WorldWideScience

Sample records for technology heterogeneity variable

  1. 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 ...

  2. Heterogeneous Systems for Information Variable Environments (HIVE)

    Science.gov (United States)

    2017-05-01

    Nothwang W, Marathe AR. Dynamic belief fusion. IEEE Transactions on Pattern Analysis and Machine Intelligence ; 2017 in preparation. 8. Lee H, Kwon...TERMS Director’s Strategic Initiative (DSI), human–autonomy integration, human variability, CV, navigation, distributed teaming, intelligent agent...was repeated 250 times per combination of HR and FAR. Analysis was done separately using each of the 4 analytical methods described previously

  3. Identification of homogeneous and heterogeneous variables in pooled cohort studies.

    Science.gov (United States)

    Cheng, Xin; Lu, Wenbin; Liu, Mengling

    2015-06-01

    Pooled analyses integrate data from multiple studies and achieve a larger sample size for enhanced statistical power. When heterogeneity exists in variables' effects on the outcome across studies, the simple pooling strategy fails to present a fair and complete picture of the effects of heterogeneous variables. Thus, it is important to investigate the homogeneous and heterogeneous structure of variables in pooled studies. In this article, we consider the pooled cohort studies with time-to-event outcomes and propose a penalized Cox partial likelihood approach with adaptively weighted composite penalties on variables' homogeneous and heterogeneous effects. We show that our method can characterize the variables as having heterogeneous, homogeneous, or null effects, and estimate non-zero effects. The results are readily extended to high-dimensional applications where the number of parameters is larger than the sample size. The proposed selection and estimation procedure can be implemented using the iterative shooting algorithm. We conduct extensive numerical studies to evaluate the performance of our proposed method and demonstrate it using a pooled analysis of gene expression in patients with ovarian cancer. © 2015, The International Biometric Society.

  4. Cognitive Heterogeneous Reconfigurable Optical Networks (CHRON): Enabling Technologies and Techniques

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Zibar, Darko; Guerrero Gonzalez, Neil;

    2011-01-01

    We present the approach of cognition applied to heterogeneous optical networks developed in the framework of the EU project CHRON: Cognitive Heterogeneous Reconfigurable Optical Network. We introduce and discuss in particular the technologies and techniques that will enable a cognitive optical ne...

  5. Variable Emissivity Through MEMS Technology

    Science.gov (United States)

    Darrin, Ann Garrison; Osiander, Robert; Champion, John; Swanson, Ted; Douglas, Donya; Grob, Lisa M.; Powers, Edward I. (Technical Monitor)

    2000-01-01

    This paper discusses a new technology for variable emissivity (vari-e) radiator surfaces, which has significant advantages over traditional radiators and promises an alternative design technique for future spacecraft thermal control systems. All spacecraft rely on radiative surfaces to dissipate waste heat. These radiators have special coatings, typically with a low solar absorptivity and a high infrared-red emissivity, that are intended to optimize performance under the expected heat load and thermal sink environment. The dynamics of the heat loads and thermal environment make it a challenge to properly size the radiator and often require some means of regulating the heat rejection rate of the radiators in order to achieve proper thermal balance. Specialized thermal control coatings, which can passively or actively adjust their emissivity offer an attractive solution to these design challenges. Such systems would allow intelligent control of the rate of heat loss from a radiator in response to heat load and thermal environmental variations. Intelligent thermal control through variable emissivity systems is well suited for nano and pico spacecraft applications where large thermal fluctuations are expected due to the small thermal mass and limited electric resources. Presently there are three different types of vari-e technologies under development: Micro ElectroMechanical Systems (MEMS) louvers, Electrochromic devices, and Electrophoretic devices. This paper will describe several prototypes of micromachined (MEMS) louvers and experimental results for the emissivity variations measured on theses prototypes. It will further discuss possible actuation mechanisms and space reliability aspects for different designs. Finally, for comparison parametric evaluations of the thermal performances of the new vari-e technology and standard thermal control systems are presented in this paper.

  6. Technologies for 3D Heterogeneous Integration

    CERN Document Server

    Wolf, Jürgen; Klumpp, Armin; Reichl, H

    2008-01-01

    3D-Integration is a promising technology towards higher interconnect densities and shorter wiring lengths between multiple chip stacks, thus achieving a very high performance level combined with low power consumption. This technology also offers the possibility to build up systems with high complexity just by combining devices of different technologies. For ultra thin silicon is the base of this integration technology, the fundamental processing steps will be described, as well as appropriate handling concepts. Three main concepts for 3D integration have been developed at IZM. The approach with the greatest flexibility called Inter Chip Via - Solid Liquid Interdiffusion (ICV-SLID) is introduced. This is a chip-to-wafer stacking technology which combines the advantages of the Inter Chip Via (ICV) process and the solid-liquid-interdiffusion technique (SLID) of copper and tin. The fully modular ICV-SLID concept allows the formation of multiple device stacks. A test chip was designed and the total process sequenc...

  7. Clinical variability and molecular heterogeneity in prostate cancer

    Directory of Open Access Journals (Sweden)

    Jonathan Shoag

    2016-01-01

    Full Text Available Prostate cancer is a clinically heterogeneous disease, with some men having indolent disease that can safely be observed, while others have aggressive, lethal disease. Over the past decade, researchers have begun to unravel some of the genomic heterogeneity that contributes to these varying clinical phenotypes. Distinct molecular sub-classes of prostate cancer have been identified, and the uniqueness of these sub-classes has been leveraged to predict clinical outcomes, design novel biomarkers for prostate cancer diagnosis, and develop novel therapeutics. Recent work has also elucidated the temporal and spatial heterogeneity of prostate cancer, helping us understand disease pathogenesis, response to therapy, and progression. New genomic techniques have provided us with a window into the remarkable clinical and genomic heterogeneity of prostate cancer, and this new perspective will increasingly impact patient care.

  8. Dynamic heterogeneity and life history variability in the kittiwake

    DEFF Research Database (Denmark)

    Steiner, Uli; Tuljapurkar, Shripad; Orzack, Steven Hecht

    2010-01-01

    differences. We quantify the diversity in life histories by metrics computed from the generating stochastic process. 4. We show how dynamic heterogeneity can be used as a null model and also how it can lead to positive associations between reproduction and survival across the life span. 5. We believe our......1. Understanding the evolution of life histories requires an assessment of the process that generates variation in life histories. Within-population heterogeneity of life histories can be dynamically generated by stochastic variation of reproduction and survival or be generated by individual...... differences that are fixed at birth. 2. We show for the kittiwake that dynamic heterogeneity is a sufficient explanation of observed variation of life histories. 3. The total heterogeneity in life histories has a small contribution from reproductive stage dynamics and a large contribution from survival...

  9. Integration Of Data From Heterogeneous Sources Using Etl Technology.

    Directory of Open Access Journals (Sweden)

    Marek Macura

    2014-01-01

    Full Text Available Data integration is a crucial issue in environments of heterogeneous data sources. At present mentioned heterogeneity is becoming widespread. Whenever, based on various data sources, we want to gain useful information and knowledge we must solve data integration problem in order to apply appropriate analytical methods on comprehensive and uniform data. Such activity is known as knowledge discovery from data process. Therefore approaches to data integration problem are very interesting and bring us closer to the "age of information". The paper presents an architecture, which implements knowledge discovery from data process. The solution combines ETL technology and wrapper layer known from mediated systems. It also provides semantic integration through connections mechanism between data elements. The solution allows for integration of any data sources and implementation of analytical methods in one environment. The proposed environment is verified by applying it to data sources on the foundry industry.

  10. Digital Microdroplet Ejection Technology-Based Heterogeneous Objects Prototyping

    Directory of Open Access Journals (Sweden)

    Na Li

    2016-01-01

    Full Text Available An integrate fabrication framework is presented to build heterogeneous objects (HEO using digital microdroplets injecting technology and rapid prototyping. The heterogeneous materials part design and manufacturing method in structure and material was used to change the traditional process. The net node method was used for digital modeling that can configure multimaterials in time. The relationship of material, color, and jetting nozzle was built. The main important contributions are to combine the structure, material, and visualization in one process and give the digital model for manufacture. From the given model, it is concluded that the method is effective for HEO. Using microdroplet rapid prototyping and the model given in the paper HEO could be gotten basically. The model could be used in 3D biomanufacturing.

  11. Hardness variability in commercial and hardened technologies

    Energy Technology Data Exchange (ETDEWEB)

    Shaneyfelt, M.R.; Winokur, P.S.; Meisenheimer, T.L.; Sexton, F.W.; Roeske, S.B.; Knoll, M.G.

    1994-03-01

    Over the past 10 years, there have been a number of advances in methods to assess and assure the radiation hardness of microelectronics in military and space applications. At the forefront of these is the Qualified Manufacturers List (QML) methodology, in which the hardness of product is ``built-in`` through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to varying radiation scenarios. At the same time, there has been renewed interest in the use of commercial technology -- with its enhanced performance, reduced cost, and higher reliability -- in military and space systems. In this paper, we initially demonstrate the application of QML techniques to assure and control the radiation response of hardened technologies. Through several examples, we demonstrate intra-die, wafer-to-wafer, and lot-to-lot variations in a hardened technology. We observe 10 to 30% variations in key technology parameters that result from variability in geometry, process, and design layout. Radiation-induced degradation is seen to mirror preirradiation characteristics. We then evaluate commercial technologies and report considerably higher variability in radiation hardness, i.e., variations by a factor of two to five. This variability is shown to arise from a lack of control of technology parameters relevant to the radiation response, which a commercial manufacturer has no interest in controlling in a normal process flow.

  12. Fluctuations in complex networks with variable dimensionality and heterogeneity

    Science.gov (United States)

    Yoo, H.-H.; Lee, D.-S.

    2016-03-01

    Synchronizing individual activities is essential for the stable functioning of diverse complex systems. Understanding the relation between dynamic fluctuations and the connection topology of substrates is therefore important, but it remains restricted to regular lattices. Here we investigate the fluctuation of loads, assigned to the locally least-loaded nodes, in the largest-connected components of heterogeneous networks while varying their link density and degree exponents. The load fluctuation becomes finite when the link density exceeds a finite threshold in weakly heterogeneous substrates, which coincides with the spectral dimension becoming larger than 2 as in the linear diffusion model. The fluctuation, however, diverges also in strongly heterogeneous networks with the spectral dimension larger than 2. This anomalous divergence is shown to be driven by large local fluctuations at hubs and their neighbors, scaling linearly with degree, which can give rise to diverging fluctuations at small-degree nodes. Our analysis framework can be useful for understanding and controlling fluctuations in real-world systems.

  13. Investigation of Cooperation Technologies in Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Zhuo Sun

    2010-01-01

    Full Text Available Heterogeneous wireless networks based on varieties of radio access technologies (RATs and standards will coexist in the future. In order to exploit this potential multiaccess gain, it is required that different RATs are managed in a cooperative fashion. This paper proposes two advanced functional architecture supporting the functionalities of interworking between WiMAX and 3GPP networks as a specific case: Radio Control Server- (RCS- and Access Point- (AP- based centralized architectures. The key technologies supporting the interworking are then investigated, including proposing the Generic Link Layer (GLL and researching the multiradio resource management (MRRM mechanisms. This paper elaborates on these topics, and the corresponding solutions are proposed with preliminary results.

  14. Technological heterogeneity, technical efficiency and subsidies in Czech agriculture

    Directory of Open Access Journals (Sweden)

    Kateřina MATULOVÁ

    2016-06-01

    Full Text Available This paper deals with an analysis of technological heterogeneity and technical efficiency in individual sectors of Czech agriculture after the EU enlargement in 2004. A parametric approach was used – Stochastic Frontier Analysis (SFA to address the research questions. Specifically, it is employed the Random Parameter Model specification, in which sector dummies are used to capture the intersectoral as well as intrasectoral differences in technology. The results show there is significant heterogeneity among the studied sectors (i.e., combined, plant, animal and other production. The analysis showed that Capital and Material are being substituted more and more for Labour in all sectors, especially in animal production. This result is to be expected, as the technology in this sector is labour-saving. However, it was found out that land elasticity is quite low in plant production and combined production; since Land is a production factor that significantly determines the level of final output, this result is quite strange. One possible explanation may be the policy of distributing subsidies among farmers, when the land is kept but used in a more extensive way. The intrasectoral differences in technology are statistically significant for all inputs. Average technical efficiency is highest in other production and lowest in animal production, while it is approximately at the same level in plant production and combined production. It was discovered that diversification (combined production of activities lowers the level of technical efficiency compared to specialisation (plant production, but on the other hand it does allow for alleviation of the negative impacts of specialization (animal production by optimizing the production program. Finally, the analysis did confirm a statistically significant positive relationship between SAPS subsidies and technical efficiency. Organic farming has a negative impact on technical efficiency and the influence of

  15. Foundational Forces & Hidden Variables in Technology Commercialization

    Science.gov (United States)

    Barnett, Brandon

    2011-03-01

    The science of physics seems vastly different from the process of technology commercialization. Physics strives to understand our world through the experimental deduction of immutable laws and dependent variables and the resulting macro-scale phenomenon. In comparison, the~goal of business is to make a profit by addressing the needs, preferences, and whims of individuals in a market. It may seem that this environment is too dynamic to identify all the hidden variables and deduct the foundational forces that impact a business's ability to commercialize innovative technologies. One example of a business ``force'' is found in the semiconductor industry. In 1965, Intel co-founder Gordon Moore predicted that the number of transistors incorporated in a chip will approximately double every 24 months. Known as Moore's Law, this prediction has become the guiding principle for the semiconductor industry for the last 40 years. Of course, Moore's Law is not really a law of nature; rather it is the result of efforts by Intel and the entire semiconductor industry. A closer examination suggests that there are foundational principles of business that underlie the macro-scale phenomenon of Moore's Law. Principles of profitability, incentive, and strategic alignment have resulted in a coordinated influx of resources that has driven technologies to market, increasing the profitability of the semiconductor industry and optimizing the fitness of its participants. New innovations in technology are subject to these same principles. So, in addition to traditional market forces, these often unrecognized forces and variables create challenges for new technology commercialization. In this talk, I will draw from ethnographic research, complex adaptive theory, and industry data to suggest a framework with which to think about new technology commercialization. Intel's bio-silicon initiative provides a case study.

  16. Idiopathic granulomatous mastitis: a heterogeneous disease with variable clinical presentation.

    Science.gov (United States)

    Baslaim, Muna M; Khayat, Hind A; Al-Amoudi, Shefaa A

    2007-08-01

    Idiopathic granulomatous mastitis (IGM) is a rare benign inflammatory breast disease that presents with variable local manifestations. We describe here the different management protocols based on the clinical presentation of these patients. A retrospective review of 20 histopathologic confirmed cases of IGM seen over a period of 10 years was performed. The median age was 34 years (age range: 21-45 years). All were married, parous with history of breast feeding. Ill-defined mass mimicking carcinoma was the commonest presentation (70%); however, with the presence of signs of inflammation like pain (55%), redness (40%), and peau d'orange (40%), an inflammatory process appeared more likely. Axillary lymph node enlargement was infrequently seen (40%). Radiologic findings (mammography and ultrasound) were nonspecific. Histopathology showed the characteristic lobular distribution of granulomatous inflammation in all cases. Surgically, 7 patients had abscess drainage with open biopsy, and 7 patients had lumpectomy. Six patients with diffuse breast involvement were diagnosed by core needle biopsy only. Microbial cultures showed no growth. Antibiotics were given empirically when signs of inflammation where present. Two patients needed further abscess drainage followed by persistent sinus excision 3-6 weeks later. The median follow-up was 24 months (range: 15-42 months). Seventeen patients (85%) were recurrence-free, and 3 patients (15%) were lost to follow-up. Management of IGM cases needs to be tailored according to the clinical presentation. Precise radiologic and pathologic data interpretation by a multidisciplinary breast team will facilitate diagnosis and minimize unnecessary intervention.

  17. Breeding site heterogeneity reduces variability in frog recruitment and population dynamics

    Science.gov (United States)

    McCaffery, Rebecca M.; Eby, Lisa A.; Maxell, Bryce A.; Corn, Paul Stephen

    2013-01-01

    Environmental stochasticity can have profound effects on the dynamics and viability of wild populations, and habitat heterogeneity provides one mechanism by which populations may be buffered against the negative effects of environmental fluctuations. Heterogeneity in breeding pond hydroperiod across the landscape may allow amphibian populations to persist despite variable interannual precipitation. We examined recruitment dynamics over 10 yr in a high-elevation Columbia spotted frog (Rana luteiventris) population that breeds in ponds with a variety of hydroperiods. We combined these data with matrix population models to quantify the consequences of heterogeneity in pond hydroperiod on net recruitment (i.e. number of metamorphs produced) and population growth rates. We compared our heterogeneous system to hypothetical homogeneous environments with only ephemeral ponds, only semi-permanent ponds, and only permanent ponds. We also examined the effects of breeding pond habitat loss on population growth rates. Most eggs were laid in permanent ponds each year, but survival to metamorphosis was highest in the semi-permanent ponds. Recruitment success varied by both year and pond type. Net recruitment and stochastic population growth rate were highest under a scenario with homogeneous semi-permanent ponds, but variability in recruitment was lowest in the scenario with the observed heterogeneity in hydroperiods. Loss of pond habitat decreased population growth rate, with greater decreases associated with loss of permanent and semi-permanent habitat. The presence of a diversity of pond hydroperiods on the landscape will influence population dynamics, including reducing variability in recruitment in an uncertain climatic future.

  18. Study on distributed generation algorithm of variable precision concept lattice based on ontology heterogeneous database

    Science.gov (United States)

    WANG, Qingrong; ZHU, Changfeng

    2017-06-01

    Integration of distributed heterogeneous data sources is the key issues under the big data applications. In this paper the strategy of variable precision is introduced to the concept lattice, and the one-to-one mapping mode of variable precision concept lattice and ontology concept lattice is constructed to produce the local ontology by constructing the variable precision concept lattice for each subsystem, and the distributed generation algorithm of variable precision concept lattice based on ontology heterogeneous database is proposed to draw support from the special relationship between concept lattice and ontology construction. Finally, based on the standard of main concept lattice of the existing heterogeneous database generated, a case study has been carried out in order to testify the feasibility and validity of this algorithm, and the differences between the main concept lattice and the standard concept lattice are compared. Analysis results show that this algorithm above-mentioned can automatically process the construction process of distributed concept lattice under the heterogeneous data sources.

  19. Adsorption of heterogeneously charged nanoparticles on a variably charged surface by the extended surface complexation approach: Charge regulation, chemical heterogeneity, and surface complexation

    NARCIS (Netherlands)

    Saito, T.; Koopal, L.K.; Nagasaki, S.; Tanaka, S.

    2008-01-01

    Adsorption of randomly branched polyelectrolytes, hairy particles and internally structured macromolecules, collectively denoted as heterogeneously charged nanoparticles, on charged surfaces is important in. many technological and natural processes. In this paper, we will focus on (1) the charge

  20. Adsorption of heterogeneously charged nanoparticles on a variably charged surface by the extended surface complexation approach: Charge regulation, chemical heterogeneity, and surface complexation

    NARCIS (Netherlands)

    Saito, T.; Koopal, L.K.; Nagasaki, S.; Tanaka, S.

    2008-01-01

    Adsorption of randomly branched polyelectrolytes, hairy particles and internally structured macromolecules, collectively denoted as heterogeneously charged nanoparticles, on charged surfaces is important in. many technological and natural processes. In this paper, we will focus on (1) the charge reg

  1. Enhanced recharge rates and altered recharge sensitivity to climate variability through subsurface heterogeneity

    Science.gov (United States)

    Hartmann, Andreas; Gleeson, Tom; Wada, Yoshihide; Wagener, Thorsten

    2017-04-01

    Karst aquifers in Europe are an important source of fresh water contributing up to half of the total drinking water supply in some countries. Karstic groundwater recharge is one of the most important components of the water balance of karst systems as it feeds the karst aquifers. Presently available large-scale hydrological models do not consider karst heterogeneity adequately. Projections of current and potential future groundwater recharge of Europe's karst aquifers are therefore unclear. In this study we compare simulations of present (1991-2010) and future (2080-2099) recharge using two different models to simulate groundwater recharge processes. One model includes karst processes (subsurface heterogeneity, lateral flow and concentrated recharge), while the other is based on the conceptual understanding of common hydrological systems (homogeneous subsurface, saturation excess overland flow). Both models are driven by the bias-corrected 5 GCMs of the ISI-MIP project (RCP8.5). To further assess sensitivity of groundwater recharge to climate variability, we calculate the elasticity of recharge rates to annual precipitation, temperature and average intensity of rainfall events, which is the median change of recharge that corresponds to the median change of these climate variables within the present and future time period, respectively. Our model comparison shows that karst regions over Europe have enhanced recharge rates with greater inter-annual variability compared to those with more homogenous subsurface properties. Furthermore, the heterogeneous representation shows stronger elasticity concerning climate variability than the homogeneous subsurface representation. This difference tends to increase towards the future. Our results suggest that water management in regions with heterogeneous subsurface can expect a higher water availability than estimated by most of the current large-scale simulations, while measures should be taken to prepare for increasingly

  2. Antibiotic susceptibility and heterogeneity in technological traits of lactobacilli isolated from Algerian goat's milk.

    Science.gov (United States)

    Bousmaha-Marroki, Leila; Marroki, Ahmed

    2015-08-01

    The objective of this study was to identify and study the heterogeneity of technological traits of lactobacilli from goat's milk of Algeria and to evaluate in vitro their safety aspect. Using API50 CHL system and 16S rDNA sequencing, 51 % of strains were assigned as Lactobacillus plantarum, 34 % as L. pentosus, 7 % as L. rhamnosus and 8 % as L. fermentum. A large variability was noted for the acidifying capacity in skim milk after 6, 12 and 24 h of incubation. All strains expressed aminopeptidase activity against alanine-ρ-NA and leucine-ρ-NA at different levels. All strains were resistant to vancomycin and most of strains showed more susceptibility to β-lactam antibiotic. High susceptibility toward the inhibitors of protein synthesis was also observed. Minimum inhibitory concentrations data obtained revealed that isolates were susceptible to penicillin and chloramphenicol, and resistant to gentamicin and vancomycin. Minimum inhibitory concentrations distribution of other antibiotics showed variability. The analysis of graphical representation of principal component analysis of technological properties of L. plantarum and L. pentosus strains showed diversity among the isolates. Finally, eight L. plantarum (LAM1, LAM3, LAM21, LAM25, LAM35, LF15, LAM34, and LAM35), four L. pentosus (LAM38, LAM39, LF9 and LF16) and two L. rhamnosus (LF3 and LF10) strains, could be good candidates as adjunct culture in dairy product in Algeria.

  3. Multi-Scale Material and Technology for Heterogeneous Integration

    NARCIS (Netherlands)

    Poelma, R.H.

    2016-01-01

    This thesis describes a series of experiments and fabrication methods on high-aspect-ratio 3D microstructures for wafer level packaging and 3D heterogeneous system integration (3D-HSI) using novel materials such as carbon nanotubes and thick-film photo-resists. Furthermore, theoretical and experimen

  4. Spatial and Temporal Variability of Soil Redistribution in a Heterogeneous Shrub Dominated Landscape

    Science.gov (United States)

    Van Pelt, R. S.; Zobeck, T. M.

    2015-12-01

    Redistribution of soil by wind results when the erosive force of the wind impacts bare, susceptible soil surfaces. In semi-arid and arid environments, many grasslands with protected surfaces are being replaced by heterogeneous shrub communities with bare, susceptible soil surfaces between the individual shrubs. The development of nutrient islands and the increases of fugitive dust in these areas is indicative of increases of soil redistribution, but few quantitative measurements have been made to date. We fenced three 1 ha areas in an approximately 100 ha coppice dune area of southeast New Mexico dominated by shinnery oak, sand sage, and mesquite and installed a 4 X 4 grid of MWAC sampler masts spaced at 20 m from each other. Weather data were collected at an automated weather station in each of the fenced areas. We found the patterns of soil redistribution to be highly variable in space and time. Differences in vegetation patterns and wind fields were noted among the plots for the same discrete time period that could explain some of the spatial variability. We also noted seasonality of wind fields that accounted for the temporally variable spatial patterns of soil redistribution. We conclude that accurate measurement of soil redistribution patterns in a heterogeneous shrub community requires a very large number of samplers and a long period of study and we believe that net soil loss from an area is limited to fine dust emissions.

  5. Heterogeneous Consumer Preferences for Nanotechnology and Genetic-Modification Technology in Food Products

    OpenAIRE

    2014-01-01

    This study investigates heterogeneous consumer preferences for nano-food and genetic-modified (GM) food and the associated benefits using the results of choice experiments with 1117 U.S. consumers. We employ a mixed logit model and a latent class logit model to capture the heterogeneity in consumer preferences by identifying consumer segments. Our results show that nano-food evokes less negative reactions compared with GM food. We identify four consumer groups: “Price Oriented/Technology Adop...

  6. Enabling Smart Workflows over Heterogeneous ID-SensingTechnologies

    Directory of Open Access Journals (Sweden)

    Guillermo Palacios

    2012-11-01

    Full Text Available Sensing technologies in mobile devices play a key role in reducing the gapbetween the physical and the digital world. The use of automatic identification capabilitiescan improve user participation in business processes where physical elements are involved(Smart Workflows. However, identifying all objects in the user surroundings does notautomatically translate into meaningful services to the user. This work introduces Parkour,an architecture that allows the development of services that match the goals of each ofthe participants in a smart workflow. Parkour is based on a pluggable architecture thatcan be extended to provide support for new tasks and technologies. In order to facilitatethe development of these plug-ins, tools that automate the development process are alsoprovided. Several Parkour-based systems have been developed in order to validate theapplicability of the proposal.

  7. High variability of the heterogeneous ice nucleation potential of oxalic acid dihydrate and sodium oxalate

    Directory of Open Access Journals (Sweden)

    R. Wagner

    2010-08-01

    Full Text Available The heterogeneous ice nucleation potential of airborne oxalic acid dihydrate and sodium oxalate particles in the deposition and condensation mode has been investigated by controlled expansion cooling cycles in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at temperatures between 244 and 228 K. Previous laboratory studies have highlighted the particular role of oxalic acid dihydrate as the only species amongst a variety of other investigated dicarboxylic acids to be capable of acting as a heterogeneous ice nucleus in both the deposition and immersion mode. We could confirm a high deposition mode ice activity for 0.03 to 0.8 μm sized oxalic acid dihydrate particles that were either formed by nucleation from a gaseous oxalic acid/air mixture or by rapid crystallisation of highly supersaturated aqueous oxalic acid solution droplets. The critical saturation ratio with respect to ice required for deposition nucleation was found to be less than 1.1 and the size-dependent ice-active fraction of the aerosol population was in the range from 0.1 to 22%. In contrast, oxalic acid dihydrate particles that had crystallised from less supersaturated solution droplets and had been allowed to slowly grow in a supersaturated environment from still unfrozen oxalic acid solution droplets over a time period of several hours were found to be much poorer heterogeneous ice nuclei. We speculate that under these conditions a crystal surface structure with less-active sites for the initiation of ice nucleation was generated. Such particles partially proved to be almost ice-inactive in both the deposition and condensation mode. At times, the heterogeneous ice nucleation ability of oxalic acid dihydrate significantly changed when the particles had been processed in preceding cloud droplet activation steps. Such behaviour was also observed for the second investigated species, namely sodium oxalate. Our experiments address the atmospheric scenario

  8. Genome Microscale Heterogeneity among Wild Potatoes Revealed by Diversity Arrays Technology Marker Sequences

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    Alessandra Traini

    2013-01-01

    Full Text Available Tuber-bearing potato species possess several genes that can be exploited to improve the genetic background of the cultivated potato Solanum tuberosum. Among them, S. bulbocastanum and S. commersonii are well known for their strong resistance to environmental stresses. However, scant information is available for these species in terms of genome organization, gene function, and regulatory networks. Consequently, genomic tools to assist breeding are meager, and efficient exploitation of these species has been limited so far. In this paper, we employed the reference genome sequences from cultivated potato and tomato and a collection of sequences of 1,423 potato Diversity Arrays Technology (DArT markers that show polymorphic representation across the genomes of S. bulbocastanum and/or S. commersonii genotypes. Our results highlighted microscale genome sequence heterogeneity that may play a significant role in functional and structural divergence between related species. Our analytical approach provides knowledge of genome structural and sequence variability that could not be detected by transcriptome and proteome approaches.

  9. Confidence Region Approach for Assessing Bioequivalence and Biosimilarity Accounting for Heterogeneity of Variability

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    Jianghao Li

    2015-01-01

    Full Text Available For approval of generic drugs, the FDA requires that evidence of bioequivalence in average bioequivalence in terms of drug absorption be provided through the conduct of a bioequivalence study. A test product is said to be average bioequivalent to a reference (innovative product if the 90% confidence interval of the ratio of means (after log-transformation is totally within (80%, 125%. This approach is considered a one-parameter approach, which does not account for possible heterogeneity of variability between drug products. In this paper, we study a two-parameter approach (i.e., confidence region approach for assessing bioequivalence, which can also be applied to assessing biosimilarity of biosimilar products. The proposed confidence region approach is compared with the traditional one-parameter approach both theoretically and numerically (i.e., simulation study for finite sample performance.

  10. Silicon-technology based microreactors for high-temperature heterogeneous partial oxidation reactions

    NARCIS (Netherlands)

    Tiggelaar, Roald Michel

    2004-01-01

    In this thesis the results of a study into the feasibility of silicon-technology based microreactors for fast oxidation reactions have been discussed. When designed properly, silicon microreactors are suitable for studying heterogeneous gas phase reactions, such as reaction kinetics of direct cataly

  11. Multiple Equilibria and Minimum Wages in Labor Markets with Informational Frictions and Heterogeneous Production Technologies

    NARCIS (Netherlands)

    G.J. van den Berg (Gerard)

    2003-01-01

    textabstractIt is often argued that a mandatory minimum wage is binding only if the wage density displays a spike at it. In this paper we analyze a model with wage setting, search frictions, and heterogeneous production technologies, in which imposition of a minimum wage affects wages even though,

  12. Variability of soil potential for biodegradation of petroleum hydrocarbons in a heterogeneous subsurface.

    Science.gov (United States)

    Kristensen, Andreas H; Poulsen, Tjalfe G; Mortensen, Lars; Moldrup, Per

    2010-07-15

    Quantifying the spatial variability of factors affecting natural attenuation of hydrocarbons in the unsaturated zone is important to (i) performing a reliable risk assessment and (ii) evaluating the possibility for bioremediation of petroleum-polluted sites. Most studies to date have focused on the shallow unsaturated zone. Based on a data set comprising analysis of about 100 soil samples taken in a 16 m-deep unsaturated zone polluted with volatile petroleum compounds, we statistically and geostatistically analysed values of essential soil properties. The subsurface of the site was highly layered, resulting in an accumulation of pollution within coarse sandy lenses. Air-filled porosity, readily available phosphorous, and the first-order rate constant (k(1)) of benzene obtained from slurry biodegradation experiments were found to depend on geologic sample characterization (P<0.05), while inorganic nitrogen was homogenously distributed across the soil stratigraphy. Semivariogram analysis showed a spatial continuity of 4-8.6 m in the vertical direction, while it was 2-5 times greater in the horizontal direction. Values of k(1) displayed strong spatial autocorrelation. Even so, the soil potential for biodegradation was highly variable, which from autoregressive state-space modeling was partly explained by changes in soil air-filled porosity and gravimetric water content. The results suggest considering biological heterogeneity when evaluating the fate of contaminants in the subsurface.

  13. 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 components ha

  14. Solute Spreading in Variably Saturated, Spatially Heterogeneous Formations: The Role of Water Saturation and Soil Texture

    Science.gov (United States)

    Russo, David

    2017-04-01

    Solute spreading provoked by the spatial heterogeneity in the soil hydraulic properties, and expressed in terms of the macrodispersion tensor, D, plays an important role in solute transport on the field scale. Under variably saturated flow conditions, quantification of D is rather complicated inasmuch as the relevant flow parameters, which depend on the formation properties, depend also on flow-controlled attributes in a highly nonlinear fashion, which, in turn, depends on the soil texture of the formation. The situation may be further complicated when the formation contains inclusions of different soil material and its hydraulic properties follow a bimodal distribution. The present talk focuses on the quantification of D in bimodal, heterogeneous, variably saturated formations, viewed as mixtures of two populations (background soil and embedded soil) of differing spatial structures. Two distinct cases are considered; in the first case, the texture of the embedded soil is finer than that of the background soil, while the second case conists of the reverse situation. First-order, Lagrangian stochastic analyses of vadose zone transport were used to invesigate the combined effect of the texture of the embedded soil and the mean pressure head on solute spreading in these formations. Results of the first-order analysis suggest that the embedded soil material may act as a capture zone for the solute particles, and, consequently, may enhance solute spreading in a manner which depends on both the texture of the embedded soil and the mean pressure head. In the first case, when the formation is relatively wet, the capture zone stems from the fine-textured embedded soil. In the second case, when the formation is relatively dry, the capture zone stems from coarse-textured embedded soil associated with very low unsaturated conductivity, which, in turn, may divert the flow into preferential flow paths around the coarse-texture, soil inclusions. Important finding of the first

  15. ECUT: Energy Conversion and Utilization Technologies program. Heterogeneous catalysis modeling program concept

    Science.gov (United States)

    Voecks, G. E.

    1983-01-01

    Insufficient theoretical definition of heterogeneous catalysts is the major difficulty confronting industrial suppliers who seek catalyst systems which are more active, selective, and stable than those currently available. In contrast, progress was made in tailoring homogeneous catalysts to specific reactions because more is known about the reaction intermediates promoted and/or stabilized by these catalysts during the course of reaction. However, modeling heterogeneous catalysts on a microscopic scale requires compiling and verifying complex information on reaction intermediates and pathways. This can be achieved by adapting homogeneous catalyzed reaction intermediate species, applying theoretical quantum chemistry and computer technology, and developing a better understanding of heterogeneous catalyst system environments. Research in microscopic reaction modeling is now at a stage where computer modeling, supported by physical experimental verification, could provide information about the dynamics of the reactions that will lead to designing supported catalysts with improved selectivity and stability.

  16. Ground and surface temperature variability for remote sensing of soil moisture in a heterogeneous landscape

    Science.gov (United States)

    Giraldo, M.A.; Bosch, D.; Madden, M.; Usery, L.; Finn, M.

    2009-01-01

    At the Little River Watershed (LRW) heterogeneous landscape near Tifton Georgia US an in situ network of stations operated by the US Department of Agriculture-Agriculture Research Service-Southeast Watershed Research Lab (USDA-ARS-SEWRL) was established in 2003 for the long term study of climatic and soil biophysical processes. To develop an accurate interpolation of the in situ readings that can be used to produce distributed representations of soil moisture (SM) and energy balances at the landscape scale for remote sensing studies, we studied (1) the temporal and spatial variations of ground temperature (GT) and infra red temperature (IRT) within 30 by 30 m plots around selected network stations; (2) the relationship between the readings from the eight 30 by 30 m plots and the point reading of the network stations for the variables SM, GT and IRT; and (3) the spatial and temporal variation of GT and IRT within agriculture landuses: grass, orchard, peanuts, cotton and bare soil in the surrounding landscape. The results showed high correlations between the station readings and the adjacent 30 by 30 m plot average value for SM; high seasonal independent variation in the GT and IRT behavior among the eight 30 by 30 m plots; and site specific, in-field homogeneity in each 30 by 30 m plot. We found statistical differences in the GT and IRT between the different landuses as well as high correlations between GT and IRT regardless of the landuse. Greater standard deviations for IRT than for GT (in the range of 2-4) were found within the 30 by 30 m, suggesting that when a single point reading for this variable is selected for the validation of either remote sensing data or water-energy models, errors may occur. The results confirmed that in this landscape homogeneous 30 by 30 m plots can be used as landscape spatial units for soil moisture and ground temperature studies. Under this landscape conditions small plots can account for local expressions of environmental

  17. An Application of Latent Variable Structural Equation Modeling For Experimental Research in Educational Technology

    National Research Council Canada - National Science Library

    Hyeon Woo LEE

    2011-01-01

      AN APPLICATION OF LATENT VARIABL AN APPLICATION OF LATENT VARIABLE STRUCTURAL EQUATION MODELING FOR EXPERIMENTAL RESEARCH IN EDUCATIONAL TECHNOLOGY As the technology-enriched learning environments...

  18. Spatially variable risk factors for malaria in a geographically heterogeneous landscape, western Kenya: an explorative study.

    Science.gov (United States)

    Homan, Tobias; Maire, Nicolas; Hiscox, Alexandra; Di Pasquale, Aurelio; Kiche, Ibrahim; Onoka, Kelvin; Mweresa, Collins; Mukabana, Wolfgang R; Ross, Amanda; Smith, Thomas A; Takken, Willem

    2016-01-04

    Large reductions in malaria transmission and mortality have been achieved over the last decade, and this has mainly been attributed to the scale-up of long-lasting insecticidal bed nets and indoor residual spraying with insecticides. Despite these gains considerable residual, spatially heterogeneous, transmission remains. To reduce transmission in these foci, researchers need to consider the local demographical, environmental and social context, and design an appropriate set of interventions. Exploring spatially variable risk factors for malaria can give insight into which human and environmental characteristics play important roles in sustaining malaria transmission. On Rusinga Island, western Kenya, malaria infection was tested by rapid diagnostic tests during two cross-sectional surveys conducted 3 months apart in 3632 individuals from 790 households. For all households demographic data were collected by means of questionnaires. Environmental variables were derived using Quickbird satellite images. Analyses were performed on 81 project clusters constructed by a traveling salesman algorithm, each containing 50-51 households. A standard linear regression model was fitted containing multiple variables to determine how much of the spatial variation in malaria prevalence could be explained by the demographic and environmental data. Subsequently, a geographically-weighted regression (GWR) was performed assuming non-stationarity of risk factors. Special attention was taken to investigate the effect of residual spatial autocorrelation and local multicollinearity. Combining the data from both surveys, overall malaria prevalence was 24%. Scan statistics revealed two clusters which had significantly elevated numbers of malaria cases compared to the background prevalence across the rest of the study area. A multivariable linear model including environmental and household factors revealed that higher socioeconomic status, outdoor occupation and population density were

  19. 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.

  20. 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.

  1. 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

    2016-01-01

    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. PMID:27376297

  2. Movement and Remediation of a Volatile, Multicomponent DNAPL in a Variably-Saturated, Heterogeneous Porous Medium

    Science.gov (United States)

    Oostrom, M.; Dane, J. H.; Wietsma, T. W.

    2004-12-01

    An intermediate-scale flow cell experiment was conducted to study the behavior of a multicomponent DNAPL at structural interfaces and subsequent remediation using two different forms of the soil vapor extraction (SVE) technique. The flow cell (100-cm long, 5-cm wide, and 80 cm high), was packed under saturated conditions with sloped layers of Hanford silt and coarse sand, embedded in a matrix of a medium-grained laboratory sand. After packing, the water table was lowered to 2 cm above the bottom of the flow cell to establish variably saturated conditions. A finite amount of a volatile multicomponent DNAPL, mimicking the organic liquid disposed at the Hanford Site, was then injected from a small source zone. The infiltration and redistribution processes were visually recorded. In addition, a dual-energy gamma radiation system was used to determine DNAPL and water saturation at more than 1000 locations. Results indicate that lateral spreading of the DNAPL is greatly enhanced by the heterogeneities. The silt layers, by virtue of their substantial non-wetting fluid entry pressures and high water saturations, completely diverted the DNAPL laterally. The relatively dry coarse-sand layers forced some of the DNAPL to move laterally but also allowed some infiltration.

  3. Spatial variability in the soil water content of a Mediterranean agroforestry system with high soil heterogeneity

    Science.gov (United States)

    Molina, Antonio Jaime; Llorens, Pilar; Aranda, Xavier; Savé, Robert; Biel, Carmen

    2013-04-01

    Variability of soil water content is known to increase with the size of spatial domain in which measurements are taken. At field scale, heterogeneity in soil, vegetation, topography, water input volume and management affects, among other factors, hydrologic plot behaviour under different mean soil water contents. The present work studies how the spatial variability of soil water content (SWC) is affected by soil type (texture, percentage of stones and the combination of them) in a timber-orientated plantation of cherry tree (Prunus avium) under Mediterranean climatic conditions. The experimental design is a randomized block one with 3 blocks * 4 treatments, based on two factors: irrigation (6 plots irrigated versus 6 plots not irrigated) and soil management (6 plots tillaged versus 6 plots not tillaged). SWC is continuously measured at 25, 50 and 100 cm depth with FDR sensors, located at two positions in each treatment: under tree influence and 2.5 m apart. This study presents the results of the monitoring during 2012 of the 24 sensors located at the 25 cm depth. In each of the measurement point, texture and percentage of stones were measured. Sandy-loam, sandy-clay-loam and loam textures were found together with a percentage of stones ranging from 20 to 70 %. The results indicated that the relationship between the daily mean SWC and its standard deviation, a common procedure used to study spatial variability, changed with texture, percentage of stones and the estimation of field capacity from the combination of both. Temporal stability analysis of SWC showed a clear pattern related to field capacity, with the measurement points of the sandy-loam texture and the high percentage of stones showing the maximun negative diference with the global mean. The high range in the mean relative difference observed (± 75 %), could indicate that the studied plot may be considered as a good field-laboratory to extrapolate results at higher spatial scales. Furthermore, the

  4. Formal Variability of Terms in the Sphere of Network Technologies

    Directory of Open Access Journals (Sweden)

    Roman Viktorovich Deniko

    2015-09-01

    Full Text Available The article addresses the problem of formal variability of terms in the sphere of network terminology in the Russian language. The research is based on data from the Internet communication in the sphere of network technologies. Such formal variability types as graphical, phonemic, word building and complex (graphic and phonetic, morphologic and accentual are discussed in this article. The authors reveal the reasons for graphic variability of foreign origin terms making up the international terminological fund. These reasons cover such aspects as the use of graphics of source language and recipient language; the presence or absence of hyphenation, etc. It is determined that the phonemic variants of terms appear as a result of oral or written borrowings. The existence of such variants is also connected with the stage of their adaptation in the Russian language after borrowing. In this case the variants are related with soft or hard pronunciation of consonants. There are also some cases of phonemic variability on the graphic level. The complex variability is regarded as a part of active processes taking place in the modern Russian language, and these processes involve both native and foreign origin terms. The particular attention is paid to the word-building variants – word-building affixes the variability of which is peculiar of network technologies. The results of the research show that the variability of professional units belonging to the network technologies sublanguage is caused by the active process of borrowing of specialpurpose vocabulary into the Russian language. The process is due to the intensification of intercultural communication in the professional spheres.

  5. Key Technology Research on Open Architecture for The Sharing of Heterogeneous Geographic Analysis Models

    Science.gov (United States)

    Yue, S. S.; Wen, Y. N.; Lv, G. N.; Hu, D.

    2013-10-01

    In recent years, the increasing development of cloud computing technologies laid critical foundation for efficiently solving complicated geographic issues. However, it is still difficult to realize the cooperative operation of massive heterogeneous geographical models. Traditional cloud architecture is apt to provide centralized solution to end users, while all the required resources are often offered by large enterprises or special agencies. Thus, it's a closed framework from the perspective of resource utilization. Solving comprehensive geographic issues requires integrating multifarious heterogeneous geographical models and data. In this case, an open computing platform is in need, with which the model owners can package and deploy their models into cloud conveniently, while model users can search, access and utilize those models with cloud facility. Based on this concept, the open cloud service strategies for the sharing of heterogeneous geographic analysis models is studied in this article. The key technology: unified cloud interface strategy, sharing platform based on cloud service, and computing platform based on cloud service are discussed in detail, and related experiments are conducted for further verification.

  6. Use of a variable-index fractional-derivative model to capture transient dispersion in heterogeneous media

    Science.gov (United States)

    Sun, HongGuang; Zhang, Yong; Chen, Wen; Reeves, Donald M.

    2014-02-01

    Field and numerical experiments of solute transport through heterogeneous porous and fractured media show that the growth of contaminant plumes may not exhibit constant scaling, and may instead transition between diffusive states (i.e., superdiffusion, subdiffusion, and Fickian diffusion) at various transport scales. These transitions are likely attributed to physical properties of the medium, such as spatial variations in medium heterogeneity. We refer to this transitory dispersive behavior as "transient dispersion", and propose a variable-index fractional-derivative model (FDM) to describe the underlying transport dynamics. The new model generalizes the standard constant-index FDM which is limited to stationary heterogeneous media. Numerical methods including an implicit Eulerian method (for spatiotemporal transient dispersion) and a Lagrangian solver (for multiscaling dispersion) are utilized to produce variable-index FDM solutions. The variable-index FDM is then applied to describe transient dispersion observed at two field tracer tests and a set of numerical experiments. Results show that 1) uranine transport at the small-scale Grimsel test site transitions from strong subdispersion to Fickian dispersion, 2) transport of tritium at the regional-scale Macrodispersion Experimental (MADE) site transitions from near-Fickian dispersion to strong superdispersion, and 3) the conservative particle transport through regional-scale discrete fracture network transitions from superdispersion to Fickian dispersion. The variable-index model can efficiently quantify these transitions, with the scale index varying linearly in time or space.

  7. Use of a variable-index fractional-derivative model to capture transient dispersion in heterogeneous media.

    Science.gov (United States)

    Sun, Hongguang; Zhang, Yong; Chen, Wen; Reeves, Donald M

    2014-02-01

    Field and numerical experiments of solute transport through heterogeneous porous and fractured media show that the growth of contaminant plumes may not exhibit constant scaling, and may instead transition between diffusive states (i.e., superdiffusion, subdiffusion, and Fickian diffusion) at various transport scales. These transitions are likely attributed to physical properties of the medium, such as spatial variations in medium heterogeneity. We refer to this transitory dispersive behavior as "transient dispersion", and propose a variable-index fractional-derivative model (FDM) to describe the underlying transport dynamics. The new model generalizes the standard constant-index FDM which is limited to stationary heterogeneous media. Numerical methods including an implicit Eulerian method (for spatiotemporal transient dispersion) and a Lagrangian solver (for multiscaling dispersion) are utilized to produce variable-index FDM solutions. The variable-index FDM is then applied to describe transient dispersion observed at two field tracer tests and a set of numerical experiments. Results show that 1) uranine transport at the small-scale Grimsel test site transitions from strong subdispersion to Fickian dispersion, 2) transport of tritium at the regional-scale Macrodispersion Experimental (MADE) site transitions from near-Fickian dispersion to strong superdispersion, and 3) the conservative particle transport through regional-scale discrete fracture network transitions from superdispersion to Fickian dispersion. The variable-index model can efficiently quantify these transitions, with the scale index varying linearly in time or space.

  8. Heterogeneous Wireless Mesh Network Technology Evaluation for Space Proximity and Surface Applications

    Science.gov (United States)

    DeCristofaro, Michael A.; Lansdowne, Chatwin A.; Schlesinger, Adam M.

    2014-01-01

    NASA has identified standardized wireless mesh networking as a key technology for future human and robotic space exploration. Wireless mesh networks enable rapid deployment, provide coverage in undeveloped regions. Mesh networks are also self-healing, resilient, and extensible, qualities not found in traditional infrastructure-based networks. Mesh networks can offer lower size, weight, and power (SWaP) than overlapped infrastructure-perapplication. To better understand the maturity, characteristics and capability of the technology, we developed an 802.11 mesh network consisting of a combination of heterogeneous commercial off-the-shelf devices and opensource firmware and software packages. Various streaming applications were operated over the mesh network, including voice and video, and performance measurements were made under different operating scenarios. During the testing several issues with the currently implemented mesh network technology were identified and outlined for future work.

  9. 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

  10. Complex heterogeneous tissue constructs containing multiple cell types prepared by inkjet printing technology.

    Science.gov (United States)

    Xu, Tao; Zhao, Weixin; Zhu, Jian-Ming; Albanna, Mohammad Z; Yoo, James J; Atala, Anthony

    2013-01-01

    This study was designed to develop a versatile method for fabricating complex and heterogeneous three-dimensional (3D) tissue constructs using simultaneous ink-jetting of multiple cell types. Human amniotic fluid-derived stem cells (hAFSCs), canine smooth muscle cells (dSMCs), and bovine aortic endothelial cells (bECs), were separately mixed with ionic cross-linker calcium chloride (CaCl(2)), loaded into separate ink cartridges and printed using a modified thermal inkjet printer. The three cell types were delivered layer-by-layer to pre-determined locations in a sodium alginate-collagen composite located in a chamber under the printer. The reaction between CaCl(2) and sodium alginate resulted in a rapid formation of a solid composite gel and the printed cells were anchored in designated areas within the gel. The printing process was repeated for several cycles leading to a complex 3D multi-cell hybrid construct. The biological functions of the 3D printed constructs were evaluated in vitro and in vivo. Each of the printed cell types maintained their viability and normal proliferation rates, phenotypic expression, and physiological functions within the heterogeneous constructs. The bioprinted constructs were able to survive and mature into functional tissues with adequate vascularization in vivo. These findings demonstrate the feasibility of fabricating complex heterogeneous tissue constructs containing multiple cell types using inkjet printing technology.

  11. Impact of bandwidth for various services in heterogeneous network and quality of service via communication technologies in Malaysian higher educational

    Directory of Open Access Journals (Sweden)

    Mohd Nazri ISMAIL

    2007-12-01

    Full Text Available This study focuses on heterogeneous services and communication technologies for retrieving and sending information between students and lecturers in Malaysian higher educational institutes. It intends to investigate pattern and significant level of various services implementation, convergence of communication technologies and bandwidth capacity for last mile users (students and lecturers. It is designed to determine which communication technologies, services, bandwidth capacity and QoS will achieve the highest level acceptance in Malaysian higher educational institutes. Heterogeneous environment can also generate mobility approaches. A survey method is used to collect data from respondents (System Network Administrator in Malaysian higher educational institutes. Statistical Analysis using t-test shows that implementation of high speed bandwidth for Internet (WAN achieved significant level. Frequency test are used to analyze the various services implementation via convergence of communication technologies in heterogeneous environment for retrieving information. The most apparent finding of this study is that various services implementation in higher educational institutes can affect convergence of communication technologies usage in accessing information over heterogeneous network environment between students and lecturers. The study or analysis confirms that Malaysia higher educational institutes have not achieved a maximum level of various services implementation via convergence of communication technologies between students and lecturers in heterogeneous network environment. Therefore, low convergence of communication technologies can produce a low mobility and ubiquitous interaction between students and lectures in Malaysian higher educational institutes.

  12. The role of topography and lateral velocity heterogeneities on near-source scattering and ground-motion variability

    KAUST Repository

    Imperatori, W.

    2015-07-28

    The scattering of seismic waves travelling in the Earth is not only caused by random velocity heterogeneity but also by surface topography. Both factors are known to strongly affect ground-motion complexity even at relatively short distance from the source. In this study, we simulate ground motion with a 3-D finite-difference wave propagation solver in the 0–5 Hz frequency band using three topography models representative of the Swiss alpine region and realistic heterogeneous media characterized by the Von Karman correlation functions. Subsequently, we analyse and quantify the characteristics of the scattered wavefield in the near-source region. Our study shows that both topography and velocity heterogeneity scattering may excite large coda waves of comparable relative amplitude, especially at around 1 Hz, although large variability in space may occur. Using the single scattering model, we estimate average QC values in the range 20–30 at 1 Hz, 36–54 at 1.5 Hz and 62–109 at 3 Hz for constant background velocity models with no intrinsic attenuation. In principle, envelopes of topography-scattered seismic waves can be qualitatively predicted by theoretical back-scattering models, while forward- or hybrid-scattering models better reproduce the effects of random velocity heterogeneity on the wavefield. This is because continuous multiple scattering caused by small-scale velocity perturbations leads to more gentle coda decay and envelope broadening, while topography abruptly scatters the wavefield once it impinges the free surface. The large impedance contrast also results in more efficient mode mixing. However, the introduction of realistic low-velocity layers near the free surface increases the complexity of ground motion dramatically and indicates that the role of topography in elastic waves scattering can be relevant especially in proximity of the source. Long-period surface waves can form most of the late coda, especially when intrinsic attenuation is taken

  13. Spatial Heterogeneity and Variability of a Large-Scale Vegetation Community Using a Power-Law Model

    Institute of Scientific and Technical Information of China (English)

    SONG Zhiyuan; HUANG Daming; SHIYOMI Masae; WANG Yusheng; TAKAHASHI Shigeo; YOSHIMICHI Hori; YAMAMURU Yasuo; CHEN Jun

    2005-01-01

    Spatial heterogeneity and stability are fundamental indices for describing vegetation communities. The spatial distribution characteristics of the vegetation in Nenjiang region of northeastern China were evaluated using a variance power-law model. The data fits the model well with estimates given for the levels of heterogeneity for not only single species but also the community as a whole. The linear regression indicates that the species in the community exhibit a consistently organized spatial pattern, as is often discovered in field surveys but rarely seen in artificial systems. The species deviations from the regression line, which exhibit a leptokurtic distribution, may reflect the variability of the community. Thus, the model provides a general tool for management and regulation of ecosystems, especially where there is human disturbances.

  14. Confidence Region Approach for Assessing Bioequivalence and Biosimilarity Accounting for Heterogeneity of Variability

    OpenAIRE

    Jianghao Li; Shein-Chung Chow

    2015-01-01

    For approval of generic drugs, the FDA requires that evidence of bioequivalence in average bioequivalence in terms of drug absorption be provided through the conduct of a bioequivalence study. A test product is said to be average bioequivalent to a reference (innovative) product if the 90% confidence interval of the ratio of means (after log-transformation) is totally within (80%, 125%). This approach is considered a one-parameter approach, which does not account for possible heterogeneity of...

  15. Preserving biological heterogeneity with a permuted surrogate variable analysis for genomics batch correction.

    Science.gov (United States)

    Parker, Hilary S; Leek, Jeffrey T; Favorov, Alexander V; Considine, Michael; Xia, Xiaoxin; Chavan, Sameer; Chung, Christine H; Fertig, Elana J

    2014-10-01

    Sample source, procurement process and other technical variations introduce batch effects into genomics data. Algorithms to remove these artifacts enhance differences between known biological covariates, but also carry potential concern of removing intragroup biological heterogeneity and thus any personalized genomic signatures. As a result, accurate identification of novel subtypes from batch-corrected genomics data is challenging using standard algorithms designed to remove batch effects for class comparison analyses. Nor can batch effects be corrected reliably in future applications of genomics-based clinical tests, in which the biological groups are by definition unknown a priori. Therefore, we assess the extent to which various batch correction algorithms remove true biological heterogeneity. We also introduce an algorithm, permuted-SVA (pSVA), using a new statistical model that is blind to biological covariates to correct for technical artifacts while retaining biological heterogeneity in genomic data. This algorithm facilitated accurate subtype identification in head and neck cancer from gene expression data in both formalin-fixed and frozen samples. When applied to predict Human Papillomavirus (HPV) status, pSVA improved cross-study validation even if the sample batches were highly confounded with HPV status in the training set. All analyses were performed using R version 2.15.0. The code and data used to generate the results of this manuscript is available from https://sourceforge.net/projects/psva. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. Parameter Estimation by Inverse Modelling of State Variable Observations in Porous Media with Hierarchical Heterogeneity

    Science.gov (United States)

    Durner, Wolfgang; Schelle, Henrike; Schlüter, Steffen; Vogel, Hans-Jörg; Ippisch, Olaf; Vanderborght, Jan

    2013-04-01

    Soils are structured on multiple spatial scales, originating from inhomogeneities of the parent material, pedogenesis, soil organisms, plant roots, or tillage. This leads to heterogeneities that affect the local hydraulic properties and thus govern the flow behavior of water in soil. To assess the impact of individual or combined structural components on the water dynamics within a soil, complex 2D and 3D virtual realities, representing cultivated soils with spatial heterogeneity on multiple scales were constructed with a high spatial resolution by the interdisciplinary research group INVEST (virtual institute of the Helmholtz Association). At these systems, numerical simulations of water dynamics under different boundary conditions were performed. From the simulation results, datasets of water contents and matric heads, as are recorded in typical field campaigns were extracted. With these data, effective soil hydraulic properties were estimated by 1D inverse simulation, which were then used to predict the water balance. The results showed that measurements, particularly those of water contents, depended strongly on the measuring position and hence led to different estimates of the soil hydraulic properties. Nevertheless, in most cases, the average of the predicted water balances obtained from the 1D simulations and the estimated effective soil hydraulic properties agreed very well with those attained from the 2D systems. In contrast, when using data from only one observation profile, the calculation of the water balance was very uncertain.

  17. Heterogeneous uptake of NO2 on soils under variable temperature and relative humidity conditions

    Institute of Scientific and Technical Information of China (English)

    Lei Wang; Weigang Wang; Maofa Ge

    2012-01-01

    Heterogeneous reactions of nitrogen dioxide (NO2) on soils collected from Dalian (S1) and Changsha (S2) were investigated over the relative humidity (RH) range of 5%-80% and temperature range of 278-328 K using a horizontal coated-wall flow tube.The initial uptake coefficients of NO2 on S2 exhibited a decreasing trend from (10 ± 1.3) × 10-8 to (3.1 ± 0.5) × 10-8 with the relative humidity increasing from 5% to 80%.In the temperature effect studies,the initial uptake coefficients of S1 and S2 decreased from (10 ± 1.2) ×10-8 to (3.8 ± 0.5) × 10-8 and from (16 ± 2.2) × 10-8 to (3.8 ± 0.4) × 10-8 when temperature increased from 278 to 288 K for S1 and from 278 to 308 K for S2,respectively.As the temperature continued to increase,the initial uptake coefficients of S1 and S2 returned to (7.9 ± 1.1) × 10-8 and (20 ± 3.1) × 10-8 at 313 and 328 K,respectively.This study shows that relative humidity could influence the uptake kinetics of NO2 on soil and temperature would impact the heterogeneous chemistry of NO2.

  18. Analytical framework for reconstructing heterogeneous environmental variables from mammal community structure.

    Science.gov (United States)

    Louys, Julien; Meloro, Carlo; Elton, Sarah; Ditchfield, Peter; Bishop, Laura C

    2015-01-01

    We test the performance of two models that use mammalian communities to reconstruct multivariate palaeoenvironments. While both models exploit the correlation between mammal communities (defined in terms of functional groups) and arboreal heterogeneity, the first uses a multiple multivariate regression of community structure and arboreal heterogeneity, while the second uses a linear regression of the principal components of each ecospace. The success of these methods means the palaeoenvironment of a particular locality can be reconstructed in terms of the proportions of heavy, moderate, light, and absent tree canopy cover. The linear regression is less biased, and more precisely and accurately reconstructs heavy tree canopy cover than the multiple multivariate model. However, the multiple multivariate model performs better than the linear regression for all other canopy cover categories. Both models consistently perform better than randomly generated reconstructions. We apply both models to the palaeocommunity of the Upper Laetolil Beds, Tanzania. Our reconstructions indicate that there was very little heavy tree cover at this site (likely less than 10%), with the palaeo-landscape instead comprising a mixture of light and absent tree cover. These reconstructions help resolve the previous conflicting palaeoecological reconstructions made for this site. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Heterogeneity of the alpha subunit of tubulin and the variability of tubulin within a single organism.

    Science.gov (United States)

    Bibring, T; Baxandall, J; Denslow, S; Walker, B

    1976-05-01

    When tubulins obtained from particular microtubules of the sea urchin (ciliary doublet A tubules, flagellar doublet microtubules, and mitotic microtubules) are analyzed by electrophoresis in a polyacrylamide gel system containing sodium dodecyl sulfate and urea, heterogeneity of the alpha subunit, and differences between the tubulins are revealed. The alpha subunit of tubulin from mitotic apparatus and from A microtubules of ciliary doublets is resolved into two bands, while the alpha subunit of flagellar doublet tubulin gives a single band. The mitotic and ciliary tubulins differ in the mobilities of their two alpha species, or in the relative amounts present, or both. The existence of differences between the tubulins has been confirmed by a preliminary analysis of their cyanogen bromide peptides.

  20. Heterogeneity of Prognostic Studies of 24-Hour Blood Pressure Variability: Systematic Review and Meta-Analysis

    Science.gov (United States)

    Taylor, Kathryn S.; Heneghan, Carl J.; Stevens, Richard J.; Adams, Emily C.; Nunan, David; Ward, Alison

    2015-01-01

    In addition to mean blood pressure, blood pressure variability is hypothesized to have important prognostic value in evaluating cardiovascular risk. We aimed to assess the prognostic value of blood pressure variability within 24 hours. Using MEDLINE, EMBASE and Cochrane Library to April 2013, we conducted a systematic review of prospective studies of adults, with at least one year follow-up and any day, night or 24-hour blood pressure variability measure as a predictor of one or more of the following outcomes: all-cause mortality, cardiovascular mortality, all cardiovascular events, stroke and coronary heart disease. We examined how blood pressure variability is defined and how its prognostic use is reported. We analysed relative risks adjusted for covariates including the appropriate mean blood pressure and considered the potential for meta-analysis. Our analysis of methods included 24 studies and analysis of predictions included 16 studies. There were 36 different measures of blood pressure variability and 13 definitions of night- and day-time periods. Median follow-up was 5.5 years (interquartile range 4.2–7.0). Comparing measures of dispersion, coefficient of variation was less well researched than standard deviation. Night dipping based on percentage change was the most researched measure and the only measure for which data could be meaningfully pooled. Night dipping or lower night-time blood pressure was associated with lower risk of cardiovascular events. The interpretation and use in clinical practice of 24-hour blood pressure variability, as an important prognostic indicator of cardiovascular events, is hampered by insufficient evidence and divergent methodologies. We recommend greater standardisation of methods. PMID:25984791

  1. Heterogeneity of prognostic studies of 24-hour blood pressure variability: systematic review and meta-analysis.

    Science.gov (United States)

    Taylor, Kathryn S; Heneghan, Carl J; Stevens, Richard J; Adams, Emily C; Nunan, David; Ward, Alison

    2015-01-01

    In addition to mean blood pressure, blood pressure variability is hypothesized to have important prognostic value in evaluating cardiovascular risk. We aimed to assess the prognostic value of blood pressure variability within 24 hours. Using MEDLINE, EMBASE and Cochrane Library to April 2013, we conducted a systematic review of prospective studies of adults, with at least one year follow-up and any day, night or 24-hour blood pressure variability measure as a predictor of one or more of the following outcomes: all-cause mortality, cardiovascular mortality, all cardiovascular events, stroke and coronary heart disease. We examined how blood pressure variability is defined and how its prognostic use is reported. We analysed relative risks adjusted for covariates including the appropriate mean blood pressure and considered the potential for meta-analysis. Our analysis of methods included 24 studies and analysis of predictions included 16 studies. There were 36 different measures of blood pressure variability and 13 definitions of night- and day-time periods. Median follow-up was 5.5 years (interquartile range 4.2-7.0). Comparing measures of dispersion, coefficient of variation was less well researched than standard deviation. Night dipping based on percentage change was the most researched measure and the only measure for which data could be meaningfully pooled. Night dipping or lower night-time blood pressure was associated with lower risk of cardiovascular events. The interpretation and use in clinical practice of 24-hour blood pressure variability, as an important prognostic indicator of cardiovascular events, is hampered by insufficient evidence and divergent methodologies. We recommend greater standardisation of methods.

  2. Heterogeneity of prognostic studies of 24-hour blood pressure variability: systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Kathryn S Taylor

    Full Text Available In addition to mean blood pressure, blood pressure variability is hypothesized to have important prognostic value in evaluating cardiovascular risk. We aimed to assess the prognostic value of blood pressure variability within 24 hours. Using MEDLINE, EMBASE and Cochrane Library to April 2013, we conducted a systematic review of prospective studies of adults, with at least one year follow-up and any day, night or 24-hour blood pressure variability measure as a predictor of one or more of the following outcomes: all-cause mortality, cardiovascular mortality, all cardiovascular events, stroke and coronary heart disease. We examined how blood pressure variability is defined and how its prognostic use is reported. We analysed relative risks adjusted for covariates including the appropriate mean blood pressure and considered the potential for meta-analysis. Our analysis of methods included 24 studies and analysis of predictions included 16 studies. There were 36 different measures of blood pressure variability and 13 definitions of night- and day-time periods. Median follow-up was 5.5 years (interquartile range 4.2-7.0. Comparing measures of dispersion, coefficient of variation was less well researched than standard deviation. Night dipping based on percentage change was the most researched measure and the only measure for which data could be meaningfully pooled. Night dipping or lower night-time blood pressure was associated with lower risk of cardiovascular events. The interpretation and use in clinical practice of 24-hour blood pressure variability, as an important prognostic indicator of cardiovascular events, is hampered by insufficient evidence and divergent methodologies. We recommend greater standardisation of methods.

  3. Heterogeneous selection on a heritable temperament trait in a variable environment.

    Science.gov (United States)

    Quinn, John L; Patrick, Samantha C; Bouwhuis, Sandra; Wilkin, Teddy A; Sheldon, Ben C

    2009-11-01

    1. Temperament traits increasingly provide a focus for investigating the evolutionary ecology of behavioural variation. Here, we examine the underlying causes and selective consequences of individual variation in the temperament trait 'exploration behaviour in a novel environment' (EB, based on an 8-min assay) in a free-ranging population of a passerine bird, the great tit Parus major. 2. First, we conducted a quantitative genetic analysis on EB using a restricted maximum likelihood-based animal model with a long-term pedigree. Although repeatability was relatively high, EB was only moderately heritable and permanent environment (V(PE)) effects contributed as much to phenotypic variance as additive genetic effects. 3. We then asked whether heterogeneous selection acted on EB at various temporal and spatial scales. Using estimates of lifetime reproductive success, we found evidence of weak negative directional selection acting on EB amongst females which was driven by selection through recruitment, but not fecundity, in one of the four breeding years. There was no evidence of any selection on EB through survival. 4. Heterogeneous selection on EB within seasons was also observed amongst males through fecundity along two fine-scale environmental gradients--local breeding density and habitat quality; we are unaware of any previous equivalent demonstrations. 5. All of these analyses were repeated on a second measure of exploration behaviour (EB(2), measured during a 2-min assay) to facilitate comparison with other studies. EB and EB(2) were strongly correlated to one another at the genetic level, but were only moderately correlated at the phenotypic level and V(PE) was undetected in EB(2). Selection on EB(2) was similar to that on EB; we conclude that both traits are broadly equivalent from an evolutionary perspective. 6. Our analyses suggest that to the extent that the temperament trait 'exploration behaviour' is subject to natural selection in this population, this

  4. Variability of drainage and solute leaching in heterogeneous urban vegetation environs

    Science.gov (United States)

    Nouri, H.; Beecham, S.; Hassanli, A. M.; Ingleton, G.

    2013-11-01

    Deep percolation enhancement from recycled wastewater irrigation may contribute to salt accumulation and water table elevation that can ultimately cause soil and ground water degradation. Variation of drainage rate and solute leaching were investigated in an urban park containing heterogeneous landscape plants that were irrigated with recycled wastewater. Field monitoring was undertaken at Veale Gardens in the Adelaide Parklands, Australia. Based on landscape variation in Veale Gardens, two landscape zones were defined: one being largely covered with turf grasses with few trees and shrubs (MG) with the second zone being mostly trees and shrubs with intermittent turf grasses (MT). Experiments were performed on two zero-tension lysimeters placed horizontally 100 cm below ground to monitor the variation of volume and quality indicators of drained water for four seasons. The outcomes showed a significant variation of drainage quantity and quality in the MT and MG zones. The low vegetation cover in the MG zone resulted in more drained water than in the high vegetation cover (MT zone). In both zones, more drainage water was collected in winter than in other seasons. This is in spite of the input water showing a maximum rate in summer. The seasonal salinities measured in the two lysimeters showed very similar trends with the lowest salinity rate in autumn with the levels increasing through winter and spring. Chemical analyses of leachate solute and salt loading indicated no impact from using recycled wastewater.

  5. Effect of Loss of Heart Rate Variability on T-Wave Heterogeneity and QT Variability in Heart Failure Patients: Implications in Ventricular Arrhythmogenesis.

    Science.gov (United States)

    Nayyar, Sachin; Hasan, Muhammad A; Roberts-Thomson, Kurt C; Sullivan, Thomas; Baumert, Mathias

    2017-03-03

    Heart rate variability (HRV) modulates dynamics of ventricular repolarization. A diminishing value of HRV is associated with increased vulnerability to life-threatening ventricular arrhythmias, however the causal relationship is not well-defined. We evaluated if fixed-rate atrial pacing that abolishes the effect of physiological HRV, will alter ventricular repolarization wavefronts and is relevant to ventricular arrhythmogenesis. The study was performed in 16 subjects: 8 heart failure patients with spontaneous ventricular tachycardia [HFVT], and 8 subjects with structurally normal hearts (H Norm). The T-wave heterogeneity descriptors [total cosine angle between QRS and T-wave loop vectors (TCRT, negative value corresponds to large difference in the 2 loops), T-wave morphology dispersion, T-wave loop dispersion] and QT intervals were analyzed in a beat-to-beat manner on 3-min records of 12-lead surface ECG at baseline and during atrial pacing at 80 and 100 bpm. The global T-wave heterogeneity was expressed as mean values of each of the T-wave morphology descriptors and variability in QT intervals (QTV) as standard deviation of QT intervals. Baseline T-wave morphology dispersion and QTV were higher in HFVT compared to H Norm subjects (p ≤ 0.02). While group differences in T-wave morphology dispersion and T-wave loop dispersion remained unaltered with atrial pacing, TCRT tended to fall more in HFVT patients compared to H Norm subjects (interaction p value = 0.086). Atrial pacing failed to reduce QTV in both groups, however group differences were augmented (p < 0.0001). Atrial pacing and consequent loss of HRV appears to introduce unfavorable changes in ventricular repolarization in HFVT subjects. It widens the spatial relationship between wavefronts of ventricular depolarization and repolarization. This may partly explain the concerning relation between poorer HRV and the risk of ventricular arrhythmias.

  6. 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.

  7. Quantifying microplastic pollution on sandy beaches: the conundrum of large sample variability and spatial heterogeneity.

    Science.gov (United States)

    Fisner, Mara; Majer, Alessandra P; Balthazar-Silva, Danilo; Gorman, Daniel; Turra, Alexander

    2017-05-01

    Despite the environmental risks posed by microplastic pollution, there are presently few standardized protocols for monitoring these materials within marine and coastal habitats. We provide a robust comparison of methods for sampling microplastics on sandy beaches using pellets as a model and attempt to define a framework for reliable standing stock estimation. We performed multiple comparisons to determine: (1) the optimal size of sampling equipment, (2) the depth to which samples should be obtained, (3) the optimal sample resolution for cross-shore transects, and (4) the number of transects required to yield reproducible along-shore estimates across the entire sections of a beach. Results affirmed that the use of a manual auger with a 20-cm diameter yielded the best compromise between reproducibility (i.e., standard deviation) and sampling/processing time. Secondly, we suggest that sediments should be profiled to a depth of at least 1 m to fully assess the depth distribution of pellets. Thirdly, although sample resolution did not have major consequence for overall density estimates, using 7-m intervals provides an optimal balance between precision (SD) and effort (total sampling time). Finally, and perhaps most importantly, comparing the minimum detectable difference yielded by different numbers of transects along a given section of beach suggests that estimating absolute particle density is probably unviable for most systems and that monitoring might be better accomplished through hierarchical or time series sampling efforts. Overall, while our study provides practical information that can improve sampling efforts, the heterogeneous nature of microplastic pollution poses a major conundrum to reproducible monitoring and management of this significant and growing problem.

  8. Variability of soil potential for biodegradation of petroleum hydrocarbons in a heterogeneous subsurface

    DEFF Research Database (Denmark)

    Kristensen, Andreas Houlberg; Poulsen, Tjalfe; Mortensen, Lars

    2010-01-01

    Quantifying the spatial variability of factors affecting natural attenuation of hydrocarbons in the unsaturated zone is important to (i) performing a reliable risk assessment and (ii) evaluating the possibility for bioremediation of petroleum-polluted sites. Most studies to date have focused...... on the shallow unsaturated zone. Based on a data set comprising analysis of about 100 soil samples taken in a 16-m-deep unsaturated zone polluted with volatile petroleum compounds, we statistically and geostatistically analyzed values of essential soil properties. The subsurface of the site was highly layered...

  9. Dual-tracer transport experiments in a physically and chemically heterogeneous porous aquifer: effective transport parameters and spatial variability

    Science.gov (United States)

    Ptak, T.; Schmid, G.

    1996-08-01

    In order to investigate the effects of reactive transport processes within a heterogeneous porous aquifer, two small-scale forced gradient tracer tests were conducted at the 'Horkheimer Insel' field site. During the experiments, two fluorescent tracers were injected simultaneously in the same fully penetrating groundwater monitoring well, located approximately 10 m from the pumping well. Fluoresceine and Rhodamine WT were used to represent the classes of practically non-sorbing and sorbing solutes, respectively. Multilevel breakthrough curves with a temporal resolution of 1 min were measured for both tracers at different depths within the pumping well using fibre-optic fluorimeters. This paper presents the tracer test design, the fibre-optic fluorimetry instrumentation, the experimental results and the interpretation of the measured multilevel breakthrough curves in terms of temporal moments and effective transport parameters. Significant sorption of Rhodamine WT is apparent from the effective retardation factors. Furthermore, an enhanced tailing of Rhodamine WT breakthrough curves is observed, which is possibly caused by a variability of aquifer sorption properties. The determined effective parameters are spatially variable, suggesting that a complex numerical flow and transport modelling approach within a stochastic framework will be needed to adequately describe the transport behaviour observed in the two experiments. Therefore, the tracer test results will serve in future work for the validation of numerical stochastic transport simulations taking into account the spatial variability of hydraulic conductivity and sorption-related aquifer properties.

  10. Variability of technological quality components in winter wheat

    Directory of Open Access Journals (Sweden)

    Zečević Veselinka

    2007-01-01

    Full Text Available Ten winter wheat cultivars created in Small Grains Research Centre of Kragujevac (KG-56, Srbijanka, Studenica, Takovčanka, KG-56S, KG­100, Toplica, Levčanka, Gruža, and Tara were grown at experimental field during four years. Variability of bread-making quality properties (sedimentation value, gluten content and quality, and rheological flour and dough properties was investigated. The sedimentation value was determined by Zeleny method, gluten content by standard method, and rheological flour and dough properties by Farinograph. Quality components depended significantly of genotype and environment factors. Obtained results have shown that the highest value of sedimentation in average was at KG-56S cultivar (61.8ml. Sedimentation in all investigated cultivars was at the level of the first quality class. Wet gluten are characterized by good physical properties, and on average ranged from 25.6% (KG-100 to 36.3% (Gruža. Wheat technological quality depended predominantly of genetic potential of cultivar, and it was on the level of A2-B2 quality group. The highest impact of phenotypic variance belonged to genotype for sedimentation value, wet gluten content and rheological flour and dough properties, while for water absorption belonged to genotype-year interaction.

  11. Heterogeneity among Mycobacterium ulcerans from French Guiana revealed by multilocus variable number tandem repeat analysis (MLVA).

    Science.gov (United States)

    Reynaud, Yann; Millet, Julie; Couvin, David; Rastogi, Nalin; Brown, Christopher; Couppié, Pierre; Legrand, Eric

    2015-01-01

    Buruli ulcer is an emerging and neglected tropical disease caused by Mycobacterium ulcerans. Few cases have been reported so far in the Americas. With 250 cases reported since 1969, French Guiana is the only Buruli ulcer endemic area in the continent. Thus far, no genetic diversity studies of strains of M. ulcerans from French Guiana have been reported. Our goal in the present study was to examine the genetic diversity of M. ulcerans strains in this region by using the Multilocus Variable Number Tandem Repeat Analysis (MLVA) approach. A total of 23 DNA samples were purified from ulcer biopsies or derived from pure cultures. MVLA was used in the study of six previously-described Variable Number of Tandem Repeat (VNTR) markers. A total of three allelic combinations were characterized in our study: genotype I which has been described previously, genotype III which is very similar to genotype I, and genotype II which has distinctly different characteristics in comparison with the other two genotypes. This high degree of genetic diversity appears to be uncommon for M. ulcerans. Further research based on complete genome sequencing of strains belonging to genotypes I and II is in progress and should lead soon to a better understanding of genetic specificities of M. ulcerans strains from French Guiana.

  12. Shock wave science and technology reference library. Vol. 4. Heterogeneous detonation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan (ed.) [Defence Research and Development Canada, Suffield, AB (Canada)

    2009-07-01

    This book, as a volume of the Shock Wave Science and Technology Reference Library, is primarily concerned with detonation waves or compression shock waves in reactive heterogeneous media, including mixtures of solid, liquid and gas phases. The topics involve a variety of energy release and control processes in such media - a contemporary research field that has found wide applications in propulsion and power, hazard prevention as well as military engineering. The six extensive chapters contained in this volume are: - Spray Detonation (SB Murray and PA Thibault) - Detonation of Gas-Particle Flow (F Zhang) - Slurry Detonation (DL Frost and F Zhang) - Detonation of Metalized Composite Explosives (MF Gogulya and MA Brazhnikov) - Shock-Induced Solid-Solid Reactions and Detonations (YA Gordopolov, SS Batsanov, and VS Trofimov) - Shock Ignition of Particles (SM Frolov and AV Fedorov). Each chapter is self-contained and can be read independently of the others, though, they are thematically interrelated. They offer a timely reference, for graduate students as well as professional scientists and engineers, by laying out the foundations and discussing the latest developments including yet unresolved challenging problems. (orig.)

  13. Variability of soil potential for biodegradation of petroleum hydrocarbons in a heterogeneous subsurface

    DEFF Research Database (Denmark)

    Kristensen, Andreas Houlberg; Poulsen, Tjalfe; Mortensen, Lars

    2010-01-01

    Quantifying the spatial variability of factors affecting natural attenuation of hydrocarbons in the unsaturated zone is important to (i) performing a reliable risk assessment and (ii) evaluating the possibility for bioremediation of petroleum-polluted sites. Most studies to date have focused...... on the shallow unsaturated zone. Based on a data set comprising analysis of about 100 soil samples taken in a 16-m-deep unsaturated zone polluted with volatile petroleum compounds, we statistically and geostatistically analyzed values of essential soil properties. The subsurface of the site was highly layered......, resulting in an accumulation of pollution within coarse sandy lenses. Air-filled porosity, readily available phosphorous, and the first-order rate constant (k1) of benzene obtained from slurry biodegradation experiments were found to depend on geologic sample characterization (P

  14. The spatial heterogeneity between Japanese encephalitis incidence distribution and environmental variables in Nepal.

    Directory of Open Access Journals (Sweden)

    Daniel E Impoinvil

    Full Text Available BACKGROUND: To identify potential environmental drivers of Japanese Encephalitis virus (JE transmission in Nepal, we conducted an ecological study to determine the spatial association between 2005 Nepal JE incidence, and climate, agricultural, and land-cover variables at district level. METHODS: District-level data on JE cases were examined using Local Indicators of Spatial Association (LISA analysis to identify spatial clusters from 2004 to 2008 and 2005 data was used to fit a spatial lag regression model with climate, agriculture and land-cover variables. RESULTS: Prior to 2006, there was a single large cluster of JE cases located in the Far-West and Mid-West terai regions of Nepal. After 2005, the distribution of JE cases in Nepal shifted with clusters found in the central hill areas. JE incidence during the 2005 epidemic had a stronger association with May mean monthly temperature and April mean monthly total precipitation compared to mean annual temperature and precipitation. A parsimonious spatial lag regression model revealed, 1 a significant negative relationship between JE incidence and April precipitation, 2 a significant positive relationship between JE incidence and percentage of irrigated land 3 a non-significant negative relationship between JE incidence and percentage of grassland cover, and 4 a unimodal non-significant relationship between JE Incidence and pig-to-human ratio. CONCLUSION: JE cases clustered in the terai prior to 2006 where it seemed to shift to the Kathmandu region in subsequent years. The spatial pattern of JE cases during the 2005 epidemic in Nepal was significantly associated with low precipitation and the percentage of irrigated land. Despite the availability of an effective vaccine, it is still important to understand environmental drivers of JEV transmission since the enzootic cycle of JEV transmission is not likely to be totally interrupted. Understanding the spatial dynamics of JE risk factors may be

  15. Influences of Contextual Variables on the Intention to Use Technology in Education: A Latent Variable Modeling Approach

    Science.gov (United States)

    Teo, Timothy

    2013-01-01

    Purpose: The purpose of this paper is to examine the influences of selected individual, technological and implementation variables on the intention to use technology, among a sample of primary school teachers in Singapore. Design/methodology/approach: In total, 385 teachers from 18 primary schools completed a survey questionnaire measuring their…

  16. Stochastic analysis of the effects of fluid density and viscosity variability on macrodispersion in heterogeneous porous media

    Energy Technology Data Exchange (ETDEWEB)

    Welty, C. (Drexel Univ., Philadelphia, PA (United States)); Gelhar, L.W. (Massachusetts Inst. of Tech., Cambridge (United States))

    1991-08-01

    Both porous medium heterogeneities and fluid density and viscosity contrasts affect solute transport in miscible fluid displacement. The effect of interaction of these processes on large-scale mixing are evaluated using spectral-based perturbation theory. A three-dimensional, statistically isotropic, exponential log permeability autocovariance is used to represent the spatial variability of the porous medium. State equations linearly relating log density and log viscosity perturbations to concentration perturbations represent the density and viscosity variability and strongly couple the flow and solute transport perturbation equations. Analytical expressions for longitudinal macrodispersivity, derived for one-dimensional mean solute transport, are functionally dependent on mean displacement distance, mean concentration and concentration gradient, density and viscosity differences, mean velocity, gravity, and correlation scale and variance of the log permeability process. Transient analysis shows that longitudinal macrodispersivity grows exponentially in time (or mean displacement distance) without bound for the case where instabilities due to viscous or gravity fingering arise (the unstable or fingering case) and that it grows at early time then decreases exponentially to an asymptotic value close to that of local dispersivity for the case where density or viscosity contrasts produce a stabilizing effect (the stable case).

  17. Habitat Heterogeneity Variably Influences Habitat Selection by Wild Herbivores in a Semi-Arid Tropical Savanna Ecosystem

    Science.gov (United States)

    Muposhi, Victor K.; Gandiwa, Edson; Chemura, Abel; Bartels, Paul; Makuza, Stanley M.; Madiri, Tinaapi H.

    2016-01-01

    An understanding of the habitat selection patterns by wild herbivores is critical for adaptive management, particularly towards ecosystem management and wildlife conservation in semi arid savanna ecosystems. We tested the following predictions: (i) surface water availability, habitat quality and human presence have a strong influence on the spatial distribution of wild herbivores in the dry season, (ii) habitat suitability for large herbivores would be higher compared to medium-sized herbivores in the dry season, and (iii) spatial extent of suitable habitats for wild herbivores will be different between years, i.e., 2006 and 2010, in Matetsi Safari Area, Zimbabwe. MaxEnt modeling was done to determine the habitat suitability of large herbivores and medium-sized herbivores. MaxEnt modeling of habitat suitability for large herbivores using the environmental variables was successful for the selected species in 2006 and 2010, except for elephant (Loxodonta africana) for the year 2010. Overall, large herbivores probability of occurrence was mostly influenced by distance from rivers. Distance from roads influenced much of the variability in the probability of occurrence of medium-sized herbivores. The overall predicted area for large and medium-sized herbivores was not different. Large herbivores may not necessarily utilize larger habitat patches over medium-sized herbivores due to the habitat homogenizing effect of water provisioning. Effect of surface water availability, proximity to riverine ecosystems and roads on habitat suitability of large and medium-sized herbivores in the dry season was highly variable thus could change from one year to another. We recommend adaptive management initiatives aimed at ensuring dynamic water supply in protected areas through temporal closure and or opening of water points to promote heterogeneity of wildlife habitats. PMID:27680673

  18. New technologies and the demand for heterogeneous labor: Firm-level evidence for the German business-related services sector

    OpenAIRE

    Kaiser, Ulrich

    1999-01-01

    This paper investigates the impact of modern information and communication technologies on the demand for heterogeneous labor. It starts with an interrelated factor demand system. The "desired" level of employment, which is needed in such models, is derived from a generalized Leontief cost function with quasi-fixed factors. Cross-sectional data taken from an innovation survey in the service sector are used in the empirical analysis. The model is estimated by a trivariate ordered probit model....

  19. Evaluating the potential nitrogen savings without yield loss using variable nitrogen application strategies in a heterogeneous winter wheat field

    DEFF Research Database (Denmark)

    Jørgensen, Rasmus Nyholm; Sørensen, Claus Aage Grøn; Søgaard, Henning Tangen

    During a single growth season, a plot trial was carried out in a selected heterogeneous field in Denmark in an attempt to estimate the optimal variable nitrogen rate applied to winter wheat. 61 Nitrogen/grain yield dose–response curves were estimated using five nitrogen application rates (30, 90,...

  20. Current performance of planter technology to support variable-rate seeding in the Southern US

    Science.gov (United States)

    Advances in planting technology are expanding opportunities to vary seeding rates on–the-go. Variable-rate seeding can help maximize overall profits by matching optimal planting rates to field production variability. An important aspect of variable-rate seeding is ensuring peak performance of the pl...

  1. Shape Morphing Adaptive Radiator Technology (SMART) for Variable Heat Rejection

    Science.gov (United States)

    Erickson, Lisa

    2016-01-01

    The proposed technology leverages the temperature dependent phase change of shape memory alloys (SMAs) to drive the shape of a flexible radiator panel. The opening/closing of the radiator panel, as a function of temperature, passively adapts the radiator's rate of heat rejection in response to a vehicle's needs.

  2. Biobjective Optimization of Radio Access Technology Selection and Resource Allocation in Heterogeneous Wireless Networks

    DEFF Research Database (Denmark)

    Zakrzewska, Anna; D’Andreagiovanni, Fabio; Ruepp, Sarah Renée

    2013-01-01

    We propose a novel optimization model for resource assignment in heterogeneous wireless network. The model adopts two objective functions maximizing the number of served users and the minimum granted utility at once. A distinctive feature of our new model is to consider two consecutive time slots...

  3. ICT Adoption and Heterogeneity in Production Technologies : Evidence for Chilean Retailers

    NARCIS (Netherlands)

    De Vries, Gaaitzen J.; Koetter, Michael

    2011-01-01

    The adoption of information and communication technology (ICT) can have far-reaching effects on the nature of production technologies. Because ICT adoption is incomplete, especially in developing countries, different groups of firms will have different production technologies. We estimate a latent c

  4. Spectral variability on primitive asteroids of the Themis and Beagle families: Space weathering effects or parent body heterogeneity?

    Science.gov (United States)

    Fornasier, S.; Lantz, C.; Perna, D.; Campins, H.; Barucci, M. A.; Nesvorny, D.

    2016-05-01

    Themis is an old and statistically robust asteroid family populating the outer main belt, and resulting from a catastrophic collision that took place 2.5 ± 1.0 Gyr ago. Within the old Themis family a young sub-family, Beagle, formed less than 10 Myr ago, has been identified. We present the results of a spectroscopic survey in the visible and near infrared range of 22 Themis and 8 Beagle families members. The Themis members investigated exhibit a wide range of spectral behaviors, including asteroids with blue/neutral and moderately red spectra, while the younger Beagle family members look spectrally bluer than the Themis ones and they have a much smaller spectral slope variability. Four Themis members, including (24) Themis, have absorption bands centered at 0.68-0.73 μm indicating the presence of aqueously altered minerals. The best meteorite spectral analogues found for both Themis and Beagle families members are carbonaceous chondrites having experienced different degrees of aqueous alteration, prevalently CM2 but also CV3 and CI, and some of them are chondrite samples being unusual or heated. The presence of aqueous altered materials on the asteroids surfaces and the meteorite matches indicate that the parent body of the Themis family experienced mild thermal metamorphism in the past. We extended the spectral analysis including the data available in the literature on Themis and Beagle families members, and we looked for correlations between spectral behavior and physical parameters using the albedo and size values derived from the WISE data. The analysis of this larger sample confirms the spectral diversity within the Themis family and that Beagle members tend to be bluer and to have an higher albedo. The differences between the two families may be partially explained by space weathering processes, which act on these primitive surfaces in a similar way than on S-type asteroids, i.e. producing reddening and darkening. However we see several Themis members

  5. Integration of aerial imaging and variable-rate technology for site-specific aerial herbicide application

    Science.gov (United States)

    As remote sensing and variable rate technology are becoming more available for aerial applicators, practical methodologies on effective integration of these technologies are needed for site-specific aerial applications of crop production and protection materials. The objectives of this study were to...

  6. Sources of inter-firm heterogeneity in accessing knowledge-creation benefits within technology clusters

    NARCIS (Netherlands)

    Arikan, A.; Knoben, J.

    2014-01-01

    We build on recent literature to highlight the distinction between knowledge-diffusion and knowledge-creation benefits of technology clustering and argue that firms located in technology clusters will have differential access to the latter. To explain the antecedents of such differential access, we

  7. Economic homogenization and heterogenization in the EU with the EMU - technological, sectoral and regional

    DEFF Research Database (Denmark)

    Pedersen, Jørgen Lindgaard

    1999-01-01

    Traditional the arguments for the EMU have been founded in arguments from the theory of optimal currency unions. Even if that should be the case there would still be problems if technological development are characterized by increasing returns. In that case growing economic differences according...... to sector, technology and region will be the result....

  8. Laser microdissection and genetic manipulation technologies to probe lignin heterogeneity and configuration in plant cell walls.

    Science.gov (United States)

    Corea, Oliver R A; Ki, Chanyoung; Cardenas, Claudia L; Davin, Laurence B; Lewis, Norman G

    2012-01-01

    Single and multiple T-DNA knockouts of genes encoding arogenate dehydratases (ADTs) in Arabidopsis were obtained in homozygous form. These were analyzed for potential differences in lignin contents and compositions, as well as for distinct phenotypes over growth and development. Of these different lines, distinct reductions in lignin contents were obtained, with those having different G:S ratios depending upon the combination of ADT genes being knocked out. Results from pyrolysis GC/MS analyses indicated that differential carbon flux occurred into the vascular bundles (vb) and interfascicular fibers (if). These results provide additional new insight into factors controlling lignin heterogeneity and configuration.

  9. TRAMS Project: variability and reliability of SRAM memories in sub-22nm bulk-CMOS technologies

    OpenAIRE

    2011-01-01

    The TRAMS (Terascale Reliable Adaptive MEMORY Systems) project addresses in an evolutionary way the ultimate CMOS scaling technologies and paves the way for revolutionary, most promising beyond-CMOS technologies. In this abstract we show the significant variability levels of future 18 and 13 nm device bulk-CMOS technologies as well as its dramatic effect on the yield of memory cells and circuits. Peer Reviewed

  10. Solution Analysis of Universal Wireless Joint Point Technologies for Heterogeneous Tactical Networks

    Science.gov (United States)

    2006-03-01

    NAC Network Admission Control NIC Network Interface Card NM Network Modules NOC Network Operation Centers OFDM Orthogonal Frequency Division...or NOC at a given time. With different wireless technologies having their own advantages and disadvantages, the need for them to transfer data back...mobile NOC Tacticomps (Tactical PDAs) ITT Card Mesh Wireless Technology Diagram (ITT Card) Planned 802.20, 802.16 or 802.11

  11. Predicting Middle School Students' Use of Web 2.0 Technologies out of School Using Home and School Technological Variables

    Science.gov (United States)

    Hughes, Joan E.; Read, Michelle F.; Jones, Sara; Mahometa, Michael

    2015-01-01

    This study used multiple regression to identify predictors of middle school students' Web 2.0 activities out of school, a construct composed of 15 technology activities. Three middle schools participated, where sixth- and seventh-grade students completed a questionnaire. Independent predictor variables included three demographic and five computer…

  12. UWB Array Design Using Variable Zo Technology and Central Force Optimization

    CERN Document Server

    Formato, Richard A

    2011-01-01

    This note applies Variable Zo technology to the design of an Ultra Wideband (UWB) Yagi-Uda array optimized using Central Force Optimization. Variable Zo is a novel and proprietary approach to antenna design and optimization that treats the feed system characteristic impedance, Zo, as a design variable instead of a fixed design parameter as is traditionally done. Variable Zo is applicable to any antenna design or optimization methodology, and using it will generally produce better antenna designs across any user-specified set of performance objectives.

  13. 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;

    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...

  14. BIGFLOW: A numerical code for simulating flow in variably saturated, heterogeneous geologic media. Theory and user`s manaual, Version 1.1

    Energy Technology Data Exchange (ETDEWEB)

    Ababou, R. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France); Bagtzoglou, A.C. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    1993-06-01

    This report documents BIGFLOW 1.1, a numerical code for simulating flow in variably saturated heterogeneous geologic media. It contains the underlying mathematical and numerical models, test problems, benchmarks, and applications of the BIGFLOW code. The BIGFLOW software package is composed of a simulation and an interactive data processing code (DATAFLOW). The simulation code solves linear and nonlinear porous media flow equations based on Darcy`s law, appropriately generalized to account for 3D, deterministic, or random heterogeneity. A modified Picard Scheme is used for linearizing unsaturated flow equations, and preconditioned iterative methods are used for solving the resulting matrix systems. The data processor (DATAFLOW) allows interactive data entry, manipulation, and analysis of 3D datasets. The report contains analyses of computational performance carried out using Cray-2 and Cray-Y/MP8 supercomputers. Benchmark tests include comparisons with other independently developed codes, such as PORFLOW and CMVSFS, and with analytical or semi-analytical solutions.

  15. Heterogeneous uptake of octamethylcyclotetrasiloxane (D 4) and decamethylcyclopentasiloxane (D 5) onto mineral dust aerosol under variable RH conditions

    Science.gov (United States)

    Navea, Juan G.; Xu, Shihe; Stanier, Charles O.; Young, Mark A.; Grassian, Vicki H.

    We have carried out kinetic studies to characterize the heterogeneous decay of octamethylcyclotetrasiloxane (D 4) and decamethylcyclopentasiloxane (D 5) in the presence of representative mineral dust aerosol in order to obtain a better understanding of the atmospheric fate of these siloxanes. The heterogeneous chemistry of D 4 and D 5 with various mineral dusts was studied in an environmental aerosol reaction chamber using FTIR absorption spectroscopy to monitor the reaction. The apparent heterogeneous uptake coefficient, γapp, for D 4 and D 5 with various mineral dusts was measured under dry conditions and as a function of relative humidity (RH). In addition, the effect of initial D 4 and D 5 concentration on the rate and yield of the reaction was examined. The uptake coefficient, γapp, for D 4 and D 5 was similar for the most reactive aerosols tested, with kaolinite ≈hematite > silica. Limited uptake onto carbon black and calcite surfaces was observed for either siloxane. Reaction with hematite and kaolinite resulted in multilayer coverages, suggesting extensive polymerization of D 4 and D 5 on the aerosol surface.

  16. Tracer travel and residence time distributions in highly heterogeneous aquifers: Coupled effect of flow variability and mass transfer

    Science.gov (United States)

    Cvetkovic, V.; Fiori, A.; Dagan, G.

    2016-12-01

    The driving mechanism of tracer transport in aquifers is groundwater flow which is controlled by the heterogeneity of hydraulic properties. We show how hydrodynamics and mass transfer are coupled in a general analytical manner to derive a physically-based (or process-based) residence time distribution for a given integral scale of the hydraulic conductivity; the result can be applied for a broad class of linear mass transfer processes. The derived tracer residence time distribution is a transfer function with parameters to be inferred from combined field and laboratory measurements. It is scalable relative to the correlation length and applicable for an arbitrary statistical distribution of the hydraulic conductivity. Based on the derived residence time distribution, the coefficient of variation and skewness of residence time are illustrated assuming a log-normal hydraulic conductivity field and first-order mass transfer. We show that for a low Damkohler number the coefficient of variation is more strongly influenced by mass transfer than by heterogeneity, whereas skewness is more strongly influenced by heterogeneity.

  17. Adaptive Traffic Route Control in QoS Provisioning for Cognitive Radio Technology with Heterogeneous Wireless Systems

    Science.gov (United States)

    Yamamoto, Toshiaki; Ueda, Tetsuro; Obana, Sadao

    As one of the dynamic spectrum access technologies, “cognitive radio technology,” which aims to improve the spectrum efficiency, has been studied. In cognitive radio networks, each node recognizes radio conditions, and according to them, optimizes its wireless communication routes. Cognitive radio systems integrate the heterogeneous wireless systems not only by switching over them but also aggregating and utilizing them simultaneously. The adaptive control of switchover use and concurrent use of various wireless systems will offer a stable and flexible wireless communication. In this paper, we propose the adaptive traffic route control scheme that provides high quality of service (QoS) for cognitive radio technology, and examine the performance of the proposed scheme through the field trials and computer simulations. The results of field trials show that the adaptive route control according to the radio conditions improves the user IP throughput by more than 20% and reduce the one-way delay to less than 1/6 with the concurrent use of IEEE802.16 and IEEE802.11 wireless media. Moreover, the simulation results assuming hundreds of mobile terminals reveal that the number of users receiving the required QoS of voice over IP (VoIP) service and the total network throughput of FTP users increase by more than twice at the same time with the proposed algorithm. The proposed adaptive traffic route control scheme can enhance the performances of the cognitive radio technologies by providing the appropriate communication routes for various applications to satisfy their required QoS.

  18. [Advanced treatment of coking wastewater with a novel heterogeneous electro-Fenton technology].

    Science.gov (United States)

    Li, Hai-Tao; Li, Yu-Ping; Zhang, An-Yang; Cao, Hong-Bin; Li, Xin-Gang; Zhang, Yi

    2011-01-01

    A novel electro-catalytic reactor, with oxygen-reduction cathode (PAQ/GF), dimensionally stable anode (IrO2-RuO2 -TiO2/ Ti) and heterogeneous catalysts, is developed for advanced treatment of coking wastewater after biological process, integrating cathodic and anodic simultaneous oxidation processes. A PAQ/GF electrode was synthesized by the electro-polymerization of 2-ethyl anthraquinone on graphite felt, which was characterized with cyclic voltametry measurements; the results indicated that the PAQ/GF electrode showed high reversibility for oxidation-reduction reaction of anthraquinone and catalytic activity for O2 reduction to H2O2; 13.5 mmol/L H2O2 was obtained after electrolysis for 6 h at -0.7 V (vs. SCE) and pH 6 with a current efficiency of 50% in a membrane reactor. Fe-Cu/Y350 catalysts, prepared by impregnation method, could catalyze the production of hydroxyl radicals (*OH) from H2O2, which was confirmed both by fading reaction of crystal violet and oxidation of *OH-probe compound (p-chlorobenzoic acid); Fe-Cu/Y350 also showed high catalytic-activity for the oxidation of organics by hypochlorous sodium, because COD removal of coking wastewater reached 26% in the catalytic process while only 11% of COD removal was obtained in the absence of Fe-Cu/Y350. COD removal of coking wastewater reached 49.4% (26.0% and 23.4% in cathodic system and anodic system, respectively) in the developed electrolytic-reactor, which was higher than that of conventional cathodic-anodic-oxidation process (29.8%). At optimal reaction condition of initial COD = 192 mg/L, I = 10A x m(-2) and pH 4-5, more than 50% COD were removed after electrolysis for 1 h. The mechanism might be as follows: in cathodic system, H2O2 is generated from reduction of O2 on PAQ/GF cathode, and catalyzed by Fe-Cu/Y350 for production of *OH, which causes mineralization and degradation of organic pollutants; in anodic system, Cl2 and HClO are generated from Cl- oxidation on IrO2-RuO2-TiO2/Ti anode and the

  19. Training Effects on Older Adults in Information and Communication Technologies Considering Psychosocial Variables

    Science.gov (United States)

    Ferreira, Sónia; Torres, Ana; Mealha, Óscar; Veloso, Ana

    2015-01-01

    The main aim of this study is to contribute knowledge about the impact of the use of information and communication technologies (ICT) on the self-concept, mood, and quality of life of institutionalized older adults in retirement homes and day care centers (Portuguese institutions). It also studies the influence of independent variables such as…

  20. Using traditional methods and indigenous technologies for coping with climate variability

    NARCIS (Netherlands)

    Stigter, C.J.; Zheng Dawei,; Onyewotu, L.O.Z.; Mei Xurong,

    2005-01-01

    In agrometeorology and management of meteorology related natural resources, many traditional methods and indigenous technologies are still in use or being revived for managing low external inputs sustainable agriculture (LEISA) under conditions of climate variability. This paper starts with the intr

  1. Training Effects on Older Adults in Information and Communication Technologies Considering Psychosocial Variables

    Science.gov (United States)

    Ferreira, Sónia; Torres, Ana; Mealha, Óscar; Veloso, Ana

    2015-01-01

    The main aim of this study is to contribute knowledge about the impact of the use of information and communication technologies (ICT) on the self-concept, mood, and quality of life of institutionalized older adults in retirement homes and day care centers (Portuguese institutions). It also studies the influence of independent variables such as…

  2. Unravelling uncertainty and variability in early stage techno-economic assessments of carbon capture technologies

    NARCIS (Netherlands)

    van der Spek, Mijndert; Sanchez Fernandez, Eva; Eldrup, Nils Henrik; Skagestad, Ragnhild; Ramirez, Andrea; Faaij, André

    2017-01-01

    This paper addresses the uncertainty and variability in techno-economic studies of carbon capture technologies, based on a detailed comparison of the results of different studies on postcombustion CO2 capture with advanced amines, and on an in-depth uncertainty analysis using a combination of sensit

  3. Mutations in NFKB2 and potential genetic heterogeneity in patients with DAVID syndrome, having variable endocrine and immune deficiencies

    OpenAIRE

    Brue, Thierry; Quentien, Marie-Hélène; Khetchoumian, Konstantin; Bensa, Marco; Capo-Chichi, José-Mario; Delemer, Brigitte; Balsalobre, Aurelio; Nassif, Christina; Papadimitriou, Dimitris T; Pagnier, Anne; Hasselmann, Caroline; Patry, Lysanne; Schwartzentruber, Jeremy; Souchon, Pierre-François; Takayasu, Shinobu

    2014-01-01

    Background DAVID syndrome is a rare condition combining anterior pituitary hormone deficiency with common variable immunodeficiency. NFKB2 mutations have recently been identified in patients with ACTH and variable immunodeficiency. A similar mutation was previously found in Nfkb2 in the immunodeficient Lym1 mouse strain, but the effect of the mutation on endocrine function was not evaluated. Methods We ascertained six unrelated DAVID syndrome families. We performed whole exome and traditional...

  4. DEVELOPMENT OF A HETEROGENIC DISTRIBUTED ENVIRONMENT FOR SPATIAL DATA PROCESSING USING CLOUD TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    A. S. Garov

    2016-06-01

    Full Text Available We are developing a unified distributed communication environment for processing of spatial data which integrates web-, desktop- and mobile platforms and combines volunteer computing model and public cloud possibilities. The main idea is to create a flexible working environment for research groups, which may be scaled according to required data volume and computing power, while keeping infrastructure costs at minimum. It is based upon the "single window" principle, which combines data access via geoportal functionality, processing possibilities and communication between researchers. Using an innovative software environment the recently developed planetary information system (http://cartsrv.mexlab.ru/geoportal will be updated. The new system will provide spatial data processing, analysis and 3D-visualization and will be tested based on freely available Earth remote sensing data as well as Solar system planetary images from various missions. Based on this approach it will be possible to organize the research and representation of results on a new technology level, which provides more possibilities for immediate and direct reuse of research materials, including data, algorithms, methodology, and components. The new software environment is targeted at remote scientific teams, and will provide access to existing spatial distributed information for which we suggest implementation of a user interface as an advanced front-end, e.g., for virtual globe system.

  5. Development of a Heterogenic Distributed Environment for Spatial Data Processing Using Cloud Technologies

    Science.gov (United States)

    Garov, A. S.; Karachevtseva, I. P.; Matveev, E. V.; Zubarev, A. E.; Florinsky, I. V.

    2016-06-01

    We are developing a unified distributed communication environment for processing of spatial data which integrates web-, desktop- and mobile platforms and combines volunteer computing model and public cloud possibilities. The main idea is to create a flexible working environment for research groups, which may be scaled according to required data volume and computing power, while keeping infrastructure costs at minimum. It is based upon the "single window" principle, which combines data access via geoportal functionality, processing possibilities and communication between researchers. Using an innovative software environment the recently developed planetary information system (http://cartsrv.mexlab.ru/geoportal) will be updated. The new system will provide spatial data processing, analysis and 3D-visualization and will be tested based on freely available Earth remote sensing data as well as Solar system planetary images from various missions. Based on this approach it will be possible to organize the research and representation of results on a new technology level, which provides more possibilities for immediate and direct reuse of research materials, including data, algorithms, methodology, and components. The new software environment is targeted at remote scientific teams, and will provide access to existing spatial distributed information for which we suggest implementation of a user interface as an advanced front-end, e.g., for virtual globe system.

  6. InP-DHBT-on-BiCMOS technology with fT/fmax of 400/350 GHz for heterogeneous integrated millimeter-wave sources

    DEFF Research Database (Denmark)

    Kraemer, Tomas; Ostermay, Ina; Jensen, Thomas;

    2013-01-01

    This paper presents a novel InP-SiGe BiCMOS technology using wafer-scale heterogeneous integration. The vertical stacking of the InP double heterojunction bipolar transistor (DHBT) circuitry directly on top of the BiCMOS wafer enables ultra-broadband interconnects with <0.2 dB insertion loss from...

  7. Improving the technology of surfacing heterogeneous working layer on hot rolling bulky rolls

    Directory of Open Access Journals (Sweden)

    Віталій Петрович Iванов

    2016-07-01

    Full Text Available Ways to increase efficiency of rolls by enhancing resistance to the formation and development of cracks due to the anisotropy of the working layer properties were explored. The destruction mechanisms of such materials were considered. The possibility of cracks deceleration, due to the layer ruptures or abrupt change of its properties has been marked. It has been shown that the optimum combination of the means braking dislocations provides for a rational metal alloying. The analysis of the rolls of rolling mills service conditions as well as the analysis of types of wear and destruction of products made it possible to formulate requirements on the surface layer of the rolls properties. However increase in strength decreases ductility and toughness of the steel. The solution of the problem of the strength and plasticity increase necessitates either methods of metal deep cleaning of contaminants development or significant grain refinement. The part played by structural formations, such as non-metallic inclusions, carbide particles, grain boundaries, etc.in the kinetics of crack propagation has been studied. Since sharp contrast of the properties at the grain boundaries is inconsistent with the requirements of welding technology, the determining factor for making up the working layer is the service conditions. The durability of the roll is determined by allowable wear out of the layer between resharpenings. The correct choice of optimum parameters for the twq adjacent layers - operating and the layer to be maintained is the reserve to improve performance of the roll. The paper has proposed welding-up compositions making it possible to extend the durability due to the optimum ratio of the mechanical and thermal properties of adjacent layers. This approach can improve the durability of the deposited products both at the stage of nucleation and at the stage of thermal fatigue cracks growth

  8. Processing word prosody – behavioral and neuroimaging evidence for heterogeneous performance in a language with variable stress

    Directory of Open Access Journals (Sweden)

    Miriam eHeisterueber

    2014-04-01

    Full Text Available In the present behavioral and fMRI study, we investigated for the first time interindividual variability in word stress processing in a language with variable stress position (German in order to identify behavioral predictors and neural correlates underlying these differences. It has been argued that speakers of languages with variable stress should perform relatively well in tasks tapping into the representation and processing of word stress, given that this is a relevant feature of their language. Nevertheless, in previous studies on word stress processing large degrees of interindividual variability have been observed but were ignored or left unexplained.Twenty-five native speakers of German performed a sequence recall task using both segmental and suprasegmental stimuli. In general, the suprasegmental condition activated a subcortico-cortico-cerebellar network including, amongst others, bilateral inferior frontal gyrus, insula, precuneus, cerebellum, the basal ganglia, pre-SMA and SMA, which has been suggested to be dedicated to the processing of temporal aspects of speech. However, substantial interindividual differences were observed. In particular, main effects of group were observed in the left middle temporal gyrus (below vs. above average performance in stress processing and in the left precuneus (above vs. below average. Moreover, condition (segmental vs. suprasegmental and group (above vs. below average interacted in the right hippocampus and cerebellum. At the behavioral level, differences in word stress processing could be partly explained by individual performance in basic auditory perception including duration discrimination and by working memory performance (WM.We conclude that even in a language with variable stress, interindividual differences in behavioral performance and in the neuro-cognitive foundations of stress processing can be observed which may partly be traced back to individual basic auditory processing and WM

  9. Processing word prosody-behavioral and neuroimaging evidence for heterogeneous performance in a language with variable stress.

    Science.gov (United States)

    Heisterueber, Miriam; Klein, Elise; Willmes, Klaus; Heim, Stefan; Domahs, Frank

    2014-01-01

    In the present behavioral and fMRI study, we investigated for the first time interindividual variability in word stress processing in a language with variable stress position (German) in order to identify behavioral predictors and neural correlates underlying these differences. It has been argued that speakers of languages with variable stress should perform relatively well in tasks tapping into the representation and processing of word stress, given that this is a relevant feature of their language. Nevertheless, in previous studies on word stress processing large degrees of interindividual variability have been observed but were ignored or left unexplained. Twenty-five native speakers of German performed a sequence recall task using both segmental and suprasegmental stimuli. In general, the suprasegmental condition activated a subcortico-cortico-cerebellar network including, amongst others, bilateral inferior frontal gyrus, insula, precuneus, cerebellum, the basal ganglia, pre-SMA and SMA, which has been suggested to be dedicated to the processing of temporal aspects of speech. However, substantial interindividual differences were observed. In particular, main effects of group were observed in the left middle temporal gyrus (below vs. above average performance in stress processing) and in the left precuneus (above vs. below average). Moreover, condition (segmental vs. suprasegmental) and group (above vs. below average) interacted in the right hippocampus and cerebellum. At the behavioral level, differences in word stress processing could be partly explained by individual performance in basic auditory perception including duration discrimination and by working memory performance (WM). We conclude that even in a language with variable stress, interindividual differences in behavioral performance and in the neuro-cognitive foundations of stress processing can be observed which may partly be traced back to individual basic auditory processing and WM performance.

  10. 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.

  11. Ultra-High Voltage DC Convertor Station Equipment Condition Data Access Technology Based on multi-Source Heterogeneous Fusion

    Science.gov (United States)

    Wang, Feng; Zhang, Bo-wen; Han, Shuai; Ren, Wei; Xu, Hai-jun; Fu, Long-ming

    2017-07-01

    With the large-scale construction of special high-voltage project, as well as power supply reliability, security, economic and other increasingly demanding, state monitoring equipment involved in more and more monitoring projects and more and more monitoring data, because these data exist in multiple isolated systems in the Ultra-High Voltage(UHV) AC-DC substation, there is no data sharing mechanism, so a holistic analysis, application and sharing approach for the data set will need a deep consideration. In this paper, the equipment condition monitoring system frame of the UHV converter station and the scheme of the equipment state data access of UHV converter station based on the multi-source and heterogeneous data fusion are presented. Then, data exchange technology of UHV equipment state early warning center was introduced, and a data access and conversion device in the Zhongzhou converter station was deployed to solve the timeliness and functionality difficult of the existing system to meet the requirements of UHV operation and maintenance support.

  12. Variable pitch fan system for NASA/Navy research and technology aircraft

    Science.gov (United States)

    Ryan, W. P.; Black, D. M.; Yates, A. F.

    1977-01-01

    Preliminary design of a shaft driven, variable-pitch lift fan and lift-cruise fan was conducted for a V/STOL Research and Technology Aircraft. The lift fan and lift-cruise fan employed a common rotor of 157.5 cm diameter, 1.18 pressure ratio variable-pitch fan designed to operate at a rotor-tip speed of 284 mps. Fan performance maps were prepared and detailed aerodynamic characteristics were established. Cost/weight/risk trade studies were conducted for the blade and fan case. Structural sizing was conducted for major components and weights determined for both the lift and lift-cruise fans.

  13. Simulating secondary waterflooding in heterogeneous rocks with variable wettability using an image-based, multiscale pore network model

    Science.gov (United States)

    Bultreys, Tom; Van Hoorebeke, Luc; Cnudde, Veerle

    2016-09-01

    The two-phase flow properties of natural rocks depend strongly on their pore structure and wettability, both of which are often heterogeneous throughout the rock. To better understand and predict these properties, image-based models are being developed. Resulting simulations are however problematic in several important classes of rocks with broad pore-size distributions. We present a new multiscale pore network model to simulate secondary waterflooding in these rocks, which may undergo wettability alteration after primary drainage. This novel approach permits to include the effect of microporosity on the imbibition sequence without the need to describe each individual micropore. Instead, we show that fluid transport through unresolved pores can be taken into account in an upscaled fashion, by the inclusion of symbolic links between macropores, resulting in strongly decreased computational demands. Rules to describe the behavior of these links in the quasistatic invasion sequence are derived from percolation theory. The model is validated by comparison to a fully detailed network representation, which takes each separate micropore into account. Strongly and weakly water-and oil-wet simulations show good results, as do mixed-wettability scenarios with different pore-scale wettability distributions. We also show simulations on a network extracted from a micro-CT scan of Estaillades limestone, which yields good agreement with water-wet and mixed-wet experimental results.

  14. TECHNOLOGY ENSURING PROTECTION OF COMPUTER NETWORKS USING THE MEANS VARIABLE IN COMPOSITION

    Directory of Open Access Journals (Sweden)

    Nadezhda Evgenyevna GALASHINA

    2015-01-01

    Full Text Available The article describes the dependence of steady operation of computer network on a deliberate change of operation modes of software and hardware.The authors consider the technologies ensuring computer network security with the use of the means variable in time and with the use of the means variable in nomenclature. Structure of the technology ensuring protection of computer networks using the softwares compatible in nomenclature has been worked through. To verify the practical implementation of the nomenclature method using two programs BitLocker and TrueCrypt was used the virtualization program VMware Workstation 11 with the operating system Microsoft Windows 7 Enterprise without a TPM. 

  15. Variable conductance heat pipe technology for precise temperature control of the NASA/DDLT transmitter

    Science.gov (United States)

    Vanevenhoven, D. E.; Antoniak, D.

    1989-01-01

    The application of variable conductance heat pipe technology for achieving precise temperature control to + or - 0.1 C for a space-based laser diode transmitter is described. Heat pipe theory of operation and test data are presented along with a discussion of its applicability for NASA's Direct Detection Laser Transceiver (DDLT) program. This design for the DDLT transmitter features a reduction in space radiator size and up to 42 percent reduction in prime power requirements.

  16. Coping with spatial heterogeneity and temporal variability in resources and risks: adaptive movement behaviour by a large grazing herbivore.

    Directory of Open Access Journals (Sweden)

    Jodie Martin

    Full Text Available Movement is a key mean for mobile species to cope with heterogeneous environments. While in herbivorous mammals large-scale migration has been widely investigated, fine-scale movement responses to local variations in resources and predation risk remain much less studied, especially in savannah environments. We developed a novel approach based on complementary movement metrics (residence time, frequency of visits and regularity of visits to relate movement patterns of a savannah grazer, the blue wildebeest Connochaetes taurinus, to fine-scale variations in food availability, predation risk and water availability in the Kruger National Park, South Africa. Wildebeests spent more time in grazing lawns where the grass is of higher quality but shorter than in seep zones, where the grass is of lower quality but more abundant. Although the daily distances moved were longer during the wet season compared to the dry season, the daily net displacement was lower, and the residence time higher, indicating a more frequent occurrence of area-concentred searching. In contrast, during the late dry season the foraging sessions were more fragmented and wildebeests moved more frequently between foraging areas. Surprisingly, predation risk appeared to be the second factor, after water availability, influencing movement during the dry season, when resources are limiting and thus expected to influence movement more. Our approach, using complementary analyses of different movement metrics, provided an integrated view of changes in individual movement with varying environmental conditions and predation risk. It makes it possible to highlight the adaptive behavioral decisions made by wildebeest to cope with unpredictable environmental variations and provides insights for population conservation.

  17. Modelling radionuclide transport in highly heterogeneous media and under variable hydrochemical conditions using a "dynamic Kd" approach

    Science.gov (United States)

    Trinchero, Paolo; Painter, Scott; Ebrahimi, Hedieh; Koskinen, Lasse; Molinero, jorge; Selroos, Jan-Olof

    2015-04-01

    Due to the high heterogeneity of fractured media and the ubiquitous lack of a complete site characterization, deterministic simulations of radionuclide transport in fractured rocks are notoriously highly uncertain. This uncertainty is usually addressed using stochastic methods; e.g. the connectivity structure of the medium is described using multiple realizations of Discrete Fracture Networks (DFN), which are then combined to particle tracking simulations. In these formulations, many complex geochemical retention processes are typically lumped into a single parameter: the distribution coefficient (Kd). This approach relies on an important assumption: the Kd values are constant in time. This hypothesis is critical under long-term geochemical changes as it is known that the distribution coefficient depends on the pH, redox conditions and major chemistry of the system. In this work, we present a novel methodology that combines the robustness of stochastic methods with an explicit description of water-solute-rock interaction processes. The reconciliation of all these is achieved by using a dynamic Kd approach. The hydrogeochemical evolution of the site of study is first computed using long-term and large-scale mechanistic reactive transport simulations. The simulated hydrochemical conditions are then used to generate a complete database of Kd values, which represent the hydrochemical conditions in every position and time of the model domain. Then, MARFA (Painter and Mancillas, 2009) is used to carry out Time Domain Random Walk (TDRW) simulations of radionuclide transport. In these simulations, Kd values are dynamically updated using the afore-mentioned database. The results (i.e. radionuclide breakthrough curves) bring the signature of the underlying changes in the background geochemistry.

  18. Twelve years of change in coastal upwelling along the central-northern coast of Chile: spatially heterogeneous responses to climatic variability.

    Directory of Open Access Journals (Sweden)

    Guillermo Aravena

    Full Text Available We use time-series analyses to characterize the effects of recent climate variability upon the local physical conditions at 11 study sites along the northern-central coast of Chile (29-34°S. Environmental indices show that the 1° Bakun upwelling index in this coastal region has fluctuated in time, starting from a stable period around the 1980's, peaking during the mid 90s, decreasing during the next ten years and increasing at a steep rate since 2010. Upwelling intensity decreased with increasing latitude, showing also a negative correlation with climate patterns (El Niño3 sea surface temperature-SST anomalies and the Multivariate El Niño Index. We hypothesize that the impacts of climate variability on upwelling events seem to be spatially heterogeneous along the region. Non-sheltered locations and, particularly, sites on prominent headlands show an immediate (lag = 0 and negative correlation between local SST, upwelling events and wind stress. We suggest that near-shore thermal conditions are closely coupled to large-scale forcing of upwelling variability and that this influence is modulated through local topographic factors.

  19. Twelve years of change in coastal upwelling along the central-northern coast of Chile: spatially heterogeneous responses to climatic variability.

    Science.gov (United States)

    Aravena, Guillermo; Broitman, Bernardo; Stenseth, Nils Christian

    2014-01-01

    We use time-series analyses to characterize the effects of recent climate variability upon the local physical conditions at 11 study sites along the northern-central coast of Chile (29-34°S). Environmental indices show that the 1° Bakun upwelling index in this coastal region has fluctuated in time, starting from a stable period around the 1980's, peaking during the mid 90s, decreasing during the next ten years and increasing at a steep rate since 2010. Upwelling intensity decreased with increasing latitude, showing also a negative correlation with climate patterns (El Niño3 sea surface temperature-SST anomalies and the Multivariate El Niño Index). We hypothesize that the impacts of climate variability on upwelling events seem to be spatially heterogeneous along the region. Non-sheltered locations and, particularly, sites on prominent headlands show an immediate (lag = 0) and negative correlation between local SST, upwelling events and wind stress. We suggest that near-shore thermal conditions are closely coupled to large-scale forcing of upwelling variability and that this influence is modulated through local topographic factors.

  20. Genetic variability and heterogeneity of Venezuelan equine encephalitis virus vector Ochlerotatus taeniorhynchus (Diptera: Culicidae) populations of the Colombian Atlantic coast, based on microsatellite loci.

    Science.gov (United States)

    Bello, F; Becerra, V

    2009-09-29

    In Colombia, the mosquito Ochlerotatus taeniorhynchus has been identified as an efficient vector of the epidemic-epizootic Venezuelan equine encephalitis virus. We evaluated the genetic variability and heterogeneity of this mosquito in Colombian populations using eight microsatellite DNA loci. Two hundred and ten mosquito specimens collected from seven populations of the Colombian Atlantic coast (San Bernardo del Viento, Coveñas, Cartagena, Barranquilla, Ciénaga, Dibulla, and Riohacha) were analyzed. We found five polymorphic microsatellite loci, with 19 alleles giving 62.5% polymorphism; the mean number of alleles per locus was 3.8. The mean expected heterogeneity ranged from 0.568 to 0.660. Most of the polymorphic microsatellite loci were in Hardy-Weinberg disequilibrium, due to both deficit and excess of heterozygotes. The Fst statistic gave a total value of 0.0369, reflecting low genetic differentiation among the populations and, as a consequence, a low degree of structuring among them, while gene flow was high (Nm = 6.52); these findings point to genetic homogeneity among these populations. There was no significant linkage disequilibrium between genotype pairs of the various populations. We concluded that this mosquito is distributed in local populations along the Colombian Atlantic coast; these findings will be useful for developing strategies for controlling this vector.

  1. HETEROGENEOUS INTEGRATION TECHNOLOGY

    Science.gov (United States)

    2017-08-24

    in- package integration. It involves the integration of circuits from fully processed wafers using micro- bumps and TSVs. There are 3 basic kinds of... bumping ” and “Cu-to-Cu” categories. The first approach involves the fabrication of micro- bumps on both sides of the thinned wafers with TSVs, and...interfacing wafers with bumps aligned. The application of pressure and heat makes permanent contact between bumps . A thin adhesive layer can be used between

  2. Preliminary Assessment of Variable Speed Power Turbine Technology on Civil Tiltrotor Size and Performance

    Science.gov (United States)

    Snyder, Christopher A.; Acree, Cecil W., Jr.

    2012-01-01

    A Large Civil Tiltrotor (LCTR) conceptual design was developed as part of the NASA Heavy Lift Rotorcraft Systems Investigation in order to establish a consistent basis for evaluating the benefits of advanced technology for large tiltrotors. The concept has since evolved into the second-generation LCTR2, designed to carry 90 passengers for 1,000 nm at 300 knots, with vertical takeoff and landing capability. This paper performs a preliminary assessment of variable-speed power turbine technology on LCTR2 sizing, while maintaining the same, advanced technology engine core. Six concepts were studied; an advanced, single-speed engine with a conventional power turbine layout (Advanced Conventional Engine, or ACE) using a multi-speed (shifting) gearbox. There were five variable-speed power turbine (VSPT) engine concepts, comprising a matrix of either three or four turbine stages, and fixed or variable guide vanes; plus a minimum weight, twostage, fixed-geometry VSPT. The ACE is the lightest engine, but requires a multi-speed (shifting) gearbox to maximize its fuel efficiency, whereas the VSPT concepts use a lighter, fixed-ratio gearbox. The NASA Design and Analysis of Rotorcraft (NDARC) design code was used to study the trades between rotor and engine efficiency and weight. Rotor performance was determined by Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II), and engine performance was estimated with the Numerical Propulsion System Simulation (NPSS). Design trades for the ACE vs. VSPT are presented in terms of vehicle gross and empty weight, propulsion system weight and mission fuel burn for the civil mission. Because of its strong effect on gearbox weight and on both rotor and engine efficiency, rotor speed was chosen as the reference design variable for comparing design trades. Major study assumptions are presented and discussed. Impressive engine power-to-weight and fuel efficiency reduced vehicle sensitivity to propulsion system choice

  3. MHD Stagnation Point Flow of Williamson Fluid over a Stretching Cylinder with Variable Thermal Conductivity and Homogeneous/Heterogeneous Reaction

    Science.gov (United States)

    Bilal, M.; Sagheer, M.; Hussain, S.; Mehmood, Y.

    2017-06-01

    The present study reveals the effect of homogeneous/hetereogeneous reaction on stagnation point flow of Williamson fluid in the presence of magnetohydrodynamics and heat generation/absorption coefficient over a stretching cylinder. Further the effects of variable thermal conductivity and thermal stratification are also considered. The governing partial differential equations are converted to ordinary differential equations with the help of similarity transformation. The system of coupled non-linear ordinary differential equations is then solved by shooting technique. MATLAB shooting code is validated by comparison with the previously published work in limiting case. Results are further strengthened when the present results are compared with MATLAB built-in function bvp4c. Effects of prominent parameters are deliberated graphically for the velocity, temperature and concentration profiles. Skin-friction coefficient and Nusselt number for the different parameters are investigated with the help of tables.

  4. Heterogeneous Disease Trajectories Explain Variable Radiographic, Function and Quality of Life Outcomes in the Canadian Early Arthritis Cohort (CATCH.

    Directory of Open Access Journals (Sweden)

    Cheryl Barnabe

    Full Text Available Our objective was to identify distinct trajectories of disease activity state (DAS and assess variation in radiographic progression, function and quality of life over the first two years of early rheumatoid arthritis (ERA. The CATCH (Canadian early ArThritis CoHort is a prospective study recruiting ERA patients from academic and community rheumatology clinics in Canada. Sequential DAS28 scores were used to identify five mutually exclusive groups in the cohort (n = 1,586 using growth-based trajectory modeling. Distinguishing baseline sociodemographic and disease variables, treatment required, and differences in radiographic progression and quality of life measures over two years were assessed. The trajectory groups are characterized as: Group 1 (20% initial high DAS improving rapidly to remission (REM; Group 2 (21% initial moderate DAS improving rapidly to REM; Group 3 (30% initial moderate DAS improving gradually to low DAS; Group 4 (19% initial high DAS improving continuously to low DAS; and Group 5 (10% initial high DAS improving gradually only to moderate DAS. Groups differed significantly in age, sex, race, education, employment, income and presence of comorbidities. Group 5 had persistent steroid requirements and the highest biologic therapy use. Group 2 had lower odds (OR 0.22, 95%CI 0.09 to 0.58 and Group 4 higher odds (OR 1.94, 95%CI 0.90 to 4.20 of radiographic progression compared to Group 1. Group 1 had the best improvement in physical function (Health Assessment Questionnaire 1.08 (SD 0.68 units, Physical Component Score (16.4 (SD 10.2 units, Mental Component Score (9.7 (SD 12.5 units and fatigue (4.1 (SD 3.3 units. In conclusion, distinct disease activity state trajectories explain variable outcomes in ERA. Early prediction of disease course to tailor therapy and addressing social determinants of health could optimize outcomes.

  5. The Impacts of Demographic Variables on Technological and Contextual Challenges of E-learning Implementation

    Science.gov (United States)

    Aldowah, Hanan; Ghazal, Samar; Naufal Umar, Irfan; Muniandy, Balakrishnan

    2017-09-01

    Information technology has achieved robust growth which has made it possible for learning to occur quickly. The rapid development of information, communication and technologies (ICT) has initiated an unparalleled transformation in universities all over the world. This development of technology and learning is offering new techniques to represent knowledge, new practices, and new global communities of learners. As a result, today’s economic and social changes force universities to try to find new learning approaches and systems. E-learning seems to be an appropriate approach in this aspect. However, the implementation of e-learning systems in universities is not an easy task because of some challenges related to context, technology, and other challenges. This paper studied the impacts of demographic data and reported the critical points for the decision makers to consider when planning and implementing e-learning in universities. A quantitative approach was used to study the effects of technological and contextual challenges on e-learning implementation in which a questionnaire was used for the data collection. According to the findings of the study, the most important challenges of the implementation of e-learning are related either to organizational (Contextual) and technological (technical) issues. The demographic variables have been found to play a direct and indirect role with the technological and contextual challenges of implementing e-learning. This paper showed that there are some significant differences in the two challenges faced by instructors in terms of the demographic variables. The result revealed that some significant differences exist between demographic variables and the two challenges of e-learning in terms of gender, age, teaching experience, ICT experience and e-learning experience. However, there is no significant difference in terms of e-learning experience. The obtained data, from such study, can provide information about what academic

  6. Use of precision agriculture technology to investigate spatial variability in nitrogen yields in cut grassland.

    Science.gov (United States)

    Bailey, J S; Wang, K; Jordan, C; Higgins, A

    2001-01-01

    Spatial variability in N uptake and utilisation by swards within uniformly managed field units could be responsible for a significant proportion of the NH3, N2O, NO3- and NOx (NO and NO2) 'pollutants' generated by agriculture and released to the environment. An investigation was commenced, therefore, to quantify, map and explain the spatial variability in sward N yield in a 'large' silage field and to assess the potential for managing this variability using some of the latest precision agriculture technology. Sward dry matter (DM) and N yields were predicted from the results of plant tissue analyses using mathematical models. Sward N yields were found to vary greatly across the field seemingly because of differences in net soil N mineralisation, but the pattern of variability appeared to remain constant with time. Conventional soil analysis of a range of soil chemical and physical properties, however, failed to explain this variability. It was concluded that the N-yield distribution map might be used in place of soil analysis as the basis for varying the rates of N application to different parts of the field with the twin objectives of maximising fertiliser use efficiency and minimising N emissions to air and water.

  7. Variable viscosity and density biofilm simulations using an immersed boundary method, part II: Experimental validation and the heterogeneous rheology-IBM

    Science.gov (United States)

    Stotsky, Jay A.; Hammond, Jason F.; Pavlovsky, Leonid; Stewart, Elizabeth J.; Younger, John G.; Solomon, Michael J.; Bortz, David M.

    2016-07-01

    The goal of this work is to develop a numerical simulation that accurately captures the biomechanical response of bacterial biofilms and their associated extracellular matrix (ECM). In this, the second of a two-part effort, the primary focus is on formally presenting the heterogeneous rheology Immersed Boundary Method (hrIBM) and validating our model by comparison to experimental results. With this extension of the Immersed Boundary Method (IBM), we use the techniques originally developed in Part I ([19]) to treat biofilms as viscoelastic fluids possessing variable rheological properties anchored to a set of moving locations (i.e., the bacteria locations). In particular, we incorporate spatially continuous variable viscosity and density fields into our model. Although in [14,15], variable viscosity is used in an IBM context to model discrete viscosity changes across interfaces, to our knowledge this work and Part I are the first to apply the IBM to model a continuously variable viscosity field. We validate our modeling approach from Part I by comparing dynamic moduli and compliance moduli computed from our model to data from mechanical characterization experiments on Staphylococcus epidermidis biofilms. The experimental setup is described in [26] in which biofilms are grown and tested in a parallel plate rheometer. In order to initialize the positions of bacteria in the biofilm, experimentally obtained three dimensional coordinate data was used. One of the major conclusions of this effort is that treating the spring-like connections between bacteria as Maxwell or Zener elements provides good agreement with the mechanical characterization data. We also found that initializing the simulations with different coordinate data sets only led to small changes in the mechanical characterization results. Matlab code used to produce results in this paper will be available at https://github.com/MathBioCU/BiofilmSim.

  8. Spectral variability on primitive asteroids of the Themis and Beagle families: space weathering effects or parent body heterogeneity?

    CERN Document Server

    Fornasier, S; Perna, D; Campins, H; Barucci, M A; Nesvorny, D

    2016-01-01

    Themis is an old and statistically robust asteroid family populating the outer main belt, and resulting from a catastrophic collision that took place 2.5$\\pm$1.0 Gyr ago. Within the old Themis family a young sub-family, Beagle, formed less than 10 Myr ago, has been identified. We present the results of a spectroscopic survey in the visible and near infrared range of 22 Themis and 8 Beagle families members. The Themis members investigated exhibit a wide range of spectral behaviors, while the younger Beagle family members look spectrally bluer with a smaller spectral slope variability. The best meteorite spectral analogues found for both Themis and Beagle families members are carbonaceous chondrites having experienced different degrees of aqueous alteration, prevalently CM2 but also CV3 and CI, and some of them are chondrite samples being unusual or heated. We extended the spectral analysis including the data available in the literature on Themis and Beagle families members, and we looked for correlations betwe...

  9. Space Technology 5 (ST-5) Observations of Field-Aligned Currents: Temporal Variability

    Science.gov (United States)

    Le, Guan

    2010-01-01

    Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from STS. The data demonstrate that masoscale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of about 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are about I min for meso-scale currents and about 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  10. Space Technology 5 Multi-Point Observations of Temporal Variability of Field-Aligned Currents

    Science.gov (United States)

    Le, Guan; Wang, Yongli; Slavin, James A.; Strangeway, Robert J.

    2008-01-01

    Space Technology 5 (ST5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that meso-scale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of approximately 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are approximately 1 min for meso-scale currents and approximately 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  11. Variable conductance heat pipe technology. [research project resulting in heat pipe experiment on OAO-3 satellite

    Science.gov (United States)

    Anderson, W. T.; Edwards, D. K.; Eninger, J. E.; Marcus, B. D.

    1974-01-01

    A research and development program in variable conductance heat pipe technology is reported. The project involved: (1) theoretical and/or experimental studies in hydrostatics, (2) hydrodynamics, (3) heat transfer into and out of the pipe, (4) fluid selection, and (5) materials compatibility. The development, fabrication, and test of the space hardware resulted in a successful flight of the heat pipe experiment on the OAO-3 satellite. A summary of the program is provided and a guide to the location of publications on the project is included.

  12. 基于solr的异构数据融合检索技术%The Retrieval Technology of Heterogeneous Data Integration Based on Solr

    Institute of Scientific and Technical Information of China (English)

    梁艳; 刘双广; 劳定雄

    2013-01-01

      For the need of enterprise heterogeneous data integration retrieval, this thesis introduces the common method of heterogeneous data integration and the basic function of Solr which is enterprise search server. Combined the XML heterogeneous data integration with the Chinese word segmentation technology and the friendlyuserinterface,thispaperbuilttheheterogeneousdataintegrationretrievalsystembasedonSolr,realized the indexing and retrieval of XML document and provided solutions for heterogeneous data integration retrieval.%  针对企业异构数据融合检索的需求,介绍了异构数据整合的常用方法和企业级搜索服务器solr的基本功能,结合xml异构数据整合、中文分词技术和友好的用户界面搭建了基于solr的异构数据融合检索系统,实现了对xml文件的索引和检索,为异构数据融合检索提供了解决方案。

  13. LCA of emerging technologies: addressing high uncertainty on inputs' variability when performing global sensitivity analysis.

    Science.gov (United States)

    Lacirignola, Martino; Blanc, Philippe; Girard, Robin; Pérez-López, Paula; Blanc, Isabelle

    2017-02-01

    In the life cycle assessment (LCA) context, global sensitivity analysis (GSA) has been identified by several authors as a relevant practice to enhance the understanding of the model's structure and ensure reliability and credibility of the LCA results. GSA allows establishing a ranking among the input parameters, according to their influence on the variability of the output. Such feature is of high interest in particular when aiming at defining parameterized LCA models. When performing a GSA, the description of the variability of each input parameter may affect the results. This aspect is critical when studying new products or emerging technologies, where data regarding the model inputs are very uncertain and may cause misleading GSA outcomes, such as inappropriate input rankings. A systematic assessment of this sensitivity issue is now proposed. We develop a methodology to analyze the sensitivity of the GSA results (i.e. the stability of the ranking of the inputs) with respect to the description of such inputs of the model (i.e. the definition of their inherent variability). With this research, we aim at enriching the debate on the application of GSA to LCAs affected by high uncertainties. We illustrate its application with a case study, aiming at the elaboration of a simple model expressing the life cycle greenhouse gas emissions of enhanced geothermal systems (EGS) as a function of few key parameters. Our methodology allows identifying the key inputs of the LCA model, taking into account the uncertainty related to their description.

  14. Space Technology 5 Multipoint Observations of Temporal and Spatial Variability of Field-Aligned Currents

    Science.gov (United States)

    Le, G.; Wang, Y.; Slavin, J. A.; Strangeway, R. L.

    2009-01-01

    Space Technology 5 (ST5) is a constellation mission consisting of three microsatellites. It provides the first multipoint magnetic field measurements in low Earth orbit, which enables us to separate spatial and temporal variations. In this paper, we present a study of the temporal variability of field-aligned currents using the ST5 data. We examine the field-aligned current observations during and after a geomagnetic storm and compare the magnetic field profiles at the three spacecraft. The multipoint data demonstrate that mesoscale current structures, commonly embedded within large-scale current sheets, are very dynamic with highly variable current density and/or polarity in approx.10 min time scales. On the other hand, the data also show that the time scales for the currents to be relatively stable are approx.1 min for mesoscale currents and approx.10 min for large-scale currents. These temporal features are very likely associated with dynamic variations of their charge carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of mesoscale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  15. The Relationships Between Selected Organizational Variables and ATM Technology Adoption in Campus Networking

    Science.gov (United States)

    Yao, Engui

    1998-06-01

    ATM (Asynchronous Transfer Mode) is an emerging technology in computer networking, which, in turn, is the physical media of information systems and networking/telecommunication systems. The technology provides potentiality for universities to build their networks based on the future vision of uniting voice, data, and video communications on ATM-technology-based equipment. A review of the literature revealed that minimal evidence exists to indicate whether the size, type, financial factors, and information processing maturity of a university affect a university's high-tech innovation adoptions. No research of this nature has been undertaken in the study of ATM adoption in any institutions of higher learning, nor has any research of this nature been found in other organizations, either. Such evidence is needed by university administrators, information systems managers, and LAN managers to understand their universities better, whether they have or have not adopted ATM, and to evaluate their current administrative, academic, and financial situations and current campus networking situations. The purpose of this study was to determine the relationships between ATM adoption and four organizational variables: university size, type, finances, and information processing maturity. Another purpose of the study was to identify the current status of ATM adoption in campus networking in the United States. Logistic regression was used as the statistical data analysis method. The results of the study provided evidence to show that ATM adoption in campus networking is significantly related to university size, university type, university finances, and university information processing maturity.

  16. Fully Scaled 0.5 Micron CMOS Technology Using Variable Shaped Electron Beam Lithography

    Science.gov (United States)

    Coane, Philip; Rudeck, Paul; Wang, Li-Kong; Wilson, Alan; Hohn, Fritz

    1988-06-01

    Over the past several years, CMOS technology has been continuously driven to achieve enhanced performance and higher density. The resulting reduction in semiconductor dimensions has surpasssed the limits attainable by the most advanced optical lithography tools. As a result, the utilization of electron beam lithography direct writing techniques to satisfy VLSI patterning requirements has increased significantly. In principle, variable shaped electron beam systems are capable of writing linewidths down to at least 0.1 micron. However, the successful application of sub-micron scaling principles to device fabrication involves an integration of tool capability and resist process control. In order to achieve the realization of improved CMOS device performance and circuit density, sub-micron ground rules (line width control and overlay) must be satisfied over the full chip. This paper reports on a high performance, fully scaled 0.5 micron CMOS technology developed for VLSI appli-cations. Significant gains in both density and performance at reduced power supply levels are realized over previously reported 1.0 micron technology. The details of the integrated lithography strategy used to achieve these results are presented.

  17. XML在Domino环境中异构数据交换技术应用%Application of XML Technology on Heterogeneous Data Exchange in Domino Environment

    Institute of Scientific and Technical Information of China (English)

    张正做; 周霖

    2013-01-01

      To effectively solve the problem of heterogeneous data integration between the drug testing management system and other systems, introduces the principle of data change using XML in Lotus Domino platform, and particularly discusses the technology of drug information exchange under the environment of Lotus Domino platform based on the XML technology. Obtains a conclusion that the corresponding application system will be flexibility and portability if uses the technology of XML for heterogeneous data change.%  为了解决本院药品检验系统中内部数据与外部数据集成问题,概括介绍利用XML在Lotus Domino 环境中进行数据交换的原理,并详细讨论在Lotus Domino环境中利用XML 实现检品信息交换的技术,得出结论在Lotus Domino环境中利用XML进行异构数据交换为应用系统带来更大的灵活性。

  18. Impact of wine technology on the variability of resveratrol and piceids in Saperavi (Vitis vinifera L.

    Directory of Open Access Journals (Sweden)

    M.A. Surguladze

    2017-03-01

    Full Text Available The biologically active stilbenoids-resveratrol and its glucosides were identified in the dry bulk wines of different types made with red-grape vintage variety of Saperavi (Vitis vinifera L.: cis-resveratrol, trans-resveratrol, cis-piceid and trans-piceid. Red and pink wines were made by different technology: I – dry, pink, of a European type; alcoholic fermentation with natural microflora; II – dry, pink, of a European type; alcoholic fermentation with dry yeast “B2000”. III – red, dry; alcoholic fermentation with no-stem pomace and aging on it for 5 months; IV – dry, red, of a Kakhetian type; alcoholic fermentation with stem pomace with natural microflora and aging on it for 5 months; V – dry, red, of a Kakhetian type, with preliminary fermentation of cluster stems, then, alcoholic fermentation with natural microflora and aging on it for 5 months. The impact of the wine-making technology on the variability of the concentrations of these substances is proved. Kakhetian bulk wines (IV and V also differ from one another. Bulk wine-V made by the fermentation of grappa fermented in advance contains little concentration of study stilbenoids as a result of the oxidation transformations caused by the preliminary treatment. The role of grape juice, stem and seed in the localization of resveratrols and piceids in the bulk wines is identified.

  19. Assessment of Label-Free Quantification in Discovery Proteomics and Impact of Technological Factors and Natural Variability of Protein Abundance.

    Science.gov (United States)

    Al Shweiki, Mhd Rami; Mönchgesang, Susann; Majovsky, Petra; Thieme, Domenika; Trutschel, Diana; Hoehenwarter, Wolfgang

    2017-04-07

    We evaluated the state of label-free discovery proteomics focusing especially on technological contributions and contributions of naturally occurring differences in protein abundance to the intersample variability in protein abundance estimates in this highly peptide-centric technology. First, the performance of popular quantitative proteomics software, Proteome Discoverer, Scaffold, MaxQuant, and Progenesis QIP, was benchmarked using their default parameters and some modified settings. Beyond this, the intersample variability in protein abundance estimates was decomposed into variability introduced by the entire technology itself and variable protein amounts inherent to individual plants of the Arabidopsis thaliana Col-0 accession. The technical component was considerably higher than the biological intersample variability, suggesting an effect on the degree and validity of reported biological changes in protein abundance. Surprisingly, the biological variability, protein abundance estimates, and protein fold changes were recorded differently by the software used to quantify the proteins, warranting caution in the comparison of discovery proteomics results. As expected, ∼99% of the proteome was invariant in the isogenic plants in the absence of environmental factors; however, few proteins showed substantial quantitative variability. This naturally occurring variation between individual organisms can have an impact on the causality of reported protein fold changes.

  20. Public acceptance of energy technologies : The effects of labeling, time, and heterogeneity in a discrete choice experiment

    NARCIS (Netherlands)

    Van Rijnsoever, Frank J.; Van Mossel, Allard; Broecks, Kevin P F

    2015-01-01

    Public acceptance is crucial for successful implementation of energy technologies in society. However, studies that use the concept do so in diverse and often inconsistent ways. They also often limit themselves to specific technologies and do not account for the effects of labeling, time, and the

  1. Public acceptance of energy technologies : The effects of labeling, time, and heterogeneity in a discrete choice experiment

    NARCIS (Netherlands)

    Van Rijnsoever, Frank J.; Van Mossel, Allard; Broecks, Kevin P F

    2015-01-01

    Public acceptance is crucial for successful implementation of energy technologies in society. However, studies that use the concept do so in diverse and often inconsistent ways. They also often limit themselves to specific technologies and do not account for the effects of labeling, time, and the he

  2. Preparation of single chain variable fragment of MG7 mAb by phage display technology

    Institute of Scientific and Technical Information of China (English)

    Zhao-Cai Yu; Jie Ding; Yong-Zhan Nie; Dai-Ming Fan; Xue-Yong Zhang

    2001-01-01

    AIM To develop the single chain variable fragment of MG7 murine anti-human gastric cancer monoclonal antibody using the phage display technology for obtaining a tumor-targeting mediator. METHODS mRNA was isolated from MG7-producing murine hybridoma cell line and converted into cDNA. The variable fragments of heavy and light chain were amplified separately and assembled into ScFv with a specially constructed DNA linker by PCR. The ScFvs DNA was ligated into the phagmid vector pCANTAB5E and the ligated sample was transformed into competent E. Coli TG1. The transformed cells were infected with M13K07 helper phage to form MG7 recombinant phage antibody library. The volume and recombinant rate of the library were evaluated by means of bacterial colony count and restriction analysis. After two rounds of panning with gastric cancer cell line KATOⅢ of highly expressing MG7binding antigen, the phage clones displaying ScFv of the antibody were selected by ELISA from the enriched phage clones. The antigen-binding affinity of the positive clone was detected by competition ELISA. HB2151 E. Coli was transfected with the positive phage clone demonstrated by competition ELISA for production of a soluble form of the MG7 ScFv. ELISA assay was used to detect the antigenbinding affinity of the soluble MG7 ScFv. Finally, the relative molecular mass of soluble MG7 ScFv was measured by SDS-PAGE. RESULTS The VH, VL and ScFv DNAs were about 340bp,320bp and 750bp, respectively. The volume of the library was up to 2 × 106 and 8 of 11 random clones were recombinants. Two phage clones could strongly compete with the original MG7 antibody for binding to the antigen expressed on KATO Ⅲ cells. Within 2 strong positive phage clones, the soluble MG7 ScFv from one clone was found to have the binding activity with KATO Ⅲ cells.SDS-PAGE showed that the relative molecular weight of soluble MG7 ScFv was 32. CONCLUSION The MG7 ScFv was successfully produced by phage antibody technology, which may

  3. Spatial Heterogeneity of Soil Moisture and the Scale Variability of Its Influencing Factors: A Case Study in the Loess Plateau of China

    Directory of Open Access Journals (Sweden)

    Mingyue Zhao

    2013-08-01

    Full Text Available Soil moisture is an important factor for vegetation restoration and ecosystem sustainability in the Loess Plateau of China. The strong spatial heterogeneity of soil moisture is controlled by many environmental factors, including topography and land use. Moreover, the spatial patterns and soil hydrological processes depend on the scale of the site being investigated, which creates a challenge for soil moisture forecasts. This study was conducted at two scales: watershed and small watershed. The goal of the study was to investigate the spatial variability in soil moisture and the scale effect of its controlling factors, as well as to provide references for soil moisture forecasting and studies of scale transformation. We took samples at 76 sites in the Ansai watershed and at 34 sites in a typical small watershed within the Ansai watershed in August. Next, we measured the soil moisture in five equal layers from a depth of 0–100 cm and recorded the land use type, location on the hill slope, slope, aspect, elevation and vegetation cover at the sampling sites. The results indicated that soil moisture was negatively correlated with relative elevation, slope and vegetation cover. As depth increased, the correlations among slope, aspect and soil moisture increased. At the small watershed and watershed scales, the soil moisture was highest in cultivated land, followed by wild grassland and lowest in garden plots, woodland and shrubland. The soil moisture was distributed similarly with respect to the location on the hill slope at both scales: upper slope < middle-upper slope < middle slope < middle-lower slope < lower slope. The deep layer soil moisture value of the slope top was high, being close to the soil moisture in the lower slope. Therefore, wild grassland or low-density woodland should be prioritized for farmland recovery in the Ansai watershed, and the locations on the hill slope, slope and elevation should be combined to configure different

  4. Combined mineralogical and EXAFS characterization of polluted sediments for the definition of technological variables and constraints

    Science.gov (United States)

    Brigatti, M. F.; Elmi, C.; Laurora, A.; Malferrari, D.; Medici, L.

    2009-04-01

    EXAFS spectra were used to define and optimize the technological variables of the recovery process.

  5. Comparative study of a responsive insertion technology (RIT colonoscope versus a variable-stiffness colonoscope

    Directory of Open Access Journals (Sweden)

    César Prieto-de-Frías

    2013-04-01

    Full Text Available Background and objectives: recently, Olympus developed a new prototype (XCF-Q180AY2L with responsive insertion technology (RIT, which besides the still known variable stiffness technology, included a passive bending section and a new high force insertion tube. Our objective was to investigate whether the use of this prototype could ease colonoscope insertion, increasing the cecal intubation rate, and/or shortening the cecal intubation time. Material and methods: the study was designed as a prospective observational study in 305 consecutive patients from a colo-rectal cancer screening program. We compared colonoscopies performed with conventional colonoscopes (CFH180AL/CFQ160L with those performed with the prototype XCF-Q180AY2L. End points were mean cecal and terminal ileal intubation times, cecum intubation rate, and need for specific maneuvers. All colonoscopies were performed under sedation with intravenous propofol. Finally, 288 patients were included. Results: no complications were observed. Complete cecal intubation rate was 100 % in both groups. The ileum could be reached in 98.95 % of cases. Mean time required to reach the cecum was shorter in the prototype endoscope group (4.31 min, SD 2.63 min than in the conventional endoscope group (4.66 min, SD 2.52 min (p < 0.05. Compared with the standard colonoscope group, we observed in the prototype group less subjective sensation of difficulty in the passage of the sigma (p < 0.01, fewer maneuvers when it proved necessary to straighten the scope (p < 0.01, and less frequent need to modify the stiffness of the endoscope (p < 0.05. Conclusion: we concluded that the prototype endoscope (XCF-Q180AY2L facilitated colonoscope insertion, requiring slightly less time to reach the cecum than a standard colonoscope.

  6. Turbocharging and variable valve trains. Fuel reducing technologies for worldwide use; Aufladung und variable Ventiltriebe. Verbrauchstechnologien fuer den weltweiten Einsatz

    Energy Technology Data Exchange (ETDEWEB)

    Klauer, Norbert; Klueting, Manfred; Steinparzer, Fritz; Unger, Harald [BMW Group, Muenchen (Germany)

    2009-07-01

    Strongly increasing prices of crude oil terrify the fear around energy shortage and result in a distinct increase of the fuel prices. The customers react to it with a changed behaviour of purchase. The national regularization increases beyond Europe strongly. With the holistic approach BMW EfficientDynamics years ago, BMW Group already began to react to these changed requirements adequately in order to secure a sustainable mobility. Electrification, energy recovery, engine start/stop and efficient propulsion technologies thereby are the substantial components of this approach. In the near future, the combustion engine plays the leading role with the vehicle drives and thus is in the focus of further reductions of consumption. With the introduction of Valvetronic 2001 at BMW Ottomotoren, a significant reduction of consumption sinking in serial production had been presented for the first time. With the direct injection and the turbocharging, further milestones could be established for the reduction of consumption by means of the engine technology. Their consistent advancement and its intelligent combination in new engine concepts and concepts of powertrain can be a main part of innovative new drives for the world-wide employment in future.

  7. Interannual climate variability and spatially heterogeneous improvement of agricultural management impede detection of a decreasing trend in nitrate pollution in an agricultural catchment

    Science.gov (United States)

    Fovet, Ophélie; Dupas, Rémi; Durand, Patrick; Gascuel-Odoux, Chantal; Gruau, Gérard; Hamon, Yannick; Petitjean, Patrice

    2016-04-01

    Despite widespread implementation of the nitrate directive in the European Union since the 1990s, the impact on nitrate concentration in rivers is limited (Bouraoui and Grizzetti, 2011). To assess whether this lack of response is due to the long time lags of nitrate transfer or to inadequate programs of measure, long term river and groundwater monitoring data are necessary. This study analyses 15 years of daily nitrate concentration data at the outlet of an intensively farmed catchment in Western France (Kervidy-Naizin, 5 km²) and quarterly nitrate concentration data in the groundwater of two hillslopes equipped with piezometers (Kerroland and Gueriniec) within the same catchment. In this catchment groundwater contribution to annual stream flow is dominant. The objectives of this study were to i) disentangle the influence of interannual climate variability and improvement of agricultural practices (i.e. reduction in N surplus) in the stream chemistry and ii) discuss the reasons for slow catchment recovery from nitrate pollution by comparing trends in groundwater and stream concentrations. Analysis of stream data showed that flow-weighted mean annual concentration at the outlet of the Kervidy-Naizin catchment has decreased by 1.2 mg NO3- l-1 yr-1 from 1999 to 2015. This decrease was slow but significant (p value 100 kg N ha-1 yr-1). We conclude that, despite the lags due to pluri annual nitrate transfer through the unsaturated and satured zones in catchments of Western France, significant decrease in nitrate concentration in groundwater and streams should be visible within less than 10 years after implementation of an efficient program of measures. Spatial heterogeneity in the implementation of programs of measures (i.e. reduction of N surplus) is a likely cause of slow, sometimes undetectable, reduction in nitrate concentration. Bouraoui, F., and Grizzetti, B.: Long term change of nutrient concentrations of rivers discharging in European seas, The Science of the

  8. Technology for Fissionable Materials Detection by Use of 100 MeV Variable Linac

    CERN Document Server

    Karasyov, Sergey P; Dovbnja, Anatoliy N; Eran, L; Kiryukhin, Nikolay M; Melnik, Yu M; Ran'iuk, Yu; Shlyakhov, Il'ya N; Trubnikov, Sergiy V

    2005-01-01

    A new concept for a two-step facility to increase the accuracy/reliability of detecting heavily shielded fissionable materials (FM) in marine containers is presented. The facility will detect FM in two steps. An existing dual-view; dual-energy X-ray scanner, which is based on 7 MeV electron accelerator, will select the suspicious places inside container. The linac with variable energy (up to 100 MeV) will be used for the second step. The technology will detect fissionable nuclei by gamma induced fission reactions and delayed neutron registration. A little-known Ukrainian experimental data obtained in Chernobil' clean-up program will be presented to ground proposed concept. The theoretical calculations of neutron fluxes scale these results to marine container size. Modified GEANT code for electron/gamma penetration and authors' own software for neutron yield/penetration are used for these calculations. Available facilities (X-ray scanners; linac; detectors), which will be used for concept proof, are described....

  9. Combination of multispectral remote sensing, variable rate technology and environmental modeling for citrus pest management.

    Science.gov (United States)

    Du, Qian; Chang, Ni-Bin; Yang, Chenghai; Srilakshmi, Kanth R

    2008-01-01

    The Lower Rio Grande Valley (LRGV) of south Texas is an agriculturally rich area supporting intensive production of vegetables, fruits, grain sorghum, and cotton. Modern agricultural practices involve the combined use of irrigation with the application of large amounts of agrochemicals to maximize crop yields. Intensive agricultural activities in past decades might have caused potential contamination of soil, surface water, and groundwater due to leaching of pesticides in the vadose zone. In an effort to promote precision farming in citrus production, this paper aims at developing an airborne multispectral technique for identifying tree health problems in a citrus grove that can be combined with variable rate technology (VRT) for required pesticide application and environmental modeling for assessment of pollution prevention. An unsupervised linear unmixing method was applied to classify the image for the grove and quantify the symptom severity for appropriate infection control. The PRZM-3 model was used to estimate environmental impacts that contribute to nonpoint source pollution with and without the use of multispectral remote sensing and VRT. Research findings using site-specific environmental assessment clearly indicate that combination of remote sensing and VRT may result in benefit to the environment by reducing the nonpoint source pollution by 92.15%. Overall, this study demonstrates the potential of precision farming for citrus production in the nexus of industrial ecology and agricultural sustainability.

  10. Tunable non-Gaussian resources for continuous-variable quantum technologies

    CERN Document Server

    Dell'Anno, F; Nocerino, G; Porzio, A; Solimeno, S; De Siena, S; Illuminati, F

    2013-01-01

    We introduce and discuss a set of tunable two-mode states of continuous-variable systems, as well as an efficient scheme for their experimental generation. This novel class of tunable entangled resources is defined by a general ansatz depending on two experimentally adjustable parameters. It is very ample and flexible as it encompasses Gaussian as well as non-Gaussian states. The latter include, among others, known states such as squeezed number states and de-Gaussified photon-added and photon-subtracted squeezed states, the latter being the most efficient non-Gaussian resources currently available in the laboratory. Moreover, it contains the classes of squeezed Bell states and even more general non-Gaussian resources that can be optimized according to the specific quantum technological task that needs to be realized. The proposed experimental scheme exploits linear optical operations and photon detections performed on a pair of uncorrelated two--mode Gaussian squeezed states. The desired non-Gaussian state i...

  11. The impact on CT dose of the variability in tube current modulation technology: a theoretical investigation

    Science.gov (United States)

    Li, Xiang; Segars, W. Paul; Samei, Ehsan

    2014-08-01

    Body CT scans are routinely performed using tube-current-modulation (TCM) technology. There is notable variability across CT manufacturers in terms of how TCM technology is implemented. Some manufacturers aim to provide uniform image noise across body regions and patient sizes, whereas others aim to provide lower noise for smaller patients. The purpose of this study was to conduct a theoretical investigation to understand how manufacturer-dependent TCM scheme affects organ dose, and to develop a generic approach for assessing organ dose across TCM schemes. The adult reference female extended cardiac-torso (XCAT) phantom was used for this study. A ray-tracing method was developed to calculate the attenuation of the phantom for a given projection angle based on phantom anatomy, CT system geometry, x-ray energy spectrum, and bowtie filter filtration. The tube current (mA) for a given projection angle was then calculated as a log-linear function of the attenuation along that projection. The slope of this function, termed modulation control strength, α, was varied from 0 to 1 to emulate the variability in TCM technology. Using a validated Monte Carlo program, organ dose was simulated for five α values (α = 0, 0.25, 0.5, 0.75, and 1) in the absence and presence of a realistic system mA limit. Organ dose was further normalized by volume-weighted CT dose index (CTDIvol) to obtain conversion factors (h factors) that are relatively independent of system specifics and scan parameters. For both chest and abdomen-pelvis scans and for 24 radiosensitive organs, organ dose conversion factors varied with α, following second-order polynomial equations. This result suggested the need for α-specific organ dose conversion factors (i.e., conversion factors specific to the modulation scheme used). On the other hand, across the full range of α values, organ dose in a TCM scan could be derived from the conversion factors established for a fixed-mA scan (hFIXED). This was possible by

  12. Climate-dependent sediment production: numerical modeling and field observations of variable grain size distributions from heterogeneous hillslope weathering of fractured basalt flows, Kohala Peninsula, Hawaii

    Science.gov (United States)

    Murphy, B. P.; Johnson, J. P.

    2012-12-01

    We present a numerical model for hillslope sediment production that includes climate-dependent chemical weathering rates and bedrock fracture spacings, and predicts how grain size distributions vary with climate and hillslope erosion rate. Understanding sediment preparation, or the in situ reduction of fractured bedrock to coarse sediment by heterogeneous weathering on hillslopes, is critical to understanding the evolution of mountainous landscapes, as sediment supply rates and size distributions can strongly influence river incision rates. The majority of soil production models assume a homogenous substrate and uniform weathering front, and therefore do not track the size of rock fragments and corestones, which become the sediment supplied to channels by hillslope erosion. Our model is inspired by the Kohala Peninsula on the big island of Hawaii, which has a gradient of mean annual precipitation (MAP) spanning over an order of magnitude that has been shown to influence the weathering rates of the basalt. Previous geochemical studies have constrained climate-dependent weathering rates for local soil production. Using these inputs, we developed a kinetics-based numerical model for the chemical weathering of initially fractured basalt into soil and coarse sediment over 150ky. Following first-order reaction kinetics, chemical weathering in the model decreases exponentially with both depth below the surface and time. The model starts with a column of repeating basalt flows (typically 1 m thick), each with fracture spacing distributions consistent with thermal-mechanical cooling characteristics. Each individual fracture-bound block is assumed to weather from the surface inwards, similar in form to a weathering rind. Since the model is constructed of discrete blocks, larger blocks remain as unweathered corestones (the "sediment"), surrounded by weathered material. In addition to a MAP-dependent initial surface weathering rate and rate constant, climate is also reflected

  13. The Differences in Career-Related Variables between Temporary and Permanent Employees in Information Technology Companies in Korea

    Science.gov (United States)

    Tak, Jinkook; Lim, Beomsik

    2008-01-01

    The purpose of this study was to examine differences in career-related variables, such as career commitment and career satisfaction, based on employment status (temporary vs. permanent employees) and job type (professional vs. nonprofessional employees). With a sample of 302 employees working in information technology companies in Korea, it was…

  14. Principals' Personal Variables and Information and Communication Technology Utilization in Federal Capital Territory Senior Secondary Schools, Abuja, Nigeria

    Science.gov (United States)

    Ogunshola, Roseline Folashade; Adeniyi, Abiodun

    2017-01-01

    The study investigated principals' personal variables and information and communication technology utilization in Federal Capital Territory (FCT) senior secondary schools, Abuja, Nigeria. The study adopted the correlational research design. The study used a sample of 94 senior secondary schools (including public and private) in FCT. Stratified…

  15. The behavioural aspect of green technology investments: A general positive model in the context of heterogeneous agents

    NARCIS (Netherlands)

    Knobloch, F.; Mercure, J.F.A.

    2016-01-01

    Studies report that firms do not invest in cost-effective green technologies. While economic barriers can explain parts of the gap, behavioural aspects cause further under-valuation. This could be partly due to systematic deviations of decision-making agents’ perceptions from normative benchmarks, a

  16. Heterogeneous DNA Methylation Patterns in the GSTP1 Promoter Lead to Discordant Results between Assay Technologies and Impede Its Implementation as Epigenetic Biomarkers in Breast Cancer.

    Science.gov (United States)

    Alnaes, Grethe I Grenaker; Ronneberg, Jo Anders; Kristensen, Vessela N; Tost, Jörg

    2015-09-17

    Altered DNA methylation patterns are found in many diseases, particularly in cancer, where the analysis of DNA methylation holds the promise to provide diagnostic, prognostic and predictive information of great clinical value. Methylation of the promoter-associated CpG island of GSTP1 occurs in many hormone-sensitive cancers, has been shown to be a biomarker for the early detection of cancerous lesions and has been associated with important clinical parameters, such as survival and response to treatment. In the current manuscript, we assessed the performance of several widely-used sodium bisulfite conversion-dependent methods (methylation-specific PCR, MethyLight, pyrosequencing and MALDI mass-spectrometry) for the analysis of DNA methylation patterns in the GSTP1 promoter. We observed large discordances between the results obtained by the different technologies. Cloning and sequencing of the investigated region resolved single-molecule DNA methylation patterns and identified heterogeneous DNA methylation patterns as the underlying cause of the differences. Heterogeneous DNA methylation patterns in the GSTP1 promoter constitute a major obstacle to the implementation of DNA methylation-based analysis of GSTP1 and might explain some of the contradictory findings in the analysis of the significance of GSTP1 promoter methylation in breast cancer.

  17. One-step fabrication of an organ-on-a-chip with spatial heterogeneity using a 3D bioprinting technology.

    Science.gov (United States)

    Lee, Hyungseok; Cho, Dong-Woo

    2016-07-05

    Although various types of organs-on-chips have been introduced recently as tools for drug discovery, the current studies are limited in terms of fabrication methods. The fabrication methods currently available not only need a secondary cell-seeding process and result in severe protein absorption due to the material used, but also have difficulties in providing various cell types and extracellular matrix (ECM) environments for spatial heterogeneity in the organs-on-chips. Therefore, in this research, we introduce a novel 3D bioprinting method for organ-on-a-chip applications. With our novel 3D bioprinting method, it was possible to prepare an organ-on-a-chip in a simple one-step fabrication process. Furthermore, protein absorption on the printed platform was very low, which will lead to accurate measurement of metabolism and drug sensitivity. Moreover, heterotypic cell types and biomaterials were successfully used and positioned at the desired position for various organ-on-a-chip applications, which will promote full mimicry of the natural conditions of the organs. The liver organ was selected for the evaluation of the developed method, and liver function was shown to be significantly enhanced on the liver-on-a-chip, which was prepared by 3D bioprinting. Consequently, the results demonstrate that the suggested 3D bioprinting method is easier and more versatile for production of organs-on-chips.

  18. The behavioural aspect of green technology investments: a general positive model in the context of heterogeneous agents

    OpenAIRE

    Knobloch, F.; Mercure, J.-F.

    2016-01-01

    This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Elsevier. Studies report that firms do not invest in cost-effective green technologies. While economic barriers can explain parts of the gap, behavioural aspects cause further under-valuation. This could be partly due to systematic deviations of decision-making agents’ perceptions from normative benchmarks, and partly due to their diversity. This paper combines available behavioural k...

  19. Variable EBV DNA Load Distributions and Heterogeneous EBV mRNA Expression Patterns in the Circulation of Solid Organ versus Stem Cell Transplant Recipients

    NARCIS (Netherlands)

    Greijer, A. E.; Stevens, S. J.; Verkuijlen, S. A.; Juwana, H.; Fleig, S. C.; Verschuuren, E. A.; Hepkema, B. G.; Cornelissen, J. J.; Brooimans, R. A.; Verdonck, L. F.; Middeldorp, J. M.

    2012-01-01

    Epstein-Barr virus (EBV) driven post-transplant lymphoproliferative disease (PTLD) is a heterogeneous and potentially life-threatening condition. Early identification of aberrant EBV activity may prevent progression to B-cell lymphoma. We measured EBV DNA load and RNA profiles in plasma and cellular

  20. Variable EBV DNA load distributions and heterogeneous EBV mRNA expression patterns in the circulation of solid organ versus stem cell transplant recipients

    NARCIS (Netherlands)

    A.E. Greijer; S.J. Stevens; S.A. Verkuijlen; H. Juwana; S.C. Fleig; E.A. Verschuuren; B.G. Hepkema (Bouke); J.J. Cornelissen (Jan); R.A. Brooimans (Rik); L.F. Verdonck (Leo); J.M. Middeldorp (Jaap)

    2012-01-01

    textabstractEpstein-Barr virus (EBV) driven post-transplant lymphoproliferative disease (PTLD) is a heterogeneous and potentially life-threatening condition. Early identification of aberrant EBV activity may prevent progression to B-cell lymphoma. We measured EBV DNA load and RNA profiles in plasma

  1. Heterogeneity in the multiple myeloma tumor clone

    NARCIS (Netherlands)

    Guikema, JEJ; Hovenga, S; Vellenga, E; Bos, NA

    2004-01-01

    Multiple Myeloma ( MM) is a plasma cell malignancy which is characterized by a very heterogeneous disease outcome. Heterogeneity in plasma cell characteristics, including morphology, maturation status, immunophenotype and genetic abnormalities partly account for the variable disease outcome. Althoug

  2. Heterogeneity in the multiple myeloma tumor clone

    NARCIS (Netherlands)

    Guikema, JEJ; Hovenga, S; Vellenga, E; Bos, NA

    Multiple Myeloma ( MM) is a plasma cell malignancy which is characterized by a very heterogeneous disease outcome. Heterogeneity in plasma cell characteristics, including morphology, maturation status, immunophenotype and genetic abnormalities partly account for the variable disease outcome.

  3. Intellectual Property Rights, Industry Heterogeneity and Technology Innovation%知识产权保护、行业异质性与技术创新

    Institute of Scientific and Technical Information of China (English)

    文豪; 陈中峰

    2014-01-01

    In order to explore the industry heterogeneity of intellectual property protection on the impact of technological innovation , we take using of the panel data of 37 industries in China from 2006 to 2011 year ,from the angle of technology gap and relative scale to re-search it .The study finds that per capita patents are ideal indicators of technological innovation ; strengthening the protection of intellectual property rights can contribute to promoting technological progress ; technological innovation channels are changing , independent innovation and domestic technology transfer are rising ;the smaller the gap the more conducive to the technological progress , the bigger the relative scale the more conducive to the technological progress .This paper suggests that in the study of technological innovation ,we can choose per capita patents as innovation practitioners ;strengthening enforcement of intellectual property rights ,so that to enhance the protection of in-tellectual property rights ; the process of technological innovation should focus on independent innovation and domestic technology transfer , narrow the technology gap with the developed countries and also expand relative industry scale .%为了探究知识产权保护对技术创新影响的行业差异,本文运用中国37个行业2006~2011年的面板数据,基于技术差距和相对规模,探究了知识产权制度变革对产业创新影响的行业异质性。研究发现:人均专利数量是衡量技术创新的理想指标;加强知识产权保护,有利于促进技术进步;技术创新渠道正在发生变化,即更注重国内自主创新和内部技术转移;技术差距越小越有利于技术进步,相对规模越大越有利于技术创新。本文建议:在研究技术创新时,可以选择从业人员人均专利数量作为创新指标;加强知识产权执法水平,提升知识产权保护力度;技术创新过程中更应该注重自主创新和内

  4. State-of-the-Art Sensor Technology in Spain: Invasive and Non-Invasive Techniques for Monitoring Respiratory Variables

    Directory of Open Access Journals (Sweden)

    Christian Domingo

    2010-05-01

    Full Text Available The interest in measuring physiological parameters (especially arterial blood gases has grown progressively in parallel to the development of new technologies. Physiological parameters were first measured invasively and at discrete time points; however, it was clearly desirable to measure them continuously and non-invasively. The development of intensive care units promoted the use of ventilators via oral intubation ventilators via oral intubation and mechanical respiratory variables were progressively studied. Later, the knowledge gained in the hospital was applied to out-of-hospital management. In the present paper we review the invasive and non-invasive techniques for monitoring respiratory variables.

  5. 基于异构模式的云计算关键技术研究%Research on heterogeneous model based key cloud computing technologies

    Institute of Scientific and Technical Information of China (English)

    张庆科; 杨波; 王琳; 陈贞翔

    2011-01-01

    结合云计算中Map/Reduce分布式编程技术引入了基于CPU—GPU异构混合并行编程模式,给出了该并行编程模式的原理和实现过程。该模式通过采用CUDA多线程并行机制提高了大规模数据处理的效率。文中对比分析了云计萍中两种典型的分布式存储系统GFS和HDFS,最后从宏观角度阐释了云计算虚拟化技术的三层部署架构和基本类型。%This paper presents a CPU-GPU heterogeneous parallel programming model based on the distributed programming technology of cloud computing, Map/Reduce. This paper also gives its principle and implementation process. It improves the efficiency of large-scale data processing with the multi-thread parallel mechanism, CUDA. We contrastively analyze two typical distributed storage systems, GFS and HDFS. We eventually present the three-layer architecture and basic type of virtualization technology.

  6. De-risking pharmaceutical tablet manufacture through process understanding, latent variable modeling, and optimization technologies.

    Science.gov (United States)

    Muteki, Koji; Swaminathan, Vidya; Sekulic, Sonja S; Reid, George L

    2011-12-01

    In pharmaceutical tablet manufacturing processes, a major source of disturbance affecting drug product quality is the (lot-to-lot) variability of the incoming raw materials. A novel modeling and process optimization strategy that compensates for raw material variability is presented. The approach involves building partial least squares models that combine raw material attributes and tablet process parameters and relate these to final tablet attributes. The resulting models are used in an optimization framework to then find optimal process parameters which can satisfy all the desired requirements for the final tablet attributes, subject to the incoming raw material lots. In order to de-risk the potential (lot-to-lot) variability of raw materials on the drug product quality, the effect of raw material lot variability on the final tablet attributes was investigated using a raw material database containing a large number of lots. In this way, the raw material variability, optimal process parameter space and tablet attributes are correlated with each other and offer the opportunity of simulating a variety of changes in silico without actually performing experiments. The connectivity obtained between the three sources of variability (materials, parameters, attributes) can be considered a design space consistent with Quality by Design principles, which is defined by the ICH-Q8 guidance (USDA 2006). The effectiveness of the methodologies is illustrated through a common industrial tablet manufacturing case study.

  7. Variable EBV DNA Load Distributions and Heterogeneous EBV mRNA Expression Patterns in the Circulation of Solid Organ versus Stem Cell Transplant Recipients

    Directory of Open Access Journals (Sweden)

    A. E. Greijer

    2012-01-01

    Full Text Available Epstein-Barr virus (EBV driven post-transplant lymphoproliferative disease (PTLD is a heterogeneous and potentially life-threatening condition. Early identification of aberrant EBV activity may prevent progression to B-cell lymphoma. We measured EBV DNA load and RNA profiles in plasma and cellular blood compartments of stem cell transplant (SCT; n=5, solid organ transplant recipients (SOT; n=15, and SOT having chronic elevated EBV-DNA load (n=12. In SCT, EBV DNA was heterogeneously distributed, either in plasma or leukocytes or both. In SOT, EBV DNA load was always cell associated, predominantly in B cells, but occasionally in T cells (CD4 and CD8 or monocytes. All SCT with cell-associated EBV DNA showed BARTs and EBNA1 expression, while LMP1 and LMP2 mRNA was found in 1 and 3 cases, respectively. In SOT, expression of BARTs was detected in all leukocyte samples. LMP2 and EBNA1 mRNA was found in 5/15 and 2/15, respectively, but LMP1 mRNA in only 1, coinciding with severe PTLD and high EBV DNA. Conclusion: EBV DNA is differently distributed between white cells and plasma in SOT versus SCT. EBV RNA profiling in blood is feasible and may have added value for understanding pathogenic virus activity in patients with elevated EBV-DNA.

  8. The History and State of the Art of Variable-Speed Wind Turbine Technology

    Science.gov (United States)

    Carlin, P. W.; Laxson, A. S.; Muljadi, E. B.

    2003-04-01

    Early wind turbines used for performing mechanical work (pumping, grinding and cutting) optimized aerodynamics by being allowed to run at variable speed. Some of the earliest DC electric wind turbines were allowed to run at variable speed. With the advent of grid-connected AC turbines, rotational speeds were limited in order to control the wind turbine AC frequency output to equal the grid frequency. With the advent of semiconductor devices, attempts began as early as the 1970s to allow variable-speed operation of large-scale turbines. The introduction of a new generation of high-voltage, high-speed power electronic components allows a wide range of variable-speed operation for very-large-scale machines. Over the past 30 years a number of designs have been tested, a few of which have entered commercial operation. A number of these designs and their histories are described. A detailed description of a wide range of electrical methods for allowing variable-speed operation is provided.

  9. Heterogeneity in breast cancer.

    Science.gov (United States)

    Polyak, Kornelia

    2011-10-01

    Breast cancer is a heterogeneous disease. There is a high degree of diversity between and within tumors as well as among cancer-bearing individuals, and all of these factors together determine the risk of disease progression and therapeutic resistance. Advances in technologies such as whole-genome sequencing and functional viability screens now allow us to analyze tumors at unprecedented depths. However, translating this increasing knowledge into clinical practice remains a challenge in part due to tumor evolution driven by the diversity of cancer cell populations and their microenvironment. The articles in this Review series discuss recent advances in our understanding of breast tumor heterogeneity, therapies tailored based on this knowledge, and future ways of assessing and treating heterogeneous tumors.

  10. Space Technology 5 (ST-5) Multipoint Observations of Temporal and Spatial Variability of Field-Aligned Currents

    Science.gov (United States)

    Le, Guan

    2010-01-01

    Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that mesoscale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of about 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are about 1 min for meso-scale currents and about 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  11. Heterogeneous Catalysts

    NARCIS (Netherlands)

    Dakka, J.; Sheldon, R.A.; Sanderson, W.A.

    1997-01-01

    Abstract of GB 2309655 (A) Heterogeneous catalysts comprising one or more metal compounds selected from the group consisting of tin, molybdenum, tungsten, zirconium and selenium compounds deposited on the surface of a silicalite are provided. Preferably Sn(IV) and/or Mo(VI) are employed. The cat

  12. Examining Social Studies and Science and Technology Preservice Teachers' Epistemological Beliefs Regarding Different Variables

    Science.gov (United States)

    Topkaya, Yavuz

    2015-01-01

    The purpose of this study is to determine epistemological beliefs of pre-service teachers who attend social studies and science and technology teaching programs; and to investigate how these beliefs varies regarding grade level, gender and departments. The sample of the study is composed of 300 social studies, 260 science and technology…

  13. Heterogenous networks and services

    DEFF Research Database (Denmark)

    Tan, Su-En

    the existing generation of technology and presents new technological performance breakthroughs. It is difficult to predict which radical technologies or innovations will result in a market disruption early on in their life cycles. Based on Clayton Christensen’s (Christensen 1997) definition of a disruptive...... of the market. If mainstream technology firms do not address the disruption, it is likely they will fail and the new disruptive firm will grow in size and importance in the industry. As we move to 3G (3rd Generation Mobile Services) and beyond 3G, one of the biggest challenges is to bridge network heterogeneity...... products and services. Schumpeter described the motor of development as the innovation itself. However, business and financial aspects must also be considered as they provide the bottom line for firms in the industry. Standardisation is increasingly required due to the number of different technologies...

  14. 分层异构无线网络的协议架构和关键技术%Key Technologies and Protocol Architectures in Heterogeneous Network

    Institute of Scientific and Technical Information of China (English)

    刘鸿雁; 胡春静; 李远

    2013-01-01

    分层异构无线网络技术因其可以有效提高网络频谱效率、满足不同热点覆盖需求、大幅提升系统容量等优点,而成为当今LTE-Advanced系统中的关键技术之一.总结了分层异构无线网络的背景、定义以及架构,并重点讨论了由于传统网络拓扑结构的改变而引发的干扰问题,详述了3GPP标准中的增强干扰协调方案,最后分析了分层异构无线网络中的其他关键技术,如网络自组织、回程链路设计、小区选择和切换、节能、认知无线电技术等.这些关键技术对于分层异构无线网络商用化部署具有指导意义.%Heterogeneous network (HetNet) is recently becoming one of the key technologies in LTE-Advanced network,because it can significantly improve spectrum efficiency and system capacity,while meeting different requirements for coverage in hotspots.The research background,term definitions and system architecture of HetNet were detailed.Furthermore,the interference problem caused by the variation in network topology,and the schemes for enhanced inter cell interference coordination (eICIC) in the 3rd generation partnership project (3GPP) standardization were focused on.Lastly,other key technologies in HetNet were also analyzed,such as self-organized network (SON),backhaul link design,mobility management,energy saving and cognitive radio,etc.Resolutions of those aforementioned key technologies have profound guiding significance for the commercial deployment of HetNet.

  15. A novel technology for control of variable speed pumped storage power plant

    Institute of Scientific and Technical Information of China (English)

    Seyed Mohammad Hassan Hosseini; Mohammad Reza Semsar

    2016-01-01

    Variable speed pumped storage machines are used extensively in wind power plant and pumped storage power plant. This paper presents direct torque and flux control (DTFC) of a variable speed pumped storage power plant (VSPSP). By this method both torque and flux have been applied to control the VSPSP. The comparison between VSPSP’s control strategies is studied. At the first, a wind turbine with the capacity 2.2 kW and DTFC control strategies simulated then a 250 MW VSPSP is simulated with all of its parts (including electrical, mechanical, hydraulic and its control system) by MATLAB software. In all of simulations, both converters including two-level voltage source converter (2LVSC) and three-level voltage source converter (3LVSC) are applied. The results of applying 2LVSC and 3LVSC are the rapid dynamic responses with better efficiency, reducing the total harmonic distortion (THD) and ripple of rotor torque and flux.

  16. The influence of desk and display design on posture and muscle activity variability whilst performing information technology tasks.

    Science.gov (United States)

    Straker, L; Burgess-Limerick, R; Pollock, C; Maslen, B

    2009-09-01

    Desk design and computer display height can affect posture and muscle activation during computer use. Amplitudes of postural variables and muscle activity during computer use do not explain the results from epidemiological studies of musculoskeletal discomfort and disorders related to computer use. The purpose of this study was to assess variability of posture and muscle activity during work with two computer display heights and book/paper, in conjunction with a curved desk designed to provide forearm support and a traditional, straight desk. 18 male and 18 female participants performed 10-min tasks involving keying, mousing, reading and writing in six desk/display conditions. 3D posture and surface emg were assessed for the final 2 min of each task. The curved desk resulted in greater postural and muscle activity variation, suggesting an advantage of this supportive surface over the straight desk. There was little difference in variability associated with the two display heights. However, greater variability of posture and muscle activity was evident with the book/paper condition. Non-touch typists had greater neck flexion variation. The design of information technology tasks and workstations can influence the short term variation in posture and muscle activity. Variation is influenced independently of mean postures and muscle amplitudes and therefore needs to be considered to adequately assess the risk of musculoskeletal disorders.

  17. Classification of Incoming Freshman in a Public University Based on the Variables of Academic Performance, Use of Digital Technology

    Directory of Open Access Journals (Sweden)

    Javier Organista Sandoval

    2012-05-01

    Full Text Available During the first semester of 2008 a research study was conducted with incoming freshman in the School of Administrative and Social Sciences (FCAyS—acronym in Spanish of the Ensenada campus of the Universidad Autónoma de Baja California (UABC. The purpose was to characterize the new students based on academic achievement (grade point averages in high school and the first semester of college, family context (parents’ schooling and use of technology (computers and the Web. A survey of technology use developed within the framework of the research was applied to a sample of 438 students. The results show that the majority of the students are female (2 out of 3 and that 4 out of 5 have computers at home. About 80% of the students showed an intermediate level of proficiency in computer technology and the Web. Two classifying techniques were employed: CHAID and a cluster analysis to explore the development of patterns based on the above-mentioned variables. The result of the applied CHAID analysis highlights the importance of the variables of gender, parental schooling and level of immersion in the Web for the classification. The cluster analysis (k-means generated four clusters; of these, cluster 1, which had the lowest average grades and the highest levels of computer and Web immersion, is noteworthy, because it suggests a non-educational use of technological resources. In contrast, cluster 4 presented the highest grade point average in college, a moderate level of computer use and a low level of immersion in the Web. This suggests a greater commitment to academics by reduced use of the computer and the Web for recreational purposes.

  18. Molecular heterogeneity in glioblastoma: potential clinical implications

    Directory of Open Access Journals (Sweden)

    Nicole Renee Parker

    2015-03-01

    Full Text Available Glioblastomas, (grade 4 astrocytomas, are aggressive primary brain tumors characterized by histopathological heterogeneity. High resolution sequencing technologies have shown that these tumors also feature significant inter-tumoral molecular heterogeneity. Molecular subtyping of these tumors has revealed several predictive and prognostic biomarkers. However, intra-tumoral heterogeneity may undermine the use of single biopsy analysis for determining tumor genotype and has implications for potential targeted therapies. The clinical relevance and theories of tumoral molecular heterogeneity in glioblastoma are discussed.

  19. Intra-tumour heterogeneity: a looking glass for cancer?

    Science.gov (United States)

    Marusyk, Andriy; Almendro, Vanessa; Polyak, Kornelia

    2012-04-19

    Populations of tumour cells display remarkable variability in almost every discernable phenotypic trait, including clinically important phenotypes such as ability to seed metastases and to survive therapy. This phenotypic diversity results from the integration of both genetic and non-genetic influences. Recent technological advances have improved the molecular understanding of cancers and the identification of targets for therapeutic interventions. However, it has become exceedingly apparent that the utility of profiles based on the analysis of tumours en masse is limited by intra-tumour genetic and epigenetic heterogeneity, as characteristics of the most abundant cell type might not necessarily predict the properties of mixed populations. In this Review, we discuss both genetic and non-genetic causes of phenotypic heterogeneity of tumour cells, with an emphasis on heritable phenotypes that serve as a substrate for clonal selection. We discuss the implications of intra-tumour heterogeneity in diagnostics and the development of therapeutic resistance.

  20. Residential Cold Climate Heat Pump (CCHP) w/Variable Speed Technology

    Energy Technology Data Exchange (ETDEWEB)

    Messmer, Craig S. [Unico, Inc., Arnold, MO (United States)

    2016-09-30

    This report summarizes the results of a three year program awarded to Unico, Inc. to commercialize a residential cold climate heat pump. Several designs were investigated. Compressors were selected using analysis from Oakridge National Laboratories followed by prototype construction and lab testing in a specially built environmental chamber capable of reaching -30°F. The initial design utilized two variable speed compressors in series with very good capacity results and acceptable efficiency at very cold temperatures. The design was then modified to reduce cost and complexity by redesigning the system using three dual-stage compressors: two in parallel followed by one in series. Extensive testing found significant challenge with oil management, reliability, weight and cost which prevented the system from being fully commercialized. Further analysis of other conceptual designs indicated that these challenges could be overcome in the future.

  1. An Analysis of Programmatic Variables Relating to the Pass Rates on the Licensure Examination by Practical Nurses in Tennessee Technology Centers

    Science.gov (United States)

    Simpson, Janis Lee

    2013-01-01

    The purpose of this quantitative research study was to determine the degree to which Licensed Practical Nursing programmatic variables positively correlate with select Tennessee Technology Center institution pass rates on the licensure examination--NCLEX-PNRTM. This study investigated the relationship between the dependent variable of NCLEX-PNRTM…

  2. Static stability analysis of smart magneto-electro-elastic heterogeneous nanoplates embedded in an elastic medium based on a four-variable refined plate theory

    Science.gov (United States)

    Ebrahimi, Farzad; Barati, Mohammad Reza

    2016-10-01

    In this article, a nonlocal four-variable refined plate theory is developed to examine the buckling behavior of nanoplates made of magneto-electro-elastic functionally graded (MEE-FG) materials resting on Winkler-Pasternak foundation. Material properties of nanoplate change in spatial coordinate based on power-law distribution. The nonlocal governing equations are deduced by employing the Hamilton principle. For various boundary conditions, the analytical solutions of nonlocal MEE-FG plates for buckling problem will be obtained based on an exact solution approach. Finally, dependency of buckling response of MEE-FG nanoplate on elastic foundation parameters, magnetic potential, external electric voltage, various boundary conditions, small scale parameter, power-law index, plate side-to-thickness ratio and aspect ratio will be figure out. These results can be advantageous for the mechanical analysis and design of intelligent nanoscale structures constructed from magneto-electro-thermo-elastic functionally graded materials.

  3. A Range-Based Vehicle Life Cycle Assessment Incorporating Variability in the Environmental Assessment of Different Vehicle Technologies and Fuels

    Directory of Open Access Journals (Sweden)

    Maarten Messagie

    2014-03-01

    Full Text Available How to compare the environmental performance of different vehicle technologies? Vehicles with lower tailpipe emissions are perceived as cleaner. However, does it make sense to look only to tailpipe emissions? Limiting the comparison only to these emissions denies the fact that there are emissions involved during the production of a fuel and this approach gives too much advantage to zero-tailpipe vehicles like battery electric vehicles (BEV and fuel cell electric vehicle (FCEV. Would it be enough to combine fuel production and tailpipe emissions? Especially when comparing the environmental performance of alternative vehicle technologies, the emissions during production of the specific components and their appropriate end-of-life treatment processes should also be taken into account. Therefore, the complete life cycle of the vehicle should be included in order to avoid problem shifting from one life stage to another. In this article, a full life cycle assessment (LCA of petrol, diesel, fuel cell electric (FCEV, compressed natural gas (CNG, liquefied petroleum gas (LPG, hybrid electric, battery electric (BEV, bio-diesel and bio-ethanol vehicles has been performed. The aim of the manuscript is to investigate the impact of the different vehicle technologies on the environment and to develop a range-based modeling system that enables a more robust interpretation of the LCA results for a group of vehicles. Results are shown for climate change, respiratory effects, acidification and mineral extraction damage of the different vehicle technologies. A broad range of results is obtained due to the variability within the car market. It is concluded that it is essential to take into account the influence of all the vehicle parameters on the LCA results.

  4. Novel automatic mapping technology on CPU-GPU heteroge-neous systems%面向CPU-GPU架构的源到源自动映射方法

    Institute of Scientific and Technical Information of China (English)

    朱正东; 刘袁; 魏洪昌; 颜康; 王寅峰; 董小社

    2015-01-01

    针对GPU上应用开发移植困难的问题,提出了一种串行计算源程序到并行计算源程序的映射方法。该方法从串行源程序中获得可并行化循环的层次信息,建立循环体结构与GPU线程的对应关系,生成GPU端核心函数代码;根据变量引用读写属性生成CPU端控制代码。基于该方法实现了一个编译原型系统,完成了C语言源程序到CUDA源程序的自动生成。对原型系统在功能和性能方面的测试结果表明,该系统生成的CUDA源程序与C语言源程序在功能上一致,其性能有显著提高,在一定程度上解决了计算密集型应用向CPU-GPU异构多核系统移植困难的问题。%Aiming at the developing and porting difficulties of GPU-based applications, a mapping approach is proposed, which converts serial computing source code into equivalent parallel computing source code. This approach acquires hier-archies of parallelizable loops from serial sources, establishes the correspondence between loop structures and GPU threads, and generates the core function code for GPU. Meanwhile, CPU control code is generated according to read/write attributes of variable references. A compiler prototype is implemented based on this approach, which translates C code into CUDA code automatically. Functionality and performance evaluations of the prototype show that the CUDA code generated is functionally equivalent to the original C code, with significant improvement in performance, thus overcomes the diffi-culty in porting compute-intensive applications to CPU-GPU heterogeneous systems.

  5. Cellular heterogeneity and molecular evolution in cancer.

    Science.gov (United States)

    Almendro, Vanessa; Marusyk, Andriy; Polyak, Kornelia

    2013-01-24

    Intratumor heterogeneity represents a major obstacle to effective cancer treatment and personalized medicine. However, investigators are now elucidating intratumor heterogeneity at the single-cell level due to improvements in technologies. Better understanding of the composition of tumors, and monitoring changes in cell populations during disease progression and treatment, will improve cancer diagnosis and therapeutic design. Measurements of intratumor heterogeneity may also be used as biomarkers to predict the risk of progression and therapeutic resistance. We summarize important considerations related to intratumor heterogeneity during tumor evolution. We also discuss experimental approaches that are commonly used to infer intratumor heterogeneity and describe how these methodologies can be translated into clinical practice.

  6. Scales of heterogeneity of water quality in rivers: Insights from high resolution maps based on integrated geospatial, sensor and ROV technologies

    Science.gov (United States)

    While the spatial heterogeneity of many aquatic ecosystems is acknowledged, rivers are often mistakenly described as homogenous and well-mixed. The collection and visualization of attributes like water quality is key to our perception and management of these ecosystems. The ass...

  7. A three-source capture-recapture estimate of the number of new HIV diagnoses in children in France from 2003–2006 with multiple imputation of a variable of heterogeneous catchability

    Directory of Open Access Journals (Sweden)

    Héraud-Bousquet Vanina

    2012-10-01

    Full Text Available Abstract Background Nearly all HIV infections in children worldwide are acquired through mother-to-child transmission (MTCT during pregnancy, labour, delivery or breastfeeding. The objective of our study was to estimate the number and rate of new HIV diagnoses in children less than 13 years of age in mainland France from 2003–2006. Methods We performed a capture-recapture analysis based on three sources of information: the mandatory HIV case reporting (DOVIH, the French Perinatal Cohort (ANRS-EPF and a laboratory-based surveillance of HIV (LaboVIH. The missing values of a variable of heterogeneous catchability were estimated through multiple imputation. Log-linear modelling provided estimates of the number of new HIV infections in children, taking into account dependencies between sources and variables of heterogeneous catchability. Results The three sources observed 216 new HIV diagnoses after record-linkage. The number of new HIV diagnoses in children was estimated at 387 (95%CI [271–503] from 2003–2006, among whom 60% were born abroad. The estimated rate of new HIV diagnoses in children in mainland France was 9.1 per million in 2006 and was 38 times higher in children born abroad than in those born in France. The estimated completeness of the three sources combined was 55.8% (95% CI [42.9 – 79.7] and varied according to the source; the completeness of DOVIH (28.4% and ANRS-EPF (26.1% were lower than that of LaboVIH (33.3%. Conclusion Our study provided, for the first time, an estimated annual rate of new HIV diagnoses in children under 13 years old in mainland France. A more systematic HIV screening of pregnant women that is repeated during pregnancy among women likely to engage in risky behaviour is needed to optimise the prevention of MTCT. HIV screening for children who migrate from countries with high HIV prevalence to France could be recommended to facilitate early diagnosis and treatment.

  8. Measuring and predicting heterogeneous recessions

    NARCIS (Netherlands)

    C. Cakmakli; R. Paap; D. van Dijk

    2011-01-01

    This paper conducts an empirical analysis of the heterogeneity of recessions in monthly U.S. coincident and leading indicator variables. Univariate Markovswitching models indicate that it is appropriate to allow for two distinct recession regimes, corresponding with ‘mild’ and ‘severe’ recessions. A

  9. DATABASE REPLICATION IN HETEROGENOUS PLATFORM

    Directory of Open Access Journals (Sweden)

    Hendro Nindito

    2014-01-01

    Full Text Available The application of diverse database technologies in enterprises today is increasingly a common practice. To provide high availability and survavibality of real-time information, a database replication technology that has capability to replicate databases under heterogenous platforms is required. The purpose of this research is to find the technology with such capability. In this research, the data source is stored in MSSQL database server running on Windows. The data will be replicated to MySQL running on Linux as the destination. The method applied in this research is prototyping in which the processes of development and testing can be done interactively and repeatedly. The key result of this research is that the replication technology applied, which is called Oracle GoldenGate, can successfully manage to do its task in replicating data in real-time and heterogeneous platforms.

  10. Viewpoint – Water Variability, Soil Nutrient Heterogeneity and Market Volatility – Why Sub-Saharan Africa’s Green Revolution Will Be Location-Specific and Knowledge-Intensive

    Directory of Open Access Journals (Sweden)

    Pieter van der Zaag

    2010-02-01

    Full Text Available In his interesting Viewpoint article in Water Alternatives, Bruce Lankford suggests that an African Green Revolution cannot come about without irrigation. But he does not convincingly explain why irrigated areas expand only very slowly. This viewpoint article argues that grain yields have remained stagnant in Africa because of high temporal rainfall variability, significant spatial soil nutrient heterogeneity, and weak and volatile markets. This combination calls for location-specific interventions that are aimed at enhancing farmers’ capacity to buffer water variations and address nutrient deficits. This finding is consistent with what Lankford dismisses as an "atomised" approach, but which would preferably be called a farmer-centred approach. Thus a massive investment in African agriculture is indeed required, primarily focused on the creation of knowledge that does justice to the local variation in water and nutrient availability. It should aim to empower farmers to experiment and be innovative, and remake agricultural extension and agricultural engineering exciting with cutting-edge disciplines. Irrigation may then emerge as the right thing to do.

  11. Wireless Internet on Heterogeneous Networks

    NARCIS (Netherlands)

    Wu, G.

    2001-01-01

    The wide proliferation of wireless systems and the use of software radio technologies enable the employment of a heterogeneous network. In this concept services are delivered via the network that is most efficient for that service. The solution is based on a common core network that interconnects ac

  12. REPLIKASI UNIDIRECTIONAL PADA HETEROGEN DATABASE

    Directory of Open Access Journals (Sweden)

    Hendro Nindito

    2013-11-01

    where development can be done quickly and testing of working models of the interaction process is done through repeated. From this research it is obtained that the database replication technology using Oracle Golden Gate can be applied in heterogeneous environments in real time as well.

  13. Diabetes and Technology for Increased Activity (DaTA Study: The effects of exercise and technology on heart rate variability and metabolic syndrome risk factors.

    Directory of Open Access Journals (Sweden)

    Melanie I Stuckey

    2013-09-01

    Full Text Available This study tested the hypothesis that an eight-week exercise intervention supported by mobile health (mHealth technology would improve metabolic syndrome (MetS risk factors and heart rate variability (HRV in a population with MetS risk factors. Participants (n=12; 3 male; aged 56.9±7.0y reported to the laboratory for assessment of MetS risk factors and fitness (VO2max at baseline (V0 and after eight-weeks (V2 of intervention. Participants received an individualized exercise prescription and a mHealth technology kit for remote monitoring of blood pressure (BP, blood glucose, physical activity and body weight via smartphone. Participants underwent 24-h ambulatory monitoring of R-R intervals following V0 and V2. Low and high frequency powers of HRV were assessed from the recording and the ratio of low-to-high frequency powers and low and high frequency power in normalized units were calculated. One-way repeated measures analysis of variance showed that waist circumference (V0: 113.1±11.0cm, V2: 108.1±14.7cm; p=0.004 and diastolic BP (V0: 81±6mmHg, V2: 76±11mmHg; p=0.04 were reduced and VO2max increased (V0: 31.3ml/kg/min, V2: 34.8ml/kg/min; p=0.02 with no changes in other MetS risk factors. Low and high frequency powers in normalized units were reduced (V0: 75.5±12.0, V2: 72.0±12.1; p=0.03 and increased (V0: 24.5±12.0, V2: 28.0±12.1; p=0.03, respectively, with no other changes in HRV. Over the intervention period, changes in systolic BP were correlated negatively with the changes in R-R interval (r=-0.600; p=0.04 and positively with the changes in heart rate (r=0.611; p=0.03, with no other associations between MetS risk factors and HRV parameters. Thus, this eight-week mHealth supported exercise intervention improved MetS risk factors and HRV parameters, but only changes in systolic BP were associated with improved autonomic function.

  14. Heterogeneity and Microeconometrics Modelling

    DEFF Research Database (Denmark)

    Browning, Martin; Carro, Jesus

    Presented at the 2005 Econometric Society World Congress Plenary Session on "Modelling Heterogeneity". We survey the treatment of heterogeneity in applied microeconometrics analyses. There are three themes. First, there is usually much more heterogeneity than empirical researchers allow for. Seco...

  15. Bandwidth sharing with heterogeneous service requirements

    NARCIS (Netherlands)

    Borst, S.C.; Núñez Queija, R.; Zwart, A.P.

    2003-01-01

    We consider a system with two heterogeneous traffic classes. The users from both classes randomly generate service requests, one class having light-tailed properties, the other one exhibiting heavy-tailed characteristics. The heterogeneity in service requirements reflects the extreme variability in

  16. Examining Music Teachers' Self-Confidence Levels in Using Information and Communication Technologies for Education Based on Measurable Variables

    Science.gov (United States)

    Kilic, Deniz Beste Çevik

    2017-01-01

    Rapid developments and innovations in technology have impact on individuals. The use of technology for one's daily life has become a necessity; therefore, the development and popularization of Information and Communication Technologies (ICTs) is use as a tool for solving educational problems. Because educational technologies play a major role both…

  17. Variability in and agreement between modeled and personal continuously measured black carbon levels using novel smartphone and sensor technologies.

    Science.gov (United States)

    Nieuwenhuijsen, Mark J; Donaire-Gonzalez, David; Rivas, Ioar; de Castro, Montserrat; Cirach, Marta; Hoek, Gerard; Seto, Edmund; Jerrett, Michael; Sunyer, Jordi

    2015-03-01

    Novel technologies, such as smartphones and small personal continuous air pollution sensors, can now facilitate better personal estimates of air pollution in relation to location. Such information can provide us with a better understanding about whether and how personal exposures relate to residential air pollution estimates, which are normally used in epidemiological studies. The aims of this study were to examine (1) the variability in personal air pollution levels during the day and (2) the relationship between modeled home and school estimates and continuously measured personal air pollution exposure levels in different microenvironments (e.g., home, school, and commute). We focused on black carbon as an indicator of traffic-related air pollution. We recruited 54 school children (aged 7-11) from 29 different schools around Barcelona as part of the BREATHE study, an epidemiological study of the relation between air pollution and brain development. For 2 typical week days during 2012-2013, the children were given a smartphone with CalFit software to obtain information on their location and physical activity level and a small sensor, the micro-aethalometer model AE51, to measure their black carbon levels simultaneously and continuously. We estimated their home and school exposure to PM2.5 filter absorbance, which is well-correlated with black carbon, using a temporally adjusted PM2.5 absorbance land use regression (LUR) model. We found considerable variation in the black carbon levels during the day, with the highest levels measured during commuting periods (geometric mean = 2.8 μg/m(3)) and the lowest levels at home (geometric mean = 1.3 μg/m(3)). Hourly temporally adjusted LUR model estimates for the home and school showed moderate to good correlation with measured personal black carbon levels at home and school (r = 0.59 and 0.68, respectively) and lower correlation with commuting trips (r = 0.32 and 0.21, respectively). The correlation between modeled home

  18. 基于层次分析法的异构网络切换技术研究%Research of switching technology in heterogeneous network based on analytic hierarchy process

    Institute of Scientific and Technical Information of China (English)

    黄超; 程乃平

    2013-01-01

    Heterogeneous network is popular in the development of mobile network,in which the switching technology plays an important role. The vertical switching technology is studied based on the heterogeneous network. Analytic hierarchy pro⁃cess is used to solve the problem of the weighting coefficient with the different attributes in the cost function. It provides a reference for the network switching when the network status is affected by multiple factors.%  异构网络是移动互联网的热门发展方向,切换技术是其研究的重要内容。基于异构网络,对其垂直切换技术进行研究。采用系统研究中的层次分析方法,解决目标代价函数中不同属性的加权系数计算问题,为多个因素共同影响网络状态时进行网络切换选择提供了参考依据。

  19. Replikasi Unidirectional pada Heterogen Database

    Directory of Open Access Journals (Sweden)

    Hendro Nindito

    2013-12-01

    Full Text Available The use of diverse database technology in enterprise today can not be avoided. Thus, technology is needed to generate information in real time. The purpose of this research is to discuss a database replication technology that can be applied in heterogeneous database environments. In this study we use Windows-based MS SQL Server database to Linux-based Oracle database as the goal. The research method used is prototyping where development can be done quickly and testing of working models of the interaction process is done through repeated. From this research it is obtained that the database replication technolgy using Oracle Golden Gate can be applied in heterogeneous environments in real time as well.

  20. Heterogeneous photonic integrated circuits

    Science.gov (United States)

    Fang, Alexander W.; Fish, Gregory; Hall, Eric

    2012-01-01

    Photonic Integrated Circuits (PICs) have been dichotomized into circuits with high passive content (silica and silicon PLCs) and high active content (InP tunable lasers and transceivers) due to the trade-off in material characteristics used within these two classes. This has led to restrictions in the adoption of PICs to systems in which only one of the two classes of circuits are required to be made on a singular chip. Much work has been done to create convergence in these two classes by either engineering the materials to achieve the functionality of both device types on a single platform, or in epitaxial growth techniques to transfer one material to the next, but have yet to demonstrate performance equal to that of components fabricated in their native substrates. Advances in waferbonding techniques have led to a new class of heterogeneously integrated photonic circuits that allow for the concurrent use of active and passive materials within a photonic circuit, realizing components on a transferred substrate that have equivalent performance as their native substrate. In this talk, we review and compare advances made in heterogeneous integration along with demonstrations of components and circuits enabled by this technology.

  1. Variability of knapping methods and technological change in the Middle Palaeolithic of the Abric Romani (Capellades, Barcelona

    Directory of Open Access Journals (Sweden)

    Vaquero, Manuel

    1999-12-01

    Full Text Available Lithic reduction sequences are a fundamental topic in palaeolithic research, since they provide data on the behavioural capabilities of early hominids. This paper studies the variability of lithic reduction strategies in the Abric Romaní (Capellades, Barcelona. This site has an extensive stratigraphic sequence, dated between 40 and 70 ka BP. In this sequence, mostly formed by travertine deposits, 27 archaeological levels have been identified, most of them corresponding to the Middle Palaeolithic. The Middle Palaeolithic levels so far excavated (B-L are dated between 40 and 52 ka BP, and suggest a reconstruction of the behavioural patterns of the Neanderthal groups preceding the early Upper Palaeolithic. The variability of the reduction sequences in a synchronous level and the changes over time are presented in the framework of the operative field concept. The results suggest that the technological changes in the Middle Palaeolithic can be explained by technical criteria that are reflected in different domains of analysis; these criteria are related to the degree of technical knowledge invested in lithic production and the range of technical options envisaged in each archaeological level.

    Las secuencias de talla lítica constituyen un tema fundamental en la investigación del Paleolítico, ya que proporcionan datos sobre las capacidades conductuales de los primeros homínidos. Este artículo estudia la variabilidad de las estrategias de talla en el Abric Romaní (Capellades, Barcelona, yacimiento que cuenta con una amplia secuencia estratigráfica datada entre los 40 y los 70 ka BP. En dicha secuencia, formada en su mayor parte por depósitos travertínicos, se han reconocido 27 niveles de ocupación, la mayor parte de los cuales atribuidos al Paleolítico Medio. Los niveles del Paleolítico Medio excavados hasta el momento (B-L, datados entre los 40 y los 52 ka BP, han permitido una reconstrucción de los patrones conductuales de los

  2. Reaction Selectivity in Heterogeneous Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, Gabor A.; Kliewer, Christopher J.

    2009-02-02

    The understanding of selectivity in heterogeneous catalysis is of paramount importance to our society today. In this review we outline the current state of the art in research on selectivity in heterogeneous catalysis. Current in-situ surface science techniques have revealed several important features of catalytic selectivity. Sum frequency generation vibrational spectroscopy has shown us the importance of understanding the reaction intermediates and mechanism of a heterogeneous reaction, and can readily yield information as to the effect of temperature, pressure, catalyst geometry, surface promoters, and catalyst composition on the reaction mechanism. DFT calculations are quickly approaching the ability to assist in the interpretation of observed surface spectra, thereby making surface spectroscopy an even more powerful tool. HP-STM has revealed three vitally important parameters in heterogeneous selectivity: adsorbate mobility, catalyst mobility, and selective site-blocking. The development of size controlled nanoparticles from 0.8 to 10 nm, of controlled shape, and of controlled bimetallic composition has revealed several important variables for catalytic selectivity. Lastly, DFT calculations may be paving the way to guiding the composition choice for multi-metallic heterogeneous catalysis for the intelligent design of catalysts incorporating the many factors of selectivity we have learned.

  3. Characterizing mutational heterogeneity in a glioblastoma patient with double recurrence.

    Directory of Open Access Journals (Sweden)

    Gabrielle C Nickel

    Full Text Available Human cancers are driven by the acquisition of somatic mutations. Separating the driving mutations from those that are random consequences of general genomic instability remains a challenge. New sequencing technology makes it possible to detect mutations that are present in only a minority of cells in a heterogeneous tumor population. We sought to leverage the power of ultra-deep sequencing to study various levels of tumor heterogeneity in the serial recurrences of a single glioblastoma multiforme patient. Our goal was to gain insight into the temporal succession of DNA base-level lesions by querying intra- and inter-tumoral cell populations in the same patient over time. We performed targeted "next-generation" sequencing on seven samples from the same patient: two foci within the primary tumor, two foci within an initial recurrence, two foci within a second recurrence, and normal blood. Our study reveals multiple levels of mutational heterogeneity. We found variable frequencies of specific EGFR, PIK3CA, PTEN, and TP53 base substitutions within individual tumor regions and across distinct regions within the same tumor. In addition, specific mutations emerge and disappear along the temporal spectrum from tumor at the time of diagnosis to second recurrence, demonstrating evolution during tumor progression. Our results shed light on the spatial and temporal complexity of brain tumors. As sequencing costs continue to decline and deep sequencing technology eventually moves into the clinic, this approach may provide guidance for treatment choices as we embark on the path to personalized cancer medicine.

  4. Are Heterogeneous or Homogeneous Groups More Beneficial to Students?

    Science.gov (United States)

    Schullery, Nancy M.; Schullery, Stephen E.

    2006-01-01

    This study investigated the relative benefits to the student of working in homogeneous versus heterogeneous classroom groups. Correlation analysis of 18 desirable outcomes versus 8 personality-based heterogeneity variables reveals that heterogeneity associates with advantages as well as disadvantages. Ways in which group composition might be…

  5. Microbial population heterogeneity versus bioreactor heterogeneity: evaluation of Redox Sensor Green as an exogenous metabolic biosensor

    DEFF Research Database (Denmark)

    Baert, Jonathan; Delepierre, Anissa; Telek, Samuel

    2016-01-01

    Microbial heterogeneity in metabolic performances has attracted a lot of attention, considering its potential impact on industrial bioprocesses. However, little is known about the impact of extracellular perturbations (i.e. bioreactor heterogeneity) on cell-to-cell variability in metabolic...

  6. Temperature chaos and quenched heterogeneities

    Science.gov (United States)

    Barucca, Paolo; Parisi, Giorgio; Rizzo, Tommaso

    2014-03-01

    We present a treatable generalization of the Sherrington-Kirkpatrick (SK) model which introduces correlations in the elements of the coupling matrix through multiplicative disorder on the single variables and investigate the consequences on the phase diagram. We define a generalized qEA parameter and test the structural stability of the SK results in this correlated case evaluating the de Almeida-Thouless line of the model. As a main result we demonstrate the increase of temperature chaos effects due to heterogeneities.

  7. Study on Calibration of Device of Heterogeneous Matrix With Uranium inside

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The device of measuring heterogeneous matrix with uranium inside is built base on ray segment scan technology and neutron analysis technology, to use to measure the heterogeneous matrix with Uranium inside which produced by chemical transformation

  8. Effects of '"Environmental Chemistry" Elective Course via Technology-Embedded Scientific Inquiry Model on Some Variables

    Science.gov (United States)

    Çalik, Muammer; Özsevgeç, Tuncay; Ebenezer, Jazlin; Artun, Hüseyin; Küçük, Zeynel

    2014-01-01

    The purpose of this study is to examine the effects of "environmental chemistry" elective course via Technology-Embedded Scientific Inquiry (TESI) model on senior science student teachers' (SSSTs) conceptions of environmental chemistry concepts/issues, attitudes toward chemistry, and technological pedagogical content knowledge…

  9. Effects of '"Environmental Chemistry" Elective Course via Technology-Embedded Scientific Inquiry Model on Some Variables

    Science.gov (United States)

    Çalik, Muammer; Özsevgeç, Tuncay; Ebenezer, Jazlin; Artun, Hüseyin; Küçük, Zeynel

    2014-01-01

    The purpose of this study is to examine the effects of "environmental chemistry" elective course via Technology-Embedded Scientific Inquiry (TESI) model on senior science student teachers' (SSSTs) conceptions of environmental chemistry concepts/issues, attitudes toward chemistry, and technological pedagogical content knowledge…

  10. An Investigation into the Secondary Schools In-Service Teachers' Selected Variables on Interactive Computer Technology (ICT) Competency

    Science.gov (United States)

    Adodo, S. O.

    2012-01-01

    The use of computer technologies has come to stay, an individual, group of individual and society who is yet to recognize this fact is merely living. The introduction of Information and Communication Technology (ICT) into the education industry has caused transformation in instructional process. The study investigated the in-service teachers…

  11. Adapting to extreme events related to natural variability and climate change: the imperative of coupling technology with strong regulation and governance.

    Science.gov (United States)

    Kythreotis, A P; Mercer, T G; Frostick, L E

    2013-09-03

    In recent years there has been an increase in extreme events related to natural variability (such as earthquakes, tsunamis and hurricanes) and climate change (such as flooding and more extreme weather). Developing innovative technologies is crucial in making society more resilient to such events. However, little emphasis has been placed on the role of human decision-making in maximizing the positive impacts of technological developments. This is exacerbated by the lack of appropriate adaptation options and the privatization of existing infrastructure, which can leave people exposed to increasing risk. This work examines the need for more robust government regulation and legislation to complement developments and innovations in technology in order to protect communities against such extreme events.

  12. Synergistic effect of UV pretreated Fe-ZSM-5 catalysts for heterogeneous catalytic complete oxidation of VOC: A technology development for sustainable use.

    Science.gov (United States)

    Aziz, Abdul; Kim, Kwang Soo

    2017-10-15

    In this work, the performance of benzene, toluene, ethylbenzene, and xylene (BTEX) removal and degradation from gas, air streams on UV pretreated Fe-ZSM-5 in a batch reactor at room temperature were studied. The Fe-ZSM-5 zeolite catalyst was prepared by hydrothermal reaction method. The influence of UV pre-irradiation time on the removal of BTEX were assessed by varying the time, ranging from 15min to 60smin. Then, sustainability of the activation of the catalyst resulted by UV pretreatment was studied by the four-cycle experiment with one time UV irradiation and after each cycle irradiation followed by BTEX removal after every cycle respectively. The results of BTEX removal depicted that 30min of UV pretreatment was sufficient for complete organics removal. The UV pretreatment effect on the catalytic oxidation and the stability of the catalyst were studied by modern instrumental techniques. The novelty of the process was the sustainable reuse of catalyst with persistent VOC removal, which works on the -adsorption-oxidation-regeneration-adsorption- cycle, which was confirmed by the characterization studies of the catalyst after four runs. The results revealed that the change in the structure, stability, morphology, and removal efficiency of the catalyst during the experiments was negligible. The VOC degradation mechanism studies showed that the oxidation occurs due to the formation of free radicals as well as hydroxyl ions, so named it heterogeneous photo-Fenton oxidation. The residual materials analysis showed the complete mineralization of VOC except small amount of acetone as oxidation product. Lastly, the kinetics of the VOC removal was studied. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Investigating IT Faculty Resistance to Learning Management System Adoption Using Latent Variables in an Acceptance Technology Model

    OpenAIRE

    Fatiha Bousbahi; Muna Saleh Alrazgan

    2015-01-01

    To enhance instruction in higher education, many universities in the Middle East have chosen to introduce learning management systems (LMS) to their institutions. However, this new educational technology is not being used at its full potential and faces resistance from faculty members. To investigate this phenomenon, we conducted an empirical research study to uncover factors influencing faculty members’ acceptance of LMS. Thus, in the Fall semester of 2014, Information Technology faculty mem...

  14. Foreign Entry and Heterogeneous Growth of Firms

    DEFF Research Database (Denmark)

    Deng, Paul Duo; Jefferson, Gary H.

    distance from foreign firms. Domestic firms with smaller technological distance from their foreign counterparts tend to experience faster productivity growth, while firms with larger technological distance tend to lag further behind. We test this hypothesis using a unique firm-level data of Chinese...... manufacturing. Our empirical results confirm that foreign entry indeed generates strong heterogeneous growth patterns among domestic firms....

  15. Homeless but connected: the role of heterogeneous social network ties and social networking technology in the mental health outcomes of street-living adolescents.

    Science.gov (United States)

    Rice, Eric; Kurzban, Seth; Ray, Diana

    2012-12-01

    Although social integration tends to have positive effects on the mental health of housed adolescents, the role of homeless adolescents' social networks is more ambiguous. Social network data were collected from 136 homeless adolescents in Hollywood, California to examine how network ties are associated with symptoms of anxiety and depression. Face-to-face relationships with street-based peers were a risk factor for both anxiety and depression, while contacting home-based friends through social networking technology was found to be protective for depression. Community-based and public agencies serving homeless adolescents should consider facilitating the maintenance of these protective relationships by providing internet access.

  16. Discrete Feature Approach for Heterogeneous Reservoir Production Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Dershowitz, William S.; Curran, Brendan; Einstein, Herbert; LaPointe, Paul; Shuttle, Dawn; Klise, Kate

    2002-07-26

    The report presents summaries of technology development for discrete feature modeling in support of the improved oil recovery (IOR) for heterogeneous reservoirs. In addition, the report describes the demonstration of these technologies at project study sites.

  17. Heterogeneity in isogenic populations of microorganisms

    DEFF Research Database (Denmark)

    Pedersen, Anne Egholm

    values for quantifiable variables are used. The reproducibility of an experiment could thus be affected by the presence of subpopulations or high levels of phenotypic variations. Ole Maaløe and colleagues did in the late 1950’ties observe that the growth rate, RNA, DNA and protein synthesis and cell...... of heterogeneity was slightly higher at intermediate inducer concentrations. Additionally, the effect of thermal stress on phenotypic heterogeneity was addressed by inflicting a heat stress to the B. subtilis GFP reporter strain. The increase in incubation temperature transient increased population heterogeneity....... Heterogeneity was investigated on a population level using a quantitative analysis of phenotypic variation in methicillin-resistant Staphylococcus aureus (MRSA). The results obtained showed that the physiological state of the culture used for the analysis affected the phenotypic variation, as heterogeneity...

  18. Variables that dynamize access to information and communication technologies in middle income families from Aburrá Valley

    Directory of Open Access Journals (Sweden)

    Sandra María López

    2010-01-01

    Full Text Available El presente artículo muestra una metodología para seleccionar las variables que tengan una influencia significativa en la dinamización del acceso a las tecnologías de información y comunicación (TIC en las familias de ingreso medio en el Valle de Aburrá, así como las interrelaciones principales entre esas variables. Las variables se escogen a partir de la combinación de tres métodos de interpretación de resultados, basados en Análisis Estructural con el software MICMAC (Impact Matrix Cross-reference Multiplication.

  19. Investigating IT Faculty Resistance to Learning Management System Adoption Using Latent Variables in an Acceptance Technology Model.

    Science.gov (United States)

    Bousbahi, Fatiha; Alrazgan, Muna Saleh

    2015-01-01

    To enhance instruction in higher education, many universities in the Middle East have chosen to introduce learning management systems (LMS) to their institutions. However, this new educational technology is not being used at its full potential and faces resistance from faculty members. To investigate this phenomenon, we conducted an empirical research study to uncover factors influencing faculty members' acceptance of LMS. Thus, in the Fall semester of 2014, Information Technology faculty members were surveyed to better understand their perceptions of the incorporation of LMS into their courses. The results showed that personal factors such as motivation, load anxiety, and organizational support play important roles in the perception of the usefulness of LMS among IT faculty members. These findings suggest adding these constructs in order to extend the Technology acceptance model (TAM) for LMS acceptance, which can help stakeholders of the university to implement the use of this system. This may assist in planning and evaluating the use of e-learning.

  20. 基于泵变频调速的航天器热控制技术%Spacecraft Thermal Control Technology Based on Variable Frequency Pump

    Institute of Scientific and Technical Information of China (English)

    宁献文; 张加迅

    2011-01-01

    文章针对某单相流体回路地面原理样机,提出采用泵变频调速技术进行控温,并对系统控温特性进行了地面试验研究,整个瞬态试验过程中控温精度一般都在士0.3℃以内,最大波动也基本不超过±0.5℃,基于泵变频调速技术的热控制策略性能优良、有效,试验结果可供实际工程设计参考.%The traditional temperature control mode using temperature-sensing valve has three deficiencies with the reliability, dynamic behavior, pump operational efficiency. In order to solve these problems, a new thermal control technology based on variable frequency pump was put forward for a fluid loop prototype model. The temperature control performance of the thermal control technology based on variable frequency pump was tested. During all transients, the controlled temperature was within the range of ±0. 3℃ around the set-point, with a maximum admissible variation range of ±0.5℃. Thermal control strategy based on variable frequency pump has effective performance.

  1. Technology.

    Science.gov (United States)

    Online-Offline, 1998

    1998-01-01

    Focuses on technology, on advances in such areas as aeronautics, electronics, physics, the space sciences, as well as computers and the attendant progress in medicine, robotics, and artificial intelligence. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books,…

  2. Improvement of optical and acoustical technologies for the protection: Project IMOTEP: Network of heterogeneous sensor types for the protection of camps or mobile troops

    Science.gov (United States)

    Hengy, Sébastien; Laurenzis, Martin; Zimpfer, Véronique; Schneider, Armin

    2014-10-01

    Snipers have emerged as a major threat to troops in recent conflicts. To reduce this menace, the objective of the French- German Research Institute of Saint Louis (ISL) research project "IMOTEP" is to improve the detection of snipers on the battlefield. Our basic approach is to combine several sources of information for a fast and appropriate reaction when an unusual signal (e.g. a flash or a shot) is detected. The project includes several technologies developed at ISL: acoustical detection, fusion of distributed sensor network data, active imaging and 3D audio communication. The protection of camps, convoys or dismounted soldiers rests on a distributed acoustical sensor network that detects and localizes sniper attacks. An early estimation of the threat position is transmitted through a network to an active imaging system in order to confirm and refine this position by 3D imaging. The refined position is then sent to the control center which generates an alert message that displays the threat position using two formats: a tactical map and a 3D audio signal. In addition, the camp is protected by an ad-hoc sensor network used for intruder detection.

  3. A novel approach in Multi-hop networks technology with the ratio distribution of two Hyper-Erlang random variables

    Directory of Open Access Journals (Sweden)

    Therrar Kadri

    2015-11-01

    Full Text Available The distribution of ratio of two random variables has been studied by several authors especially when the two random variables are independent and come from the same family. In this paper, the exact distribution of the ratio of two independent Hyper-Erlang distribution is derived. However, closed expressions of the probability density, cumulative distribution function, reliability function, hazard function, moment generating function and the rth moment are found for this ratio distribution and proved to be a linear combination of the Generalized-F distribution. Finally, we will apply our results to real life application in analyzing the performance of wireless communication systems.

  4. Factorial experimental design of winery wastewaters treatment by heterogeneous photo-Fenton process.

    Science.gov (United States)

    Mosteo, Rosa; Ormad, Peña; Mozas, Engracia; Sarasa, Judith; Ovelleiro, José Luis

    2006-05-01

    Winery wastewaters are difficult to treat by conventional biological processes because they are seasonal and experience a substantial flow variations. Photocatalytic advanced oxidation is a promising technology for wastewaters containing high amounts of organic matter. In this work, the photo-Fenton process in heterogeneous phase is presented as an alternative methodology for the treatment of winery wastewaters. As a consequence of the great number of existing variables, an experimental design methodology has been used in order to study the influence and interaction of various variables and to obtain a reduced empirical model which describes the organic matter degradation process. Applying photo-Fenton treatment in heterogeneous phase under energetic conditions for synthetic samples simulating winery wastewaters results in purification levels of up to 50% (measured as total organic carbon). Different reduced models are obtained and their utilization depends mainly on the degree of degradation of organic matter required.

  5. The Integration of Group Technology and Simulation Optimization to Solve the Flow Shop with Highly Variable Cycle Time Process: A Surgery Scheduling Case Study

    Directory of Open Access Journals (Sweden)

    T. K. Wang

    2014-01-01

    Full Text Available Surgery scheduling must balance capacity utilization and demand so that the arrival rate does not exceed the effective production rate. However, authorized overtime increases because of random patient arrivals and cycle times. This paper proposes an algorithm that allows the estimation of the mean effective process time and the coefficient of variation. The algorithm quantifies patient flow variability. When the parameters are identified, takt time approach gives a solution that minimizes the variability in production rates and workload, as mentioned in the literature. However, this approach has limitations for the problem of a flow shop with an unbalanced, highly variable cycle time process. The main contribution of the paper is to develop a method called takt time, which is based on group technology. A simulation model is combined with the case study, and the capacity buffers are optimized against the remaining variability for each group. The proposed methodology results in a decrease in the waiting time for each operating room from 46 minutes to 5 minutes and a decrease in overtime from 139 minutes to 75 minutes, which represents an improvement of 89% and 46%, respectively.

  6. Flow variability and its physical causes in infusion technology: a systematic review of in vitro measurement and modeling studies.

    Science.gov (United States)

    Snijder, Roland A; Konings, Maurits K; Lucas, Peter; Egberts, Toine C; Timmerman, Annemoon D

    2015-08-01

    Infusion therapy is medically and technically challenging and frequently associated with medical errors. When administering pharmaceuticals by means of infusion, dosing errors can occur due to flow rate variability. These dosing errors may lead to adverse effects. We aimed to systematically review the available biomedical literature for in vitro measurement and modeling studies that investigated the physical causes of flow rate variability. Special focus was given to syringe pump setups, which are typically used if very accurate drug delivery is required. We aimed to extract from literature the component with the highest mechanical compliance in syringe pump setups. We included 53 studies, six of which were theoretical models, two articles were earlier reviews of infusion literature, and 45 were in vitro measurement studies. Mechanical compliance, flow resistance, and dead volume of infusion systems were stated as the most important and frequently identified physical causes of flow rate variability. The syringe was indicated as the most important source of mechanical compliance in syringe pump setups (9.0×10-9 to 2.1×10-8 l/Pa). Mechanical compliance caused longer flow rate start-up times (from several minutes up to approximately 70 min) and delayed occlusion alarm times (up to 117 min).

  7. A Range-Based Vehicle Life Cycle Assessment Incorporating Variability in the Environmental Assessment of Different Vehicle Technologies and Fuels

    OpenAIRE

    2014-01-01

    How to compare the environmental performance of different vehicle technologies? Vehicles with lower tailpipe emissions are perceived as cleaner. However, does it make sense to look only to tailpipe emissions? Limiting the comparison only to these emissions denies the fact that there are emissions involved during the production of a fuel and this approach gives too much advantage to zero-tailpipe vehicles like battery electric vehicles (BEV) and fuel cell electric vehicle (FCEV). Would it be ...

  8. Investigating IT Faculty Resistance to Learning Management System Adoption Using Latent Variables in an Acceptance Technology Model

    Directory of Open Access Journals (Sweden)

    Fatiha Bousbahi

    2015-01-01

    Full Text Available To enhance instruction in higher education, many universities in the Middle East have chosen to introduce learning management systems (LMS to their institutions. However, this new educational technology is not being used at its full potential and faces resistance from faculty members. To investigate this phenomenon, we conducted an empirical research study to uncover factors influencing faculty members’ acceptance of LMS. Thus, in the Fall semester of 2014, Information Technology faculty members were surveyed to better understand their perceptions of the incorporation of LMS into their courses. The results showed that personal factors such as motivation, load anxiety, and organizational support play important roles in the perception of the usefulness of LMS among IT faculty members. These findings suggest adding these constructs in order to extend the Technology acceptance model (TAM for LMS acceptance, which can help stakeholders of the university to implement the use of this system. This may assist in planning and evaluating the use of e-learning.

  9. Global gene expression profiling of individual human oocytes and embryos demonstrates heterogeneity in early development.

    Directory of Open Access Journals (Sweden)

    Lisa Shaw

    Full Text Available Early development in humans is characterised by low and variable embryonic viability, reflected in low fecundity and high rates of miscarriage, relative to other mammals. Data from assisted reproduction programmes provides additional evidence that this is largely mediated at the level of embryonic competence and is highly heterogeneous among embryos. Understanding the basis of this heterogeneity has important implications in a number of areas including: the regulation of early human development, disorders of pregnancy, assisted reproduction programmes, the long term health of children which may be programmed in early development, and the molecular basis of pluripotency in human stem cell populations. We have therefore investigated global gene expression profiles using polyAPCR amplification and microarray technology applied to individual human oocytes and 4-cell and blastocyst stage embryos. In order to explore the basis of any variability in detail, each developmental stage is replicated in triplicate. Our data show that although transcript profiles are highly stage-specific, within each stage they are relatively variable. We describe expression of a number of gene families and pathways including apoptosis, cell cycle and amino acid metabolism, which are variably expressed and may be reflective of embryonic developmental competence. Overall, our data suggest that heterogeneity in human embryo developmental competence is reflected in global transcript profiles, and that the vast majority of existing human embryo gene expression data based on pooled oocytes and embryos need to be reinterpreted.

  10. Technology

    Directory of Open Access Journals (Sweden)

    Xu Jing

    2016-01-01

    Full Text Available The traditional answer card reading method using OMR (Optical Mark Reader, most commonly, OMR special card special use, less versatile, high cost, aiming at the existing problems proposed a method based on pattern recognition of the answer card identification method. Using the method based on Line Segment Detector to detect the tilt of the image, the existence of tilt image rotation correction, and eventually achieve positioning and detection of answers to the answer sheet .Pattern recognition technology for automatic reading, high accuracy, detect faster

  11. The relationship of document and quantitative literacy with learning styles and selected personal variables for aerospace technology students at Indiana State University

    Science.gov (United States)

    Martin, Royce Ann

    The purpose of this study was to determine the extent that student scores on a researcher-constructed quantitative and document literacy test, the Aviation Documents Delineator (ADD), were associated with (a) learning styles (imaginative, analytic, common sense, dynamic, and undetermined), as identified by the Learning Type Measure, (b) program curriculum (aerospace administration, professional pilot, both aerospace administration and professional pilot, other, or undeclared), (c) overall cumulative grade point average at Indiana State University, and (d) year in school (freshman, sophomore, junior, or senior). The Aviation Documents Delineator (ADD) was a three-part, 35 question survey that required students to interpret graphs, tables, and maps. Tasks assessed in the ADD included (a) locating, interpreting, and describing specific data displayed in the document, (b) determining data for a specified point on the table through interpolation, (c) comparing data for a string of variables representing one aspect of aircraft performance to another string of variables representing a different aspect of aircraft performance, (d) interpreting the documents to make decisions regarding emergency situations, and (e) performing single and/or sequential mathematical operations on a specified set of data. The Learning Type Measure (LTM) was a 15 item self-report survey developed by Bernice McCarthy (1995) to profile an individual's processing and perception tendencies in order to reveal different individual approaches to learning. The sample used in this study included 143 students enrolled in Aerospace Technology Department courses at Indiana State University in the fall of 1996. The ADD and the LTM were administered to each subject. Data collected in this investigation were analyzed using a stepwise multiple regression analysis technique. Results of the study revealed that the variables, year in school and GPA, were significant predictors of the criterion variables, document

  12. Coordinated Use of Heterogeneous Infrastructures for Scientific Computing at CIEMAT by means of Grid Technologies; Aprovechamiento Coordinado de las Infraestructuras Heterogeneas para Calculo Cientifico Participadas por el CIEMAT por medio de Tecnologias Grid

    Energy Technology Data Exchange (ETDEWEB)

    Rubio-Montero, A. J.

    2008-08-06

    Usually, research data centres maintain platforms from a wide range of architectures to cover the computational needs of their scientists. These centres are also frequently involved in diverse national and international Grid projects. Besides, it is very difficult to achieve a complete and efficient utilization of these recourses, due to the heterogeneity in their hardware and software configurations and their unequal use along the time. This report offers a solution to the problem of enabling a simultaneous and coordinated access to the variety of computing infrastructures and platforms available in great Research Organisms such as CIEMAT. For this purpose, new Grid technologies have been deployed in order to facilitate a common interface which enables the final user to access the internal and external resources. The previous computing infrastructure has not been modified and the independence on its administration has been guaranteed. For a sake of comparison, a feasibility study has been performed with the execution of the Drift Kinetic Equation solver (Dikes) tool, a high throughput scientific application used in the TJ-II Flexible Heliac at National Fusion Laboratory. (Author) 35 refs.

  13. Laser metal deposition with spatial variable orientation based on hollow-laser beam with internal powder feeding technology

    Science.gov (United States)

    Shi, Tuo; Lu, Bingheng; Shi, Shihong; Meng, Weidong; Fu, Geyan

    2017-02-01

    In this study, a hollow-laser beam with internal powder feeding (HLB-IPF) head is applied to achieve non-horizontal cladding and deposition of overhanging structure. With the features of this head such as uniform scan energy distribution, thin and straight spraying of the powder beam, the deposition in spatial variable orientation is conducted using a 6-axis robot. During the deposition process the head keeps tangential to the growth direction of the part. In the experiment, a "vase" shaped metal part with overhanging structure is successfully deposited, and the largest overhanging angle achieves 80° to the vertical direction. The "step effect" between cladding layers is completely eliminated with the best surface roughness of Ra=3.864 μm. Cross section of cladding layers with unequal height are deposited for angle change. Test results indicate that the formed part has uniform wall thickness, fine microstructure and high microhardness.

  14. Real-Time Prediction of Gamers Behavior Using Variable Order Markov and Big Data Technology: A Case of Study

    Directory of Open Access Journals (Sweden)

    Alejandro Baldominos Gómez

    2016-03-01

    Full Text Available This paper presents the results and conclusions found when predicting the behavior of gamers in commercial videogames datasets. In particular, it uses Variable-Order Markov (VOM to build a probabilistic model that is able to use the historic behavior of gamers and to infer what will be their next actions. Being able to predict with accuracy the next user’s actions can be of special interest to learn from the behavior of gamers, to make them more engaged and to reduce churn rate. In order to support a big volume and velocity of data, the system is built on top of the Hadoop ecosystem, using HBase for real-time processing; and the prediction tool is provided as a service (SaaS and accessible through a RESTful API. The prediction system is evaluated using a case of study with two commercial videogames, attaining promising results with high prediction accuracies.

  15. Fundamental concepts in heterogeneous catalysis

    CERN Document Server

    Norskov, Jens K; Abild-Pedersen, Frank; Bligaard, Thomas

    2014-01-01

    This book is based on a graduate course and suitable as a primer for any newcomer to the field, this book is a detailed introduction to the experimental and computational methods that are used to study how solid surfaces act as catalysts.   Features include:First comprehensive description of modern theory of heterogeneous catalysisBasis for understanding and designing experiments in the field   Allows reader to understand catalyst design principlesIntroduction to important elements of energy transformation technologyTest driven at Stanford University over several semesters

  16. Kinetics of heterogeneous catalytic reactions

    CERN Document Server

    Boudart, Michel

    2014-01-01

    This book is a critical account of the principles of the kinetics of heterogeneous catalytic reactions in the light of recent developments in surface science and catalysis science. Originally published in 1984. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase acc

  17. Heterogeneous network architectures

    DEFF Research Database (Denmark)

    Christiansen, Henrik Lehrmann

    2006-01-01

    Future networks will be heterogeneous! Due to the sheer size of networks (e.g., the Internet) upgrades cannot be instantaneous and thus heterogeneity appears. This means that instead of trying to find the olution, networks hould be designed as being heterogeneous. One of the key equirements here...... is flexibility. This thesis investigates such heterogeneous network architectures and how to make them flexible. A survey of algorithms for network design is presented, and it is described how using heuristics can increase the speed. A hierarchical, MPLS based network architecture is described...... and it is discussed that it is advantageous to heterogeneous networks and illustrated by a number of examples. Modeling and simulation is a well-known way of doing performance evaluation. An approach to event-driven simulation of communication networks is presented and mixed complexity modeling, which can simplify...

  18. Understanding the Nature of Cooperation Variability

    DEFF Research Database (Denmark)

    Fosgaard, Toke Reinholt; Hansen, Lars Gårn; Wengström, Erik Roland

    and the behavioral heterogeneity of cooperation variability. We find that framing only has a small effect on the average level of cooperation but a substantial effect on behavioral heterogeneity and we show that this can be explained almost exclusively by a corresponding change in the heterogeneity of beliefs about...

  19. Scale Reliability Evaluation with Heterogeneous Populations

    Science.gov (United States)

    Raykov, Tenko; Marcoulides, George A.

    2015-01-01

    A latent variable modeling approach for scale reliability evaluation in heterogeneous populations is discussed. The method can be used for point and interval estimation of reliability of multicomponent measuring instruments in populations representing mixtures of an unknown number of latent classes or subpopulations. The procedure is helpful also…

  20. Generalised maximum entropy and heterogeneous technologies

    NARCIS (Netherlands)

    Oude Lansink, A.G.J.M.

    1999-01-01

    Generalised maximum entropy methods are used to estimate a dual model of production on panel data of Dutch cash crop farms over the period 1970-1992. The generalised maximum entropy approach allows a coherent system of input demand and output supply equations to be estimated for each farm in the sam

  1. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  2. Dissecting cancer evolution at the macro-heterogeneity and micro-heterogeneity scale.

    Science.gov (United States)

    Barber, Louise J; Davies, Matthew N; Gerlinger, Marco

    2015-02-01

    Intratumour heterogeneity complicates biomarker discovery and treatment personalization, and pervasive cancer evolution is a key mechanism leading to therapy failure and patient death. Thus, understanding subclonal heterogeneity architectures and cancer evolution processes is critical for the development of effective therapeutic approaches which can control or thwart cancer evolutionary plasticity. Current insights into heterogeneity are mainly limited to the macroheterogeneity level, established by cancer subclones that have undergone significant clonal expansion. Novel single cell sequencing and blood-based subclonal tracking technologies are enabling detailed insights into microheterogeneity and the dynamics of clonal evolution. We assess how this starts to delineate the rules governing cancer evolution and novel angles for more effective therapeutic intervention.

  3. Foreign Entry and Heterogeneous Growth of Firms

    DEFF Research Database (Denmark)

    Deng, Paul Duo; Jefferson, Gary H.

    We adopt the framework of Schumpeterian creative destruction formalized by Aghion et al. (2009) to analyze the impact of foreign entry on the productivity growth of domestic firms. In the face of foreign entry, domestic firms exhibit heterogeneous patterns of growth depending on their technological...

  4. Foreign Entry and Heterogeneous Growth of Firms

    DEFF Research Database (Denmark)

    Deng, Paul Duo; Jefferson, Gary H.

    We adopt the framework of Schumpeterian creative destruction formalized by Aghion et al. (2009) to analyze the impact of foreign entry on the productivity growth of domestic firms. In the face of foreign entry, domestic firms exhibit heterogeneous patterns of growth depending on their technologic...

  5. Cooperative Radio Resource Management for Heterogeneous Networks

    DEFF Research Database (Denmark)

    Mihovska, Albena D.; Tragos, Elias; Luo, Jijun

    2009-01-01

    The heterogeneity in technology and also in ownership leads to complex systems and interworking problems, which can be seen from the ability to establish and maintain connections with required quality, in fault detection and location, in resource allocation and in charging of the usage of the net...

  6. On the area spectral efficiency improvement of heterogeneous network by exploiting the integration of macro-femto cellular networks

    KAUST Repository

    Shakir, Muhammad

    2012-06-01

    Heterogeneous networks are an attractive means of expanding mobile network capacity. A heterogeneous network is typically composed of multiple radio access technologies (RATs) where the base stations are transmitting with variable power. In this paper, we consider a Heterogeneous network where we complement the macrocell network with low-power low-cost user deployed nodes, such as femtocell base stations to increase the mean achievable capacity of the system. In this context, we integrate macro-femto cellular networks and derive the area spectral efficiency of the proposed two tier Heterogeneous network. We consider the deployment of femtocell base stations around the edge of the macrocell such that this configuration is referred to as femto-on-edge (FOE) configuration. Moreover, FOE configuration mandates reduction in intercell interference due to the mobile users which are located around the edge of the macrocell since these femtocell base stations are low-power nodes which has significantly lower transmission power than macrocell base stations. We present a mathematical analysis to calculate the instantaneous carrier to interference ratio (CIR) of the desired mobile user in macro and femto cellular networks and determine the total area spectral efficiency of the Heterogeneous network. Details of the simulation processes are included to support the analysis and show the efficacy of the proposed deployment. It has been shown that the proposed setup of the Heterogeneous network offers higher area spectral efficiency which aims to fulfill the expected demand of the future mobile users. © 2012 IEEE.

  7. Teaching Heterogeneous Classes.

    Science.gov (United States)

    Millrood, Radislav

    2002-01-01

    Discusses an approach to teaching heterogeneous English-as-a-Second/Foreign-Language classes. Draws on classroom research data to describe the features of a success-building lesson context. (Author/VWL)

  8. Subgroup effects despite homogeneous heterogeneity test results

    Directory of Open Access Journals (Sweden)

    Lubsen Jacobus

    2010-05-01

    Full Text Available Abstract Background Statistical tests of heterogeneity are very popular in meta-analyses, as heterogeneity might indicate subgroup effects. Lack of demonstrable statistical heterogeneity, however, might obscure clinical heterogeneity, meaning clinically relevant subgroup effects. Methods A qualitative, visual method to explore the potential for subgroup effects was provided by a modification of the forest plot, i.e., adding a vertical axis indicating the proportion of a subgroup variable in the individual trials. Such a plot was used to assess the potential for clinically relevant subgroup effects and was illustrated by a clinical example on the effects of antibiotics in children with acute otitis media. Results Statistical tests did not indicate heterogeneity in the meta-analysis on the effects of amoxicillin on acute otitis media (Q = 3.29, p = 0.51; I2 = 0%; T2 = 0. Nevertheless, in a modified forest plot, in which the individual trials were ordered by the proportion of children with bilateral otitis, a clear relation between bilaterality and treatment effects was observed (which was also found in an individual patient data meta-analysis of the included trials: p-value for interaction 0.021. Conclusions A modification of the forest plot, by including an additional (vertical axis indicating the proportion of a certain subgroup variable, is a qualitative, visual, and easy-to-interpret method to explore potential subgroup effects in studies included in meta-analyses.

  9. Teaching Gene Technology in an Outreach Lab: Students' Assigned Cognitive Load Clusters and the Clusters' Relationships to Learner Characteristics, Laboratory Variables, and Cognitive Achievement

    Science.gov (United States)

    Scharfenberg, Franz-Josef; Bogner, Franz X.

    2013-02-01

    This study classified students into different cognitive load (CL) groups by means of cluster analysis based on their experienced CL in a gene technology outreach lab which has instructionally been designed with regard to CL theory. The relationships of the identified student CL clusters to learner characteristics, laboratory variables, and cognitive achievement were examined using a pre-post-follow-up design. Participants of our day-long module Genetic Fingerprinting were 409 twelfth-graders. During the module instructional phases (pre-lab, theoretical, experimental, and interpretation phases), we measured the students' mental effort (ME) as an index of CL. By clustering the students' module-phase-specific ME pattern, we found three student CL clusters which were independent of the module instructional phases, labeled as low-level, average-level, and high-level loaded clusters. Additionally, we found two student CL clusters that were each particular to a specific module phase. Their members reported especially high ME invested in one phase each: within the pre-lab phase and within the interpretation phase. Differentiating the clusters, we identified uncertainty tolerance, prior experience in experimentation, epistemic interest, and prior knowledge as relevant learner characteristics. We found relationships to cognitive achievement, but no relationships to the examined laboratory variables. Our results underscore the importance of pre-lab and interpretation phases in hands-on teaching in science education and the need for teachers to pay attention to these phases, both inside and outside of outreach laboratory learning settings.

  10. Voice over IP in Wireless Heterogeneous Networks

    DEFF Research Database (Denmark)

    Fathi, Hanane; Chakraborty, Shyam; Prasad, Ramjee

    The convergence of different types of traffic has preceded the convergence of systems and services in a wireless heterogeneous network. Voice and data traffic are usually treated separate in both 2G and 2.5G wireless networks. With advances in packet switching technology and especially......IP communications are difficult to achieve in a time-varying environment due to channel errors and traffic congestion and across different systems. The provision of VoIP in wireless heterogeneous networks requires a set of time-efficient control mechanisms to support a VoIP session with acceptable quality...

  11. Heterogeneous Computing with OpenCL

    CERN Document Server

    Gaster, Benedict; Kaeli, David R; Mistry, Perhaad; Schaa, Dana

    2011-01-01

    Heterogeneous Computing with OpenCL teaches OpenCL and parallel programming for complex systems that may include a variety of device architectures: multi-core CPUs, GPUs, and fully-integrated Accelerated Processing Units (APUs) such as AMD Fusion technology. Designed to work on multiple platforms and with wide industry support, OpenCL will help you more effectively program for a heterogeneous future. Written by leaders in the parallel computing and OpenCL communities, this book will give you hands-on OpenCL experience to address a range of fundamental parallel algorithms. The authors explore m

  12. Green heterogeneous wireless networks

    CERN Document Server

    Ismail, Muhammad; Nee, Hans-Peter; Qaraqe, Khalid A; Serpedin, Erchin

    2016-01-01

    This book focuses on the emerging research topic "green (energy efficient) wireless networks" which has drawn huge attention recently from both academia and industry. This topic is highly motivated due to important environmental, financial, and quality-of-experience (QoE) considerations. Specifically, the high energy consumption of the wireless networks manifests in approximately 2% of all CO2 emissions worldwide. This book presents the authors’ visions and solutions for deployment of energy efficient (green) heterogeneous wireless communication networks. The book consists of three major parts. The first part provides an introduction to the "green networks" concept, the second part targets the green multi-homing resource allocation problem, and the third chapter presents a novel deployment of device-to-device (D2D) communications and its successful integration in Heterogeneous Networks (HetNets). The book is novel in that it specifically targets green networking in a heterogeneous wireless medium, which re...

  13. Heterogenous networks and services

    DEFF Research Database (Denmark)

    Tan, Su-En

    . Incremental technological changes are characterised by small changes that are linked to the previous generation of technology and are seen to be advancements of that technology. Radical technological changes, on the other hand, are characterised by a new innovative technology that is different from...... the existing generation of technology and presents new technological performance breakthroughs. It is difficult to predict which radical technologies or innovations will result in a market disruption early on in their life cycles. Based on Clayton Christensen’s (Christensen 1997) definition of a disruptive......; that is, different types of access networks are inter-connected and interoperable, allowing users seamless roaming between different network types. Technology, business as well as standardisation will play a large role in achieving this. Technological innovation and advancement are the foundations of new...

  14. Thermal infrared remote sensing for riverscape analysis of water temperature heterogeneity: current research and future directions

    Science.gov (United States)

    Dugdale, S.; Hannah, D. M.; Malcolm, I.; Bergeron, N.; St-Hilaire, A.

    2016-12-01

    Climate change will increase summer water temperatures in northern latitude rivers. It is likely that this will have a negative impact on fish species such as salmonids, which are sensitive to elevated temperatures. Salmonids currently avoid heat stress by opportunistically using cool water zones that arise from the spatio-temporal mosaic of thermal habitats present within rivers. However, there is a general lack of information about the processes driving this thermal habitat heterogeneity or how these spatio-temporal patterns might vary under climate change. In this paper, we document how thermal infrared imaging has previously been used to better understand the processes driving river temperature patterns. We then identify key knowledge gaps that this technology can help to address in the future. First, we demonstrate how repeat thermal imagery has revealed the role of short-term hydrometeorological variability in influencing longitudinal river temperature patterns, showing that precipitation depth is strongly correlated with the degree of longitudinal temperature heterogeneity. Second, we document how thermal infrared imagery of a large watershed in Eastern Canada has shed new light on the landscape processes driving the spatial distribution of cool water patches, revealing that the distribution of cool patches is strongly linked to channel confinement, channel curvature and the proximity of dry tributary valleys. Finally, we detail gaps in current understanding of spatio-temporal patterns of river temperature heterogeneity. We explain how advances in unmanned aerial vehicle technology and deterministic temperature modelling will be combined to address these current limitations, shedding new light on the landscape processes driving geographical variability in patterns of river temperature heterogeneity. We then detail how such advances will help to identify rivers that will be resilient to future climatic warming, improving current and future strategies for

  15. Modeling Approaches for Describing Microbial Population Heterogeneity

    DEFF Research Database (Denmark)

    Lencastre Fernandes, Rita

    , ethanol and biomass throughout the reactor. This work has proven that the integration of CFD and population balance models, for describing the growth of a microbial population in a spatially heterogeneous reactor, is feasible, and that valuable insight on the interplay between flow and the dynamics......Although microbial populations are typically described by averaged properties, individual cells present a certain degree of variability. Indeed, initially clonal microbial populations develop into heterogeneous populations, even when growing in a homogeneous environment. A heterogeneous microbial......) to predict distributions of certain population properties including particle size, mass or volume, and molecular weight. Similarly, PBM allow for a mathematical description of distributed cell properties within microbial populations. Cell total protein content distributions (a measure of cell mass) have been...

  16. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  17. Heterogeneous Reburning By Mixed Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Anderson Hall

    2009-03-31

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  18. HETEROGENEOUS REBURNING BY MIXED FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Yin Chen; Benson B. Gathitu

    2005-01-14

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  19. Interference Management Based on Interference Draining Technology in LTE-A High-density Heterogeneous Network%LTE-A高密异构网场景下基于干扰排污技术的干扰管理

    Institute of Scientific and Technical Information of China (English)

    芳艳; 孙长印; 卢光跃; 谢永斌

    2015-01-01

    在LTE-A高密异构网场景下,干扰对齐( IA)被用来消除小区间的干扰。然而,随着小区数目的增加,干扰对齐的条件会变得很难满足。针对此问题,提出了干扰排污( ID )的思想,通过寻找未被充分利用的系统资源空间,并且适当地放宽干扰对齐的条件,实现对空域、频域自由度( DOF)的充分利用。首先,寻找干扰排污空间,然后基于交替最小化的方法求解小区的预编码矩阵和接收滤波器,最后对干扰排污空间用户利用IRC( Interference Rejection Combine)算法重新求解其接收滤波器。仿真结果表明,可以在每个基站天线数目固定的条件下不断地增加小区数目,并且同时获得一定的吞吐量增益。%Interference alignment( IA) technology can be used to eliminate inter-cell interference( ICI) in the LTE-A high-density heterogeneous network. However,due to an increase of cell number,interference alignment conditions cannot be always met. In view of this problem,this paper proposes a scheme based on interference draining( ID) thoughts. By looking for the underused space of system resource and appropriate-ly relaxing the IA conditions,the full utilization of degrees of freedom( DOF) in the spatial and frequency domain is achieved. Firstly,it looks for the available draining space,then obtains the pre-coding and re-ceive filter according to the alternating minimization approach. Finally,for the draining space provider,it u-ses Interference Rejection Combine( IRC) algorithm to solve the receiving filter again. Simulation results indicate that the scheme is effective to get some throughput gain when fixed number of base station anten-nas is assumed and the number of cells continues to increase.

  20. Heterogeneous computing with OpenCL

    CERN Document Server

    2013-01-01

    Heterogeneous Computing with OpenCL teaches OpenCL and parallel programming for complex systems that may include a variety of device architectures: multi-core CPUs, GPUs, and fully-integrated Accelerated Processing Units (APUs) such as AMD Fusion technology. Designed to work on multiple platforms and with wide industry support, OpenCL will help you more effectively program for a heterogeneous future. Written by leaders in the parallel computing and OpenCL communities, this book will give you hands-on OpenCL experience to address a range of fundamental parallel algorithms. The authors explore memory spaces, optimization techniques, graphics interoperability, extensions, and debugging and profiling. Intended to support a parallel programming course, Heterogeneous Computing with OpenCL includes detailed examples throughout, plus additional online exercises and other supporting materials.

  1. Heterogeneous Uncertainty Management

    Science.gov (United States)

    2008-03-08

    probabilistic ( HTP ) agents, the concept of probabilistic version of XML and RDF, and probabilistic methods to reason about collections of moving objects. S...heterogeneous temporal probabilistic ( HTP ) agents, the concept of probabilistic version of XML and RDF, and probabilistic methods to reason about...temporal probabilistic ( HTP ) agent. HTP agents can build temporal probabilistic reasoning capabilities on top of multiple databases and software

  2. Heterogeneous Computing in Economics

    DEFF Research Database (Denmark)

    Dziubinski, M.P.; Grassi, S.

    2014-01-01

    This paper shows the potential of heterogeneous computing in solving dynamic equilibrium models in economics. We illustrate the power and simplicity of C++ Accelerated Massive Parallelism (C++ AMP) recently introduced by Microsoft. Starting from the same exercise as Aldrich et al. (J Econ Dyn...

  3. Heterogeneity of Intellectual Assets

    DEFF Research Database (Denmark)

    Dahlgren, Johan Henrich; Lund Jensen, Rasmus; Valentin, Finn

    2004-01-01

    This paper deals with methodological issues of assessing the composition and level ofheterogeneity of firms' intellectual assets. It develops an original metric - referred to asthe H-index - for measuring heterogeneity using data extracted from patent documents.The main purpose is to improve...

  4. 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 silica-c

  5. 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 and the...

  6. Heterogeneity of Dutch rainfall

    NARCIS (Netherlands)

    Witter, J.V.

    1984-01-01

    Rainfall data for the Netherlands have been used in this study to investigate aspects of heterogeneity of rainfall, in particular local differences in rainfall levels, time trends in rainfall, and local differences in rainfall trend. The possible effect of urbanization and industrialization on the

  7. Receiver Heterogeneity Helps

    DEFF Research Database (Denmark)

    Kovács, Erika R.; Pedersen, Morten Videbæk; Roetter, Daniel Enrique Lucani;

    2014-01-01

    Heterogeneity amongst devices and desired service are commonly seen as a source of additional challenges for setting up an efficient multi-layer multicast service. In particular, devices requiring only the base layer can become a key bottleneck to the performance for other devices. This paper...

  8. Glioblastoma Multiforme: A Look Inside Its Heterogeneous Nature

    Directory of Open Access Journals (Sweden)

    Maria-del-Mar Inda

    2014-01-01

    Full Text Available Heterogeneity is a hallmark of tumors and has a crucial role in the outcome of the malignancy, because it not only confounds diagnosis, but also challenges the design of effective therapies. There are two types of heterogeneity: inter-tumor and intra-tumor heterogeneity. While inter-tumor heterogeneity has been studied widely, intra-tumor heterogeneity has been neglected even though numerous studies support this aspect of tumor pathobiology. The main reason has been the technical difficulties, but with new advances in single-cell technology, intra-tumor heterogeneity is becoming a key area in the study of cancer. Several models try to explain the origin and maintenance of intra-tumor heterogeneity, however, one prominent model compares cancer with a tree where the ubiquitous mutations compose the trunk and mutations present in subpopulations of cells are represented by the branches. In this review we will focus on the intra-tumor heterogeneity of glioblastoma multiforme (GBM, the most common brain tumor in adults that is characterized by a marked heterogeneity at the cellular and molecular levels. Better understanding of this heterogeneity will be essential to design effective therapies against this devastating disease to avoid tumor escape.

  9. Glioblastoma Multiforme: A Look Inside Its Heterogeneous Nature

    Energy Technology Data Exchange (ETDEWEB)

    Inda, Maria-del-Mar, E-mail: mminda@vhio.net; Bonavia, Rudy [Translational Research Program, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron University Hospital, 119-129 Passeig Vall d’Hebron, Barcelona 08035 (Spain); Seoane, Joan [Translational Research Program, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron University Hospital, 119-129 Passeig Vall d’Hebron, Barcelona 08035 (Spain); Catalan Institution of Research and Advanced Studies (ICREA), Barcelona 08035 (Spain)

    2014-01-27

    Heterogeneity is a hallmark of tumors and has a crucial role in the outcome of the malignancy, because it not only confounds diagnosis, but also challenges the design of effective therapies. There are two types of heterogeneity: inter-tumor and intra-tumor heterogeneity. While inter-tumor heterogeneity has been studied widely, intra-tumor heterogeneity has been neglected even though numerous studies support this aspect of tumor pathobiology. The main reason has been the technical difficulties, but with new advances in single-cell technology, intra-tumor heterogeneity is becoming a key area in the study of cancer. Several models try to explain the origin and maintenance of intra-tumor heterogeneity, however, one prominent model compares cancer with a tree where the ubiquitous mutations compose the trunk and mutations present in subpopulations of cells are represented by the branches. In this review we will focus on the intra-tumor heterogeneity of glioblastoma multiforme (GBM), the most common brain tumor in adults that is characterized by a marked heterogeneity at the cellular and molecular levels. Better understanding of this heterogeneity will be essential to design effective therapies against this devastating disease to avoid tumor escape.

  10. The SMOS Validation Campaign 2010 in the Upper Danube Catchment: A Data Set for Studies of Soil Moisture, Brightness Temperature, and Their Spatial Variability Over a Heterogeneous Land Surface

    DEFF Research Database (Denmark)

    T. dall' Amico, Johanna; Schlenz, Florian; Loew, Alexander;

    2013-01-01

    The Soil Moisture and Ocean Salinity mission has been launched by the European Space Agency (ESA) in November 2009. It is the worldwide first satellite dedicated to retrieve soil moisture information at the global scale, with a high temporal resolution, and from spaceborne L-band radiometry...... as of meteorological parameters such as air temperature and humidity, precipitation, wind speed, and radiation. All data have undergone thorough postprocessing and quality checking. Their values and trends fit well among each other and with the theoretically expected behavior. The aim of this paper is to present...... these data which may contribute to potential further studies of soil moisture, brightness temperature, and their spatial variability. The presented data are available to the scientific community upon request to ESA....

  11. Intelligent Mobility Management Model for Heterogeneous Wireless Networks

    OpenAIRE

    Sanjeev Prakash; R. B. Patel; Jain, V.K.

    2015-01-01

    Growing consumer demands for access of communication services in a ubiquitous environment is a driving force behind the development of new technologies. The rapid development in communication technology permits the end users to access heterogeneous wireless networks to utilize the swerve range of data rate service “anywhere any time”. These forces to technology developers to integrate different wireless access technologies which is known as fourth generation (4G). It is become possible to red...

  12. Modelling the Heterogeneous Markov Attrition Process .

    Directory of Open Access Journals (Sweden)

    Jau Yeu Menq

    1993-01-01

    Full Text Available A model for heterogeneous dynamics combat as a continuos-time Markov process has been studied, and on account of the special form of its infinitesimal generator, recursive algorithms are derived to compute the important characteristics of the combat, such as the combat time distribution, expected value and variance, and the probability of winning and expected survivors. Numerical results are also presented. This approach can also be used to consider initial contact forces of both sides as random variables.

  13. Asthma in childhood: a complex, heterogeneous disease

    OpenAIRE

    2011-01-01

    Asthma in childhood is a heterogeneous disease with different phenotypes and variable clinical manifestations, which depend on the age, gender, genetic background, and environmental influences of the patients. Several longitudinal studies have been conducted to classify the phenotypes of childhood asthma, on the basis of the symptoms, triggers of wheezing illness, or pathophysiological features of the disease. These studies have provided us with important information about the different wheez...

  14. HCC Heterogeneity: Molecular Pathogenesis and Clinical Implications

    Directory of Open Access Journals (Sweden)

    Emilia Fransvea

    2009-01-01

    Full Text Available Background: Hepatocellular carcinoma (HCC poses a major challenge because of the extreme variability of the clinical outcome, which makes it difficult to properly stage the disease and thereby estimate the prognosis. There is growing evidence that this heterogeneous clinical behavior is attributable to several different biological pathways. A novel approach to mapping these differences is by investigating the epigenetics associated with certain clinical aspects.

  15. The Research of Heterogeneous Data Source Integration Method Based on Ontology

    Institute of Scientific and Technical Information of China (English)

    Lou,Yabin; Tao,Fengmei; Ma,Yuan

    2005-01-01

    This paper provides an integration scheme of heterogeneous data source based on ontology, and this scheme settles basically syntactic and semantic heterogeneity in heterogeneous data sources; meanwhile, it provides an effective technology measure for the interior information of enterprises to be shared in time accurately.

  16. A study of the physical-chemical mechanisms and variables which affect the transport of inorganic and organic heterogeneous systems: Progress report for period December 15, 1987--December 14, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.A.; Tejedor-Tejedor, M.I.; Zeltner, W.A.

    1988-08-01

    Our primary goal in this research is to investigate the reaction mechanisms and important non-biological variables which affect the partitioning of microcontaminants in aqueous systems between the bulk solution and solid-phase adsorbents. The primary technique used for this work is cylindrical internal reflection-Fourier transform infrared (CIR-FTIR) spectroscopy, in conjunction with wet chemical adsorption studies, and electrophoretic mobility and acoustophoresis measurements. We have had limited success in attempting to develop CIR-FTIR spectroscopy into a quantitative technique for the study of suspensions. Difficulties are related primarily to the nature of the arrangement of suspension particles around the CIR crystal and the design of the CIR optics. Because of the importance of particle-particle interactions and agglomeration in these more concentrated suspensions, we are using a new technique, acoustophoresis, to aid in evaluating the interparticle forces which determine the arrangement of these particles. These interparticle forces affect particle-particle organization not only in the CIR cell but also in the environment. This report discusses our initial efforts to utilize acoustophoresis instrumentation. 7 refs., 4 figs.

  17. Cognitive resource management for heterogeneous cellular networks

    CERN Document Server

    Liu, Yongkang

    2014-01-01

    This Springer Brief focuses on cognitive resource management in heterogeneous cellular networks (Het Net) with small cell deployment for the LTE-Advanced system. It introduces the Het Net features, presents practical approaches using cognitive radio technology in accommodating small cell data relay and optimizing resource allocation and examines the effectiveness of resource management among small cells given limited coordination bandwidth and wireless channel uncertainty. The authors introduce different network characteristics of small cell, investigate the mesh of small cell access points in

  18. Heterogeneous Voter Models

    CERN Document Server

    Masuda, Naoki; Redner, S

    2010-01-01

    We introduce the heterogeneous voter model (HVM), in which each agent has its own intrinsic rate to change state, reflective of the heterogeneity of real people, and the partisan voter model (PVM), in which each agent has an innate and fixed preference for one of two possible opinion states. For the HVM, the time until consensus is reached is much longer than in the classic voter model. For the PVM in the mean-field limit, a population evolves to a "selfish" state, where each agent tends to be aligned with its internal preference. For finite populations, discrete fluctuations ultimately lead to consensus being reached in a time that scales exponentially with population size.

  19. 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...

  20. Heterogeneity of monoclonal antibodies.

    Science.gov (United States)

    Liu, Hongcheng; Gaza-Bulseco, Georgeen; Faldu, Dinesh; Chumsae, Chris; Sun, Joanne

    2008-07-01

    Heterogeneity of monoclonal antibodies is common due to the various modifications introduced over the lifespan of the molecules from the point of synthesis to the point of complete clearance from the subjects. The vast number of modifications presents great challenge to the thorough characterization of the molecules. This article reviews the current knowledge of enzymatic and nonenzymatic modifications of monoclonal antibodies including the common ones such as incomplete disulfide bond formation, glycosylation, N-terminal pyroglutamine cyclization, C-terminal lysine processing, deamidation, isomerization, and oxidation, and less common ones such as modification of the N-terminal amino acids by maleuric acid and amidation of the C-terminal amino acid. In addition, noncovalent associations with other molecules, conformational diversity and aggregation of monoclonal antibodies are also discussed. Through a complete understanding of the heterogeneity of monoclonal antibodies, strategies can be employed to better identify the potential modifications and thoroughly characterize the molecules.

  1. Micromechanics of heterogeneous materials

    CERN Document Server

    Buryachenko, Valeriy

    2007-01-01

    Here is an accurate and timely account of micromechanics, which spans materials science, mechanical engineering, applied mathematics, technical physics, geophysics, and biology. The book features rigorous and unified theoretical methods of applied mathematics and statistical physics in the material science of microheterogeneous media. Uniquely, it offers a useful demonstration of the systematic and fundamental research of the microstructure of the wide class of heterogeneous materials of natural and synthetic nature.

  2. Electrokinetics of heterogeneous interfaces.

    Science.gov (United States)

    Zembala, Maria

    2004-12-31

    The influence of surface heterogeneity of various types on electrokinetic parameters is reviewed. The scope of the paper covers classical electrokinetic phenomena characterized by linear dependence of electrokinetic parameters vs. related driving forces. Neither non-linear effects nor the effects of non-equilibrium electric double layer are considered. A historical description of hydrodynamic aspect of electrokinetic phenomena exploiting the slip plane idea is briefly outlined. Attempts to estimate the slip plane location by comparing the diffuse layer and zeta potential values for some model systems are presented. The surface heterogeneity was divided into three categories. Heterogeneity of the first type was related to geometrical morphology of an interfacial region characterized by a considerable surface development producing a three-dimensional interfacial region. The effects of solid roughness, hairy surface, dense polymer layers and gel-like layers are discussed here. The very high surface conductivity detected for such interfaces seems to be a good indicator of the presence of structured layers of this type. Heterogeneous interfaces of the second class cover systems exhibiting non-uniform distribution of surface charge. The non-uniform surface charge distribution can be either of a molecular (discrete charges) or of a microscale (two-dimensional micropatches or three-dimensional structures formed by polyelectrolyte multilayers). The last class of systems examined includes interfaces composed of charged substrate covered by charged bulky objects (particles). In comparison to the homogeneous surfaces, adsorbed charged particles modify both hydrodynamic flow and the electrostatic field significantly altering the electrokinetic parameters. The new description of electrokinetics of composed interfaces presented here takes into account both hydrodynamic and electric field modification and is free of the previously assumed slip plane shift caused by adsorbed

  3. Dynamic heterogeneity in life histories

    DEFF Research Database (Denmark)

    Tuljapurkar, Shripad; Steiner, Uli; Orzack, Steven Hecht

    2009-01-01

    generate dynamic heterogeneity: life-history differences produced by stochastic stratum dynamics. We characterize dynamic heterogeneity in a range of species across taxa by properties of the Markov chain: the entropy, which describes the extent of heterogeneity, and the subdominant eigenvalue, which...... distributions of lifetime reproductive success. Dynamic heterogeneity contrasts with fixed heterogeneity: unobserved differences that generate variation between life histories. We show by an example that observed distributions of lifetime reproductive success are often consistent with the claim that little...... or no fixed heterogeneity influences this trait. We propose that dynamic heterogeneity provides a 'neutral' model for assessing the possible role of unobserved 'quality' differences between individuals. We discuss fitness for dynamic life histories, and the implications of dynamic heterogeneity...

  4. A novel design of ultra-broadband, high-gain and high-linearity variable gain distributed amplifier in 0.13 μm CMOS technology

    Science.gov (United States)

    Baharvand, Zainab; Hakimi, Ahmad; Rashedi, Esmat

    2016-12-01

    A high-gain, high-linearity and ultra-broadband variable gain distributed amplifier (VGDA) based on employing multiple techniques is presented to substantially increase the gain. The complete design is composed of two major parts including a VGDA part followed by a single stage distributed amplifier (SSDA) part. The VGDA part makes it possible to achieve different gain settings. For high gain considerations, the SSDA part cascades with the VGDA part that takes the benefits of the multiplicative gain mechanism. A theory is presented to enhance the linearity without imposing further DC power consumption. This idea has been validated by simulation results as expected. The design is analysed and simulated in the standard 0.13 μm CMOS technology. It presents the large gain tuning range of 35 dB, from -5 dB attenuation gain up to +30 dB maximum amplification gain, in relation to the control voltage (Vctr) that varies between 0.42 and 1.1 V. At the maximum amplification gain setting, it presents a DC up to 16 GHz 3 dB bandwidth, an average noise figure of 3.2 dB and an IIP3 of -2 dB m. Furthermore, it dissipates 46.42 mW from 0.7 and 0.9 V power supplies of the drain lines of VGDA and SSDA parts, respectively. Additionally, the Monte Carlo (MC) simulation has been performed to predict an estimate of the accuracy of performance of the proposed design under various conditions.

  5. Network and Service Monitoring in Heterogeneous Home Networks

    NARCIS (Netherlands)

    Delphinanto, A.

    2012-01-01

    Home networks are becoming dynamic and technologically heterogeneous. They consist of an increasing number of devices which offer several functionalities and can be used for many different services. In the home, these devices are interconnected using a mixture of networking technologies (for

  6. Network and Service Monitoring in Heterogeneous Home Networks

    NARCIS (Netherlands)

    Delphinanto, A.

    2012-01-01

    Home networks are becoming dynamic and technologically heterogeneous. They consist of an increasing number of devices which offer several functionalities and can be used for many different services. In the home, these devices are interconnected using a mixture of networking technologies (for example

  7. Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes

    CERN Document Server

    Yang, Hui; Gross, Thilo

    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 heterogeneity 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. Here, we point out that for real world applications, this result should not be regarded independently of the intra-individual heterogeneity between people. Our results show that, if heterogeneity among people is taken into account, networks that are more heterogeneous in connectivity can be more resistant to epidemic spreading. We study a susceptible-infected-susceptible model with adaptive disease avoidance. Results from this model suggest that this reversal of the effect of network heterogeneity is likely to occur in populations in which the individuals are aware of t...

  8. Habitat heterogeneity favors asexual reproduction in natural populations of grassthrips.

    Science.gov (United States)

    Lavanchy, Guillaume; Strehler, Marie; Llanos Roman, Maria Noemi; Lessard-Therrien, Malie; Humbert, Jean-Yves; Dumas, Zoé; Jalvingh, Kirsten; Ghali, Karim; Fontcuberta García-Cuenca, Amaranta; Zijlstra, Bart; Arlettaz, Raphaël; Schwander, Tanja

    2016-08-01

    Explaining the overwhelming success of sex among eukaryotes is difficult given the obvious costs of sex relative to asexuality. Different studies have shown that sex can provide benefits in spatially heterogeneous environments under specific conditions, but whether spatial heterogeneity commonly contributes to the maintenance of sex in natural populations remains unknown. We experimentally manipulated habitat heterogeneity for sexual and asexual thrips lineages in natural populations and under seminatural mesocosm conditions by varying the number of hostplants available to these herbivorous insects. Asexual lineages rapidly replaced the sexual ones, independently of the level of habitat heterogeneity in mesocosms. In natural populations, the success of sexual thrips decreased with increasing habitat heterogeneity, with sexual thrips apparently only persisting in certain types of hostplant communities. Our results illustrate how genetic diversity-based mechanisms can favor asexuality instead of sex when sexual lineages co-occur with genetically variable asexual lineages.

  9. Dealing with spatial heterogeneity

    Science.gov (United States)

    Marsily, Gh.; Delay, F.; Gonçalvès, J.; Renard, Ph.; Teles, V.; Violette, S.

    2005-03-01

    Heterogeneity can be dealt with by defining homogeneous equivalent properties, known as averaging, or by trying to describe the spatial variability of the rock properties from geologic observations and local measurements. The techniques available for these descriptions are mostly continuous Geostatistical models, or discontinuous facies models such as the Boolean, Indicator or Gaussian-Threshold models and the Markov chain model. These facies models are better suited to treating issues of rock strata connectivity, e.g. buried high permeability channels or low permeability barriers, which greatly affect flow and, above all, transport in aquifers. Genetic models provide new ways to incorporate more geology into the facies description, an approach that has been well developed in the oil industry, but not enough in hydrogeology. The conclusion is that future work should be focused on improving the facies models, comparing them, and designing new in situ testing procedures (including geophysics) that would help identify the facies geometry and properties. A world-wide catalog of aquifer facies geometry and properties, which could combine site genesis and description with methods used to assess the system, would be of great value for practical applications. On peut aborder le problème de l'hétérogénéité en s'efforçant de définir une perméabilité équivalente homogène, par prise de moyenne, ou au contraire en décrivant la variation dans l'espace des propriétés des roches à partir des observations géologiques et des mesures locales. Les techniques disponibles pour une telle description sont soit continues, comme l'approche Géostatistique, soit discontinues, comme les modèles de faciès, Booléens, ou bien par Indicatrices ou Gaussiennes Seuillées, ou enfin Markoviens. Ces modèles de faciès sont mieux capables de prendre en compte la connectivité des strates géologiques, telles que les chenaux enfouis à forte perméabilité, ou au contraire les faci

  10. Variable polarity arc welding

    Science.gov (United States)

    Bayless, E. O., Jr.

    1991-01-01

    Technological advances generate within themselves dissatisfactions that lead to further advances in a process. A series of advances in welding technology which culminated in the Variable Polarity Plasma Arc (VPPA) Welding Process and an advance instituted to overcome the latest dissatisfactions with the process: automated VPPA welding are described briefly.

  11. 个人健康档案异构数据源统一检索爬虫技术设计%Personal Health Record Heterogeneous Resources Federated Search Crawler Technology

    Institute of Scientific and Technical Information of China (English)

    史嘉兴; 赵直枉

    2011-01-01

    目前,国内、外区域卫生信息平台(Regional Health Information Plaffom,RHIP)建设现状及建议,使用爬虫技术思想解决个人健康档案数据中心异构资源的统一访问问题,在众多异构资源中有效检索个人健康信息,大量减少数据中心庞大资源消耗,并可简化健康档案的应用.%The present construction and Suggestions of RHIP at home and abroad, use the crawler technologicalideas to solve personal health records data center of heterogeneous resources unity access problems, in numerousof heterogeneous resources effectively personal health information retrieval, a large number of reducing datacenter huge resource consumption, and can simplify the application of health records.

  12. Heterogeneity of Intellectual Assets

    DEFF Research Database (Denmark)

    Dahlgren, Johan Henrich; Lund Jensen, Rasmus; Valentin, Finn

    2004-01-01

    This paper deals with methodological issues of assessing the composition and level ofheterogeneity of firms' intellectual assets. It develops an original metric - referred to asthe H-index - for measuring heterogeneity using data extracted from patent documents.The main purpose is to improve...... the characterisation of research activities within firmsin the biotechnology sector. Although the H-index grew out of research on biotechfirms, the metric carries broader relevance for all patent-intensive industries. Themeasurement and calculation of the H-index is illustrated using some empiricalexamples from our...

  13. Seamless and secure communications over heterogeneous wireless networks

    CERN Document Server

    Cao, Jiannong

    2014-01-01

    This brief provides an overview of the requirements, challenges, design issues and major techniques for seamless and secure communications over heterogeneous wireless networks. It summarizes and provides detailed insights into the latest research on handoff management, mobility management, fast authentication and security management to support seamless and secure roaming for mobile clients. The reader will also learn about the challenges in developing relevant technologies and providing ubiquitous Internet access over heterogeneous wireless networks. The authors have extensive experience in im

  14. Voice over IP in Wireless Heterogeneous Networks

    DEFF Research Database (Denmark)

    Fathi, Hanane; Chakraborty, Shyam; Prasad, Ramjee

    The convergence of different types of traffic has preceded the convergence of systems and services in a wireless heterogeneous network. Voice and data traffic are usually treated separate in both 2G and 2.5G wireless networks. With advances in packet switching technology and especially with the d...... and to the discruption caused by the user mobility during the session. Voice over IP in Wireless Hetetrogeneous Networks thus investigates and proposes cross-layer techniques for realizing time-efficient control mechanisms for VoIP: signaling, mobility and security.......The convergence of different types of traffic has preceded the convergence of systems and services in a wireless heterogeneous network. Voice and data traffic are usually treated separate in both 2G and 2.5G wireless networks. With advances in packet switching technology and especially....... The focus of Voice over IP in Wierless Heterogeneous Networks is on mechanisms that affect the VoIP user satisfaction  while not explicitly involved in the media session. This relates to the extra delays introduced by the security and the signaling protocols used to set up an authorized VoIP session...

  15. On Aggregating Human Capital Across Heterogeneous Cohorts

    DEFF Research Database (Denmark)

    Growiec, Jakub; Groth, Christian

    Based on a general framework for computing the aggregate human capital stock under heterogeneity across population cohorts, the paper derives aggregate human capital stocks in the whole population and in the labor force, and relates these variables to average years of schooling and average work...... experience. Under the scenarios considered here, the "macro-Mincer" (log-linear) relationship between aggregate human capital and average years of schooling is obtained only in cases which are inconsistent with heterogeneity in years of schooling and based on empirically implausible demographic survival laws....... Our numerical results indicate that the macro-Mincer equation can be a reasonable approximation of the true relationship only if returns to schooling and work experience are roughly constant across countries...

  16. On Aggregating Human Capital Across Heterogeneous Cohorts

    DEFF Research Database (Denmark)

    Growiec, Jakub; Groth, Christian

    Based on a general framework for computing the aggregate human capital stock under heterogeneity across population cohorts, the paper derives aggregate human capital stocks in the whole population and in the labor force, and relates these variables to average years of schooling and average work...... experience. Under the scenarios considered here, the "macro-Mincer" (log-linear) relationship between aggregate human capital and average years of schooling is obtained only in cases which are inconsistent with heterogeneity in years of schooling and based on empirically implausible demographic survival laws....... Our numerical results indicate that the macro-Mincer equation can be a reasonable approximation of the true relationship only if returns to schooling and work experience are roughly constant across countries...

  17. Satellite Cell Heterogeneity in Skeletal Muscle Homeostasis.

    Science.gov (United States)

    Tierney, Matthew T; Sacco, Alessandra

    2016-06-01

    The cellular turnover required for skeletal muscle maintenance and repair is mediated by resident stem cells, also termed satellite cells. Satellite cells normally reside in a quiescent state, intermittently entering the cell cycle to fuse with neighboring myofibers and replenish the stem cell pool. However, the mechanisms by which satellite cells maintain the precise balance between self-renewal and differentiation necessary for long-term homeostasis remain unclear. Recent work has supported a previously unappreciated heterogeneity in the satellite cell compartment that may underlie the observed variability in cell fate and function. In this review, we examine the work supporting this notion as well as the potential governing principles, developmental origins, and principal determinants of satellite cell heterogeneity.

  18. Disordered hyperuniform heterogeneous materials

    Science.gov (United States)

    Torquato, Salvatore

    2016-10-01

    Disordered hyperuniform many-body systems are distinguishable states of matter that lie between a crystal and liquid: they are like perfect crystals in the way they suppress large-scale density fluctuations and yet are like liquids or glasses in that they are statistically isotropic with no Bragg peaks. These systems play a vital role in a number of fundamental and applied problems: glass formation, jamming, rigidity, photonic and electronic band structure, localization of waves and excitations, self-organization, fluid dynamics, quantum systems, and pure mathematics. Much of what we know theoretically about disordered hyperuniform states of matter involves many-particle systems. In this paper, we derive new rigorous criteria that disordered hyperuniform two-phase heterogeneous materials must obey and explore their consequences. Two-phase heterogeneous media are ubiquitous; examples include composites and porous media, biological media, foams, polymer blends, granular media, cellular solids, and colloids. We begin by obtaining some results that apply to hyperuniform two-phase media in which one phase is a sphere packing in d-dimensional Euclidean space {{{R}}d} . Among other results, we rigorously establish the requirements for packings of spheres of different sizes to be ‘multihyperuniform’. We then consider hyperuniformity for general two-phase media in {{{R}}d} . Here we apply realizability conditions for an autocovariance function and its associated spectral density of a two-phase medium, and then incorporate hyperuniformity as a constraint in order to derive new conditions. We show that some functional forms can immediately be eliminated from consideration and identify other forms that are allowable. Specific examples and counterexamples are described. Contact is made with well-known microstructural models (e.g. overlapping spheres and checkerboards) as well as irregular phase-separation and Turing-type patterns. We also ascertain a family of

  19. Modelling heterogeneous interfaces for solar water splitting

    Science.gov (United States)

    Pham, Tuan Anh; Ping, Yuan; Galli, Giulia

    2017-04-01

    The generation of hydrogen from water and sunlight offers a promising approach for producing scalable and sustainable carbon-free energy. The key of a successful solar-to-fuel technology is the design of efficient, long-lasting and low-cost photoelectrochemical cells, which are responsible for absorbing sunlight and driving water splitting reactions. To this end, a detailed understanding and control of heterogeneous interfaces between photoabsorbers, electrolytes and catalysts present in photoelectrochemical cells is essential. Here we review recent progress and open challenges in predicting physicochemical properties of heterogeneous interfaces for solar water splitting applications using first-principles-based approaches, and highlights the key role of these calculations in interpreting increasingly complex experiments.

  20. Modelling heterogeneous interfaces for solar water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Tuan Anh; Ping, Yuan; Galli, Giulia

    2017-01-09

    The generation of hydrogen from water and sunlight others a promising approach for producing scalable and sustainable carbon-free energy. The key of a successful solar-to-fuel technology is the design of efficient, long-lasting and low-cost photoelectrochemical cells, which are responsible for absorbing sunlight and driving water splitting reactions. To this end, a detailed understanding and control of heterogeneous interfaces between photoabsorbers, electrolytes and catalysts present in photoelectrochemical cells is essential. Here we review recent progress and open challenges in predicting physicochemical properties of heterogeneous interfaces for solar water splitting applications using first-principles-based approaches, and highlights the key role of these calculations in interpreting increasingly complex experiments.

  1. Survey on Horizontal QoS Mapping Strategy and Technology over Wireless Heterogeneous Networks%泛在异构网络水平QoS映射方案和技术综述

    Institute of Scientific and Technical Information of China (English)

    王再见; 董育宁; 张晖; 孙刚友; 杜盼盼

    2012-01-01

    不同网络的QoS机制存在差异,各种应用的QoS需求也不同,给泛在异构网络QoS保证带来挑战.为了满足异构网络QoS需求,最大化利用网络资源,最小化操作代价,应建立一种能够保证异构网络QoS的机制.QoS映射是有效的解决方案,它可以完成不同网络QoS之间的自动翻译,有利于降低问题的复杂度,能保证异构网络的QoS需求.因此,本文对现有的异构网络水平QoS映射方案和技术进行综述和比较,重点介绍了AQCM - ASM映射策略和FAbS模型,并给出了今后的研究方向.%End-to-end QoS provisioning in heterogeneous networks is a challenging research issue,since QoS mechanisms in various networks are different and with the requirement to support a variety of user applications of different characteristics. To maximize network resources utilization and minimize operational costs,proper QoS mechanism that can supply heterogeneous networks QoS assurance should be established. QoS mapping seems to be an effective solution, which can perform automatic translation of QoS classes between different networks, relieve the problem complexity and support QoS over heterogeneous networks. This paper surveys current horizontal QoS mapping strategies and architectures for heterogeneous networks,and introduces AQCM-ASM mapping scheme and FAbS model. Comparisons of different QoS mapping strategies and possible future research directions are given at the end of the paper.

  2. Heterogeneous logics of competition

    DEFF Research Database (Denmark)

    Mossin, Christiane

    2015-01-01

    The purpose of the article is to demonstrate that in order to understand competition as a socially organizing phenomenon, we should not examine competition in isolation, but as constellations of heterogeneous logics. More precisely, the article is based on two main theoretical points: (1) Logics...... of competition are only realized as particular forms of social organization by virtue of interplaying with other kinds of logics, like legal logics. (2) Competition logics enjoy a peculiar status in-between constructedness and givenness; although competition depends on laws and mechanisms of socialization, we...... still experience competition as an expression of spontaneous human activities. On the basis of these perspectives, a study of fundamental rights of EU law, springing from the principle of ‘free movement of people’, is conducted. The first part of the empirical analysis seeks to detect the presence...

  3. Heterogeneous logics of competition

    DEFF Research Database (Denmark)

    Mossin, Christiane

    2015-01-01

    The purpose of the article is to demonstrate that in order to understand competition as a socially organizing phenomenon, we should not examine competition in isolation, but as constellations of heterogeneous logics. More precisely, the article is based on two main theoretical points: (1) Logics...... still experience competition as an expression of spontaneous human activities. On the basis of these perspectives, a study of fundamental rights of EU law, springing from the principle of ‘free movement of people’, is conducted. The first part of the empirical analysis seeks to detect the presence...... of a presumed logic of competition within EU law, whereas the second part focuses on particular legal logics. In this respect, the so-called ‘real link criterion’ (determining the access to transnational social rights for certain groups of unemployed people) is given special attention. What is particularly...

  4. Noise and Neuronal Heterogeneity

    CERN Document Server

    Barber, Michael J

    2010-01-01

    We consider signal transaction in a simple neuronal model featuring intrinsic noise. The presence of noise limits the precision of neural responses and impacts the quality of neural signal transduction. We assess the signal transduction quality in relation to the level of noise, and show it to be maximized by a non-zero level of noise, analogous to the stochastic resonance effect. The quality enhancement occurs for a finite range of stimuli to a single neuron; we show how to construct networks of neurons that extend the range. The range increases more rapidly with network size when we make use of heterogeneous populations of neurons with a variety of thresholds, rather than homogeneous populations of neurons all with the same threshold. The limited precision of neural responses thus can have a direct effect on the optimal network structure, with diverse functional properties of the constituent neurons supporting an economical information processing strategy that reduces the metabolic costs of handling a broad...

  5. Heterogeneity in recombinant protein production

    DEFF Research Database (Denmark)

    Schalén, Martin; Johanson, Ted; Lundin, Luisa;

    2012-01-01

    contribute to make a population in a fermenter heterogeneous, resulting in cell-to-cell variation in physiological parameters of the microbial culture. Our study aims at investigating how population heterogeneity and recombinant protein production is affected by environmental gradients in bioreactors...... are simulated in small bioreactors and the population heterogeneity can be visualised by analysing single cells with flow cytometry. This can give new insights to cell physiology and recombinant protein production at the industrial scale....

  6. 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...

  7. Reduced dose to urethra and rectum with the use of variable needle spacing in prostate brachytherapy: a potential role for robotic technology.

    Science.gov (United States)

    Vyas, Shilpa; Le, Yi; Zhang, Zhe; Armour, Woody; Song, Daniel Y

    2015-08-01

    Several robotic delivery systems for prostate brachytherapy are under development or in pre-clinical testing. One of the features of robotic brachytherapy is the ability to vary spacing of needles at non-fixed intervals. This feature may play an important role in prostate brachytherapy, which is traditionally template-based with fixed needle spacing of 0.5 cm. We sought to quantify potential reductions in the dose to urethra and rectum by utilizing variable needle spacing, as compared to fixed needle spacing. Transrectal ultrasound images from 10 patients were used by 3 experienced planners to create 120 treatment plans. Each planner created 4 plan variations per patient with respect to needle positions: (125)I fixed spacing, (125)I variable spacing, (103)Pd fixed spacing, and (103)Pd variable spacing. The primary planning objective was to achieve a prostate V100 of 100% while minimizing dose to urethra and rectum. All plans met the objective of achieving prostate V100 of 100%. Combined results for all plans show statistically significant improvements in all assessed dosimetric variables for urethra (Umax, Umean, D30, D5) and rectum (Rmax, Rmean, RV100) when using variable spacing. The dose reductions for mean and maximum urethra dose using variable spacing had p values of 0.011 and 0.024 with (103)Pd, and 0.007 and 0.029 with (125)I plans. Similarly dose reductions for mean and maximum rectal dose using variable spacing had p values of 0.007 and 0.052 with (103)Pd, and 0.012 and 0.037 with (125)I plans. The variable needle spacing achievable by the use of robotics in prostate brachytherapy allows for reductions in both urethral and rectal planned doses while maintaining prostate dose coverage. Such dosimetric advantages have the potential in translating to significant clinical benefits with the use of robotic brachytherapy.

  8. Heterogeneous Photocatalysis: Recent Advances and Applications

    Directory of Open Access Journals (Sweden)

    Alex Omo Ibhadon

    2013-03-01

    Full Text Available Semiconductor heterogeneous photocatalysis, the subject of this review, is a versatile, low-cost and environmentally benign treatment technology for a host of pollutants. These may be of biological, organic and inorganic in origin within water and air. The efficient and successful application of photocatalysis demands that the pollutant, the catalyst and source of illumination are in close proximity or contact with each other. The ability of advanced oxidation technology to remove low levels of persistent organic pollutants as well as microorganisms in water has been widely demonstrated and, progressively, the technology is now being commercialized in many areas of the world including developing nations. This review considers recent developments in the research and application of heterogeneous semiconductor photocatalysis for the treatment of low-level concentrations of pollutants in water and air using titanium dioxide as a “model” semiconductor. The review considers charge transport characteristics on the semiconductor surface, photocatalyst reactor design and organic degradation mechanistic pathways. The effects of photoreactor operating parameters on the photocatalytic process are discussed in addition to mineralization and disinfection kinetics.

  9. 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)

  10. Fiscal Consolidations and Heterogeneous Expectations

    NARCIS (Netherlands)

    C. Hommes; J. Lustenhouwer; K. Mavromatis

    2015-01-01

    We analyze fiscal consolidations using a New Keynesian model where agents have heterogeneous expectations and are uncertain about the composition of consoidations. Heterogeneity in expectations may amplify expansions, stabilizing thus the debt-to-GDP ratio faster under tax based consolidations, in t

  11. Coordination Frictions and Job Heterogeneity

    DEFF Research Database (Denmark)

    Kennes, John; le Maire, Christian Daniel

    This paper develops and extends a dynamic, discrete time, job to worker matching model in which jobs are heterogeneous in equilibrium. The key assumptions of this economic environment are (i) matching is directed and (ii) coordination frictions lead to heterogeneous local labor markets. We de- rive...

  12. 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)

  13. Heterogeneously integrated microsystem-on-a-chip

    Science.gov (United States)

    Chanchani, Rajen

    2008-02-26

    A microsystem-on-a-chip comprises a bottom wafer of normal thickness and a series of thinned wafers can be stacked on the bottom wafer, glued and electrically interconnected. The interconnection layer comprises a compliant dielectric material, an interconnect structure, and can include embedded passives. The stacked wafer technology provides a heterogeneously integrated, ultra-miniaturized, higher performing, robust and cost-effective microsystem package. The highly integrated microsystem package, comprising electronics, sensors, optics, and MEMS, can be miniaturized both in volume and footprint to the size of a bottle-cap or less.

  14. Intelligent Mobility Management Model for Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Sanjeev Prakash

    2015-12-01

    Full Text Available Growing consumer demands for access of communication services in a ubiquitous environment is a driving force behind the development of new technologies. The rapid development in communication technology permits the end users to access heterogeneous wireless networks to utilize the swerve range of data rate service “anywhere any time”. These forces to technology developers to integrate different wireless access technologies which is known as fourth generation (4G. It is become possible to reduce the size of mobile nodes (MNs with manifold network interfaces and development in IP-based applications. 4G mobile/wireless computing and communication heterogeneous environment consist of various access technologies that differ in bandwidth, network conditions, service type, latency and cost. A major challenge of the 4G wireless network is seamless vertical handoff across the heterogeneous wireless access network as the users are roaming in the heterogeneous wireless network environment. Today communication devices are portable and equipped with manifold interfaces and are capable to roam seamlessly among the various access technology networks for maintaining the network connectivity, since no single-interface technology provides ubiquitous coverage and quality-of-service (QoS. This paper reports a mobile agent based heterogeneous wireless network management system. In this system agent’s decision focuses on multi parameter system (MPS. This system works on the parameters- network delay, received signal strength, network latency and study of the collected information about adjoining network cells viz., accessible channel. System is simulated and a comparative study is also made. From results it is observed that system improves the performance of wireless network.

  15. Heterogeneity: multilingualism and democracy

    Directory of Open Access Journals (Sweden)

    Hans-Jürgen Krumm

    2004-01-01

    Full Text Available Linguistic diversity and multilingualism on the part of individuals are aprerequisite and a constitutive condition of enabling people to live togetherin a world of growing heterogeneity. Foreign language teaching plays animportant part in democratic education because it can be seen as a trainingin respecting otherness and developing an intercultural, non-ethnocentricperception and attitude. This is all the more important because of the neces-sity of integrating children from migrant families into school life.My article argues that language education policy has to take this per-spective into account, i.e., of establishing a planned diversification so thatpupils (and their parents will not feel satisfied with learning English only,but also become motivated to learn languages of their own neighbourhood,such as migrant and minority languages. However, in order to make use ofthe linguistic resources in the classroom, relating it to the democratic impetusof foreign language education, it is necessary to revise existing languagepolicies and to develop a multilingual perspective for all educational institutions.

  16. Heterogeneous recording media

    Science.gov (United States)

    Sukhanov, Vitaly I.

    1991-02-01

    The paper summarizes the results of investigations performed to obtain deep 3-D holograms with 102 i0 mkm physical thickness allowing the postexposure amplification and the a posteriori changing of the grating parameters. This aim has been achieved by developing heterogeneous systems on the basis of porous glass with light-sensitive compositions introduced into it. 1. INTRODUCTION. LIGHT-SENSITIVE MEDIA FOR 3-D HOLOGRAMS RECORDING. The 3-D holograms have many useful properties: very high diffraction efficiency angular and spectral selectivity but low level of noise. It shoud be noted that in this case deep 3-D holograms are dealt with whose physical thickness is as high as 102 -i mkm. Such hologram recording is usually done using homogeneous light-sensitive media for example dyed acid-halide and electrooptical crystals photochrome glass photostructurized polimer compositions and so on. The nature of photophisical and photochemical processes responsible for the light sensitivity of these materials exclude the possibility of post-exposure treatment. This does not allow to enhance the recorded holograms and considerably hampers their fixing or makes it practically impossible. The object of our work is to create the media which are quite suitable for two-stage processes of the deep hologram formation with post-exposure processing. Such material must satisfy the following requirements: a)they must have high permeability for the developing substances in order to make the development duration suitable for practical applications b)they must be shrinkproof to prevent deformation of the

  17. Parsing Heterogeneous Striatal Activity

    Directory of Open Access Journals (Sweden)

    Kae Nakamura

    2017-05-01

    Full Text Available The striatum is an input channel of the basal ganglia and is well known to be involved in reward-based decision making and learning. At the macroscopic level, the striatum has been postulated to contain parallel functional modules, each of which includes neurons that perform similar computations to support selection of appropriate actions for different task contexts. At the single-neuron level, however, recent studies in monkeys and rodents have revealed heterogeneity in neuronal activity even within restricted modules of the striatum. Looking for generality in the complex striatal activity patterns, here we briefly survey several types of striatal activity, focusing on their usefulness for mediating behaviors. In particular, we focus on two types of behavioral tasks: reward-based tasks that use salient sensory cues and manipulate outcomes associated with the cues; and perceptual decision tasks that manipulate the quality of noisy sensory cues and associate all correct decisions with the same outcome. Guided by previous insights on the modular organization and general selection-related functions of the basal ganglia, we relate striatal activity patterns on these tasks to two types of computations: implementation of selection and evaluation. We suggest that a parsing with the selection/evaluation categories encourages a focus on the functional commonalities revealed by studies with different animal models and behavioral tasks, instead of a focus on aspects of striatal activity that may be specific to a particular task setting. We then highlight several questions in the selection-evaluation framework for future explorations.

  18. A new dynamic model for heterogeneous traffic flow

    Science.gov (United States)

    Tang, T. Q.; Huang, H. J.; Zhao, S. G.; Shang, H. Y.

    2009-06-01

    Based on the property of heterogeneous traffic flow, we in this Letter present a new car-following model. Applying the relationship between the micro and macro variables, a new dynamic model for heterogeneous traffic flow is obtained. The fundamental diagram and the jam density of the heterogeneous traffic flow consisting of bus and car are studied under three different conditions: (1) without any restrictions, (2) under the action of the traffic control policy that restrains some private cars and (3) using bus to replace the private cars restrained by the traffic control policy. The numerical results show that our model can describe some qualitative properties of the heterogeneous traffic flow consisting of bus and car, which verifies that our model is reasonable.

  19. Influence of main process variables on the treatment of waste waters using a new technology Mixer-Settler based on Phase Inversion (MSPI)

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, N.A.; Paulo, J.B.A.; Medeiros, G.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia Quimica], e-mail: norberto@eq.ufrn.br

    2011-04-15

    The prototype of a device on a semi-industrial scale to treat wastewaters from the oil industry has been widely studied as a viable alternative to conventional equipment. The device, called Mixer-Settler based on Phase Inversion (MSPI), uses the phase inversion method as operating principle. Using experimental planning (2{sup 4} factorial with four repetitions in the central point), it was determined the influence of the main variables on the oil/water separation process for waters containing between 30 and 100 mg of oil per liter of water. The following variables were evaluated: specific throughput, organic/aqueous phase ratio, agitation in the mixing chamber, and coconut oil concentration. The response variable was the oil/water separation efficiency. The results show that the separation efficiency of the device is a function of the effective throughput and the organic/aqueous phase ratio. (author)

  20. Features and heterogeneities in growing network models

    CERN Document Server

    Ferretti, Luca; Yang, Bin; Marmorini, Giacomo; Bianconi, Ginestra

    2011-01-01

    Many complex networks from the World-Wide-Web to biological networks are growing taking into account the heterogeneous features of the nodes. The feature of a node might be a discrete quantity such as a classification of a URL document as personal page, thematic website, news, blog, search engine, social network, ect. or the classification of a gene in a functional module. Moreover the feature of a node can be a continuous variable such as the position of a node in the embedding space. In order to account for these properties, in this paper we provide a generalization of growing network models with preferential attachment that includes the effect of heterogeneous features of the nodes. The main effect of heterogeneity is the emergence of an "effective fitness" for each class of nodes, determining the rate at which nodes acquire new links. Beyond the degree distribution, in this paper we give a full characterization of the other relevant properties of the model. We evaluate the clustering coefficient and show ...

  1. Study of vehicular interactions in heterogeneous traffic

    Energy Technology Data Exchange (ETDEWEB)

    Arasan, V.T.; Krishnamurthy, K. [Indian Inst. of Technology, Madras, Chennai (India). Dept. of Civil Engineering

    2007-07-01

    In planning, design and operation of road systems, knowledge of traffic flow characteristics and the associated analytical techniques is necessary. Traffic flow represents the traffic load on the road and the interaction between these loadings and the facility capacity determines the operational performance of the system. This paper presented the results of a study that examined the basic characteristics of heterogeneous traffic flow on Indian city roads through extensive traffic surveys; revalidated the indigenously developed simulation model of heterogeneous traffic flow on mid block sections of urban roads for application of the model to study the interaction between vehicles over a wide range of traffic flow conditions; and, quantified the vehicular interactions in terms of Passenger Car Units (PCU) by applying the validated simulation model for a wide range of traffic flow conditions. The paper provided some background information on road traffic in India and discussed the simulation model and input variables. It also discussed model validation and application. It was concluded that the simulation model of heterogeneous traffic, when validated, replicated the field observed traffic flow to a satisfactory extent and that the Passenger Car Unit value of different types of vehicles varied significantly with variation in traffic volume. 9 refs., 6 tabs., 9 figs.

  2. Sensemaking technologies

    DEFF Research Database (Denmark)

    Madsen, Charlotte Øland

    Research scope: The scope of the project is to study technological implementation processes by using Weick's sensemaking concept (Weick, 1995). The purpose of using a social constructivist approach to investigate technological implementation processes is to find out how new technologies transform......, Orlikowski 2000). Viewing the use of technology as a process of enactment opens up for investigating the social processes of interpreting new technology into the organisation (Orlikowski 2000). The scope of the PhD project will therefore be to gain a deeper understanding of how the enactment of new...... & Brass, 1990; Kling 1991; Orlikowski 2000). It also demonstrates that technology is a flexible variable adapted to the organisation's needs, culture, climate and management philosophy, thus leading to different uses and outcomes of the same technology in different organisations (Barley 1986; 1990...

  3. Effects of Normalized Difference Vegetation Index and Related Wavebands' Characteristics on Detecting Spatial Heterogeneity Using Variogram-based Analysis

    Institute of Scientific and Technical Information of China (English)

    WEN Zhaofei; ZHANG Ce; ZHANG Shuqing; DING Changhong; LIU Chunyue; PAN Xin; LI Huapeng; SUN Yan

    2012-01-01

    Spatial heterogeneity is widely used in diverse applications,such as recognizing ecological process,guiding ecological restoration,managing land use,etc.Many researches have focused on the inherent scale multiplicity of spatial heterogeneity by using various environmental variables.How these variables affect their corresponding spatial heterogeneities,however,have received little attention.In this paper,we examined the effects of characteristics of normalized difference vegetation index (NDVI) and its related bands variable images,namely red and near infrared (NIR),on their corresponding spatial heterogeneity detection based on variogram models.In a coastal wetland region,two groups of study sites with distinct fractal vegetation cover were tested and analyzed.The results show that:1) in high fractal vegetation cover (H-FVC) area,NDVI and NIR variables display a similar ability in detecting the spatial heterogeneity caused by vegetation growing status structure; 2) in low fractal vegetation cover (L-FVC) area,the NIR and red variables outperform NDVI in the survey of soil spatial heterogeneity; and 3) generally,NIR variable is ubiquitously applicable for vegetation spatial heterogeneity investigation in different fractal vegetation covers.Moreover,as variable selection for remote sensing applications should fully take the characteristics of variables and the study object into account,the proposed variogram analysis method can make the variable selection objectively and scientifically,especially in studies related to spatial heterogeneity using remotely sensed data.

  4. Hierarchical unilamellar vesicles of controlled compositional heterogeneity.

    Directory of Open Access Journals (Sweden)

    Maik Hadorn

    Full Text Available Eukaryotic life contains hierarchical vesicular architectures (i.e. organelles that are crucial for material production and trafficking, information storage and access, as well as energy production. In order to perform specific tasks, these compartments differ among each other in their membrane composition and their internal cargo and also differ from the cell membrane and the cytosol. Man-made structures that reproduce this nested architecture not only offer a deeper understanding of the functionalities and evolution of organelle-bearing eukaryotic life but also allow the engineering of novel biomimetic technologies. Here, we show the newly developed vesicle-in-water-in-oil emulsion transfer preparation technique to result in giant unilamellar vesicles internally compartmentalized by unilamellar vesicles of different membrane composition and internal cargo, i.e. hierarchical unilamellar vesicles of controlled compositional heterogeneity. The compartmentalized giant unilamellar vesicles were subsequently isolated by a separation step exploiting the heterogeneity of the membrane composition and the encapsulated cargo. Due to the controlled, efficient, and technically straightforward character of the new preparation technique, this study allows the hierarchical fabrication of compartmentalized giant unilamellar vesicles of controlled compositional heterogeneity and will ease the development of eukaryotic cell mimics that resemble their natural templates as well as the fabrication of novel multi-agent drug delivery systems for combination therapies and complex artificial microreactors.

  5. Organic pollutants removal in wastewater by heterogeneous photocatalytic ozonation.

    Science.gov (United States)

    Xiao, Jiadong; Xie, Yongbing; Cao, Hongbin

    2015-02-01

    Heterogeneous photocatalysis and ozonation are robust advanced oxidation processes for eliminating organic contaminants in wastewater. The combination of these two methods is carried out in order to enhance the overall mineralization of refractory organics. An apparent synergism between heterogeneous photocatalysis and ozonation has been demonstrated in many literatures, which gives rise to an improvement of total organic carbon removal. The present overview dissects the heterogeneous catalysts and the influences of different operational parameters, followed by the discussion on the kinetics, mechanism, economic feasibility and future trends of this integrated technology. The enhanced oxidation rate mainly results from a large amount of hydroxyl radicals generated from a synergistically induced decomposition of dissolved ozone, besides superoxide ion radicals and the photo-induced holes. Six reaction pathways possibly exist for the generation of hydroxyl radicals in the reaction mechanism of heterogeneous photocatalytic ozonation.

  6. Context Management Middleware in Heterogeneous Mobile Computing Environments

    Science.gov (United States)

    Qureshi, Salim Raza

    2010-11-01

    Mobile computing environments are characterized by heterogeneity—systems consisting of different device types, operating systems, network interfaces, and communication protocols. Such heterogeneity calls for middleware that can adapt to different execution contexts, hide heterogeneity from applications, and transparently and dynamically switch between network and sensor technologies. Additionally, middleware for context-aware systems must keep a context model (a model of their environment), taking into account several aspects of the environment. The more complex and heterogeneous an execution environment is, the more complicated its underlying context model. Moreover, because systems can evolve, context management must also support model evolution without restarting, reconfiguring, or redeploying applications and services. We describe a context management middleware that can efficiently handle context despite the execution environment's heterogeneity and evolution. It uses context meta-information to improve a context-aware system's overall performance.

  7. Sensemaking technologies

    DEFF Research Database (Denmark)

    Madsen, Charlotte Øland

    & Brass, 1990; Kling 1991; Orlikowski 2000). It also demonstrates that technology is a flexible variable adapted to the organisation's needs, culture, climate and management philosophy, thus leading to different uses and outcomes of the same technology in different organisations (Barley 1986; 1990......, Orlikowski 2000). Viewing the use of technology as a process of enactment opens up for investigating the social processes of interpreting new technology into the organisation (Orlikowski 2000). The scope of the PhD project will therefore be to gain a deeper understanding of how the enactment of new...

  8. Intelligent handoff decision in radio heterogeneous network

    Institute of Scientific and Technical Information of China (English)

    GUO Qiang; XU Xiang-hua; WANG Ying-long

    2008-01-01

    In order to improve the accuracy of vertical handoff decision for radio heterogeneous network, this paper proposes an intelligent adaptive multi-criteria vertical handoff (AMVHO) decision algorithm. This algo-rithm uses a fuzzy inference system (FIS) and a modified Elman neural network (MENN). The FIS adopts the crucial criteria of vertical handoff as input variables and makes handoff decision based on the defined rule base. The MENN helps to predict the number of users of the after-bandoff network, which is a pivotal variable of the FIS. Simulation results show that, compared with the conventional method, the AMVHO decision algorithm a-chieves better performance in guaranteeing the quality of service (QoS) of the after-handoff communication.

  9. Simultaneous decomposition of depression heterogeneity on the person-, symptom- and time-level: the use of three-mode principal component analysis.

    NARCIS (Netherlands)

    Monden, R.; Wardenaar, K.J.; Stegeman, A.; Conradi, H.J.; de Jonge, P.

    2015-01-01

    Although heterogeneity of depression hinders research and clinical practice, attempts to reduce it with latent variable models have yielded inconsistent results, probably because these techniques cannot account for all interacting sources of heterogeneity at the same time. Therefore, to simultaneous

  10. Simultaneous Decomposition of Depression Heterogeneity on the Person-, Symptom- and Time-Level : The Use of Three-Mode Principal Component Analysis

    NARCIS (Netherlands)

    Monden, Rei; Wardenaar, Klaas J.; Stegeman, Alwin; Conradi, Henk Jan; de Jonge, Peter

    2015-01-01

    Although heterogeneity of depression hinders research and clinical practice, attempts to reduce it with latent variable models have yielded inconsistent results, probably because these techniques cannot account for all interacting sources of heterogeneity at the same time. Therefore, to simultaneous

  11. Modeling mechanical response of heterogeneous materials

    Science.gov (United States)

    Pal, Siladitya

    Heterogeneous materials are ubiquitous in nature and as synthetic materials. These materials provide unique combination of desirable mechanical properties emerging from its heterogeneities at different length scales. Future structural and technological applications will require the development of advanced light weight materials with superior strength and toughness. Cost effective design of the advanced high performance synthetic materials by tailoring their microstructure is the challenge facing the materials design community. Prior knowledge of structure-property relationships for these materials is imperative for optimal design. Thus, understanding such relationships for heterogeneous materials is of primary interest. Furthermore, computational burden is becoming critical concern in several areas of heterogeneous materials design. Therefore, computationally efficient and accurate predictive tools are highly essential. In the present study, we mainly focus on mechanical behavior of soft cellular materials and tough biological material such as mussel byssus thread. Cellular materials exhibit microstructural heterogeneity by interconnected network of same material phase. However, mussel byssus thread comprises of two distinct material phases. A robust numerical framework is developed to investigate the micromechanisms behind the macroscopic response of both of these materials. Using this framework, effect of microstuctural parameters has been addressed on the stress state of cellular specimens during split Hopkinson pressure bar test. A voronoi tessellation based algorithm has been developed to simulate the cellular microstructure. Micromechanisms (microinertia, microbuckling and microbending) governing macroscopic behavior of cellular solids are investigated thoroughly with respect to various microstructural and loading parameters. To understand the origin of high toughness of mussel byssus thread, a Genetic Algorithm (GA) based optimization framework has been

  12. Muscle perfusion and metabolic heterogeneity: insights from noninvasive imaging techniques

    DEFF Research Database (Denmark)

    Kalliokoski, Kari K; Scheede-Bergdahl, Celena; Kjaer, Michael

    2006-01-01

    Recent developments in noninvasive imaging techniques have enabled the study of local changes in perfusion and metabolism in skeletal muscle as well as patterns of heterogeneity in these variables in humans. In this review, the principles of these techniques along with some recent findings on fun...

  13. Regulation, pollution and heterogeneity in Japanese steam power generation companies

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Carlos Pestana [Instituto Superior de Economia e Gestao, Technical University of Lisbon Rua Miguel Lupi, Lisbon (Portugal); Managi, Shunsuke [Faculty of Business Administration, Yokohama National University, 79-4, Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)

    2009-08-15

    In this paper, the random stochastic frontier model is used to estimate the technical efficiency of Japanese steam power generation companies taking into regulation and pollution. The companies are ranked according to their productivity for the period 1976-2003 and homogenous and heterogeneous variables in the cost function are disentangled. Policy implication is derived. (author)

  14. Adjustment for heterogeneous variances due to days in milk and ...

    African Journals Online (AJOL)

    ARC-IRENE

    Adjustment of heterogeneous variances and a calving year effect in test-day ... Regression Test-Day Model (FRTDM), which assumes equal variances of the response variable at different .... random residual error .... records were included in the selection, while in the unadjusted data set, lactations consisting of six and more.

  15. The Effect of Heterogeneity on Numerical Ordering in Rhesus Monkeys

    Science.gov (United States)

    Cantlon, Jessica F.; Brannon, Elizabeth M.

    2006-01-01

    We investigated how within-stimulus heterogeneity affects the ability of rhesus monkeys to order pairs of the numerosities 1 through 9. Two rhesus monkeys were tested in a touch screen task where the variability of elements within each visual array was systematically varied by allowing elements to vary in color, size, shape, or any combination of…

  16. Influence of Social Cognitive and Gender Variables on Technological Academic Interest among Spanish High-School Students: Testing Social Cognitive Career Theory

    Science.gov (United States)

    Rodríguez, Carmen; Inda, Mercedes; Fernández, Carmen Mª

    2016-01-01

    This study tested social cognitive career theory (SCCT) in the technological domain with 2,359 high-school students in Asturias (Spain). Path analyses were run to determine the influence of gender on the SCCT model and to explain the influence of personal (emotional state, gender-role attitudes), contextual (perceived social supports and…

  17. Forming technology of variable-data rolling and application in manufacturing of farming taper leaf spring%变值轧制成型技术及其在农用板簧制造方面的应用

    Institute of Scientific and Technical Information of China (English)

    刘军营; 杨自栋; 李素玲

    2003-01-01

    The variable data rolling forming that is variable cross-section rolling forming, is a new technological method which has a bright future in the building technique, using the rolling method to produce work-pieces or semi-finished products. Basic principle of the variable data rolling forming technology is introduced in this paper. When variable cross-section rolling, roll gap opening changes with the preset data which is the function of the length of work-piece. The influence on precision of work-piece thickness by preset gap and rolling force as well as mill rigidity, is analyzed. The application of the variable data rolling is introduced by example of the forming theory and manufacturing process of taper leaf spring of farming machinery and vehicle and truck. The variable data rolling forming will become the major methods to produce work-piece which has variable section structure.%变值轧制成型是采用轧制的方式制造零件或毛坯的工艺方法,是一种新兴的有发展前途的制造技术.介绍了变值轧制成型工艺的基本原理和工艺方法,变值轧制成型时,辊缝跟踪设定的数值,辊缝是工件长度的函数,同时分析了设定辊缝、轧制压力、轧机刚度等因素对被成型工件厚度精度的影响.以变截面板弹簧形成理论和制造过程为例,介绍了变值轧制成型技术在农业机械和农用运输车变截面板簧制造方面的应用.变值轧制成型技术将成为制造具有变截面形状结构零件的主要方法.

  18. Research on Heterogeneous Data Sharing in Early Warning System for Grain Security

    Institute of Scientific and Technical Information of China (English)

    GUO Heng-chuan; ZHAO Guo-zeng

    2010-01-01

    The data nodes with heterogeneous database in early waming system for grain security seriously hampered the effective data collection in this system.In this article,the existing middleware technologies was analyzed,the problem-solution approach of heterogeneous data sharing was discussed through middleware technologies.Based on this method,and according to the characteristics of early warning system for grain security,the technology of data sharing in this system were researched and explored to solve the issues of collection of heterogeneous data sharing.

  19. Softward-Defined Networking in Heterogeneous Radio Access Networks

    DEFF Research Database (Denmark)

    Yu, Hao

    2014-01-01

    Integrating diff erent wireless access technologies to provide users with data service will definitely result in a heterogeneous radio access network. Moving from one wireless domain to another causes traffic being switched from one interface to another. This results in a reestablishment of TCP c...

  20. 4G and Beyond - Exploiting Heterogeneity in Mobile Networks

    DEFF Research Database (Denmark)

    Zakrzewska, Anna

    Current and future mobile networks will constitute of multiple coexisting Radio Access Technologies (RATs), cells of different size (macro-, metro-, pico-, femtocells) forming a Heterogeneous Network (HetNet), and Base Stations (BSs) of various architectures. This thesis addresses different aspec...

  1. Querying Patterns in High-Dimensional Heterogenous Datasets

    Science.gov (United States)

    Singh, Vishwakarma

    2012-01-01

    The recent technological advancements have led to the availability of a plethora of heterogenous datasets, e.g., images tagged with geo-location and descriptive keywords. An object in these datasets is described by a set of high-dimensional feature vectors. For example, a keyword-tagged image is represented by a color-histogram and a…

  2. Analysis on construction monitoring technology of a multispan variable cross -section continuous girder bridge%浅析某多跨变截面连续梁桥施工监控技术

    Institute of Scientific and Technical Information of China (English)

    俞梁友

    2016-01-01

    Discusses the combination of construction monitoring technology of variable cross section continuous beam bridge bridge,introduces the finite element model theory,alignment monitoring,stress control of the content,to provide reference for similar bridge construction monitoring.%结合某桥多跨变截面连续梁桥施工监控技术进行探讨,详细介绍了有限元模型建立理论、线形监控、应力监控等内容,为类似桥梁施工监测提供参考。

  3. Elicitation of Quantitative Data from a heterogeneous expert panel : formal process and application in animal health

    NARCIS (Netherlands)

    Fels-Klerx, van der H.J.; Goossens, H.J.; Saatkamp, H.W.; Horst, H.S.

    2002-01-01

    This paper presents a protocol for a formal expert judgment process using a heterogeneous expert panel aimed at the quantification of continuous variables. The emphasis is on the process's requirements related to the nature of expertise within the panel, in particular the heterogeneity of both

  4. 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)

  5. Heterogeneity, correlations and financial contagion

    OpenAIRE

    FABIO CACCIOLI; Thomas A. Catanach; J Doyne Farmer

    2011-01-01

    We consider a model of contagion in financial networks recently introduced in Gai, P. and Kapadia, S. [Contagion in financial networks, Proc. R. Soc. A 466(2120) (2010) 2401–2423], and we characterize the effect of a few features empirically observed in real networks on the stability of the system. Notably, we consider the effect of heterogeneous degree distributions, heterogeneous balance sheet size and degree correlations between banks. We study the probability of contagion conditional on t...

  6. Variable gravity research facility

    Science.gov (United States)

    Allan, Sean; Ancheta, Stan; Beine, Donna; Cink, Brian; Eagon, Mark; Eckstein, Brett; Luhman, Dan; Mccowan, Daniel; Nations, James; Nordtvedt, Todd

    1988-01-01

    Spin and despin requirements; sequence of activities required to assemble the Variable Gravity Research Facility (VGRF); power systems technology; life support; thermal control systems; emergencies; communication systems; space station applications; experimental activities; computer modeling and simulation of tether vibration; cost analysis; configuration of the crew compartments; and tether lengths and rotation speeds are discussed.

  7. Spatial Dependence and Heterogeneity in Bayesian Factor Analysis : A Cross-National Investigation of Schwartz Values

    NARCIS (Netherlands)

    Stakhovych, Stanislav; Bijmolt, Tammo H. A.; Wedel, Michel

    2012-01-01

    In this article, we present a Bayesian spatial factor analysis model. We extend previous work on confirmatory factor analysis by including geographically distributed latent variables and accounting for heterogeneity and spatial autocorrelation. The simulation study shows excellent recovery of the

  8. Biological responses to environmental heterogeneity under future ocean conditions.

    Science.gov (United States)

    Boyd, Philip W; Cornwall, Christopher E; Davison, Andrew; Doney, Scott C; Fourquez, Marion; Hurd, Catriona L; Lima, Ivan D; McMinn, Andrew

    2016-08-01

    Organisms are projected to face unprecedented rates of change in future ocean conditions due to anthropogenic climate-change. At present, marine life encounters a wide range of environmental heterogeneity from natural fluctuations to mean climate change. Manipulation studies suggest that biota from more variable marine environments have more phenotypic plasticity to tolerate environmental heterogeneity. Here, we consider current strategies employed by a range of representative organisms across various habitats - from short-lived phytoplankton to long-lived corals - in response to environmental heterogeneity. We then discuss how, if and when organismal responses (acclimate/migrate/adapt) may be altered by shifts in the magnitude of the mean climate-change signal relative to that for natural fluctuations projected for coming decades. The findings from both novel climate-change modelling simulations and prior biological manipulation studies, in which natural fluctuations are superimposed on those of mean change, provide valuable insights into organismal responses to environmental heterogeneity. Manipulations reveal that different experimental outcomes are evident between climate-change treatments which include natural fluctuations vs. those which do not. Modelling simulations project that the magnitude of climate variability, along with mean climate change, will increase in coming decades, and hence environmental heterogeneity will increase, illustrating the need for more realistic biological manipulation experiments that include natural fluctuations. However, simulations also strongly suggest that the timescales over which the mean climate-change signature will become dominant, relative to natural fluctuations, will vary for individual properties, being most rapid for CO2 (~10 years from present day) to 4 decades for nutrients. We conclude that the strategies used by biota to respond to shifts in environmental heterogeneity may be complex, as they will have to

  9. Wafer-level heterogeneous 3D integration for MEMS and NEMS

    OpenAIRE

    Niklaus, Frank; Lapisa, Martin; Bleiker, Simon J.; Dubois, Valentin; Roxhed, Niclas; Fischer, Andreas C.; Forsberg, Fredrik; Stemme, Goran; Grogg, Daniel; Despont, Michel

    2012-01-01

    In this paper the state-of-the-art in wafer-level heterogeneous 3D integration technologies for micro-electromechanical systems (MEMS) and nano-electromechanical systems (NEMS) is reviewed. Various examples of commercial and experimental heterogeneous 3D integration processes for MEMS and NEMS devices are presented and discussed. QC 20120907

  10. 异质性视角下FDI技术溢出的门槛效应研究%The Research of Threshold between Technology Gaps Based on the Heterogenicity

    Institute of Scientific and Technical Information of China (English)

    田泽永; 江可申

    2014-01-01

    利用2003-2011年省际制造业面板数据,构建吸收能力指标体系,探讨技术差距门槛对FDI溢出效果的影响。从整体情况看来,全国30个省市全要素生产率年均增长9.8%,技术进步是主要因素;国有、外资、民营制造业出现了不同程度增长,民营制造业增长最快,达到10.7%,远超过国有、外资。省际吸收能力差异较大,技术差距构成了FDI溢出技术的双重吸收门槛,国有企业门槛值分别为1.060、3.430,民营企业门槛值分别为2.2、8.260。对国有企业而言,FDI技术溢出的效果随技术差距扩大而下降;民营企业由于行业间技术溢出,溢出效果是技术差距的增函数。%Using the panel data of manufacturing sector from 2003-201 1 years and establishing the absorptive capacity in-dicator,the technology spillover effects were analyzed.From the overall situation,total factor productivity of 30 provinces was 9.8%,and technological progress was the main factor.State-owned,foreign,private economy got different growing rate.Among them,the private economy rose fastest and reached 10.7%,far more than state-owned and foreign econo-my.Being the large differences of absorptive capacity,the double thresholds were formed in 30 provinces.The values of two way thresholds in state-owned enterprises were 1.060,3.430,and the threshold values of private enterprises were 2.2,8.260.The state-owned enterprises received less FDI technology spillovers.Being the role of spillovers between industries,the effect is the increasing function of technology gap in private enterprises.

  11. Summarization on variable liquid thrust rocket engines

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The technology actuality and development trend of variable thrust rocket engines at home and abroad are summarized. Key technologies of developing variable thrust rocket engines are analyzed. Development advices on developing variable thrust rocket engines that are adapted to the situation of our country are brought forward.

  12. Evolution of market shares with repeated purchases and heterogeneous network externalities

    NARCIS (Netherlands)

    M.C.W. Janssen (Maarten); E. Mendys

    2007-01-01

    textabstractWe investigate how market shares change when a new, superior technology exhibiting network externalities is introduced in a market initially dominated by an old technology. This is done under the assumption that consumers are heterogeneous in their valuation of technology quality and net

  13. Evidence for magnesium isotope heterogeneity in the solar protoplanetary disk

    DEFF Research Database (Denmark)

    Larsen, Kirsten Kolbjørn; Trinquier, Anne Marie-Pierre Emilie; Paton, Chad

    2011-01-01

    With a half-life of 0.73 Myr, the 26Al-to-26Mg decay system is the most widely used short-lived chronometer for understanding the formation and earliest evolution of the solar protoplanetary disk. However, the validity of 26Al–26Mg ages of meteorites and their components relies on the critical......, and planets demonstrating the existence of widespread heterogeneity in the mass-independent 26Mg composition (µ26Mg*) of bulk solar system reservoirs with solar or near-solar Al/Mg ratios. This variability may represent heterogeneity in the initial abundance of 26Al across the solar protoplanetary disk...

  14. Heterogeneous complementarity and technological innovation of Japanese firms in the globali7ation%异质互补与国际化中的日本企业技术创新

    Institute of Scientific and Technical Information of China (English)

    张化尧; 史小坤

    2011-01-01

    Japanese firms have been showing different characteristics in the innovation globallzation. The patents of Japanese finns are analyzed to show whether or not they are performing the international wisdom of heterogeneous complementarity in the innovation. Patents from the database of OECD triadic patent families of five Japanese finns and two benchmark American finns in addition to all patent families within area H (Electrlcs) are analyzed. The results show that although Japanese firms have stronger centralization tendency comparing with their America rivals in innovation, in term of application of resources seeking and capability complementary strategies, Japanese finns stand the same position with their American counterparts. The meaning is that Chinese firms should be paid much attention not only to the beckword status of Japanese firms in the innovation globalization, but also to their enterprise innovative strategy in the changing trends.%日本企业在创新国际化上表现出与欧美企业不同的特色,本文对日本国际化大公司的专利进行分析从而观察其是否遵循异质互补的国际共识。研究选取五个日本国际化大公司和两个美国参照公司的专利作为讨论重点,并配合对全部电学领域专利的分析,考察日本企业的创新特征。本文的分析得出虽然日本企业在创新国际化上有明显的创新向心化倾向,但对资源寻求和能力互补战略的运用并不落后于美国的国际化大公司。本文的研究对于中国企业的启示是不应只看到日本企业在创新国际化中落后的一面,更应注重从其变化的趋势中思考企业创新战略。

  15. Component-level modeling technology for variable cycle engine%变循环发动机部件级建模技术

    Institute of Scientific and Technical Information of China (English)

    苟学中; 周文祥; 黄金泉

    2013-01-01

    以双外涵变循环发动机为研究对象,建立了其整机部件级稳态及动态数学模型,建模过程中考虑了导叶角和导向器面积变化对压气机和涡轮部件特性的影响,考虑了模式选择活门面积变化对副外涵进口空气流量的影响,所建立的模型能够执行变循环发动机2种典型工作模式:稳态及模式切换过渡态仿真.仿真结果表明:随着模式选择活门逐渐关闭,前段风扇喘振裕度显著减小;双涵工作模式下发动机耗油率低,适用于亚声速巡航飞行;单涵工作模式下发动机单位推力高,适用于超声速巡航飞行.%A steady and transient component-level mathematical model of a double bypass variable cycle engine (DBVCE) was constructed considering the effects of variable inlet guide vane and variable turbine nozzle area on component characteristics of compressor and turbine. Besides, the effects of the mode selector valve area on deputy bypass inlet air flow were also considered during the modeling process of DBVCE; two typical operation modes such as steady state and mode switching transient process were simulated. Results show that as the mode selector valve closes down, the surge margin of front fan block decreases obviously. When working in double bypass mode, the specific fuel consumption of DBVCE is lower, which is fit for subsonic cruise flight; otherwise, the specific thrust is higher in single bypass mode, which is fit for supersonic cruise flight.

  16. Heterogeneous photocatalysis for air and water treatment: Fundamental needs for quantum efficiency enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Ollis, D.F. [North Carolina State Univ., Raleigh, NC (United States)

    1996-09-01

    In the remediation industries, a useful treatment technology must be {open_quotes}general, robust, and cheap{close_quotes}. Among oxidation processes, heterogeneous photocatalysis is now broadly demonstrated to destroy common water and air contaminants. The potential process uses of highly stable titania, long lived lamps (one year), and room temperature operation, indicating a simple and robust process. We are left to address the third criterion: Can photocatalysis be {open_quotes}cheap{close_quotes}? In both liquid phase and gas phase treatment and purification by photocatalysis, it is established that the primary barrier to commercialization is often cost. Cost in return is dominated by the efficiency with which solar or lamp photons are harvested for productive light, and subsequent dark, reactions. This paper therefore defines fundamental needs in photocatalysis for pollution control in terms of activities which could lead to quantum efficiency enhancement. We first recall three related definitions. The quantum yield (QY) is the ratio of molecules of reactant converted per photon absorbed, a fundamental quantity. A less fundamental, but more easily measured variable is the quantum efficiency (QE), the ratio of molecules converted per photon entering the reactor. A third variable is the energy required per order of magnitude pollutant reduction, or EEO, a definition which provides for easy energy cost comparisons among different technologies. Each measure cited here reflects the photon, and thus the electrical, cost of this photochemistry.

  17. Ashtekar variables

    Science.gov (United States)

    Ashtekar, Abhay

    2015-05-01

    In the spirit of Scholarpedia, this invited article is addressed to students and younger researchers. It provides the motivation and background material, a summary of the main physical ideas, mathematical structures and results, and an outline of applications of the connection variables for general relativity. These variables underlie both the canonical/Hamiltonian and the spinfoam/path integral approaches in loop quantum gravity.

  18. Enhanced CO2 Dissolution in Heterogeneous Porous Media

    Science.gov (United States)

    Daniels, K.; Neufeld, J. A.; Bickle, M. J.; Hallworth, M. A.

    2014-12-01

    Long-term and secure geological storage of CO2 through technologies such as Carbon Capture and Storage (CCS) within reservoirs is seen as a technological means to reduce anthropogenic CO2 emissions. The long-term viability of this technology is reliant on the structural and secondary trapping of supercritical CO2 within heterogeneous reservoirs. Secondary trapping, primarily through the dissolution of CO2 into ambient reservoir brine to produce a denser fluid, is capable of retaining CO2 in the subsurface and thus reducing the risks of storage. To model secondary trapping we need to understand how the flow of CO2 through heterogeneous reservoir rocks enhances dissolution of supercritical CO2 in reservoir brines. Here we experimentally investigate the dissolution of CO2 in reservoir brines in layered, heterogeneous geological formations. Using analogue experiments, designed to approximate an enhanced oil recovery (EOR) setting, the processes of mixing, dispersion and dissolution are examined. These are compared against test results from non-layered, homogeneous porous media experiments. We find that heterogeneities significantly enhance mixing, particularly between adjacent porous layers. During fluid propagation, pore-scale viscous fingers grow and retreat, thereby providing an increased surface area between the flow and the ambient reservoir fluid. This enhanced mixing is predicted to substantially increase the dissolution of CO2 in reservoir brines. Both permeability and viscosity differences are found to have a significant effect on the interface between the two fluids, and therefore the likely amount of dissolution of CO2.

  19. 二维码防伪技术在可变数据印刷中的应用%Application of Anti-counterfeiting Technology Based on Two-dimensional Bar Code in Variable Data Printing

    Institute of Scientific and Technical Information of China (English)

    肖菲菲; 刘真

    2011-01-01

    The principle of two-dimensional bar code anti-counterfeiting technology was analyzed.A plan of applying two-dimensional code anti-counterfeiting technology in variable-data printing was put forward.On the basis of experiments on generation and recognition of two-dimensional bar code,anti-counterfeiting properties of two different two-dimensional bar codes(PDF417 code and QR code) were obtained and their difference was compared.The theoretical analysis and experiment results showed that anti-counterfeiting technology based on two-dimensional bar code can be used in variable data printing,besides,different two-dimensional bar codes have different anti-counterfeiting properties;different two-dimensional bar code should be selected according to specific requirements.%分析了二维码的防伪原理,提出了在可变数据印刷中应用二维码进行防伪的方案,在完成基于可变数据印刷的二维码的生成和识别实验的基础上,设计实验比较得出了不同二维码(PDF417码与QR码)的防伪特性的差异。理论分析及实验结果表明,利用二维码对可变数据印刷进行防伪的方案是可行的,并且不同二维码的防伪特性存在差异,在实际应用中可以根据具体的要求选用不同的二维码。

  20. A Framework for Multiple and Heterogeneous Earthquake Disaster Information Fusion

    Directory of Open Access Journals (Sweden)

    Jinghai Xu

    2011-03-01

    Full Text Available To realize the fusion of multiple and heterogeneous earthquake disaster information and get effective disaster information, situation and characteristics are addressed on different earthquake disaster information acquiring methods, in which some new earthquake disaster information acquiring methods are described. A fusion architecture of multiple and heterogeneous disaster information is put forward, including data level, fusion level and application level. And function principle of each level is described. Finally key technologies and realization methods in the fusion architecture are expounded, which are transformation and match of multiple disaster information and coding of the information.

  1. Heterogeneous catalytic hydrogenation reactions in continuous-flow reactors.

    Science.gov (United States)

    Irfan, Muhammad; Glasnov, Toma N; Kappe, C Oliver

    2011-03-21

    Microreactor technology and continuous flow processing in general are key features in making organic synthesis both more economical and environmentally friendly. Heterogeneous catalytic hydrogenation reactions under continuous flow conditions offer significant benefits compared to batch processes which are related to the unique gas-liquid-solid triphasic reaction conditions present in these transformations. In this review article recent developments in continuous flow heterogeneous catalytic hydrogenation reactions using molecular hydrogen are summarized. Available flow hydrogenation techniques, reactors, commonly used catalysts and examples of synthetic applications with an emphasis on laboratory-scale flow hydrogenation reactions are presented.

  2. Influence of variable water-soluble soy extract and inulin contents on the rheological, technological and sensory properties of grapeflavored yogurt-like beverages made from caprine milk

    Directory of Open Access Journals (Sweden)

    José Evangelista Santos Ribeiro

    2016-04-01

    Full Text Available The present study aimed to evaluate the influences of the partial substitution of caprine milk for water-soluble soy extract (WSSE and the addition of inulin on the rheological, technological and sensory properties of grapeflavored yogurt-like beverages. For this purpose, a Central Composite Design (CCD in conjunction with Response Surface Methodology (RSM was employed. WSSE and inulin influenced the overall acceptability of the product, whereas syneresis, water holding capacity and rheological properties (the consistency index and the flow behavior index were influenced only by the WSSE content. RSM was shown to be an adequate statistical tool that can be used for the development of formulations with specified properties in the range of the ingredient concentrations studied.

  3. Climatic response variability and machine learning: development of a modular technology framework for predicting bio-climatic change in pacific northwest ecosystems"

    Science.gov (United States)

    Seamon, E.; Gessler, P. E.; Flathers, E.

    2015-12-01

    The creation and use of large amounts of data in scientific investigations has become common practice. Data collection and analysis for large scientific computing efforts are not only increasing in volume as well as number, the methods and analysis procedures are evolving toward greater complexity (Bell, 2009, Clarke, 2009, Maimon, 2010). In addition, the growth of diverse data-intensive scientific computing efforts (Soni, 2011, Turner, 2014, Wu, 2008) has demonstrated the value of supporting scientific data integration. Efforts to bridge this gap between the above perspectives have been attempted, in varying degrees, with modular scientific computing analysis regimes implemented with a modest amount of success (Perez, 2009). This constellation of effects - 1) an increasing growth in the volume and amount of data, 2) a growing data-intensive science base that has challenging needs, and 3) disparate data organization and integration efforts - has created a critical gap. Namely, systems of scientific data organization and management typically do not effectively enable integrated data collaboration or data-intensive science-based communications. Our research efforts attempt to address this gap by developing a modular technology framework for data science integration efforts - with climate variation as the focus. The intention is that this model, if successful, could be generalized to other application areas. Our research aim focused on the design and implementation of a modular, deployable technology architecture for data integration. Developed using aspects of R, interactive python, SciDB, THREDDS, Javascript, and varied data mining and machine learning techniques, the Modular Data Response Framework (MDRF) was implemented to explore case scenarios for bio-climatic variation as they relate to pacific northwest ecosystem regions. Our preliminary results, using historical NETCDF climate data for calibration purposes across the inland pacific northwest region

  4. Variable Heat Rejection (VHR) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop advanced technologies to enable a variable heat rejection Thermal Control System (TCS) capable of operating through a wide range of thermal environments...

  5. Organizational heterogeneity of vertebrate genomes.

    Directory of Open Access Journals (Sweden)

    Svetlana Frenkel

    Full Text Available Genomes of higher eukaryotes are mosaics of segments with various structural, functional, and evolutionary properties. The availability of whole-genome sequences allows the investigation of their structure as "texts" using different statistical and computational methods. One such method, referred to as Compositional Spectra (CS analysis, is based on scoring the occurrences of fixed-length oligonucleotides (k-mers in the target DNA sequence. CS analysis allows generating species- or region-specific characteristics of the genome, regardless of their length and the presence of coding DNA. In this study, we consider the heterogeneity of vertebrate genomes as a joint effect of regional variation in sequence organization superimposed on the differences in nucleotide composition. We estimated compositional and organizational heterogeneity of genome and chromosome sequences separately and found that both heterogeneity types vary widely among genomes as well as among chromosomes in all investigated taxonomic groups. The high correspondence of heterogeneity scores obtained on three genome fractions, coding, repetitive, and the remaining part of the noncoding DNA (the genome dark matter--GDM allows the assumption that CS-heterogeneity may have functional relevance to genome regulation. Of special interest for such interpretation is the fact that natural GDM sequences display the highest deviation from the corresponding reshuffled sequences.

  6. Organizational heterogeneity of vertebrate genomes.

    Science.gov (United States)

    Frenkel, Svetlana; Kirzhner, Valery; Korol, Abraham

    2012-01-01

    Genomes of higher eukaryotes are mosaics of segments with various structural, functional, and evolutionary properties. The availability of whole-genome sequences allows the investigation of their structure as "texts" using different statistical and computational methods. One such method, referred to as Compositional Spectra (CS) analysis, is based on scoring the occurrences of fixed-length oligonucleotides (k-mers) in the target DNA sequence. CS analysis allows generating species- or region-specific characteristics of the genome, regardless of their length and the presence of coding DNA. In this study, we consider the heterogeneity of vertebrate genomes as a joint effect of regional variation in sequence organization superimposed on the differences in nucleotide composition. We estimated compositional and organizational heterogeneity of genome and chromosome sequences separately and found that both heterogeneity types vary widely among genomes as well as among chromosomes in all investigated taxonomic groups. The high correspondence of heterogeneity scores obtained on three genome fractions, coding, repetitive, and the remaining part of the noncoding DNA (the genome dark matter--GDM) allows the assumption that CS-heterogeneity may have functional relevance to genome regulation. Of special interest for such interpretation is the fact that natural GDM sequences display the highest deviation from the corresponding reshuffled sequences.

  7. Features and heterogeneities in growing network models

    Science.gov (United States)

    Ferretti, Luca; Cortelezzi, Michele; Yang, Bin; Marmorini, Giacomo; Bianconi, Ginestra

    2012-06-01

    Many complex networks from the World Wide Web to biological networks grow taking into account the heterogeneous features of the nodes. The feature of a node might be a discrete quantity such as a classification of a URL document such as personal page, thematic website, news, blog, search engine, social network, etc., or the classification of a gene in a functional module. Moreover the feature of a node can be a continuous variable such as the position of a node in the embedding space. In order to account for these properties, in this paper we provide a generalization of growing network models with preferential attachment that includes the effect of heterogeneous features of the nodes. The main effect of heterogeneity is the emergence of an “effective fitness” for each class of nodes, determining the rate at which nodes acquire new links. The degree distribution exhibits a multiscaling behavior analogous to the the fitness model. This property is robust with respect to variations in the model, as long as links are assigned through effective preferential attachment. Beyond the degree distribution, in this paper we give a full characterization of the other relevant properties of the model. We evaluate the clustering coefficient and show that it disappears for large network size, a property shared with the Barabási-Albert model. Negative degree correlations are also present in this class of models, along with nontrivial mixing patterns among features. We therefore conclude that both small clustering coefficients and disassortative mixing are outcomes of the preferential attachment mechanism in general growing networks.

  8. The establishment of heterogeneous networks in performative spaces

    DEFF Research Database (Denmark)

    Suenson, Valinka; Harder, Henrik

    2010-01-01

    This paper presents an empirical research combining the Actor Network Theory with a development of RFID (Radio Frequency Identification) technology for tracking indoor movement behavior. The aim of the paper is to disucss the value of RFID technology as a method for observing heterogeneous networks...... and architecture through this theoretical perspective, it highlights the importance of the user involvement in the performative spaces where materiality becomes an actant on equal terms with the users. This paper discusses the use of RFID technology for tracking indoor movenment behavior as a method for examining...

  9. 非均质超厚活跃沥青层安全钻井技术探讨%Discussion on Safe Drilling Technology for Heterogeneous,Ultra-Thick and Active Bitumen Zone

    Institute of Scientific and Technical Information of China (English)

    何青水; 宋明全; 肖超; 黄在福; 王学杰

    2013-01-01

    During development of Y Oilfield, several wells were drilled through Kazhdumi Formation which contains ultra-thick active bitumen. Those heterogeneous and scatterly-distributed formations brought severe challenges to drilling operation. In particular,drilling fluid contamination,simultaneous mud loss and well kick,escaping H2 S and other complexities have caused abandonment of several wells and tampered with the overall progress of Y Oilfield development. Based on actual drilling data, the active bitumen zone is investigated in respect to formation pressure,connecting channel,bitumen feature and its distribution, and treatment difficulties are also analyzed. Then,the technical solution is proposed for further study on the distribution of bitumen and optimize casing program and managed pressure drilling(MPD)along with bitumen hardening process. The results show that the pressure of active bitumen is 1. 58-1. 65 g/cm3 and the long open hole where bitumen zone is encountered in current casing program is a bottleneck in the treatment of active bitumen. However,bitumen hardening agent YHJ-6 can increase the softening point of bitumen by over 60癈. Field test shows that this agent can effectively reduce the volume of bitumen invading into wellbore and enhance the sealing of leaking channel in bitumen environment.%Y油田开发过程中多口井钻遇Kazhdumi层超厚活跃沥青,沥青地层的非均质性、空间分布的不确定性给钻井施工带来极大挑战,钻井液污染、涌漏并发、硫化氢逸出等复杂情况导致多口井工程弃井,严重影响了Y油田的整体开发进度.根据已钻井实钻资料,从沥青层压力、连通通道、沥青特征及分布规律等方面研究了沥青层环境因素,分析了活跃沥青层处理难点.在此基础上,提出强化沥青层分布规律研究、优化调整井身结构和控压钻井技术配合沥青硬化处理等技术对策.分析认为,活跃沥青层地层压力当量钻井液密度1

  10. Sensemaking technology

    DEFF Research Database (Denmark)

    Madsen, Charlotte Øland

    Research objective: The object of the LOK research project is to gain a better understanding of the technological strategic processes in organisations by using the concept/metaphor of sensemaking. The project will investigate the technological strategies in organisations in order to gain a deeper...... understanding of the cognitive competencies and barriers towards implementing new technology in organisations. The research will therefore concentrate on researching the development process in the organisation's perception of the external environmental elements of customers, suppliers, competitors, internal...... and external technology and legislation and the internal environmental elements of structure, power relations and political arenas. All of these variables have influence on which/how technologies are implemented thus creating different outcomes all depending on the social dynamics that are triggered by changes...

  11. Sensemaking technology

    DEFF Research Database (Denmark)

    Madsen, Charlotte Øland

    Research objective: The object of the LOK research project is to gain a better understanding of the technological strategic processes in organisations by using the concept/metaphor of sensemaking. The project will investigate the technological strategies in organisations in order to gain a deeper...... understanding of the cognitive competencies and barriers towards implementing new technology in organisations. The research will therefore concentrate on researching the development process in the organisation's perception of the external environmental elements of customers, suppliers, competitors, internal...... and external technology and legislation and the internal environmental elements of structure, power relations and political arenas. All of these variables have influence on which/how technologies are implemented thus creating different outcomes all depending on the social dynamics that are triggered by changes...

  12. Emerging heterogeneous integrated photonic platforms on silicon

    Directory of Open Access Journals (Sweden)

    Fathpour Sasan

    2015-05-01

    Full Text Available Silicon photonics has been established as a mature and promising technology for optoelectronic integrated circuits, mostly based on the silicon-on-insulator (SOI waveguide platform. However, not all optical functionalities can be satisfactorily achieved merely based on silicon, in general, and on the SOI platform, in particular. Long-known shortcomings of silicon-based integrated photonics are optical absorption (in the telecommunication wavelengths and feasibility of electrically-injected lasers (at least at room temperature. More recently, high two-photon and free-carrier absorptions required at high optical intensities for third-order optical nonlinear effects, inherent lack of second-order optical nonlinearity, low extinction ratio of modulators based on the free-carrier plasma effect, and the loss of the buried oxide layer of the SOI waveguides at mid-infrared wavelengths have been recognized as other shortcomings. Accordingly, several novel waveguide platforms have been developing to address these shortcomings of the SOI platform. Most of these emerging platforms are based on heterogeneous integration of other material systems on silicon substrates, and in some cases silicon is integrated on other substrates. Germanium and its binary alloys with silicon, III–V compound semiconductors, silicon nitride, tantalum pentoxide and other high-index dielectric or glass materials, as well as lithium niobate are some of the materials heterogeneously integrated on silicon substrates. The materials are typically integrated by a variety of epitaxial growth, bonding, ion implantation and slicing, etch back, spin-on-glass or other techniques. These wide range of efforts are reviewed here holistically to stress that there is no pure silicon or even group IV photonics per se. Rather, the future of the field of integrated photonics appears to be one of heterogenization, where a variety of different materials and waveguide platforms will be used for

  13. Heterogeneity in Preferences and Productivity

    DEFF Research Database (Denmark)

    Gørtz, Mette

    choices of expenditure, household production and leisure for people in and around retirement. The unobserved individual heterogeneity factor is isolated by comparing cross-sectional evidence and panel data estimates of the effects of retirement on consumption and time allocation. Based on cross......-section data, we can identify a difference in consumption due to retirement status, but when the panel nature of the data is exploited, the effect of retirement on consumption is small and insignificant. Moreover, the analyses point at a large positive effect of retirement on household production. Our results......This paper discusses the determinants of the retirement decision and the implications of retirement on economic well-being. The main contribution of the paper is to formulate the role of individual heterogeneity explicitly. We argue that individual heterogeneity in 1) productivity of market work...

  14. Phenotypic heterogeneity of monogenic frontotemporal dementia

    Directory of Open Access Journals (Sweden)

    Alberto eBenussi

    2015-09-01

    Full Text Available Frontotemporal dementia (FTD is a genetically and pathologically heterogeneous disorder characterized by personality changes, language impairment and deficits of executive functions associated with frontal and temporal lobe degeneration. Different phenotypes have been defined on the basis of presenting clinical symptoms, i.e. the behavioral variant of FTD (bvFTD, the agrammatic variant of Primary Progressive Aphasia (avPPA and the semantic variant of PPA (svPPA. Some patients have an associated movement disorder, either parkinsonism, as in Progressive Supranuclear Palsy (PSP and Corticobasal Syndrome (CBS, or motor neuron disease (FTD-MND. A family history of dementia is found in 40% of cases of FTD and about 10% have a clear autosomal dominant inheritance. Genetic studies have identified several genes associated to monogenic FTD: microtubule-associated protein tau (MAPT, progranulin (GRN, TAR DNA-binding protein 43 (TARBDP, valosin-containing protein (VCP, charged multivesicular body protein 2B (CHMP2B, fused in sarcoma (FUS and the hexanucleotide repeat expansion in intron 1 of the chromosome 9 open reading frame 72 (C9orf72. Patients often present with an extensive phenotypic variability, even among different members of the same kindred carrying an identical disease mutation. The objective of the present work is to review and evaluate available literature data in order to highlight recent advances in clinical, biological and neuroimaging features of monogenic frontotemporal lobar degeneration and try to identify different mechanisms underlying the extreme phenotypic heterogeneity that characterizes this disease.

  15. Asthma in childhood: a complex, heterogeneous disease

    Directory of Open Access Journals (Sweden)

    Hai Lee Chung

    2011-01-01

    Full Text Available Asthma in childhood is a heterogeneous disease with different phenotypes and variable clinical manifestations, which depend on the age, gender, genetic background, and environmental influences of the patients. Several longitudinal studies have been conducted to classify the phenotypes of childhood asthma, on the basis of the symptoms, triggers of wheezing illness, or pathophysiological features of the disease. These studies have provided us with important information about the different wheezing phenotypes in young children and about potential mechanisms and risk factors for the development of chronic asthma. The goal of these studies was to provide a better insight into the causes and natural course of childhood asthma. It is well-known that complicated interactions between genes and environmental factors contribute to the development of asthma. Because childhood is a period of rapid growth in both the lungs and the immune system, developmental factors should be considered in the pathogenesis of childhood asthma. The pulmonary system continues to grow and develop until linear growth is completed. Longitudinal studies have reported significant age-related immune development during postnatal early life. These observations suggest that the phenotypes of childhood asthma vary among children and also in an individual child over time. Improved classification of heterogeneous conditions of the disease will help determine novel strategies for primary and secondary prevention and for the development of individualized treatment for childhood asthma.

  16. Using the Research Domain Criteria Framework to Explore Associations Between MMPI-2-RF Constructs and Physiological Variables Assessed by Eye-Tracker Technology.

    Science.gov (United States)

    McCord, David M; Achee, Margaret C; Cannon, Elissa M; Harrop, Tiffany M; Poynter, William D

    2017-01-01

    The National Institute of Mental Health has proposed a paradigm shift in the conceptualization of psychopathology, abandoning the traditional categorical model in favor of one based on hierarchically organized dimensional constructs (Insel et al., 2010 ). One explicit goal of this initiative, the Research Domain Criteria (RDoC) project, is to facilitate the incorporation of newly available neurobiologic variables into research on psychopathology. The Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008/2011 ) represents a similar paradigm shift, also adopting a hierarchical arrangement of dimensional constructs. This study examined associations between MMPI-2-RF measures of psychopathology and eye-movement metrics. Participants were college students (n = 270) who completed the MMPI-2-RF and then viewed a sequence of 30-s video clips. Results show a pattern of positive correlations between pupil size and emotional/internalizing dysfunction scales when viewing video eliciting negative emotional reactions, reflecting greater arousability in individuals with higher scores on these measures. In contrast, when viewing stimuli depicting angry, threatening material, a clear pattern of negative correlations was found between pupil size and behavioral/externalizing trait measures. These data add to the construct validity of the MMPI-2-RF and support the use of the RDoC matrix as a framework for research on psychopathology.

  17. Dynamic fracture of heterogeneous materials

    Energy Technology Data Exchange (ETDEWEB)

    Stout, M.G.; Liu, C.; Addessio, F.L.; Williams, T.O.; Bennett, J.G.; Haberman, K.S.; Asay, B.W.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to investigate the fundamental aspects of the process of dynamic fracture propagation in heterogeneous materials. The work focused on three important, but poorly understood, aspects of dynamic fracture for materials with a heterogeneous microstructure. These were: the appropriateness of using a single-parameter asymptotic analysis to describe dynamic crack-tip deformation fields, the temperature rises at the tip and on the flanks of a running crack, and the constitutive modeling of damage initiation and accumulation.

  18. Job Heterogeneity and Coordination Frictions

    DEFF Research Database (Denmark)

    Kennes, John; le Maire, Daniel

    the job ladder, how the identification of assortative matching is fundamentally different in directed and undirected search models, how our theory accounts for business cycle facts related to inter-temporal changes in job offer distributions, and how our model could also be used to identify......We develop a new directed search model of a frictional labor market with a continuum of heterogenous workers and firms. We estimate two versions of the model - auction and price posting - using Danish data on wages and productivities. Assuming heterogenous workers with no comparative advantage, we...

  19. Metastable dynamics in heterogeneous neural fields

    Directory of Open Access Journals (Sweden)

    Cordula eSchwappach

    2015-06-01

    Full Text Available We present numerical simulations of metastable states in heterogeneous neural fields that are connected along heteroclinic orbits. Such trajectories are possible representations of transient neural activity as observed, for example, in the electroencephalogram. Based on previous theoretical findings on learning algorithms for neural fields, we directly construct synaptic weight kernels from Lotka-Volterra neural population dynamics without supervised training approaches. We deliver a MATLAB neural field toolbox validated by two examples of one- and two-dimensional neural fields. We demonstrate trial-to-trial variability and distributed representations in our simulations which might therefore be regarded as a proof-of-concept for more advanced neural field models of metastable dynamics in neurophysiological data.

  20. Metastable dynamics in heterogeneous neural fields

    Science.gov (United States)

    Schwappach, Cordula; Hutt, Axel; beim Graben, Peter

    2015-01-01

    We present numerical simulations of metastable states in heterogeneous neural fields that are connected along heteroclinic orbits. Such trajectories are possible representations of transient neural activity as observed, for example, in the electroencephalogram. Based on previous theoretical findings on learning algorithms for neural fields, we directly construct synaptic weight kernels from Lotka-Volterra neural population dynamics without supervised training approaches. We deliver a MATLAB neural field toolbox validated by two examples of one- and two-dimensional neural fields. We demonstrate trial-to-trial variability and distributed representations in our simulations which might therefore be regarded as a proof-of-concept for more advanced neural field models of metastable dynamics in neurophysiological data. PMID:26175671

  1. The technological analysis of earthen architectural remains: the variability of building techniques and the characterization of burned or cemented daub in polished section

    Directory of Open Access Journals (Sweden)

    Alessandro Peinetti

    2016-12-01

    Full Text Available Earthen architectural fragments (burned or cemented are often collected during the excavation in Italian prehistoric and protohistoric sites. The technological characterization of these remains is relevant to recognize the existence of local or regional building traditions and to understand the exploitation of raw materials and, more in general, the ancient production strategies. In addition to the current macroscopic analysis (morphology of fragments and classification of pastes and before the realization of archaeometric analysis, it’s possible to complete the analytical protocol of daub with some observations in polished section. To realize a polished section, the daub sample is cut and the resulting section is polished with sandpaper. The realization of this kind of section allows a better description of the arrangement of the constituents, to identify the processes of transformation and deformation of raw materials during the building activity. The aim of these mesoscopic analysis is to characterize the behavioral chain referred to the processing of raw materials and their installation, linking the observed characteristics to specific actions. It’s possible to obtain some functional data about the original function of the earthen structures or the dynamics of entrance in the archaeological record a well. This paper presents some case-studies and some preliminary keys to understand the features observed in polished section. The use of this analytical technique gives some encouraging results, especially in comparing the number of relevant data to the low cost of production of a polished section.

  2. Advanced Treatment of Coking Wastewater with a Novel Heterogeneous Electro-Fenton Technology%新型非均相电-Fenton技术深度处理焦化废水

    Institute of Scientific and Technical Information of China (English)

    李海涛; 李玉平; 张安洋; 曹宏斌; 李鑫钢; 张懿

    2011-01-01

    分别采用高效氯气还原阴极PAQ/GF和形稳性阳极IrO2-RuO2-TiO2/Ti做为阴、阳极,填充非均相催化剂,研究一种阴、阳极同时催化氧化的电化学过程,并应用于焦化废水生化出水深度处理.采用在石墨毡上电聚合蒽醌制备PAQ/GF电极,并用循环伏安进行了表征.结果表明,蒽醌在电极表面具有很好的可逆性,并对电催化还原氧气生成过氧化氢(H2O2)表现很高的电催化活性;隔膜电解槽中PAQ/GF做阴极,在-0.7 V(相对饱和甘汞电极)和pH 6下电解6 h后,H2O2浓度为13.5mmol/L,电流效率>50%.采用浸渍法制备了非均相催化剂Fe-Cu/Y350,通过结晶紫褪色反应和羟自由基探针化合物(对氯苯甲酸)氧化反应验证Fe-Cu/Y350催化H 202产生了羟基自由基(·OH);使用Fe-Cu/Y350催化次氯酸钠氧化处理焦化废水,COD去除率达到26%,远高于没有催化剂时的11%.利用组装的电催化反应器对焦化废水进行处理,COD去除率达到49.4%,远高于传统的双极氧化过程(29.8%),其中阴极与阳极催化过程对COD去除的贡献率分别为26.0%和23.4%.在优化条件下(初始COD=192 mg/L、I=10 A·m-2、pH 4~5)电解1 h后,焦化废水COD去除率>50%.反应途径可能为:氧气在PAQ/GF电极上高效电催化还原为H2O2,再经Fe-Cu/Y350催化分解产生·OH,从而将有机污染物氧化分解;氯离子在IrO2-RuO2-TiO2/Ti电极氧化产生Cl2或次氯酸,并在Fe-Cu/Y350催化作用下将有机污染物氧化或有机物在阳极直接氧化降解.%A novel electro-catalytic reactor, with oxygen-reduction cathode (PAQ/GF), dimensionally stable anode (IrO2-RuO2-TiO2/Ti) and heterogeneous catalysts, is developed for advanced treatment of coking wastewater after biological process, integrating cathodic and anodic simultaneous oxidation processes. A PAQ/GF electrode was synthesized by the electro-polymerization of 2-ethyl anthraquinone on graphite felt, which was characterized with cyclic vohametry measurements

  3. Numerical Modeling of Variable Fluid Injection-Rate Modes on Fracturing Network Evolution in Naturally Fractured Formations

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2016-05-01

    Full Text Available In this study, variable injection-rate technology was numerically investigated in a pre-existing discrete fracture network (DFN formation, the Tarim Basin in China. A flow-stress-damage (FSD coupling model has been used in an initial attempt towards how reservoir response to variable injection-rates at different hydraulic fracturing stages. The established numerical model simultaneously considered the macroscopic and microscopic heterogeneity characteristics. Eight numerical cases were studied. Four cases were used to study the variable injection-rate technology, and the other four cases were applied for a constant injection-rate in order to compare with the variable injection-rate technology. The simulation results show that the variable injection-rate technology is a potentially good method to a form complex fracturing networks. The hydraulic fracturing effectiveness when increasing the injection-rate at each stage is the best, also, the total injected fluid is at a minimum. At the initial stage, many under-fracturing points appear around the wellbore with a relatively low injection-rate; the sudden increase of injection rate drives the dynamic propagation of hydraulic fractures along many branching fracturing points. However, the case with decreasing injection rate is the worst. By comparing with constant injection-rate cases, the hydraulic fracturing effectiveness with variable flow rate technology is generally better than those with constant injection-rate technology. This work strongly links the production technology and hydraulic fracturing effectiveness evaluation and aids in the understanding and optimization of hydraulic fracturing simulations in naturally fractured reservoirs.

  4. Selective Oxidations using Nanostructured Heterogeneous Catalysts

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen

    nanoparticles with particular emphasis on the nature of the active site and the requirements needed to be considered when designing new catalytic systems. Furthermore, the chapter describes some of the most important methods to synthesise small and disperse gold nanoparticles on different supports. Chapter 4...... technological developments in biomass processing have made bioethanol a promising platform molecule for the production of a variety of value-added chemicals. Furthermore, the chapter describes a simple and effective method to encapsulate gold nanoparticles into a MFI zeolite and demonstrate their remarkable...... and because they produce H2O as the only by-product. Chapter 1 gives a short introduction to basic concepts in heterogeneous catalysis and green chemistry. Furthermore, the chapter gives an overview of the most important strategies to synthesise functional nanostructured materials and highlights how detailed...

  5. Imaging plants dynamics in heterogenic environments.

    Science.gov (United States)

    Fiorani, Fabio; Rascher, Uwe; Jahnke, Siegfried; Schurr, Ulrich

    2012-04-01

    Noninvasive imaging sensors and computer vision approaches are key technologies to quantify plant structure, physiological status, and performance. Today, imaging sensors exploit a wide range of the electromagnetic spectrum, and they can be deployed to measure a growing number of traits, also in heterogenic environments. Recent advances include the possibility to acquire high-resolution spectra by imaging spectroscopy and classify signatures that might be informative of plant development, nutrition, health, and disease. Three-dimensional (3D) reconstruction of surfaces and volume is of particular interest, enabling functional and mechanistic analyses. While taking pictures is relatively easy, quantitative interpretation often remains challenging and requires integrating knowledge of sensor physics, image analysis, and complex traits characterizing plant phenotypes.

  6. Variability of Contact Process in Complex Networks

    CERN Document Server

    Gong, Kai; Yang, Hui; Shang, Mingsheng; 10.1063/1.3664403

    2012-01-01

    We study numerically how the structures of distinct networks influence the epidemic dynamics in contact process. We first find that the variability difference between homogeneous and heterogeneous networks is very narrow, although the heterogeneous structures can induce the lighter prevalence. Contrary to non-community networks, strong community structures can cause the secondary outbreak of prevalence and two peaks of variability appeared. Especially in the local community, the extraordinarily large variability in early stage of the outbreak makes the prediction of epidemic spreading hard. Importantly, the bridgeness plays a significant role in the predictability, meaning the further distance of the initial seed to the bridgeness, the less accurate the predictability is. Also, we investigate the effect of different disease reaction mechanisms on variability, and find that the different reaction mechanisms will result in the distinct variabilities at the end of epidemic spreading.

  7. Integration and publication of heterogeneous text-mined relationships on the Semantic Web.

    Science.gov (United States)

    Coulet, Adrien; Garten, Yael; Dumontier, Michel; Altman, Russ B; Musen, Mark A; Shah, Nigam H

    2011-05-17

    Advances in Natural Language Processing (NLP) techniques enable the extraction of fine-grained relationships mentioned in biomedical text. The variability and the complexity of natural language in expressing similar relationships causes the extracted relationships to be highly heterogeneous, which makes the construction of knowledge bases difficult and poses a challenge in using these for data mining or question answering. We report on the semi-automatic construction of the PHARE relationship ontology (the PHArmacogenomic RElationships Ontology) consisting of 200 curated relations from over 40,000 heterogeneous relationships extracted via text-mining. These heterogeneous relations are then mapped to the PHARE ontology using synonyms, entity descriptions and hierarchies of entities and roles. Once mapped, relationships can be normalized and compared using the structure of the ontology to identify relationships that have similar semantics but different syntax. We compare and contrast the manual procedure with a fully automated approach using WordNet to quantify the degree of integration enabled by iterative curation and refinement of the PHARE ontology. The result of such integration is a repository of normalized biomedical relationships, named PHARE-KB, which can be queried using Semantic Web technologies such as SPARQL and can be visualized in the form of a biological network. The PHARE ontology serves as a common semantic framework to integrate more than 40,000 relationships pertinent to pharmacogenomics. The PHARE ontology forms the foundation of a knowledge base named PHARE-KB. Once populated with relationships, PHARE-KB (i) can be visualized in the form of a biological network to guide human tasks such as database curation and (ii) can be queried programmatically to guide bioinformatics applications such as the prediction of molecular interactions. PHARE is available at http://purl.bioontology.org/ontology/PHARE.

  8. Communicating to heterogeneous target groups

    DEFF Research Database (Denmark)

    Pedersen, Karsten

    very often have to communicate to rather heterogeneous target groups that have little more in common than a certain geographical habitat. That goes against most schoolbook teaching in the field of communication, but is none the less the terms with which that kind of communication has to live...

  9. Dynamic heterogeneity and life histories

    DEFF Research Database (Denmark)

    Tuljapurkar, Shripad; Steiner, Uli

    2010-01-01

    of the variation among individual characteristics that is generated by dynamic heterogeneity. We conclude by discussing our ongoing and planned work on animals and humans. We also discuss the connections between our work and recent work on human mortality, disability and health, and life course theory....

  10. Social Capital and Community Heterogeneity

    Science.gov (United States)

    Coffe, Hilde

    2009-01-01

    Recent findings indicate that more pronounced community heterogeneity is associated with lower levels of social capital. These studies, however, concentrate on specific aspects in which people differ (such as income inequality or ethnic diversity). In the present paper, we introduce the number of parties in the local party system as a more…

  11. Social capital and community heterogeneity

    NARCIS (Netherlands)

    Coffé, Hilde R.

    2009-01-01

    Abstract Recent findings indicate that more pronounced community heterogeneity is associated with lower levels of social capital. These studies, however, concentrate on specific aspects in which people differ (such as income inequality or ethnic diversity). In the present paper, we introduce the

  12. Prices and heterogeneous search costs

    NARCIS (Netherlands)

    Luis Moraga-Gonzalez, Jose; Sandor, Zsolt; Wildenbeest, Matthijs R.

    2017-01-01

    We study price formation in a model of consumer search for differentiated products in which consumers have heterogeneous search costs. We provide conditions under which a pure-strategy symmetric Nash equilibrium exists and is unique. Search costs affect two margins-the intensive search margin (or se

  13. Floodplain heterogeneity and meander migration

    Science.gov (United States)

    The impact of horizontal heterogeneity of floodplain soils on rates and patterns of meander migration is analyzed with a Ikeda et al. (1981)-type model for hydrodynamics and bed morphodynamics, coupled with a physically-based bank erosion model according to the approach developed by Motta et al. (20...

  14. Formation of Rationally Heterogeneous Expectations

    NARCIS (Netherlands)

    Pfajfar, D.

    2012-01-01

    Abstract: This paper models expectation formation by taking into account that agents produce heterogeneous expectations due to model uncertainty, informational frictions and different capacities for processing information. We show that there are two general classes of steady states within this frame

  15. Heterogeneous catalysis through microcontact printing

    NARCIS (Netherlands)

    Spruell, Jason M.; Sheriff, Bonnie A.; Rozkiewicz, D.I.; Dichtel, William R.; Rohde, Rosemary D.; Reinhoudt, David; Stoddart, Fraser; Heath, James R.

    2008-01-01

    Minting a Stamp: The preparation of copper metal-coated elastomeric stamps and their use in catalyzing the Cu-catalyzed azide-alkyne cycloaddition reaction heterogeneously through microcontact printing is described. This StampCat process is compared to other conventional surface-functionalization te

  16. Surface science of heterogeneous reactions.

    Science.gov (United States)

    White, J M

    1982-10-29

    Some of the present and future directions for surface science as a growing and naturally interdisciplinary subject are reviewed. Particular attention is given to surface reaction chemistry as it is related to heterogenous catalysis, a subject area where there are abundant opportunities for detailed measurements of structure and dynamics at the molecular level.

  17. Influence of bed material size heterogeneity on bedload transport uncertainty

    Science.gov (United States)

    Chen, Li; Stone, Mark C.

    2008-01-01

    The bed material grain size distribution of gravel bed streams is often spatially heterogeneous. The heterogeneity is actually a random parameter, even for a "well-mixed mixture," which potentially causes the transport rate for a given bed material to become an uncertain variable. The cause of bed material heterogeneity is the nonuniformity of the bed material, which is analyzed in this paper using examples from field observations and experimental data. The Monte Carlo simulation method is applied to study the uncertainty of the bedload transport rate using Wilcock's experimental data (P. R. Wilcock et al., 2001; P. R. Wilcock and J. C. Crowe, 2003). Each realization of the Monte Carlo simulation employed a randomly generated grain size distribution field for the entire simulation domain. With sufficient realizations the simulation results were adequate to show that the transport rates were a random variable and the mean transport rates did not fall on a single-valued curve when the local heterogeneity was taken into account. The results indicate that the bedload transport rate of nonuniform sediment has an intrinsic uncertainty that can result solely from the bed material. The results also partially account for the scatter of the fractional transport rate within Wilcock's experimental data. This study presents an important concept in understanding the uncertainty associated with estimates of sediment transport.

  18. Bifurcation of equilibrium points in the potential of heterogeneous Itokawa

    Science.gov (United States)

    Lan, L.; Wang, X.; Baoyin, H.; Li, J.

    2017-09-01

    The bifurcation of equilibrium points in the potential of heterogeneous 25143 Itokawa is investigated in this paper. First, we introduce a method improving upon the conventional polyhedral method to model a heterogeneous asteroid based on the process of disassembly and re-combination. Secondly, we compare the equilibrium points and zero-velocity curves of the homogeneous and heterogeneous cases. Moreover, a variable bulk density ratio δ of two regions is introduced to investigate the evolution of the equilibrium points. It is found that the number of equilibrium points experiences two changes when the ratio varies from 1 to 2.5. Specifically, a new pair of equilibrium points appears at a ratio δ1 = 1.5036, and another pair merges and then disappears at a ratio δ2 = 2.1785. Therefore, the number of equilibrium points changes from five to seven and then returns to five with increasing ratio δ. The topological structure of the equilibrium points is also investigated to achieve a better understanding of the dynamic environment around a heterogeneous body. An in-depth study of the positions and stabilities of the equilibrium points outside may facilitate a better choice of orbits in missions near heterogeneous bodies. Moreover, the investigation of the equilibrium points inside may reflect the internal structure and pressure of the body in a different manner than in the homogeneous case.

  19. Spatial variability of sedimentary interbed properties near the Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory, Idaho

    Science.gov (United States)

    Winfield, Kari A.

    2003-01-01

    The subsurface at the Idaho National Engineering and Environmental Laboratory (INEEL) is complex, comprised primarily of thick, fractured basalt flows interbedded with thinner sedimentary intervals. The unsaturated zone can be as thick as 200 m in the southwestern part of the INEEL. The Vadose Zone Research Park (VZRP), located approximately 10 km southwest of the Idaho Nuclear Technology and Engineering Center (INTEC), was established in 2001 to study the subsurface of a relatively undisturbed part of the INEEL. Waste percolation ponds for the INTEC were relocated to the VZRP due to concerns that perched water within the vadose zone under the original infiltration ponds (located immediately south of the INTEC) could contribute to migration of contaminants to the Snake River Plain aquifer. Knowledge of the spatial distribution of texture and hydraulic properties is important for developing a better understanding of subsurface flow processes within the interbeds, for example, by identifying low permeability layers that could lead to the formation of perched ground-water zones. Because particle-size distributions are easier to measure than hydraulic properties, particle size serves as an analog for determining how the unsaturated hydraulic properties vary both vertically within particular interbeds and laterally within the VZRP. As part of the characterization program for the subsurface at the VZRP, unsaturated and saturated hydraulic properties were measured on 10 core samples from six boreholes. Bulk properties, including particle size, bulk density, particle density, and specific surface area, were determined on material from the same depth intervals as the core samples, with an additional 66 particle- size distributions measured on bulk samples from the same boreholes. From lithologic logs of the 32 boreholes at the VZRP, three relatively thick interbeds (in places up to 10 m thick) were identified at depths of 35, 45, and 55 m below land surface. The 35-m

  20. Discussion on the Construction Technology of Variable Cross-section Hollow Thin-walled Pier%浅谈变截面空心薄壁方墩施工技术

    Institute of Scientific and Technical Information of China (English)

    陈显福

    2014-01-01

    Variable cross-section hol ow thin-walled pier has the obvious superiority and good economy, and can use less material to obtain larger sectional resistance moment which is often used by mountain bridge engineering. Taking the Yujiagou1# bridge as the example, this article introduces the construction technology of variable cross-section hol ow thin-wal ed pier, and provides reference for similar engineering construction.%变截面空心薄壁方墩具有明显的优越性和较好的经济性,可以用较少的材料获取较大的截面抵抗矩,这种技术常常被山区、深沟建桥的工程所采用。本文以余家沟1号大桥为例,介绍了变截面空心薄壁方墩施工技术,可为类似工程施工提供借鉴。

  1. 基于中间技术的保障性住宅可变多适性设计方法%Design pointing on Variable adaptability of Indemnificatory Housing-Based on Intermediate technology

    Institute of Scientific and Technical Information of China (English)

    周曦; 张芳

    2014-01-01

    Nowadays plenty of Indemnificatory Houses in smal Huxing have been build in China. For variable needs of the users and the adaptability for future upgrade, the house type of Indemnificatory Housing should base on the existing condition, develop and use the Intermediate technology to achieve variable adaptability. The inside of the apartment design may focus on the living room, leaving kitchen and dinning room mix the rest area, moreover, toilet and bathroom can be adapted with simple technical facilities, and the entire apartment spatial ar angement can be organized with gal ery. The public sector should also leave feasibility for future adaptability.%近年来我国建设了大量小套型保障性住宅。为了适应住户的多样化需求和未来升级改造的需要,保障性住宅套型设计中应结合目前条件,发展中间技术实现有限的可变多适性设计。套型内以居室空间为主,餐厨空间融合,卫浴设施采用简单的技术措施实现可调节;套间组合宜采用简单统一的通廊形式。此外公共部分还应留有升级改造空间。

  2. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  3. The Adoption of Business to Business E-Commerce: Heterogeneity and Network Externality Effects

    OpenAIRE

    Bonaccorsi, Andrea; Rossi, Cristina

    2002-01-01

    The decision to adopt e-commerce technology depends on a variety of variables. This paper explores the relative importance of structural firm-specific variables, the intrinsic value of the technology, expectations concerning the evolution of the technology, and the adoption behaviour of other agents. Almost all variables pertaining to the conventional structure of firms, including size, and the value of technology, are found to have no importance in the adoption decision, whereas the expected...

  4. Tripod of Requirements in Horizontal Heterogeneous Mobile Cloud Computing

    CERN Document Server

    Sanaei, Zohreh; Gani, Abdullah; Khokhar, Rashid Hafeez

    2012-01-01

    Recent trend of mobile computing is emerging toward executing resource-intensive applications in mobile devices regardless of underlying resource restrictions (e.g. limited processor and energy) that necessitate imminent technologies. Prosperity of cloud computing in stationary computers breeds Mobile Cloud Computing (MCC) technology that aims to augment computing and storage capabilities of mobile devices besides conserving energy. However, MCC is more heterogeneous and unreliable (due to wireless connectivity) compare to cloud computing. Problems like variations in OS, data fragmentation, and security and privacy discourage and decelerate implementation and pervasiveness of MCC. In this paper, we describe MCC as a horizontal heterogeneous ecosystem and identify thirteen critical metrics and approaches that influence on mobile-cloud solutions and success of MCC. We divide them into three major classes, namely ubiquity, trust, and energy efficiency and devise a tripod of requirements in MCC. Our proposed trip...

  5. Identifying the influential aquifer heterogeneity factor on nitrate reduction processes by numerical simulation

    Science.gov (United States)

    Jang, E.; He, W.; Savoy, H.; Dietrich, P.; Kolditz, O.; Rubin, Y.; Schüth, C.; Kalbacher, T.

    2017-01-01

    Nitrate reduction reactions in groundwater systems are strongly influenced by various aquifer heterogeneity factors that affect the transport of chemical species, spatial distribution of redox reactive substances and, as a result, the overall nitrate reduction efficiency. In this study, we investigated the influence of physical and chemical aquifer heterogeneity, with a focus on nitrate transport and redox transformation processes. A numerical modeling study for simulating coupled hydrological-geochemical aquifer heterogeneity was conducted in order to improve our understanding of the influence of the aquifer heterogeneity on the nitrate reduction reactions and to identify the most influential aquifer heterogeneity factors throughout the simulation. Results show that the most influential aquifer heterogeneity factors could change over time. With abundant presence of electron donors in the high permeable zones (initial stage), physical aquifer heterogeneity significantly influences the nitrate reduction since it enables the preferential transport of nitrate to these zones and enhances mixing of reactive partners. Chemical aquifer heterogeneity plays a comparatively minor role. Increasing the spatial variability of the hydraulic conductivity also increases the nitrate removal efficiency of the system. However, ignoring chemical aquifer heterogeneity can lead to an underestimation of nitrate removals in long-term behavior. With the increase of the spatial variability of the electron donor, i.e. chemical heterogeneity, the number of the "hot spots" i.e. zones with comparably higher reactivity, should also increase. Hence, nitrate removal efficiencies will also be spatially variable but overall removal efficiency will be sustained if longer time scales are considered and nitrate fronts reach these high reactivity zones.

  6. Generalized Method for Sampling Spatially Correlated Heterogeneous Speckled Imagery

    Directory of Open Access Journals (Sweden)

    Alejandro C. Frery

    2001-06-01

    Full Text Available This paper presents a general result for the simulation of correlated heterogeneous targets, which are present in images corrupted by speckle noise. This technique is based on the use of a correlation mask and Gaussian random variables, in order to obtain spatially dependent Gamma deviates. These Gamma random variables, in turn, allow the obtainment of correlated 𝒦 deviates with specified correlation structure. The theoretical properties of the procedure are presented, along with the corresponding algorithm.

  7. Rate heterogeneity in the evolution of Helicobacter pylori and the behavior of homoplasious sites

    Science.gov (United States)

    Helicobacter pylori are bacteria with substantial strain-to-strain variability. Although frequent recombination events have been proposed as contributing to the variability, the effects of nucleotide substitution rate heterogeneities on the reconstruction of H. pylori genealogies have not been stud...

  8. A Unified Access Model for Interconnecting Heterogeneous Wireless Networks

    Science.gov (United States)

    2015-05-01

    with each other via a central controller. The 2 access technologies used were 802.11 ( WiFi ) and a Carrier-Sense Multiple Access (CSMA) protocol ...wireless subnets could communicate with each other. 3. Results and Discussion Using the 3-VM LTE/ WiFi configuration, we placed a User Datagram Protocol ...control plane protocols . A network model that can abstract disparate MAC layers in heterogeneous networks and interconnect them using a unified and

  9. Proportional Fair Traffic Splitting and Aggregation in Heterogeneous Wireless Networks

    OpenAIRE

    2015-01-01

    Traffic load balancing and resource allocation is set to play a crucial role in leveraging the dense and increasingly heterogeneous deployment of multi-radio wireless networks. Traffic aggregation across different access points (APs)/radio access technologies (RATs) has become an important feature of recently introduced cellular standards on LTE dual connectivity and LTE-WLAN aggregation (LWA). Low complexity traffic splitting solutions for scenarios where the APs are not necessarily collocat...

  10. Lyophobic heterogeneous system (LHS) application to payload comfort

    OpenAIRE

    Michelin-Jamois, Millán

    2014-01-01

    Competition in aerospace industry forces to follow a constant evolution of technologies linked to launching costs decreasing and reliability increasing. An improvement of payload protection systems is a way to achieve these conditions. The main issue of this PhD thesis is to verify the applicability of lyophobic heterogeneous systems (association of a nanoporous material and a non- wetting liquid) in vibrations damping for payload comfort. Intrusion of liquid in LH S requires a high mechanica...

  11. Applicable or non-applicable: investigations of clinical heterogeneity in systematic reviews

    Directory of Open Access Journals (Sweden)

    Laura E. Chess

    2016-02-01

    Full Text Available Abstract Background Clinical heterogeneity can be defined as differences in participant characteristics, types or timing of outcome measurements and intervention characteristics. Clinical heterogeneity in systematic reviews has the possibility to significantly affect statistical heterogeneity leading to inaccurate conclusions and misled decision making. The aim of this study is to identify to what extent investigators are assessing clinical heterogeneity in both Cochrane and non-Cochrane systematic reviews. Methods The most recent 100 systematic reviews from the top five journals in medicine—JAMA, Archives of Internal Medicine, British Medical Journal, The Lancet, and PLOS Medicine—and the 100 most recently published and/or updated systematic reviews from Cochrane were collected. Various defined items of clinical heterogeneity were extracted from the included reviews. Investigators used chi-squared tests, logarithmic modeling and linear regressions to determine if the presence of such items served as a predictor for clinical heterogeneity when comparing Cochrane to non-Cochrane reviews. Extracted variables include number of studies, number of participants, presence of quantitative synthesis, exploration of clinical heterogeneity, heterogeneous characteristics explored, basis and methods used for investigating clinical heterogeneity, plotting/visual aids, author contact, inferences from clinical heterogeneity investigation, reporting assessment, and the presence of a priori or post-hoc analysis. Results A total of 317 systematic reviews were considered, of which 199 were in the final analysis. A total of 81 % of Cochrane reviews and 90 % of non-Cochrane reviews explored characteristics that are considered aspects of clinical heterogeneity and also described the methods they planned to use to investigate the influence of those characteristics. Only 1 % of non-Cochrane reviews and 8 % of Cochrane reviews explored the clinical

  12. Unobserved Heterogeneity in the Binary Logit Model with Cross-Sectional Data and Short Panels

    DEFF Research Database (Denmark)

    Holm, Anders; Jæger, Mads Meier; Pedersen, Morten

    This paper proposes a new approach to dealing with unobserved heterogeneity in applied research using the binary logit model with cross-sectional data and short panels. Unobserved heterogeneity is particularly important in non-linear regression models such as the binary logit model because, unlike...... in linear regression models, estimates of the effects of observed independent variables are biased even when omitted independent variables are uncorrelated with the observed independent variables. We propose an extension of the binary logit model based on a finite mixture approach in which we conceptualize...

  13. Seepage Anisotropy of Heterogeneous Body

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ore dumps are heterogeneous bodies with anisotropic seepage characteristics because of the ore segregation.In an indoor experiment, a dump was constructed with three strata, where the horizontal and vertical seepage experiments were carried out.Horizontals flow are regarded as phreatic plan flows without penetration.Its seepage law satifies the Dupuit equation.With parallel lay seepage model, the equivalent seepage coefficient in the horizontal flow was obtained and was equivalent to the weighted mean of the seepage coefficient of each stratum.An unsaturated flow appeared in the vertical experiment, with a hydraulic gradient of 1.The vertical flow was equivalent to the seepage model that moved in vertical bedding; its equivalent seepage coefficient depended on the stratum with the minimum seepage coefficient.That the experiment showed clear anisotropy in a heterogeneous body was obvious with an anisotropic coefficient between 63 and 155, which is 25 to 100 times larger than that of a homogeneous body.

  14. Biodiesel production using heterogeneous catalysts.

    Science.gov (United States)

    Semwal, Surbhi; Arora, Ajay K; Badoni, Rajendra P; Tuli, Deepak K

    2011-02-01

    The production and use of biodiesel has seen a quantum jump in the recent past due to benefits associated with its ability to mitigate greenhouse gas (GHG). There are large number of commercial plants producing biodiesel by transesterification of vegetable oils and fats based on base catalyzed (caustic) homogeneous transesterification of oils. However, homogeneous process needs steps of glycerol separation, washings, very stringent and extremely low limits of Na, K, glycerides and moisture limits in biodiesel. Heterogeneous catalyzed production of biodiesel has emerged as a preferred route as it is environmentally benign needs no water washing and product separation is much easier. The present report is review of the progress made in development of heterogeneous catalysts suitable for biodiesel production. This review shall help in selection of suitable catalysts and the optimum conditions for biodiesel production.

  15. Heterogeneity of intracellular polymer storage states in enhanced biological phosphorus removal (EBPR)--observation and modeling.

    Science.gov (United States)

    Bucci, Vanni; Majed, Nehreen; Hellweger, Ferdi L; Gu, April Z

    2012-03-20

    A number of agent-based models (ABMs) for biological wastewater treatment processes have been developed, but their skill in predicting heterogeneity of intracellular storage states has not been tested against observations due to the lack of analytical methods for measuring single-cell intracellular properties. Further, several mechanisms can produce and maintain heterogeneity (e.g., different histories, uneven division) and their relative importance has not been explored. This article presents an ABM for the enhanced biological phosphorus removal (EBPR) treatment process that resolves heterogeneity in three intracellular polymer storage compounds (i.e., polyphosphate, polyhydroxybutyrate, and glycogen) in three functional microbial populations (i.e., polyphosphate-accumulating, glycogen-accumulating, and ordinary heterotrophic organisms). Model predicted distributions were compared to those based on single-cell estimates obtained using a Raman microscopy method for a laboratory-scale sequencing batch reactor (SBR) system. The model can reproduce many features of the observed heterogeneity. Two methods for introducing heterogeneity were evaluated. First, biological variability in individual cell behavior was simulated by randomizing model parameters (e.g., maximum acetate uptake rate) at division. This method produced the best fit to the data. An optimization algorithm was used to determine the best variability (i.e., coefficient of variance) for each parameter, which suggests large variability in acetate uptake. Second, biological variability in individual cell states was simulated by randomizing state variables (e.g., internal nutrient) at division, which was not able to maintain heterogeneity because the memory in the internal states is too short. These results demonstrate the ability of ABM to predict heterogeneity and provide insights into the factors that contribute to it. Comparison of the ABM with an equivalent population-level model illustrates the effect

  16. Surface fluxes in heterogeneous landscape

    Energy Technology Data Exchange (ETDEWEB)

    Bay Hasager, C.

    1997-01-01

    The surface fluxes in homogeneous landscapes are calculated by similarity scaling principles. The methodology is well establish. In heterogeneous landscapes with spatial changes in the micro scale range, i e from 100 m to 10 km, advective effects are significant. The present work focus on these effects in an agricultural countryside typical for the midlatitudes. Meteorological and satellite data from a highly heterogeneous landscape in the Rhine Valley, Germany was collected in the large-scale field experiment TRACT (Transport of pollutants over complex terrain) in 1992. Classified satellite images, Landsat TM and ERS SAR, are used as basis for roughness maps. The roughnesses were measured at meteorological masts in the various cover classes and assigned pixel by pixel to the images. The roughness maps are aggregated, i e spatially averaged, into so-called effective roughness lengths. This calculation is performed by a micro scale aggregation model. The model solves the linearized atmospheric flow equations by a numerical (Fast Fourier Transform) method. This model also calculate maps of friction velocity and momentum flux pixel wise in heterogeneous landscapes. It is indicated how the aggregation methodology can be used to calculate the heat fluxes based on the relevant satellite data i e temperature and soil moisture information. (au) 10 tabs., 49 ills., 223 refs.

  17. Analyzing and modeling heterogeneous behavior

    Science.gov (United States)

    Lin, Zhiting; Wu, Xiaoqing; He, Dongyue; Zhu, Qiang; Ni, Jixiang

    2016-05-01

    Recently, it was pointed out that the non-Poisson statistics with heavy tail existed in many scenarios of human behaviors. But most of these studies claimed that power-law characterized diverse aspects of human mobility patterns. In this paper, we suggest that human behavior may not be driven by identical mechanisms and can be modeled as a Semi-Markov Modulated Process. To verify our suggestion and model, we analyzed a total of 1,619,934 records of library visitations (including undergraduate and graduate students). It is found that the distribution of visitation intervals is well fitted with three sections of lines instead of the traditional power law distribution in log-log scale. The results confirm that some human behaviors cannot be simply expressed as power law or any other simple functions. At the same time, we divided the data into groups and extracted period bursty events. Through careful analysis in different groups, we drew a conclusion that aggregate behavior might be composed of heterogeneous behaviors, and even the behaviors of the same type tended to be different in different period. The aggregate behavior is supposed to be formed by "heterogeneous groups". We performed a series of experiments. Simulation results showed that we just needed to set up two states Semi-Markov Modulated Process to construct proper representation of heterogeneous behavior.

  18. Viscosity-Modification to Improve Remediation Efficiencies within Heterogeneous Contaminated Groundwater Aquifers: Laboratory and Field-Scale Evaluation

    Science.gov (United States)

    Silva, J. A.; Crimi, M.

    2013-12-01

    A key challenge in in situ groundwater remediation practice is achieving efficient contact between the injected remedial fluid and the target contamination in the presence of subsurface permeability heterogeneities. Even apparently small permeability contrasts can affect the delivery and subsurface distribution of injected remedial fluids, as a result of preferential flows, and reduce treatment effectiveness as a result of bypassing of contaminated media of lower permeability. Viscosity-modification is a technique that can be used to mitigate the effects of permeability heterogeneity and improve the delivery and distribution of remediation fluids during subsurface injection. Viscosity-modification involves increasing the viscosity of the injected fluid, and modifying the fluids rheological character in some cases. The increased viscosity provides a reduced fluid mobility condition within higher permeability media that, in turn, enhances the penetration of fluids into adjacent lower permeability media, improving the overall sweep efficiency within heterogeneous geomedia. Herein, we present the results of laboratory (two-dimensional flow tank) and numerical experiments that were designed to critically evaluate the utility of viscosity-modification for groundwater remediation application. Specifically, we will address the benefits and limitations of the approach and highlight the effect of system variables on the degree sweep efficiency improvement achievable. We also present the results of a recently completed Environmental Security Technology Certification Program (ESTCP) technology validation project in which viscosity-modification was applied to permanganate in situ chemical oxidation. Site selection criteria, implementation design considerations, and the long-term effects of viscosity-modified fluid treatments will be discussed.

  19. Heterogeneous MEMS device assembly and integration

    Science.gov (United States)

    Topart, Patrice; Picard, Francis; Ilias, Samir; Alain, Christine; Chevalier, Claude; Fisette, Bruno; Paultre, Jacques E.; Généreux, Francis; Legros, Mathieu; Lepage, Jean-François; Laverdière, Christian; Ngo Phong, Linh; Caron, Jean-Sol; Desroches, Yan

    2014-03-01

    In recent years, smart phone applications have both raised the pressure for cost and time to market reduction, and the need for high performance MEMS devices. This trend has led the MEMS community to develop multi-die packaging of different functionalities or multi-technology (i.e. wafer) approaches to fabricate and assemble devices respectively. This paper reports on the fabrication, assembly and packaging at INO of various MEMS devices using heterogeneous assembly at chip and package-level. First, the performance of a giant (e.g. about 3 mm in diameter), electrostatically actuated beam steering mirror is presented. It can be rotated about two perpendicular axes to steer an optical beam within an angular cone of up to 60° in vector scan mode with an angular resolution of 1 mrad and a response time of 300 ms. To achieve such angular performance relative to mirror size, the microassembly was performed from sub-components fabricated from 4 different wafers. To combine infrared detection with inertial sensing, an electroplated proof mass was flip-chipped onto a 256×1 pixel uncooled bolometric FPA and released using laser ablation. In addition to the microassembly technology, performance results of packaged devices are presented. Finally, to simulate a 3072×3 pixel uncooled detector for cloud and fire imaging in mid and long-wave IR, the staggered assembly of six 512×3 pixel FPAs with a less than 50 micron pixel co-registration is reported.

  20. Grid heterogeneity in in-silico experiments: an exploration of drug screening using DOCK on cloud environments.

    Science.gov (United States)

    Yim, Wen-Wai; Chien, Shu; Kusumoto, Yasuyuki; Date, Susumu; Haga, Jason

    2010-01-01

    Large-scale in-silico screening is a necessary part of drug discovery and Grid computing is one answer to this demand. A disadvantage of using Grid computing is the heterogeneous computational environments characteristic of a Grid. In our study, we have found that for the molecular docking simulation program DOCK, different clusters within a Grid organization can yield inconsistent results. Because DOCK in-silico virtual screening (VS) is currently used to help select chemical compounds to test with in-vitro experiments, such differences have little effect on the validity of using virtual screening before subsequent steps in the drug discovery process. However, it is difficult to predict whether the accumulation of these discrepancies over sequentially repeated VS experiments will significantly alter the results if VS is used as the primary means for identifying potential drugs. Moreover, such discrepancies may be unacceptable for other applications requiring more stringent thresholds. This highlights the need for establishing a more complete solution to provide the best scientific accuracy when executing an application across Grids. One possible solution to platform heterogeneity in DOCK performance explored in our study involved the use of virtual machines as a layer of abstraction. This study investigated the feasibility and practicality of using virtual machine and recent cloud computing technologies in a biological research application. We examined the differences and variations of DOCK VS variables, across a Grid environment composed of different clusters, with and without virtualization. The uniform computer environment provided by virtual machines eliminated inconsistent DOCK VS results caused by heterogeneous clusters, however, the execution time for the DOCK VS increased. In our particular experiments, overhead costs were found to be an average of 41% and 2% in execution time for two different clusters, while the actual magnitudes of the execution time

  1. 5G heterogeneous networks self-organizing and optimization

    CERN Document Server

    Rong, Bo; Kadoch, Michel; Sun, Songlin; Li, Wenjing

    2016-01-01

    This SpringerBrief provides state-of-the-art technical reviews on self-organizing and optimization in 5G systems. It covers the latest research results from physical-layer channel modeling to software defined network (SDN) architecture. This book focuses on the cutting-edge wireless technologies such as heterogeneous networks (HetNets), self-organizing network (SON), smart low power node (LPN), 3D-MIMO, and more. It will help researchers from both the academic and industrial worlds to better understand the technical momentum of 5G key technologies.

  2. Understanding the consequences of seed dispersal in a heterogeneous environment.

    Science.gov (United States)

    Baythavong, Brooke S; Stanton, Maureen L; Rice, Kevin J

    2009-08-01

    Plant distributions are in part determined by environmental heterogeneity on both large (landscape) and small (several meters) spatial scales. Plant populations can respond to environmental heterogeneity via genetic differentiation between large distinct patches, and via phenotypic plasticity in response to heterogeneity occurring at small scales relative to dispersal distance. As a result, the level of environmental heterogeneity experienced across generations, as determined by seed dispersal distance, may itself be under selection. Selection could act to increase or decrease seed dispersal distance, depending on patterns of heterogeneity in environmental quality with distance from a maternal home site. Serpentine soils, which impose harsh and variable abiotic stress on non-adapted plants, have been partially invaded by Erodium cicutarium in northern California, USA. Using nearby grassland sites characterized as either serpentine or non-serpentine, we collected seeds from dense patches of E. cicutarium on both soil types in spring 2004 and subsequently dispersed those seeds to one of four distances from their maternal home site (0, 0.5, 1, or 10 m). We examined distance-dependent patterns of variation in offspring lifetime fitness, conspecific density, soil availability, soil water content, and aboveground grass and forb biomass. ANOVA revealed a distinct fitness peak when seeds were dispersed 0.5 m from their maternal home site on serpentine patches. In non-serpentine patches, fitness was reduced only for seeds placed back into the maternal home site. Conspecific density was uniformly high within 1 m of a maternal home site on both soils, whereas soil water content and grass biomass were significantly heterogeneous among dispersal distances only on serpentine soils. Structural equation modeling and multigroup analysis revealed significantly stronger direct and indirect effects linking abiotic and biotic variation to offspring performance on serpentine soils than

  3. Wheat Transpiration Response to Soil Heterogeneity

    Science.gov (United States)

    Langensiepen, M.; Kupisch, M.; Cai, G.; Vanderborght, J.; Stadler, A.; Hüging, H.; Ewert, F.

    2014-12-01

    Measuring sap-flow in thin wheat tillers has been difficult so far due to technical difficulties associated with the application of the heat-balance method for this purpose. We developed a new method which solved this problem (Langensiepen et al. 2014) and applied it during four consecutive vegetation seasons for determining tiller transpiration rates in a wheat field with strong soil heterogeneity. The transpiration rates differed insignificantly between different field sections characterized by strong differences in physical soil conditions, regardless whether the crop was irrigated or supplied with variable rainwater. Tiller transpiration in a sheltered section was slightly reduced. Maximum leaf vapor conductance didn't differ among these different conditions, except under severe water stress conditions. Leaf water potential varied considerably during daily cycles under all circumstances. These responses are typical for plants with anisohydric behaviors which are characterized by small sensitivities of guard cells to critical leaf water potential thresholds and high photosynthetic productivity under absent or mild water stress. Recent studies conducted in Eucalyptus, tomato, and Arabidopsis plants have shown that the transition from mild to severe stress in anisohydric plants is marked by an increasing sensitivity of stomatal control to the transpiration rate. The results of this study demonstrate that this also seems to be the case for wheat. This practically implies that the parameterization of models calculating wheat canopy flux responses to soil heterogeneity patterns must not only account for the crop-type specific soil-vegetation pattern interaction under absent or mild stress, but also for additional mechanisms which kick in when water stress becomes severe. Langensiepen, M., Kupisch, M., Graf, A., Schmidt, M., Ewert, F. (2014) Improving the stem heat balance method for determining sap-flow in wheat. Agric. For. Met. 186: 34-42

  4. Transfers in heterogeneous environments; Transferts en milieux heterogenes

    Energy Technology Data Exchange (ETDEWEB)

    Flesselles, J.M. [Saint-Gobain Recherche, 93 - Aubervilliers (France); Gouesbet, G.; Mees, L.; Roze, C.; Girasole, Th.; Grehan, G. [Laboratoire d' Electromagnetisme et Systemes Particulaires (LESP), UMR CNRS 6614, CORIA. Universite de Rouen et INSA de Rouen, 76 - Saint-Etienne du Rouvray (France); Goyheneche, J.M.; Vignoles, G.; Coindreau, O. [Laboratoire des Composites Thermostructuraux (LCTS), UMR 5801, 33 - Pessac (France); Moyne, Ch. [LEMTA (UMR 7563) CNRS-INPL-UHP, 54 - Vandoeuvre les Nancy (France); Coussy, O. [Institut Navier - ENPC, 77 - Marne-la-Vallee (France); Lassabatere, Th. [Electricite de France Les Renardieres, Dept. Materiaux Mecanique des Composants, 77 - Moret sur Loing (France); Tadrist, L. [IUSTI - UMR 6595, 13 - Marseille (France)

    2004-07-01

    This document gathers the articles and transparencies of the invited talks given at the 2004 French congress of thermal engineering about transfers in heterogeneous environment. Content: transfer phenomena in industrial glass furnaces; simple and multiple scattering diagnosis by femto-second pulsed laser: application to particulate diagnoses; thermal modeling of thermo-structural composites; hybrid mixtures theory, average volumic measurement, periodical or stochastic homogenization: advance in scale change processes; thermo-hydro-chemical-mechanical coupling in porous medium: application to young concrete structures and to clay barriers of disposal facilities; transfers and flows in fluidization: recent advances and future challenges. (J.S.)

  5. 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 so

  6. 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 so

  7. Explicit kinetic heterogeneity: mechanistic models for interpretation of labeling data in heterogeneous populations

    Energy Technology Data Exchange (ETDEWEB)

    Ganusov, Vitaly V [Los Alamos National Laboratory

    2008-01-01

    Estimation of division and death rates of lymphocytes in different conditions is vital for quantitative understanding of the immune system. Deuterium, in the form of deuterated glucose or heavy water, can be used to measure rates of proliferation and death of lymphocytes in vivo. Inferring these rates from labeling and delabeling curves has been subject to considerable debate with different groups suggesting different mathematical models for that purpose. We show that the three models that are most commonly used are in fact mathematically identical and differ only in their interpretation of the estimated parameters. By extending these previous models, we here propose a more mechanistic approach for the analysis of data from deuterium labeling experiments. We construct a model of 'kinetic heterogeneity' in which the total cell population consists of many sub-populations with different rates of cell turnover. In this model, for a given distribution of the rates of turnover, the predicted fraction of labeled DNA accumulated and lost can be calculated. Our model reproduces several previously made experimental observations, such as a negative correlation between the length of the labeling period and the rate at which labeled DNA is lost after label cessation. We demonstrate the reliability of the new explicit kinetic heterogeneity model by applying it to artificially generated datasets, and illustrate its usefulness by fitting experimental data. In contrast to previous models, the explicit kinetic heterogeneity model (1) provides a mechanistic way of interpreting labeling data; (2) allows for a non-exponential loss of labeled cells during delabeling, and (3) can be used to describe data with variable labeling length.

  8. Explicit kinetic heterogeneity: mechanistic models for interpretation of labeling data in heterogeneous populations

    Energy Technology Data Exchange (ETDEWEB)

    Ganusov, Vitaly V [Los Alamos National Laboratory

    2008-01-01

    Estimation of division and death rates of lymphocytes in different conditions is vital for quantitative understanding of the immune system. Deuterium, in the form of deuterated glucose or heavy water, can be used to measure rates of proliferation and death of lymphocytes in vivo. Inferring these rates from labeling and delabeling curves has been subject to considerable debate with different groups suggesting different mathematical models for that purpose. We show that the three models that are most commonly used are in fact mathematically identical and differ only in their interpretation of the estimated parameters. By extending these previous models, we here propose a more mechanistic approach for the analysis of data from deuterium labeling experiments. We construct a model of 'kinetic heterogeneity' in which the total cell population consists of many sub-populations with different rates of cell turnover. In this model, for a given distribution of the rates of turnover, the predicted fraction of labeled DNA accumulated and lost can be calculated. Our model reproduces several previously made experimental observations, such as a negative correlation between the length of the labeling period and the rate at which labeled DNA is lost after label cessation. We demonstrate the reliability of the new explicit kinetic heterogeneity model by applying it to artificially generated datasets, and illustrate its usefulness by fitting experimental data. In contrast to previous models, the explicit kinetic heterogeneity model (1) provides a mechanistic way of interpreting labeling data; (2) allows for a non-exponential loss of labeled cells during delabeling, and (3) can be used to describe data with variable labeling length.

  9. Molecular Heterogeneity in Primary Breast Carcinomas and Axillary Lymph Node Metastases Assessed by Genomic Fingerprinting Analysis

    Science.gov (United States)

    Ellsworth, Rachel E; Toro, Allyson L; Blackburn, Heather L; Decewicz, Alisha; Deyarmin, Brenda; Mamula, Kimberly A; Costantino, Nicholas S; Hooke, Jeffrey A; Shriver, Craig D; Ellsworth, Darrell L

    2015-01-01

    Molecular heterogeneity within primary breast carcinomas and among axillary lymph node (LN) metastases may impact diagnosis and confound treatment. In this study, we used short tandem repeated sequences to assess genomic heterogeneity and to determine hereditary relationships among primary tumor areas and regional metastases from 30 breast cancer patients. We found that primary carcinomas were genetically heterogeneous and sampling multiple areas was necessary to adequately assess genomic variability. LN metastases appeared to originate at different time periods during disease progression from different sites of the primary tumor and the extent of genomic divergence among regional metastases was associated with a less favorable patient outcome (P = 0.009). In conclusion, metastasis is a complex process influenced by primary tumor heterogeneity and variability in the timing of dissemination. Genomic variation in primary breast tumors and regional metastases may negatively impact clinical diagnostics and contribute to therapeutic resistance. PMID:26279627

  10. [Effects of spatial heterogeneity on spatial extrapolation of sampling plot data].

    Science.gov (United States)

    Liang, Yu; He, Hong-Shi; Hu, Yuan-Man; Bu, Ren-Cang

    2012-01-01

    By using model combination method, this paper simulated the changes of response variable (tree species distribution area at landscape level under climate change) under three scenarios of environmental spatial heterogeneous level, analyzed the differentiation of simulated results under different scenarios, and discussed the effects of environmental spatial heterogeneity on the larger spatial extrapolation of the tree species responses to climate change observed in sampling plots. For most tree species, spatial heterogeneity had little effects on the extrapolation from plot scale to class scale; for the tree species insensitive to climate warming and the azonal species, spatial heterogeneity also had little effects on the extrapolation from plot-scale to zonal scale. By contrast, for the tree species sensitive to climate warming, spatial heterogeneity had effects on the extrapolation from plot scale to zonal scale, and the effects could be varied under different scenarios.

  11. Cognitive heterogeneity in Williams syndrome.

    Science.gov (United States)

    Porter, Melanie A; Coltheart, Max

    2005-01-01

    This study used the Woodcock-Johnson Tests of Cognitive Ability-Revised to investigate a wide range of cognitive abilities in people with Williams syndrome (WS). It involved a comparatively large sample of 31 people with WS, but took a case-series approach. The study addressed the widespread claims of a characteristic "WS cognitive profile" by looking for heterogeneity rather than homogeneity. People with WS showed a variety of preserved (significantly above mental age [MA]), expected (at MA), and significantly impaired (significantly below MA) levels of functioning. Such results provide clear evidence for heterogeneity in cognitive functions within WS. We found the most homogeneity on a test of phonological processing and a test of phonological short-term memory, with half of the WS sample performing at MA levels on these tests. Interestingly, no WS individual showed a weakness on a test of nonverbal reasoning, and only one WS individual showed a weakness on a test of verbal comprehension. In addition, we found that strengths on analysis-synthesis and verbal analogies occurred only for WS individuals with an MA less than 5.5 years (our sample median MA); people with an MA greater than 5.5 years performed at MA level on these 2 tests. Results also provided preliminary evidence for distinct subgroups of WS people based on their cognitive strengths and weaknesses on a broad range of cognitive functions. On the basis of the findings, caution should be made in declaring a single cognitive profile that is characteristic of all individuals with WS. Just as there is heterogeneity in genetic and physical anomalies within WS, not all WS individuals share the same cognitive strengths and weaknesses. Also, not all WS individuals show the profile of a strength in verbal abilities and a weakness in spatial functions.

  12. Complex variables

    CERN Document Server

    Taylor, Joseph L

    2011-01-01

    The text covers a broad spectrum between basic and advanced complex variables on the one hand and between theoretical and applied or computational material on the other hand. With careful selection of the emphasis put on the various sections, examples, and exercises, the book can be used in a one- or two-semester course for undergraduate mathematics majors, a one-semester course for engineering or physics majors, or a one-semester course for first-year mathematics graduate students. It has been tested in all three settings at the University of Utah. The exposition is clear, concise, and lively

  13. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  14. Ubiquitous Robotic Technology for Smart Manufacturing System.

    Science.gov (United States)

    Wang, Wenshan; Zhu, Xiaoxiao; Wang, Liyu; Qiu, Qiang; Cao, Qixin

    2016-01-01

    As the manufacturing tasks become more individualized and more flexible, the machines in smart factory are required to do variable tasks collaboratively without reprogramming. This paper for the first time discusses the similarity between smart manufacturing systems and the ubiquitous robotic systems and makes an effort on deploying ubiquitous robotic technology to the smart factory. Specifically, a component based framework is proposed in order to enable the communication and cooperation of the heterogeneous robotic devices. Further, compared to the service robotic domain, the smart manufacturing systems are often in larger size. So a hierarchical planning method was implemented to improve the planning efficiency. A test bed of smart factory is developed. It demonstrates that the proposed framework is suitable for industrial domain, and the hierarchical planning method is able to solve large problems intractable with flat methods.

  15. Ubiquitous Robotic Technology for Smart Manufacturing System

    Directory of Open Access Journals (Sweden)

    Wenshan Wang

    2016-01-01

    Full Text Available As the manufacturing tasks become more individualized and more flexible, the machines in smart factory are required to do variable tasks collaboratively without reprogramming. This paper for the first time discusses the similarity between smart manufacturing systems and the ubiquitous robotic systems and makes an effort on deploying ubiquitous robotic technology to the smart factory. Specifically, a component based framework is proposed in order to enable the communication and cooperation of the heterogeneous robotic devices. Further, compared to the service robotic domain, the smart manufacturing systems are often in larger size. So a hierarchical planning method was implemented to improve the planning efficiency. A test bed of smart factory is developed. It demonstrates that the proposed framework is suitable for industrial domain, and the hierarchical planning method is able to solve large problems intractable with flat methods.

  16. Heterogeneous photocatalysts in organic synthesis

    Science.gov (United States)

    Cherevatskaya, M.; König, B.

    2014-03-01

    The review deals with the application of inorganic semiconductors in organic synthesis. Although the majority of reported reactions still aim at the photocatalytic decomposition of organic compounds, the number of examples in synthetic applications is growing. The principal mechanisms of heterogeneous semiconductor photocatalysis are considered and examples illustrating the use of inorganic semiconductors in organic synthesis are given. The discussion is arranged according to the required excitation wavelength (UV or visible light) and to the new bond that is formed (carbon-carbon or carbon-heteroatom bond). The bibliography includes 47 references.

  17. Computer Aided Design Modeling for Heterogeneous Objects

    CERN Document Server

    Gupta, Vikas; Tandon, Puneet

    2010-01-01

    Heterogeneous object design is an active research area in recent years. The conventional CAD modeling approaches only provide geometry and topology of the object, but do not contain any information with regard to the materials of the object and so can not be used for the fabrication of heterogeneous objects (HO) through rapid prototyping. Current research focuses on computer-aided design issues in heterogeneous object design. A new CAD modeling approach is proposed to integrate the material information into geometric regions thus model the material distributions in the heterogeneous object. The gradient references are used to represent the complex geometry heterogeneous objects which have simultaneous geometry intricacies and accurate material distributions. The gradient references helps in flexible manipulability and control to heterogeneous objects, which guarantees the local control over gradient regions of developed heterogeneous objects. A systematic approach on data flow, processing, computer visualizat...

  18. PL/SQL and Bind Variable: the two ways to increase the efficiency of Network Databases

    Directory of Open Access Journals (Sweden)

    Hitesh KUMAR SHARMA

    2011-12-01

    Full Text Available Modern data analysis applications are driven by the Network databases. They are pushing traditional database and data warehousing technologies beyond their limits due to their massively increasing data volumes and demands for low latency. There are three major challenges in working with network databases: interoperability due to heterogeneous data repositories, proactively due to autonomy of data sources and high efficiency to meet the application demand. This paper provides the two ways to meet the third challenge of network databases. This goal can be achieved by network database administrator with the usage of PL/SQL blocks and bind variable. The paper will explain the effect of PL/SQL block and bind variable on Network database efficiency to meet the modern data analysis application demand.

  19. Effect of heterogeneous investments on the evolution of cooperation in spatial public goods game.

    Science.gov (United States)

    Huang, Keke; Wang, Tao; Cheng, Yuan; Zheng, Xiaoping

    2015-01-01

    Understanding the emergence of cooperation in spatial public goods game remains a grand challenge across disciplines. In most previous studies, it is assumed that the investments of all the cooperators are identical, and often equal to 1. However, it is worth mentioning that players are diverse and heterogeneous when choosing actions in the rapidly developing modern society and researchers have shown more interest to the heterogeneity of players recently. For modeling the heterogeneous players without loss of generality, it is assumed in this work that the investment of a cooperator is a random variable with uniform distribution, the mean value of which is equal to 1. The results of extensive numerical simulations convincingly indicate that heterogeneous investments can promote cooperation. Specifically, a large value of the variance of the random variable can decrease the two critical values for the result of behavioral evolution effectively. Moreover, the larger the variance is, the better the promotion effect will be. In addition, this article has discussed the impact of heterogeneous investments when the coevolution of both strategy and investment is taken into account. Comparing the promotion effect of coevolution of strategy and investment with that of strategy imitation only, we can conclude that the coevolution of strategy and investment decreases the asymptotic fraction of cooperators by weakening the heterogeneity of investments, which further demonstrates that heterogeneous investments can promote cooperation in spatial public goods game.

  20. Preliminary Investigations of Challenges in Dynamic Integration of Heterogeneous Services

    Directory of Open Access Journals (Sweden)

    Makaziwe Makamba

    2016-02-01

    Full Text Available The progress of technology prompted the proliferation of services. Services are distinct, loosely coupled units of functionalities that are self-contained. These services are however developed by various vendors without following appropriate standards. However, the need for interoperability and reusability prompts the need for service integration. Service integration is not a new arena but emphasis is mostly on homogeneous services. However, the challenge lies on the integration of heterogeneous services to enforce reusability and maximize Total Cost of Deployment (TCD and Total Cost of Ownership (TCO at organization level. The issue of service integration has become critical, due to the increase of these diverse services as they have different platforms, architecture and use different programming languages. The current methods of integrating heterogeneous services are manual integration methods. Therefore, the challenge with the current methods is time consumption, lack of flexibility, cost (TCO and TCD, total time to development, because the process is manual. In this paper, we explore the challenges regarding dynamic integration of heterogeneous services and identify key issues that need to be addressed, in order to develop a successful mechanism that will enable dynamic integration of heterogeneous services.

  1. Porting AMG2013 to Heterogeneous CPU+GPU Nodes

    Energy Technology Data Exchange (ETDEWEB)

    Samfass, Philipp [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-01-26

    LLNL's future advanced technology system SIERRA will feature heterogeneous compute nodes that consist of IBM PowerV9 CPUs and NVIDIA Volta GPUs. Conceptually, the motivation for such an architecture is quite straightforward: While GPUs are optimized for throughput on massively parallel workloads, CPUs strive to minimize latency for rather sequential operations. Yet, making optimal use of heterogeneous architectures raises new challenges for the development of scalable parallel software, e.g., with respect to work distribution. Porting LLNL's parallel numerical libraries to upcoming heterogeneous CPU+GPU architectures is therefore a critical factor for ensuring LLNL's future success in ful lling its national mission. One of these libraries, called HYPRE, provides parallel solvers and precondi- tioners for large, sparse linear systems of equations. In the context of this intern- ship project, I consider AMG2013 which is a proxy application for major parts of HYPRE that implements a benchmark for setting up and solving di erent systems of linear equations. In the following, I describe in detail how I ported multiple parts of AMG2013 to the GPU (Section 2) and present results for di erent experiments that demonstrate a successful parallel implementation on the heterogeneous ma- chines surface and ray (Section 3). In Section 4, I give guidelines on how my code should be used. Finally, I conclude and give an outlook for future work (Section 5).

  2. Spatial heterogeneity of ocean surface boundary conditions under sea ice

    Science.gov (United States)

    Barthélemy, Antoine; Fichefet, Thierry; Goosse, Hugues

    2016-06-01

    The high heterogeneity of sea ice properties implies that its effects on the ocean are spatially variable at horizontal scales as small as a few meters. Previous studies have shown that taking this variability into account in models could be required to simulate adequately mixed layer processes and the upper ocean temperature and salinity structures. Although many advanced sea ice models include a subgrid-scale ice thickness distribution, potentially providing heterogeneous surface boundary conditions, the information is lost in the coupling with a unique ocean grid cell underneath. The present paper provides a thorough examination of boundary conditions at the ocean surface in the NEMO-LIM model, which can be used as a guideline for studies implementing subgrid-scale ocean vertical mixing schemes. Freshwater, salt, solar heat and non-solar heat fluxes are examined, as well as the norm of the surface stress. All of the thermohaline fluxes vary considerably between the open water and ice fractions of grid cells. To a lesser extent, this is also the case for the surface stress. Moreover, the salt fluxes in both hemispheres and the solar heat fluxes in the Arctic show a dependence on the ice thickness category, with more intense fluxes for thinner ice, which promotes further subgrid-scale heterogeneity. Our analysis also points out biases in the simulated open water fraction and in the ice thickness distribution, which should be investigated in more details in order to ensure that the latter is used to the best advantage.

  3. Force spectroscopy of complex biopolymers with heterogeneous elasticity

    Science.gov (United States)

    Valdman, David; Lopez, Benjamin J.

    2013-01-01

    Cellular biopolymers can exhibit significant compositional heterogeneities as a result of the non-uniform binding of associated proteins, the formation of microstructural defects during filament assembly, or the imperfect bundling of filaments into composite structures of variable diameter. These can lead to significant variations in the local mechanical properties of biopolymers along their length. Existing spectral analysis methods assume filament homogeneity and therefore report only a single average stiffness for the entire filament. However, understanding how local effects modulate biopolymer mechanics in a spatially resolved manner is essential to understanding how binding and bundling proteins regulate biopolymer stiffness and function in cellular contexts. Here, we present a new method to determine the spatially varying material properties of individual complex biopolymers from the observation of passive thermal fluctuations of the filament conformation. We develop new statistical mechanics-based approaches for heterogeneous filaments that estimate local bending elasticities as a function of the filament arc-length. We validate this methodology using simulated polymers with known stiffness distributions, and find excellent agreement between derived and expected values. We then determine the bending elasticity of microtubule filaments of variable composition generated by repeated rounds of tubulin polymerization using either GTP or GMPCPP, a nonhydrolyzable GTP analog. Again, we find excellent agreement between mechanical and compositional heterogeneities. PMID:24049545

  4. Heterogeneous Transmutation Sodium Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. E. Bays

    2007-09-01

    The threshold-fission (fertile) nature of Am-241 is used to destroy this minor actinide by capitalizing upon neutron capture instead of fission within a sodium fast reactor. This neutron-capture and its subsequent decay chain leads to the breeding of even neutron number plutonium isotopes. A slightly moderated target design is proposed for breeding plutonium in an axial blanket located above the active “fast reactor” driver fuel region. A parametric study on the core height and fuel pin diameter-to-pitch ratio is used to explore the reactor and fuel cycle aspects of this design. This study resulted in both non-flattened and flattened core geometries. Both of these designs demonstrated a high capacity for removing americium from the fuel cycle. A reactivity coefficient analysis revealed that this heterogeneous design will have comparable safety aspects to a homogeneous reactor of comparable size. A mass balance analysis revealed that the heterogeneous design may reduce the number of fast reactors needed to close the current once-through light water reactor fuel cycle.

  5. Immunophenotype Heterogeneity in Nasal Glomangiopericytoma

    Directory of Open Access Journals (Sweden)

    Adriana Handra-Luca

    2015-01-01

    Full Text Available Nasal glomangiopericytoma is rare. The immunophenotype is heterogeneous, more frequently smooth-muscle-actin and CD34-positive. We report expression patterns for several vascular-related proteins such as CD99, CD146, Bcl2, and WT1 as well as for treatment-related proteins such as mTOR and EGFR in a nasal glomangiopericytoma. The patient (woman, 86 years presented with a left nasal tumefaction. The resected specimen (1.5-cm showed a glomangiopericytoma. Tumor cells expressed smooth-muscle-actin, CD31, CD34, and progesterone receptor. They also expressed the vascular-cell-related proteins Bcl2, CD99, CD146, and WT1, as well as mTOR and EGFR. Nasal glomangiopericytomas show immunohistochemical heterogeneity for vascular-related markers, suggesting a possible extensive pericytic differentiation. The expression of potential targets for drug treatments such as mTOR and EGFR may impact on the clinical follow-up of these tumors occurring at advanced ages, which may require complex surgery.

  6. 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...

  7. Technology development and technology gap among Latin American countries

    OpenAIRE

    Serrano Moya, Edgar David

    2014-01-01

    Objective: to study the source of the technology gaps amongst some Latin American countries and to identify whether a regional system of technological progress may be strengthened. ethodology: technology development within some Latin America countries was researched based on the technology frontier concept. In order to do that, the technological advancement of such countries was compared using standard variables and institutional systems. The concept and scope of the technology frontier, whic...

  8. International Migration with Heterogeneous Agents: Theory and Evidence

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Brücker, Herbert

    of German migration stocks and flows since 1967. We find that (i) panel-unit root tests reject the hypothesis that migration flows and the explanatory variables are integrated of the same order, while migration stocks and the explanatory variables are all I(1) variables, and (ii) the hypothesis......Temporary migration, though empirically relevant, is often ignored in formal models. This paper proposes a migration model with heterogeneous agents and persistent cross country income differentials that features temporary migration. In equilibrium there exists a positive relation between the stock...... of migrants and the income differential, while the net migration flow becomes zero. Consequently, existing empirical migration models, estimating net migration flows, instead of stocks, may be misspecified. This suspicion appears to be confirmed by our investigation of the cointegration relationships...

  9. Heterogeneously Catalyzed Endothermic Fuel Cracking

    Science.gov (United States)

    2016-08-28

    T. Zheu, H. Huang (United Technologies Research Center) R. Lobo, D. G. Vlachos, E. Schreiner, T. Forsido, H. Shen (Univ. Delaware ) 5d. PROJECT...University of Delaware , United Technologies Research Center, and the Colorado School of Mines. Models were developed to describe high-pressure...19b. TELEPHONE NUMBER (Include area code) 303-273-3643 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std . Z39.18 Adobe Professional 7.0 Reset

  10. Dynamic heterogeneity and DNA methylation in embryonic stem cells.

    KAUST Repository

    Singer, Zakary S

    2014-07-01

    Cell populations can be strikingly heterogeneous, composed of multiple cellular states, each exhibiting stochastic noise in its gene expression. A major challenge is to disentangle these two types of variability and to understand the dynamic processes and mechanisms that control them. Embryonic stem cells (ESCs) provide an ideal model system to address this issue because they exhibit heterogeneous and dynamic expression of functionally important regulatory factors. We analyzed gene expression in individual ESCs using single-molecule RNA-FISH and quantitative time-lapse movies. These data discriminated stochastic switching between two coherent (correlated) gene expression states and burst-like transcriptional noise. We further showed that the "2i" signaling pathway inhibitors modulate both types of variation. Finally, we found that DNA methylation plays a key role in maintaining these metastable states. Together, these results show how ESC gene expression states and dynamics arise from a combination of intrinsic noise, coherent cellular states, and epigenetic regulation.

  11. Maximum estimates for generalized Forchheimer flows in heterogeneous porous media

    Science.gov (United States)

    Celik, Emine; Hoang, Luan

    2017-02-01

    This article continues the study in [4] of generalized Forchheimer flows in heterogeneous porous media. Such flows are used to account for deviations from Darcy's law. In heterogeneous media, the derived nonlinear partial differential equation for the pressure can be singular and degenerate in the spatial variables, in addition to being degenerate for large pressure gradient. Here we obtain the estimates for the L∞-norms of the pressure and its time derivative in terms of the initial and the time-dependent boundary data. They are established by implementing De Giorgi-Moser's iteration in the context of weighted norms with the weights specifically defined by the Forchheimer equation's coefficient functions. With these weights, we prove suitable weighted parabolic Poincaré-Sobolev inequalities and use them to facilitate the iteration. Moreover, local in time L∞-bounds are combined with uniform Gronwall-type energy inequalities to obtain long-time L∞-estimates.

  12. Climate heterogeneity modulates impact of warming on tropical insects.

    Science.gov (United States)

    Bonebrake, Timothy C; Deutsch, Curtis A

    2012-03-01

    Evolutionary history and physiology mediate species responses to climate change. Tropical species that do not naturally experience high temperature variability have a narrow thermal tolerance compared to similar taxa at temperate latitudes and could therefore be most vulnerable to warming. However, the thermal adaptation of a species may also be influenced by spatial temperature variations over its geographical range. Spatial climate gradients, especially from topography, may also broaden thermal tolerance and therefore act to buffer warming impacts. Here we show that for low-seasonality environments, high spatial heterogeneity in temperature correlates significantly with greater warming tolerance in insects globally. Based on this relationship, we find that climate change projections of direct physiological impacts on insect fitness highlight the vulnerability of tropical lowland areas to future warming. Thus, in addition to seasonality, spatial heterogeneity may play a critical role in thermal adaptation and climate change impacts particularly in the tropics.

  13. Finite mixture varying coefficient models for analyzing longitudinal heterogenous data.

    Science.gov (United States)

    Lu, Zhaohua; Song, Xinyuan

    2012-03-15

    This paper aims to develop a mixture model to study heterogeneous longitudinal data on the treatment effect of heroin use from a California Civil Addict Program. Each component of the mixture is characterized by a varying coefficient mixed effect model. We use the Bayesian P-splines approach to approximate the varying coefficient functions. We develop Markov chain Monte Carlo algorithms to estimate the smooth functions, unknown parameters, and latent variables in the model. We use modified deviance information criterion to determine the number of components in the mixture. A simulation study demonstrates that the modified deviance information criterion selects the correct number of components and the estimation of unknown quantities is accurate. We apply the proposed model to the heroin treatment study. Furthermore, we identify heterogeneous longitudinal patterns.

  14. Adaptable formations utilizing heterogeneous unmanned systems

    Science.gov (United States)

    Barnes, Laura E.; Garcia, Richard; Fields, MaryAnne; Valavanis, Kimon

    2009-05-01

    This paper addresses the problem of controlling and coordinating heterogeneous unmanned systems required to move as a group while maintaining formation. We propose a strategy to coordinate groups of unmanned ground vehicles (UGVs) with one or more unmanned aerial vehicles (UAVs). UAVs can be utilized in one of two ways: (1) as alpha robots to guide the UGVs; and (2) as beta robots to surround the UGVs and adapt accordingly. In the first approach, the UAV guides a swarm of UGVs controlling their overall formation. In the second approach, the UGVs guide the UAVs controlling their formation. The unmanned systems are brought into a formation utilizing artificial potential fields generated from normal and sigmoid functions. These functions control the overall swarm geometry. Nonlinear limiting functions are defined to provide tighter swarm control by modifying and adjusting a set of control variables forcing the swarm to behave according to set constraints. Formations derived are subsets of elliptical curves but can be generalized to any curvilinear shape. Both approaches are demonstrated in simulation and experimentally. To demonstrate the second approach in simulation, a swarm of forty UAVs is utilized in a convoy protection mission. As a convoy of UGVs travels, UAVs dynamically and intelligently adapt their formation in order to protect the convoy of vehicles as it moves. Experimental results are presented to demonstrate the approach using a fully autonomous group of three UGVs and a single UAV helicopter for coordination.

  15. EMERGING TECHNOLOGY BULLETIN: SPOUTED BED REACTOR

    Science.gov (United States)

    The Spouted Bed Reactor (SBR) technology utilizes the unique attributes of the "spouting " fluidization regime, which can provide heat transfer rates comparable to traditional fluid beds, while providing robust circulation of highly heterogeneous solids, concurrent with very agg...

  16. Palladium clusters deposited on the heterogeneous substrates

    Science.gov (United States)

    Wang, Kun; Liu, Juanfang; Chen, Qinghua

    2016-07-01

    To improve the performance of the Pd composite membrane prepared by the cold spraying technology, it is extremely essential to give insights into the deposition process of the cluster and the heterogeneous deposition of the big Pd cluster at the different incident velocities on the atomic level. The deposition behavior, morphologies, energetic and interfacial configuration were examined by the molecular dynamic simulation and characterized by the cluster flattening ratio, the substrate maximum local temperature, the atom-embedded layer number and the surface-alloy formation. According to the morphology evolution, three deposition stages and the corresponding structural and energy evolution were clearly identified. The cluster deformation and penetrating depth increased with the enhancement of the incident velocity, but the increase degree also depended on the substrate hardness. The interfacial interaction between the cluster and the substrate can be improved by the higher substrate local temperature. Furthermore, it is found that the surface alloys were formed by exchanging sites between the cluster and substrate atoms, and the cluster atoms rearranged following as the substrate lattice arrangement from bottom to up in the deposition course. The ability and scope of the structural reconstruction are largely determined by both the size and incident energy of the impacted cluster.

  17. Seamless Mobility in Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Faouzi Zarai

    2010-12-01

    Full Text Available In next generation of wireless networks, different technologies belonging to one or more operators should be integrated to form a heterogeneous environment based on an IP core network infrastructure. This ensures user mobility and service continuity by maintaining connections when switching between varioustechnologies and it introduces new resources and possibilities for applications. In this context, an automatic interface selection based on instantaneous and practical constraints and user preferences (Quality of Service (QoS parameters, available resources, security, power consumption, etc is therefore required. The different network selection and handover schemes proposed in the literature can be classified into three approaches according to who is responsible for making the handover decision: the terminal, the network or thanks to a cooperation between both of them. However, these approaches keep presenting some drawbacks; namely the problem of resources management and network load balancing whenever the selection is controlled by the mobile terminal (MT and the problem of scalability and unknown operator’s management policy whenever the selection is rather controlled by the network. In this article, first we propose a new architecture and new network selection scheme that explicitly take into account the current resource usage and the user preferences. Furthermore, our solution ensures the selection of the most suitable network for each flow while taking into consideration its expectations in terms of QoS. A feasibility study of our architecture is then triggered on a single MT by using typical scenarios and using various algorithms to evaluate their performances.

  18. Modeling Heterogeneity in Networks using Uncertainty Quantification Tools

    CERN Document Server

    Rajendran, Karthikeyan; Siettos, Constantinos I; Laing, Carlo R; Kevrekidis, Ioannis G

    2015-01-01

    Using the dynamics of information propagation on a network as our illustrative example, we present and discuss a systematic approach to quantifying heterogeneity and its propagation that borrows established tools from Uncertainty Quantification. The crucial assumption underlying this mathematical and computational "technology transfer" is that the evolving states of the nodes in a network quickly become correlated with the corresponding node "identities": features of the nodes imparted by the network structure (e.g. the node degree, the node clustering coefficient). The node dynamics thus depend on heterogeneous (rather than uncertain) parameters, whose distribution over the network results from the network structure. Knowing these distributions allows us to obtain an efficient coarse-grained representation of the network state in terms of the expansion coefficients in suitable orthogonal polynomials. This representation is closely related to mathematical/computational tools for uncertainty quantification (th...

  19. Hotsotpots and hot moments; the control of structural heterogeneity on the thermal regime of the peatland soil-atmosphere interface.

    Science.gov (United States)

    Leonard, Rhoswen; Moore, Paul; Kettridge, Nicholas; Krause, Stefan; Devito, Kevin; Waddington, James Michael

    2017-04-01

    Peat surface temperature acts as a master variable driving non-linear terrestrial biogeochemical, ecohydrological, and micrometeorological processes, inducing short-lived extremes or spatially isolated events across heterogeneous peatland surfaces. Changes to ecosystem structure such as canopy removal may change the temperature extremes and spatio-temporal location of these non-linear processes. In order to understand the impact of structural disturbances on peat surface thermal regimes, we simulate how different ecosystem structural layers (i.e. tree layer, lower vascular layer, bryophyte layer, micro topography) influence the spatial and temporal variability of peatland surface temperatures on a carbon rich forested peatland system. Simulations of peat temperatures are validated using more than 1.9 million peat surface temperature measurements across a 10 m2 area of peatland under un-disturbed, trees removed, and lower vascular vegetation removed conditions (through the use of Fibre Optic Distributed Temperature Sensing Technology). The simulations of peat temperature using different structural complexity allows us to determine how ecosystem layers may simplify or complicate surface thermal patterns and promote or dampen temperature extremes. Our study provides important insight into spatial and temporal variability in peatland biogeochemical functioning and the production of hot spots or hot moments in peatland carbon storage or export.

  20. Seamless Data Services for Real Time Communication in a Heterogeneous Networks using Network Tracking and Management

    CERN Document Server

    T, Adiline Macriga

    2010-01-01

    Heterogeneous Networks is the integration of all existing networks under a single environment with an understanding between the functional operations and also includes the ability to make use of multiple broadband transport technologies and to support generalized mobility. It is a challenging feature for Heterogeneous networks to integrate several IP-based access technologies in a seamless way. The focus of this paper is on the requirements of a mobility management scheme for multimedia real-time communication services - Mobile Video Conferencing. Nowadays, the range of available wireless access network technologies includes cellular or wide-area wireless systems, such as cellular networks (GSM/GPRS/UMTS) or Wi-Max, local area Network or personal area wireless systems, comprising for example, WLAN (802.11 a/b/g) and Bluetooth. As the mobile video conferencing is considered, the more advanced mobile terminals are capable of having more than one interface active at the same time. In addition, the heterogeneity ...

  1. Harvesting Information from Heterogeneous Sources

    DEFF Research Database (Denmark)

    2011-01-01

    The abundance of information regarding any topic makes the Internet a very good resource. Even though searching the Internet is very easy, what remains difficult is to automate the process of information extraction from the available online information due to the lack of structure and the diversity...... in the sharing methods. Most of the times, information is stored in different proprietary formats, complying with different standards and protocols which makes tasks like data mining and information harvesting very difficult. In this paper, an information harvesting tool (heteroHarvest) is presented...... with objectives to address these problems by filtering the useful information and then normalizing the information in a singular non hypertext format. We also discuss state of the art tools along with the shortcomings and present the results of an analysis carried out over different heterogeneous formats along...

  2. Emerging heterogeneities in Italian customs

    CERN Document Server

    Agliari, Elena; Galluzzi, Andrea; Javarone, Marco Alberto; Pizzoferrato, Andrea; Tantari, Daniele

    2015-01-01

    Since its unification, more than a century ago, Italy has experienced strong social and economical diversities between its southern and northern regions. In the last decades, Italy has undergone a severe economical and political crisis reflecting corruption at various levels of social stratification as well as a poor involvement of its population in the number of elections that occurred. This might be explained by a lack of confidence, or interest in the country as a whole, as if the primary social and political focus of its citizens could still lay at smaller regional scales, possibly evidencing the persistence of different cultural heritages. In order to shed lights on the possible existence of such heterogeneities, we perform a statistical-mechanics-driven analysis focusing on key social quantifiers, namely the evolution of autochthonous marriages (as family still plays as a fundamental brick in the edification of social aggregates) and of mixed marriages, namely those involving a foreign-born and a native...

  3. Heterogeneous fuel for hybrid rocket

    Science.gov (United States)

    Stickler, David B. (Inventor)

    1996-01-01

    Heterogeneous fuel compositions suitable for use in hybrid rocket engines and solid-fuel ramjet engines, The compositions include mixtures of a continuous phase, which forms a solid matrix, and a dispersed phase permanently distributed therein. The dispersed phase or the matrix vaporizes (or melts) and disperses into the gas flow much more rapidly than the other, creating depressions, voids and bumps within and on the surface of the remaining bulk material that continuously roughen its surface, This effect substantially enhances heat transfer from the combusting gas flow to the fuel surface, producing a correspondingly high burning rate, The dispersed phase may include solid particles, entrained liquid droplets, or gas-phase voids having dimensions roughly similar to the displacement scale height of the gas-flow boundary layer generated during combustion.

  4. Mesoscale poroelasticity of heterogeneous media

    Science.gov (United States)

    Monfared, Siavash; Laubie, Hadrien; Radjai, Farhang; Pellenq, Roland; Ulm, Franz-Josef

    Poroelastic behavior of heterogeneous media is revisited. Lattice Element Method (LEM) is used to model interaction between solid constituents due to a pressurized pore space. Exploring beyond mean-field based theories in continuum microporomechanics, local textural variations and its contribution to the global anisotropic poroelastic behavior of real multiphase porous media are captured. To this end, statistical distributions of mesoscale poroelastic coefficients from numerical simulations on X-ray microscopy scans of two different organic-rich shales with different microtextures are presented. The results are compared with predictions using mean-field based tools of continuum micromechanics. The textural dependency of strain localization and stress chain formation captured in this framework promises a powerful tool for modeling poroelastic response of complex porous composites and a path to incorporate local textural and elastic variations into a continuum description. Visiting Scientist, CNRS-MIT, MIT.

  5. Genetic heterogeneity of hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Unsal, H.; Isselbacher, K.J. (Massachusetts General Hospital Cancer Center, Charlestown, MA (United States)); Yakicier, C.; Marcais, C.; Ozturk, M. (Institut National de la Sante et de la Recherche Medicale, Lyon (France)); Kew, M. (Univ. of Witwatersrand, Johannesburg (South Africa)); Volkmann, M. (Univ. of Heidelberg (Germany)); Zentgraf, H. (Deutsches Krebsforschungszentrum, Heidelberg (Germany))

    1994-01-18

    The authors studied 80 hepatocellular carcinomas from three continents for p53 gene (TP53) mutations and hepatitis B virus (HBV) sequences. p53 mutations were frequent in tumors from Mozambique but not in tumors from South Africa, China, and Germany. Independent of geographic origin, most tumors were positive for HBV sequences. X gene coding sequences of HBV were detected in 78% of tumors, whereas viral sequences in the surface antigen- and core antigen-encoding regions were present in less than 35% of tumors. These observations indicate that hepatocellular carcinomas are genetically heterogeneous. Mozambican-types of hepatocellular carcinomas are characterized by a high incidence of p53 mutations related to aflatoxins. In other tumors, the rarity of p53 mutations combined with the frequent presence of viral X gene coding sequences suggests a possible interference of HBV with the wild-type p53 function.

  6. Operando research in heterogeneous catalysis

    CERN Document Server

    Groot, Irene

    2017-01-01

    This book is devoted to the emerging field of techniques for visualizing atomic-scale properties of active catalysts under actual working conditions, i.e. high gas pressures and high temperatures. It explains how to understand these observations in terms of the surface structures and dynamics and their detailed interplay with the gas phase. This provides an important new link between fundamental surface physics and chemistry, and applied catalysis. The book explains the motivation and the necessity of operando studies, and positions these with respect to the more traditional low-pressure investigations on the one hand and the reality of industrial catalysis on the other. The last decade has witnessed a rapid development of new experimental and theoretical tools for operando studies of heterogeneous catalysis. The book has a strong emphasis on the new techniques and illustrates how the challenges introduced by the harsh, operando conditions are faced for each of these new tools. Therefore, one can also read th...

  7. Heterogeneity in Preferences and Productivity

    DEFF Research Database (Denmark)

    Gørtz, Mette

    versus housework, 2) preferences for leisure compared to consumption, and 3) marginal utility of wealth, is correlated with the retirement decision. Based on US consumption and time use data for 2001 and 2003 from the Consumptions and Activities Mail Survey (CAMS), we study the patterns of individual...... choices of expenditure, household production and leisure for people in and around retirement. The unobserved individual heterogeneity factor is isolated by comparing cross-sectional evidence and panel data estimates of the effects of retirement on consumption and time allocation. Based on cross......-section data, we can identify a difference in consumption due to retirement status, but when the panel nature of the data is exploited, the effect of retirement on consumption is small and insignificant. Moreover, the analyses point at a large positive effect of retirement on household production. Our results...

  8. [Heterogenous expression of antimicrobial peptides].

    Science.gov (United States)

    Song, Shanshan; Hu, Guobin; Dong, Xianzhi

    2009-12-01

    Antimicrobial peptides (AMPs), a class of short proteins with a broad spectrum of antibacterial activities, are isolated from a wide variety of animals, both vertebrates and invertebrates, and plants as well as from bacteria and fungi. They are a key component of the innate immune response in most multicellular organisms. Owing to their potent, broad-spectrum antibacterial activities and uneasy developing of drug resistance, these peptides are of great clinical significance. However, preparation of AMPs at a large scale is a severe challenge to the development of the commercial products. Undoubtedly, construction of high-level biological expression systems for the production of AMPs is the key in its clinical application process. Herein, we summarize the progress in researches on heterogenous expression of AMPs in prokaryotic expression systems and eukaryotic expression systems.

  9. Biodiesel forming reactions using heterogeneous catalysis

    Science.gov (United States)

    Liu, Yijun

    Biodiesel synthesis from biomass provides a means for utilizing effectively renewable resources, a way to convert waste vegetable oils and animal fats to a useful product, a way to recycle carbon dioxide for a combustion fuel, and production of a fuel that is biodegradable, non-toxic, and has a lower emission profile than petroleum-diesel. Free fatty acid (FFA) esterification and triglyceride (TG) transesterification with low molecular weight alcohols constitute the synthetic routes to prepare biodiesel from lipid feedstocks. This project was aimed at developing a better understanding of important fundamental issues involved in heterogeneous catalyzed biodiesel forming reactions using mainly model compounds, representing part of on-going efforts to build up a rational base for assay, design, and performance optimization of solid acids/bases in biodiesel synthesis. As FFA esterification proceeds, water is continuously formed as a byproduct and affects reaction rates in a negative manner. Using sulfuric acid (as a catalyst) and acetic acid (as a model compound for FFA), the impact of increasing concentrations of water on acid catalysis was investigated. The order of the water effect on reaction rate was determined to be -0.83. Sulfuric acid lost up to 90% activity as the amount of water present increased. The nature of the negative effect of water on esterification was found to go beyond the scope of reverse hydrolysis and was associated with the diminished acid strength of sulfuric acid as a result of the preferential solvation by water molecules of its catalytic protons. The results indicate that as esterification progresses and byproduct water is produced, deactivation of a Bronsted acid catalyst like H2SO4 occurs. Using a solid composite acid (SAC-13) as an example of heterogeneous catalysts and sulfuric acid as a homogeneous reference, similar reaction inhibition by water was demonstrated for homogeneous and heterogeneous catalysis. This similarity together with

  10. Accounting for substitution and spatial heterogeneity in a labelled choice experiment.

    Science.gov (United States)

    Lizin, S; Brouwer, R; Liekens, I; Broeckx, S

    2016-10-01

    Many environmental valuation studies using stated preferences techniques are single-site studies that ignore essential spatial aspects, including possible substitution effects. In this paper substitution effects are captured explicitly in the design of a labelled choice experiment and the inclusion of different distance variables in the choice model specification. We test the effect of spatial heterogeneity on welfare estimates and transfer errors for minor and major river restoration works, and the transferability of river specific utility functions, accounting for key variables such as site visitation, spatial clustering and income. River specific utility functions appear to be transferable, resulting in low transfer errors. However, ignoring spatial heterogeneity increases transfer errors.

  11. Avian Species and Functional Diversity in Agricultural Landscapes: Does Landscape Heterogeneity Matter?

    Science.gov (United States)

    Lee, Myung-Bok; Martin, James A

    2017-01-01

    While the positive relationship between avian diversity and habitat heterogeneity is widely accepted, it is primarily based on observed species richness without accounting for imperfect detection. Other facets of diversity such as functional diversity are also rarely explored. We investigated the avian diversity-landscape heterogeneity relationship in agricultural landscapes by considering two aspects of diversity: taxonomic diversity (species richness) estimated from a multi-species dynamic occupancy model, and functional diversity (functional evenness [FEve] and divergence [FDiv]) based on traits of occurring species. We also assessed how agricultural lands enrolled in a conservation program managed on behalf of declining early successional bird species (hereafter CP38 fields, an agri-environment scheme) influenced avian diversity. We analyzed breeding bird data collected at CP38 fields in Mississippi, USA, during 2010-2012, and two principal components of environmental variables: a gradient of heterogeneity (Shannon's landscape diversity index) and of the amount of CP38 fields (percent cover of CP38 fields; CP38). FEve did not show significant responses to environmental variables, whereas FDiv responded positively to heterogeneity and negatively to CP38. However, most FDiv values did not significantly differ from random expectations along an environmental gradient. When there was a significant difference, FDiv was lower than that expected. Unlike functional diversity, species richness showed a clear pattern. Species richness increased with increasing landscape heterogeneity but decreased with increasing amounts of CP38 fields. Only one species responded negatively to heterogeneity and positively to CP38. Our results suggest that the relationships between avian diversity and landscape heterogeneity may vary depending on the aspect of diversity considered: strong positive effects of heterogeneity on taxonomic diversity, but weakly positive or non

  12. Intelligent Classification in Huge Heterogeneous Data Sets

    Science.gov (United States)

    2015-06-01

    INTELLIGENT CLASSIFICATION IN HUGE HETEROGENEOUS DATA SETS JUNE 2015 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED...To) JUL 2013 – APR 2015 4. TITLE AND SUBTITLE INTELLIGENT CLASSIFICATION IN HUGE HETEROGENEOUS DATA SETS 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT...signals and through data dimension reduction, and to develop and tailor algorithms for the extraction of intelligence from several huge heterogeneous

  13. In-situ characterization of heterogeneous catalysts

    CERN Document Server

    Rodriguez, Jose A; Chupas, Peter J

    2013-01-01

    Helps researchers develop new catalysts for sustainable fuel and chemical production Reviewing the latest developments in the field, this book explores the in-situ characterization of heterogeneous catalysts, enabling readers to take full advantage of the sophisticated techniques used to study heterogeneous catalysts and reaction mechanisms. In using these techniques, readers can learn to improve the selectivity and the performance of catalysts and how to prepare catalysts as efficiently as possible, with minimum waste. In-situ Characterization of Heterogeneous Catalysts feat

  14. Demographic heterogeneity, cohort selection, and population growth

    OpenAIRE

    Bruce E. Kendall; Fox, Gordon A.; Fujiwara, Masami; Nogeire, Theresa M.

    2011-01-01

    Demographic heterogeneity—variation among individuals in survival and reproduction—is ubiquitous in natural populations. Structured population models address heterogeneity due to age, size, or major developmental stages. However, other important sources of demographic heterogeneity, such as genetic variation, spatial heterogeneity in the environment, maternal effects, and differential exposure to stressors, are often not easily measured and hence are modeled as stochasticity. Recent research ...

  15. Research on the configuration design method of heterogeneous constellation reconstruction under the multiple objective and multiple constraint

    Science.gov (United States)

    Zhao, Shuang; Xu, Yanli; Dai, Huayu

    2017-05-01

    Aiming at the problem of configuration design of heterogeneous constellation reconstruction, a design method of heterogeneous constellation reconstruction based on multi objective and multi constraints is proposed. At first, the concept of heterogeneous constellation is defined. Secondly, the heterogeneous constellation reconstruction methods were analyzed, and then the two typical existing design methods of reconstruction, phase position uniformity method and reconstruction configuration design method based on optimization algorithm are summarized. The advantages and shortcomings of different reconstruction configuration design methods are compared, finally the heterogeneous constellation reconstruction configuration design is currently facing problems are analyzed and put forward the thinking about the reconstruction index system of heterogeneous constellation and the selection of optimal variables and the establishment of constraints in the optimization design of the configuration.

  16. Effect of heterogeneity on enhanced reductive dechlorination: Analysis of remediation efficiency and groundwater acidification

    Science.gov (United States)

    Brovelli, A.; Lacroix, E.; Robinson, C. E.; Gerhard, J.; Holliger, C.; Barry, D. A.

    2011-12-01

    Enhanced reductive dehalogenation is an attractive in situ treatment technology for chlorinated contaminants. The process includes two acid-forming microbial reactions: fermentation of an organic substrate resulting in short-chain fatty acids, and dehalogenation resulting in hydrochloric acid. The accumulation of acids and the resulting drop of groundwater pH are controlled by the mass and distribution of chlorinated solvents in the source zone, type of electron donor, alternative terminal electron acceptors available and presence of soil mineral phases able to buffer the pH (such as carbonates). Groundwater acidification may reduce or halt microbial activity, and thus dehalogenation, significantly increasing the time and costs required to remediate the aquifer. In previous work a detailed geochemical and groundwater flow simulator able to model the fermentation-dechlorination reactions and associated pH change was developed. The model accounts for the main processes influencing microbial activity and groundwater pH, including the groundwater composition, the electron donor used and soil mineral phase interactions. In this study, the model was applied to investigate how spatial variability occurring at the field scale affects dechlorination rates, groundwater pH and ultimately the remediation efficiency. Numerical simulations were conducted to examine the influence of heterogeneous hydraulic conductivity on the distribution of the injected, fermentable substrate and on the accumulation/dilution of the acidic products of reductive dehalogenation. The influence of the geometry of the DNAPL source zone was studied, as well as the spatial distribution of soil minerals. The results of this study showed that the heterogeneous distribution of the soil properties have a potentially large effect on the remediation efficiency. For examples, zones of high hydraulic conductivity can prevent the accumulation of acids and alleviate the problem of groundwater acidification. The

  17. Fixed export cost heterogeneity, trade and welfare

    DEFF Research Database (Denmark)

    Jørgensen, Jan Guldager; Schröder, Philipp J.H.

    2008-01-01

    -country intra-industry trade model where firms are of two different marginal costs types and where fixed export costs are heterogeneous across firms. This model traces many of the stylized facts of international trade. However, we find that with heterogeneous fixed export costs there exists a positive bilateral......Recent literature on the workhorse model of intra-industry trade has explored heterogeneous cost structures at the firm level. These approaches have proven to add realism and predictive power. This paper presents a new and simple heterogeneous-firms specification. We develop a symmetric two...

  18. Seismic wave propagation on heterogeneous systems with CHAPEL

    Science.gov (United States)

    Gokhberg, Alexey; Fichtner, Andreas

    2014-05-01

    Simulations of seismic wave propagation play a key role in the exploration of the Earth's internal structure, the prediction of earthquake-induced ground motion, and numerous other applications. In order to harness modern heterogeneous HPC systems, we implement a spectral-element discretization of the seismic wave equation using the emerging parallel programming language Chapel. High-performance massively parallel computing systems are widely used for solving seismological problems. A recent trend in the evolution of such systems is a transition from homogeneous architectures based on the conventional CPU to faster and more energy-efficient heterogeneous architectures that combine CPU with the special purpose GPU accelerators. These new heterogeneous architectures have much higher hardware complexity and are thus more difficult to program. Therefore transition to heterogeneous computing systems widens the well known gap between the performance of the new hardware and the programmers' productivity. In particular, programming heterogeneous systems typically involves a mix of various programming technologies like MPI, CUDA, or OpenACC. This conventional approach increases complexity of application code, limits its portability and reduces the programmers' productivity. We are approaching this problem by introducing a unified high-level programming model suitable for both conventional and hybrid architectures. Our model is based on the Partitioned Global Address Space (PGAS) paradigm used by several modern parallel programming languages. We implemented this model by extending Chapel, the emerging parallel programming language created at Cray Inc. In particular, we introduced the language abstractions for GPU-based domain mapping and extended the open source Chapel compiler (version 1.8.0) with facilities designed to translate Chapel high-level parallel programming constructs into CUDA kernels. We used this extended Chapel implementation to re-program the package for the

  19. Variability control: key to regulatory compliance and sustainability goals.

    Science.gov (United States)

    Englande, A J; Eckenfelder, W W; Jin, G

    2006-01-01

    The focus of this paper is on variability concerns in wastewater treatment and approaches to control unacceptable fluctuations in effluent quality. Areas considered include: factors contributing to variability in both waste loads and process technology performance; variability assessment; control of variability employing the process best management practice (BMP); design/operation of biological waste treatment technologies for variability reduction; and modelling to enhance process control.

  20. Research related to variable sweep aircraft development

    Science.gov (United States)

    Polhamus, E. C.; Toll, T. A.

    1981-01-01

    Development in high speed, variable sweep aircraft research is reviewed. The 1946 Langley wind tunnel studies related to variable oblique and variable sweep wings and results from the X-5 and the XF1OF variable sweep aircraft are discussed. A joint program with the British, evaluation of the British "Swallow", development of the outboard pivot wing/aft tail configuration concept by Langley, and the applied research program that followed and which provided the technology for the current, variable sweep military aircraft is outlined. The relative state of variable sweep as a design option is also covered.

  1. Staff Knowledge Absorption of Business Model Innovation Effect--With Employee Social Network Heterogeneity for Regulating Variable%员工知识吸收对商业模式创新的影响--以员工的社会网络异质性为调节变量

    Institute of Scientific and Technical Information of China (English)

    丁浩; 王炳成

    2013-01-01

      商业模式创新将会是未来企业获取竞争优势的重要手段,但驱动商业模式创新的因素却很少被研究.本文运用结构方程模型,探讨了员工知识吸收对商业模式创新的影响,及员工的社会网络异质性在员工知识吸收与商业模式创新的关系中的调节作用.研究过程中,采用利克特五点量表对员工知识吸收和商业模式创新进行测量,运用自我中心网络对员工的社会网络异质性进行了测量.在108有效问卷的基础上,运用AMOS7.0软件,检验了相关的假设.研究结果表明,员工知识吸收对商业模式创新的影响达到显著水平,员工社会网络异质性对商业模式创新的作用未达到显著水平,但员工社会网络异质性会在员工知识吸收与商业模式创新关系中起到调节作用.最后,论文给出了相关的建议.%Business model innovation will be an important means for the future enterprises to gain competitive advantage, but the factors driving business model innovation have rarely been studied. This paper uses the method of structural equation model to explore the direct effect of employees' knowledge absorptive capacity on business model innovation, and the moderating effects of employees' social network heterogeneity between employees' knowledge absorptive capacity and business model innovation. In the process of this study, we use Likert five-point scale to measure employees' knowledge absorptive capacity and business model innovation, and use ego-centered network to measure employees' social network heterogeneity. Based on 108 valid questionnaires, we uses AMOS7.0 to test the hypothesis. The result shows, employees' knowledge absorption capacity will significantly affect business model innovation, while employees' social network heterogeneity has limited direct influence on business model innovation, but employees' social network heterogeneity has significant moderate effect on the

  2. Compositional multiphase flow and transport in heterogeneous porous media

    Energy Technology Data Exchange (ETDEWEB)

    Huber, R.U.

    2000-07-01

    This work first treats the conceptual models for the description of multiphase flow processes in porous media. The thermodynamic laws are explained and the description and quantification of multi-fluid equilibria are discussed in order to account for fluid composition. The fully and weakly coupled approaches for the mathematical description of such flow processes with respect to systems consisting of two and three fluid phases as well as with respect to compositional single and multiphase systems are assessed. For the discretization of the two-phase flow equations node- and cell-centered finite volume methods and mixed and mixed-hybrid finite element approaches are applied. Based upon these methods five solution algorithms are developed. Four of these algorithms are based on the simultaneous solution of the discretized equations in combination with the Newton-Raphson technique. Methods 1 and 2 treat two- three-phase flow processes, Method 3 applies to the solution of partially miscible three-component systems while Method 4 is created for three-phase three-component systems. The latter method uses a variable substitution dependent on the local presence of the fluid phases. Method 5 is based on the IMPES/IMPESC concept. The time-implicit pressure equation is discretized with the mixed-hybrid finite element method. The saturation and concentration equations, respectively, are solved with a cell-centered finite volume scheme. The developed algorithms are applied to the two- and three-phase Buckley-Leverett problems. A partitioning interwell tracer test is simulated. The propagation behavior of nonaqueous phase liquids (NAPLs) in the saturated and unsaturated ground zone under the influence of heterogeneities are examined. In addition, a larger-scale experiment is simulated, which involves an injection of trichloroethylene into the subsurface and the subsequent distribution. Here, the development of a dissolved contaminant plume as well as the behavior of organic

  3. Unconditional Continuous Variable Dense Coding

    CERN Document Server

    Ralph, T C

    2002-01-01

    We investigate the conditions under which unconditional dense coding can be achieved using continuous variable entanglement. We consider the effect of entanglement impurity and detector efficiency and discuss experimental verification. We conclude that the requirements for a strong demonstration are not as stringent as previously thought and are within the reach of present technology.

  4. Temporal variability in aboveground plant biomass decreases as spatial variability increases.

    Science.gov (United States)

    McGranahan, Devan Allen; Hovick, Torre J; Elmore, R Dwayne; Engle, David M; Fuhlendorf, Samuel D; Winter, Stephen L; Miller, James R; Debinski, Diane M

    2016-03-01

    Ecological theory predicts that diversity decreases variability in ecosystem function. We predict that, at the landscape scale, spatial variability created by a mosaic of contrasting patches that differ in time since disturbance will decrease temporal variability in aboveground plant biomass. Using data from a multi-year study of seven grazed tallgrass prairie landscapes, each experimentally managed for one to eight patches, we show that increased spatial variability driven by spatially patchy fire and herbivory reduces temporal variability in aboveground plant biomass. This pattern is associated with statistical evidence for the portfolio effect and a positive relationship between temporal variability and functional group synchrony as predicted by metacommunity variability theory. As disturbance from fire and grazing interact to create a shifting mosaic of spatially heterogeneous patches within a landscape, temporal variability in aboveground plant biomass can be dampened. These results suggest that spatially heterogeneous disturbance regimes contribute to a portfolio of ecosystem functions provided by biodiversity, including wildlife habitat, fuel, and forage. We discuss how spatial patterns of disturbance drive variability within and among patches.

  5. Effect of methacholine on peripheral lung mechanics and ventilation heterogeneity in asthma.

    Science.gov (United States)

    Downie, Sue R; Salome, Cheryl M; Verbanck, Sylvia; Thompson, Bruce R; Berend, Norbert; King, Gregory G

    2013-03-15

    The forced oscillation technique (FOT) and multiple-breath nitrogen washout (MBNW) are noninvasive tests that are potentially sensitive to peripheral airways, with MBNW indexes being especially sensitive to heterogeneous changes in ventilation. The objective was to study methacholine-induced changes in the lung periphery of asthmatic patients and determine how changes in FOT variables of respiratory system reactance (Xrs) and resistance (Rrs) and frequency dependence of resistance (Rrs5-Rrs19) can be linked to changes in ventilation heterogeneity. The contributions of air trapping and airway closure, as extreme forms of heterogeneity, were also investigated. Xrs5, Rrs5, Rrs19, Rrs5-Rrs19, and inspiratory capacity (IC) were calculated from the FOT. Ventilation heterogeneity in acinar and conducting airways, and trapped gas (percent volume of trapped gas at functional residual capacity/vital capacity), were calculated from the MBNW. Measurements were repeated following methacholine. Methacholine-induced airway closure (percent change in forced vital capacity) and hyperinflation (change in IC) were also recorded. In 40 mild to moderate asthmatic patients, increase in Xrs5 after methacholine was predicted by increases in ventilation heterogeneity in acinar airways and forced vital capacity (r(2) = 0.37, P ventilation heterogeneity in conducting airway increase or IC decrease. Increases in Rrs5 and Rrs5-Rrs19 after methacholine were not correlated with increases in ventilation heterogeneity, trapped gas, hyperinflation, or airway closure. Increased reactance in asthmatic patients after methacholine was indicative of heterogeneous changes in the lung periphery and airway closure. By contrast, increases in resistance and frequency dependence of resistance were not related to ventilation heterogeneity or airway closure and were more indicative of changes in central airway caliber than of heterogeneity.

  6. MIRAI Architecture for Heterogeneous Network

    NARCIS (Netherlands)

    Wu, Gang; Mizuno, Mitsuhiko; Havinga, Paul J.M.

    One of the keywords that describe next-generation wireless communications is "seamless." As part of the e-Japan Plan promoted by the Japanese Government, the Multimedia Integrated Network by Radio Access Innovation project has as its goal the development of new technologies to enable seamless

  7. Explaining the heterogeneous scrapie surveillance figures across Europe: a meta-regression approach

    Directory of Open Access Journals (Sweden)

    Ru Giuseppe

    2007-06-01

    Full Text Available Abstract Background Two annual surveys, the abattoir and the fallen stock, monitor the presence of scrapie across Europe. A simple comparison between the prevalence estimates in different countries reveals that, in 2003, the abattoir survey appears to detect more scrapie in some countries. This is contrary to evidence suggesting the greater ability of the fallen stock survey to detect the disease. We applied meta-analysis techniques to study this apparent heterogeneity in the behaviour of the surveys across Europe. Furthermore, we conducted a meta-regression analysis to assess the effect of country-specific characteristics on the variability. We have chosen the odds ratios between the two surveys to inform the underlying relationship between them and to allow comparisons between the countries under the meta-regression framework. Baseline risks, those of the slaughtered populations across Europe, and country-specific covariates, available from the European Commission Report, were inputted in the model to explain the heterogeneity. Results Our results show the presence of significant heterogeneity in the odds ratios between countries and no reduction in the variability after adjustment for the different risks in the baseline populations. Three countries contributed the most to the overall heterogeneity: Germany, Ireland and The Netherlands. The inclusion of country-specific covariates did not, in general, reduce the variability except for one variable: the proportion of the total adult sheep population sampled as fallen stock by each country. A large residual heterogeneity remained in the model indicating the presence of substantial effect variability between countries. Conclusion The meta-analysis approach was useful to assess the level of heterogeneity in the implementation of the surveys and to explore the reasons for the variation between countries.

  8. Variable-Frequency Ultrasonic Treatment on Microstructure and Mechanical Properties of ZK60 Alloy during Large Diameter Semi-Continuous Casting

    Directory of Open Access Journals (Sweden)

    Xingrui Chen

    2017-05-01

    Full Text Available Traditional fixed-frequency ultrasonic technology and a variable-frequency ultrasonic technology were applied to refine the as-cast microstructure and improve the mechanical properties of a ZK60 (Mg–Zn–Zr alloy during large diameter semi-continuous casting. The acoustic field propagation was obtained by numerical simulation. The microstructure of the as-cast samples was characterized by optical and scanning electron microscopy. The variable-frequency ultrasonic technology shows its outstanding ability in grain refinement compared with traditional fixed-ultrasonic technology. The variable-frequency acoustic field promoted the formation of small α-Mg globular grains and changed the distribution and morphology of β-phases throughout the castings. Ultimate tensile strength and elongation are increased to 280 MPa and 8.9%, respectively, which are 19.1% and 45.9% higher than the values obtained from billets without ultrasonic treatment and are 11.6% and 18.7% higher than fixed-frequency ultrasound treated billets. Different refinement efficiencies appear in different districts of billets attributed to the sound attenuation in melt. The variable-frequency acoustic field improves the refinement effect by enhancing cavitation-enhanced heterogeneous nucleation and dendrite fragmentation effects.

  9. Purchasing Power Parity and Heterogeneous Mean Reversion

    NARCIS (Netherlands)

    C.G. Koedijk (Kees); B. Tims (Ben); M.A. van Dijk (Mathijs)

    2005-01-01

    textabstractThis paper analyzes the properties of multivariate tests of purchasing power parity (PPP) that fail to take heterogeneity in the speed of mean reversion across real exchange rates into account. We compare the performance of homogeneous and heterogeneous unit root testing methodologies.

  10. Fixed export cost heterogeneity, trade and welfare

    DEFF Research Database (Denmark)

    Jørgensen, Jan Guldager; Schröder, Philipp J.H.

    2008-01-01

    Recent literature on the workhorse model of intra-industry trade has explored heterogeneous cost structures at the firm level. These approaches have proven to add realism and predictive power. This paper presents a new and simple heterogeneous-firms specification. We develop a symmetric two...

  11. Hybrid Interconnect Design for Heterogeneous Hardware Accelerators

    NARCIS (Netherlands)

    Pham-Quoc Cuong, P.

    2015-01-01

    Heterogeneous multicore systems are becoming increasingly important as the need for computation power grows, especially when we are entering into the big data era. As one of the main trends in heterogeneous multicore, hardware accelerator systems provide application specific hardware circuits and

  12. Modelling income processes with lots of heterogeneity

    DEFF Research Database (Denmark)

    Browning, Martin; Ejrnæs, Mette; Alvarez, Javier

    2010-01-01

    this observable homogeneity, we find more latent heterogeneity than previous investigators. We show that allowance for heterogeneity makes substantial differences to estimates of model parameters and to outcomes of interest. Additionally, we find strong evidence against the hypothesis that any worker has a unit...

  13. Characterizing heterogeneous cellular responses to perturbations.

    Science.gov (United States)

    Slack, Michael D; Martinez, Elisabeth D; Wu, Lani F; Altschuler, Steven J

    2008-12-01

    Cellular populations have been widely observed to respond heterogeneously to perturbation. However, interpreting the observed heterogeneity is an extremely challenging problem because of the complexity of possible cellular phenotypes, the large dimension of potential perturbations, and the lack of methods for separating meaningful biological information from noise. Here, we develop an image-based approach to characterize cellular phenotypes based on patterns of signaling marker colocalization. Heterogeneous cellular populations are characterized as mixtures of phenotypically distinct subpopulations, and responses to perturbations are summarized succinctly as probabilistic redistributions of these mixtures. We apply our method to characterize the heterogeneous responses of cancer cells to a panel of drugs. We find that cells treated with drugs of (dis-)similar mechanism exhibit (dis-)similar patterns of heterogeneity. Despite the observed phenotypic diversity of cells observed within our data, low-complexity models of heterogeneity were sufficient to distinguish most classes of drug mechanism. Our approach offers a computational framework for assessing the complexity of cellular heterogeneity, investigating the degree to which perturbations induce redistributions of a limited, but nontrivial, repertoire of underlying states and revealing functional significance contained within distinct patterns of heterogeneous responses.

  14. The composition of heterogeneous control laws

    Science.gov (United States)

    Kuipers, Benjamin; Astrom, Karl

    1991-01-01

    The fuzzy control literature and industrial practice provide certain nonlinear methods for combining heterogeneous control laws, but these methods have been very difficult to analyze theoretically. An alternate formulation and extension of this approach is presented that has several practical and theoretical benefits. An example of heterogeneous control is given and two alternate analysis methods are presented.

  15. Surface temperature excess in heterogeneous catalysis

    NARCIS (Netherlands)

    Zhu, L.

    2005-01-01

    In this dissertation we study the surface temperature excess in heterogeneous catalysis. For heterogeneous reactions, such as gas-solid catalytic reactions, the reactions take place at the interfaces between the two phases: the gas and the solid catalyst. Large amount of reaction heats are released

  16. 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...

  17. Hybrid Interconnect Design for Heterogeneous Hardware Accelerators

    NARCIS (Netherlands)

    Pham-Quoc Cuong, P.

    2015-01-01

    Heterogeneous multicore systems are becoming increasingly important as the need for computation power grows, especially when we are entering into the big data era. As one of the main trends in heterogeneous multicore, hardware accelerator systems provide application specific hardware circuits and ar

  18. Heterogeneity in Health Care Computing Environments

    OpenAIRE

    Sengupta, Soumitra

    1989-01-01

    This paper discusses issues of heterogeneity in computer systems, networks, databases, and presentation techniques, and the problems it creates in developing integrated medical information systems. The need for institutional, comprehensive goals are emphasized. Using the Columbia-Presbyterian Medical Center's computing environment as the case study, various steps to solve the heterogeneity problem are presented.

  19. Understanding the Executive Functioning Heterogeneity in Schizophrenia

    Science.gov (United States)

    Raffard, Stephane; Bayard, Sophie

    2012-01-01

    Schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions implied in the executive functioning. The dysexecutive syndrome is one of the most prominent and functionally cognitive features of schizophrenia. Nevertheless, it is not clear to what extend executive deficits are heterogeneous in schizophrenia…

  20. Towards an Organizational Economics of Heterogeneous Capabilities

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul

    The notion of “capability” has long been influential in management research as an approach to address firm-level heterogeneity and heterogeneity in competitive outcomes. I discuss how recent advances in economics may allow for a more rigorous understanding and measurement of capability that take...