent manner, depending on the phase difference between the two systems. When two further oscillatory inputs are added to the coupled systems, this system dynamically selects one of the two inputs by synchronizing, selection depending on the internal phase differences between the two systems. These results indicate that the effective direction of information transmission dynamically changes, induced by a switching of phase differences between the two systems.

  7. Classification Of Heterogeneous Operating System

    OpenAIRE

    Sharma, Kamlesh; Prasad, T. V.

    2012-01-01

    Operating system is a bridge between system and user. An operating system (OS) is a software program that manages the hardware and software resources of a computer. The OS performs basic tasks, such as controlling and allocating memory, prioritizing the processing of instructions, controlling input and output devices, facilitating networking, and managing files. It is difficult to present a complete as well as deep account of operating systems developed till date. So, this paper tries to over...

  8. Scheduling Driven Partitioning of Heterogeneous Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    1998-01-01

    In this paper we present an algorithm for system level hardware/software partitioning of heterogeneous embedded systems. The system is represented as an abstract graph which captures both data-flow and the flow of control. Given an architecture consisting of several processors, ASICs and shared b...

  9. Heterogeneous Multicore Processor Technologies for Embedded Systems

    CERN Document Server

    Uchiyama, Kunio; Kasahara, Hironori; Nojiri, Tohru; Noda, Hideyuki; Tawara, Yasuhiro; Idehara, Akio; Iwata, Kenichi; Shikano, Hiroaki

    2012-01-01

    To satisfy the higher requirements of digitally converged embedded systems, this book describes heterogeneous multicore technology that uses various kinds of low-power embedded processor cores on a single chip. With this technology, heterogeneous parallelism can be implemented on an SoC, and greater flexibility and superior performance per watt can then be achieved. This book defines the heterogeneous multicore architecture and explains in detail several embedded processor cores including CPU cores and special-purpose processor cores that achieve highly arithmetic-level parallelism. The authors developed three multicore chips (called RP-1, RP-2, and RP-X) according to the defined architecture with the introduced processor cores. The chip implementations, software environments, and applications running on the chips are also explained in the book. Provides readers an overview and practical discussion of heterogeneous multicore technologies from both a hardware and software point of view; Discusses a new, high-p...

  10. Optimization of Hierarchically Scheduled Heterogeneous Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Traian; Pop, Paul; Eles, Petru

    2005-01-01

    We present an approach to the analysis and optimization of heterogeneous distributed embedded systems. The systems are heterogeneous not only in terms of hardware components, but also in terms of communication protocols and scheduling policies. When several scheduling policies share a resource......, they are organized in a hierarchy. In this paper, we address design problems that are characteristic to such hierarchically scheduled systems: assignment of scheduling policies to tasks, mapping of tasks to hardware components, and the scheduling of the activities. We present algorithms for solving these problems....... Our heuristics are able to find schedulable implementations under limited resources, achieving an efficient utilization of the system. The developed algorithms are evaluated using extensive experiments and a real-life example....

  11. A random walk solution for modeling solute transport with network reactions and multi-rate mass transfer in heterogeneous systems: Impact of biofilms

    Science.gov (United States)

    Henri, Christopher V.; Fernàndez-Garcia, Daniel

    2015-12-01

    The interplay between the spatial variability of the aquifer hydraulic properties, mass transfer due to sub-grid heterogeneity and chemical reactions often complicates reactive transport simulations. It is well documented that hydro-biochemical properties are ubiquitously heterogeneous and that diffusion and slow advection at the sub-grid scale typically leads to the conceptualization of an aquifer as a multi-porosity system. Within this context, chemical reactions taking place in mobile/immobile water regions can be substantially different between each other. This paper presents a particle-based method that can efficiently simulate heterogeneity, network reactions and multi-rate mass transfer. The approach is based on the development of transition probabilities that describe the likelihood that particles belonging to a given species and mobile/immobile domain at a given time will be transformed into another species and mobile/immobile domain afterwards. The joint effect of mass transfer and sequential degradation is shown to be non-trivial. A characteristic rebound of degradation products can be observed. This late rebound of concentrations is not driven by any change in the flow regime (e.g., pumping ceases in the pump-and-treat remediation strategy) but due to the natural interplay between mass transfer and chemical reactions. To illustrate that the method can simultaneously represent mass transfer, spatially varying properties and network reactions without numerical problems, we have simulated the degradation of tetrachloroethylene (PCE) in a three-dimensional fully heterogeneous aquifer subjected to rate-limited mass transfer. Two types of degradation modes were considered to compare the effect of an active biofilm with that of clay pods present in the aquifer. Results of the two scenarios display significantly differences. Biofilms that promote the degradation of compounds in an immobile region are shown to significantly enhance degradation, rapidly producing

  12. Systemic risk and heterogeneous leverage in banking networks

    Science.gov (United States)

    Kuzubaş, Tolga Umut; Saltoğlu, Burak; Sever, Can

    2016-11-01

    This study probes systemic risk implications of leverage heterogeneity in banking networks. We show that the presence of heterogeneous leverages drastically changes the systemic effects of defaults and the nature of the contagion in interbank markets. Using financial leverage data from the US banking system, through simulations, we analyze the systemic significance of different types of borrowers, the evolution of the network, the consequences of interbank market size and the impact of market segmentation. Our study is related to the recent Basel III regulations on systemic risk and the treatment of the Global Systemically Important Banks (GSIBs). We also assess the extent to which the recent capital surcharges on GSIBs may curb financial fragility. We show the effectiveness of surcharge policy for the most-levered banks vis-a-vis uniform capital injection.

  13. Impact of structural heterogeneity in solar absorber layers (Conference Presentation)

    Science.gov (United States)

    Toney, Michael

    2016-09-01

    Impact of structural heterogeneity in solar absorber layers Michael F Toney SLAC National Accelerator Laboratory Structural and morphological heterogeneity is common in thin film and emerging solar cell absorber layers, including organic photovoltaic bulk heterojunctions (OPV BHJs), hybrid organic-inorganic perovskites (HOIP), and Cu2ZnSn(S,Se)4 (CZTSSe), and has a significant impact on the (opto)electronic heterogeneity and hence absorber properties. In this talk I will use X-ray based methods, including scattering and spectroscopies, to characterize and quantify the heterogeneity in OPV BHJs and HOIP absorber layers. The BHJ films are blends of the small molecule X2 and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) where it has been established that there are three distinct region of the films - pure PC71BM, pure X2 and intimately mixed X2:PC71BM. This talk will show how the absolute concentration of the mixed phase can be used to explain the large PC71BM:X2 composition range where good performance is observed [1]. The talk will also show that spin cast CH3NH3PbI3 films consistent of both crystalline and amorphous regions, which can explain previous heterogeneity in the PL imaging [2]. [1] Huang et al., Adv. Energy Mater. 4, 1301886 (2014). [2] deQuilettes et al., Science 348, 683 (2015).

  14. Formal heterogeneous system modeling with SystemC

    DEFF Research Database (Denmark)

    Niaki, Seyed Hosein Attarzadeh; Jakobsen, Mikkel Koefoed; Sulonen, Tero

    2012-01-01

    Electronic System Level (ESL) design of embedded systems proposes raising the abstraction level of the design entry to cope with the increasing complexity of such systems. To exploit the benefits of ESL, design languages should allow specification of models which are a) heterogeneous, to describe......C, targeting heterogeneous embedded system design, based on four models of computation. The library has a formal basis where all elements are well defined and lead in construction of analyzable models. The semantics of communication and computation are implemented by the library, which allows the designer...

  15. Impact of mineralogical heterogeneity on reactive transport modelling

    Science.gov (United States)

    Liu, Min; Shabaninejad, Mehdi; Mostaghimi, Peyman

    2017-07-01

    Impact of mineralogical heterogeneity of rocks in reactive modelling is investigated by applying a pore scale model based on the Lattice Boltzmann and Finite Volume Methods. Mass transport, chemical reaction and solid structure modification are included in the model. A two-dimensional mineral map of a sandstone rock is acquired using the imaging technique of QEMSCAN SEM with Energy-Dispersive X-ray Spectroscopy (EDS). The mineralogical heterogeneity is explored by conducting multi-mineral reaction simulations on images containing various minerals. The results are then compared with the prediction of single mineral dissolution modelling. Dissolution patterns and permeability variations of multi-mineral and single mineral reactions are presented. The errors of single mineral reaction modelling are also estimated. Numerical results show that mineralogical heterogeneity can cause significant errors in permeability prediction, if a uniform mineral distribution is assumed. The errors are smaller in high Péclet regimes than in low Péclet regimes in this sample.

  16. Impact tolerance in mussel thread networks by heterogeneous material distribution

    Science.gov (United States)

    Qin, Zhao; Buehler, Markus J.

    2013-07-01

    The Mytilidae, generally known as marine mussels, are known to attach to most substrates including stone, wood, concrete and iron by using a network of byssus threads. Mussels are subjected to severe mechanical impacts caused by waves. However, how the network of byssus threads keeps the mussel attached in this challenging mechanical environment is puzzling, as the dynamical forces far exceed the measured strength of byssus threads and their attachment to the environment. Here we combine experiment and simulation, and show that the heterogeneous material distribution in byssus threads has a critical role in decreasing the effect of impact loading. We find that a combination of stiff and soft materials at an 80:20 ratio enables mussels to rapidly and effectively dissipate impact energy. Notably, this facilitates a significantly enhanced strength under dynamical loading over 900% that of the strength under static loading.

  17. Impact of correction tables of heterogeneities in radiotherapy planning systems; Impacto das tabelas de correcao de heterogeneidades em sistemas de planejamento radioterapico

    Energy Technology Data Exchange (ETDEWEB)

    Ragonezi, Aline; Santos, Thallis A.; Tokarski, Marcio; Biazotto, Bruna [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

    2016-07-01

    It has been acquired different tomographic images of a phantom with known heterogeneities, varying parameters of acquisition. With these images, it was possible to get Hounsfield unit of regions where the electronic density is known and, with these data, to make inhomogeneity correction's table. These tables showed variations in the response of Hounsfield unit when varying kVp (5,3%) and filters, both physical (12,3%) as image's reconstruction (5,6%).It was evaluated the differences in the calculation of doses using every correction's tables made, observing differences up to 0,5% in the calculated dose. (author)

  18. Integration of Heterogeneous Systems as Multi-Agent Systems

    Directory of Open Access Journals (Sweden)

    Ammar Lahlouhi

    2014-08-01

    Full Text Available Systems integration is a difficult matter particularly when its components are varied. The problem becomes even more difficult when such components are heterogeneous such as humans, robots and software systems. Currently, the humans are regarded as users of artificial systems (robots and software systems. This has several disadvantages such as: (1 incoherence of artificial systems exploitation where humans’ roles are not clear, and (2 vain research of a user’s universal model. In this paper, we adopted a cooperative approach where the system’s components are regarded as being of the same level and they cooperate for the service of the global system. We concretized such approach by considering humans, robots and software systems as autonomous agents assuming roles in an organization. The latter will be implemented as a multi-agent system developed using a multi-agent development methodology.

  19. Spatial and Geochemical Spatial and Geochemical Heterogeneity Impacts on Iron Biomineralization and Uranium Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Scott Fendorf; Shawn Benner; Jim Neiss; Colleen Hansel; Peter Nico; Chris Francis; Phil Jardine

    2004-03-17

    Bioreductive transformations of iron (hydr)oxides are a critically important processes controlling the fate and transport of contaminants in soil and aquifer systems. Heterogeneity arising from both chemical and physical conditions will lead to various biomineralization products of iron oxides and will additionally alter reactions controlling the partitioning of hazardous elements such as uranium. We are presently exploring chemical and mineralogical transformations within physically complex material having a range of pore-size distribution and chemical environments. Here we discuss the impact of calcium on the reactive transport of uranium and the spatial heterogeneity in iron hydroxide mineralization and concomitant uranium reduction along a diffusive flow path.

  20. Behavioral rationality and heterogeneous expectations in complex economic systems

    NARCIS (Netherlands)

    Hommes, C.H.

    2013-01-01

    Recognising that the economy is a complex system with boundedly rational interacting agents, the book presents a theory of behavioral rationality and heterogeneous expectations in complex economic systems and confronts the nonlinear dynamic models with empirical stylized facts and laboratory

  1. On the programmability of heterogeneous massively-parallel computing systems

    OpenAIRE

    Gelado Fernández, Isaac

    2010-01-01

    Heterogeneous parallel computing combines general purpose processors with accelerators to efficiently execute both sequential control-intensive and data-parallel phases of applications. Existing programming models for heterogeneous parallel computing impose added coding complexity when compared to traditional sequential shared-memory programming models for homogeneous systems. This extra code complexity is assumable in supercomputing environments, where programmability is sacrificed in pursui...

  2. Modeling vaccination in a heterogeneous metapopulation system

    Science.gov (United States)

    Lachiany, Menachem

    2016-09-01

    We present here a multicity SIS epidemic model with vaccination. The model describes the dynamics of heterogeneous metapopulations that contain imperfectly vaccinated individuals. The effect of vaccination on heterogeneous multicity models has not been previously studied. We show that under very generic conditions, the epidemic threshold does not depend on the diffusion coefficient of the vaccinated individuals, but it does depend on the diffusion coefficient of the infected population. We then show, using a novel methodology, that the reproduction number is determined by the homogeneous model parameters and by the maximal number of neighbors a city can have, when the diffusion coefficient of the infected population is low. Finally, we present numerical simulations to support the analytical results.

  3. Global specification and validation of embedded systems integrating heterogeneous components

    CERN Document Server

    Nicolescu, G

    2007-01-01

    Offers a deep understanding of concepts and practices behind the composition of heterogeneous componentsIntroduces a systematic approach to build an execution model for systems composed of heterogeneous componentsMixed continuous/discrete and hardware/software systems will be used to illustrate these concepts.Gives a clear vision on the theory and practice of specification and validation of complex modern systemsExamples give the designers solutions applicable in their daily practice.

  4. Increasing Robustness of Multi-homed Systems in Heterogeneous Environment

    Directory of Open Access Journals (Sweden)

    Matej Rohlik

    2014-01-01

    Full Text Available Nowadays, packet error rate in fixed networks can be considered as a negligible value. However, the increasing requirements for transmission speed of mobile devices, heterogeneous technology, and other high frequency sources cause interference growth within the electromagnetic spectrum. This affects the overall reliability and throughput of the network and may cause undesirable operation malfunction of application-level services. Higher speeds can be achieved by advanced modulation techniques, but at the price of lower resistance against the interference. On the other hand, error-correcting codes or higher-level protocols are utilized to correct the delivery failures. We introduce a novel method for increasing robustness of communication for multi-homed systems in heterogeneous environment. Furthermore, we propose a security measure to ensure confidentiality, integrity and availability of the transmitted data without influencing the transmission parameters. Finally, we show positive impact of the proposed method on transmission efficiency and effective throughput, especially in networks with high probability of error occurrence.

  5. Direct optimization of heterogeneous systems in electrical engineering; Optimisation directe de systemes heterogenes en Genie electrique

    Energy Technology Data Exchange (ETDEWEB)

    Fefermann, Y.

    2002-12-15

    Today, a global viewpoint in the design of devices called 'system approach', is imposed by couplings between physical fields and multiple interactions between sub-systems. Indeed, concerning static and electromechanical converters, or control systems, numerous issues of design are more and more mastered when each element is separately conceived. However, as soon as designing an heterogeneous system seen as a 'complex of elements in interaction' is at stake, arises the problem of the global optimization with respect to multiple criteria which characterize the quality of its behavior. The works realized in this thesis concern the multi-criteria optimization of systems by direct methods not related to the analytical calculation of the gradient. These techniques are applied to a typical electrical vehicle. We propose for each of the sub-systems a modeling adapted to the problem. In particular, an original method based on variations by similarity was elaborated for the design procedure of the PMSM machine. The parameters (DC supply voltage, geometrical parameters,...) can be fitted to all the system levels. They optimize performance criteria: minimization of the losses, of the embedded mass,... The methods of optimization used to resolve this non-linear problem are the Nelder and Mead's Simplex and Hooke and Jeeves algorithm. The constraints of the problem are treated by penalties (exact and quadratic) and a simple heuristic is proposed allowing a constraints normalization and a better algorithm convergence. The optimization results enable to underline the couplings between the various sub-systems, a significant point of the analysis. They have also shown the interest of a global approach in the design and the study of electric systems. (author)

  6. A study of the impact of scheduling parameters in heterogeneous computing environments

    Energy Technology Data Exchange (ETDEWEB)

    Powers, Sarah S [ORNL

    2014-01-01

    This paper describes a tool for exploring system scheduler parameter settings in a heterogeneous computing environment. Through the coupling of simulation and optimization techniques, this work investigates optimal scheduling intervals, the impact of job arrival prediction on scheduling, as well as how to best apply fair use policies. The developed simulation framework is quick and modular, enabling decision makers to further explore decisions in real-time regarding scheduling policies or parameter changes.

  7. Impact of cell culture on recombinant monoclonal antibody product heterogeneity.

    Science.gov (United States)

    Liu, Hongcheng; Nowak, Christine; Shao, Mei; Ponniah, Gomathinayagam; Neill, Alyssa

    2016-09-01

    Recombinant monoclonal antibodies are commonly expressed in mammalian cell culture and purified by several steps of filtration and chromatography. The resulting high purity bulk drug substance still contains product variants differing in properties such as charge and size. Posttranslational modifications and degradations occurring during cell culture are the major sources of heterogeneity in bulk drug substance of recombinant monoclonal antibodies. The focus of the current review is the impact of cell culture conditions on the types and levels of various modifications and degradations of recombinant monoclonal antibodies. Understanding the relationship between cell culture and product variants can help to make consistently safe and efficacious products. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1103-1112, 2016. © 2016 American Institute of Chemical Engineers.

  8. Astrophysical Particle Simulations on Heterogeneous CPU-GPU Systems

    OpenAIRE

    Nakasato, Naohito; Ogiya, Go; Miki, Yohei; Mori, Masao; Nomoto, Ken'ichi

    2012-01-01

    A heterogeneous CPU-GPU node is getting popular in HPC clusters. We need to rethink algorithms and optimization techniques for such system depending on the relative performance of CPU vs. GPU. In this paper, we report a performance optimized particle simulation code "OTOO", that is based on the octree method, for heterogenous systems. Main applications of OTOO are astrophysical simulations such as N-body models and the evolution of a violent merger of stars. We propose optimal task split betw...

  9. Scaling of flow and transport behavior in heterogeneous groundwater systems

    Science.gov (United States)

    Scheibe, Timothy; Yabusaki, Steven

    1998-11-01

    Three-dimensional numerical simulations using a detailed synthetic hydraulic conductivity field developed from geological considerations provide insight into the scaling of subsurface flow and transport processes. Flow and advective transport in the highly resolved heterogeneous field were modeled using massively parallel computers, providing a realistic baseline for evaluation of the impacts of parameter scaling. Upscaling of hydraulic conductivity was performed at a variety of scales using a flexible power law averaging technique. A series of tests were performed to determine the effects of varying the scaling exponent on a number of metrics of flow and transport behavior. Flow and transport simulation on high-performance computers and three-dimensional scientific visualization combine to form a powerful tool for gaining insight into the behavior of complex heterogeneous systems. Many quantitative groundwater models utilize upscaled hydraulic conductivity parameters, either implicitly or explicitly. These parameters are designed to reproduce the bulk flow characteristics at the grid or field scale while not requiring detailed quantification of local-scale conductivity variations. An example from applied groundwater modeling is the common practice of calibrating grid-scale model hydraulic conductivity or transmissivity parameters so as to approximate observed hydraulic head and boundary flux values. Such parameterizations, perhaps with a bulk dispersivity imposed, are then sometimes used to predict transport of reactive or non-reactive solutes. However, this work demonstrates that those parameters that lead to the best upscaling for hydraulic conductivity and head do not necessarily correspond to the best upscaling for prediction of a variety of transport behaviors. This result reflects the fact that transport is strongly impacted by the existence and connectedness of extreme-valued hydraulic conductivities, in contrast to bulk flow which depends more strongly on

  10. Robust mechanobiological behavior emerges in heterogeneous myosin systems

    Science.gov (United States)

    Egan, Paul F.; Moore, Jeffrey R.; Ehrlicher, Allen J.; Weitz, David A.; Schunn, Christian; Cagan, Jonathan; LeDuc, Philip

    2017-09-01

    Biological complexity presents challenges for understanding natural phenomenon and engineering new technologies, particularly in systems with molecular heterogeneity. Such complexity is present in myosin motor protein systems, and computational modeling is essential for determining how collective myosin interactions produce emergent system behavior. We develop a computational approach for altering myosin isoform parameters and their collective organization, and support predictions with in vitro experiments of motility assays with α-actinins as molecular force sensors. The computational approach models variations in single myosin molecular structure, system organization, and force stimuli to predict system behavior for filament velocity, energy consumption, and robustness. Robustness is the range of forces where a filament is expected to have continuous velocity and depends on used myosin system energy. Myosin systems are shown to have highly nonlinear behavior across force conditions that may be exploited at a systems level by combining slow and fast myosin isoforms heterogeneously. Results suggest some heterogeneous systems have lower energy use near stall conditions and greater energy consumption when unloaded, therefore promoting robustness. These heterogeneous system capabilities are unique in comparison with homogenous systems and potentially advantageous for high performance bionanotechnologies. Findings open doors at the intersections of mechanics and biology, particularly for understanding and treating myosin-related diseases and developing approaches for motor molecule-based technologies.

  11. Analysis and optimisation of heterogeneous real-time embedded systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2006-01-01

    An increasing number of real-time applications are today implemented using distributed heterogeneous architectures composed of interconnected networks of processors. The systems are heterogeneous, not only in terms of hardware components, but also in terms of communication protocols and scheduling...... policies. Each network has its own communication protocol, each processor in the architecture can have its own scheduling policy, and several scheduling policies can share a processor. In this context, the task of designing such systems is becoming increasingly important and difficult at the same time....... The success of such new design methods depends on the availability of analysis and optimisation techniques. Analysis and optimisation techniques for heterogeneous real-time embedded systems are presented in the paper. The authors address in more detail a particular class of such systems called multi...

  12. Analysis and optimisation of heterogeneous real-time embedded systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2005-01-01

    An increasing number of real-time applications are today implemented using distributed heterogeneous architectures composed of interconnected networks of processors. The systems are heterogeneous, not only in terms of hardware components, but also in terms of communication protocols and scheduling...... policies. Each network has its own communication protocol, each processor in the architecture can have its own scheduling policy, and several scheduling policies can share a processor. In this context, the task of designing such systems is becoming increasingly important and difficult at the same time....... The success of such new design methods depends on the availability of analysis and optimisation techniques. Analysis and optimisation techniques for heterogeneous real-time embedded systems are presented in the paper. The authors address in more detail a particular class of such systems called multi...

  13. Analysis and Optimization of Heterogeneous Real-Time Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2005-01-01

    An increasing number of real-time applications are today implemented using distributed heterogeneous architectures composed of interconnected networks of processors. The systems are heterogeneous not only in terms of hardware components, but also in terms of communication protocols and scheduling...... policies. Each network has its own communication protocol, each processor in the architecture can have its own scheduling policy, and several scheduling policies can share a processor. In this context, the task of designing such systems is becoming increasingly important and difficult at the same time....... The success of such new design methods depends on the availability of analysis and optimization techniques. In this paper, we present analysis and optimization techniques for heterogeneous real-time embedded systems. We address in more detail a particular class of such systems called multi-clusters, composed...

  14. Robust decentralized output regulation for uncertain heterogeneous systems

    NARCIS (Netherlands)

    Persis, Claudio De; Liu, Hui; Cao, Ming

    2012-01-01

    We consider the problem in which N heterogeneous uncertain linear systems aim at tracking a reference signal generated by a given exosystem under the restriction that not all the systems are directly connected to the exosystem. To tackle this problem, the reference signal is reconstructed via local

  15. Heterogeneous information network model for equipment-standard system

    Science.gov (United States)

    Yin, Liang; Shi, Li-Chen; Zhao, Jun-Yan; Du, Song-Yang; Xie, Wen-Bo; Yuan, Fei; Chen, Duan-Bing

    2018-01-01

    Entity information network is used to describe structural relationships between entities. Taking advantage of its extension and heterogeneity, entity information network is more and more widely applied to relationship modeling. Recent years, lots of researches about entity information network modeling have been proposed, while seldom of them concentrate on equipment-standard system with properties of multi-layer, multi-dimension and multi-scale. In order to efficiently deal with some complex issues in equipment-standard system such as standard revising, standard controlling, and production designing, a heterogeneous information network model for equipment-standard system is proposed in this paper. Three types of entities and six types of relationships are considered in the proposed model. Correspondingly, several different similarity-measuring methods are used in the modeling process. The experiments show that the heterogeneous information network model established in this paper can reflect relationships between entities accurately. Meanwhile, the modeling process has a good performance on time consumption.

  16. Implications of heterogeneous impacts of protected areas on deforestation and poverty.

    Science.gov (United States)

    Hanauer, Merlin M; Canavire-Bacarreza, Gustavo

    2015-11-05

    Protected areas are a popular policy instrument in the global fight against loss of biodiversity and ecosystem services. However, the effectiveness of protected areas in preventing deforestation, and their impacts on poverty, are not well understood. Recent studies have found that Bolivia's protected-area system, on average, reduced deforestation and poverty. We implement several non-parametric and semi-parametric econometric estimators to characterize the heterogeneity in Bolivia's protected-area impacts on joint deforestation and poverty outcomes across a number of socioeconomic and biophysical moderators. Like previous studies from Costa Rica and Thailand, we find that Bolivia's protected areas are not associated with poverty traps. Our results also indicate that protection did not have a differential impact on indigenous populations. However, results from new multidimensional non-parametric estimators provide evidence that the biophysical characteristics associated with the greatest avoided deforestation are the characteristics associated with the potential for poverty exacerbation from protection. We demonstrate that these results would not be identified using the methods implemented in previous studies. Thus, this study provides valuable practical information on the impacts of Bolivia's protected areas for conservation practitioners and demonstrates methods that are likely to be valuable to researchers interested in better understanding the heterogeneity in conservation impacts. © 2015 The Author(s).

  17. Implications of heterogeneous impacts of protected areas on deforestation and poverty

    Science.gov (United States)

    Hanauer, Merlin M.; Canavire-Bacarreza, Gustavo

    2015-01-01

    Protected areas are a popular policy instrument in the global fight against loss of biodiversity and ecosystem services. However, the effectiveness of protected areas in preventing deforestation, and their impacts on poverty, are not well understood. Recent studies have found that Bolivia's protected-area system, on average, reduced deforestation and poverty. We implement several non-parametric and semi-parametric econometric estimators to characterize the heterogeneity in Bolivia's protected-area impacts on joint deforestation and poverty outcomes across a number of socioeconomic and biophysical moderators. Like previous studies from Costa Rica and Thailand, we find that Bolivia's protected areas are not associated with poverty traps. Our results also indicate that protection did not have a differential impact on indigenous populations. However, results from new multidimensional non-parametric estimators provide evidence that the biophysical characteristics associated with the greatest avoided deforestation are the characteristics associated with the potential for poverty exacerbation from protection. We demonstrate that these results would not be identified using the methods implemented in previous studies. Thus, this study provides valuable practical information on the impacts of Bolivia's protected areas for conservation practitioners and demonstrates methods that are likely to be valuable to researchers interested in better understanding the heterogeneity in conservation impacts. PMID:26460125

  18. IMPACTS OF SOURCE TERM HETEROGENEITIES ON WATER PATHWAY DOSE.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, T.; GUSKOV, A.; POSKAS, P.; RUPERTI, N.; HANUSIK, V.; ET AL.

    2004-09-15

    specific activities and small physical sizes and for which a solution has to be found in term of long-term disposal. Together with their casing and packaging, they are one form of heterogeneous waste; many other forms of waste with heterogeneous properties exist. They may arise in very small quantities and with very specific characteristics in the case of small producers, or in larger streams with standard characteristics in others. This wide variety of waste induces three main different levels of waste heterogeneity: (1) hot spot (e.g. disused sealed sources); (2) large item inside a package (e.g. metal components); and (3) very large items to be disposed of directly in the disposal unit (e.g. irradiated pipes, vessels). Safety assessments generally assume a certain level of waste homogeneity in most of the existing or proposed disposal facilities. There is a need to evaluate the appropriateness of such an assumption and the influence on the results of safety assessment. This need is especially acute in the case of sealed sources. There are many cases where are storage conditions are poor, or there is improper management leading to a radiological accident, some with significant or detrimental impacts. Disposal in a near surface disposal facility has been used in the past for some disused sealed sources. This option is currently in use for others sealed sources, or is being studied for the rest of them. The regulatory framework differs greatly between countries. In some countries, large quantities of disused sealed sources have been disposed of without any restriction, in others their disposal is forbidden by law. In any case, evaluation of the acceptability of disposal of disused sealed sources in near surface disposal facility is of utmost importance.

  19. Reliable neuronal systems: the importance of heterogeneity.

    Science.gov (United States)

    Lengler, Johannes; Jug, Florian; Steger, Angelika

    2013-01-01

    For every engineer it goes without saying: in order to build a reliable system we need components that consistently behave precisely as they should. It is also well known that neurons, the building blocks of brains, do not satisfy this constraint. Even neurons of the same type come with huge variances in their properties and these properties also vary over time. Synapses, the connections between neurons, are highly unreliable in forwarding signals. In this paper we argue that both these fact add variance to neuronal processes, and that this variance is not a handicap of neural systems, but that instead predictable and reliable functional behavior of neural systems depends crucially on this variability. In particular, we show that higher variance allows a recurrently connected neural population to react more sensitively to incoming signals, and processes them faster and more energy efficient. This, for example, challenges the general assumption that the intrinsic variability of neurons in the brain is a defect that has to be overcome by synaptic plasticity in the process of learning.

  20. Reliable neuronal systems: the importance of heterogeneity.

    Directory of Open Access Journals (Sweden)

    Johannes Lengler

    Full Text Available For every engineer it goes without saying: in order to build a reliable system we need components that consistently behave precisely as they should. It is also well known that neurons, the building blocks of brains, do not satisfy this constraint. Even neurons of the same type come with huge variances in their properties and these properties also vary over time. Synapses, the connections between neurons, are highly unreliable in forwarding signals. In this paper we argue that both these fact add variance to neuronal processes, and that this variance is not a handicap of neural systems, but that instead predictable and reliable functional behavior of neural systems depends crucially on this variability. In particular, we show that higher variance allows a recurrently connected neural population to react more sensitively to incoming signals, and processes them faster and more energy efficient. This, for example, challenges the general assumption that the intrinsic variability of neurons in the brain is a defect that has to be overcome by synaptic plasticity in the process of learning.

  1. Impacts on oil recovery from capillary pressure and capillary heterogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Bognoe, Thomas

    2008-07-01

    The main conclusions drawn from this thesis are; 7 scientific papers are published on a broad variety of subjects, and describes in detail the experiments and research treated in this thesis. Scientific research has been performed, investigating the subjects of capillary pressure and capillary heterogeneities from different angles. This thesis discusses the findings in this study and aims to illustrate the benefits of the results obtained for further development of other experiments, and/or even the industrial benefits in field development. The methods for wettability alteration have developed throughout the work. From producing heterogeneous wettability alterations, the methods have improved to giving both radial and lateral uniform wettability alterations, which also remains unaltered throughout the duration of the experimental work. The alteration of wettability is dependent on initial water saturation, flow rate, aging time and crude oil composition. Capillary pressure and relative permeability curves have been measured for core plugs at different wettabilities using conventional centrifuge methods. The trends observed are mostly consistent with theory. The production mechanisms of strongly and moderately water wet chalk has been investigated. At strongly water wet conditions in fractured chalk; the flow is governed by capillary forces, showing strong impact from the fractures. At moderately water wet conditions, the impact of the fractures are absent, and a dispersed water front is observed during the displacement. The oil recovery is about the same, at the two wettabilities. Fracture crossing mechanisms at the same wettability conditions have been mapped. And the observations are consistent with those of the water floods. During strongly water wet displacement, the fracture crossing is occurring once the inlet core has reached endpoint of spontaneous imbibition. At moderately water wet conditions the fracture crossing is less abrupt, and creation of wetting

  2. Efficient Thread Mapping for Heterogeneous Multicore IoT Systems

    Directory of Open Access Journals (Sweden)

    Thomas Mezmur Birhanu

    2017-01-01

    Full Text Available This paper proposes a thread scheduling mechanism primed for heterogeneously configured multicore systems. Our approach considers CPU utilization for mapping running threads with the appropriate core that can potentially deliver the actual needed capacity. The paper also introduces a mapping algorithm that is able to map threads to cores in an O(N log M time complexity, where N is the number of cores and M is the number of types of cores. In addition to that we also introduced a method of profiling heterogeneous architectures based on the discrepancy between the performances of individual cores. Our heterogeneity aware scheduler was able to speed up processing by 52.62% and save power by 2.22% as compared to the CFS scheduler that is a default in Linux systems.

  3. Distributed heterogeneous inspecting system and its middleware-based solution

    Institute of Scientific and Technical Information of China (English)

    黄理灿; 吴朝晖; 潘云鹤

    2003-01-01

    There are many cases when an organization needs to monitor the data and operations of its super-vised departments, especially those departments which are not owned by this organization and are managed by their own information systems. Distributed Heterogeneous Inspecting System (DHIS) is the system an organization uses to monitor its supervised departments by inspecting their information systems. In DHIS, the inspected systems are generally distributed, heterogeneous, and constructed by different companies. DHIS has three key processes-abstracting core data sets and core operation sets, collecting these sets, and inspecting these collected sets. In this paper, we present the concept and mathematical definition of DHIS, a metadata method for solving the interoperability, a security strategy for data transferring, and a middleware-based solution of DHIS. We also describe an example of the inspecting system at WENZHOU custom.

  4. Impacts of Low-Carbon Innovation and Its Heterogeneous Components on CO2 Emissions

    Directory of Open Access Journals (Sweden)

    Zheming Yan

    2017-04-01

    Full Text Available This paper aims to investigate the impact of low-carbon innovation on CO2 emissions. Using patent statistics, we measured low-carbon innovations for 15 major economies during the period of 1992–2012. Then, we classified low-carbon technology into clean and gray technology according to the patent classification system. Following the empirical Environmental Kuznets Curve (EKC framework, we explored the effects of low-carbon innovation and its components on CO2 emissions. We did not find any evidence of significant influence of low-carbon innovation. Through further estimations, a significantly negative effect of clean innovation was found while the effect of gray innovation is not clear. Heterogeneous impacts within low-carbon technology provide an explanation for the insignificant impact of low-carbon innovation.

  5. Heterogeneous System Architectures from APUs to discrete GPUs

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    We will present the Heterogeneous Systems Architectures that new AMD processors are bringing with the new GCN based GPUs and the new APUs. We will show how together they represent a huge step forward for programming flexibility and performance efficiently for Compute.

  6. Data and Network Science for Noisy Heterogeneous Systems

    Science.gov (United States)

    Rider, Andrew Kent

    2013-01-01

    Data in many growing fields has an underlying network structure that can be taken advantage of. In this dissertation we apply data and network science to problems in the domains of systems biology and healthcare. Data challenges in these fields include noisy, heterogeneous data, and a lack of ground truth. The primary thesis of this work is that…

  7. The Impact of Epithelial-Stromal Interactions on Human Breast Tumor Heterogeneity

    Science.gov (United States)

    2015-10-01

    AWARD NUMBER: W81XWH-13-1-0357 TITLE: The Impact of Epithelial-Stromal Interactions on Human Breast Tumor Heterogeneity PRINCIPAL... Heterogeneity 5b. GRANT NUMBER W81XWH-13-1-0357 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr. Crista Thompson 5d. PROJECT NUMBER 5e. TASK NUMBER E-Mail... Heterogeneity is a key factor underlying the variability in patient response to treatment, especially in Triple-Negative (TN) breast cancer cases. In

  8. Seasonal and spatial heterogeneities in host and vector abundances impact the spatiotemporal spread of bluetongue

    National Research Council Canada - National Science Library

    Charron, Maud V P; Kluiters, Georgette; Langlais, Michel; Seegers, Henri; Baylis, Matthew; Ezanno, Pauline

    2013-01-01

    .... Our objective was to assess, using a modelling approach, how spatiotemporal heterogeneities in abundance and distribution of hosts and vectors impact the occurrence and amplitude of local and regional BT epidemics...

  9. Clinical impact of leukemic blast heterogeneity at diagnosis in cytogenetic intermediate-risk acute myeloid leukemia

    DEFF Research Database (Denmark)

    Hoffmann, Marianne Hutchings; Klausen, Tobias Wirenfeldt; Boegsted, Martin

    2012-01-01

    Individual cellular heterogeneity within the acute myeloid leukemia (AML) bone marrow samples can be observed by multi parametric flow cytometry analysis (MFC) indicating that immunophenotypic screening for leukemic blast subsets may have prognostic impact.......Individual cellular heterogeneity within the acute myeloid leukemia (AML) bone marrow samples can be observed by multi parametric flow cytometry analysis (MFC) indicating that immunophenotypic screening for leukemic blast subsets may have prognostic impact....

  10. Short-term synaptic plasticity and heterogeneity in neural systems

    Science.gov (United States)

    Mejias, J. F.; Kappen, H. J.; Longtin, A.; Torres, J. J.

    2013-01-01

    We review some recent results on neural dynamics and information processing which arise when considering several biophysical factors of interest, in particular, short-term synaptic plasticity and neural heterogeneity. The inclusion of short-term synaptic plasticity leads to enhanced long-term memory capacities, a higher robustness of memory to noise, and irregularity in the duration of the so-called up cortical states. On the other hand, considering some level of neural heterogeneity in neuron models allows neural systems to optimize information transmission in rate coding and temporal coding, two strategies commonly used by neurons to codify information in many brain areas. In all these studies, analytical approximations can be made to explain the underlying dynamics of these neural systems.

  11. 3D stacked chips from emerging processes to heterogeneous systems

    CERN Document Server

    Fettweis, Gerhard

    2016-01-01

    This book explains for readers how 3D chip stacks promise to increase the level of on-chip integration, and to design new heterogeneous semiconductor devices that combine chips of different integration technologies (incl. sensors) in a single package of the smallest possible size.  The authors focus on heterogeneous 3D integration, addressing some of the most important challenges in this emerging technology, including contactless, optics-based, and carbon-nanotube-based 3D integration, as well as signal-integrity and thermal management issues in copper-based 3D integration. Coverage also includes the 3D heterogeneous integration of power sources, photonic devices, and non-volatile memories based on new materials systems.   •Provides single-source reference to the latest research in 3D optoelectronic integration: process, devices, and systems; •Explains the use of wireless 3D integration to improve 3D IC reliability and yield; •Describes techniques for monitoring and mitigating thermal behavior in 3D I...

  12. Non-Aqueous Biocatalysis in Heterogeneous Solvent Systems

    Directory of Open Access Journals (Sweden)

    Tej Bhatnagar

    2004-01-01

    Full Text Available Biocatalysis has become a useful alternative to chemical transformations for the production of a range of compounds with applications in the food, feed, chemical and pharmaceutical industries. However, it is not necessarily an easy task to obtain the desired levels of performance in terms of rate, yield and selectivity of the reaction. One strategy for optimizing biocatalyst performance is to use non-conventional media, such as non-aqueous heterogeneous systems. In this article, we highlight some of the current trends in biocatalysis in such systems, focusing on reverse micelles, supercritical fluids and ionic liquids.

  13. Middleware Based Model of Heterogeneous Systems for SCADA Distributed Applications

    Directory of Open Access Journals (Sweden)

    UNGUREAN, I.

    2010-05-01

    Full Text Available Infrastructure underlying the distributed information systems is heterogeneous and very complex. Middleware allows the development of distributed information systems, without knowing the functioning details of an infrastructure, by its abstracting. An essential issue on designing such systems is represented by choosing the middleware technologies. An architectural model of a SCADA system based on middleware is proposed in this paper. This system is formed of servers that centralize data and clients, which receive information from a server, thus allowing the chart displaying of such information. All these components own a specific functionality and can exchange information, by means of a middleware bus. A middleware bus signifies a software bus, where more middleware technologies can coexist.

  14. Colorectal Cancer Classification and Cell Heterogeneity: A Systems Oncology Approach

    Directory of Open Access Journals (Sweden)

    Moisés Blanco-Calvo

    2015-06-01

    Full Text Available Colorectal cancer is a heterogeneous disease that manifests through diverse clinical scenarios. During many years, our knowledge about the variability of colorectal tumors was limited to the histopathological analysis from which generic classifications associated with different clinical expectations are derived. However, currently we are beginning to understand that under the intense pathological and clinical variability of these tumors there underlies strong genetic and biological heterogeneity. Thus, with the increasing available information of inter-tumor and intra-tumor heterogeneity, the classical pathological approach is being displaced in favor of novel molecular classifications. In the present article, we summarize the most relevant proposals of molecular classifications obtained from the analysis of colorectal tumors using powerful high throughput techniques and devices. We also discuss the role that cancer systems biology may play in the integration and interpretation of the high amount of data generated and the challenges to be addressed in the future development of precision oncology. In addition, we review the current state of implementation of these novel tools in the pathological laboratory and in clinical practice.

  15. Genetic and epigenetic heterogeneity and the impact on cancer relapse.

    Science.gov (United States)

    Hassan, Ciaran; Afshinnekoo, Ebrahim; Li, Sheng; Wu, Shixiu; Mason, Christopher E

    2017-10-01

    Acute myeloid leukemia (AML) is an aggressive hematopoietic malignancy with an exceedingly poor prognosis: a 5-year overall survival rate of 40%-45% in the young and a 5-year survival rate of less than 10% in the elderly (>60 years of age). Although a high percentage of patients enters complete remission after chemotherapeutic intervention, the majority of patients relapse within 3 years. Such stark prognostic outcomes highlight the need for additional clinical research, basic discovery, and molecular delineation of the etiologies and mechanisms behind responses to therapy that lead to relapse. Here, we summarize recent discoveries in tumor heterogeneity at the genetic and epigenetic levels and their independent molecular trajectories and dynamics in response to therapy. These new discoveries may have significant implications for understanding, monitoring, and treating leukemia and other cancers. Copyright © 2017 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

  16. Scaling impacts on environmental controls and spatial heterogeneity of soil organic carbon stocks

    Science.gov (United States)

    Mishra, U.; Riley, W. J.

    2015-07-01

    The spatial heterogeneity of land surfaces affects energy, moisture, and greenhouse gas exchanges with the atmosphere. However, representing the heterogeneity of terrestrial hydrological and biogeochemical processes in Earth system models (ESMs) remains a critical scientific challenge. We report the impact of spatial scaling on environmental controls, spatial structure, and statistical properties of soil organic carbon (SOC) stocks across the US state of Alaska. We used soil profile observations and environmental factors such as topography, climate, land cover types, and surficial geology to predict the SOC stocks at a 50 m spatial scale. These spatially heterogeneous estimates provide a data set with reasonable fidelity to the observations at a sufficiently high resolution to examine the environmental controls on the spatial structure of SOC stocks. We upscaled both the predicted SOC stocks and environmental variables from finer to coarser spatial scales (s = 100, 200, and 500 m and 1, 2, 5, and 10 km) and generated various statistical properties of SOC stock estimates. We found different environmental factors to be statistically significant predictors at different spatial scales. Only elevation, temperature, potential evapotranspiration, and scrub land cover types were significant predictors at all scales. The strengths of control (the median value of geographically weighted regression coefficients) of these four environmental variables on SOC stocks decreased with increasing scale and were accurately represented using mathematical functions (R2 = 0.83-0.97). The spatial structure of SOC stocks across Alaska changed with spatial scale. Although the variance (sill) and unstructured variability (nugget) of the calculated variograms of SOC stocks decreased exponentially with scale, the correlation length (range) remained relatively constant across scale. The variance of predicted SOC stocks decreased with spatial scale over the range of 50 m to ~ 500 m, and remained

  17. Micro-physics of aircraft-generated aerosols and their potential impact on heterogeneous plume chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kaercher, B.; Luo, B.P. [Muenchen Univ., Freising (Germany). Lehrstuhl fuer Bioklimatologie und Immissionsforschung

    1997-12-31

    Answers are attempted to give to open questions concerning physico-chemical processes in near-field aircraft plumes, with emphasis on their potential impact on subsequent heterogeneous chemistry. Research issues concerning the nucleation of aerosols and their interactions among themselves and with exhaust gases are summarized. Microphysical properties of contrail ice particles, formation of liquid ternary mixtures, and nucleation of nitric acid trihydrate particles in contrails are examined and possible implications for heterogeneous plume chemistry are discussed. (author) 19 refs.

  18. Leader-Based Consensus of Heterogeneous Nonlinear Multiagent Systems

    Directory of Open Access Journals (Sweden)

    Tairen Sun

    2014-01-01

    Full Text Available This paper considers the leader-based consensus of heterogeneous multiple agents with nonlinear uncertain systems. Based on the information obtained from the following agents’ neighbors, leader observers are designed by the following agents to estimate the leader’s states and nonlinear dynamics. Then, to achieve leader-based consensus, adaptive distributed controllers are designed for the following agents to track the designed corresponding leader observers. The effectiveness of the leader observers and distributed consensus controllers are illustrated by formal proof and simulation results.

  19. Educational Resources Recommendation System for a heterogeneous Student Group

    Directory of Open Access Journals (Sweden)

    Paula Andrea RODRÍGUEZ MARÍN

    2016-12-01

    Full Text Available In a face-class, where the student group is heterogeneous, it is necessary to select the most appropriate educational resources that support learning for all. In this sense, multi-agent system (MAS can be used to simulate the features of the students in the group, including their learning style, in order to help the professor find the best resources for your class. In this paper, we present MAS to educational resources recommendation for group students, simulating their profiles and selecting resources that best fit. Obtained promising results show that proposed MAS is able to delivered educational resources for a student group.

  20. Heterogeneity and Context in Semantic-Web-Enabled HCLS Systems

    Science.gov (United States)

    Zimmermann, Antoine; Sahay, Ratnesh; Fox, Ronan; Polleres, Axel

    The need for semantics preserving integration of complex data has been widely recognized in the healthcare domain. While standards such as Health Level Seven (HL7) have been developed in this direction, they have mostly been applied in limited, controlled environments, still being used incoherently across countries, organizations, or hospitals. In a more mobile and global society, data and knowledge are going to be commonly exchanged between various systems at Web scale. Specialists in this domain have increasingly argued in favor of using Semantic Web technologies for modeling healthcare data in a well formalized way. This paper provides a reality check in how far current Semantic Web standards can tackle interoperability issues arising in such systems driven by the modeling of concrete use cases on exchanging clinical data and practices. Recognizing the insufficiency of standard OWL to model our scenario, we survey theoretical approaches to extend OWL by modularity and context towards handling heterogeneity in Semantic-Web-enabled health care and life sciences (HCLS) systems. We come to the conclusion that none of these approaches addresses all of our use case heterogeneity aspects in its entirety. We finally sketch paths on how better approaches could be devised by combining several existing techniques.

  1. Interference Mitigation for Coexistence of Heterogeneous Ultra-Wideband Systems

    Directory of Open Access Journals (Sweden)

    Wu Haitao

    2006-01-01

    Full Text Available Two ultra-wideband (UWB specifications, that is, direct-sequence (DS UWB and multiband-orthogonal frequency division multiplexing (MB-OFDM UWB, have been proposed as the candidates of the IEEE 802.15.3a, competing for the standard of high-speed wireless personal area networks (WPAN. Due to the withdrawal of the standardization process, the two heterogeneous UWB technologies will coexist in the future commercial market. In this paper, we investigate the mutual interference of such coexistence scenarios by physical layer Monte Carlo simulations. The results reveal that the coexistence severely degrades the performance of both UWB systems. Moreover, such interference is asymmetric due to the heterogeneity of the two systems. Therefore, we propose the goodput-oriented utility-based transmit power control (GUTPC algorithm for interference mitigation. The feasible condition and the convergence property of GUTPC are investigated, and the choice of the coefficients is discussed for fairness and efficiency. Numerical results demonstrate that GUTPC improves the goodput of the coexisting systems effectively and fairly with saved power.

  2. Impact Management System

    Data.gov (United States)

    US Agency for International Development — IMS (developed w/Iraq mission) is a system for conducting quality portfolio impact analysis, linking projects to strategy through integration of context data. IMS...

  3. How to Represent 100-meter Spatial Heterogeneity in Earth System Models

    Science.gov (United States)

    Chaney, Nathaniel; Shevliakova, Elena; Malyshev, Sergey

    2016-04-01

    Terrestrial ecosystems play a pivotal role in the Earth system; they have a profound impact on the global climate, food and energy production, freshwater resources, and biodiversity. One of the most fascinating yet challenging aspects of characterizing terrestrial ecosystems is their field-scale (~100 m) spatial heterogeneity. It has been observed repeatedly that the water, energy, and biogeochemical cycles at multiple temporal and spatial scales have deep ties to an ecosystem's spatial structure. Current Earth system models largely disregard this important relationship leading to an inadequate representation of ecosystem dynamics. In this presentation, we will show how existing hyperresolution environmental datasets can be harnessed to explicitly represent field-scale spatial heterogeneity in Earth system models. For each macroscale grid cell, these environmental data are clustered according to their field-scale soil and topographic attributes to define unique sub-grid tiles or hydrologic response units (HRUs). The novel Geophysical Fluid Dynamics Laboratory (GFDL) LM3-TiHy-PPA land model is then used to simulate these HRUs and their spatial interactions via the exchange of water, energy, and nutrients along explicit topographic gradients. Using historical simulations over the contiguous United States, we will show how a robust representation of field-scale spatial heterogeneity impacts modeled ecosystem dynamics including the water, energy, and biogeochemical cycles as well as vegetation composition and distribution.

  4. Evaluating the Impact of Database Heterogeneity on Observational Study Results

    Science.gov (United States)

    Madigan, David; Ryan, Patrick B.; Schuemie, Martijn; Stang, Paul E.; Overhage, J. Marc; Hartzema, Abraham G.; Suchard, Marc A.; DuMouchel, William; Berlin, Jesse A.

    2013-01-01

    Clinical studies that use observational databases to evaluate the effects of medical products have become commonplace. Such studies begin by selecting a particular database, a decision that published papers invariably report but do not discuss. Studies of the same issue in different databases, however, can and do generate different results, sometimes with strikingly different clinical implications. In this paper, we systematically study heterogeneity among databases, holding other study methods constant, by exploring relative risk estimates for 53 drug-outcome pairs and 2 widely used study designs (cohort studies and self-controlled case series) across 10 observational databases. When holding the study design constant, our analysis shows that estimated relative risks range from a statistically significant decreased risk to a statistically significant increased risk in 11 of 53 (21%) of drug-outcome pairs that use a cohort design and 19 of 53 (36%) of drug-outcome pairs that use a self-controlled case series design. This exceeds the proportion of pairs that were consistent across databases in both direction and statistical significance, which was 9 of 53 (17%) for cohort studies and 5 of 53 (9%) for self-controlled case series. Our findings show that clinical studies that use observational databases can be sensitive to the choice of database. More attention is needed to consider how the choice of data source may be affecting results. PMID:23648805

  5. Scheduling Heterogeneous Wireless Systems for Efficient Spectrum Access

    Directory of Open Access Journals (Sweden)

    Lichun Bao

    2010-01-01

    Full Text Available The spectrum scarcity problem emerged in recent years, due to unbalanced utilization of RF (radio frequency bands in the current state of wireless spectrum allocations. Spectrum access scheduling addresses challenges arising from spectrum sharing by interleaving the channel access among multiple wireless systems in a TDMA fashion. Different from cognitive radio approaches which are opportunistic and noncollaborative in general, spectrum access scheduling proactively structures and interleaves the channel access pattern of heterogeneous wireless systems, using collaborative designs by implementing a crucial architectural component—the base stations on software defined radios (SDRs. We discuss our system design choices for spectrum sharing from multiple perspectives and then present the mechanisms for spectrum sharing and coexistence of GPRS+WiMAX and GPRS+WiFi as use cases, respectively. Simulations were carried out to prove that spectrum access scheduling is an alternative, feasible, and promising approach to the spectrum scarcity problem.

  6. Nanoscale magnetic stirring bars for heterogeneous catalysis in microscopic systems.

    Science.gov (United States)

    Yang, Shuliang; Cao, Changyan; Sun, Yongbin; Huang, Peipei; Wei, Fangfang; Song, Weiguo

    2015-02-23

    Nanometer-sized magnetic stirring bars containing Pd nanoparticles (denoted as Fe3 O4 -NC-PZS-Pd) for heterogeneous catalysis in microscopic system were prepared through a facile two-step process. In the hydrogenation of styrene, Fe3 O4 -NC-PZS-Pd showed an activity similar to that of the commercial Pd/C catalyst, but much better stability. In microscopic catalytic systems, Fe3 O4 -NC-PZS-Pd can effectively stir the reaction solution within microdrops to accelerate mass transfer, and displays far better catalytic activity than the commercial Pd/C for the hydrogenation of methylene blue in an array of microdroplets. These results suggested that the Fe3 O4 -NC-PZS-Pd could be used as nanoscale stirring bars in nanoreactors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Biodegradable Electronic Systems in 3D, Heterogeneously Integrated Formats.

    Science.gov (United States)

    Chang, Jan-Kai; Chang, Hui-Ping; Guo, Qinglei; Koo, Jahyun; Wu, Chih-I; Rogers, John A

    2018-01-19

    Biodegradable electronic systems represent an emerging class of technology with unique application possibilities, from temporary biomedical implants to "green" consumer gadgets. This paper introduces materials and processing methods for 3D, heterogeneously integrated devices of this type, with various functional examples in sophisticated forms of silicon-based electronics. Specifically, techniques for performing multilayer assembly by transfer printing and for fabricating layer-to-layer vias and interconnects by lithographic procedures serve as routes to biodegradable, 3D integrated circuits composed of functional building blocks formed using specialized approaches or sourced from commercial semiconductor foundries. Demonstration examples range from logic gates and analog circuits that undergo functional transformation by transience to systems that integrate multilayer resistive sensors for in situ, continuous electrical monitoring of the processes of transience. The results significantly expand the scope of engineering options for biodegradable electronics and other types of transient microsystem technologies. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. IEPLC Framework, Automated Communication in a Heterogeneous Control System Environment

    CERN Document Server

    Locci, F

    2014-01-01

    In CERN accelerators control system several components are essential such as: Programmable Logic Controller (PLC), PCI Extensions for Instrumentation (PXI), and other micro-controller families. Together with their weaknesses and their strength points they typically present custom communication protocols and it is therefore difficult to federate them into the control system using a single communication strategy. Furthermore this dependency to the physical device interfaces and protocols makes most of the code not reusable and the replacement of old technology a difficult problem. The purpose of IEPLC ([1]) is to mitigate the communication issues given by this heterogeneity; it proposes a framework to define communication interfaces in a hardware independent manner. In addition it automatically generates all the resources needed on master side (typically represented by a FEC: Front-End Computer) and slave side (typically represented by the controller) to implement a common and generic Ethernet communication. Th...

  9. Spatial Heterogeneity in Earthquake Fault-Like Systems

    Science.gov (United States)

    Kazemian, J.; Dominguez, R.; Tiampo, K. F.; Klein, W.

    2015-08-01

    The inhomogeneity of materials with different physical properties is responsible for a wide variety of spatial and temporal behavior. In this work, we studied an earthquake fault model based on the Olami-Feder-Christensen and Rundle-Jackson-Brown cellular automata models with particular aspects of spatial heterogeneities and long-range stress interactions. In our model some localized stress accumulators were added into the system by converting a percentage of randomly selected sites into stronger sites that are called `asperity cells'. These asperity cells support much higher failure stresses than the surrounding regular lattice sites but eventually rupture when applied stress reaches their threshold stress. We found that changing the spatial configuration of those stronger sites generally increased the ability of the fault system to generate larger events, but that the total percentage of asperities is important as well. We also observed an increasing number of larger events associated with the total number of asperities in the lattice.

  10. Secure collaborative system in heterogenous wireless sensor networks

    Directory of Open Access Journals (Sweden)

    M. Kasraoui

    2015-04-01

    Full Text Available The IPv6 over Low power Wireless Personal Area Networks (6LoWPANs have turned out to be one of the most emerging field in Wireless Sensor Networks (WSNs which can be integrated with Internet technology. 6LoWPAN network consists of heterogeneous wireless sensors which have high resource-constraints such as bandwidth, processing power, memory, energy, etc. The resource-constraints put forth many challenges to apply the available standard security protocols such as Transport Layer Security (TLS, Internet Protocol Security (IPSec, Internet Key Exchange version 2 (IKEv2, etc., for the interconnection of Heterogeneous Wireless Sensor Networks (HWSNs with Internet. To overcome these situations, the researchers aimed to reinforce and adapt the end-to-end security between Internet and the IP enabled sensor networks. The above mentioned security protocols are not modified at the Internet end point in HWSNs. Hence we are proposing a novel Cooperative Key Exchange System (CKES by using the concept of Chinese Remainder Theorem (CRT. We have used NS2 simulator to implement the proposed concept and also compared with IKEv2.

  11. Full-waveform inversion on heterogeneous HPC systems

    Science.gov (United States)

    Gokhberg, Alexey; Fichtner, Andreas

    2016-04-01

    We present a spectral-element implementation of full seismic waveform inversion for large heterogeneous HPC systems. In this we address the optimal parallelisation configurations of individual simulations, the large I/O requirements of adjoint simulations, and the scheduling of large numbers of forward and adjoint solves, typical for realistic inversions. Using GPU accelerators allows us to achieve a 3.5-4 times performance improvement over the best known homogeneous implementation. We achieve GPU memory throughput varying from 60 to 80% of the peak bandwidth, thus providing good utilisation of hardware resources. We demonstrate the practical applicability of our developments in a real-data application in the western Mediterranean. With the help of GPU accelerators, we are able to model and invert seismic wave propagation in a frequency band that is broader than permitted by the use of CPUs alone, which helps bridging the traditional gap between crustal and mantle tomography.

  12. The Impact of Effect Size Heterogeneity on Meta-Analysis: A Monte Carlo Experiment

    NARCIS (Netherlands)

    Koetse, Mark J.; Florax, Raymond J.G.M.; Groot, de Henri L.F.

    2007-01-01

    In this paper we use Monte Carlo simulation to investigate the impact of effect size heterogeneity on the results of a meta-analysis. Specifically, we address the small sample behaviour of the OLS, the fixed effects regression and the mixed effects meta-estimators under three alternative scenarios

  13. 2D and 3D Multiscale/Multicomponent Modeling of Impact Response of Heterogeneous Energetic Composites

    Science.gov (United States)

    2016-06-01

    Mechanics, The Institute of Mechanics, Chinese Academy of Science, Beijing, China , April 17, 2013;  32. An ignition criterion for heterogeneous...School of Mechanical Engineering & The School of Materials Science and Engineering Georgia Institute of Technology Atlanta, GA 30332-0405 Tel: 404...the relation between mathematical Weibull model and physical process of ignition probability. The effect of impact velocity on each Weibull

  14. Modelling and monitoring of Aquifer Thermal Energy Storage : impacts of soil heterogeneity, thermal interference and bioremediation

    NARCIS (Netherlands)

    Sommer, W.T.

    2015-01-01

    Modelling and monitoring of Aquifer Thermal Energy Storage Impacts of heterogeneity, thermal interference and bioremediation Wijbrand Sommer
    PhD thesis, Wageningen University, Wageningen, NL (2015)
    ISBN 978-94-6257-294-2 Abstract Aquifer thermal energy storage (ATES) is

  15. System for Performing Single Query Searches of Heterogeneous and Dispersed Databases

    Science.gov (United States)

    Maluf, David A. (Inventor); Gurram, Mohana M. (Inventor); Knight, Christopher D. (Inventor); Okimura, Takeshi (Inventor); Tran, Vu Hoang (Inventor); Trinh, Anh Ngoc (Inventor)

    2017-01-01

    The present invention is a distributed computer system of heterogeneous databases joined in an information grid and configured with an Application Programming Interface hardware which includes a search engine component for performing user-structured queries on multiple heterogeneous databases in real time. This invention reduces overhead associated with the impedance mismatch that commonly occurs in heterogeneous database queries.

  16. Incorporating systems dynamics and spatial heterogeneity in integrated assessment of agricultural production systems

    NARCIS (Netherlands)

    Antle, J.M.; Stoorvogel, J.J.

    2006-01-01

    Agricultural systems are complex and dynamic, being made up of interacting bio-physical and human sub-systems. Moreover, agricultural systems are remarkably diverse, both within geographic regions and across regions. Accordingly, this paper focuses on dynamics and heterogeneity in coupled,

  17. Moving Object Detection in Heterogeneous Conditions in Embedded Systems.

    Science.gov (United States)

    Garbo, Alessandro; Quer, Stefano

    2017-07-01

    This paper presents a system for moving object exposure, focusing on pedestrian detection, in external, unfriendly, and heterogeneous environments. The system manipulates and accurately merges information coming from subsequent video frames, making small computational efforts in each single frame. Its main characterizing feature is to combine several well-known movement detection and tracking techniques, and to orchestrate them in a smart way to obtain good results in diversified scenarios. It uses dynamically adjusted thresholds to characterize different regions of interest, and it also adopts techniques to efficiently track movements, and detect and correct false positives. Accuracy and reliability mainly depend on the overall receipt, i.e., on how the software system is designed and implemented, on how the different algorithmic phases communicate information and collaborate with each other, and on how concurrency is organized. The application is specifically designed to work with inexpensive hardware devices, such as off-the-shelf video cameras and small embedded computational units, eventually forming an intelligent urban grid. As a matter of fact, the major contribution of the paper is the presentation of a tool for real-time applications in embedded devices with finite computational (time and memory) resources. We run experimental results on several video sequences (both home-made and publicly available), showing the robustness and accuracy of the overall detection strategy. Comparisons with state-of-the-art strategies show that our application has similar tracking accuracy but much higher frame-per-second rates.

  18. Moving Object Detection in Heterogeneous Conditions in Embedded Systems

    Directory of Open Access Journals (Sweden)

    Alessandro Garbo

    2017-07-01

    Full Text Available This paper presents a system for moving object exposure, focusing on pedestrian detection, in external, unfriendly, and heterogeneous environments. The system manipulates and accurately merges information coming from subsequent video frames, making small computational efforts in each single frame. Its main characterizing feature is to combine several well-known movement detection and tracking techniques, and to orchestrate them in a smart way to obtain good results in diversified scenarios. It uses dynamically adjusted thresholds to characterize different regions of interest, and it also adopts techniques to efficiently track movements, and detect and correct false positives. Accuracy and reliability mainly depend on the overall receipt, i.e., on how the software system is designed and implemented, on how the different algorithmic phases communicate information and collaborate with each other, and on how concurrency is organized. The application is specifically designed to work with inexpensive hardware devices, such as off-the-shelf video cameras and small embedded computational units, eventually forming an intelligent urban grid. As a matter of fact, the major contribution of the paper is the presentation of a tool for real-time applications in embedded devices with finite computational (time and memory resources. We run experimental results on several video sequences (both home-made and publicly available, showing the robustness and accuracy of the overall detection strategy. Comparisons with state-of-the-art strategies show that our application has similar tracking accuracy but much higher frame-per-second rates.

  19. Using Runtime Systems Tools to Implement Efficient Preconditioners for Heterogeneous Architectures

    Directory of Open Access Journals (Sweden)

    Roussel Adrien

    2016-11-01

    Full Text Available Solving large sparse linear systems is a time-consuming step in basin modeling or reservoir simulation. The choice of a robust preconditioner strongly impact the performance of the overall simulation. Heterogeneous architectures based on General Purpose computing on Graphic Processing Units (GPGPU or many-core architectures introduce programming challenges which can be managed in a transparent way for developer with the use of runtime systems. Nevertheless, algorithms need to be well suited for these massively parallel architectures. In this paper, we present preconditioning techniques which enable to take advantage of emerging architectures. We also present our task-based implementations through the use of the HARTS (Heterogeneous Abstract RunTime System runtime system, which aims to manage the recent architectures. We focus on two preconditoners. The first is ILU(0 preconditioner implemented on distributing memory systems. The second one is a multi-level domain decomposition method implemented on a shared-memory system. Obtained results are then presented on corresponding architectures, which open the way to discuss on the scalability of such methods according to numerical performances while keeping in mind that the next step is to propose a massively parallel implementations of these techniques.

  20. Impacts of cloud heterogeneities on cirrus optical properties retrieved from spatial thermal infrared radiometry

    Science.gov (United States)

    Fauchez, T.; Dubuisson, P.; Cornet, C.; Szczap, F.; Garnier, A.; Pelon, J.

    2014-08-01

    This paper presents a study, based on simulations, of the impact of cirrus cloud heterogeneities on the retrieval of cloud parameters (optical thickness and effective diameter) for the Imaging Infrared Radiometer (IIR) on board CALIPSO. Cirrus clouds are generated by the stochastic model 3DCLOUD for two different cloud fields and for several averaged cloud parameters. One is obtained from a cirrus observed on the 25 May 2007 during the airborne campaign CIRCLE-2 and the other is a cirrus uncinus. The radiative transfer is simulated with the code 3DMCPOL. To assess the errors due to cloud heterogeneities, two related retrieval algorithms are used: (i) The split window technique to retrieve the ice crystal effective diameter and (ii) an algorithm similar to the IIR operational algorithm to retrieve the effective emissivity and the effective optical thickness. Differences between input parameters and retrieved parameters are compared as a function of different cloud properties such as the mean optical thickness, the heterogeneity parameter and the effective diameter. The optical thickness heterogeneity for each 1 km × 1 km observation pixel is represented by the optical thickness standard deviation computed using 100 m × 100 m subpixels. We show that optical thickness heterogeneity may have a strong impact on the retrieved parameters, mainly due to the Plane Parallel Approximation (PPA). In particular, for cirrus cloud with ice crystal size of approximately 10 μm, the averaged error on the retrieved effective diameter is about 2.5 μm (~ 25%) and on the effective optical thickness of about -0.20 (~ 12%). Then, these biases decrease with the increase of the ice effective size due to a decrease of the cloud absorption and thus of the PPA bias. Cloud heterogeneity effects are much more higher than other possible sources of error. They become larger than the retrieval incertitude of the IIR algorithm from a standard deviation of the optical thickness, inside the

  1. Impacts of Physical and Chemical Heterogeneity on Cocontaminant Transport in a Sandy Porous Medium

    Science.gov (United States)

    Tompson, Andrew F. B.; Schafer, Annette L.; Smith, Robert W.

    1996-04-01

    A simplified numerical study of the transport of a uranyl-citric acid mixture through a nonuniform and reactive sandy porous medium is presented. The study seeks to identify the more important impacts of medium heterogeneity, as embodied in spatially variable physical and chemical properties, on the migration and dilution rates of a model cocontaminant mixture, as well as on the overall partitioning among the aqueous and solid species formed from complexation and sorption reactions. Solid phase reactions are considered to occur on hydrous-ferric oxide (goethite) coatings on the sand and are controlled by the abundance of the oxide as a function of the specific sand surface area and larger-scale patterns of oxide deposition. The simulations involve calculation of fluid flow and chemical migration within highly resolved, two- and three-dimensional regions with synthetic material properties that approximate observed conditions in a sandy coastal aquifer. Model simulations in this system indicate that (1) the impact of correlation between reactive surface area and hydraulic conductivity, although evident, seems much less significant than the overall abundance and distribution of the reactive area, such as the kind of banded goethite patterns observed in a coastal sand body; (2) strong multicomponent interactions clearly reinforce the need to treat the mixture as a coupled system, as opposed to a series of independently reactive compounds; (3) simplifications can be made in extremely dilute problems that allow retardation effects to become concentration independent; and (4) for nonlinear reaction problems, three-dimensional models will be more appropriate than two-dimensional models to the extent that dispersion in the added dimension accelerates chemical dilution rates.

  2. The middleware architecture supports heterogeneous network systems for module-based personal robot system

    Science.gov (United States)

    Choo, Seongho; Li, Vitaly; Choi, Dong Hee; Jung, Gi Deck; Park, Hong Seong; Ryuh, Youngsun

    2005-12-01

    On developing the personal robot system presently, the internal architecture is every module those occupy separated functions are connected through heterogeneous network system. This module-based architecture supports specialization and division of labor at not only designing but also implementation, as an effect of this architecture, it can reduce developing times and costs for modules. Furthermore, because every module is connected among other modules through network systems, we can get easy integrations and synergy effect to apply advanced mutual functions by co-working some modules. In this architecture, one of the most important technologies is the network middleware that takes charge communications among each modules connected through heterogeneous networks systems. The network middleware acts as the human nerve system inside of personal robot system; it relays, transmits, and translates information appropriately between modules that are similar to human organizations. The network middleware supports various hardware platform, heterogeneous network systems (Ethernet, Wireless LAN, USB, IEEE 1394, CAN, CDMA-SMS, RS-232C). This paper discussed some mechanisms about our network middleware to intercommunication and routing among modules, methods for real-time data communication and fault-tolerant network service. There have designed and implemented a layered network middleware scheme, distributed routing management, network monitoring/notification technology on heterogeneous networks for these goals. The main theme is how to make routing information in our network middleware. Additionally, with this routing information table, we appended some features. Now we are designing, making a new version network middleware (we call 'OO M/W') that can support object-oriented operation, also are updating program sources itself for object-oriented architecture. It is lighter, faster, and can support more operation systems and heterogeneous network systems, but other general

  3. Introduction of Sap ERP System Into a Heterogeneous Academic Community

    Science.gov (United States)

    Mornar, Vedran; Fertalj, Krešimir; Kalpić, Damir

    2010-06-01

    Introduction of a complex ERP system like SAP into a heterogeneous academic environment like the University of Zagreb is far from being a trivial task. The University comprises more than 30 constituents, called faculties or academies, geographically dispersed, with long and specific traditions. Financing according to the lump sum principle, enforced in Croatia as a side effect of the in Europe obligatory and omnipresent Bologna process, requires a unified view on the educational institutions in order to provide a more just and appropriate financing scheme than the current one. After the experience with own development to support educational tasks and student administration, for standard financial and administration tasks SAP has been chosen as the most appropriate platform. The developer was selected after public bidding and the authors' institution was chosen for the pilot project. The authors were playing principal roles in the process of successful deployment and still expect to offer their expertise for implementation in the rest of the University. However, serious risks stemming from lack of motivation by some constituents are present.

  4. Elastic Cloud Computing Architecture and System for Heterogeneous Spatiotemporal Computing

    Science.gov (United States)

    Shi, X.

    2017-10-01

    Spatiotemporal computation implements a variety of different algorithms. When big data are involved, desktop computer or standalone application may not be able to complete the computation task due to limited memory and computing power. Now that a variety of hardware accelerators and computing platforms are available to improve the performance of geocomputation, different algorithms may have different behavior on different computing infrastructure and platforms. Some are perfect for implementation on a cluster of graphics processing units (GPUs), while GPUs may not be useful on certain kind of spatiotemporal computation. This is the same situation in utilizing a cluster of Intel's many-integrated-core (MIC) or Xeon Phi, as well as Hadoop or Spark platforms, to handle big spatiotemporal data. Furthermore, considering the energy efficiency requirement in general computation, Field Programmable Gate Array (FPGA) may be a better solution for better energy efficiency when the performance of computation could be similar or better than GPUs and MICs. It is expected that an elastic cloud computing architecture and system that integrates all of GPUs, MICs, and FPGAs could be developed and deployed to support spatiotemporal computing over heterogeneous data types and computational problems.

  5. Basin-scale heterogeneity in Antarctic precipitation and its impact on surface mass variability

    Directory of Open Access Journals (Sweden)

    J. Fyke

    2017-11-01

    Full Text Available Annually averaged precipitation in the form of snow, the dominant term of the Antarctic Ice Sheet surface mass balance, displays large spatial and temporal variability. Here we present an analysis of spatial patterns of regional Antarctic precipitation variability and their impact on integrated Antarctic surface mass balance variability simulated as part of a preindustrial 1800-year global, fully coupled Community Earth System Model simulation. Correlation and composite analyses based on this output allow for a robust exploration of Antarctic precipitation variability. We identify statistically significant relationships between precipitation patterns across Antarctica that are corroborated by climate reanalyses, regional modeling and ice core records. These patterns are driven by variability in large-scale atmospheric moisture transport, which itself is characterized by decadal- to centennial-scale oscillations around the long-term mean. We suggest that this heterogeneity in Antarctic precipitation variability has a dampening effect on overall Antarctic surface mass balance variability, with implications for regulation of Antarctic-sourced sea level variability, detection of an emergent anthropogenic signal in Antarctic mass trends and identification of Antarctic mass loss accelerations.

  6. H∞ Consensus for Multiagent Systems with Heterogeneous Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Beibei Wang

    2013-01-01

    Full Text Available We apply the linear matrix inequality method to consensus and H∞ consensus problems of the single integrator multiagent system with heterogeneous delays in directed networks. To overcome the difficulty caused by heterogeneous time-varying delays, we rewrite the multiagent system into a partially reduced-order system and an integral system. As a result, a particular Lyapunov function is constructed to derive sufficient conditions for consensus of multiagent systems with fixed (switched topologies. We also apply this method to the H∞ consensus of multiagent systems with disturbances and heterogeneous delays. Numerical examples are given to illustrate the theoretical results.

  7. Genetic heterogeneity of hereditary diseases of nervous system: problems and solutions

    Directory of Open Access Journals (Sweden)

    E. L. Dadali

    2012-01-01

    Full Text Available A hereditary disorders of the nervous system is one of the largest group of human monogenic disorders with high-grade genetic heterogeneity and clinical polymorphism. The main types of genetic heterogeneity and their possible causes are explained by giving typical examples of different nosological forms. The basic problems and feasible solution of medico-genetic counseling and education of high-risk families in case of genetic heterogeneity are discussed.

  8. Quantification of the impact of single and multiple mild stresses on outgrowth heterogeneity of Bacillus cereus spores

    NARCIS (Netherlands)

    Melis, van C.C.J.; Besten, den H.M.W.; Nierop Groot, M.N.; Abee, T.

    2014-01-01

    Outgrowth heterogeneity of bacterial spore populations complicates both prediction and efficient control of spore outgrowth. In this study, the impact of mild preservation stresses on outgrowth of Bacillus cereus ATCC 14579 spores was quantified during the first stages of outgrowth. Heterogeneity in

  9. Genetic Heterogeneity and Clonal Evolution of Tumor Cells and their Impact on Precision Cancer Medicine.

    Science.gov (United States)

    Sabaawy, Hatem E

    2013-11-18

    The efficacy of targeted therapies in leukemias and solid tumors depends upon the accurate detection and sustained targeting of initial and evolving driver mutations and/or aberrations in cancer cells. Tumor clonal evolution of the diverse populations of cancer cells during cancer progression contributes to the longitudinal variations of clonal, morphological, anatomical, and molecular heterogeneity of tumors. Moreover, drug-resistant subclones present at initiation of therapy or emerging as a result of targeted therapies represent major challenges for achieving success of personalized therapies in providing meaningful improvement in cancer survival rates. Here, I briefly portray tumor cell clonal evolution at the cellular and molecular levels, and present the multiple types of genetic heterogeneity in tumors, with a focus on their impact on the implementation of personalized or precision cancer medicine.

  10. Impact of Cattaneo-Christov Heat Flux in Jeffrey Fluid Flow with Homogeneous-Heterogeneous Reactions.

    Directory of Open Access Journals (Sweden)

    Tasawar Hayat

    Full Text Available Two-dimensional stretched flow of Jeffrey fluid in view of Cattaneo-Christov heat flux is addressed. Effects of homogeneous-heterogeneous reactions are also considered. Suitable transformations are used to form ordinary differential equations. Convergent series solutions are computed. Impact of significant parameters on the velocity, temperature, concentration and skin friction coefficient is addressed. Analysis of thermal relaxation is made. The obtained results show that ratio of relaxation to retardation times and Deborah number have inverse relation for velocity profile. Temperature distribution has decreasing behavior for Prandtl number and thermal relaxation time. Also concentration decreases for larger values of strength of homogeneous reaction parameter while it increases for strength of heterogeneous reaction parameter.

  11. Gold colloids: from quasi-homogeneous to heterogeneous catalytic systems.

    Science.gov (United States)

    Prati, Laura; Villa, Alberto

    2014-03-18

    Ruby red colloids of gold have been used for thousands of years and in the past have attracted much attention due to their optical properties. Surface plasmon resonance (SPR) bands are responsible for gold colloid colors and typically appear for nanometer-sized gold nanoparticles (GNPs). These lie in the visible range and their position (and intensity) depends on the size, distribution of size, and shape of GNPs but also on their interaction with other materials (i.e., support). Scientists consider colloids as quasi-homogeneous systems, but because of their intrinsic thermodynamic instability, they need different capping agents providing sufficient stability. The strength and the nature of the interaction between the protective (or functionalizing) molecule and the GNP surface is of utmost importance. It can determine the catalytic properties of the nanoparticles, as they mainly interact with the active sites, thus interfering with reactant. Therefore, the protective layer should contribute to the colloid stability, but at the same time, it should not be irreversibly adsorbed on the active site of the GNP surface providing convenient accessibility to reactant. From a catalytic point of view, the milder the interaction is between the particle surface and the capping agent, the more the activity increases. Unfortunately, the reaction conditions often do not allow the required stability of GNPs, which constitutes a fundamental prerequisite for stable catalytic activity. Anchoring GNPs on suitable supports can circumvent the problem, and this technique is now considered a valuable alternative to classical methods to produce highly dispersed gold catalysts. In this Account, we describe the advantages in using this technique to produce gold heterogeneous catalysts of high metal dispersion on a large variety of supports with the possibility of tuning to a large extent the size and (even partially) the shape of GNPs. We also review our recent progress on the sol

  12. Optimization of large-scale heterogeneous system-of-systems models.

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, Ojas; Watson, Jean-Paul; Phillips, Cynthia Ann; Siirola, John; Swiler, Laura Painton; Hough, Patricia Diane (Sandia National Laboratories, Livermore, CA); Lee, Herbert K. H. (University of California, Santa Cruz, Santa Cruz, CA); Hart, William Eugene; Gray, Genetha Anne (Sandia National Laboratories, Livermore, CA); Woodruff, David L. (University of California, Davis, Davis, CA)

    2012-01-01

    Decision makers increasingly rely on large-scale computational models to simulate and analyze complex man-made systems. For example, computational models of national infrastructures are being used to inform government policy, assess economic and national security risks, evaluate infrastructure interdependencies, and plan for the growth and evolution of infrastructure capabilities. A major challenge for decision makers is the analysis of national-scale models that are composed of interacting systems: effective integration of system models is difficult, there are many parameters to analyze in these systems, and fundamental modeling uncertainties complicate analysis. This project is developing optimization methods to effectively represent and analyze large-scale heterogeneous system of systems (HSoS) models, which have emerged as a promising approach for describing such complex man-made systems. These optimization methods enable decision makers to predict future system behavior, manage system risk, assess tradeoffs between system criteria, and identify critical modeling uncertainties.

  13. Resource management for heterogeneous networks in LTE systems

    CERN Document Server

    Hu, Rose Qingyang

    2014-01-01

    This SpringerBrief provides an in-depth look at the key issues that affect the performance of heterogeneous networks and presents schemes that can effectively tackle these issues. In particular, this book discusses unbalanced traffic load among the macro and micro Base Stations (BSs) caused by the transmit power disparity, and a load-balancing based mobile association scheme to balance the traffic load among the macro and micro BSs. This book also introduces a fractional frequency reuse (FFR) scheme with proper power control to help reduce interference at the UEs which are most vulnerable to such intra-cell interference. The last section investigates radio resource allocation issues for heterogeneous networks with cooperative relays, and proposes a resource allocation framework that could achieve proportional fairness among the UEs. Numerical results are provided to demonstrate the effectiveness of the proposed solutions in tackling the problem and improving network performance. Resource Management for Hetero...

  14. Temporal Heterogeneity and the Value of Slowness in Robotic Systems

    Science.gov (United States)

    2015-11-01

    Abstract— Robot teaming is a well-studied area, but little research to date has been conducted on the fundamental benefits of heterogeneous... establish it through theoretical analysis and experimental results conducted in simulation and actual robotic platforms. REFERENCES [1] J.D. Madden...with an Ecological Augmented Virtuality Interface, Proceedings of AISB-HRI Symposium: New Frontiers in Human- Robot Interaction, Scotland , 2009. [18

  15. Using Mathematical Modeling Methods for Estimating Entrance Flow Heterogeneity Impact on Aviation GTE Parameters and Performances

    Directory of Open Access Journals (Sweden)

    Yu. A. Ezrokhi

    2017-01-01

    Full Text Available The paper considers methodological approaches to the mathematical models (MM of various levels, dedicated to estimate an impact of the entrance flow heterogeneity on the main parameters and performances of the aviation GTE and it units. By an example of calculation of a twin-shaft turbofan engine in cruiser mode, demonstrates engineering mathematical model capabilities to define the impact of the total pressure field distortion on engine trust and air flow parameters, and also gas dynamic stability margin of the both compressors.It is shown that the presented first level mathematical model allows us to estimate sufficiently the impact of entrance total pressure heterogeneity on the engine parameters. Here reliability of calculations is proved to be true by their comparison with the results, obtained owing to well fulfilled 2D & 3D mathematical models of the engine, which have been repeatedly identified by the results of experiments.It is shown that received results including those on decreasing values of stability margin of both compressors can be used for tentative estimates when choosing a desirable stability margin, providing steady operation of compressors and engine in an entire range of its operating modes. Carrying out a definitive testing calculation using the specialized engine MM of a higher level will not only confirm the results obtained, but also reduce their expected error with regard to the real values reached as a result of tests.

  16. Impact of Heterogeneity and Secrecy on the Capacity of Wireless Sensor Networks.

    Science.gov (United States)

    Liu, Qiuming; Yu, Li; Liu, Zuhao; Zheng, Jun

    2015-12-10

    This paper investigates the achievable secrecy throughput of an inhomogeneous wireless sensor network. We consider the impact of topology heterogeneity and the secrecy constraint on the throughput. For the topology heterogeneity, by virtue of percolation theory, a set of connected highways and information pipelines is established; while for the secrecy constraint, the concept of secrecy zone is adopted to ensure secrecy transmission. The secrecy zone means there is no eavesdropper around the legitimate node. The results demonstrate that, if the eavesdropper's intensity is λ(e)= o((log n)(-(3δ-4)/(δ-2))), a per-node secrecy rate of Ω [formula: see text] can be achieved on the highways, where δ is the exponent of heterogeneity, n and n(v) represent the number of nodes and clusters in the network, respectively. It is also shown that, with the density of the eavesdropper λ(e) = o((log(n Φ ̲ ))(-2)), the per-node secrecy rate of Ω (√(Φ ̲ /n)) can be obtained in the information pipelines, where Φ ̲ denotes the minimum node density in the network.

  17. Impact of Heterogeneity and Secrecy on theCapacity of Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Qiuming Liu

    2015-12-01

    Full Text Available This paper investigates the achievable secrecy throughput of an inhomogeneous wireless sensor network. We consider the impact of topology heterogeneity and the secrecy constraint on the throughput. For the topology heterogeneity, by virtue of percolation theory, a set of connected highways and information pipelines is established; while for the secrecy constraint, the concept of secrecy zone is adopted to ensure secrecy transmission. The secrecy zone means there is no eavesdropper around the legitimate node. The results demonstrate that, if the eavesdropper’s intensity is λe= o log n - 3 δ - 4 δ - 2 , a per-node secrecy rate of Ω 1 n 1 - v ( 1 - v log n can be achieved on the highways, where δ is the exponent of heterogeneity, n and n v represent the number of nodes and clusters in the network, respectively. It is also shown that, with the density of the eavesdropper λ e = o log n Φ ̲ - 2 , the per-node secrecy rate of Ω Φ ̲ n can be obtained in the information pipelines, where Φ ̲ denotes the minimum node density in the network.

  18. Site-specific time heterogeneity of the substitution process and its impact on phylogenetic inference

    Directory of Open Access Journals (Sweden)

    Philippe Hervé

    2011-01-01

    Full Text Available Abstract Background Model violations constitute the major limitation in inferring accurate phylogenies. Characterizing properties of the data that are not being correctly handled by current models is therefore of prime importance. One of the properties of protein evolution is the variation of the relative rate of substitutions across sites and over time, the latter is the phenomenon called heterotachy. Its effect on phylogenetic inference has recently obtained considerable attention, which led to the development of new models of sequence evolution. However, thus far focus has been on the quantitative heterogeneity of the evolutionary process, thereby overlooking more qualitative variations. Results We studied the importance of variation of the site-specific amino-acid substitution process over time and its possible impact on phylogenetic inference. We used the CAT model to define an infinite mixture of substitution processes characterized by equilibrium frequencies over the twenty amino acids, a useful proxy for qualitatively estimating the evolutionary process. Using two large datasets, we show that qualitative changes in site-specific substitution properties over time occurred significantly. To test whether this unaccounted qualitative variation can lead to an erroneous phylogenetic tree, we analyzed a concatenation of mitochondrial proteins in which Cnidaria and Porifera were erroneously grouped. The progressive removal of the sites with the most heterogeneous CAT profiles across clades led to the recovery of the monophyly of Eumetazoa (Cnidaria+Bilateria, suggesting that this heterogeneity can negatively influence phylogenetic inference. Conclusion The time-heterogeneity of the amino-acid replacement process is therefore an important evolutionary aspect that should be incorporated in future models of sequence change.

  19. Energy management for dynamically reconfigurable heterogeneous mobile systems

    NARCIS (Netherlands)

    Havinga, Paul J.M.; Smit, L.T.; Smit, Gerardus Johannes Maria; Bos, M.; Bos, M.; Heysters, P.M.; Smit, Jaap

    Dynamically reconfigurable systems offer the potential for realising efficient systems as well as providing adaptability to changing system requirements. Such systems are suitable for future mobile multimedia systems that have limited battery resources, must handle diverse data types, and must

  20. Wireless sensors in heterogeneous networked systems configuration and operation middleware

    CERN Document Server

    Cecilio, José

    2014-01-01

    This book presents an examination of the middleware that can be used to configure and operate heterogeneous node platforms and sensor networks. The middleware requirements for a range of application scenarios are compared and analysed. The text then defines middleware architecture that has been integrated in an approach demonstrated live in a refinery. Features: presents a thorough introduction to the major concepts behind wireless sensor networks (WSNs); reviews the various application scenarios and existing middleware solutions for WSNs; discusses the middleware mechanisms necessary for hete

  1. High Velocity Impact Interaction of Metal Particles with Porous Heterogeneous Materials with an Inorganic Matrix

    Science.gov (United States)

    Glazunov, A. A.; Ishchenko, A. N.; Afanasyeva, S. A.; Belov, N. N.; Burkin, V. V.; Rogaev, K. S.; Tabachenko, A. N.; Khabibulin, M. V.; Yugov, N. T.

    2016-03-01

    A computational-experimental investigation of stress-strain state and fracture of a porous heterogeneous material with an inorganic matrix, used as a thermal barrier coating of flying vehicles, under conditions of a high-velocity impact by a spherical steel projectile imitating a meteorite particle is discussed. Ballistic tests are performed at the velocities about 2.5 km/s. Numerical modeling of the high-velocity impact is described within the framework of a porous elastoplastic model including fracture and different phase states of the materials. The calculations are performed using the Euler and Lagrange numerical techniques for the velocities up to 10 km/s in a complete-space problem statement.

  2. Impact of Roles Assignation on Heterogeneous Populations in Evolutionary Dictator Game

    Science.gov (United States)

    Deng, Xinyang; Liu, Qi; Sadiq, Rehan; Deng, Yong

    2014-11-01

    The evolution of cooperation is a hot and challenging topic in the field of evolutionary game theory. Altruistic behavior, as a particular form of cooperation, has been widely studied by the ultimatum game but not by the dictator game, which provides a more elegant way to identify the altruistic component of behaviors. In this paper, the evolutionary dictator game is applied to model the real motivations of altruism. A degree-based regime is utilized to assess the impact of the assignation of roles on evolutionary outcome in populations of heterogeneous structure with two kinds of strategic updating mechanisms, which are based on Darwin's theory of evolution and punctuated equilibrium, respectively. The results show that the evolutionary outcome is affected by the role assignation and that this impact also depends on the strategic updating mechanisms, the function used to evaluate players' success, and the structure of populations.

  3. Radiative Impacts of Cloud Heterogeneity and Overlap in an Atmospheric General Circulation Model

    Science.gov (United States)

    Oreopoulos, L.; Lee, D.; Sud, Y. C.; Suarez, M. J.

    2012-01-01

    The radiative impacts of introducing horizontal heterogeneity of layer cloud condensate, and vertical overlap of condensate and cloud fraction are examined with the aid of a new radiation package operating in the GEOS-5 Atmospheric General Circulation Model. The impacts are examined in terms of diagnostic top-of-the-atmosphere shortwave (SW) and longwave (LW) cloud radiative effect (CRE) calculations for a range of assumptions and parameter specifications about the overlap. The investigation is conducted for two distinct cloud schemes, the one that comes with the standard GEOS-5 distribution, and another which has been recently used experimentally for its enhanced GEOS-5 distribution, and another which has been recently used experimentally for its enhanced cloud microphysical capabilities; both are coupled to a cloud generator allowing arbitrary cloud overlap specification. We find that cloud overlap radiative impacts are significantly stronger for the operational cloud scheme for which a change of cloud fraction overlap from maximum-random to generalized results to global changes of SW and LW CRE of approximately 4 Watts per square meter, and zonal changes of up to approximately 10 Watts per square meter. This is because of fewer occurrences compared to the other scheme of large layer cloud fractions and of multi-layer situations with large numbers of atmospheric being simultaneously cloudy, conditions that make overlap details more important. The impact on CRE of the details of condensate distribution overlap is much weaker. Once generalized overlap is adopted, both cloud schemes are only modestly sensitive to the exact values of the overlap parameters. We also find that if one of the CRE components is overestimated and the other underestimated, both cannot be driven towards observed values by adjustments to cloud condensate heterogeneity and overlap alone.

  4. The impact of phenotypic and genetic heterogeneity on results of genome wide association studies of complex diseases.

    Science.gov (United States)

    Manchia, Mirko; Cullis, Jeffrey; Turecki, Gustavo; Rouleau, Guy A; Uher, Rudolf; Alda, Martin

    2013-01-01

    Phenotypic misclassification (between cases) has been shown to reduce the power to detect association in genetic studies. However, it is conceivable that complex traits are heterogeneous with respect to individual genetic susceptibility and disease pathophysiology, and that the effect of heterogeneity has a larger magnitude than the effect of phenotyping errors. Although an intuitively clear concept, the effect of heterogeneity on genetic studies of common diseases has received little attention. Here we investigate the impact of phenotypic and genetic heterogeneity on the statistical power of genome wide association studies (GWAS). We first performed a study of simulated genotypic and phenotypic data. Next, we analyzed the Wellcome Trust Case-Control Consortium (WTCCC) data for diabetes mellitus (DM) type 1 (T1D) and type 2 (T2D), using varying proportions of each type of diabetes in order to examine the impact of heterogeneity on the strength and statistical significance of association previously found in the WTCCC data. In both simulated and real data, heterogeneity (presence of "non-cases") reduced the statistical power to detect genetic association and greatly decreased the estimates of risk attributed to genetic variation. This finding was also supported by the analysis of loci validated in subsequent large-scale meta-analyses. For example, heterogeneity of 50% increases the required sample size by approximately three times. These results suggest that accurate phenotype delineation may be more important for detecting true genetic associations than increase in sample size.

  5. The impact of phenotypic and genetic heterogeneity on results of genome wide association studies of complex diseases.

    Directory of Open Access Journals (Sweden)

    Mirko Manchia

    Full Text Available Phenotypic misclassification (between cases has been shown to reduce the power to detect association in genetic studies. However, it is conceivable that complex traits are heterogeneous with respect to individual genetic susceptibility and disease pathophysiology, and that the effect of heterogeneity has a larger magnitude than the effect of phenotyping errors. Although an intuitively clear concept, the effect of heterogeneity on genetic studies of common diseases has received little attention. Here we investigate the impact of phenotypic and genetic heterogeneity on the statistical power of genome wide association studies (GWAS. We first performed a study of simulated genotypic and phenotypic data. Next, we analyzed the Wellcome Trust Case-Control Consortium (WTCCC data for diabetes mellitus (DM type 1 (T1D and type 2 (T2D, using varying proportions of each type of diabetes in order to examine the impact of heterogeneity on the strength and statistical significance of association previously found in the WTCCC data. In both simulated and real data, heterogeneity (presence of "non-cases" reduced the statistical power to detect genetic association and greatly decreased the estimates of risk attributed to genetic variation. This finding was also supported by the analysis of loci validated in subsequent large-scale meta-analyses. For example, heterogeneity of 50% increases the required sample size by approximately three times. These results suggest that accurate phenotype delineation may be more important for detecting true genetic associations than increase in sample size.

  6. Potential impact of soil microbial heterogeneity on the persistence of hydrocarbons in contaminated subsurface soils.

    Science.gov (United States)

    Aleer, Sam; Adetutu, Eric M; Weber, John; Ball, Andrew S; Juhasz, Albert L

    2014-04-01

    In situ bioremediation is potentially a cost effective treatment strategy for subsurface soils contaminated with petroleum hydrocarbons, however, limited information is available regarding the impact of soil spatial heterogeneity on bioremediation efficacy. In this study, we assessed issues associated with hydrocarbon biodegradation and soil spatial heterogeneity (samples designated as FTF 1, 5 and 8) from a site in which in situ bioremediation was proposed for hydrocarbon removal. Test pit activities showed similarities in FTF soil profiles with elevated hydrocarbon concentrations detected in all soils at 2 m below ground surface. However, PCR-DGGE-based cluster analysis showed that the bacterial community in FTF 5 (at 2 m) was substantially different (53% dissimilar) and 2-3 fold more diverse than communities in FTF 1 and 8 (with 80% similarity). When hydrocarbon degrading potential was assessed, differences were observed in the extent of (14)C-benzene mineralisation under aerobic conditions with FTF 5 exhibiting the highest hydrocarbon removal potential compared to FTF 1 and 8. Further analysis indicated that the FTF 5 microbial community was substantially different from other FTF samples and dominated by putative hydrocarbon degraders belonging to Pseudomonads, Xanthomonads and Enterobacteria. However, hydrocarbon removal in FTF 5 under anaerobic conditions with nitrate and sulphate electron acceptors was limited suggesting that aerobic conditions were crucial for hydrocarbon removal. This study highlights the importance of assessing available microbial capacity prior to bioremediation and shows that the site's spatial heterogeneity can adversely affect the success of in situ bioremediation unless area-specific optimizations are performed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Evolutionary Game Theory-Based Evaluation of P2P File-Sharing Systems in Heterogeneous Environments

    Directory of Open Access Journals (Sweden)

    Yusuke Matsuda

    2010-01-01

    Full Text Available Peer-to-Peer (P2P file sharing is one of key technologies for achieving attractive P2P multimedia social networking. In P2P file-sharing systems, file availability is improved by cooperative users who cache and share files. Note that file caching carries costs such as storage consumption and processing load. In addition, users have different degrees of cooperativity in file caching and they are in different surrounding environments arising from the topological structure of P2P networks. With evolutionary game theory, this paper evaluates the performance of P2P file sharing systems in such heterogeneous environments. Using micro-macro dynamics, we analyze the impact of the heterogeneity of user selfishness on the file availability and system stability. Further, through simulation experiments with agent-based dynamics, we reveal how other aspects, for example, synchronization among nodes and topological structure, affect the system performance. Both analytical and simulation results show that the environmental heterogeneity contributes to the file availability and system stability.

  8. A multi-chip data acquisition system based on a heterogeneous system-on-chip platform

    CERN Document Server

    Fiergolski, Adrian

    2017-01-01

    The Control and Readout Inner tracking BOard (CaRIBOu) is a versatile readout system targeting a multitude of detector prototypes. It profits from the heterogeneous platform of the Zynq System-on-Chip (SoC) and integrates in a monolithic device front-end FPGA resources with a back-end software running on a hard-core ARM-based processor. The user-friendly Linux terminal with the pre-installed DAQ software is combined with the efficiency and throughput of a system fully implemented in the FPGA fabric. The paper presents the design of the SoC-based DAQ system and its building blocks. It also shows examples of the achieved functionality for the CLICpix2 readout ASIC.

  9. Thermodynamic and kinetic analysis of heterogeneous photocatalysis for semiconductor systems.

    Science.gov (United States)

    Liu, Baoshun; Zhao, Xiujian; Terashima, Chiaki; Fujishima, Akira; Nakata, Kazuya

    2014-05-21

    Since the report of the Honda-Fujishima effect, heterogeneous photocatalysis has attracted much attention around the world because of its potential energy and environmental applications. Although great progresses have been made in recent years, most were focused on preparing highly-active photocatalysts and investigating visible light utilization. In fact, we are still unclear on the thermodynamic and kinetic nature of photocatalysis to date, which sometimes leads to misunderstandings for experimental results. It is timely to give a review and discussion on the thermodynamics and kinetics of photocatalysis, so as to direct future researches. However, there is an absence of a detailed review on this topic until now. In this article, we tried to review and discuss the thermodynamics and kinetics of photocatalysis. We explained the thermodynamic driving force of photocatalysis, and distinguished the functions of light and heat in photocatalysis. The Langmuir-Hinshelwood kinetic model, the ˙OH oxidation mechanism, and the direct-indirect (D-I) kinetic model were reviewed and compared. Some applications of the D-I model to study photocatalytic kinetics were also discussed. The electron transport mode and its importance in photocatalysis were investigated. Finally, the intrinsic relation between the kinetics and the thermodynamics of photocatalytic reactions was discussed.

  10. Optimization Techniques for Dimensionally Truncated Sparse Grids on Heterogeneous Systems

    KAUST Repository

    Deftu, A.

    2013-02-01

    Given the existing heterogeneous processor landscape dominated by CPUs and GPUs, topics such as programming productivity and performance portability have become increasingly important. In this context, an important question refers to how can we develop optimization strategies that cover both CPUs and GPUs. We answer this for fastsg, a library that provides functionality for handling efficiently high-dimensional functions. As it can be employed for compressing and decompressing large-scale simulation data, it finds itself at the core of a computational steering application which serves us as test case. We describe our experience with implementing fastsg\\'s time critical routines for Intel CPUs and Nvidia Fermi GPUs. We show the differences and especially the similarities between our optimization strategies for the two architectures. With regard to our test case for which achieving high speedups is a "must" for real-time visualization, we report a speedup of up to 6.2x times compared to the state-of-the-art implementation of the sparse grid technique for GPUs. © 2013 IEEE.

  11. The impact of resource quality on the evolution of virulence in spatially heterogeneous environments.

    Science.gov (United States)

    Su, Min; Boots, Mike

    2017-03-07

    Understanding the drivers of parasite evolution and in particular disease virulence remains a major focus of evolutionary theory. Here, we examine the role of resource quality and in particular spatial environmental heterogeneity in the distribution of these resources on the evolution of virulence. There may be direct effects of resources on host susceptibility and pathogenicity alongside effects on reproduction that indirectly impact host-parasite population dynamics. Therefore, we assume that high resource quality may lead to both increased host reproduction and/or increased disease resistance. In completely mixed populations there is no effect of resource quality on the outcome of disease evolution. However, when there are local interactions higher resource quality generally selects for higher virulence/transmission for both linear and saturating transmission-virulence trade-off assumptions. The exception is that in castrators (i.e., infected hosts have no reproduction), higher virulence is selected for both low and high resource qualities at mixed local and global infection. Heterogeneity in the distribution of environment resources only has an effect on the outcome in castrators where random distributions generally select for higher virulence. Overall, our results further underline the importance of considering spatial structure in order to understand evolutionary processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Impact of Heterogeneous Consumers on Pricing Decisions under Dual-Channel Competition

    Directory of Open Access Journals (Sweden)

    Ying Wei

    2015-01-01

    Full Text Available This paper studies impact of heterogeneous consumer behavior on optimal pricing decisions under dual channel supply chain competition, which consists of one manufacturer and one retailer. The manufacturer is market leader with two sales channels: one is direct channel facing consumers directly and the other is indirect channel facing the retailer. Consumers decide whether to buy and from which channel to buy products. Purchasing decisions are based on considerations of prices posted on different channels, preference or loyalty to specific channels, and degree of rationality in decision-making process. Due to the complexity of heterogeneous consumer decision behavior, traditional mathematical analysis to the pricing problem becomes quite challenging. An agent-based modeling and simulation approach is then proposed and implemented. Simulation results reveal that consumer behavior influences both prices and profits. When consumers are increasingly loyal to the retailing channel, the retailer can make a higher selling price and more benefits. On the other hand, when consumers are increasingly loyal to the direct channel, the number of purchases from the direct channel increases and the manufacturer is better off. It is also interesting to note that as rationality level increases, selling prices for both channels slightly decrease.

  13. Impact of aquifer heterogeneity structure and local-scale dispersion on solute concentration uncertainty

    Science.gov (United States)

    Srzic, Veljko; Cvetkovic, Vladimir; Andricevic, Roko; Gotovac, Hrvoje

    2013-06-01

    In this paper, we study the influence of high log-conductivity variance (σY2) and local-scale dispersion on the first two concentration moments as well as on higher-order moments, skewness, and kurtosis, in a 2-D heterogeneous aquifer. Three different heterogeneity structures are considered, defined with one and the same global isotropic Gaussian variogram. The three structures differ in terms of spatial connectivity patterns at extreme log-conductivity values. Our numerical approach to simulate contaminant transport through heterogeneous porous media is based on the Lagrangian framework with a reverse tracking formulation. Advection and local-scale dispersion are two competing and controlling mechanisms, with a relative ratio defined by the Peclet number (Pe); hydraulic log-conductivity variance σY2 in the simulations is assumed to be one or eight. The term local-scale dispersion is used as a combined effect of molecular diffusion and mechanical dispersion. Uncertainty of the concentration field is quantified by the second-order moment, or the coefficient of variation (CVC) as a function of the sampling position along a centerline, Peclet number, and σY2, as well as by higher-order moments, i.e., skewness and kurtosis. The parameter σY2 shows a strong influence on the concentration statistics, while the three different structures have a minor impact in the case of low heterogeneity. The results also indicate that for σY2=8, the influence of local-scale dispersion is significant after five integral scales (IY) from the source for the connected (CN) field, while in case of a disconnected field, the local-scale dispersion effect is observed after 20IY from the source. In the case of unit σY2, local-scale dispersion acts very slowly affecting concentration uncertainty at distances higher than 20IY from the source. Our inspection of Monte Carlo concentration skewness and kurtosis with the ones obtained from the Beta distribution show the discrepancies for high

  14. Impacts of heterogeneous chemistry on heavy pollution in the JJJ (Beijing-Tianjin-Hebei) region

    Science.gov (United States)

    Tang, Yu Jia; Xian Liu, Bao; Sun, Feng; Wang, Li Hua; Zhang, Da Wei; Yin, Wen Jun; Zhang, Meng; Ma, Junwen

    2017-04-01

    The NO2 heterogeneous reaction on soot surfaces was incorporated into the WRF-Chem model to assess the impacts of the heterogeneous chemistry on the concentrations of HONO, HOx, O3, NO3-, and NH4+ in the JJJ (Beijing-Tianjin-Hebei) region. Results showed that the soot redox process with a γ value of 10-4 at night and the soot heterogeneous photochemistry with the γ formula of JNO2/10 in the daytime yielded a nighttime HONO increase of 0.4-1.8 ppb and a percentage enhancement of 10%-50% for HOx, 2%-6% for O3, 5%-21% for NO3-, and 6%-17% for NH4+ in the major cities of the JJJ region. The HONO simulations in this case were reasonable compared with observations in Beijing. Minor enhancements were found for HONO, HOx, O3, NO3-, and NH4+, with a maximum increase of 0.2 ppb for HONO and ≤ 6% for HOx, O3, NO3-, and NH4+ when γ was ≤ 10-5. When γ was increased to 10-3, produced are a nighttime maximum enhancement of 8.6 ppb for HONO, and a maximum percentage enhancement of 79% for HOx, 17% for O3, 211% for NO3-, and 152% for NH4+. This case considerably overestimated HONO and NO3- concentrations in Beijing in most cases. The soot surface area per unit volume of air (As) was another key parameter for the NO2 heterogeneous reaction on soot. The As values showed a sharp decrease from 3×103 μm2 cm-3 near the ground to 6×102 μm2 cm-3 at 200 m at night. Although the surface areas of major aerosol components at nighttime were  three times larger than that of those in the daytime, the surface area fractions of the major aerosol components showed minor variations between day and night. The surface area fractions of NO3-, SO42-, and soot were 32%-36%, 25%-28%, and 25%-26%, respectively.

  15. Impact of Pathogen Population Heterogeneity and Stress-Resistant Variants on Food Safety.

    Science.gov (United States)

    Abee, T; Koomen, J; Metselaar, K I; Zwietering, M H; den Besten, H M W

    2016-01-01

    This review elucidates the state-of-the-art knowledge about pathogen population heterogeneity and describes the genotypic and phenotypic analyses of persister subpopulations and stress-resistant variants. The molecular mechanisms underlying the generation of persister phenotypes and genetic variants are identified. Zooming in on Listeria monocytogenes, a comparative whole-genome sequence analysis of wild types and variants that enabled the identification of mutations in variants obtained after a single exposure to lethal food-relevant stresses is described. Genotypic and phenotypic features are compared to those for persistent strains isolated from food processing environments. Inactivation kinetics, models used for fitting, and the concept of kinetic modeling-based schemes for detection of variants are presented. Furthermore, robustness and fitness parameters of L. monocytogenes wild type and variants are used to model their performance in food chains. Finally, the impact of stress-resistant variants and persistence in food processing environments on food safety is discussed.

  16. Distributed containment control of heterogeneous fractional-order multi-agent systems with communication delays

    Science.gov (United States)

    Yang, Hongyong; Han, Fujun; Zhao, Mei; Zhang, Shuning; Yue, Jun

    2017-08-01

    Because many networked systems can only be characterized with fractional-order dynamics in complex environments, fractional-order calculus has been studied deeply recently. When diverse individual features are shown in different agents of networked systems, heterogeneous fractional-order dynamics will be used to describe the complex systems. Based on the distinguishing properties of agents, heterogeneous fractional-order multi-agent systems (FOMAS) are presented. With the supposition of multiple leader agents in FOMAS, distributed containment control of FOMAS is studied in directed weighted topologies. By applying Laplace transformation and frequency domain theory of the fractional-order operator, an upper bound of delays is obtained to ensure containment consensus of delayed heterogenous FOMAS. Consensus results of delayed FOMAS in this paper can be extended to systems with integer-order models. Finally, numerical examples are used to verify our results.

  17. Impact experiments onto heterogeneous targets and their interpretation in relation with formation of the asteroid families

    Science.gov (United States)

    Leliwa-Kopystynski, J.; Arakawa, M.

    2014-07-01

    Results of laboratory impact experiments, when extrapolated to the planetary scale of events, are aimed for better understanding of cratering and/or disruption of asteroids, satellites, and cometary nuclei. There is absolutely no reason to assume that these bodies are uniform rocky or icy monoliths. So, we studied reactions of the heterogeneous targets on the impacts. A series of impact experiments onto solid decimeter-sized cylinders made of porous gypsum mixed with approximately one-centimeter-sized pebbles have been performed. The mean density of the material of the targets was 1867 kg m^{-3}, the mean mass ratio (pebbles / gypsum) = 0.856 / 0.144, and the mean volume ratio (pebbles / gypsum / pores) = 0.585 / 0.116 / 0.299. The target densities and their heterogeneous structures could be representative of those of the asteroids Ida, Eros, and many others, because asteroid sub-surface volumes could be composed of consolidated boulders formed by self-compaction and/or by impact compaction. Impact velocities in the experiments ranged from 2.0 km/s to 6.7 km/s (collision velocity in the asteroid main belt is approximately 5 km/s). By means of weighting and counting the post-impact fragments, their distribution function was found. Let Q [J/kg] be the specific energy of impact per unit of the target mass. Of particular interest is the value of impact strength, that is, the specific energy of disruption Q^*, corresponding to the ratio (mass of the largest fragment) / (mass of the target) = m_l/M = 0.5, which is, by convention, the value separating the cratering events from the catastrophic disruption impacts. Mass or size distribution of the post-impact fragments is expressed by the power law N ∝ m^{-p} ∝ r^{-3p}, p=p(Q/Q^{*}) A parameter that can be measured in the laboratory is the exponent p. For the case of a swarm of asteroids forming an asteroid family, the observationally estimated value is not the exponent p but rather the exponent q = 3p, since the sizes

  18. The NASA Astrophysics Data System: A Heterogeneous Distributed Data Environment

    Science.gov (United States)

    Kurtz, M. J.; Eichhorn, G.; Murray, S. S.; Grant, C. S.; Accomazzi, A.

    The NASA Astrophysics Data System (ADS) is a distributed information system which provides access to archive, catalog and bibliographic data in astronomy. because of recent technical and budgetary developments the ADS has become a smaller project and changed its focus. While continuing to provide access to certain archives and databases te ADS will substantially expand its already extensive bibliographic service to include the whole text of articles from the major journals in astronomy; it will thus become a major digital library.

  19. Impacts of surface adsorbed catechol on tropospheric aerosol surrogates: heterogeneous ozonolysis and its effects on water uptake.

    Science.gov (United States)

    Woodill, Laurie A; O'Neill, Erinn M; Hinrichs, Ryan Z

    2013-07-11

    Surface adsorbed organics are ubiquitous components of inorganic tropospheric aerosols and have the potential to alter aerosol chemical and physical properties. To assess the impact of adsorbed organics on water uptake by inorganic substrates, we used diffuse reflectance infrared spectroscopy to compared water adsorption isotherms for uncoated NaCl and α-Al2O3 samples, samples containing a monolayer of adsorbed catechol, and adsorbed catechol samples following ozonolysis. Adsorption of gaseous catechol on to the inorganic substrates produced vibrational features indicating physisorption on NaCl and displacement of surface hydroxyl groups forming binuclear bidentate catecholate on α-Al2O3, with surface concentrations of 2-3 × 10(18) molecules m(-2). Subsequent heterogeneous ozonolysis produced muconic acid at a rate 4-5 times faster on NaCl compared to α-Al2O3, with predicted atmospheric lifetimes of 4.3 and 18 h, respectively, assuming a tropospheric ozone concentration of 40 ppb. Water adsorption isotherms for all NaCl samples were indistinguishable within experimental uncertainty, indicating that these organic monolayers had negligible impact on coadsorbed water surface concentrations for these systems. α-Al2O3-catechol samples exhibited dramatically less water uptake compared to uncoated α-Al2O3, while oxidation of surface adsorbed catechol had no effect on the extent of water uptake. For both substrates, adsorbed organics increased the relative abundance of "ice-like" versus "liquid-like" water, with the effect larger for catechol than oxidized ozonolysis products. These results highlight the importance of aerosol substrate in understanding the heterogeneous ozonolysis of adsorbed polyphenols and suggest such coatings may impair ice nucleation by aluminosilicate mineral aerosol.

  20. The impact of aquifer heterogeneity on the performance of aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Valstar, J.R.; Gaans, van P.; Grotenhuis, J.T.C.; Rijnaarts, H.

    2013-01-01

    Heterogeneity in hydraulic properties of the subsurface is not accounted for in current design calculations of aquifer thermal energy storage (ATES). However, the subsurface is heterogeneous and thus affects the heat distribution around ATES wells. In this paper, the influence of heterogeneity on

  1. The water budget of heterogeneous areas : impact of soil and rainfall variability

    NARCIS (Netherlands)

    Kim, C.P.

    1995-01-01

    In this thesis the heterogeneity of the soil water budget components is investigated. Heterogeneity of soil hydraulic properties and rainfall rate are taken into account by using stochastic methods. The importance of lateral groundwater flow in causing heterogeneity of the water budget

  2. Park size and disturbance: impact on soil heterogeneity - a case study Tel-Aviv- Jaffa.

    Science.gov (United States)

    Zhevelev, Helena; Sarah, Pariente; Oz, Atar

    2015-04-01

    Parks and gardens are poly-functional elements of great importance in urban areas, and can be used for optimization of physical and social components in these areas. This study aimed to investigate alteration of soil properties with land usages within urban park and with area size of park. Ten parks differed by size (2 - 50 acres) were chosen, in random, in Tel-Aviv- Jaffa city. Soil was sampled in four microenvironments ((lawn, path, picnic and peripheral area (unorganized area) of each the park)), in three points and three depth (0-2, 5-10 and 10-20 cm). Penetration depth was measured in all point of sampling. For each soil sample electrical conductivity and organic matter content were determined. Averages of penetration depth drastically increased from the most disturbed microenvironments (path and picnic) to the less disturbed ones (lawn and peripheral). The maximal heterogeneity (by variances and percentiles) of penetration depth was found in the peripheral area. In this area, penetration depth increased with increasing park size, i.e., from 2.6 cm to 3.7 cm in the small and large parks, respectively. Averages of organic matter content and electrical conductivity decreased with soil depth in all microenvironments and increased with decreasing disturbance of microenvironments. Maximal heterogeneity for both of these properties was found in the picnic area. Increase of park size was accompanied by increasing of organic matter content in the upper depth in the peripheral area, i.e., from 2.4% in the small parks to 4.5% in the large ones. In all microenvironments the increasing of averages of all studied soil properties was accompanied by increasing heterogeneity, i.e., variances and upper percentiles. The increase in the heterogeneity of the studied soil properties is attributed to improved ecological soil status in the peripheral area, on the one hand, and to the high anthropogenic pressure in the picnic area, on the other. This means that the urban park offers

  3. Data Storing Proposal from Heterogeneous Systems into a Specialized Repository

    Directory of Open Access Journals (Sweden)

    Václavová Andrea

    2016-12-01

    Full Text Available The aim of this paper is to analyze and to propose an appropriate system for processing and simultaneously storing a vast volume of structured and unstructured data. The paper consists of three parts. The first part addresses the issue of structured and unstructured data. The second part provides the detailed analysis of data repositories and subsequent evaluation indicating which system would be for the given type and volume of data optimal. The third part focuses on the use of gathered information to transfer data to the proposed repository.

  4. Implementation of Multi-standard Wireless Communication Receivers in a Heterogeneous Reconfigurable System-on-Chip

    NARCIS (Netherlands)

    Rauwerda, G.K.; Smit, Gerardus Johannes Maria; Heysters, P.M.

    Future mobile terminals become multi-mode communication systems. In order to handle different standards, we propose to perform baseband processing in heterogeneous reconfigurable hardware. Not only the baseband processing but also error decoding differs for every communication system. We already

  5. Robust decentralized output regulation with single or multiple reference signals for uncertain heterogeneous systems

    NARCIS (Netherlands)

    Liu, Hui; De Persis, Claudio; Cao, Ming

    We consider the problem in which N coupled heterogeneous uncertain linear systems aim at tracking one or more reference signals generated by given exosystems under the restriction that not all the systems are directly connected to the exosystems. To tackle this problem, the reference signals are

  6. The impact of strain-specific immunity on Lyme disease incidence is spatially heterogeneous.

    Science.gov (United States)

    Khatchikian, Camilo E; Nadelman, Robert B; Nowakowski, John; Schwartz, Ira; Wormser, Gary P; Brisson, Dustin

    2017-12-01

    Lyme disease, caused by the bacterium Borrelia burgdorferi, is the most common tick-borne infection in the US. Recent studies have demonstrated that the incidence of human Lyme disease would have been even greater were it not for the presence of strain-specific immunity, which protects previously infected patients against subsequent infections by the same B. burgdorferi strain. Here, spatial heterogeneity is incorporated into epidemiological models to accurately estimate the impact of strain-specific immunity on human Lyme disease incidence. The estimated reduction in the number of Lyme disease cases is greater in epidemiologic models that explicitly include the spatial distribution of Lyme disease cases reported at the county level than those that utilize nationwide data. strain-specific immunity has the greatest epidemiologic impact in geographic areas with the highest Lyme disease incidence due to the greater proportion of people that have been previously infected and have developed strain-specific immunity. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Robust Architectures for Complex Multi-Agent Heterogeneous Systems

    Science.gov (United States)

    2014-07-23

    E. Xargay N. Hovakimyan, I. Kaminer, C. Cao, I. Gregory, Multicriteria Analysis of an 1L Adaptive Flight Control System, Proceedings of the...Game-theoretic analysis of a visibility based pursuit-evasion game in the presence of a circular obstacle, In Proceedings (1479) of American

  8. Heterogeneous computing for a real-time pig monitoring system

    Science.gov (United States)

    Choi, Younchang; Kim, Jinseong; Kim, Jaehak; Chung, Yeonwoo; Chung, Yongwha; Park, Daihee; Kim, Hakjae

    2017-06-01

    Video sensor data has been widely used in automatic surveillance applications. In this study, we present a method that automatically detects pigs in a pig room by using depth information obtained from a Kinect sensor. For a real-time implementation, we propose a means of reducing the execution time by applying parallel processing techniques. In general, most parallel processing techniques have been used to parallelize a specific task. In this study, we consider parallelization of an entire system that consists of several tasks. By applying a scheduling strategy to identify a computing device for each task and implementing it with OpenCL, we can reduce the total execution time efficiently. Experimental results reveal that the proposed method can automatically detect pigs using a CPU-GPU hybrid system in real time, regardless of the relative performance between the CPU and GPU.

  9. High-Temperatures Rheometric Analysis Of Selected Heterogeneous Slag Systems

    Directory of Open Access Journals (Sweden)

    Migas P.

    2015-06-01

    Full Text Available It is known that the dynamic viscosity coefficient of slag – with an increased titanium compounds content in the reducing conditions of the blast furnace - may rapidly change. The products of the reduction reaction, precipitation and separation of titanium compounds are responsible for the thickening effect of the slag and the problems of permeability of blast furnace, causing anomalies in the dipping zone. The presence of solid components (particles in the melts determines the rheological character of the entire system. Identifying the rheological character of semi-solid slag systems provides opportunities for the development of mathematical modeling of liquid phase flows in a dripping zone of the blast furnace, allowing e.g to indentify the unstable parts of a metallurgical aggregate.

  10. Fusion of Heterogeneous Intrusion Detection Systems for Network Attack Detection.

    Science.gov (United States)

    Kaliappan, Jayakumar; Thiagarajan, Revathi; Sundararajan, Karpagam

    2015-01-01

    An intrusion detection system (IDS) helps to identify different types of attacks in general, and the detection rate will be higher for some specific category of attacks. This paper is designed on the idea that each IDS is efficient in detecting a specific type of attack. In proposed Multiple IDS Unit (MIU), there are five IDS units, and each IDS follows a unique algorithm to detect attacks. The feature selection is done with the help of genetic algorithm. The selected features of the input traffic are passed on to the MIU for processing. The decision from each IDS is termed as local decision. The fusion unit inside the MIU processes all the local decisions with the help of majority voting rule and makes the final decision. The proposed system shows a very good improvement in detection rate and reduces the false alarm rate.

  11. Fusion of Heterogeneous Intrusion Detection Systems for Network Attack Detection

    Directory of Open Access Journals (Sweden)

    Jayakumar Kaliappan

    2015-01-01

    Full Text Available An intrusion detection system (IDS helps to identify different types of attacks in general, and the detection rate will be higher for some specific category of attacks. This paper is designed on the idea that each IDS is efficient in detecting a specific type of attack. In proposed Multiple IDS Unit (MIU, there are five IDS units, and each IDS follows a unique algorithm to detect attacks. The feature selection is done with the help of genetic algorithm. The selected features of the input traffic are passed on to the MIU for processing. The decision from each IDS is termed as local decision. The fusion unit inside the MIU processes all the local decisions with the help of majority voting rule and makes the final decision. The proposed system shows a very good improvement in detection rate and reduces the false alarm rate.

  12. An Overview of MSHN: The Management System for Heterogeneous Networks

    Science.gov (United States)

    1999-04-01

    Naval Postgraduate School Monterey, CA USA µNOEMIX San Diego, CA USA ¶Electrical and Computer Engineering University of Southern California Los Angeles...critical applications”, Workshop on Middleware for Distributed Real-Time Systems, 1997, pp. 179-186. [25] O. Ibarra and Kim, “Heuristic algorithms for...Siegel, J. K. Antonio , and Y. A. Li, “Minimizing the application execution time through scheduling of subtasks and communication traffic in a

  13. Multi-heuristic dynamic task allocation using genetic algorithms in a heterogeneous distributed system

    Science.gov (United States)

    Page, Andrew J.; Keane, Thomas M.; Naughton, Thomas J.

    2010-01-01

    We present a multi-heuristic evolutionary task allocation algorithm to dynamically map tasks to processors in a heterogeneous distributed system. It utilizes a genetic algorithm, combined with eight common heuristics, in an effort to minimize the total execution time. It operates on batches of unmapped tasks and can preemptively remap tasks to processors. The algorithm has been implemented on a Java distributed system and evaluated with a set of six problems from the areas of bioinformatics, biomedical engineering, computer science and cryptography. Experiments using up to 150 heterogeneous processors show that the algorithm achieves better efficiency than other state-of-the-art heuristic algorithms. PMID:20862190

  14. Decomposing the dynamics of heterogeneous delayed networks with applications to connected vehicle systems.

    Science.gov (United States)

    Szalai, Róbert; Orosz, Gábor

    2013-10-01

    Delay-coupled networks are investigated with nonidentical delay times and the effects of such heterogeneity on the emergent dynamics of complex systems are characterized. A simple decomposition method is presented that decouples the dynamics of the network into node-size modal equations in the vicinity of equilibria. The resulting independent components contain distributed delays that map the spatiotemporal complexity of the system to the time domain. We demonstrate that this approach can be used to reveal physical phenomena in heterogenous vehicular traffic when vehicles are linked via vehicle-to-vehicle communication.

  15. Workload Balancing on Heterogeneous Systems: A Case Study of Sparse Grid Interpolation

    KAUST Repository

    Muraraşu, Alin

    2012-01-01

    Multi-core parallelism and accelerators are becoming common features of today’s computer systems, as they allow for computational power without sacrificing energy efficiency. Due to heterogeneity, tuning for each type of compute unit and adequate load balancing is essential. This paper proposes static and dynamic solutions for load balancing in the context of an application for visualizing high-dimensional simulation data. The application relies on the sparse grid technique for data compression. Its performance critical part is the interpolation routine used for decompression. Results show that our load balancing scheme allows for an efficient acceleration of interpolation on heterogeneous systems containing multi-core CPUs and GPUs.

  16. Local environmental context conditions the impact of Russian olive in a heterogeneous riparian ecosystem

    Science.gov (United States)

    Tuttle, Graham M.; Katz, Gabrielle L.; Friedman, Jonathan M.; Norton, Andrew P.

    2016-01-01

    Local abiotic and biotic conditions can alter the strength of exotic species impacts. To better understand the effects of exotic species on invaded ecosystems and to prioritize management efforts, it is important that exotic species impacts are put in local environmental context. We studied how differences in plant community composition, photosynthetically active radiation (PAR), and available soil N associated with Russian olive presence are conditioned by local environmental variation within a western U.S. riparian ecosystem. In four sites along the South Fork of the Republican River in Colorado, we established 200 pairs of plots (underneath and apart from Russian olive) to measure the effects of invasion across the ecosystem. We used a series of a priori mixed models to identify environmental variables that altered the effects of Russian olive. For all response variables, models that included the interaction of environmental characteristics, such as presence/absence of an existing cottonwood canopy, with the presence/absence of Russian olive canopy were stronger candidate models than those that just included Russian olive canopy presence as a factor. Compared with reference plots outside of Russian olive canopy, plots underneath Russian olive had higher relative exotic cover (exotic/total cover), lower perennial C4 grass cover, and higher perennial forb cover. These effects were reduced, however, in the presence of a cottonwood canopy. As expected, Russian olive was associated with reduced PAR and increased N, but these effects were reduced under cottonwood canopy. Our results demonstrate that local abiotic and biotic environmental factors condition the effects of Russian olive within a heterogeneous riparian ecosystem and suggest that management efforts should be focused in open areas where Russian olive impacts are strongest.

  17. Pancreatic cancer: systemic combination therapies for a heterogeneous disease.

    Science.gov (United States)

    Melisi, Davide; Calvetti, Lorenzo; Frizziero, Melissa; Tortora, Giampaolo

    2014-01-01

    Pancreatic cancer is the only human malignancy for which patients' survival has not improved substantially during the past 30 years. Despite advances in the comprehension of the molecular mechanisms underlying pancreatic carcinogenesis, current systemic treatments offer only a modest benefit in tumor-related symptoms and survival. Over the past decades, gemcitabine and its combination with other standard cytotoxic agents have been the reference treatments for advanced pancreatic cancer patients. The recent introduction of the three-drug combination regimen FOLFIRINOX or the new taxane nab-paclitaxel represent key advances for a better control of the disease. Novel agents targeting molecular mechanisms involved in cancer development and maintenance are currently under clinical investigation. This review describes the most important findings in the field of systemic combination therapies for the treatment of pancreatic cancer. We discuss the emerging evidences for the clinical activity of combination treatments with standard chemotherapy plus novel agents targeting tumor cell-autonomous and tumor microenvironment signaling pathways. We present some of the most important advances in the comprehension of the molecular mechanisms responsible for the chemoresistance of pancreatic cancer and the emerging therapeutic targets to overcome this resistance.

  18. Wear forms of heterogeneous electro-rheological fluids working in a hydraulic clutch system

    Science.gov (United States)

    Ziabska, E.; Duchowski, J.; Olszak, A.; Osowski, K.; Kesy, A.; Kesy, Z.; Choi, S. B.

    2017-09-01

    The paper presents experimental results concerning the wear of heterogeneous electro-rheological (ER) fluids operating as working fluids in a complex clutch system consisting of a hydrodynamic clutch and a cylinder viscous clutch. The change of electric field intensity in the clutches results in change of sheer stress values in working fluids what causes the change of transmitted torque. This work shows that the most important factors affecting the wear of the ER fluid are the electric field of high intensity, the accompanying electrical breakdown, and the high temperature of the silicone oil. In addition, the water from the humid air absorbed mainly by hygroscopic particles influences a significant impact on the wear of the working fluid. Various forms of wear particles of the fluid depending on the prevailing conditions such as working mode are observed from the microscopic aspects. It is observed that the particles are flattened, rolled out or smashed into smaller fragments, partially melted, wrinkled and glued or caked. In addition, it is identified that the partial destruction of silicone oil is occurred due to the damage of the hydrocarbon chains, as evidenced by the decrease in its viscosity and the presence of the particle matter newly containing silicon.

  19. Fibronectin and avidin-biotin as a heterogeneous ligand system for enhanced endothelial cell adhesion.

    Science.gov (United States)

    Bhat, V D; Truskey, G A; Reichert, W M

    1998-09-05

    A preadsorbed layer of "heterogeneous" integrin-dependent and -independent protein was used to enhance initial integrin-mediated endothelial cell attachment and spreading. Glass substrates were treated with fibronectin (Fn) and avidin coupled through adsorbed biotinylated bovine serum albumin (b-BSA). The slides then were seeded with biotinylated BAEC. Control "homogeneous" surfaces were slides adsorbed with either Fn or avidin coupled to b-BSA. The cells were incubated for 0.5 h in serum-containing media and exposed to a range of shear stresses in a laminar flow variable-height flow chamber. The critical shear stress to detach 50% of the seeded cells on the heterogeneous ligand surface was significantly greater than for either of the control homogeneous ligand systems (p < 0.001). Cellular spreading during the initial period of 0-2 h also was higher (p < 0.05) on the heterogeneous ligand-treated surface than on the surface of either of the homogeneous controls. The close contact area of the cell membrane with the substrate 1 h after seeding in serum-containing media was measured using TIRFM. Cells attached onto the heterogeneous ligand-treated surfaces had a significantly (p < 0.01) higher area of close contact with the substrate, which is consistent with a greater degree of attachment and spreading. The results indicate that the combination of integrin-dependent and -independent adhesion systems using heterogeneous ligands further enhances initial endothelial cell attachment and spreading.

  20. Impact of sorbic acid on germination and outgrowth heterogeneity of Bacillus cereus ATCC 14579 spores.

    Science.gov (United States)

    den Besten, Heidy M W; van Melis, Clint C J; Sanders, Jan Willem; Nierop Groot, Masja N; Abee, Tjakko

    2012-12-01

    Population heterogeneity complicates the predictability of the outgrowth kinetics of individual spores. Flow cytometry sorting and monitoring of the germination and outgrowth of single dormant spores allowed the quantification of acid-induced spore population heterogeneity at pH 5.5 and in the presence of sorbic acid. This showed that germination efficiency was not a good predictor for heterogeneity in final outgrowth.

  1. Experimental Investigation of Heterogeneous Power Systems on the Basis of Lyophobic Liquids and Porous Media

    Directory of Open Access Journals (Sweden)

    V. D. Borman

    2014-01-01

    Full Text Available The use of non-traditional ways for energy accumulation (absorption is a reserve to increase efficiency of accumulating and damping devices. The work is aimed at experimental and theoretical verification of possibility to create the accumulating and energy damping devices based on the heterogeneous systems (HS. The HS includes a couple i.e. a porous body (silochromes with pore diameter from 20 nm to 360 nm and a lyophobic (non-wetting liquid (Wood's alloy. The paper briefly presents provisions of the theory of processes in HS based on the kinetics of percolation transition that allows us to calculate power, power and temporary characteristics of devices and prove the methods for choosing the couples for HS with the specified characteristics. It explains effect of hysteresis function of changing liquid volume that fills a porous body and outflows from it under the differential pressure, as well as conditions to realize effect of non-outflowing liquid after removal of the differential pressure thanks to which energy accumulation in HS is possible. The stand diagram, device parameters to study static and dynamic processes in HS, and measurement system characteristics are provided. Research results of static processes to fill (outflow pores of various silochromes with Wood's alloy are presented. It is shown that among considered HS the most efficient one is the HS possessing S-120 silochrome, hexamethyldisilazane-modified. The certain filling pores specific energy of HS made 71 J/g, while the outflow specific energy was 28 J/g. The paper presents a scheme of device model damping a force impact on the support. Test results of spring and hydraulic dampers and the model, as well, with HS based on silochromes with various lyophobic liquids are given. High HS efficiency that allows the 4 times less impact value is shown. Further researches concern a development of engineering techniques to design and optimize the HS parameters and a choice of the most

  2. Modeling global impacts of heterogeneous loss of HO2 on cloud droplets, ice particles and aerosols

    Science.gov (United States)

    Huijnen, V.; Williams, J. E.; Flemming, J.

    2014-03-01

    The abundance and spatial variability of the hydroperoxyl radical (HO2) in the troposphere strongly affects atmospheric composition through tropospheric ozone production and associated HOx chemistry. One of the largest uncertainties in the chemical HO2 budget is its heterogeneous loss on the surface of cloud droplets, ice particles and aerosols. We quantify the importance of the heterogeneous HO2 loss at global scale using the latest recommendations on the scavenging efficiency on various surfaces. For this we included the simultaneous loss on cloud droplets and ice particles as well as aerosol in the Composition-Integrated Forecast System (C-IFS). We show that cloud surface area density (SAD) is typically an order of magnitude larger than aerosol SAD, using assimilated satellite retrievals to constrain both meteorology and global aerosol distributions. Depending on the assumed uptake coefficients, loss on liquid water droplets and ice particles accounts for ∼53-70% of the total heterogeneous loss of HO2, due to the ubiquitous presence of cloud droplets. This indicates that HO2 uptake on cloud should be included in chemistry transport models that already include uptake on aerosol. Our simulations suggest that the zonal mean mixing ratios of HO2 are reduced by ∼25% in the tropics and up to ∼50% elsewhere. The subsequent decrease in oxidative capacity leads to a global increase of the tropospheric carbon monoxide (CO) burden of up to 7%, and an increase in the ozone tropospheric lifetime of ∼6%. This increase results in an improvement in the global distribution when compared against CO surface observations over the Northern Hemisphere, although it does not fully resolve the wintertime bias in the C-IFS. There is a simultaneous increase in the high bias in C-IFS for tropospheric CO over the Southern Hemisphere, which constrains on the assumptions regarding HO2 uptake on a global scale. We show that enhanced HO2 uptake on aerosol types associated with

  3. Energy-aware Thread and Data Management in Heterogeneous Multi-core, Multi-memory Systems

    Energy Technology Data Exchange (ETDEWEB)

    Su, Chun-Yi [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2014-12-16

    By 2004, microprocessor design focused on multicore scaling—increasing the number of cores per die in each generation—as the primary strategy for improving performance. These multicore processors typically equip multiple memory subsystems to improve data throughput. In addition, these systems employ heterogeneous processors such as GPUs and heterogeneous memories like non-volatile memory to improve performance, capacity, and energy efficiency. With the increasing volume of hardware resources and system complexity caused by heterogeneity, future systems will require intelligent ways to manage hardware resources. Early research to improve performance and energy efficiency on heterogeneous, multi-core, multi-memory systems focused on tuning a single primitive or at best a few primitives in the systems. The key limitation of past efforts is their lack of a holistic approach to resource management that balances the tradeoff between performance and energy consumption. In addition, the shift from simple, homogeneous systems to these heterogeneous, multicore, multi-memory systems requires in-depth understanding of efficient resource management for scalable execution, including new models that capture the interchange between performance and energy, smarter resource management strategies, and novel low-level performance/energy tuning primitives and runtime systems. Tuning an application to control available resources efficiently has become a daunting challenge; managing resources in automation is still a dark art since the tradeoffs among programming, energy, and performance remain insufficiently understood. In this dissertation, I have developed theories, models, and resource management techniques to enable energy-efficient execution of parallel applications through thread and data management in these heterogeneous multi-core, multi-memory systems. I study the effect of dynamic concurrent throttling on the performance and energy of multi-core, non-uniform memory access

  4. Abiotic Dissolution of a Tetrachloroethene (PCE) Pool in an Anaerobic Sand Tank Aquifer System with Heterogeneous Flow

    Science.gov (United States)

    Klemm, Sara; Seagren, Eric; Becker, Jennifer

    2017-04-01

    Intrinsic and engineered in situ bioremediation are made technologically challenging by the physically and chemically heterogeneous nature of the subsurface environment. Subsurface heterogeneities are important because they influence interfacial mass-transfer processes that impact the availability of substrates to the microorganisms. The laboratory experiments reported here examined the dissolution of a dense nonaqueous phase liquid (DNAPL) tetrachloroethene (PCE) pool, and transport of the dissolved PCE plume in a aquifer simulated system with heterogeneous flow. These abiotic experiments were performed in a saturated intermediate-scale flow cell (1.2 m), with flow parallel to the PCE pool. A steady-state mass balance approach was used to estimate the PCE dissolution rate at two different flow rates. As expected, increasing the flow rate decreased the effluent dissolved PCE concentration and increased the dissolution flux. However, the effluent PCE concentration was higher than expected based on modeling predictions assuming a uniform distribution of flow across the depth of the tank. Nonreactive tracer studies confirmed that there was a velocity profile with depth, with the slowest velocity at the top of the tank, and the highest velocity at the bottom of the tank, possible due to consolidation of the sand that occurred during a wetting/drainage cycle. Revised modeling using the vertical flow variation provided an improved prediction of the effluent PCE concentration. These results have important implications for predicting DNAPL pool dissolution in the field. Whereas experimental systems in the laboratory typically employ porous media with uniform flow distribution, flow heterogeneities are the rule rather than the exception in the field, and it is well known that velocity impacts pool dissolution. In the case of this experimental system, the pore water velocity near the pool was greater than the average pore water velocity across the system, resulting in a

  5. Impact modeling of cylindrical lithium-ion battery cells: a heterogeneous approach

    Science.gov (United States)

    Gilaki, Mehdi; Avdeev, Ilya

    2016-10-01

    In this study, a heterogeneous finite element model was developed in LS-DYNA to investigate lateral impact on 6P cylindrical lithium-ion battery cells manufactured by Johnson Controls Inc. The results were compared to those from a homogenized model previously reported by the authors and also experimental data and showed a good agreement. In order to find the stress-strain curves needed for the finite element simulations, compression tests were conducted on stacks of jellyroll's individual layers, i.e. coated aluminum, coated copper and separator. It was found that the load carrying capacity of the jellyroll comes primarily from the coated aluminum layers. SEM images of the separator layers showed their trilayer structure and how they collapse under excessive compressive loads. Compression experiments were also performed on flattened jellyroll samples after being soaked in electrolyte for 24 h. The measured stress-strain relations showed a very good agreement with the results from a similar set of experiments on dry jellyrolls. This suggested that characterizing dry cells could predict how live cells would react under compression/crash tests without dealing with all the safety provisions needed for those experiments.

  6. Impact of heterogeneous activity and community structure on the evolutionary success of cooperators in social networks.

    Science.gov (United States)

    Wu, Zhi-Xi; Rong, Zhihai; Yang, Han-Xin

    2015-01-01

    Recent empirical studies suggest that heavy-tailed distributions of human activities are universal in real social dynamics [L. Muchnik, S. Pei, L. C. Parra, S. D. S. Reis, J. S. Andrade Jr., S. Havlin, and H. A. Makse, Sci. Rep. 3, 1783 (2013)]. On the other hand, community structure is ubiquitous in biological and social networks [M. E. J. Newman, Nat. Phys. 8, 25 (2012)]. Motivated by these facts, we here consider the evolutionary prisoner's dilemma game taking place on top of a real social network to investigate how the community structure and the heterogeneity in activity of individuals affect the evolution of cooperation. In particular, we account for a variation of the birth-death process (which can also be regarded as a proportional imitation rule from a social point of view) for the strategy updating under both weak and strong selection (meaning the payoffs harvested from games contribute either slightly or heavily to the individuals' performance). By implementing comparative studies, where the players are selected either randomly or in terms of their actual activities to play games with their immediate neighbors, we figure out that heterogeneous activity benefits the emergence of collective cooperation in a harsh environment (the action for cooperation is costly) under strong selection, whereas it impairs the formation of altruism under weak selection. Moreover, we find that the abundance of communities in the social network can evidently foster the formation of cooperation under strong selection, in contrast to the games evolving on randomized counterparts. Our results are therefore helpful for us to better understand the evolution of cooperation in real social systems.

  7. Impact of heterogeneous activity and community structure on the evolutionary success of cooperators in social networks

    Science.gov (United States)

    Wu, Zhi-Xi; Rong, Zhihai; Yang, Han-Xin

    2015-01-01

    Recent empirical studies suggest that heavy-tailed distributions of human activities are universal in real social dynamics [L. Muchnik, S. Pei, L. C. Parra, S. D. S. Reis, J. S. Andrade Jr., S. Havlin, and H. A. Makse, Sci. Rep. 3, 1783 (2013), 10.1038/srep01783]. On the other hand, community structure is ubiquitous in biological and social networks [M. E. J. Newman, Nat. Phys. 8, 25 (2012), 10.1038/nphys2162]. Motivated by these facts, we here consider the evolutionary prisoner's dilemma game taking place on top of a real social network to investigate how the community structure and the heterogeneity in activity of individuals affect the evolution of cooperation. In particular, we account for a variation of the birth-death process (which can also be regarded as a proportional imitation rule from a social point of view) for the strategy updating under both weak and strong selection (meaning the payoffs harvested from games contribute either slightly or heavily to the individuals' performance). By implementing comparative studies, where the players are selected either randomly or in terms of their actual activities to play games with their immediate neighbors, we figure out that heterogeneous activity benefits the emergence of collective cooperation in a harsh environment (the action for cooperation is costly) under strong selection, whereas it impairs the formation of altruism under weak selection. Moreover, we find that the abundance of communities in the social network can evidently foster the formation of cooperation under strong selection, in contrast to the games evolving on randomized counterparts. Our results are therefore helpful for us to better understand the evolution of cooperation in real social systems.

  8. A Parallel Strategy for Convolutional Neural Network Based on Heterogeneous Cluster for Mobile Information System

    Directory of Open Access Journals (Sweden)

    Jilin Zhang

    2017-01-01

    Full Text Available With the development of the mobile systems, we gain a lot of benefits and convenience by leveraging mobile devices; at the same time, the information gathered by smartphones, such as location and environment, is also valuable for business to provide more intelligent services for customers. More and more machine learning methods have been used in the field of mobile information systems to study user behavior and classify usage patterns, especially convolutional neural network. With the increasing of model training parameters and data scale, the traditional single machine training method cannot meet the requirements of time complexity in practical application scenarios. The current training framework often uses simple data parallel or model parallel method to speed up the training process, which is why heterogeneous computing resources have not been fully utilized. To solve these problems, our paper proposes a delay synchronization convolutional neural network parallel strategy, which leverages the heterogeneous system. The strategy is based on both synchronous parallel and asynchronous parallel approaches; the model training process can reduce the dependence on the heterogeneous architecture in the premise of ensuring the model convergence, so the convolution neural network framework is more adaptive to different heterogeneous system environments. The experimental results show that the proposed delay synchronization strategy can achieve at least three times the speedup compared to the traditional data parallelism.

  9. Statistical thermodynamics of fluids with orientation - dependent interactions : applications to water in homogeneous and heterogeneous systems

    NARCIS (Netherlands)

    Besseling, N.A.M.

    1993-01-01

    The aim of the present study was to develop a lattice theory for systems, homogeneous as well as heterogeneous, containing molecules with orientation- dependent interactions such as water. It was soon recognised that the so-called Bragg-Williams mean-field approximation is not capable of

  10. The Use of Coumarins as Environmentally-Sensitive Fluorescent Probes of Heterogeneous Inclusion Systems

    Directory of Open Access Journals (Sweden)

    Brian D. Wagner

    2009-01-01

    Full Text Available Coumarins, as a family of molecules, exhibit a wide range of fluorescence emission properties. In many cases, this fluorescence is extremely sensitive to the local environment of the molecule, especially the local polarity and microviscosity. In addition, coumarins show a wide range of size, shape, and hydrophobicity. These properties make them especially useful as fluorescent probes of heterogeneous environments, such as supramolecular host cavities, micelles, polymers and solids. This article will review the use of coumarins to probe such heterogeneous systems using fluorescence spectroscopy.

  11. Multifunctional optical system-on-a-chip for heterogeneous fiber optic sensor networks

    Science.gov (United States)

    Yu, Miao; Pang, Cheng; Gupta, Ashwani

    2015-08-01

    In this article, we review our recent progress on the development of a multifunctional optical system-on-a-chip platform, which can be used for achieving heterogeneous wireless fiber optical sensor networks. A multifunctional optical sensor platform based on the micro-electromechanical systems (MEMS) technology is developed. The key component of the multifunctional optical sensor platform is a MEMS based tunable Fabry-Pérot (FP) filter, which can be used as a phase modulator or a wavelength tuning device in a multifunctional optical sensing system. Mechanics model of the FP filter and optics model of the multifunctional optical sensing system are developed to facilitate the design of the filter. The MEMS FP filter is implemented in a multifunctional optical sensing system including both Fabry-Perot interferometer based sensors and Fiber Bragg grating sensors. The experimental results indicate that this large dynamic range tunable filter can enable high performance heterogeneous optical sensing for many applications.

  12. Spatial heterogeneity of biofouling under different cross-flow velocities in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia

    2016-09-06

    The spatially heterogeneous distribution of biofouling in spiral wound membrane systems restricts (i) the water distribution over the membrane surface and therefore (ii) the membrane-based water treatment. The objective of the study was to assess the spatial heterogeneity of biofilm development over the membrane fouling simulator (MFS) length (inlet and outlet part) at three different cross-flow velocities (0.08, 0.12 and 0.16 m/s). The MFS contained sheets of membrane and feed spacer and simulated the first 0.20 m of spiral-wound membrane modules where biofouling accumulates the most in practice. In-situ non-destructive oxygen imaging using planar optodes was applied to determine the biofilm spatially resolved activity and heterogeneity.

  13. Impact of sorbic acid on germination and outgrowth heterogeneity of Bacillus cereus ATCC 14579 spores

    NARCIS (Netherlands)

    Besten, den H.M.W.; Melis, van C.C.J.; Sanders, J.W.; Nierop Groot, M.N.; Abee, T.

    2012-01-01

    Population heterogeneity complicates the predictability of the outgrowth kinetics of individual spores. Flow cytometry sorting and monitoring of the germination and outgrowth of single dormant spores allowed the quantification of acid-induced spore population heterogeneity at pH 5.5 and in the

  14. Heterogeneity in infection outcome: lessons from a bumblebee-trypanosome system.

    Science.gov (United States)

    Sadd, B M; Barribeau, S M

    2013-11-01

    Interactions between insect hosts and their parasites are significant because their parasites can also be parasites of humans and of species that we utilize. Host-parasite interactions are complex, even in insects, and there can be heterogeneous outcomes in infection success, load, virulence and transmission, with consequences for the evolution of hosts and their parasites, and also for epidemiology. A comprehension that the triad of host, parasite and environment interact to dictate infection outcome is key for anyone interested in host-parasite research. Studies in model systems used to good effect to characterize insect immunity and infection rarely scrutinize such heterogeneity. Evolutionary ecology studies addressing natural variation offer a window on the causes and consequences of such heterogeneity. A system at the forefront in this area is that of bumblebees and their trypanosome parasite Crithidia. Placing results and interpretations in a broader context we synthesize the plethora of work on bumblebee immunity and parasite interactions. We describe and discuss the sources of heterogeneity that should also be considered in human-relevant insect-parasite systems, including genotypic variation in both parasites and hosts, the mediating role of the environment, and explore the emerging evidence for microbiota modulating defence against parasites. © 2013 John Wiley & Sons Ltd.

  15. System Architecture and Key Technologies for 5G Heterogeneous Cloud Radio Access Networks

    OpenAIRE

    Peng, Mugen; Li, Yong; Zhao, Zhongyuan; Wang, Chonggang

    2014-01-01

    Compared with the fourth generation (4G) cellular systems, the fifth generation wireless communication systems (5G) are anticipated to provide spectral and energy efficiency growth by a factor of at least 10, and the area throughput growth by a factor of at least 25. To achieve these goals, a heterogeneous cloud radio access network (H-CRAN) is presented in this article as the advanced wireless access network paradigm, where cloud computing is used to fulfill the centralized large-scale coope...

  16. A Heterogeneous High-Performance System for Computational and Computer Science

    Science.gov (United States)

    2016-11-15

    System for Computational and Computer Science Report Title This DoD HBC/MI Equipment/Instrumentation grant was awarded in October 2014 for the purchase... Computing (HPC) course taught in the department of computer science as to attract more graduate students from many disciplines where their research...AND SUBTITLE A Heterogeneous High-Performance System for Computational and Computer Science 5a. CONTRACT NUMBER W911NF-15-1-0023 5b

  17. Analysis of phosphorescence in heterogeneous systems using distributions of quencher concentration.

    Science.gov (United States)

    Golub, A S; Popel, A S; Zheng, L; Pittman, R N

    1997-07-01

    A continuous distribution approach, instead of the traditional mono- and multiexponential analysis, for determining quencher concentration in a heterogeneous system has been developed. A mathematical model of phosphorescence decay inside a volume with homogeneous concentration of phosphor and heterogeneous concentration of quencher was formulated to obtain pulse-response fitting functions for four different distributions of quencher concentration: rectangular, normal (Gaussian), gamma, and multimodal. The analysis was applied to parameter estimates of a heterogeneous distribution of oxygen tension (PO2) within a volume. Simulated phosphorescence decay data were randomly generated for different distributions and heterogeneity of PO2 inside the excitation/emission volume, consisting of 200 domains, and then fit with equations developed for the four models. Analysis using a monoexponential fit yielded a systematic error (underestimate) in mean PO2 that increased with the degree of heterogeneity. The fitting procedures based on the continuous distribution approach returned more accurate values for parameters of the generated PO2 distribution than did the monoexponential fit. The parameters of the fit (M = mean; sigma = standard deviation) were investigated as a function of signal-to-noise ratio (SNR = maximum signal amplitude/peak-to-peak noise). The best-fit parameter values were stable when SNR > or = 20. All four fitting models returned accurate values of M and sigma for different PO2 distributions. The ability of our procedures to resolve two different heterogeneous compartments was also demonstrated using a bimodal fitting model. An approximate scheme was formulated to allow calculation of the first moments of a spatial distribution of quencher without specifying the distribution. In addition, a procedure for the recovery of a histogram, representing the quencher concentration distribution, was developed and successfully tested.

  18. Selective habitat utilisation and impact on vegetation by African elephant within a heterogeneous landscape

    Directory of Open Access Journals (Sweden)

    A. Steyn

    2001-07-01

    Full Text Available Since 1992, a total of 33 elephants have been reintroduced to a 31 000 ha game-fenced section of the Songimvelo Game Reserve in the Barberton Mountainland, South Africa. The impact from elephant was assessed on the attainment of the primary management objectives which are the conservation of plant community and plant species diversity. A total of 160 semi-quantitative plots were systematically sampled along foraging paths. Vegetation was assessed in terms of dominant species composition and species utilised. Elephant activity is mostly confined to a rugged 1 200 ha portion of the reserve. Forest, thickets and woodlands are positively selected, whereas shrublands and grasslands are little utilised. A total of 73 woody species were recorded within the sample plots. Thirtynine of these species were utilised in the woodlands, 31 in the forest and thickets, and only 18 in the shrublands. Acacia ataxacantha, Dalbergia armata and Acacia caffra are ranked highest in dominance and in utilisation values. In contrast, Cussonia spicata and Pterocarpus angolensis are less common but are much selected. Continued utilisation at present levels could significantly threaten their persistence. These preliminary results indicate that the present low overall density of elephants relative to many other conservation areas already has a marked effect on certain plant species. Absolute elephant density figures are relatively meaningless within a heterogeneous landscape. The specific community and species make-up of the landscape needs to be taken into account for the determination of bounds to elephant numbers in order to ensure the maintenance of present plant species diversity levels.

  19. Surface Wave Mode Conversion due to Lateral Heterogeneity and its Impact on Waveform Inversions

    Science.gov (United States)

    Datta, A.; Priestley, K. F.; Chapman, C. H.; Roecker, S. W.

    2016-12-01

    Surface wave tomography based on great circle ray theory has certain limitations which become increasingly significant with increasing frequency. One such limitation is the assumption of different surface wave modes propagating independently from source to receiver, valid only in case of smoothly varying media. In the real Earth, strong lateral gradients can cause significant interconversion among modes, thus potentially wreaking havoc with ray theory based tomographic inversions that make use of multimode information. The issue of mode coupling (with either normal modes or surface wave modes) for accurate modelling and inversion of body wave data has received significant attention in the seismological literature, but its impact on inversion of surface waveforms themselves remains much less understood.We present an empirical study with synthetic data, to investigate this problem with a two-fold approach. In the first part, 2D forward modelling using a new finite difference method that allows modelling a single mode at a time, is used to build a general picture of energy transfer among modes as a function of size, strength and sharpness of lateral heterogeneities. In the second part, we use the example of a multimode waveform inversion technique based on the Cara and Leveque (1987) approach of secondary observables, to invert our synthetic data and assess how mode conversion can affect the process of imaging the Earth. We pay special attention to ensuring that any biases or artefacts in the resulting inversions can be unambiguously attributed to mode conversion effects. This study helps pave the way towards the next generation of (non-numerical) surface wave tomography techniques geared to exploit higher frequencies and mode numbers than are typically used today.

  20. FOREWORD: Heterogenous nucleation and microstructure formation—a scale- and system-bridging approach Heterogenous nucleation and microstructure formation—a scale- and system-bridging approach

    Science.gov (United States)

    Emmerich, H.

    2009-11-01

    Scope and aim of this volume. Nucleation and initial microstructure formation play an important role in almost all aspects of materials science [1-5]. The relevance of the prediction and control of nucleation and the subsequent microstructure formation is fully accepted across many areas of modern surface and materials science and technology. One reason is that a large range of material properties, from mechanical ones such as ductility and hardness to electrical and magnetic ones such as electric conductivity and magnetic hardness, depend largely on the specific crystalline structure that forms in nucleation and the subsequent initial microstructure growth. A very demonstrative example for the latter is the so called bamboo structure of an integrated circuit, for which resistance against electromigration [6] , a parallel alignment of grain boundaries vertical to the direction of electricity, is most favorable. Despite the large relevance of predicting and controlling nucleation and the subsequent microstructure formation, and despite significant progress in the experimental analysis of the later stages of crystal growth in line with new theoretical computer simulation concepts [7], details about the initial stages of solidification are still far from being satisfactorily understood. This is in particular true when the nucleation event occurs as heterogenous nucleation. The Priority Program SPP 1296 'Heterogenous Nucleation and Microstructure Formation—a Scale- and System-Bridging Approach' [8] sponsored by the German Research Foundation, DFG, intends to contribute to this open issue via a six year research program that enables approximately twenty research groups in Germany to work interdisciplinarily together following this goal. Moreover, it enables the participants to embed themselves in the international community which focuses on this issue via internationally open joint workshops, conferences and summer schools. An outline of such activities can be found

  1. A MODEL OF HETEROGENEOUS DISTRIBUTED SYSTEM FOR FOREIGN EXCHANGE PORTFOLIO ANALYSIS

    Directory of Open Access Journals (Sweden)

    Dragutin Kermek

    2006-06-01

    Full Text Available The paper investigates the design of heterogeneous distributed system for foreign exchange portfolio analysis. The proposed model includes few separated and dislocated but connected parts through distributed mechanisms. Making system distributed brings new perspectives to performance busting where software based load balancer gets very important role. Desired system should spread over multiple, heterogeneous platforms in order to fulfil open platform goal. Building such a model incorporates different patterns from GOF design patterns, business patterns, J2EE patterns, integration patterns, enterprise patterns, distributed design patterns to Web services patterns. The authors try to find as much as possible appropriate patterns for planned tasks in order to capture best modelling and programming practices.

  2. Experiments and Simulations of Fluid Flow in Heterogeneous Reservoir Models - Emphasis on Impacts from Crossbeds and Fractures

    Energy Technology Data Exchange (ETDEWEB)

    Boerresen, Knut Arne

    1996-12-31

    Hydrocarbon recovery from subsurface reservoirs has become increasingly dependent on advanced recovery techniques that require improved understanding of the physics of fluid flow within and across geological units including small-scale heterogeneities and fractures. In this thesis, impacts from heterogeneities on local fluid flow are studied experimentally by means of imaging techniques to visualize fluid flow in two dimensions during flooding of larger reservoir models. Part 1 reflects the multi-disciplinary collaboration, by briefly introducing the relevant geology, the literature on experiments on fluid flow in bedded structures, and outlining the applied numerical simulator and imaging techniques applied to visualize fluid flow. The second part contains a synopsis of displacement experiments in naturally laminated sandstones and in crossbed laboratory models, and of the impact from incipient shear fractures on oil recovery. The detailed results obtained from the experiments and simulations are described in six papers, all included. 215 refs., 108 figs., 16 tabs.

  3. The impact of heterogeneous response on coupled spreading dynamics in multiplex networks

    Science.gov (United States)

    Nie, Xiaoyu; Tang, Ming; Zou, Yong; Guan, Shuguang; Zhou, Jie

    2017-10-01

    Many recent studies have demonstrated that individual awareness of disease may significantly affect the spreading process of infectious disease. In the majority of these studies, the response of the awareness is generally treated homogeneously. Considering of diversity and heterogeneity in the human behavior which widely exist under different circumstances, in this paper we study heterogeneous response when people are aware of the prevalence of infectious diseases. Specifically, we consider that an individual with more neighbors may take more preventive measures as a reaction when he is aware of the disease. A suppression strength is introduced to describe such heterogeneity, and we find that a more evident heterogeneity may cause a more effective suppressing effect to the spreading of epidemics. A mean-field theory is developed to support the results which are verified on the multiplex networks with different interlayer degree correlation.

  4. Impacts of Streambed Heterogeneity and Anisotropy on Residence Time of Hyporheic Zone.

    Science.gov (United States)

    Liu, Suning; Chui, Ting Fong May

    2017-09-14

    The hyporheic zone (HZ), which is the region beneath or alongside a streambed, plays an important role in the stream's ecology. The duration that a water molecule or a solute remains within the HZ, or residence time (RT), is one of the most common metrics used to evaluate the function of the HZ. The RT is greatly influenced by the streambed's hydraulic conductivity (K), which is intrinsically difficult to characterize due to its heterogeneity and anisotropy. Many laboratory and numerical studies of the HZ have simplified the streambed K to a constant, thus producing RT values that may differ from those gathered from the field. Some studies have considered the heterogeneity of the HZ, but very few have accounted for anisotropy or the natural K distributions typically found in real streambeds. This study developed numerical models in MODFLOW to examine the influence of heterogeneity and anisotropy, and that of the natural K distribution in a streambed, on the RT of the HZ. Heterogeneity and anisotropy were both found to shorten the mean and median RTs while increasing the range of the RTs. Moreover, heterogeneous K fields arranged in a more orderly pattern had longer RTs than those with random K distributions. These results could facilitate the design of streambed K values and distributions to achieve the desired RT during river restoration. They could also assist the translation of results from the more commonly considered homogeneous and/or isotropic conditions into heterogeneous and anisotropic field situations. © 2017, National Ground Water Association.

  5. Design And Planning Of E- Learning EnvironmentE-Education System On Heterogeneous Wireless Network Control System

    Directory of Open Access Journals (Sweden)

    ThandarOo

    2015-06-01

    Full Text Available Abstract The purpose of this research is to provide a more efficient and effective communication method between teacher and student with the use of heterogeneous network. Moreover the effective use of heterogeneous network can be emphasized. The system of e-education can develop utilizing wireless network.The e-Education system can help students to communicate with their teacher more easily and effectively using a heterogeneous wireless network system. In this wireless network system students who are blind or dumb will also be able to communicate and learn from the teacher as normal students can do. All the devices or laptops will be connected on wireless LAN. Even when the teacher is not around he will be able to help his students with their study or give instructions easily by using the mobile phone to send text or voice signal. When the teacher sends information to the dumb student it will be converted into sign language for the student to be able to understand. When the dumb student sends the information to the teacher it will be converted into text for the teacher to understand. For the blind student text instructions from the teacher will be converted into audio signal using text-to-speech conversion.Thus the performance of heterogeneous wireless network model can evaluate by using Robust Optimization Method. Therefore the e-Education systems performance improves by evaluating Robust Optimization Method.

  6. Automation of multi-agent control for complex dynamic systems in heterogeneous computational network

    Science.gov (United States)

    Oparin, Gennady; Feoktistov, Alexander; Bogdanova, Vera; Sidorov, Ivan

    2017-01-01

    The rapid progress of high-performance computing entails new challenges related to solving large scientific problems for various subject domains in a heterogeneous distributed computing environment (e.g., a network, Grid system, or Cloud infrastructure). The specialists in the field of parallel and distributed computing give the special attention to a scalability of applications for problem solving. An effective management of the scalable application in the heterogeneous distributed computing environment is still a non-trivial issue. Control systems that operate in networks, especially relate to this issue. We propose a new approach to the multi-agent management for the scalable applications in the heterogeneous computational network. The fundamentals of our approach are the integrated use of conceptual programming, simulation modeling, network monitoring, multi-agent management, and service-oriented programming. We developed a special framework for an automation of the problem solving. Advantages of the proposed approach are demonstrated on the parametric synthesis example of the static linear regulator for complex dynamic systems. Benefits of the scalable application for solving this problem include automation of the multi-agent control for the systems in a parallel mode with various degrees of its detailed elaboration.

  7. SPORT: An Algorithm for Divisible Load Scheduling with Result Collection on Heterogeneous Systems

    Science.gov (United States)

    Ghatpande, Abhay; Nakazato, Hidenori; Beaumont, Olivier; Watanabe, Hiroshi

    Divisible Load Theory (DLT) is an established mathematical framework to study Divisible Load Scheduling (DLS). However, traditional DLT does not address the scheduling of results back to source (i. e., result collection), nor does it comprehensively deal with system heterogeneity. In this paper, the DLSRCHETS (DLS with Result Collection on HET-erogeneous Systems) problem is addressed. The few papers to date that have dealt with DLSRCHETS, proposed simplistic LIFO (Last In, First Out) and FIFO (First In, First Out) type of schedules as solutions to DLSRCHETS. In this paper, a new polynomial time heuristic algorithm, SPORT (System Parameters based Optimized Result Transfer), is proposed as a solution to the DLSRCHETS problem. With the help of simulations, it is proved that the performance of SPORT is significantly better than existing algorithms. The other major contributions of this paper include, for the first time ever, (a) the derivation of the condition to identify the presence of idle time in a FIFO schedule for two processors, (b) the identification of the limiting condition for the optimality of FIFO and LIFO schedules for two processors, and (c) the introduction of the concept of equivalent processor in DLS for heterogeneous systems with result collection.

  8. Information and Heterogeneous Beliefs

    DEFF Research Database (Denmark)

    Christensen, Peter Ove; Qin, Zhenjiang

    2014-01-01

    In an incomplete market with heterogeneous prior beliefs, we show public information can have a substantial impact on the ex ante cost of capital, trading volume, and investor welfare. The Pareto effcient public information system is the system enjoying the maximum ex ante cost of capital...... ante risk premium is unaffected by the informativeness of the public information system. Similar results are obtained in a production economy, but the impact on the ex ante cost of capital is dampened compared to the exchange economy due to welfare improving reductions in real investments to smooth...... and the maximum expected abnormal trading volume. Imperfect public information increases the gains-to-trade based on heterogeneously updated posterior beliefs. In an exchange economy, this leads to higher growth in the investors' certainty equivalents and, thus, a higher equilibrium interest rate, whereas the ex...

  9. Low Impact Docking System (LIDS)

    Science.gov (United States)

    LaBauve, Tobie E.

    2009-01-01

    Since 1996, NASA has been developing a docking system that will simplify operations and reduce risks associated with mating spacecraft. This effort has focused on developing and testing an original, reconfigurable, active, closed-loop, force-feedback controlled docking system using modern technologies. The primary objective of this effort has been to design a docking interface that is tunable to the unique performance requirements for all types of mating operations (i.e. docking and berthing, autonomous and piloted rendezvous, and in-space assembly of vehicles, modules and structures). The docking system must also support the transfer of crew, cargo, power, fluid, and data. As a result of the past 10 years of docking system advancement, the Low Impact Docking System or LIDS was developed. The current LIDS design incorporates the lessons learned and development experiences from both previous and existing docking systems. LIDS feasibility was established through multiple iterations of prototype hardware development and testing. Benefits of LIDS include safe, low impact mating operations, more effective and flexible mission implementation with an anytime/anywhere mating capability, system level redundancy, and a more affordable and sustainable mission architecture with reduced mission and life cycle costs. In 1996 the LIDS project, then known as the Advanced Docking Berthing System (ADBS) project, launched a four year developmental period. At the end of the four years, the team had built a prototype of the soft-capture hardware and verified the control system that will be used to control the soft-capture system. In 2001, the LIDS team was tasked to work with the X- 38 Crew Return Vehicle (CRV) project and build its first Engineering Development Unit (EDU).

  10. Performance and operational experience with the heterogeneous farm of the ATLAS Trigger and Data Acquisition system.

    CERN Document Server

    Garelli, N; The ATLAS collaboration; Vandelli, W

    2011-01-01

    The ATLAS trigger and data acquisition (TDAQ) is a distributed, multi trigger level, data-acquisition system, mostly made of off-the-shelf processing units organized in a farm. In its final configuration the system will account more than 2000 nodes, sporting heterogeneous capabilities and network connectivities, due to the TDAQ program for rolling expansions and upgrades. In this paper we will present how we dealt with the farm heterogeneity during the proton-proton collisions of 2010 and 2011: a period characterized by changing working conditions, and constantly increasing LHC instantaneous luminosity. We will describe a graphical tool to show, control, modify and balance the computing-power and bandwidth sharing across the trigger farms, a data-flow monitoring daemon which provides a high-level resource-aware data-flow operational information, and the evolution of data-flow communication protocols.

  11. Performance and Operational Experience with the Heterogeneous Farm of the ATLAS Trigger and Data Acquisition System

    CERN Document Server

    Garelli, N; The ATLAS collaboration; Vandelli, W

    2011-01-01

    The ATLAS trigger and data acquisition (TDAQ) is a distributed, multi trigger level, data-acquisition system, mostly made of off-the-shelf processing units organized in a farm. In its final configuration the system will account more than 2000 nodes, sporting heterogeneous capabilities and network connections, due to the TDAQ program for rolling expansions and upgrades. In this paper we present how we dealt with the farm heterogeneity during the proton-proton collisions of 2010 and 2011: a period characterized by changing working conditions, and constantly increasing LHC instantaneous luminosity. We describe a graphical tool to balance the computing-power and bandwidth sharing across the trigger farms, a data-flow monitoring daemon that provides high-level resource-aware data-flow operational information and the evolution of data-flow communication protocols.

  12. How to ensure sustainable interoperability in heterogeneous distributed systems through architectural approach.

    Science.gov (United States)

    Pape-Haugaard, Louise; Frank, Lars

    2011-01-01

    A major obstacle in ensuring ubiquitous information is the utilization of heterogeneous systems in eHealth. The objective in this paper is to illustrate how an architecture for distributed eHealth databases can be designed without lacking the characteristic features of traditional sustainable databases. The approach is firstly to explain traditional architecture in central and homogeneous distributed database computing, followed by a possible approach to use an architectural framework to obtain sustainability across disparate systems i.e. heterogeneous databases, concluded with a discussion. It is seen that through a method of using relaxed ACID properties on a service-oriented architecture it is possible to achieve data consistency which is essential when ensuring sustainable interoperability.

  13. Impact resistant battery enclosure systems

    Science.gov (United States)

    Tsutsui, Waterloo; Feng, Yuezhong; Chen, Weinong Wayne; Siegmund, Thomas Heinrich

    2017-10-31

    Battery enclosure arrangements for a vehicular battery system. The arrangements, capable of impact resistance include plurality of battery cells and a plurality of kinetic energy absorbing elements. The arrangements further include a frame configured to encase the plurality of the kinetic energy absorbing elements and the battery cells. In some arrangements the frame and/or the kinetic energy absorbing elements can be made of topologically interlocked materials.

  14. Analysis and Synthesis of Communication-Intensive Heterogeneous Real-Time Systems

    DEFF Research Database (Denmark)

    Pop, Paul

    2003-01-01

    Embedded computer systems are now everywhere: from alarm clocks to PDAs, from mobile phones to cars, almost all the devices we use are controlled by embedded computer systems. An important class of embedded computer systems is that of real-time systems, which have to fulfill strict timing...... not only in terms of platforms and communication protocols, but also in terms of scheduling policies. Regarding this last aspect, in this thesis we consider time-driven systems, event-driven systems, and a combination of both, called multi-cluster systems. The analysis takes into account the heterogeneous...... applications, and the design problem is to implement new functionality on top of this system. Hence, in addition to the analysis and synthesis methods proposed, we have also considered mapping and scheduling within such an incremental design process. The analysis and synthesis techniques proposed have been...

  15. Using heterogeneous wireless sensor networks in a telemonitoring system for healthcare.

    Science.gov (United States)

    Corchado, Juan M; Bajo, Javier; Tapia, Dante I; Abraham, Ajith

    2010-03-01

    Ambient intelligence has acquired great importance in recent years and requires the development of new innovative solutions. This paper presents a distributed telemonitoring system, aimed at improving healthcare and assistance to dependent people at their homes. The system implements a service-oriented architecture based platform, which allows heterogeneous wireless sensor networks to communicate in a distributed way independent of time and location restrictions. This approach provides the system with a higher ability to recover from errors and a better flexibility to change their behavior at execution time. Preliminary results are presented in this paper.

  16. A FAST AND ELITIST BI-OBJECTIVE EVOLUTIONARY ALGORITHM FOR SCHEDULING INDEPENDENT TASKS ON HETEROGENEOUS SYSTEMS

    Directory of Open Access Journals (Sweden)

    G.Subashini

    2010-07-01

    Full Text Available To meet the increasing computational demands, geographically distributed resources need to be logically coupled to make them work as a unified resource. In analyzing the performance of such distributed heterogeneous computing systems scheduling a set of tasks to the available set of resources for execution is highly important. Task scheduling being an NP-complete problem, use of metaheuristics is more appropriate in obtaining optimal solutions. Schedules thus obtained can be evaluated using several criteria that may conflict with one another which require multi objective problem formulation. This paper investigates the application of an elitist Nondominated Sorting Genetic Algorithm (NSGA-II, to efficiently schedule a set of independent tasks in a heterogeneous distributed computing system. The objectives considered in this paper include minimizing makespan and average flowtime simultaneously. The implementation of NSGA-II algorithm and Weighted-Sum Genetic Algorithm (WSGA has been tested on benchmark instances for distributed heterogeneous systems. As NSGA-II generates a set of Pareto optimal solutions, to verify the effectiveness of NSGA-II over WSGA a fuzzy based membership value assignment method is employed to choose the best compromise solution from the obtained Pareto solution set.

  17. Impactites as a random medium—Using variations in physical properties to assess heterogeneity within the Bosumtwi meteorite impact crater

    Science.gov (United States)

    L'Heureux, Elizabeth; Milkereit, Bernd

    The recent drilling of the Bosumtwi impact structure, Ghana, has provided a unique opportunity to study the petrophysical properties of a young, well-preserved impact crater. The damage induced by impact results in extensive fracturing and mixing of target materials. We discuss here a means of using sonic velocity and density logs from two boreholes through the Bosumtwi crater fill and basement to estimate the degree of heterogeneity and fracturing within the impacted target, in order to understand the discrepancy between the large impedances derived from the log data and the nonreflective zone of impactites observed in seismic sections. Based on an analysis of the stochastic fluctuations in the log data, the Bosumtwi impactites are characterized by vertical scale lengths of 2-3 m. From the resolution of the seismic data over the crater, horizontal scale lengths are estimated at energy will propagate through the medium with little disruption. Scale lengths as small as these are observed in the fractured basement rocks of impact structures, whereas non-impact related crystalline environments are characterized by scale lengths an order of magnitude larger. Assuming that the high-frequency fluctuations observed in the log data are more sensitive to fracture distribution than petrology, this suggests that the small scale lengths observed within impact structures are characteristic of impact-induced damage, and could be used to estimate the extent of fracturing undergone by the rocks at any depth below an impact structure.

  18. Significant impacts of heterogeneous reactions on the chemical composition and mixing state of dust particles: A case study during dust events over northern China

    Science.gov (United States)

    Wang, Zhe; Pan, Xiaole; Uno, Itsushi; Li, Jie; Wang, Zifa; Chen, Xueshun; Fu, Pingqing; Yang, Ting; Kobayashi, Hiroshi; Shimizu, Atsushi; Sugimoto, Nobuo; Yamamoto, Shigekazu

    2017-06-01

    The impact of heterogeneous reactions on the chemical components and mixing state of dust particles are investigated by observations and an air quality model over northern China between March 27, 2015 and April 2, 2015. Synergetic observations were conducted using a polarization optical particle counter (POPC), a depolarized two-wavelength Lidar and filter samples in Beijing. During this period, dust plume passed through Beijing on March 28, and flew back on March 29 because of synoptic weather changes. Mineral dust mixed with anthropogenic pollutants was simulated using the Nested Air Quality Prediction Modeling System (NAQPMS) to examine the role of heterogeneous processes on the dust. A comparison of observations shows that the NAQPMS successfully reproduces the time series of the vertical profile, particulate matter concentration, and chemical components of fine mode (diameter ≤ 2.5 μm) and coarse mode (2.5 μm < diameter ≤ 10 μm) particles. After considering the heterogeneous reactions, the simulated nitrate, ammonium, and sulfate are in better agreement with the observed values during this period. The modeling results with observations show that heterogeneous reactions are the major mechanisms producing nitrate reaching 19 μg/m3, and sulfate reaching 7 μg/m3, on coarse mode dust particles, which were almost 100% of the coarse mode nitrate and sulfate. The heterogeneous reactions are also important for fine mode secondary aerosols, for producing 17% of nitrate and 11% of sulfate on fine mode dust particles, with maximum mass concentrations of 6 μg/m3 and 4 μg/m3. In contrast, due to uptake of acid gases (e.g. HNO3 and SO2) by dust particles, the fine mode anthropogenic ammonium nitrate and ammonium sulfate decreased. As a result, the total fine mode nitrate decreased with a maximum of 14 μg/m3, while the total fine mode sulfate increased with a maximum of 2 μg/m3. Because of heterogeneous reactions, 15% of fine mode secondary inorganic aerosols and

  19. Heterogeneous systems biocatalysis; the path to the fabrication of self-sufficient artificial metabolic cells.

    Science.gov (United States)

    López-Gallego, Fernando; Jackson, Eriene; Betancor, Lorena

    2017-09-26

    Industrial biocatalysis is playing a key role in the development of the global bio-economy that must change our current productive model to pair the socio-economical development with the preservation of our already harmed planet. The exploitation of isolated multi-enzyme systems and the discovery of novel biocatalytic activities are leading us to manufacture chemicals that were inaccessible through biological routes in the early past. These endeavors have been grouped in the concept of Systems biocatalysis. However, by using isolated biological machineries, fundamental features underlying the protein confinement found inside the living cells are missed. To re-gain these properties such concept can be expanded to a new concept; heterogeneous systems biocatalysis. This new concept is based on the fabrication of heterogeneous biocatalysts inspired by the spatial organization and compartmentalization that orchestrate metabolic pathways within cells. By assembling biological machineries (including enzymes and cofators) into artificial solid chassis, one can fabricate self-sufficient and robust cell-free systems able to catalyze orchestrated chemical processes. Furthermore, the confinement of enzymes and "artificial cofactor" inside solid materials has also attracted our attention since these self-sufficient systems exert de novo and non natural functionalities. Herein, we pursue going beyond immobilization of multi-enzyme systems, discussing only those enzymatic systems that have been co-immobilized with their cofactor or exogenous partners to enhance their cooperative action. In this article, we review the latest architectures developed to fabricate self-sufficient heterogeneous biocatalysts with application in chemical manufacturing, biosensing or energy production. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Soil Microbiome Is More Heterogeneous in Organic Than in Conventional Farming System

    Science.gov (United States)

    Lupatini, Manoeli; Korthals, Gerard W.; de Hollander, Mattias; Janssens, Thierry K. S.; Kuramae, Eiko E.

    2017-01-01

    Organic farming system and sustainable management of soil pathogens aim at reducing the use of agricultural chemicals in order to improve ecosystem health. Despite the essential role of microbial communities in agro-ecosystems, we still have limited understanding of the complex response of microbial diversity and composition to organic and conventional farming systems and to alternative methods for controlling plant pathogens. In this study we assessed the microbial community structure, diversity and richness using 16S rRNA gene next generation sequences and report that conventional and organic farming systems had major influence on soil microbial diversity and community composition while the effects of the soil health treatments (sustainable alternatives for chemical control) in both farming systems were of smaller magnitude. Organically managed system increased taxonomic and phylogenetic richness, diversity and heterogeneity of the soil microbiota when compared with conventional farming system. The composition of microbial communities, but not the diversity nor heterogeneity, were altered by soil health treatments. Soil health treatments exhibited an overrepresentation of specific microbial taxa which are known to be involved in soil suppressiveness to pathogens (plant-parasitic nematodes and soil-borne fungi). Our results provide a comprehensive survey on the response of microbial communities to different agricultural systems and to soil treatments for controlling plant pathogens and give novel insights to improve the sustainability of agro-ecosystems by means of beneficial microorganisms. PMID:28101080

  1. Soil Microbiome Is More Heterogeneous in Organic Than in Conventional Farming System.

    Science.gov (United States)

    Lupatini, Manoeli; Korthals, Gerard W; de Hollander, Mattias; Janssens, Thierry K S; Kuramae, Eiko E

    2016-01-01

    Organic farming system and sustainable management of soil pathogens aim at reducing the use of agricultural chemicals in order to improve ecosystem health. Despite the essential role of microbial communities in agro-ecosystems, we still have limited understanding of the complex response of microbial diversity and composition to organic and conventional farming systems and to alternative methods for controlling plant pathogens. In this study we assessed the microbial community structure, diversity and richness using 16S rRNA gene next generation sequences and report that conventional and organic farming systems had major influence on soil microbial diversity and community composition while the effects of the soil health treatments (sustainable alternatives for chemical control) in both farming systems were of smaller magnitude. Organically managed system increased taxonomic and phylogenetic richness, diversity and heterogeneity of the soil microbiota when compared with conventional farming system. The composition of microbial communities, but not the diversity nor heterogeneity, were altered by soil health treatments. Soil health treatments exhibited an overrepresentation of specific microbial taxa which are known to be involved in soil suppressiveness to pathogens (plant-parasitic nematodes and soil-borne fungi). Our results provide a comprehensive survey on the response of microbial communities to different agricultural systems and to soil treatments for controlling plant pathogens and give novel insights to improve the sustainability of agro-ecosystems by means of beneficial microorganisms.

  2. Applying the Earth System Grid Security System in a Heterogeneous Environment of Data Access Services

    Science.gov (United States)

    Kershaw, Philip; Lawrence, Bryan; Lowe, Dominic; Norton, Peter; Pascoe, Stephen

    2010-05-01

    CEDA (Centre for Environmental Data Archival) based at STFC Rutherford Appleton Laboratory is host to the BADC (British Atmospheric Data Centre) and NEODC (NERC Earth Observation Data Centre) with data holdings of over half a Petabyte. In the coming months this figure is set to increase by over one Petabyte through the BADC's role as one of three data centres to host the CMIP5 (Coupled Model Intercomparison Project Phase 5) core archive of climate model data. Quite apart from the problem of managing the storage of such large volumes there is the challenge of collating the data together from the modelling centres around the world and enabling access to these data for the user community. An infrastructure to support this is being developed under the US Earth System Grid (ESG) and related projects bringing together participating organisations together in a federation. The ESG architecture defines Gateways, the web interfaces that enable users to access data and data serving applications organised into Data Nodes. The BADC has been working in collaboration with US Earth System Grid team and other partners to develop a security system to restrict access to data. This provides single sign-on via both OpenID and PKI based means and uses role based authorisation facilitated by SAML and OpenID based interfaces for attribute retrieval. This presentation will provide an overview of the access control architecture and look at how this has been implemented for CEDA. CEDA has developed an expertise in data access and information services over several years through a number of projects to develop and enhance these capabilities. Participation in CMIP5 comes at a time when a number of other software development activities are coming to fruition. New services are in the process of being deployed alongside services making up the system for ESG. The security system must apply access control across this heterogeneous environment of different data services and technologies. One strand

  3. Targeting resources within diverse, heterogeneous and dynamic farming systems: Towards a ‘uniquely African green revolution’

    NARCIS (Netherlands)

    Tittonell, P.A.; Vanlauwe, B.; Misiko, M.; Giller, K.E.

    2011-01-01

    Smallholder farms in sub-Saharan Africa (SSA) are highly diverse and heterogeneous, often operating in complex socio-ecological environments. Much of the heterogeneity within the farming systems is caused by spatial soil variability, which results in its turn from the interaction between inherent

  4. The Impact of Homogeneous vs. Heterogeneous Collaborative Learning Groups in Multicultural Classes on the Achievement and Attitudes of Nine Graders towards Learning Science

    Science.gov (United States)

    Faris, Ahmed O.

    2009-01-01

    The current study aims at investigating the impact of homogeneous versus heterogeneous collaborative learning grouping in multicultural classes on the students' achievements and attitudes towards learning science. In the present study, heterogeneity was unpacked through two dimensions: the cultural background, represented by the different…

  5. Power-Aware DVB-H Mobile TV System on Heterogeneous Multicore Platform

    Directory of Open Access Journals (Sweden)

    Yu-Sheng Lu

    2010-01-01

    Full Text Available In mobile communication network, the mobile device integrated with TV player is a novel technology that provides TV program services to end users. As TV program is a real-time video service, it has greater technical difficulties to overcome than a traditional video file download or online streaming, especially when TV programs are played on handheld devices. A challenge is how to save power in order to provide users with longer TV program services. To address this issue, this study proposes a mobile TV system on a heterogeneous multicore platform, which utilizes a Digital Video Broadcasting-Handheld (DVB-H wireless network to receive the TV program signal, thus, saving power according to the features of DVB-H TV signal and heterogeneous multi-core.

  6. Integrated Management of Heterogeneous Geodata with a Hybrid 3d Geoinformation System

    Science.gov (United States)

    Becker, S.; Walter, V.; Fritsch, D.

    2012-07-01

    The availability of 3D geodata is increasing tremendously. However, there is still a lack of appropriate tools for integrated data management and analysis solutions that can cope with the great diversity of geodata. Thus, our goal is a hybrid 3D geoinformation system which is able to combine and analyse heterogeneous 3D geodata in an efficient and consistent way. Based on the accepted standard ISO 19107, we propose a hybrid data model to overcome structural, geometric and topological data heterogeneity on a conceptual level. Our concept is hybrid with respect to data given in different data models, dimensions and quality levels. Through the explicit modelling of geometric correspondences, multiple representations and data inconsistency can be handled.

  7. Cooperative Output Regulation of Heterogeneous Linear Multi-Agent Systems by Event-Triggered Control.

    Science.gov (United States)

    Hu, Wenfeng; Liu, Lu

    2017-01-01

    In this paper, we consider the cooperative output regulation problem of heterogeneous linear multi-agent systems (MASs) by event-triggered control. We first develop an event-triggering mechanism for leader-following consensus of homogeneous MASs. Then by proposing an internal reference model for each agent, a novel distributed event-triggered control scheme is developed to solve the cooperative output regulation problem of heterogeneous MASs. Furthermore, a novel self-triggered control scheme is also proposed, such that continuous monitoring of measurement errors can be avoided. The feasibility of both proposed control schemes is studied by excluding Zeno behavior for each agent. An example is finally provided to demonstrate the effectiveness of the control schemes.

  8. Meso-design of heterogeneous dielectric material systems: Structure property relationships

    Directory of Open Access Journals (Sweden)

    Jeffrey Baker

    2014-04-01

    Full Text Available Heterogeneous materials are inherently dielectric, and charge distribution and transport in such materials involves complex local fields and polarizations that are remarkably sensitive to morphology and the interaction of conduction and permittivity. Trial and error design of such material systems is time consuming and expensive, and often ineffectual. However, heterogeneous materials are essential for energy conversion and storage, and they have become the foundation for major advances in the performance of devices such as batteries, fuel cells, separation membranes, and solar cells. The present paper presents some relationships in support of rational design based on an extensive experimental validation of the concepts and analysis that form a foundation for that design. Salient results include the prediction and confirmation of volume fraction effects (including nondilute mixtures, and the prediction and direct measurement of surface charge effects at internal interfaces as a function of constituent morphology and orientation.

  9. Epidemic modeling in metapopulation systems with heterogeneous coupling pattern: theory and simulations

    CERN Document Server

    Colizza, Vittoria

    2007-01-01

    The spatial structure of populations is a key element in the understanding of the large scale spreading of epidemics. Motivated by the recent empirical evidence on the heterogeneous properties of transportation and commuting patterns among urban areas, we present a thorough analysis of the behavior of infectious diseases in metapopulation models characterized by heterogeneous connectivity and mobility patterns. We derive the basic reaction-diffusion equation describing the metapopulation system at the mechanistic level and derive an early stage dynamics approximation for the subpopulation invasion dynamics. The analytical description uses degree block variables that allows us to take into account arbitrary degree distribution of the metapopulation network. We show that along with the usual single population epidemic threshold the metapopulation network exhibits a global threshold for the subpopulation invasion. We find an explicit analytic expression for the invasion threshold that determines the minimum numb...

  10. A state-of-the-art review of interoperability amongst heterogeneous software systems

    Directory of Open Access Journals (Sweden)

    Carlos Mario Zapata Jaramillo

    2009-05-01

    Full Text Available Information systems are sets of interacting elements aimed at supporting entrepreneurial or business activities; they cannot thus coexist in an isolated way but require their data to be shared so as to increase their productivity. Such systems’ interoperability is normally accomplished through mark-up standards, query languages and web services. The literature contains work related to software system interoperability; however, it presents some difficulties, such as the need for using the same platforms and different programming languages, the use of read only languages and the deficiencies in the formalism used for achieving it. This paper presents a critical review of the advances made regarding heterogeneous software systems’ interoperability.

  11. Impact of trade on viability and exporter selection with heterogeneous fixed cost in the Melitz model

    NARCIS (Netherlands)

    Chang, H.H.; van Marrewijk, C.

    2012-01-01

    This paper presents a model aim to reconcile the discrepancy between the theoretical and empirical depiction of the productivity distribution. The Melitz (2003) while being able to reflect on the asymmetric selection of heterogeneous firms in trade, the model strictly truncate the least productive

  12. Systematic Evaluation of the Prognostic Impact and Intratumour Heterogeneity of Clear Cell Renal Cell Carcinoma Biomarkers

    DEFF Research Database (Denmark)

    Gulati, Sakshi; Martinez, Pierre; Joshi, Tejal

    2014-01-01

    BackgroundCandidate biomarkers have been identified for clear cell renal cell carcinoma (ccRCC) patients, but most have not been validated. ObjectiveTo validate published ccRCC prognostic biomarkers in an independent patient cohort and to assess intratumour heterogeneity (ITH) of the most promisi...

  13. Evaluation of the heterogeneity corrections impact in lung stereotactic body radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Jose Eduardo V.; Chiara, Ana Claudia M. de; Casagrande, Thais M.; Alves, Tatiana M.M.T.; Neves-Junior, Wellington F.P.; Mancini, Anselmo; Capella, Eliana; Pelosi, Edilson; Haddad, Cecilia K., E-mail: eduvan_rmm@hotmail.com [Hospital Sirio Libanes, Sao Paulo, SP (Brazil)

    2011-07-01

    Stereotactic body radiation therapy refers to an emerging radiotherapy that is highly effective in controlling early primary and oligometastic cancers at locations throughout the abdominopelvic and thoracic cavities, and at spinal and paraspinal sites. Some protocols have been developed for this procedure. In the special cases of lung, there are protocols in use that consider heterogeneity corrections and others that do not make use of heterogeneity correction. In this work, we recalculated, considering the different tissue densities plans initially optimized without heterogeneity corrections to evaluate the dosimetric changes that occurs, for example, PTV (planning target volume) coverage, dose to isocenter and dose to critical structures, and we calculated gamma function between the dose plans originated in the two conditions. We also performed the superposition between the calculated gamma function with the respective CT slice in order to evaluate in what conditions occur the major differences between the conditions of calculus considered. The results showed that relevant variations occur between the two situations of calculus. With the superposition of the image relative to {gamma} index and its respective CT slice, we could visualize where the greatest discrepancies occur. These data allow us to evaluate with more accuracy the doses delivered to the target and organs at risk and compare different protocols, independently of the use or non-use of heterogeneity corrections. (author)

  14. Surface heterogeneity impacts on boundary layer dynamics via energy balance partitioning

    Science.gov (United States)

    The role of land-atmosphere interactions under heterogeneous surface conditions is investigated in order to identify mechanisms responsible for altering surface heat and moisture fluxes. Twelve coupled land surface – large eddy simulation scenarios with four different length scales of surface variab...

  15. Phenotypic heterogeneity in the endothelium of the human vortex vein system.

    Science.gov (United States)

    Yu, Paula K; Tan, Priscilla E Z; Cringle, Stephen J; McAllister, Ian L; Yu, Dao-Yi

    2013-10-01

    The vortex vein system is the drainage pathway for the choroidal circulation and serves an important function in the effective drainage of the exceptionally high blood flow from the choroidal circulation. As there are only 4-6 vortex veins, a large volume of blood must be drained from many choroidal veins into each individual vortex vein. The vortex vein system must also cope with passing through tissues of different rigidity and significant pressure gradient as it transverses from the intrao-cular to the extra-ocular compartments. However, little is known about how the vortex vein system works under such complex situations in both physiological and pathological condition. Endothelial cells play a vital role in other vascular systems, but they have not been studied in detail in the vortex vein system. The purpose of this study is to characterise the intracellular structures and morphology in both the intra-and extra-ocular regions of the human vortex vein system. We hypothesise the presence of endothelial phenotypic heterogeneity through the vortex vein system. The inferior temporal vortex vein system from human donor eyes were obtained and studied histologically using confocal microscopy. The f-actin cytoskeleton and nuclei were labelled using Alexa Fluor conjugated Phalloidin and YO-PRO-1. Eight regions of the vortex vein system were examined with the venous endothelium studied in detail with quantitative data obtained for endothelial cell and nuclei size and shape. Significant endothelial phenotypic heterogeneity was found throughout the vortex vein system with the most obvious differences observed between the ampulla and its downstream regions. Variation in the distribution pattern of smooth muscle cells, in particular the absence of smooth muscle cells around the ampulla, was noted. Our results suggest the presence of significantly different haemodynamic forces in different regions of the vortex vein system and indicate that the vortex vein system may play

  16. Regional heterogeneity of endothelial cells in the porcine vortex vein system.

    Science.gov (United States)

    Tan, Priscilla Ern Zhi; Yu, Paula K; Cringle, Stephen J; Morgan, William H; Yu, Dao-Yi

    2013-09-01

    The aim of this study was to investigate whether region-dependent endothelial heterogeneity is present within the porcine vortex vein system. The superior temporal vortex vein in young adult pig eyes were dissected out and cannulated. The intact vortex vein system down to the choroidal veins was then perfused with labels for f-actin and nucleic acid. The endothelial cells within the choroidal veins, pre-ampulla, anterior portion of the ampulla, mid-ampulla, posterior portion of the ampulla, post-ampulla, intra-scleral canal and the extra-ocular vortex vein regions were studied in detail using a confocal microscopy technique. The endothelial cell and nuclei length, width, area and perimeter were measured and compared between the different regions. Significant regional differences in the endothelial cell and nuclei length, width, area and perimeter were observed throughout the porcine vortex vein system. Most notably, very narrow and elongated endothelia were found in the post-ampulla region. A lack of smooth muscle cells was noted in the ampulla region compared to other regions. Heterogeneity in endothelial cell morphology is present throughout the porcine vortex vein system and there is a lack of smooth muscle cells in the ampulla region. This likely reflects the highly varied haemodynamic conditions and potential blood flow control mechanisms in different regions of the vortex vein system. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Implementation of integrated heterogeneous electronic electrocardiography data into Maharaj Nakorn Chiang Mai Hospital Information System.

    Science.gov (United States)

    Khumrin, Piyapong; Chumpoo, Pitupoom

    2016-03-01

    Electrocardiography is one of the most important non-invasive diagnostic tools for diagnosing coronary heart disease. The electrocardiography information system in Maharaj Nakorn Chiang Mai Hospital required a massive manual labor effort. In this article, we propose an approach toward the integration of heterogeneous electrocardiography data and the implementation of an integrated electrocardiography information system into the existing Hospital Information System. The system integrates different electrocardiography formats into a consistent electrocardiography rendering by using Java software. The interface acts as middleware to seamlessly integrate different electrocardiography formats. Instead of using a common electrocardiography protocol, we applied a central format based on Java classes for mapping different electrocardiography formats which contains a specific parser for each electrocardiography format to acquire the same information. Our observations showed that the new system improved the effectiveness of data management, work flow, and data quality; increased the availability of information; and finally improved quality of care. © The Author(s) 2014.

  18. Cancer Care Coordinators to Improve Tamoxifen Persistence in Breast Cancer: How Heterogeneity in Baseline Prognosis Impacts on Cost-Effectiveness.

    Science.gov (United States)

    Nair, Nisha; Kvizhinadze, Giorgi; Blakely, Tony

    2016-12-01

    To assess the cost-effectiveness of a cancer care coordinator (CCC) in helping women with estrogen receptor positive (ER+) early breast cancer persist with tamoxifen for 5 years. We investigated the cost-effectiveness of a CCC across eight breast cancer subtypes, defined by progesterone receptor (PR) status, human epidermal growth factor receptor 2 (HER2) status, and local/regional spread. These subtypes range from excellent to poorer prognoses. The CCC helped in improving tamoxifen persistence by providing information, checking-in by phone, and "troubleshooting" concerns. We constructed a Markov macrosimulation model to estimate health gain (in quality-adjusted life-years or QALYs) and health system costs in New Zealand, compared with no CCC. Participants were modeled until death or till the age of 110 years. Some input parameters (e.g., the impact of a CCC on tamoxifen persistence) had sparse evidence. Therefore, we used estimates with generous uncertainty and conducted sensitivity analyses. The cost-effectiveness of a CCC for regional ER+/PR-/HER2+ breast cancer (worst prognosis) was NZ $23,400 (US $15,800) per QALY gained, compared with NZ $368,500 (US $248,800) for local ER+/PR+/HER2- breast cancer (best prognosis). Using a cost-effectiveness threshold of NZ $45,000 (US $30,400) per QALY, a CCC would be cost-effective only in the four subtypes with the worst prognoses. There is value in investigating cost-effectiveness by different subtypes within a disease. In this example of breast cancer, the poorer the prognosis, the greater the health gains from a CCC and the better the cost-effectiveness. Incorporating heterogeneity in a cost-utility analysis is important and can inform resource allocation decisions. It is also feasible to undertake in practice. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  19. Developing Verification Systems for Building Information Models of Heritage Buildings with Heterogeneous Datasets

    Science.gov (United States)

    Chow, L.; Fai, S.

    2017-08-01

    The digitization and abstraction of existing buildings into building information models requires the translation of heterogeneous datasets that may include CAD, technical reports, historic texts, archival drawings, terrestrial laser scanning, and photogrammetry into model elements. In this paper, we discuss a project undertaken by the Carleton Immersive Media Studio (CIMS) that explored the synthesis of heterogeneous datasets for the development of a building information model (BIM) for one of Canada's most significant heritage assets - the Centre Block of the Parliament Hill National Historic Site. The scope of the project included the development of an as-found model of the century-old, six-story building in anticipation of specific model uses for an extensive rehabilitation program. The as-found Centre Block model was developed in Revit using primarily point cloud data from terrestrial laser scanning. The data was captured by CIMS in partnership with Heritage Conservation Services (HCS), Public Services and Procurement Canada (PSPC), using a Leica C10 and P40 (exterior and large interior spaces) and a Faro Focus (small to mid-sized interior spaces). Secondary sources such as archival drawings, photographs, and technical reports were referenced in cases where point cloud data was not available. As a result of working with heterogeneous data sets, a verification system was introduced in order to communicate to model users/viewers the source of information for each building element within the model.

  20. Dosimetric verification of a high dose rate brachytherapy treatment planning system in homogeneous and heterogeneous media.

    Science.gov (United States)

    Uniyal, S C; Sharma, S D; Naithani, U C

    2013-03-01

    To verify the dosimetric accuracy of treatment plans in high dose rate (HDR) brachytherapy by using Gafchromic EBT2 film and to demonstrate the adequacy of dose calculations of a commercial treatment planning system (TPS) in a heterogeneous medium. Absorbed doses at chosen points in anatomically different tissue equivalent phantoms were measured using Gafchromic EBT2 film. In one case, tandem ovoid brachytherapy was performed in a homogeneous cervix phantom, whereas in the other, organ heterogeneities were introduced in a phantom to replicate the upper thorax for esophageal brachytherapy treatment. A commercially available TPS was used to perform treatment planning in each case and the EBT2 films were irradiated with the HDR Ir-192 brachytherapy source. Film measurements in the cervix phantom were found to agree with the TPS calculated values within 3% in the clinically relevant volume. In the thorax phantom, the presence of surrounding heterogeneities was not seen to affect the dose distribution in the volume being treated, whereas, a little dose perturbation was observed at the lung surface. Doses to the spinal cord and to the sternum bone were overestimated and underestimated by 14.6% and 16.5% respectively by the TPS relative to the film measurements. At the trachea wall facing the esophagus, a dose reduction of 10% was noticed in the measurements. The dose calculation accuracy of the TPS was confirmed in homogeneous medium, whereas, it was proved inadequate to produce correct dosimetric results in conditions of tissue heterogeneity. Copyright © 2012 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  1. Understanding Heterogeneity in the Impact of National Neglected Tropical Disease Control Programmes: Evidence from School-Based Deworming in Kenya

    Science.gov (United States)

    Nikolay, Birgit; Mwandawiro, Charles S.; Kihara, Jimmy H.; Okoyo, Collins; Cano, Jorge; Mwanje, Mariam T.; Sultani, Hadley; Alusala, Dorcas; Turner, Hugo C.; Teti, Caroline; Garn, Josh; Freeman, Matthew C.; Allen, Elizabeth; Anderson, Roy M.; Pullan, Rachel L.; Njenga, Sammy M.; Brooker, Simon J.

    2015-01-01

    Background The implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya. Materials and Methods Data on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels. Principal Findings The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores. Conclusions

  2. A Heterogeneous System Based on Latent Semantic Analysis Using GPU and Multi-CPU

    Directory of Open Access Journals (Sweden)

    Gabriel A. León-Paredes

    2017-01-01

    Full Text Available Latent Semantic Analysis (LSA is a method that allows us to automatically index and retrieve information from a set of objects by reducing the term-by-document matrix using the Singular Value Decomposition (SVD technique. However, LSA has a high computational cost for analyzing large amounts of information. The goals of this work are (i to improve the execution time of semantic space construction, dimensionality reduction, and information retrieval stages of LSA based on heterogeneous systems and (ii to evaluate the accuracy and recall of the information retrieval stage. We present a heterogeneous Latent Semantic Analysis (hLSA system, which has been developed using General-Purpose computing on Graphics Processing Units (GPGPUs architecture, which can solve large numeric problems faster through the thousands of concurrent threads on multiple CUDA cores of GPUs and multi-CPU architecture, which can solve large text problems faster through a multiprocessing environment. We execute the hLSA system with documents from the PubMed Central (PMC database. The results of the experiments show that the acceleration reached by the hLSA system for large matrices with one hundred and fifty thousand million values is around eight times faster than the standard LSA version with an accuracy of 88% and a recall of 100%.

  3. Heterogeneous impact of smoking on major salivary gland cancer according to histopathological subtype: A case-control study.

    Science.gov (United States)

    Sawabe, Michi; Ito, Hidemi; Takahara, Taishi; Oze, Isao; Kawakita, Daisuke; Yatabe, Yasushi; Hasegawa, Yasuhisa; Murakami, Shingo; Matsuo, Keitaro

    2018-01-01

    Major salivary gland cancers (M-SGCs) are rare, and have distinct heterogeneous histopathological subtypes. To the authors' knowledge, no consistent evidence of an association between cigarette smoking and the risk of M-SGCs has appeared to date. Furthermore, evidence of potential heterogeneity in the impact of smoking on histopathological subtypes is scarce, despite the fact that the histopathological subtypes of M-SGC exhibit different genetic features. The authors conducted a case-control study to investigate the association between smoking and M-SGC by histopathological subtype. Cases were 81 patients with M-SGCs and the controls were 810 age-matched and sex-matched first-visit outpatients without cancer treated at Aichi Cancer Center Hospital from 1988 to 2005. Odds ratios (OR) and 95% confidence intervals (95% CI) were assessed by conditional logistic regression analysis with adjustment for potential confounders. Smoking was found to be associated with a significantly increased risk of M-SGC overall, with an OR of 3.45 (95% CI, 1.58-7.51; P =.001) for heavy smokers compared with never-smokers. A significant dose-response relationship was observed (P for trend, .001). When stratified by histological subtype, no obvious impact of smoking was observed among patients with mucoepidermoid carcinoma (MEC). In contrast, smoking demonstrated a significantly increased risk of M-SGCs other than MEC, with an OR of 5.15 (95% CI, 2.06-12.87; Psmoking on risk between MEC and M-SGCs other than MEC (P for heterogeneity, .052). The results of the current study demonstrate a significant positive association between cigarette smoking and the risk of M-SGC overall. However, the impact of smoking appeared to be limited to M-SGCs other than MEC. Cancer 2018;124:118-24. © 2017 American Cancer Society. © 2017 American Cancer Society.

  4. A road to food? : efficacy of nutrient management options targeted to heterogeneous soilscapes in the Teso farming system, Uganda

    NARCIS (Netherlands)

    Ebanyat, P.

    2009-01-01

    Key words: Land use change; Heterogeneity in soil fertility; Targeting; Integrated soil fertility management; Nutrient use efficiencies; Rehabilitation of degraded fields; Fertiliser requirements, Finger millet; QUEFTS model; Smallholder systems; sub-Saharan Africa. Poor soil fertility in

  5. An Evolutionary Video Assignment Optimization Technique for VOD System in Heterogeneous Environment

    Directory of Open Access Journals (Sweden)

    King-Man Ho

    2010-01-01

    Full Text Available We investigate the video assignment problem of a hierarchical Video-on-Demand (VOD system in heterogeneous environments where different quality levels of videos can be encoded using either replication or layering. In such systems, videos are delivered to clients either through a proxy server or video broadcast/unicast channels. The objective of our work is to determine the appropriate coding strategy as well as the suitable delivery mechanism for a specific quality level of a video such that the overall system blocking probability is minimized. In order to find a near-optimal solution for such a complex video assignment problem, an evolutionary approach based on genetic algorithm (GA is proposed. From the results, it is shown that the system performance can be significantly enhanced by efficiently coupling the various techniques.

  6. Environmental dynamics of metal oxide nanoparticles in heterogeneous systems: A review

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Sung Hee, E-mail: s.joo1@miami.edu [Department of Civil, Architectural, and Environmental Engineering, University of Miami, 1251 Memorial Dr. McArthur Engineering Building, Coral Gables, FL 33146-0630 (United States); Zhao, Dongye [Department of Civil and Environmental Engineering, 238 Harbert Engineering Center, Auburn University, Auburn, AL 36849 (United States)

    2017-01-15

    Highlights: • Influence of contaminants on the mobility of metal oxide nanoparticles (MNPs). • Synergistic effects of MNPs in the presence of contaminants. • Effect of environmental factors on the transformed MNPs. • Research direction on the toxicity modeling assessment of heterogeneous systems. - Abstract: Metal oxide nanoparticles (MNPs) have been used for many purposes including water treatment, health, cosmetics, electronics, food packaging, and even food products. As their applications continue to expand, concerns have been mounting about the environmental fate and potential health risks of the nanoparticles in the environment. Based on the latest information, this review provides an overview of the factors that affect the fate, transformation and toxicity of MNPs. Emphasis is placed on the effects of various aquatic contaminants under various environmental conditions on the transformation of metal oxides and their transport kinetics – both in homogeneous and heterogeneous systems – and the effects of contaminants on the toxicity of MNPs. The presence of existing contaminants decreases bioavailability through hetero-aggregation, sorption, and/or complexation upon an interaction with MNPs. Contaminants also influence the fate and transport of MNPs and exhibit their synergistic toxic effects that contribute to the extent of the toxicity. This review will help regulators, engineers, and scientists in this field to understand the latest development on MNPs, their interactions with aquatic contaminants as well as the environmental dynamics of their fate and transformation. The knowledge gap and future research needs are also identified, and the challenges in assessing the environmental fate and transport of nanoparticles in heterogeneous systems are discussed.

  7. Impacts of physical and chemical aquifer heterogeneity on basin-scale solute transport: Vulnerability of deep groundwater to arsenic contamination in Bangladesh

    Science.gov (United States)

    Michael, Holly A.; Khan, Mahfuzur R.

    2016-12-01

    Aquifer heterogeneity presents a primary challenge in predicting the movement of solutes in groundwater systems. The problem is particularly difficult on very large scales, across which permeability, chemical properties, and pumping rates may vary by many orders of magnitude and data are often sparse. An example is the fluvio-deltaic aquifer system of Bangladesh, where naturally-occurring arsenic (As) exists over tens of thousands of square kilometers in shallow groundwater. Millions of people in As-affected regions rely on deep (≥150 m) groundwater as a safe source of drinking water. The sustainability of this resource has been evaluated with models using effective properties appropriate for a basin-scale contamination problem, but the extent to which preferential flow affects the timescale of downward migration of As-contaminated shallow groundwater is unknown. Here we embed detailed, heterogeneous representations of hydraulic conductivity (K), pumping rates, and sorptive properties (Kd) within a basin-scale numerical groundwater flow and solute transport model to evaluate their effects on vulnerability and deviations from simulations with homogeneous representations in two areas with different flow systems. Advective particle tracking shows that heterogeneity in K does not affect average travel times from shallow zones to 150 m depth, but the travel times of the fastest 10% of particles decreases by a factor of ∼2. Pumping distributions do not strongly affect travel times if irrigation remains shallow, but increases in the deep pumping rate substantially reduce travel times. Simulation of advective-dispersive transport with sorption shows that deep groundwater is protected from contamination over a sustainable timeframe (>1000 y) if the spatial distribution of Kd is uniform. However, if only low-K sediments sorb As, 30% of the aquifer is not protected. Results indicate that sustainable management strategies in the Bengal Basin should consider impacts of both

  8. Nanolithographic Fabrication and Heterogeneous Reaction Studies ofTwo-Dimensional Platinum Model Catalyst Systems

    Energy Technology Data Exchange (ETDEWEB)

    Contreras, Anthony Marshall [Univ. of California, Berkeley, CA (United States)

    2006-05-20

    In order to better understand the fundamental components that govern catalytic activity, two-dimensional model platinum nanocatalyst arrays have been designed and fabricated. These catalysts arrays are meant to model the interplay of the metal and support important to industrial heterogeneous catalytic reactions. Photolithography and sub-lithographic techniques such as electron beam lithography, size reduction lithography and nanoimprint lithography have been employed to create these platinum nanoarrays. Both in-situ and ex-situ surface science techniques and catalytic reaction measurements were used to correlate the structural parameters of the system to catalytic activity.

  9. Interfacial tension in cooled heterogeneous liquid acetonitrile-ethyl acetate-isopropanol-water-phenol systems

    Science.gov (United States)

    Rudakov, O. B.; Khorokhordina, E. A.; Preobrazhenskii, M. A.

    2017-04-01

    It is found that the tension at the interfacial boundary of liquid phases formed by mixtures of acetonitrile-ethyl acetate-isopropanol (85 : 15 : 0 and 80 : 15 : 5 vol/vol/vol %) and water at 263 K falls exponentially as the concentration of phenols grows within 0-1 mg/mL. It is shown that the relatively low values of interfacial tension (11-32 mN/m) observed in cooled heterogeneous systems promote the redistribution of phenols between two liquid phases.

  10. BIOZON: a system for unification, management and analysis of heterogeneous biological data

    Directory of Open Access Journals (Sweden)

    Yona Golan

    2006-02-01

    Full Text Available Abstract Background Integration of heterogeneous data types is a challenging problem, especially in biology, where the number of databases and data types increase rapidly. Amongst the problems that one has to face are integrity, consistency, redundancy, connectivity, expressiveness and updatability. Description Here we present a system (Biozon that addresses these problems, and offers biologists a new knowledge resource to navigate through and explore. Biozon unifies multiple biological databases consisting of a variety of data types (such as DNA sequences, proteins, interactions and cellular pathways. It is fundamentally different from previous efforts as it uses a single extensive and tightly connected graph schema wrapped with hierarchical ontology of documents and relations. Beyond warehousing existing data, Biozon computes and stores novel derived data, such as similarity relationships and functional predictions. The integration of similarity data allows propagation of knowledge through inference and fuzzy searches. Sophisticated methods of query that span multiple data types were implemented and first-of-a-kind biological ranking systems were explored and integrated. Conclusion The Biozon system is an extensive knowledge resource of heterogeneous biological data. Currently, it holds more than 100 million biological documents and 6.5 billion relations between them. The database is accessible through an advanced web interface that supports complex queries, "fuzzy" searches, data materialization and more, online at http://biozon.org.

  11. Sequential application of heterogeneous models for the safetyanalysis of a control system: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Bobbio, A.; Ciancamerla, E.; Franceschinis, G.; Gaeta, R.; Minichino, M.; Portinale, L

    2003-09-01

    This paper shows how heterogeneous stochastic modelling techniques of increasing modelling power can be applied to assess the safety of a digital control system. First, a Fault-Tree (FT) has been built to model the system, assuming two-state components and independent failures. Then, the FT is automatically converted into a Bayesian Network, allowing to include more modelling details and localized dependencies. Finally, in order to accommodate repair activities and perform an availability analysis, the FT is converted into a Stochastic Petri Net (SPN). Moving from a combinatorial model (the FT) to a state space based model (the SPN) increases the modelling flexibility, but incurs into the state space explosion problem. In order to alleviate the state space explosion problem, this paper resorts to the use of a particular type of high level (coloured) Petri nets called SWN. A digital control system is considered as a case study, and safety measures have been evaluated, referring to the emergent standard IEC 61508.

  12. Landscape heterogeneity shapes predation in a newly restored predator-prey system.

    Science.gov (United States)

    Kauffman, Matthew J; Varley, Nathan; Smith, Douglas W; Stahler, Daniel R; MacNulty, Daniel R; Boyce, Mark S

    2007-08-01

    Because some native ungulates have lived without top predators for generations, it has been uncertain whether runaway predation would occur when predators are newly restored to these systems. We show that landscape features and vegetation, which influence predator detection and capture of prey, shape large-scale patterns of predation in a newly restored predator-prey system. We analysed the spatial distribution of wolf (Canis lupus) predation on elk (Cervus elaphus) on the Northern Range of Yellowstone National Park over 10 consecutive winters. The influence of wolf distribution on kill sites diminished over the course of this study, a result that was likely caused by territorial constraints on wolf distribution. In contrast, landscape factors strongly influenced kill sites, creating distinct hunting grounds and prey refugia. Elk in this newly restored predator-prey system should be able to mediate their risk of predation by movement and habitat selection across a heterogeneous risk landscape.

  13. HER2 aberrations and heterogeneity in cancers of the digestive system: Implications for pathologists and gastroenterologists.

    Science.gov (United States)

    Fusco, Nicola; Bosari, Silvano

    2016-09-21

    Management of cancers of the digestive system has progressed rapidly into the molecular era. Despite the significant recent achievements in the diagnosis and treatment of these patients, the number of deaths for these tumors has currently plateaued. Many investigations have assessed the role of HER2 in tumors of the digestive system in both prognostic and therapeutic settings, with heterogeneous results. Novel testing and treatment guidelines are emerging, in particular in gastric and colorectal cancers. However, further advances are needed. In this review we provide a comprehensive overview of the current state-of-knowledge of HER2 alterations in the most common tumors of the digestive system and discuss the operational implications of HER2 testing.

  14. An energy-efficient underground localization system based on heterogeneous wireless networks.

    Science.gov (United States)

    Yuan, Yazhou; Chen, Cailian; Guan, Xinping; Yang, Qiuling

    2015-05-26

    A precision positioning system with energy efficiency is of great necessity for guaranteeing personnel safety in underground mines. The location information of the miners' should be transmitted to the control center timely and reliably; therefore, a heterogeneous network with the backbone based on high speed Industrial Ethernet is deployed. Since the mobile wireless nodes are working in an irregular tunnel, a specific wireless propagation model cannot fit all situations. In this paper, an underground localization system is designed to enable the adaptation to kinds of harsh tunnel environments, but also to reduce the energy consumption and thus prolong the lifetime of the network. Three key techniques are developed and implemented to improve the system performance, including a step counting algorithm with accelerometers, a power control algorithm and an adaptive packets scheduling scheme. The simulation study and experimental results show the effectiveness of the proposed algorithms and the implementation.

  15. An Energy-Efficient Underground Localization System Based on Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Yazhou Yuan

    2015-05-01

    Full Text Available A precision positioning system with energy efficiency is of great necessity for guaranteeing personnel safety in underground mines. The location information of the miners’ should be transmitted to the control center timely and reliably; therefore, a heterogeneous network with the backbone based on high speed Industrial Ethernet is deployed. Since the mobile wireless nodes are working in an irregular tunnel, a specific wireless propagation model cannot fit all situations. In this paper, an underground localization system is designed to enable the adaptation to kinds of harsh tunnel environments, but also to reduce the energy consumption and thus prolong the lifetime of the network. Three key techniques are developed and implemented to improve the system performance, including a step counting algorithm with accelerometers, a power control algorithm and an adaptive packets scheduling scheme. The simulation study and experimental results show the effectiveness of the proposed algorithms and the implementation.

  16. Distinguishing the impact of postponement, spacing and stopping on birth intervals: evidence from a model with heterogeneous fecundity.

    Science.gov (United States)

    Timæus, Ian M; Moultrie, Tom A

    2013-05-01

    This paper investigates the impact on birth intervals of three distinct birth control strategies: stopping childbearing, spacing births and the postponement of further childbearing for reasons unrelated to women's family-building histories. A macro-simulation model of the family-building process is described that incorporates heterogeneity in fecundability. This model is used to demonstrate that the postponement of further childbearing has a distinctive impact on schedules of duration-specific fertility rates that differs from that of both family-size limitation and birth spacing. In particular, the simulation results, supplemented by an analytical exposition, show that reductions in fertility due to spacing are a function of interval duration and its log, while reductions due to postponement are a function of interval duration and its square. This provides a way to test statistically for the presence of, and distinguish between, differential postponement and spacing in regression analyses of birth history data.

  17. High bee and wasp diversity in a heterogeneous tropical farming system compared to protected forest.

    Science.gov (United States)

    Schüepp, Christof; Rittiner, Sarah; Entling, Martin H

    2012-01-01

    It is a globally important challenge to meet increasing demands for resources and, at the same time, protect biodiversity and ecosystem services. Farming is usually regarded as a major threat to biodiversity due to its expansion into natural areas. We compared biodiversity of bees and wasps between heterogeneous small-scale farming areas and protected forest in northern coastal Belize, Central America. Malaise traps operated for three months during the transition from wet to dry season. Farming areas consisted of a mosaic of mixed crop types, open habitat, secondary forest, and agroforestry. Mean species richness per site (alpha diversity), as well as spatial and temporal community variation (beta diversity) of bees and wasps were equal or higher in farming areas compared to protected forest. The higher species richness and community variation in farmland was due to additional species that did not occur in the forest, whereas most species trapped in forest were also found in farming areas. The overall regional species richness (gamma diversity) increased by 70% with the inclusion of farming areas. Our results suggest that small-scale farming systems adjacent to protected forest may not only conserve, but even favour, biodiversity of some taxonomic groups. We can, however, not exclude possible declines of bee and wasp diversity in more intensified farmland or in landscapes completely covered by heterogeneous farming systems.

  18. A Context-Aware Adaptive Streaming Media Distribution System in a Heterogeneous Network with Multiple Terminals

    Directory of Open Access Journals (Sweden)

    Yepeng Ni

    2016-01-01

    Full Text Available We consider the problem of streaming media transmission in a heterogeneous network from a multisource server to home multiple terminals. In wired network, the transmission performance is limited by network state (e.g., the bandwidth variation, jitter, and packet loss. In wireless network, the multiple user terminals can cause bandwidth competition. Thus, the streaming media distribution in a heterogeneous network becomes a severe challenge which is critical for QoS guarantee. In this paper, we propose a context-aware adaptive streaming media distribution system (CAASS, which implements the context-aware module to perceive the environment parameters and use the strategy analysis (SA module to deduce the most suitable service level. This approach is able to improve the video quality for guarantying streaming QoS. We formulate the optimization problem of QoS relationship with the environment parameters based on the QoS testing algorithm for IPTV in ITU-T G.1070. We evaluate the performance of the proposed CAASS through 12 types of experimental environments using a prototype system. Experimental results show that CAASS can dynamically adjust the service level according to the environment variation (e.g., network state and terminal performances and outperforms the existing streaming approaches in adaptive streaming media distribution according to peak signal-to-noise ratio (PSNR.

  19. Environmental dynamics of metal oxide nanoparticles in heterogeneous systems: A review.

    Science.gov (United States)

    Joo, Sung Hee; Zhao, Dongye

    2017-01-15

    Metal oxide nanoparticles (MNPs) have been used for many purposes including water treatment, health, cosmetics, electronics, food packaging, and even food products. As their applications continue to expand, concerns have been mounting about the environmental fate and potential health risks of the nanoparticles in the environment. Based on the latest information, this review provides an overview of the factors that affect the fate, transformation and toxicity of MNPs. Emphasis is placed on the effects of various aquatic contaminants under various environmental conditions on the transformation of metal oxides and their transport kinetics - both in homogeneous and heterogeneous systems - and the effects of contaminants on the toxicity of MNPs. The presence of existing contaminants decreases bioavailability through hetero-aggregation, sorption, and/or complexation upon an interaction with MNPs. Contaminants also influence the fate and transport of MNPs and exhibit their synergistic toxic effects that contribute to the extent of the toxicity. This review will help regulators, engineers, and scientists in this field to understand the latest development on MNPs, their interactions with aquatic contaminants as well as the environmental dynamics of their fate and transformation. The knowledge gap and future research needs are also identified, and the challenges in assessing the environmental fate and transport of nanoparticles in heterogeneous systems are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Hot news recommendation system from heterogeneous websites based on bayesian model.

    Science.gov (United States)

    Xia, Zhengyou; Xu, Shengwu; Liu, Ningzhong; Zhao, Zhengkang

    2014-01-01

    The most current news recommendations are suitable for news which comes from a single news website, not for news from different heterogeneous news websites. Previous researches about news recommender systems based on different strategies have been proposed to provide news personalization services for online news readers. However, little research work has been reported on utilizing hundreds of heterogeneous news websites to provide top hot news services for group customers (e.g., government staffs). In this paper, we propose a hot news recommendation model based on Bayesian model, which is from hundreds of different news websites. In the model, we determine whether the news is hot news by calculating the joint probability of the news. We evaluate and compare our proposed recommendation model with the results of human experts on the real data sets. Experimental results demonstrate the reliability and effectiveness of our method. We also implement this model in hot news recommendation system of Hangzhou city government in year 2013, which achieves very good results.

  1. Hot News Recommendation System from Heterogeneous Websites Based on Bayesian Model

    Directory of Open Access Journals (Sweden)

    Zhengyou Xia

    2014-01-01

    Full Text Available The most current news recommendations are suitable for news which comes from a single news website, not for news from different heterogeneous news websites. Previous researches about news recommender systems based on different strategies have been proposed to provide news personalization services for online news readers. However, little research work has been reported on utilizing hundreds of heterogeneous news websites to provide top hot news services for group customers (e.g., government staffs. In this paper, we propose a hot news recommendation model based on Bayesian model, which is from hundreds of different news websites. In the model, we determine whether the news is hot news by calculating the joint probability of the news. We evaluate and compare our proposed recommendation model with the results of human experts on the real data sets. Experimental results demonstrate the reliability and effectiveness of our method. We also implement this model in hot news recommendation system of Hangzhou city government in year 2013, which achieves very good results.

  2. Vivaldi: A Domain-Specific Language for Volume Processing and Visualization on Distributed Heterogeneous Systems.

    Science.gov (United States)

    Choi, Hyungsuk; Choi, Woohyuk; Quan, Tran Minh; Hildebrand, David G C; Pfister, Hanspeter; Jeong, Won-Ki

    2014-12-01

    As the size of image data from microscopes and telescopes increases, the need for high-throughput processing and visualization of large volumetric data has become more pressing. At the same time, many-core processors and GPU accelerators are commonplace, making high-performance distributed heterogeneous computing systems affordable. However, effectively utilizing GPU clusters is difficult for novice programmers, and even experienced programmers often fail to fully leverage the computing power of new parallel architectures due to their steep learning curve and programming complexity. In this paper, we propose Vivaldi, a new domain-specific language for volume processing and visualization on distributed heterogeneous computing systems. Vivaldi's Python-like grammar and parallel processing abstractions provide flexible programming tools for non-experts to easily write high-performance parallel computing code. Vivaldi provides commonly used functions and numerical operators for customized visualization and high-throughput image processing applications. We demonstrate the performance and usability of Vivaldi on several examples ranging from volume rendering to image segmentation.

  3. High Bee and Wasp Diversity in a Heterogeneous Tropical Farming System Compared to Protected Forest

    Science.gov (United States)

    Schüepp, Christof; Rittiner, Sarah; Entling, Martin H.

    2012-01-01

    It is a globally important challenge to meet increasing demands for resources and, at the same time, protect biodiversity and ecosystem services. Farming is usually regarded as a major threat to biodiversity due to its expansion into natural areas. We compared biodiversity of bees and wasps between heterogeneous small-scale farming areas and protected forest in northern coastal Belize, Central America. Malaise traps operated for three months during the transition from wet to dry season. Farming areas consisted of a mosaic of mixed crop types, open habitat, secondary forest, and agroforestry. Mean species richness per site (alpha diversity), as well as spatial and temporal community variation (beta diversity) of bees and wasps were equal or higher in farming areas compared to protected forest. The higher species richness and community variation in farmland was due to additional species that did not occur in the forest, whereas most species trapped in forest were also found in farming areas. The overall regional species richness (gamma diversity) increased by 70% with the inclusion of farming areas. Our results suggest that small-scale farming systems adjacent to protected forest may not only conserve, but even favour, biodiversity of some taxonomic groups. We can, however, not exclude possible declines of bee and wasp diversity in more intensified farmland or in landscapes completely covered by heterogeneous farming systems. PMID:23300598

  4. Hot News Recommendation System from Heterogeneous Websites Based on Bayesian Model

    Science.gov (United States)

    Xia, Zhengyou; Xu, Shengwu; Liu, Ningzhong; Zhao, Zhengkang

    2014-01-01

    The most current news recommendations are suitable for news which comes from a single news website, not for news from different heterogeneous news websites. Previous researches about news recommender systems based on different strategies have been proposed to provide news personalization services for online news readers. However, little research work has been reported on utilizing hundreds of heterogeneous news websites to provide top hot news services for group customers (e.g., government staffs). In this paper, we propose a hot news recommendation model based on Bayesian model, which is from hundreds of different news websites. In the model, we determine whether the news is hot news by calculating the joint probability of the news. We evaluate and compare our proposed recommendation model with the results of human experts on the real data sets. Experimental results demonstrate the reliability and effectiveness of our method. We also implement this model in hot news recommendation system of Hangzhou city government in year 2013, which achieves very good results. PMID:25093207

  5. High bee and wasp diversity in a heterogeneous tropical farming system compared to protected forest.

    Directory of Open Access Journals (Sweden)

    Christof Schüepp

    Full Text Available It is a globally important challenge to meet increasing demands for resources and, at the same time, protect biodiversity and ecosystem services. Farming is usually regarded as a major threat to biodiversity due to its expansion into natural areas. We compared biodiversity of bees and wasps between heterogeneous small-scale farming areas and protected forest in northern coastal Belize, Central America. Malaise traps operated for three months during the transition from wet to dry season. Farming areas consisted of a mosaic of mixed crop types, open habitat, secondary forest, and agroforestry. Mean species richness per site (alpha diversity, as well as spatial and temporal community variation (beta diversity of bees and wasps were equal or higher in farming areas compared to protected forest. The higher species richness and community variation in farmland was due to additional species that did not occur in the forest, whereas most species trapped in forest were also found in farming areas. The overall regional species richness (gamma diversity increased by 70% with the inclusion of farming areas. Our results suggest that small-scale farming systems adjacent to protected forest may not only conserve, but even favour, biodiversity of some taxonomic groups. We can, however, not exclude possible declines of bee and wasp diversity in more intensified farmland or in landscapes completely covered by heterogeneous farming systems.

  6. Quantifying the impacts of landscape heterogeneity and model resolution on dust emissions in the Arabian Peninsula

    KAUST Repository

    Shi, Mingjie

    2016-01-11

    This study evaluates the spatiotemporal variability of dust emission in the Arabian Peninsula and quantifies the emission sensitivity to the land-cover heterogeneity by using the Community Land Model version 4 (CLM43) at three different spatial resolutions. The land-cover heterogeneity is represented by the CLM4-default plant function types (PFTs) and the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover types, respectively, at different grids. We area-average surface vegetation data and use the default nearest neighbor method to interpolate meteorological variables. We find that using MODIS data leads to a slightly higher coverage of vegetated land than the default PFT data; the former also gives more dust emission than the latter at 25- and 50-km grids as the default PFT data have more gridcells favoring less dust emission. The research highlights the importance of using proper data-processing methods or dust emission thresholds to preserve the dust emission accuracy in land models. © 2016 Elsevier Ltd.

  7. Heterogeneity of amygdala response in major depressive disorder: the impact of lifetime subthreshold mania.

    Science.gov (United States)

    Fournier, J C; Keener, M T; Mullin, B C; Hafeman, D M; Labarbara, E J; Stiffler, R S; Almeida, J; Kronhaus, D M; Frank, E; Phillips, M L

    2013-02-01

    Patients with major depressive disorder (MDD) present with highly heterogeneous symptom profiles. We aimed to examine whether individual differences in amygdala activity to emotionally salient stimuli were related to heterogeneity in lifetime levels of depressive and subthreshold manic symptoms among adults with MDD. We compared age- and gender-matched adults with MDD (n = 26) with healthy controls (HC, n = 28). While undergoing functional magnetic resonance imaging, participants performed an implicit emotional faces task: they labeled a color flash superimposed upon initially neutral faces that dynamically morphed into one of four emotions (angry, fearful, sad, happy). Region of interest analyses examined group differences in amygdala activity. For conditions in which adults with MDD displayed abnormal amygdala activity versus HC, within-group analyses examined amygdala activity as a function of scores on a continuous measure of lifetime depression-related and mania-related pathology. Adults with MDD showed significantly greater right-sided amygdala activity to angry and happy conditions than HC (p depressed adults with MDD, lifetime features of subthreshold mania were associated with abnormally elevated amygdala activity to emerging happy faces. These findings are a first step toward identifying biomarkers that reflect individual differences in neural mechanisms in MDD, and challenge conventional mood disorder diagnostic boundaries by suggesting that some adults with MDD are characterized by pathophysiological processes that overlap with bipolar disorder.

  8. Direction-sensitive smart monitoring of structures using heterogeneous smartphone sensor data and coordinate system transformation

    Science.gov (United States)

    Ozer, Ekin; Feng, Maria Q.

    2017-04-01

    Mobile, heterogeneous, and smart sensor networks produce pervasive structural health monitoring (SHM) information. With various embedded sensors, smartphones have emerged to innovate SHM by empowering citizens to serve as sensors. By default, smartphones meet the fundamental smart sensor criteria, thanks to the built-in processor, memory, wireless communication units and mobile operating system. SHM using smartphones, however, faces technical challenges due to citizen-induced uncertainties, undesired sensor-structure integration, and lack of control over the sensing platform. Previously, the authors presented successful applications of smartphone accelerometers for structural vibration measurement and proposed a monitoring framework under citizen-induced spatiotemporal uncertainties. This study aims at extending the capabilities of smartphone-based SHM with a special focus on the lack of control over the sensor (i.e., the phone) positioning by citizens resulting in unknown sensor orientations. Using smartphone gyroscope, accelerometer, and magnetometer; instantaneous sensor orientation can be obtained with respect to gravitational and magnetic north directions. Using these sensor data, mobile operating system frameworks return processed features such as attitude and heading that can be used to correct misaligned sensor signals. For this purpose, a coordinate transformation procedure is proposed and illustrated on a two-story laboratory structural model and real-scale bridges with various sensor positioning examples. The proposed method corrects the sensor signals by tracking their orientations and improves measurement accuracy. Moreover, knowing structure’s coordinate system a priori, even the data from arbitrarily positioned sensors can automatically be transformed to the structural coordinates. In addition, this paper also touches some secondary mobile and heterogeneous data issues including imperfect sampling and geolocation services. The coordinate system

  9. On robust synchronization of heterogeneous linear multi-agent systems with static couplings

    NARCIS (Netherlands)

    Seyboth, Georg S.; Dimarogonas, Dimos V.; Johansson, Karl Henrik; Frasca, Paolo; Allgöwer, Frank

    This paper addresses cooperative control problems in heterogeneous groups of linear dynamical agents that are coupled by diffusive links. We study networks with parameter uncertainties, resulting in heterogeneous agent dynamics, and we analyze the robustness of their output synchronization. The

  10. A Preliminary Study on the Multiple Mapping Structure of Classification Systems for Heterogeneous Databases

    Directory of Open Access Journals (Sweden)

    Seok-Hyoung Lee

    2012-06-01

    Full Text Available While science and technology information service portals and heterogeneous databases produced in Korea and other countries are integrated, methods of connecting the unique classification systems applied to each database have been studied. Results of technologists' research, such as, journal articles, patent specifications, and research reports, are organically related to each other. In this case, if the most basic and meaningful classification systems are not connected, it is difficult to achieve interoperability of the information and thus not easy to implement meaningful science technology information services through information convergence. This study aims to address the aforementioned issue by analyzing mapping systems between classification systems in order to design a structure to connect a variety of classification systems used in the academic information database of the Korea Institute of Science and Technology Information, which provides science and technology information portal service. This study also aims to design a mapping system for the classification systems to be applied to actual science and technology information services and information management systems.

  11. Heterogeneity and Self-Organization of Complex Systems Through an Application to Financial Market with Multiagent Systems

    Science.gov (United States)

    Lucas, Iris; Cotsaftis, Michel; Bertelle, Cyrille

    2017-12-01

    Multiagent systems (MAS) provide a useful tool for exploring the complex dynamics and behavior of financial markets and now MAS approach has been widely implemented and documented in the empirical literature. This paper introduces the implementation of an innovative multi-scale mathematical model for a computational agent-based financial market. The paper develops a method to quantify the degree of self-organization which emerges in the system and shows that the capacity of self-organization is maximized when the agent behaviors are heterogeneous. Numerical results are presented and analyzed, showing how the global market behavior emerges from specific individual behavior interactions.

  12. A quenched-flow system for measuring heterogeneous enzyme kinetics with sub-second time resolution.

    Science.gov (United States)

    Olsen, Johan P; Kari, Jeppe; Borch, Kim; Westh, Peter

    2017-10-01

    Even though many enzyme processes occur at the interface of an insoluble substrate, these reactions are generally much less studied than homogenous enzyme reactions in the aqueous bulk. Interfacial (or heterogeneous) enzyme reactions involve several reaction steps, and the established experimental approach to elucidate multi-step reactions is transient (or pre steady-state) kinetics. A key requirement for pre steady-state measurements is good time resolution, and while this has been amply achieved in different commercial instruments, they are generally not applicable to precipitating suspensions of insoluble substrate. Perhaps for this reason, transient kinetics has rarely been reported for heterogeneous enzyme reactions. Here, we describe a quenched-flow system using peristaltic pumps and stirred substrate suspensions with a dead time below 100ms. The general performance was verified by alkali catalyzed hydrolysis of 2,4-dinitrophenyl acetate (DNPA), and the applicability to heterogeneous reactions was documented by two cellulases (Cel7A and Cel7B) acting on suspensions of microcrystalline cellulose (Avicel) at different loads up to 15g/l. The results showed distinctive differences between the two enzymes. In particular, we found that endo-lytic Cel7B combined very quickly with the substrate and reached the maximal activity within the dead-time of the instrument. Conversely, exo-lytic Cel7A showed a much slower initiation with maximal activity after 5-8s and a 10-fold lower turnover. We suggest that the instrument may provide an important tool in attempts to elucidate the mechanism of cellulases and other enzymes' action on insoluble substrate. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Dynamic heterogeneity: a framework to promote ecological integration and hypothesis generation in urban systems

    Science.gov (United States)

    S. T. A. Pickett; M. L. Cadenasso; E. J. Rosi-Marshall; Ken Belt; P. M. Groffman; Morgan Grove; E. G. Irwin; S. S. Kaushal; S. L. LaDeau; C. H. Nilon; C. M. Swan; P. S. Warren

    2016-01-01

    Urban areas are understood to be extraordinarily spatially heterogeneous. Spatial heterogeneity, and its causes, consequences, and changes, are central to ecological science. The social sciences and urban design and planning professions also include spatial heterogeneity as a key concern. However, urban ecology, as a pursuit that integrates across these disciplines,...

  14. Metaheuristic based scheduling meta-tasks in distributed heterogeneous computing systems.

    Science.gov (United States)

    Izakian, Hesam; Abraham, Ajith; Snášel, Václav

    2009-01-01

    Scheduling is a key problem in distributed heterogeneous computing systems in order to benefit from the large computing capacity of such systems and is an NP-complete problem. In this paper, we present a metaheuristic technique, namely the Particle Swarm Optimization (PSO) algorithm, for this problem. PSO is a population-based search algorithm based on the simulation of the social behavior of bird flocking and fish schooling. Particles fly in problem search space to find optimal or near-optimal solutions. The scheduler aims at minimizing makespan, which is the time when finishes the latest task. Experimental studies show that the proposed method is more efficient and surpasses those of reported PSO and GA approaches for this problem.

  15. An "inverse square law" for the currency market: Uncovering hidden universality in heterogeneous complex systems

    CERN Document Server

    Chakraborty, Abhijit; Sinha, Sitabhra

    2016-01-01

    Identifying universal behavior is a challenging task for far-from-equilibrium complex systems. Here we investigate the collective dynamics of the international currency exchange market and show the existence of a semi-invariant signature masked by the high degree of heterogeneity in this complex system. The cumulative fluctuation distribution in the exchange rates of different currencies possess heavy tails characterized by exponents varying around a median value of 2. The systematic deviation of individual currencies from this putative universal form (the "inverse square law") can be partly ascribed to the differences in their economic prosperity and diversity of export products. The distinct nature of the fluctuation dynamics for currencies of developed, emerging and frontier economies are characterized in detail by detrended fluctuation analysis and variance-ratio tests, which shows that less developed economies are associated with sub-diffusive random walk processes. We hierarchically cluster the currenci...

  16. Distributed memory in a heterogeneous network, as used in the CERN-PS complex timing system

    CERN Document Server

    Kovaltsov, V I

    1995-01-01

    The Distributed Table Manager (DTM) is a fast and efficient utility for distributing named binary data structures called Tables, of arbitrary size and structure, around a heterogeneous network of computers to a set of registered clients. The Tables are transmitted over a UDP network between DTM servers in network format, where the servers perform the conversions to and from host format for local clients. The servers provide clients with synchronization mechanisms, a choice of network data flows, and table options such as keeping table disc copies, shared memory or heap memory table allocation, table read/write permissions, and table subnet broadcasting. DTM has been designed to be easily maintainable, and to automatically recover from the type of errors typically encountered in a large control system network. The DTM system is based on a three level server daemon hierarchy, in which an inter daemon protocol handles network failures, and incorporates recovery procedures which will guarantee table consistency w...

  17. Rapid Prototyping for Heterogeneous Multicomponent Systems: An MPEG-4 Stream over a UMTS Communication Link

    Directory of Open Access Journals (Sweden)

    Sorel Y

    2006-01-01

    Full Text Available Future generations of mobile phones, including advanced video and digital communication layers, represent a great challenge in terms of real-time embedded systems. Programmable multicomponent architectures can provide suitable target solutions combining flexibility and computation power. The aim of our work is to develop a fast and automatic prototyping methodology dedicated to signal processing application implementation on parallel heterogeneous architectures, two major features required by future systems. This paper presents the whole methodology based on the SynDEx CAD tool that directly generates a distributed implementation onto various platforms from a high-level application description, taking real-time aspects into account. It illustrates the methodology in the context of real-time distributed executives for multilayer applications based on an MPEG-4 video codec and a UMTS telecommunication link.

  18. Rapid Prototyping for Heterogeneous Multicomponent Systems: An MPEG-4 Stream over a UMTS Communication Link

    Science.gov (United States)

    Raulet, M.; Urban, F.; Nezan, J.-F.; Moy, C.; Deforges, O.; Sorel, Y.

    2006-12-01

    Future generations of mobile phones, including advanced video and digital communication layers, represent a great challenge in terms of real-time embedded systems. Programmable multicomponent architectures can provide suitable target solutions combining flexibility and computation power. The aim of our work is to develop a fast and automatic prototyping methodology dedicated to signal processing application implementation on parallel heterogeneous architectures, two major features required by future systems. This paper presents the whole methodology based on the SynDEx CAD tool that directly generates a distributed implementation onto various platforms from a high-level application description, taking real-time aspects into account. It illustrates the methodology in the context of real-time distributed executives for multilayer applications based on an MPEG-4 video codec and a UMTS telecommunication link.

  19. Real-Time Scheduling in Heterogeneous Systems Considering Cache Reload Time Using Genetic Algorithms

    Science.gov (United States)

    Miryani, Mohammad Reza; Naghibzadeh, Mahmoud

    Since optimal assignment of tasks in a multiprocessor system is, in almost all practical cases, an NP-hard problem, in recent years some algorithms based on genetic algorithms have been proposed. Some of these algorithms have considered real-time applications with multiple objectives, total tardiness, completion time, etc. Here, we propose a suboptimal static scheduler of nonpreemptable tasks in hard real-time heterogeneous multiprocessor systems considering time constraints and cache reload time. The approach makes use of genetic algorithm to minimize total completion time and number of processors used, simultaneously. One important issue which makes this research different from previous ones is cache reload time. The method is implemented and the results are compared against a similar method.

  20. Metaheuristic Based Scheduling Meta-Tasks in Distributed Heterogeneous Computing Systems

    Science.gov (United States)

    Izakian, Hesam; Abraham, Ajith; Snášel, Václav

    2009-01-01

    Scheduling is a key problem in distributed heterogeneous computing systems in order to benefit from the large computing capacity of such systems and is an NP-complete problem. In this paper, we present a metaheuristic technique, namely the Particle Swarm Optimization (PSO) algorithm, for this problem. PSO is a population-based search algorithm based on the simulation of the social behavior of bird flocking and fish schooling. Particles fly in problem search space to find optimal or near-optimal solutions. The scheduler aims at minimizing makespan, which is the time when finishes the latest task. Experimental studies show that the proposed method is more efficient and surpasses those of reported PSO and GA approaches for this problem. PMID:22346701

  1. Second Energy Variation for Heterogeneous Systems with Electrostatic and Magnetostatic Interaction

    Science.gov (United States)

    Greenfield, Michael; Greenfield, Pavel

    2017-10-01

    Systems carrying electric charges and magnetic dipoles are widespread in nature and applications. Variational principles and methods play key role in modelling these systems, and they have been developed for a couple of centuries (see, Landau, L.D. and Lifshitz, E.M. Electrodynamics of Continuous Media, Pergamon, 1963). Nonetheless, even a quick glance at the literature shows that the variational approach remains unfinished. In particular, in terms of calculus of variations, all the studies are based on the analysis of first energy variations (i.e., analysis of ponderomotive forces and conditions of equilibrium.) The analysis of the second variation, the cornerstone of the stability analysis, is not even touched in a systematic manner. We partially fixed this gap in (Grinfeld, M., Grinfeld, P., A Variational Approach to Electrostatics of Polarizable Heterogeneous Substances, Advances in Mathematical Physics, Article ID 659127, 2015). In this paper, we present corresponding results relating to the problems of plasma physics.

  2. Heterogeneity of Systemic Oxidative Stress Profiles in COPD: A Potential Role of Gender

    Directory of Open Access Journals (Sweden)

    Jonathan Maury

    2015-01-01

    Full Text Available Oxidative stress (OS plays a key role in the muscle impairment and exercise capacity of COPD patients. However, the literature reveals that systemic OS markers show great heterogeneity, which may hinder the prescription of effective antioxidant supplementation. This study therefore aimed to identify OS markers imbalance of COPD patients, relative to validated normal reference values, and to investigate the possibility of systemic OS profiles. We measured systemic enzymatic/nonenzymatic antioxidant and lipid peroxidation (LP levels in 54 stable COPD patients referred for a rehabilitation program. The main systemic antioxidant deficits in these patients concerned vitamins and trace elements. Fully 89% of the COPD patients showed a systemic antioxidant imbalance which may have caused the elevated systemic LP levels in 69% of them. Interestingly, two patient profiles (clusters 3 and 4 had a more elevated increase in LP combined with increased copper and/or decreased vitamin C, GSH, and GPx. Further analysis revealed that the systemic LP level was higher in COPD women and associated with exercise capacity. Our present data therefore support future supplementations with antioxidant vitamins and trace elements to improve exercise capacity, but COPD patients will probably show different positive responses.

  3. Computer-aided multiple-head 3D printing system for printing of heterogeneous organ/tissue constructs

    OpenAIRE

    Jin Woo Jung; Jung-Seob Lee; Dong-Woo Cho

    2016-01-01

    Recently, much attention has focused on replacement or/and enhancement of biological tissues via the use of cell-laden hydrogel scaffolds with an architecture that mimics the tissue matrix, and with the desired three-dimensional (3D) external geometry. However, mimicking the heterogeneous tissues that most organs and tissues are formed of is challenging. Although multiple-head 3D printing systems have been proposed for fabricating heterogeneous cell-laden hydrogel scaffolds, to date only the ...

  4. Impact of Soft Tissue Heterogeneity on Augmented Reality for Liver Surgery.

    Science.gov (United States)

    Haouchine, Nazim; Cotin, Stephane; Peterlik, Igor; Dequidt, Jeremie; Lopez, Mario Sanz; Kerrien, Erwan; Berger, Marie-Odile

    2015-05-01

    This paper presents a method for real-time augmented reality of internal liver structures during minimally invasive hepatic surgery. Vessels and tumors computed from pre-operative CT scans can be overlaid onto the laparoscopic view for surgery guidance. Compared to current methods, our method is able to locate the in-depth positions of the tumors based on partial three-dimensional liver tissue motion using a real-time biomechanical model. This model permits to properly handle the motion of internal structures even in the case of anisotropic or heterogeneous tissues, as it is the case for the liver and many anatomical structures. Experimentations conducted on phantom liver permits to measure the accuracy of the augmentation while real-time augmentation on in vivo human liver during real surgery shows the benefits of such an approach for minimally invasive surgery.

  5. Heterogeneous Impacts on Earnings from an Early Effort in Labor Market Programs

    DEFF Research Database (Denmark)

    Sørensen, Kenneth Lykke

    Labor market programs that are found to shorten unemployment duration might not be societal efficient if participants do not find suitable jobs in terms of stability, wages, occupation, etc. This paper investigates whether a program, that previously has been shown to lower unemployment duration......, also had positive effects on jobs with respect to labor market earnings. The contribution of the paper is two-fold: First, we show that the program had positive effects on earnings in the short term for men, and in the medium and long term for men in one county, which we attribute to the mere taxing...... of leisure time and human capital accumulation/removal of frictions, respectively. Second, we show that the positive effects are heterogenous across earnings distributions. Taxing leisure time primarily affects low earners while human capital accumulation and removing frictions tend to help high earners....

  6. Embryonal Origin of MTSCC of Kidney May Explain its Morphological Heterogeneity: Diagnostic Impact of Genetic Analysis.

    Science.gov (United States)

    Banyai, Daniel; Vastag, Fanni; Yusenko, Maria; Bugert, Peter; Kovacs, Gyula

    2017-03-01

    Previous genetic and morphologic characterisation of mucinous tubular and spindle cell carcinoma (MTSCC) have yielded controversial results. The aim of this study was to explain the phenotypic heterogeneity of MTSCC diagnosed by genetic means. We analyzed 7 MTSCC by array CGH and microsatellite allelotyping and by histology for morphological variation. We worked-up two entire kidneys with MTSCC to find microscopic alterations. We confirmed the diagnosis of MTSCC by detecting copy number changes at chromosomes 1, 4, 6, 8, 13, 14, 15, 18 and 22. We detected 13 small, microscopic precursor lesions in the two kidneys and found similar histological structures in precursor lesions and MTSCC. MTSCC develops from embryonal rest-like lesions of impaired differentiation which may explain its morphological variations. Until diagnosis of a "malignant" MTSCC" is not confirmed by genetic means, it should not be called carcinoma. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  7. The impact of genetic heterogeneity on biomarker development in kidney cancer assessed by multiregional sampling.

    Science.gov (United States)

    Sankin, Alexander; Hakimi, Abraham A; Mikkilineni, Nina; Ostrovnaya, Irina; Silk, Mikhail T; Liang, Yupu; Mano, Roy; Chevinsky, Michael; Motzer, Robert J; Solomon, Stephen B; Cheng, Emily H; Durack, Jeremy C; Coleman, Jonathan A; Russo, Paul; Hsieh, James J

    2014-12-01

    Primary clear cell renal cell carcinoma (ccRCC) genetic heterogeneity may lead to an underestimation of the mutational burden detected from a single site evaluation. We sought to characterize the extent of clonal branching involving key tumor suppressor mutations in primary ccRCC and determine if genetic heterogeneity could limit the mutation profiling from a single region assessment. Ex vivo core needle biopsies were obtained from three to five different regions of resected renal tumors at a single institution from 2012 to 2013. DNA was extracted and targeted sequencing was performed on five genes associated with ccRCC (von-Hippel Lindau [VHL], PBRM1, SETD2, BAP1, and KDM5C). We constructed phylogenetic trees by inferring clonal evolution based on the mutations present within each core and estimated the predictive power of detecting a mutation for each successive tumor region sampled. We obtained 47 ex vivo biopsy cores from 14 primary ccRCC's (median tumor size 4.5 cm, IQR 4.0-5.9 cm). Branching patterns of various complexities were observed in tumors with three or more mutations. A VHL mutation was detected in nine tumors (64%), each time being present ubiquitously throughout the tumor. Other genes had various degrees of regional mutational variation. Based on the mutations' prevalence we estimated that three different tumor regions should be sampled to detect mutations in PBRM1, SETD2, BAP1, and/or KDM5C with 90% certainty. The mutational burden of renal tumors varies by region sampled. Single site assessment of key tumor suppressor mutations in primary ccRCC may not adequately capture the genetic predictors of tumor behavior. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  8. Heterogeneous photo-catalysis system for the degradation of azo dye Reactive Black 5 (RB5).

    Science.gov (United States)

    Huang, Yao-Hui; Wei, Hau-Cheng; Chen, Hung-Ta

    2012-01-01

    This study investigated a heterogeneous photo-catalysis system by introducing a novel brick supported iron oxide (denoted as B1) for the heterogeneous photoassisted degradation of Reactive Black 5 (RB5) at pH value from 3 to 7 in a three-phase (gas-liquid-solid) fluidized bed reactor (3P-FBR). Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD) and N(2) adsorption/desorption were used to characterize the B1 catalyst. The in situ formation of hydrogen peroxide and the depletion of oxalic acid by photochemical cycle of Fe(III)-oxalate complex under UVA light (λ = 365 nm) were studied. The effects of the solution pH and the concentration of oxalic acid on the degradation of RB5 are elucidated. About 90% decolourization was measured and 80% of the total organic carbon (TOC) was eliminated at pH 5.0 after 120 min for 20 mg/L RB5 in presence of 10 g/L B1 catalyst, 30 mg/L oxalic acid under 15 W UVA light. A mechanism for the photocatalytic degradation of RB5 over B1 catalyst is proposed.

  9. Capillary pressure heterogeneity and hysteresis for the supercritical CO2/water system in a sandstone

    Science.gov (United States)

    Pini, Ronny; Benson, Sally M.

    2017-10-01

    We report results from an experimental investigation on the hysteretic behaviour of the capillary pressure curve for the supercritical CO2-water system in a Berea Sandstone core. Previous observations have highlighted the importance of subcore-scale capillary heterogeneity in developing local saturations during drainage; we show in this study that the same is true for the imbibition process. Spatially distributed drainage and imbibition scanning curves were obtained for mm-scale subsets of the rock sample non-invasively using X-ray CT imagery. Core- and subcore-scale measurements are well described using the Brooks-Corey formalism, which uses a linear trapping model to compute mobile saturations during imbibition. Capillary scaling yields two separate universal drainage and imbibition curves that are representative of the full subcore-scale data set. This enables accurate parameterisation of rock properties at the subcore-scale in terms of capillary scaling factors and permeability, which in turn serve as effective indicators of heterogeneity at the same scale even when hysteresis is a factor. As such, the proposed core-analysis workflow is quite general and provides the required information to populate numerical models that can be used to extend core-flooding experiments to conditions prevalent in the subsurface, which would be otherwise not attainable in the laboratory.

  10. A method of determining where to target surveillance efforts in heterogeneous epidemiological systems.

    Directory of Open Access Journals (Sweden)

    Alexander J Mastin

    2017-08-01

    Full Text Available The spread of pathogens into new environments poses a considerable threat to human, animal, and plant health, and by extension, human and animal wellbeing, ecosystem function, and agricultural productivity, worldwide. Early detection through effective surveillance is a key strategy to reduce the risk of their establishment. Whilst it is well established that statistical and economic considerations are of vital importance when planning surveillance efforts, it is also important to consider epidemiological characteristics of the pathogen in question-including heterogeneities within the epidemiological system itself. One of the most pronounced realisations of this heterogeneity is seen in the case of vector-borne pathogens, which spread between 'hosts' and 'vectors'-with each group possessing distinct epidemiological characteristics. As a result, an important question when planning surveillance for emerging vector-borne pathogens is where to place sampling resources in order to detect the pathogen as early as possible. We answer this question by developing a statistical function which describes the probability distributions of the prevalences of infection at first detection in both hosts and vectors. We also show how this method can be adapted in order to maximise the probability of early detection of an emerging pathogen within imposed sample size and/or cost constraints, and demonstrate its application using two simple models of vector-borne citrus pathogens. Under the assumption of a linear cost function, we find that sampling costs are generally minimised when either hosts or vectors, but not both, are sampled.

  11. Cm-scale Heterogeneity in Degradation - Potential Impact on Leaching of MCPA through a Variably-Saturated Macroporous Clayey Till

    Science.gov (United States)

    Rosenbom, A. E.; Johnsen, A. R.; Aamand, J.; Binning, P. J.; Dechesne, A.; Smets, B. F.; "Cream-Spatial Heterogeneity"-Team

    2011-12-01

    Recent research has revealed a large variation in pesticide mineralization potentials, but little is known about the scale at which these heterogeneities impact the spreading of contaminants. A modeling study aiming at quantifying how heterogeneous degradation potentials in agricultural soil will affect MCPA degradation and leaching was conducted. 2D-distributions (96-well micro plate mineralization assay) of the mineralization potentials of phenoxy acid herbicides (MCPA, 2,4-D) representing layers in the upper meter of variably-saturated clayey till were applied. The rapid mineralization measured was represented by Monod mineralization kinetics, whereas the rest were either represented by slow 0-order mineralization kinetics or no degradation. Five 3D-modelling scenarios were set up using the COMSOL Multiphysics 4.1 toolbox (COMSOL Inc., Burlington, MA, USA): 1) simple matrix flow of water with no biodegradation of the MCPA at all nodes; 2) preferential flow (including a wormhole) of water with no biodegradation of the MCPA at all nodes; 3) simple matrix flow of water with average biodegradation of the MCPA at all nodes, which corresponds to results derived from a conventional homogenized soil sample; 4) simple matrix flow of water with the observed high variation in biodegradation of the MCPA corresponding to random variation in degradation; and 5) vertical structure in water flow combined with vertically structured degradation (defined hot spots and cold spots), which corresponds to a situation where both flow and degradation are associated with macropores/wormholes. Results show that cm-scale heterogeneity in degradation potential with simple matrix flow has a negligible effect on MCPA leaching at one meter below soil surface. By introducing a wormhole in the low-permeable 3D-soil modeling domain, however, the risk of MCPA-leaching below one meter depth increase drastically with low degradation potential along the wall of macropores/wormholes.

  12. A modelling framework to assess climate change and adaptation impact on heterogeneous crop-livestock farming communities

    NARCIS (Netherlands)

    Descheemaeker, K.K.E.; Masikati, P.; Homann-Kee Tui, S.; Chibwana, G.A.; Crespo, O.

    2015-01-01

    Climate change will impact the productivity of maize-based crop-livestock systems and the livelihoods of smallholders depending on them in semi-arid Zimbabwe. The large diversity in resource endowment and production objectives in rural communities differentially influences this impact and the

  13. Heterogeneous Multi-Robot System for Mapping Environmental Variables of Greenhouses

    Directory of Open Access Journals (Sweden)

    Juan Jesús Roldán

    2016-07-01

    Full Text Available The productivity of greenhouses highly depends on the environmental conditions of crops, such as temperature and humidity. The control and monitoring might need large sensor networks, and as a consequence, mobile sensory systems might be a more suitable solution. This paper describes the application of a heterogeneous robot team to monitor environmental variables of greenhouses. The multi-robot system includes both ground and aerial vehicles, looking to provide flexibility and improve performance. The multi-robot sensory system measures the temperature, humidity, luminosity and carbon dioxide concentration in the ground and at different heights. Nevertheless, these measurements can be complemented with other ones (e.g., the concentration of various gases or images of crops without a considerable effort. Additionally, this work addresses some relevant challenges of multi-robot sensory systems, such as the mission planning and task allocation, the guidance, navigation and control of robots in greenhouses and the coordination among ground and aerial vehicles. This work has an eminently practical approach, and therefore, the system has been extensively tested both in simulations and field experiments.

  14. Heterogeneous Multi-Robot System for Mapping Environmental Variables of Greenhouses.

    Science.gov (United States)

    Roldán, Juan Jesús; Garcia-Aunon, Pablo; Garzón, Mario; de León, Jorge; Del Cerro, Jaime; Barrientos, Antonio

    2016-07-01

    The productivity of greenhouses highly depends on the environmental conditions of crops, such as temperature and humidity. The control and monitoring might need large sensor networks, and as a consequence, mobile sensory systems might be a more suitable solution. This paper describes the application of a heterogeneous robot team to monitor environmental variables of greenhouses. The multi-robot system includes both ground and aerial vehicles, looking to provide flexibility and improve performance. The multi-robot sensory system measures the temperature, humidity, luminosity and carbon dioxide concentration in the ground and at different heights. Nevertheless, these measurements can be complemented with other ones (e.g., the concentration of various gases or images of crops) without a considerable effort. Additionally, this work addresses some relevant challenges of multi-robot sensory systems, such as the mission planning and task allocation, the guidance, navigation and control of robots in greenhouses and the coordination among ground and aerial vehicles. This work has an eminently practical approach, and therefore, the system has been extensively tested both in simulations and field experiments.

  15. SU-F-19A-01: APBI Brachytherapy Treatment Planning: The Impact of Heterogeneous Dose Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Loupot, S; Han, T; Salehpour, M; Gifford, K [M.D. Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    Purpose: To quantify the difference in dose to PTV-EVAL and OARs (skin and rib) as calculated by (TG43) and heterogeneous calculations (CCC). Methods: 25 patient plans (5 Contura and 20 SAVI) were selected for analysis. Clinical dose distributions were computed with a commercially available treatment planning algorithm (TG43-D-(w,w)) and then recomputed with a pre-clinical collapsed cone convolution algorithm (CCCD-( m,m)). PTV-EVAL coverage (V90%, V95%), and rib and skin maximum dose were compared via percent difference. Differences in dose to normal tissue (V150cc, V200cc of PTV-EVAL) were also compared. Changes in coverage and maximum dose to organs at risk are reported in percent change, (100*(TG43 − CCC) / TG43)), and changes in maximum dose to normal tissue are absolute change in cc (TG43 − CCC). Results: Mean differences in V90, V95, V150, and V200 for the SAVI cases were −0.2%, −0.4%, −0.03cc, and −0.14cc, respectively, with maximum differences of −0.78%, −1.7%, 1.28cc, and 1.01cc, respectively. Mean differences in the 0.1cc dose to the rib and skin were −1.4% and −0.22%, respectively, with maximum differences of −4.5% and 16%, respectively. Mean differences in V90, V95, V150, and V200 for the Contura cases were −1.2%, −2.1%, −1.8cc, and −0.59cc, respectively, with maximum differences of −2.0%, −3.16%, −2.9cc, and −0.76cc, respectively. Mean differences in the 0.1cc dose to the rib and skin were −2.6% and −3.9%, respectively, with maximum differences of −3.2% and −5.7%, respectively. Conclusion: The effects of translating clinical knowledge based on D-(w,w) to plans reported in D-(m,m) are minimal (2% or less) on average, but vary based on the type and placement of the device, source, and heterogeneity information.

  16. SDN Controlled mmWave Massive MIMO Hybrid Precoding for 5G Heterogeneous Mobile Systems

    Directory of Open Access Journals (Sweden)

    Na Chen

    2016-01-01

    Full Text Available In 5G mobile network, millimeter wave (mmWave and heterogeneous networks (Hetnets are significant techniques to sustain coverage and spectral efficiency. In this paper, we utilize the hybrid precoding to overcome hardware constraints on the analog-only beamforming in mmWave systems. Particularly, we identify the complicated antenna coordination and vast spatial domain information as the outstanding challenges in mmWave Hetnets. In our work, we employ software defined network (SDN to accomplish radio resource management (RRM and achieve flexible spacial coordination in mmWave Hetnets. In our proposed scheme, SDN controller is responsible for collecting the user channel state information (CSI and applying hybrid precoding based on the calculated null-space of victim users. Simulation results show that our design can effectively reduce the interference to victim users and support high quality of service.

  17. A grid-enabled MPI : message passing in heterogeneous distributed computing systems.

    Energy Technology Data Exchange (ETDEWEB)

    Foster, I.; Karonis, N. T.

    2000-11-30

    Application development for high-performance distributed computing systems, or computational grids as they are sometimes called, requires grid-enabled tools that hide mundate aspects of the heterogeneous grid environment without compromising performance. As part of an investigation of these issues, they have developed MPICH-G, a grid-enabled implementation of the Message Passing Interface (MPI) that allows a user to run MPI programs across multiple computers at different sites using the same commands that would be used on a parallel computer. This library extends the Argonne MPICH implementation of MPI to use services provided by the globus grid toolkit. In this paper, they describe the MPICH-G implementation and present preliminary performance results.

  18. Iron oxide-mediated semiconductor photocatalysis vs. heterogeneous photo-Fenton treatment of viruses in wastewater. Impact of the oxide particle size.

    Science.gov (United States)

    Giannakis, Stefanos; Liu, Siting; Carratalà, Anna; Rtimi, Sami; Talebi Amiri, Masoud; Bensimon, Michaël; Pulgarin, César

    2017-10-05

    The photo-Fenton process is recognized as a promising technique towards microorganism disinfection in wastewater, but its efficiency is hampered at near-neutral pH operating values. In this work, we overcome these obstacles by using the heterogeneous photo-Fenton process as the default disinfecting technique, targeting MS2 coliphage in wastewater. The use of low concentrations of iron oxides in wastewater without H2O2 (wüstite, maghemite, magnetite) has demonstrated limited semiconductor-mediated MS2 inactivation. Changing the operational pH and the size of the oxide particles indicated that the isoelectric point of the iron oxides and the active surface area are crucial in the success of the process, and the possible underlying mechanisms are investigated. Furthermore, the addition of low amounts of Fe-oxides (1mgL-1) and H2O2 in the system (1, 5 and 10mgL-1) greatly enhanced the inactivation process, leading to heterogeneous photo-Fenton processes on the surface of the magnetically separable oxides used. Additionally, photo-dissolution of iron in the bulk, lead to homogeneous photo-Fenton, further aided by the complexation by the dissolved organic matter in the solution. Finally, we assess the impact of the presence of the bacterial host and the difference caused by the different iron sources (salts, oxides) and the Fe-oxide size (normal, nano-sized). Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Clinical Heterogeneity of Guillain-Barré Syndrome in the Emergency Department: Impact on Clinical Outcome

    Directory of Open Access Journals (Sweden)

    Athanasios Papathanasiou

    2016-01-01

    Full Text Available Guillain-Barré syndrome (GBS is mainly classified into acute inflammatory demyelinating polyneuropathy (AIDP and acute motor axonal neuropathy (AMAN. Although diagnosis of GBS requires progressive weakness and universal areflexia or hyporeflexia, cases of GBS with preserved or increased deep tendon reflexes (DTRs have been increasingly recognized. We report three cases of GBS, presenting at a single unit in six months. Our first case presented with pure sensory symptoms. The second case had nonspecific generalized weakness, while the third presented with typical ascending weakness. One of our patients had preserved DTRs, while the other two had increased DTRs. Our two cases with hyperreflexia were found to have a preceding Campylobacter jejuni infection and anti-ganglioside antibodies, and their electrophysiological studies revealed AMAN. The other case had an AIDP. Only one case was offered a diagnosis and treatment from the first emergency department (ED visit and had a better clinical outcome. Clinical diagnosis of GBS in the ED can be challenging. Delay in diagnosis of GBS in the ED is common due to cases with intact or increased DTRs, atypical pattern of weakness, or pure sensory symptoms. Emergency physicians should be aware of GBS clinical heterogeneity, because early diagnosis and treatment improve clinical outcome.

  20. Impact of Spatial LAI Heterogeneity on Estimate of Directional Gap Fraction from SPOT-Satellite Data

    Directory of Open Access Journals (Sweden)

    Zhao-Liang Li

    2008-06-01

    Full Text Available Directional gap probability or gap fraction is a basic parameter in the optical remote sensing modeling. Although some approaches have been proposed to estimate this gap probability from remotely sensed measurements, few efforts have been made to investigate the scaling effects of this parameter. This paper analyzes the scaling effect through aggregating the high-resolution directional gap probability (pixel size of 20 meters estimated from leaf area index (LAI images of VALERI database by means of Beer's law and introduces an extension of clumping index, Ĉ, to compensate the scaling bias. The results show that the scaling effect depends on both the surface heterogeneity and the nonlinearity degree of the retrieved function. Analytical expressions for the scaling bias of gap probability and Ĉ are established in function of the variance of LAI and the mean value of LAI in a coarse pixel. With the VALERI dataset, the study in this paper shows that relative scaling bias of gap probability increases with decreasing spatial resolution for most of land cover types. Large relative biases are found for most of crops sites and a mixed forest site due to their relative large variance of LAI, while very small biases occur over grassland and shrubs sites. As for Ĉ, it varies slowly in the pure forest, grassland and shrubs sites, while more significantly in crops and mixed forest.

  1. Impact of distributions on the archetypes and prototypes in heterogeneous nanoparticle ensembles.

    Science.gov (United States)

    Fernandez, Michael; Wilson, Hugh F; Barnard, Amanda S

    2017-01-05

    The magnitude and complexity of the structural and functional data available on nanomaterials requires data analytics, statistical analysis and information technology to drive discovery. We demonstrate that multivariate statistical analysis can recognise the sets of truly significant nanostructures and their most relevant properties in heterogeneous ensembles with different probability distributions. The prototypical and archetypal nanostructures of five virtual ensembles of Si quantum dots (SiQDs) with Boltzmann, frequency, normal, Poisson and random distributions are identified using clustering and archetypal analysis, where we find that their diversity is defined by size and shape, regardless of the type of distribution. At the complex hull of the SiQD ensembles, simple configuration archetypes can efficiently describe a large number of SiQDs, whereas more complex shapes are needed to represent the average ordering of the ensembles. This approach provides a route towards the characterisation of computationally intractable virtual nanomaterial spaces, which can convert big data into smart data, and significantly reduce the workload to simulate experimentally relevant virtual samples.

  2. The Impact of Teachers' Individualized Practices on Gifted Students in Rural, Heterogeneous Classrooms.

    Science.gov (United States)

    Davalos, Ruth; Griffin, Glenda

    1999-01-01

    A study involving six gifted fifth graders investigated the effectiveness of training teachers to differentiate for gifted students' needs by curricular adaptations. When the setting of goals was left to individual trained teachers, some chose goals that were easy to implement and had little or no real impact on instructional techniques. (CR)

  3. A Queueing System with Heterogeneous Impatient Customers and Consumable Additional Items

    Directory of Open Access Journals (Sweden)

    Baek Janghyun

    2017-06-01

    Full Text Available A single-server queueing system with a marked Markovian arrival process of heterogeneous customers is considered. Type-1 customers have limited preemptive priority over type-2 customers. There is an infinite buffer for type-2 customers and no buffer for type-1 customers. There is also a finite buffer (stock for consumable additional items (semi-products, half-stocks, etc. which arrive according to the Markovian arrival process. Service of a customer requires a fixed number of consumable additional items depending on the type of the customer. The service time has a phase-type distribution depending on the type of the customer. Customers in the buffer are impatient and may leave the system without service after an exponentially distributed amount of waiting time. Aiming to minimize the loss probability of type-1 customers and maximize throughput of the system, a threshold strategy of admission to service of type-2 customers is offered. Service of type-2 customer can start only if the server is idle and the number of consumable additional items in the stock exceeds the fixed threshold. Stationary distributions of the system states and the waiting time are computed. In the numerical example, we show some interesting effects and illustrate a possibility of application of the presented results for solution of optimization problems.

  4. Heterogeneous structure in colloidal systems: the role of the microion disposition.

    Science.gov (United States)

    Schmitz, Kenneth S

    2002-12-01

    Under certain conditions colloidal systems exhibit a heterogeneous structure sometimes referred to as a "two state" structure, "spinodal instability," or a "phase separation." The present study focuses on the "orbital model" for the description of two geometries of colloidal clusters: a 7-particle diamond shape array and an 8-particle simple cubic array. The orbital model envisions the distribution of the microions as being dictated by the specific configuration of all the macroions in the system, in much the same way that electron distributions in molecules are determined by the array of atoms. Brownian dynamics simulations were performed as two similar clusters approached each other in rectangular cells at the volume fraction of phi(p)=0.01. The number distributions of both the counterion and coion species were determined three ways: the one-dimensional projection along the long axis of the computations cell; the three-dimensional number distributions in "real" space; and a "constant concentration" contour profile. It was found that as the two clusters approached each other the diamond cluster system became less stable whereas the simple cubic cluster system became more stable. This difference in behavior is attributed to the relative abilities of these structures to "share" counterions and the exclusion of the coions.

  5. [Review on landscape heterogeneity].

    Science.gov (United States)

    Zhao, Yutao; Yu, Xinxiao; Guang, Wenbin

    2002-04-01

    On the base of precedent studies, the occurring mechanism, classification, measurement methods, and the important role of landscape heterogeneity in landscape ecology were reviewed. The inner and outer uncertain factors result in landscape heterogeneity. Landscape heterogeneity has close relations with landscape stability, landscape design, architecture, management and disturbance, scale and ecological diversity in ecology. Complexity of landscape heterogeneity research, non-system of measurement indices and methods, difficulties and limitations of landscape heterogeneity modelling were all discussed respectively. In addition, it is suggested that the theory and methods of ecological complexity should be used to improve landscape heterogeneity research.

  6. Spindle-shaped nanoscale yolk/shell magnetic stirring bars for heterogeneous catalysis in macro- and microscopic systems.

    Science.gov (United States)

    Yang, Shuliang; Cao, Changyan; Peng, Li; Huang, Peipei; Sun, Yongbin; Wei, Fang; Song, Weiguo

    2016-01-28

    A new type of spindle-shaped nanoscale yolk/shell magnetic stirring bar containing noble metal nanoparticles was prepared. The as-synthesized Pd-Fe@meso-SiO2 not only showed impressive activity and stability as a heterogeneous catalyst in a macroscopic flask system, but also acted as an efficient nanoscale magnetic stir bar in a microscopic droplet system.

  7. Heterogeneous Gossip

    Science.gov (United States)

    Frey, Davide; Guerraoui, Rachid; Kermarrec, Anne-Marie; Koldehofe, Boris; Mogensen, Martin; Monod, Maxime; Quéma, Vivien

    Gossip-based information dissemination protocols are considered easy to deploy, scalable and resilient to network dynamics. Load-balancing is inherent in these protocols as the dissemination work is evenly spread among all nodes. Yet, large-scale distributed systems are usually heterogeneous with respect to network capabilities such as bandwidth. In practice, a blind load-balancing strategy might significantly hamper the performance of the gossip dissemination.

  8. The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape.

    Science.gov (United States)

    Rossetto, Maurizio; Thurlby, Katie Ag; Offord, Catherine A; Allen, Chris B; Weston, Peter H

    2011-05-18

    Inter-population distance and differences in breeding times are barriers to reproduction that can contribute to genotypic differentiation between populations. Temporal changes in environmental conditions and local selective processes can further contribute to the establishment of reproductive barriers. Telopea speciosissima (Proteaceae) is an excellent subject for studying the effect of geographic, edaphic and phenological heterogeneity on genotypic differentiation because previous studies show that these factors are correlated with morphological variation. Molecular, morphological and environmental datasets were combined to characterise the relative influence of these factors on inter-population differentiation, and Bayesian analyses were used to investigate current levels of admixture between differentiated genomes. A landscape genetic approach involving molecular and morphological analyses identified three endpoints of differentiated population groups: coastal, upland and southern. The southern populations, isolated from the other populations by an edaphic barrier, show low migration and no evidence of admixture with other populations. Amongst the northern populations, coastal and upland populations are connected along a skewed altitudinal gradient by genetically intermediate populations. The strong association between temperature and flowering time in Telopea speciosissima was shown to maintain a temporally unstable reproductive barrier between coastal and upland populations. Substrate-mediated allopatry appears to be responsible for long-term genetic isolation of the southern populations. However, the temperature-dependent reproductive barrier between upland and coastal populations bears the genetic signature of temporal adjustments. The extreme climatic events of the last glacial maximum are likely to have caused more complete allochronic isolation between upland and coastal populations, as well as exerting increased selective pressure upon local genomes

  9. Identification of allelic heterogeneity at type-2 diabetes loci and impact on prediction.

    Directory of Open Access Journals (Sweden)

    Yann C Klimentidis

    Full Text Available Although over 60 single nucleotide polymorphisms (SNPs have been identified by meta-analysis of genome-wide association studies for type-2 diabetes (T2D among individuals of European descent, much of the genetic variation remains unexplained. There are likely many more SNPs that contribute to variation in T2D risk, some of which may lie in the regions surrounding established SNPs--a phenomenon often referred to as allelic heterogeneity. Here, we use the summary statistics from the DIAGRAM consortium meta-analysis of T2D genome-wide association studies along with linkage disequilibrium patterns inferred from a large reference sample to identify novel SNPs associated with T2D surrounding each of the previously established risk loci. We then examine the extent to which the use of these additional SNPs improves prediction of T2D risk in an independent validation dataset. Our results suggest that multiple SNPs at each of 3 loci contribute to T2D susceptibility (TCF7L2, CDKN2A/B, and KCNQ1; p<5×10(-8. Using a less stringent threshold (p<5×10(-4, we identify 34 additional loci with multiple associated SNPs. The addition of these SNPs slightly improves T2D prediction compared to the use of only the respective lead SNPs, when assessed using an independent validation cohort. Our findings suggest that some currently established T2D risk loci likely harbor multiple polymorphisms which contribute independently and collectively to T2D risk. This opens a promising avenue for improving prediction of T2D, and for a better understanding of the genetic architecture of T2D.

  10. Lunar impact basins and crustal heterogeneity: New western limb and far side data from galileo

    Science.gov (United States)

    Belton, M.J.S.; Head, J. W.; Pieters, C.M.; Greeley, R.; McEwen, A.S.; Neukum, G.; Klaasen, K.P.; Anger, C.D.; Carr, M.H.; Chapman, C.R.; Davies, M.E.; Fanale, F.P.; Gierasch, P.J.; Greenberg, R.; Ingersoll, A.P.; Johnson, T.; Paczkowski, B.; Pilcher, C.B.; Veverka, J.

    1992-01-01

    Multispectral images of the lunar western limb and far side obtained from Galileo reveal the compositional nature of several prominent lunar features and provide new information on lunar evolution. The data reveal that the ejecta from the Orientale impact basin (900 kilometers in diameter) lying outside the Cordillera Mountains was excavated from the crust, not the mantle, and covers pre-Orientale terrain that consisted of both highland materials and relatively large expanses of ancient mare basalts. The inside of the far side South Pole-Aitken basin (>2000 kilometers in diameter) has low albedo, red color, and a relatively high abundance of iron- and magnesium-rich materials. These features suggest that the impact may have penetrated into the deep crust or lunar mantle or that the basin contains ancient mare basalts that were later covered by highlands ejecta.

  11. Lunar impact basins and crustal heterogeneity - New western limb and far side data from Galileo

    Science.gov (United States)

    Belton, Michael J. S.; Head, James W., III; Pieters, Carle M.; Greeley, Ronald; Mcewen, Alfred S.; Neukum, Gerhard; Klaasen, Kenneth P.; Anger, Clifford D.; Carr, Michael H.; Chapman, Clark R.

    1992-01-01

    Multispectral images of the lunar western limb and far side obtained from Galileo reveal the compositional nature of several prominent lunar features and provide new information on lunar evolution. The data reveal that the ejecta from the Orientale impact basin (900 kilometers in diameter) lying outside the Cordillera Mountains was excavated from the crust, not the mantle, and covers pre-Orientale terrain that consisted of both highland materials and relatively large expanses of ancient mare basalts. The inside of the far side South Pole-Aitken basin (greater than 2000 kilometers in diameter) has low albedo, red color, and a relatively high abundance of iron- and magnesium-rich materials. These features suggest that the impact may have penetrated into the deep crust or lunar mantle or that the basin contains ancient mare basalts that were later covered by highlands ejecta.

  12. Soil Components in Heterogeneous Impact Glass in Martian Meteorite EETA79001

    Science.gov (United States)

    Schrader, C. M.; Cohen, B. A.; Donovan, J. J.; Vicenzi, E. P.

    2010-01-01

    Martian soil composition can illuminate past and ongoing near-surface processes such as impact gardening [2] and hydrothermal and volcanic activity [3,4]. Though the Mars Exploration Rovers (MER) have analyzed the major-element composition of Martian soils, no soil samples have been returned to Earth for detailed chemical analysis. Rao et al. [1] suggested that Martian meteorite EETA79001 contains melted Martian soil in its impact glass (Lithology C) based on sulfur enrichment of Lithology C relative to the meteorite s basaltic lithologies (A and B) [1,2]. If true, it may be possible to extract detailed soil chemical analyses using this meteoritic sample. We conducted high-resolution (0.3 m/pixel) element mapping of Lithology C in thin section EETA79001,18 by energy dispersive spectrometry (EDS). We use these data for principal component analysis (PCA).

  13. Distributed Impact Detection System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Automated impact detection and characterization on manned spacecraft has been an elusive goal due to the transitory nature of the detectable high-frequency signals....

  14. The Impact of the Tobin Tax in a Heterogeneous Agent Model of the Foreign Exchange Market

    Czech Academy of Sciences Publication Activity Database

    Staněk, F.; Kukačka, Jiří

    (2018) ISSN 0927-7099 R&D Projects: GA ČR(CZ) GBP402/12/G097 Grant - others:GA UK(CZ) 588912; GA MŠk(CZ) SVV260233 Institutional support: RVO:67985556 Keywords : Tobin tax * Foreign exchange market * Agent-based modeling * Walrasian auctioneer Subject RIV: AH - Economics Impact factor: 1.053, year: 2016 http:// library .utia.cas.cz/separaty/2017/E/kukacka-0472380.pdf

  15. Performance of Goddard Earth Observing System GCM Column Radiation Models under Heterogeneous Cloud Conditions

    Science.gov (United States)

    Oreopoulos, L.; Chou, M.-D.; Khairoutdinov, M.; Barker, H. W.; Cahalan, R. F.

    2003-01-01

    We test the performance of the shortwave (SW) and longwave (LW) Column Radiation Models (CORAMs) of Chou and collaborators with heterogeneous cloud fields from a global single-day dataset produced by NCAR's Community Atmospheric Model with a 2-D CRM installed in each gridbox. The original SW version of the CORAM performs quite well compared to reference Independent Column Approximation (ICA) calculations for boundary fluxes, largely due to the success of a combined overlap and cloud scaling parameterization scheme. The absolute magnitude of errors relative to ICA are even smaller for the LW CORAM which applies similar overlap. The vertical distribution of heating and cooling within the atmosphere is also simulated quite well with daily-averaged zonal errors always below 0.3 K/d for SW heating rates and 0.6 K/d for LW cooling rates. The SW CORAM's performance improves by introducing a scheme that accounts for cloud inhomogeneity. These results suggest that previous studies demonstrating the inaccuracy of plane-parallel models may have unfairly focused on worst scenario cases, and that current radiative transfer algorithms of General Circulation Models (GCMs) may be more capable than previously thought in estimating realistic spatial and temporal averages of radiative fluxes, as long as they are provided with correct mean cloud profiles. However, even if the errors of the particular CORAMs are small, they seem to be systematic, and the impact of the biases can be fully assessed only with GCM climate simulations.

  16. Impact of treated wastewater irrigation on heterogeneity and on the fate of salts and nutrients in the subsurface

    Science.gov (United States)

    Gomes Hochberg, C.; Furman, A.; Weisbrod, N.

    2013-12-01

    Reuse of treated wastewater (TWW) for irrigation is one of the solutions to water shortage. Not only it saves water, it also supplies organic matter (OM) and other nutrients to the soil. However, long term application of TWW can affect soil physical and chemical properties. Additionally, substances added via TWW irrigation can accentuate already existent soil heterogeneity, which may impact physical and chemical processes in soils. As more agricultural fields are being irrigated with TWW, it is crucial to understand its implications on soils. The objectives of this research are to investigate: (a) the impact of TWW irrigation on soil heterogeneity, and on hydraulic processes; and (b) the fate of salts and nutrients in the subsurface in soils irrigated with TWW vs. tap water (TP). The experiment is carried out in Lachish farm, Israel. Two trenches were dug and a sensors network of 38 tensiometers, 37 TDRs, 6 redox probes, and 38 thermocouples was installed in high resolution in each cross section (1.5 x 1.5 m). The cross sections are 13 meters apart in a vineyard irrigated for over 10 years with TP and TWW. One cross section is in a TP area while the other is in TWW area. Soil samples were collected according to visually observed heterogeneity of the soil profiles and randomly. Chemical analyses were conducted in both soil and water samples. In addition, infiltration rate, Leaf Area Index (LAI), and harvest yield were determined. For irrigation water analyses, DOM in TWW is higher than TP (average concentrations of 25.9 and 1.4 mg/L, respectively). Soil organic matter is in average 1% higher in soils irrigated with TWW in the first 10 cm, while for lower depths OM content is the same under both treatments. No repellency was detected for either soils (WDPT40%). ESP, EC and pH were higher for TWW soils, but not high enough to be characterized as saline and/or sodic. However, it presented SAR and EC levels of moderate infiltration reduction risk. Infiltration rate was

  17. A Heterogeneous Sensing System-Based Method for Unmanned Aerial Vehicle Indoor Positioning

    Directory of Open Access Journals (Sweden)

    Can Wang

    2017-08-01

    Full Text Available The indoor environment has brought new challenges for micro Unmanned Aerial Vehicles (UAVs in terms of their being able to execute tasks with high positioning accuracy. Conventional positioning methods based on GPS are unreliable, although certain circumstances of limited space make it possible to apply new technologies. In this paper, we propose a novel indoor self-positioning system of UAV based on a heterogeneous sensing system, which integrates data from a structured light scanner, ultra-wideband (UWB, and an inertial navigation system (INS. We made the structured light scanner, which is composed of a low-cost structured light and camera, ourselves to improve the positioning accuracy at a specified area. We applied adaptive Kalman filtering to fuse the data from the INS and UWB while the vehicle was moving, as well as Gauss filtering to fuse the data from the UWB and the structured light scanner in a hovering state. The results of our simulations and experiments demonstrate that the proposed strategy significantly improves positioning accuracy in motion and also in the hovering state, as compared to using a single sensor.

  18. A Heterogeneous Sensing System-Based Method for Unmanned Aerial Vehicle Indoor Positioning.

    Science.gov (United States)

    Wang, Can; Li, Kang; Liang, Guoyuan; Chen, Haoyao; Huang, Sheng; Wu, Xinyu

    2017-08-10

    The indoor environment has brought new challenges for micro Unmanned Aerial Vehicles (UAVs) in terms of their being able to execute tasks with high positioning accuracy. Conventional positioning methods based on GPS are unreliable, although certain circumstances of limited space make it possible to apply new technologies. In this paper, we propose a novel indoor self-positioning system of UAV based on a heterogeneous sensing system, which integrates data from a structured light scanner, ultra-wideband (UWB), and an inertial navigation system (INS). We made the structured light scanner, which is composed of a low-cost structured light and camera, ourselves to improve the positioning accuracy at a specified area. We applied adaptive Kalman filtering to fuse the data from the INS and UWB while the vehicle was moving, as well as Gauss filtering to fuse the data from the UWB and the structured light scanner in a hovering state. The results of our simulations and experiments demonstrate that the proposed strategy significantly improves positioning accuracy in motion and also in the hovering state, as compared to using a single sensor.

  19. The fate of pesticides in soil and aquifers from a small-scale point of view: Does microbial and spatial heterogeneity have an impact?

    DEFF Research Database (Denmark)

    Aamand, J.; Badawi, N.; Rosenbom, Annette Elisabeth

    herbicides (MCPA, 2,4-D) were spatially distributed in soil, subsoil, and groundwater aquifers using a 96-well microplate mineralisation assay. In the top soil, all samples showed rapid mineralisation following Monod mineralisation kinetics. In the subsoil sediments, a more heterogeneous distribution...... of mineralisation potentials was observed with fewer samples showing rapid mineralisation and more samples showing either slow 0-order mineralisation kinetics or no degradation. A heterogeneous distribution of herbicide mineralisation potentials was also observed in the groundwater sediment showing the most rapid...... mineralization close to the water table. The impacts of microbial heterogeneity on degradation and leaching of MCPA through the upper meter of subsurface sediment is evaluated with a numerical model. Results show that for reasonably uniform soils, heterogeneity in mineralisation has little effect on leached...

  20. Finite-size scaling in the system of coupled oscillators with heterogeneity in coupling strength.

    Science.gov (United States)

    Hong, Hyunsuk

    2017-07-01

    We consider a mean-field model of coupled phase oscillators with random heterogeneity in the coupling strength. The system that we investigate here is a minimal model that contains randomness in diverse values of the coupling strength, and it is found to return to the original Kuramoto model [Y. Kuramoto, Prog. Theor. Phys. Suppl. 79, 223 (1984)10.1143/PTPS.79.223] when the coupling heterogeneity disappears. According to one recent paper [H. Hong, H. Chaté, L.-H. Tang, and H. Park, Phys. Rev. E 92, 022122 (2015)10.1103/PhysRevE.92.022122], when the natural frequency of the oscillator in the system is "deterministically" chosen, with no randomness in it, the system is found to exhibit the finite-size scaling exponent ν[over ¯]=5/4. Also, the critical exponent for the dynamic fluctuation of the order parameter is found to be given by γ=1/4, which is different from the critical exponents for the Kuramoto model with the natural frequencies randomly chosen. Originally, the unusual finite-size scaling behavior of the Kuramoto model was reported by Hong et al. [H. Hong, H. Chaté, H. Park, and L.-H. Tang, Phys. Rev. Lett. 99, 184101 (2007)10.1103/PhysRevLett.99.184101], where the scaling behavior is found to be characterized by the unusual exponent ν[over ¯]=5/2. On the other hand, if the randomness in the natural frequency is removed, it is found that the finite-size scaling behavior is characterized by a different exponent, ν[over ¯]=5/4 [H. Hong, H. Chaté, L.-H. Tang, and H. Park, Phys. Rev. E 92, 022122 (2015)10.1103/PhysRevE.92.022122]. Those findings brought about our curiosity and led us to explore the effects of the randomness on the finite-size scaling behavior. In this paper, we pay particular attention to investigating the finite-size scaling and dynamic fluctuation when the randomness in the coupling strength is considered.

  1. Survivability of systems under multiple factor impact

    Energy Technology Data Exchange (ETDEWEB)

    Korczak, Edward [Telecommunications Research Institute, Warsaw (Poland); Levitin, Gregory [Israel Electric Corporation Ltd., Haifa (Israel)]. E-mail: levitin@iec.co.il

    2007-02-15

    The paper considers vulnerable multi-state series-parallel systems operating under influence of external impacts. Both the external impacts and internal failures affect system survivability, which is determined as the probability of meeting a given demand. The external impacts are characterized by several destructive factors affecting the system or its parts simultaneously. In order to increase the system's survivability a multilevel protection against the destructive factors can be applied to its subsystems. In such systems, the protected subsystems can be destroyed only if all of the levels of their protection are destroyed. The paper presents an algorithm for evaluating the survivability of series-parallel systems with arbitrary configuration of multilevel protection against multiple destructive factor impacts. The algorithm is based on a composition of Boolean and the Universal Generating Function techniques. Illustrative examples are presented.

  2. A multi-agent conversational system with heterogeneous data sources access

    KAUST Repository

    Eisman, Eduardo M.

    2016-01-28

    In many of the problems that can be found nowadays, information is scattered across different heterogeneous data sources. Most of the natural language interfaces just focus on a very specific part of the problem (e.g. an interface to a relational database, or an interface to an ontology). However, from the point of view of users, it does not matter where the information is stored, they just want to get the knowledge in an integrated, transparent, efficient, effective, and pleasant way. To solve this problem, this article proposes a generic multi-agent conversational architecture that follows the divide and conquer philosophy and considers two different types of agents. Expert agents are specialized in accessing different knowledge sources, and decision agents coordinate them to provide a coherent final answer to the user. This architecture has been used to design and implement SmartSeller, a specific system which includes a Virtual Assistant to answer general questions and a Bookseller to query a book database. A deep analysis regarding other relevant systems has demonstrated that our proposal provides several improvements at some key features presented along the paper.

  3. A HETEROGENEOUS MULTIPROCESSOR SYSTEM-ON-CHIP ARCHITECTURE INCORPORATING MEMORY ALLOCATION

    Directory of Open Access Journals (Sweden)

    T.Thillaikkarasi

    2010-06-01

    Full Text Available This paper describes the development of a Multiprocessor System-on-Chip (MPSoC with a novel interconnect architecture incorporating memory allocation. It addresses the problem of mapping a process network with data dependent behavior and soft real time constraints onto the heterogeneous multiprocessor System on Chip (SoC architectures and focuses on a memory allocation step which is based on an integer linear programming model. An application is modeled as Kahn Process Network (KPN which makes the parallelism present in the application explicit. The main contribution of our work is an MILP based approach which can be used to map the KPN of streaming applications with data dependent behavior and interleaved computation and communication. Our solution minimizes hardware cost while taking into account the performance constraints. One of the salient features of our work is that it takes into account the additional overheads because of data communication conflicts. It permits to obtain an optimal distributed shared memory architecture minimizing the global cost to access the shared data in the application, and the memory cost. Our approach allows automatic generation of an architecture-level specification of the application.

  4. A DAG Scheduling Scheme on Heterogeneous Computing Systems Using Tuple-Based Chemical Reaction Optimization

    Science.gov (United States)

    Jiang, Yuyi; Shao, Zhiqing; Guo, Yi

    2014-01-01

    A complex computing problem can be solved efficiently on a system with multiple computing nodes by dividing its implementation code into several parallel processing modules or tasks that can be formulated as directed acyclic graph (DAG) problems. The DAG jobs may be mapped to and scheduled on the computing nodes to minimize the total execution time. Searching an optimal DAG scheduling solution is considered to be NP-complete. This paper proposed a tuple molecular structure-based chemical reaction optimization (TMSCRO) method for DAG scheduling on heterogeneous computing systems, based on a very recently proposed metaheuristic method, chemical reaction optimization (CRO). Comparing with other CRO-based algorithms for DAG scheduling, the design of tuple reaction molecular structure and four elementary reaction operators of TMSCRO is more reasonable. TMSCRO also applies the concept of constrained critical paths (CCPs), constrained-critical-path directed acyclic graph (CCPDAG) and super molecule for accelerating convergence. In this paper, we have also conducted simulation experiments to verify the effectiveness and efficiency of TMSCRO upon a large set of randomly generated graphs and the graphs for real world problems. PMID:25143977

  5. Effects of dispersal on total biomass in a patchy, heterogeneous system: analysis and experiment.

    Science.gov (United States)

    Zhang, Bo; Liu, Xin; DeAngelis, Donald L.; Ni, Wei-Ming; Wang, G Geoff

    2015-01-01

    An intriguing recent result from mathematics is that a population diffusing at an intermediate rate in an environment in which resources vary spatially will reach a higher total equilibrium biomass than the population in an environment in which the same total resources are distributed homogeneously. We extended the current mathematical theory to apply to logistic growth and also showed that the result applies to patchy systems with dispersal among patches, both for continuous and discrete time. This allowed us to make specific predictions, through simulations, concerning the biomass dynamics, which were verified by a laboratory experiment. The experiment was a study of biomass growth of duckweed (Lemna minor Linn.), where the resources (nutrients added to water) were distributed homogeneously among a discrete series of water-filled containers in one treatment, and distributed heterogeneously in another treatment. The experimental results showed that total biomass peaked at an intermediate, relatively low, diffusion rate, higher than the total carrying capacity of the system and agreeing with the simulation model. The implications of the experiment to dynamics of source, sink, and pseudo-sink dynamics are discussed.

  6. Effects of dispersal on total biomass in a patchy, heterogeneous system: Analysis and experiment.

    Science.gov (United States)

    Zhang, Bo; Liu, Xin; DeAngelis, D L; Ni, Wei-Ming; Wang, G Geoff

    2015-06-01

    An intriguing recent result from mathematics is that a population diffusing at an intermediate rate in an environment in which resources vary spatially will reach a higher total equilibrium biomass than the population in an environment in which the same total resources are distributed homogeneously. We extended the current mathematical theory to apply to logistic growth and also showed that the result applies to patchy systems with dispersal among patches, both for continuous and discrete time. This allowed us to make specific predictions, through simulations, concerning the biomass dynamics, which were verified by a laboratory experiment. The experiment was a study of biomass growth of duckweed (Lemna minor Linn.), where the resources (nutrients added to water) were distributed homogeneously among a discrete series of water-filled containers in one treatment, and distributed heterogeneously in another treatment. The experimental results showed that total biomass peaked at an intermediate, relatively low, diffusion rate, higher than the total carrying capacity of the system and agreeing with the simulation model. The implications of the experiment to dynamics of source, sink, and pseudo-sink dynamics are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Output Containment Control of Linear Heterogeneous Multi-Agent Systems Using Internal Model Principle.

    Science.gov (United States)

    Zuo, Shan; Song, Yongduan; Lewis, Frank L; Davoudi, Ali

    2017-01-04

    This paper studies the output containment control of linear heterogeneous multi-agent systems, where the system dynamics and even the state dimensions can generally be different. Since the states can have different dimensions, standard results from state containment control do not apply. Therefore, the control objective is to guarantee the convergence of the output of each follower to the dynamic convex hull spanned by the outputs of leaders. This can be achieved by making certain output containment errors go to zero asymptotically. Based on this formulation, two different control protocols, namely, full-state feedback and static output-feedback, are designed based on internal model principles. Sufficient local conditions for the existence of the proposed control protocols are developed in terms of stabilizing the local followers' dynamics and satisfying a certain H∞ criterion. Unified design procedures to solve the proposed two control protocols are presented by formulation and solution of certain local state-feedback and static output-feedback problems, respectively. Numerical simulations are given to validate the proposed control protocols.

  8. Biologically-inspired approaches for self-organization, adaptation, and collaboration of heterogeneous autonomous systems

    Science.gov (United States)

    Steinberg, Marc

    2011-06-01

    This paper presents a selective survey of theoretical and experimental progress in the development of biologicallyinspired approaches for complex surveillance and reconnaissance problems with multiple, heterogeneous autonomous systems. The focus is on approaches that may address ISR problems that can quickly become mathematically intractable or otherwise impractical to implement using traditional optimization techniques as the size and complexity of the problem is increased. These problems require dealing with complex spatiotemporal objectives and constraints at a variety of levels from motion planning to task allocation. There is also a need to ensure solutions are reliable and robust to uncertainty and communications limitations. First, the paper will provide a short introduction to the current state of relevant biological research as relates to collective animal behavior. Second, the paper will describe research on largely decentralized, reactive, or swarm approaches that have been inspired by biological phenomena such as schools of fish, flocks of birds, ant colonies, and insect swarms. Next, the paper will discuss approaches towards more complex organizational and cooperative mechanisms in team and coalition behaviors in order to provide mission coverage of large, complex areas. Relevant team behavior may be derived from recent advances in understanding of the social and cooperative behaviors used for collaboration by tens of animals with higher-level cognitive abilities such as mammals and birds. Finally, the paper will briefly discuss challenges involved in user interaction with these types of systems.

  9. Ultrasonic-impact grinder system

    Science.gov (United States)

    Calkins, N.C.

    1982-09-30

    The disclosure relates to an ultrasonic impact grinding apparatus utilizing a counterweight to set an unloaded friction free condition. An added weight is used to optimize feed rate in accordance with the material to be cut, tool size and the like.

  10. Computer-aided multiple-head 3D printing system for printing of heterogeneous organ/tissue constructs

    Science.gov (United States)

    Jung, Jin Woo; Lee, Jung-Seob; Cho, Dong-Woo

    2016-01-01

    Recently, much attention has focused on replacement or/and enhancement of biological tissues via the use of cell-laden hydrogel scaffolds with an architecture that mimics the tissue matrix, and with the desired three-dimensional (3D) external geometry. However, mimicking the heterogeneous tissues that most organs and tissues are formed of is challenging. Although multiple-head 3D printing systems have been proposed for fabricating heterogeneous cell-laden hydrogel scaffolds, to date only the simple exterior form has been realized. Here we describe a computer-aided design and manufacturing (CAD/CAM) system for this application. We aim to develop an algorithm to enable easy, intuitive design and fabrication of a heterogeneous cell-laden hydrogel scaffolds with a free-form 3D geometry. The printing paths of the scaffold are automatically generated from the 3D CAD model, and the scaffold is then printed by dispensing four materials; i.e., a frame, two kinds of cell-laden hydrogel and a support. We demonstrated printing of heterogeneous tissue models formed of hydrogel scaffolds using this approach, including the outer ear, kidney and tooth tissue. These results indicate that this approach is particularly promising for tissue engineering and 3D printing applications to regenerate heterogeneous organs and tissues with tailored geometries to treat specific defects or injuries. PMID:26899876

  11. Computer-aided multiple-head 3D printing system for printing of heterogeneous organ/tissue constructs

    Science.gov (United States)

    Jung, Jin Woo; Lee, Jung-Seob; Cho, Dong-Woo

    2016-02-01

    Recently, much attention has focused on replacement or/and enhancement of biological tissues via the use of cell-laden hydrogel scaffolds with an architecture that mimics the tissue matrix, and with the desired three-dimensional (3D) external geometry. However, mimicking the heterogeneous tissues that most organs and tissues are formed of is challenging. Although multiple-head 3D printing systems have been proposed for fabricating heterogeneous cell-laden hydrogel scaffolds, to date only the simple exterior form has been realized. Here we describe a computer-aided design and manufacturing (CAD/CAM) system for this application. We aim to develop an algorithm to enable easy, intuitive design and fabrication of a heterogeneous cell-laden hydrogel scaffolds with a free-form 3D geometry. The printing paths of the scaffold are automatically generated from the 3D CAD model, and the scaffold is then printed by dispensing four materials; i.e., a frame, two kinds of cell-laden hydrogel and a support. We demonstrated printing of heterogeneous tissue models formed of hydrogel scaffolds using this approach, including the outer ear, kidney and tooth tissue. These results indicate that this approach is particularly promising for tissue engineering and 3D printing applications to regenerate heterogeneous organs and tissues with tailored geometries to treat specific defects or injuries.

  12. Artistic Creativity and Extreme Events: The Heterogeneous Impact of War on Composers’ Production

    DEFF Research Database (Denmark)

    Borowiecki, Karol Jan

    2014-01-01

    1800. The study investigates how their productivity changes during various types of war and over their lifetime. Composers’ productivity decreases during war, however not so much for those turning 30 or those in late 50s or above. Interestingly, the effect is not negative for all types of war: higher......The relationship between extreme events and creativity is rather ambiguous and yet of significance across several disciplines. The following study adds to the debate by analyzing the impact of war on individual artistic output by building on a global sample of 115 prominent composers born after...... output can be observed during defensive or victorious international wars. This result could be attributable to emotional factors....

  13. Impact of sub-horizontal discontinuities and vertical heterogeneities on recharge processes in a weathered crystalline aquifer in southern India

    Science.gov (United States)

    Nicolas, Madeleine; Selles, Adrien; Bour, Olivier; Maréchal, Jean-Christophe; Crenner, Marion; Wajiduddin, Mohammed; Ahmed, Shakeel

    2017-04-01

    In the face of increasing demands for irrigated agriculture, many states in India are facing water scarcity issues, leading to severe groundwater depletion. Because perennial water resources in southern India consist mainly of crystalline aquifers, understanding how recharge takes place and the role of preferential flow zones in such heterogeneous media is of prime importance for successful and sustainable aquifer management. Here we investigate how vertical heterogeneities and highly transmissive sub-horizontal discontinuities may control groundwater flows and recharge dynamics. Recharge processes in the vadose zone were examined by analysing the propagation of an infiltration front and mass transfers resulting from the implementation of a managed aquifer recharge (MAR) structure. Said structure was set up in the Experimental Hydrogeological Park in Telangana (Southern India), a well-equipped and continuously monitored site, which is periodically supplied with surface water deviated from the nearby Musi river, downstream of Hyderabad. An initial volume balance equation was applied to quantify the overall inputs from the MAR structure into the groundwater system, which was confirmed using a chloride mass balance approach. To understand how this incoming mass is then distributed within the aquifer, we monitored the evolution of water volumes in the tank, and the resulting lateral propagation front observed in the surrounding borehole network. Borehole logs of temperature and conductivity were regularly performed to identify preferential flow paths. As a result we observed that mass transfers take place in the way of preferential lateral flow through the most transmissive zones of the profile. These include the interface between the lower portion of the upper weathered horizon (the saprolite) and the upper part of the underlying fissured granite, as well as the first flowing fractures. This leads to a rapid lateral transfer of recharge, which allows quick

  14. Identifying functional zones of denitrification in heterogeneous aquifer systems by numerical simulations - a case study

    Science.gov (United States)

    Jang, E.; Kalbacher, T.; He, W.; Shao, H.; Schueth, C.; Kolditz, O.

    2014-12-01

    Nitrate contamination in shallow groundwater is still one of the common problems in many countries. Because of its high solubility and anionic nature, nitrate can easily leach through soil and persist in groundwater for decades. High nitrate concentration has been suggested as a major cause of accelerated eutrophication, methemoglobinemia and gastric cancer. There are several factors influencing the fate of nitrate in groundwater system, which is e.g. distribution of N- sources to soil and groundwater, distribution and amount of reactive substances maintaining denitrification, rate of nitrate degradation and its kinetics, and geological characteristics of the aquifer. Nitrate transport and redox transformation processes are closely linked to complex and spatially distributed physical and chemical interaction, therefore it is difficult to predict and quantify in the field and laboratory experiment. Models can play a key role in elucidation of nitrate reduction pathway in groundwater system and in the design and evaluation of field tests to investigate in situ remediation technologies as well. The goal of the current study is to predict groundwater vulnerability to nitrate, to identify functional zones of denitrification in heterogeneous aquifer systems and to describe the uncertainty of the predictions due to scale effects. For this aim, we developed a kinetic model using multi-component mass transport code OpenGeoSys coupling with IPhreeqc module of the geochemical solver PHREEQC. The developed model included sequential aerobic and nitrate-based respiration, multi-Monod kinetics, multi-species biogeochemical reactions, and geological characteristics of the groundwater aquifer. Moreover water-rock interaction such as secondary mineral precipitation was also included in this model. In this presentation, we focused on the general modelling approach and present the simulation results of nitrate transport simulation in a hypothetical aquifer systems based on data from

  15. CMSA: a heterogeneous CPU/GPU computing system for multiple similar RNA/DNA sequence alignment.

    Science.gov (United States)

    Chen, Xi; Wang, Chen; Tang, Shanjiang; Yu, Ce; Zou, Quan

    2017-06-24

    The multiple sequence alignment (MSA) is a classic and powerful technique for sequence analysis in bioinformatics. With the rapid growth of biological datasets, MSA parallelization becomes necessary to keep its running time in an acceptable level. Although there are a lot of work on MSA problems, their approaches are either insufficient or contain some implicit assumptions that limit the generality of usage. First, the information of users' sequences, including the sizes of datasets and the lengths of sequences, can be of arbitrary values and are generally unknown before submitted, which are unfortunately ignored by previous work. Second, the center star strategy is suited for aligning similar sequences. But its first stage, center sequence selection, is highly time-consuming and requires further optimization. Moreover, given the heterogeneous CPU/GPU platform, prior studies consider the MSA parallelization on GPU devices only, making the CPUs idle during the computation. Co-run computation, however, can maximize the utilization of the computing resources by enabling the workload computation on both CPU and GPU simultaneously. This paper presents CMSA, a robust and efficient MSA system for large-scale datasets on the heterogeneous CPU/GPU platform. It performs and optimizes multiple sequence alignment automatically for users' submitted sequences without any assumptions. CMSA adopts the co-run computation model so that both CPU and GPU devices are fully utilized. Moreover, CMSA proposes an improved center star strategy that reduces the time complexity of its center sequence selection process from O(mn 2 ) to O(mn). The experimental results show that CMSA achieves an up to 11× speedup and outperforms the state-of-the-art software. CMSA focuses on the multiple similar RNA/DNA sequence alignment and proposes a novel bitmap based algorithm to improve the center star strategy. We can conclude that harvesting the high performance of modern GPU is a promising approach to

  16. Modeling permeability evolution by precipitation and dissolution: from a single-pore channel to heterogeneous multi-pore systems

    Science.gov (United States)

    Silin, D.; Molins, S.

    2011-12-01

    , the model needs to account for heterogeneous nucleation and enhanced reactivity of new precipitates rather than uniform reactivity. We evaluate the impact of this pore-scale heterogeneity on the permeability evolution of multi-pore systems by comparing the output to earlier results. Averaging the local velocities and reaction rates over the computational domain yields the correlation between Darcy velocity and effective reaction rates. Tracking the pore-space and flow evolution produces porosity-permeability correlations.

  17. Annual economic impacts of seasonal influenza on US counties: Spatial heterogeneity and patterns

    Directory of Open Access Journals (Sweden)

    Mao Liang

    2012-05-01

    Full Text Available Abstract Economic impacts of seasonal influenza vary across US counties, but little estimation has been conducted at the county level. This research computed annual economic costs of seasonal influenza for 3143 US counties based on Census 2010, identified inherent spatial patterns, and investigated cost-benefits of vaccination strategies. The computing model modified existing methods for national level estimation, and further emphasized spatial variations between counties, in terms of population size, age structure, influenza activity, and income level. Upon such a model, four vaccination strategies that prioritize different types of counties were simulated and their net returns were examined. The results indicate that the annual economic costs of influenza varied from $13.9 thousand to $957.5 million across US counties, with a median of $2.47 million. Prioritizing vaccines to counties with high influenza attack rates produces the lowest influenza cases and highest net returns. This research fills the current knowledge gap by downscaling the estimation to a county level, and adds spatial variability into studies of influenza economics and interventions. Compared to the national estimates, the presented statistics and maps will offer detailed guidance for local health agencies to fight against influenza.

  18. The Genetic Heterogeneity among Different Mouse Strains Impacts the Lung Injury Potential of Multiwalled Carbon Nanotubes.

    Science.gov (United States)

    Wang, Xiang; Liao, Yu-Pei; Telesca, Donatello; Chang, Chong Hyun; Xia, Tian; Nel, André E

    2017-09-01

    Genetic variation constitutes an important variable impacting the susceptibility to inhalable toxic substances and air pollutants, as reflected by epidemiological studies in humans and differences among animal strains. While multiwalled carbon nanotubes (MWCNTs) are capable of causing lung fibrosis in rodents, it is unclear to what extent the genetic variation in different mouse strains influence the outcome. Four inbred mouse strains, including C57Bl/6, Balb/c, NOD/ShiLtJ, and A/J, to test the pro-fibrogenic effects of a library of MWCNTs in vitro and in vivo are chosen. Ex vivo analysis of IL-1β production in bone marrow-derived macrophages (BMDMs) as molecular initiating event (MIE) is performed. The order of cytokine production (Balb/c > A/J > C57Bl/6 > NOD/ShiLtJ) in BMDMs is also duplicated during assessment of IL-1β production in the bronchoalveolar lavage fluid of the same mouse strains 40 h after oropharyngeal instillation of a representative MWCNT. Animal test after 21 d also confirms a similar hierarchy in TGF-β1 production and collagen deposition in the lung. Statistical analysis confirms a correlation between IL-1β production in BMDM and the lung fibrosis. All considered, these data demonstrate that genetic background indeed plays a major role in determining the pro-fibrogenic response to MWCNTs in the lung. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Performance of a Polymer Flood with Shear-Thinning Fluid in Heterogeneous Layered Systems with Crossflow

    Directory of Open Access Journals (Sweden)

    Kun Sang Lee

    2011-08-01

    Full Text Available Assessment of the potential of a polymer flood for mobility control requires an accurate model on the viscosities of displacement fluids involved in the process. Because most polymers used in EOR exhibit shear-thinning behavior, the effective viscosity of a polymer solution is a highly nonlinear function of shear rate. A reservoir simulator including the model for the shear-rate dependence of viscosity was used to investigate shear-thinning effects of polymer solution on the performance of the layered reservoir in a five-spot pattern operating under polymer flood followed by waterflood. The model can be used as a quantitative tool to evaluate the comparative studies of different polymer flooding scenarios with respect to shear-rate dependence of fluids’ viscosities. Results of cumulative oil recovery and water-oil ratio are presented for parameters of shear-rate dependencies, permeability heterogeneity, and crossflow. The results of this work have proven the importance of taking non-Newtonian behavior of polymer solution into account for the successful evaluation of polymer flood processes. Horizontal and vertical permeabilities of each layer are shown to impact the predicted performance substantially. In reservoirs with a severe permeability contrast between horizontal layers, decrease in oil recovery and sudden increase in WOR are obtained by the low sweep efficiency and early water breakthrough through highly permeable layer, especially for shear-thinning fluids. An increase in the degree of crossflow resulting from sufficient vertical permeability is responsible for the enhanced sweep of the low permeability layers, which results in increased oil recovery. It was observed that a thinning fluid coefficient would increase injectivity significantly from simulations with various injection rates. A thorough understanding of polymer rheology in the reservoir and accurate numerical modeling are of fundamental importance for the exact estimation

  20. Do existing classification systems capture mountain snowpack heterogeneity? Accounting for spatial variability in a changing environment

    Science.gov (United States)

    Tennant, C.; Godsey, S.; Harpold, A. A.; Link, T. E.; Rajagopal, S.; Larsen, L.

    2016-12-01

    Spatial patterns of snow accumulation and melt control water and nutrient fluxes from mountain landscapes and determine the dynamics of resource availability for nearby human and ecological communities. Because seasonal snowpack is sensitive to changes in regional climate, there is a growing need for a snowpack classification system that (1) recognizes salient processes, (2) captures the variance of the system, (3) recognizes temporal and/or spatial change, and (4) has application to predicting snowmelt runoff regimes. Previous classification systems have focused on textural and stratigraphic snow characteristics or climatological observations to map broad geographic classes (e.g. maritime, continental, ephemeral, etc.). While these approaches have revealed general patterns, they may not capture the spatial heterogeneity of snowpack characteristics that are common across high relief terrain. Here, we use 1 km resolution gridded outputs from a physically based, spatially-distributed energy- and mass-balance snow model (SNODAS) to produce a snow classification system for the western U.S. and Great Plains. To meet the outlined criterion, we initially explored the ability of a large number of metrics (13) to characterize the amount, timing, and melt-rate of snowpack. Principal components analysis and pairwise correlations were used to identify a subset of metrics (6) that captured the variance of the system but also contributed unique information. K-means was used to delineate 12 process-based groups that reveal both climatic and orographic influences on snowpack accumulation, timing, and melt rate. The important effects of elevation-mediated processes in our classification system suggest a greater spatial diversity in snowpack patterns than suggested by previous characterizations (e.g. maritime-to-continental). Application of the system from the early 2000's to present reveals that interannual temporal and spatial variability have been greatest in the Columbia Plateau

  1. Test System Impact on System Availability

    DEFF Research Database (Denmark)

    Pau, L. F.

    1987-01-01

    The specifications are presented for an imperfect automatic test system (ATS) (test frequency distribution, reliability, false alarm rate, nondetection rate) in order to account for the availability, readiness, mean time between unscheduled repairs (MTBUR), reliability, and maintenance of the sys......The specifications are presented for an imperfect automatic test system (ATS) (test frequency distribution, reliability, false alarm rate, nondetection rate) in order to account for the availability, readiness, mean time between unscheduled repairs (MTBUR), reliability, and maintenance...... of the system subject to monitoring and test. A time-dependent Markov model is presented, and applied in three cases, with examples of numerical results provided for preventive maintenance decisions, design of an automatic test system, buffer testing in computers, and data communications....

  2. Heterogeneous world model and collaborative scenarios of transition to globally sustainable nuclear energy systems

    Directory of Open Access Journals (Sweden)

    Kuznetsov Vladimir

    2015-01-01

    Full Text Available The International Atomic Energy Agency's International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO is to help ensure that nuclear energy is available to contribute to meeting global energy needs of the 21st century in a sustainable manner. The INPRO task titled “Global scenarios” is to develop global and regional nuclear energy scenarios that lead to a global vision of sustainable nuclear energy in the 21st century. Results of multiple studies show that the criteria for developing sustainable nuclear energy cannot be met without innovations in reactor and nuclear fuel cycle technologies. Combining different reactor types and associated fuel chains creates a multiplicity of nuclear energy system arrangements potentially contributing to global sustainability of nuclear energy. In this, cooperation among countries having different policy regarding fuel cycle back end would be essential to bring sustainability benefits from innovations in technology to all interested users. INPRO has developed heterogeneous global model to capture countries’ different policies regarding the back end of the nuclear fuel cycle in regional and global scenarios of nuclear energy evolution and applied in a number of studies performed by participants of the project. This paper will highlight the model and major conclusions obtained in the studies.

  3. A Reconfigurable Readout Integrated Circuit for Heterogeneous Display-Based Multi-Sensor Systems

    Directory of Open Access Journals (Sweden)

    Kyeonghwan Park

    2017-04-01

    Full Text Available This paper presents a reconfigurable multi-sensor interface and its readout integrated circuit (ROIC for display-based multi-sensor systems, which builds up multi-sensor functions by utilizing touch screen panels. In addition to inherent touch detection, physiological and environmental sensor interfaces are incorporated. The reconfigurable feature is effectively implemented by proposing two basis readout topologies of amplifier-based and oscillator-based circuits. For noise-immune design against various noises from inherent human-touch operations, an alternate-sampling error-correction scheme is proposed and integrated inside the ROIC, achieving a 12-bit resolution of successive approximation register (SAR of analog-to-digital conversion without additional calibrations. A ROIC prototype that includes the whole proposed functions and data converters was fabricated in a 0.18 μm complementary metal oxide semiconductor (CMOS process, and its feasibility was experimentally verified to support multiple heterogeneous sensing functions of touch, electrocardiogram, body impedance, and environmental sensors.

  4. A multiscale dataset for understanding complex eco-hydrological processes in a heterogeneous oasis system

    Science.gov (United States)

    Li, Xin; Liu, Shaomin; Xiao, Qin; Ma, Mingguo; Jin, Rui; Che, Tao; Wang, Weizhen; Hu, Xiaoli; Xu, Ziwei; Wen, Jianguang; Wang, Liangxu

    2017-06-01

    We introduce a multiscale dataset obtained from Heihe Watershed Allied Telemetry Experimental Research (HiWATER) in an oasis-desert area in 2012. Upscaling of eco-hydrological processes on a heterogeneous surface is a grand challenge. Progress in this field is hindered by the poor availability of multiscale observations. HiWATER is an experiment designed to address this challenge through instrumentation on hierarchically nested scales to obtain multiscale and multidisciplinary data. The HiWATER observation system consists of a flux observation matrix of eddy covariance towers, large aperture scintillometers, and automatic meteorological stations; an eco-hydrological sensor network of soil moisture and leaf area index; hyper-resolution airborne remote sensing using LiDAR, imaging spectrometer, multi-angle thermal imager, and L-band microwave radiometer; and synchronical ground measurements of vegetation dynamics, and photosynthesis processes. All observational data were carefully quality controlled throughout sensor calibration, data collection, data processing, and datasets generation. The data are freely available at figshare and the Cold and Arid Regions Science Data Centre. The data should be useful for elucidating multiscale eco-hydrological processes and developing upscaling methods.

  5. Towards Large-Scale, Heterogeneous Anomaly Detection Systems in Industrial Networks: A Survey of Current Trends

    Directory of Open Access Journals (Sweden)

    Mikel Iturbe

    2017-01-01

    Full Text Available Industrial Networks (INs are widespread environments where heterogeneous devices collaborate to control and monitor physical processes. Some of the controlled processes belong to Critical Infrastructures (CIs, and, as such, IN protection is an active research field. Among different types of security solutions, IN Anomaly Detection Systems (ADSs have received wide attention from the scientific community. While INs have grown in size and in complexity, requiring the development of novel, Big Data solutions for data processing, IN ADSs have not evolved at the same pace. In parallel, the development of Big Data frameworks such as Hadoop or Spark has led the way for applying Big Data Analytics to the field of cyber-security, mainly focusing on the Information Technology (IT domain. However, due to the particularities of INs, it is not feasible to directly apply IT security mechanisms in INs, as IN ADSs face unique characteristics. In this work we introduce three main contributions. First, we survey the area of Big Data ADSs that could be applicable to INs and compare the surveyed works. Second, we develop a novel taxonomy to classify existing IN-based ADSs. And, finally, we present a discussion of open problems in the field of Big Data ADSs for INs that can lead to further development.

  6. Performance analysis of general purpose and digital signal processor kernels for heterogeneous systems-on-chip

    Directory of Open Access Journals (Sweden)

    T. von Sydow

    2003-01-01

    Full Text Available Various reasons like technology progress, flexibility demands, shortened product cycle time and shortened time to market have brought up the possibility and necessity to integrate different architecture blocks on one heterogeneous System-on-Chip (SoC. Architecture blocks like programmable processor cores (DSP- and GPP-kernels, embedded FPGAs as well as dedicated macros will be integral parts of such a SoC. Especially programmable architecture blocks and associated optimization techniques are discussed in this contribution. Design space exploration and thus the choice which architecture blocks should be integrated in a SoC is a challenging task. Crucial to this exploration is the evaluation of the application domain characteristics and the costs caused by individual architecture blocks integrated on a SoC. An ATE-cost function has been applied to examine the performance of the aforementioned programmable architecture blocks. Therefore, representative discrete devices have been analyzed. Furthermore, several architecture dependent optimization steps and their effects on the cost ratios are presented.

  7. The tsunami service bus, an integration platform for heterogeneous sensor systems

    Science.gov (United States)

    Haener, R.; Waechter, J.; Kriegel, U.; Fleischer, J.; Mueller, S.

    2009-04-01

    components remain unchanged, components can be maintained and evolved independently on each other and service functionality as a whole can be reused. In GITEWS the functional integration pattern was adopted by applying the principles of an Enterprise Service Bus (ESB) as a backbone. Four services provided by the so called Tsunami Service Bus (TSB) which are essential for early warning systems are realized compliant to services specified within the Sensor Web Enablement (SWE) initiative of the Open Geospatial Consortium (OGC). 3. ARCHITECTURE The integration platform was developed to access proprietary, heterogeneous sensor data and to provide them in a uniform manner for further use. Its core, the TSB provides both a messaging-backbone and -interfaces on the basis of a Java Messaging Service (JMS). The logical architecture of GITEWS consists of four independent layers: • A resource layer where physical or virtual sensors as well as data or model storages provide relevant measurement-, event- and analysis-data: Utilizable for the TSB are any kind of data. In addition to sensors databases, model data and processing applications are adopted. SWE specifies encoding both to access and to describe these data in a comprehensive way: 1. Sensor Model Language (SensorML): Standardized description of sensors and sensor data 2. Observations and Measurements (O&M): Model and encoding of sensor measurements • A service layer to collect and conduct data from heterogeneous and proprietary resources and provide them via standardized interfaces: The TSB enables interaction with sensors via the following services: 1. Sensor Observation Service (SOS): Standardized access to sensor data 2. Sensor Planning Service (SPS): Controlling of sensors and sensor networks 3. Sensor Alert Service (SAS): Active sending of data if defined events occur 4. Web Notification Service (WNS): Conduction of asynchronous dialogues between services • An orchestration layer where atomic services are composed and

  8. The metastatic infiltration at the metastasis/brain parenchyma-interface is very heterogeneous and has a significant impact on survival in a prospective study

    Science.gov (United States)

    Siam, Laila; Bleckmann, Annalen; Chaung, Han-Ning; Mohr, Alexander; Klemm, Florian; Barrantes-Freer, Alonso; Blazquez, Raquel; Wolff, Hendrik A.; Lüke, Florian; Rohde, Veit; Stadelmann, Christine; Pukrop, Tobias

    2015-01-01

    The current approach to brain metastases resection is macroscopic removal of metastasis until reaching the glial pseudo-capsule (gross total resection (GTR)). However, autopsy studies demonstrated infiltrating metastatic cells into the parenchyma at the metastasis/brain parenchyma (M/BP)-interface. Aims/Methods: To analyze the astrocyte reaction and metastatic infiltration pattern at the M/BP-interface with an organotypic brain slice coculture system. Secondly, to evaluate the significance of infiltrating metastatic tumor cells in a prospective biopsy study. Therefore, after GTR, biopsies were obtained from the brain parenchyma beyond the glial pseudo-capsule and analyzed histomorphologically. Results: The coculture revealed three types of cancer cell infiltration. Interestingly, the astrocyte reaction was significantly different in the coculture with a benign, neuroectodermal-derived cell line. In the prospective biopsy study 58/167 (34.7%) samples revealed infiltrating metastatic cells. Altogether, 25/39 patients (64.1%) had proven to exhibit infiltration in at least one biopsy specimen with significant impact on survival (OS) (3.4 HR; p = 0.009; 2-year OS was 6.6% versus 43.5%). Exceptionally, in the non-infiltrating cohort three patients were long-term survivors. Conclusions: Metastatic infiltration has a significant impact on prognosis. Secondly, the astrocyte reaction at the M/BP-interface is heterogeneous and supports our previous concept of the organ-specific defense against metastatic (organ-foreign) cells. PMID:26299612

  9. The Impact of Heterogeneous Thresholds on Social Contagion with Multiple Initiators

    CERN Document Server

    Karampourniotis, Panagiotis D; Szymanski, Boleslaw K; Korniss, Gyorgy

    2015-01-01

    The threshold model is a simple but classic model of contagion spreading in complex social systems. To capture the complex nature of social influencing we investigate numerically and analytically the transition in the behavior of threshold-limited cascades in the presence of multiple initiators as the distribution of thresholds is varied between the two extreme cases of identical thresholds and a uniform distribution. We accomplish this by employing a truncated normal distribution of the nodes' thresholds and observe a non-monotonic change in the cascade size as we vary the standard deviation. Further, for a sufficiently large spread in the threshold distribution, the tipping-point behavior of the social influencing process disappears and is replaced by a smooth crossover governed by the size of initiator set. We demonstrate that for a given size of the initiator set, there is a specific variance of the threshold distribution for which an opinion spreads optimally. Furthermore, in the case of synthetic graphs...

  10. Reporting Heterogeneity in Self-Assessed Health among Elderly Europeans: The Impact of Mental and Physical Health Status

    OpenAIRE

    Pfarr, Christian; Schmid, Andreas; Schneider, Udo

    2011-01-01

    Self-assessed health (SAH) is a frequently used measure of individuals’ health status. It is also prone to reporting heterogeneity. To control for reporting heterogeneity valid measures of the objective health status are needed. The topic becomes even more complex for cross-country comparisons, as many key variables tend to vary strongly across countries, influenced by cultural and institutional differences. This study aims at exploring the key drivers for reporting heterogeneity in SAH in an...

  11. Impact of heterogeneous properties of soil and LNAPL on surfactant-enhanced capillary desaturation.

    Science.gov (United States)

    Robert, Thomas; Martel, Richard; Lefebvre, René; Lauzon, Jean-Marc; Morin, Annie

    2017-09-01

    This paper investigates low-concentration (soil permeability, pore-size distribution, mineralogy, light non-aqueous phase liquid (LNAPL) weathering and groundwater hardness were quantified through batch and soil column tests. Compatibility issues between the mixed mineralogy soils, hard groundwater, mixed LNAPL and usual anionic surfactants were observed. The selected solution was a Winsor type I system promoting an interfacial tension of 0.06mN/m between the site LNAPL and the amphoteric surfactant CAS in aqueous solution at pH12. Surfactant loses to adsorption and pore media plugging were observed in the fine soil fraction. The capillary desaturation curves (CDC) obtained with the column tests suggested mixed-wettability behavior. The soil permeability strongly influenced LNAPL recovery, as expressed by the relationship obtained between capillary numbers (NCa) and hydraulic gradients. In this case, the critical NCa, marking the onset of capillary desaturation, could only be obtained with realistic hydraulic gradients in the coarse soil fraction. At those gradients, potential LNAPL recovery was 30% at the most. Unlike previously published CDCs, the relationship between NCa (log-scale) and LNAPL recovery was not linear but dependant on residual LNAPL saturation. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Control of synchronization and spiking regularity by heterogenous aperiodic high-frequency signal in coupled excitable systems

    Science.gov (United States)

    Qin, Ying-Mei; Wang, Jiang; Men, Cong; Chan, Wai-Lok; Wei, Xi-Le; Deng, Bin

    2013-10-01

    This paper investigates the synchronization and spiking regularity induced by heterogenous aperiodic (HA) signal in coupled excitable FitzHugh-Nagumo systems. We found new nontrivial effects of couplings and HA signals on the firing regularity and synchronization in coupled excitable systems without a periodic external driving. The phenomenon is similar to array enhanced coherence resonance (AECR), and it is shown that AECR-type behavior is not limited to systems driven by noises. It implies that the HA signal may be beneficial for the brain function, which is similar to the role of noise. Furthermore, it is also found that the mean frequencies, the amplitudes and the heterogeneity of HA stimuli can serve as control parameters in modulating spiking regularity and synchronization in coupled excitable systems. These results may be significant for the control of the synchronized firing of the brain in neural diseases like epilepsy.

  13. Global warming potential impact of bioenergy systems

    DEFF Research Database (Denmark)

    Tonini, Davide; Hamelin, L.; Wenzel, H.

    environmental consequences related to land use changes. In this study the global warming potential impact associated with six alternative bioenergy systems based on willow and Miscanthus was assessed by means of life-cycle assessment. The results showed that bioenergy production may generate higher global...... warming impacts than the reference fossil fuel system, when the impacts from indirect land use changes are accounted for. In a life-cycle perspective, only highly-efficient co-firing with fossil fuel achieved a (modest) GHG emission reduction....

  14. THE IMPACT OF SERVICE VARIETY ON ORGANIZATIONAL STRUCTURE IN A HETEROGENEOUS SECTOR: A REGRESSION ANALYSIS OF GERMAN RETAIL HORTICULTURE

    Directory of Open Access Journals (Sweden)

    Engelke C.

    2017-06-01

    Full Text Available Structural change towards services becomes exigent when the sales do not meet operational direction anymore. Thus, the a priori strong heterogeneity in German retail horticulture (GRH requires knowledge in the interaction of relevant internal parameters to find the best individual combination. On this account, the present paper has two goals: First, to systematise relevant, internal characteristics (contingency, considering previous research, by running a confirmatory factor analysis. Second, we investigate the impact of the service variety on the organizational structure and economic parameters, in order to find the right combination for GRH by running regression analysis. Based on a previous exploratory study, 283 retail nurseries were asked questions in an online survey and their answers were interpreted in a quantitative way. Part 1: We gave proof that relevant situational characteristics on GRH include size, level of controlling, experience and service variety as internal factor variables, showing high eigenvalues. Part 2: We found causal relationships between the service variety and the number of hierarchy, span of control and hierarchy configuration (H1. The size is also of significant importance but on a minor level. Size faces positive correlation on delegation (H2, and the size and the level of controlling also have adequate impact on the sales volume. Meanwhile the configuration variables have no impact on the sales volume. This means that sales volume is related to the size and the level of controlling but independent of the configuration. Accordingly, there is no coordinated interaction of contingency, structure and delegation variables with impact on the sales volumes (H3. Structural delegations on sales volume are significantly acquisition/ marketing and planning as operational performance-variables, which are mostly done by the owner/CEO himself. These tasks show negative coefficients, which lead to the proposal that with growing

  15. Olivine-hosted melt inclusions as an archive of redox heterogeneity in magmatic systems

    Science.gov (United States)

    Hartley, Margaret E.; Shorttle, Oliver; Maclennan, John; Moussallam, Yves; Edmonds, Marie

    2017-12-01

    -equilibration of fO2 between inclusions and carrier melts occurs on timescales of hours to days, causing a drop in the sulfur content at sulfide saturation (SCSS) and driving the exsolution of immiscible sulfide globules in the inclusions. Our data demonstrate the roles of magma mixing, progressive re-equilibration, and degassing in redox evolution within magmatic systems, and the open-system nature of melt inclusions to fO2 during these processes. Redox heterogeneity present at the time of inclusion trapping may be overprinted by rapid re-equilibration of melt inclusion fO2 with the external environment, both in the magma chamber and during slow cooling in lava at the surface. This can decouple the melt inclusion archives of fO2, major and trace element chemistry, and mask associations between fO2, magmatic differentiation and mantle source heterogeneity unless the assembly of diverse magmas is rapidly followed by eruption. Our tools for understanding the redox conditions of magmas are thus limited; however, careful reconstruction of pre- and post-eruptive magmatic history has enabled us to confirm the relatively oxidised nature of ocean island-type mantle compared to that of mid-ocean ridge mantle.

  16. Development of a phantom to validate high-dose-rate brachytherapy treatment planning systems with heterogeneous algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Eduardo S., E-mail: emoura@wisc.edu [Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin 53705 and Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil); Micka, John A.; Hammer, Cliff G.; Culberson, Wesley S.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin 53705 (United States); Rostelato, Maria Elisa C. M.; Zeituni, Carlos A. [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil)

    2015-04-15

    Purpose: This work presents the development of a phantom to verify the treatment planning system (TPS) algorithms used for high-dose-rate (HDR) brachytherapy. It is designed to measure the relative dose in a heterogeneous media. The experimental details used, simulation methods, and comparisons with a commercial TPS are also provided. Methods: To simulate heterogeneous conditions, four materials were used: Virtual Water™ (VM), BR50/50™, cork, and aluminum. The materials were arranged in 11 heterogeneity configurations. Three dosimeters were used to measure the relative response from a HDR {sup 192}Ir source: TLD-100™, Gafchromic{sup ®} EBT3 film, and an Exradin™ A1SL ionization chamber. To compare the results from the experimental measurements, the various configurations were modeled in the PENELOPE/penEasy Monte Carlo code. Images of each setup geometry were acquired from a CT scanner and imported into BrachyVision™ TPS software, which includes a grid-based Boltzmann solver Acuros™. The results of the measurements performed in the heterogeneous setups were normalized to the dose values measured in the homogeneous Virtual Water™ setup and the respective differences due to the heterogeneities were considered. Additionally, dose values calculated based on the American Association of Physicists in Medicine-Task Group 43 formalism were compared to dose values calculated with the Acuros™ algorithm in the phantom. Calculated doses were compared at the same points, where measurements have been performed. Results: Differences in the relative response as high as 11.5% were found from the homogeneous setup when the heterogeneous materials were inserted into the experimental phantom. The aluminum and cork materials produced larger differences than the plastic materials, with the BR50/50™ material producing results similar to the Virtual Water™ results. Our experimental methods agree with the PENELOPE/penEasy simulations for most setups and dosimeters. The

  17. Application of Heterogeneous Catalysis in Small-Scale Biomass Combustion Systems

    Directory of Open Access Journals (Sweden)

    Christian Thiel

    2012-04-01

    Full Text Available Combustion of solid biomass fuels for heat generation is an important renewable energy resource. The major part among biomass combustion applications is being played by small-scale systems like wood log stoves and small wood pellet burners, which account for 75% of the overall biomass heat production. Despite an environmentally friendly use of renewable energies, incomplete combustion in small-scale systems can lead to the emission of environmental pollutants as well as substances which are hazardous to health. Besides particles of ash and soot, a wide variety of gaseous substances can also be emitted. Among those, polycyclic aromatic hydrocarbons (PAH and several organic volatile and semi-volatile compounds (VOC are present. Heterogeneous catalysis is applied for the reduction of various gaseous compounds as well as soot. Some research has been done to examine the application of catalytic converters in small-scale biomass combustion systems. In addition to catalyst selection with respect to complete oxidation of different organic compounds, parameters such as long-term stability and durability under flue gas conditions are considered for use in biomass combustion furnaces. Possible catalytic procedures have been identified for investigation by literature and market research. Experimental studies with two selected oxidation catalysts based on noble metals have been carried out on a wood log stove with a retrofit system. The measurements have been performed under defined conditions based on practical mode of operation. The measurements have shown that the catalytic flue gas treatment is a promising method to reduce carbon monoxide and volatile organic compounds. Even a reduction of particulate matter was observed, although no filtering effect could be detected. Therefore, the oxidation of soot or soot precursors can be assumed. The selected catalysts differed in their activity, depending on the compound to be oxidized. Examinations showed that

  18. Low-impact mating system

    Science.gov (United States)

    Lewis, James L. (Inventor); Carroll, Monty B. (Inventor); Le, Thang D. (Inventor); Morales, Ray H. (Inventor); Robertson, Brandan R. (Inventor)

    2009-01-01

    An androgynous mating system for mating two exoatmospheric space modules comprising a first mating assembly capable of mating with a second mating assembly; a second mating assembly structurally identical to said first mating assembly, said first mating assembly comprising; a load ring; a plurality of load cell subassemblies; a plurality of actuators; a base ring; a tunnel; a closed loop control system; one or more electromagnets; and one or more striker plates, wherein said one or more electomagnets on said second mating assembly are capable of mating with said one or more striker plates on said first mating assembly, and wherein said one or more striker plates is comprised of a plate of predetermined shape and a 5-DOF mechanism capable of maintaining predetermined contact requirements during said mating of said one or more electromagnets and said one or more striker plates.

  19. Dynamic task scheduling algorithm with load balancing for heterogeneous computing system

    Directory of Open Access Journals (Sweden)

    Doaa M. Abdelkader

    2012-07-01

    Full Text Available In parallel computation, the scheduling and mapping tasks is considered the most critical problem which needs High Performance Computing (HPC to solve it by breaking the problem into subtasks and working on those subtasks at the same time. The application sub tasks are assigned to underline machines and ordered for execution according to its proceeding to grantee efficient use of available resources such as minimize execution time and satisfy load balance between processors of the underline machine. The underline infrastructure may be homogeneous or heterogeneous. Homogeneous infrastructure could use the same machines power and performance. While heterogeneous infrastructure include machines differ in its performance, speed, and interconnection. According to work in this paper a new dynamic task scheduling algorithm for Heterogeneous called a Clustering Based HEFT with Duplication (CBHD have been developed. The CBHD algorithm is considered an amalgamation between the most two important task scheduling in Heterogeneous machine, The Heterogeneous Earliest Finish Time (HEFT and the Triplet Clustering algorithms. In the CBHD algorithm the duplication is required to improve the performance of algorithm. A comparative study among the developed CBHD, the HEFT, and the Triplet Cluster algorithms has been done. According to the comparative results, it is found that the developed CBHD algorithm satisfies better execution time than both HEFT algorithm and Triplet Cluster algorithm, and in the same time, it achieves the load balancing which considered one of the main performance factors in the dynamic environment.

  20. Assessing the Implicit Curriculum in Social Work Education: Heterogeneity of Students' Experiences and Impact on Professional Empowerment

    Science.gov (United States)

    Peterson, N. Andrew; Farmer, Antoinette Y.; Donnelly, Louis; Forenza, Brad

    2014-01-01

    The implicit curriculum, which refers to a student's learning environment, has been described as an essential feature of an integrated professional social work curriculum. Very little is known, however, about the heterogeneity of students' experiences with the implicit curriculum, how this heterogeneity may be distributed across groups of…

  1. An investigation of interference coordination in heterogeneous network for LTE-Advanced systems

    Science.gov (United States)

    Hasan, M. K.; Ismail, A. F.; H, Aisha-Hassan A.; Abdullah, Khaizuran; Ramli, H. A. M.

    2013-12-01

    The novel "femtocell" in Heterogeneous Network (HetNet) for LTE-Advanced (LTE-A) set-up will allow Malaysian wireless telecommunication operators (Maxis, Celcom, Digi, U-Mobile, P1, YTL and etc2.) to extend connectivity coverage where access would otherwise be limited or unavailable, particularly indoors of large building complexes. A femtocell is a small-sized cellular base station that encompasses all the functionality of a typical station. It therefore allows a simpler and self-contained deployment including private residences. For the Malaysian service providers, the main attractions of femtocell usage are the improvements to both coverage and capacity. The operators can provide a better service to end-users in turn reduce much of the agitations and complaints. There will be opportunity for new services at reduced cost. In addition, the operator not only benefits from the improved capacity and coverage but also can reduce both capital expenditure and operating expense i.e. alternative to brand new base station or macrocell installation. Interference is a key issue associated with femtocell development. There are a large number of issues associated with interference all of which need to be investigated, identified, quantified and solved. This is to ensure that the deployment of any femtocells will take place successfully. Among the most critical challenges in femtocell deployment is the interference between femtocell-to-macrocell and femtocell-to-femtocell in HetNets. In this paper, all proposed methods and algorithms will be investigated in the OFDMA femtocell system considering HetNet scenarios for LTE-A.

  2. Support Systems after Divorce: Incidence and Impact.

    Science.gov (United States)

    Colletta, Nancy Donahue

    1979-01-01

    Examined the impact of support systems on post-divorce family functioning. Results suggest that families under extreme stress need to be provided with relatively high levels of support or their dissatisfaction with support systems will appear in harsher and more restrictive relationships with children. (Author)

  3. Mars Pathfinder Airbag Impact Attenuation System

    Science.gov (United States)

    Waye, Donald; Cole, J. Kenneth; Rivellini, Tommaso P.

    1995-01-01

    The Mars Pathfinder spacecraft, scheduled for launch in December 1996, is designed to validate a low cost Entry, Descent, and Landing system and to perform scientific surface operations. The Jet Propulsion Laboratory and Sandia National Laboratories teamed to design, fabricate, test and validate a prototype 0.38 scale model of an airbag impact attenuation system. A computer code was developed to predict the performance of the airbag system. A test program in Sandia's High Altitude Chamber was performed to validate the code and demonstrate the feasibility of the airbag concept and design. In addition, freefall tests were performed at representative velocities to demonstrate the structural integrity of the airbag system design. The feasibility program demonstrated that the airbag impact attenuation design will protect the lander upon impact with the Martian surface.

  4. Seeing the forests and the trees—innovative approaches to exploring heterogeneity in systematic reviews of complex interventions to enhance health system decision-making: a protocol

    Science.gov (United States)

    2014-01-01

    Background To improve quality of care and patient outcomes, health system decision-makers need to identify and implement effective interventions. An increasing number of systematic reviews document the effects of quality improvement programs to assist decision-makers in developing new initiatives. However, limitations in the reporting of primary studies and current meta-analysis methods (including approaches for exploring heterogeneity) reduce the utility of existing syntheses for health system decision-makers. This study will explore the role of innovative meta-analysis approaches and the added value of enriched and updated data for increasing the utility of systematic reviews of complex interventions. Methods/Design We will use the dataset from our recent systematic review of 142 randomized trials of diabetes quality improvement programs to evaluate novel approaches for exploring heterogeneity. These will include exploratory methods, such as multivariate meta-regression analyses and all-subsets combinatorial meta-analysis. We will then update our systematic review to include new trials and enrich the dataset by surveying authors of all included trials. In doing so, we will explore the impact of variables not, reported in previous publications, such as details of study context, on the effectiveness of the intervention. We will use innovative analytical methods on the enriched and updated dataset to identify key success factors in the implementation of quality improvement interventions for diabetes. Decision-makers will be involved throughout to help identify and prioritize variables to be explored and to aid in the interpretation and dissemination of results. Discussion This study will inform future systematic reviews of complex interventions and describe the value of enriching and updating data for exploring heterogeneity in meta-analysis. It will also result in an updated comprehensive systematic review of diabetes quality improvement interventions that will be

  5. Does National Culture Impact Capital Budgeting Systems?

    Directory of Open Access Journals (Sweden)

    Peter J. Graham

    2017-06-01

    Full Text Available We examine how national culture impacts organisational selection of capital budgeting systems to develop our understanding of what influence a holistic formulation of national culture has on capital budgeting systems. Such an understanding is important as it would not only provide a clearer link between national culture and capital budgeting systems and advance extant literature but would also help multinational firms that have business relationships with Indonesian firms in suitably designing strategies. We conducted semi-structured interviews of selected finance managers of listed firms in Indonesia and Australia. Consistent with the contingency theory, we found that economic, political, legal and social uncertainty impact on the use of capital budgeting systems. The levels of uncertainty were higher in Indonesia than Australia and need to be reckoned in the selection of capital budgeting systems used by firms. We also found that firms are influenced by project size and complexity, when selecting capital budgeting systems.

  6. Role of genetic heterogeneity and epistasis in bladder cancer susceptibility and outcome: a learning classifier system approach.

    Science.gov (United States)

    Urbanowicz, Ryan John; Andrew, Angeline S; Karagas, Margaret Rita; Moore, Jason H

    2013-01-01

    Detecting complex patterns of association between genetic or environmental risk factors and disease risk has become an important target for epidemiological research. In particular, strategies that provide multifactor interactions or heterogeneous patterns of association can offer new insights into association studies for which traditional analytic tools have had limited success. To concurrently examine these phenomena, previous work has successfully considered the application of learning classifier systems (LCSs), a flexible class of evolutionary algorithms that distributes learned associations over a population of rules. Subsequent work dealt with the inherent problems of knowledge discovery and interpretation within these algorithms, allowing for the characterization of heterogeneous patterns of association. Whereas these previous advancements were evaluated using complex simulation studies, this study applied these collective works to a 'real-world' genetic epidemiology study of bladder cancer susceptibility. We replicated the identification of previously characterized factors that modify bladder cancer risk--namely, single nucleotide polymorphisms from a DNA repair gene, and smoking. Furthermore, we identified potentially heterogeneous groups of subjects characterized by distinct patterns of association. Cox proportional hazard models comparing clinical outcome variables between the cases of the two largest groups yielded a significant, meaningful difference in survival time in years (survivorship). A marginally significant difference in recurrence time was also noted. These results support the hypothesis that an LCS approach can offer greater insight into complex patterns of association. This methodology appears to be well suited to the dissection of disease heterogeneity, a key component in the advancement of personalized medicine.

  7. Investigating the Impact of Surface Heterogeneity on the Convective Boundary Layer Over Urban Areas Through Coupled Large-Eddy Simulation and Remote Sensing

    Science.gov (United States)

    Dominguez, Anthony; Kleissl, Jan P.; Luvall, Jeffrey C.

    2011-01-01

    Large-eddy Simulation (LES) was used to study convective boundary layer (CBL) flow through suburban regions with both large and small scale heterogeneities in surface temperature. Constant remotely sensed surface temperatures were applied at the surface boundary at resolutions of 10 m, 90 m, 200 m, and 1 km. Increasing the surface resolution from 1 km to 200 m had the most significant impact on the mean and turbulent flow characteristics as the larger scale heterogeneities became resolved. While previous studies concluded that scales of heterogeneity much smaller than the CBL inversion height have little impact on the CBL characteristics, we found that further increasing the surface resolution (resolving smaller scale heterogeneities) results in an increase in mean surface heat flux, thermal blending height, and potential temperature profile. The results of this study will help to better inform sub-grid parameterization for meso-scale meteorological models. The simulation tool developed through this study (combining LES and high resolution remotely sensed surface conditions) is a significant step towards future studies on the micro-scale meteorology in urban areas.

  8. A system for simulating shared memory in heterogeneous distributed-memory networks with specialization for robotics applications

    Energy Technology Data Exchange (ETDEWEB)

    Jones, J.P.; Bangs, A.L.; Butler, P.L.

    1991-01-01

    Hetero Helix is a programming environment which simulates shared memory on a heterogeneous network of distributed-memory computers. The machines in the network may vary with respect to their native operating systems and internal representation of numbers. Hetero Helix presents a simple programming model to developers, and also considers the needs of designers, system integrators, and maintainers. The key software technology underlying Hetero Helix is the use of a compiler'' which analyzes the data structures in shared memory and automatically generates code which translates data representations from the format native to each machine into a common format, and vice versa. The design of Hetero Helix was motivated in particular by the requirements of robotics applications. Hetero Helix has been used successfully in an integration effort involving 27 CPUs in a heterogeneous network and a body of software totaling roughly 100,00 lines of code. 25 refs., 6 figs.

  9. Modeling hypothermia induced effects for the heterogeneous ventricular tissue from cellular level to the impact on the ECG.

    Directory of Open Access Journals (Sweden)

    Roland Kienast

    Full Text Available Hypothermia has a profound impact on the electrophysiological mechanisms of the heart. Experimental investigations provide a better understanding of electrophysiological alterations associated with cooling. However, there is a lack of computer models suitable for simulating the effects of hypothermia in cardio-electrophysiology. In this work, we propose a model that describes the cooling-induced electrophysiological alterations in ventricular tissue in a temperature range from 27°C to 37°C. To model the electrophysiological conditions in a 3D left ventricular tissue block it was essential to consider the following anatomical and physiological parameters in the model: the different cell types (endocardial, M, epicardial, the heterogeneous conductivities in longitudinal, transversal and transmural direction depending on the prevailing temperature, the distinct fiber orientations and the transmural repolarization sequences. Cooling-induced alterations on the morphology of the action potential (AP of single myocardial cells thereby are described by an extension of the selected Bueno-Orovio model for human ventricular tissue using Q10 temperature coefficients. To evaluate alterations on tissue level, the corresponding pseudo electrocardiogram (pECG was calculated. Simulations show that cooling-induced AP and pECG-related parameters, i.e. AP duration, morphology of the notch of epicardial AP, maximum AP upstroke velocity, AP rise time, QT interval, QRS duration and J wave formation are in good accordance with literature and our experimental data. The proposed model enables us to further enhance our knowledge of cooling-induced electrophysiological alterations from cellular to tissue level in the heart and may help to better understand electrophysiological mechanisms, e.g. in arrhythmias, during hypothermia.

  10. Modeling hypothermia induced effects for the heterogeneous ventricular tissue from cellular level to the impact on the ECG.

    Science.gov (United States)

    Kienast, Roland; Handler, Michael; Stöger, Markus; Baumgarten, Daniel; Hanser, Friedrich; Baumgartner, Christian

    2017-01-01

    Hypothermia has a profound impact on the electrophysiological mechanisms of the heart. Experimental investigations provide a better understanding of electrophysiological alterations associated with cooling. However, there is a lack of computer models suitable for simulating the effects of hypothermia in cardio-electrophysiology. In this work, we propose a model that describes the cooling-induced electrophysiological alterations in ventricular tissue in a temperature range from 27°C to 37°C. To model the electrophysiological conditions in a 3D left ventricular tissue block it was essential to consider the following anatomical and physiological parameters in the model: the different cell types (endocardial, M, epicardial), the heterogeneous conductivities in longitudinal, transversal and transmural direction depending on the prevailing temperature, the distinct fiber orientations and the transmural repolarization sequences. Cooling-induced alterations on the morphology of the action potential (AP) of single myocardial cells thereby are described by an extension of the selected Bueno-Orovio model for human ventricular tissue using Q10 temperature coefficients. To evaluate alterations on tissue level, the corresponding pseudo electrocardiogram (pECG) was calculated. Simulations show that cooling-induced AP and pECG-related parameters, i.e. AP duration, morphology of the notch of epicardial AP, maximum AP upstroke velocity, AP rise time, QT interval, QRS duration and J wave formation are in good accordance with literature and our experimental data. The proposed model enables us to further enhance our knowledge of cooling-induced electrophysiological alterations from cellular to tissue level in the heart and may help to better understand electrophysiological mechanisms, e.g. in arrhythmias, during hypothermia.

  11. Impact of land surface heterogeneity on urban heat island circulation and sea-land breeze circulation in Hong Kong

    Science.gov (United States)

    Wang, Y.; Di Sabatino, S.; Martilli, A.; Li, Y.; Wong, M. S.; Gutiérrez, E.; Chan, P. W.

    2017-04-01

    Hong Kong is one of the most high-rise and highly compact cities in the world. The urban land surface is highly heterogeneous, which creates low-level convergence zones in urban areas, particularly the Kowloon Peninsula. The low-level convergence zone is due to the combined effect of urban heat island circulation (UHIC) and sea-land breeze circulation (SLBC) under weak northeasterly synoptic flow. To study the impacts of anthropogenic fluxes and built-up areas on the local circulation, the Weather Research and Forecasting (WRF) mesoscale model is combined with the multilayer urban canopy building effect parameterization/building energy model (BEP/BEM) parameterization to produce a 3 day simulation of an air pollution episode in Hong Kong in September 2012. To better represent the city land surface features, building information is assimilated in the central part of the Kowloon Peninsula. The WRF-BEP-BEM model captures the 2 m temperature distribution and local wind rotation reasonably well but overestimates the 10 m wind speed with a mean bias error of 0.70 m/s. A dome-shaped feature with a high level of moisture is captured in the convergence zones due to intensified UHIC and inflowing SLBC. The anthropogenic heat increases the air temperature by around 0.3°C up to 250 m, which in turn modifies the SLBC. A new drag coefficient based on λP, plan area per unit ground area, is tested. Besides the basic physical characteristics captured by the WRF-BEP-BEM model, the stagnation of wind in the lower level convergence zone is better captured by this approach than by the traditional constant value coefficient.

  12. Impact of heterogeneity-corrected dose calculation using a grid-based Boltzmann solver on breast and cervix cancer brachytherapy

    Directory of Open Access Journals (Sweden)

    Julia Hofbauer

    2016-04-01

    Full Text Available Purpose : To analyze the impact of heterogeneity-corrected dose calculation on dosimetric quality parameters in gyne¬cological and breast brachytherapy using Acuros, a grid-based Boltzmann equation solver (GBBS, and to evaluate the shielding effects of different cervix brachytherapy applicators. Material and methods: Calculations with TG-43 and Acuros were based on computed tomography (CT retrospectively, for 10 cases of accelerated partial breast irradiation and 9 cervix cancer cases treated with tandem-ring applicators. Phantom CT-scans of different applicators (plastic and titanium were acquired. For breast cases the Vimpact on clinical dose parameters was found for the cervix cases. Applicator material causes

  13. Impact of heterogeneity-corrected dose calculation using a grid-based Boltzmann solver on breast and cervix cancer brachytherapy.

    Science.gov (United States)

    Hofbauer, Julia; Kirisits, Christian; Resch, Alexandra; Xu, Yingjie; Sturdza, Alina; Pötter, Richard; Nesvacil, Nicole

    2016-04-01

    To analyze the impact of heterogeneity-corrected dose calculation on dosimetric quality parameters in gynecological and breast brachytherapy using Acuros, a grid-based Boltzmann equation solver (GBBS), and to evaluate the shielding effects of different cervix brachytherapy applicators. Calculations with TG-43 and Acuros were based on computed tomography (CT) retrospectively, for 10 cases of accelerated partial breast irradiation and 9 cervix cancer cases treated with tandem-ring applicators. Phantom CT-scans of different applicators (plastic and titanium) were acquired. For breast cases the V20Gyαβ3 to lung, the D0.1cm(3) , D1cm(3) , D2cm(3) to rib, the D0.1cm(3) , D1cm(3) , D10cm(3) to skin, and Dmax for all structures were reported. For cervix cases, the D0.1cm(3) , D2cm(3) to bladder, rectum and sigmoid, and the D50, D90, D98, V100 for the CTVHR were reported. For the phantom study, surrogates for target and organ at risk were created for a similar dose volume histogram (DVH) analysis. Absorbed dose and equivalent dose to 2 Gy fractionation (EQD2) were used for comparison. Calculations with TG-43 overestimated the dose for all dosimetric indices investigated. For breast, a decrease of ~8% was found for D10cm(3) to the skin and 5% for D2cm(3) to rib, resulting in a difference ~ -1.5 Gy EQD2 for overall treatment. Smaller effects were found for cervix cases with the plastic applicator, with up to -2% (-0.2 Gy EQD2) per fraction for organs at risk and -0.5% (-0.3 Gy EQD2) per fraction for CTVHR. The shielding effect of the titanium applicator resulted in a decrease of 2% for D2cm(3) to the organ at risk versus 0.7% for plastic. Lower doses were reported when calculating with Acuros compared to TG-43. Differences in dose parameters were larger in breast cases. A lower impact on clinical dose parameters was found for the cervix cases. Applicator material causes systematic shielding effects that can be taken into account.

  14. Statistical analysis of liquid seepage in partially saturated heterogeneous fracture systems

    Energy Technology Data Exchange (ETDEWEB)

    Liou, Tai -Sheng [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    Field evidence suggests that water flow in unsaturated fracture systems may occur along fast preferential flow paths. However, conventional macroscale continuum approaches generally predict the downward migration of water as a spatially uniform wetting front subjected to strong inhibition into the partially saturated rock matrix. One possible cause of this discrepancy may be the spatially random geometry of the fracture surfaces, and hence, the irregular fracture aperture. Therefore, a numerical model was developed in this study to investigate the effects of geometric features of natural rock fractures on liquid seepage and solute transport in 2-D planar fractures under isothermal, partially saturated conditions. The fractures were conceptualized as 2-D heterogeneous porous media that are characterized by their spatially correlated permeability fields. A statistical simulator, which uses a simulated annealing (SA) algorithm, was employed to generate synthetic permeability fields. Hypothesized geometric features that are expected to be relevant for seepage behavior, such as spatially correlated asperity contacts, were considered in the SA algorithm. Most importantly, a new perturbation mechanism for SA was developed in order to consider specifically the spatial correlation near conditioning asperity contacts. Numerical simulations of fluid flow and solute transport were then performed in these synthetic fractures by the flow simulator TOUGH2, assuming that the effects of matrix permeability, gas phase pressure, capillary/permeability hysteresis, and molecular diffusion can be neglected. Results of flow simulation showed that liquid seepage in partially saturated fractures is characterized by localized preferential flow, along with bypassing, funneling, and localized ponding. Seepage pattern is dominated by the fraction of asperity contracts, and their shape, size, and spatial correlation. However, the correlation structure of permeability field is less important

  15. Chemical reactivity of {alpha}-isosaccharinic acid in heterogeneous alkaline systems

    Energy Technology Data Exchange (ETDEWEB)

    Glaus, M. A.; Loon, L. R. Van

    2009-05-15

    Cellulose degradation under alkaline conditions is of relevance for the mobility of many radionuclides in the near-field of a cementitious repository for radioactive waste, because metal-binding degradation products may be formed. Among these, {alpha}- isosaccharinic acid ({alpha}-ISA) is the strongest complexant. The prediction of the equilibrium concentration of {alpha}-ISA in cement pore water is therefore an important step in the assessment of the influence of cellulose degradation products on the speciation of radionuclides in such environments. The present report focuses on possible chemical transformation reactions of {alpha}-ISA in heterogeneous alkaline model systems containing either Ca(OH){sub 2} or crushed hardened cement paste. The transformation reactions were monitored by measuring the concentration of {alpha}-ISA by high performance anion exchange chromatography and the formation of reaction products by high performance ion exclusion chromatography. The overall loss of organic species from solution was monitored by measuring the concentration of non-purgeable organic carbon. The reactions were examined in diluted and compacted suspensions, at either 25 {sup o}C or 90 {sup o}C, and under anaerobic atmospheres obtained by various methods. It was found that {alpha}-ISA was transformed under all conditions tested to some extent. Reaction products, such as glycolate, formate, lactate and acetate, all compounds with less complexing strength than {alpha}-ISA, were detected. The amount of reaction products identified by the chromatographic technique applied was {approx} 50 % of the amount of {alpha}-ISA reacted. Sorption of {alpha}-ISA to Ca(OH){sub 2} contributed only to a minor extent to the loss of {alpha}-ISA from the solution phase. As the most important conclusion of the present work it was demonstrated that the presence of oxidising agents had a distinctive influence on the turnover of {alpha}-ISA. Under aerobic conditions {alpha}-ISA was

  16. The development and testing of a 2D laboratory seismic modelling system for heterogeneous structure investigations

    Science.gov (United States)

    Mo, Yike; Greenhalgh, Stewart A.; Robertsson, Johan O. A.; Karaman, Hakki

    2015-05-01

    Lateral velocity variations and low velocity near-surface layers can produce strong scattered and guided waves which interfere with reflections and lead to severe imaging problems in seismic exploration. In order to investigate these specific problems by laboratory seismic modelling, a simple 2D ultrasonic model facility has been recently assembled within the Wave Propagation Lab at ETH Zurich. The simulated geological structures are constructed from 2 mm thick metal and plastic sheets, cut and bonded together. The experiments entail the use of a piezoelectric source driven by a pulse amplifier at ultrasonic frequencies to generate Lamb waves in the plate, which are detected by piezoelectric receivers and recorded digitally on a National Instruments recording system, under LabVIEW software control. The 2D models employed were constructed in-house in full recognition of the similitude relations. The first heterogeneous model features a flat uniform low velocity near-surface layer and deeper dipping and flat interfaces separating different materials. The second model is comparable but also incorporates two rectangular shaped inserts, one of low velocity, the other of high velocity. The third model is identical to the second other than it has an irregular low velocity surface layer of variable thickness. Reflection as well as transmission experiments (crosshole & vertical seismic profiling) were performed on each model. The two dominant Lamb waves recorded are the fundamental symmetric mode (non-dispersive) and the fundamental antisymmetric (flexural) dispersive mode, the latter normally being absent when the source transducer is located on a model edge but dominant when it is on the flat planar surface of the plate. Experimental group and phase velocity dispersion curves were determined and plotted for both modes in a uniform aluminium plate. For the reflection seismic data, various processing techniques were applied, as far as pre-stack Kirchhoff migration. The

  17. Normalising impacts in an environmental systems analysis of wastewater systems.

    Science.gov (United States)

    Kärrman, E; Jönsson, H

    2001-01-01

    In an environmental systems analysis of four wasterwater systems, the environmental aspects were prioritised by normalisation of predicted impacts from the studied systems to the total impacts from society. Priority Group 1 (highest priority) consisted of discharges (flows) of nitrogen, cadmium, lead and mercury to water, recycling of nitrogen and phosphorus to arable land and flows of heavy metals to arable land. A conventional wastewater system (A) was compared to irrigation of energy forest with biologically treated wastewater (B), liquid composting of toilet wastewater (C) and a conventional system supplemented with urine separation (D). Analysing the aspects in priority group one, systems B-D improved the management of plant nutrients and decreased the flow of heavy metals to water, while the flow to arable land increased, especially for system B. The suggested method is useful in municipal environmental planning and when choosing a wastewater system.

  18. The impact of the sensory experience on scale and preference heterogeneity: The GMNL model approach applied to pig castration and meat quality

    OpenAIRE

    Kallas, Zein; Borrisser-Pairó,, Francesc; Martínez, Beatriz; Vieira, Ceferina; Rubio, Begonia; Panella, Nuria; Gil, Marta; Linares, Belén; Garrido, María Dolores; Olivares, Álvaro; Ibañez, Miguel; Oliver, M. Angels; Gil Roig, José María

    2015-01-01

    The EU is considering a future ban on surgical pig castration by 2018 which may affect markets and consumers preferences. This study analysed consumers’ expected preference toward a masking strategy obtained from a mixture of spices and smoking of high level boar taint frankfurter sausages. In addition, we analysed the impact of the sensory experience on the nonobserved heterogeneity both at the scale and mean preferences. We carried out two Non-Hypothetical Discrete Choice Experiments ...

  19. System-on-Chip Environment: A SpecC-Based Framework for Heterogeneous MPSoC Design

    Directory of Open Access Journals (Sweden)

    Daniel D. Gajski

    2008-07-01

    Full Text Available The constantly growing complexity of embedded systems is a challenge that drives the development of novel design automation techniques. C-based system-level design addresses the complexity challenge by raising the level of abstraction and integrating the design processes for the heterogeneous system components. In this article, we present a comprehensive design framework, the system-on-chip environment (SCE which is based on the influential SpecC language and methodology. SCE implements a top-down system design flow based on a specify-explore-refine paradigm with support for heterogeneous target platforms consisting of custom hardware components, embedded software processors, dedicated IP blocks, and complex communication bus architectures. Starting from an abstract specification of the desired system, models at various levels of abstraction are automatically generated through successive step-wise refinement, resulting in a pin-and cycle-accurate system implementation. The seamless integration of automatic model generation, estimation, and verification tools enables rapid design space exploration and efficient MPSoC implementation. Using a large set of industrial-strength examples with a wide range of target architectures, our experimental results demonstrate the effectiveness of our framework and show significant productivity gains in design time.

  20. System-on-Chip Environment: A SpecC-Based Framework for Heterogeneous MPSoC Design

    Directory of Open Access Journals (Sweden)

    Dömer Rainer

    2008-01-01

    Full Text Available Abstract The constantly growing complexity of embedded systems is a challenge that drives the development of novel design automation techniques. C-based system-level design addresses the complexity challenge by raising the level of abstraction and integrating the design processes for the heterogeneous system components. In this article, we present a comprehensive design framework, the system-on-chip environment (SCE which is based on the influential SpecC language and methodology. SCE implements a top-down system design flow based on a specify-explore-refine paradigm with support for heterogeneous target platforms consisting of custom hardware components, embedded software processors, dedicated IP blocks, and complex communication bus architectures. Starting from an abstract specification of the desired system, models at various levels of abstraction are automatically generated through successive step-wise refinement, resulting in a pin-and cycle-accurate system implementation. The seamless integration of automatic model generation, estimation, and verification tools enables rapid design space exploration and efficient MPSoC implementation. Using a large set of industrial-strength examples with a wide range of target architectures, our experimental results demonstrate the effectiveness of our framework and show significant productivity gains in design time.

  1. Reevaluation of JACS code system benchmark analyses of the heterogeneous system. Fuel rods in U+Pu nitric acid solution system

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Tomoyuki; Miyoshi, Yoshinori; Katakura, Jun-ichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    In order to perform accuracy evaluation of the critical calculation by the combination of multi-group constant library MGCL and 3-dimensional Monte Carlo code KENO-IV among critical safety evaluation code system JACS, benchmark calculation was carried out from 1980 in 1982. Some cases where the neutron multiplication factor calculated in the heterogeneous system in it was less than 0.95 were seen. In this report, it re-calculated by considering the cause about the heterogeneous system of the U+Pu nitric acid solution systems containing the neutron poison shown in JAERI-M 9859. The present study has shown that the k{sub eff} value less than 0.95 given in JAERI-M 9859 is caused by the fact that the water reflector below a cylindrical container was not taken into consideration in the KENO-IV calculation model. By taking into the water reflector, the KENO-IV calculation gives a k{sub eff} value greater than 0.95 and a good agreement with the experiment. (author)

  2. Theoretical and Numerical Evaluation of the MTC Noise Estimate in 2-D 2-group Heterogeneous Systems

    Energy Technology Data Exchange (ETDEWEB)

    Demaziere, Christophe [Chalmers Univ. of Tech., Goeteborg (Sweden). Dept. of Reactor Pysics

    2002-01-01

    The effect of a heterogeneous distribution of the temperature noise on the MTC estimation by noise analysis is investigated. This investigation relies on the 2-group diffusion theory, and all the calculations are performed in a 2-D realistic heterogeneous core. It is shown, similarly to the 1-D case, that the main reason of the MTC underestimation by noise analysis compared to its design-predicted value lies with the fact that the temperature noise might not be homogeneous in the core, and therefore using the local temperature noise in the MTC noise estimation gives erroneous results. A new MTC estimator, which was previously proposed for 1-D 1-group homogeneous cases and which is able to take this heterogeneity into account, was extended to 2-D 2- group heterogeneous cases. It was proven that this new estimator is always able to give a correct MTC estimation with an accuracy of 4%. This small discrepancy comes from the fact that the reactor does not behave in a point-kinetic way, contrary to the assumptions used in the noise estimators. This discrepancy is however quite small. One quantitative result of the present work is a measure of the underestimation of the traditional method as a function of the correlation length of the temperature fluctuations. It is found that the underestimation is larger in 2-D for the same correlation length as in the 1-D case. An underestimation with a factor 5 in the present model is obtained with a radial correlation length of 150 cm. Comparisons with measurements will be possible to make in measurements to be performed in Ringhals.

  3. A heterogeneous multi-core platform for low power signal processing in systems-on-chip

    DEFF Research Database (Denmark)

    Paker, Ozgun; Sparsø, Jens; Haandbæk, Niels

    2002-01-01

    This paper presents a low-power and programmable DSP architecture - a heterogeneous multiprocessor platform consisting of standard CPU/DSP cores, and a set of simple instruction set processors called mini-cores each optimized for a particular class of algorithm (FIR, IIR, LMS, etc.). Communication...... than 6-21 times lower than a general purpose CPU/DSP corewhile executing non-trivial industrial applications....

  4. Reducing Response Time Bounds for DAG-Based Task Systems on Heterogeneous Multicore Platforms

    Science.gov (United States)

    2016-01-01

    signal processors ( DSPs ), or one of many types of hardware accelerators. Each dataflow is represented by a DAG, the nodes (resp., edges) of which...with identical processors . Such complications are impeding advancements in the em- bedded computing industry today. Problem considered herein. In this...of DAGs as just described on a heterogeneous hardware platform consisting of differ- ent types of CEs. A given CE might be a CPU, DSP , or some

  5. Energy system impacts of desalination in Jordan

    Directory of Open Access Journals (Sweden)

    Poul Alberg Østergaard

    2014-02-01

    Full Text Available Climate change mitigation calls for energy systems minimising end-use demands, optimising the fuel efficiency of conversion systems, increasing the use of renewable energy sources and exploiting synergies wherever possible. In parallel, global fresh water resources are strained due to amongst others population and wealth increase and competitive water uses from agriculture and industry is causing many nations to turn to desalination technologies. This article investigates a Jordanian energy scenario with two different desalination technologies; reverse osmosis (RO driven by electricity and Multi Stage Flash (MSF desalination driven by Cogeneration of Heat and Power (CHP. The two systems impact the energy systems in different ways due to the technologies’ particular characteristics. The systems are analyses in the energy systems analysis model EnergyPLAN to determine the impacts on energy system performance. Results indicate that RO and MSF are similar in fuel use. While there is no use of waste heat from condensing mode plants, efficiencies for CHP and MSF are not sufficiently good to results in lower fuel usage than RO. The Jordanian energy system is somewhat inflexible giving cause to Critical Excess Electricity Production (CEEP even at relatively modest wind power penetrations. Here RO assists the energy system in decreasing CEEP – and even more if water storage is applied.

  6. Extensions to the Parallel Real-Time Artificial Intelligence System (PRAIS) for fault-tolerant heterogeneous cycle-stealing reasoning

    Science.gov (United States)

    Goldstein, David

    1991-01-01

    Extensions to an architecture for real-time, distributed (parallel) knowledge-based systems called the Parallel Real-time Artificial Intelligence System (PRAIS) are discussed. PRAIS strives for transparently parallelizing production (rule-based) systems, even under real-time constraints. PRAIS accomplished these goals (presented at the first annual C Language Integrated Production System (CLIPS) conference) by incorporating a dynamic task scheduler, operating system extensions for fact handling, and message-passing among multiple copies of CLIPS executing on a virtual blackboard. This distributed knowledge-based system tool uses the portability of CLIPS and common message-passing protocols to operate over a heterogeneous network of processors. Results using the original PRAIS architecture over a network of Sun 3's, Sun 4's and VAX's are presented. Mechanisms using the producer-consumer model to extend the architecture for fault-tolerance and distributed truth maintenance initiation are also discussed.

  7. Experience of integrated measurements using heterogeneous systems at different startup stages of a WWER-1200 power unit

    Directory of Open Access Journals (Sweden)

    V.I. Pavelko

    2017-03-01

    Full Text Available A major feature specific to commissioning of NPPs in Russia and of Russian-designed NPPs in foreign countries is a great deal of measurement involved at different pre-commissioning stages, which differs from foreign experience where emphases is placed on computational justification and the scope of in-situ commissioning testing is smaller. The use of various measuring systems in pre-commissioning operations requires the involvement of a large number of personnel from different organizations, infrequently with no data acquisition coordination among them. This leads to both measuring channels and the information gathered being multiply duplicated (assembly, installation, adjustment, which is one of the sources for its misrepresentation, and to a greatly increased cost of operations. At the same time, most modern power units are equipped with test systems (TS [1–4] consisting of heterogeneous measuring channels. The current TS commissioning practice required systems to be adjusted and started up only after the 100% unit power level was reached which did not make it possible to use test systems at pre-commissioning and power ascension stages. This study is an attempt to create an integrated information system composed of heterogeneous local systems to enable the largest possible number of standard channels to be used simultaneously with temporarily installed channels for pre-commissioning measurements to provide sound and high-quality information on the state of the unit.

  8. IMPACT: A facility to study the interaction of low-energy intense particle beams with dynamic heterogeneous surfaces

    Science.gov (United States)

    Allain, J. P.; Nieto, M.; Hendricks, M. R.; Plotkin, P.; Harilal, S. S.; Hassanein, A.

    2007-11-01

    The Interaction of Materials with Particles and Components Testing (IMPACT) experimental facility is furnished with multiple ion sources and in situ diagnostics to study the modification of surfaces undergoing physical, chemical, and electronic changes during exposure to energetic particle beams. Ion beams with energies in the range between 20 and 5000eV can bombard samples at flux levels in the range of 1010-1015cm-2s-1; parameters such as ion angle of incidence and exposed area are also controllable during the experiment. IMPACT has diagnostics that allow full characterization of the beam, including a Faraday cup, a beam imaging system, and a retarding field energy analyzer. IMPACT is equipped with multiple diagnostics, such as electron (Auger, photoelectron) and ion scattering spectroscopies that allow different probing depths of the sample to monitor compositional changes in multicomponent and/or layered targets. A unique real-time erosion diagnostic based on a dual quartz crystal microbalance measures deposition from an eroding surface with rates smaller than 0.01nm/s, which can be converted to a sputter yield measurement. The monitoring crystal can be rotated and placed in the target position so that the deposited material on the quartz crystal oscillator surface can be characterized without transfer outside of the vacuum chamber.

  9. Single-cell profiling reveals heterogeneity and functional patterning of GPCR expression in the vascular system.

    Science.gov (United States)

    Kaur, H; Carvalho, J; Looso, M; Singh, P; Chennupati, R; Preussner, J; Günther, S; Albarrán-Juárez, J; Tischner, D; Classen, S; Offermanns, S; Wettschureck, N

    2017-06-16

    G-protein-coupled receptor (GPCR) expression is extensively studied in bulk cDNA, but heterogeneity and functional patterning of GPCR expression in individual vascular cells is poorly understood. Here, we perform a microfluidic-based single-cell GPCR expression analysis in primary smooth muscle cells (SMC) and endothelial cells (EC). GPCR expression is highly heterogeneous in all cell types, which is confirmed in reporter mice, on the protein level and in human cells. Inflammatory activation in murine models of sepsis or atherosclerosis results in characteristic changes in the GPCR repertoire, and we identify functionally relevant subgroups of cells that are characterized by specific GPCR patterns. We further show that dedifferentiating SMC upregulate GPCRs such as Gpr39, Gprc5b, Gprc5c or Gpr124, and that selective targeting of Gprc5b modulates their differentiation state. Taken together, single-cell profiling identifies receptors expressed on pathologically relevant subpopulations and provides a basis for the development of new therapeutic strategies in vascular diseases.

  10. Software Defined Resource Orchestration System for Multitask Application in Heterogeneous Mobile Cloud Computing

    Directory of Open Access Journals (Sweden)

    Qi Qi

    2016-01-01

    Full Text Available The mobile cloud computing (MCC that combines mobile computing and cloud concept takes wireless access network as the transmission medium and uses mobile devices as the client. When offloading the complicated multitask application to the MCC environment, each task executes individually in terms of its own computation, storage, and bandwidth requirement. Due to user’s mobility, the provided resources contain different performance metrics that may affect the destination choice. Nevertheless, these heterogeneous MCC resources lack integrated management and can hardly cooperate with each other. Thus, how to choose the appropriate offload destination and orchestrate the resources for multitask is a challenge problem. This paper realizes a programming resource provision for heterogeneous energy-constrained computing environments, where a software defined controller is responsible for resource orchestration, offload, and migration. The resource orchestration is formulated as multiobjective optimal problem that contains the metrics of energy consumption, cost, and availability. Finally, a particle swarm algorithm is used to obtain the approximate optimal solutions. Simulation results show that the solutions for all of our studied cases almost can hit Pareto optimum and surpass the comparative algorithm in approximation, coverage, and execution time.

  11. Homogeneous and Heterogeneous Reaction and Transformation of Hg and Trace Metals in Combustion Systems

    Energy Technology Data Exchange (ETDEWEB)

    J. Helble; Clara Smith; David Miller

    2009-08-31

    The overall goal of this project was to produce a working dynamic model to predict the transformation and partitioning of trace metals resulting from combustion of a broad range of fuels. The information provided from this model will be instrumental in efforts to identify fuels and conditions that can be varied to reduce metal emissions. Through the course of this project, it was determined that mercury (Hg) and arsenic (As) would be the focus of the experimental investigation. Experiments were therefore conducted to examine homogeneous and heterogeneous mercury oxidation pathways, and to assess potential interactions between arsenic and calcium. As described in this report, results indicated that the role of SO{sub 2} on Hg oxidation was complex and depended upon overall gas phase chemistry, that iron oxide (hematite) particles contributed directly to heterogeneous Hg oxidation, and that As-Ca interactions occurred through both gas-solid and within-char reaction pathways. Modeling based on this study indicated that, depending upon coal type and fly ash particle size, vaporization-condensation, vaporization-surface reaction, and As-CaO in-char reaction all play a role in arsenic transformations under combustion conditions.

  12. The Impact of Landscape Heterogeneity on the Composition of Local Communities: Butterflies in the Steppe Reserves of South Moravia

    OpenAIRE

    ŠLANCAROVÁ, Jana

    2011-01-01

    This thesis aims to answer the question whether heterogeneity of agricultural landscapes affects the richness of species, and looks at community composition of butterflies inhabiting 38 insular steppe grassland reserves situated in Southern Moravia, Czech Republic, using quantitative butterfly records and digitised data on landscape composition within the reserves and in surrounding perimeters.

  13. Reaction Rates in Chemically Heterogeneous Rock: Coupled Impact of Structure and Flow Properties Studied by X-ray Microtomography.

    Science.gov (United States)

    Al-Khulaifi, Yousef; Lin, Qingyang; Blunt, Martin J; Bijeljic, Branko

    2017-04-04

    We study dissolution in a chemically heterogeneous medium consisting of two minerals with contrasting initial structure and transport properties. We perform a reactive transport experiment using CO 2 -saturated brine at reservoir conditions in a millimeter-scale composite core composed of Silurian dolomite and Ketton limestone (calcite) arranged in series. We repeatedly image the composite core using X-ray microtomography (XMT) and collect effluent to assess the individual mineral dissolution. The mineral dissolution from image analysis was comparable to that measured from effluent analysis using inductively coupled plasma mass spectrometry (ICP-MS). We find that the ratio of the effective reaction rate of calcite to that of dolomite decreases with time, indicating the influence of dynamic transport effects originating from changes in pore structure coupled with differences in intrinsic reaction rates. Moreover, evolving flow and transport heterogeneity in the initially heterogeneous dolomite is a key determinant in producing a two-stage dissolution in the calcite. The first stage is characterized by a uniform dissolution of the pore space, while the second stage follows a single-channel growth regime. This implies that spatial memory effects in the medium with a heterogeneous flow characteristic (dolomite) can change the dissolution patterns in the medium with a homogeneous flow characteristic (calcite).

  14. Output Consensus of Heterogeneous Linear Multi-Agent Systems by Distributed Event-Triggered/Self-Triggered Strategy.

    Science.gov (United States)

    Hu, Wenfeng; Liu, Lu; Feng, Gang

    2016-09-02

    This paper addresses the output consensus problem of heterogeneous linear multi-agent systems. We first propose a novel distributed event-triggered control scheme. It is shown that, with the proposed control scheme, the output consensus problem can be solved if two matrix equations are satisfied. Then, we further propose a novel self-triggered control scheme, with which continuous monitoring is avoided. By introducing a fixed timer into both event- and self-triggered control schemes, Zeno behavior can be ruled out for each agent. The effectiveness of the event- and self-triggered control schemes is illustrated by an example.

  15. Global warming potential impact of bioenergy systems

    Directory of Open Access Journals (Sweden)

    Wenzel H.

    2012-10-01

    Full Text Available Reducing dependence on fossil fuels and mitigation of GHG emissions is a main focus in the energy strategy of many Countries. In the case of Demark, for instance, the long-term target of the energy policy is to reach 100% renewable energy system. This can be achieved by drastic reduction of the energy demand, optimization of production/distribution and substitution of fossil fuels with biomasses. However, a large increase in biomass consumption will finally induce conversion of arable and currently cultivated land into fields dedicated to energy crops production determining significant environmental consequences related to land use changes. In this study the global warming potential impact associated with six alternative bioenergy systems based on willow and Miscanthus was assessed by means of life-cycle assessment. The results showed that bioenergy production may generate higher global warming impacts than the reference fossil fuel system, when the impacts from indirect land use changes are accounted for. In a life-cycle perspective, only highly-efficient co-firing with fossil fuel achieved a (modest GHG emission reduction.

  16. The Impact of Systems Biology on Bioprocessing

    DEFF Research Database (Denmark)

    Campbell, Kate; Xia, Jianye; Nielsen, Jens

    2017-01-01

    Bioprocessing offers a sustainable and green approach to the production of chemicals. However, a bottleneck in introducing bioprocesses is cell factory development, which is costly and time-consuming. A systems biology approach can expedite cell factory design by using genome-wide analyses...... and its regulation, which can be achieved using quantitative and integrated omic characterization, alongside more advanced analytical methods. We discuss here the current impact of systems biology and challenges of closing the gap between bioprocessing and more traditional methods of chemical production....

  17. A comparison of discrete versus continuous adjoint states to invert groundwater flow in heterogeneous dual porosity systems

    Science.gov (United States)

    Delay, Frederick; Badri, Hamid; Fahs, Marwan; Ackerer, Philippe

    2017-12-01

    Dual porosity models become increasingly used for simulating groundwater flow at the large scale in fractured porous media. In this context, model inversions with the aim of retrieving the system heterogeneity are frequently faced with huge parameterizations for which descent methods of inversion with the assistance of adjoint state calculations are well suited. We compare the performance of discrete and continuous forms of adjoint states associated with the flow equations in a dual porosity system. The discrete form inherits from previous works by some of the authors, as the continuous form is completely new and here fully differentiated for handling all types of model parameters. Adjoint states assist descent methods by calculating the gradient components of the objective function, these being a key to good convergence of inverse solutions. Our comparison on the basis of synthetic exercises show that both discrete and continuous adjoint states can provide very similar solutions close to reference. For highly heterogeneous systems, the calculation grid of the continuous form cannot be too coarse, otherwise the method may show lack of convergence. This notwithstanding, the continuous adjoint state is the most versatile form as its non-intrusive character allows for plugging an inversion toolbox quasi-independent from the code employed for solving the forward problem.

  18. Distributed Impact Detector System (DIDS) Health Monitoring System Evaluation

    Science.gov (United States)

    Prosser, William H.; Madaras, Eric I.

    2010-01-01

    Damage due to impacts from micrometeoroids and orbital debris is one of the most significant on-orbit hazards for spacecraft. Impacts to thermal protection systems must be detected and the damage evaluated to determine if repairs are needed to allow safe re-entry. To address this issue for the International Space Station Program, Langley Research Center and Johnson Space Center technologists have been working to develop and implement advanced methods for detecting impacts and resultant leaks. LaRC funded a Small Business Innovative Research contract to Invocon, Inc. to develop special wireless sensor systems that are compact, light weight, and have long battery lifetimes to enable applications to long duration space structures. These sensor systems are known as distributed impact detection systems (DIDS). In an assessment, the NASA Engineering and Safety Center procured two prototype DIDS sensor units to evaluate their capabilities in laboratory testing and field testing in an ISS Node 1 structural test article. This document contains the findings of the assessment.

  19. Transient decay of longitudinal magnetization in heterogeneous spin systems under selective saturation

    Science.gov (United States)

    Yeung, Hong N.; Swanson, Scott D.

    The transient behavior of the longitudinal magnetization of the mobile protons in aqueous heterogeneous materials is investigated both theoretically and experimentally when selective saturation is applied by off resonance, RF irradiation to the homogeneously broadened, immobile protons which are coupled to the mobile protons through cross relaxation. Analytical solution of this problem is obtained by a generalization of H. C. Torrey's solution to the Bloch equations. Progressive (but indirect) saturation of the magnetization of the mobile protons under this RF irradiation is dynamically monitored using very-small-tip-angle sampling pulses. The apparent relaxation rate of heat-denatured egg albumin was measured as a function of frequency offset of the saturating RF with different amplitudes using a new dispersion method modified from a broadband technique recently invented for the rapid acquisition of a cross-relaxation z spectrum.

  20. Recent Advances in Transition-Metal-Mediated Electrocatalytic CO2 Reduction: From Homogeneous to Heterogeneous Systems

    KAUST Repository

    Feng, Da-Ming

    2017-12-01

    Global climate change and increasing demands for clean energy have brought intensive interest in the search for proper electrocatalysts in order to reduce carbon dioxide (CO2) to higher value carbon products such as hydrocarbons. Recently, transition-metal-centered molecules or organic frameworks have been reported to show outstanding electrocatalytic activity in the liquid phase. Their d-orbital electrons are believed to be one of the key factors to capture and convert CO2 molecules to value-added low-carbon fuels. In this review, recent advances in electrocatalytic CO2 reduction have been summarized based on the targeted products, ranging from homogeneous reactions to heterogeneous ones. Their advantages and fallbacks have been pointed out and the existing challenges, especially with respect to the practical and industrial application are addressed.

  1. Recent Advances in Transition-Metal-Mediated Electrocatalytic CO2 Reduction: From Homogeneous to Heterogeneous Systems

    Directory of Open Access Journals (Sweden)

    Da-Ming Feng

    2017-12-01

    Full Text Available Global climate change and increasing demands for clean energy have brought intensive interest in the search for proper electrocatalysts in order to reduce carbon dioxide (CO2 to higher value carbon products such as hydrocarbons. Recently, transition-metal-centered molecules or organic frameworks have been reported to show outstanding electrocatalytic activity in the liquid phase. Their d-orbital electrons are believed to be one of the key factors to capture and convert CO2 molecules to value-added low-carbon fuels. In this review, recent advances in electrocatalytic CO2 reduction have been summarized based on the targeted products, ranging from homogeneous reactions to heterogeneous ones. Their advantages and fallbacks have been pointed out and the existing challenges, especially with respect to the practical and industrial application are addressed.

  2. Ion Microprobe Measurements of Comet Dust and Implications for Models of Oxygen Isotope Heterogeneity in the Solar System

    Science.gov (United States)

    Snead, C. J.; McKeegan, K. D.; Keller, L. P.; Messenger, S.

    2017-01-01

    ]. These studies have been largely focused on the coarse-grained terminal particles extracted from aerogel collectors; hypervelocity capture into aerogel resulted in fine-grained material that was melted and intimately mixed with the SiO2 capture medium. Hypervelocity impacts into Al foils surrounding the aerogel tiles produced impact craters that captured material from the impactor without significant oxygen contamination, allowing for analysis of both the coarse and fine-grained components of the Wild 2 dust. To date, no particles with definitive hydrated mineralogy have been observed in Stardust samples, though this may be a result of alteration due to hypervelocity capture. High-carbon hydrated CS-IDPs have been suggested as resulting from the aqueous alteration of CP-IDPs [7], and may retain evidence for interaction with O-17, O-18-enriched "cometary" water predicted by CO self-shielding. Here we present results of oxygen isotope measurements of twelve Stardust foil craters and four C-rich hydrated IDPs [8, 9], and discuss implications for models of oxygen isotope heterogeneity in the early solar system.

  3. Impact of Heterogeneity in Sexual Behavior on Effectiveness in Reducing HIV Transmission with Test-and-Treat Strategy.

    Directory of Open Access Journals (Sweden)

    Ganna Rozhnova

    2016-08-01

    Full Text Available The WHO's early-release guideline for antiretroviral treatment (ART of HIV infection based on a recent trial conducted in 34 countries recommends starting treatment immediately upon an HIV diagnosis. Therefore, the test-and-treat strategy may become more widely used in an effort to scale up HIV treatment and curb further transmission. Here we examine behavioural determinants of HIV transmission and how heterogeneity in sexual behaviour influences the outcomes of this strategy. Using a deterministic model, we perform a systematic investigation into the effects of various mixing patterns in a population of men who have sex with men (MSM, stratified by partner change rates, on the elimination threshold and endemic HIV prevalence. We find that both the level of overdispersion in the distribution of the number of sexual partners and mixing between population subgroups have a large influence on endemic prevalence before introduction of ART and on possible long term effectiveness of ART. Increasing heterogeneity in risk behavior may lead to lower endemic prevalence levels, but requires higher coverage levels of ART for elimination. Elimination is only feasible for populations with a rather low degree of assortativeness of mixing and requires treatment coverage of almost 80% if rates of testing and treatment uptake by all population subgroups are equal. In this case, for fully assortative mixing and 80% coverage endemic prevalence is reduced by 57%. In the presence of heterogeneity in ART uptake, elimination is easier to achieve when the subpopulation with highest risk behavior is tested and treated more often than the rest of the population, and vice versa when it is less. The developed framework can be used to extract information on behavioral heterogeneity from existing data which is otherwise hard to determine from population surveys.

  4. Impact of Heterogeneity in Sexual Behavior on Effectiveness in Reducing HIV Transmission with Test-and-Treat Strategy.

    Science.gov (United States)

    Rozhnova, Ganna; van der Loeff, Maarten F Schim; Heijne, Janneke C M; Kretzschmar, Mirjam E

    2016-08-01

    The WHO's early-release guideline for antiretroviral treatment (ART) of HIV infection based on a recent trial conducted in 34 countries recommends starting treatment immediately upon an HIV diagnosis. Therefore, the test-and-treat strategy may become more widely used in an effort to scale up HIV treatment and curb further transmission. Here we examine behavioural determinants of HIV transmission and how heterogeneity in sexual behaviour influences the outcomes of this strategy. Using a deterministic model, we perform a systematic investigation into the effects of various mixing patterns in a population of men who have sex with men (MSM), stratified by partner change rates, on the elimination threshold and endemic HIV prevalence. We find that both the level of overdispersion in the distribution of the number of sexual partners and mixing between population subgroups have a large influence on endemic prevalence before introduction of ART and on possible long term effectiveness of ART. Increasing heterogeneity in risk behavior may lead to lower endemic prevalence levels, but requires higher coverage levels of ART for elimination. Elimination is only feasible for populations with a rather low degree of assortativeness of mixing and requires treatment coverage of almost 80% if rates of testing and treatment uptake by all population subgroups are equal. In this case, for fully assortative mixing and 80% coverage endemic prevalence is reduced by 57%. In the presence of heterogeneity in ART uptake, elimination is easier to achieve when the subpopulation with highest risk behavior is tested and treated more often than the rest of the population, and vice versa when it is less. The developed framework can be used to extract information on behavioral heterogeneity from existing data which is otherwise hard to determine from population surveys.

  5. Does microbial centimeter-scale heterogeneity impact MCPA degradation in and leaching from a loamy agricultural soil?

    Science.gov (United States)

    Rosenbom, Annette E; Binning, Philip J; Aamand, Jens; Dechesne, Arnaud; Smets, Barth F; Johnsen, Anders R

    2014-02-15

    The potential for pesticide degradation varies greatly at the centimeter-scale in agricultural soil. Three dimensional numerical simulations were conducted to evaluate how such small-scale spatial heterogeneity may affect the leaching of the biodegradable pesticide 2-methyl-4-chlorophenoxyacetic acid (MCPA) in the upper meter of a variably-saturated, loamy soil profile. To incorporate realistic spatial variation in degradation potential, we used data from a site where 420 mineralization curves over 5 depths have been measured. Monod kinetics was fitted to the individual curves to derive initial degrader biomass values, which were incorporated in a reactive transport model to simulate heterogeneous biodegradation. Six scenarios were set up using COMSOL Multiphysics to evaluate the difference between models having different degrader biomass distributions (homogeneous, heterogeneous, or no biomass) and either matrix flow or preferential flow through a soil matrix with a wormhole. MCPA leached, within 250 days, below 1m only when degrader biomass was absent and preferential flow occurred. Both biodegradation in the plow layer and the microbially active lining of the wormhole contributed to reducing MCPA-leaching below 1m. The spatial distribution of initial degrader biomass within each soil matrix layer, however, had little effect on the overall MCPA-leaching. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. A Distributed Dynamic Super Peer Selection Method Based on Evolutionary Game for Heterogeneous P2P Streaming Systems

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2013-01-01

    Full Text Available Due to high efficiency and good scalability, hierarchical hybrid P2P architecture has drawn more and more attention in P2P streaming research and application fields recently. The problem about super peer selection, which is the key problem in hybrid heterogeneous P2P architecture, is becoming highly challenging because super peers must be selected from a huge and dynamically changing network. A distributed super peer selection (SPS algorithm for hybrid heterogeneous P2P streaming system based on evolutionary game is proposed in this paper. The super peer selection procedure is modeled based on evolutionary game framework firstly, and its evolutionarily stable strategies are analyzed. Then a distributed Q-learning algorithm (ESS-SPS according to the mixed strategies by analysis is proposed for the peers to converge to the ESSs based on its own payoff history. Compared to the traditional randomly super peer selection scheme, experiments results show that the proposed ESS-SPS algorithm achieves better performance in terms of social welfare and average upload rate of super peers and keeps the upload capacity of the P2P streaming system increasing steadily with the number of peers increasing.

  7. Development of a web-based support system for both homogeneous and heterogeneous air quality control networks: process and product.

    Science.gov (United States)

    Andrade, J; Ares, J; García, R; Presa, J; Rodríguez, S; Piñeiro-Iglesias, M; López-Mahía, P; Muniategui, S; Prada, D

    2007-10-01

    The Environmental Laboratories Automation Software System or PALMA (Spanish abbreviation) was developed by a multidisciplinary team in order to support the main tasks of heterogeneous air quality control networks. The software process for PALMA development, which can be perfectly applied to similar multidisciplinary projects, was (a) well-defined, (b) arranged between environmental technicians and informatics, (c) based on quality guides, and (d) clearly user-centred. Moreover, it introduces some interesting advantages with regard to the classical step-by-step approaches. PALMA is a web-based system that allows 'off-line' and automated telematic data acquisition from distributed inmission stations belonging not only to homogeneous but also to heterogeneous air quality control networks. It provides graphic and tabular representations for a comprehensive and centralised analysis of acquired data, and considers the daily work that is associated with such networks: validation of the acquired data, alerts with regard to (periodical) tasks (e.g., analysers verification), downloading of files with environmental information (e.g., dust forecasts), etc. The implantation of PALMA has provided qualitative and quantitative improvements in the work performed by the people in charge of the considered control network.

  8. ISP: an optimal out-of-core image-set processing streaming architecture for parallel heterogeneous systems.

    Science.gov (United States)

    Ha, Linh Khanh; Krüger, Jens; Dihl Comba, João Luiz; Silva, Cláudio T; Joshi, Sarang

    2012-06-01

    Image population analysis is the class of statistical methods that plays a central role in understanding the development, evolution, and disease of a population. However, these techniques often require excessive computational power and memory that are compounded with a large number of volumetric inputs. Restricted access to supercomputing power limits its influence in general research and practical applications. In this paper we introduce ISP, an Image-Set Processing streaming framework that harnesses the processing power of commodity heterogeneous CPU/GPU systems and attempts to solve this computational problem. In ISP, we introduce specially designed streaming algorithms and data structures that provide an optimal solution for out-of-core multiimage processing problems both in terms of memory usage and computational efficiency. ISP makes use of the asynchronous execution mechanism supported by parallel heterogeneous systems to efficiently hide the inherent latency of the processing pipeline of out-of-core approaches. Consequently, with computationally intensive problems, the ISP out-of-core solution can achieve the same performance as the in-core solution. We demonstrate the efficiency of the ISP framework on synthetic and real datasets.

  9. Heterogeneous Catalysis.

    Science.gov (United States)

    Miranda, R.

    1989-01-01

    Described is a heterogeneous catalysis course which has elements of materials processing embedded in the classical format of catalytic mechanisms and surface chemistry. A course outline and list of examples of recent review papers written by students are provided. (MVL)

  10. Energy-Efficient User Association Strategy for Hyperdense Heterogeneous Networking in the Fifth Generation Systems

    Directory of Open Access Journals (Sweden)

    Lei Li

    2015-01-01

    Full Text Available Redesigning user association strategies to improve energy efficiency (EE has been viewed as one of the promising shifting paradigms for the fifth generation (5G cellular networks. In this paper, we investigate how to optimize users’ association to enhance EE for hyper dense heterogeneous networking in the 5G cellular networks, where the low-power node (LPN much outnumbers the high-power node (HPN. To characterize that densely deployed LPNs would undertake a majority of high-rate services, while HPNs mainly support coverage; the EE metric is defined as average weighted EE of access nodes with the unit of bit per joule. Then, the EE optimization objective function is formulated and proved to be nonconvex. Two mathematical transformation techniques are presented to solve the nonconvex problem. In the first case, the original problem is reformulated as an equivalent problem involving the maximization of a biconcave function. In the second case, it is equivalent to a concave minimization problem. We focus on the solution of the biconcave framework, and, by exploiting the biconcave structure, a novel iterative algorithm based on dual theory is proposed, where a partially optimal solution can be achieved. Simulation results have verified the effectiveness of the proposed algorithm.

  11. Use of Persistent Identifiers to link Heterogeneous Data Systems in the Integrated Earth Data Applications (IEDA) Facility

    Science.gov (United States)

    Hsu, L.; Lehnert, K. A.; Carbotte, S. M.; Arko, R. A.; Ferrini, V.; O'hara, S. H.; Walker, J. D.

    2012-12-01

    The Integrated Earth Data Applications (IEDA) facility maintains multiple data systems with a wide range of solid earth data types from the marine, terrestrial, and polar environments. Examples of the different data types include syntheses of ultra-high resolution seafloor bathymetry collected on large collaborative cruises and analytical geochemistry measurements collected by single investigators in small, unique projects. These different data types have historically been channeled into separate, discipline-specific databases with search and retrieval tailored for the specific data type. However, a current major goal is to integrate data from different systems to allow interdisciplinary data discovery and scientific analysis. To increase discovery and access across these heterogeneous systems, IEDA employs several unique IDs, including sample IDs (International Geo Sample Number, IGSN), person IDs (GeoPass ID), funding award IDs (NSF Award Number), cruise IDs (from the Marine Geoscience Data System Expedition Metadata Catalog), dataset IDs (DOIs), and publication IDs (DOIs). These IDs allow linking of a sample registry (System for Earth SAmple Registration), data libraries and repositories (e.g. Geochemical Research Library, Marine Geoscience Data System), integrated synthesis databases (e.g. EarthChem Portal, PetDB), and investigator services (IEDA Data Compliance Tool). The linked systems allow efficient discovery of related data across different levels of granularity. In addition, IEDA data systems maintain links with several external data systems, including digital journal publishers. Links have been established between the EarthChem Portal and ScienceDirect through publication DOIs, returning sample-level objects and geochemical analyses for a particular publication. Linking IEDA-hosted data to digital publications with IGSNs at the sample level and with IEDA-allocated dataset DOIs are under development. As an example, an individual investigator could sign up

  12. Benchmarking of hospital information systems: Monitoring of discharge letters and scheduling can reveal heterogeneities and time trends

    Science.gov (United States)

    Dugas, Martin; Eckholt, Markus; Bunzemeier, Holger

    2008-01-01

    Background Monitoring of hospital information system (HIS) usage can provide insights into best practices within a hospital and help to assess time trends. In terms of effort and cost of benchmarking, figures derived automatically from the routine HIS system are preferable to manual methods like surveys, in particular for repeated analysis. Methods Due to relevance for quality management and efficient resource utilization we focused on time-to-completion of discharge letters (assessed by CT-plots) and usage of patient scheduling. We analyzed these parameters monthly during one year at a major university hospital in Germany. Results We found several distinct patterns of discharge letter documentation indicating a large heterogeneity of HIS usage between different specialties (completeness 51 – 99%, delays 0 – 90 days). Overall usage of scheduling increased during the observation period by 62%, but again showed a considerable variation between departments. Conclusion Regular monitoring of HIS key figures can contribute to a continuous HIS improvement process. PMID:18423046

  13. The Impact of DNAPL Source-Zone Architecture on Contaminant Mass Flux and Plume Evolution in Heterogeneous Porous Media

    Science.gov (United States)

    2013-08-01

    M.D.; Jawitz, J.W. 2008. Laboratory investigation of flux reduction from dense non-aqueous phase liquid (DNAPL) partial source zone remediation by...project was designed to accomplish a systematic study of the mass-transfer behavior of chlorinated-solvent immiscible liquids in heterogeneous porous...5.1.3-1b Summary of experimental conditions……………………………………… 43 Tables 5.3.1-1 Summary of miscible -displacement experiments…………………………… 63 Table 5.3.1

  14. Trends in practical applications of heterogeneous multi-agent systems : the PAAMS collection

    CERN Document Server

    Rodríguez, Juan; Mathieu, Philippe; Campbell, Andrew; Ortega, Alfonso; Adam, Emmanuel; Navarro, Elena; Ahrndt, Sebastian; Moreno, María; Julián, Vicente

    2014-01-01

    PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems. This volume presents the papers that have been accepted for the 2014 special sessions: Agents Behaviours and Artificial Markets (ABAM), Agents and Mobile Devices (AM), Bio-Inspired and Multi-Agents Systems: Applications to Languages (BioMAS), Multi-Agent Systems and Ambient Intelligence (MASMAI), Self-Explaining Agents (SEA), Web Mining and Recommender systems (WebMiRes) and Intelligent Educational Systems (SSIES).

  15. Land Systems Impacts of Hydropower Development

    Science.gov (United States)

    Wu, G. C.; Torn, M. S.

    2016-12-01

    that indirect land use change should be considered in the energy planning process and design of environmental impact assessments. The large-scale land system impact assessment method used in this study can be extended to examine other intensive development projects such as road construction and mining.

  16. High-performance simulation-based algorithms for an alpine ski racer’s trajectory optimization in heterogeneous computer systems

    Directory of Open Access Journals (Sweden)

    Dębski Roman

    2014-09-01

    Full Text Available Effective, simulation-based trajectory optimization algorithms adapted to heterogeneous computers are studied with reference to the problem taken from alpine ski racing (the presented solution is probably the most general one published so far. The key idea behind these algorithms is to use a grid-based discretization scheme to transform the continuous optimization problem into a search problem over a specially constructed finite graph, and then to apply dynamic programming to find an approximation of the global solution. In the analyzed example it is the minimum-time ski line, represented as a piecewise-linear function (a method of elimination of unfeasible solutions is proposed. Serial and parallel versions of the basic optimization algorithm are presented in detail (pseudo-code, time and memory complexity. Possible extensions of the basic algorithm are also described. The implementation of these algorithms is based on OpenCL. The included experimental results show that contemporary heterogeneous computers can be treated as μ-HPC platforms-they offer high performance (the best speedup was equal to 128 while remaining energy and cost efficient (which is crucial in embedded systems, e.g., trajectory planners of autonomous robots. The presented algorithms can be applied to many trajectory optimization problems, including those having a black-box represented performance measure

  17. The Impact of Systems Biology on Bioprocessing.

    Science.gov (United States)

    Campbell, Kate; Xia, Jianye; Nielsen, Jens

    2017-12-01

    Bioprocessing offers a sustainable and green approach to the production of chemicals. However, a bottleneck in introducing bioprocesses is cell factory development, which is costly and time-consuming. A systems biology approach can expedite cell factory design by using genome-wide analyses alongside mathematical modeling to characterize and predict cellular physiology. This approach can drive cycles of design, build, test, and learn implemented by metabolic engineers to optimize the cell factory performance. Streamlining of the design phase requires a clearer understanding of metabolism and its regulation, which can be achieved using quantitative and integrated omic characterization, alongside more advanced analytical methods. We discuss here the current impact of systems biology and challenges of closing the gap between bioprocessing and more traditional methods of chemical production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Heterogeneous impact of body mass index on in-hospital mortality in acute heart failure syndromes: An analysis from the ATTEND Registry.

    Science.gov (United States)

    Yoshihisa, Akiomi; Sato, Takamasa; Kajimoto, Katsuya; Sato, Naoki; Takeishi, Yasuchika

    2017-03-01

    Although the obesity paradox may vary depending upon clinical background factors such as age, gender, aetiology of heart failure and comorbidities, the reasons underlying the heterogeneous impact of body mass index (BMI) on in-hospital cardiac mortality under various conditions in patients with acute heart failure syndromes (AHFSs) remain unclear. Among 4617 hospitalised patients with AHFSs enrolled in the Acute Decompensated Heart Failure Syndromes (ATTEND) registry, the patient characteristics and in-hospital cardiac mortality rates in those with low BMI (BMI valvular aetiologies and a history of prior hospitalisation for AHFS. The low-BMI group also had lower prevalence rates of diabetes, dyslipidaemia, hypertension and atrial fibrillation and higher prevalence rates of anaemia and chronic obstructive pulmonary disease. In addition, cardiac mortality was significantly higher in the low-BMI group than in the high-BMI group (5.5 vs. 1.5%, p disease and hyponatremia (all p < 0.05), although there were no interactions between the impacts of BMI and age, gender, other aetiologies, prior hospitalisation, diabetes, anaemia, cardio-renal function and in-hospital management. It is necessary to appreciate the obesity paradox in AHFS patients, and a patient's heterogeneous background should also be considered.

  19. Reaction and Transport Effects in the Heterogeneous Systems for Lean Gas Purification.

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Svoboda, Karel; Pohořelý, Michael; Šyc, Michal; Skoblia, S.; Chyou, Y.-P.

    2017-01-01

    Roč. 71, č. 3 (2017), s. 563-577 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GC14-09692J Grant - others:NSC(TW) 102WBS0300011; NSC(TW) 103-2923-E-042A-001-MY3 Institutional support: RVO:67985858 Keywords : differential reactor * gas chemisorption * alkaline solids Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.258, year: 2016

  20. Environmental impacts and sustainability of egg production systems 1

    National Research Council Canada - National Science Library

    Xin, H; Gates, R. S; Green, A. R; Mitloehner, F. M; Moore, P. A; Wathes, C. M

    2011-01-01

    ABSTRACT As part of a systemic assessment toward social sustainability of egg production, we have reviewed current knowledge about the environmental impacts of egg production systems and identified...

  1. SCS-CN parameter determination using rainfall-runoff data in heterogeneous watersheds – the two-CN system approach

    Directory of Open Access Journals (Sweden)

    J. D. Valiantzas

    2012-03-01

    Full Text Available The Soil Conservation Service Curve Number (SCS-CN approach is widely used as a simple method for predicting direct runoff volume for a given rainfall event. The CN parameter values corresponding to various soil, land cover, and land management conditions can be selected from tables, but it is preferable to estimate the CN value from measured rainfall-runoff data if available. However, previous researchers indicated that the CN values calculated from measured rainfall-runoff data vary systematically with the rainfall depth. Hence, they suggested the determination of a single asymptotic CN value observed for very high rainfall depths to characterize the watersheds' runoff response. In this paper, the hypothesis that the observed correlation between the calculated CN value and the rainfall depth in a watershed reflects the effect of soils and land cover spatial variability on its hydrologic response is being tested. Based on this hypothesis, the simplified concept of a two-CN heterogeneous system is introduced to model the observed CN-rainfall variation by reducing the CN spatial variability into two classes. The behaviour of the CN-rainfall function produced by the simplified two-CN system is approached theoretically, it is analysed systematically, and it is found to be similar to the variation observed in natural watersheds. Synthetic data tests, natural watersheds examples, and detailed study of two natural experimental watersheds with known spatial heterogeneity characteristics were used to evaluate the method. The results indicate that the determination of CN values from rainfall runoff data using the proposed two-CN system approach provides reasonable accuracy and it over performs the previous methods based on the determination of a single asymptotic CN value. Although the suggested method increases the number of unknown parameters to three (instead of one, a clear physical reasoning for them is presented.

  2. Heterogeneity in regional notification patterns and its impact on aggregate national case notification data: the example of measles in Italy

    Directory of Open Access Journals (Sweden)

    Butler Alisa R

    2003-07-01

    Full Text Available Abstract Background A monthly time series of measles case notifications exists for Italy from 1949 onwards, although its usefulness is seriously undermined by extensive under-reporting which varies strikingly between regions, giving rise to the possibility of significant distortions in epidemic patterns seen in aggregated national data. Results A corrected national time series is calculated using an algorithm based upon the approximate equality between births and measles cases; under-reporting estimates are presented for each Italian region, and poor levels of reporting in Southern Italy are confirmed. Conclusion Although an order of magnitude larger, despite great heterogeneity between regions in under-reporting and in epidemic patterns, the shape of the corrected national time series remains close to that of the aggregated uncorrected data. This suggests such aggregate data may be quite robust to great heterogeneity in reporting and epidemic patterns at the regional level. The corrected data set maintains an epidemic pattern distinct from that of England and Wales.

  3. The impact of environmental heterogeneity and life stage on the hindgut microbiota of Holotrichia parallela larvae (Coleoptera: Scarabaeidae.

    Directory of Open Access Journals (Sweden)

    Shengwei Huang

    Full Text Available Gut microbiota has diverse ecological and evolutionary effects on its hosts. However, the ways in which it responds to environmental heterogeneity and host physiology remain poorly understood. To this end, we surveyed intestinal microbiota of Holotrichia parallela larvae at different instars and from different geographic regions. Bacterial 16S rRNA gene clone libraries were constructed and clones were subsequently screened by DGGE and sequenced. Firmicutes and Proteobacteria were the major phyla, and bacteria belonging to Ruminococcaceae, Lachnospiraceae, Enterobacteriaceae, Desulfovibrionaceae and Rhodocyclaceae families were commonly found in all natural populations. However, bacterial diversity (Chao1 and Shannon indices and community structure varied across host populations, and the observed variation can be explained by soil pH, organic carbon and total nitrogen, and the climate factors (e.g., mean annual temperature of the locations where the populations were sampled. Furthermore, increases in the species richness and diversity of gut microbiota were observed during larval growth. Bacteroidetes comprised the dominant group in the first instar; however, Firmicutes composed the majority of the hindgut microbiota during the second and third instars. Our results suggest that the gut's bacterial community changes in response to environmental heterogeneity and host's physiology, possibly to meet the host's ecological needs or physiological demands.

  4. Predicting chemical impacts on vertebrate endocrine systems.

    Science.gov (United States)

    Nichols, John W; Breen, Miyuki; Denver, Robert J; Distefano, Joseph J; Edwards, Jeremy S; Hoke, Robert A; Volz, David C; Zhang, Xiaowei

    2011-01-01

    Animals have evolved diverse protective mechanisms for responding to toxic chemicals of both natural and anthropogenic origin. From a governmental regulatory perspective, these protective responses complicate efforts to establish acceptable levels of chemical exposure. To explore this issue, we considered vertebrate endocrine systems as potential targets for environmental contaminants. Using the hypothalamic-pituitary-thyroid (HPT), hypothalamic-pituitary-gonad (HPG), and hypothalamic-pituitary-adrenal (HPA) axes as case examples, we identified features of these systems that allow them to accommodate and recover from chemical insults. In doing so, a distinction was made between effects on adults and those on developing organisms. This distinction was required because endocrine system disruption in early life stages may alter development of organs and organ systems, resulting in permanent changes in phenotypic expression later in life. Risk assessments of chemicals that impact highly regulated systems must consider the dynamics of these systems in relation to complex environmental exposures. A largely unanswered question is whether successful accommodation to a toxic insult exerts a fitness cost on individual animals, resulting in adverse consequences for populations. Mechanistically based mathematical models of endocrine systems provide a means for better understanding accommodation and recovery. In the short term, these models can be used to design experiments and interpret study findings. Over the long term, a set of validated models could be used to extrapolate limited in vitro and in vivo testing data to a broader range of untested chemicals, species, and exposure scenarios. With appropriate modification, Tier 2 assays developed in support of the U.S. Environmental Protection Agency's Endocrine Disruptor Screening Program could be used to assess the potential for accommodation and recovery and inform the development of mechanistically based models. © 2010

  5. Hybrid Broad Phase Contact Detection Method for Lunar/Mars Regolith Modeling Designed for Use on Heterogeneous Computer Systems

    Science.gov (United States)

    Kulchitsky, A. V.; Johnson, J. B.

    2010-12-01

    Discrete element method (DEM) simulation is used for the modeling of mobility and excavation on Mars and the Moon, due to many prohibitive limitations of continuum models. One of the most computationally expensive parts of all DEM codes is contact detection between different particles and objects in the system. Taking a naive approach, the operation costs grow as a square of the number of elements. This is prohibitive even for a small number of particles. Instead, most of the impossible contacts are filtered by broad phase contact detection systems. However, such systems are generally hard to run on parallel heterogeneous systems due to many conditionals and to large global memory transactions. In this work, we report on a new broad phase contact detection system, suitable for heterogeneous computational systems such as the IBM Cell and CPU/GPU systems. The approach is based on space partitioning and sweep and prune methods. The particle space is divided by regular columns, where every column is filled with particles. Each particle belongs to up to 4 columns. A sweep and prune method is used in every column. Due to every column containing number of particles proportional to a cubic root of total number of particles, the column fits in small messages or in small memory chunks and can be independently processed on a small operational unit, such as an SPU on the IBM Cell processor. The special method used to enforce the contact list produced by this procedure, so that it contain no duplicates of collisions. Further parallelization is allowed on other stages due to this feature of the method, as well. We discuss the usage and performance of this method on an IBM Cell QS22 cluster with 12 blades, available at Arctic Region Supercomputing Center. We compare to CPU based supercomputers. To make the code portable between different systems, we abstract the parallel level to a separate software library. The main code is "aware" it needs to run in a parallel mode. However

  6. A system level approach for a dependable heterogeneous MPSoC

    NARCIS (Netherlands)

    Ibrahim, Ahmed Mohammed Youssef; Kerkhoff, Hans G.

    Mission-critical systems require a dependable operation during their lifetime. However, the current ongoing aggressive scaling of technology has resulted in increasing reliability issues. Dependability of such systems has become a major concern in the design process. In this work we aim to enhance

  7. Security of Heterogeneous Content in Cloud Based Library Information Systems Using an Ontology Based Approach

    Directory of Open Access Journals (Sweden)

    Mihai DOINEA

    2014-01-01

    Full Text Available As in any domain that involves the use of software, the library information systems take advantages of cloud computing. The paper highlights the main aspect of cloud based systems, describing some public solutions provided by the most important players on the market. Topics related to content security in cloud based services are tackled in order to emphasize the requirements that must be met by these types of systems. A cloud based implementation of an Information Library System is presented and some adjacent tools that are used together with it to provide digital content and metadata links are described. In a cloud based Information Library System security is approached by means of ontologies. Aspects such as content security in terms of digital rights are presented and a methodology for security optimization is proposed.

  8. Feeding Our Immune System: Impact on Metabolism

    Directory of Open Access Journals (Sweden)

    Isabelle Wolowczuk

    2008-01-01

    Full Text Available Endogenous intestinal microflora and environmental factors, such as diet, play a central role in immune homeostasis and reactivity. In addition, microflora and diet both influence body weight and insulin-resistance, notably through an action on adipose cells. Moreover, it is known since a long time that any disturbance in metabolism, like obesity, is associated with immune alteration, for example, inflammation. The purpose of this review is to provide an update on how nutrients-derived factors (mostly focusing on fatty acids and glucose impact the innate and acquired immune systems, including the gut immune system and its associated bacterial flora. We will try to show the reader how the highly energy-demanding immune cells use glucose as a main source of fuel in a way similar to that of insulin-responsive adipose tissue and how Toll-like receptors (TLRs of the innate immune system, which are found on immune cells, intestinal cells, and adipocytes, are presently viewed as essential actors in the complex balance ensuring bodily immune and metabolic health. Understanding more about these links will surely help to study and understand in a more fundamental way the common observation that eating healthy will keep you and your immune system healthy.

  9. Multilevel Methodology for Simulation of Spatio-Temporal Systems with Heterogeneous Activity; Application to Spread of Valley Fever Fungus

    Science.gov (United States)

    Jammalamadaka, Rajanikanth

    2009-01-01

    This report consists of a dissertation submitted to the faculty of the Department of Electrical and Computer Engineering, in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Graduate College, The University of Arizona, 2008. Spatio-temporal systems with heterogeneity in their structure and behavior have two major problems associated with them. The first one is that such complex real world systems extend over very large spatial and temporal domains and consume so many computational resources to simulate that they are infeasible to study with current computational platforms. The second one is that the data available for understanding such systems is limited because they are spread over space and time making it hard to obtain micro and macro measurements. This also makes it difficult to get the data for validation of their constituent processes while simultaneously considering their global behavior. For example, the valley fever fungus considered in this dissertation is spread over a large spatial grid in the arid Southwest and typically needs to be simulated over several decades of time to obtain useful information. It is also hard to get the temperature and moisture data (which are two critical factors on which the survival of the valley fever fungus depends) at every grid point of the spatial domain over the region of study. In order to address the first problem, we develop a method based on the discrete event system specification which exploits the heterogeneity in the activity of the spatio-temporal system and which has been shown to be effective in solving relatively simple partial differential equation systems. The benefit of addressing the first problem is that it now makes it feasible to address the second problem. We address the second problem by making use of a multilevel methodology based on modeling and simulation and systems theory. This methodology helps us in the construction of models with different resolutions (base and

  10. Heterogeneity and diversity of IgM and IgG lupus anticoagulants in an individual with systemic lupus erythematosus.

    Science.gov (United States)

    Nakamura, N; Azuma, C; Akamizu, T; Sugawa, H; Matsuda, F; Mitsuda, N; Honjo, T; Mori, T; Yamaji, K

    1994-09-30

    From one patient with systemic lupus erythematosus retaining lupus anticoagulant (LAC), we established 6 Epstein-Barr virus-transformed human B cell clones secreting antibodies that affect the coagulation assay. Two and 4 of the clones secreted IgM and IgG antibodies, respectively. Although all 6 antibodies displayed anticardiolipin activity in ELISA, the increased binding activity in the presence of beta 2-glycoprotein I was limited only to the IgG antibodies. Five antibodies (two IgM and three IgG) had LAC activity which prolonged the activated partial thromboplastin time (APTT), whereas one IgG antibody shortened the APTT. Two of the IgG producing clones had an identical Ig heavy chain gene rearrangement despite their opposite effects on the coagulation assay. These results demonstrated the heterogeneity of LACs and diversity among their physiological functions.

  11. InterMine: a flexible data warehouse system for the integration and analysis of heterogeneous biological data.

    Science.gov (United States)

    Smith, Richard N; Aleksic, Jelena; Butano, Daniela; Carr, Adrian; Contrino, Sergio; Hu, Fengyuan; Lyne, Mike; Lyne, Rachel; Kalderimis, Alex; Rutherford, Kim; Stepan, Radek; Sullivan, Julie; Wakeling, Matthew; Watkins, Xavier; Micklem, Gos

    2012-12-01

    InterMine is an open-source data warehouse system that facilitates the building of databases with complex data integration requirements and a need for a fast customizable query facility. Using InterMine, large biological databases can be created from a range of heterogeneous data sources, and the extensible data model allows for easy integration of new data types. The analysis tools include a flexible query builder, genomic region search and a library of 'widgets' performing various statistical analyses. The results can be exported in many commonly used formats. InterMine is a fully extensible framework where developers can add new tools and functionality. Additionally, there is a comprehensive set of web services, for which client libraries are provided in five commonly used programming languages. Freely available from http://www.intermine.org under the LGPL license. g.micklem@gen.cam.ac.uk Supplementary data are available at Bioinformatics online.

  12. Child maltreatment characteristics as predictors of heterogeneity in internalizing symptom trajectories among children in the child welfare system.

    Science.gov (United States)

    Yoon, Susan

    2017-10-01

    This study investigated heterogeneity in the developmental trajectories of internalizing symptoms among 541 children who were involved with the child welfare system and examined child maltreatment characteristics, including types, level of harm, and timing, as predictors of internalizing trajectory patterns. Secondary longitudinal research was conducted using data from the National Survey of Child and Adolescent Well-Being-I, collected from 1999 to 2007 in the United States. Three distinct trajectory groups were identified: high-decreasing; low-increasing; and low-stable Sexual abuse, emotional abuse, neglect, and more severe levels of harm from maltreatment predicted membership in two maladaptive groups compared to the low-stable group. The findings of the study suggest the importance of providing a thorough assessment of the type and severity of maltreatment experiences and continued monitoring of internalizing symptoms for children with child welfare involvement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture.

    Science.gov (United States)

    Dodd, Ian C; Egea, Gregorio; Davies, William J

    2008-01-01

    When soil moisture is heterogeneous, sap flow from, and ABA status of, different parts of the root system impact on leaf xylem ABA concentration ([X-ABA]leaf). The robustness of a model for predicting [X-ABA]leaf was assessed. 'Two root-one shoot' grafted sunflower (Helianthus annuus L.) plants received either deficit irrigation (DI, each root system received the same irrigation volumes) or partial rootzone drying (PRD, only one root system was watered and the other dried the soil). Irrespective of whether relative sap flow was assessed using sap flow sensors in vivo or by pressurization of de-topped roots, each root system contributed similarly to total sap flow during DI, while sap flow from roots in drying soil declined linearly with soil water potential (Psisoil) during PRD. Although Psisoil of the irrigated pot determined the threshold Psisoil at which sap flow from roots in drying soil decreased, the slope of this decrease was independent of the wet pot Psisoil. Irrespective of whether sap was collected from the wet or dry root system of PRD plants, or a DI plant, root xylem ABA concentration increased as Psisoil declined. The model, which weighted ABA contributions of each root system according to the sap flow from each, almost perfectly explained [X-ABA] immediately above the graft union. That the model overestimated measured [X-ABA]leaf may result from changes in [X-ABA] along the transport pathway or an artefact of collecting xylem sap from detached leaves. The implications of declining sap flow through partially dry roots during PRD for the control of stomatal behaviour and irrigation scheduling are discussed.

  14. Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture

    Science.gov (United States)

    Dodd, Ian C.; Egea, Gregorio; Davies, William J.

    2008-01-01

    When soil moisture is heterogeneous, sap flow from, and ABA status of, different parts of the root system impact on leaf xylem ABA concentration ([X-ABA]leaf). The robustness of a model for predicting [X-ABA]leaf was assessed. ‘Two root-one shoot’ grafted sunflower (Helianthus annuus L.) plants received either deficit irrigation (DI, each root system received the same irrigation volumes) or partial rootzone drying (PRD, only one root system was watered and the other dried the soil). Irrespective of whether relative sap flow was assessed using sap flow sensors in vivo or by pressurization of de-topped roots, each root system contributed similarly to total sap flow during DI, while sap flow from roots in drying soil declined linearly with soil water potential (Ψsoil) during PRD. Although Ψsoil of the irrigated pot determined the threshold Ψsoil at which sap flow from roots in drying soil decreased, the slope of this decrease was independent of the wet pot Ψsoil. Irrespective of whether sap was collected from the wet or dry root system of PRD plants, or a DI plant, root xylem ABA concentration increased as Ψsoil declined. The model, which weighted ABA contributions of each root system according to the sap flow from each, almost perfectly explained [X-ABA] immediately above the graft union. That the model overestimated measured [X-ABA]leaf may result from changes in [X-ABA] along the transport pathway or an artefact of collecting xylem sap from detached leaves. The implications of declining sap flow through partially dry roots during PRD for the control of stomatal behaviour and irrigation scheduling are discussed. PMID:18940933

  15. Data Description Exchange Services for Heterogeneous Vehicle and Spaceport Control and Monitor Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — CCT proposes an advanced data description exchange approach for space/spaceport systems that will provide a generic platform independent software capability for...

  16. Space Qualified Heterogeneous Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro proposes to develop a radiation hardened, monolithic, heterogeneous processor for space imaging and radar systems. High performance processors are needed...

  17. Simple messaging and collaboration system for heterogeneous organizations operating in disaster environments

    OpenAIRE

    Meyer, Ramsey

    2011-01-01

    Approved for public release; distribution is unlimited. A novel communication system for use by a wide variety of first responders in disaster response is described. The system is based primarily on SMS messaging technologies and either indigenous mobile phone service providers or mobile phone service brought in via cellular-on-wheels (COWs), UAVs, rapidly deployed towers, etc. End users use either their own cell phones, running a native SMS application, or low-cost phones that are dist...

  18. Extreme genetic heterogeneity among the nine major tribal Taiwanese island populations detected with a new generation Y23 STR system.

    Science.gov (United States)

    Zeng, Zhaoshu; Garcia-Bertrand, Ralph; Calderon, Silvia; Li, Li; Zhong, Mingxia; Herrera, Rene J

    2014-09-01

    The Taiwanese aborigines have been regarded as the source populations for the Austronesian expansion that populated Oceania to the east and Madagascar off Africa to the West. Although a number of genetic studies have been performed on some of these important tribes, the scope of the investigations has been limited, varying in the specific populations examined as well as the maker systems employed. This has made direct comparison among studies difficult. In an attempt to alleviate this lacuna, we investigate, for the first time, the genetic diversity of all nine major Taiwanese aboriginal tribes (Ami, Atayal, Bunun, Rukai, Paiwan, Saisat, Puyuma, Tsou and Yami) utilizing a new generation multiplex Y-STR system that allows for the genotyping of 23 loci from a single amplification reaction. This comprehensive approach examining 293 individuals from all nine main tribes with the same battery of forensic markers provides for the much-needed equivalent data essential for comparative analyses. Our results have uncovered that these nine major aboriginal populations exhibit limited intrapopulation genetic diversity and are highly heterogeneous from each other, possibly the result of endogamy, isolation, drift and/or unique ancestral populations. Specifically, genetic diversity, discrimination capacity, fraction of unique haplotypes and the most frequent haplotypes differ among the nine tribes, with the Tsou possessing the lowest values for the first three of these parameters. The phylogenetic analyses performed indicate that the genetic diversity among all nine tribes is greater than the diversity observed among the worldwide reference populations examined, indicating an extreme case of genetic heterogeneity among these tribes that have lived as close neighbors for thousands of years confined to the limited geographical area of an island. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. Cm-scale Heterogeneity in Degradation - Potential Impact on Leaching of MCPA through a Variably-Saturated Macroporous Clayey Till

    DEFF Research Database (Denmark)

    Rosenbom, Annette Elisabeth; Johnsen, Anders R.; Aamand, Jens

    with no biodegradation of the MCPA at all nodes; 2) preferential flow (including a wormhole) of water with no biodegradation of the MCPA at all nodes; 3) simple matrix flow of water with average biodegradation of the MCPA at all nodes, which corresponds to results derived from a conventional homogenized soil sample; 4...... both flow and degradation are associated with macropores/wormholes. Results show that cm-scale heterogeneity in degradation potential with simple matrix flow has a negligible effect on MCPA leaching at one meter below soil surface. By introducing a wormhole in the low-permeable 3D-soil modeling domain......, however, the risk of MCPA-leaching below one meter depth increase drastically with low degradation potential along the wall of macropores/wormholes....

  20. Lithological and hydrological influences on ground-water composition in a heterogeneous carbonate-clay aquifer system

    Science.gov (United States)

    Kauffman, S.J.; Herman, J.S.; Jones, B.F.

    1998-01-01

    The influence of clay units on ground-water composition was investigated in a heterogeneous carbonate aquifer system of Miocene age in southwest Florida, known as the Intermediate aquifer system. Regionally, the ground water is recharged inland, flows laterally and to greater depths in the aquifer systems, and is discharged vertically upward at the saltwater interface along the coast. A depth profile of water composition was obtained by sampling ground water from discrete intervals within the permeable carbonate units during coring and by squeezing pore water from a core of the less-permeable clay layers. A normative salt analysis of solute compositions in the water indicated a marine origin for both types of water and an evolutionary pathway for the clay water that involves clay diagenesis. The chemical composition of the ground water in the carbonate bedrock is significantly different from that of the pore water in the clay layers. Dissolution of clays and opaline silica results in high silica concentrations relative to water in other parts of the Intermediate aquifer system. Water enriched in chloride relative to the overlying and underlying ground water recharges the aquifer inland where the confining clay layer is absent, and it dissolves carbonate and silicate minerals and reacts with clays along its flow path, eventually reaching this coastal site and resulting in the high chloride and silica concentrations observed in the middle part of the Intermediate aquifer system. Reaction-path modeling suggests that the recharging surficial water mixes with sulfate-rich water upwelling from the Upper Floridan aquifer, and carbonate mineral dissolution and precipitation, weathering and exchange reactions, clay mineral diagenesis, clay and silica dissolution, organic carbon oxidation, and iron and sulfate reduction result in the observed water compositions.A study was conducted to clarify the influence of clay units on ground-water composition in a heterogeneous

  1. The impact of selection, gene flow and demographic history on heterogeneous genomic divergence: three-spine sticklebacks in divergent environments.

    Science.gov (United States)

    Ferchaud, Anne-Laure; Hansen, Michael M

    2016-01-01

    Heterogeneous genomic divergence between populations may reflect selection, but should also be seen in conjunction with gene flow and drift, particularly population bottlenecks. Marine and freshwater three-spine stickleback (Gasterosteus aculeatus) populations often exhibit different lateral armour plate morphs. Moreover, strikingly parallel genomic footprints across different marine-freshwater population pairs are interpreted as parallel evolution and gene reuse. Nevertheless, in some geographic regions like the North Sea and Baltic Sea, different patterns are observed. Freshwater populations in coastal regions are often dominated by marine morphs, suggesting that gene flow overwhelms selection, and genomic parallelism may also be less pronounced. We used RAD sequencing for analysing 28 888 SNPs in two marine and seven freshwater populations in Denmark, Europe. Freshwater populations represented a variety of environments: river populations accessible to gene flow from marine sticklebacks and large and small isolated lakes with and without fish predators. Sticklebacks in an accessible river environment showed minimal morphological and genomewide divergence from marine populations, supporting the hypothesis of gene flow overriding selection. Allele frequency spectra suggested bottlenecks in all freshwater populations, and particularly two small lake populations. However, genomic footprints ascribed to selection could nevertheless be identified. No genomic regions were consistent freshwater-marine outliers, and parallelism was much lower than in other comparable studies. Two genomic regions previously described to be under divergent selection in freshwater and marine populations were outliers between different freshwater populations. We ascribe these patterns to stronger environmental heterogeneity among freshwater populations in our study as compared to most other studies, although the demographic history involving bottlenecks should also be considered in the

  2. Lewis Carroll's Doublets net of English words: network heterogeneity in a complex system.

    Directory of Open Access Journals (Sweden)

    Hsieh Fushing

    Full Text Available Lewis Carroll's English word game Doublets is represented as a system of networks with each node being an English word and each connectivity edge confirming that its two ending words are equal in letter length, but different by exactly one letter. We show that this system, which we call the Doublets net, constitutes a complex body of linguistic knowledge concerning English word structure that has computable multiscale features. Distributed morphological, phonological and orthographic constraints and the language's local redundancy are seen at the node level. Phonological communities are seen at the network level. And a balancing act between the language's global efficiency and redundancy is seen at the system level. We develop a new measure of intrinsic node-to-node distance and a computational algorithm, called community geometry, which reveal the implicit multiscale structure within binary networks. Because the Doublets net is a modular complex cognitive system, the community geometry and computable multi-scale structural information may provide a foundation for understanding computational learning in many systems whose network structure has yet to be fully analyzed.

  3. Application of heterogeneous blading systems is the way for improving efficiency of centrifugal energy pumps

    Science.gov (United States)

    Pochylý, F.; Haluza, M.; Fialová, S.; Dobšáková, L.; Volkov, A. V.; Parygin, A. G.; Naumov, A. V.; Vikhlyantsev, A. A.; Druzhinin, A. A.

    2017-11-01

    The results of independent research implemented by the teams of authors representing the Brno University of technology (Czech Republic) and Moscow Power Engineering Institute National Research University (Russia) are presented and compared. The possibilities for improving the energy efficiency of slow-speed centrifugal pumps (with a specific speed coefficient n s chemical industries too. The research was focused on achieving the shape of the pump efficiency characteristics providing a significant extension of its effective working zone and increasing its integrated efficiency. The results were obtained based on new approaches to the formation of a blading system of an impeller of a slow-speed centrifugal pump different from the traditional blading system. The analytical dependences illustrating the influence of individual geometry of a blading system on the efficiency were presented. The possibilities of purposeful changing of its structure were demonstrated. It was experimentally confirmed that use of the innovative blading system makes it possible to increase the pump efficiency by 1-4% (in the experiments for the pumps with n s = 33 and 55) and to extend its efficient working zone approximately by 15-20% (in the experiment for the pumps with n s = 33 and 66). The latter is especially important for the supply pumps of NPP power units. The experimental results for all investigated pumps are presented in comparison with the characteristics of the efficiency provided by the blading systems designed by traditional methods.

  4. Combining heterogeneous inputs for the development of adaptive and multimodal interaction systems

    Directory of Open Access Journals (Sweden)

    David GRIOL

    2013-11-01

    Full Text Available In this paper we present a novel framework for the integration of visual sensor networks and speech-based interfaces. Our proposal follows the standard reference architecture in fusion systems (JDL, and combines different techniques related to Artificial Intelligence, Natural Language Processing and User Modeling to provide an enhanced interaction with their users. Firstly, the framework integrates a Cooperative Surveillance Multi-Agent System (CS-MAS, which includes several types of autonomous agents working in a coalition to track and make inferences on the positions of the targets. Secondly, enhanced conversational agents facilitate human-computer interaction by means of speech interaction. Thirdly, a statistical methodology allows modeling the user conversational behavior, which is learned from an initial corpus and improved with the knowledge acquired from the successive interactions. A technique is proposed to facilitate the multimodal fusion of these information sources and consider the result for the decision of the next system action.

  5. Resolving Heterogeneity

    DEFF Research Database (Denmark)

    Hölzenspies, Jurriaan; Dela Cruz, Gelo Victoriano; M Brickman, Joshua

    2016-01-01

    sets of pluripotency and differentiation markers. It has become increasingly apparent that this transcriptional heterogeneity is an important characteristic of ESC culture. By sorting for specific populations of ESCs it is possible to enrich for cells with a capacity to colonize the embryo proper...

  6. MULTIDISCIPLINARY INFORMATION SYSTEM OF ASSYRIAN CUNEIFORM TABLETS ENHANCING NEW RESEARCH POSSIBILITIES VIA HETEROGENEOUS DATA IN RECORDS

    Directory of Open Access Journals (Sweden)

    J. Valach

    2017-08-01

    Full Text Available This paper outlines recently started project dedicated to creation and development of information system for cuneiform tablets. The contribution deals with the architecture of a virtual collection of cuneiform tablets, conceived as a complex system combining and integrating several domains of information obtained from various types of analyses. The research team includes experts from the field of collection conservation with philologists and researchers in the 3D scanning and physical measurement. Multidisciplinary databases like the one described, represent a new tool in digital humanities and help to improve accessibility of collections to public and researchers.

  7. Microviscosity of water-containing heterogeneous systems. An ESR spin probe study

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, B.; Hanke, T.; Reuther, F.

    The microstructure of maltodextrin gels was studied by ESR spin probe technique. From investigations of the time dependence of the gelling process and from the Arrhenius plot of the rotational correlation time, important information about the phase behavior of the system is obtained. The microviscosity decreases with swelling time, whereas the macroviscosity increases. The conclusion is drawn that the maltodextrin gel is a two-phase system and can be characterized in the nomenclature of Papkov as a gel of the second type. (author).

  8. Multidisciplinary Information System of Assyrian Cuneiform Tablets Enhancing New Research Possibilities via Heterogeneous Data in Records

    Science.gov (United States)

    Valach, J.; Štefcová, P.; Bruna, R.; Zemánek, P.

    2017-08-01

    This paper outlines recently started project dedicated to creation and development of information system for cuneiform tablets. The contribution deals with the architecture of a virtual collection of cuneiform tablets, conceived as a complex system combining and integrating several domains of information obtained from various types of analyses. The research team includes experts from the field of collection conservation with philologists and researchers in the 3D scanning and physical measurement. Multidisciplinary databases like the one described, represent a new tool in digital humanities and help to improve accessibility of collections to public and researchers.

  9. Evaluating architecture impact on system energy efficiency.

    Science.gov (United States)

    Yu, Shijie; Yang, Hailong; Wang, Rui; Luan, Zhongzhi; Qian, Depei

    2017-01-01

    As the energy consumption has been surging in an unsustainable way, it is important to understand the impact of existing architecture designs from energy efficiency perspective, which is especially valuable for High Performance Computing (HPC) and datacenter environment hosting tens of thousands of servers. One obstacle hindering the advance of comprehensive evaluation on energy efficiency is the deficient power measuring approach. Most of the energy study relies on either external power meters or power models, both of these two methods contain intrinsic drawbacks in their practical adoption and measuring accuracy. Fortunately, the advent of Intel Running Average Power Limit (RAPL) interfaces has promoted the power measurement ability into next level, with higher accuracy and finer time resolution. Therefore, we argue it is the exact time to conduct an in-depth evaluation of the existing architecture designs to understand their impact on system energy efficiency. In this paper, we leverage representative benchmark suites including serial and parallel workloads from diverse domains to evaluate the architecture features such as Non Uniform Memory Access (NUMA), Simultaneous Multithreading (SMT) and Turbo Boost. The energy is tracked at subcomponent level such as Central Processing Unit (CPU) cores, uncore components and Dynamic Random-Access Memory (DRAM) through exploiting the power measurement ability exposed by RAPL. The experiments reveal non-intuitive results: 1) the mismatch between local compute and remote memory node caused by NUMA effect not only generates dramatic power and energy surge but also deteriorates the energy efficiency significantly; 2) for multithreaded application such as the Princeton Application Repository for Shared-Memory Computers (PARSEC), most of the workloads benefit a notable increase of energy efficiency using SMT, with more than 40% decline in average power consumption; 3) Turbo Boost is effective to accelerate the workload execution

  10. Evaluating architecture impact on system energy efficiency

    Science.gov (United States)

    Yu, Shijie; Wang, Rui; Luan, Zhongzhi; Qian, Depei

    2017-01-01

    As the energy consumption has been surging in an unsustainable way, it is important to understand the impact of existing architecture designs from energy efficiency perspective, which is especially valuable for High Performance Computing (HPC) and datacenter environment hosting tens of thousands of servers. One obstacle hindering the advance of comprehensive evaluation on energy efficiency is the deficient power measuring approach. Most of the energy study relies on either external power meters or power models, both of these two methods contain intrinsic drawbacks in their practical adoption and measuring accuracy. Fortunately, the advent of Intel Running Average Power Limit (RAPL) interfaces has promoted the power measurement ability into next level, with higher accuracy and finer time resolution. Therefore, we argue it is the exact time to conduct an in-depth evaluation of the existing architecture designs to understand their impact on system energy efficiency. In this paper, we leverage representative benchmark suites including serial and parallel workloads from diverse domains to evaluate the architecture features such as Non Uniform Memory Access (NUMA), Simultaneous Multithreading (SMT) and Turbo Boost. The energy is tracked at subcomponent level such as Central Processing Unit (CPU) cores, uncore components and Dynamic Random-Access Memory (DRAM) through exploiting the power measurement ability exposed by RAPL. The experiments reveal non-intuitive results: 1) the mismatch between local compute and remote memory node caused by NUMA effect not only generates dramatic power and energy surge but also deteriorates the energy efficiency significantly; 2) for multithreaded application such as the Princeton Application Repository for Shared-Memory Computers (PARSEC), most of the workloads benefit a notable increase of energy efficiency using SMT, with more than 40% decline in average power consumption; 3) Turbo Boost is effective to accelerate the workload execution

  11. Enabling Communications in Heterogeneous Multi-Agent Systems: Electricity Markets Ontology

    Directory of Open Access Journals (Sweden)

    Gabriel SANTOS

    2016-11-01

    Full Text Available Electricity markets worldwide are complex and dynamic environments with very particular characteristics, resulting from their restructuring and evolution into regional and continental scales, along with the constant changes brought by the increasing necessity for an adequate integration of renewable energy sources. The rising complexity and unpredictability in electricity markets has increased the need for the intervenient entities in foreseeing market behaviour. Several modelling tools directed to the study of restructured wholesale electricity markets have emerged. However, they have a common limitation: the lack of interoperability between the various systems to allow the exchange of information and knowledge, to test different market models and to allow market players from different systems to interact in common market environments. This paper proposes the Electricity Markets Ontology, which integrates the essential necessary concepts related with electricity markets, while enabling an easier cooperation and adequate communication between related systems. Additionally, it can be extended and complemented according to the needs of other simulators and real systems in this area

  12. Heterogeneity in consumer perceptions of the animal friendliness of broiler production systems

    NARCIS (Netherlands)

    Jonge, de J.; Trijp, van J.C.M.

    2014-01-01

    Animal welfare-based product differentiation through private sector initiatives has led to the introduction of ‘compromise’ meat products, which are produced at beyond regulatory standards for animal welfare, but are cheaper than organic meat. A variety of production system characteristics serve as

  13. Fingering in unsaturated zone flow: a qualitative review with laboratory experiments on heterogeneous systems

    CSIR Research Space (South Africa)

    Sililo, OTN

    2000-11-01

    Full Text Available of flow will be greatest where the fine-grained layer is thinnest; (5) surface depressions in an upper fine-grained layer will concentrate flow, with fingers forming below such areas; and (6) in systems where an upper fine-grained layer has macro pores...

  14. Cross-training workers in dual resource constrained systems with heterogeneous processing times

    NARCIS (Netherlands)

    Bokhorst, J. A. C.; Gaalman, G. J. C.

    2009-01-01

    In this paper, we explore the effect of cross-training workers in Dual Resource Constrained (DRC) systems with machines having different mean processing times. By means of queuing and simulation analysis, we show that the detrimental effects of pooling (cross-training) previously found in single

  15. VLab: A Science Gateway for Distributed First Principles Calculations in Heterogeneous High Performance Computing Systems

    Science.gov (United States)

    da Silveira, Pedro Rodrigo Castro

    2014-01-01

    This thesis describes the development and deployment of a cyberinfrastructure for distributed high-throughput computations of materials properties at high pressures and/or temperatures--the Virtual Laboratory for Earth and Planetary Materials--VLab. VLab was developed to leverage the aggregated computational power of grid systems to solve…

  16. Soil microbiome is more heterogeneous in organic than in conventional farming system

    NARCIS (Netherlands)

    Lupatini, M.; Korthals, G.W.; De Hollander, M.; Janssens, Thierry K.S.; Kuramae, E.E.

    2017-01-01

    Organic farming system and sustainable management of soil pathogens aim at reducing the use of agricultural chemicals in order to improve ecosystem health. Despite the essential role of microbial communities in agro-ecosystems, we still have limited understanding of the complex response of microbial

  17. Design and Experimental Evaluation of Distributed Heterogeneous Graph-Processing Systems

    NARCIS (Netherlands)

    Guo, Y.; Varbanescu, A.L.; Epema, D.H.J.; Iosup, A.

    2016-01-01

    Graph processing is increasingly used in a variety of domains, from engineering to logistics and from scientific computing to online gaming. To process graphs efficiently, GPU-enabled graph-processing systems such as TOTEM and Medusa exploit the GPU or the combined CPU+GPU capabilities of a single

  18. Alternative electrical transmission systems and their environmental impact

    Energy Technology Data Exchange (ETDEWEB)

    Schiefelbein, G.F.

    1977-08-01

    A general description is provided of electrical transmission systems as an aid in determining their environmental impacts. Alternating current, direct current, overhead systems, underground systems, and water crossings are treated. The cost, performance, reliability, safety, and environmental impact of these systems are compared.

  19. Tumor Heterogeneity in Breast Cancer

    Science.gov (United States)

    Turashvili, Gulisa; Brogi, Edi

    2017-01-01

    Breast cancer is a heterogeneous disease and differs greatly among different patients (intertumor heterogeneity) and even within each individual tumor (intratumor heterogeneity). Clinical and morphologic intertumor heterogeneity is reflected by staging systems and histopathologic classification of breast cancer. Heterogeneity in the expression of established prognostic and predictive biomarkers, hormone receptors, and human epidermal growth factor receptor 2 oncoprotein is the basis for targeted treatment. Molecular classifications are indicators of genetic tumor heterogeneity, which is probed with multigene assays and can lead to improved stratification into low- and high-risk groups for personalized therapy. Intratumor heterogeneity occurs at the morphologic, genomic, transcriptomic, and proteomic levels, creating diagnostic and therapeutic challenges. Understanding the molecular and cellular mechanisms of tumor heterogeneity that are relevant to the development of treatment resistance is a major area of research. Despite the improved knowledge of the complex genetic and phenotypic features underpinning tumor heterogeneity, there has been only limited advancement in diagnostic, prognostic, or predictive strategies for breast cancer. The current guidelines for reporting of biomarkers aim to maximize patient eligibility for targeted therapy, but do not take into account intratumor heterogeneity. The molecular classification of breast cancer is not implemented in routine clinical practice. Additional studies and in-depth analysis are required to understand the clinical significance of rapidly accumulating data. This review highlights inter- and intratumor heterogeneity of breast carcinoma with special emphasis on pathologic findings, and provides insights into the clinical significance of molecular and cellular mechanisms of heterogeneity. PMID:29276709

  20. A Heterogeneous Chemical Origin for the Mass-Independent Distribution of Oxygen Isotopes in the Solar System?

    Science.gov (United States)

    Dominguez, G.; Chakraborty, S.; Jackson, T. L.; Thiemens, M. H.

    2010-12-01

    One of the longest standing problems in planetary science is the origin of the mass-independently fractionated oxygen isotopic reservoirs in the solar system. The oldest minerals formed in the solar system, calcium-aluminum-rich inclusions (CAIs), are 16O enriched compared to the terrestrial bodies (Earth, Mars, asteroids, and comets). In contrast to most terrestrial solids, whose enrichment-depletion patterns in 18O/16O and 17O/16O are well understood to result from mass-dependent processes, the oxygen isotopic distribution of the solar system requires one (or more) physical processes that produced distinct 16O enriched and 16O depleted reservoirs. Several mechanism have been proposed to date including: I) The injection of pure 16O by a supernova II) isotope selective photo-dissociation of CO and, III) symmetry-dependent chemical fractionation processes in the pre-solar nebula. Mechanism I has been ruled out, while recent experimental tests of mechanism II have cast doubt on the basic assumptions that underlie self-shielding models. Recently it was proposed that the 16O-rich and 16O-poor reservoirs present in the early solar system were produced by the heterogeneous chemical processes that produce H2O on the surface of interstellar dust grains in dense molecular clouds, the astrophysical setting where star formation is observed to occur (1). The production of mass-independently fractionated H2O is expected because its major precursors in these environments, O3(surf.) and HO2 (surf.) are well-known carriers of mass-independently fractionated oxygen isotopic anomalies in Earth’s atmosphere. The formation of complex molecular species in molecular clouds is widely believed to be dominated by chemical reactions that occur on the surfaces of cold interstellar dust grains. This talk will review how these heterogeneous chemical reactions, which in many ways mimic the photo-chemistry present in Earth’s atmosphere, leads to the formation of molecular species such as O2

  1. Effect of Structural Heterogeneity of 17Mn1Si Steel on the Temperature Dependence of Impact Deformation and Fracture

    Directory of Open Access Journals (Sweden)

    Dmitry Moiseenko

    2017-07-01

    Full Text Available The paper deals with a theoretical and experimental study of the relationship between the microstructural parameters, mechanical properties, and impact deformation and fracture of steels using the example of 17Mn1Si pipe steel. A model for the behavior of a polycrystalline grain conglomerate under impact loading at different temperatures was proposed within a cellular automata framework. It was shown that the intensity of dissipation processes explicitly depends on temperature and these processes play an important role in stress relaxation at the boundaries of structural elements. The Experimental study reveals the relationship between pendulum impact test temperature and the deformation/fracture energy of the steel. The impact toughness was shown to decrease almost linearly with the decreasing test temperature, which agrees with the fractographic analysis data confirming the increase in the fraction of brittle fracture in this case. It was shown with the aid of the proposed model and numerical simulations that the use of the excitable cellular automata method and an explicit account of test temperature through the possibility of energy release at internal interfaces help to explain the experimentally observed features of impact failure at different temperatures.

  2. Homogeneous, Heterogeneous, and Enzymatic Catalysis.

    Science.gov (United States)

    Oyama, S. Ted; Somorjai, Gabor A.

    1988-01-01

    Discusses three areas of catalysis: homegeneous, heterogeneous, and enzymatic. Explains fundamentals and economic impact of catalysis. Lists and discusses common industrial catalysts. Provides a list of 107 references. (MVL)

  3. Heterogeneity in Body Contouring Outcomes Based Research: The Pittsburgh Body Contouring Complication Reporting System.

    Science.gov (United States)

    Guest, Rachel A; Amar, Dalit; Czerniak, Sharona; Dreifuss, Stephanie E; Schusterman, Mark A; Kenny, Elizabeth M; Chernoff, Eva F; Barnett, Joshua M; Koesarie, Kathleen R; Gusenoff, Jeffrey A

    2017-12-13

    Body contouring complications after massive weight loss (MWL) vary significantly in frequency and type. Currently, no standardized recommendations exist regarding which complications are most important to report. We aim to provide a guideline for complication reporting in the body contouring literature. The Pittsburgh Body Contouring Complication Reporting System (PBCCRS) will aid in risk stratification of body contouring procedures and will decrease under-, over-, and nonreporting of complications. The authors reviewed the literature for the terms "body contouring," "MWL," and "complications." Elimination criteria included: non-English language, case report, meta-analysis, outpatient, non-MWL, unclear demographics, N Pittsburgh Body Contouring Complication Reporting System provides suggested recommendations on complication reporting in massive weight loss body contouring surgery.

  4. A Heterogeneous Multi-core Architecture with a Hardware Kernel for Control Systems

    DEFF Research Database (Denmark)

    Li, Gang; Guan, Wei; Sierszecki, Krzysztof

    2012-01-01

    several advantages over a similar kernel implemented in software: higher-speed processing capability, parallel computation, and separation between the kernel itself and the applications being run. A microbenchmark has been used to compare the hardware kernel with the software kernel, and compare......Rapid industrialisation has resulted in a demand for improved embedded control systems with features such as predictability, high processing performance and low power consumption. Software kernel implementation on a single processor is becoming more difficult to satisfy those constraints....... This paper presents a multi-core architecture incorporating a hardware kernel on FPGAs, intended for high performance applications in control engineering domain. First, the hardware kernel is investigated on the basis of a component-based real-time kernel HARTEX (Hard Real-Time Executive for Control Systems...

  5. 3D Printing of Transparent and Conductive Heterogeneous Hydrogel-Elastomer Systems.

    Science.gov (United States)

    Tian, Kevin; Bae, Jinhye; Bakarich, Shannon E; Yang, Canhui; Gately, Reece D; Spinks, Geoffrey M; In Het Panhuis, Marc; Suo, Zhigang; Vlassak, Joost J

    2017-03-01

    A hydrogel-dielectric-elastomer system, polyacrylamide and poly(dimethylsiloxane) (PDMS), is adapted for extrusion printing for integrated device fabrication. A lithium-chloride-containing hydrogel printing ink is developed and printed onto treated PDMS with no visible signs of delamination and geometrically scaling resistance under moderate uniaxial tension and fatigue. A variety of designs are demonstrated, including a resistive strain gauge and an ionic cable. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Traveller Information System for Heterogeneous Traffic Condition: A Case Study in Thiruvananthapuram City, India

    Science.gov (United States)

    Satyakumar, M.; Anil, R.; Sreeja, G. S.

    2017-12-01

    Traffic in Kerala has been growing at a rate of 10-11% every year, resulting severe congestion especially in urban areas. Because of the limitation of spaces it is not always possible to construct new roads. Road users rely on travel time information for journey planning and route choice decisions, while road system managers are increasingly viewing travel time as an important network performance indicator. More recently Advanced Traveler Information Systems (ATIS) are being developed to provide real-time information to roadway users. For ATIS various methodologies have been developed for dynamic travel time prediction. For this work the Kalman Filter Algorithm was selected for dynamic travel time prediction of different modes. The travel time data collected using handheld GPS device were used for prediction. Congestion Index were calculated and Range of CI values were determined according to the percentage speed drop. After prediction using Kalman Filter, the predicted values along with the GPS data was integrated to GIS and using Network Analysis of ArcGIS the offline route navigation guide was prepared. Using this database a program for route navigation based on travel time was developed. This system will help the travelers with pre-trip information.

  7. Engineering aspects of heterogeneous and homogeneous reactors

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Jr, P W

    1977-01-01

    The core arrangement in an LMFBR can potentially affect the lower internals, upper internals, radial shielding, vessel, hot leg transients, head access area and control systems as well as breeding ratio, doubling time and core inventory. This paper describes the results of a study of the impact on these components and parameters that would result if the Clinch River Breeder Reactor were to incorporate a heterogeneous core.

  8. GIOTTO DUST IMPACT DETECTOR SYSTEM DATA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — Dust Impact Detection System (DIDSY) consists of six independent subsystems with the primary aim of registering the impacts of all particulates of significant mass...

  9. Heterogeneous photocatalysis of tris(2-chloroethyl) phosphate by UV/TiO2: Degradation products and impacts on bacterial proteome.

    Science.gov (United States)

    Ye, Jinshao; Liu, Juan; Li, Chongshu; Zhou, Pulin; Wu, Shuang; Ou, Huase

    2017-11-01

    The widespread, persistent and toxic organophosphorus esters (OPEs) have become one category of emerging environmental contaminants. Thus, it is in urgent need to develop a cost-effective and safe treatment technology for OPEs control. The current study is a comprehensive attempt to use UV/TiO 2 heterogeneous photocatalysis for the degradation of a water dissolved OPEs, tris(2-chloroethyl) phosphate (TCEP). A pseudo-first order degradation reaction with a k obs of 0.3167 min -1 was observed, while hydroxyl radical may be the dominating reactive oxidative species. As the reaction proceeded, TCEP was transformed to a series of hydroxylated and dechlorinated products. The degradation efficiency was significantly affected by pH value, natural organic matters and anions, implying that the complete mineralization of TCEP would be difficult to achieve in actual water treatment process. Based on the proteomics analysis regarding the metabolism reactions, pathways and networks, the significant activation of transmembrane transport and energy generation in Escherichia coli exposed to preliminary degrading products suggested that they can be transported and utilized through cellular metabolism. Furthermore, the descending trend of stress resistance exhibited that the toxicity of products was obviously weakened as the treatment proceeded. In conclusion, hydroxylation and dechlorination of TCEP with incomplete mineralization were likewise effective for its detoxification, indicating that UV/TiO 2 will be an alternative treatment method for OPEs control. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. The impact of heterogeneity and dark acceptor states on FRET: implications for using fluorescent protein donors and acceptors.

    Directory of Open Access Journals (Sweden)

    Steven S Vogel

    Full Text Available Förster resonance energy transfer (FRET microscopy is widely used to study protein interactions in living cells. Typically, spectral variants of the Green Fluorescent Protein (FPs are incorporated into proteins expressed in cells, and FRET between donor and acceptor FPs is assayed. As appreciable FRET occurs only when donors and acceptors are within 10 nm of each other, the presence of FRET can be indicative of aggregation that may denote association of interacting species. By monitoring the excited-state (fluorescence decay of the donor in the presence and absence of acceptors, dual-component decay analysis has been used to reveal the fraction of donors that are FRET positive (i.e., in aggregates._However, control experiments using constructs containing both a donor and an acceptor FP on the same protein repeatedly indicate that a large fraction of these donors are FRET negative, thus rendering the interpretation of dual-component analysis for aggregates between separately donor-containing and acceptor-containing proteins problematic. Using Monte-Carlo simulations and analytical expressions, two possible sources for such anomalous behavior are explored: 1 conformational heterogeneity of the proteins, such that variations in the distance separating donor and acceptor FPs and/or their relative orientations persist on time-scales long in comparison with the excited-state lifetime, and 2 FP dark states.

  11. Physico-Chemical Heterogeneity of Organic-Rich Sediments in the Rifle Aquifer, CO: Impact on Uranium Biogeochemistry.

    Science.gov (United States)

    Janot, Noémie; Lezama Pacheco, Juan S; Pham, Don Q; O'Brien, Timothy M; Hausladen, Debra; Noël, Vincent; Lallier, Florent; Maher, Kate; Fendorf, Scott; Williams, Kenneth H; Long, Philip E; Bargar, John R

    2016-01-05

    The Rifle alluvial aquifer along the Colorado River in west central Colorado contains fine-grained, diffusion-limited sediment lenses that are substantially enriched in organic carbon and sulfides, as well as uranium, from previous milling operations. These naturally reduced zones (NRZs) coincide spatially with a persistent uranium groundwater plume. There is concern that uranium release from NRZs is contributing to plume persistence or will do so in the future. To better define the physical extent, heterogeneity and biogeochemistry of these NRZs, we investigated sediment cores from five neighboring wells. The main NRZ body exhibited uranium concentrations up to 100 mg/kg U as U(IV) and contains ca. 286 g of U in total. Uranium accumulated only in areas where organic carbon and reduced sulfur (as iron sulfides) were present, emphasizing the importance of sulfate-reducing conditions to uranium retention and the essential role of organic matter. NRZs further exhibited centimeter-scale variations in both redox status and particle size. Mackinawite, greigite, pyrite and sulfate coexist in the sediments, indicating that dynamic redox cycling occurs within NRZs and that their internal portions can be seasonally oxidized. We show that oxidative U(VI) release to the aquifer has the potential to sustain a groundwater contaminant plume for centuries. NRZs, known to exist in other uranium-contaminated aquifers, may be regionally important to uranium persistence.

  12. Towards improved characterization of high-risk releases using heterogeneous indoor sensor systems

    Energy Technology Data Exchange (ETDEWEB)

    Sreedharan, Priya; Sohn, Michael D.; Nazaroff, William W.; J. Gadgil, Ashok

    2010-06-30

    The sudden release of toxic contaminants that reach indoor spaces can be hazardous to building occupants. For an acutely toxic contaminant, the speed of the emergency response strongly influences the consequences to occupants. The design of a real time sensor system is made challenging both by the urgency and complex nature of the event, and by the imperfect sensors and models available to describe it. In this research, we use Bayesian modeling to combine information from multiple types of sensors to improve the characterization of a release. We discuss conceptual and algorithmic considerations for selecting and fusing information from disparate sensors. To explore system performance, we use both real tracer gas data from experiments in a three story building, along with synthetic data, including information from door position sensors. The added information from door position sensors is found to be useful for many scenarios, but not always. We discuss the physical conditions and design factors that affect these results, such as the influence of the door positions on contaminant transport. We highlight potential benefits of multisensor data fusion, challenges in realizing those benefits, and opportunities for further improvement.

  13. Towards improved characterization of high-risk releases using heterogeneous indoor sensor systems

    Energy Technology Data Exchange (ETDEWEB)

    Sreedharan, Priya [Department of Mechanical Engineering, University of California, Berkeley, CA 94720-1740 (United States); Indoor Environment Department, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Sohn, Michael D. [Indoor Environment Department, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Nazaroff, William W.; Gadgil, Ashok J. [Indoor Environment Department, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710 (United States)

    2011-02-15

    The sudden release of toxic contaminants that reach indoor spaces can be hazardous to building occupants. For an acutely toxic contaminant, the speed of the emergency response strongly influences the consequences to occupants. The design of a real-time sensor system is made challenging both by the urgency and complex nature of the event, and by the imperfect sensors and models available to describe it. In this research, we use Bayesian modeling to combine information from multiple types of sensors to improve the characterization of a release. We discuss conceptual and algorithmic considerations for selecting and fusing information from disparate sensors. To explore system performance, we use both real tracer gas data from experiments in a three-story building, along with synthetic data, including information from door-position sensors. The added information from door-position sensors is found to be useful for many scenarios, but not always. We discuss the physical conditions and design factors that affect these results, such as the influence of the door positions on contaminant transport. We highlight potential benefits of multisensor data fusion, challenges in realizing those benefits, and opportunities for further improvement. (author)

  14. A new method for registration of heterogeneous sensors in a dimensional measurement system

    Science.gov (United States)

    Zhao, Yan; Wang, Zhong; Fu, Luhua; Qu, Xinghua; Zhang, Heng; Liu, Changjie

    2017-10-01

    Registration of multiple sensors is a basic step in multi-sensor dimensional or coordinate measuring systems before any measurement. In most cases, a common standard is used to be measured by all sensors, and this may work well for general registration of multiple homogeneous sensors. However, when inhomogeneous sensors detect a common standard, it is usually very difficult to obtain the same information, because of the different working principles of the sensors. In this paper, a new method called multiple steps registration is proposed to register two sensors: a video camera sensor (VCS) and a tactile probe sensor (TPS). In this method, the two sensors measure two separated standards: a chrome circle on a reticle and a reference sphere with a constant distance between them, fixed on a steel plate. The VCS captures only the circle and the TPS touches only the sphere. Both simulations and real experiments demonstrate that the proposed method is robust and accurate in the registration of multiple inhomogeneous sensors in a dimensional measurement system.

  15. Molecular System Dynamics for Self-Organization in Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Milner StuartD

    2010-01-01

    Full Text Available We have been looking at the properties of physical configurations that occur in nature in order to characterize, predict, and control network robustness in dynamic communication networks. Our framework is based on the definition of a potential energy function to characterize robustness in communication networks and the study of first- and second-order variations of the potential energy to provide prediction and control strategies for network-performance optimization. This paper describes novel investigations within this framework that draw from molecular system dynamics. The Morse potential, which governs the energy stored in bonds within molecules, is considered for the characterization of the potential energy of communication links in the presence of physical constraints such as the power available at the transmitters in a network. The inclusion of the Morse potential translates into improved control strategies, where forces on network nodes drive the release, retention, or reconfiguration of communication links based on their role within the network architecture. The performance of the proposed approach is measured in terms of the number of source-to-destination connections that have an end-to-end communications path. Simulation results show the effectiveness of our control mechanism, where the physical topology reorganizes to maximize the number of source-to-destination communicating pairs. The algorithms developed are completely distributed, show constant time complexity and produce optimal solutions from local interactions, thus preserving the system's self-organizing capability.

  16. Micro-scale investigations on soil heterogeneity: Impacts on Zn retention and uptake in Zn contaminated soils

    Science.gov (United States)

    Metal contaminants in soils can persist for millennia, causing lasting negative impacts on local ecosystems. Long-term contaminant bioavailability is related to soil pH and the strength and stability of their solid phase associations. We combined physical density separation with synchrotron-based mi...

  17. Heterogeneity of organic matter distribution in relation to a transgressive systems tract: Kimmeridge Clay (Jurassic), England

    Energy Technology Data Exchange (ETDEWEB)

    Herbin, J.P.; Muller, C. (Inst. Francais du Petrole, Rueil-Malmaison (France)); Geyssant, J.; Melieres, F.; Penn, I.

    1991-03-01

    The Kimmeridge clay has been drilled in four continuously cored boreholes put down to sample the organic carbon content of the formation. Three of them sited in the Cleveland basin (Yorkshire) prove over 200 m of strata ranging from Mutabilis to Pectinatus zones; the fourth, completing a 35 km transect, proves the lower part of the Kimmeridge clay of the thinner Eastern England shelf. The results show the total organic carbon content (TOC) increasing by 50% when traced from shelf into the basin where deeper bathymetry and more rapid sedimentation have favored preservation of organic matter. The study of stratigraphical variation of % TOC enables evaluation of fundamental problems of these cycles in which organic matter is one of the major constituents. Such cycles exist throughout the Jurassic and Lower-Middle Cretaceous sequences but a transgressive systems tract such as that of the Kimmeridgian Stage enables the phenomenon to be studied in detail.

  18. Twisting in the excited state of an N-methylpyridinium fluorescent dye modulated by nano-heterogeneous micellar systems.

    Science.gov (United States)

    Cesaretti, A; Carlotti, B; Gentili, P L; Germani, R; Spalletti, A; Elisei, F

    2016-04-01

    A push-pull N-methylpyridinium fluorescent dye with a pyrenyl group as the electron-donor portion was investigated within the nano-heterogeneous media provided by some micellar systems. The molecule was studied by stationary and time-resolved spectroscopic techniques in spherical micellar solutions and viscoelastic hydrogels, in order to throw light on the role played by twisting in its excited state deactivation. As proven by femtosecond fluorescence up-conversion and transient absorption experiments, the excited state dynamics of the molecule is ruled by charge transfer and twisting processes, which, from the locally excited (LE) state initially populated upon excitation, progressively lead to twisted (TICT) and planar (PICT) intramolecular charge transfer states. The inclusion within micellar aggregates was found to slow down and/or limit the rotation of the molecule with respect to what had previously been observed in water, while its confinement within the hydrophobic domains of the gel matrixes prevents any molecular torsion. The increasing viscosity of the medium, when passing from water to micellar systems, implies that the detected steady-state fluorescence comes from an excited state which is not fully relaxed, as is the case with the TICT state in micelles or the LE state in hydrogels, where the detected emission changes its usual orange colour to yellow.

  19. Heterogeneous IT Knowledge of Students: the Didactic Approach how to meet it in the Interdisciplinary Course Program Intelligent Transport Systems

    Directory of Open Access Journals (Sweden)

    Harald Wahl

    2013-02-01

    Full Text Available At the University of Applied Sciences (UAS Technikum Wien, Intelligent Transport System is a highly interdisciplinary Bachelor's degree program. Its curriculum covers several mainly technical oriented disciplines. Especially the IT courses account for the high drop-out rate of the course program. Students come with different IT knowledge depending on the one hand on their previous school education and on the other hand depending on their personal interest in IT topics. Normally, for students, IT is not the number one reason for choosing this program. Nevertheless, IT is extremely important as it interacts with all other disciplines. Especially the heterogeneity of the IT knowledge made it necessary to rethink the way of teaching. The paper describes the new didactic approach of the IT courses in the course program Intelligent Transport Systems. The new approach faces the students' difficulties and tries to overcome the varying pre-knowledge of students. Furthermore, it tries to increase students' motivation by paying particular attention to the students' assumed interests.

  20. Removal of bisphenol derivatives through quinone oxidation by polyphenol oxidase and subsequent quinone adsorption on chitosan in the heterogeneous system.

    Science.gov (United States)

    Kimura, Yuji; Takahashi, Ayumi; Kashiwada, Ayumi; Yamada, Kazunori

    2015-01-01

    In this study, the combined use of a biopolymer chitosan and an oxidoreductase polyphenol oxidase (PPO) was systematically investigated for the removal of bisphenol derivatives from aqueous medium. The process parameters, such as the pH value, temperature, and PPO concentration, were estimated to conduct the enzymatic quinone oxidation of bisphenol derivatives by as little enzyme as possible. Bisphenol derivatives effectively underwent PPO-catalysed quinone oxidation without H2O2 unlike other oxidoreductases, such as peroxidase and tyrosinase, and the optimum conditions were determined to be pH 7.0 and 40°C for bisphenol B, bisphenol E, bisphenol O, and bisphenol Z; pH 7.0 and 30°C for bisphenol C and bisphenol F; and pH 8.0 and 40°C for bisphenol T. They were completely removed through adsorption of enzymatically generated quinone derivatives on chitosan beads or chitosan powders. Quinone adsorption on chitosan beads or chitosan powders in the heterogeneous system was found to be a more effective procedure than generation of aggregates in the homogeneous system with chitosan solution. The removal time was shortened by increasing the amount of chitosan beads or decreasing the size of the chitosan powders.

  1. Optimization procedure for algorithms of task scheduling in high performance heterogeneous distributed computing systems

    Directory of Open Access Journals (Sweden)

    Nirmeen A. Bahnasawy

    2011-11-01

    Full Text Available In distributed computing, the schedule by which tasks are assigned to processors is critical to minimizing the execution time of the application. However, the problem of discovering the schedule that gives the minimum execution time is NP-complete. In this paper, a new task scheduling algorithm called Sorted Nodes in Leveled DAG Division (SNLDD is introduced and developed for HeDCSs with consider a bounded number of processors. The main principle of the developed algorithm is to divide the Directed Acyclic Graph (DAG into levels and sort the tasks in each level according to their computation size in descending order. To evaluate the performance of the developed SNLDD algorithm, a comparative study has been done between the developed SNLDD algorithm and the Longest Dynamic Critical Path (LDCP algorithm which is considered the most efficient existing algorithm. According to the comparative results, it is found that the performance of the developed algorithm provides better performance than the LDCP algorithm in terms of speedup, efficiency, complexity, and quality. Also, a new procedure called Superior Performance Optimization Procedure (SPOP has been introduced and implemented in the developed SNLDD algorithm and the LDCP algorithm to minimize the sleek time of the processors in the system. Again, the performance of the SNLDD algorithm outperforms the existing LDCP algorithm after adding the SPOP procedure.

  2. The effect of spatial heterogeneity on nitrate reduction in soil systems

    DEFF Research Database (Denmark)

    Pedersen, Lasse Lu

    Nitrogen is not only an abundant element on earth, making up roughly 80%of the earth's atmosphere, it is also essential for life, and a functional nitrogen cycle is of great importance to human activities and our ecosystems. The nitrogen cycle ultimately returns reactive nitrogen, which was chemi......Nitrogen is not only an abundant element on earth, making up roughly 80%of the earth's atmosphere, it is also essential for life, and a functional nitrogen cycle is of great importance to human activities and our ecosystems. The nitrogen cycle ultimately returns reactive nitrogen, which...... of reactive nitrogen from the system. On top of that nitrous oxide is an important air pollutant and greenhouse gas, with a global warming potential per unit mass 300 times higher than carbon dioxide. DNRA, on the other hand, converts nitrate to ammonium, which is more easily retained in soils than nitrate...... a fascinating scientific activity, it may very well be central to gaining insights to influence fundamental soil processes such as nitrogen metabolism, promising advancement of agricultural and pollution prevention and remediation techniques.A number of conceptual and quantitative frameworks have been developed...

  3. Heterogeneity of peripheral blood monocytes, endothelial dysfunction and subclinical atherosclerosis in patients with systemic lupus erythematosus.

    Science.gov (United States)

    Mikołajczyk, T P; Osmenda, G; Batko, B; Wilk, G; Krezelok, M; Skiba, D; Sliwa, T; Pryjma, J R; Guzik, T J

    2016-01-01

    Systemic lupus erythematosus (SLE) is characterized by increased cardiovascular morbidity and mortality. SLE patients have increased prevalence of subclinical atherosclerosis, although the mechanisms of this observation remain unclear. Considering the emerging role of monocytes in atherosclerosis, we aimed to investigate the relationship between subclinical atherosclerosis, endothelial dysfunction and the phenotype of peripheral blood monocytes in SLE patients. We characterized the phenotype of monocyte subsets defined by the expression of CD14 and CD16 in 42 patients with SLE and 42 non-SLE controls. Using ultrasonography, intima-media thickness (IMT) of carotid arteries and brachial artery flow-mediated dilation (FMD) as well as nitroglycerin-induced dilation (NMD) were assessed. Patients with SLE had significantly, but only modestly, increased IMT when compared with non-SLE controls (median (25th/75th percentile) 0.65 (0.60/0.71) mm vs 0.60 (0.56/0.68) mm; p subclinical atherosclerosis in SLE, although the mechanism appears to be independent of endothelial dysfunction. © The Author(s) 2015.

  4. Stability of positive stationary solutions to a spatially heterogeneous cooperative system with cross-diffusion

    Directory of Open Access Journals (Sweden)

    Wan-Tong Li

    2012-12-01

    Full Text Available In the previous article [Y.-X. Wang and W.-T. Li, J. Differential Equations, 251 (2011 1670-1695], the authors have shown that the set of positive stationary solutions of a cross-diffusive Lotka-Volterra cooperative system can form an unbounded fish-hook shaped branch $Gamma_p$. In the present paper, we will show some criteria for the stability of positive stationary solutions on $Gamma_p$. Our results assert that if $d_1/d_2$ is small enough, then unstable positive stationary solutions bifurcate from semitrivial solutions, the stability changes only at every turning point of $Gamma_p$ and no Hopf bifurcation occurs. While as $d_1/d_2$ becomes large, the stability has a drastic change when $mu<0$ in the supercritical case. Original stable positive stationary solutions at certain point may lose their stability, and Hopf bifurcation can occur. These results are very different from those of the spatially homogeneous case.

  5. Tropical anvil characteristics and water vapor of the tropical tropopause layer: Impact of heterogeneous and homogeneous freezing parameterizations

    OpenAIRE

    Fan, Jiwen; Comstock, Jennifer M.; Ovchinnikov, Mikhail; McFarlane, Sally A.; McFarquhar, Greg; Allen, Grant

    2010-01-01

    Two isolated deep convective clouds (DCCs) that developed in clean-humid and polluted-dry air masses, observed during the Tropical Pacific Warm Pool International Cloud Experiment (TWP-ICE) and U.K. Aerosol and Chemical Transport in Tropical Convection (ACTIVE) campaigns, respectively, are simulated using a three-dimensional cloud-resolving model with size-resolved aerosol and cloud microphysics. We examine the impacts of different homogeneous and immersion freezing parameterizations on the a...

  6. CURRENT VIEWS ON THE HETEROGENEITY OF RENAL INVOLVEMENTS IN PATIENTS WITH SYSTEMIC SCLEROSIS

    Directory of Open Access Journals (Sweden)

    A. V. Gordeev

    2015-01-01

    Full Text Available Systemic sclerosis (SS, is an autoimmune connective tissue disease, the main clinical signs of which are due to disseminated microcirculatory disorders and fibrosis of the skin and viscera. Morphological examinations showed that 80% of patients with SS had renal changes, including those unassociated with rheumatic diseases. Whereas the prevalence of scleroderma renal crisis is now estimated to be 2–5%, there is considerably often an asymptomatic reduction in renal function (silent uremia, which is caused by multimorbidity and comorbidity. Its incidence in patients with SS may be as high as 55%. The presence of autoimmune connective tissue disease may be itself regarded as a risk factor of renal involvement. Fifteen-year survival is 72% in SS patients with no renal involvement and not more than 13% in those having renal involvement. In patients with SS, proteinuria is one of the most important independent risk factors for fatal outcomes (relative risk, 3.34, leaving far behind canonical risk factors, such as pulmonary hypertension, restrictive lung disease (a forced expiratory volume in one second to forced vital capacity ratio of <80%, respiratory failure (NYHA Class III and IV, as well as decreased lung diffuse capacity and high skin scores. The authors first propose a concept of the existence and pathogenesis of chronic scleroderma nephropathy, the basis for which is the vascular endothelial dysfunction phenomenon developing in different structural components of the nephron and kidney as a whole.

  7. Minimizing the Impacts of the Forest Road System

    Science.gov (United States)

    Johnny M. Grace

    2003-01-01

    Sediment movement from forest road systems is a major concern in forest management due to the degrading impacts of stream sedimentation. Controlling sediment movement from road systems is a key objective to achieve the goat of reducing the impact of forest management activities. Sediment control systems minimizing sediment travel distances downslope are likely...

  8. Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes

    OpenAIRE

    Hui Yang; Ming Tang; Thilo Gross

    2015-01-01

    One of the famous results of network science states that networks with heterogeneous connectivity are more susceptible to epidemic spreading than their more homogeneous counterparts. In particular, in networks of identical nodes it has been shown that network heterogeneity, i.e. a broad degree distribution, can lower the epidemic threshold at which epidemics can invade the system. Network heterogeneity can thus allow diseases with lower transmission probabilities to persist and spread. Howeve...

  9. Understanding Enterprise Systems' Impact(s) on Business Relationships

    Science.gov (United States)

    Ekman, Peter; Thilenius, Peter

    Enterprise systems (ESs), i.e. standardized applications supplied from software vendors such as SAP or Oracle, have been extensively employed by companies during the last decade. Today all Fortune 500 companies have, or are in the process of installing, this kind of information system (Seddon et al. 2003). A wide-spread denotation for these applications is enterprise resource planning (ERP) systems. But the broad utilization use of these software packages in business is rendering this labelling too narrow (Davenport 2000).

  10. Impacts of Vegetation and Precipitation on Throughfall Heterogeneity in a Tropical Pre-Montane Transitional Cloud Forest

    Science.gov (United States)

    Teale, N. G.; Mahan, H.; Bleakney, S.; Berger, A.; Frauenfeld, O. W.; Rapp, A. D.; Quiring, S. M.; Roark, E.

    2013-12-01

    within a 2.2-hectare tropical forest watershed. Random sampling of all 129 gauges indicated that 126 gauges are required to produce a mean within 1% of the true mean TF at the 95% confidence interval. However, only 6 and 20 gauges are necessary to produce means within 10% and 5%, respectively. This study suggests that the spatial TF variability is highly heterogeneous, and the result of multiple compounding effects.

  11. Comparison of Two Impact Simulation Methods Used for Nonlinear Vibroimpact Systems with Rigid and Soft Impacts

    Directory of Open Access Journals (Sweden)

    V. A. Bazhenov

    2013-01-01

    shown that both methods are applied and give the coinciding results for system with elastic rigid impact under periodic external loading. Loading curves built by parameter continuation method are confirming this result. Impact simulation by the second method is also fulfilled for vibroimpact system with rigid impact under random external loading. For vibroimpact system with soft impact, the simulation of impact by the second method gives a better result. The application of linear elastic force as contact one is possible too but the use of Hertz's contact force is more preferable. The authors consider that the impact simulation by Hertz contact interaction force gives good results for nonlinear vibroimpact systems with impacts of any kind if all limitations with Hertz's law used are observed.

  12. Adaptive discrete cosine transform-based image compression method on a heterogeneous system platform using Open Computing Language

    Science.gov (United States)

    Alqudami, Nasser; Kim, Shin-Dug

    2014-11-01

    Discrete cosine transform (DCT) is one of the major operations in image compression standards and it requires intensive and complex computations. Recent computer systems and handheld devices are equipped with high computing capability devices such as a general-purpose graphics processing unit (GPGPU) in addition to the traditional multicores CPU. We develop an optimized parallel implementation of the forward DCT algorithm for the JPEG image compression using the recently proposed Open Computing Language (OpenCL). This OpenCL parallel implementation combines a multicore CPU and a GPGPU in a single solution to perform DCT computations in an efficient manner by applying certain optimization techniques to enhance the kernel execution time and data movements. A separate optimal OpenCL kernel code was developed (CPU-based and GPU-based kernels) based on certain appropriate device-based optimization factors, such as thread-mapping, thread granularity, vector-based memory access, and the given workload. The performance of DCT is evaluated on a heterogeneous environment and our OpenCL parallel implementation results in speeding up the execution of the DCT by the factors of 3.68 and 5.58 for different image sizes and formats in terms of workload allocations and data transfer mechanisms. The obtained speedup indicates the scalability of the DCT performance.

  13. Aggregation effects on tritium-based mean transit times and young water fractions in spatially heterogeneous catchments and groundwater systems

    Directory of Open Access Journals (Sweden)

    M. K. Stewart

    2017-09-01

    Full Text Available Kirchner (2016a demonstrated that aggregation errors due to spatial heterogeneity, represented by two homogeneous subcatchments, could cause severe underestimation of the mean transit times (MTTs of water travelling through catchments when simple lumped parameter models were applied to interpret seasonal tracer cycle data. Here we examine the effects of such errors on the MTTs and young water fractions estimated using tritium concentrations in two-part hydrological systems. We find that MTTs derived from tritium concentrations in streamflow are just as susceptible to aggregation bias as those from seasonal tracer cycles. Likewise, groundwater wells or springs fed by two or more water sources with different MTTs will also have aggregation bias. However, the transit times over which the biases are manifested are different because the two methods are applicable over different time ranges, up to 5 years for seasonal tracer cycles and up to 200 years for tritium concentrations. Our virtual experiments with two water components show that the aggregation errors are larger when the MTT differences between the components are larger and the amounts of the components are each close to 50 % of the mixture. We also find that young water fractions derived from tritium (based on a young water threshold of 18 years are almost immune to aggregation errors as were those derived from seasonal tracer cycles with a threshold of about 2 months.

  14. Aggregation effects on tritium-based mean transit times and young water fractions in spatially heterogeneous catchments and groundwater systems

    Science.gov (United States)

    Stewart, Michael K.; Morgenstern, Uwe; Gusyev, Maksym A.; Małoszewski, Piotr

    2017-09-01

    Kirchner (2016a) demonstrated that aggregation errors due to spatial heterogeneity, represented by two homogeneous subcatchments, could cause severe underestimation of the mean transit times (MTTs) of water travelling through catchments when simple lumped parameter models were applied to interpret seasonal tracer cycle data. Here we examine the effects of such errors on the MTTs and young water fractions estimated using tritium concentrations in two-part hydrological systems. We find that MTTs derived from tritium concentrations in streamflow are just as susceptible to aggregation bias as those from seasonal tracer cycles. Likewise, groundwater wells or springs fed by two or more water sources with different MTTs will also have aggregation bias. However, the transit times over which the biases are manifested are different because the two methods are applicable over different time ranges, up to 5 years for seasonal tracer cycles and up to 200 years for tritium concentrations. Our virtual experiments with two water components show that the aggregation errors are larger when the MTT differences between the components are larger and the amounts of the components are each close to 50 % of the mixture. We also find that young water fractions derived from tritium (based on a young water threshold of 18 years) are almost immune to aggregation errors as were those derived from seasonal tracer cycles with a threshold of about 2 months.

  15. Modeling Kinetics of CO2 (Carbon Dioxide Mineral Sequestration in Heterogeneous Aqueous Suspensions Systems of Cement Dust

    Directory of Open Access Journals (Sweden)

    Henryk Świnder

    2013-01-01

    Full Text Available The necessity to reduce CO2 emission in the environment has encouraged people to search for solutions for its safe capture and storage. Known methods for carbon dioxide mineral sequestration are based primarily on the use of its binding reaction with metal oxides, mainly earth metals. Increasingly important, due to the availability and price, are processes based on the suspension of various wastes such as fly ash, cement dust or furnace slag. Due to the complexity of the mineral sequestration of CO2 in water-waste suspensions, an important issue is to determine the reaction mechanisms. This applies mainly to the initial period of the transformation phase of mineral wastes, and consequently with the occurrence of a number of transition states of ionic equilibria. The mechanisms and reaction rates in the various stages of the process of CO2 mineral sequestration in heterogeneous systems containing selected wastes are defined herein. This paper presents a method of modeling kinetics of this type of process, developed on the basis of the results of the absorption of CO2 thanks to the aqueous suspension of fly ash and cement dust. This allowed for the transfer of obtained experimental results into the mathematical formula, using the invariant function method, used to describe the processes.

  16. Subsurface high resolution definition of subsurface heterogeneity for understanding the biodynamics of natural field systems: Advancing the ability for scaling to field conditions. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Majer, E.L. [Lawrence Berkeley National Lab., CA (US); Brockman, F.J. [Pacific Northwest National Lab., Richland, WA (US)

    1998-06-01

    'This research is an integrated physical (geophysical and hydrologic) and microbial study using innovative geophysical imaging and microbial characterization methods to identify key scales of physical heterogeneities that affect the biodynamics of natural subsurface environments. Data from controlled laboratory and in-situ experiments at the INEEL Test Area North (TAN) site are being used to determine the dominant physical characteristics (lithologic, structural, and hydrologic) that can be imaged in-situ and correlated with microbial properties. The overall goal of this research is to contribute to the understanding of the interrelationships between transport properties and spatially varying physical, chemical, and microbiological heterogeneity. The outcome will be an improved understanding of the relationship between physical and microbial heterogeneity, thus facilitating the design of bioremediation strategies in similar environments. This report summarizes work as of May 1998, the second year of the project. This work is an extension of basic research on natural heterogeneity first initiated within the DOE/OHER Subsurface Science Program (SSP) and is intended to be one of the building blocks of an integrated and collaborative approach with an INEEL/PNNL effort aimed at understanding the effect of physical heterogeneity on transport properties and biodynamics in natural systems. The work is closely integrated with other EMSP projects at INEEL (Rick Colwell et al.) and PNNL (Fred Brockman and Jim Fredrickson).'

  17. WRF-Chem model predictions of the regional impacts of N2O5 heterogeneous processes on night-time chemistry over north-western Europe

    Science.gov (United States)

    Lowe, D.; Archer-Nicholls, S.; Morgan, W.; Allan, J.; Utembe, S.; Ouyang, B.; Aruffo, E.; Le Breton, M.; Zaveri, R. A.; Di Carlo, P.; Percival, C.; Coe, H.; Jones, R.; McFiggans, G.

    2015-02-01

    comparable for dimethylsulfide (DMS). However the suppression of NO3 mixing ratios across the domain by N2O5 heterogeneous chemistry has only a very slight, negative, influence on this oxidative capacity. The influence on regional particulate nitrate mass loadings is stronger. Night-time N2O5 heterogeneous chemistry maintains the production of particulate nitrate within polluted regions: when this process is taken into consideration, the daytime peak (for the 95th percentile) of PM10 nitrate mass loadings remains around 5.6 μg kg-1air, but the night-time minimum increases from 3.5 to 4.6 μg kg-1air. The sustaining of higher particulate mass loadings through the night by this process improves model skill at matching measured aerosol nitrate diurnal cycles and will negatively impact on regional air quality, requiring this process to be included in regional models.

  18. WRF-Chem model predictions of the regional impacts of N2O5 heterogeneous processes on night-time chemistry over north-western Europe

    Directory of Open Access Journals (Sweden)

    D. Lowe

    2015-02-01

    for alkenes (× 80 and comparable for dimethylsulfide (DMS. However the suppression of NO3 mixing ratios across the domain by N2O5 heterogeneous chemistry has only a very slight, negative, influence on this oxidative capacity. The influence on regional particulate nitrate mass loadings is stronger. Night-time N2O5 heterogeneous chemistry maintains the production of particulate nitrate within polluted regions: when this process is taken into consideration, the daytime peak (for the 95th percentile of PM10 nitrate mass loadings remains around 5.6 μg kg−1air, but the night-time minimum increases from 3.5 to 4.6 μg kg−1air. The sustaining of higher particulate mass loadings through the night by this process improves model skill at matching measured aerosol nitrate diurnal cycles and will negatively impact on regional air quality, requiring this process to be included in regional models.

  19. Numerical validation of a Eulerian hydrochemical code using a 1D multisolute mass transport system involving heterogeneous kinetically controlled reactions

    Science.gov (United States)

    Gérard, F.; Clément, A.; Fritz, B.

    1998-04-01

    the convergence and to extend the numerical test to mixed advective-dispersive mass transport. However, the skewness factor involves numerical oscillations that prevent to compute different grid spacing. The use of a different chemically controlled time step constraint in both calculations induces some inconsistencies into the validation tests. This numerical validation method may be applied as well as to check a thermo-kinetic hydrochemical finite element based code, from a 1D heterogeneous systems, and 2D-3D systems provided that they are designed so as to be 1D equivalent. A one-step algorithm and the use of a numerical reference coming from the Eulerian code to be tested ensure the potential success (accuracy) of the numerical validation method.

  20. The impact of patient heterogeneity and socioeconomic factors on abatacept retention in rheumatoid arthritis across nine European countries

    DEFF Research Database (Denmark)

    Finckh, A; Neto, D; Iannone, F

    2015-01-01

    ) retention in patients with rheumatoid arthritis (RA) treated in clinical practice. METHODS: Data from nine European observational RA cohorts of patients treated with ABA were pooled. Kaplan-Meier analysis was used to compare drug retention across registries. Specific causes of drug retention were......BACKGROUND: There are substantial differences in accessibility to biological disease modifying antirheumatic drugs (bDMARDs) across countries. The objective of this study was to analyse the impact of patient demographics, disease characteristics and gross domestic product (GDP) on abatacept (ABA...... investigated using competing risks multivariate Cox regression. RESULTS: A total of 3961 patients treated with ABA, with 6188 patient-years of follow-up, were included. Patients in the different national registries had similar demographic features, but varied in baseline disease characteristics. ABA drug...

  1. Heterogeneous chromium catalysts

    NARCIS (Netherlands)

    2005-01-01

    The present invention relates to a heterogeneous chromium catalyst system for the polymerisation of ethylene and/or alpha olefins prepared by the steps of: (a) providing a silica-containing support, (b) treating the silica-containing support with a chromium compound to form a chromium-based

  2. Enabling technologies for millimeter-wave radio-over-fiber systems in next generation heterogeneous mobile access networks

    Science.gov (United States)

    Zhang, Junwen; Yu, Jianjun; Wang, Jing; Xu, Mu; Cheng, Lin; Lu, Feng; Shen, Shuyi; Yan, Yan; Cho, Hyunwoo; Guidotti, Daniel; Chang, Gee-kung

    2017-01-01

    Fifth-generation (5G) wireless access network promises to support higher access data rate with more than 1,000 times capacity with respect to current long-term evolution (LTE) systems. New radio-access-technologies (RATs) based on higher carrier frequencies to millimeter-wave (MMW) radio-over-fiber, and carrier-aggregation (CA) using multi-band resources are intensively studied to support the high data rate access and effectively use of frequency resources in heterogeneous mobile network (Het-Net). In this paper, we investigate several enabling technologies for MMW RoF systems in 5G Het-Net. Efficient mobile fronthaul (MFH) solutions for 5G centralized radio access network (C-RAN) and beyond are proposed, analyzed and experimentally demonstrated based on the analog scheme. Digital predistortion based on memory polynomial for analog MFH linearization are presented with improved EVM performances and receiver sensitivity. We also propose and experimentally demonstrate a novel inter-/intra- RAT CA scheme for 5G Het- Net. The real-time standard 4G-LTE signal is carrier-aggregated with three broadband 60GHz MMW signals based on proposed optical-domain band-mapping method. RATs based on new waveforms have also been studied here to achieve higher spectral-efficiency (SE) in asynchronous environments. Full-duplex asynchronous quasi-gapless carrier aggregation scheme for MMW ROF inter-/intra-RAT based on the FBMC is also presented with 4G-LTE signals. Compared with OFDM-based signals with large guard-bands, FBMC achieves higher spectral-efficiency with better EVM performance at less received power and smaller guard-bands.

  3. Are bad health and pain making us grumpy? An empirical evaluation of reporting heterogeneity in rating health system responsiveness.

    Science.gov (United States)

    Fiorentini, Gianluca; Ragazzi, Giovanni; Robone, Silvana

    2015-11-01

    In recent years, the concept of responsiveness has been put forward as one desirable measure of the performance of health systems. Responsiveness can be defined as a system's ability to respond to the legitimate expectations of potential users regarding non-health enhancing aspects of care. However, since responsiveness is evaluated by patients on a categorical scale, their self-evaluation can be affected by the phenomenon of reporting heterogeneity. A few studies have investigated how standard socio-demographic characteristics influence the reporting style of patients with regard to responsiveness. However, we are not aware of studies that focus explicitly on the influence that both the patients' state of health and their experiencing of pain have on their reporting style on responsiveness. This paper tries to bridge this gap by using data regarding a sample of about 2500 patients hospitalized in four Local Health Authorities (LHA) in Italy's Emilia-Romagna region between 2010 and 2012. These patients have evaluated 27 different aspects of the quality of care, concerning five domains of responsiveness (communication, privacy, dignity, waiting times and quality of facilities). Data have been stratified into five sub-samples, according to these domains. We estimate a generalized ordered probit model, an extension of the standard ordered probit model which permits the reporting behaviour of respondents to be modelled as a function of certain respondents' characteristics, which in our analysis are represented by the variables "state of health" and "pain". Our results suggest that unhealthier patients and patients experiencing pain are more likely to report a lower level of responsiveness, all other things being equal. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Environmental impact directory system: preliminary implementation for geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Hess, F.D.; Hall, R.T.; Fullenwider, E.D.

    1976-07-01

    An Environmental Impact Directory System (EIDS) was proposed as a method for a computerized search of the widely distributed data files and models pertaining to energy-related environmental effects. To define the scope and content of the system, an example was prepared for the case of geothermal energy. The resulting sub-directory is known as GEIDs (Geothermal Environmental Impact Directory System). In preparing or reviewing an Environmental Impact Statement (EIS), the user may employ GEIDS as an extensive checklist to make sure he has taken into account all predictable impacts at any level of severity.

  5. Evaluating architecture impact on system energy efficiency

    National Research Council Canada - National Science Library

    Shijie Yu; Hailong Yang; Rui Wang; Zhongzhi Luan; Depei Qian

    2017-01-01

    As the energy consumption has been surging in an unsustainable way, it is important to understand the impact of existing architecture designs from energy efficiency perspective, which is especially...

  6. Differential item functioning due to cognitive status does not impact depressive symptom measures in four heterogeneous samples of older adults.

    Science.gov (United States)

    Fieo, Robert; Mukherjee, Shubhabrata; Dmitrieva, Natalia O; Fyffe, Denise C; Gross, Alden L; Sanders, Elizabeth R; Romero, Heather R; Potter, Guy G; Manly, Jennifer J; Mungas, Dan M; Gibbons, Laura E

    2015-09-01

    The objective of this study is to determine whether differential item functioning (DIF) due to cognitive status impacted three depressive symptoms measures commonly used with older adults. Differential item functioning in depressive symptoms was assessed among participants (N = 3558) taking part in four longitudinal studies of cognitive aging, using the Geriatric Depression Scale, the Montgomery-Åsberg Depression Rating Scale, and the Center for Epidemiologic Studies Depression Scale. Participants were grouped by cognitive status using a general cognitive performance score derived from each study's neuropsychological battery and linked to a national average using a population-based survey representative of the US population. The Clinical Dementia Rating score was used as an alternate grouping variable in three of the studies. Although statistically significant DIF based on cognitive status was found for some depressive symptom items (e.g., items related to memory complaints, appetite loss, lack of energy, and mood), the effect of item bias on the total score for each scale was negligible. The depressive symptoms scales in these four studies measured depression in the same way, regardless of cognitive status. This may reduce concerns about using these depression measures in cognitive aging research, as relationships between depression and cognitive decline are unlikely to have been due to item bias, at least in the ways that were measured in the datasets we considered. Copyright © 2014 John Wiley & Sons, Ltd.

  7. Leader-following exponential consensus of fractional order nonlinear multi-agents system with hybrid time-varying delay: A heterogeneous impulsive method

    Science.gov (United States)

    Wang, Fei; Yang, Yongqing

    2017-09-01

    In this paper, we study the leader-following exponential consensus of multi-agent system. Each agent in the system is described by nonlinear fractional order differential equation. Both the internal delay and coupling delay are taken into consideration. The heterogeneous impulsive control is used for ensuring the consensus of all agents. Based on Lyapunov function method and matrix analysis, some sufficient conditions for exponential consensus are obtained. Finally, some illustrative examples are given to show the effectiveness of the obtained results.

  8. Yucatan Subsurface Stratigraphy from Geophysical Data, Well Logs and Core Analyses in the Chicxulub Impact Crater and Implications for Target Heterogeneities

    Science.gov (United States)

    Canales, I.; Fucugauchi, J. U.; Perez-Cruz, L. L.; Camargo, A. Z.; Perez-Cruz, G.

    2011-12-01

    Asymmetries in the geophysical signature of Chicxulub crater are being evaluated to investigate on effects of impact angle and trajectory and pre-existing target structural controls for final crater form. Early studies interpreted asymmetries in the gravity anomaly in the offshore sector to propose oblique either northwest- and northeast-directed trajectories. An oblique impact was correlated to the global ejecta distribution and enhanced environmental disturbance. In contrast, recent studies using marine seismic data and computer modeling have shown that crater asymmetries correlate with pre-existing undulations of the Cretaceous continental shelf, suggesting a structural control of target heterogeneities. Documentation of Yucatan subsurface stratigraphy has been limited by lack of outcrops of pre-Paleogene rocks. The extensive cover of platform carbonate rocks has not been affected by faulting or deformation and with no rivers cutting the carbonates, information comes mainly from the drilling programs and geophysical surveys. Here we revisit the subsurface stratigraphy in the crater area from the well log data and cores retrieved in the drilling projects and marine seismic reflection profiles. Other source of information being exploited comes from the impact breccias, which contain a sampling of disrupted target sequences, including crystalline basement and Mesozoic sediments. We analyze gravity and seismic data from the various exploration surveys, including multiple Pemex profiles in the platform and the Chicxulub experiments. Analyses of well log data and seismic profiles identify contacts for Lower Cretaceous, Cretaceous/Jurassic and K/Pg boundaries. Results show that the Cretaceous continental shelf was shallower on the south and southwest than on the east, with emerged areas in Quintana Roo and Belize. Mesozoic and upper Paleozoic sediments show variable thickness, possibly reflecting the crystalline basement regional structure. Paleozoic and Precambrian

  9. The Brazilian Seed Law and its impacts on agrobiodiversity and on local and traditional agricultural systems

    Directory of Open Access Journals (Sweden)

    Juliana Santilli

    2012-08-01

    Full Text Available The article makes a critical analysis of the impacts of the Brazilian Seed Law (10.711/2003 on agricultural biodiversity and on traditional and local agriculture. The above-mentioned law caters to the needs and interests of 'formal' seed systems, and does not consider the important role played by local and traditional seed systems (frequently called 'informal', in which the production, exchange, breeding and conservation of seeds are carried out by the farmers themselves, through their social networks and according to local rules. 'Formal' seed systems tend to focus mainly on crops of commercial value, and widely used in homogeneous environments. Therefore, they are not interested in producing seeds that are adapted to specific local conditions and uses, nor in attending the needs of local and traditional farmers, which have limited resources and live in regions that are culturally and environmentally heterogeneous.

  10. SU-E-T-626: Accuracy of Dose Calculation Algorithms in MultiPlan Treatment Planning System in Presence of Heterogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Moignier, C; Huet, C [Radioprotection and Nuclear Safety Institute IRSN, Fontenay-aux-Roses (France); Barraux, V; Loiseau, C; Sebe-Mercier, K; Batalla, A [Francois Baclesse Center, Caen (France); Makovicka, L [IRMA/CE UMR 6249 CNRS, Franche-Comte University, Montbeliard (France)

    2014-06-15

    Purpose: Advanced stereotactic radiotherapy (SRT) treatments require accurate dose calculation for treatment planning especially for treatment sites involving heterogeneous patient anatomy. The purpose of this study was to evaluate the accuracy of dose calculation algorithms, Raytracing and Monte Carlo (MC), implemented in the MultiPlan treatment planning system (TPS) in presence of heterogeneities. Methods: First, the LINAC of a CyberKnife radiotherapy facility was modeled with the PENELOPE MC code. A protocol for the measurement of dose distributions with EBT3 films was established and validated thanks to comparison between experimental dose distributions and calculated dose distributions obtained with MultiPlan Raytracing and MC algorithms as well as with the PENELOPE MC model for treatments planned with the homogenous Easycube phantom. Finally, bones and lungs inserts were used to set up a heterogeneous Easycube phantom. Treatment plans with the 10, 7.5 or the 5 mm field sizes were generated in Multiplan TPS with different tumor localizations (in the lung and at the lung/bone/soft tissue interface). Experimental dose distributions were compared to the PENELOPE MC and Multiplan calculations using the gamma index method. Results: Regarding the experiment in the homogenous phantom, 100% of the points passed for the 3%/3mm tolerance criteria. These criteria include the global error of the method (CT-scan resolution, EBT3 dosimetry, LINAC positionning …), and were used afterwards to estimate the accuracy of the MultiPlan algorithms in heterogeneous media. Comparison of the dose distributions obtained in the heterogeneous phantom is in progress. Conclusion: This work has led to the development of numerical and experimental dosimetric tools for small beam dosimetry. Raytracing and MC algorithms implemented in MultiPlan TPS were evaluated in heterogeneous media.

  11. Query Expansion Using Heterogeneous Thesauri.

    Science.gov (United States)

    Mandala, Rila; Tokunaga, Takenobu; Tanaka, Hozumi

    2000-01-01

    Proposes a method to improve the performance of information retrieval systems by expanding queries using heterogeneous thesauri. Experiments show that using heterogeneous thesauri with an appropriate weighting method results in better retrieval performance than using only one type of thesaurus. (Author/LRW)

  12. The oleic acid-ozone heterogeneous reaction system: products, kinetics, secondary chemistry, and atmospheric implications of a model system – a review

    Directory of Open Access Journals (Sweden)

    J. Zahardis

    2007-01-01

    Full Text Available The heterogeneous processing of organic aerosols by trace oxidants has many implications to atmospheric chemistry and climate regulation. This review covers a model heterogeneous reaction system (HRS: the oleic acid-ozone HRS and other reaction systems featuring fatty acids, and their derivatives. The analysis of the commonly observed aldehyde and organic acid products of ozonolysis (azelaic acid, nonanoic acid, 9-oxononanoic acid, nonanal is described. The relative product yields are noted and explained by the observation of secondary chemical reactions. The secondary reaction products arising from reactive Criegee intermediates are mainly peroxidic, notably secondary ozonides and α-acyloxyalkyl hydroperoxide oligomers and polymers, and their formation is in accord with solution and liquid-phase ozonolysis. These highly oxygenated products are of low volatility and hydrophilic which may enhance the ability of particles to act as cloud condensation nuclei (CCN. The kinetic description of this HRS is critically reviewed. Most kinetic studies suggest this oxidative processing is either a near surface reaction that is limited by the diffusion of ozone or a surface based reaction. Internally mixed particles and coatings represent the next stage in the progression towards more realistic proxies of tropospheric organic aerosols and a description of the products and the kinetics resulting from the ozonolysis of these proxies, which are based on fatty acids or their derivatives, is presented. Finally, the main atmospheric implications of oxidative processing of particulate containing fatty acids are presented. These implications include the extended lifetime of unsaturated species in the troposphere facilitated by the presence of solids, semi-solids or viscous phases, and an enhanced rate of ozone uptake by particulate unsaturates compared to corresponding gas-phase organics. Ozonolysis of oleic acid enhances its CCN activity, which implies that

  13. The effect of heterogeneity on invasion in spatial epidemics: from theory to experimental evidence in a model system.

    Directory of Open Access Journals (Sweden)

    Franco M Neri

    2011-09-01

    Full Text Available Heterogeneity in host populations is an important factor affecting the ability of a pathogen to invade, yet the quantitative investigation of its effects on epidemic spread is still an open problem. In this paper, we test recent theoretical results, which extend the established "percolation paradigm" to the spread of a pathogen in discrete heterogeneous host populations. In particular, we test the hypothesis that the probability of epidemic invasion decreases when host heterogeneity is increased. We use replicated experimental microcosms, in which the ubiquitous pathogenic fungus Rhizoctonia solani grows through a population of discrete nutrient sites on a lattice, with nutrient sites representing hosts. The degree of host heterogeneity within different populations is adjusted by changing the proportion and the nutrient concentration of nutrient sites. The experimental data are analysed via Bayesian inference methods, estimating pathogen transmission parameters for each individual population. We find a significant, negative correlation between heterogeneity and the probability of pathogen invasion, thereby validating the theory. The value of the correlation is also in remarkably good agreement with the theoretical predictions. We briefly discuss how our results can be exploited in the design and implementation of disease control strategies.

  14. The cardiac sodium channel displays differential distribution in the conduction system and transmural heterogeneity in the murine ventricular myocardium.

    Science.gov (United States)

    Remme, C A; Verkerk, A O; Hoogaars, W M H; Aanhaanen, W T J; Scicluna, B P; Annink, C; van den Hoff, M J B; Wilde, A A M; van Veen, T A B; Veldkamp, M W; de Bakker, J M T; Christoffels, V M; Bezzina, C R

    2009-09-01

    Cardiac sodium channels are responsible for conduction in the normal and diseased heart. We aimed to investigate regional and transmural distribution of sodium channel expression and function in the myocardium. Sodium channel Scn5a mRNA and Na(v)1.5 protein distribution was investigated in adult and embryonic mouse heart through immunohistochemistry and in situ hybridization. Functional sodium channel availability in subepicardial and subendocardial myocytes was assessed using patch-clamp technique. Adult and embryonic (ED14.5) mouse heart sections showed low expression of Na(v)1.5 in the HCN4-positive sinoatrial and atrioventricular nodes. In contrast, high expression levels of Na(v)1.5 were observed in the HCN4-positive and Cx43-negative AV or His bundle, bundle branches and Purkinje fibers. In both ventricles, a transmural gradient was observed, with a low Na(v)1.5 labeling intensity in the subepicardium as compared to the subendocardium. Similar Scn5a mRNA expression patterns were observed on in situ hybridization of embryonic and adult tissue. Maximal action potential upstroke velocity was significantly lower in subepicardial myocytes (mean +/- SEM 309 +/- 32 V/s; n = 14) compared to subendocardial myocytes (394 +/- 32 V/s; n = 11; P channel availability in subepicardium compared to subendocardium. Scn5a and Na(v)1.5 show heterogeneous distribution patterns within the cardiac conduction system and across the ventricular wall. This differential distribution of the cardiac sodium channel may have profound consequences for conduction disease phenotypes and arrhythmogenesis in the setting of sodium channel disease.

  15. ANTI-HETEROGENEOUS NUCLEAR RIBONUCLEOPROTEIN B1 (ANTI-RA33 ANTIBODIES IN RHEUMATOID ARTHRITIS AND SYSTEMIC SCLEROSIS

    Directory of Open Access Journals (Sweden)

    P. A. Kuznetsova

    2017-01-01

    Full Text Available Anti-heterogeneous nuclear ribonucleoprotein (RNP autoantibodies (AAbs are encountered in many autoimmune rheumatic diseases (ARDs. The potential diagnostic value of the RA33 AAb complex consisting of RNP A2 and alternative domains of the splicing proteins RNP B1 and RNP B2 is now of interest to rheumatologists. Subjects and methods. The authors studied the frequency of anti-RNP B1 AAbs in 300 patients with systemic ARDs, including those with rheumatoid arthritis (RA, ankylosing spondylitis (AS, systemic lupus erythematosus (SLE, systemic sclerosis (SSc, and Sjö gren's syndrome (SS and in 53 people without ARDs, who constituted a control group. Serum anti-RNP B1 AAbs were assessed by enzyme immunoassay. Results and discussion. The frequency of anti-RNP B1 AAbs in patients with ARDs was much higher than that in the control group: 170/300 (56.6% and 8/53 (13% patients, respectively. Anti-RNP B1 AAbs were detected in 78.5% (113/144 of the patients with RA; 40.3% (23/57 of those with AS, in 67.5% (27/40 of those with SSc, in 36.4% (16/44 of those with SLE, and in 13.3% (2/15 of those with SS. The diagnostic sensitivity of the marker for RA was 78.5%, its diagnostic specificity was 84.9%; the likelihood ratio of positive and negative results was 5.24 and 0.24, respectively. In the patients with RA, the level of anti-RNP B1 AAbs significantly correlated with that of C-reactive protein and erythrocyte sedimentation rate, while in those with SSc the detection of anti-RNP B1 AAbs was related to the rigidity of the vascular wall and the presence of hypertension. The frequency of anti-RNP B1 AAbs among the RA patients seronegative for rheumatoid factor and anti-cyclic citrullinated peptide antibodies was 15.4%. Conclusion. Anti-RNP B1 AAs are a useful laboratory marker (with the upper limit of the normal range being 3.3 U/ml, but are of limited value in the diagnosis of RA. Anti-RNP B1 AAbs may be regarded as an additional diagnostic marker for RA.

  16. Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes.

    Science.gov (United States)

    Yang, Hui; Tang, Ming; Gross, Thilo

    2015-08-21

    One of the famous results of network science states that networks with heterogeneous connectivity are more susceptible to epidemic spreading than their more homogeneous counterparts. In particular, in networks of identical nodes it has been shown that network heterogeneity, i.e. a broad degree distribution, can lower the epidemic threshold at which epidemics can invade the system. Network heterogeneity can thus allow diseases with lower transmission probabilities to persist and spread. However, it has been pointed out that networks in which the properties of nodes are intrinsically heterogeneous can be very resilient to disease spreading. Heterogeneity in structure can enhance or diminish the resilience of networks with heterogeneous nodes, depending on the correlations between the topological and intrinsic properties. Here, we consider a plausible scenario where people have intrinsic differences in susceptibility and adapt their social network structure to the presence of the disease. We show that the resilience of networks with heterogeneous connectivity can surpass those of networks with homogeneous connectivity. For epidemiology, this implies that network heterogeneity should not be studied in isolation, it is instead the heterogeneity of infection risk that determines the likelihood of outbreaks.

  17. Cell Culture System for Analysis of Genetic Heterogeneity Within Hepatocellular Carcinomas and Response to Pharmacologic Agents.

    Science.gov (United States)

    Gao, Qiang; Wang, Zhi-Chao; Duan, Meng; Lin, Yi-Hui; Zhou, Xue-Ya; Worthley, Daniel L; Wang, Xiao-Ying; Niu, Gang; Xia, Yuchao; Deng, Minghua; Liu, Long-Zi; Shi, Jie-Yi; Yang, Liu-Xiao; Zhang, Shu; Ding, Zhen-Bin; Zhou, Jian; Liang, Chun-Min; Cao, Ya; Xiong, Lei; Xi, Ruibin; Shi, Yong-Yong; Fan, Jia

    2017-01-01

    No targeted therapies have been found to be effective against hepatocellular carcinoma (HCC), possibly due to the large degree of intratumor heterogeneity. We performed genetic analyses of different regions of HCCs to evaluate levels of intratumor heterogeneity and associate alterations with responses to different pharmacologic agents. We obtained samples of HCCs (associated with hepatitis B virus infection) from 10 patients undergoing curative resection, before adjuvant therapy, at hospitals in China. We collected 4-9 spatially distinct samples from each tumor (55 regions total), performed histologic analyses, isolated cancer cells, and carried them low-passage culture. We performed whole-exome sequencing, copy-number analysis, and high-throughput screening of the cultured primary cancer cells. We tested responses of an additional 105 liver cancer cell lines to a fibroblast growth factor receptor (FGFR) 4 inhibitor. We identified a total of 3670 non-silent mutations (3192 missense, 94 splice-site variants, and 222 insertions or deletions) in the tumor samples. We observed considerable intratumor heterogeneity and branched evolution in all 10 tumors; the mean percentage of heterogeneous mutations in each tumor was 39.7% (range, 12.9%-68.5%). We found significant mutation shifts toward C>T and C>G substitutions in branches of phylogenetic trees among samples from each tumor (P heterogeneity. Our patient-derived cell line-based model, integrating genetic and pharmacologic data from multiregional cancer samples, provides a platform to elucidate how intratumor heterogeneity affects sensitivity to different therapeutic agents. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  18. Impact of bathymetric system advances on hydrography

    Digital Repository Service at National Institute of Oceanography (India)

    Ranade, G.

    reference systems, water column physical characteristics measuring devices and lastly the non acoustic depth determining systems like LIDAR (LIght Detection And Ranging). 89 All the depth-determining systems are coupled with the navigation and inertial... for incorporating refraction related range calculations. 11. Tremendous growth in the computing power has enabled handling of voluminous data generated by the state of art systems needed for a bathymetric survey. As a comparison we can say that in a water depth...

  19. Impacts of heterogeneous uptake of dinitrogen pentoxide and chlorine activation on ozone and reactive nitrogen partitioning: improvement and application of the WRF-Chem model in southern China

    Directory of Open Access Journals (Sweden)

    Q. Li

    2016-12-01

    Full Text Available The uptake of dinitrogen pentoxide (N2O5 on aerosol surfaces and the subsequent production of nitryl chloride (ClNO2 can have a significant impact on the oxidising capability and thus on secondary pollutants such as ozone. The range of such an impact, however, has not been well quantified in different geographical regions. In this study, we applied the Weather Research and Forecasting coupled with Chemistry (WRF-Chem model to investigate the impact of the N2O5 uptake processes in the Hong Kong–Pearl River Delta (HK–PRD region, where the highest ever reported N2O5 and ClNO2 concentrations were observed in our recent field study. We first incorporated into the WRF-Chem an aerosol thermodynamics model (ISORROPIA II, recent parameterisations for N2O5 heterogeneous uptake and ClNO2 production and gas-phase chlorine chemistry. The revised model was then used to simulate the spatiotemporal distribution of N2O5 and ClNO2 over the HK–PRD region and the impact of N2O5 uptake and Cl activation on ozone and reactive nitrogen in the planetary boundary layer (PBL. The updated model can generally capture the temporal variation of N2O5 and ClNO2 observed at a mountaintop site in Hong Kong, but it overestimates N2O5 uptake and ClNO2 production. The model results suggest that under average conditions, elevated levels of ClNO2 (> 0.25 ppb within the PBL are present in the south-western PRD, with the highest values (> 1.00 ppb predicted near the ground surface (0–200 m above ground level; a.g.l.. In contrast, during the night when very high levels of ClNO2 and N2O5 were measured in well-processed plumes from the PRD, ClNO2 is mostly concentrated within the residual layer ( ∼  300 m a.g.l.. The addition of N2O5 heterogeneous uptake and Cl activation reduces the NO and NO2 levels by as much as 1.93 ppb ( ∼  7.4 % and 4.73 ppb ( ∼  16.2 %, respectively, and it increases the total nitrate and ozone concentrations by

  20. Is the even distribution of insecticide-treated cattle essential for tsetse control? Modelling the impact of baits in heterogeneous environments.

    Directory of Open Access Journals (Sweden)

    Steve J Torr

    2011-10-01

    Full Text Available BACKGROUND: Eliminating Rhodesian sleeping sickness, the zoonotic form of Human African Trypanosomiasis, can be achieved only through interventions against the vectors, species of tsetse (Glossina. The use of insecticide-treated cattle is the most cost-effective method of controlling tsetse but its impact might be compromised by the patchy distribution of livestock. A deterministic simulation model was used to analyse the effects of spatial heterogeneities in habitat and baits (insecticide-treated cattle and targets on the distribution and abundance of tsetse. METHODOLOGY/PRINCIPAL FINDINGS: The simulated area comprised an operational block extending 32 km from an area of good habitat from which tsetse might invade. Within the operational block, habitat comprised good areas mixed with poor ones where survival probabilities and population densities were lower. In good habitat, the natural daily mortalities of adults averaged 6.14% for males and 3.07% for females; the population grew 8.4× in a year following a 90% reduction in densities of adults and pupae, but expired when the population density of males was reduced to 3 km wide are cattle-free then insecticide-treated targets should be deployed to compensate for the lack of cattle.

  1. Spatial Heterogeneity in Shallow Streambed Water Temperatures, Copper River Delta, Alaska: Implications for Understanding Landscape-Scale Climate Change Impacts to Pacific Salmon Egg Incubation Rates

    Science.gov (United States)

    Adelfio, L. A.; Wondzell, S. M.; Reeves, G. H.; Mantua, N. J.

    2015-12-01

    Shallow streambed water temperature is a driving factor for Pacific salmon egg incubation. Small (1 to 2 oC) increases in incubation period water temperature may accelerate embryo development. We collected year-round water temperature data at 14 salmon spawning areas on the Copper River Delta (CRD), a 100 km wide coastal foreland in Southcentral Alaska. Our data show considerable temporal and spatial heterogeneity in shallow streambed water temperatures. Different water sources (precipitation vs. groundwater) and a spectrum of hydraulic conductivity and pressure head conditions were also observed. Landscape-scale patterns were not adequately characterized by typical watershed metrics including elevation, area, and slope. We found that catchment- and reach- scale geomorphology and surficial geology govern the surface-groundwater interactions that determine shallow streambed water temperature. The observed differences indicate that, across the CRD landscape, shallow streambed water temperature will not respond equally to projected climatic changes. Water temperature sensitivity to atmospheric conditions also varied by season, suggesting that year-round water temperature data are valuable for assessing potential climate change impacts to Pacific salmon in catchments where incubation period air temperatures are projected to exceed the freezing point with increasing frequency.

  2. When good statistical models of aquifer heterogeneity go right: The impact of aquifer permeability structures on 3D flow and transport

    Science.gov (United States)

    Jankovic, I.; Maghrebi, M.; Fiori, A.; Dagan, G.

    2017-02-01

    Natural gradient steady flow of mean velocity U takes place in heterogeneous aquifers of random logconductivity Y = lnK , characterized by the univariate PDF f(Y) and autocorrelation ρY. Solute transport is analyzed through the Breakthrough Curve (BTC) at planes at distance x from the injection plane. The study examines the impact of permeability structures sharing same f(Y) and ρY, but differing in higher order statistics (integral scales of variograms of Y classes) upon the numerical solution of flow and transport. Flow and transport are solved for 3D structures, rather than the 2D models adopted in most of previous works. We considered a few permeability structures, including the widely employed multi-Gaussian, the connected and disconnected fields introduced by Zinn and Harvey [2003] and a model characterized by equipartition of the correlation scale among Y values. We also consider the impact of statistical anisotropy of Y, the shape of ρY and local diffusion. The main finding is that unlike 2D, the prediction of the BTC of ergodic plumes by numerical and analytical models for different structures is quite robust, displaying a seemingly universal behavior, and can be used with confidence in applications. However, as a prerequisite the basic parameters KG (the geometric mean), σY2 (the logconductivity variance) and I (the horizontal integral scale of ρY) have to be identified from field data. The results suggest that narrowing down the gap between the BTCs in applications can be achieved by obtaining Kef (the effective conductivity) or U independently (e.g. by pumping tests), rather than attempting to characterize the permeability structure beyond f(Y) and ρY.

  3. Industrial Membrane Filtration and Short-bed Fractal Separation Systems for Separating Monomers from Heterogeneous Plant Material

    Energy Technology Data Exchange (ETDEWEB)

    Kearney, M; Kochergin, V; Hess, R; Foust, T; Herbst, R; Mann, N

    2005-03-31

    Large-scale displacement of petroleum will come from low-cost cellulosic feedstocks such as straw and corn stover crop residues. This project has taken a step toward making this projection a reality by reducing capital and energy costs, the two largest cost factors associated with converting cellulosic biomass to chemicals and fuels. The technology exists for using acid or enzyme hydrolysis processes to convert biomass feedstock (i.e., waste cellulose such as straw, corn stover, and wood) into their base monomeric sugar building blocks, which can, in turn, be processed into chemicals and fuels using a number of innovative fermentation technologies. However, while these processes are technically possible, practical and economic barriers make these processes only marginally feasible or not feasible at all. These barriers are due in part to the complexity and large fixed and recurring capital costs of unit operations including filtration, chromatographic separation, and ion exchange. This project was designed to help remove these barriers by developing and implementing new purification and separation technologies that will reduce the capital costs of the purification and chromatographic separation units by 50% to 70%. The technologies fundamental to these improvements are: (a) highly efficient clarification and purification systems that use screening and membrane filtration to eliminate suspended solids and colloidal material from feed streams and (b) fractal technology based chromatographic separation and ion exchange systems that can substitute for conventional systems but at much smaller size and cost. A non-hazardous ''raw sugar beet juice'' stream (75 to 100 gal/min) was used for prototype testing of these technologies. This raw beet juice stream from the Amalgamated Sugar LLC plant in Twin Falls, Idaho contained abrasive materials and membrane foulants. Its characteristics were representative of an industrial-scale heterogeneous plant extract

  4. Field heterogeneity: some basic issues

    Energy Technology Data Exchange (ETDEWEB)

    Philip, J.R.

    1980-04-01

    Present-day soil-water physics enables useful quantitative predictions in the laboratory and in simple field situations. However, difficulties frequently arise for areas of appreciable size in the field. Two types of heterogeneity are distinguished: deterministic and stochastic. The first often demands an extension of established analyses and may involve important phenomena absent from the analogous homogeneous problem. Stochastic heterogeneity may involve many scales and is imperfectly known. The statistical properties may be stationary, but in more complicated cases, randomness may be embedded in (either known or unknown) systematic trends. Some aspects of unsaturated and generally unsteady flow in heterogeneous systems are reviewed: the mathematical nature of the flow equation; the concept of scale-heterogeneity; analytical and quasianalytical solutions. The enormity of the total problem of unsaturated unsteady flow in stochastic heterogeneous systems is illustrated through a dialectic of 8 successive stages of simplification. 37 references.

  5. Subsurface high-resolution definition of subsurface heterogeneity for understanding the biodynamics of natural field systems: Advancing the ability for scaling to field conditions. 1997 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Majer, E.L.

    1997-01-01

    'This research is an integrated physical (geophysical and hydrologic) and microbial study using innovative geophysical imaging and microbial characterization methods to identify key scales of physical heterogeneities that affect the biodynamics of natural subsurface environments. Data from controlled laboratory and in situ experiments at the INEEL Test Area North (TAN) site are being used to determine the dominant physical characteristics (lithologic, structural, and hydrologic) that can be imaged in situ and correlated with microbial properties. Emphasis is being placed on identifying fundamental scales of variation of physical parameters that control transport behavior relative to predicting subsurface microbial dynamics. The outcome will be an improved understanding of the relationship between physical and microbial heterogeneity, thus facilitating the design of bioremediation strategies in similar environments. This work is an extension of basic research on natural heterogeneity first initiated within the DOE/OHER Subsurface Science Program (SSP) and is intended to be one of the building blocks of an integrated and collaborative approach with an INEEL/PNNL effort aimed at understanding the effect of physical heterogeneity on transport properties and biodynamics in natural systems. The work is closely integrated with other EMSP projects at INEEL (Rick Colwell et al.) and PNNL (Fred Brockman and Jim Fredrickson).'

  6. Soil, Water, and Greenhouse-gas Impacts of Alternative Biomass Cropping Systems

    Science.gov (United States)

    Schulte Moore, L. A.; Bach, E.; Cambardella, C.; Hargreaves, S.; Helmers, M.; Hofmockel, K.; Isenhart, T.; Kolka, R. K.; Ontl, T.; Welsh, W.; Williams, R.; Landscape Biomass Team

    2010-12-01

    Through the 2008 Energy Independence and Security Act and other state and federal mandates, the U.S. is embarking on an aggressive agenda to reduce dependency on fossil fuels. While grain-derived ethanol will be used to largely meet initial renewable fuels targets, advanced biofuels derived from lignocellulosic materials are expected to comprise a growing proportion of the renewable energy portfolio and provide a more sustainable solution. As part of our interdisciplinary research, we are assessing the environmental impacts of four lignocellulosic biomass cropping systems and comparing them to a conventional corn cropping system. This comparison is conducted using a randomized, replicated experiment initiated in fall 2008, which compares the five cropping systems across a toposequence (i.e., floodplain, toeslope, backslope, shoulder, summit). In addition to assessing herbaceous and woody biomass yields, we are evaluating the environmental performance of these systems through changes in water quality, greenhouse-gas emissions, and carbon pools. Initial results document baseline soil parameters, including the capacity of the soils to sequester carbon across the toposequence, and the impacts of landscape heterogeneity and cropping system on soil moisture and nitrate-nitrogen levels in the vadose zone. Additional results on greenhouse-gas emissions and carbon dynamics are forthcoming from this year’s field research. The fuller understanding of the environmental performance of these systems will help inform federal and state policies seeking to incentivize the development of a sustainable bioenergy industry.

  7. Spatially heterogeneous environmental selection strengthens evolution of reproductively isolated populations in a Dobzhansky-Muller system of hybrid incompatability.

    Directory of Open Access Journals (Sweden)

    Samuel A Cushman

    2016-11-01

    Full Text Available Within-species hybrid incompatibility can arise when combinations of alleles at more than one locus have low fitness but where possession of one of those alleles has little or no fitness consequence for the carriers. Limited dispersal with small numbers of mate potentials alone can lead to the evolution of clusters of reproductively isolated genotypes despite the absence of any geographical barriers or heterogeneous selection. In this paper, we explore how adding heterogeneous natural selection on the genotypes (e.g., gene environment associations that are involved in reproductive incompatibility affects the frequency, size and duration of evolution of reproductively isolated clusters. We conducted a simulation experiment that varied landscape heterogeneity, dispersal ability and strength of selection in a continuously distributed population. In our simulations involving spatially heterogeneous selection, strong patterns of adjacency of mutually incompatible genotypes emerged such that these clusters were truly reproductively isolated from each other, with no reproductively compatible bridge individuals in the intervening landscape to allow gene flow between the clusters. This pattern was strong across levels of gene flow and strength of selection, suggesting that even relatively weak selection acting in the context of strong gene flow may produce reproductively isolated clusters that are large and persistent, enabling incipient speciation in a continuous population without geographic isolation.

  8. A rule driven bi-directional translation system for remapping queries and result sets between a mediated schema and heterogeneous data sources.

    OpenAIRE

    Shaker, R.; Mork, P.; Barclay, M; Tarczy-Hornoch, P.

    2002-01-01

    As the number of online biomedical data sources increases, so too do the number of ways to access such data. The research described herein focuses on creating a data access system that provides bi-directional translation and mapping of data between heterogeneous databases and a mediated schema. Semantic mapping rules stored in a knowledge base are used by our generalized software to convert XML query results obtained from each data source to a common schema representing a single ontology. We ...

  9. Quantifying Third-Party Impacts and Environmental Externalities from a Cap-And-Trade System for Groundwater Management

    Science.gov (United States)

    Khan, H. F.; Yang, Y. C. E.; Brown, C.

    2016-12-01

    Economic decision models, such as the cap-and-trade system, have been shown to be useful in the context of groundwater management. A uniformly applied cap-and-trade system can however result in significant spatially and temporally varying hydrogeologic impacts that reduce public welfare. Hydrological challenges associated with the cap-and-trade system for groundwater management include establishing appropriate system boundaries, setting system-wide sustainable yield and limiting third party impacts from extractions. Given these challenges, these economic models need to be supplemented with physically based hydrogeologic models that are able to represent the spatial and temporal heterogeneity in conditions across a region. This investigation assesses third-party impacts and environmental externalities resulting from a cap-and-trade system in a sub-basin of the Republican River Basin, overlying the Ogallala aquifer in the High Plains of the United States. The economic model is coupled with a calibrated physically based groundwater model. The cap-and-trade system is developed using a multi-agent system model where individual benefits of each self-interested agent are maximized subject to bounds on irrigation requirements and water use permits. We then compare the performance of the cap-and-trade system with a smart groundwater market which, in addition to a cap on total groundwater extraction, also incorporates streamflow constraints. The results quantify third-party impacts and environmental externalities resulting from uncontrolled trading. This analysis demonstrates the value added by a well-designed cap-and-trade system able to account for basin-wide heterogeneity in hydrogeologic and ecological conditions by establishing trading limits, managing inter-area transfers and setting exchange rates for permit trading.

  10. Impact of Thermodynamic Principles in Systems Biology

    NARCIS (Netherlands)

    Heijnen, J.J.

    2010-01-01

    It is shown that properties of biological systems which are relevant for systems biology motivated mathematical modelling are strongly shaped by general thermodynamic principles such as osmotic limit, Gibbs energy dissipation, near equilibria and thermodynamic driving force. Each of these aspects

  11. The Impact of Narcoterrorism on HRM Systems

    DEFF Research Database (Denmark)

    Ramirez, Jacobo; Madero, Sergio; Muñiz, Carlos

    2016-01-01

    This paper presents a study on the emergence of human resource management (HRM) systems in a narcoterrorism context based on a mixed-method approach. We conducted 40 interviews at 24 firms in Mexico to explore emerging HRM systems in narcoterrorism environments. The interviews were complemented...

  12. Environmental impact assessment system and process: A study on ...

    African Journals Online (AJOL)

    An efficient system of decision making for sustainable socioeconomic development, with an effective environmental management of the sources of environmental impact and effects of such impacts, need to be put in place in order to implement the government policy of environmental protection and safety at the regional ...

  13. The Impact of ERP Systems on Business Decision-Making

    OpenAIRE

    Dusanka Lecic; Aleksandar Kupusinac

    2013-01-01

    In this paper, the authors will introduce you to the ERP system and refer to its impact on decision-making within a company. The fact that they have on their decisions, automatically affect the company's business. The basis of business process automation is the use of a well-organized information system. Because of existence two markets in producing ERP systems, business management system creates a confusing picture when choosing the appropriate solutions for business information systems.

  14. Multi-Modal Intelligent Traffic Signal Systems (MMITSS) impacts assessment.

    Science.gov (United States)

    2015-08-01

    The study evaluates the potential network-wide impacts of the Multi-Modal Intelligent Transportation Signal System : (MMITSS) based on a field data analysis utilizing data collected from a MMITSS prototype and a simulation analysis. : The Intelligent...

  15. Adverse weather impacts on arable cropping systems

    Science.gov (United States)

    Gobin, Anne

    2016-04-01

    Damages due to extreme or adverse weather strongly depend on crop type, crop stage, soil conditions and management. The impact is largest during the sensitive periods of the farming calendar, and requires a modelling approach to capture the interactions between the crop, its environment and the occurrence of the meteorological event. The hypothesis is that extreme and adverse weather events can be quantified and subsequently incorporated in current crop models. Since crop development is driven by thermal time and photoperiod, a regional crop model was used to examine the likely frequency, magnitude and impacts of frost, drought, heat stress and waterlogging in relation to the cropping season and crop sensitive stages. Risk profiles and associated return levels were obtained by fitting generalized extreme value distributions to block maxima for air humidity, water balance and temperature variables. The risk profiles were subsequently confronted with yields and yield losses for the major arable crops in Belgium, notably winter wheat, winter barley, winter oilseed rape, sugar beet, potato and maize at the field (farm records) to regional scale (statistics). The average daily vapour pressure deficit (VPD) and reference evapotranspiration (ET0) during the growing season is significantly lower (p methodology of defining meteorological risks and subsequently relating the risk to the cropping calendar will be demonstrated for major arable crops in Belgium. Physically based crop models assist in understanding the links between adverse weather events, sensitive crop stages and crop damage. Financial support was obtained from Belspo under research contract SD/RI/03A.

  16. Geomorphic Response to Two Lowhead Dam Removals in a Mid-Sized Urban River System, Columbus, Ohio, USA: Export of Impounded Reservoir Sediments Results in Upstream Coarsening and Moderate Increases in Downstream Bathymetric Heterogeneity

    Science.gov (United States)

    Comes, E.; Jaeger, K. L.

    2016-12-01

    Lowhead dams have had a profound cumulative impact on rivers and streams. Their removal is an increasingly popular restoration method, however, geomorphic response remains poorly resolved. This study quantified geomorphic change following two lowhead dam removal in the Olentangy River and the downstream Scioto River, which flows through Columbus, Ohio. A paired control-treatment design compared change above and below a removed dam (treatment) to an existing dam (control) in each river system over a two and three-year period. Upstream treatment reaches included passive and active restoration via in-channel engineering. Channel change was quantified through repeat bathymetric surveys using an acoustic Doppler current profiles and near-surface riverbed substrate sampling at several time periods ( 2 surveys/year). Differencing of digital elevation models from each bathymetric survey quantified changes in erosion and deposition patterns and bathymetric heterogeneity. Results indicate upstream treatment reaches were net erosional with overall substrate coarsening that included D84 sand to gravel clast size shifts. The Olentangy River's downstream treatment reach experienced concurrent erosion and deposition within a given survey although net erosion dominated the first year of the three-year study period. The downstream treatment reach also experienced substantial grain size fluctuation between surveys with little overall change. Unanticipated engineering activities in the downstream treatment reach of the Scioto River confounded geomorphic change in this reach. Non-metric multidimensional scaling analysis indicates a moderate, but abrupt change towards overall increased heterogeneity in the first year following dam removal in the downstream reach with little overall change in the following two years. Active restoration activities in the upstream treatment reach resulted in abrupt, but slight shifts towards decreased bathymetric heterogeneity despite substantial riverbed

  17. Energy system impacts of desalination in Jordan

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg; Lund, Henrik; Mathiesen, Brian Vad

    2014-01-01

    Climate change mitigation calls for energy systems minimising end-use demands, optimising the fuel efficiency of conversion systems, increasing the use of renewable energy sources and exploiting synergies wherever possible. In parallel, global fresh water resources are strained due to amongst...... others population and wealth increase and competitive water uses from agriculture and industry is causing many nations to turn to desalination technologies. This article investigates a Jordanian energy scenario with two different desalination technologies; reverse osmosis (RO) driven by electricity...

  18. Mixed Responses to Systemic Therapy Revealed Potential Genetic Heterogeneity and Poor Survival in Patients with Non-Small Cell Lung Cancer.

    Science.gov (United States)

    Dong, Zhong-Yi; Zhai, Hao-Ran; Hou, Qing-Yi; Su, Jian; Liu, Si-Yang; Yan, Hong-Hong; Li, Yang-Si; Chen, Zhi-Yong; Zhong, Wen-Zhao; Wu, Yi-Long

    2017-01-01

    A subset of patients with non-small cell lung cancer (NSCLC) fosters mixed responses (MRs) to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) or chemotherapy. However, little is known about the clinical and molecular features or the prognostic significance and potential mechanisms. The records of 246 consecutive patients with NSCLC receiving single-line chemotherapy or TKI treatment and who were assessed by baseline and interim positron emission tomography/computed tomography scans were collected retrospectively. The clinicopathological correlations of the MR were analyzed, and a multivariate analysis was performed to explore the prognostic significance of MR. The overall incidence of MR to systemic therapy was 21.5% (53/246) and predominated in patients with stage IIIB-IV, EGFR mutations and those who received TKI therapy (p heterogeneity. MR was not a rare event in patients with NSCLC and tended to occur in those with advanced lung adenocarcinoma treated with a TKI. MR may result from genetic heterogeneity and is an unfavorable prognostic factor for survival. Further studies are imperative to explore subsequent treatment strategies. The Oncologist 2017;22:61-69Implications for Practice: Tumor heterogeneity tends to produce mixed responses (MR) to systemic therapy, including TKI and chemotherapy; however, the clinical significance and potential mechanisms are not fully understood, and the subsequent treatment after MR is also a clinical concern. The present study systemically assessed patients by PET/CT and differentiated MR and therapies. The study identified a relatively high incidence of MR in patients with advanced NSCLC, particularly those treated with targeted therapies. An MR may be an unfavorable prognostic factor and originate from genetic heterogeneity. Further studies are imperative to explore subsequent treatment strategies. © AlphaMed Press 2017.

  19. HETEROGENEOUS INTEGRATION TECHNOLOGY

    Science.gov (United States)

    2017-08-24

    the “product component” is a result of technology push only, it struggles to fit into a conservative system environment . If the “product component...makes the categorization difficult. In a technology push environment , the evolution of technology is easier to track since it starts evolving from a... environmental information. The role of the heterogeneous integration technology for reducing the size and the power consumption of small sensors was studied

  20. Heterogeneous chromium catalysts

    OpenAIRE

    2005-01-01

    The present invention relates to a heterogeneous chromium catalyst system for the polymerisation of ethylene and/or alpha olefins prepared by the steps of: (a) providing a silica-containing support, (b) treating the silica-containing support with a chromium compound to form a chromium-based silica-containing support, (c) activating the chromium-based silica-containing support, (d) chemically reducing the activated chromium-based silica-containing support to produce a precursor catalyst, (e) r...