Large-scale data analytics

CERN Document Server

Gkoulalas-Divanis, Aris

2014-01-01

Provides cutting-edge research in large-scale data analytics from diverse scientific areas Surveys varied subject areas and reports on individual results of research in the field Shares many tips and insights into large-scale data analytics from authors and editors with long-term experience and specialization in the field

AN UNBIASED 1.3 mm EMISSION LINE SURVEY OF THE PROTOPLANETARY DISK ORBITING LkCa 15

Energy Technology Data Exchange (ETDEWEB)

Punzi, K. M.; Kastner, J. H. [Center for Imaging Science, School of Physics and Astronomy, and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Hily-Blant, P.; Forveille, T. [UJF—Grenoble 1/CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, F-38041, Grenoble (France); Sacco, G. G. [INAF—Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze (Italy)

2015-06-01

The outer (>30 AU) regions of the dusty circumstellar disk orbiting the ∼2–5 Myr old, actively accreting solar analog LkCa 15 are known to be chemically rich, and the inner disk may host a young protoplanet within its central cavity. To obtain a complete census of the brightest molecular line emission emanating from the LkCa 15 disk over the 210–270 GHz (1.4–1.1 mm) range, we have conducted an unbiased radio spectroscopic survey with the Institute de Radioastronomie Millimétrique (IRAM) 30 m telescope. The survey demonstrates that in this spectral region, the most readily detectable lines are those of CO and its isotopologues {sup 13}CO and C{sup 18}O, as well as HCO{sup +}, HCN, CN, C{sub 2}H, CS, and H{sub 2}CO. All of these species had been previously detected in the LkCa 15 disk; however, the present survey includes the first complete coverage of the CN (2–1) and C{sub 2}H (3–2) hyperfine complexes. Modeling of these emission complexes indicates that the CN and C{sub 2}H either reside in the coldest regions of the disk or are subthermally excited, and that their abundances are enhanced relative to molecular clouds and young stellar object environments. These results highlight the value of unbiased single-dish line surveys in guiding future high-resolution interferometric imaging of disks.

The ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES) . I. Project description, survey sample, and quality assessment

Science.gov (United States)

Cox, Nick L. J.; Cami, Jan; Farhang, Amin; Smoker, Jonathan; Monreal-Ibero, Ana; Lallement, Rosine; Sarre, Peter J.; Marshall, Charlotte C. M.; Smith, Keith T.; Evans, Christopher J.; Royer, Pierre; Linnartz, Harold; Cordiner, Martin A.; Joblin, Christine; van Loon, Jacco Th.; Foing, Bernard H.; Bhatt, Neil H.; Bron, Emeric; Elyajouri, Meriem; de Koter, Alex; Ehrenfreund, Pascale; Javadi, Atefeh; Kaper, Lex; Khosroshadi, Habib G.; Laverick, Mike; Le Petit, Franck; Mulas, Giacomo; Roueff, Evelyne; Salama, Farid; Spaans, Marco

2017-10-01

The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the C60^+ fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort tosystematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectral-type stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution (R 70 000-100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305-1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided.

The Topology of Large-Scale Structure in the 1.2 Jy IRAS Redshift Survey

Science.gov (United States)

Protogeros, Zacharias A. M.; Weinberg, David H.

1997-11-01

We measure the topology (genus) of isodensity contour surfaces in volume-limited subsets of the 1.2 Jy IRAS redshift survey, for smoothing scales λ = 4, 7, and 12 h-1 Mpc. At 12 h-1 Mpc, the observed genus curve has a symmetric form similar to that predicted for a Gaussian random field. At the shorter smoothing lengths, the observed genus curve shows a modest shift in the direction of an isolated cluster or ``meatball'' topology. We use mock catalogs drawn from cosmological N-body simulations to investigate the systematic biases that affect topology measurements in samples of this size and to determine the full covariance matrix of the expected random errors. We incorporate the error correlations into our evaluations of theoretical models, obtaining both frequentist assessments of absolute goodness of fit and Bayesian assessments of models' relative likelihoods. We compare the observed topology of the 1.2 Jy survey to the predictions of dynamically evolved, unbiased, gravitational instability models that have Gaussian initial conditions. The model with an n = -1 power-law initial power spectrum achieves the best overall agreement with the data, though models with a low-density cold dark matter power spectrum and an n = 0 power-law spectrum are also consistent. The observed topology is inconsistent with an initially Gaussian model that has n = -2, and it is strongly inconsistent with a Voronoi foam model, which has a non-Gaussian, bubble topology.

Large-Scale Outflows in Seyfert Galaxies

Science.gov (United States)

Colbert, E. J. M.; Baum, S. A.

1995-12-01

\\catcode`\\@=11 \\ialign{m @th#1hfil ##hfil \\crcr#2\\crcr\\sim\\crcr}}} \\catcode`\\@=12 Highly collimated outflows extend out to Mpc scales in many radio-loud active galaxies. In Seyfert galaxies, which are radio-quiet, the outflows extend out to kpc scales and do not appear to be as highly collimated. In order to study the nature of large-scale (>~1 kpc) outflows in Seyferts, we have conducted optical, radio and X-ray surveys of a distance-limited sample of 22 edge-on Seyfert galaxies. Results of the optical emission-line imaging and spectroscopic survey imply that large-scale outflows are present in >~{{1} /{4}} of all Seyferts. The radio (VLA) and X-ray (ROSAT) surveys show that large-scale radio and X-ray emission is present at about the same frequency. Kinetic luminosities of the outflows in Seyferts are comparable to those in starburst-driven superwinds. Large-scale radio sources in Seyferts appear diffuse, but do not resemble radio halos found in some edge-on starburst galaxies (e.g. M82). We discuss the feasibility of the outflows being powered by the active nucleus (e.g. a jet) or a circumnuclear starburst.

Disclosure Control using Partially Synthetic Data for Large-Scale Health Surveys, with Applications to CanCORS

OpenAIRE

Loong, Bronwyn; Zaslavsky, Alan M.; He, Yulei; Harrington, David P.

2013-01-01

Statistical agencies have begun to partially synthesize public-use data for major surveys to protect the confidentiality of respondents’ identities and sensitive attributes, by replacing high disclosure risk and sensitive variables with multiple imputations. To date, there are few applications of synthetic data techniques to large-scale healthcare survey data. Here, we describe partial synthesis of survey data collected by CanCORS, a comprehensive observational study of the experiences, treat...

LSD: Large Survey Database framework

Science.gov (United States)

Juric, Mario

2012-09-01

The Large Survey Database (LSD) is a Python framework and DBMS for distributed storage, cross-matching and querying of large survey catalogs (>10^9 rows, >1 TB). The primary driver behind its development is the analysis of Pan-STARRS PS1 data. It is specifically optimized for fast queries and parallel sweeps of positionally and temporally indexed datasets. It transparently scales to more than >10^2 nodes, and can be made to function in "shared nothing" architectures.

Markovian description of unbiased polymer translocation

International Nuclear Information System (INIS)

Mondaini, Felipe; Moriconi, L.

2012-01-01

We perform, with the help of cloud computing resources, extensive Langevin simulations which provide compelling evidence in favor of a general Markovian framework for unbiased three-dimensional polymer translocation. Our statistical analysis consists of careful evaluations of (i) two-point correlation functions of the translocation coordinate and (ii) the empirical probabilities of complete polymer translocation (taken as a function of the initial number of monomers on a given side of the membrane). We find good agreement with predictions derived from the Markov chain approach recently addressed in the literature by the present authors. -- Highlights: ► We investigate unbiased polymer translocation through membrane pores. ► Large statistical ensembles have been produced with the help of cloud computing resources. ► We evaluate the two-point correlation function of the translocation coordinate. ► We evaluate empirical probabilities for complete polymer translocation. ► Unbiased polymer translocation is described as a Markov stochastic process.

Markovian description of unbiased polymer translocation

Energy Technology Data Exchange (ETDEWEB)

Mondaini, Felipe [Instituto de Física, Universidade Federal do Rio de Janeiro, C.P. 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Centro Federal de Educação Tecnológica Celso Suckow da Fonseca, UnED Angra dos Reis, Angra dos Reis, 23953-030, RJ (Brazil); Moriconi, L., E-mail: moriconi@if.ufrj.br [Instituto de Física, Universidade Federal do Rio de Janeiro, C.P. 68528, 21945-970 Rio de Janeiro, RJ (Brazil)

2012-10-01

We perform, with the help of cloud computing resources, extensive Langevin simulations which provide compelling evidence in favor of a general Markovian framework for unbiased three-dimensional polymer translocation. Our statistical analysis consists of careful evaluations of (i) two-point correlation functions of the translocation coordinate and (ii) the empirical probabilities of complete polymer translocation (taken as a function of the initial number of monomers on a given side of the membrane). We find good agreement with predictions derived from the Markov chain approach recently addressed in the literature by the present authors. -- Highlights: ► We investigate unbiased polymer translocation through membrane pores. ► Large statistical ensembles have been produced with the help of cloud computing resources. ► We evaluate the two-point correlation function of the translocation coordinate. ► We evaluate empirical probabilities for complete polymer translocation. ► Unbiased polymer translocation is described as a Markov stochastic process.

The Use of Online Social Networks by Polish Former Erasmus Students: A Large-Scale Survey

Science.gov (United States)

Bryla, Pawel

2014-01-01

There is an increasing role of online social networks in the life of young Poles. We conducted a large-scale survey among Polish former Erasmus students. We have received 2450 completed questionnaires from alumni of 115 higher education institutions all over Poland. 85.4% of our respondents reported they kept in touch with their former Erasmus…

Chirping for large-scale maritime archaeological survey

DEFF Research Database (Denmark)

Grøn, Ole; Boldreel, Lars Ole

2014-01-01

Archaeological wrecks exposed on the sea floor are mapped using side-scan and multibeam techniques, whereas the detection of submerged archaeological sites, such as Stone Age settlements, and wrecks, partially or wholly embedded in sea-floor sediments, requires the application of high-resolution ...... the present state of this technology, it appears well suited to large-scale maritime archaeological mapping....

Unbiased contaminant removal for 3D galaxy power spectrum measurements

Science.gov (United States)

Kalus, B.; Percival, W. J.; Bacon, D. J.; Samushia, L.

2016-11-01

We assess and develop techniques to remove contaminants when calculating the 3D galaxy power spectrum. We separate the process into three separate stages: (I) removing the contaminant signal, (II) estimating the uncontaminated cosmological power spectrum and (III) debiasing the resulting estimates. For (I), we show that removing the best-fitting contaminant (mode subtraction) and setting the contaminated components of the covariance to be infinite (mode deprojection) are mathematically equivalent. For (II), performing a quadratic maximum likelihood (QML) estimate after mode deprojection gives an optimal unbiased solution, although it requires the manipulation of large N_mode^2 matrices (Nmode being the total number of modes), which is unfeasible for recent 3D galaxy surveys. Measuring a binned average of the modes for (II) as proposed by Feldman, Kaiser & Peacock (FKP) is faster and simpler, but is sub-optimal and gives rise to a biased solution. We present a method to debias the resulting FKP measurements that does not require any large matrix calculations. We argue that the sub-optimality of the FKP estimator compared with the QML estimator, caused by contaminants, is less severe than that commonly ignored due to the survey window.

Unbiased stereologic techniques for practical use in diagnostic histopathology

DEFF Research Database (Denmark)

Sørensen, Flemming Brandt

1995-01-01

by introducing quantitative techniques in the histopathologic discipline of malignancy grading. Unbiased stereologic methods, especially based on measurements of nuclear three-dimensional mean size, have during the last decade proved their value in this regard. In this survey, the methods are reviewed regarding......Grading of malignancy by the examination of morphologic and cytologic details in histologic sections from malignant neoplasms is based exclusively on qualitative features, associated with significant subjectivity, and thus rather poor reproducibility. The traditional way of malignancy grading may...... of solid tumors. This new, unbiased attitude to malignancy grading is associated with excellent virtues, which ultimately may help the clinician in the choice of optimal treatment of the individual patient suffering from cancer. Stereologic methods are not solely applicable to the field of malignancy...

Validating Bayesian truth serum in large-scale online human experiments.

Science.gov (United States)

Frank, Morgan R; Cebrian, Manuel; Pickard, Galen; Rahwan, Iyad

2017-01-01

Bayesian truth serum (BTS) is an exciting new method for improving honesty and information quality in multiple-choice survey, but, despite the method's mathematical reliance on large sample sizes, existing literature about BTS only focuses on small experiments. Combined with the prevalence of online survey platforms, such as Amazon's Mechanical Turk, which facilitate surveys with hundreds or thousands of participants, BTS must be effective in large-scale experiments for BTS to become a readily accepted tool in real-world applications. We demonstrate that BTS quantifiably improves honesty in large-scale online surveys where the "honest" distribution of answers is known in expectation on aggregate. Furthermore, we explore a marketing application where "honest" answers cannot be known, but find that BTS treatment impacts the resulting distributions of answers.

Entanglement in mutually unbiased bases

Energy Technology Data Exchange (ETDEWEB)

Wiesniak, M; Zeilinger, A [Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna (Austria); Paterek, T, E-mail: tomasz.paterek@nus.edu.sg [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore (Singapore)

2011-05-15

One of the essential features of quantum mechanics is that most pairs of observables cannot be measured simultaneously. This phenomenon manifests itself most strongly when observables are related to mutually unbiased bases. In this paper, we shed some light on the connection between mutually unbiased bases and another essential feature of quantum mechanics, quantum entanglement. It is shown that a complete set of mutually unbiased bases of a bipartite system contains a fixed amount of entanglement, independent of the choice of the set. This has implications for entanglement distribution among the states of a complete set. In prime-squared dimensions we present an explicit experiment-friendly construction of a complete set with a particularly simple entanglement distribution. Finally, we describe the basic properties of mutually unbiased bases composed of product states only. The constructions are illustrated with explicit examples in low dimensions. We believe that the properties of entanglement in mutually unbiased bases may be one of the ingredients to be taken into account to settle the question of the existence of complete sets. We also expect that they will be relevant to applications of bases in the experimental realization of quantum protocols in higher-dimensional Hilbert spaces.

Growth Limits in Large Scale Networks

DEFF Research Database (Denmark)

Knudsen, Thomas Phillip

limitations. The rising complexity of network management with the convergence of communications platforms is shown as problematic for both automatic management feasibility and for manpower resource management. In the fourth step the scope is extended to include the present society with the DDN project as its......The Subject of large scale networks is approached from the perspective of the network planner. An analysis of the long term planning problems is presented with the main focus on the changing requirements for large scale networks and the potential problems in meeting these requirements. The problems...... the fundamental technological resources in network technologies are analysed for scalability. Here several technological limits to continued growth are presented. The third step involves a survey of major problems in managing large scale networks given the growth of user requirements and the technological...

Measuring Cosmic Expansion and Large Scale Structure with Destiny

Science.gov (United States)

Benford, Dominic J.; Lauer, Tod R.

2007-01-01

Destiny is a simple, direct, low cost mission to determine the properties of dark energy by obtaining a cosmologically deep supernova (SN) type Ia Hubble diagram and by measuring the large-scale mass power spectrum over time. Its science instrument is a 1.65m space telescope, featuring a near-infrared survey camera/spectrometer with a large field of view. During its first two years, Destiny will detect, observe, and characterize 23000 SN Ia events over the redshift interval 0.4Destiny will be used in its third year as a high resolution, wide-field imager to conduct a weak lensing survey covering >lo00 square degrees to measure the large-scale mass power spectrum. The combination of surveys is much more powerful than either technique on its own, and will have over an order of magnitude greater sensitivity than will be provided by ongoing ground-based projects.

Circulating tumor cell detection: A direct comparison between negative and unbiased enrichment in lung cancer.

Science.gov (United States)

Xu, Yan; Liu, Biao; Ding, Fengan; Zhou, Xiaodie; Tu, Pin; Yu, Bo; He, Yan; Huang, Peilin

2017-06-01

Circulating tumor cells (CTCs), isolated as a 'liquid biopsy', may provide important diagnostic and prognostic information. Therefore, rapid, reliable and unbiased detection of CTCs are required for routine clinical analyses. It was demonstrated that negative enrichment, an epithelial marker-independent technique for isolating CTCs, exhibits a better efficiency in the detection of CTCs compared with positive enrichment techniques that only use specific anti-epithelial cell adhesion molecules. However, negative enrichment techniques incur significant cell loss during the isolation procedure, and as it is a method that uses only one type of antibody, it is inherently biased. The detection procedure and identification of cell types also relies on skilled and experienced technicians. In the present study, the detection sensitivity of using negative enrichment and a previously described unbiased detection method was compared. The results revealed that unbiased detection methods may efficiently detect >90% of cancer cells in blood samples containing CTCs. By contrast, only 40-60% of CTCs were detected by negative enrichment. Additionally, CTCs were identified in >65% of patients with stage I/II lung cancer. This simple yet efficient approach may achieve a high level of sensitivity. It demonstrates a potential for the large-scale clinical implementation of CTC-based diagnostic and prognostic strategies.

Liquid metal fast breeder reactor steam generator survey of the consequences of large scale sodium water reaction

International Nuclear Information System (INIS)

Vambenepe, G.

1978-01-01

The ''Retona'' three-dimensional hydrodynamic computing code is being developed by Electricity de France to survey the consequences, on the very plant, of a large scale sodium water reaction in liquid metal steam generators. In this communication, the heat-exchanger geometry is schematized and the problem solving process briefly described under assumed simplifying hypotheses. The application of the results to the Creusot-Loire steam generator selected for Super-Phenix are given as an example. (author)

Indicators to examine quality of large scale survey data: an example through district level household and facility survey.

Directory of Open Access Journals (Sweden)

Kakoli Borkotoky

Full Text Available BACKGROUND: Large scale surveys are the main source of data pertaining to all the social and demographic indicators, hence its quality is also of great concern. In this paper, we discuss the indicators used to examine the quality of data. We focus on age misreporting, incompleteness and inconsistency of information; and skipping of questions on reproductive and sexual health related issues. In order to observe the practical consequences of errors in a survey; the District Level Household and Facility Survey (DLHS-3 is used as an example dataset. METHODS: Whipple's and Myer's indices are used to identify age misreporting. Age displacements are identified by estimating downward and upward transfers for women from bordering age groups of the eligible age range. Skipping pattern is examined by recording the responses to the questions which precede the sections on birth history, immunization, and reproductive and sexual health. RESULTS: The study observed errors in age reporting, in all the states, but the extent of misreporting differs by state and individual characteristics. Illiteracy, rural residence and poor economic condition are the major factors that lead to age misreporting. Female were excluded from the eligible age group, to reduce the duration of interview. The study further observed that respondents tend to skip questions on HIV/RTI and other questions which follow a set of questions. CONCLUSION: The study concludes that age misreporting, inconsistency and incomplete response are three sources of error that need to be considered carefully before drawing conclusions from any survey. DLHS-3 also suffers from age misreporting, particularly for female in the reproductive ages. In view of the coverage of the survey, it may not be possible to control age misreporting completely, but some extra effort to probe a better answer may help in improving the quality of data in the survey.

Large scale electrolysers

International Nuclear Information System (INIS)

B Bello; M Junker

2006-01-01

Hydrogen production by water electrolysis represents nearly 4 % of the world hydrogen production. Future development of hydrogen vehicles will require large quantities of hydrogen. Installation of large scale hydrogen production plants will be needed. In this context, development of low cost large scale electrolysers that could use 'clean power' seems necessary. ALPHEA HYDROGEN, an European network and center of expertise on hydrogen and fuel cells, has performed for its members a study in 2005 to evaluate the potential of large scale electrolysers to produce hydrogen in the future. The different electrolysis technologies were compared. Then, a state of art of the electrolysis modules currently available was made. A review of the large scale electrolysis plants that have been installed in the world was also realized. The main projects related to large scale electrolysis were also listed. Economy of large scale electrolysers has been discussed. The influence of energy prices on the hydrogen production cost by large scale electrolysis was evaluated. (authors)

Catalogue of antibiotic resistome and host-tracking in drinking water deciphered by a large scale survey.

Science.gov (United States)

Ma, Liping; Li, Bing; Jiang, Xiao-Tao; Wang, Yu-Lin; Xia, Yu; Li, An-Dong; Zhang, Tong

2017-11-28

Excesses of antibiotic resistance genes (ARGs), which are regarded as emerging environmental pollutants, have been observed in various environments. The incidence of ARGs in drinking water causes potential risks to human health and receives more attention from the public. However, ARGs harbored in drinking water remain largely unexplored. In this study, we aimed at establishing an antibiotic resistome catalogue in drinking water samples from a wide range of regions and to explore the potential hosts of ARGs. A catalogue of antibiotic resistome in drinking water was established, and the host-tracking of ARGs was conducted through a large-scale survey using metagenomic approach. The drinking water samples were collected at the point of use in 25 cities in mainland China, Hong Kong, Macau, Taiwan, South Africa, Singapore and the USA. In total, 181 ARG subtypes belonging to 16 ARG types were detected with an abundance range of 2.8 × 10 -2 to 4.2 × 10 -1 copies of ARG per cell. The highest abundance was found in northern China (Henan Province). Bacitracin, multidrug, aminoglycoside, sulfonamide, and beta-lactam resistance genes were dominant in drinking water. Of the drinking water samples tested, 84% had a higher ARG abundance than typical environmental ecosystems of sediment and soil. Metagenomic assembly-based host-tracking analysis identified Acidovorax, Acinetobacter, Aeromonas, Methylobacterium, Methyloversatilis, Mycobacterium, Polaromonas, and Pseudomonas as the hosts of ARGs. Moreover, potential horizontal transfer of ARGs in drinking water systems was proposed by network and Procrustes analyses. The antibiotic resistome catalogue compiled using a large-scale survey provides a useful reference for future studies on the global surveillance and risk management of ARGs in drinking water. .

Coverage of the migrant population in large-scale assessment surveys. Experiences from PIAAC in Germany

Directory of Open Access Journals (Sweden)

Débora B. Maehler

2017-03-01

Full Text Available Abstract Background European countries, and especially Germany, are currently very much affected by human migration flows, with the result that the task of integration has become a challenge. Only very little empirical evidence on topics such as labor market participation and processes of social integration of migrant subpopulations is available to date from large-scale population surveys. The present paper provides an overview of the representation of the migrant population in the German Programme for the International Assessment of Adult Competencies (PIAAC sample and evaluates reasons for the under-coverage of this population. Methods We examine outcome rates and reasons for nonresponse among the migrant population based on sampling frame data, and we also examine para data from the interviewers’ contact protocols to evaluate time patterns for the successful contacting of migrants. Results and Conclusions This is the first time that results of this kind have been presented for a large-scale assessment in educational research. These results are also discussed in the context of future PIAAC cycles. Overall, they confirm the expectations in the literature that factors such as language problems result in lower contact and response rates among migrants.

Nonlinear unbiased minimum-variance filter for Mars entry autonomous navigation under large uncertainties and unknown measurement bias.

Science.gov (United States)

Xiao, Mengli; Zhang, Yongbo; Fu, Huimin; Wang, Zhihua

2018-05-01

High-precision navigation algorithm is essential for the future Mars pinpoint landing mission. The unknown inputs caused by large uncertainties of atmospheric density and aerodynamic coefficients as well as unknown measurement biases may cause large estimation errors of conventional Kalman filters. This paper proposes a derivative-free version of nonlinear unbiased minimum variance filter for Mars entry navigation. This filter has been designed to solve this problem by estimating the state and unknown measurement biases simultaneously with derivative-free character, leading to a high-precision algorithm for the Mars entry navigation. IMU/radio beacons integrated navigation is introduced in the simulation, and the result shows that with or without radio blackout, our proposed filter could achieve an accurate state estimation, much better than the conventional unscented Kalman filter, showing the ability of high-precision Mars entry navigation algorithm. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Google Street View as an alternative method to car surveys in large-scale vegetation assessments.

Science.gov (United States)

Deus, Ernesto; Silva, Joaquim S; Catry, Filipe X; Rocha, Miguel; Moreira, Francisco

2015-10-01

Car surveys (CS) are a common method for assessing the distribution of alien invasive plants. Google Street View (GSV), a free-access web technology where users may experience a virtual travel along roads, has been suggested as a cost-effective alternative to car surveys. We tested if we could replicate the results from a countrywide survey conducted by car in Portugal using GSV as a remote sensing tool, aiming at assessing the distribution of Eucalyptus globulus Labill. wildlings on roadsides adjacent to eucalypt stands. Georeferenced points gathered along CS were used to create road transects visible as lines overlapping the road in GSV environment, allowing surveying the same sampling areas using both methods. This paper presents the results of the comparison between the two methods. Both methods produced similar models of plant abundance, selecting the same explanatory variables, in the same hierarchical order of importance and depicting a similar influence on plant abundance. Even though the GSV model had a lower performance and the GSV survey detected fewer plants, additional variables collected exclusively with GSV improved model performance and provided a new insight into additional factors influencing plant abundance. The survey using GSV required ca. 9 % of the funds and 62 % of the time needed to accomplish the CS. We conclude that GSV may be a cost-effective alternative to CS. We discuss some advantages and limitations of GSV as a survey method. We forecast that GSV may become a widespread tool in road ecology, particularly in large-scale vegetation assessments.

Cosmology with weak lensing surveys

International Nuclear Information System (INIS)

Munshi, Dipak; Valageas, Patrick; Waerbeke, Ludovic van; Heavens, Alan

2008-01-01

Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

Cosmology with weak lensing surveys

Energy Technology Data Exchange (ETDEWEB)

Munshi, Dipak [Institute of Astronomy, Madingley Road, Cambridge, CB3 OHA (United Kingdom); Astrophysics Group, Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE (United Kingdom)], E-mail: munshi@ast.cam.ac.uk; Valageas, Patrick [Service de Physique Theorique, CEA Saclay, 91191 Gif-sur-Yvette (France); Waerbeke, Ludovic van [University of British Columbia, Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Heavens, Alan [SUPA - Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)

2008-06-15

Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

Validation of a short qualitative food frequency list used in several German large scale surveys.

Science.gov (United States)

Winkler, G; Döring, A

1998-09-01

Our study aimed to test the validity of a short, qualitative food frequency list (FFL) used in several German large scale surveys. In the surveys of the MONICA project Augsburg, the FFL was used in randomly selected adults. In 1984/85, a dietary survey with 7-day records (DR) was conducted within the subsample of men aged 45 to 64 (response 70%). The 899 DR were used to validate the FFL. Mean weekly food intake frequency and mean daily food intake were compared and Spearman rank order correlation coefficients and classification into tertiles with values of the statistic Kappa were calculated. Spearman correlations range between 0.15 for the item "Other sweets (candies, compote)" and 0.60 for the items "Curds, yoghurt, sour milk", "Milk including butter milk" and "Mineral water"; values for statistic Kappa vary between 0.04 ("White bread, brown bread, crispbread") and 0.41 ("Flaked oats, muesli, cornflakes" and "milk including butter milk"). With the exception of two items, FFL data can be used for analysis on group level. Analysis on individual level should be done with caution. It seems, as if some food groups are generally easier to ask for in FFL than others.

Large-Scale Star Formation-Driven Outflows at 13D-HST Survey

Science.gov (United States)

Lundgren, Britt; Brammer, G.; Van Dokkum, P. G.; Bezanson, R.; Franx, M.; Fumagalli, M.; Momcheva, I. G.; Nelson, E.; Skelton, R.; Wake, D.; Whitaker, K. E.; da Cunha, E.; Erb, D.; Fan, X.; Kriek, M.; Labbe, I.; Marchesini, D.; Patel, S.; Rix, H.; Schmidt, K.; van der Wel, A.

2013-01-01

We present evidence of large-scale outflows from three low-mass star-forming galaxies observed at z=1.24, z=1.35 and z=1.75 in the 3D-HST Survey. Each of these galaxies is located within a projected physical distance of 60 kpc around the sight line to the quasar SDSS J123622.93+621526.6, which exhibits well-separated strong (W>0.8A) MgII absorption systems matching precisely to the redshifts of the three galaxies. We derive the star formation surface densities from the H-alpha emission in the WFC3 G141 grism observations for the galaxies and find that in each case the star formation surface density well-exceeds 0.1 solar mass / yr / kpc^2, the typical threshold for starburst galaxies in the local Universe. From a small but complete parallel census of the 0.650.8A MgII covering fraction of star-forming galaxies at 10.4A MgII absorbing gas around star-forming galaxies may evolve from 2 to the present, consistent with recent observations of an increasing collimation of star formation-driven outflows with time from 3.

Authors’ perspectives on academic publishing: initial observations from a large-scale global survey

Directory of Open Access Journals (Sweden)

Basil D’Souza

2018-02-01

Full Text Available Authors are at the heart of academic publishing, but their voices are underrepresented in discussions about improving the academic publishing system. To understand the viewpoints of authors on various aspects of academic publishing and the challenges they face, we developed a large-scale survey entitled “Author perspectives on the academic publishing process” and made it available in December 2016. The survey has received 8,795 responses; this paper is based on the interim results drawn from 5,293 survey responses, and presents some interesting and thought-provoking trends that were observed in the authors’ responses, such as their interpretation of plagiarism and decisive factors in journal selection, as well as their thoughts on what needs to change in the publishing system for it to be more author-friendly. Some of the most important findings of the survey were: (1 the majority of the authors found manuscript preparation to be the most challenging task in the publication process, (2 the impact factor of a journal was reported to be the most important consideration for journal selection, (3 most authors found journal guidelines to be incomplete, (4 major gaps existed in author-journal communication, and (5 although awareness of ethics was high, awareness of good publication practice standards was low. Moreover, more than half of the participants indicated that among areas for improvement in the publishing system, they would like to see changes in the time it takes to publish a paper, the peer review process, and the fairness and objectivity of the publication process. These findings indicate the necessity of making the journal publication process more author-centered and smoothing the way for authors to get published.

Survey and analysis of selected jointly owned large-scale electric utility storage projects

Energy Technology Data Exchange (ETDEWEB)

1982-05-01

The objective of this study was to examine and document the issues surrounding the curtailment in commercialization of large-scale electric storage projects. It was sensed that if these issues could be uncovered, then efforts might be directed toward clearing away these barriers and allowing these technologies to penetrate the market to their maximum potential. Joint-ownership of these projects was seen as a possible solution to overcoming the major barriers, particularly economic barriers, of commercializaton. Therefore, discussions with partners involved in four pumped storage projects took place to identify the difficulties and advantages of joint-ownership agreements. The four plants surveyed included Yards Creek (Public Service Electric and Gas and Jersey Central Power and Light); Seneca (Pennsylvania Electric and Cleveland Electric Illuminating Company); Ludington (Consumers Power and Detroit Edison, and Bath County (Virginia Electric Power Company and Allegheny Power System, Inc.). Also investigated were several pumped storage projects which were never completed. These included Blue Ridge (American Electric Power); Cornwall (Consolidated Edison); Davis (Allegheny Power System, Inc.) and Kttatiny Mountain (General Public Utilities). Institutional, regulatory, technical, environmental, economic, and special issues at each project were investgated, and the conclusions relative to each issue are presented. The major barriers preventing the growth of energy storage are the high cost of these systems in times of extremely high cost of capital, diminishing load growth and regulatory influences which will not allow the building of large-scale storage systems due to environmental objections or other reasons. However, the future for energy storage looks viable despite difficult economic times for the utility industry. Joint-ownership can ease some of the economic hardships for utilites which demonstrate a need for energy storage.

The ALMA Protostellar Interferometric Line Survey (PILS). First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA

Science.gov (United States)

Jørgensen, J. K.; van der Wiel, M. H. D.; Coutens, A.; Lykke, J. M.; Müller, H. S. P.; van Dishoeck, E. F.; Calcutt, H.; Bjerkeli, P.; Bourke, T. L.; Drozdovskaya, M. N.; Favre, C.; Fayolle, E. C.; Garrod, R. T.; Jacobsen, S. K.; Öberg, K. I.; Persson, M. V.; Wampfler, S. F.

2016-11-01

Context. The inner regions of the envelopes surrounding young protostars are characterized by a complex chemistry, with prebiotic molecules present on the scales where protoplanetary disks eventually may form. The Atacama Large Millimeter/submillimeter Array (ALMA) provides an unprecedented view of these regions zooming in on solar system scales of nearby protostars and mapping the emission from rare species. Aims: The goal is to introduce a systematic survey, the Protostellar Interferometric Line Survey (PILS), of the chemical complexity of one of the nearby astrochemical templates, the Class 0 protostellar binary IRAS 16293-2422, using ALMA in order to understand the origin of the complex molecules formed in its vicinity. In addition to presenting the overall survey, the analysis in this paper focuses on new results for the prebiotic molecule glycolaldehyde, its isomers, and rarer isotopologues and other related molecules. Methods: An unbiased spectral survey of IRAS 16293-2422 covering the full frequency range from 329 to 363 GHz (0.8 mm) has been obtained with ALMA, in addition to a few targeted observations at 3.0 and 1.3 mm. The data consist of full maps of the protostellar binary system with an angular resolution of 0.5'' (60 AU diameter), a spectral resolution of 0.2 km s-1, and a sensitivity of 4-5 mJy beam-1 km s-1, which is approximately two orders of magnitude better than any previous studies. Results: More than 10 000 features are detected toward one component in the protostellar binary, corresponding to an average line density of approximately one line per 3 km s-1. Glycolaldehyde; its isomers, methyl formate and acetic acid; and its reduced alcohol, ethylene glycol, are clearly detected and their emission well-modeled with an excitation temperature of 300 K. For ethylene glycol both lowest state conformers, aGg' and gGg', are detected, the latter for the first time in the interstellar medium (ISM). The abundance of glycolaldehyde is comparable to or

Application of Singh et al., unbiased estimator in a dual to ratio-cum ...

African Journals Online (AJOL)

This paper applied an unbiased estimator in a dual to ratio–cum-product estimator in sample surveys to double sampling design. Its efficiency over the conventional biased double sampling design estimator was determined based on the conditions attached to its supremacy. Three different data sets were used to testify to ...

Unbiased classification of spatial strategies in the Barnes maze.

Science.gov (United States)

Illouz, Tomer; Madar, Ravit; Clague, Charlotte; Griffioen, Kathleen J; Louzoun, Yoram; Okun, Eitan

2016-11-01

Spatial learning is one of the most widely studied cognitive domains in neuroscience. The Morris water maze and the Barnes maze are the most commonly used techniques to assess spatial learning and memory in rodents. Despite the fact that these tasks are well-validated paradigms for testing spatial learning abilities, manual categorization of performance into behavioral strategies is subject to individual interpretation, and thus to bias. We have previously described an unbiased machine-learning algorithm to classify spatial strategies in the Morris water maze. Here, we offer a support vector machine-based, automated, Barnes-maze unbiased strategy (BUNS) classification algorithm, as well as a cognitive score scale that can be used for memory acquisition, reversal training and probe trials. The BUNS algorithm can greatly benefit Barnes maze users as it provides a standardized method of strategy classification and cognitive scoring scale, which cannot be derived from typical Barnes maze data analysis. Freely available on the web at http://okunlab.wix.com/okunlab as a MATLAB application. eitan.okun@biu.ac.ilSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Impact of large-scale tides on cosmological distortions via redshift-space power spectrum

Science.gov (United States)

Akitsu, Kazuyuki; Takada, Masahiro

2018-03-01

Although large-scale perturbations beyond a finite-volume survey region are not direct observables, these affect measurements of clustering statistics of small-scale (subsurvey) perturbations in large-scale structure, compared with the ensemble average, via the mode-coupling effect. In this paper we show that a large-scale tide induced by scalar perturbations causes apparent anisotropic distortions in the redshift-space power spectrum of galaxies in a way depending on an alignment between the tide, wave vector of small-scale modes and line-of-sight direction. Using the perturbation theory of structure formation, we derive a response function of the redshift-space power spectrum to large-scale tide. We then investigate the impact of large-scale tide on estimation of cosmological distances and the redshift-space distortion parameter via the measured redshift-space power spectrum for a hypothetical large-volume survey, based on the Fisher matrix formalism. To do this, we treat the large-scale tide as a signal, rather than an additional source of the statistical errors, and show that a degradation in the parameter is restored if we can employ the prior on the rms amplitude expected for the standard cold dark matter (CDM) model. We also discuss whether the large-scale tide can be constrained at an accuracy better than the CDM prediction, if the effects up to a larger wave number in the nonlinear regime can be included.

Large deviations in the presence of cooperativity and slow dynamics

Science.gov (United States)

Whitelam, Stephen

2018-06-01

We study simple models of intermittency, involving switching between two states, within the dynamical large-deviation formalism. Singularities appear in the formalism when switching is cooperative or when its basic time scale diverges. In the first case the unbiased trajectory distribution undergoes a symmetry breaking, leading to a change in shape of the large-deviation rate function for a particular dynamical observable. In the second case the symmetry of the unbiased trajectory distribution remains unbroken. Comparison of these models suggests that singularities of the dynamical large-deviation formalism can signal the dynamical equivalent of an equilibrium phase transition but do not necessarily do so.

Mutually unbiased bases and semi-definite programming

Energy Technology Data Exchange (ETDEWEB)

Brierley, Stephen; Weigert, Stefan, E-mail: steve.brierley@ulb.ac.be, E-mail: stefan.weigert@york.ac.uk

2010-11-01

A complex Hilbert space of dimension six supports at least three but not more than seven mutually unbiased bases. Two computer-aided analytical methods to tighten these bounds are reviewed, based on a discretization of parameter space and on Groebner bases. A third algorithmic approach is presented: the non-existence of more than three mutually unbiased bases in composite dimensions can be decided by a global optimization method known as semidefinite programming. The method is used to confirm that the spectral matrix cannot be part of a complete set of seven mutually unbiased bases in dimension six.

Mutually unbiased bases and semi-definite programming

International Nuclear Information System (INIS)

Brierley, Stephen; Weigert, Stefan

2010-01-01

A complex Hilbert space of dimension six supports at least three but not more than seven mutually unbiased bases. Two computer-aided analytical methods to tighten these bounds are reviewed, based on a discretization of parameter space and on Groebner bases. A third algorithmic approach is presented: the non-existence of more than three mutually unbiased bases in composite dimensions can be decided by a global optimization method known as semidefinite programming. The method is used to confirm that the spectral matrix cannot be part of a complete set of seven mutually unbiased bases in dimension six.

Large Pelagics Intercept Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Large Pelagics Intercept Survey (LPIS) is a dockside survey of private and charterboat captains who have just completed fishing trips directed at large pelagic...

A Polar Rover for Large-Scale Scientific Surveys: Design, Implementation and Field Test Results

Directory of Open Access Journals (Sweden)

Yuqing He

2015-10-01

Full Text Available Exploration of polar regions is of great importance to scientific research. Unfortunately, due to the harsh environment, most of the regions on the Antarctic continent are still unreachable for humankind. Therefore, in 2011, the Chinese National Antarctic Research Expedition (CHINARE launched a project to design a rover to conduct large-scale scientific surveys on the Antarctic. The main challenges for the rover are twofold: one is the mobility, i.e., how to make a rover that could survive the harsh environment and safely move on the uneven, icy and snowy terrain; the other is the autonomy, in that the robot should be able to move at a relatively high speed with little or no human intervention so that it can explore a large region in a limit time interval under the communication constraints. In this paper, the corresponding techniques, especially the polar rover's design and autonomous navigation algorithms, are introduced in detail. Subsequently, an experimental report of the fields tests on the Antarctic is given to show some preliminary evaluation of the rover. Finally, experiences and existing challenging problems are summarized.

2MASS Constraints on the Local Large-Scale Structure: A Challenge to LCDM?

OpenAIRE

Frith, W. J.; Shanks, T.; Outram, P. J.

2004-01-01

We investigate the large-scale structure of the local galaxy distribution using the recently completed 2 Micron All Sky Survey (2MASS). First, we determine the K-band number counts over the 4000 sq.deg. APM survey area where evidence for a large-scale `local hole' has previously been detected and compare them to a homogeneous prediction. Considering a LCDM form for the 2-point angular correlation function, the observed deficiency represents a 5 sigma fluctuation in the galaxy distribution. We...

Disclosure control using partially synthetic data for large-scale health surveys, with applications to CanCORS.

Science.gov (United States)

Loong, Bronwyn; Zaslavsky, Alan M; He, Yulei; Harrington, David P

2013-10-30

Statistical agencies have begun to partially synthesize public-use data for major surveys to protect the confidentiality of respondents' identities and sensitive attributes by replacing high disclosure risk and sensitive variables with multiple imputations. To date, there are few applications of synthetic data techniques to large-scale healthcare survey data. Here, we describe partial synthesis of survey data collected by the Cancer Care Outcomes Research and Surveillance (CanCORS) project, a comprehensive observational study of the experiences, treatments, and outcomes of patients with lung or colorectal cancer in the USA. We review inferential methods for partially synthetic data and discuss selection of high disclosure risk variables for synthesis, specification of imputation models, and identification disclosure risk assessment. We evaluate data utility by replicating published analyses and comparing results using original and synthetic data and discuss practical issues in preserving inferential conclusions. We found that important subgroup relationships must be included in the synthetic data imputation model, to preserve the data utility of the observed data for a given analysis procedure. We conclude that synthetic CanCORS data are suited best for preliminary data analyses purposes. These methods address the requirement to share data in clinical research without compromising confidentiality. Copyright © 2013 John Wiley & Sons, Ltd.

How many hours do you usually work? An analysis of the working hours questions in 26 large-scale surveys in 6 countries and the European Union.

OpenAIRE

Dragstra, A.; Tijdens, K.

2004-01-01

This paper reviews how working hours are asked in 26 large-scale surveys in 6 countries plus the European Union. Four dimensions of working time were investigated, notably number of working hours, timing of work, predictability and control over hours, and commuting time. Although almost all questionnaires ask for hours worked, the terminology varies largely. In only half of the cases a reference period is taken into account and in half the reasons for working more/less in the survey week than...

Mutually unbiased bases

Indian Academy of Sciences (India)

Mutually unbiased bases play an important role in quantum cryptography [2] and in the optimal determination of the density operator of an ensemble [3,4]. A density operator ρ in N-dimensions depends on N2 1 real quantities. With the help of MUB's, any such density operator can be encoded, in an optimal way, in terms of ...

Large-scale Star-formation-driven Outflows at 1 3D-HST Survey

Science.gov (United States)

Lundgren, Britt F.; Brammer, Gabriel; van Dokkum, Pieter; Bezanson, Rachel; Franx, Marijn; Fumagalli, Mattia; Momcheva, Ivelina; Nelson, Erica; Skelton, Rosalind E.; Wake, David; Whitaker, Katherine; da Cunha, Elizabete; Erb, Dawn K.; Fan, Xiaohui; Kriek, Mariska; Labbé, Ivo; Marchesini, Danilo; Patel, Shannon; Rix, Hans Walter; Schmidt, Kasper; van der Wel, Arjen

2012-11-01

We present evidence of large-scale outflows from three low-mass (log(M */M ⊙) ~ 9.75) star-forming (SFR > 4 M ⊙ yr-1) galaxies observed at z = 1.24, z = 1.35, and z = 1.75 in the 3D-HST Survey. Each of these galaxies is located within a projected physical distance of 60 kpc around the sight line to the quasar SDSS J123622.93+621526.6, which exhibits well-separated strong (W λ2796 r >~ 0.8 Å) Mg II absorption systems matching precisely to the redshifts of the three galaxies. We derive the star formation surface densities from the Hα emission in the WFC3 G141 grism observations for the galaxies and find that in each case the star formation surface density well exceeds 0.1 M ⊙ yr-1 kpc-2, the typical threshold for starburst galaxies in the local universe. From a small but complete parallel census of the 0.65 0.8 Å Mg II covering fraction of star-forming galaxies at 1 0.4 Å Mg II absorbing gas around star-forming galaxies may evolve from z ~ 2 to the present, consistent with recent observations of an increasing collimation of star-formation-driven outflows with time from z ~ 3.

Efficient Topology Estimation for Large Scale Optical Mapping

CERN Document Server

Elibol, Armagan; Garcia, Rafael

2013-01-01

Large scale optical mapping methods are in great demand among scientists who study different aspects of the seabed, and have been fostered by impressive advances in the capabilities of underwater robots in gathering optical data from the seafloor. Cost and weight constraints mean that low-cost ROVs usually have a very limited number of sensors. When a low-cost robot carries out a seafloor survey using a down-looking camera, it usually follows a predefined trajectory that provides several non time-consecutive overlapping image pairs. Finding these pairs (a process known as topology estimation) is indispensable to obtaining globally consistent mosaics and accurate trajectory estimates, which are necessary for a global view of the surveyed area, especially when optical sensors are the only data source. This book contributes to the state-of-art in large area image mosaicing methods for underwater surveys using low-cost vehicles equipped with a very limited sensor suite. The main focus has been on global alignment...

Survey of large protein complexes D. vulgaris reveals great structural diversity

Energy Technology Data Exchange (ETDEWEB)

Han, B.-G.; Dong, M.; Liu, H.; Camp, L.; Geller, J.; Singer, M.; Hazen, T. C.; Choi, M.; Witkowska, H. E.; Ball, D. A.; Typke, D.; Downing, K. H.; Shatsky, M.; Brenner, S. E.; Chandonia, J.-M.; Biggin, M. D.; Glaeser, R. M.

2009-08-15

An unbiased survey has been made of the stable, most abundant multi-protein complexes in Desulfovibrio vulgaris Hildenborough (DvH) that are larger than Mr {approx} 400 k. The quaternary structures for 8 of the 16 complexes purified during this work were determined by single-particle reconstruction of negatively stained specimens, a success rate {approx}10 times greater than that of previous 'proteomic' screens. In addition, the subunit compositions and stoichiometries of the remaining complexes were determined by biochemical methods. Our data show that the structures of only two of these large complexes, out of the 13 in this set that have recognizable functions, can be modeled with confidence based on the structures of known homologs. These results indicate that there is significantly greater variability in the way that homologous prokaryotic macromolecular complexes are assembled than has generally been appreciated. As a consequence, we suggest that relying solely on previously determined quaternary structures for homologous proteins may not be sufficient to properly understand their role in another cell of interest.

Cardinality Estimation Algorithm in Large-Scale Anonymous Wireless Sensor Networks

KAUST Repository

Douik, Ahmed

2017-08-30

Consider a large-scale anonymous wireless sensor network with unknown cardinality. In such graphs, each node has no information about the network topology and only possesses a unique identifier. This paper introduces a novel distributed algorithm for cardinality estimation and topology discovery, i.e., estimating the number of node and structure of the graph, by querying a small number of nodes and performing statistical inference methods. While the cardinality estimation allows the design of more efficient coding schemes for the network, the topology discovery provides a reliable way for routing packets. The proposed algorithm is shown to produce a cardinality estimate proportional to the best linear unbiased estimator for dense graphs and specific running times. Simulation results attest the theoretical results and reveal that, for a reasonable running time, querying a small group of nodes is sufficient to perform an estimation of 95% of the whole network. Applications of this work include estimating the number of Internet of Things (IoT) sensor devices, online social users, active protein cells, etc.

Can we do better than the grid survey: Optimal synoptic surveys in presence of variable uncertainty and decorrelation scales

Science.gov (United States)

Frolov, Sergey; Garau, Bartolame; Bellingham, James

2014-08-01

Regular grid ("lawnmower") survey is a classical strategy for synoptic sampling of the ocean. Is it possible to achieve a more effective use of available resources if one takes into account a priori knowledge about variability in magnitudes of uncertainty and decorrelation scales? In this article, we develop and compare the performance of several path-planning algorithms: optimized "lawnmower," a graph-search algorithm (A*), and a fully nonlinear genetic algorithm. We use the machinery of the best linear unbiased estimator (BLUE) to quantify the ability of a vehicle fleet to synoptically map distribution of phytoplankton off the central California coast. We used satellite and in situ data to specify covariance information required by the BLUE estimator. Computational experiments showed that two types of sampling strategies are possible: a suboptimal space-filling design (produced by the "lawnmower" and the A* algorithms) and an optimal uncertainty-aware design (produced by the genetic algorithm). Unlike the space-filling designs that attempted to cover the entire survey area, the optimal design focused on revisiting areas of high uncertainty. Results of the multivehicle experiments showed that fleet performance predictors, such as cumulative speed or the weight of the fleet, predicted the performance of a homogeneous fleet well; however, these were poor predictors for comparing the performance of different platforms.

Large-scale solar purchasing

International Nuclear Information System (INIS)

1999-01-01

The principal objective of the project was to participate in the definition of a new IEA task concerning solar procurement (''the Task'') and to assess whether involvement in the task would be in the interest of the UK active solar heating industry. The project also aimed to assess the importance of large scale solar purchasing to UK active solar heating market development and to evaluate the level of interest in large scale solar purchasing amongst potential large scale purchasers (in particular housing associations and housing developers). A further aim of the project was to consider means of stimulating large scale active solar heating purchasing activity within the UK. (author)

Survey and research for the enhancement of large-scale technology development 2. How large-scale technology development should be in the future; Ogata gijutsu kaihatsu suishin no tame no chosa kenkyu. 2. Kongo no ogata gijutsu kaihatsu no arikata

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

A survey is conducted over the subject matter by holding interviews with people, employed with the entrusted businesses participating in the large-scale industrial technology development system, who are engaged in the development of industrial technologies, and with people of experience or academic background involved in the project enhancement effort. Needs of improvement are pointed out that the competition principle based for example on parallel development be introduced; that research-on-research be practiced for effective task institution; midway evaluation be substantiated since prior evaluation is difficult; efforts be made to organize new industries utilizing the fruits of large-scale industrial technology for the creation of markets, not to induce economic conflicts; that transfer of technologies be enhanced from the private sector to public sector. Studies are made about the review of research conducting systems; utilization of the power of private sector research and development efforts; enlightening about industrial proprietorship; and the diffusion of large-scale project systems. In this connection, problems are pointed out, requests are submitted, and remedial measures and suggestions are presented. (NEDO)

Understanding uncertainties in non-linear population trajectories: a Bayesian semi-parametric hierarchical approach to large-scale surveys of coral cover.

Directory of Open Access Journals (Sweden)

Julie Vercelloni

Full Text Available Recently, attempts to improve decision making in species management have focussed on uncertainties associated with modelling temporal fluctuations in populations. Reducing model uncertainty is challenging; while larger samples improve estimation of species trajectories and reduce statistical errors, they typically amplify variability in observed trajectories. In particular, traditional modelling approaches aimed at estimating population trajectories usually do not account well for nonlinearities and uncertainties associated with multi-scale observations characteristic of large spatio-temporal surveys. We present a Bayesian semi-parametric hierarchical model for simultaneously quantifying uncertainties associated with model structure and parameters, and scale-specific variability over time. We estimate uncertainty across a four-tiered spatial hierarchy of coral cover from the Great Barrier Reef. Coral variability is well described; however, our results show that, in the absence of additional model specifications, conclusions regarding coral trajectories become highly uncertain when considering multiple reefs, suggesting that management should focus more at the scale of individual reefs. The approach presented facilitates the description and estimation of population trajectories and associated uncertainties when variability cannot be attributed to specific causes and origins. We argue that our model can unlock value contained in large-scale datasets, provide guidance for understanding sources of uncertainty, and support better informed decision making.

UNBIASED ESTIMATORS OF SPECIFIC CONNECTIVITY

Directory of Open Access Journals (Sweden)

Jean-Paul Jernot

2011-05-01

Full Text Available This paper deals with the estimation of the specific connectivity of a stationary random set in IRd. It turns out that the "natural" estimator is only asymptotically unbiased. The example of a boolean model of hypercubes illustrates the amplitude of the bias produced when the measurement field is relatively small with respect to the range of the random set. For that reason unbiased estimators are desired. Such an estimator can be found in the literature in the case where the measurement field is a right parallelotope. In this paper, this estimator is extended to apply to measurement fields of various shapes, and to possess a smaller variance. Finally an example from quantitative metallography (specific connectivity of a population of sintered bronze particles is given.

Birth Satisfaction Scale/Birth Satisfaction Scale-Revised (BSS/BSS-R): A large scale United States planned home birth and birth centre survey

OpenAIRE

Fleming, Susan E.; Donovan-Batson, Colleen.; Burduli, Ekaterina.; Barbosa-Leiker, Celestina.; Hollins Martin, Caroline J.; Martin, Colin R.

2016-01-01

Objective:\\ud to explore the prevalence of birth satisfaction for childbearing women planning to birth in their home or birth centers in the United States. Examining differences in birth satisfaction of the home and birth centers; and those who birthed in a hospital using the 30-item Birth Satisfaction Scale (BSS) and the 10-item Birth Satisfaction Scale-Revised (BSS-R).\\ud Study design:\\ud a quantitative survey using the BSS and BSS-R were employed. Additional demographic data were collected...

Large-Scale Structure Behind The Milky Way with ALFAZOA

Science.gov (United States)

Sanchez Barrantes, Monica; Henning, Patricia A.; Momjian, Emmanuel; McIntyre, Travis; Minchin, Robert F.

2018-06-01

The region of the sky behind the Milky Way (the Zone of Avoidance; ZOA) is not well studied due to high obscuration from gas and dust in our galaxy as well as stellar confusion, which results in low detection rate of galaxies in this region. Because of this, little is known about the distribution of galaxies in the ZOA, and other all sky redshift surveys have incomplete maps (e.g. the 2MASS Redshift survey in NIR has a gap of 5-8 deg around the Galactic plane). There is still controversy about the dipole anisotropy calculated from the comparison between the CMB and galaxy and redshift surveys, in part due to the incomplete sky mapping and redshift depth of these surveys. Fortunately, there is no ZOA at radio wavelengths because such wavelengths can pass unimpeded through dust and are not affected by stellar confusion. Therefore, we can detect and make a map of the distribution of obscured galaxies that contain the 21cm neutral hydrogen emission line, and trace the large-scale structure across the Galactic plane. The Arecibo L-Band Feed Array Zone of Avoidance (ALFAZOA) survey is a blind HI survey for galaxies behind the Milky Way that covers more than 1000 square degrees of the sky, conducted in two phases: shallow (completed) and deep (ongoing). We show the results of the finished shallow phase of the survey, which mapped a region between the galactic longitude l=30-75 deg, and latitude b <|10 deg|, and detected 418 galaxies to about 12,000 km/s, including galaxy properties and mapped large-scale structure. We do the same for new results from the deep phase, which is ongoing and covers 30 < l < 75 deg and b < |2| deg for the inner galaxy and 175 < l < 207 deg, with -2 < b < 1 for the outer galaxy.

The CIDA-QUEST large-scale survey of Orion OB1: evidence for rapid disk dissipation in a dispersed stellar population.

Science.gov (United States)

Briceño, C; Vivas, A K; Calvet, N; Hartmann, L; Pacheco, R; Herrera, D; Romero, L; Berlind, P; Sánchez, G; Snyder, J A; Andrews, P

2001-01-05

We are conducting a large-scale, multiepoch, optical photometric survey [Centro de Investigaciones de Astronomia-Quasar Equatorial Survey Team (CIDA-QUEST)] covering about 120 square degrees to identify the young low-mass stars in the Orion OB1 association. We present results for an area of 34 square degrees. Using photometric variability as our main selection criterion, as well as follow-up spectroscopy, we confirmed 168 previously unidentified pre-main sequence stars that are about 0.6 to 0.9 times the mass of the sun (Mo), with ages of about 1 million to 3 million years (Ori OB1b) and about 3 million to 10 million years (Ori OB1a). The low-mass stars are spatially coincident with the high-mass (at least 3 Mo) members of the associations. Indicators of disk accretion such as Halpha emission and near-infrared emission from dusty disks fall sharply from Ori OB1b to Ori OB1a, indicating that the time scale for disk dissipation and possibly the onset of planet formation is a few million years.

Unbiased Sampling and Meshing of Isosurfaces

KAUST Repository

Yan, Dongming

2014-05-07

In this paper, we present a new technique to generate unbiased samples on isosurfaces. An isosurface, F(x,y,z) = c , of a function, F , is implicitly defined by trilinear interpolation of background grid points. The key idea of our approach is that of treating the isosurface within a grid cell as a graph (height) function in one of the three coordinate axis directions, restricted to where the slope is not too high, and integrating / sampling from each of these three. We use this unbiased sampling algorithm for applications in Monte Carlo integration, Poisson-disk sampling, and isosurface meshing.

Unbiased Sampling and Meshing of Isosurfaces

KAUST Repository

Yan, Dongming; Wallner, Johannes; Wonka, Peter

2014-01-01

In this paper, we present a new technique to generate unbiased samples on isosurfaces. An isosurface, F(x,y,z) = c , of a function, F , is implicitly defined by trilinear interpolation of background grid points. The key idea of our approach is that of treating the isosurface within a grid cell as a graph (height) function in one of the three coordinate axis directions, restricted to where the slope is not too high, and integrating / sampling from each of these three. We use this unbiased sampling algorithm for applications in Monte Carlo integration, Poisson-disk sampling, and isosurface meshing.

Assessing outcomes of large-scale public health interventions in the absence of baseline data using a mixture of Cox and binomial regressions

Science.gov (United States)

2014-01-01

Background Large-scale public health interventions with rapid scale-up are increasingly being implemented worldwide. Such implementation allows for a large target population to be reached in a short period of time. But when the time comes to investigate the effectiveness of these interventions, the rapid scale-up creates several methodological challenges, such as the lack of baseline data and the absence of control groups. One example of such an intervention is Avahan, the India HIV/AIDS initiative of the Bill & Melinda Gates Foundation. One question of interest is the effect of Avahan on condom use by female sex workers with their clients. By retrospectively reconstructing condom use and sex work history from survey data, it is possible to estimate how condom use rates evolve over time. However formal inference about how this rate changes at a given point in calendar time remains challenging. Methods We propose a new statistical procedure based on a mixture of binomial regression and Cox regression. We compare this new method to an existing approach based on generalized estimating equations through simulations and application to Indian data. Results Both methods are unbiased, but the proposed method is more powerful than the existing method, especially when initial condom use is high. When applied to the Indian data, the new method mostly agrees with the existing method, but seems to have corrected some implausible results of the latter in a few districts. We also show how the new method can be used to analyze the data of all districts combined. Conclusions The use of both methods can be recommended for exploratory data analysis. However for formal statistical inference, the new method has better power. PMID:24397563

Large-scale motions in the universe: a review

International Nuclear Information System (INIS)

Burstein, D.

1990-01-01

The expansion of the universe can be retarded in localised regions within the universe both by the presence of gravity and by non-gravitational motions generated in the post-recombination universe. The motions of galaxies thus generated are called 'peculiar motions', and the amplitudes, size scales and coherence of these peculiar motions are among the most direct records of the structure of the universe. As such, measurements of these properties of the present-day universe provide some of the severest tests of cosmological theories. This is a review of the current evidence for large-scale motions of galaxies out to a distance of ∼5000 km s -1 (in an expanding universe, distance is proportional to radial velocity). 'Large-scale' in this context refers to motions that are correlated over size scales larger than the typical sizes of groups of galaxies, up to and including the size of the volume surveyed. To orient the reader into this relatively new field of study, a short modern history is given together with an explanation of the terminology. Careful consideration is given to the data used to measure the distances, and hence the peculiar motions, of galaxies. The evidence for large-scale motions is presented in a graphical fashion, using only the most reliable data for galaxies spanning a wide range in optical properties and over the complete range of galactic environments. The kinds of systematic errors that can affect this analysis are discussed, and the reliability of these motions is assessed. The predictions of two models of large-scale motion are compared to the observations, and special emphasis is placed on those motions in which our own Galaxy directly partakes. (author)

Generating mock data sets for large-scale Lyman-α forest correlation measurements

Energy Technology Data Exchange (ETDEWEB)

Font-Ribera, Andreu [Institut de Ciències de l' Espai (CSIC-IEEC), Campus UAB, Fac. Ciències, torre C5 parell 2, Bellaterra, Catalonia (Spain); McDonald, Patrick [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Miralda-Escudé, Jordi, E-mail: font@ieec.uab.es, E-mail: pvmcdonald@lbl.gov, E-mail: miralda@icc.ub.edu [Institució Catalana de Recerca i Estudis Avançats, Barcelona, Catalonia (Spain)

2012-01-01

Massive spectroscopic surveys of high-redshift quasars yield large numbers of correlated Lyα absorption spectra that can be used to measure large-scale structure. Simulations of these surveys are required to accurately interpret the measurements of correlations and correct for systematic errors. An efficient method to generate mock realizations of Lyα forest surveys is presented which generates a field over the lines of sight to the survey sources only, instead of having to generate it over the entire three-dimensional volume of the survey. The method can be calibrated to reproduce the power spectrum and one-point distribution function of the transmitted flux fraction, as well as the redshift evolution of these quantities, and is easily used for modeling any survey systematic effects. We present an example of how these mock surveys are applied to predict the measurement errors in a survey with similar parameters as the BOSS quasar survey in SDSS-III.

Generating mock data sets for large-scale Lyman-α forest correlation measurements

International Nuclear Information System (INIS)

Font-Ribera, Andreu; McDonald, Patrick; Miralda-Escudé, Jordi

2012-01-01

Massive spectroscopic surveys of high-redshift quasars yield large numbers of correlated Lyα absorption spectra that can be used to measure large-scale structure. Simulations of these surveys are required to accurately interpret the measurements of correlations and correct for systematic errors. An efficient method to generate mock realizations of Lyα forest surveys is presented which generates a field over the lines of sight to the survey sources only, instead of having to generate it over the entire three-dimensional volume of the survey. The method can be calibrated to reproduce the power spectrum and one-point distribution function of the transmitted flux fraction, as well as the redshift evolution of these quantities, and is easily used for modeling any survey systematic effects. We present an example of how these mock surveys are applied to predict the measurement errors in a survey with similar parameters as the BOSS quasar survey in SDSS-III

Cosmological Parameter Estimation with Large Scale Structure Observations

CERN Document Server

Di Dio, Enea; Durrer, Ruth; Lesgourgues, Julien

2014-01-01

We estimate the sensitivity of future galaxy surveys to cosmological parameters, using the redshift dependent angular power spectra of galaxy number counts, $C_\\ell(z_1,z_2)$, calculated with all relativistic corrections at first order in perturbation theory. We pay special attention to the redshift dependence of the non-linearity scale and present Fisher matrix forecasts for Euclid-like and DES-like galaxy surveys. We compare the standard $P(k)$ analysis with the new $C_\\ell(z_1,z_2)$ method. We show that for surveys with photometric redshifts the new analysis performs significantly better than the $P(k)$ analysis. For spectroscopic redshifts, however, the large number of redshift bins which would be needed to fully profit from the redshift information, is severely limited by shot noise. We also identify surveys which can measure the lensing contribution and we study the monopole, $C_0(z_1,z_2)$.

Large scale mapping: an empirical comparison of pixel-based and ...

African Journals Online (AJOL)

In the past, large scale mapping was carried using precise ground survey methods. Later, paradigm shift in data collection using medium to low resolution and, recently, high resolution images brought to bear the problem of accurate data analysis and fitness-for-purpose challenges. Using high resolution satellite images ...

Automation of Survey Data Processing, Documentation and Dissemination: An Application to Large-Scale Self-Reported Educational Survey.

Science.gov (United States)

Shim, Eunjae; Shim, Minsuk K.; Felner, Robert D.

Automation of the survey process has proved successful in many industries, yet it is still underused in educational research. This is largely due to the facts (1) that number crunching is usually carried out using software that was developed before information technology existed, and (2) that the educational research is to a great extent trapped…

Energy transfers in large-scale and small-scale dynamos

Science.gov (United States)

Samtaney, Ravi; Kumar, Rohit; Verma, Mahendra

2015-11-01

We present the energy transfers, mainly energy fluxes and shell-to-shell energy transfers in small-scale dynamo (SSD) and large-scale dynamo (LSD) using numerical simulations of MHD turbulence for Pm = 20 (SSD) and for Pm = 0.2 on 10243 grid. For SSD, we demonstrate that the magnetic energy growth is caused by nonlocal energy transfers from the large-scale or forcing-scale velocity field to small-scale magnetic field. The peak of these energy transfers move towards lower wavenumbers as dynamo evolves, which is the reason for the growth of the magnetic fields at the large scales. The energy transfers U2U (velocity to velocity) and B2B (magnetic to magnetic) are forward and local. For LSD, we show that the magnetic energy growth takes place via energy transfers from large-scale velocity field to large-scale magnetic field. We observe forward U2U and B2B energy flux, similar to SSD.

FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN): Molecular clouds toward W 33; possible evidence for a cloud-cloud collision triggering O star formation

Science.gov (United States)

Kohno, Mikito; Torii, Kazufumi; Tachihara, Kengo; Umemoto, Tomofumi; Minamidani, Tetsuhiro; Nishimura, Atsushi; Fujita, Shinji; Matsuo, Mitsuhiro; Yamagishi, Mitsuyoshi; Tsuda, Yuya; Kuriki, Mika; Kuno, Nario; Ohama, Akio; Hattori, Yusuke; Sano, Hidetoshi; Yamamoto, Hiroaki; Fukui, Yasuo

2018-05-01

We observed molecular clouds in the W 33 high-mass star-forming region associated with compact and extended H II regions using the NANTEN2 telescope as well as the Nobeyama 45 m telescope in the J = 1-0 transitions of 12CO, 13CO, and C18O as part of the FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN) legacy survey. We detected three velocity components at 35 km s-1, 45 km s-1, and 58 km s-1. The 35 km s-1 and 58 km s-1 clouds are likely to be physically associated with W 33 because of the enhanced 12CO J = 3-2 to J = 1-0 intensity ratio as R_3-2/1-0} > 1.0 due to the ultraviolet irradiation by OB stars, and morphological correspondence between the distributions of molecular gas and the infrared and radio continuum emissions excited by high-mass stars. The two clouds show complementary distributions around W 33. The velocity separation is too large to be gravitationally bound, and yet not explained by expanding motion by stellar feedback. Therefore, we discuss whether a cloud-cloud collision scenario likely explains the high-mass star formation in W 33.

Inflation Physics from the Cosmic Microwave Background and Large Scale Structure

Science.gov (United States)

Abazajian, K.N.; Arnold,K.; Austermann, J.; Benson, B.A.; Bischoff, C.; Bock, J.; Bond, J.R.; Borrill, J.; Buder, I.; Burke, D.L.;

How many hours do you usually work? An analysis of the working hours questions in 26 large-scale surveys in 6 countries and the European Union.

NARCIS (Netherlands)

Dragstra, A.; Tijdens, K.

2004-01-01

This paper reviews how working hours are asked in 26 large-scale surveys in 6 countries plus the European Union. Four dimensions of working time were investigated, notably number of working hours, timing of work, predictability and control over hours, and commuting time. Although almost all

How many hours do you usually work? An analysis of the working hours questions in 26 large-scale surveys in six countries and the European Union

NARCIS (Netherlands)

Tijdens, K.; Dragstra, A.

2007-01-01

This article reviews how working hours are asked for in 26 large-scale surveys in six countries plus the European Union. Four dimensions of working time were investigated, notably number of working hours, timing of work, predictability and control over hours, and commuting time. Although almost all

The effective field theory of cosmological large scale structures

Energy Technology Data Exchange (ETDEWEB)

Carrasco, John Joseph M. [Stanford Univ., Stanford, CA (United States); Hertzberg, Mark P. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Senatore, Leonardo [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)

2012-09-20

Large scale structure surveys will likely become the next leading cosmological probe. In our universe, matter perturbations are large on short distances and small at long scales, i.e. strongly coupled in the UV and weakly coupled in the IR. To make precise analytical predictions on large scales, we develop an effective field theory formulated in terms of an IR effective fluid characterized by several parameters, such as speed of sound and viscosity. These parameters, determined by the UV physics described by the Boltzmann equation, are measured from N-body simulations. We find that the speed of sound of the effective fluid is c²_s ≈ 10^–6c² and that the viscosity contributions are of the same order. The fluid describes all the relevant physics at long scales k and permits a manifestly convergent perturbative expansion in the size of the matter perturbations δ(k) for all the observables. As an example, we calculate the correction to the power spectrum at order δ(k)⁴. As a result, the predictions of the effective field theory are found to be in much better agreement with observation than standard cosmological perturbation theory, already reaching percent precision at this order up to a relatively short scale k ≃ 0.24h Mpc^–1.

Multiresolution comparison of precipitation datasets for large-scale models

Science.gov (United States)

Chun, K. P.; Sapriza Azuri, G.; Davison, B.; DeBeer, C. M.; Wheater, H. S.

2014-12-01

Gridded precipitation datasets are crucial for driving large-scale models which are related to weather forecast and climate research. However, the quality of precipitation products is usually validated individually. Comparisons between gridded precipitation products along with ground observations provide another avenue for investigating how the precipitation uncertainty would affect the performance of large-scale models. In this study, using data from a set of precipitation gauges over British Columbia and Alberta, we evaluate several widely used North America gridded products including the Canadian Gridded Precipitation Anomalies (CANGRD), the National Center for Environmental Prediction (NCEP) reanalysis, the Water and Global Change (WATCH) project, the thin plate spline smoothing algorithms (ANUSPLIN) and Canadian Precipitation Analysis (CaPA). Based on verification criteria for various temporal and spatial scales, results provide an assessment of possible applications for various precipitation datasets. For long-term climate variation studies (~100 years), CANGRD, NCEP, WATCH and ANUSPLIN have different comparative advantages in terms of their resolution and accuracy. For synoptic and mesoscale precipitation patterns, CaPA provides appealing performance of spatial coherence. In addition to the products comparison, various downscaling methods are also surveyed to explore new verification and bias-reduction methods for improving gridded precipitation outputs for large-scale models.

Large-scale grid management

International Nuclear Information System (INIS)

Langdal, Bjoern Inge; Eggen, Arnt Ove

2003-01-01

The network companies in the Norwegian electricity industry now have to establish a large-scale network management, a concept essentially characterized by (1) broader focus (Broad Band, Multi Utility,...) and (2) bigger units with large networks and more customers. Research done by SINTEF Energy Research shows so far that the approaches within large-scale network management may be structured according to three main challenges: centralization, decentralization and out sourcing. The article is part of a planned series

Quantum process reconstruction based on mutually unbiased basis

International Nuclear Information System (INIS)

Fernandez-Perez, A.; Saavedra, C.; Klimov, A. B.

2011-01-01

We study a quantum process reconstruction based on the use of mutually unbiased projectors (MUB projectors) as input states for a D-dimensional quantum system, with D being a power of a prime number. This approach connects the results of quantum-state tomography using mutually unbiased bases with the coefficients of a quantum process, expanded in terms of MUB projectors. We also study the performance of the reconstruction scheme against random errors when measuring probabilities at the MUB projectors.

Dipolar modulation of Large-Scale Structure

Science.gov (United States)

Yoon, Mijin

For the last two decades, we have seen a drastic development of modern cosmology based on various observations such as the cosmic microwave background (CMB), type Ia supernovae, and baryonic acoustic oscillations (BAO). These observational evidences have led us to a great deal of consensus on the cosmological model so-called LambdaCDM and tight constraints on cosmological parameters consisting the model. On the other hand, the advancement in cosmology relies on the cosmological principle: the universe is isotropic and homogeneous on large scales. Testing these fundamental assumptions is crucial and will soon become possible given the planned observations ahead. Dipolar modulation is the largest angular anisotropy of the sky, which is quantified by its direction and amplitude. We measured a huge dipolar modulation in CMB, which mainly originated from our solar system's motion relative to CMB rest frame. However, we have not yet acquired consistent measurements of dipolar modulations in large-scale structure (LSS), as they require large sky coverage and a number of well-identified objects. In this thesis, we explore measurement of dipolar modulation in number counts of LSS objects as a test of statistical isotropy. This thesis is based on two papers that were published in peer-reviewed journals. In Chapter 2 [Yoon et al., 2014], we measured a dipolar modulation in number counts of WISE matched with 2MASS sources. In Chapter 3 [Yoon & Huterer, 2015], we investigated requirements for detection of kinematic dipole in future surveys.

Examining Agencies' Satisfaction with Electronic Record Management Systems in e-Government: A Large-Scale Survey Study

Science.gov (United States)

Hsu, Fang-Ming; Hu, Paul Jen-Hwa; Chen, Hsinchun; Hu, Han-Fen

While e-government is propelling and maturing steadily, advanced technological capabilities alone cannot guarantee agencies’ realizing the full benefits of the enabling computer-based systems. This study analyzes information systems in e-government settings by examining agencies’ satisfaction with an electronic record management system (ERMS). Specifically, we investigate key satisfaction determinants that include regulatory compliance, job relevance, and satisfaction with support services for using the ERMS. We test our model and the hypotheses in it, using a large-scale survey that involves a total of 1,652 government agencies in Taiwan. Our results show significant effects of regulatory compliance on job relevance and satisfaction with support services, which in turn determine government agencies’ satisfaction with an ERMS. Our data exhibit a reasonably good fit to our model, which can explain a significant portion of the variance in agencies’ satisfaction with an ERMS. Our findings have several important implications to research and practice, which are also discussed.

How many hours do you usually work? An analysis of the working hours questions in 26 large-scale surveys in six countries and the European Union

OpenAIRE

Tijdens, K.; Dragstra, A.

2007-01-01

This article reviews how working hours are asked for in 26 large-scale surveys in six countries plus the European Union. Four dimensions of working time were investigated, notably number of working hours, timing of work, predictability and control over hours, and commuting time. Although almost all questionnaires ask for hours worked, the terminology varies greatly. In only half of the cases a reference period is taken into account and in half the reasons for working more/less in the survey w...

Unbiased stereologic techniques for practical use in diagnostic histopathology

DEFF Research Database (Denmark)

Sørensen, Flemming Brandt

1995-01-01

Grading of malignancy by the examination of morphologic and cytologic details in histologic sections from malignant neoplasms is based exclusively on qualitative features, associated with significant subjectivity, and thus rather poor reproducibility. The traditional way of malignancy grading may...... by introducing quantitative techniques in the histopathologic discipline of malignancy grading. Unbiased stereologic methods, especially based on measurements of nuclear three-dimensional mean size, have during the last decade proved their value in this regard. In this survey, the methods are reviewed regarding...... the basic technique involved, sampling, efficiency, and reproducibility. Various types of cancers, where stereologic grading of malignancy has been used, are reviewed and discussed with regard to the development of a new objective and reproducible basis for carrying out prognosis-related malignancy grading...

Ethics of large-scale change

OpenAIRE

Arler, Finn

2006-01-01

  The subject of this paper is long-term large-scale changes in human society. Some very significant examples of large-scale change are presented: human population growth, human appropriation of land and primary production, the human use of fossil fuels, and climate change. The question is posed, which kind of attitude is appropriate when dealing with large-scale changes like these from an ethical point of view. Three kinds of approaches are discussed: Aldo Leopold's mountain thinking, th...

Updating Geospatial Data from Large Scale Data Sources

Science.gov (United States)

Zhao, R.; Chen, J.; Wang, D.; Shang, Y.; Wang, Z.; Li, X.; Ai, T.

2011-08-01

In the past decades, many geospatial databases have been established at national, regional and municipal levels over the world. Nowadays, it has been widely recognized that how to update these established geo-spatial database and keep them up to date is most critical for the value of geo-spatial database. So, more and more efforts have been devoted to the continuous updating of these geospatial databases. Currently, there exist two main types of methods for Geo-spatial database updating: directly updating with remote sensing images or field surveying materials, and indirectly updating with other updated data result such as larger scale newly updated data. The former method is the basis because the update data sources in the two methods finally root from field surveying and remote sensing. The later method is often more economical and faster than the former. Therefore, after the larger scale database is updated, the smaller scale database should be updated correspondingly in order to keep the consistency of multi-scale geo-spatial database. In this situation, it is very reasonable to apply map generalization technology into the process of geo-spatial database updating. The latter is recognized as one of most promising methods of geo-spatial database updating, especially in collaborative updating environment in terms of map scale, i.e , different scale database are produced and maintained separately by different level organizations such as in China. This paper is focused on applying digital map generalization into the updating of geo-spatial database from large scale in the collaborative updating environment for SDI. The requirements of the application of map generalization into spatial database updating are analyzed firstly. A brief review on geospatial data updating based digital map generalization is then given. Based on the requirements analysis and review, we analyze the key factors for implementing updating geospatial data from large scale including technical

Alignment between galaxies and large-scale structure

International Nuclear Information System (INIS)

Faltenbacher, A.; Li Cheng; White, Simon D. M.; Jing, Yi-Peng; Mao Shude; Wang Jie

2009-01-01

Based on the Sloan Digital Sky Survey DR6 (SDSS) and the Millennium Simulation (MS), we investigate the alignment between galaxies and large-scale structure. For this purpose, we develop two new statistical tools, namely the alignment correlation function and the cos(2θ)-statistic. The former is a two-dimensional extension of the traditional two-point correlation function and the latter is related to the ellipticity correlation function used for cosmic shear measurements. Both are based on the cross correlation between a sample of galaxies with orientations and a reference sample which represents the large-scale structure. We apply the new statistics to the SDSS galaxy catalog. The alignment correlation function reveals an overabundance of reference galaxies along the major axes of red, luminous (L ∼ * ) galaxies out to projected separations of 60 h- 1 Mpc. The signal increases with central galaxy luminosity. No alignment signal is detected for blue galaxies. The cos(2θ)-statistic yields very similar results. Starting from a MS semi-analytic galaxy catalog, we assign an orientation to each red, luminous and central galaxy, based on that of the central region of the host halo (with size similar to that of the stellar galaxy). As an alternative, we use the orientation of the host halo itself. We find a mean projected misalignment between a halo and its central region of ∼ 25 deg. The misalignment decreases slightly with increasing luminosity of the central galaxy. Using the orientations and luminosities of the semi-analytic galaxies, we repeat our alignment analysis on mock surveys of the MS. Agreement with the SDSS results is good if the central orientations are used. Predictions using the halo orientations as proxies for central galaxy orientations overestimate the observed alignment by more than a factor of 2. Finally, the large volume of the MS allows us to generate a two-dimensional map of the alignment correlation function, which shows the reference

Quantifying high dimensional entanglement with two mutually unbiased bases

Directory of Open Access Journals (Sweden)

Paul Erker

2017-07-01

Full Text Available We derive a framework for quantifying entanglement in multipartite and high dimensional systems using only correlations in two unbiased bases. We furthermore develop such bounds in cases where the second basis is not characterized beyond being unbiased, thus enabling entanglement quantification with minimal assumptions. Furthermore, we show that it is feasible to experimentally implement our method with readily available equipment and even conservative estimates of physical parameters.

Unbiased diffusion of Brownian particles on disordered correlated potentials

International Nuclear Information System (INIS)

Salgado-Garcia, Raúl; Maldonado, Cesar

2015-01-01

In this work we study the diffusion of non-interacting overdamped particles, moving on unbiased disordered correlated potentials, subjected to Gaussian white noise. We obtain an exact expression for the diffusion coefficient which allows us to prove that the unbiased diffusion of overdamped particles on a random polymer does not depend on the correlations of the disordered potentials. This universal behavior of the unbiased diffusivity is a direct consequence of the validity of the Einstein relation and the decay of correlations of the random polymer. We test the independence on correlations of the diffusion coefficient for correlated polymers produced by two different stochastic processes, a one-step Markov chain and the expansion-modification system. Within the accuracy of our simulations, we found that the numerically obtained diffusion coefficient for these systems agree with the analytically calculated ones, confirming our predictions. (paper)

Political consultation and large-scale research

International Nuclear Information System (INIS)

Bechmann, G.; Folkers, H.

1977-01-01

Large-scale research and policy consulting have an intermediary position between sociological sub-systems. While large-scale research coordinates science, policy, and production, policy consulting coordinates science, policy and political spheres. In this very position, large-scale research and policy consulting lack of institutional guarantees and rational back-ground guarantee which are characteristic for their sociological environment. This large-scale research can neither deal with the production of innovative goods under consideration of rentability, nor can it hope for full recognition by the basis-oriented scientific community. Policy consulting knows neither the competence assignment of the political system to make decisions nor can it judge succesfully by the critical standards of the established social science, at least as far as the present situation is concerned. This intermediary position of large-scale research and policy consulting has, in three points, a consequence supporting the thesis which states that this is a new form of institutionalization of science: These are: 1) external control, 2) the organization form, 3) the theoretical conception of large-scale research and policy consulting. (orig.) [de

Unbiased multi-fidelity estimate of failure probability of a free plane jet

Science.gov (United States)

Marques, Alexandre; Kramer, Boris; Willcox, Karen; Peherstorfer, Benjamin

2017-11-01

Estimating failure probability related to fluid flows is a challenge because it requires a large number of evaluations of expensive models. We address this challenge by leveraging multiple low fidelity models of the flow dynamics to create an optimal unbiased estimator. In particular, we investigate the effects of uncertain inlet conditions in the width of a free plane jet. We classify a condition as failure when the corresponding jet width is below a small threshold, such that failure is a rare event (failure probability is smaller than 0.001). We estimate failure probability by combining the frameworks of multi-fidelity importance sampling and optimal fusion of estimators. Multi-fidelity importance sampling uses a low fidelity model to explore the parameter space and create a biasing distribution. An unbiased estimate is then computed with a relatively small number of evaluations of the high fidelity model. In the presence of multiple low fidelity models, this framework offers multiple competing estimators. Optimal fusion combines all competing estimators into a single estimator with minimal variance. We show that this combined framework can significantly reduce the cost of estimating failure probabilities, and thus can have a large impact in fluid flow applications. This work was funded by DARPA.

Large-scale multimedia modeling applications

International Nuclear Information System (INIS)

Droppo, J.G. Jr.; Buck, J.W.; Whelan, G.; Strenge, D.L.; Castleton, K.J.; Gelston, G.M.

1995-08-01

Over the past decade, the US Department of Energy (DOE) and other agencies have faced increasing scrutiny for a wide range of environmental issues related to past and current practices. A number of large-scale applications have been undertaken that required analysis of large numbers of potential environmental issues over a wide range of environmental conditions and contaminants. Several of these applications, referred to here as large-scale applications, have addressed long-term public health risks using a holistic approach for assessing impacts from potential waterborne and airborne transport pathways. Multimedia models such as the Multimedia Environmental Pollutant Assessment System (MEPAS) were designed for use in such applications. MEPAS integrates radioactive and hazardous contaminants impact computations for major exposure routes via air, surface water, ground water, and overland flow transport. A number of large-scale applications of MEPAS have been conducted to assess various endpoints for environmental and human health impacts. These applications are described in terms of lessons learned in the development of an effective approach for large-scale applications

Implementation of a Computerized Tablet-Survey in an Adolescent Large-Scale, School-Based Study.

Science.gov (United States)

Delk, Joanne; Harrell, Melissa B; Fakhouri, Tala H I; Muir, Katelyn A; Perry, Cheryl L

2017-07-01

Computerized surveys present many advantages over paper surveys. However, school-based adolescent research questionnaires still mainly rely on paper-and-pencil surveys as access to computers in schools is often not practical. Tablet-assisted self-interviews (TASI) present a possible solution, but their use is largely untested. This paper presents a method for and our experiences with implementing a TASI in a school setting. A TASI was administered to 3907 middle and high school students from 79 schools. The survey assessed use of tobacco products and exposure to tobacco marketing. To assess in-depth tobacco use behaviors, the TASI employed extensive skip patterns to reduce the number of not-applicable questions that nontobacco users received. Pictures were added to help respondents identify the tobacco products they were being queried about. Students were receptive to the tablets and required no instructions in their use. None were lost, stolen, or broken. Item nonresponse, unanswered questions, was a pre-administration concern; however, 92% of participants answered 96% or more of the questions. This method was feasible and successful among a diverse population of students and schools. It generated a unique dataset of in-depth tobacco use behaviors that would not have been possible through a paper-and-pencil survey. © 2017, American School Health Association.

CLASS: The Cosmology Large Angular Scale Surveyor

Science.gov (United States)

Essinger-Hileman, Thomas; Ali, Aamir; Amiri, Mandana; Appel, John W.; Araujo, Derek; Bennett, Charles L.; Boone, Fletcher; Chan, Manwei; Cho, Hsiao-Mei; Chuss, David T.;

Imprint of thawing scalar fields on the large scale galaxy overdensity

Science.gov (United States)

Dinda, Bikash R.; Sen, Anjan A.

2018-04-01

We investigate the observed galaxy power spectrum for the thawing class of scalar field models taking into account various general relativistic corrections that occur on very large scales. We consider the full general relativistic perturbation equations for the matter as well as the dark energy fluid. We form a single autonomous system of equations containing both the background and the perturbed equations of motion which we subsequently solve for different scalar field potentials. First we study the percentage deviation from the Λ CDM model for different cosmological parameters as well as in the observed galaxy power spectra on different scales in scalar field models for various choices of scalar field potentials. Interestingly the difference in background expansion results from the enhancement of power from Λ CDM on small scales, whereas the inclusion of general relativistic (GR) corrections results in the suppression of power from Λ CDM on large scales. This can be useful to distinguish scalar field models from Λ CDM with future optical/radio surveys. We also compare the observed galaxy power spectra for tracking and thawing types of scalar field using some particular choices for the scalar field potentials. We show that thawing and tracking models can have large differences in observed galaxy power spectra on large scales and for smaller redshifts due to different GR effects. But on smaller scales and for larger redshifts, the difference is small and is mainly due to the difference in background expansion.

Decentralized Large-Scale Power Balancing

DEFF Research Database (Denmark)

Halvgaard, Rasmus; Jørgensen, John Bagterp; Poulsen, Niels Kjølstad

2013-01-01

problem is formulated as a centralized large-scale optimization problem but is then decomposed into smaller subproblems that are solved locally by each unit connected to an aggregator. For large-scale systems the method is faster than solving the full problem and can be distributed to include an arbitrary...

Large Pelagics Telephone Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Large Pelagics Telephone Survey (LPTS) collects fishing effort information directly from captains holding Highly Migratory Species (HMS) permits (required by...

Convolutional neural networks for transient candidate vetting in large-scale surveys

Science.gov (United States)

Gieseke, Fabian; Bloemen, Steven; van den Bogaard, Cas; Heskes, Tom; Kindler, Jonas; Scalzo, Richard A.; Ribeiro, Valério A. R. M.; van Roestel, Jan; Groot, Paul J.; Yuan, Fang; Möller, Anais; Tucker, Brad E.

2017-12-01

Current synoptic sky surveys monitor large areas of the sky to find variable and transient astronomical sources. As the number of detections per night at a single telescope easily exceeds several thousand, current detection pipelines make intensive use of machine learning algorithms to classify the detected objects and to filter out the most interesting candidates. A number of upcoming surveys will produce up to three orders of magnitude more data, which renders high-precision classification systems essential to reduce the manual and, hence, expensive vetting by human experts. We present an approach based on convolutional neural networks to discriminate between true astrophysical sources and artefacts in reference-subtracted optical images. We show that relatively simple networks are already competitive with state-of-the-art systems and that their quality can further be improved via slightly deeper networks and additional pre-processing steps - eventually yielding models outperforming state-of-the-art systems. In particular, our best model correctly classifies about 97.3 per cent of all 'real' and 99.7 per cent of all 'bogus' instances on a test set containing 1942 'bogus' and 227 'real' instances in total. Furthermore, the networks considered in this work can also successfully classify these objects at hand without relying on difference images, which might pave the way for future detection pipelines not containing image subtraction steps at all.

Automating large-scale reactor systems

International Nuclear Information System (INIS)

Kisner, R.A.

1985-01-01

This paper conveys a philosophy for developing automated large-scale control systems that behave in an integrated, intelligent, flexible manner. Methods for operating large-scale systems under varying degrees of equipment degradation are discussed, and a design approach that separates the effort into phases is suggested. 5 refs., 1 fig

Large Pelagics Biological Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Large Pelagics Biological Survey (LPBS) collects additional length and weight information and body parts such as otoliths, caudal vertebrae, dorsal spines, and...

Galaxy redshift surveys with sparse sampling

International Nuclear Information System (INIS)

Chiang, Chi-Ting; Wullstein, Philipp; Komatsu, Eiichiro; Jee, Inh; Jeong, Donghui; Blanc, Guillermo A.; Ciardullo, Robin; Gronwall, Caryl; Hagen, Alex; Schneider, Donald P.; Drory, Niv; Fabricius, Maximilian; Landriau, Martin; Finkelstein, Steven; Jogee, Shardha; Cooper, Erin Mentuch; Tuttle, Sarah; Gebhardt, Karl; Hill, Gary J.

2013-01-01

Survey observations of the three-dimensional locations of galaxies are a powerful approach to measure the distribution of matter in the universe, which can be used to learn about the nature of dark energy, physics of inflation, neutrino masses, etc. A competitive survey, however, requires a large volume (e.g., V survey ∼ 10Gpc 3 ) to be covered, and thus tends to be expensive. A ''sparse sampling'' method offers a more affordable solution to this problem: within a survey footprint covering a given survey volume, V survey , we observe only a fraction of the volume. The distribution of observed regions should be chosen such that their separation is smaller than the length scale corresponding to the wavenumber of interest. Then one can recover the power spectrum of galaxies with precision expected for a survey covering a volume of V survey (rather than the volume of the sum of observed regions) with the number density of galaxies given by the total number of observed galaxies divided by V survey (rather than the number density of galaxies within an observed region). We find that regularly-spaced sampling yields an unbiased power spectrum with no window function effect, and deviations from regularly-spaced sampling, which are unavoidable in realistic surveys, introduce calculable window function effects and increase the uncertainties of the recovered power spectrum. On the other hand, we show that the two-point correlation function (pair counting) is not affected by sparse sampling. While we discuss the sparse sampling method within the context of the forthcoming Hobby-Eberly Telescope Dark Energy Experiment, the method is general and can be applied to other galaxy surveys

TOPOLOGY OF A LARGE-SCALE STRUCTURE AS A TEST OF MODIFIED GRAVITY

International Nuclear Information System (INIS)

Wang Xin; Chen Xuelei; Park, Changbom

2012-01-01

The genus of the isodensity contours is a robust measure of the topology of a large-scale structure, and it is relatively insensitive to nonlinear gravitational evolution, galaxy bias, and redshift-space distortion. We show that the growth of density fluctuations is scale dependent even in the linear regime in some modified gravity theories, which opens a new possibility of testing the theories observationally. We propose to use the genus of the isodensity contours, an intrinsic measure of the topology of the large-scale structure, as a statistic to be used in such tests. In Einstein's general theory of relativity, density fluctuations grow at the same rate on all scales in the linear regime, and the genus per comoving volume is almost conserved as structures grow homologously, so we expect that the genus-smoothing-scale relation is basically time independent. However, in some modified gravity models where structures grow with different rates on different scales, the genus-smoothing-scale relation should change over time. This can be used to test the gravity models with large-scale structure observations. We study the cases of the f(R) theory, DGP braneworld theory as well as the parameterized post-Friedmann models. We also forecast how the modified gravity models can be constrained with optical/IR or redshifted 21 cm radio surveys in the near future.

Higher Education Teachers' Descriptions of Their Own Learning: A Large-Scale Study of Finnish Universities of Applied Sciences

Science.gov (United States)

Töytäri, Aija; Piirainen, Arja; Tynjälä, Päivi; Vanhanen-Nuutinen, Liisa; Mäki, Kimmo; Ilves, Vesa

2016-01-01

In this large-scale study, higher education teachers' descriptions of their own learning were examined with qualitative analysis involving application of principles of phenomenographic research. This study is unique: it is unusual to use large-scale data in qualitative studies. The data were collected through an e-mail survey sent to 5960 teachers…

The Software Reliability of Large Scale Integration Circuit and Very Large Scale Integration Circuit

OpenAIRE

Artem Ganiyev; Jan Vitasek

2010-01-01

This article describes evaluation method of faultless function of large scale integration circuits (LSI) and very large scale integration circuits (VLSI). In the article there is a comparative analysis of factors which determine faultless of integrated circuits, analysis of already existing methods and model of faultless function evaluation of LSI and VLSI. The main part describes a proposed algorithm and program for analysis of fault rate in LSI and VLSI circuits.

Solving large scale structure in ten easy steps with COLA

Energy Technology Data Exchange (ETDEWEB)

Tassev, Svetlin [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Zaldarriaga, Matias [School of Natural Sciences, Institute for Advanced Study, Olden Lane, Princeton, NJ 08540 (United States); Eisenstein, Daniel J., E-mail: stassev@cfa.harvard.edu, E-mail: matiasz@ias.edu, E-mail: deisenstein@cfa.harvard.edu [Center for Astrophysics, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-06-01

We present the COmoving Lagrangian Acceleration (COLA) method: an N-body method for solving for Large Scale Structure (LSS) in a frame that is comoving with observers following trajectories calculated in Lagrangian Perturbation Theory (LPT). Unlike standard N-body methods, the COLA method can straightforwardly trade accuracy at small-scales in order to gain computational speed without sacrificing accuracy at large scales. This is especially useful for cheaply generating large ensembles of accurate mock halo catalogs required to study galaxy clustering and weak lensing, as those catalogs are essential for performing detailed error analysis for ongoing and future surveys of LSS. As an illustration, we ran a COLA-based N-body code on a box of size 100 Mpc/h with particles of mass ≈ 5 × 10{sup 9}M{sub s}un/h. Running the code with only 10 timesteps was sufficient to obtain an accurate description of halo statistics down to halo masses of at least 10{sup 11}M{sub s}un/h. This is only at a modest speed penalty when compared to mocks obtained with LPT. A standard detailed N-body run is orders of magnitude slower than our COLA-based code. The speed-up we obtain with COLA is due to the fact that we calculate the large-scale dynamics exactly using LPT, while letting the N-body code solve for the small scales, without requiring it to capture exactly the internal dynamics of halos. Achieving a similar level of accuracy in halo statistics without the COLA method requires at least 3 times more timesteps than when COLA is employed.

Traffic assignment models in large-scale applications

DEFF Research Database (Denmark)

Rasmussen, Thomas Kjær

the potential of the method proposed and the possibility to use individual-based GPS units for travel surveys in real-life large-scale multi-modal networks. Congestion is known to highly influence the way we act in the transportation network (and organise our lives), because of longer travel times...... of observations of actual behaviour to obtain estimates of the (monetary) value of different travel time components, thereby increasing the behavioural realism of largescale models. vii The generation of choice sets is a vital component in route choice models. This is, however, not a straight-forward task in real......, but the reliability of the travel time also has a large impact on our travel choices. Consequently, in order to improve the realism of transport models, correct understanding and representation of two values that are related to the value of time (VoT) are essential: (i) the value of congestion (VoC), as the Vo...

Large Survey Database: A Distributed Framework for Storage and Analysis of Large Datasets

Science.gov (United States)

Juric, Mario

2011-01-01

The Large Survey Database (LSD) is a Python framework and DBMS for distributed storage, cross-matching and querying of large survey catalogs (>10^9 rows, >1 TB). The primary driver behind its development is the analysis of Pan-STARRS PS1 data. It is specifically optimized for fast queries and parallel sweeps of positionally and temporally indexed datasets. It transparently scales to more than >10^2 nodes, and can be made to function in "shared nothing" architectures. An LSD database consists of a set of vertically and horizontally partitioned tables, physically stored as compressed HDF5 files. Vertically, we partition the tables into groups of related columns ('column groups'), storing together logically related data (e.g., astrometry, photometry). Horizontally, the tables are partitioned into partially overlapping ``cells'' by position in space (lon, lat) and time (t). This organization allows for fast lookups based on spatial and temporal coordinates, as well as data and task distribution. The design was inspired by the success of Google BigTable (Chang et al., 2006). Our programming model is a pipelined extension of MapReduce (Dean and Ghemawat, 2004). An SQL-like query language is used to access data. For complex tasks, map-reduce ``kernels'' that operate on query results on a per-cell basis can be written, with the framework taking care of scheduling and execution. The combination leverages users' familiarity with SQL, while offering a fully distributed computing environment. LSD adds little overhead compared to direct Python file I/O. In tests, we sweeped through 1.1 Grows of PanSTARRS+SDSS data (220GB) less than 15 minutes on a dual CPU machine. In a cluster environment, we achieved bandwidths of 17Gbits/sec (I/O limited). Based on current experience, we believe LSD should scale to be useful for analysis and storage of LSST-scale datasets. It can be downloaded from http://mwscience.net/lsd.

Phylogenetic distribution of large-scale genome patchiness

Directory of Open Access Journals (Sweden)

Hackenberg Michael

2008-04-01

Full Text Available Abstract Background The phylogenetic distribution of large-scale genome structure (i.e. mosaic compositional patchiness has been explored mainly by analytical ultracentrifugation of bulk DNA. However, with the availability of large, good-quality chromosome sequences, and the recently developed computational methods to directly analyze patchiness on the genome sequence, an evolutionary comparative analysis can be carried out at the sequence level. Results The local variations in the scaling exponent of the Detrended Fluctuation Analysis are used here to analyze large-scale genome structure and directly uncover the characteristic scales present in genome sequences. Furthermore, through shuffling experiments of selected genome regions, computationally-identified, isochore-like regions were identified as the biological source for the uncovered large-scale genome structure. The phylogenetic distribution of short- and large-scale patchiness was determined in the best-sequenced genome assemblies from eleven eukaryotic genomes: mammals (Homo sapiens, Pan troglodytes, Mus musculus, Rattus norvegicus, and Canis familiaris, birds (Gallus gallus, fishes (Danio rerio, invertebrates (Drosophila melanogaster and Caenorhabditis elegans, plants (Arabidopsis thaliana and yeasts (Saccharomyces cerevisiae. We found large-scale patchiness of genome structure, associated with in silico determined, isochore-like regions, throughout this wide phylogenetic range. Conclusion Large-scale genome structure is detected by directly analyzing DNA sequences in a wide range of eukaryotic chromosome sequences, from human to yeast. In all these genomes, large-scale patchiness can be associated with the isochore-like regions, as directly detected in silico at the sequence level.

Managing large-scale models: DBS

International Nuclear Information System (INIS)

1981-05-01

A set of fundamental management tools for developing and operating a large scale model and data base system is presented. Based on experience in operating and developing a large scale computerized system, the only reasonable way to gain strong management control of such a system is to implement appropriate controls and procedures. Chapter I discusses the purpose of the book. Chapter II classifies a broad range of generic management problems into three groups: documentation, operations, and maintenance. First, system problems are identified then solutions for gaining management control are disucssed. Chapters III, IV, and V present practical methods for dealing with these problems. These methods were developed for managing SEAS but have general application for large scale models and data bases

Large Scale Self-Organizing Information Distribution System

National Research Council Canada - National Science Library

Low, Steven

2005-01-01

This project investigates issues in "large-scale" networks. Here "large-scale" refers to networks with large number of high capacity nodes and transmission links, and shared by a large number of users...

Large scale structure and baryogenesis

International Nuclear Information System (INIS)

Kirilova, D.P.; Chizhov, M.V.

2001-08-01

We discuss a possible connection between the large scale structure formation and the baryogenesis in the universe. An update review of the observational indications for the presence of a very large scale 120h -1 Mpc in the distribution of the visible matter of the universe is provided. The possibility to generate a periodic distribution with the characteristic scale 120h -1 Mpc through a mechanism producing quasi-periodic baryon density perturbations during inflationary stage, is discussed. The evolution of the baryon charge density distribution is explored in the framework of a low temperature boson condensate baryogenesis scenario. Both the observed very large scale of a the visible matter distribution in the universe and the observed baryon asymmetry value could naturally appear as a result of the evolution of a complex scalar field condensate, formed at the inflationary stage. Moreover, for some model's parameters a natural separation of matter superclusters from antimatter ones can be achieved. (author)

Automatic management software for large-scale cluster system

International Nuclear Information System (INIS)

Weng Yunjian; Chinese Academy of Sciences, Beijing; Sun Gongxing

2007-01-01

At present, the large-scale cluster system faces to the difficult management. For example the manager has large work load. It needs to cost much time on the management and the maintenance of large-scale cluster system. The nodes in large-scale cluster system are very easy to be chaotic. Thousands of nodes are put in big rooms so that some managers are very easy to make the confusion with machines. How do effectively carry on accurate management under the large-scale cluster system? The article introduces ELFms in the large-scale cluster system. Furthermore, it is proposed to realize the large-scale cluster system automatic management. (authors)

FIELD-SCALE EFFECTIVE MATRIX DIFFUSION COEFFICIENT FOR FRACTURED ROCK: RESULTS FROM LITERATURE SURVEY

International Nuclear Information System (INIS)

Zhou, Q.; Hui-Hai Liu; Molz, F.J.; Zhang, Y.; Bodvarsson, G.S.

2005-01-01

Matrix diffusion is an important mechanism for solute transport in fractured rock. We recently conducted a literature survey on the effective matrix diffusion coefficient, D m e , a key parameter for describing matrix diffusion processes at the field scale. Forty field tracer tests at 15 fractured geologic sites were surveyed and selected for the study, based on data availability and quality. Field-scale D m e values were calculated, either directly using data reported in the literature or by reanalyzing the corresponding field tracer tests. Surveyed data indicate that the effective-matrix-diffusion-coefficient factor F D (defined as the ratio of D m e to the lab-scale matrix diffusion coefficient [D m ] of the same tracer) is generally larger than one, indicating that the effective matrix diffusion coefficient in the field is comparatively larger than the matrix diffusion coefficient at the rock-core scale. This larger value can be attributed to the many mass-transfer processes at different scales in naturally heterogeneous, fractured rock systems. Furthermore, we observed a moderate trend toward systematic increase in the F D value with observation scale, indicating that the effective matrix diffusion coefficient is likely to be statistically scale dependent. The F D value ranges from 1 to 10,000 for observation scales from 5 to 2,000 m. At a given scale, the F D value varies by two orders of magnitude, reflecting the influence of differing degrees of fractured rock heterogeneity at different sites. In addition, the surveyed data indicate that field-scale longitudinal dispersivity generally increases with observation scale, which is consistent with previous studies. The scale-dependent field-scale matrix diffusion coefficient (and dispersivity) may have significant implications for assessing long-term, large-scale radionuclide and contaminant transport events in fractured rock, both for nuclear waste disposal and contaminant remediation

Relation between metabolic syndrome and body compositions among Chinese adolescents and adults from a large-scale population survey

Directory of Open Access Journals (Sweden)

Tao Xu

2017-04-01

Full Text Available Abstract Background Few nationally representative surveys regarding body composition and metabolic syndrome (MetS have been done in a large-scale representative Chinese population to explore the prediction of body composition indicators for MetS. The objective of this study was to examine the relation of body composition and MetS and to determine the optimal cut-off values of body composition indicators that predict MetS in a large representative Chinese sample based on multiple provinces and ethnicities, covering a broad age range from 10 to 80 years old. Methods The subjects came from a large-scale population survey on Chinese physiological constants and health conditions conducted in six provinces. 32,036 subjects completed all blood biochemical testing and body composition measure. Subjects meeting at least 3 of the following 5 criteria qualify as having MetS: elevated blood pressure, lower high density lipoprotein cholesterol level, higher triglyceride level, higher fasting glucose level and abdominal obesity. Results The total prevalence rate of MetS for males (9.29% was lower than for females (11.58%. The prevalence rates were 12.03% for male adults and 15.57% for female adults respectively. The risk of MetS increased 44.6% (OR = 1.446, 95%CI: 1.414–1.521 for males and 53.4% (OR = 1.534, 95%CI: 1.472–1.598 for females with each 5% increase of percentage of body fat. The risk of MetS increased two-fold (OR = 2.020, 95%CI: 1.920–2.125 for males; OR = 2.047, 95%CI: 1.954–2.144 for females respectively with each 5% increase of waist-hip ratio. The risk of MetS increased three-fold (OR = 2.915, 95%CI: 2.742–3.099 for males; OR = 2.950, 95%CI: 2.784–3.127 for females respectively with each 5% increase of Waist-to-Height Ratio (WHtR. Areas under the receiver operating curve (AUC of most body composition indicators were larger than 0.70 and the sensitivities and the specificities of most cut-off values were larger than 0

Large scale network-centric distributed systems

CERN Document Server

Sarbazi-Azad, Hamid

2014-01-01

A highly accessible reference offering a broad range of topics and insights on large scale network-centric distributed systems Evolving from the fields of high-performance computing and networking, large scale network-centric distributed systems continues to grow as one of the most important topics in computing and communication and many interdisciplinary areas. Dealing with both wired and wireless networks, this book focuses on the design and performance issues of such systems. Large Scale Network-Centric Distributed Systems provides in-depth coverage ranging from ground-level hardware issu

Revisiting AFLP fingerprinting for an unbiased assessment of genetic structure and differentiation of taurine and zebu cattle

Science.gov (United States)

2014-01-01

Background Descendants from the extinct aurochs (Bos primigenius), taurine (Bos taurus) and zebu cattle (Bos indicus) were domesticated 10,000 years ago in Southwestern and Southern Asia, respectively, and colonized the world undergoing complex events of admixture and selection. Molecular data, in particular genome-wide single nucleotide polymorphism (SNP) markers, can complement historic and archaeological records to elucidate these past events. However, SNP ascertainment in cattle has been optimized for taurine breeds, imposing limitations to the study of diversity in zebu cattle. As amplified fragment length polymorphism (AFLP) markers are discovered and genotyped as the samples are assayed, this type of marker is free of ascertainment bias. In order to obtain unbiased assessments of genetic differentiation and structure in taurine and zebu cattle, we analyzed a dataset of 135 AFLP markers in 1,593 samples from 13 zebu and 58 taurine breeds, representing nine continental areas. Results We found a geographical pattern of expected heterozygosity in European taurine breeds decreasing with the distance from the domestication centre, arguing against a large-scale introgression from European or African aurochs. Zebu cattle were found to be at least as diverse as taurine cattle. Western African zebu cattle were found to have diverged more from Indian zebu than South American zebu. Model-based clustering and ancestry informative markers analyses suggested that this is due to taurine introgression. Although a large part of South American zebu cattle also descend from taurine cows, we did not detect significant levels of taurine ancestry in these breeds, probably because of systematic backcrossing with zebu bulls. Furthermore, limited zebu introgression was found in Podolian taurine breeds in Italy. Conclusions The assessment of cattle diversity reported here contributes an unbiased global view to genetic differentiation and structure of taurine and zebu cattle

SCALE INTERACTION IN A MIXING LAYER. THE ROLE OF THE LARGE-SCALE GRADIENTS

KAUST Repository

Fiscaletti, Daniele

2015-08-23

The interaction between scales is investigated in a turbulent mixing layer. The large-scale amplitude modulation of the small scales already observed in other works depends on the crosswise location. Large-scale positive fluctuations correlate with a stronger activity of the small scales on the low speed-side of the mixing layer, and a reduced activity on the high speed-side. However, from physical considerations we would expect the scales to interact in a qualitatively similar way within the flow and across different turbulent flows. Therefore, instead of the large-scale fluctuations, the large-scale gradients modulation of the small scales has been additionally investigated.

Survey on the technological development issues for large-scale methanol engine power generation plant; Ogata methanol engine hatsuden plant ni kansuru gijutsu kaihatsu kadai chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-03-01

Based on the result of `Survey on the feasibility of large-scale methanol engine power generation plant` in fiscal 1992, concrete technological development issues were studied for its practical use, and the technological R & D scheme was prepared for large-scale methanol engine power plant featured by low NOx and high efficiency. Technological development issues of this plant were as follows: improvement of thermal efficiency, reduction of NOx emission, improvement of the reliability and durability of ignition and fuel injection systems, and reduction of vibration. As the economical effect of the technological development, the profitability of NOx control measures was compared between this methanol engine and conventional heavy oil diesel engines or gas engines. As a result, this engine was more economical than conventional engines. It was suggested that development of the equipment will be completed in nearly 4 years through every component study, single-cylinder model experiment and real engine test. 21 refs., 43 figs., 19 tabs.

Tracing The Sound Horizon Scale With Photometric Redshift Surveys

CERN Document Server

Sanchez, E; Garcia-Bellido, J; Gaztanaga, E; de Simoni, F; Crocce, M; Cabre, A; Fosalba, P; Alonso, D

2010-01-01

We propose a new method for cosmological parameters extraction using the baryon acoustic oscillation scale as a standard ruler in deep galaxy surveys with photometric determination of redshifts. The method consists in a simple empirical parametric fit to the angular 2-point correlation function w(theta). It is parametrized as a power law to describe the continuum plus a Gaussian to describe the BAO bump. The location of the Gaussian is used as the basis for the measurement of the sound horizon scale. This method, although simple, actually provides a robust estimation, since the inclusion of the power law and the use of the Gaussian removes the shifts which affect the local maximum. We discuss the effects of projection bias, non-linearities, redshift space distortions and photo-z precision, and apply our method to a mock catalog of the Dark Energy Survey, built upon a large N-body simulation provided by the MICE collaboration. We discuss the main systematic errors associated to our method and show that they ar...

Dissecting the large-scale galactic conformity

Science.gov (United States)

Seo, Seongu

2018-01-01

Galactic conformity is an observed phenomenon that galaxies located in the same region have similar properties such as star formation rate, color, gas fraction, and so on. The conformity was first observed among galaxies within in the same halos (“one-halo conformity”). The one-halo conformity can be readily explained by mutual interactions among galaxies within a halo. Recent observations however further witnessed a puzzling connection among galaxies with no direct interaction. In particular, galaxies located within a sphere of ~5 Mpc radius tend to show similarities, even though the galaxies do not share common halos with each other ("two-halo conformity" or “large-scale conformity”). Using a cosmological hydrodynamic simulation, Illustris, we investigate the physical origin of the two-halo conformity and put forward two scenarios. First, back-splash galaxies are likely responsible for the large-scale conformity. They have evolved into red galaxies due to ram-pressure stripping in a given galaxy cluster and happen to reside now within a ~5 Mpc sphere. Second, galaxies in strong tidal field induced by large-scale structure also seem to give rise to the large-scale conformity. The strong tides suppress star formation in the galaxies. We discuss the importance of the large-scale conformity in the context of galaxy evolution.

Mutually Unbiased Maximally Entangled Bases for the Bipartite System Cd⊗ C^{dk}

Science.gov (United States)

Nan, Hua; Tao, Yuan-Hong; Wang, Tian-Jiao; Zhang, Jun

2016-10-01

The construction of maximally entangled bases for the bipartite system Cd⊗ Cd is discussed firstly, and some mutually unbiased bases with maximally entangled bases are given, where 2≤ d≤5. Moreover, we study a systematic way of constructing mutually unbiased maximally entangled bases for the bipartite system Cd⊗ C^{dk}.

COMBINED EFFECTS OF GALAXY INTERACTIONS AND LARGE-SCALE ENVIRONMENT ON GALAXY PROPERTIES

International Nuclear Information System (INIS)

Park, Changbom; Choi, Yun-Young

2009-01-01

We inspect the coupled dependence of physical parameters of the Sloan Digital Sky Survey galaxies on the small-scale (distance to and morphology of the nearest neighbor galaxy) and the large-scale (background density smoothed over 20 nearby galaxies) environments. The impacts of interaction on galaxy properties are detected at least out to the neighbor separation corresponding to the virial radius of galaxies, which is typically between 200 and 400 h -1 kpc for the galaxies in our sample. To detect these long-range interaction effects, it is crucial to divide galaxy interactions into four cases dividing the morphology of target and neighbor galaxies into early and late types. We show that there are two characteristic neighbor-separation scales where the galaxy interactions cause abrupt changes in the properties of galaxies. The first scale is the virial radius of the nearest neighbor galaxy r vir,nei . Many physical parameters start to deviate from those of extremely isolated galaxies at the projected neighbor separation r p of about r vir,nei . The second scale is at r p ∼ 0.05r vir,nei = 10-20 h -1 kpc, and is the scale at which the galaxies in pairs start to merge. We find that late-type neighbors enhance the star formation activity of galaxies while early-type neighbors reduce it, and that these effects occur within r vir,nei . The hot halo gas and cold disk gas must be participating in the interactions at separations less than the virial radius of the galaxy plus dark halo system. Our results also show that the role of the large-scale density in determining galaxy properties is minimal once luminosity and morphology are fixed. We propose that the weak residual dependence of galaxy properties on the large-scale density is due to the dependence of the halo gas property on the large-scale density.

Large-Scale Astrophysical Visualization on Smartphones

Science.gov (United States)

Becciani, U.; Massimino, P.; Costa, A.; Gheller, C.; Grillo, A.; Krokos, M.; Petta, C.

2011-07-01

Nowadays digital sky surveys and long-duration, high-resolution numerical simulations using high performance computing and grid systems produce multidimensional astrophysical datasets in the order of several Petabytes. Sharing visualizations of such datasets within communities and collaborating research groups is of paramount importance for disseminating results and advancing astrophysical research. Moreover educational and public outreach programs can benefit greatly from novel ways of presenting these datasets by promoting understanding of complex astrophysical processes, e.g., formation of stars and galaxies. We have previously developed VisIVO Server, a grid-enabled platform for high-performance large-scale astrophysical visualization. This article reviews the latest developments on VisIVO Web, a custom designed web portal wrapped around VisIVO Server, then introduces VisIVO Smartphone, a gateway connecting VisIVO Web and data repositories for mobile astrophysical visualization. We discuss current work and summarize future developments.

New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools. I. UKIDSS LAS DR5 vs. SDSS DR7

Science.gov (United States)

Lodieu, N.; Espinoza Contreras, M.; Zapatero Osorio, M. R.; Solano, E.; Aberasturi, M.; Martín, E. L.

2012-06-01

Aims: The aim of the project is to improve our knowledge of the low-mass and low-metallicity population to investigate the influence of metallicity on the stellar (and substellar) mass function. Methods: We present the results of a photometric and proper motion search aimed at discovering ultracool subdwarfs in large-scale surveys. We employed and combined the Fifth Data Release (DR5) of the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) and the Sloan Digital Sky Survey (SDSS) Data Release 7 complemented with ancillary data from the Two Micron All-Sky Survey (2MASS), the DEep Near-Infrared Survey (DENIS) and the SuperCOSMOS Sky Surveys (SSS). Results: The SDSS DR7 vs. UKIDSS LAS DR5 search returned a total of 32 ultracool subdwarf candidates, only two of which are recognised as a subdwarf in the literature. Twenty-seven candidates, including the two known ones, were followed-up spectroscopically in the optical between 600 and 1000 nm, thus covering strong spectral features indicative of low metallicity (e.g., CaH), 21 with the Very Large Telescope, one with the Nordic Optical Telescope, and five were extracted from the Sloan spectroscopic database to assess (or refute) their low-metal content. We confirm 20 candidates as subdwarfs, extreme subdwarfs, or ultra-subdwarfs with spectral types later than M5; this represents a success rate of ≥ 60%. Among those 20 new subdwarfs, we identify two early-L subdwarfs that are very likely located within 100 pc, which we propose as templates for future searches because they are the first examples of their subclass. Another seven sources are solar-metallicity M dwarfs with spectral types between M4 and M7 without Hα emission, suggesting that they are old M dwarfs. The remaining five candidates do not have spectroscopic follow-up yet; only one remains as a bona-fide ultracool subdwarf after revision of their proper motions. We assigned spectral types based on the current classification schemes and, when

Inflationary tensor fossils in large-scale structure

Energy Technology Data Exchange (ETDEWEB)

Dimastrogiovanni, Emanuela [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Fasiello, Matteo [Department of Physics, Case Western Reserve University, Cleveland, OH 44106 (United States); Jeong, Donghui [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Kamionkowski, Marc, E-mail: ema@physics.umn.edu, E-mail: mrf65@case.edu, E-mail: duj13@psu.edu, E-mail: kamion@jhu.edu [Department of Physics and Astronomy, 3400 N. Charles St., Johns Hopkins University, Baltimore, MD 21218 (United States)

2014-12-01

Inflation models make specific predictions for a tensor-scalar-scalar three-point correlation, or bispectrum, between one gravitational-wave (tensor) mode and two density-perturbation (scalar) modes. This tensor-scalar-scalar correlation leads to a local power quadrupole, an apparent departure from statistical isotropy in our Universe, as well as characteristic four-point correlations in the current mass distribution in the Universe. So far, the predictions for these observables have been worked out only for single-clock models in which certain consistency conditions between the tensor-scalar-scalar correlation and tensor and scalar power spectra are satisfied. Here we review the requirements on inflation models for these consistency conditions to be satisfied. We then consider several examples of inflation models, such as non-attractor and solid-inflation models, in which these conditions are put to the test. In solid inflation the simplest consistency conditions are already violated whilst in the non-attractor model we find that, contrary to the standard scenario, the tensor-scalar-scalar correlator probes directly relevant model-dependent information. We work out the predictions for observables in these models. For non-attractor inflation we find an apparent local quadrupolar departure from statistical isotropy in large-scale structure but that this power quadrupole decreases very rapidly at smaller scales. The consistency of the CMB quadrupole with statistical isotropy then constrains the distance scale that corresponds to the transition from the non-attractor to attractor phase of inflation to be larger than the currently observable horizon. Solid inflation predicts clustering fossils signatures in the current galaxy distribution that may be large enough to be detectable with forthcoming, and possibly even current, galaxy surveys.

Higher-dimensional orbital-angular-momentum-based quantum key distribution with mutually unbiased bases

CSIR Research Space (South Africa)

Mafu, M

2013-09-01

Full Text Available We present an experimental study of higher-dimensional quantum key distribution protocols based on mutually unbiased bases, implemented by means of photons carrying orbital angular momentum. We perform (d + 1) mutually unbiased measurements in a...

Going Digital: A Survey on Digitalization and Large Scale Data Analytics in Healthcare

OpenAIRE

Tresp, Volker; Overhage, J. Marc; Bundschus, Markus; Rabizadeh, Shahrooz; Fasching, Peter A.; Yu, Shipeng

2016-01-01

We provide an overview of the recent trends towards digitalization and large scale data analytics in healthcare. It is expected that these trends are instrumental in the dramatic changes in the way healthcare will be organized in the future. We discuss the recent political initiatives designed to shift care delivery processes from paper to electronic, with the goals of more effective treatments with better outcomes; cost pressure is a major driver of innovation. We describe newly developed ne...

Large-scale perspective as a challenge

NARCIS (Netherlands)

Plomp, M.G.A.

2012-01-01

1. Scale forms a challenge for chain researchers: when exactly is something ‘large-scale’? What are the underlying factors (e.g. number of parties, data, objects in the chain, complexity) that determine this? It appears to be a continuum between small- and large-scale, where positioning on that

Algorithm 896: LSA: Algorithms for Large-Scale Optimization

Czech Academy of Sciences Publication Activity Database

Lukšan, Ladislav; Matonoha, Ctirad; Vlček, Jan

2009-01-01

Roč. 36, č. 3 (2009), 16-1-16-29 ISSN 0098-3500 R&D Pro jects: GA AV ČR IAA1030405; GA ČR GP201/06/P397 Institutional research plan: CEZ:AV0Z10300504 Keywords : algorithms * design * large-scale optimization * large-scale nonsmooth optimization * large-scale nonlinear least squares * large-scale nonlinear minimax * large-scale systems of nonlinear equations * sparse pro blems * partially separable pro blems * limited-memory methods * discrete Newton methods * quasi-Newton methods * primal interior-point methods Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.904, year: 2009

Scale interactions in a mixing layer – the role of the large-scale gradients

KAUST Repository

Fiscaletti, D.

2016-02-15

© 2016 Cambridge University Press. The interaction between the large and the small scales of turbulence is investigated in a mixing layer, at a Reynolds number based on the Taylor microscale of , via direct numerical simulations. The analysis is performed in physical space, and the local vorticity root-mean-square (r.m.s.) is taken as a measure of the small-scale activity. It is found that positive large-scale velocity fluctuations correspond to large vorticity r.m.s. on the low-speed side of the mixing layer, whereas, they correspond to low vorticity r.m.s. on the high-speed side. The relationship between large and small scales thus depends on position if the vorticity r.m.s. is correlated with the large-scale velocity fluctuations. On the contrary, the correlation coefficient is nearly constant throughout the mixing layer and close to unity if the vorticity r.m.s. is correlated with the large-scale velocity gradients. Therefore, the small-scale activity appears closely related to large-scale gradients, while the correlation between the small-scale activity and the large-scale velocity fluctuations is shown to reflect a property of the large scales. Furthermore, the vorticity from unfiltered (small scales) and from low pass filtered (large scales) velocity fields tend to be aligned when examined within vortical tubes. These results provide evidence for the so-called \\'scale invariance\\' (Meneveau & Katz, Annu. Rev. Fluid Mech., vol. 32, 2000, pp. 1-32), and suggest that some of the large-scale characteristics are not lost at the small scales, at least at the Reynolds number achieved in the present simulation.

Exploring Genetic Suppression Interactions on a Global Scale

OpenAIRE

van Leeuwen, Jolanda; Pons, Carles; Mellor, Joseph C.; Yamaguchi, Takafumi N.; Friesen, Helena; Koschwanez, John; Ušaj, Mojca Mattiazzi; Pechlaner, Maria; Takar, Mehmet; Ušaj, Matej; VanderSluis, Benjamin; Andrusiak, Kerry; Bansal, Pritpal; Baryshnikova, Anastasia; Boone, Claire

2016-01-01

Genetic suppression occurs when the phenotypic defects caused by a mutation in a particular gene are rescued by a mutation in a second gene. To explore the principles of genetic suppression, we examined both literature-curated and unbiased experimental data, involving systematic genetic mapping and whole-genome sequencing, to generate a large-scale suppression network among yeast genes. Most suppression pairs identified novel relationships among functionally related genes, providing new insig...

A new unbiased stochastic derivative estimator for discontinuous sample performances with structural parameters

NARCIS (Netherlands)

Peng, Yijie; Fu, Michael C.; Hu, Jian Qiang; Heidergott, Bernd

In this paper, we propose a new unbiased stochastic derivative estimator in a framework that can handle discontinuous sample performances with structural parameters. This work extends the three most popular unbiased stochastic derivative estimators: (1) infinitesimal perturbation analysis (IPA), (2)

Analysis using large-scale ringing data

Directory of Open Access Journals (Sweden)

Baillie, S. R.

2004-06-01

]; Peach et al., 1998; DeSante et al., 2001 are generally co–ordinated by ringing centres such as those that make up the membership of EURING. In some countries volunteer census work (often called Breeding Bird Surveys is undertaken by the same organizations while in others different bodies may co–ordinate this aspect of the work. This session was concerned with the analysis of such extensive data sets and the approaches that are being developed to address the key theoretical and applied issues outlined above. The papers reflect the development of more spatially explicit approaches to analyses of data gathered at large spatial scales. They show that while the statistical tools that have been developed in recent years can be used to derive useful biological conclusions from such data, there is additional need for further developments. Future work should also consider how to best implement such analytical developments within future study designs. In his plenary paper Andy Royle (Royle, 2004 addresses this theme directly by describing a general framework for modelling spatially replicated abundance data. The approach is based on the idea that a set of spatially referenced local populations constitutes a metapopulation, within which local abundance is determined as a random process. This provides an elegant and general approach in which the metapopulation model as described above is combined with a data–generating model specific to the type of data being analysed to define a simple hierarchical model that can be analysed using conventional methods. It should be noted, however, that further software development will be needed if the approach is to be made readily available to biologists. The approach is well suited to dealing with sparse data and avoids the need for data aggregation prior to analysis. Spatial synchrony has received most attention in studies of species whose populations show cyclic fluctuations, particularly certain game birds and small mammals. However

Observing trans-Planckian ripples in the primordial power spectrum with future large scale structure probes

DEFF Research Database (Denmark)

Hamann, Jan; Hannestad, Steen; Sloth, Martin Snoager

2008-01-01

We revisit the issue of ripples in the primordial power spectra caused by trans-Planckian physics, and the potential for their detection by future cosmological probes. We find that for reasonably large values of the first slow-roll parameter epsilon (> 0.001), a positive detection of trans......-Planckian ripples can be made even if the amplitude is as low as 10^-4. Data from the Large Synoptic Survey Telescope (LSST) and the proposed future 21 cm survey with the Fast Fourier Transform Telescope (FFTT) will be particularly useful in this regard. If the scale of inflation is close to its present upper bound...

Large-scale matrix-handling subroutines 'ATLAS'

International Nuclear Information System (INIS)

Tsunematsu, Toshihide; Takeda, Tatsuoki; Fujita, Keiichi; Matsuura, Toshihiko; Tahara, Nobuo

1978-03-01

Subroutine package ''ATLAS'' has been developed for handling large-scale matrices. The package is composed of four kinds of subroutines, i.e., basic arithmetic routines, routines for solving linear simultaneous equations and for solving general eigenvalue problems and utility routines. The subroutines are useful in large scale plasma-fluid simulations. (auth.)

THE OPTICALLY UNBIASED GRB HOST (TOUGH) SURVEY. III. REDSHIFT DISTRIBUTION

Energy Technology Data Exchange (ETDEWEB)

Jakobsson, P.; Chapman, R.; Vreeswijk, P. M. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik (Iceland); Hjorth, J.; Malesani, D.; Fynbo, J. P. U.; Milvang-Jensen, B. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen (Denmark); Tanvir, N. R.; Starling, R. L. C. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Letawe, G. [Departement d' Astrophysique, Geophysique et Oceanographie, ULg, Allee du 6 aout, 17-Bat. B5c B-4000 Liege (Sart-Tilman) (Belgium)

2012-06-10

We present 10 new gamma-ray burst (GRB) redshifts and another five redshift limits based on host galaxy spectroscopy obtained as part of a large program conducted at the Very Large Telescope (VLT). The redshifts span the range 0.345 {<=} z {approx}< 2.54. Three of our measurements revise incorrect values from the literature. The homogeneous host sample researched here consists of 69 hosts that originally had a redshift completeness of 55% (with 38 out of 69 hosts having redshifts considered secure). Our project, including VLT/X-shooter observations reported elsewhere, increases this fraction to 77% (53/69), making the survey the most comprehensive in terms of redshift completeness of any sample to the full Swift depth, analyzed to date. We present the cumulative redshift distribution and derive a conservative, yet small, associated uncertainty. We constrain the fraction of Swift GRBs at high redshift to a maximum of 14% (5%) for z > 6 (z > 7). The mean redshift of the host sample is assessed to be (z) {approx}> 2.2, with the 10 new redshifts reducing it significantly. Using this more complete sample, we confirm previous findings that the GRB rate at high redshift (z {approx}> 3) appears to be in excess of predictions based on assumptions that it should follow conventional determinations of the star formation history of the universe, combined with an estimate of its likely metallicity dependence. This suggests that either star formation at high redshifts has been significantly underestimated, for example, due to a dominant contribution from faint, undetected galaxies, or that GRB production is enhanced in the conditions of early star formation, beyond that usually ascribed to lower metallicity.

The VIMOS Public Extragalactic Redshift Survey (VIPERS). An unprecedented view of galaxies and large-scale structure at 0.5 < z < 1.2

Science.gov (United States)

Guzzo, L.; Scodeggio, M.; Garilli, B.; Granett, B. R.; Fritz, A.; Abbas, U.; Adami, C.; Arnouts, S.; Bel, J.; Bolzonella, M.; Bottini, D.; Branchini, E.; Cappi, A.; Coupon, J.; Cucciati, O.; Davidzon, I.; De Lucia, G.; de la Torre, S.; Franzetti, P.; Fumana, M.; Hudelot, P.; Ilbert, O.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marulli, F.; McCracken, H. J.; Paioro, L.; Peacock, J. A.; Polletta, M.; Pollo, A.; Schlagenhaufer, H.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zamorani, G.; Zanichelli, A.; Burden, A.; Di Porto, C.; Marchetti, A.; Marinoni, C.; Mellier, Y.; Moscardini, L.; Nichol, R. C.; Percival, W. J.; Phleps, S.; Wolk, M.

2014-06-01

We describe the construction and general features of VIPERS, the VIMOS Public Extragalactic Redshift Survey. This ESO Large Programme is using the Very Large Telescope with the aim of building a spectroscopic sample of ~ 100 000 galaxies with iABcontamination is found to be only 3.2%, endorsing the quality of the star-galaxy separation process and fully confirming the original estimates based on the VVDS data, which also indicate a galaxy incompleteness from this process of only 1.4%. Using a set of 1215 repeated observations, we estimate an rms redshift error σz/ (1 + z) = 4.7 × 10-4 and calibrate the internal spectral quality grading. Benefiting from the combination of size and detailed sampling of this dataset, we conclude by presenting a map showing in unprecedented detail the large-scale distribution of galaxies between 5 and 8 billion years ago. Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile, using the Very Large Telescope under programmes 182.A-0886 and partly 070.A-9007. Also based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. The VIPERS website is http://www.vipers.inaf.it/

State-of-the-Art in GPU-Based Large-Scale Volume Visualization

KAUST Repository

Beyer, Johanna

2015-05-01

This survey gives an overview of the current state of the art in GPU techniques for interactive large-scale volume visualization. Modern techniques in this field have brought about a sea change in how interactive visualization and analysis of giga-, tera- and petabytes of volume data can be enabled on GPUs. In addition to combining the parallel processing power of GPUs with out-of-core methods and data streaming, a major enabler for interactivity is making both the computational and the visualization effort proportional to the amount and resolution of data that is actually visible on screen, i.e. \\'output-sensitive\\' algorithms and system designs. This leads to recent output-sensitive approaches that are \\'ray-guided\\', \\'visualization-driven\\' or \\'display-aware\\'. In this survey, we focus on these characteristics and propose a new categorization of GPU-based large-scale volume visualization techniques based on the notions of actual output-resolution visibility and the current working set of volume bricks-the current subset of data that is minimally required to produce an output image of the desired display resolution. Furthermore, we discuss the differences and similarities of different rendering and data traversal strategies in volume rendering by putting them into a common context-the notion of address translation. For our purposes here, we view parallel (distributed) visualization using clusters as an orthogonal set of techniques that we do not discuss in detail but that can be used in conjunction with what we present in this survey. © 2015 The Eurographics Association and John Wiley & Sons Ltd.

State-of-the-Art in GPU-Based Large-Scale Volume Visualization

KAUST Repository

Beyer, Johanna; Hadwiger, Markus; Pfister, Hanspeter

2015-01-01

This survey gives an overview of the current state of the art in GPU techniques for interactive large-scale volume visualization. Modern techniques in this field have brought about a sea change in how interactive visualization and analysis of giga-, tera- and petabytes of volume data can be enabled on GPUs. In addition to combining the parallel processing power of GPUs with out-of-core methods and data streaming, a major enabler for interactivity is making both the computational and the visualization effort proportional to the amount and resolution of data that is actually visible on screen, i.e. 'output-sensitive' algorithms and system designs. This leads to recent output-sensitive approaches that are 'ray-guided', 'visualization-driven' or 'display-aware'. In this survey, we focus on these characteristics and propose a new categorization of GPU-based large-scale volume visualization techniques based on the notions of actual output-resolution visibility and the current working set of volume bricks-the current subset of data that is minimally required to produce an output image of the desired display resolution. Furthermore, we discuss the differences and similarities of different rendering and data traversal strategies in volume rendering by putting them into a common context-the notion of address translation. For our purposes here, we view parallel (distributed) visualization using clusters as an orthogonal set of techniques that we do not discuss in detail but that can be used in conjunction with what we present in this survey. © 2015 The Eurographics Association and John Wiley & Sons Ltd.

Large-scale solar heat

Energy Technology Data Exchange (ETDEWEB)

Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics

1998-12-31

In this project a large domestic solar heating system was built and a solar district heating system was modelled and simulated. Objectives were to improve the performance and reduce costs of a large-scale solar heating system. As a result of the project the benefit/cost ratio can be increased by 40 % through dimensioning and optimising the system at the designing stage. (orig.)

Probes of large-scale structure in the Universe

International Nuclear Information System (INIS)

Suto, Yasushi; Gorski, K.; Juszkiewicz, R.; Silk, J.

1988-01-01

Recent progress in observational techniques has made it possible to confront quantitatively various models for the large-scale structure of the Universe with detailed observational data. We develop a general formalism to show that the gravitational instability theory for the origin of large-scale structure is now capable of critically confronting observational results on cosmic microwave background radiation angular anisotropies, large-scale bulk motions and large-scale clumpiness in the galaxy counts. (author)

The Cosmology Large Angular Scale Surveyor (CLASS)

Science.gov (United States)

Cleary, Joseph

2018-01-01

The Cosmology Large Angular Scale Surveyor (CLASS) is an array of four telescopes designed to measure the polarization of the Cosmic Microwave Background. CLASS aims to detect the B-mode polarization from primordial gravitational waves predicted by cosmic inflation theory, as well as the imprint left by reionization upon the CMB E-mode polarization. This will be achieved through a combination of observing strategy and state-of-the-art instrumentation. CLASS is observing 70% of the sky to characterize the CMB at large angular scales, which will measure the entire CMB power spectrum from the reionization peak to the recombination peak. The four telescopes operate at frequencies of 38, 93, 145, and 217 GHz, in order to estimate Galactic synchrotron and dust foregrounds while avoiding atmospheric absorption. CLASS employs rapid polarization modulation to overcome atmospheric and instrumental noise. Polarization sensitive cryogenic detectors with low noise levels provide CLASS the sensitivity required to constrain the tensor-to-scalar ratio down to levels of r ~ 0.01 while also measuring the optical depth the reionization to sample-variance levels. These improved constraints on the optical depth to reionization are required to pin down the mass of neutrinos from complementary cosmological data. CLASS has completed a year of observations at 38 GHz and is in the process of deploying the rest of the telescope array. This poster provides an overview and update on the CLASS science, hardware and survey operations.

Projection Effects of Large-scale Structures on Weak-lensing Peak Abundances

Science.gov (United States)

Yuan, Shuo; Liu, Xiangkun; Pan, Chuzhong; Wang, Qiao; Fan, Zuhui

2018-04-01

High peaks in weak lensing (WL) maps originate dominantly from the lensing effects of single massive halos. Their abundance is therefore closely related to the halo mass function and thus a powerful cosmological probe. However, besides individual massive halos, large-scale structures (LSS) along lines of sight also contribute to the peak signals. In this paper, with ray-tracing simulations, we investigate the LSS projection effects. We show that for current surveys with a large shape noise, the stochastic LSS effects are subdominant. For future WL surveys with source galaxies having a median redshift z med ∼ 1 or higher, however, they are significant. For the cosmological constraints derived from observed WL high-peak counts, severe biases can occur if the LSS effects are not taken into account properly. We extend the model of Fan et al. by incorporating the LSS projection effects into the theoretical considerations. By comparing with simulation results, we demonstrate the good performance of the improved model and its applicability in cosmological studies.

Large-scale grid management; Storskala Nettforvaltning

Energy Technology Data Exchange (ETDEWEB)

Langdal, Bjoern Inge; Eggen, Arnt Ove

2003-07-01

The network companies in the Norwegian electricity industry now have to establish a large-scale network management, a concept essentially characterized by (1) broader focus (Broad Band, Multi Utility,...) and (2) bigger units with large networks and more customers. Research done by SINTEF Energy Research shows so far that the approaches within large-scale network management may be structured according to three main challenges: centralization, decentralization and out sourcing. The article is part of a planned series.

Large-scale geographic variation in distribution and abundance of Australian deep-water kelp forests.

Directory of Open Access Journals (Sweden)

Ezequiel M Marzinelli

Full Text Available Despite the significance of marine habitat-forming organisms, little is known about their large-scale distribution and abundance in deeper waters, where they are difficult to access. Such information is necessary to develop sound conservation and management strategies. Kelps are main habitat-formers in temperate reefs worldwide; however, these habitats are highly sensitive to environmental change. The kelp Ecklonia radiate is the major habitat-forming organism on subtidal reefs in temperate Australia. Here, we provide large-scale ecological data encompassing the latitudinal distribution along the continent of these kelp forests, which is a necessary first step towards quantitative inferences about the effects of climatic change and other stressors on these valuable habitats. We used the Autonomous Underwater Vehicle (AUV facility of Australia's Integrated Marine Observing System (IMOS to survey 157,000 m2 of seabed, of which ca 13,000 m2 were used to quantify kelp covers at multiple spatial scales (10-100 m to 100-1,000 km and depths (15-60 m across several regions ca 2-6° latitude apart along the East and West coast of Australia. We investigated the large-scale geographic variation in distribution and abundance of deep-water kelp (>15 m depth and their relationships with physical variables. Kelp cover generally increased with latitude despite great variability at smaller spatial scales. Maximum depth of kelp occurrence was 40-50 m. Kelp latitudinal distribution along the continent was most strongly related to water temperature and substratum availability. This extensive survey data, coupled with ongoing AUV missions, will allow for the detection of long-term shifts in the distribution and abundance of habitat-forming kelp and the organisms they support on a continental scale, and provide information necessary for successful implementation and management of conservation reserves.

Japanese large-scale interferometers

CERN Document Server

Kuroda, K; Miyoki, S; Ishizuka, H; Taylor, C T; Yamamoto, K; Miyakawa, O; Fujimoto, M K; Kawamura, S; Takahashi, R; Yamazaki, T; Arai, K; Tatsumi, D; Ueda, A; Fukushima, M; Sato, S; Shintomi, T; Yamamoto, A; Suzuki, T; Saitô, Y; Haruyama, T; Sato, N; Higashi, Y; Uchiyama, T; Tomaru, T; Tsubono, K; Ando, M; Takamori, A; Numata, K; Ueda, K I; Yoneda, H; Nakagawa, K; Musha, M; Mio, N; Moriwaki, S; Somiya, K; Araya, A; Kanda, N; Telada, S; Sasaki, M; Tagoshi, H; Nakamura, T; Tanaka, T; Ohara, K

2002-01-01

The objective of the TAMA 300 interferometer was to develop advanced technologies for kilometre scale interferometers and to observe gravitational wave events in nearby galaxies. It was designed as a power-recycled Fabry-Perot-Michelson interferometer and was intended as a step towards a final interferometer in Japan. The present successful status of TAMA is presented. TAMA forms a basis for LCGT (large-scale cryogenic gravitational wave telescope), a 3 km scale cryogenic interferometer to be built in the Kamioka mine in Japan, implementing cryogenic mirror techniques. The plan of LCGT is schematically described along with its associated R and D.

The Gould's Belt very large array survey. III. The Orion region

Energy Technology Data Exchange (ETDEWEB)

Kounkel, Marina; Hartmann, Lee [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Loinard, Laurent; Ortiz-León, Gisela N.; Rodríguez, Luis F.; Pech, Gerardo; Rivera, Juana L. [Centro de Radiostronomía y Astrofísica, Universidad Nacional Autónoma de Mexico, Morelia 58089 (Mexico); Mioduszewski, Amy J. [National Radio Astronomy Observatory, 1003 Lopezville Road, Socorro, NM 87801 (United States); Dzib, Sergio A. [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Torres, Rosa M. [Instituto de Astronomía y Meteorología, Universidad de Guadalajara, Avenida Vallarta No. 2602, Col. Arcos Vallarta, CP 44130, Guadalajara, Jalisco (Mexico); Boden, Andrew F. [Division of Physics, Math and Astronomy, California Institute of Technology, 1200 E California Blvd., Pasadena, CA 91125 (United States); Evans, Neal J. II [Department of Astronomy, The University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712 (United States); Briceño, Cesar [Cerro Tololo Interamerican Observatory, Casilla 603, La Serena (Chile); Tobin, John [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States)

2014-07-20

We present results from a high-sensitivity (60 μJy), large-scale (2.26 deg{sup 2}) survey obtained with the Karl G. Jansky Very Large Array as part of the Gould's Belt Survey program. We detected 374 and 354 sources at 4.5 and 7.5 GHz, respectively. Of these, 148 are associated with previously known young stellar objects (YSOs). Another 86 sources previously unclassified at either optical or infrared wavelengths exhibit radio properties that are consistent with those of young stars. The overall properties of our sources at radio wavelengths such as their variability and radio to X-ray luminosity relation are consistent with previous results from the Gould's Belt Survey. Our detections provide target lists for follow-up Very Long Baseline Array radio observations to determine their distances as YSOs are located in regions of high nebulosity and extinction, making it difficult to measure optical parallaxes.

Large scale model testing

International Nuclear Information System (INIS)

Brumovsky, M.; Filip, R.; Polachova, H.; Stepanek, S.

1989-01-01

Fracture mechanics and fatigue calculations for WWER reactor pressure vessels were checked by large scale model testing performed using large testing machine ZZ 8000 (with a maximum load of 80 MN) at the SKODA WORKS. The results are described from testing the material resistance to fracture (non-ductile). The testing included the base materials and welded joints. The rated specimen thickness was 150 mm with defects of a depth between 15 and 100 mm. The results are also presented of nozzles of 850 mm inner diameter in a scale of 1:3; static, cyclic, and dynamic tests were performed without and with surface defects (15, 30 and 45 mm deep). During cyclic tests the crack growth rate in the elastic-plastic region was also determined. (author). 6 figs., 2 tabs., 5 refs

Why small-scale cannabis growers stay small: five mechanisms that prevent small-scale growers from going large scale.

Science.gov (United States)

Hammersvik, Eirik; Sandberg, Sveinung; Pedersen, Willy

2012-11-01

Over the past 15-20 years, domestic cultivation of cannabis has been established in a number of European countries. New techniques have made such cultivation easier; however, the bulk of growers remain small-scale. In this study, we explore the factors that prevent small-scale growers from increasing their production. The study is based on 1 year of ethnographic fieldwork and qualitative interviews conducted with 45 Norwegian cannabis growers, 10 of whom were growing on a large-scale and 35 on a small-scale. The study identifies five mechanisms that prevent small-scale indoor growers from going large-scale. First, large-scale operations involve a number of people, large sums of money, a high work-load and a high risk of detection, and thus demand a higher level of organizational skills than for small growing operations. Second, financial assets are needed to start a large 'grow-site'. Housing rent, electricity, equipment and nutrients are expensive. Third, to be able to sell large quantities of cannabis, growers need access to an illegal distribution network and knowledge of how to act according to black market norms and structures. Fourth, large-scale operations require advanced horticultural skills to maximize yield and quality, which demands greater skills and knowledge than does small-scale cultivation. Fifth, small-scale growers are often embedded in the 'cannabis culture', which emphasizes anti-commercialism, anti-violence and ecological and community values. Hence, starting up large-scale production will imply having to renegotiate or abandon these values. Going from small- to large-scale cannabis production is a demanding task-ideologically, technically, economically and personally. The many obstacles that small-scale growers face and the lack of interest and motivation for going large-scale suggest that the risk of a 'slippery slope' from small-scale to large-scale growing is limited. Possible political implications of the findings are discussed. Copyright

Distributed large-scale dimensional metrology new insights

CERN Document Server

Franceschini, Fiorenzo; Maisano, Domenico

2011-01-01

Focuses on the latest insights into and challenges of distributed large scale dimensional metrology Enables practitioners to study distributed large scale dimensional metrology independently Includes specific examples of the development of new system prototypes

Sub-bottom profiling for large-scale maritime archaeological survey An experience-based approach

DEFF Research Database (Denmark)

Grøn, Ole; Boldreel, Lars Ole

2013-01-01

and wrecks partially or wholly embedded in the sea-floor sediments demands the application of highresolution sub-bottom profilers. This paper presents a strategy for the cost-effective large-scale mapping of unknown sedimentembedded sites such as submerged Stone Age settlements or wrecks, based on sub...... of the submerged cultural heritage. Elements such as archaeological wreck sites exposed on the sea floor are mapped using side-scan and multi-beam techniques. These can also provide information on bathymetric patterns representing potential Stone Age settlements, whereas the detection of such archaeological sites...

SCALE INTERACTION IN A MIXING LAYER. THE ROLE OF THE LARGE-SCALE GRADIENTS

KAUST Repository

Fiscaletti, Daniele; Attili, Antonio; Bisetti, Fabrizio; Elsinga, Gerrit E.

2015-01-01

from physical considerations we would expect the scales to interact in a qualitatively similar way within the flow and across different turbulent flows. Therefore, instead of the large-scale fluctuations, the large-scale gradients modulation of the small scales has been additionally investigated.

Towards a 'standard model' of large scale structure formation

International Nuclear Information System (INIS)

Shafi, Q.

1994-01-01

We explore constraints on inflationary models employing data on large scale structure mainly from COBE temperature anisotropies and IRAS selected galaxy surveys. In models where the tensor contribution to the COBE signal is negligible, we find that the spectral index of density fluctuations n must exceed 0.7. Furthermore the COBE signal cannot be dominated by the tensor component, implying n > 0.85 in such models. The data favors cold plus hot dark matter models with n equal or close to unity and Ω HDM ∼ 0.2 - 0.35. Realistic grand unified theories, including supersymmetric versions, which produce inflation with these properties are presented. (author). 46 refs, 8 figs

The European Large Area ISO Survey

DEFF Research Database (Denmark)

Oliver, S.; Rowan-Robinson, M.; Alexander, D.M.

2000-01-01

We describe the European Large Area ISO Survey (ELAIS). ELAIS was the largest single Open Time project conducted by ISO, mapping an area of 12 deg(2) at 15 mu m with ISOCAM and at 90 mu m with ISOPHOT. Secondary surveys in other ISO bands were undertaken by the ELAIS team within the fields of the...

Chinese large solar telescopes site survey

Science.gov (United States)

Liu, Yu

2017-04-01

In order to observe the solar surface with unprecedentedly higher resolution, Chinse solar physics society decided to launch their solar site survey project in 2010 as the first step to look for the best candidate sites for the Chinese next-generation large-aperture solar telescopes, i.e., the 5-8 meter Chinese Giant Solar Telescope, and the 1 meter level coronagraph. We have built two long-term monitoring sites in Daocheng, with altitudes of around 4800 meters above the sea level located in the large Shangri-La mountain area, and we have collected systematic site data since 2014. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that the large Shangri-La area owns the potential conditions of excellent seeing level and sufficient amount of clear-sky hours suitable for developing large solar telescopes. We will review the site survey progress and present the preliminary statistical results in this talk.

A survey of large scale gamma irradiators in the United States

International Nuclear Information System (INIS)

Smyth, R.C.; Simmons, R.C.; Dougherty, D.K.

1987-01-01

NUS Corporation (NUS) was contracted by the US Department of Energy (DOE) to perform a survey of Cs-137 and Co-60 irradiators in the US. The results of this survey, in the form of matrix listings of irradiators and their specifications, are included in subsequent sections of this report. The US Department of Agriculture (USDA) will use the survey results as a preliminary guide for potential use in regionalized food irradiation research. The survey was limited to the identification of operable irradiators which are owned and/or operated by private industry, educational institutions, and government facilities. To the extent available, specific information for each unit was included in the report. This information includes radioactive material, chemical matrix of fuel, containment capsule material and form, curies per capsule and total activity, sample chamber size, and irradiator availability

Topology Analysis of the Sloan Digital Sky Survey. I. Scale and Luminosity Dependence

Science.gov (United States)

Park, Changbom; Choi, Yun-Young; Vogeley, Michael S.; Gott, J. Richard, III; Kim, Juhan; Hikage, Chiaki; Matsubara, Takahiko; Park, Myeong-Gu; Suto, Yasushi; Weinberg, David H.; SDSS Collaboration

2005-11-01

We measure the topology of volume-limited galaxy samples selected from a parent sample of 314,050 galaxies in the Sloan Digital Sky Survey (SDSS), which is now complete enough to describe the fully three-dimensional topology and its dependence on galaxy properties. We compare the observed genus statistic G(νf) to predictions for a Gaussian random field and to the genus measured for mock surveys constructed from new large-volume simulations of the ΛCDM cosmology. In this analysis we carefully examine the dependence of the observed genus statistic on the Gaussian smoothing scale RG from 3.5 to 11 h-1 Mpc and on the luminosity of galaxies over the range -22.50meatball'' (i.e., cluster dominated) topology, while faint galaxies show a positive shift toward a ``bubble'' (i.e., void dominated) topology. The transition from negative to positive shift occurs approximately at the characteristic absolute magnitude Mr*=-20.4. Even in this analysis of the largest galaxy sample to date, we detect the influence of individual large-scale structures, as the shift parameter Δν and cluster multiplicity AC reflect (at ~3 σ) the presence of the Sloan Great Wall and an X-shaped structure that runs for several hundred megaparsecs across the survey volume.

Trends in large-scale testing of reactor structures

International Nuclear Information System (INIS)

Blejwas, T.E.

2003-01-01

Large-scale tests of reactor structures have been conducted at Sandia National Laboratories since the late 1970s. This paper describes a number of different large-scale impact tests, pressurization tests of models of containment structures, and thermal-pressure tests of models of reactor pressure vessels. The advantages of large-scale testing are evident, but cost, in particular limits its use. As computer models have grown in size, such as number of degrees of freedom, the advent of computer graphics has made possible very realistic representation of results - results that may not accurately represent reality. A necessary condition to avoiding this pitfall is the validation of the analytical methods and underlying physical representations. Ironically, the immensely larger computer models sometimes increase the need for large-scale testing, because the modeling is applied to increasing more complex structural systems and/or more complex physical phenomena. Unfortunately, the cost of large-scale tests is a disadvantage that will likely severely limit similar testing in the future. International collaborations may provide the best mechanism for funding future programs with large-scale tests. (author)

Rasch scaling paranormal belief and experience: structure and semantics of Thalbourne's Australian Sheep-Goat Scale.

Science.gov (United States)

Lange, Rense; Thalbourne, Michael A

2002-12-01

Research on the relation between demographic variables and paranormal belief remains controversial given the possible semantic distortions introduced by item and test level biases. We illustrate how Rasch scaling can be used to detect such biases and to quantify their effects, using the Australian Sheep-Goal Scale as a substantive example. Based on data from 1.822 respondents, this test was Rasch scalable, reliable, and unbiased at the test level. Consistent with other research in which unbiased measures of paranormal belief were used, extremely weak age and sex effects were found (partial eta2 = .005 and .012, respectively).

LARGE-SCALE STAR-FORMATION-DRIVEN OUTFLOWS AT 1 < z < 2 IN THE 3D-HST SURVEY

International Nuclear Information System (INIS)

Lundgren, Britt F.; Van Dokkum, Pieter; Bezanson, Rachel; Momcheva, Ivelina; Nelson, Erica; Skelton, Rosalind E.; Wake, David; Whitaker, Katherine; Brammer, Gabriel; Franx, Marijn; Fumagalli, Mattia; Labbé, Ivo; Patel, Shannon; Da Cunha, Elizabete; Rix, Hans Walter; Schmidt, Kasper; Erb, Dawn K.; Fan Xiaohui; Kriek, Mariska; Marchesini, Danilo

2012-01-01

We present evidence of large-scale outflows from three low-mass (log(M * /M ☉ ) ∼ 9.75) star-forming (SFR > 4 M ☉ yr –1 ) galaxies observed at z = 1.24, z = 1.35, and z = 1.75 in the 3D-HST Survey. Each of these galaxies is located within a projected physical distance of 60 kpc around the sight line to the quasar SDSS J123622.93+621526.6, which exhibits well-separated strong (W λ2796 r ∼> 0.8 Å) Mg II absorption systems matching precisely to the redshifts of the three galaxies. We derive the star formation surface densities from the Hα emission in the WFC3 G141 grism observations for the galaxies and find that in each case the star formation surface density well exceeds 0.1 M ☉ yr –1 kpc –2 , the typical threshold for starburst galaxies in the local universe. From a small but complete parallel census of the 0.65 140 ∼ r > 0.8 Å Mg II covering fraction of star-forming galaxies at 1 r > 0.4 Å Mg II absorbing gas around star-forming galaxies may evolve from z ∼ 2 to the present, consistent with recent observations of an increasing collimation of star-formation-driven outflows with time from z ∼ 3.

Large Scale Computations in Air Pollution Modelling

DEFF Research Database (Denmark)

Zlatev, Z.; Brandt, J.; Builtjes, P. J. H.

Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

Isocurvature modes and Baryon Acoustic Oscillations II: gains from combining CMB and Large Scale Structure

International Nuclear Information System (INIS)

Carbone, Carmelita; Mangilli, Anna; Verde, Licia

2011-01-01

We consider cosmological parameters estimation in the presence of a non-zero isocurvature contribution in the primordial perturbations. A previous analysis showed that even a tiny amount of isocurvature perturbation, if not accounted for, could affect standard rulers calibration from Cosmic Microwave Background observations such as those provided by the Planck mission, affect Baryon Acoustic Oscillations interpretation, and introduce biases in the recovered dark energy properties that are larger than forecasted statistical errors from future surveys. Extending on this work, here we adopt a general fiducial cosmology which includes a varying dark energy equation of state parameter and curvature. Beside Baryon Acoustic Oscillations measurements, we include the information from the shape of the galaxy power spectrum and consider a joint analysis of a Planck-like Cosmic Microwave Background probe and a future, space-based, Large Scale Structure probe not too dissimilar from recently proposed surveys. We find that this allows one to break the degeneracies that affect the Cosmic Microwave Background and Baryon Acoustic Oscillations combination. As a result, most of the cosmological parameter systematic biases arising from an incorrect assumption on the isocurvature fraction parameter f iso , become negligible with respect to the statistical errors. We find that the Cosmic Microwave Background and Large Scale Structure combination gives a statistical error σ(f iso ) ∼ 0.008, even when curvature and a varying dark energy equation of state are included, which is smaller that the error obtained from Cosmic Microwave Background alone when flatness and cosmological constant are assumed. These results confirm the synergy and complementarity between Cosmic Microwave Background and Large Scale Structure, and the great potential of future and planned galaxy surveys

Small-scale microwave background anisotropies implied by large-scale data

Science.gov (United States)

Kashlinsky, A.

1993-01-01

In the absence of reheating microwave background radiation (MBR) anisotropies on arcminute scales depend uniquely on the amplitude and the coherence length of the primordial density fluctuations (PDFs). These can be determined from the recent data on galaxy correlations, xi(r), on linear scales (APM survey). We develop here expressions for the MBR angular correlation function, C(theta), on arcminute scales in terms of the power spectrum of PDFs and demonstrate their accuracy by comparing with detailed calculations of MBR anisotropies. We then show how to evaluate C(theta) directly in terms of the observed xi(r) and show that the APM data give information on the amplitude, C(O), and the coherence angle of MBR anisotropies on small scales.

Hierarchical thinking in network biology: the unbiased modularization of biochemical networks.

Science.gov (United States)

Papin, Jason A; Reed, Jennifer L; Palsson, Bernhard O

2004-12-01

As reconstructed biochemical reaction networks continue to grow in size and scope, there is a growing need to describe the functional modules within them. Such modules facilitate the study of biological processes by deconstructing complex biological networks into conceptually simple entities. The definition of network modules is often based on intuitive reasoning. As an alternative, methods are being developed for defining biochemical network modules in an unbiased fashion. These unbiased network modules are mathematically derived from the structure of the whole network under consideration.

A frequency-domain implementation of a sliding-window traffic sign detector for large scale panoramic datasets

NARCIS (Netherlands)

Creusen, I.M.; Hazelhoff, L.; With, de P.H.N.

2013-01-01

In large-scale automatic traffic sign surveying systems, the primary computational effort is concentrated at the traffic sign detection stage. This paper focuses on reducing the computational load of particularly the sliding window object detection algorithm which is employed for traffic sign

Large-Scale 3D Printing: The Way Forward

Science.gov (United States)

Jassmi, Hamad Al; Najjar, Fady Al; Ismail Mourad, Abdel-Hamid

2018-03-01

Research on small-scale 3D printing has rapidly evolved, where numerous industrial products have been tested and successfully applied. Nonetheless, research on large-scale 3D printing, directed to large-scale applications such as construction and automotive manufacturing, yet demands a great a great deal of efforts. Large-scale 3D printing is considered an interdisciplinary topic and requires establishing a blended knowledge base from numerous research fields including structural engineering, materials science, mechatronics, software engineering, artificial intelligence and architectural engineering. This review article summarizes key topics of relevance to new research trends on large-scale 3D printing, particularly pertaining (1) technological solutions of additive construction (i.e. the 3D printers themselves), (2) materials science challenges, and (3) new design opportunities.

The CTIO surveys for large redshift quasars

International Nuclear Information System (INIS)

Osmer, P.S.

1978-01-01

Lyman α emission in large redshift quasars is readily detectable on slitless spectrograms taken with an objective combination on the 4m telescope. This provides a new survey method, independent of color for finding radio-quiet quasars in large numbers. Surveys by Smith with the Curtis Schmidt and Hoag and Smith with the 4 m telescope, have produced more than 200 candidates with 1.5< z<3.5 and 16< m<21. Spectroscopic observations with the CTIO SIT vidicon system have been carried out for more than 50 of the candidates, with the result that the basic properties of the surveys are known. To date three 16th magnitude quasars with zapproximately2.2 and six quasars with 3.0< z<3.25 have been found. One of the most important uses of the surveys will be the determination of the surface and surface densities of large redshift quasars. A preliminary analysis of the data indicates that the space density of quasars is at least constant, if not increasing, over the interval 1.0< z<3.25. However, the Hoag-Smith sample has only one candidate with z<3.2.(Auth.)

Cosmology with the Large Synoptic Survey Telescope: an overview

Science.gov (United States)

Zhan, Hu; Tyson, J. Anthony

2018-06-01

The Large Synoptic Survey Telescope (LSST) is a high étendue imaging facility that is being constructed atop Cerro Pachón in northern Chile. It is scheduled to begin science operations in 2022. With an ( effective) aperture, a novel three-mirror design achieving a seeing-limited field of view, and a 3.2 gigapixel camera, the LSST has the deep-wide-fast imaging capability necessary to carry out an survey in six passbands (ugrizy) to a coadded depth of over 10 years using of its observational time. The remaining of the time will be devoted to considerably deeper and faster time-domain observations and smaller surveys. In total, each patch of the sky in the main survey will receive 800 visits allocated across the six passbands with exposure visits. The huge volume of high-quality LSST data will provide a wide range of science opportunities and, in particular, open a new era of precision cosmology with unprecedented statistical power and tight control of systematic errors. In this review, we give a brief account of the LSST cosmology program with an emphasis on dark energy investigations. The LSST will address dark energy physics and cosmology in general by exploiting diverse precision probes including large-scale structure, weak lensing, type Ia supernovae, galaxy clusters, and strong lensing. Combined with the cosmic microwave background data, these probes form interlocking tests on the cosmological model and the nature of dark energy in the presence of various systematics. The LSST data products will be made available to the US and Chilean scientific communities and to international partners with no proprietary period. Close collaborations with contemporaneous imaging and spectroscopy surveys observing at a variety of wavelengths, resolutions, depths, and timescales will be a vital part of the LSST science program, which will not only enhance specific studies but, more importantly, also allow a more complete understanding of the Universe through different windows.

Accelerating sustainability in large-scale facilities

CERN Multimedia

Marina Giampietro

2011-01-01

Scientific research centres and large-scale facilities are intrinsically energy intensive, but how can big science improve its energy management and eventually contribute to the environmental cause with new cleantech? CERN’s commitment to providing tangible answers to these questions was sealed in the first workshop on energy management for large scale scientific infrastructures held in Lund, Sweden, on the 13-14 October.   Participants at the energy management for large scale scientific infrastructures workshop. The workshop, co-organised with the European Spallation Source (ESS) and  the European Association of National Research Facilities (ERF), tackled a recognised need for addressing energy issues in relation with science and technology policies. It brought together more than 150 representatives of Research Infrastrutures (RIs) and energy experts from Europe and North America. “Without compromising our scientific projects, we can ...

TIMASSS: the IRAS 16293-2422 millimeter and submillimeter spectral survey. I. Observations, calibration, and analysis of the line kinematics

NARCIS (Netherlands)

Caux, E.; Kahane, C.; Castets, A.; Coutens, A.; Ceccarelli, C.; Bacmann, A.; Bisschop, S.; Bottinelli, S.; Comito, C.; Helmich, F. P.; Lefloch, B.; Parise, B.; Schilke, P.; Tielens, A. G. G. M.; van Dishoeck, E.; Vastel, C.; Wakelam, V.; Walters, A.

Context. Unbiased spectral surveys are powerful tools to study the chemistry and the physics of star forming regions, because they can provide a complete census of the molecular content and the observed lines probe the physical structure of the source. Aims. While unbiased surveys at the millimeter

Large scale reflood test

International Nuclear Information System (INIS)

Hirano, Kemmei; Murao, Yoshio

1980-01-01

The large-scale reflood test with a view to ensuring the safety of light water reactors was started in fiscal 1976 based on the special account act for power source development promotion measures by the entrustment from the Science and Technology Agency. Thereafter, to establish the safety of PWRs in loss-of-coolant accidents by joint international efforts, the Japan-West Germany-U.S. research cooperation program was started in April, 1980. Thereupon, the large-scale reflood test is now included in this program. It consists of two tests using a cylindrical core testing apparatus for examining the overall system effect and a plate core testing apparatus for testing individual effects. Each apparatus is composed of the mock-ups of pressure vessel, primary loop, containment vessel and ECCS. The testing method, the test results and the research cooperation program are described. (J.P.N.)

Cosmological parameters from large scale structure - geometric versus shape information

CERN Document Server

Hamann, Jan; Lesgourgues, Julien; Rampf, Cornelius; Wong, Yvonne Y Y

2010-01-01

The matter power spectrum as derived from large scale structure (LSS) surveys contains two important and distinct pieces of information: an overall smooth shape and the imprint of baryon acoustic oscillations (BAO). We investigate the separate impact of these two types of information on cosmological parameter estimation, and show that for the simplest cosmological models, the broad-band shape information currently contained in the SDSS DR7 halo power spectrum (HPS) is by far superseded by geometric information derived from the baryonic features. An immediate corollary is that contrary to popular beliefs, the upper limit on the neutrino mass m_\

State-of-the-art of large scale biogas plants

International Nuclear Information System (INIS)

Prisum, J.M.; Noergaard, P.

1992-01-01

A survey of the technological state of large scale biogas plants in Europe treating manure is given. 83 plants are in operation at present. Of these, 16 are centralised digestion plants. Transport costs at centralised digestion plants amounts to between 25 and 40 percent of the total operational costs. Various transport equipment is used. Most large scale digesters are CSTRs, but serial, contact, 2-step, and plug-flow digesters are also found. Construction materials are mostly steel and concrete. Mesophilic digestion is most common (56%), thermophilic digestion is used in 17% of the plants, combined mesophilic and thermophilic digestion is used in 28% of the centralised plants. Mixing of digester content is performed with gas injection, propellers, and gas-liquid displacement. Heating is carried out using external or internal heat exchangers. Heat recovery is only used in Denmark. Gas purification equipment is commonplace, but not often needed. Several plants use separation of the digested manure, often as part of a post-treatment/-purification process or for the production of 'compost'. Screens, sieve belt separaters, centrifuges and filter presses are employed. The use of biogas varies considerably. In some cases, combined heat and power stations are supplying the grid and district heating systems. Other plants use only either the electricity or heat. (au)

Study of multi-functional precision optical measuring system for large scale equipment

Science.gov (United States)

Jiang, Wei; Lao, Dabao; Zhou, Weihu; Zhang, Wenying; Jiang, Xingjian; Wang, Yongxi

2017-10-01

The effective application of high performance measurement technology can greatly improve the large-scale equipment manufacturing ability. Therefore, the geometric parameters measurement, such as size, attitude and position, requires the measurement system with high precision, multi-function, portability and other characteristics. However, the existing measuring instruments, such as laser tracker, total station, photogrammetry system, mostly has single function, station moving and other shortcomings. Laser tracker needs to work with cooperative target, but it can hardly meet the requirement of measurement in extreme environment. Total station is mainly used for outdoor surveying and mapping, it is hard to achieve the demand of accuracy in industrial measurement. Photogrammetry system can achieve a wide range of multi-point measurement, but the measuring range is limited and need to repeatedly move station. The paper presents a non-contact opto-electronic measuring instrument, not only it can work by scanning the measurement path but also measuring the cooperative target by tracking measurement. The system is based on some key technologies, such as absolute distance measurement, two-dimensional angle measurement, automatically target recognition and accurate aiming, precision control, assembly of complex mechanical system and multi-functional 3D visualization software. Among them, the absolute distance measurement module ensures measurement with high accuracy, and the twodimensional angle measuring module provides precision angle measurement. The system is suitable for the case of noncontact measurement of large-scale equipment, it can ensure the quality and performance of large-scale equipment throughout the process of manufacturing and improve the manufacturing ability of large-scale and high-end equipment.

Large Scale Cosmological Anomalies and Inhomogeneous Dark Energy

Directory of Open Access Journals (Sweden)

Leandros Perivolaropoulos

2014-01-01

Full Text Available A wide range of large scale observations hint towards possible modifications on the standard cosmological model which is based on a homogeneous and isotropic universe with a small cosmological constant and matter. These observations, also known as “cosmic anomalies” include unexpected Cosmic Microwave Background perturbations on large angular scales, large dipolar peculiar velocity flows of galaxies (“bulk flows”, the measurement of inhomogenous values of the fine structure constant on cosmological scales (“alpha dipole” and other effects. The presence of the observational anomalies could either be a large statistical fluctuation in the context of ΛCDM or it could indicate a non-trivial departure from the cosmological principle on Hubble scales. Such a departure is very much constrained by cosmological observations for matter. For dark energy however there are no significant observational constraints for Hubble scale inhomogeneities. In this brief review I discuss some of the theoretical models that can naturally lead to inhomogeneous dark energy, their observational constraints and their potential to explain the large scale cosmic anomalies.

Large-scale patterns in Rayleigh-Benard convection

International Nuclear Information System (INIS)

Hardenberg, J. von; Parodi, A.; Passoni, G.; Provenzale, A.; Spiegel, E.A.

2008-01-01

Rayleigh-Benard convection at large Rayleigh number is characterized by the presence of intense, vertically moving plumes. Both laboratory and numerical experiments reveal that the rising and descending plumes aggregate into separate clusters so as to produce large-scale updrafts and downdrafts. The horizontal scales of the aggregates reported so far have been comparable to the horizontal extent of the containers, but it has not been clear whether that represents a limitation imposed by domain size. In this work, we present numerical simulations of convection at sufficiently large aspect ratio to ascertain whether there is an intrinsic saturation scale for the clustering process when that ratio is large enough. From a series of simulations of Rayleigh-Benard convection with Rayleigh numbers between 10 5 and 10 8 and with aspect ratios up to 12π, we conclude that the clustering process has a finite horizontal saturation scale with at most a weak dependence on Rayleigh number in the range studied

Birth Satisfaction Scale/Birth Satisfaction Scale-Revised (BSS/BSS-R): A large scale United States planned home birth and birth centre survey.

Science.gov (United States)

Fleming, Susan E; Donovan-Batson, Colleen; Burduli, Ekaterina; Barbosa-Leiker, Celestina; Hollins Martin, Caroline J; Martin, Colin R

2016-10-01

to explore the prevalence of birth satisfaction for childbearing women planning to birth in their home or birth centers in the United States. Examining differences in birth satisfaction of the home and birth centers; and those who birthed in a hospital using the 30-item Birth Satisfaction Scale (BSS) and the 10-item Birth Satisfaction Scale-Revised (BSS-R). a quantitative survey using the BSS and BSS-R were employed. Additional demographic data were collected using electronic linkages (Qualtrics ™ ). a convenience sample of childbearing women (n=2229) who had planned to birth in their home or birth center from the US (United States) participated. Participants were recruited via professional and personal contacts, primarily their midwives. the total 30-item BSS score mean was 128.98 (SD 16.92) and the 10-item BSS-R mean score was 31.94 (SD 6.75). Sub-scale mean scores quantified the quality of care provision, women's personal attributes, and stress experienced during labour. Satisfaction was higher for women with vaginal births compared with caesareans deliveries. In addition, satisfaction was higher for women who had both planned to deliver in a home or a birth centre, and who had actually delivered in a home or a birth center. total and subscale birth satisfaction scores were positive and high for the overall sample IMPLICATIONS FOR PRACTICE: the BSS and the BSS-R provide a robust tool to quantify women's experiences of childbirth between variables such as birth types, birth settings and providers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prevalence and determinants of child maltreatment among high school students in Southern China: A large scale school based survey

Directory of Open Access Journals (Sweden)

Chen WQ

2008-09-01

Full Text Available Abstract Background Child maltreatment can cause significant physical and psychological problems. The present study aimed to investigate the prevalence and determinants of child maltreatment in Guangzhou, China, where such issues are often considered a taboo subject. Methods A school-based survey was conducted in southern China in 2005. 24 high schools were selected using stratified random sampling strategy based on their districts and bandings. The self-administered validated Chinese version of parent-child Conflict Tactics Scale (CTSPC was used as the main assessment tool to measure the abusive experiences encountered by students in the previous six months. Results The response rate of this survey was 99.7%. Among the 6592 responding students, the mean age was 14.68. Prevalence of parental psychological aggression, corporal punishment, severe and very serve physical maltreatment in the past 6 months were 78.3%, 23.2%, 15.1% and 2.8% respectively. The prevalence of sexual abuse is 0.6%. The most commonly cited reasons for maltreatment included 'disobedience to parents', 'poor academic performance', and 'quarrelling between parents'. Age, parental education, places of origins and types of housing were found to be associated with physical maltreatments whereas gender and fathers' education level were associated with sexual abuse. Conclusion Though largely unspoken, child maltreatment is a common problem in China. Identification of significant determinants in this study can provide valuable information for teachers and health professionals so as to pay special attention to those at-risk children.

Prevalence and determinants of child maltreatment among high school students in Southern China: a large scale school based survey.

Science.gov (United States)

Leung, Phil W S; Wong, William C W; Chen, W Q; Tang, Catherine S K

2008-09-29

Child maltreatment can cause significant physical and psychological problems. The present study aimed to investigate the prevalence and determinants of child maltreatment in Guangzhou, China, where such issues are often considered a taboo subject. A school-based survey was conducted in southern China in 2005. 24 high schools were selected using stratified random sampling strategy based on their districts and bandings. The self-administered validated Chinese version of parent-child Conflict Tactics Scale (CTSPC) was used as the main assessment tool to measure the abusive experiences encountered by students in the previous six months. The response rate of this survey was 99.7%. Among the 6592 responding students, the mean age was 14.68. Prevalence of parental psychological aggression, corporal punishment, severe and very serve physical maltreatment in the past 6 months were 78.3%, 23.2%, 15.1% and 2.8% respectively. The prevalence of sexual abuse is 0.6%. The most commonly cited reasons for maltreatment included 'disobedience to parents', 'poor academic performance', and 'quarrelling between parents'. Age, parental education, places of origins and types of housing were found to be associated with physical maltreatments whereas gender and fathers' education level were associated with sexual abuse. Though largely unspoken, child maltreatment is a common problem in China. Identification of significant determinants in this study can provide valuable information for teachers and health professionals so as to pay special attention to those at-risk children.

Cluster galaxy dynamics and the effects of large-scale environment

Science.gov (United States)

White, Martin; Cohn, J. D.; Smit, Renske

2010-11-01

Advances in observational capabilities have ushered in a new era of multi-wavelength, multi-physics probes of galaxy clusters and ambitious surveys are compiling large samples of cluster candidates selected in different ways. We use a high-resolution N-body simulation to study how the influence of large-scale structure in and around clusters causes correlated signals in different physical probes and discuss some implications this has for multi-physics probes of clusters (e.g. richness, lensing, Compton distortion and velocity dispersion). We pay particular attention to velocity dispersions, matching galaxies to subhaloes which are explicitly tracked in the simulation. We find that not only do haloes persist as subhaloes when they fall into a larger host, but groups of subhaloes retain their identity for long periods within larger host haloes. The highly anisotropic nature of infall into massive clusters, and their triaxiality, translates into an anisotropic velocity ellipsoid: line-of-sight galaxy velocity dispersions for any individual halo show large variance depending on viewing angle. The orientation of the velocity ellipsoid is correlated with the large-scale structure, and thus velocity outliers correlate with outliers caused by projection in other probes. We quantify this orientation uncertainty and give illustrative examples. Such a large variance suggests that velocity dispersion estimators will work better in an ensemble sense than for any individual cluster, which may inform strategies for obtaining redshifts of cluster members. We similarly find that the ability of substructure indicators to find kinematic substructures is highly viewing angle dependent. While groups of subhaloes which merge with a larger host halo can retain their identity for many Gyr, they are only sporadically picked up by substructure indicators. We discuss the effects of correlated scatter on scaling relations estimated through stacking, both analytically and in the simulations

Manufacturing test of large scale hollow capsule and long length cladding in the large scale oxide dispersion strengthened (ODS) martensitic steel

International Nuclear Information System (INIS)

Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Fujiwara, Masayuki

2004-04-01

Mass production capability of oxide dispersion strengthened (ODS) martensitic steel cladding (9Cr) has being evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube (raw materials powder production, mechanical alloying (MA) by ball mill, canning, hot extrusion, and machining) is a dominant factor in the total cost for manufacturing ODS ferritic steel cladding. In this study, the large-sale 9Cr-ODS martensitic steel mother tube which is made with a large-scale hollow capsule, and long length claddings were manufactured, and the applicability of these processes was evaluated. Following results were obtained in this study. (1) Manufacturing the large scale mother tube in the dimension of 32 mm OD, 21 mm ID, and 2 m length has been successfully carried out using large scale hollow capsule. This mother tube has a high degree of accuracy in size. (2) The chemical composition and the micro structure of the manufactured mother tube are similar to the existing mother tube manufactured by a small scale can. And the remarkable difference between the bottom and top sides in the manufactured mother tube has not been observed. (3) The long length cladding has been successfully manufactured from the large scale mother tube which was made using a large scale hollow capsule. (4) For reducing the manufacturing cost of the ODS steel claddings, manufacturing process of the mother tubes using a large scale hollow capsules is promising. (author)

Amplification of large-scale magnetic field in nonhelical magnetohydrodynamics

KAUST Repository

Kumar, Rohit

2017-08-11

It is typically assumed that the kinetic and magnetic helicities play a crucial role in the growth of large-scale dynamo. In this paper, we demonstrate that helicity is not essential for the amplification of large-scale magnetic field. For this purpose, we perform nonhelical magnetohydrodynamic (MHD) simulation, and show that the large-scale magnetic field can grow in nonhelical MHD when random external forcing is employed at scale 1/10 the box size. The energy fluxes and shell-to-shell transfer rates computed using the numerical data show that the large-scale magnetic energy grows due to the energy transfers from the velocity field at the forcing scales.

Mapping neighborhood scale survey responses with uncertainty metrics

Directory of Open Access Journals (Sweden)

Charles Robert Ehlschlaeger

2016-12-01

Full Text Available This paper presents a methodology of mapping population-centric social, infrastructural, and environmental metrics at neighborhood scale. This methodology extends traditional survey analysis methods to create cartographic products useful in agent-based modeling and geographic information analysis. It utilizes and synthesizes survey microdata, sub-upazila attributes, land use information, and ground truth locations of attributes to create neighborhood scale multi-attribute maps. Monte Carlo methods are employed to combine any number of survey responses to stochastically weight survey cases and to simulate survey cases' locations in a study area. Through such Monte Carlo methods, known errors from each of the input sources can be retained. By keeping individual survey cases as the atomic unit of data representation, this methodology ensures that important covariates are retained and that ecological inference fallacy is eliminated. These techniques are demonstrated with a case study from the Chittagong Division in Bangladesh. The results provide a population-centric understanding of many social, infrastructural, and environmental metrics desired in humanitarian aid and disaster relief planning and operations wherever long term familiarity is lacking. Of critical importance is that the resulting products have easy to use explicit representation of the errors and uncertainties of each of the input sources via the automatically generated summary statistics created at the application's geographic scale.

Hydrometeorological variability on a large french catchment and its relation to large-scale circulation across temporal scales

Science.gov (United States)

Massei, Nicolas; Dieppois, Bastien; Fritier, Nicolas; Laignel, Benoit; Debret, Maxime; Lavers, David; Hannah, David

2015-04-01

In the present context of global changes, considerable efforts have been deployed by the hydrological scientific community to improve our understanding of the impacts of climate fluctuations on water resources. Both observational and modeling studies have been extensively employed to characterize hydrological changes and trends, assess the impact of climate variability or provide future scenarios of water resources. In the aim of a better understanding of hydrological changes, it is of crucial importance to determine how and to what extent trends and long-term oscillations detectable in hydrological variables are linked to global climate oscillations. In this work, we develop an approach associating large-scale/local-scale correlation, enmpirical statistical downscaling and wavelet multiresolution decomposition of monthly precipitation and streamflow over the Seine river watershed, and the North Atlantic sea level pressure (SLP) in order to gain additional insights on the atmospheric patterns associated with the regional hydrology. We hypothesized that: i) atmospheric patterns may change according to the different temporal wavelengths defining the variability of the signals; and ii) definition of those hydrological/circulation relationships for each temporal wavelength may improve the determination of large-scale predictors of local variations. The results showed that the large-scale/local-scale links were not necessarily constant according to time-scale (i.e. for the different frequencies characterizing the signals), resulting in changing spatial patterns across scales. This was then taken into account by developing an empirical statistical downscaling (ESD) modeling approach which integrated discrete wavelet multiresolution analysis for reconstructing local hydrometeorological processes (predictand : precipitation and streamflow on the Seine river catchment) based on a large-scale predictor (SLP over the Euro-Atlantic sector) on a monthly time-step. This approach

Superconducting materials for large scale applications

International Nuclear Information System (INIS)

Dew-Hughes, D.

1975-01-01

Applications of superconductors capable of carrying large current densities in large-scale electrical devices are examined. Discussions are included on critical current density, superconducting materials available, and future prospects for improved superconducting materials. (JRD)

Digital Archiving of People Flow by Recycling Large-Scale Social Survey Data of Developing Cities

Science.gov (United States)

Sekimoto, Y.; Watanabe, A.; Nakamura, T.; Horanont, T.

2012-07-01

Data on people flow has become increasingly important in the field of business, including the areas of marketing and public services. Although mobile phones enable a person's position to be located to a certain degree, it is a challenge to acquire sufficient data from people with mobile phones. In order to grasp people flow in its entirety, it is important to establish a practical method of reconstructing people flow from various kinds of existing fragmentary spatio-temporal data such as social survey data. For example, despite typical Person Trip Survey Data collected by the public sector showing the fragmentary spatio-temporal positions accessed, the data are attractive given the sufficiently large sample size to estimate the entire flow of people. In this study, we apply our proposed basic method to Japan International Cooperation Agency (JICA) PT data pertaining to developing cities around the world, and we propose some correction methods to resolve the difficulties in applying it to many cities and stably to infrastructure data.

Large-scale influences in near-wall turbulence.

Science.gov (United States)

Hutchins, Nicholas; Marusic, Ivan

2007-03-15

Hot-wire data acquired in a high Reynolds number facility are used to illustrate the need for adequate scale separation when considering the coherent structure in wall-bounded turbulence. It is found that a large-scale motion in the log region becomes increasingly comparable in energy to the near-wall cycle as the Reynolds number increases. Through decomposition of fluctuating velocity signals, it is shown that this large-scale motion has a distinct modulating influence on the small-scale energy (akin to amplitude modulation). Reassessment of DNS data, in light of these results, shows similar trends, with the rate and intensity of production due to the near-wall cycle subject to a modulating influence from the largest-scale motions.

Talking About The Smokes: a large-scale, community-based participatory research project.

Science.gov (United States)

Couzos, Sophia; Nicholson, Anna K; Hunt, Jennifer M; Davey, Maureen E; May, Josephine K; Bennet, Pele T; Westphal, Darren W; Thomas, David P

2015-06-01

To describe the Talking About The Smokes (TATS) project according to the World Health Organization guiding principles for conducting community-based participatory research (PR) involving indigenous peoples, to assist others planning large-scale PR projects. The TATS project was initiated in Australia in 2010 as part of the International Tobacco Control Policy Evaluation Project, and surveyed a representative sample of 2522 Aboriginal and Torres Strait Islander adults to assess the impact of tobacco control policies. The PR process of the TATS project, which aimed to build partnerships to create equitable conditions for knowledge production, was mapped and summarised onto a framework adapted from the WHO principles. Processes describing consultation and approval, partnerships and research agreements, communication, funding, ethics and consent, data and benefits of the research. The TATS project involved baseline and follow-up surveys conducted in 34 Aboriginal community-controlled health services and one Torres Strait community. Consistent with the WHO PR principles, the TATS project built on community priorities and strengths through strategic partnerships from project inception, and demonstrated the value of research agreements and trusting relationships to foster shared decision making, capacity building and a commitment to Indigenous data ownership. Community-based PR methodology, by definition, needs adaptation to local settings and priorities. The TATS project demonstrates that large-scale research can be participatory, with strong Indigenous community engagement and benefits.

Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4

Energy Technology Data Exchange (ETDEWEB)

Järvelä, Emilia [Metsähovi Radio Observatory, Aalto University, Espoo (Finland); Department of Electronics and Nanoengineering, Aalto University, Espoo (Finland); Lähteenmäki, A. [Metsähovi Radio Observatory, Aalto University, Espoo (Finland); Department of Electronics and Nanoengineering, Aalto University, Espoo (Finland); Tartu Observatory, Tõravere (Estonia); Lietzen, H., E-mail: emilia.jarvela@aalto.fi [Tartu Observatory, Tõravere (Estonia)

2017-11-30

The large-scale environment is believed to affect the evolution and intrinsic properties of galaxies. It offers a new perspective on narrow-line Seyfert 1 galaxies (NLS1) which have not been extensively studied in this context before. We study a large and diverse sample of 960 NLS1 galaxies using a luminosity-density field constructed using Sloan Digital Sky Survey. We investigate how the large-scale environment is connected to the properties of NLS1 galaxies, especially their radio loudness. Furthermore, we compare the large-scale environment properties of NLS1 galaxies with other active galactic nuclei (AGN) classes, for example, other jetted AGN and broad-line Seyfert 1 (BLS1) galaxies, to shed light on their possible relations. In general NLS1 galaxies reside in less dense large-scale environments than any of our comparison samples, thus supporting their young age. The average luminosity-density and distribution to different luminosity-density regions of NLS1 sources is significantly different compared to BLS1 galaxies. This contradicts the simple orientation-based unification of NLS1 and BLS1 galaxies, and weakens the hypothesis that BLS1 galaxies are the parent population of NLS1 galaxies. The large-scale environment density also has an impact on the intrinsic properties of NLS1 galaxies; the radio loudness increases with the increasing luminosity-density. However, our results suggest that the NLS1 population is indeed heterogeneous, and that a considerable fraction of them are misclassified. We support a suggested description that the traditional classification based on the radio loudness should be replaced with the division to jetted and non-jetted sources.

A fast approach to generate large-scale topographic maps based on new Chinese vehicle-borne Lidar system

International Nuclear Information System (INIS)

Youmei, Han; Bogang, Yang

2014-01-01

Large -scale topographic maps are important basic information for city and regional planning and management. Traditional large- scale mapping methods are mostly based on artificial mapping and photogrammetry. The traditional mapping method is inefficient and limited by the environments. While the photogrammetry methods(such as low-altitude aerial mapping) is an economical and effective way to map wide and regulate range of large scale topographic map but doesn't work well in the small area due to the high cost of manpower and resources. Recent years, the vehicle-borne LIDAR technology has a rapid development, and its application in surveying and mapping is becoming a new topic. The main objective of this investigation is to explore the potential of vehicle-borne LIDAR technology to be used to fast mapping large scale topographic maps based on new Chinese vehicle-borne LIDAR system. It studied how to use the new Chinese vehicle-borne LIDAR system measurement technology to map large scale topographic maps. After the field data capture, it can be mapped in the office based on the LIDAR data (point cloud) by software which programmed by ourselves. In addition, the detailed process and accuracy analysis were proposed by an actual case. The result show that this new technology provides a new fast method to generate large scale topographic maps, which is high efficient and accuracy compared to traditional methods

PKI security in large-scale healthcare networks.

Science.gov (United States)

Mantas, Georgios; Lymberopoulos, Dimitrios; Komninos, Nikos

2012-06-01

During the past few years a lot of PKI (Public Key Infrastructures) infrastructures have been proposed for healthcare networks in order to ensure secure communication services and exchange of data among healthcare professionals. However, there is a plethora of challenges in these healthcare PKI infrastructures. Especially, there are a lot of challenges for PKI infrastructures deployed over large-scale healthcare networks. In this paper, we propose a PKI infrastructure to ensure security in a large-scale Internet-based healthcare network connecting a wide spectrum of healthcare units geographically distributed within a wide region. Furthermore, the proposed PKI infrastructure facilitates the trust issues that arise in a large-scale healthcare network including multi-domain PKI infrastructures.

Large-scale protein-protein interaction analysis in Arabidopsis mesophyll protoplasts by split firefly luciferase complementation.

Science.gov (United States)

Li, Jian-Feng; Bush, Jenifer; Xiong, Yan; Li, Lei; McCormack, Matthew

2011-01-01

Protein-protein interactions (PPIs) constitute the regulatory network that coordinates diverse cellular functions. There are growing needs in plant research for creating protein interaction maps behind complex cellular processes and at a systems biology level. However, only a few approaches have been successfully used for large-scale surveys of PPIs in plants, each having advantages and disadvantages. Here we present split firefly luciferase complementation (SFLC) as a highly sensitive and noninvasive technique for in planta PPI investigation. In this assay, the separate halves of a firefly luciferase can come into close proximity and transiently restore its catalytic activity only when their fusion partners, namely the two proteins of interest, interact with each other. This assay was conferred with quantitativeness and high throughput potential when the Arabidopsis mesophyll protoplast system and a microplate luminometer were employed for protein expression and luciferase measurement, respectively. Using the SFLC assay, we could monitor the dynamics of rapamycin-induced and ascomycin-disrupted interaction between Arabidopsis FRB and human FKBP proteins in a near real-time manner. As a proof of concept for large-scale PPI survey, we further applied the SFLC assay to testing 132 binary PPIs among 8 auxin response factors (ARFs) and 12 Aux/IAA proteins from Arabidopsis. Our results demonstrated that the SFLC assay is ideal for in vivo quantitative PPI analysis in plant cells and is particularly powerful for large-scale binary PPI screens.

Large-scale protein-protein interaction analysis in Arabidopsis mesophyll protoplasts by split firefly luciferase complementation.

Directory of Open Access Journals (Sweden)

Jian-Feng Li

Full Text Available Protein-protein interactions (PPIs constitute the regulatory network that coordinates diverse cellular functions. There are growing needs in plant research for creating protein interaction maps behind complex cellular processes and at a systems biology level. However, only a few approaches have been successfully used for large-scale surveys of PPIs in plants, each having advantages and disadvantages. Here we present split firefly luciferase complementation (SFLC as a highly sensitive and noninvasive technique for in planta PPI investigation. In this assay, the separate halves of a firefly luciferase can come into close proximity and transiently restore its catalytic activity only when their fusion partners, namely the two proteins of interest, interact with each other. This assay was conferred with quantitativeness and high throughput potential when the Arabidopsis mesophyll protoplast system and a microplate luminometer were employed for protein expression and luciferase measurement, respectively. Using the SFLC assay, we could monitor the dynamics of rapamycin-induced and ascomycin-disrupted interaction between Arabidopsis FRB and human FKBP proteins in a near real-time manner. As a proof of concept for large-scale PPI survey, we further applied the SFLC assay to testing 132 binary PPIs among 8 auxin response factors (ARFs and 12 Aux/IAA proteins from Arabidopsis. Our results demonstrated that the SFLC assay is ideal for in vivo quantitative PPI analysis in plant cells and is particularly powerful for large-scale binary PPI screens.

Emerging large-scale solar heating applications

International Nuclear Information System (INIS)

Wong, W.P.; McClung, J.L.

2009-01-01

Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

Emerging large-scale solar heating applications

Energy Technology Data Exchange (ETDEWEB)

Wong, W.P.; McClung, J.L. [Science Applications International Corporation (SAIC Canada), Ottawa, Ontario (Canada)

2009-07-01

Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

Sampling scales define occupancy and underlying occupancy-abundance relationships in animals.

Science.gov (United States)

Steenweg, Robin; Hebblewhite, Mark; Whittington, Jesse; Lukacs, Paul; McKelvey, Kevin

2018-01-01

Occupancy-abundance (OA) relationships are a foundational ecological phenomenon and field of study, and occupancy models are increasingly used to track population trends and understand ecological interactions. However, these two fields of ecological inquiry remain largely isolated, despite growing appreciation of the importance of integration. For example, using occupancy models to infer trends in abundance is predicated on positive OA relationships. Many occupancy studies collect data that violate geographical closure assumptions due to the choice of sampling scales and application to mobile organisms, which may change how occupancy and abundance are related. Little research, however, has explored how different occupancy sampling designs affect OA relationships. We develop a conceptual framework for understanding how sampling scales affect the definition of occupancy for mobile organisms, which drives OA relationships. We explore how spatial and temporal sampling scales, and the choice of sampling unit (areal vs. point sampling), affect OA relationships. We develop predictions using simulations, and test them using empirical occupancy data from remote cameras on 11 medium-large mammals. Surprisingly, our simulations demonstrate that when using point sampling, OA relationships are unaffected by spatial sampling grain (i.e., cell size). In contrast, when using areal sampling (e.g., species atlas data), OA relationships are affected by spatial grain. Furthermore, OA relationships are also affected by temporal sampling scales, where the curvature of the OA relationship increases with temporal sampling duration. Our empirical results support these predictions, showing that at any given abundance, the spatial grain of point sampling does not affect occupancy estimates, but longer surveys do increase occupancy estimates. For rare species (low occupancy), estimates of occupancy will quickly increase with longer surveys, even while abundance remains constant. Our results

Quantifying expert consensus against the existence of a secret, large-scale atmospheric spraying program

Science.gov (United States)

Shearer, Christine; West, Mick; Caldeira, Ken; Davis, Steven J.

2016-08-01

Nearly 17% of people in an international survey said they believed the existence of a secret large-scale atmospheric program (SLAP) to be true or partly true. SLAP is commonly referred to as ‘chemtrails’ or ‘covert geoengineering’, and has led to a number of websites purported to show evidence of widespread chemical spraying linked to negative impacts on human health and the environment. To address these claims, we surveyed two groups of experts—atmospheric chemists with expertize in condensation trails and geochemists working on atmospheric deposition of dust and pollution—to scientifically evaluate for the first time the claims of SLAP theorists. Results show that 76 of the 77 scientists (98.7%) that took part in this study said they had not encountered evidence of a SLAP, and that the data cited as evidence could be explained through other factors, including well-understood physics and chemistry associated with aircraft contrails and atmospheric aerosols. Our goal is not to sway those already convinced that there is a secret, large-scale spraying program—who often reject counter-evidence as further proof of their theories—but rather to establish a source of objective science that can inform public discourse.

Unbiased methods for removing systematics from galaxy clustering measurements

Science.gov (United States)

Elsner, Franz; Leistedt, Boris; Peiris, Hiranya V.

2016-02-01

Measuring the angular clustering of galaxies as a function of redshift is a powerful method for extracting information from the three-dimensional galaxy distribution. The precision of such measurements will dramatically increase with ongoing and future wide-field galaxy surveys. However, these are also increasingly sensitive to observational and astrophysical contaminants. Here, we study the statistical properties of three methods proposed for controlling such systematics - template subtraction, basic mode projection, and extended mode projection - all of which make use of externally supplied template maps, designed to characterize and capture the spatial variations of potential systematic effects. Based on a detailed mathematical analysis, and in agreement with simulations, we find that the template subtraction method in its original formulation returns biased estimates of the galaxy angular clustering. We derive closed-form expressions that should be used to correct results for this shortcoming. Turning to the basic mode projection algorithm, we prove it to be free of any bias, whereas we conclude that results computed with extended mode projection are biased. Within a simplified setup, we derive analytical expressions for the bias and discuss the options for correcting it in more realistic configurations. Common to all three methods is an increased estimator variance induced by the cleaning process, albeit at different levels. These results enable unbiased high-precision clustering measurements in the presence of spatially varying systematics, an essential step towards realizing the full potential of current and planned galaxy surveys.

Implicit solvers for large-scale nonlinear problems

International Nuclear Information System (INIS)

Keyes, David E; Reynolds, Daniel R; Woodward, Carol S

2006-01-01

Computational scientists are grappling with increasingly complex, multi-rate applications that couple such physical phenomena as fluid dynamics, electromagnetics, radiation transport, chemical and nuclear reactions, and wave and material propagation in inhomogeneous media. Parallel computers with large storage capacities are paving the way for high-resolution simulations of coupled problems; however, hardware improvements alone will not prove enough to enable simulations based on brute-force algorithmic approaches. To accurately capture nonlinear couplings between dynamically relevant phenomena, often while stepping over rapid adjustments to quasi-equilibria, simulation scientists are increasingly turning to implicit formulations that require a discrete nonlinear system to be solved for each time step or steady state solution. Recent advances in iterative methods have made fully implicit formulations a viable option for solution of these large-scale problems. In this paper, we overview one of the most effective iterative methods, Newton-Krylov, for nonlinear systems and point to software packages with its implementation. We illustrate the method with an example from magnetically confined plasma fusion and briefly survey other areas in which implicit methods have bestowed important advantages, such as allowing high-order temporal integration and providing a pathway to sensitivity analyses and optimization. Lastly, we overview algorithm extensions under development motivated by current SciDAC applications

Large-scale regions of antimatter

International Nuclear Information System (INIS)

Grobov, A. V.; Rubin, S. G.

2015-01-01

Amodified mechanism of the formation of large-scale antimatter regions is proposed. Antimatter appears owing to fluctuations of a complex scalar field that carries a baryon charge in the inflation era

Large-scale regions of antimatter

Energy Technology Data Exchange (ETDEWEB)

Grobov, A. V., E-mail: alexey.grobov@gmail.com; Rubin, S. G., E-mail: sgrubin@mephi.ru [National Research Nuclear University MEPhI (Russian Federation)

2015-07-15

Amodified mechanism of the formation of large-scale antimatter regions is proposed. Antimatter appears owing to fluctuations of a complex scalar field that carries a baryon charge in the inflation era.

Large-scaled biomonitoring of trace-element air pollution: goals and approaches

International Nuclear Information System (INIS)

Wolterbeek, H.T.

2000-01-01

Biomonitoring is often used in multi-parameter approaches in especially larger scaled surveys. The information obtained may consist of thousands of data points, which can be processed in a variety of mathematical routines to permit a condensed and strongly-smoothed presentation of results and conclusions. Although reports on larger-scaled biomonitoring surveys are 'easy- to-read' and often include far-reaching interpretations, it is not possible to obtain an insight into the real meaningfulness or quality of the survey performed. In any set-up, the aims of the survey should be put forward as clear as possible. Is the survey to provide information on atmospheric element levels, or on total, wet and dry deposition, what should be the time- or geographical scale and resolution of the survey, which elements should be determined, is the survey to give information on emission or immission characteristics? Answers to all these questions are of paramount importance, not only regarding the choice of the biomonitoring species or necessary handling/analysis techniques, but also with respect to planning and personnel, and, not to forget, the expected/available means of data interpretation. In considering a survey set-up, rough survey dimensions may follow directly from the goals; in practice, however, they will be governed by other aspects such as available personnel, handling means/capacity, costs, etc. In what sense and to what extent these factors may cause the survey to drift away from the pre-set goals should receive ample attention: in extreme cases the survey should not be carried out. Bearing in mind the above considerations, the present paper focuses on goals, quality and approaches of larger-scaled biomonitoring surveys on trace element air pollution. The discussion comprises practical problems, options, decisions, analytical means, quality measures, and eventual survey results. (author)

Large-Scale Analysis of Art Proportions

DEFF Research Database (Denmark)

Jensen, Karl Kristoffer

2014-01-01

While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square) and with majo......While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square...

The Expanded Large Scale Gap Test

Science.gov (United States)

1987-03-01

NSWC TR 86-32 DTIC THE EXPANDED LARGE SCALE GAP TEST BY T. P. LIDDIARD D. PRICE RESEARCH AND TECHNOLOGY DEPARTMENT ’ ~MARCH 1987 Ap~proved for public...arises, to reduce the spread in the LSGT 50% gap value.) The worst charges, such as those with the highest or lowest densities, the largest re-pressed...Arlington, VA 22217 PE 62314N INS3A 1 RJ14E31 7R4TBK 11 TITLE (Include Security CIlmsilficatiorn The Expanded Large Scale Gap Test . 12. PEIRSONAL AUTHOR() T

Large scale and big data processing and management

CERN Document Server

Sakr, Sherif

2014-01-01

Large Scale and Big Data: Processing and Management provides readers with a central source of reference on the data management techniques currently available for large-scale data processing. Presenting chapters written by leading researchers, academics, and practitioners, it addresses the fundamental challenges associated with Big Data processing tools and techniques across a range of computing environments.The book begins by discussing the basic concepts and tools of large-scale Big Data processing and cloud computing. It also provides an overview of different programming models and cloud-bas

Large scale cluster computing workshop

International Nuclear Information System (INIS)

Dane Skow; Alan Silverman

2002-01-01

Recent revolutions in computer hardware and software technologies have paved the way for the large-scale deployment of clusters of commodity computers to address problems heretofore the domain of tightly coupled SMP processors. Near term projects within High Energy Physics and other computing communities will deploy clusters of scale 1000s of processors and be used by 100s to 1000s of independent users. This will expand the reach in both dimensions by an order of magnitude from the current successful production facilities. The goals of this workshop were: (1) to determine what tools exist which can scale up to the cluster sizes foreseen for the next generation of HENP experiments (several thousand nodes) and by implication to identify areas where some investment of money or effort is likely to be needed. (2) To compare and record experimences gained with such tools. (3) To produce a practical guide to all stages of planning, installing, building and operating a large computing cluster in HENP. (4) To identify and connect groups with similar interest within HENP and the larger clustering community

Large-Scale Agriculture and Outgrower Schemes in Ethiopia

DEFF Research Database (Denmark)

Wendimu, Mengistu Assefa

, the impact of large-scale agriculture and outgrower schemes on productivity, household welfare and wages in developing countries is highly contentious. Chapter 1 of this thesis provides an introduction to the study, while also reviewing the key debate in the contemporary land ‘grabbing’ and historical large...... sugarcane outgrower scheme on household income and asset stocks. Chapter 5 examines the wages and working conditions in ‘formal’ large-scale and ‘informal’ small-scale irrigated agriculture. The results in Chapter 2 show that moisture stress, the use of untested planting materials, and conflict over land...... commands a higher wage than ‘formal’ large-scale agriculture, while rather different wage determination mechanisms exist in the two sectors. Human capital characteristics (education and experience) partly explain the differences in wages within the formal sector, but play no significant role...

Disruption of circumstellar discs by large-scale stellar magnetic fields

Science.gov (United States)

ud-Doula, Asif; Owocki, Stanley P.; Kee, Nathaniel Dylan

2018-05-01

Spectropolarimetric surveys reveal that 8-10% of OBA stars harbor large-scale magnetic fields, but thus far no such fields have been detected in any classical Be stars. Motivated by this, we present here MHD simulations for how a pre-existing Keplerian disc - like that inferred to form from decretion of material from rapidly rotating Be stars - can be disrupted by a rotation-aligned stellar dipole field. For characteristic stellar and disc parameters of a near-critically rotating B2e star, we find that a polar surface field strength of just 10 G can significantly disrupt the disc, while a field of 100 G, near the observational upper limit inferred for most Be stars, completely destroys the disc over just a few days. Our parameter study shows that the efficacy of this magnetic disruption of a disc scales with the characteristic plasma beta (defined as the ratio between thermal and magnetic pressure) in the disc, but is surprisingly insensitive to other variations, e.g. in stellar rotation speed, or the mass loss rate of the star's radiatively driven wind. The disc disruption seen here for even a modest field strength suggests that the presumed formation of such Be discs by decretion of material from the star would likely be strongly inhibited by such fields; this provides an attractive explanation for why no large-scale fields are detected from such Be stars.

Economically viable large-scale hydrogen liquefaction

Science.gov (United States)

Cardella, U.; Decker, L.; Klein, H.

2017-02-01

The liquid hydrogen demand, particularly driven by clean energy applications, will rise in the near future. As industrial large scale liquefiers will play a major role within the hydrogen supply chain, production capacity will have to increase by a multiple of today’s typical sizes. The main goal is to reduce the total cost of ownership for these plants by increasing energy efficiency with innovative and simple process designs, optimized in capital expenditure. New concepts must ensure a manageable plant complexity and flexible operability. In the phase of process development and selection, a dimensioning of key equipment for large scale liquefiers, such as turbines and compressors as well as heat exchangers, must be performed iteratively to ensure technological feasibility and maturity. Further critical aspects related to hydrogen liquefaction, e.g. fluid properties, ortho-para hydrogen conversion, and coldbox configuration, must be analysed in detail. This paper provides an overview on the approach, challenges and preliminary results in the development of efficient as well as economically viable concepts for large-scale hydrogen liquefaction.

Large-scale survey for novel genotypes of Plasmodium falciparum chloroquine-resistance gene pfcrt

Directory of Open Access Journals (Sweden)

Takahashi Nobuyuki

2012-03-01

Full Text Available Abstract Background In Plasmodium falciparum, resistance to chloroquine (CQ is conferred by a K to T mutation at amino acid position 76 (K76T in the P. falciparum CQ transporter (PfCRT. To date, at least 15 pfcrt genotypes, which are represented by combinations of five amino acids at positions 72-76, have been described in field isolates from various endemic regions. To identify novel mutant pfcrt genotypes and to reveal the genetic relatedness of pfcrt genotypes, a large-scale survey over a wide geographic area was performed. Methods Sequences for exon 2 in pfcrt, including known polymorphic sites at amino acid positions 72, 74, 75 and 76, were obtained from 256 P. falciparum isolates collected from eight endemic countries in Asia (Bangladesh, Cambodia, Lao P.D.R., the Philippines and Thailand, Melanesia (Papua New Guinea and Vanuatu and Africa (Ghana. A haplotype network was constructed based on six microsatellite markers located -29 kb to 24 kb from pfcrt in order to examine the genetic relatedness among mutant pfcrt genotypes. Results In addition to wild type (CVMNK at positions 72-76, four mutant pfcrt were identified; CVIET, CVIDT, SVMNT and CVMNT (mutated amino acids underlined. Haplotype network revealed that there were only three mutant pfcrt lineages, originating in Indochina, Philippines and Melanesia. Importantly, the Indochina lineage contained two mutant pfcrt genotypes, CVIET (n = 95 and CVIDT (n = 14, indicating that CVIDT shares a common origin with CVIET. Similarly, one major haplotype in the Melanesian lineage contained two pfcrt genotypes; SVMNT (n = 71 and CVMNT (n = 3. In Africa, all mutant pfcrt genotypes were the CVIET of the Indochina lineage, probably resulting from the intercontinental migration of CQ resistance from Southeast Asia. Conclusions The number of CQ-mutant lineages observed in this study was identical to that found in previous studies. This supports the hypothesis that the emergence of novel CQ resistance

Large scale chromatographic separations using continuous displacement chromatography (CDC)

International Nuclear Information System (INIS)

Taniguchi, V.T.; Doty, A.W.; Byers, C.H.

1988-01-01

A process for large scale chromatographic separations using a continuous chromatography technique is described. The process combines the advantages of large scale batch fixed column displacement chromatography with conventional analytical or elution continuous annular chromatography (CAC) to enable large scale displacement chromatography to be performed on a continuous basis (CDC). Such large scale, continuous displacement chromatography separations have not been reported in the literature. The process is demonstrated with the ion exchange separation of a binary lanthanide (Nd/Pr) mixture. The process is, however, applicable to any displacement chromatography separation that can be performed using conventional batch, fixed column chromatography

About mutually unbiased bases in even and odd prime power dimensions

Science.gov (United States)

Durt, Thomas

2005-06-01

Mutually unbiased bases generalize the X, Y and Z qubit bases. They possess numerous applications in quantum information science. It is well known that in prime power dimensions N = pm (with p prime and m a positive integer), there exists a maximal set of N + 1 mutually unbiased bases. In the present paper, we derive an explicit expression for those bases, in terms of the (operations of the) associated finite field (Galois division ring) of N elements. This expression is shown to be equivalent to the expressions previously obtained by Ivanovic (1981 J. Phys. A: Math. Gen. 14 3241) in odd prime dimensions, and Wootters and Fields (1989 Ann. Phys. 191 363) in odd prime power dimensions. In even prime power dimensions, we derive a new explicit expression for the mutually unbiased bases. The new ingredients of our approach are, basically, the following: we provide a simple expression of the generalized Pauli group in terms of the additive characters of the field, and we derive an exact groupal composition law between the elements of the commuting subsets of the generalized Pauli group, renormalized by a well-chosen phase-factor.

About mutually unbiased bases in even and odd prime power dimensions

International Nuclear Information System (INIS)

Durt, Thomas

2005-01-01

Mutually unbiased bases generalize the X, Y and Z qubit bases. They possess numerous applications in quantum information science. It is well known that in prime power dimensions N = p m (with p prime and m a positive integer), there exists a maximal set of N + 1 mutually unbiased bases. In the present paper, we derive an explicit expression for those bases, in terms of the (operations of the) associated finite field (Galois division ring) of N elements. This expression is shown to be equivalent to the expressions previously obtained by Ivanovic (1981 J. Phys. A: Math. Gen. 14 3241) in odd prime dimensions, and Wootters and Fields (1989 Ann. Phys. 191 363) in odd prime power dimensions. In even prime power dimensions, we derive a new explicit expression for the mutually unbiased bases. The new ingredients of our approach are, basically, the following: we provide a simple expression of the generalized Pauli group in terms of the additive characters of the field, and we derive an exact groupal composition law between the elements of the commuting subsets of the generalized Pauli group, renormalized by a well-chosen phase-factor

DIGITAL ARCHIVING OF PEOPLE FLOW BY RECYCLING LARGE-SCALE SOCIAL SURVEY DATA OF DEVELOPING CITIES

Directory of Open Access Journals (Sweden)

Y. Sekimoto

2012-07-01

Full Text Available Data on people flow has become increasingly important in the field of business, including the areas of marketing and public services. Although mobile phones enable a person's position to be located to a certain degree, it is a challenge to acquire sufficient data from people with mobile phones. In order to grasp people flow in its entirety, it is important to establish a practical method of reconstructing people flow from various kinds of existing fragmentary spatio-temporal data such as social survey data. For example, despite typical Person Trip Survey Data collected by the public sector showing the fragmentary spatio-temporal positions accessed, the data are attractive given the sufficiently large sample size to estimate the entire flow of people. In this study, we apply our proposed basic method to Japan International Cooperation Agency (JICA PT data pertaining to developing cities around the world, and we propose some correction methods to resolve the difficulties in applying it to many cities and stably to infrastructure data.

Age-related differences in the relations between individualised HRM and organisational performance: a large-scale employer survey

NARCIS (Netherlands)

Bal, P.M.; Dorenbosch, L.

2015-01-01

The current study aimed to investigate the relationship between individualised HRM practices and several measures of organisational performance, including the moderating role of employee age in these relationships. A large-scale representative study among 4,591 organisations in the Netherlands

Large Scale Processes and Extreme Floods in Brazil

Science.gov (United States)

Ribeiro Lima, C. H.; AghaKouchak, A.; Lall, U.

2016-12-01

Persistent large scale anomalies in the atmospheric circulation and ocean state have been associated with heavy rainfall and extreme floods in water basins of different sizes across the world. Such studies have emerged in the last years as a new tool to improve the traditional, stationary based approach in flood frequency analysis and flood prediction. Here we seek to advance previous studies by evaluating the dominance of large scale processes (e.g. atmospheric rivers/moisture transport) over local processes (e.g. local convection) in producing floods. We consider flood-prone regions in Brazil as case studies and the role of large scale climate processes in generating extreme floods in such regions is explored by means of observed streamflow, reanalysis data and machine learning methods. The dynamics of the large scale atmospheric circulation in the days prior to the flood events are evaluated based on the vertically integrated moisture flux and its divergence field, which are interpreted in a low-dimensional space as obtained by machine learning techniques, particularly supervised kernel principal component analysis. In such reduced dimensional space, clusters are obtained in order to better understand the role of regional moisture recycling or teleconnected moisture in producing floods of a given magnitude. The convective available potential energy (CAPE) is also used as a measure of local convection activities. We investigate for individual sites the exceedance probability in which large scale atmospheric fluxes dominate the flood process. Finally, we analyze regional patterns of floods and how the scaling law of floods with drainage area responds to changes in the climate forcing mechanisms (e.g. local vs large scale).

Large-scale correlations in gas traced by Mg II absorbers around low-mass galaxies

Science.gov (United States)

Kauffmann, Guinevere

2018-03-01

The physical origin of the large-scale conformity in the colours and specific star formation rates of isolated low-mass central galaxies and their neighbours on scales in excess of 1 Mpc is still under debate. One possible scenario is that gas is heated over large scales by feedback from active galactic nuclei (AGNs), leading to coherent modulation of cooling and star formation between well-separated galaxies. In this Letter, the metal line absorption catalogue of Zhu & Ménard is used to probe gas out to large projected radii around a sample of a million galaxies with stellar masses ˜1010M⊙ and photometric redshifts in the range 0.4 Survey imaging data. This galaxy sample covers an effective volume of 2.2 Gpc3. A statistically significant excess of Mg II absorbers is present around the red-low-mass galaxies compared to their blue counterparts out to projected radii of 10 Mpc. In addition, the equivalent width distribution function of Mg II absorbers around low-mass galaxies is shown to be strongly affected by the presence of a nearby (Rp < 2 Mpc) radio-loud AGNs out to projected radii of 5 Mpc.

Computing in Large-Scale Dynamic Systems

NARCIS (Netherlands)

Pruteanu, A.S.

2013-01-01

Software applications developed for large-scale systems have always been difficult to de- velop due to problems caused by the large number of computing devices involved. Above a certain network size (roughly one hundred), necessary services such as code updating, topol- ogy discovery and data

Fires in large scale ventilation systems

International Nuclear Information System (INIS)

Gregory, W.S.; Martin, R.A.; White, B.W.; Nichols, B.D.; Smith, P.R.; Leslie, I.H.; Fenton, D.L.; Gunaji, M.V.; Blythe, J.P.

1991-01-01

This paper summarizes the experience gained simulating fires in large scale ventilation systems patterned after ventilation systems found in nuclear fuel cycle facilities. The series of experiments discussed included: (1) combustion aerosol loading of 0.61x0.61 m HEPA filters with the combustion products of two organic fuels, polystyrene and polymethylemethacrylate; (2) gas dynamic and heat transport through a large scale ventilation system consisting of a 0.61x0.61 m duct 90 m in length, with dampers, HEPA filters, blowers, etc.; (3) gas dynamic and simultaneous transport of heat and solid particulate (consisting of glass beads with a mean aerodynamic diameter of 10μ) through the large scale ventilation system; and (4) the transport of heat and soot, generated by kerosene pool fires, through the large scale ventilation system. The FIRAC computer code, designed to predict fire-induced transients in nuclear fuel cycle facility ventilation systems, was used to predict the results of experiments (2) through (4). In general, the results of the predictions were satisfactory. The code predictions for the gas dynamics, heat transport, and particulate transport and deposition were within 10% of the experimentally measured values. However, the code was less successful in predicting the amount of soot generation from kerosene pool fires, probably due to the fire module of the code being a one-dimensional zone model. The experiments revealed a complicated three-dimensional combustion pattern within the fire room of the ventilation system. Further refinement of the fire module within FIRAC is needed. (orig.)

A large-scale study of misophonia

NARCIS (Netherlands)

Rouw, R.; Erfanian, M.

2018-01-01

Objective We aim to elucidate misophonia, a condition in which particular sounds elicit disproportionally strong aversive reactions. Method A large online study extensively surveyed personal, developmental, and clinical characteristics of over 300 misophonics. Results Most participants indicated

Ridge regression estimator: combining unbiased and ordinary ridge regression methods of estimation

Directory of Open Access Journals (Sweden)

Sharad Damodar Gore

2009-10-01

Full Text Available Statistical literature has several methods for coping with multicollinearity. This paper introduces a new shrinkage estimator, called modified unbiased ridge (MUR. This estimator is obtained from unbiased ridge regression (URR in the same way that ordinary ridge regression (ORR is obtained from ordinary least squares (OLS. Properties of MUR are derived. Results on its matrix mean squared error (MMSE are obtained. MUR is compared with ORR and URR in terms of MMSE. These results are illustrated with an example based on data generated by Hoerl and Kennard (1975.

Large-scale Complex IT Systems

OpenAIRE

Sommerville, Ian; Cliff, Dave; Calinescu, Radu; Keen, Justin; Kelly, Tim; Kwiatkowska, Marta; McDermid, John; Paige, Richard

2011-01-01

This paper explores the issues around the construction of large-scale complex systems which are built as 'systems of systems' and suggests that there are fundamental reasons, derived from the inherent complexity in these systems, why our current software engineering methods and techniques cannot be scaled up to cope with the engineering challenges of constructing such systems. It then goes on to propose a research and education agenda for software engineering that identifies the major challen...

Large-scale complex IT systems

OpenAIRE

Sommerville, Ian; Cliff, Dave; Calinescu, Radu; Keen, Justin; Kelly, Tim; Kwiatkowska, Marta; McDermid, John; Paige, Richard

2012-01-01

12 pages, 2 figures This paper explores the issues around the construction of large-scale complex systems which are built as 'systems of systems' and suggests that there are fundamental reasons, derived from the inherent complexity in these systems, why our current software engineering methods and techniques cannot be scaled up to cope with the engineering challenges of constructing such systems. It then goes on to propose a research and education agenda for software engineering that ident...

Galaxies distribution in the universe: large-scale statistics and structures

International Nuclear Information System (INIS)

Maurogordato, Sophie

1988-01-01

This research thesis addresses the distribution of galaxies in the Universe, and more particularly large scale statistics and structures. Based on an assessment of the main used statistical techniques, the author outlines the need to develop additional tools to correlation functions in order to characterise the distribution. She introduces a new indicator: the probability of a volume randomly tested in the distribution to be void. This allows a characterisation of void properties at the work scales (until 10h"-"1 Mpc) in the Harvard Smithsonian Center for Astrophysics Redshift Survey, or CfA catalog. A systematic analysis of statistical properties of different sub-samples has then been performed with respect to the size and location, luminosity class, and morphological type. This analysis is then extended to different scenarios of structure formation. A program of radial speed measurements based on observations allows the determination of possible relationships between apparent structures. The author also presents results of the search for south extensions of Perseus supernova [fr

First Mile Challenges for Large-Scale IoT

KAUST Repository

Bader, Ahmed; Elsawy, Hesham; Gharbieh, Mohammad; Alouini, Mohamed-Slim; Adinoyi, Abdulkareem; Alshaalan, Furaih

2017-01-01

The Internet of Things is large-scale by nature. This is not only manifested by the large number of connected devices, but also by the sheer scale of spatial traffic intensity that must be accommodated, primarily in the uplink direction. To that end

Large-scale recovery of an endangered amphibian despite ongoing exposure to multiple stressors

Science.gov (United States)

Knapp, Roland A.; Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Vrendenburg, Vance T.; Rosenblum, Erica Bree; Briggs, Cheryl J.

2016-01-01

Amphibians are one of the most threatened animal groups, with 32% of species at risk for extinction. Given this imperiled status, is the disappearance of a large fraction of the Earth’s amphibians inevitable, or are some declining species more resilient than is generally assumed? We address this question in a species that is emblematic of many declining amphibians, the endangered Sierra Nevada yellow-legged frog (Rana sierrae). Based on >7,000 frog surveys conducted across Yosemite National Park over a 20-y period, we show that, after decades of decline and despite ongoing exposure to multiple stressors, including introduced fish, the recently emerged disease chytridiomycosis, and pesticides, R. sierrae abundance increased sevenfold during the study and at a rate of 11% per year. These increases occurred in hundreds of populations throughout Yosemite, providing a rare example of amphibian recovery at an ecologically relevant spatial scale. Results from a laboratory experiment indicate that these increases may be in part because of reduced frog susceptibility to chytridiomycosis. The disappearance of nonnative fish from numerous water bodies after cessation of stocking also contributed to the recovery. The large-scale increases in R. sierrae abundance that we document suggest that, when habitats are relatively intact and stressors are reduced in their importance by active management or species’ adaptive responses, declines of some amphibians may be partially reversible, at least at a regional scale. Other studies conducted over similarly large temporal and spatial scales are critically needed to provide insight and generality about the reversibility of amphibian declines at a global scale.

Large-scale volcanism associated with coronae on Venus

Science.gov (United States)

Roberts, K. Magee; Head, James W.

1993-01-01

The formation and evolution of coronae on Venus are thought to be the result of mantle upwellings against the crust and lithosphere and subsequent gravitational relaxation. A variety of other features on Venus have been linked to processes associated with mantle upwelling, including shield volcanoes on large regional rises such as Beta, Atla and Western Eistla Regiones and extensive flow fields such as Mylitta and Kaiwan Fluctus near the Lada Terra/Lavinia Planitia boundary. Of these features, coronae appear to possess the smallest amounts of associated volcanism, although volcanism associated with coronae has only been qualitatively examined. An initial survey of coronae based on recent Magellan data indicated that only 9 percent of all coronae are associated with substantial amounts of volcanism, including interior calderas or edifices greater than 50 km in diameter and extensive, exterior radial flow fields. Sixty-eight percent of all coronae were found to have lesser amounts of volcanism, including interior flooding and associated volcanic domes and small shields; the remaining coronae were considered deficient in associated volcanism. It is possible that coronae are related to mantle plumes or diapirs that are lower in volume or in partial melt than those associated with the large shields or flow fields. Regional tectonics or variations in local crustal and thermal structure may also be significant in determining the amount of volcanism produced from an upwelling. It is also possible that flow fields associated with some coronae are sheet-like in nature and may not be readily identified. If coronae are associated with volcanic flow fields, then they may be a significant contributor to plains formation on Venus, as they number over 300 and are widely distributed across the planet. As a continuation of our analysis of large-scale volcanism on Venus, we have reexamined the known population of coronae and assessed quantitatively the scale of volcanism associated

Monitoring carnivore populations at the landscape scale: occupancy modelling of tigers from sign surveys

Science.gov (United States)

Karanth, Kota Ullas; Gopalaswamy, Arjun M.; Kumar, Narayanarao Samba; Vaidyanathan, Srinivas; Nichols, James D.; MacKenzie, Darryl I.

2011-01-01

1. Assessing spatial distributions of threatened large carnivores at landscape scales poses formidable challenges because of their rarity and elusiveness. As a consequence of logistical constraints, investigators typically rely on sign surveys. Most survey methods, however, do not explicitly address the central problem of imperfect detections of animal signs in the field, leading to underestimates of true habitat occupancy and distribution. 2. We assessed habitat occupancy for a tiger Panthera tigris metapopulation across a c. 38 000-km2 landscape in India, employing a spatially replicated survey to explicitly address imperfect detections. Ecological predictions about tiger presence were confronted with sign detection data generated from occupancy sampling of 205 sites, each of 188 km2. 3. A recent occupancy model that considers Markovian dependency among sign detections on spatial replicates performed better than the standard occupancy model (ΔAIC = 184·9). A formulation of this model that fitted the data best showed that density of ungulate prey and levels of human disturbance were key determinants of local tiger presence. Model averaging resulted in a replicate-level detection probability [inline image] = 0·17 (0·17) for signs and a tiger habitat occupancy estimate of [inline image] = 0·665 (0·0857) or 14 076 (1814) km2 of potential habitat of 21 167 km2. In contrast, a traditional presence-versus-absence approach underestimated occupancy by 47%. Maps of probabilities of local site occupancy clearly identified tiger source populations at higher densities and matched observed tiger density variations, suggesting their potential utility for population assessments at landscape scales. 4. Synthesis and applications. Landscape-scale sign surveys can efficiently assess large carnivore spatial distributions and elucidate the factors governing their local presence, provided ecological and observation processes are both explicitly modelled. Occupancy

Prospects for large scale electricity storage in Denmark

DEFF Research Database (Denmark)

Krog Ekman, Claus; Jensen, Søren Højgaard

2010-01-01

In a future power systems with additional wind power capacity there will be an increased need for large scale power management as well as reliable balancing and reserve capabilities. Different technologies for large scale electricity storage provide solutions to the different challenges arising w...

Income Inequality and Adolescent Gambling Severity: Findings from a Large-Scale Italian Representative Survey

Directory of Open Access Journals (Sweden)

Natale Canale

2017-08-01

Full Text Available Background: Studies have shown that problems related to adult gambling have a geographical and social gradient. For instance, adults experiencing gambling-related harms live in areas of greater deprivation; are unemployed, and have lower income. However, little is known about the impact of socioeconomic inequalities on adolescent problem gambling. The main purpose of the present study was to investigate the contextual influences of income inequality on at-risk or problem gambling (ARPG in a large-scale nationally representative sample of Italian adolescents. A secondary aim was to analyze the association between perceived social support (from family, peers, teachers, and classmates and ARPG.Methods: Data from the 2013–2014 Health Behavior in School-aged Children Survey (HBSC Study was used for cross-sectional analyses of ARPG. A total of 20,791 15-year-old students completed self-administered questionnaires. Region-level data on income inequality (GINI index and overall wealth (GDP per capita were retrieved from the National Institute of Statistics (Istat. The data were analyzed using the multi-level logistic regression analysis, with students at the first level and regions at the second level.Results: The study demonstrated a North–South gradient for the prevalence of ARPG, with higher prevalence of ARPG in the Southern/Islands/Central Regions (e.g., 11% in Sicily than in Northern Italy (e.g., 2% in Aosta Valley. Students in regions of high-income inequality were significantly more likely than those in regions of low-income inequality to be at-risk or problem gamblers (following adjustment for sex, family structure, family affluence, perceived social support, and regionale wealth. Additionally, perceived social support from parents and teachers were negatively related to ARPG.Conclusions: Income inequality may have a contextual influence on ARPG. More specifically, living in regions of highest income inequality appeared to be a potential

Evolution of scaling emergence in large-scale spatial epidemic spreading.

Science.gov (United States)

Wang, Lin; Li, Xiang; Zhang, Yi-Qing; Zhang, Yan; Zhang, Kan

2011-01-01

Zipf's law and Heaps' law are two representatives of the scaling concepts, which play a significant role in the study of complexity science. The coexistence of the Zipf's law and the Heaps' law motivates different understandings on the dependence between these two scalings, which has still hardly been clarified. In this article, we observe an evolution process of the scalings: the Zipf's law and the Heaps' law are naturally shaped to coexist at the initial time, while the crossover comes with the emergence of their inconsistency at the larger time before reaching a stable state, where the Heaps' law still exists with the disappearance of strict Zipf's law. Such findings are illustrated with a scenario of large-scale spatial epidemic spreading, and the empirical results of pandemic disease support a universal analysis of the relation between the two laws regardless of the biological details of disease. Employing the United States domestic air transportation and demographic data to construct a metapopulation model for simulating the pandemic spread at the U.S. country level, we uncover that the broad heterogeneity of the infrastructure plays a key role in the evolution of scaling emergence. The analyses of large-scale spatial epidemic spreading help understand the temporal evolution of scalings, indicating the coexistence of the Zipf's law and the Heaps' law depends on the collective dynamics of epidemic processes, and the heterogeneity of epidemic spread indicates the significance of performing targeted containment strategies at the early time of a pandemic disease.

Large-Scale Structure and Hyperuniformity of Amorphous Ices

Science.gov (United States)

Martelli, Fausto; Torquato, Salvatore; Giovambattista, Nicolas; Car, Roberto

2017-09-01

We investigate the large-scale structure of amorphous ices and transitions between their different forms by quantifying their large-scale density fluctuations. Specifically, we simulate the isothermal compression of low-density amorphous ice (LDA) and hexagonal ice to produce high-density amorphous ice (HDA). Both HDA and LDA are nearly hyperuniform; i.e., they are characterized by an anomalous suppression of large-scale density fluctuations. By contrast, in correspondence with the nonequilibrium phase transitions to HDA, the presence of structural heterogeneities strongly suppresses the hyperuniformity and the system becomes hyposurficial (devoid of "surface-area fluctuations"). Our investigation challenges the largely accepted "frozen-liquid" picture, which views glasses as structurally arrested liquids. Beyond implications for water, our findings enrich our understanding of pressure-induced structural transformations in glasses.

Point process models for spatio-temporal distance sampling data from a large-scale survey of blue whales

KAUST Repository

Yuan, Yuan; Bachl, Fabian E.; Lindgren, Finn; Borchers, David L.; Illian, Janine B.; Buckland, Stephen T.; Rue, Haavard; Gerrodette, Tim

2017-01-01

Distance sampling is a widely used method for estimating wildlife population abundance. The fact that conventional distance sampling methods are partly design-based constrains the spatial resolution at which animal density can be estimated using these methods. Estimates are usually obtained at survey stratum level. For an endangered species such as the blue whale, it is desirable to estimate density and abundance at a finer spatial scale than stratum. Temporal variation in the spatial structure is also important. We formulate the process generating distance sampling data as a thinned spatial point process and propose model-based inference using a spatial log-Gaussian Cox process. The method adopts a flexible stochastic partial differential equation (SPDE) approach to model spatial structure in density that is not accounted for by explanatory variables, and integrated nested Laplace approximation (INLA) for Bayesian inference. It allows simultaneous fitting of detection and density models and permits prediction of density at an arbitrarily fine scale. We estimate blue whale density in the Eastern Tropical Pacific Ocean from thirteen shipboard surveys conducted over 22 years. We find that higher blue whale density is associated with colder sea surface temperatures in space, and although there is some positive association between density and mean annual temperature, our estimates are consistent with no trend in density across years. Our analysis also indicates that there is substantial spatially structured variation in density that is not explained by available covariates.

Point process models for spatio-temporal distance sampling data from a large-scale survey of blue whales

KAUST Repository

Yuan, Yuan

2017-12-28

Distance sampling is a widely used method for estimating wildlife population abundance. The fact that conventional distance sampling methods are partly design-based constrains the spatial resolution at which animal density can be estimated using these methods. Estimates are usually obtained at survey stratum level. For an endangered species such as the blue whale, it is desirable to estimate density and abundance at a finer spatial scale than stratum. Temporal variation in the spatial structure is also important. We formulate the process generating distance sampling data as a thinned spatial point process and propose model-based inference using a spatial log-Gaussian Cox process. The method adopts a flexible stochastic partial differential equation (SPDE) approach to model spatial structure in density that is not accounted for by explanatory variables, and integrated nested Laplace approximation (INLA) for Bayesian inference. It allows simultaneous fitting of detection and density models and permits prediction of density at an arbitrarily fine scale. We estimate blue whale density in the Eastern Tropical Pacific Ocean from thirteen shipboard surveys conducted over 22 years. We find that higher blue whale density is associated with colder sea surface temperatures in space, and although there is some positive association between density and mean annual temperature, our estimates are consistent with no trend in density across years. Our analysis also indicates that there is substantial spatially structured variation in density that is not explained by available covariates.

Multifractals embedded in short time series: An unbiased estimation of probability moment

Science.gov (United States)

Qiu, Lu; Yang, Tianguang; Yin, Yanhua; Gu, Changgui; Yang, Huijie

2016-12-01

An exact estimation of probability moments is the base for several essential concepts, such as the multifractals, the Tsallis entropy, and the transfer entropy. By means of approximation theory we propose a new method called factorial-moment-based estimation of probability moments. Theoretical prediction and computational results show that it can provide us an unbiased estimation of the probability moments of continuous order. Calculations on probability redistribution model verify that it can extract exactly multifractal behaviors from several hundred recordings. Its powerfulness in monitoring evolution of scaling behaviors is exemplified by two empirical cases, i.e., the gait time series for fast, normal, and slow trials of a healthy volunteer, and the closing price series for Shanghai stock market. By using short time series with several hundred lengths, a comparison with the well-established tools displays significant advantages of its performance over the other methods. The factorial-moment-based estimation can evaluate correctly the scaling behaviors in a scale range about three generations wider than the multifractal detrended fluctuation analysis and the basic estimation. The estimation of partition function given by the wavelet transform modulus maxima has unacceptable fluctuations. Besides the scaling invariance focused in the present paper, the proposed factorial moment of continuous order can find its various uses, such as finding nonextensive behaviors of a complex system and reconstructing the causality relationship network between elements of a complex system.

Getting leverage on inflation with a large photometric redshift survey

CERN Document Server

Basse, Tobias; Hannestad, Steen; Wong, Yvonne Y Y

2015-01-01

We assess the potential of a future large-volume photometric redshift survey to constrain observational inflationary parameters using three large-scale structure observables: the angular shear and galaxy power spectra, and the cluster mass function measured through weak lensing. When used in combination with Planck-like CMB measurements, we find that the spectral index n_s can be constrained to a 1 sigma precision of up to 0.0025. The sensitivity to the running of the spectral index can potentially improve to 0.0017, roughly a factor of five better than the present 1 sigma~constraint from Planck and auxiliary CMB data, allowing us to test the assumptions of the slow-roll scenario with unprecedented accuracy. Interestingly, neither CMB+shear nor CMB+galaxy nor CMB+clusters alone can achieve this level of sensitivity; it is the combined power of all three probes that conspires to break the different parameter degeneracies inherent in each type of observations. We make our forecast software publicly available vi...

Recent Developments in Language Assessment and the Case of Four Large-Scale Tests of ESOL Ability

Science.gov (United States)

Stoynoff, Stephen

2009-01-01

This review article surveys recent developments and validation activities related to four large-scale tests of L2 English ability: the iBT TOEFL, the IELTS, the FCE, and the TOEIC. In addition to describing recent changes to these tests, the paper reports on validation activities that were conducted on the measures. The results of this research…

Double inflation: A possible resolution of the large-scale structure problem

International Nuclear Information System (INIS)

Turner, M.S.; Villumsen, J.V.; Vittorio, N.; Silk, J.; Juszkiewicz, R.

1986-11-01

A model is presented for the large-scale structure of the universe in which two successive inflationary phases resulted in large small-scale and small large-scale density fluctuations. This bimodal density fluctuation spectrum in an Ω = 1 universe dominated by hot dark matter leads to large-scale structure of the galaxy distribution that is consistent with recent observational results. In particular, large, nearly empty voids and significant large-scale peculiar velocity fields are produced over scales of ∼100 Mpc, while the small-scale structure over ≤ 10 Mpc resembles that in a low density universe, as observed. Detailed analytical calculations and numerical simulations are given of the spatial and velocity correlations. 38 refs., 6 figs

Large-scale fracture mechancis testing -- requirements and possibilities

International Nuclear Information System (INIS)

Brumovsky, M.

1993-01-01

Application of fracture mechanics to very important and/or complicated structures, like reactor pressure vessels, brings also some questions about the reliability and precision of such calculations. These problems become more pronounced in cases of elastic-plastic conditions of loading and/or in parts with non-homogeneous materials (base metal and austenitic cladding, property gradient changes through material thickness) or with non-homogeneous stress fields (nozzles, bolt threads, residual stresses etc.). For such special cases some verification by large-scale testing is necessary and valuable. This paper discusses problems connected with planning of such experiments with respect to their limitations, requirements to a good transfer of received results to an actual vessel. At the same time, an analysis of possibilities of small-scale model experiments is also shown, mostly in connection with application of results between standard, small-scale and large-scale experiments. Experience from 30 years of large-scale testing in SKODA is used as an example to support this analysis. 1 fig

Ethics of large-scale change

DEFF Research Database (Denmark)

Arler, Finn

2006-01-01

, which kind of attitude is appropriate when dealing with large-scale changes like these from an ethical point of view. Three kinds of approaches are discussed: Aldo Leopold's mountain thinking, the neoclassical economists' approach, and finally the so-called Concentric Circle Theories approach...

Losing the rose tinted glasses: neural substrates of unbiased belief updating in depression

Directory of Open Access Journals (Sweden)

Neil eGarrett

2014-08-01

Full Text Available Recent evidence suggests that a state of good mental health is associated with biased processing of information that supports a positively skewed view of the future. Depression, on the other hand, is associated with unbiased processing of such information. Here, we use brain imaging in conjunction with a belief update task administered to clinically depressed patients and healthy controls to characterize brain activity that supports unbiased belief updating in clinically depressed individuals. Our results reveal that unbiased belief updating in depression is mediated by strong neural coding of estimation errors in response to both good news (in left inferior frontal gyrus and bilateral superior frontal gyrus and bad news (in right inferior parietal lobule and right inferior frontal gyrus regarding the future. In contrast, intact mental health was linked to a relatively attenuated neural coding of bad news about the future. These findings identify a neural substrate mediating the breakdown of biased updating in Major Depression Disorder, which may be essential for mental health.

Comparison Between Overtopping Discharge in Small and Large Scale Models

DEFF Research Database (Denmark)

Helgason, Einar; Burcharth, Hans F.

2006-01-01

The present paper presents overtopping measurements from small scale model test performed at the Haudraulic & Coastal Engineering Laboratory, Aalborg University, Denmark and large scale model tests performed at the Largde Wave Channel,Hannover, Germany. Comparison between results obtained from...... small and large scale model tests show no clear evidence of scale effects for overtopping above a threshold value. In the large scale model no overtopping was measured for waveheights below Hs = 0.5m as the water sunk into the voids between the stones on the crest. For low overtopping scale effects...

The Oslo Health Study: The impact of self-selection in a large, population-based survey

Science.gov (United States)

Søgaard, Anne Johanne; Selmer, Randi; Bjertness, Espen; Thelle, Dag

2004-01-01

Background Research on health equity which mainly utilises population-based surveys, may be hampered by serious selection bias due to a considerable number of invitees declining to participate. Sufficient information from all the non-responders is rarely available to quantify this bias. Predictors of attendance, magnitude and direction of non-response bias in prevalence estimates and association measures, are investigated based on information from all 40 888 invitees to the Oslo Health Study. Methods The analyses were based on linkage between public registers in Statistics Norway and the Oslo Health Study, a population-based survey conducted in 2000/2001 inviting all citizens aged 30, 40, 45, 59–60 and 75–76 years. Attendance was 46%. Weighted analyses, logistic regression and sensitivity analyses are performed to evaluate possible selection bias. Results The response rate was positively associated with age, educational attendance, total income, female gender, married, born in a Western county, living in the outer city residential regions and not receiving disability benefit. However, self-rated health, smoking, BMI and mental health (HCSL) in the attendees differed only slightly from estimated prevalence values in the target population when weighted by the inverse of the probability of attendance. Observed values differed only moderately provided that the non-attending individuals differed from those attending by no more than 50%. Even though persons receiving disability benefit had lower attendance, the associations between disability and education, residential region and marital status were found to be unbiased. The association between country of birth and disability benefit was somewhat more evident among attendees. Conclusions Self-selection according to sociodemographic variables had little impact on prevalence estimates. As indicated by disability benefit, unhealthy persons attended to a lesser degree than healthy individuals, but social inequality in

The Oslo Health Study: The impact of self-selection in a large, population-based survey

Directory of Open Access Journals (Sweden)

Bjertness Espen

2004-05-01

Full Text Available Abstract Background Research on health equity which mainly utilises population-based surveys, may be hampered by serious selection bias due to a considerable number of invitees declining to participate. Sufficient information from all the non-responders is rarely available to quantify this bias. Predictors of attendance, magnitude and direction of non-response bias in prevalence estimates and association measures, are investigated based on information from all 40 888 invitees to the Oslo Health Study. Methods The analyses were based on linkage between public registers in Statistics Norway and the Oslo Health Study, a population-based survey conducted in 2000/2001 inviting all citizens aged 30, 40, 45, 59–60 and 75–76 years. Attendance was 46%. Weighted analyses, logistic regression and sensitivity analyses are performed to evaluate possible selection bias. Results The response rate was positively associated with age, educational attendance, total income, female gender, married, born in a Western county, living in the outer city residential regions and not receiving disability benefit. However, self-rated health, smoking, BMI and mental health (HCSL in the attendees differed only slightly from estimated prevalence values in the target population when weighted by the inverse of the probability of attendance. Observed values differed only moderately provided that the non-attending individuals differed from those attending by no more than 50%. Even though persons receiving disability benefit had lower attendance, the associations between disability and education, residential region and marital status were found to be unbiased. The association between country of birth and disability benefit was somewhat more evident among attendees. Conclusions Self-selection according to sociodemographic variables had little impact on prevalence estimates. As indicated by disability benefit, unhealthy persons attended to a lesser degree than healthy individuals

Study of depression influencing factors with zero-inflated regression models in a large-scale population survey

OpenAIRE

Xu, Tao; Zhu, Guangjin; Han, Shaomei

2017-01-01

Objectives The number of depression symptoms can be considered as count data in order to get complete and accurate analyses findings in studies of depression. This study aims to compare the goodness of fit of four count outcomes models by a large survey sample to identify the optimum model for a risk factor study of the number of depression symptoms. Methods 15 820 subjects, aged 10 to 80 years old, who were not suffering from serious chronic diseases and had not run a high fever in the past ...

Large-scale absence of sharks on reefs in the greater-Caribbean: a footprint of human pressures.

Directory of Open Access Journals (Sweden)

Christine A Ward-Paige

Full Text Available BACKGROUND: In recent decades, large pelagic and coastal shark populations have declined dramatically with increased fishing; however, the status of sharks in other systems such as coral reefs remains largely unassessed despite a long history of exploitation. Here we explore the contemporary distribution and sighting frequency of sharks on reefs in the greater-Caribbean and assess the possible role of human pressures on observed patterns. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed 76,340 underwater surveys carried out by trained volunteer divers between 1993 and 2008. Surveys were grouped within one km2 cells, which allowed us to determine the contemporary geographical distribution and sighting frequency of sharks. Sighting frequency was calculated as the ratio of surveys with sharks to the total number of surveys in each cell. We compared sighting frequency to the number of people in the cell vicinity and used population viability analyses to assess the effects of exploitation on population trends. Sharks, with the exception of nurse sharks occurred mainly in areas with very low human population or strong fishing regulations and marine conservation. Population viability analysis suggests that exploitation alone could explain the large-scale absence; however, this pattern is likely to be exacerbated by additional anthropogenic stressors, such as pollution and habitat degradation, that also correlate with human population. CONCLUSIONS/SIGNIFICANCE: Human pressures in coastal zones have lead to the broad-scale absence of sharks on reefs in the greater-Caribbean. Preventing further loss of sharks requires urgent management measures to curb fishing mortality and to mitigate other anthropogenic stressors to protect sites where sharks still exist. The fact that sharks still occur in some densely populated areas where strong fishing regulations are in place indicates the possibility of success and encourages the implementation of conservation measures.

Large-scale absence of sharks on reefs in the greater-Caribbean: a footprint of human pressures.

Science.gov (United States)

Ward-Paige, Christine A; Mora, Camilo; Lotze, Heike K; Pattengill-Semmens, Christy; McClenachan, Loren; Arias-Castro, Ery; Myers, Ransom A

2010-08-05

In recent decades, large pelagic and coastal shark populations have declined dramatically with increased fishing; however, the status of sharks in other systems such as coral reefs remains largely unassessed despite a long history of exploitation. Here we explore the contemporary distribution and sighting frequency of sharks on reefs in the greater-Caribbean and assess the possible role of human pressures on observed patterns. We analyzed 76,340 underwater surveys carried out by trained volunteer divers between 1993 and 2008. Surveys were grouped within one km2 cells, which allowed us to determine the contemporary geographical distribution and sighting frequency of sharks. Sighting frequency was calculated as the ratio of surveys with sharks to the total number of surveys in each cell. We compared sighting frequency to the number of people in the cell vicinity and used population viability analyses to assess the effects of exploitation on population trends. Sharks, with the exception of nurse sharks occurred mainly in areas with very low human population or strong fishing regulations and marine conservation. Population viability analysis suggests that exploitation alone could explain the large-scale absence; however, this pattern is likely to be exacerbated by additional anthropogenic stressors, such as pollution and habitat degradation, that also correlate with human population. Human pressures in coastal zones have lead to the broad-scale absence of sharks on reefs in the greater-Caribbean. Preventing further loss of sharks requires urgent management measures to curb fishing mortality and to mitigate other anthropogenic stressors to protect sites where sharks still exist. The fact that sharks still occur in some densely populated areas where strong fishing regulations are in place indicates the possibility of success and encourages the implementation of conservation measures.

Survey and research for the enhancement of large-scale technology development 1. Japan's large-scale technology development and the effects; Ogata gijutsu kaihatsu suishin no tame no chosa kenkyu. 1. Nippon no daikibo gijutsu kaihatsu to sono koka

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

A survey is conducted into the effects of projects implemented under the large-scale industrial technology research and development system. In the development of 'ultraperformance computers,' each of the technologies is being widely utilized, and the data service system of Nippon Telegraph and Telephone Public Corporation and the large computer (HITAC8800) owe much for their success to the fruits of the development endeavor. In the development of the 'desulfurization technology,' the fruits are in use by Tokyo Electric Power Co., Inc., and Chubu Electric Power Co., Inc., incorporated into their desulfurization systems. Although there is no practical plant based on the 'great-depth remotely controlled submarine oil drilling rig,' yet oceanic technologies and control methods are being utilized in various fields. The 'seawater desalination and by-product utilization' technologies have enabled the establishment of technologies of the top level in the world thanks to the resultant manufacture of concrete evaporator and related technologies. Eleven plants have been completed utilizing the fruits of the development. In the field of 'electric vehicle,' there is no commercialization in progress due to problems in cost effectiveness though remarkable improvement has been achieved in terms of performance. Technologies about weight reduction, semiconductor devices, battery parts and components, etc., are being utilized in many fields. (NEDO)

Needs, opportunities, and options for large scale systems research

Energy Technology Data Exchange (ETDEWEB)

Thompson, G.L.

1984-10-01

The Office of Energy Research was recently asked to perform a study of Large Scale Systems in order to facilitate the development of a true large systems theory. It was decided to ask experts in the fields of electrical engineering, chemical engineering and manufacturing/operations research for their ideas concerning large scale systems research. The author was asked to distribute a questionnaire among these experts to find out their opinions concerning recent accomplishments and future research directions in large scale systems research. He was also requested to convene a conference which included three experts in each area as panel members to discuss the general area of large scale systems research. The conference was held on March 26--27, 1984 in Pittsburgh with nine panel members, and 15 other attendees. The present report is a summary of the ideas presented and the recommendations proposed by the attendees.

Large-scale structure of the Universe

International Nuclear Information System (INIS)

Doroshkevich, A.G.

1978-01-01

The problems, discussed at the ''Large-scale Structure of the Universe'' symposium are considered on a popular level. Described are the cell structure of galaxy distribution in the Universe, principles of mathematical galaxy distribution modelling. The images of cell structures, obtained after reprocessing with the computer are given. Discussed are three hypothesis - vortical, entropic, adiabatic, suggesting various processes of galaxy and galaxy clusters origin. A considerable advantage of the adiabatic hypothesis is recognized. The relict radiation, as a method of direct studying the processes taking place in the Universe is considered. The large-scale peculiarities and small-scale fluctuations of the relict radiation temperature enable one to estimate the turbance properties at the pre-galaxy stage. The discussion of problems, pertaining to studying the hot gas, contained in galaxy clusters, the interactions within galaxy clusters and with the inter-galaxy medium, is recognized to be a notable contribution into the development of theoretical and observational cosmology

Seismic safety in conducting large-scale blasts

Science.gov (United States)

Mashukov, I. V.; Chaplygin, V. V.; Domanov, V. P.; Semin, A. A.; Klimkin, M. A.

2017-09-01

In mining enterprises to prepare hard rocks for excavation a drilling and blasting method is used. With the approach of mining operations to settlements the negative effect of large-scale blasts increases. To assess the level of seismic impact of large-scale blasts the scientific staff of Siberian State Industrial University carried out expertise for coal mines and iron ore enterprises. Determination of the magnitude of surface seismic vibrations caused by mass explosions was performed using seismic receivers, an analog-digital converter with recording on a laptop. The registration results of surface seismic vibrations during production of more than 280 large-scale blasts at 17 mining enterprises in 22 settlements are presented. The maximum velocity values of the Earth’s surface vibrations are determined. The safety evaluation of seismic effect was carried out according to the permissible value of vibration velocity. For cases with exceedance of permissible values recommendations were developed to reduce the level of seismic impact.

Scaling and criticality in a stochastic multi-agent model of a financial market

Science.gov (United States)

Lux, Thomas; Marchesi, Michele

1999-02-01

Financial prices have been found to exhibit some universal characteristics that resemble the scaling laws characterizing physical systems in which large numbers of units interact. This raises the question of whether scaling in finance emerges in a similar way - from the interactions of a large ensemble of market participants. However, such an explanation is in contradiction to the prevalent `efficient market hypothesis' in economics, which assumes that the movements of financial prices are an immediate and unbiased reflection of incoming news about future earning prospects. Within this hypothesis, scaling in price changes would simply reflect similar scaling in the `input' signals that influence them. Here we describe a multi-agent model of financial markets which supports the idea that scaling arises from mutual interactions of participants. Although the `news arrival process' in our model lacks both power-law scaling and any temporal dependence in volatility, we find that it generates such behaviour as a result of interactions between agents.

Image-based Exploration of Large-Scale Pathline Fields

KAUST Repository

Nagoor, Omniah H.

2014-05-27

While real-time applications are nowadays routinely used in visualizing large nu- merical simulations and volumes, handling these large-scale datasets requires high-end graphics clusters or supercomputers to process and visualize them. However, not all users have access to powerful clusters. Therefore, it is challenging to come up with a visualization approach that provides insight to large-scale datasets on a single com- puter. Explorable images (EI) is one of the methods that allows users to handle large data on a single workstation. Although it is a view-dependent method, it combines both exploration and modification of visual aspects without re-accessing the original huge data. In this thesis, we propose a novel image-based method that applies the concept of EI in visualizing large flow-field pathlines data. The goal of our work is to provide an optimized image-based method, which scales well with the dataset size. Our approach is based on constructing a per-pixel linked list data structure in which each pixel contains a list of pathlines segments. With this view-dependent method it is possible to filter, color-code and explore large-scale flow data in real-time. In addition, optimization techniques such as early-ray termination and deferred shading are applied, which further improves the performance and scalability of our approach.

Homogenization of Large-Scale Movement Models in Ecology

Science.gov (United States)

Garlick, M.J.; Powell, J.A.; Hooten, M.B.; McFarlane, L.R.

2011-01-01

A difficulty in using diffusion models to predict large scale animal population dispersal is that individuals move differently based on local information (as opposed to gradients) in differing habitat types. This can be accommodated by using ecological diffusion. However, real environments are often spatially complex, limiting application of a direct approach. Homogenization for partial differential equations has long been applied to Fickian diffusion (in which average individual movement is organized along gradients of habitat and population density). We derive a homogenization procedure for ecological diffusion and apply it to a simple model for chronic wasting disease in mule deer. Homogenization allows us to determine the impact of small scale (10-100 m) habitat variability on large scale (10-100 km) movement. The procedure generates asymptotic equations for solutions on the large scale with parameters defined by small-scale variation. The simplicity of this homogenization procedure is striking when compared to the multi-dimensional homogenization procedure for Fickian diffusion,and the method will be equally straightforward for more complex models. ?? 2010 Society for Mathematical Biology.

High-Performance Monitoring Architecture for Large-Scale Distributed Systems Using Event Filtering

Science.gov (United States)

Maly, K.

1998-01-01

with the monitoring architecture to reduce the volume of event traffic flow in the system, and thereby reduce the intrusiveness of the monitoring process. We are developing an event filtering architecture to efficiently process the large volume of event traffic generated by LSD systems (such as distributed interactive applications). This filtering architecture is used to monitor collaborative distance learning application for obtaining debugging and feedback information. Our architecture supports the dynamic (re)configuration and optimization of event filters in large-scale distributed systems. Our work represents a major contribution by (1) survey and evaluating existing event filtering mechanisms In supporting monitoring LSD systems and (2) devising an integrated scalable high- performance architecture of event filtering that spans several kev application domains, presenting techniques to improve the functionality, performance and scalability. This paper describes the primary characteristics and challenges of developing high-performance event filtering for monitoring LSD systems. We survey existing event filtering mechanisms and explain key characteristics for each technique. In addition, we discuss limitations with existing event filtering mechanisms and outline how our architecture will improve key aspects of event filtering.

The role of large-scale, extratropical dynamics in climate change

Energy Technology Data Exchange (ETDEWEB)

Shepherd, T.G. [ed.

1994-02-01

The climate modeling community has focused recently on improving our understanding of certain processes, such as cloud feedbacks and ocean circulation, that are deemed critical to climate-change prediction. Although attention to such processes is warranted, emphasis on these areas has diminished a general appreciation of the role played by the large-scale dynamics of the extratropical atmosphere. Lack of interest in extratropical dynamics may reflect the assumption that these dynamical processes are a non-problem as far as climate modeling is concerned, since general circulation models (GCMs) calculate motions on this scale from first principles. Nevertheless, serious shortcomings in our ability to understand and simulate large-scale dynamics exist. Partly due to a paucity of standard GCM diagnostic calculations of large-scale motions and their transports of heat, momentum, potential vorticity, and moisture, a comprehensive understanding of the role of large-scale dynamics in GCM climate simulations has not been developed. Uncertainties remain in our understanding and simulation of large-scale extratropical dynamics and their interaction with other climatic processes, such as cloud feedbacks, large-scale ocean circulation, moist convection, air-sea interaction and land-surface processes. To address some of these issues, the 17th Stanstead Seminar was convened at Bishop`s University in Lennoxville, Quebec. The purpose of the Seminar was to promote discussion of the role of large-scale extratropical dynamics in global climate change. Abstracts of the talks are included in this volume. On the basis of these talks, several key issues emerged concerning large-scale extratropical dynamics and their climatic role. Individual records are indexed separately for the database.

The role of large-scale, extratropical dynamics in climate change

International Nuclear Information System (INIS)

Shepherd, T.G.

1994-02-01

The climate modeling community has focused recently on improving our understanding of certain processes, such as cloud feedbacks and ocean circulation, that are deemed critical to climate-change prediction. Although attention to such processes is warranted, emphasis on these areas has diminished a general appreciation of the role played by the large-scale dynamics of the extratropical atmosphere. Lack of interest in extratropical dynamics may reflect the assumption that these dynamical processes are a non-problem as far as climate modeling is concerned, since general circulation models (GCMs) calculate motions on this scale from first principles. Nevertheless, serious shortcomings in our ability to understand and simulate large-scale dynamics exist. Partly due to a paucity of standard GCM diagnostic calculations of large-scale motions and their transports of heat, momentum, potential vorticity, and moisture, a comprehensive understanding of the role of large-scale dynamics in GCM climate simulations has not been developed. Uncertainties remain in our understanding and simulation of large-scale extratropical dynamics and their interaction with other climatic processes, such as cloud feedbacks, large-scale ocean circulation, moist convection, air-sea interaction and land-surface processes. To address some of these issues, the 17th Stanstead Seminar was convened at Bishop's University in Lennoxville, Quebec. The purpose of the Seminar was to promote discussion of the role of large-scale extratropical dynamics in global climate change. Abstracts of the talks are included in this volume. On the basis of these talks, several key issues emerged concerning large-scale extratropical dynamics and their climatic role. Individual records are indexed separately for the database

A Subaru galaxy redshift survey: WFMOS survey

International Nuclear Information System (INIS)

Takada, M

2008-01-01

A planned galaxy redshift survey with the Subaru 8.2m telescope, the WFMOS survey, offers a unique opportunity for probing detailed properties of large-scale structure formation in the expanding universe by measuring clustering strength of galaxy distribution as a function of distance scale and redshift. In particular, the precise measurement of the galaxy power spectrum, combined with the cosmic microwave background experiments, allows us to obtain stringent constraints on or even determine absolute mass scales of the Big-Bang relic neutrinos as the neutrinos imprint characteristic scale- and redshift-dependent modifications onto the galaxy power spectrum shape. Here we describe the basic concept of how the galaxy clustering measurement can be used to explore the neutrino masses, with particular emphasis on advantages of the WFMOS survey over the existing low-redshift surveys such as SDSS

Status: Large-scale subatmospheric cryogenic systems

International Nuclear Information System (INIS)

Peterson, T.

1989-01-01

In the late 1960's and early 1970's an interest in testing and operating RF cavities at 1.8K motivated the development and construction of four large (300 Watt) 1.8K refrigeration systems. in the past decade, development of successful superconducting RF cavities and interest in obtaining higher magnetic fields with the improved Niobium-Titanium superconductors has once again created interest in large-scale 1.8K refrigeration systems. The L'Air Liquide plant for Tore Supra is a recently commissioned 300 Watt 1.8K system which incorporates new technology, cold compressors, to obtain the low vapor pressure for low temperature cooling. CEBAF proposes to use cold compressors to obtain 5KW at 2.0K. Magnetic refrigerators of 10 Watt capacity or higher at 1.8K are now being developed. The state of the art of large-scale refrigeration in the range under 4K will be reviewed. 28 refs., 4 figs., 7 tabs

A topological analysis of large-scale structure, studied using the CMASS sample of SDSS-III

International Nuclear Information System (INIS)

Parihar, Prachi; Gott, J. Richard III; Vogeley, Michael S.; Choi, Yun-Young; Kim, Juhan; Kim, Sungsoo S.; Speare, Robert; Brownstein, Joel R.; Brinkmann, J.

2014-01-01

We study the three-dimensional genus topology of large-scale structure using the northern region of the CMASS Data Release 10 (DR10) sample of the SDSS-III Baryon Oscillation Spectroscopic Survey. We select galaxies with redshift 0.452 < z < 0.625 and with a stellar mass M stellar > 10 11.56 M ☉ . We study the topology at two smoothing lengths: R G = 21 h –1 Mpc and R G = 34 h –1 Mpc. The genus topology studied at the R G = 21 h –1 Mpc scale results in the highest genus amplitude observed to date. The CMASS sample yields a genus curve that is characteristic of one produced by Gaussian random phase initial conditions. The data thus support the standard model of inflation where random quantum fluctuations in the early universe produced Gaussian random phase initial conditions. Modest deviations in the observed genus from random phase are as expected from shot noise effects and the nonlinear evolution of structure. We suggest the use of a fitting formula motivated by perturbation theory to characterize the shift and asymmetries in the observed genus curve with a single parameter. We construct 54 mock SDSS CMASS surveys along the past light cone from the Horizon Run 3 (HR3) N-body simulations, where gravitationally bound dark matter subhalos are identified as the sites of galaxy formation. We study the genus topology of the HR3 mock surveys with the same geometry and sampling density as the observational sample and find the observed genus topology to be consistent with ΛCDM as simulated by the HR3 mock samples. We conclude that the topology of the large-scale structure in the SDSS CMASS sample is consistent with cosmological models having primordial Gaussian density fluctuations growing in accordance with general relativity to form galaxies in massive dark matter halos.

Large-scale weakly supervised object localization via latent category learning.

Science.gov (United States)

Chong Wang; Kaiqi Huang; Weiqiang Ren; Junge Zhang; Maybank, Steve

2015-04-01

Localizing objects in cluttered backgrounds is challenging under large-scale weakly supervised conditions. Due to the cluttered image condition, objects usually have large ambiguity with backgrounds. Besides, there is also a lack of effective algorithm for large-scale weakly supervised localization in cluttered backgrounds. However, backgrounds contain useful latent information, e.g., the sky in the aeroplane class. If this latent information can be learned, object-background ambiguity can be largely reduced and background can be suppressed effectively. In this paper, we propose the latent category learning (LCL) in large-scale cluttered conditions. LCL is an unsupervised learning method which requires only image-level class labels. First, we use the latent semantic analysis with semantic object representation to learn the latent categories, which represent objects, object parts or backgrounds. Second, to determine which category contains the target object, we propose a category selection strategy by evaluating each category's discrimination. Finally, we propose the online LCL for use in large-scale conditions. Evaluation on the challenging PASCAL Visual Object Class (VOC) 2007 and the large-scale imagenet large-scale visual recognition challenge 2013 detection data sets shows that the method can improve the annotation precision by 10% over previous methods. More importantly, we achieve the detection precision which outperforms previous results by a large margin and can be competitive to the supervised deformable part model 5.0 baseline on both data sets.

Large-scale networks in engineering and life sciences

CERN Document Server

Findeisen, Rolf; Flockerzi, Dietrich; Reichl, Udo; Sundmacher, Kai

2014-01-01

This edited volume provides insights into and tools for the modeling, analysis, optimization, and control of large-scale networks in the life sciences and in engineering. Large-scale systems are often the result of networked interactions between a large number of subsystems, and their analysis and control are becoming increasingly important. The chapters of this book present the basic concepts and theoretical foundations of network theory and discuss its applications in different scientific areas such as biochemical reactions, chemical production processes, systems biology, electrical circuits, and mobile agents. The aim is to identify common concepts, to understand the underlying mathematical ideas, and to inspire discussions across the borders of the various disciplines.  The book originates from the interdisciplinary summer school “Large Scale Networks in Engineering and Life Sciences” hosted by the International Max Planck Research School Magdeburg, September 26-30, 2011, and will therefore be of int...

A Panoramic View of Star Formation in Milky Way: Recent Results from Galactic Plane FIR/Sub-mm Surveys

Science.gov (United States)

Elia, Davide

2017-11-01

The star formation process involves a continuous gas flow from galactic (kpc) down to stellar (AU) scales. While targeted observations of single star forming sources are needed to understand the steps of this process with increasing detail, large unbiased Galactic plane surveys permit to reconstruct the map of star forming sites across the Milky Way, considered as an unique star formation engine. On the one hand, such surveys provide the community with a huge number of candidate targets for future follow-up observations with state-of-the-art telescope facilities, on the other hand they can provide reliable estimates of global parameters, such as Galactic star formation efficiency and rate, through which it is possible to establish comparisons with other galaxies. In this talk I will review the main results of recent FIR/sub-mm continuum emission Galactic surveys, with special attention to the Hi-GAL Herschel project, having the advantage (but also the complication) of being a multi-wavelength survey covering the spectral range in which the cold interstellar dust is expected to emit. The subsequent VIALACTEA project represents an articulate effort to combine Hi-GAL with other continuum and line surveys to refine the census of star forming clumps in the Galactic plane, and to use it to describe the Milky Way as a whole. Interpretation limitations imposed by the loss of detail with increasing distance are also discussed.

An Novel Architecture of Large-scale Communication in IOT

Science.gov (United States)

Ma, Wubin; Deng, Su; Huang, Hongbin

2018-03-01

In recent years, many scholars have done a great deal of research on the development of Internet of Things and networked physical systems. However, few people have made the detailed visualization of the large-scale communications architecture in the IOT. In fact, the non-uniform technology between IPv6 and access points has led to a lack of broad principles of large-scale communications architectures. Therefore, this paper presents the Uni-IPv6 Access and Information Exchange Method (UAIEM), a new architecture and algorithm that addresses large-scale communications in the IOT.

Benefits of transactive memory systems in large-scale development

OpenAIRE

Aivars, Sablis

2016-01-01

Context. Large-scale software development projects are those consisting of a large number of teams, maybe even spread across multiple locations, and working on large and complex software tasks. That means that neither a team member individually nor an entire team holds all the knowledge about the software being developed and teams have to communicate and coordinate their knowledge. Therefore, teams and team members in large-scale software development projects must acquire and manage expertise...

Study of a large scale neutron measurement channel

International Nuclear Information System (INIS)

Amarouayache, Anissa; Ben Hadid, Hayet.

1982-12-01

A large scale measurement channel allows the processing of the signal coming from an unique neutronic sensor, during three different running modes: impulses, fluctuations and current. The study described in this note includes three parts: - A theoretical study of the large scale channel and its brief description are given. The results obtained till now in that domain are presented. - The fluctuation mode is thoroughly studied and the improvements to be done are defined. The study of a fluctuation linear channel with an automatic commutation of scales is described and the results of the tests are given. In this large scale channel, the method of data processing is analogical. - To become independent of the problems generated by the use of a an analogical processing of the fluctuation signal, a digital method of data processing is tested. The validity of that method is improved. The results obtained on a test system realized according to this method are given and a preliminary plan for further research is defined [fr

78 FR 70015 - Proposed Information Collection; Comment Request; Large Pelagic Fishing Survey

Science.gov (United States)

2013-11-22

... Collection; Comment Request; Large Pelagic Fishing Survey AGENCY: National Oceanic and Atmospheric... effort to reduce paperwork and respondent burden, invites the general public and other Federal agencies... Pelagics Headboat Survey (LPHS) component. Increase the annual Large Pelagics Telephone Survey (LPTS...

Capabilities of the Large-Scale Sediment Transport Facility

Science.gov (United States)

2016-04-01

pump flow meters, sediment trap weigh tanks , and beach profiling lidar. A detailed discussion of the original LSTF features and capabilities can be...ERDC/CHL CHETN-I-88 April 2016 Approved for public release; distribution is unlimited. Capabilities of the Large-Scale Sediment Transport...describes the Large-Scale Sediment Transport Facility (LSTF) and recent upgrades to the measurement systems. The purpose of these upgrades was to increase

Spatiotemporal property and predictability of large-scale human mobility

Science.gov (United States)

Zhang, Hai-Tao; Zhu, Tao; Fu, Dongfei; Xu, Bowen; Han, Xiao-Pu; Chen, Duxin

2018-04-01

Spatiotemporal characteristics of human mobility emerging from complexity on individual scale have been extensively studied due to the application potential on human behavior prediction and recommendation, and control of epidemic spreading. We collect and investigate a comprehensive data set of human activities on large geographical scales, including both websites browse and mobile towers visit. Numerical results show that the degree of activity decays as a power law, indicating that human behaviors are reminiscent of scale-free random walks known as Lévy flight. More significantly, this study suggests that human activities on large geographical scales have specific non-Markovian characteristics, such as a two-segment power-law distribution of dwelling time and a high possibility for prediction. Furthermore, a scale-free featured mobility model with two essential ingredients, i.e., preferential return and exploration, and a Gaussian distribution assumption on the exploration tendency parameter is proposed, which outperforms existing human mobility models under scenarios of large geographical scales.

Comparison of neighborhood-scale residential wood smoke emissions inventories using limited and intensive survey data

International Nuclear Information System (INIS)

Baxter, T.E.

1998-01-01

Emission inventory based estimations of pollutants resulting from residential combustion of wood are typically determined by collecting survey data that represent a single but relatively large area. While the pollutants in wood smoke emissions may represent a relatively low fraction (<10%) of an area's total annual emissions mass inventory, they can concentrate within the specific neighborhood areas where emitted. Thus, while the representativeness of a large-area survey approach is valid and useful, its application for estimating wood smoke pollutant levels within any particular neighborhood may be limited. The ability to obtain a better estimation of pollutant levels for evaluating potential health-related impacts within neighborhoods where wood smoke pollutants can concentrate requires survey data more representative of the particular area. This study compares residential wood combustion survey data collected from six residential neighborhoods in the metropolitan area of Flagstaff, Arizona. The primary purpose of this study is to determine the ability of data collected from a limited neighborhood-scale survey effort to represent that neighborhood's wood fuel consumption characteristics and wood smoke emissions. In addition, the variation that occurs between different neighborhoods regarding residential consumption of wood is also evaluated. Residential wood combustion survey data were collected compare wood burning device distribution, wood types and quantities burned, and emission rates. One neighborhood was surveyed once at approximately a 10% distribution rate and again at a 100% distribution rate providing data for evaluating the ability of a limited-effort survey to represent a more intensive survey. Survey methodology, results and recommendations are presented

Involvement of herbal medicine as a cause of mesenteric phlebosclerosis: results from a large-scale nationwide survey.

Science.gov (United States)

Shimizu, Seiji; Kobayashi, Taku; Tomioka, Hideo; Ohtsu, Kensei; Matsui, Toshiyuki; Hibi, Toshifumi

2017-03-01

Mesenteric phlebosclerosis (MP) is a rare disease characterized by venous calcification extending from the colonic wall to the mesentery, with chronic ischemic changes from venous return impairment in the intestine. It is an idiopathic disease, but increasing attention has been paid to the potential involvement of herbal medicine, or Kampo, in its etiology. Until now, there were scattered case reports, but no large-scale studies have been conducted to unravel the clinical characteristics and etiology of the disease. A nationwide survey was conducted using questionnaires to assess possible etiology (particularly the involvement of herbal medicine), clinical manifestations, disease course, and treatment of MP. Data from 222 patients were collected. Among the 169 patients (76.1 %), whose history of herbal medicine was obtained, 147 (87.0 %) used herbal medicines. The use of herbal medicines containing sanshishi (gardenia fruit, Gardenia jasminoides Ellis) was reported in 119 out of 147 patients (81.0 %). Therefore, the use of herbal medicine containing sanshishi was confirmed in 70.4 % of 169 patients whose history of herbal medicine was obtained. The duration of sanshishi use ranged from 3 to 51 years (mean 13.6 years). Patients who discontinued sanshishi showed a better outcome compared with those who continued it. The use of herbal medicine containing sanshishi is associated with the etiology of MP. Although it may not be the causative factor, it is necessary for gastroenterologists to be aware of the potential risk of herbal medicine containing sanshishi for the development of MP.

Problems of large-scale vertically-integrated aquaculture

Energy Technology Data Exchange (ETDEWEB)

Webber, H H; Riordan, P F

1976-01-01

The problems of vertically-integrated aquaculture are outlined; they are concerned with: species limitations (in the market, biological and technological); site selection, feed, manpower needs, and legal, institutional and financial requirements. The gaps in understanding of, and the constraints limiting, large-scale aquaculture are listed. Future action is recommended with respect to: types and diversity of species to be cultivated, marketing, biotechnology (seed supply, disease control, water quality and concerted effort), siting, feed, manpower, legal and institutional aids (granting of water rights, grants, tax breaks, duty-free imports, etc.), and adequate financing. The last of hard data based on experience suggests that large-scale vertically-integrated aquaculture is a high risk enterprise, and with the high capital investment required, banks and funding institutions are wary of supporting it. Investment in pilot projects is suggested to demonstrate that large-scale aquaculture can be a fully functional and successful business. Construction and operation of such pilot farms is judged to be in the interests of both the public and private sector.

Drivers and barriers for municipal retrofitting activities – Evidence from a large-scale survey of German local authorities

NARCIS (Netherlands)

Polzin, Friedemann|info:eu-repo/dai/nl/413317404; Nolden, Colin; von Flotow, Paschen

2018-01-01

Local authorities are key actors for implementing innovative energy efficiency technologies (retrofitting) to reduce end-use energy demand and consequently reduce negative effects of high energy use such as climate change and public budget deficits. This paper reports the results of a large-scale

Large-scale computing with Quantum Espresso

International Nuclear Information System (INIS)

Giannozzi, P.; Cavazzoni, C.

2009-01-01

This paper gives a short introduction to Quantum Espresso: a distribution of software for atomistic simulations in condensed-matter physics, chemical physics, materials science, and to its usage in large-scale parallel computing.

Linking Large-Scale Reading Assessments: Comment

Science.gov (United States)

Hanushek, Eric A.

2016-01-01

E. A. Hanushek points out in this commentary that applied researchers in education have only recently begun to appreciate the value of international assessments, even though there are now 50 years of experience with these. Until recently, these assessments have been stand-alone surveys that have not been linked, and analysis has largely focused on…

VESPA: Very large-scale Evolutionary and Selective Pressure Analyses

Directory of Open Access Journals (Sweden)

Andrew E. Webb

2017-06-01

Full Text Available Background Large-scale molecular evolutionary analyses of protein coding sequences requires a number of preparatory inter-related steps from finding gene families, to generating alignments and phylogenetic trees and assessing selective pressure variation. Each phase of these analyses can represent significant challenges, particularly when working with entire proteomes (all protein coding sequences in a genome from a large number of species. Methods We present VESPA, software capable of automating a selective pressure analysis using codeML in addition to the preparatory analyses and summary statistics. VESPA is written in python and Perl and is designed to run within a UNIX environment. Results We have benchmarked VESPA and our results show that the method is consistent, performs well on both large scale and smaller scale datasets, and produces results in line with previously published datasets. Discussion Large-scale gene family identification, sequence alignment, and phylogeny reconstruction are all important aspects of large-scale molecular evolutionary analyses. VESPA provides flexible software for simplifying these processes along with downstream selective pressure variation analyses. The software automatically interprets results from codeML and produces simplified summary files to assist the user in better understanding the results. VESPA may be found at the following website: http://www.mol-evol.org/VESPA.

Statistics as Unbiased Estimators: Exploring the Teaching of Standard Deviation

Science.gov (United States)

Wasserman, Nicholas H.; Casey, Stephanie; Champion, Joe; Huey, Maryann

2017-01-01

This manuscript presents findings from a study about the knowledge for and planned teaching of standard deviation. We investigate how understanding variance as an unbiased (inferential) estimator--not just a descriptive statistic for the variation (spread) in data--is related to teachers' instruction regarding standard deviation, particularly…

Large scale filaments associated with Milky Way spiral arms

Science.gov (United States)

Wang, Ke; Testi, Leonardo; Ginsburg, Adam; Walmsley, Malcolm; Molinari, Sergio; Schisano, Eugenio

2015-08-01

The ubiquity of filamentary structure at various scales through out the Galaxy has triggered a renewed interest in their formation, evolution, and role in star formation. The largest filaments can reach up to Galactic scale as part of the spiral arm structure. However, such large scale filaments are hard to identify systematically due to limitations in identifying methodology (i.e., as extinction features). We present a new approach to directly search for the largest, coldest, and densest filaments in the Galaxy, making use of sensitive Herschel Hi-GAL data complemented by spectral line cubes. We present a sample of the 9 most prominent Herschel filaments from a pilot search field. These filaments measure 37-99 pc long and 0.6-3.0 pc wide with masses (0.5-8.3)×104 Msun, and beam-averaged (28", or 0.4-0.7 pc) peak H2 column densities of (1.7-9.3)x1022 cm-2. The bulk of the filaments are relatively cold (17-21 K), while some local clumps have a dust temperature up to 25-47 K due to local star formation activities. All the filaments are located within spiral arm model incorporating the latest parallax measurements, we find that 7/9 of them reside within arms, but most are close to arm edges. These filaments are comparable in length to the Galactic scale height and therefore are not simply part of a grander turbulent cascade. These giant filaments, which often contain regularly spaced pc-scale clumps, are much larger than the filaments found in the Herschel Gould's Belt Survey, and they form the upper ends in the filamentary hierarchy. Full operational ALMA and NOEMA will be able to resolve and characterize similar filaments in nearby spiral galaxies, allowing us to compare the star formation in a uniform context of spiral arms.

RESTRUCTURING OF THE LARGE-SCALE SPRINKLERS

Directory of Open Access Journals (Sweden)

Paweł Kozaczyk

2016-09-01

Full Text Available One of the best ways for agriculture to become independent from shortages of precipitation is irrigation. In the seventies and eighties of the last century a number of large-scale sprinklers in Wielkopolska was built. At the end of 1970’s in the Poznan province 67 sprinklers with a total area of 6400 ha were installed. The average size of the sprinkler reached 95 ha. In 1989 there were 98 sprinklers, and the area which was armed with them was more than 10 130 ha. The study was conducted on 7 large sprinklers with the area ranging from 230 to 520 hectares in 1986÷1998. After the introduction of the market economy in the early 90’s and ownership changes in agriculture, large-scale sprinklers have gone under a significant or total devastation. Land on the State Farms of the State Agricultural Property Agency has leased or sold and the new owners used the existing sprinklers to a very small extent. This involved a change in crop structure, demand structure and an increase in operating costs. There has also been a threefold increase in electricity prices. Operation of large-scale irrigation encountered all kinds of barriers in practice and limitations of system solutions, supply difficulties, high levels of equipment failure which is not inclined to rational use of available sprinklers. An effect of a vision of the local area was to show the current status of the remaining irrigation infrastructure. The adopted scheme for the restructuring of Polish agriculture was not the best solution, causing massive destruction of assets previously invested in the sprinkler system.

Alignment between Satellite and Central Galaxies in the SDSS DR7: Dependence on Large-scale Environment

Science.gov (United States)

Wang, Peng; Luo, Yu; Kang, Xi; Libeskind, Noam I.; Wang, Lei; Zhang, Youcai; Tempel, Elmo; Guo, Quan

2018-06-01

The alignment between satellites and central galaxies has been studied in detail both in observational and theoretical works. The widely accepted fact is that satellites preferentially reside along the major axis of their central galaxy. However, the origin and large-scale environmental dependence of this alignment are still unknown. In an attempt to determine these variables, we use data constructed from Sloan Digital Sky Survey DR7 to investigate the large-scale environmental dependence of this alignment with emphasis on examining the alignment’s dependence on the color of the central galaxy. We find a very strong large-scale environmental dependence of the satellite–central alignment (SCA) in groups with blue centrals. Satellites of blue centrals in knots are preferentially located perpendicular to the major axes of the centrals, and the alignment angle decreases with environment, namely, when going from knots to voids. The alignment angle strongly depends on the {}0.1(g-r) color of centrals. We suggest that the SCA is the result of a competition between satellite accretion within large-scale structure (LSS) and galaxy evolution inside host halos. For groups containing red central galaxies, the SCA is mainly determined by the evolution effect, while for blue central dominated groups, the effect of the LSS plays a more important role, especially in knots. Our results provide an explanation for how the SCA forms within different large-scale environments. The perpendicular case in groups and knots with blue centrals may also provide insight into understanding similar polar arrangements, such as the formation of the Milky Way and Centaurus A’s satellite system.

Large-scale synthesis of YSZ nanopowder by Pechini method

Indian Academy of Sciences (India)

Administrator

structure and chemical purity of 99⋅1% by inductively coupled plasma optical emission spectroscopy on a large scale. Keywords. Sol–gel; yttria-stabilized zirconia; large scale; nanopowder; Pechini method. 1. Introduction. Zirconia has attracted the attention of many scientists because of its tremendous thermal, mechanical ...

Building unbiased estimators from non-Gaussian likelihoods with application to shear estimation

International Nuclear Information System (INIS)

Madhavacheril, Mathew S.; Sehgal, Neelima; McDonald, Patrick; Slosar, Anže

2015-01-01

We develop a general framework for generating estimators of a given quantity which are unbiased to a given order in the difference between the true value of the underlying quantity and the fiducial position in theory space around which we expand the likelihood. We apply this formalism to rederive the optimal quadratic estimator and show how the replacement of the second derivative matrix with the Fisher matrix is a generic way of creating an unbiased estimator (assuming choice of the fiducial model is independent of data). Next we apply the approach to estimation of shear lensing, closely following the work of Bernstein and Armstrong (2014). Our first order estimator reduces to their estimator in the limit of zero shear, but it also naturally allows for the case of non-constant shear and the easy calculation of correlation functions or power spectra using standard methods. Both our first-order estimator and Bernstein and Armstrong's estimator exhibit a bias which is quadratic in true shear. Our third-order estimator is, at least in the realm of the toy problem of Bernstein and Armstrong, unbiased to 0.1% in relative shear errors Δg/g for shears up to |g|=0.2

The build up of the correlation between halo spin and the large-scale structure

Science.gov (United States)

Wang, Peng; Kang, Xi

2018-01-01

Both simulations and observations have confirmed that the spin of haloes/galaxies is correlated with the large-scale structure (LSS) with a mass dependence such that the spin of low-mass haloes/galaxies tend to be parallel with the LSS, while that of massive haloes/galaxies tend to be perpendicular with the LSS. It is still unclear how this mass dependence is built up over time. We use N-body simulations to trace the evolution of the halo spin-LSS correlation and find that at early times the spin of all halo progenitors is parallel with the LSS. As time goes on, mass collapsing around massive halo is more isotropic, especially the recent mass accretion along the slowest collapsing direction is significant and it brings the halo spin to be perpendicular with the LSS. Adopting the fractional anisotropy (FA) parameter to describe the degree of anisotropy of the large-scale environment, we find that the spin-LSS correlation is a strong function of the environment such that a higher FA (more anisotropic environment) leads to an aligned signal, and a lower anisotropy leads to a misaligned signal. In general, our results show that the spin-LSS correlation is a combined consequence of mass flow and halo growth within the cosmic web. Our predicted environmental dependence between spin and large-scale structure can be further tested using galaxy surveys.

RECOVERY OF LARGE ANGULAR SCALE CMB POLARIZATION FOR INSTRUMENTS EMPLOYING VARIABLE-DELAY POLARIZATION MODULATORS

Energy Technology Data Exchange (ETDEWEB)

Miller, N. J.; Marriage, T. A.; Appel, J. W.; Bennett, C. L.; Eimer, J.; Essinger-Hileman, T.; Harrington, K.; Rostem, K.; Watts, D. J. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States); Chuss, D. T. [Department of Physics, Villanova University, 800 E Lancaster, Villanova, PA 19085 (United States); Wollack, E. J.; Fixsen, D. J.; Moseley, S. H.; Switzer, E. R., E-mail: Nathan.J.Miller@nasa.gov [Observational Cosmology Laboratory, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2016-02-20

Variable-delay Polarization Modulators (VPMs) are currently being implemented in experiments designed to measure the polarization of the cosmic microwave background on large angular scales because of their capability for providing rapid, front-end polarization modulation and control over systematic errors. Despite the advantages provided by the VPM, it is important to identify and mitigate any time-varying effects that leak into the synchronously modulated component of the signal. In this paper, the effect of emission from a 300 K VPM on the system performance is considered and addressed. Though instrument design can greatly reduce the influence of modulated VPM emission, some residual modulated signal is expected. VPM emission is treated in the presence of rotational misalignments and temperature variation. Simulations of time-ordered data are used to evaluate the effect of these residual errors on the power spectrum. The analysis and modeling in this paper guides experimentalists on the critical aspects of observations using VPMs as front-end modulators. By implementing the characterizations and controls as described, front-end VPM modulation can be very powerful for mitigating 1/f noise in large angular scale polarimetric surveys. None of the systematic errors studied fundamentally limit the detection and characterization of B-modes on large scales for a tensor-to-scalar ratio of r = 0.01. Indeed, r < 0.01 is achievable with commensurately improved characterizations and controls.

The Phoenix series large scale LNG pool fire experiments.

Energy Technology Data Exchange (ETDEWEB)

Simpson, Richard B.; Jensen, Richard Pearson; Demosthenous, Byron; Luketa, Anay Josephine; Ricks, Allen Joseph; Hightower, Marion Michael; Blanchat, Thomas K.; Helmick, Paul H.; Tieszen, Sheldon Robert; Deola, Regina Anne; Mercier, Jeffrey Alan; Suo-Anttila, Jill Marie; Miller, Timothy J.

2010-12-01

The increasing demand for natural gas could increase the number and frequency of Liquefied Natural Gas (LNG) tanker deliveries to ports across the United States. Because of the increasing number of shipments and the number of possible new facilities, concerns about the potential safety of the public and property from an accidental, and even more importantly intentional spills, have increased. While improvements have been made over the past decade in assessing hazards from LNG spills, the existing experimental data is much smaller in size and scale than many postulated large accidental and intentional spills. Since the physics and hazards from a fire change with fire size, there are concerns about the adequacy of current hazard prediction techniques for large LNG spills and fires. To address these concerns, Congress funded the Department of Energy (DOE) in 2008 to conduct a series of laboratory and large-scale LNG pool fire experiments at Sandia National Laboratories (Sandia) in Albuquerque, New Mexico. This report presents the test data and results of both sets of fire experiments. A series of five reduced-scale (gas burner) tests (yielding 27 sets of data) were conducted in 2007 and 2008 at Sandia's Thermal Test Complex (TTC) to assess flame height to fire diameter ratios as a function of nondimensional heat release rates for extrapolation to large-scale LNG fires. The large-scale LNG pool fire experiments were conducted in a 120 m diameter pond specially designed and constructed in Sandia's Area III large-scale test complex. Two fire tests of LNG spills of 21 and 81 m in diameter were conducted in 2009 to improve the understanding of flame height, smoke production, and burn rate and therefore the physics and hazards of large LNG spills and fires.

Small scale hydroelectric power potential in Nevada: a preliminary reconnaissance survey

Energy Technology Data Exchange (ETDEWEB)

Cochran, G.F.; Fordham, J.W.; Richard, K.; Loux, R.

1981-04-01

This preliminary reconnaissance survey is intended to: develop a first estimate as to the potential number, location and characteristics of small-scale (50 kW to 15 MW) hydroelectric sites in Nevada; provide a compilation of various Federal and state laws and regulations, including tax and financing regulations, that affect small-scale hydroelectric development and provide information on sources of small-scale hydroelectric generation hardware and consultants/ contractors who do small scale hydroelectric work. The entire survey has been conducted in the office working with various available data bases. The site survey and site evaluation methods used are described, and data are tabulated on the flow, power potential, predicted capital expenditures required, etc. for 61 potential sites with measured flows and for 77 sites with derived flows. A map showing potential site locations is included. (LCL)

Geospatial Optimization of Siting Large-Scale Solar Projects

Energy Technology Data Exchange (ETDEWEB)

Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Quinby, Ted [National Renewable Energy Lab. (NREL), Golden, CO (United States); Caulfield, Emmet [Stanford Univ., CA (United States); Gerritsen, Margot [Stanford Univ., CA (United States); Diffendorfer, Jay [U.S. Geological Survey, Boulder, CO (United States); Haines, Seth [U.S. Geological Survey, Boulder, CO (United States)

2014-03-01

Recent policy and economic conditions have encouraged a renewed interest in developing large-scale solar projects in the U.S. Southwest. However, siting large-scale solar projects is complex. In addition to the quality of the solar resource, solar developers must take into consideration many environmental, social, and economic factors when evaluating a potential site. This report describes a proof-of-concept, Web-based Geographical Information Systems (GIS) tool that evaluates multiple user-defined criteria in an optimization algorithm to inform discussions and decisions regarding the locations of utility-scale solar projects. Existing siting recommendations for large-scale solar projects from governmental and non-governmental organizations are not consistent with each other, are often not transparent in methods, and do not take into consideration the differing priorities of stakeholders. The siting assistance GIS tool we have developed improves upon the existing siting guidelines by being user-driven, transparent, interactive, capable of incorporating multiple criteria, and flexible. This work provides the foundation for a dynamic siting assistance tool that can greatly facilitate siting decisions among multiple stakeholders.

Large-scale Agricultural Land Acquisitions in West Africa | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

This project will examine large-scale agricultural land acquisitions in nine West African countries -Burkina Faso, Guinea-Bissau, Guinea, Benin, Mali, Togo, Senegal, Niger, and Côte d'Ivoire. ... They will use the results to increase public awareness and knowledge about the consequences of large-scale land acquisitions.

State of the Art in Large-Scale Soil Moisture Monitoring

Science.gov (United States)

Ochsner, Tyson E.; Cosh, Michael Harold; Cuenca, Richard H.; Dorigo, Wouter; Draper, Clara S.; Hagimoto, Yutaka; Kerr, Yan H.; Larson, Kristine M.; Njoku, Eni Gerald; Small, Eric E.;

Controls of dissolved organic matter quality: Evidence from a large-scale boreal lake survey

DEFF Research Database (Denmark)

Kothawala, D.N.; Stedmon, Colin; Müller, R.A.

2014-01-01

Inland waters transport large amounts of dissolved organic matter (DOM) from terrestrial environments to the oceans, but DOM also reacts en route, with substantial water column losses by mineralization and sedimentation. For DOM transformations along the aquatic continuum, lakes play an important...... role as they retain waters in the landscape allowing for more time to alter DOM. We know DOM losses are significant at the global scale, yet little is known about how the reactivity of DOM varies across landscapes and climates. DOM reactivity is inherently linked to its chemical composition. We used...... analyzed in relation to lake chemistry, catchment, and climate characteristics. Land cover, particularly the percentage of water in the catchment, was a primary factor explaining variability in PARAFAC components. Likewise, lake water retention time influenced DOM quality. These results suggest...

A route to explosive large-scale magnetic reconnection in a super-ion-scale current sheet

Directory of Open Access Journals (Sweden)

K. G. Tanaka

2009-01-01

Full Text Available How to trigger magnetic reconnection is one of the most interesting and important problems in space plasma physics. Recently, electron temperature anisotropy (αeo=Te⊥/Te|| at the center of a current sheet and non-local effect of the lower-hybrid drift instability (LHDI that develops at the current sheet edges have attracted attention in this context. In addition to these effects, here we also study the effects of ion temperature anisotropy (αio=Ti⊥/Ti||. Electron anisotropy effects are known to be helpless in a current sheet whose thickness is of ion-scale. In this range of current sheet thickness, the LHDI effects are shown to weaken substantially with a small increase in thickness and the obtained saturation level is too low for a large-scale reconnection to be achieved. Then we investigate whether introduction of electron and ion temperature anisotropies in the initial stage would couple with the LHDI effects to revive quick triggering of large-scale reconnection in a super-ion-scale current sheet. The results are as follows. (1 The initial electron temperature anisotropy is consumed very quickly when a number of minuscule magnetic islands (each lateral length is 1.5~3 times the ion inertial length form. These minuscule islands do not coalesce into a large-scale island to enable large-scale reconnection. (2 The subsequent LHDI effects disturb the current sheet filled with the small islands. This makes the triggering time scale to be accelerated substantially but does not enhance the saturation level of reconnected flux. (3 When the ion temperature anisotropy is added, it survives through the small island formation stage and makes even quicker triggering to happen when the LHDI effects set-in. Furthermore the saturation level is seen to be elevated by a factor of ~2 and large-scale reconnection is achieved only in this case. Comparison with two-dimensional simulations that exclude the LHDI effects confirms that the saturation level

Large-scale Labeled Datasets to Fuel Earth Science Deep Learning Applications

Science.gov (United States)

Maskey, M.; Ramachandran, R.; Miller, J.

2017-12-01

Deep learning has revolutionized computer vision and natural language processing with various algorithms scaled using high-performance computing. However, generic large-scale labeled datasets such as the ImageNet are the fuel that drives the impressive accuracy of deep learning results. Large-scale labeled datasets already exist in domains such as medical science, but creating them in the Earth science domain is a challenge. While there are ways to apply deep learning using limited labeled datasets, there is a need in the Earth sciences for creating large-scale labeled datasets for benchmarking and scaling deep learning applications. At the NASA Marshall Space Flight Center, we are using deep learning for a variety of Earth science applications where we have encountered the need for large-scale labeled datasets. We will discuss our approaches for creating such datasets and why these datasets are just as valuable as deep learning algorithms. We will also describe successful usage of these large-scale labeled datasets with our deep learning based applications.

The health system and population health implications of large-scale diabetes screening in India: a microsimulation model of alternative approaches.

Directory of Open Access Journals (Sweden)

Sanjay Basu

2015-05-01

Full Text Available Like a growing number of rapidly developing countries, India has begun to develop a system for large-scale community-based screening for diabetes. We sought to identify the implications of using alternative screening instruments to detect people with undiagnosed type 2 diabetes among diverse populations across India.We developed and validated a microsimulation model that incorporated data from 58 studies from across the country into a nationally representative sample of Indians aged 25-65 y old. We estimated the diagnostic and health system implications of three major survey-based screening instruments and random glucometer-based screening. Of the 567 million Indians eligible for screening, depending on which of four screening approaches is utilized, between 158 and 306 million would be expected to screen as "high risk" for type 2 diabetes, and be referred for confirmatory testing. Between 26 million and 37 million of these people would be expected to meet international diagnostic criteria for diabetes, but between 126 million and 273 million would be "false positives." The ratio of false positives to true positives varied from 3.9 (when using random glucose screening to 8.2 (when using a survey-based screening instrument in our model. The cost per case found would be expected to be from US$5.28 (when using random glucose screening to US$17.06 (when using a survey-based screening instrument, presenting a total cost of between US$169 and US$567 million. The major limitation of our analysis is its dependence on published cohort studies that are unlikely fully to capture the poorest and most rural areas of the country. Because these areas are thought to have the lowest diabetes prevalence, this may result in overestimation of the efficacy and health benefits of screening.Large-scale community-based screening is anticipated to produce a large number of false-positive results, particularly if using currently available survey-based screening

AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. II. THE NEAR-INFRARED SPECTROSCOPIC CATALOG

International Nuclear Information System (INIS)

Shimonishi, Takashi; Onaka, Takashi; Kato, Daisuke; Sakon, Itsuki; Ita, Yoshifusa; Kawamura, Akiko; Kaneda, Hidehiro

2013-01-01

We performed a near-infrared spectroscopic survey toward an area of ∼10 deg 2 of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R ∼ 20) spectra in 2-5 μm for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 μm, and 67% of the sources also have photometric data up to 24 μm. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color-color and color-magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2-5 μm can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the LMC in the near

Large-scale structure observables in general relativity

International Nuclear Information System (INIS)

Jeong, Donghui; Schmidt, Fabian

2015-01-01

We review recent studies that rigorously define several key observables of the large-scale structure of the Universe in a general relativistic context. Specifically, we consider (i) redshift perturbation of cosmic clock events; (ii) distortion of cosmic rulers, including weak lensing shear and magnification; and (iii) observed number density of tracers of the large-scale structure. We provide covariant and gauge-invariant expressions of these observables. Our expressions are given for a linearly perturbed flat Friedmann–Robertson–Walker metric including scalar, vector, and tensor metric perturbations. While we restrict ourselves to linear order in perturbation theory, the approach can be straightforwardly generalized to higher order. (paper)

Fatigue Analysis of Large-scale Wind turbine

Directory of Open Access Journals (Sweden)

Zhu Yongli

2017-01-01

Full Text Available The paper does research on top flange fatigue damage of large-scale wind turbine generator. It establishes finite element model of top flange connection system with finite element analysis software MSC. Marc/Mentat, analyzes its fatigue strain, implements load simulation of flange fatigue working condition with Bladed software, acquires flange fatigue load spectrum with rain-flow counting method, finally, it realizes fatigue analysis of top flange with fatigue analysis software MSC. Fatigue and Palmgren-Miner linear cumulative damage theory. The analysis result indicates that its result provides new thinking for flange fatigue analysis of large-scale wind turbine generator, and possesses some practical engineering value.

Real-time simulation of large-scale floods

Science.gov (United States)

Liu, Q.; Qin, Y.; Li, G. D.; Liu, Z.; Cheng, D. J.; Zhao, Y. H.

2016-08-01

According to the complex real-time water situation, the real-time simulation of large-scale floods is very important for flood prevention practice. Model robustness and running efficiency are two critical factors in successful real-time flood simulation. This paper proposed a robust, two-dimensional, shallow water model based on the unstructured Godunov- type finite volume method. A robust wet/dry front method is used to enhance the numerical stability. An adaptive method is proposed to improve the running efficiency. The proposed model is used for large-scale flood simulation on real topography. Results compared to those of MIKE21 show the strong performance of the proposed model.

Biased and unbiased perceptual decision-making on vocal emotions.

Science.gov (United States)

Dricu, Mihai; Ceravolo, Leonardo; Grandjean, Didier; Frühholz, Sascha

2017-11-24

Perceptual decision-making on emotions involves gathering sensory information about the affective state of another person and forming a decision on the likelihood of a particular state. These perceptual decisions can be of varying complexity as determined by different contexts. We used functional magnetic resonance imaging and a region of interest approach to investigate the brain activation and functional connectivity behind two forms of perceptual decision-making. More complex unbiased decisions on affective voices recruited an extended bilateral network consisting of the posterior inferior frontal cortex, the orbitofrontal cortex, the amygdala, and voice-sensitive areas in the auditory cortex. Less complex biased decisions on affective voices distinctly recruited the right mid inferior frontal cortex, pointing to a functional distinction in this region following decisional requirements. Furthermore, task-induced neural connectivity revealed stronger connections between these frontal, auditory, and limbic regions during unbiased relative to biased decision-making on affective voices. Together, the data shows that different types of perceptual decision-making on auditory emotions have distinct patterns of activations and functional coupling that follow the decisional strategies and cognitive mechanisms involved during these perceptual decisions.

Large-scale numerical simulations of plasmas

International Nuclear Information System (INIS)

Hamaguchi, Satoshi

2004-01-01

The recent trend of large scales simulations of fusion plasma and processing plasmas is briefly summarized. Many advanced simulation techniques have been developed for fusion plasmas and some of these techniques are now applied to analyses of processing plasmas. (author)

Nearly incompressible fluids: Hydrodynamics and large scale inhomogeneity

International Nuclear Information System (INIS)

Hunana, P.; Zank, G. P.; Shaikh, D.

2006-01-01

A system of hydrodynamic equations in the presence of large-scale inhomogeneities for a high plasma beta solar wind is derived. The theory is derived under the assumption of low turbulent Mach number and is developed for the flows where the usual incompressible description is not satisfactory and a full compressible treatment is too complex for any analytical studies. When the effects of compressibility are incorporated only weakly, a new description, referred to as 'nearly incompressible hydrodynamics', is obtained. The nearly incompressible theory, was originally applied to homogeneous flows. However, large-scale gradients in density, pressure, temperature, etc., are typical in the solar wind and it was unclear how inhomogeneities would affect the usual incompressible and nearly incompressible descriptions. In the homogeneous case, the lowest order expansion of the fully compressible equations leads to the usual incompressible equations, followed at higher orders by the nearly incompressible equations, as introduced by Zank and Matthaeus. With this work we show that the inclusion of large-scale inhomogeneities (in this case time-independent and radially symmetric background solar wind) modifies the leading-order incompressible description of solar wind flow. We find, for example, that the divergence of velocity fluctuations is nonsolenoidal and that density fluctuations can be described to leading order as a passive scalar. Locally (for small lengthscales), this system of equations converges to the usual incompressible equations and we therefore use the term 'locally incompressible' to describe the equations. This term should be distinguished from the term 'nearly incompressible', which is reserved for higher-order corrections. Furthermore, we find that density fluctuations scale with Mach number linearly, in contrast to the original homogeneous nearly incompressible theory, in which density fluctuations scale with the square of Mach number. Inhomogeneous nearly

Performance Health Monitoring of Large-Scale Systems

Energy Technology Data Exchange (ETDEWEB)

Rajamony, Ram [IBM Research, Austin, TX (United States)

2014-11-20

This report details the progress made on the ASCR funded project Performance Health Monitoring for Large Scale Systems. A large-­scale application may not achieve its full performance potential due to degraded performance of even a single subsystem. Detecting performance faults, isolating them, and taking remedial action is critical for the scale of systems on the horizon. PHM aims to develop techniques and tools that can be used to identify and mitigate such performance problems. We accomplish this through two main aspects. The PHM framework encompasses diagnostics, system monitoring, fault isolation, and performance evaluation capabilities that indicates when a performance fault has been detected, either due to an anomaly present in the system itself or due to contention for shared resources between concurrently executing jobs. Software components called the PHM Control system then build upon the capabilities provided by the PHM framework to mitigate degradation caused by performance problems.

Large-scale high-resolution non-invasive geophysical archaeological prospection for the investigation of entire archaeological landscapes

Science.gov (United States)

Trinks, Immo; Neubauer, Wolfgang; Hinterleitner, Alois; Kucera, Matthias; Löcker, Klaus; Nau, Erich; Wallner, Mario; Gabler, Manuel; Zitz, Thomas

2014-05-01

Over the past three years the 2010 in Vienna founded Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology (http://archpro.lbg.ac.at), in collaboration with its ten European partner organizations, has made considerable progress in the development and application of near-surface geophysical survey technology and methodology mapping square kilometres rather than hectares in unprecedented spatial resolution. The use of multiple novel motorized multichannel GPR and magnetometer systems (both Förster/Fluxgate and Cesium type) in combination with advanced and centimetre precise positioning systems (robotic totalstations and Realtime Kinematic GPS) permitting efficient navigation in open fields have resulted in comprehensive blanket coverage archaeological prospection surveys of important cultural heritage sites, such as the landscape surrounding Stonehenge in the framework of the Stonehenge Hidden Landscape Project, the mapping of the World Cultural Heritage site Birka-Hovgården in Sweden, or the detailed investigation of the Roman urban landscape of Carnuntum near Vienna. Efficient state-of-the-art archaeological prospection survey solutions require adequate fieldwork methodologies and appropriate data processing tools for timely quality control of the data in the field and large-scale data visualisations after arrival back in the office. The processed and optimized visualisations of the geophysical measurement data provide the basis for subsequent archaeological interpretation. Integration of the high-resolution geophysical prospection data with remote sensing data acquired through aerial photography, airborne laser- and hyperspectral-scanning, terrestrial laser-scanning or detailed digital terrain models derived through photogrammetric methods permits improved understanding and spatial analysis as well as the preparation of comprehensible presentations for the stakeholders (scientific community, cultural heritage managers, public). Of

Statistics and Dynamics in the Large-scale Structure of the Universe

International Nuclear Information System (INIS)

Matsubara, Takahiko

2006-01-01

In cosmology, observations and theories are related to each other by statistics in most cases. Especially, statistical methods play central roles in analyzing fluctuations in the universe, which are seeds of the present structure of the universe. The confrontation of the statistics and dynamics is one of the key methods to unveil the structure and evolution of the universe. I will review some of the major statistical methods in cosmology, in connection with linear and nonlinear dynamics of the large-scale structure of the universe. The present status of analyses of the observational data such as the Sloan Digital Sky Survey, and the future prospects to constrain the nature of exotic components of the universe such as the dark energy will be presented

Sampling large landscapes with small-scale stratification-User's Manual

Science.gov (United States)

Bart, Jonathan

2011-01-01

This manual explains procedures for partitioning a large landscape into plots, assigning the plots to strata, and selecting plots in each stratum to be surveyed. These steps are referred to as the "sampling large landscapes (SLL) process." We assume that users of the manual have a moderate knowledge of ArcGIS and Microsoft ® Excel. The manual is written for a single user but in many cases, some steps will be carried out by a biologist designing the survey and some steps will be carried out by a quantitative assistant. Thus, the manual essentially may be passed back and forth between these users. The SLL process primarily has been used to survey birds, and we refer to birds as subjects of the counts. The process, however, could be used to count any objects. ®

Learning from large scale neural simulations

DEFF Research Database (Denmark)

Serban, Maria

2017-01-01

Large-scale neural simulations have the marks of a distinct methodology which can be fruitfully deployed to advance scientific understanding of the human brain. Computer simulation studies can be used to produce surrogate observational data for better conceptual models and new how...

Phenomenology of two-dimensional stably stratified turbulence under large-scale forcing

KAUST Repository

Kumar, Abhishek; Verma, Mahendra K.; Sukhatme, Jai

2017-01-01

In this paper, we characterise the scaling of energy spectra, and the interscale transfer of energy and enstrophy, for strongly, moderately and weakly stably stratified two-dimensional (2D) turbulence, restricted in a vertical plane, under large-scale random forcing. In the strongly stratified case, a large-scale vertically sheared horizontal flow (VSHF) coexists with small scale turbulence. The VSHF consists of internal gravity waves and the turbulent flow has a kinetic energy (KE) spectrum that follows an approximate k−3 scaling with zero KE flux and a robust positive enstrophy flux. The spectrum of the turbulent potential energy (PE) also approximately follows a k−3 power-law and its flux is directed to small scales. For moderate stratification, there is no VSHF and the KE of the turbulent flow exhibits Bolgiano–Obukhov scaling that transitions from a shallow k−11/5 form at large scales, to a steeper approximate k−3 scaling at small scales. The entire range of scales shows a strong forward enstrophy flux, and interestingly, large (small) scales show an inverse (forward) KE flux. The PE flux in this regime is directed to small scales, and the PE spectrum is characterised by an approximate k−1.64 scaling. Finally, for weak stratification, KE is transferred upscale and its spectrum closely follows a k−2.5 scaling, while PE exhibits a forward transfer and its spectrum shows an approximate k−1.6 power-law. For all stratification strengths, the total energy always flows from large to small scales and almost all the spectral indicies are well explained by accounting for the scale-dependent nature of the corresponding flux.

Phenomenology of two-dimensional stably stratified turbulence under large-scale forcing

KAUST Repository

Kumar, Abhishek

2017-01-11

In this paper, we characterise the scaling of energy spectra, and the interscale transfer of energy and enstrophy, for strongly, moderately and weakly stably stratified two-dimensional (2D) turbulence, restricted in a vertical plane, under large-scale random forcing. In the strongly stratified case, a large-scale vertically sheared horizontal flow (VSHF) coexists with small scale turbulence. The VSHF consists of internal gravity waves and the turbulent flow has a kinetic energy (KE) spectrum that follows an approximate k−3 scaling with zero KE flux and a robust positive enstrophy flux. The spectrum of the turbulent potential energy (PE) also approximately follows a k−3 power-law and its flux is directed to small scales. For moderate stratification, there is no VSHF and the KE of the turbulent flow exhibits Bolgiano–Obukhov scaling that transitions from a shallow k−11/5 form at large scales, to a steeper approximate k−3 scaling at small scales. The entire range of scales shows a strong forward enstrophy flux, and interestingly, large (small) scales show an inverse (forward) KE flux. The PE flux in this regime is directed to small scales, and the PE spectrum is characterised by an approximate k−1.64 scaling. Finally, for weak stratification, KE is transferred upscale and its spectrum closely follows a k−2.5 scaling, while PE exhibits a forward transfer and its spectrum shows an approximate k−1.6 power-law. For all stratification strengths, the total energy always flows from large to small scales and almost all the spectral indicies are well explained by accounting for the scale-dependent nature of the corresponding flux.

Exploring the large-scale structure of Taylor–Couette turbulence through Large-Eddy Simulations

Science.gov (United States)

Ostilla-Mónico, Rodolfo; Zhu, Xiaojue; Verzicco, Roberto

2018-04-01

Large eddy simulations (LES) of Taylor-Couette (TC) flow, the flow between two co-axial and independently rotating cylinders are performed in an attempt to explore the large-scale axially-pinned structures seen in experiments and simulations. Both static and dynamic LES models are used. The Reynolds number is kept fixed at Re = 3.4 · 104, and the radius ratio η = ri /ro is set to η = 0.909, limiting the effects of curvature and resulting in frictional Reynolds numbers of around Re τ ≈ 500. Four rotation ratios from Rot = ‑0.0909 to Rot = 0.3 are simulated. First, the LES of TC is benchmarked for different rotation ratios. Both the Smagorinsky model with a constant of cs = 0.1 and the dynamic model are found to produce reasonable results for no mean rotation and cyclonic rotation, but deviations increase for increasing rotation. This is attributed to the increasing anisotropic character of the fluctuations. Second, “over-damped” LES, i.e. LES with a large Smagorinsky constant is performed and is shown to reproduce some features of the large-scale structures, even when the near-wall region is not adequately modeled. This shows the potential for using over-damped LES for fast explorations of the parameter space where large-scale structures are found.

Large-scale fuel cycle centres

International Nuclear Information System (INIS)

Smiley, S.H.; Black, K.M.

1977-01-01

The US Nuclear Regulatory Commission (NRC) has considered the nuclear energy centre concept for fuel cycle plants in the Nuclear Energy Centre Site Survey 1975 (NECSS-75) Rep. No. NUREG-0001, an important study mandated by the US Congress in the Energy Reorganization Act of 1974 which created the NRC. For this study, the NRC defined fuel cycle centres as consisting of fuel reprocessing and mixed-oxide fuel fabrication plants, and optional high-level waste and transuranic waste management facilities. A range of fuel cycle centre sizes corresponded to the fuel throughput of power plants with a total capacity of 50,000-300,000MW(e). The types of fuel cycle facilities located at the fuel cycle centre permit the assessment of the role of fuel cycle centres in enhancing the safeguard of strategic special nuclear materials - plutonium and mixed oxides. Siting fuel cycle centres presents a smaller problem than siting reactors. A single reprocessing plant of the scale projected for use in the USA (1500-2000t/a) can reprocess fuel from reactors producing 50,000-65,000MW(e). Only two or three fuel cycle centres of the upper limit size considered in the NECSS-75 would be required in the USA by the year 2000. The NECSS-75 fuel cycle centre evaluation showed that large-scale fuel cycle centres present no real technical siting difficulties from a radiological effluent and safety standpoint. Some construction economies may be achievable with fuel cycle centres, which offer opportunities to improve waste-management systems. Combined centres consisting of reactors and fuel reprocessing and mixed-oxide fuel fabrication plants were also studied in the NECSS. Such centres can eliminate shipment not only of Pu but also mixed-oxide fuel. Increased fuel cycle costs result from implementation of combined centres unless the fuel reprocessing plants are commercial-sized. Development of Pu-burning reactors could reduce any economic penalties of combined centres. The need for effective fissile

Public appraisal of government efforts and participation intent in medico-ethical policymaking in Japan: a large scale national survey concerning brain death and organ transplant

Science.gov (United States)

Sato, Hajime; Akabayashi, Akira; Kai, Ichiro

2005-01-01

Background Public satisfaction with policy process influences the legitimacy and acceptance of policies, and conditions the future political process, especially when contending ethical value judgments are involved. On the other hand, public involvement is required if effective policy is to be developed and accepted. Methods Using the data from a large-scale national opinion survey, this study evaluates public appraisal of past government efforts to legalize organ transplant from brain-dead bodies in Japan, and examines the public's intent to participate in future policy. Results A relatively large percentage of people became aware of the issue when government actions were initiated, and many increasingly formed their own opinions on the policy in question. However, a significant number (43.3%) remained unaware of any legislative efforts, and only 26.3% of those who were aware provided positive appraisals of the policymaking process. Furthermore, a majority of respondents (61.8%) indicated unwillingness to participate in future policy discussions of bioethical issues. Multivariate analysis revealed the following factors are associated with positive appraisals of policy development: greater age; earlier opinion formation; and familiarity with donor cards. Factors associated with likelihood of future participation in policy discussion include younger age, earlier attention to the issue, and knowledge of past government efforts. Those unwilling to participate cited as their reasons that experts are more knowledgeable and that the issues are too complex. Conclusions Results of an opinion survey in Japan were presented, and a set of factors statistically associated with them were discussed. Further efforts to improve policy making process on bioethical issues are desirable. PMID:15661080

Large-scale preparation of hollow graphitic carbon nanospheres

International Nuclear Information System (INIS)

Feng, Jun; Li, Fu; Bai, Yu-Jun; Han, Fu-Dong; Qi, Yong-Xin; Lun, Ning; Lu, Xi-Feng

2013-01-01

Hollow graphitic carbon nanospheres (HGCNSs) were synthesized on large scale by a simple reaction between glucose and Mg at 550 °C in an autoclave. Characterization by X-ray diffraction, Raman spectroscopy and transmission electron microscopy demonstrates the formation of HGCNSs with an average diameter of 10 nm or so and a wall thickness of a few graphenes. The HGCNSs exhibit a reversible capacity of 391 mAh g −1 after 60 cycles when used as anode materials for Li-ion batteries. -- Graphical abstract: Hollow graphitic carbon nanospheres could be prepared on large scale by the simple reaction between glucose and Mg at 550 °C, which exhibit superior electrochemical performance to graphite. Highlights: ► Hollow graphitic carbon nanospheres (HGCNSs) were prepared on large scale at 550 °C ► The preparation is simple, effective and eco-friendly. ► The in situ yielded MgO nanocrystals promote the graphitization. ► The HGCNSs exhibit superior electrochemical performance to graphite.

Accelerating large-scale phase-field simulations with GPU

Directory of Open Access Journals (Sweden)

Xiaoming Shi

2017-10-01

Full Text Available A new package for accelerating large-scale phase-field simulations was developed by using GPU based on the semi-implicit Fourier method. The package can solve a variety of equilibrium equations with different inhomogeneity including long-range elastic, magnetostatic, and electrostatic interactions. Through using specific algorithm in Compute Unified Device Architecture (CUDA, Fourier spectral iterative perturbation method was integrated in GPU package. The Allen-Cahn equation, Cahn-Hilliard equation, and phase-field model with long-range interaction were solved based on the algorithm running on GPU respectively to test the performance of the package. From the comparison of the calculation results between the solver executed in single CPU and the one on GPU, it was found that the speed on GPU is enormously elevated to 50 times faster. The present study therefore contributes to the acceleration of large-scale phase-field simulations and provides guidance for experiments to design large-scale functional devices.

First Mile Challenges for Large-Scale IoT

KAUST Repository

Bader, Ahmed

2017-03-16

The Internet of Things is large-scale by nature. This is not only manifested by the large number of connected devices, but also by the sheer scale of spatial traffic intensity that must be accommodated, primarily in the uplink direction. To that end, cellular networks are indeed a strong first mile candidate to accommodate the data tsunami to be generated by the IoT. However, IoT devices are required in the cellular paradigm to undergo random access procedures as a precursor to resource allocation. Such procedures impose a major bottleneck that hinders cellular networks\\' ability to support large-scale IoT. In this article, we shed light on the random access dilemma and present a case study based on experimental data as well as system-level simulations. Accordingly, a case is built for the latent need to revisit random access procedures. A call for action is motivated by listing a few potential remedies and recommendations.

Small-scale and reconnaissance surveys

Science.gov (United States)

Bart, Jonathan; Andres, Brad A.; Elliott, Kyle; Francis, Charles M.; Johnston, Victoria; Morrison, R.I.G.; Pierce, Elin P.; Rausch, Jennie; Bart, Jonathan; Johnston, Victoria

2012-01-01

This brief chapter addresses two related issues: how effort should be allocated to different parts of the sampling plan and, given optimal allocation, how large a sample will be required to achieve the PRISM accuracy target. Simulations based on data collected to date showed that 2 plots per cluster on rapid surveys, 2 intensive camps per field crew-year, 2-4 intensive plots per intensive camp, and 2-3 rapid surveys per intensive plot is the most efficient allocation of resources. Using this design, we investigated how crew-years should be allocated to each region in order to meet the PRISM accuracy target most efficiently. The analysis indicated that 40-50 crew-years would achieve the accuracy target for 18-24 of the 26 species breeding widely in the Arctic. This analysis was based on assuming that two rounds of surveys were conducted and that a 50% decline occurred between them. We discuss the complexity of making these estimates and why they should be viewed as first approximations.

Large-scale, high-definition Ground Penetrating Radar prospection in archaeology

Science.gov (United States)

Trinks, I.; Kucera, M.; Hinterleitner, A.; Löcker, K.; Nau, E.; Neubauer, W.; Zitz, T.

2012-04-01

The future demands on professional archaeological prospection will be its ability to cover large areas in a time and cost efficient manner with very high spatial resolution and accuracy. The objective of the 2010 in Vienna established Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology (LBI ArchPro) in collaboration with its eight European partner organisations is the advancement of state-of-the-art archaeological sciences. The application and specific further development of remote sensing, geophysical prospection and virtual reality applications, as well as of novel integrated interpretation approaches dedicated to non-invasive spatial archaeology combining near-surface prospection methods with advanced computer science is crucial for modern archaeology. Within the institute's research programme different areas for distinct case studies in Austria, Germany, Norway, Sweden and the UK have been selected as basis for the development and testing of new concepts for efficient and universally applicable tools for spatial, non-invasive archaeology. In terms of geophysical prospection the investigation of entire archaeological landscapes for the exploration and protection of Europe's buried cultural heritage requires new measurement devices, which are fast, accurate and precise. Therefore the further development of motorized, multichannel survey systems and advanced navigation solutions is required. The use of motorized measurement devices for archaeological prospection implicates several technological and methodological challenges. Latest multichannel Ground Penetrating Radar (GPR) arrays mounted in front off, or towed behind motorized survey vehicles permit large-scale GPR prospection surveys with unprecedented spatial resolution. In particular the motorized 16 channel 400 MHz MALÅ Imaging Radar Array (MIRA) used by the LBI ArchPro in combination with latest automatic data positioning and navigation solutions permits the reliable high

Thermal power generation projects ``Large Scale Solar Heating``; EU-Thermie-Projekte ``Large Scale Solar Heating``

Energy Technology Data Exchange (ETDEWEB)

Kuebler, R.; Fisch, M.N. [Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik, Stuttgart (Germany)

1998-12-31

The aim of this project is the preparation of the ``Large-Scale Solar Heating`` programme for an Europe-wide development of subject technology. The following demonstration programme was judged well by the experts but was not immediately (1996) accepted for financial subsidies. In November 1997 the EU-commission provided 1,5 million ECU which allowed the realisation of an updated project proposal. By mid 1997 a small project was approved, that had been requested under the lead of Chalmes Industriteteknik (CIT) in Sweden and is mainly carried out for the transfer of technology. (orig.) [Deutsch] Ziel dieses Vorhabens ist die Vorbereitung eines Schwerpunktprogramms `Large Scale Solar Heating`, mit dem die Technologie europaweit weiterentwickelt werden sollte. Das daraus entwickelte Demonstrationsprogramm wurde von den Gutachtern positiv bewertet, konnte jedoch nicht auf Anhieb (1996) in die Foerderung aufgenommen werden. Im November 1997 wurden von der EU-Kommission dann kurzfristig noch 1,5 Mio ECU an Foerderung bewilligt, mit denen ein aktualisierter Projektvorschlag realisiert werden kann. Bereits Mitte 1997 wurde ein kleineres Vorhaben bewilligt, das unter Federfuehrung von Chalmers Industriteknik (CIT) in Schweden beantragt worden war und das vor allem dem Technologietransfer dient. (orig.)

Re-thinking china's densified biomass fuel policies: Large or small scale?

International Nuclear Information System (INIS)

Shan, Ming; Li, Dingkai; Jiang, Yi; Yang, Xudong

2016-01-01

Current policies and strategies related to the utilization of densified biomass fuel (DBF) in China are mainly focused on medium- or large-scale manufacturing modes, which cannot provide feasible solutions to solve the household energy problems in China's rural areas. To simplify commercial processes related to the collection of DBF feedstock and the production and utilization of fuel, a novel village-scale DBF approach is proposed. Pilot demonstration projects have shown the feasibility and flexibility of this new approach in realizing sustainable development in rural China. Effective utilization of DBF in rural China will lead to gains for global, regional, and local energy savings, environmental protection, sustainable development, and related social benefits. It could also benefit other developing countries for better utilization of biomass as a viable household energy source. This proposal therefore delivers the possibility of reciprocal gains, and as such deserves the attention of policy makers and various stakeholders. - Highlights: •A field survey of Chinese densified biomass fuel (DBF) development is conducted. •The current situation and problems related to China's DBF industry are analyzed. •A novel and viable village-scale DBF utilization mode is proposed. •Further actions are suggested to boost the utilization of DBF in rural China.

Seismic texture and amplitude analysis of large scale fluid escape pipes using time lapses seismic surveys: examples from the Loyal Field (Scotland, UK)

Science.gov (United States)

Maestrelli, Daniele; Jihad, Ali; Iacopini, David; Bond, Clare

2016-04-01

Fluid escape pipes are key features of primary interest for the analysis of vertical fluid flow and secondary hydrocarbon migration in sedimentary basin. Identified worldwide (Løset et al., 2009), they acquired more and more importance as they represent critical pathways for supply of methane and potential structure for leakage into the storage reservoir (Cartwright & Santamarina, 2015). Therefore, understanding their genesis, internal characteristics and seismic expression, is of great significance for the exploration industry. Here we propose a detailed characterization of the internal seismic texture of some seal bypass system (e.g fluid escape pipes) from a 4D seismic survey (released by the BP) recently acquired in the Loyal Field. The seal by pass structure are characterized by big-scale fluid escape pipes affecting the Upper Paleogene/Neogene stratigraphic succession in the Loyal Field, Scotland (UK). The Loyal field, is located on the edge of the Faroe-Shetland Channel slope, about 130 km west of Shetland (Quadrants 204/205 of the UKCS) and has been recently re-appraised and re developed by a consortium led by BP. The 3D detailed mapping analysis of the full and partial stack survey (processed using amplitude preservation workflows) shows a complex system of fluid pipe structure rooted in the pre Lista formation and developed across the paleogene and Neogene Units. Geometrical analysis show that pipes got diameter varying between 100-300 m and a length of 500 m to 2 km. Most pipes seem to terminate abruptly at discrete subsurface horizons or in diffuse termination suggesting multiple overpressured events and lateral fluid migration (through Darcy flows) across the overburden units. The internal texture analysis of the large pipes, (across both the root and main conduit zones), using near, medium and far offset stack dataset (processed through an amplitude preserved PSTM workflow) shows a tendency of up-bending of reflection (rather than pulls up artefacts

Large-scale filaments associated with Milky Way spiral arms

Science.gov (United States)

Wang, Ke; Testi, Leonardo; Ginsburg, Adam; Walmsley, C. Malcolm; Molinari, Sergio; Schisano, Eugenio

2015-07-01

The ubiquity of filamentary structure at various scales throughout the Galaxy has triggered a renewed interest in their formation, evolution, and role in star formation. The largest filaments can reach up to Galactic scale as part of the spiral arm structure. However, such large-scale filaments are hard to identify systematically due to limitations in identifying methodology (i.e. as extinction features). We present a new approach to directly search for the largest, coldest, and densest filaments in the Galaxy, making use of sensitive Herschel Hi-GAL (Herschel Infrared Galactic Plane Survey) data complemented by spectral line cubes. We present a sample of the nine most prominent Herschel filaments, including six identified from a pilot search field plus three from outside the field. These filaments measure 37-99 pc long and 0.6-3.0 pc wide with masses (0.5-8.3) × 104 M⊙, and beam-averaged (28 arcsec, or 0.4-0.7 pc) peak H2 column densities of (1.7-9.3)× 1022 cm- 2. The bulk of the filaments are relatively cold (17-21 K), while some local clumps have a dust temperature up to 25-47 K. All the filaments are located within ≲60 pc from the Galactic mid-plane. Comparing the filaments to a recent spiral arm model incorporating the latest parallax measurements, we find that 7/9 of them reside within arms, but most are close to arm edges. These filaments are comparable in length to the Galactic scaleheight and therefore are not simply part of a grander turbulent cascade.

Large-scale retrieval for medical image analytics: A comprehensive review.

Science.gov (United States)

Li, Zhongyu; Zhang, Xiaofan; Müller, Henning; Zhang, Shaoting

2018-01-01

Over the past decades, medical image analytics was greatly facilitated by the explosion of digital imaging techniques, where huge amounts of medical images were produced with ever-increasing quality and diversity. However, conventional methods for analyzing medical images have achieved limited success, as they are not capable to tackle the huge amount of image data. In this paper, we review state-of-the-art approaches for large-scale medical image analysis, which are mainly based on recent advances in computer vision, machine learning and information retrieval. Specifically, we first present the general pipeline of large-scale retrieval, summarize the challenges/opportunities of medical image analytics on a large-scale. Then, we provide a comprehensive review of algorithms and techniques relevant to major processes in the pipeline, including feature representation, feature indexing, searching, etc. On the basis of existing work, we introduce the evaluation protocols and multiple applications of large-scale medical image retrieval, with a variety of exploratory and diagnostic scenarios. Finally, we discuss future directions of large-scale retrieval, which can further improve the performance of medical image analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Photorealistic large-scale urban city model reconstruction.

Science.gov (United States)

Poullis, Charalambos; You, Suya

2009-01-01

The rapid and efficient creation of virtual environments has become a crucial part of virtual reality applications. In particular, civil and defense applications often require and employ detailed models of operations areas for training, simulations of different scenarios, planning for natural or man-made events, monitoring, surveillance, games, and films. A realistic representation of the large-scale environments is therefore imperative for the success of such applications since it increases the immersive experience of its users and helps reduce the difference between physical and virtual reality. However, the task of creating such large-scale virtual environments still remains a time-consuming and manual work. In this work, we propose a novel method for the rapid reconstruction of photorealistic large-scale virtual environments. First, a novel, extendible, parameterized geometric primitive is presented for the automatic building identification and reconstruction of building structures. In addition, buildings with complex roofs containing complex linear and nonlinear surfaces are reconstructed interactively using a linear polygonal and a nonlinear primitive, respectively. Second, we present a rendering pipeline for the composition of photorealistic textures, which unlike existing techniques, can recover missing or occluded texture information by integrating multiple information captured from different optical sensors (ground, aerial, and satellite).

Prototype Vector Machine for Large Scale Semi-Supervised Learning

Energy Technology Data Exchange (ETDEWEB)

Zhang, Kai; Kwok, James T.; Parvin, Bahram

2009-04-29

Practicaldataminingrarelyfalls exactlyinto the supervisedlearning scenario. Rather, the growing amount of unlabeled data poses a big challenge to large-scale semi-supervised learning (SSL). We note that the computationalintensivenessofgraph-based SSLarises largely from the manifold or graph regularization, which in turn lead to large models that are dificult to handle. To alleviate this, we proposed the prototype vector machine (PVM), a highlyscalable,graph-based algorithm for large-scale SSL. Our key innovation is the use of"prototypes vectors" for effcient approximation on both the graph-based regularizer and model representation. The choice of prototypes are grounded upon two important criteria: they not only perform effective low-rank approximation of the kernel matrix, but also span a model suffering the minimum information loss compared with the complete model. We demonstrate encouraging performance and appealing scaling properties of the PVM on a number of machine learning benchmark data sets.

Research on the Application of Rapid Surveying and Mapping for Large Scare Topographic Map by Uav Aerial Photography System

Science.gov (United States)

Gao, Z.; Song, Y.; Li, C.; Zeng, F.; Wang, F.

2017-08-01

Rapid acquisition and processing method of large scale topographic map data, which relies on the Unmanned Aerial Vehicle (UAV) low-altitude aerial photogrammetry system, is studied in this paper, elaborating the main work flow. Key technologies of UAV photograph mapping is also studied, developing a rapid mapping system based on electronic plate mapping system, thus changing the traditional mapping mode and greatly improving the efficiency of the mapping. Production test and achievement precision evaluation of Digital Orth photo Map (DOM), Digital Line Graphic (DLG) and other digital production were carried out combined with the city basic topographic map update project, which provides a new techniques for large scale rapid surveying and has obvious technical advantage and good application prospect.

Large-area Soil Moisture Surveys Using a Cosmic-ray Rover: Approaches and Results from Australia

Science.gov (United States)

Hawdon, A. A.; McJannet, D. L.; Renzullo, L. J.; Baker, B.; Searle, R.

2017-12-01

Recent improvements in satellite instrumentation has increased the resolution and frequency of soil moisture observations, and this in turn has supported the development of higher resolution land surface process models. Calibration and validation of these products is restricted by the mismatch of scales between remotely sensed and contemporary ground based observations. Although the cosmic ray neutron soil moisture probe can provide estimates soil moisture at a scale useful for the calibration and validation purposes, it is spatially limited to a single, fixed location. This scaling issue has been addressed with the development of mobile soil moisture monitoring systems that utilizes the cosmic ray neutron method, typically referred to as a `rover'. This manuscript describes a project designed to develop approaches for undertaking rover surveys to produce soil moisture estimates at scales comparable to satellite observations and land surface process models. A custom designed, trailer-mounted rover was used to conduct repeat surveys at two scales in the Mallee region of Victoria, Australia. A broad scale survey was conducted at 36 x 36 km covering an area of a standard SMAP pixel and an intensive scale survey was conducted over a 10 x 10 km portion of the broad scale survey, which is at a scale equivalent to that used for national water balance modelling. We will describe the design of the rover, the methods used for converting neutron counts into soil moisture and discuss factors controlling soil moisture variability. We found that the intensive scale rover surveys produced reliable soil moisture estimates at 1 km resolution and the broad scale at 9 km resolution. We conclude that these products are well suited for future analysis of satellite soil moisture retrievals and finer scale soil moisture models.

Minimizing the stochasticity of halos in large-scale structure surveys

Science.gov (United States)

Hamaus, Nico; Seljak, Uroš; Desjacques, Vincent; Smith, Robert E.; Baldauf, Tobias

2010-08-01

In recent work (Seljak, Hamaus, and Desjacques 2009) it was found that weighting central halo galaxies by halo mass can significantly suppress their stochasticity relative to the dark matter, well below the Poisson model expectation. This is useful for constraining relations between galaxies and the dark matter, such as the galaxy bias, especially in situations where sampling variance errors can be eliminated. In this paper we extend this study with the goal of finding the optimal mass-dependent halo weighting. We use N-body simulations to perform a general analysis of halo stochasticity and its dependence on halo mass. We investigate the stochasticity matrix, defined as Cij≡⟨(δi-biδm)(δj-bjδm)⟩, where δm is the dark matter overdensity in Fourier space, δi the halo overdensity of the i-th halo mass bin, and bi the corresponding halo bias. In contrast to the Poisson model predictions we detect nonvanishing correlations between different mass bins. We also find the diagonal terms to be sub-Poissonian for the highest-mass halos. The diagonalization of this matrix results in one large and one low eigenvalue, with the remaining eigenvalues close to the Poisson prediction 1/n¯, where n¯ is the mean halo number density. The eigenmode with the lowest eigenvalue contains most of the information and the corresponding eigenvector provides an optimal weighting function to minimize the stochasticity between halos and dark matter. We find this optimal weighting function to match linear mass weighting at high masses, while at the low-mass end the weights approach a constant whose value depends on the low-mass cut in the halo mass function. This weighting further suppresses the stochasticity as compared to the previously explored mass weighting. Finally, we employ the halo model to derive the stochasticity matrix and the scale-dependent bias from an analytical perspective. It is remarkably successful in reproducing our numerical results and predicts that the

Red Geyser: A New Class of Galaxy with Large-scale AGN-driven Winds

Science.gov (United States)

Roy, Namrata; Bundy, Kevin; Cheung, Edmond; MaNGA Team

2018-01-01

A new class of quiescent (non-star-forming) galaxies harboring possible AGN-driven winds have been discovered using the spatially resolved optical spectroscopy from the ongoing SDSS-IV MaNGA (Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory) survey. These galaxies named "red geysers" constitute 5%-10% of the local quiescent galaxy population and are characterized by narrow bisymmetric ionized gas emission patterns. These enhanced patterns are seen in equivalent width maps of Hα, [OIII] and other strong emission lines. They are co-aligned with the ionized gas velocity gradients but significantly misaligned with stellar velocity gradients. They also show very high gas velocity dispersions (~200 km/s). Considering these observations in light of models of the gravitational potential, Cheung et al. argued that red geysers host large-scale AGN-driven winds of ionized gas that may play a role in suppressing star formation at late times. In this work, we test the hypothesis that AGN activity is ultimately responsible for the red geyser phenomenon. We compare the nuclear radio activity of the red geysers to a matched control sample of galaxies of similar stellar mass, redshift, rest frame NUV–r color and axis ratio. and additionally, control for the presence of ionized gas. We have used 1.4 GHz radio continuum data from the VLA FIRST Survey to stack the radio flux from the red geyser sample and control sample. We find that the red geysers have a higher average radio flux than the control galaxies at > 3σ significance. Our sample is restricted to rest-frame NUV–r color > 5, thus ruling out possible radio emission due to star formation activity. We conclude that red geysers are associated with more active AGN, supporting a feedback picture in which episodic AGN activity drives large-scale but relatively weak ionized winds in many in many early-type galaxies.

Large-Scale Survey Findings Inform Patients’ Experiences in Using Secure Messaging to Engage in Patient-Provider Communication and Self-Care Management: A Quantitative Assessment

Science.gov (United States)

Patel, Nitin R; Lind, Jason D; Antinori, Nicole

2015-01-01

Background Secure email messaging is part of a national transformation initiative in the United States to promote new models of care that support enhanced patient-provider communication. To date, only a limited number of large-scale studies have evaluated users’ experiences in using secure email messaging. Objective To quantitatively assess veteran patients’ experiences in using secure email messaging in a large patient sample. Methods A cross-sectional mail-delivered paper-and-pencil survey study was conducted with a sample of respondents identified as registered for the Veteran Health Administrations’ Web-based patient portal (My HealtheVet) and opted to use secure messaging. The survey collected demographic data, assessed computer and health literacy, and secure messaging use. Analyses conducted on survey data include frequencies and proportions, chi-square tests, and one-way analysis of variance. Results The majority of respondents (N=819) reported using secure messaging 6 months or longer (n=499, 60.9%). They reported secure messaging to be helpful for completing medication refills (n=546, 66.7%), managing appointments (n=343, 41.9%), looking up test results (n=350, 42.7%), and asking health-related questions (n=340, 41.5%). Notably, some respondents reported using secure messaging to address sensitive health topics (n=67, 8.2%). Survey responses indicated that younger age (P=.039) and higher levels of education (P=.025) and income (P=.003) were associated with more frequent use of secure messaging. Females were more likely to report using secure messaging more often, compared with their male counterparts (P=.098). Minorities were more likely to report using secure messaging more often, at least once a month, compared with nonminorities (P=.086). Individuals with higher levels of health literacy reported more frequent use of secure messaging (P=.007), greater satisfaction (P=.002), and indicated that secure messaging is a useful (P=.002) and easy

Large-Scale Survey Findings Inform Patients' Experiences in Using Secure Messaging to Engage in Patient-Provider Communication and Self-Care Management: A Quantitative Assessment.

Science.gov (United States)

Haun, Jolie N; Patel, Nitin R; Lind, Jason D; Antinori, Nicole

2015-12-21

Secure email messaging is part of a national transformation initiative in the United States to promote new models of care that support enhanced patient-provider communication. To date, only a limited number of large-scale studies have evaluated users' experiences in using secure email messaging. To quantitatively assess veteran patients' experiences in using secure email messaging in a large patient sample. A cross-sectional mail-delivered paper-and-pencil survey study was conducted with a sample of respondents identified as registered for the Veteran Health Administrations' Web-based patient portal (My HealtheVet) and opted to use secure messaging. The survey collected demographic data, assessed computer and health literacy, and secure messaging use. Analyses conducted on survey data include frequencies and proportions, chi-square tests, and one-way analysis of variance. The majority of respondents (N=819) reported using secure messaging 6 months or longer (n=499, 60.9%). They reported secure messaging to be helpful for completing medication refills (n=546, 66.7%), managing appointments (n=343, 41.9%), looking up test results (n=350, 42.7%), and asking health-related questions (n=340, 41.5%). Notably, some respondents reported using secure messaging to address sensitive health topics (n=67, 8.2%). Survey responses indicated that younger age (P=.039) and higher levels of education (P=.025) and income (P=.003) were associated with more frequent use of secure messaging. Females were more likely to report using secure messaging more often, compared with their male counterparts (P=.098). Minorities were more likely to report using secure messaging more often, at least once a month, compared with nonminorities (P=.086). Individuals with higher levels of health literacy reported more frequent use of secure messaging (P=.007), greater satisfaction (P=.002), and indicated that secure messaging is a useful (P=.002) and easy-to-use (P≤.001) communication tool, compared

Connecting the small scale to the large scale: young massive stars and their environments from the Red MSX Source Survey.

Science.gov (United States)

Figura, Charles C.; Urquhart, James S.; Morgan, Lawrence

2015-01-01

We have conducted a detailed multi-wavelength investigation of a variety of massive star forming regions in order to characterise the impact of the interactions between the substructure of the dense protostellar clumps and their local environment, including feedback from the embedded proto-cluster.A selection of 70 MYSOs and HII regions identified by the RMS survey have been followed up with observations of the ammonia (1,1) and (2,2) inversion transitions made with the KFPA on the GBT. These maps have been combined with archival CO data to investigate the thermal and kinematic structure of the extended envelopes down to the dense clumps. We complement this larger-scale picture with high resolution near- and mid-infrared images to probe the properties of the embedded objects themselves.We present an overview of several sources from this sample that illustrate some of the the interactions that we observe. We find that high molecular column densities and kinetic temperatures are coincident with embedded sources and with shocks and outflows as exhibited in gas kinematics.

A large-scale study of epilepsy in Ecuador: methodological aspects.

Science.gov (United States)

Placencia, M; Suarez, J; Crespo, F; Sander, J W; Shorvon, S D; Ellison, R H; Cascante, S M

1992-01-01

The methodology is presented of a large-scale study of epilepsy carried out in a highland area in northern Ecuador, South America, covering a population of 72,121 people; The study was carried out in two phases, the first, a cross-sectional phase, consisted of a house-to-house survey of all persons in this population, screening for epileptic seizures using a specially designed questionnaire. Possible cases identified in screening were assessed in a cascade diagnostic procedure applied by general doctors and neurologists. Its objectives were: to establish a comprehensive epidemiological profile of epileptic seizures; to describe the clinical phenomenology of this condition in the community; to validate methods for diagnosis and classification of epileptic seizures by a non-specialised team; and to ascertain the community's knowledge, attitudes and practices regarding epilepsy. A sample was selected in this phase in order to study the social aspects of epilepsy in this community. The second phase, which was longitudinal, assessed the ability of non-specialist care in the treatment of epilepsy. It consisted of a prospective clinical trial of antiepileptic therapy in untreated patients using two standard anti-epileptic drugs. Patients were followed for 12 months by a multidisciplinary team consisting of a primary health worker, rural doctor, neurologist, anthropologist, and psychologist. Standardised, reproducible instruments and methods were used. This study was carried out through co-operation between the medical profession, political agencies and the pharmaceutical industry, at an international level. We consider this a model for further large-scale studies of this type.

Conducting a large, multi-site survey about patients’ views on broad consent: challenges and solutions

Directory of Open Access Journals (Sweden)

Maureen E. Smith

2016-11-01

Full Text Available Abstract Background As biobanks play an increasing role in the genomic research that will lead to precision medicine, input from diverse and large populations of patients in a variety of health care settings will be important in order to successfully carry out such studies. One important topic is participants’ views towards consent and data sharing, especially since the 2011 Advanced Notice of Proposed Rulemaking (ANPRM, and subsequently the 2015 Notice of Proposed Rulemaking (NPRM were issued by the Department of Health and Human Services (HHS and Office of Science and Technology Policy (OSTP. These notices required that participants consent to research uses of their de-identified tissue samples and most clinical data, and allowing such consent be obtained in a one-time, open-ended or “broad” fashion. Conducting a survey across multiple sites provides clear advantages to either a single site survey or using a large online database, and is a potentially powerful way of understanding the views of diverse populations on this topic. Methods A workgroup of the Electronic Medical Records and Genomics (eMERGE Network, a national consortium of 9 sites (13 separate institutions, 11 clinical centers supported by the National Human Genome Research Institute (NHGRI that combines DNA biorepositories with electronic medical record (EMR systems for large-scale genetic research, conducted a survey to understand patients’ views on consent, sample and data sharing for future research, biobank governance, data protection, and return of research results. Results Working across 9 sites to design and conduct a national survey presented challenges in organization, meeting human subjects guidelines at each institution, and survey development and implementation. The challenges were met through a committee structure to address each aspect of the project with representatives from all sites. Each committee’s output was integrated into the overall survey plan. A

Recent Progress in Large-Scale Structure

CERN Multimedia

CERN. Geneva

2014-01-01

I will discuss recent progress in the understanding of how to model galaxy clustering. While recent analyses have focussed on the baryon acoustic oscillations as a probe of cosmology, galaxy redshift surveys contain a lot more information than the acoustic scale. In extracting this additional information three main issues need to be well understood: nonlinear evolution of matter fluctuations, galaxy bias and redshift-space distortions. I will present recent progress in modeling these three effects that pave the way to constraining cosmology and galaxy formation with increased precision.

Reconstructing Information in Large-Scale Structure via Logarithmic Mapping

Science.gov (United States)

Szapudi, Istvan

We propose to develop a new method to extract information from large-scale structure data combining two-point statistics and non-linear transformations; before, this information was available only with substantially more complex higher-order statistical methods. Initially, most of the cosmological information in large-scale structure lies in two-point statistics. With non- linear evolution, some of that useful information leaks into higher-order statistics. The PI and group has shown in a series of theoretical investigations how that leakage occurs, and explained the Fisher information plateau at smaller scales. This plateau means that even as more modes are added to the measurement of the power spectrum, the total cumulative information (loosely speaking the inverse errorbar) is not increasing. Recently we have shown in Neyrinck et al. (2009, 2010) that a logarithmic (and a related Gaussianization or Box-Cox) transformation on the non-linear Dark Matter or galaxy field reconstructs a surprisingly large fraction of this missing Fisher information of the initial conditions. This was predicted by the earlier wave mechanical formulation of gravitational dynamics by Szapudi & Kaiser (2003). The present proposal is focused on working out the theoretical underpinning of the method to a point that it can be used in practice to analyze data. In particular, one needs to deal with the usual real-life issues of galaxy surveys, such as complex geometry, discrete sam- pling (Poisson or sub-Poisson noise), bias (linear, or non-linear, deterministic, or stochastic), redshift distortions, pro jection effects for 2D samples, and the effects of photometric redshift errors. We will develop methods for weak lensing and Sunyaev-Zeldovich power spectra as well, the latter specifically targetting Planck. In addition, we plan to investigate the question of residual higher- order information after the non-linear mapping, and possible applications for cosmology. Our aim will be to work out

Analyzing the cosmic variance limit of remote dipole measurements of the cosmic microwave background using the large-scale kinetic Sunyaev Zel'dovich effect

Energy Technology Data Exchange (ETDEWEB)

Terrana, Alexandra; Johnson, Matthew C. [Department of Physics and Astronomy, York University, Toronto, Ontario, M3J 1P3 (Canada); Harris, Mary-Jean, E-mail: aterrana@perimeterinstitute.ca, E-mail: mharris8@perimeterinstitute.ca, E-mail: mjohnson@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada)

2017-02-01

Due to cosmic variance we cannot learn any more about large-scale inhomogeneities from the primary cosmic microwave background (CMB) alone. More information on large scales is essential for resolving large angular scale anomalies in the CMB. Here we consider cross correlating the large-scale kinetic Sunyaev Zel'dovich (kSZ) effect and probes of large-scale structure, a technique known as kSZ tomography. The statistically anisotropic component of the cross correlation encodes the CMB dipole as seen by free electrons throughout the observable Universe, providing information about long wavelength inhomogeneities. We compute the large angular scale power asymmetry, constructing the appropriate transfer functions, and estimate the cosmic variance limited signal to noise for a variety of redshift bin configurations. The signal to noise is significant over a large range of power multipoles and numbers of bins. We present a simple mode counting argument indicating that kSZ tomography can be used to estimate more modes than the primary CMB on comparable scales. A basic forecast indicates that a first detection could be made with next-generation CMB experiments and galaxy surveys. This paper motivates a more systematic investigation of how close to the cosmic variance limit it will be possible to get with future observations.

Large Whale Biology Survey (DE9908, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The large whale biology survey primarily focuses on right whales in the coastal and continental shelf areas, with the following objectives: 1) Develop a better...

Accelerating Relevance Vector Machine for Large-Scale Data on Spark

Directory of Open Access Journals (Sweden)

Liu Fang

2017-01-01

Full Text Available Relevance vector machine (RVM is a machine learning algorithm based on a sparse Bayesian framework, which performs well when running classification and regression tasks on small-scale datasets. However, RVM also has certain drawbacks which restricts its practical applications such as (1 slow training process, (2 poor performance on training large-scale datasets. In order to solve these problem, we propose Discrete AdaBoost RVM (DAB-RVM which incorporate ensemble learning in RVM at first. This method performs well with large-scale low-dimensional datasets. However, as the number of features increases, the training time of DAB-RVM increases as well. To avoid this phenomenon, we utilize the sufficient training samples of large-scale datasets and propose all features boosting RVM (AFB-RVM, which modifies the way of obtaining weak classifiers. In our experiments we study the differences between various boosting techniques with RVM, demonstrating the performance of the proposed approaches on Spark. As a result of this paper, two proposed approaches on Spark for different types of large-scale datasets are available.

Quantum circuit implementation of cyclic mutually unbiased bases

Energy Technology Data Exchange (ETDEWEB)

Seyfarth, Ulrich; Dittmann, Niklas; Alber, Gernot [Institut fuer Angewandte Physik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany)

2013-07-01

Complete sets of mutually unbiased bases (MUBs) play an important role in the areas of quantum state tomography and quantum cryptography. Sets which can be generated cyclically may eliminate certain side-channel attacks. To profit from the advantages of these MUBs we propose a method for deriving a quantum circuit that implements the generator of a set into an experimental setup. For some dimensions this circuit is minimal. The presented method is in principle applicable for a larger set of operations and generalizes recently published results.

Characteristic properties of Fibonacci-based mutually unbiased bases

Energy Technology Data Exchange (ETDEWEB)

Seyfarth, Ulrich; Alber, Gernot [Institut fuer Angewandte Physik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Ranade, Kedar [Institut fuer Quantenphysik, Universitaet Ulm, Albert-Einstein-Allee 11, 89069 Ulm (Germany)

2012-07-01

Complete sets of mutually unbiased bases (MUBs) offer interesting applications in quantum information processing ranging from quantum cryptography to quantum state tomography. Different construction schemes provide different perspectives on these bases which are typically also deeply connected to various mathematical research areas. In this talk we discuss characteristic properties resulting from a recently established connection between construction methods for cyclic MUBs and Fibonacci polynomials. As a remarkable fact this connection leads to construction methods which do not involve any relations to mathematical properties of finite fields.

Bayesian hierarchical model for large-scale covariance matrix estimation.

Science.gov (United States)

Zhu, Dongxiao; Hero, Alfred O

2007-12-01

Many bioinformatics problems implicitly depend on estimating large-scale covariance matrix. The traditional approaches tend to give rise to high variance and low accuracy due to "overfitting." We cast the large-scale covariance matrix estimation problem into the Bayesian hierarchical model framework, and introduce dependency between covariance parameters. We demonstrate the advantages of our approaches over the traditional approaches using simulations and OMICS data analysis.

Genomic divergences among cattle, dog and human estimated from large-scale alignments of genomic sequences

Directory of Open Access Journals (Sweden)

Shade Larry L

2006-06-01

Full Text Available Abstract Background Approximately 11 Mb of finished high quality genomic sequences were sampled from cattle, dog and human to estimate genomic divergences and their regional variation among these lineages. Results Optimal three-way multi-species global sequence alignments for 84 cattle clones or loci (each >50 kb of genomic sequence were constructed using the human and dog genome assemblies as references. Genomic divergences and substitution rates were examined for each clone and for various sequence classes under different functional constraints. Analysis of these alignments revealed that the overall genomic divergences are relatively constant (0.32–0.37 change/site for pairwise comparisons among cattle, dog and human; however substitution rates vary across genomic regions and among different sequence classes. A neutral mutation rate (2.0–2.2 × 10(-9 change/site/year was derived from ancestral repetitive sequences, whereas the substitution rate in coding sequences (1.1 × 10(-9 change/site/year was approximately half of the overall rate (1.9–2.0 × 10(-9 change/site/year. Relative rate tests also indicated that cattle have a significantly faster rate of substitution as compared to dog and that this difference is about 6%. Conclusion This analysis provides a large-scale and unbiased assessment of genomic divergences and regional variation of substitution rates among cattle, dog and human. It is expected that these data will serve as a baseline for future mammalian molecular evolution studies.

Creating Large Scale Database Servers

International Nuclear Information System (INIS)

Becla, Jacek

2001-01-01

The BaBar experiment at the Stanford Linear Accelerator Center (SLAC) is designed to perform a high precision investigation of the decays of the B-meson produced from electron-positron interactions. The experiment, started in May 1999, will generate approximately 300TB/year of data for 10 years. All of the data will reside in Objectivity databases accessible via the Advanced Multi-threaded Server (AMS). To date, over 70TB of data have been placed in Objectivity/DB, making it one of the largest databases in the world. Providing access to such a large quantity of data through a database server is a daunting task. A full-scale testbed environment had to be developed to tune various software parameters and a fundamental change had to occur in the AMS architecture to allow it to scale past several hundred terabytes of data. Additionally, several protocol extensions had to be implemented to provide practical access to large quantities of data. This paper will describe the design of the database and the changes that we needed to make in the AMS for scalability reasons and how the lessons we learned would be applicable to virtually any kind of database server seeking to operate in the Petabyte region

Creating Large Scale Database Servers

Energy Technology Data Exchange (ETDEWEB)

Becla, Jacek

2001-12-14

The BaBar experiment at the Stanford Linear Accelerator Center (SLAC) is designed to perform a high precision investigation of the decays of the B-meson produced from electron-positron interactions. The experiment, started in May 1999, will generate approximately 300TB/year of data for 10 years. All of the data will reside in Objectivity databases accessible via the Advanced Multi-threaded Server (AMS). To date, over 70TB of data have been placed in Objectivity/DB, making it one of the largest databases in the world. Providing access to such a large quantity of data through a database server is a daunting task. A full-scale testbed environment had to be developed to tune various software parameters and a fundamental change had to occur in the AMS architecture to allow it to scale past several hundred terabytes of data. Additionally, several protocol extensions had to be implemented to provide practical access to large quantities of data. This paper will describe the design of the database and the changes that we needed to make in the AMS for scalability reasons and how the lessons we learned would be applicable to virtually any kind of database server seeking to operate in the Petabyte region.

Large-scale pool fires

Directory of Open Access Journals (Sweden)

Steinhaus Thomas

2007-01-01

Full Text Available A review of research into the burning behavior of large pool fires and fuel spill fires is presented. The features which distinguish such fires from smaller pool fires are mainly associated with the fire dynamics at low source Froude numbers and the radiative interaction with the fire source. In hydrocarbon fires, higher soot levels at increased diameters result in radiation blockage effects around the perimeter of large fire plumes; this yields lower emissive powers and a drastic reduction in the radiative loss fraction; whilst there are simplifying factors with these phenomena, arising from the fact that soot yield can saturate, there are other complications deriving from the intermittency of the behavior, with luminous regions of efficient combustion appearing randomly in the outer surface of the fire according the turbulent fluctuations in the fire plume. Knowledge of the fluid flow instabilities, which lead to the formation of large eddies, is also key to understanding the behavior of large-scale fires. Here modeling tools can be effectively exploited in order to investigate the fluid flow phenomena, including RANS- and LES-based computational fluid dynamics codes. The latter are well-suited to representation of the turbulent motions, but a number of challenges remain with their practical application. Massively-parallel computational resources are likely to be necessary in order to be able to adequately address the complex coupled phenomena to the level of detail that is necessary.

Modeling CMB lensing cross correlations with CLEFT

Energy Technology Data Exchange (ETDEWEB)

Modi, Chirag; White, Martin [Department of Physics, University of California, Berkeley, CA 94720 (United States); Vlah, Zvonimir, E-mail: modichirag@berkeley.edu, E-mail: mwhite@berkeley.edu, E-mail: zvlah@stanford.edu [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94306 (United States)

2017-08-01

A new generation of surveys will soon map large fractions of sky to ever greater depths and their science goals can be enhanced by exploiting cross correlations between them. In this paper we study cross correlations between the lensing of the CMB and biased tracers of large-scale structure at high z . We motivate the need for more sophisticated bias models for modeling increasingly biased tracers at these redshifts and propose the use of perturbation theories, specifically Convolution Lagrangian Effective Field Theory (CLEFT). Since such signals reside at large scales and redshifts, they can be well described by perturbative approaches. We compare our model with the current approach of using scale independent bias coupled with fitting functions for non-linear matter power spectra, showing that the latter will not be sufficient for upcoming surveys. We illustrate our ideas by estimating σ{sub 8} from the auto- and cross-spectra of mock surveys, finding that CLEFT returns accurate and unbiased results at high z . We discuss uncertainties due to the redshift distribution of the tracers, and several avenues for future development.

Decentralised stabilising controllers for a class of large-scale linear ...

Indian Academy of Sciences (India)

subsystems resulting from a new aggregation-decomposition technique. The method has been illustrated through a numerical example of a large-scale linear system consisting of three subsystems each of the fourth order. Keywords. Decentralised stabilisation; large-scale linear systems; optimal feedback control; algebraic ...

Self-Report Measures of the Home Learning Environment in Large Scale Research: Measurement Properties and Associations with Key Developmental Outcomes

Science.gov (United States)

Niklas, Frank; Nguyen, Cuc; Cloney, Daniel S.; Tayler, Collette; Adams, Raymond

2016-01-01

Favourable home learning environments (HLEs) support children's literacy, numeracy and social development. In large-scale research, HLE is typically measured by self-report survey, but there is little consistency between studies and many different items and latent constructs are observed. Little is known about the stability of these items and…

Similitude and scaling of large structural elements: Case study

Directory of Open Access Journals (Sweden)

M. Shehadeh

2015-06-01

Full Text Available Scaled down models are widely used for experimental investigations of large structures due to the limitation in the capacities of testing facilities along with the expenses of the experimentation. The modeling accuracy depends upon the model material properties, fabrication accuracy and loading techniques. In the present work the Buckingham π theorem is used to develop the relations (i.e. geometry, loading and properties between the model and a large structural element as that is present in the huge existing petroleum oil drilling rigs. The model is to be designed, loaded and treated according to a set of similitude requirements that relate the model to the large structural element. Three independent scale factors which represent three fundamental dimensions, namely mass, length and time need to be selected for designing the scaled down model. Numerical prediction of the stress distribution within the model and its elastic deformation under steady loading is to be made. The results are compared with those obtained from the full scale structure numerical computations. The effect of scaled down model size and material on the accuracy of the modeling technique is thoroughly examined.

Large-scale preparation of hollow graphitic carbon nanospheres

Energy Technology Data Exchange (ETDEWEB)

Feng, Jun; Li, Fu [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Bai, Yu-Jun, E-mail: byj97@126.com [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); State Key laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Han, Fu-Dong; Qi, Yong-Xin; Lun, Ning [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Lu, Xi-Feng [Lunan Institute of Coal Chemical Engineering, Jining 272000 (China)

2013-01-15

Hollow graphitic carbon nanospheres (HGCNSs) were synthesized on large scale by a simple reaction between glucose and Mg at 550 Degree-Sign C in an autoclave. Characterization by X-ray diffraction, Raman spectroscopy and transmission electron microscopy demonstrates the formation of HGCNSs with an average diameter of 10 nm or so and a wall thickness of a few graphenes. The HGCNSs exhibit a reversible capacity of 391 mAh g{sup -1} after 60 cycles when used as anode materials for Li-ion batteries. -- Graphical abstract: Hollow graphitic carbon nanospheres could be prepared on large scale by the simple reaction between glucose and Mg at 550 Degree-Sign C, which exhibit superior electrochemical performance to graphite. Highlights: Black-Right-Pointing-Pointer Hollow graphitic carbon nanospheres (HGCNSs) were prepared on large scale at 550 Degree-Sign C Black-Right-Pointing-Pointer The preparation is simple, effective and eco-friendly. Black-Right-Pointing-Pointer The in situ yielded MgO nanocrystals promote the graphitization. Black-Right-Pointing-Pointer The HGCNSs exhibit superior electrochemical performance to graphite.

Large-scale impact cratering on the terrestrial planets

International Nuclear Information System (INIS)

Grieve, R.A.F.

1982-01-01

The crater densities on the earth and moon form the basis for a standard flux-time curve that can be used in dating unsampled planetary surfaces and constraining the temporal history of endogenic geologic processes. Abundant evidence is seen not only that impact cratering was an important surface process in planetary history but also that large imapact events produced effects that were crucial in scale. By way of example, it is noted that the formation of multiring basins on the early moon was as important in defining the planetary tectonic framework as plate tectonics is on the earth. Evidence from several planets suggests that the effects of very-large-scale impacts go beyond the simple formation of an impact structure and serve to localize increased endogenic activity over an extended period of geologic time. Even though no longer occurring with the frequency and magnitude of early solar system history, it is noted that large scale impact events continue to affect the local geology of the planets. 92 references

Optical interconnect for large-scale systems

Science.gov (United States)

Dress, William

2013-02-01

This paper presents a switchless, optical interconnect module that serves as a node in a network of identical distribution modules for large-scale systems. Thousands to millions of hosts or endpoints may be interconnected by a network of such modules, avoiding the need for multi-level switches. Several common network topologies are reviewed and their scaling properties assessed. The concept of message-flow routing is discussed in conjunction with the unique properties enabled by the optical distribution module where it is shown how top-down software control (global routing tables, spanning-tree algorithms) may be avoided.

Relationships between aquatic vegetation and water turbidity: A field survey across seasons and spatial scales.

Science.gov (United States)

Austin, Åsa N; Hansen, Joakim P; Donadi, Serena; Eklöf, Johan S

2017-01-01

Field surveys often show that high water turbidity limits cover of aquatic vegetation, while many small-scale experiments show that vegetation can reduce turbidity by decreasing water flow, stabilizing sediments, and competing with phytoplankton for nutrients. Here we bridged these two views by exploring the direction and strength of causal relationships between aquatic vegetation and turbidity across seasons (spring and late summer) and spatial scales (local and regional), using causal modeling based on data from a field survey along the central Swedish Baltic Sea coast. The two best-fitting regional-scale models both suggested that in spring, high cover of vegetation reduces water turbidity. In summer, the relationships differed between the two models; in the first model high vegetation cover reduced turbidity; while in the second model reduction of summer turbidity by high vegetation cover in spring had a positive effect on summer vegetation which suggests a positive feedback of vegetation on itself. Nitrogen load had a positive effect on turbidity in both seasons, which was comparable in strength to the effect of vegetation on turbidity. To assess whether the effect of vegetation was primarily caused by sediment stabilization or a reduction of phytoplankton, we also tested models where turbidity was replaced by phytoplankton fluorescence or sediment-driven turbidity. The best-fitting regional-scale models suggested that high sediment-driven turbidity in spring reduces vegetation cover in summer, which in turn has a negative effect on sediment-driven turbidity in summer, indicating a potential positive feedback of sediment-driven turbidity on itself. Using data at the local scale, few relationships were significant, likely due to the influence of unmeasured variables and/or spatial heterogeneity. In summary, causal modeling based on data from a large-scale field survey suggested that aquatic vegetation can reduce turbidity at regional scales, and that high

Relationships between aquatic vegetation and water turbidity: A field survey across seasons and spatial scales.

Directory of Open Access Journals (Sweden)

Åsa N Austin

Full Text Available Field surveys often show that high water turbidity limits cover of aquatic vegetation, while many small-scale experiments show that vegetation can reduce turbidity by decreasing water flow, stabilizing sediments, and competing with phytoplankton for nutrients. Here we bridged these two views by exploring the direction and strength of causal relationships between aquatic vegetation and turbidity across seasons (spring and late summer and spatial scales (local and regional, using causal modeling based on data from a field survey along the central Swedish Baltic Sea coast. The two best-fitting regional-scale models both suggested that in spring, high cover of vegetation reduces water turbidity. In summer, the relationships differed between the two models; in the first model high vegetation cover reduced turbidity; while in the second model reduction of summer turbidity by high vegetation cover in spring had a positive effect on summer vegetation which suggests a positive feedback of vegetation on itself. Nitrogen load had a positive effect on turbidity in both seasons, which was comparable in strength to the effect of vegetation on turbidity. To assess whether the effect of vegetation was primarily caused by sediment stabilization or a reduction of phytoplankton, we also tested models where turbidity was replaced by phytoplankton fluorescence or sediment-driven turbidity. The best-fitting regional-scale models suggested that high sediment-driven turbidity in spring reduces vegetation cover in summer, which in turn has a negative effect on sediment-driven turbidity in summer, indicating a potential positive feedback of sediment-driven turbidity on itself. Using data at the local scale, few relationships were significant, likely due to the influence of unmeasured variables and/or spatial heterogeneity. In summary, causal modeling based on data from a large-scale field survey suggested that aquatic vegetation can reduce turbidity at regional scales

Effects of baryons on the statistical properties of large scale structure of the Universe

International Nuclear Information System (INIS)

Guillet, T.

2010-01-01

Observations of weak gravitational lensing will provide strong constraints on the cosmic expansion history and the growth rate of large scale structure, yielding clues to the properties and nature of dark energy. Their interpretation is impacted by baryonic physics, which are expected to modify the total matter distribution at small scales. My work has focused on determining and modeling the impact of baryons on the statistics of the large scale matter distribution in the Universe. Using numerical simulations, I have extracted the effect of baryons on the power spectrum, variance and skewness of the total density field as predicted by these simulations. I have shown that a model based on the halo model construction, featuring a concentrated central component to account for cool condensed baryons, is able to reproduce accurately, and down to very small scales, the measured amplifications of both the variance and skewness of the density field. Because of well-known issues with baryons in current cosmological simulations, I have extended the central component model to rely on as many observation-based ingredients as possible. As an application, I have studied the effect of baryons on the predictions of the upcoming Euclid weak lensing survey. During the course of this work, I have also worked at developing and extending the RAMSES code, in particular by developing a parallel self-gravity solver, which offers significant performance gains, in particular for the simulation of some astrophysical setups such as isolated galaxy or cluster simulations. (author) [fr

Triangulation based inclusion probabilities: a design-unbiased sampling approach

OpenAIRE

Fehrmann, Lutz; Gregoire, Timothy; Kleinn, Christoph

2011-01-01

A probabilistic sampling approach for design-unbiased estimation of area-related quantitative characteristics of spatially dispersed population units is proposed. The developed field protocol includes a fixed number of 3 units per sampling location and is based on partial triangulations over their natural neighbors to derive the individual inclusion probabilities. The performance of the proposed design is tested in comparison to fixed area sample plots in a simulation with two forest stands. ...

[A large-scale accident in Alpine terrain].

Science.gov (United States)

Wildner, M; Paal, P

2015-02-01

Due to the geographical conditions, large-scale accidents amounting to mass casualty incidents (MCI) in Alpine terrain regularly present rescue teams with huge challenges. Using an example incident, specific conditions and typical problems associated with such a situation are presented. The first rescue team members to arrive have the elementary tasks of qualified triage and communication to the control room, which is required to dispatch the necessary additional support. Only with a clear "concept", to which all have to adhere, can the subsequent chaos phase be limited. In this respect, a time factor confounded by adverse weather conditions or darkness represents enormous pressure. Additional hazards are frostbite and hypothermia. If priorities can be established in terms of urgency, then treatment and procedure algorithms have proven successful. For evacuation of causalities, a helicopter should be strived for. Due to the low density of hospitals in Alpine regions, it is often necessary to distribute the patients over a wide area. Rescue operations in Alpine terrain have to be performed according to the particular conditions and require rescue teams to have specific knowledge and expertise. The possibility of a large-scale accident should be considered when planning events. With respect to optimization of rescue measures, regular training and exercises are rational, as is the analysis of previous large-scale Alpine accidents.

Hierarchical Cantor set in the large scale structure with torus geometry

Energy Technology Data Exchange (ETDEWEB)

Murdzek, R. [Physics Department, ' Al. I. Cuza' University, Blvd. Carol I, Nr. 11, Iassy 700506 (Romania)], E-mail: rmurdzek@yahoo.com

2008-12-15

The formation of large scale structures is considered within a model with string on toroidal space-time. Firstly, the space-time geometry is presented. In this geometry, the Universe is represented by a string describing a torus surface. Thereafter, the large scale structure of the Universe is derived from the string oscillations. The results are in agreement with the cellular structure of the large scale distribution and with the theory of a Cantorian space-time.

Large-scale clustering of galaxies in the CfA Redshift Survey

Science.gov (United States)

Vogeley, Michael S.; Park, Changbom; Geller, Margaret J.; Huchra, John P.

1992-01-01

The power spectrum of the galaxy distribution in the Center for Astrophysics Redshift Survey (de Lapparent et al., 1986; Geller and Huchra, 1989; and Huchra et al., 1992) is measured up to wavelengths of 200/h Mpc. Results are compared with several cosmological simulations with Gaussian initial conditions. It is shown that the power spectrum of the standard CDM model is inconsistent with the observed power spectrum at the 99 percent confidence level.

Large-scale Motion of Solar Filaments

Indian Academy of Sciences (India)

tribpo

Large-scale Motion of Solar Filaments. Pavel Ambrož, Astronomical Institute of the Acad. Sci. of the Czech Republic, CZ-25165. Ondrejov, The Czech Republic. e-mail: pambroz@asu.cas.cz. Alfred Schroll, Kanzelhöehe Solar Observatory of the University of Graz, A-9521 Treffen,. Austria. e-mail: schroll@solobskh.ac.at.

Sensitivity analysis for large-scale problems

Science.gov (United States)

Noor, Ahmed K.; Whitworth, Sandra L.

1987-01-01

The development of efficient techniques for calculating sensitivity derivatives is studied. The objective is to present a computational procedure for calculating sensitivity derivatives as part of performing structural reanalysis for large-scale problems. The scope is limited to framed type structures. Both linear static analysis and free-vibration eigenvalue problems are considered.

Topology Optimization of Large Scale Stokes Flow Problems

DEFF Research Database (Denmark)

Aage, Niels; Poulsen, Thomas Harpsøe; Gersborg-Hansen, Allan

2008-01-01

This note considers topology optimization of large scale 2D and 3D Stokes flow problems using parallel computations. We solve problems with up to 1.125.000 elements in 2D and 128.000 elements in 3D on a shared memory computer consisting of Sun UltraSparc IV CPUs.......This note considers topology optimization of large scale 2D and 3D Stokes flow problems using parallel computations. We solve problems with up to 1.125.000 elements in 2D and 128.000 elements in 3D on a shared memory computer consisting of Sun UltraSparc IV CPUs....

The Big Drink Debate: perceptions of the impact of price on alcohol consumption from a large scale cross-sectional convenience survey in north west England.

Science.gov (United States)

Cook, Penny A; Phillips-Howard, Penelope A; Morleo, Michela; Harkins, Corinne; Briant, Linford; Bellis, Mark A

2011-08-23

A large-scale survey was conducted in 2008 in north west England, a region with high levels of alcohol-related harm, during a regional 'Big Drink Debate' campaign. The aim of this paper is to explore perceptions of how alcohol consumption would change if alcohol prices were to increase or decrease. A convenience survey of residents (≥ 18 years) of north west England measured demographics, income, alcohol consumption in previous week, and opinions on drinking behaviour under two pricing conditions: low prices and discounts and increased alcohol prices (either 'decrease', 'no change' or 'increase'). Multinomial logistic regression used three outcomes: 'completely elastic' (consider that lower prices increase drinking and higher prices decrease drinking); 'lower price elastic' (lower prices increase drinking, higher prices have no effect); and 'price inelastic' (no change for either). Of 22,780 drinkers surveyed, 80.3% considered lower alcohol prices and discounts would increase alcohol consumption, while 22.1% thought raising prices would decrease consumption, making lower price elasticity only (i.e. lower prices increase drinking, higher prices have no effect) the most common outcome (62%). Compared to a high income/high drinking category, the lightest drinkers with a low income (adjusted odds ratio AOR = 1.78, 95% confidence intervals CI 1.38-2.30) or medium income (AOR = 1.88, CI 1.47-2.41) were most likely to be lower price elastic. Females were more likely than males to be lower price elastic (65% vs 57%) while the reverse was true for complete elasticity (20% vs 26%, P price of alcohol reduces consumption, and one in five of the surveyed population agreed; more work is required to increase this agreement to achieve public support for policy change. Such policy should also recognise that alcohol is an addictive drug, and the population may be prepared to pay more to drink the amount they now feel they need.

The Cosmology Large Angular Scale Surveyor

Science.gov (United States)

Harrington, Kathleen; Marriage, Tobias; Ali, Aamir; Appel, John; Bennett, Charles; Boone, Fletcher; Brewer, Michael; Chan, Manwei; Chuss, David T.; Colazo, Felipe;

Prehospital Acute Stroke Severity Scale to Predict Large Artery Occlusion: Design and Comparison With Other Scales.

Science.gov (United States)

Hastrup, Sidsel; Damgaard, Dorte; Johnsen, Søren Paaske; Andersen, Grethe

2016-07-01

We designed and validated a simple prehospital stroke scale to identify emergent large vessel occlusion (ELVO) in patients with acute ischemic stroke and compared the scale to other published scales for prediction of ELVO. A national historical test cohort of 3127 patients with information on intracranial vessel status (angiography) before reperfusion therapy was identified. National Institutes of Health Stroke Scale (NIHSS) items with the highest predictive value of occlusion of a large intracranial artery were identified, and the most optimal combination meeting predefined criteria to ensure usefulness in the prehospital phase was determined. The predictive performance of Prehospital Acute Stroke Severity (PASS) scale was compared with other published scales for ELVO. The PASS scale was composed of 3 NIHSS scores: level of consciousness (month/age), gaze palsy/deviation, and arm weakness. In derivation of PASS 2/3 of the test cohort was used and showed accuracy (area under the curve) of 0.76 for detecting large arterial occlusion. Optimal cut point ≥2 abnormal scores showed: sensitivity=0.66 (95% CI, 0.62-0.69), specificity=0.83 (0.81-0.85), and area under the curve=0.74 (0.72-0.76). Validation on 1/3 of the test cohort showed similar performance. Patients with a large artery occlusion on angiography with PASS ≥2 had a median NIHSS score of 17 (interquartile range=6) as opposed to PASS <2 with a median NIHSS score of 6 (interquartile range=5). The PASS scale showed equal performance although more simple when compared with other scales predicting ELVO. The PASS scale is simple and has promising accuracy for prediction of ELVO in the field. © 2016 American Heart Association, Inc.

Progress of site survey for large solar telescopes in western China

Science.gov (United States)

Liu, Yu; Song, Tengfei; Zhang, Xuefei; Liu, Shunqing; Zhao, Mingyu; Tian, Zhanjun; Miao, Yuhu; Li, Hongbo; Huang, Jing; Su, Baoyu; Lu, Yongyin; Li, Xiaobo; Song, Qiwu

Excellent sites are necessary for developing and installing ground-based large telescopes. For very-high-resolution solar observations, it had been unclear whether there exist good candidate sites in the west areas in China, including the Tibetan Plateau and the Pamirs Plateau. The project of solar site survey for the next-generation large solar telescopes, i.e., the Chinese Giant Solar Telescope (CGST) and the large coronagraph, has been launched since 2011. Based on the close collaboration among Chinese solar society and the scientists from NSO, HAO and other institutes, we have successfully developed the standard instruments for solar site survey and applied them to more than 50 different sites distributed in Xinjiang, Tibet, Qinghai, Sichuan, Yunnan and Ningxia provinces. We have built two long-term monitoring sites in Tibet and the large Shangri-La to take systematic site data. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that a few potential sites in the large Tibetan areas should obtain the excellent astronomical conditions for our purpose to develop CGST and large coronagraph. We introduce the fresh site survey results in this report.

Fast Simulation of Large-Scale Floods Based on GPU Parallel Computing

OpenAIRE

Qiang Liu; Yi Qin; Guodong Li

2018-01-01

Computing speed is a significant issue of large-scale flood simulations for real-time response to disaster prevention and mitigation. Even today, most of the large-scale flood simulations are generally run on supercomputers due to the massive amounts of data and computations necessary. In this work, a two-dimensional shallow water model based on an unstructured Godunov-type finite volume scheme was proposed for flood simulation. To realize a fast simulation of large-scale floods on a personal...

Managing Risk and Uncertainty in Large-Scale University Research Projects

Science.gov (United States)

Moore, Sharlissa; Shangraw, R. F., Jr.

2011-01-01

Both publicly and privately funded research projects managed by universities are growing in size and scope. Complex, large-scale projects (over $50 million) pose new management challenges and risks for universities. This paper explores the relationship between project success and a variety of factors in large-scale university projects. First, we…

Encoding mutually unbiased bases in orbital angular momentum for quantum key distribution

CSIR Research Space (South Africa)

Dudley, Angela L

2013-07-01

Full Text Available We encode mutually unbiased bases (MUBs) using the higher-dimensional orbital angular momentum (OAM) degree of freedom associated with optical fields. We illustrate how these states are encoded with the use of a spatial light modulator (SLM). We...

Experimental studies of unbiased gluon jets from $e^{+}e^{-}$ annihilations using the jet boost algorithm

CERN Document Server

Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Buesser, K.; Burckhart, H.J.; Campana, S.; Carnegie, R.K.; Caron, B.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Csilling, A.; Cuffiani, M.; Dado, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Furtjes, A.; Gagnon, P.; Gary, John William; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harder, K.; Harel, A.; Harin-Dirac, M.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Hensel, C.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hoffman, Kara Dion; Horvath, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kormos, Laura L.; Kramer, T.; Krieger, P.; von Krogh, J.; Kruger, K.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Layter, J.G.; Leins, A.; Lellouch, D.; Letts, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, J.; Macpherson, A.; Mader, W.; Marcellini, S.; Martin, A.J.; Masetti, G.; Mashimo, T.; Mattig, Peter; McDonald, W.J.; McKenna, J.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Menges, W.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Rick, H.; Roney, J.M.; Rosati, S.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schoerner-Sadenius, Thomas; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Siroli, G.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Stephens, K.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Taylor, R.J.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vollmer, C.F.; Vannerem, P.; Vertesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Warsinsky, M.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija

2004-01-01

We present the first experimental results based on the jet boost algorithm, a technique to select unbiased samples of gluon jets in e+e- annihilations, i.e. gluon jets free of biases introduced by event selection or jet finding criteria. Our results are derived from hadronic Z0 decays observed with the OPAL detector at the LEP e+e- collider at CERN. First, we test the boost algorithm through studies with Herwig Monte Carlo events and find that it provides accurate measurements of the charged particle multiplicity distributions of unbiased gluon jets for jet energies larger than about 5 GeV, and of the jet particle energy spectra (fragmentation functions) for jet energies larger than about 14 GeV. Second, we apply the boost algorithm to our data to derive unbiased measurements of the gluon jet multiplicity distribution for energies between about 5 and 18 GeV, and of the gluon jet fragmentation function at 14 and 18 GeV. In conjunction with our earlier results at 40 GeV, we then test QCD calculations for the en...

Parallel clustering algorithm for large-scale biological data sets.

Science.gov (United States)

Wang, Minchao; Zhang, Wu; Ding, Wang; Dai, Dongbo; Zhang, Huiran; Xie, Hao; Chen, Luonan; Guo, Yike; Xie, Jiang

2014-01-01

Recent explosion of biological data brings a great challenge for the traditional clustering algorithms. With increasing scale of data sets, much larger memory and longer runtime are required for the cluster identification problems. The affinity propagation algorithm outperforms many other classical clustering algorithms and is widely applied into the biological researches. However, the time and space complexity become a great bottleneck when handling the large-scale data sets. Moreover, the similarity matrix, whose constructing procedure takes long runtime, is required before running the affinity propagation algorithm, since the algorithm clusters data sets based on the similarities between data pairs. Two types of parallel architectures are proposed in this paper to accelerate the similarity matrix constructing procedure and the affinity propagation algorithm. The memory-shared architecture is used to construct the similarity matrix, and the distributed system is taken for the affinity propagation algorithm, because of its large memory size and great computing capacity. An appropriate way of data partition and reduction is designed in our method, in order to minimize the global communication cost among processes. A speedup of 100 is gained with 128 cores. The runtime is reduced from serval hours to a few seconds, which indicates that parallel algorithm is capable of handling large-scale data sets effectively. The parallel affinity propagation also achieves a good performance when clustering large-scale gene data (microarray) and detecting families in large protein superfamilies.

Large-scale fuel cycle centers

International Nuclear Information System (INIS)

Smiley, S.H.; Black, K.M.

1977-01-01

The United States Nuclear Regulatory Commission (NRC) has considered the nuclear energy center concept for fuel cycle plants in the Nuclear Energy Center Site Survey - 1975 (NECSS-75) -- an important study mandated by the U.S. Congress in the Energy Reorganization Act of 1974 which created the NRC. For the study, NRC defined fuel cycle centers to consist of fuel reprocessing and mixed oxide fuel fabrication plants, and optional high-level waste and transuranic waste management facilities. A range of fuel cycle center sizes corresponded to the fuel throughput of power plants with a total capacity of 50,000 - 300,000 MWe. The types of fuel cycle facilities located at the fuel cycle center permit the assessment of the role of fuel cycle centers in enhancing safeguarding of strategic special nuclear materials -- plutonium and mixed oxides. Siting of fuel cycle centers presents a considerably smaller problem than the siting of reactors. A single reprocessing plant of the scale projected for use in the United States (1500-2000 MT/yr) can reprocess the fuel from reactors producing 50,000-65,000 MWe. Only two or three fuel cycle centers of the upper limit size considered in the NECSS-75 would be required in the United States by the year 2000 . The NECSS-75 fuel cycle center evaluations showed that large scale fuel cycle centers present no real technical difficulties in siting from a radiological effluent and safety standpoint. Some construction economies may be attainable with fuel cycle centers; such centers offer opportunities for improved waste management systems. Combined centers consisting of reactors and fuel reprocessing and mixed oxide fuel fabrication plants were also studied in the NECSS. Such centers can eliminate not only shipment of plutonium, but also mixed oxide fuel. Increased fuel cycle costs result from implementation of combined centers unless the fuel reprocessing plants are commercial-sized. Development of plutonium-burning reactors could reduce any

Biased Tracers in Redshift Space in the EFT of Large-Scale Structure

Energy Technology Data Exchange (ETDEWEB)

Perko, Ashley [Stanford U., Phys. Dept.; Senatore, Leonardo [KIPAC, Menlo Park; Jennings, Elise [Chicago U., KICP; Wechsler, Risa H. [Stanford U., Phys. Dept.

2016-10-28

The Effective Field Theory of Large-Scale Structure (EFTofLSS) provides a novel formalism that is able to accurately predict the clustering of large-scale structure (LSS) in the mildly non-linear regime. Here we provide the first computation of the power spectrum of biased tracers in redshift space at one loop order, and we make the associated code publicly available. We compare the multipoles $\\ell=0,2$ of the redshift-space halo power spectrum, together with the real-space matter and halo power spectra, with data from numerical simulations at $z=0.67$. For the samples we compare to, which have a number density of $\\bar n=3.8 \\cdot 10^{-2}(h \\ {\\rm Mpc}^{-1})^3$ and $\\bar n=3.9 \\cdot 10^{-4}(h \\ {\\rm Mpc}^{-1})^3$, we find that the calculation at one-loop order matches numerical measurements to within a few percent up to $k\\simeq 0.43 \\ h \\ {\\rm Mpc}^{-1}$, a significant improvement with respect to former techniques. By performing the so-called IR-resummation, we find that the Baryon Acoustic Oscillation peak is accurately reproduced. Based on the results presented here, long-wavelength statistics that are routinely observed in LSS surveys can be finally computed in the EFTofLSS. This formalism thus is ready to start to be compared directly to observational data.

Large-scale nuclear structure calculations for spin-dependent WIMP scattering with chiral effective field theory currents

OpenAIRE

Klos, P.; Menéndez, J.; Gazit, D.; Schwenk, A.

2013-01-01

We perform state-of-the-art large-scale shell-model calculations of the structure factors for elastic spin-dependent WIMP scattering off 129,131Xe, 127I, 73Ge, 19F, 23Na, 27Al, and 29Si. This comprehensive survey covers the non-zero-spin nuclei relevant to direct dark matter detection. We include a pedagogical presentation of the formalism necessary to describe elastic and inelastic WIMP-nucleus scattering. The valence spaces and nuclear interactions employed have been previously used in nucl...

Adaptive visualization for large-scale graph

International Nuclear Information System (INIS)

Nakamura, Hiroko; Shinano, Yuji; Ohzahata, Satoshi

2010-01-01

We propose an adoptive visualization technique for representing a large-scale hierarchical dataset within limited display space. A hierarchical dataset has nodes and links showing the parent-child relationship between the nodes. These nodes and links are described using graphics primitives. When the number of these primitives is large, it is difficult to recognize the structure of the hierarchical data because many primitives are overlapped within a limited region. To overcome this difficulty, we propose an adaptive visualization technique for hierarchical datasets. The proposed technique selects an appropriate graph style according to the nodal density in each area. (author)

Stabilization Algorithms for Large-Scale Problems

DEFF Research Database (Denmark)

Jensen, Toke Koldborg

2006-01-01

The focus of the project is on stabilization of large-scale inverse problems where structured models and iterative algorithms are necessary for computing approximate solutions. For this purpose, we study various iterative Krylov methods and their abilities to produce regularized solutions. Some......-curve. This heuristic is implemented as a part of a larger algorithm which is developed in collaboration with G. Rodriguez and P. C. Hansen. Last, but not least, a large part of the project has, in different ways, revolved around the object-oriented Matlab toolbox MOORe Tools developed by PhD Michael Jacobsen. New...

Unbiased estimators for spatial distribution functions of classical fluids

Science.gov (United States)

Adib, Artur B.; Jarzynski, Christopher

2005-01-01

We use a statistical-mechanical identity closely related to the familiar virial theorem, to derive unbiased estimators for spatial distribution functions of classical fluids. In particular, we obtain estimators for both the fluid density ρ(r) in the vicinity of a fixed solute and the pair correlation g(r) of a homogeneous classical fluid. We illustrate the utility of our estimators with numerical examples, which reveal advantages over traditional histogram-based methods of computing such distributions.

Unraveling cognitive traits using the Morris water maze unbiased strategy classification (MUST-C) algorithm.

Science.gov (United States)

Illouz, Tomer; Madar, Ravit; Louzon, Yoram; Griffioen, Kathleen J; Okun, Eitan

2016-02-01

The assessment of spatial cognitive learning in rodents is a central approach in neuroscience, as it enables one to assess and quantify the effects of treatments and genetic manipulations from a broad perspective. Although the Morris water maze (MWM) is a well-validated paradigm for testing spatial learning abilities, manual categorization of performance in the MWM into behavioral strategies is subject to individual interpretation, and thus to biases. Here we offer a support vector machine (SVM) - based, automated, MWM unbiased strategy classification (MUST-C) algorithm, as well as a cognitive score scale. This model was examined and validated by analyzing data obtained from five MWM experiments with changing platform sizes, revealing a limitation in the spatial capacity of the hippocampus. We have further employed this algorithm to extract novel mechanistic insights on the impact of members of the Toll-like receptor pathway on cognitive spatial learning and memory. The MUST-C algorithm can greatly benefit MWM users as it provides a standardized method of strategy classification as well as a cognitive scoring scale, which cannot be derived from typical analysis of MWM data. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Large scale structures in the kinetic gravity braiding model that can be unbraided

International Nuclear Information System (INIS)

Kimura, Rampei; Yamamoto, Kazuhiro

2011-01-01

We study cosmological consequences of a kinetic gravity braiding model, which is proposed as an alternative to the dark energy model. The kinetic braiding model we study is characterized by a parameter n, which corresponds to the original galileon cosmological model for n = 1. We find that the background expansion of the universe of the kinetic braiding model is the same as the Dvali-Turner's model, which reduces to that of the standard cold dark matter model with a cosmological constant (ΛCDM model) for n equal to infinity. We also find that the evolution of the linear cosmological perturbation in the kinetic braiding model reduces to that of the ΛCDM model for n = ∞. Then, we focus our study on the growth history of the linear density perturbation as well as the spherical collapse in the nonlinear regime of the density perturbations, which might be important in order to distinguish between the kinetic braiding model and the ΛCDM model when n is finite. The theoretical prediction for the large scale structure is confronted with the multipole power spectrum of the luminous red galaxy sample of the Sloan Digital Sky survey. We also discuss future prospects of constraining the kinetic braiding model using a future redshift survey like the WFMOS/SuMIRe PFS survey as well as the cluster redshift distribution in the South Pole Telescope survey

Design study on sodium cooled large-scale reactor

International Nuclear Information System (INIS)

Murakami, Tsutomu; Hishida, Masahiko; Kisohara, Naoyuki

2004-07-01

In Phase 1 of the 'Feasibility Studies on Commercialized Fast Reactor Cycle Systems (F/S)', an advanced loop type reactor has been selected as a promising concept of sodium-cooled large-scale reactor, which has a possibility to fulfill the design requirements of the F/S. In Phase 2, design improvement for further cost reduction of establishment of the plant concept has been performed. This report summarizes the results of the design study on the sodium-cooled large-scale reactor performed in JFY2003, which is the third year of Phase 2. In the JFY2003 design study, critical subjects related to safety, structural integrity and thermal hydraulics which found in the last fiscal year has been examined and the plant concept has been modified. Furthermore, fundamental specifications of main systems and components have been set and economy has been evaluated. In addition, as the interim evaluation of the candidate concept of the FBR fuel cycle is to be conducted, cost effectiveness and achievability for the development goal were evaluated and the data of the three large-scale reactor candidate concepts were prepared. As a results of this study, the plant concept of the sodium-cooled large-scale reactor has been constructed, which has a prospect to satisfy the economic goal (construction cost: less than 200,000 yens/kWe, etc.) and has a prospect to solve the critical subjects. From now on, reflecting the results of elemental experiments, the preliminary conceptual design of this plant will be preceded toward the selection for narrowing down candidate concepts at the end of Phase 2. (author)

Design study on sodium-cooled large-scale reactor

International Nuclear Information System (INIS)

Shimakawa, Yoshio; Nibe, Nobuaki; Hori, Toru

2002-05-01

In Phase 1 of the 'Feasibility Study on Commercialized Fast Reactor Cycle Systems (F/S)', an advanced loop type reactor has been selected as a promising concept of sodium-cooled large-scale reactor, which has a possibility to fulfill the design requirements of the F/S. In Phase 2 of the F/S, it is planed to precede a preliminary conceptual design of a sodium-cooled large-scale reactor based on the design of the advanced loop type reactor. Through the design study, it is intended to construct such a plant concept that can show its attraction and competitiveness as a commercialized reactor. This report summarizes the results of the design study on the sodium-cooled large-scale reactor performed in JFY2001, which is the first year of Phase 2. In the JFY2001 design study, a plant concept has been constructed based on the design of the advanced loop type reactor, and fundamental specifications of main systems and components have been set. Furthermore, critical subjects related to safety, structural integrity, thermal hydraulics, operability, maintainability and economy have been examined and evaluated. As a result of this study, the plant concept of the sodium-cooled large-scale reactor has been constructed, which has a prospect to satisfy the economic goal (construction cost: less than 200,000yens/kWe, etc.) and has a prospect to solve the critical subjects. From now on, reflecting the results of elemental experiments, the preliminary conceptual design of this plant will be preceded toward the selection for narrowing down candidate concepts at the end of Phase 2. (author)

Failure Impact Assessment for Large-Scale Landslides Located Near Human Settlement: Case Study in Southern Taiwan

Directory of Open Access Journals (Sweden)

Ming-Chien Chung

2018-05-01

Full Text Available In 2009, Typhoon Morakot caused over 680 deaths and more than 20,000 landslides in Taiwan. From 2010 to 2015, the Central Geological Survey of the Ministry of Economic Affairs identified 1047 potential large-scale landslides in Taiwan, of which 103 may have affected human settlements. This paper presents an analytical procedure that can be applied to assess the possible impact of a landslide collapse on nearby settlements. In this paper, existing technologies, including interpretation of remote sensing images, hydrogeological investigation, and numerical analysis, are integrated to evaluate potential failure scenarios and the landslide scale of a specific case: the Xinzhuang landslide. GeoStudio and RAMMS analysis modes and hazard classification produced the following results: (1 evaluation of the failure mechanisms and the influence zones of large-scale landslides; (2 assessment of the migration and accumulation of the landslide mass after failure; and (3 a landslide hazard and evacuation map. The results of the case study show that this analytical procedure can quantitatively estimate potential threats to human settlements. Furthermore, it can be applied to other villages and used as a reference in disaster prevention and evacuation planning.

Unbiased stereological methods used for the quantitative evaluation of guided bone regeneration

DEFF Research Database (Denmark)

Aaboe, Else Merete; Pinholt, E M; Schou, S

1998-01-01

The present study describes the use of unbiased stereological methods for the quantitative evaluation of the amount of regenerated bone. Using the principle of guided bone regeneration the amount of regenerated bone after placement of degradable or non-degradable membranes covering defects...

Large scale CMB anomalies from thawing cosmic strings

Energy Technology Data Exchange (ETDEWEB)

Ringeval, Christophe [Centre for Cosmology, Particle Physics and Phenomenology, Institute of Mathematics and Physics, Louvain University, 2 Chemin du Cyclotron, 1348 Louvain-la-Neuve (Belgium); Yamauchi, Daisuke; Yokoyama, Jun' ichi [Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan); Bouchet, François R., E-mail: christophe.ringeval@uclouvain.be, E-mail: yamauchi@resceu.s.u-tokyo.ac.jp, E-mail: yokoyama@resceu.s.u-tokyo.ac.jp, E-mail: bouchet@iap.fr [Institut d' Astrophysique de Paris, UMR 7095-CNRS, Université Pierre et Marie Curie, 98bis boulevard Arago, 75014 Paris (France)

2016-02-01

Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings imprint their signature in the Cosmic Microwave Background (CMB) Anisotropies after recombination. Being almost frozen in the Hubble flow, these strings are quasi static and evade almost all of the previously derived constraints on their tension while being able to source large scale anisotropies in the CMB sky. Using a local variance estimator on thousand of numerically simulated Nambu-Goto all sky maps, we compute the expected signal and show that it can mimic a dipole modulation at large angular scales while being negligible at small angles. Interestingly, such a scenario generically produces one cold spot from the thawing of a cosmic string loop. Mixed with anisotropies of inflationary origin, we find that a few strings of tension GU = O(1) × 10{sup −6} match the amplitude of the dipole modulation reported in the Planck satellite measurements and could be at the origin of other large scale anomalies.

Mutually unbiased coarse-grained measurements of two or more phase-space variables

Science.gov (United States)

Paul, E. C.; Walborn, S. P.; Tasca, D. S.; Rudnicki, Łukasz

2018-05-01

Mutual unbiasedness of the eigenstates of phase-space operators—such as position and momentum, or their standard coarse-grained versions—exists only in the limiting case of infinite squeezing. In Phys. Rev. Lett. 120, 040403 (2018), 10.1103/PhysRevLett.120.040403, it was shown that mutual unbiasedness can be recovered for periodic coarse graining of these two operators. Here we investigate mutual unbiasedness of coarse-grained measurements for more than two phase-space variables. We show that mutual unbiasedness can be recovered between periodic coarse graining of any two nonparallel phase-space operators. We illustrate these results through optics experiments, using the fractional Fourier transform to prepare and measure mutually unbiased phase-space variables. The differences between two and three mutually unbiased measurements is discussed. Our results contribute to bridging the gap between continuous and discrete quantum mechanics, and they could be useful in quantum-information protocols.

Exploiting multi-scale parallelism for large scale numerical modelling of laser wakefield accelerators

International Nuclear Information System (INIS)

Fonseca, R A; Vieira, J; Silva, L O; Fiuza, F; Davidson, A; Tsung, F S; Mori, W B

2013-01-01

A new generation of laser wakefield accelerators (LWFA), supported by the extreme accelerating fields generated in the interaction of PW-Class lasers and underdense targets, promises the production of high quality electron beams in short distances for multiple applications. Achieving this goal will rely heavily on numerical modelling to further understand the underlying physics and identify optimal regimes, but large scale modelling of these scenarios is computationally heavy and requires the efficient use of state-of-the-art petascale supercomputing systems. We discuss the main difficulties involved in running these simulations and the new developments implemented in the OSIRIS framework to address these issues, ranging from multi-dimensional dynamic load balancing and hybrid distributed/shared memory parallelism to the vectorization of the PIC algorithm. We present the results of the OASCR Joule Metric program on the issue of large scale modelling of LWFA, demonstrating speedups of over 1 order of magnitude on the same hardware. Finally, scalability to over ∼10 6 cores and sustained performance over ∼2 P Flops is demonstrated, opening the way for large scale modelling of LWFA scenarios. (paper)

Testing the statistical isotropy of large scale structure with multipole vectors

International Nuclear Information System (INIS)

Zunckel, Caroline; Huterer, Dragan; Starkman, Glenn D.

2011-01-01

A fundamental assumption in cosmology is that of statistical isotropy - that the Universe, on average, looks the same in every direction in the sky. Statistical isotropy has recently been tested stringently using cosmic microwave background data, leading to intriguing results on large angular scales. Here we apply some of the same techniques used in the cosmic microwave background to the distribution of galaxies on the sky. Using the multipole vector approach, where each multipole in the harmonic decomposition of galaxy density field is described by unit vectors and an amplitude, we lay out the basic formalism of how to reconstruct the multipole vectors and their statistics out of galaxy survey catalogs. We apply the algorithm to synthetic galaxy maps, and study the sensitivity of the multipole vector reconstruction accuracy to the density, depth, sky coverage, and pixelization of galaxy catalog maps.

Balancing modern Power System with large scale of wind power

DEFF Research Database (Denmark)

Basit, Abdul; Altin, Müfit; Hansen, Anca Daniela

2014-01-01

Power system operators must ensure robust, secure and reliable power system operation even with a large scale integration of wind power. Electricity generated from the intermittent wind in large propor-tion may impact on the control of power system balance and thus deviations in the power system...... frequency in small or islanded power systems or tie line power flows in interconnected power systems. Therefore, the large scale integration of wind power into the power system strongly concerns the secure and stable grid operation. To ensure the stable power system operation, the evolving power system has...... to be analysed with improved analytical tools and techniques. This paper proposes techniques for the active power balance control in future power systems with the large scale wind power integration, where power balancing model provides the hour-ahead dispatch plan with reduced planning horizon and the real time...

Testing Inflation with Large Scale Structure: Connecting Hopes with Reality

Energy Technology Data Exchange (ETDEWEB)

Alvarez, Marcello [Univ. of Toronto, ON (Canada); Baldauf, T. [Inst. of Advanced Studies, Princeton, NJ (United States); Bond, J. Richard [Univ. of Toronto, ON (Canada); Canadian Inst. for Advanced Research, Toronto, ON (Canada); Dalal, N. [Univ. of Illinois, Urbana-Champaign, IL (United States); Putter, R. D. [Jet Propulsion Lab., Pasadena, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States); Dore, O. [Jet Propulsion Lab., Pasadena, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States); Green, Daniel [Univ. of Toronto, ON (Canada); Canadian Inst. for Advanced Research, Toronto, ON (Canada); Hirata, Chris [The Ohio State Univ., Columbus, OH (United States); Huang, Zhiqi [Univ. of Toronto, ON (Canada); Huterer, Dragan [Univ. of Michigan, Ann Arbor, MI (United States); Jeong, Donghui [Pennsylvania State Univ., University Park, PA (United States); Johnson, Matthew C. [York Univ., Toronto, ON (Canada); Perimeter Inst., Waterloo, ON (Canada); Krause, Elisabeth [Stanford Univ., CA (United States); Loverde, Marilena [Univ. of Chicago, IL (United States); Meyers, Joel [Univ. of Toronto, ON (Canada); Meeburg, Daniel [Univ. of Toronto, ON (Canada); Senatore, Leonardo [Stanford Univ., CA (United States); Shandera, Sarah [Pennsylvania State Univ., University Park, PA (United States); Silverstein, Eva [Stanford Univ., CA (United States); Slosar, Anze [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, Kendrick [Perimeter Inst., Waterloo, Toronto, ON (Canada); Zaldarriaga, Matias [Univ. of Toronto, ON (Canada); Assassi, Valentin [Cambridge Univ. (United Kingdom); Braden, Jonathan [Univ. of Toronto, ON (Canada); Hajian, Amir [Univ. of Toronto, ON (Canada); Kobayashi, Takeshi [Perimeter Inst., Waterloo, Toronto, ON (Canada); Univ. of Toronto, ON (Canada); Stein, George [Univ. of Toronto, ON (Canada); Engelen, Alexander van [Univ. of Toronto, ON (Canada)

2014-12-15

The statistics of primordial curvature fluctuations are our window into the period of inflation, where these fluctuations were generated. To date, the cosmic microwave background has been the dominant source of information about these perturbations. Large-scale structure is, however, from where drastic improvements should originate. In this paper, we explain the theoretical motivations for pursuing such measurements and the challenges that lie ahead. In particular, we discuss and identify theoretical targets regarding the measurement of primordial non-Gaussianity. We argue that when quantified in terms of the local (equilateral) template amplitude f$loc\\atop{NL}$ (f$eq\\atop{NL}$), natural target levels of sensitivity are Δf$loc, eq\\atop{NL}$ ≃ 1. We highlight that such levels are within reach of future surveys by measuring 2-, 3- and 4-point statistics of the galaxy spatial distribution. This paper summarizes a workshop held at CITA (University of Toronto) on October 23-24, 2014.

Single-field consistency relations of large scale structure part III: test of the equivalence principle

Energy Technology Data Exchange (ETDEWEB)

Creminelli, Paolo [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, Trieste, 34151 (Italy); Gleyzes, Jérôme; Vernizzi, Filippo [CEA, Institut de Physique Théorique, Gif-sur-Yvette cédex, F-91191 France (France); Hui, Lam [Physics Department and Institute for Strings, Cosmology and Astroparticle Physics, Columbia University, New York, NY, 10027 (United States); Simonović, Marko, E-mail: creminel@ictp.it, E-mail: jerome.gleyzes@cea.fr, E-mail: lhui@astro.columbia.edu, E-mail: msimonov@sissa.it, E-mail: filippo.vernizzi@cea.fr [SISSA, via Bonomea 265, Trieste, 34136 (Italy)

2014-06-01

The recently derived consistency relations for Large Scale Structure do not hold if the Equivalence Principle (EP) is violated. We show it explicitly in a toy model with two fluids, one of which is coupled to a fifth force. We explore the constraints that galaxy surveys can set on EP violation looking at the squeezed limit of the 3-point function involving two populations of objects. We find that one can explore EP violations of order 10{sup −3}÷10{sup −4} on cosmological scales. Chameleon models are already very constrained by the requirement of screening within the Solar System and only a very tiny region of the parameter space can be explored with this method. We show that no violation of the consistency relations is expected in Galileon models.

Large-Scale Graph Processing Using Apache Giraph

KAUST Repository

Sakr, Sherif

2017-01-07

This book takes its reader on a journey through Apache Giraph, a popular distributed graph processing platform designed to bring the power of big data processing to graph data. Designed as a step-by-step self-study guide for everyone interested in large-scale graph processing, it describes the fundamental abstractions of the system, its programming models and various techniques for using the system to process graph data at scale, including the implementation of several popular and advanced graph analytics algorithms.

Large-Scale Graph Processing Using Apache Giraph

KAUST Repository

Sakr, Sherif; Orakzai, Faisal Moeen; Abdelaziz, Ibrahim; Khayyat, Zuhair

2017-01-01

This book takes its reader on a journey through Apache Giraph, a popular distributed graph processing platform designed to bring the power of big data processing to graph data. Designed as a step-by-step self-study guide for everyone interested in large-scale graph processing, it describes the fundamental abstractions of the system, its programming models and various techniques for using the system to process graph data at scale, including the implementation of several popular and advanced graph analytics algorithms.

An interactive display system for large-scale 3D models

Science.gov (United States)

Liu, Zijian; Sun, Kun; Tao, Wenbing; Liu, Liman

2018-04-01

With the improvement of 3D reconstruction theory and the rapid development of computer hardware technology, the reconstructed 3D models are enlarging in scale and increasing in complexity. Models with tens of thousands of 3D points or triangular meshes are common in practical applications. Due to storage and computing power limitation, it is difficult to achieve real-time display and interaction with large scale 3D models for some common 3D display software, such as MeshLab. In this paper, we propose a display system for large-scale 3D scene models. We construct the LOD (Levels of Detail) model of the reconstructed 3D scene in advance, and then use an out-of-core view-dependent multi-resolution rendering scheme to realize the real-time display of the large-scale 3D model. With the proposed method, our display system is able to render in real time while roaming in the reconstructed scene and 3D camera poses can also be displayed. Furthermore, the memory consumption can be significantly decreased via internal and external memory exchange mechanism, so that it is possible to display a large scale reconstructed scene with over millions of 3D points or triangular meshes in a regular PC with only 4GB RAM.

Large-scale hydrology in Europe : observed patterns and model performance

Energy Technology Data Exchange (ETDEWEB)

Gudmundsson, Lukas

2011-06-15

In a changing climate, terrestrial water storages are of great interest as water availability impacts key aspects of ecosystem functioning. Thus, a better understanding of the variations of wet and dry periods will contribute to fully grasp processes of the earth system such as nutrient cycling and vegetation dynamics. Currently, river runoff from small, nearly natural, catchments is one of the few variables of the terrestrial water balance that is regularly monitored with detailed spatial and temporal coverage on large scales. River runoff, therefore, provides a foundation to approach European hydrology with respect to observed patterns on large scales, with regard to the ability of models to capture these.The analysis of observed river flow from small catchments, focused on the identification and description of spatial patterns of simultaneous temporal variations of runoff. These are dominated by large-scale variations of climatic variables but also altered by catchment processes. It was shown that time series of annual low, mean and high flows follow the same atmospheric drivers. The observation that high flows are more closely coupled to large scale atmospheric drivers than low flows, indicates the increasing influence of catchment properties on runoff under dry conditions. Further, it was shown that the low-frequency variability of European runoff is dominated by two opposing centres of simultaneous variations, such that dry years in the north are accompanied by wet years in the south.Large-scale hydrological models are simplified representations of our current perception of the terrestrial water balance on large scales. Quantification of the models strengths and weaknesses is the prerequisite for a reliable interpretation of simulation results. Model evaluations may also enable to detect shortcomings with model assumptions and thus enable a refinement of the current perception of hydrological systems. The ability of a multi model ensemble of nine large-scale

Large-scale perturbations from the waterfall field in hybrid inflation

International Nuclear Information System (INIS)

Fonseca, José; Wands, David; Sasaki, Misao

2010-01-01

We estimate large-scale curvature perturbations from isocurvature fluctuations in the waterfall field during hybrid inflation, in addition to the usual inflaton field perturbations. The tachyonic instability at the end of inflation leads to an explosive growth of super-Hubble scale perturbations, but they retain the steep blue spectrum characteristic of vacuum fluctuations in a massive field during inflation. The power spectrum thus peaks around the Hubble-horizon scale at the end of inflation. We extend the usual δN formalism to include the essential role of these small fluctuations when estimating the large-scale curvature perturbation. The resulting curvature perturbation due to fluctuations in the waterfall field is second-order and the spectrum is expected to be of order 10 −54 on cosmological scales

Decoupling local mechanics from large-scale structure in modular metamaterials

Science.gov (United States)

Yang, Nan; Silverberg, Jesse L.

2017-04-01

A defining feature of mechanical metamaterials is that their properties are determined by the organization of internal structure instead of the raw fabrication materials. This shift of attention to engineering internal degrees of freedom has coaxed relatively simple materials into exhibiting a wide range of remarkable mechanical properties. For practical applications to be realized, however, this nascent understanding of metamaterial design must be translated into a capacity for engineering large-scale structures with prescribed mechanical functionality. Thus, the challenge is to systematically map desired functionality of large-scale structures backward into a design scheme while using finite parameter domains. Such “inverse design” is often complicated by the deep coupling between large-scale structure and local mechanical function, which limits the available design space. Here, we introduce a design strategy for constructing 1D, 2D, and 3D mechanical metamaterials inspired by modular origami and kirigami. Our approach is to assemble a number of modules into a voxelized large-scale structure, where the module’s design has a greater number of mechanical design parameters than the number of constraints imposed by bulk assembly. This inequality allows each voxel in the bulk structure to be uniquely assigned mechanical properties independent from its ability to connect and deform with its neighbors. In studying specific examples of large-scale metamaterial structures we show that a decoupling of global structure from local mechanical function allows for a variety of mechanically and topologically complex designs.

Personalized recommendation based on unbiased consistence

Science.gov (United States)

Zhu, Xuzhen; Tian, Hui; Zhang, Ping; Hu, Zheng; Zhou, Tao

2015-08-01

Recently, in physical dynamics, mass-diffusion-based recommendation algorithms on bipartite network provide an efficient solution by automatically pushing possible relevant items to users according to their past preferences. However, traditional mass-diffusion-based algorithms just focus on unidirectional mass diffusion from objects having been collected to those which should be recommended, resulting in a biased causal similarity estimation and not-so-good performance. In this letter, we argue that in many cases, a user's interests are stable, and thus bidirectional mass diffusion abilities, no matter originated from objects having been collected or from those which should be recommended, should be consistently powerful, showing unbiased consistence. We further propose a consistence-based mass diffusion algorithm via bidirectional diffusion against biased causality, outperforming the state-of-the-art recommendation algorithms in disparate real data sets, including Netflix, MovieLens, Amazon and Rate Your Music.

The origin of large scale cosmic structure

International Nuclear Information System (INIS)

Jones, B.J.T.; Palmer, P.L.

1985-01-01

The paper concerns the origin of large scale cosmic structure. The evolution of density perturbations, the nonlinear regime (Zel'dovich's solution and others), the Gott and Rees clustering hierarchy, the spectrum of condensations, and biassed galaxy formation, are all discussed. (UK)

A practical process for light-water detritiation at large scales

Energy Technology Data Exchange (ETDEWEB)

Boniface, H.A. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Robinson, J., E-mail: jr@tyne-engineering.com [Tyne Engineering, Burlington, ON (Canada); Gnanapragasam, N.V.; Castillo, I.; Suppiah, S. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

2014-07-01

AECL and Tyne Engineering have recently completed a preliminary engineering design for a modest-scale tritium removal plant for light water, intended for installation at AECL's Chalk River Laboratories (CRL). This plant design was based on the Combined Electrolysis and Catalytic Exchange (CECE) technology developed at CRL over many years and demonstrated there and elsewhere. The general features and capabilities of this design have been reported as well as the versatility of the design for separating any pair of the three hydrogen isotopes. The same CECE technology could be applied directly to very large-scale wastewater detritiation, such as the case at Fukushima Daiichi Nuclear Power Station. However, since the CECE process scales linearly with throughput, the required capital and operating costs are substantial for such large-scale applications. This paper discusses some options for reducing the costs of very large-scale detritiation. Options include: Reducing tritium removal effectiveness; Energy recovery; Improving the tolerance of impurities; Use of less expensive or more efficient equipment. A brief comparison with alternative processes is also presented. (author)

Qualitative approaches to large scale studies and students' achievements in Science and Mathematics - An Australian and Nordic Perspective

DEFF Research Database (Denmark)

Davidsson, Eva; Sørensen, Helene

Large scale studies play an increasing role in educational politics and results from surveys such as TIMSS and PISA are extensively used in medial debates about students' knowledge in science and mathematics. Although this debate does not usually shed light on the more extensive quantitative...... analyses, there is a lack of investigations which aim at exploring what is possible to conclude or not to conclude from these analyses. There is also a need for more detailed discussions about what trends could be discern concerning students' knowledge in science and mathematics. The aim of this symposium...... is therefore to highlight and discuss different approaches to how data from large scale studies could be used for additional analyses in order to increase our understanding of students' knowledge in science and mathematics, but also to explore possible longitudinal trends, hidden in the data material...

Within-subject template estimation for unbiased longitudinal image analysis.

Science.gov (United States)

Reuter, Martin; Schmansky, Nicholas J; Rosas, H Diana; Fischl, Bruce

2012-07-16

Longitudinal image analysis has become increasingly important in clinical studies of normal aging and neurodegenerative disorders. Furthermore, there is a growing appreciation of the potential utility of longitudinally acquired structural images and reliable image processing to evaluate disease modifying therapies. Challenges have been related to the variability that is inherent in the available cross-sectional processing tools, to the introduction of bias in longitudinal processing and to potential over-regularization. In this paper we introduce a novel longitudinal image processing framework, based on unbiased, robust, within-subject template creation, for automatic surface reconstruction and segmentation of brain MRI of arbitrarily many time points. We demonstrate that it is essential to treat all input images exactly the same as removing only interpolation asymmetries is not sufficient to remove processing bias. We successfully reduce variability and avoid over-regularization by initializing the processing in each time point with common information from the subject template. The presented results show a significant increase in precision and discrimination power while preserving the ability to detect large anatomical deviations; as such they hold great potential in clinical applications, e.g. allowing for smaller sample sizes or shorter trials to establish disease specific biomarkers or to quantify drug effects. Copyright © 2012 Elsevier Inc. All rights reserved.

Concurrent Validity and Feasibility of Short Tests Currently Used to Measure Early Childhood Development in Large Scale Studies.

Directory of Open Access Journals (Sweden)

Marta Rubio-Codina

Full Text Available In low- and middle-income countries (LIMCs, measuring early childhood development (ECD with standard tests in large scale surveys and evaluations of interventions is difficult and expensive. Multi-dimensional screeners and single-domain tests ('short tests' are frequently used as alternatives. However, their validity in these circumstances is unknown. We examined the feasibility, reliability, and concurrent validity of three multi-dimensional screeners (Ages and Stages Questionnaires (ASQ-3, Denver Developmental Screening Test (Denver-II, Battelle Developmental Inventory screener (BDI-2 and two single-domain tests (MacArthur-Bates Short-Forms (SFI and SFII, WHO Motor Milestones (WHO-Motor in 1,311 children 6-42 months in Bogota, Colombia. The scores were compared with those on the Bayley Scales of Infant and Toddler Development (Bayley-III, taken as the 'gold standard'. The Bayley-III was given at a center by psychologists; whereas the short tests were administered in the home by interviewers, as in a survey setting. Findings indicated good internal validity of all short tests except the ASQ-3. The BDI-2 took long to administer and was expensive, while the single-domain tests were quickest and cheapest and the Denver-II and ASQ-3 were intermediate. Concurrent validity of the multi-dimensional tests' cognitive, language, and fine motor scales with the corresponding Bayley-III scale was low below 19 months. However, it increased with age, becoming moderate-to-high over 30 months. In contrast, gross motor scales' concurrence was high under 19 months and then decreased. Of the single-domain tests, the WHO-Motor had high validity with gross motor under 16 months, and the SFI and SFII expressive scales showed moderate correlations with language under 30 months. Overall, the Denver-II was the most feasible and valid multi-dimensional test and the ASQ-3 performed poorly under 31 months. By domain, gross motor development had the highest concurrence

OffshoreDC DC grids for integration of large scale wind power

DEFF Research Database (Denmark)

Zeni, Lorenzo; Endegnanew, Atsede Gualu; Stamatiou, Georgios

The present report summarizes the main findings of the Nordic Energy Research project “DC grids for large scale integration of offshore wind power – OffshoreDC”. The project is been funded by Nordic Energy Research through the TFI programme and was active between 2011 and 2016. The overall...... objective of the project was to drive the development of the VSC based HVDC technology for future large scale offshore grids, supporting a standardised and commercial development of the technology, and improving the opportunities for the technology to support power system integration of large scale offshore...

Low-Complexity Transmit Antenna Selection and Beamforming for Large-Scale MIMO Communications

Directory of Open Access Journals (Sweden)

Kun Qian

2014-01-01

Full Text Available Transmit antenna selection plays an important role in large-scale multiple-input multiple-output (MIMO communications, but optimal large-scale MIMO antenna selection is a technical challenge. Exhaustive search is often employed in antenna selection, but it cannot be efficiently implemented in large-scale MIMO communication systems due to its prohibitive high computation complexity. This paper proposes a low-complexity interactive multiple-parameter optimization method for joint transmit antenna selection and beamforming in large-scale MIMO communication systems. The objective is to jointly maximize the channel outrage capacity and signal-to-noise (SNR performance and minimize the mean square error in transmit antenna selection and minimum variance distortionless response (MVDR beamforming without exhaustive search. The effectiveness of all the proposed methods is verified by extensive simulation results. It is shown that the required antenna selection processing time of the proposed method does not increase along with the increase of selected antennas, but the computation complexity of conventional exhaustive search method will significantly increase when large-scale antennas are employed in the system. This is particularly useful in antenna selection for large-scale MIMO communication systems.

Temporal flexibility and careers: The role of large-scale organizations for physicians

OpenAIRE

Forrest Briscoe

2006-01-01

Temporal flexibility and careers: The role of large-scale organizations for physicians. Forrest Briscoe Briscoe This study investigates how employment in large-scale organizations affects the work lives of practicing physicians. Well-established theory associates larger organizations with bureaucratic constraint, loss of workplace control, and dissatisfaction, but this author finds that large scale is also associated with greater schedule and career flexibility. Ironically, the bureaucratic p...

The role of large scale motions on passive scalar transport

Science.gov (United States)

Dharmarathne, Suranga; Araya, Guillermo; Tutkun, Murat; Leonardi, Stefano; Castillo, Luciano

2014-11-01

We study direct numerical simulation (DNS) of turbulent channel flow at Reτ = 394 to investigate effect of large scale motions on fluctuating temperature field which forms a passive scalar field. Statistical description of the large scale features of the turbulent channel flow is obtained using two-point correlations of velocity components. Two-point correlations of fluctuating temperature field is also examined in order to identify possible similarities between velocity and temperature fields. The two-point cross-correlations betwen the velocity and temperature fluctuations are further analyzed to establish connections between these two fields. In addition, we use proper orhtogonal decompotion (POD) to extract most dominant modes of the fields and discuss the coupling of large scale features of turbulence and the temperature field.

A BAYESIAN ESTIMATE OF THE CMB–LARGE-SCALE STRUCTURE CROSS-CORRELATION

Energy Technology Data Exchange (ETDEWEB)

Moura-Santos, E. [Instituto de Física, Universidade de São Paulo, Rua do Matão trav. R 187, 05508-090, São Paulo—SP (Brazil); Carvalho, F. C. [Departamento de Física, Universidade do Estado do Rio Grande do Norte, 59610-210, Mossoró-RN (Brazil); Penna-Lima, M. [APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cité, 10, rue Alice Domon et Léonie Duquet, F-75205 Paris Cedex 13 (France); Novaes, C. P.; Wuensche, C. A., E-mail: emoura@if.usp.br, E-mail: fabiocabral@uern.br, E-mail: pennal@apc.in2p3.fr, E-mail: cawuenschel@das.inpe.br, E-mail: camilanovaes@on.br [Observatório Nacional, Rua General José Cristino 77, São Cristóvão, 20921-400, Rio de Janeiro, RJ (Brazil)

2016-08-01

Evidences for late-time acceleration of the universe are provided by multiple probes, such as Type Ia supernovae, the cosmic microwave background (CMB), and large-scale structure (LSS). In this work, we focus on the integrated Sachs–Wolfe (ISW) effect, i.e., secondary CMB fluctuations generated by evolving gravitational potentials due to the transition between, e.g., the matter and dark energy (DE) dominated phases. Therefore, assuming a flat universe, DE properties can be inferred from ISW detections. We present a Bayesian approach to compute the CMB–LSS cross-correlation signal. The method is based on the estimate of the likelihood for measuring a combined set consisting of a CMB temperature and galaxy contrast maps, provided that we have some information on the statistical properties of the fluctuations affecting these maps. The likelihood is estimated by a sampling algorithm, therefore avoiding the computationally demanding techniques of direct evaluation in either pixel or harmonic space. As local tracers of the matter distribution at large scales, we used the Two Micron All Sky Survey galaxy catalog and, for the CMB temperature fluctuations, the ninth-year data release of the Wilkinson Microwave Anisotropy Probe ( WMAP 9). The results show a dominance of cosmic variance over the weak recovered signal, due mainly to the shallowness of the catalog used, with systematics associated with the sampling algorithm playing a secondary role as sources of uncertainty. When combined with other complementary probes, the method presented in this paper is expected to be a useful tool to late-time acceleration studies in cosmology.

Signatures of non-universal large scales in conditional structure functions from various turbulent flows

International Nuclear Information System (INIS)

Blum, Daniel B; Voth, Greg A; Bewley, Gregory P; Bodenschatz, Eberhard; Gibert, Mathieu; Xu Haitao; Gylfason, Ármann; Mydlarski, Laurent; Yeung, P K

2011-01-01

We present a systematic comparison of conditional structure functions in nine turbulent flows. The flows studied include forced isotropic turbulence simulated on a periodic domain, passive grid wind tunnel turbulence in air and in pressurized SF 6 , active grid wind tunnel turbulence (in both synchronous and random driving modes), the flow between counter-rotating discs, oscillating grid turbulence and the flow in the Lagrangian exploration module (in both constant and random driving modes). We compare longitudinal Eulerian second-order structure functions conditioned on the instantaneous large-scale velocity in each flow to assess the ways in which the large scales affect the small scales in a variety of turbulent flows. Structure functions are shown to have larger values when the large-scale velocity significantly deviates from the mean in most flows, suggesting that dependence on the large scales is typical in many turbulent flows. The effects of the large-scale velocity on the structure functions can be quite strong, with the structure function varying by up to a factor of 2 when the large-scale velocity deviates from the mean by ±2 standard deviations. In several flows, the effects of the large-scale velocity are similar at all the length scales we measured, indicating that the large-scale effects are scale independent. In a few flows, the effects of the large-scale velocity are larger on the smallest length scales. (paper)

Cytology of DNA Replication Reveals Dynamic Plasticity of Large-Scale Chromatin Fibers.

Science.gov (United States)

Deng, Xiang; Zhironkina, Oxana A; Cherepanynets, Varvara D; Strelkova, Olga S; Kireev, Igor I; Belmont, Andrew S

2016-09-26

In higher eukaryotic interphase nuclei, the 100- to >1,000-fold linear compaction of chromatin is difficult to reconcile with its function as a template for transcription, replication, and repair. It is challenging to imagine how DNA and RNA polymerases with their associated molecular machinery would move along the DNA template without transient decondensation of observed large-scale chromatin "chromonema" fibers [1]. Transcription or "replication factory" models [2], in which polymerases remain fixed while DNA is reeled through, are similarly difficult to conceptualize without transient decondensation of these chromonema fibers. Here, we show how a dynamic plasticity of chromatin folding within large-scale chromatin fibers allows DNA replication to take place without significant changes in the global large-scale chromatin compaction or shape of these large-scale chromatin fibers. Time-lapse imaging of lac-operator-tagged chromosome regions shows no major change in the overall compaction of these chromosome regions during their DNA replication. Improved pulse-chase labeling of endogenous interphase chromosomes yields a model in which the global compaction and shape of large-Mbp chromatin domains remains largely invariant during DNA replication, with DNA within these domains undergoing significant movements and redistribution as they move into and then out of adjacent replication foci. In contrast to hierarchical folding models, this dynamic plasticity of large-scale chromatin organization explains how localized changes in DNA topology allow DNA replication to take place without an accompanying global unfolding of large-scale chromatin fibers while suggesting a possible mechanism for maintaining epigenetic programming of large-scale chromatin domains throughout DNA replication. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of drought propagation in an ensemble mean of large-scale hydrological models

NARCIS (Netherlands)

Loon, van A.F.; Huijgevoort, van M.H.J.; Lanen, van H.A.J.

2012-01-01

Hydrological drought is increasingly studied using large-scale models. It is, however, not sure whether large-scale models reproduce the development of hydrological drought correctly. The pressing question is how well do large-scale models simulate the propagation from meteorological to hydrological

Configuration management in large scale infrastructure development

NARCIS (Netherlands)

Rijn, T.P.J. van; Belt, H. van de; Los, R.H.

2000-01-01

Large Scale Infrastructure (LSI) development projects such as the construction of roads, rail-ways and other civil engineering (water)works is tendered differently today than a decade ago. Traditional workflow requested quotes from construction companies for construction works where the works to be

Dual Decomposition for Large-Scale Power Balancing

DEFF Research Database (Denmark)

Halvgaard, Rasmus; Jørgensen, John Bagterp; Vandenberghe, Lieven

2013-01-01

Dual decomposition is applied to power balancing of exible thermal storage units. The centralized large-scale problem is decomposed into smaller subproblems and solved locallyby each unit in the Smart Grid. Convergence is achieved by coordinating the units consumption through a negotiation...

Generation of large-scale vortives in compressible helical turbulence

International Nuclear Information System (INIS)

Chkhetiani, O.G.; Gvaramadze, V.V.

1989-01-01

We consider generation of large-scale vortices in compressible self-gravitating turbulent medium. The closed equation describing evolution of the large-scale vortices in helical turbulence with finite correlation time is obtained. This equation has the form similar to the hydromagnetic dynamo equation, which allows us to call the vortx genertation effect the vortex dynamo. It is possible that principally the same mechanism is responsible both for amplification and maintenance of density waves and magnetic fields in gaseous disks of spiral galaxies. (author). 29 refs

Biomass Gasification - A synthesis of technical barriers and current research issues for deployment at large scale

Energy Technology Data Exchange (ETDEWEB)

Heyne, Stefan [Chalmers Univ. of Technology, Gothenburg (Sweden); Liliedahl, Truls [KTH, Royal Inst. of Technology, Stockholm (Sweden); Marklund, Magnus [Energy Technology Centre, Piteaa (Sweden)

2013-09-01

Thermal gasification at large scale for cogeneration of power and heat and/or production of fuels and materials is a main pathway for a sustainable deployment of biomass resources. However, so far no such full scale production exists and biomass gasification projects remain at the pilot or demonstration scale. This report focuses on the key critical technology challenges for the large-scale deployment of the following biomass-based gasification concepts: Direct Fluidized Bed Gasification (FBG), Entrained Flow Gasification (EFG) and indirect Dual Fluidized Bed Gasification (DFBG). The main content in this report is based on responses from a number of experts in biomass gasification obtained from a questionnaire. The survey was composed of a number of more or less specific questions on technical barriers as to the three gasification concepts considered. For formalising the questionnaire, the concept of Technology Readiness Level (TRL 1-9) was used for grading the level of technical maturity of the different sub-processes within the three generic biomass gasification technologies. For direct fluidized bed gasification (FBG) it is mentioned that the technology is already available at commercial scale as air-blown technology and thus that air-blown FBG gasification may be reckoned a mature technology. The remaining technical challenge is the conversion to operation on oxygen with the final goal of producing chemicals or transport fuels. Tar reduction, in particular, and gas cleaning and upgrading in general are by far the most frequently named technical issues considered problematic. Other important aspects are problems that may occur when operating on low-grade fuels - i.e. low-cost fuels. These problems include bed agglomeration/ash sintering as well as alkali fouling. Even the preparation and feeding of these low-grade fuels tend to be problematic and require further development to be used on a commercial scale. Furthermore, efficient char conversion is mentioned by

Large-scale Intelligent Transporation Systems simulation

Energy Technology Data Exchange (ETDEWEB)

Ewing, T.; Canfield, T.; Hannebutte, U.; Levine, D.; Tentner, A.

1995-06-01

A prototype computer system has been developed which defines a high-level architecture for a large-scale, comprehensive, scalable simulation of an Intelligent Transportation System (ITS) capable of running on massively parallel computers and distributed (networked) computer systems. The prototype includes the modelling of instrumented ``smart`` vehicles with in-vehicle navigation units capable of optimal route planning and Traffic Management Centers (TMC). The TMC has probe vehicle tracking capabilities (display position and attributes of instrumented vehicles), and can provide 2-way interaction with traffic to provide advisories and link times. Both the in-vehicle navigation module and the TMC feature detailed graphical user interfaces to support human-factors studies. The prototype has been developed on a distributed system of networked UNIX computers but is designed to run on ANL`s IBM SP-X parallel computer system for large scale problems. A novel feature of our design is that vehicles will be represented by autonomus computer processes, each with a behavior model which performs independent route selection and reacts to external traffic events much like real vehicles. With this approach, one will be able to take advantage of emerging massively parallel processor (MPP) systems.

Organizational Influences on Interdisciplinary Interactions during Research and Design of Large-Scale Complex Engineered Systems

Science.gov (United States)

McGowan, Anna-Maria R.; Seifert, Colleen M.; Papalambros, Panos Y.

2012-01-01

The design of large-scale complex engineered systems (LaCES) such as an aircraft is inherently interdisciplinary. Multiple engineering disciplines, drawing from a team of hundreds to thousands of engineers and scientists, are woven together throughout the research, development, and systems engineering processes to realize one system. Though research and development (R&D) is typically focused in single disciplines, the interdependencies involved in LaCES require interdisciplinary R&D efforts. This study investigates the interdisciplinary interactions that take place during the R&D and early conceptual design phases in the design of LaCES. Our theoretical framework is informed by both engineering practices and social science research on complex organizations. This paper provides preliminary perspective on some of the organizational influences on interdisciplinary interactions based on organization theory (specifically sensemaking), data from a survey of LaCES experts, and the authors experience in the research and design. The analysis reveals couplings between the engineered system and the organization that creates it. Survey respondents noted the importance of interdisciplinary interactions and their significant benefit to the engineered system, such as innovation and problem mitigation. Substantial obstacles to interdisciplinarity are uncovered beyond engineering that include communication and organizational challenges. Addressing these challenges may ultimately foster greater efficiencies in the design and development of LaCES and improved system performance by assisting with the collective integration of interdependent knowledge bases early in the R&D effort. This research suggests that organizational and human dynamics heavily influence and even constrain the engineering effort for large-scale complex systems.

The Hamburg large scale geostrophic ocean general circulation model. Cycle 1

International Nuclear Information System (INIS)

Maier-Reimer, E.; Mikolajewicz, U.

1992-02-01

The rationale for the Large Scale Geostrophic ocean circulation model (LSG-OGCM) is based on the observations that for a large scale ocean circulation model designed for climate studies, the relevant characteristic spatial scales are large compared with the internal Rossby radius throughout most of the ocean, while the characteristic time scales are large compared with the periods of gravity modes and barotropic Rossby wave modes. In the present version of the model, the fast modes have been filtered out by a conventional technique of integrating the full primitive equations, including all terms except the nonlinear advection of momentum, by an implicit time integration method. The free surface is also treated prognostically, without invoking a rigid lid approximation. The numerical scheme is unconditionally stable and has the additional advantage that it can be applied uniformly to the entire globe, including the equatorial and coastal current regions. (orig.)

Soft X-ray Emission from Large-Scale Galactic Outflows in Seyfert Galaxies

Science.gov (United States)

Colbert, E. J. M.; Baum, S.; O'Dea, C.; Veilleux, S.

1998-01-01

Kiloparsec-scale soft X-ray nebulae extend along the galaxy minor axes in several Seyfert galaxies, including NGC 2992, NGC 4388 and NGC 5506. In these three galaxies, the extended X-ray emission observed in ROSAT HRI images has 0.2-2.4 keV X-ray luminosities of 0.4-3.5 x 10(40) erg s(-1) . The X-ray nebulae are roughly co-spatial with the large-scale radio emission, suggesting that both are produced by large-scale galactic outflows. Assuming pressure balance between the radio and X-ray plasmas, the X-ray filling factor is >~ 10(4) times as large as the radio plasma filling factor, suggesting that large-scale outflows in Seyfert galaxies are predominantly winds of thermal X-ray emitting gas. We favor an interpretation in which large-scale outflows originate as AGN-driven jets that entrain and heat gas on kpc scales as they make their way out of the galaxy. AGN- and starburst-driven winds are also possible explanations if the winds are oriented along the rotation axis of the galaxy disk. Since large-scale outflows are present in at least 50 percent of Seyfert galaxies, the soft X-ray emission from the outflowing gas may, in many cases, explain the ``soft excess" X-ray feature observed below 2 keV in X-ray spectra of many Seyfert 2 galaxies.

Pro website development and operations streamlining DevOps for large-scale websites

CERN Document Server

Sacks, Matthew

2012-01-01

Pro Website Development and Operations gives you the experience you need to create and operate a large-scale production website. Large-scale websites have their own unique set of problems regarding their design-problems that can get worse when agile methodologies are adopted for rapid results. Managing large-scale websites, deploying applications, and ensuring they are performing well often requires a full scale team involving the development and operations sides of the company-two departments that don't always see eye to eye. When departments struggle with each other, it adds unnecessary comp

Neutrinos and large-scale structure

International Nuclear Information System (INIS)

Eisenstein, Daniel J.

2015-01-01

I review the use of cosmological large-scale structure to measure properties of neutrinos and other relic populations of light relativistic particles. With experiments to measure the anisotropies of the cosmic microwave anisotropies and the clustering of matter at low redshift, we now have securely measured a relativistic background with density appropriate to the cosmic neutrino background. Our limits on the mass of the neutrino continue to shrink. Experiments coming in the next decade will greatly improve the available precision on searches for the energy density of novel relativistic backgrounds and the mass of neutrinos

Neutrinos and large-scale structure

Energy Technology Data Exchange (ETDEWEB)

Eisenstein, Daniel J. [Daniel J. Eisenstein, Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS #20, Cambridge, MA 02138 (United States)

2015-07-15

I review the use of cosmological large-scale structure to measure properties of neutrinos and other relic populations of light relativistic particles. With experiments to measure the anisotropies of the cosmic microwave anisotropies and the clustering of matter at low redshift, we now have securely measured a relativistic background with density appropriate to the cosmic neutrino background. Our limits on the mass of the neutrino continue to shrink. Experiments coming in the next decade will greatly improve the available precision on searches for the energy density of novel relativistic backgrounds and the mass of neutrinos.

Evaluation of Large-scale Public Sector Reforms

DEFF Research Database (Denmark)

Breidahl, Karen Nielsen; Gjelstrup, Gunnar; Hansen, Hanne Foss

2017-01-01

and more delimited policy areas take place. In our analysis we apply four governance perspectives (rational-instrumental, rational-interest based, institutional-cultural and a chaos perspective) in a comparative analysis of the evaluations of two large-scale public sector reforms in Denmark and Norway. We...

Highly Scalable Trip Grouping for Large Scale Collective Transportation Systems

DEFF Research Database (Denmark)

Gidofalvi, Gyozo; Pedersen, Torben Bach; Risch, Tore

2008-01-01

Transportation-related problems, like road congestion, parking, and pollution, are increasing in most cities. In order to reduce traffic, recent work has proposed methods for vehicle sharing, for example for sharing cabs by grouping "closeby" cab requests and thus minimizing transportation cost...... and utilizing cab space. However, the methods published so far do not scale to large data volumes, which is necessary to facilitate large-scale collective transportation systems, e.g., ride-sharing systems for large cities. This paper presents highly scalable trip grouping algorithms, which generalize previous...

Penalized Estimation in Large-Scale Generalized Linear Array Models

DEFF Research Database (Denmark)

Lund, Adam; Vincent, Martin; Hansen, Niels Richard

2017-01-01

Large-scale generalized linear array models (GLAMs) can be challenging to fit. Computation and storage of its tensor product design matrix can be impossible due to time and memory constraints, and previously considered design matrix free algorithms do not scale well with the dimension...

Large-scale coastal impact induced by a catastrophic storm

DEFF Research Database (Denmark)

Fruergaard, Mikkel; Andersen, Thorbjørn Joest; Johannessen, Peter N

breaching. Our results demonstrate that violent, millennial-scale storms can trigger significant large-scale and long-term changes on barrier coasts, and that coastal changes assumed to take place over centuries or even millennia may occur in association with a single extreme storm event....

Large-eddy simulation with accurate implicit subgrid-scale diffusion

NARCIS (Netherlands)

B. Koren (Barry); C. Beets

1996-01-01

textabstractA method for large-eddy simulation is presented that does not use an explicit subgrid-scale diffusion term. Subgrid-scale effects are modelled implicitly through an appropriate monotone (in the sense of Spekreijse 1987) discretization method for the advective terms. Special attention is

Challenges for Large Scale Structure Theory

CERN Multimedia

CERN. Geneva

2018-01-01

I will describe some of the outstanding questions in Cosmology where answers could be provided by observations of the Large Scale Structure of the Universe at late times.I will discuss some of the theoretical challenges which will have to be overcome to extract this information from the observations. I will describe some of the theoretical tools that might be useful to achieve this goal. 

Macroecological factors explain large-scale spatial population patterns of ancient agriculturalists

NARCIS (Netherlands)

Xu, C.; Chen, B.; Abades, S.; Reino, L.; Teng, S.; Ljungqvist, F.C.; Huang, Z.Y.X.; Liu, X.

2015-01-01

Aim: It has been well demonstrated that the large-scale distribution patterns of numerous species are driven by similar macroecological factors. However, understanding of this topic remains limited when applied to our own species. Here we take a large-scale look at ancient agriculturalist

Large Scale Investments in Infrastructure : Competing Policy regimes to Control Connections

NARCIS (Netherlands)

Otsuki, K.; Read, M.L.; Zoomers, E.B.

2016-01-01

This paper proposes to analyse implications of large-scale investments in physical infrastructure for social and environmental justice. While case studies on the global land rush and climate change have advanced our understanding of how large-scale investments in land, forests and water affect

Rotation invariant fast features for large-scale recognition

Science.gov (United States)

Takacs, Gabriel; Chandrasekhar, Vijay; Tsai, Sam; Chen, David; Grzeszczuk, Radek; Girod, Bernd

2012-10-01

We present an end-to-end feature description pipeline which uses a novel interest point detector and Rotation- Invariant Fast Feature (RIFF) descriptors. The proposed RIFF algorithm is 15× faster than SURF1 while producing large-scale retrieval results that are comparable to SIFT.2 Such high-speed features benefit a range of applications from Mobile Augmented Reality (MAR) to web-scale image retrieval and analysis.

Green Routing Fuel Saving Opportunity Assessment: A Case Study on California Large-Scale Real-World Travel Data

Energy Technology Data Exchange (ETDEWEB)

Zhu, Lei [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Holden, Jacob [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gonder, Jeffrey D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wood, Eric W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-07-31

New technologies, such as connected and automated vehicles, have attracted more and more researchers for improving the energy efficiency and environmental impact of current transportation systems. The green routing strategy instructs a vehicle to select the most fuel-efficient route before the vehicle departs. It benefits the current transportation system with fuel saving opportunity through identifying the greenest route. This paper introduces an evaluation framework for estimating benefits of green routing based on large-scale, real-world travel data. The framework has the capability to quantify fuel savings by estimating the fuel consumption of actual routes and comparing to routes procured by navigation systems. A route-based fuel consumption estimation model, considering road traffic conditions, functional class, and road grade is proposed and used in the framework. An experiment using a large-scale data set from the California Household Travel Survey global positioning system trajectory data base indicates that 31% of actual routes have fuel savings potential with a cumulative estimated fuel savings of 12%.

Large-scale bioenergy production: how to resolve sustainability trade-offs?

Science.gov (United States)

Humpenöder, Florian; Popp, Alexander; Bodirsky, Benjamin Leon; Weindl, Isabelle; Biewald, Anne; Lotze-Campen, Hermann; Dietrich, Jan Philipp; Klein, David; Kreidenweis, Ulrich; Müller, Christoph; Rolinski, Susanne; Stevanovic, Miodrag

2018-02-01

Large-scale 2nd generation bioenergy deployment is a key element of 1.5 °C and 2 °C transformation pathways. However, large-scale bioenergy production might have negative sustainability implications and thus may conflict with the Sustainable Development Goal (SDG) agenda. Here, we carry out a multi-criteria sustainability assessment of large-scale bioenergy crop production throughout the 21st century (300 EJ in 2100) using a global land-use model. Our analysis indicates that large-scale bioenergy production without complementary measures results in negative effects on the following sustainability indicators: deforestation, CO2 emissions from land-use change, nitrogen losses, unsustainable water withdrawals and food prices. One of our main findings is that single-sector environmental protection measures next to large-scale bioenergy production are prone to involve trade-offs among these sustainability indicators—at least in the absence of more efficient land or water resource use. For instance, if bioenergy production is accompanied by forest protection, deforestation and associated emissions (SDGs 13 and 15) decline substantially whereas food prices (SDG 2) increase. However, our study also shows that this trade-off strongly depends on the development of future food demand. In contrast to environmental protection measures, we find that agricultural intensification lowers some side-effects of bioenergy production substantially (SDGs 13 and 15) without generating new trade-offs—at least among the sustainability indicators considered here. Moreover, our results indicate that a combination of forest and water protection schemes, improved fertilization efficiency, and agricultural intensification would reduce the side-effects of bioenergy production most comprehensively. However, although our study includes more sustainability indicators than previous studies on bioenergy side-effects, our study represents only a small subset of all indicators relevant for the

Large-scale structure in the universe: Theory vs observations

International Nuclear Information System (INIS)

Kashlinsky, A.; Jones, B.J.T.

1990-01-01

A variety of observations constrain models of the origin of large scale cosmic structures. We review here the elements of current theories and comment in detail on which of the current observational data provide the principal constraints. We point out that enough observational data have accumulated to constrain (and perhaps determine) the power spectrum of primordial density fluctuations over a very large range of scales. We discuss the theories in the light of observational data and focus on the potential of future observations in providing even (and ever) tighter constraints. (orig.)

SWFSC/MMTD: Collaborative Large Whale Survey (CLaWS) 2015

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Collaborative Large Whale Survey is a joint field effort by Southwest Fisheries Science Center (SWFSC) and Alaska Fisheries Science Center (AFSC). The 4-month...

Evaluation of drought propagation in an ensemble mean of large-scale hydrological models

Directory of Open Access Journals (Sweden)

A. F. Van Loon

2012-11-01

Full Text Available Hydrological drought is increasingly studied using large-scale models. It is, however, not sure whether large-scale models reproduce the development of hydrological drought correctly. The pressing question is how well do large-scale models simulate the propagation from meteorological to hydrological drought? To answer this question, we evaluated the simulation of drought propagation in an ensemble mean of ten large-scale models, both land-surface models and global hydrological models, that participated in the model intercomparison project of WATCH (WaterMIP. For a selection of case study areas, we studied drought characteristics (number of droughts, duration, severity, drought propagation features (pooling, attenuation, lag, lengthening, and hydrological drought typology (classical rainfall deficit drought, rain-to-snow-season drought, wet-to-dry-season drought, cold snow season drought, warm snow season drought, composite drought.

Drought characteristics simulated by large-scale models clearly reflected drought propagation; i.e. drought events became fewer and longer when moving through the hydrological cycle. However, more differentiation was expected between fast and slowly responding systems, with slowly responding systems having fewer and longer droughts in runoff than fast responding systems. This was not found using large-scale models. Drought propagation features were poorly reproduced by the large-scale models, because runoff reacted immediately to precipitation, in all case study areas. This fast reaction to precipitation, even in cold climates in winter and in semi-arid climates in summer, also greatly influenced the hydrological drought typology as identified by the large-scale models. In general, the large-scale models had the correct representation of drought types, but the percentages of occurrence had some important mismatches, e.g. an overestimation of classical rainfall deficit droughts, and an

AGN Populations in Large-volume X-Ray Surveys: Photometric Redshifts and Population Types Found in the Stripe 82X Survey

Science.gov (United States)

Ananna, Tonima Tasnin; Salvato, Mara; LaMassa, Stephanie; Urry, C. Megan; Cappelluti, Nico; Cardamone, Carolin; Civano, Francesca; Farrah, Duncan; Gilfanov, Marat; Glikman, Eilat; Hamilton, Mark; Kirkpatrick, Allison; Lanzuisi, Giorgio; Marchesi, Stefano; Merloni, Andrea; Nandra, Kirpal; Natarajan, Priyamvada; Richards, Gordon T.; Timlin, John

2017-11-01

Multiwavelength surveys covering large sky volumes are necessary to obtain an accurate census of rare objects such as high-luminosity and/or high-redshift active galactic nuclei (AGNs). Stripe 82X is a 31.3 X-ray survey with Chandra and XMM-Newton observations overlapping the legacy Sloan Digital Sky Survey Stripe 82 field, which has a rich investment of multiwavelength coverage from the ultraviolet to the radio. The wide-area nature of this survey presents new challenges for photometric redshifts for AGNs compared to previous work on narrow-deep fields because it probes different populations of objects that need to be identified and represented in the library of templates. Here we present an updated X-ray plus multiwavelength matched catalog, including Spitzer counterparts, and estimated photometric redshifts for 5961 (96% of a total of 6181) X-ray sources that have a normalized median absolute deviation, σnmad=0.06, and an outlier fraction, η = 13.7%. The populations found in this survey and the template libraries used for photometric redshifts provide important guiding principles for upcoming large-area surveys such as eROSITA and 3XMM (in X-ray) and the Large Synoptic Survey Telescope (optical).

Child Wasting in Emergency Pockets: A Meta-Analysis of Small-Scale Surveys from Ethiopia

Directory of Open Access Journals (Sweden)

Chiara Altare

2016-01-01

Full Text Available Child undernutrition is a major public health concern in Ethiopia (stunting national prevalence: 44%; wasting: 10%, despite the overall improvement in child health status during the last decade. Hundreds of small-scale surveys are conducted in Ethiopia’s emergency pockets under ENCU’s supervision. We reviewed the evidence from small-scale surveys conducted between 2008 and 2013 with two objectives: to provide a summary estimate of wasting prevalence from emergency pockets and to examine reasons for variation in prevalence estimates. We created a dataset by combining data from the Complex Emergency Database, the Famine Early Warning System Network and the Armed Conflict Location Event Data. We conducted a meta-analysis of small-scale surveys using a random effects model with known within-study heterogeneity. The influence of survey covariates on estimated prevalence was investigated with meta-regression techniques. We included 158 surveys in the analysis. A high degree of heterogeneity among surveys was observed. The overall estimate of wasting prevalence was 10.6% (95% CI 9.8–11.4, with differences among regions and between residents and refugees. Meta-regression results showed that vaccination coverage, child mortality, diarrhea prevalence and food insecurity are significantly associated with wasting prevalence. Child care and displacement status were not. Aggregated analysis of small-scale surveys provides insights into the prevalence of wasting and factors explaining its variation. It can also guide survey planning towards areas with limited data availability.

Toward Instructional Leadership: Principals' Perceptions of Large-Scale Assessment in Schools

Science.gov (United States)

Prytula, Michelle; Noonan, Brian; Hellsten, Laurie

2013-01-01

This paper describes a study of the perceptions that Saskatchewan school principals have regarding large-scale assessment reform and their perceptions of how assessment reform has affected their roles as principals. The findings revealed that large-scale assessments, especially provincial assessments, have affected the principal in Saskatchewan…

A large scale field experiment in the Amazon basin (LAMBADA/BATERISTA)

NARCIS (Netherlands)

Dolman, A.J.; Kabat, P.; Gash, J.H.C.; Noilhan, J.; Jochum, A.M.; Nobre, C.

1995-01-01

A description is given of a large-scale field experiment planned in the Amazon basin, aimed at assessing the large-scale balances of energy, water and carbon dioxide. The embedding of this experiment in global change programmes is described, viz. the Biospheric Aspects of the Hydrological Cycle

Large-scale derived flood frequency analysis based on continuous simulation

Science.gov (United States)

Dung Nguyen, Viet; Hundecha, Yeshewatesfa; Guse, Björn; Vorogushyn, Sergiy; Merz, Bruno

2016-04-01

There is an increasing need for spatially consistent flood risk assessments at the regional scale (several 100.000 km2), in particular in the insurance industry and for national risk reduction strategies. However, most large-scale flood risk assessments are composed of smaller-scale assessments and show spatial inconsistencies. To overcome this deficit, a large-scale flood model composed of a weather generator and catchments models was developed reflecting the spatially inherent heterogeneity. The weather generator is a multisite and multivariate stochastic model capable of generating synthetic meteorological fields (precipitation, temperature, etc.) at daily resolution for the regional scale. These fields respect the observed autocorrelation, spatial correlation and co-variance between the variables. They are used as input into catchment models. A long-term simulation of this combined system enables to derive very long discharge series at many catchment locations serving as a basic for spatially consistent flood risk estimates at the regional scale. This combined model was set up and validated for major river catchments in Germany. The weather generator was trained by 53-year observation data at 528 stations covering not only the complete Germany but also parts of France, Switzerland, Czech Republic and Australia with the aggregated spatial scale of 443,931 km2. 10.000 years of daily meteorological fields for the study area were generated. Likewise, rainfall-runoff simulations with SWIM were performed for the entire Elbe, Rhine, Weser, Donau and Ems catchments. The validation results illustrate a good performance of the combined system, as the simulated flood magnitudes and frequencies agree well with the observed flood data. Based on continuous simulation this model chain is then used to estimate flood quantiles for the whole Germany including upstream headwater catchments in neighbouring countries. This continuous large scale approach overcomes the several

Black-Box Search by Unbiased Variation

DEFF Research Database (Denmark)

Lehre, Per Kristian; Witt, Carsten

2012-01-01

The complexity theory for black-box algorithms, introduced by Droste, Jansen, and Wegener (Theory Comput. Syst. 39:525–544, 2006), describes common limits on the efficiency of a broad class of randomised search heuristics. There is an obvious trade-off between the generality of the black-box model...... and the strength of the bounds that can be proven in such a model. In particular, the original black-box model provides for well-known benchmark problems relatively small lower bounds, which seem unrealistic in certain cases and are typically not met by popular search heuristics.In this paper, we introduce a more...... restricted black-box model for optimisation of pseudo-Boolean functions which we claim captures the working principles of many randomised search heuristics including simulated annealing, evolutionary algorithms, randomised local search, and others. The key concept worked out is an unbiased variation operator...

Socio-cultural impacts of large-scale cruise tourism in Souq Mutrah, Sultanate of Oman

Directory of Open Access Journals (Sweden)

Manuela Gutberlet

2016-02-01

Full Text Available The following paper explores socio-cultural impacts of large-scale cruise liner tourism on the traditional bazaar (souq in the district of Mutrah. The souq is located opposite the port in the Omani capital Muscat. Large-scale cruise tourism in Muscat started only in 2004 and has increased in scale and numbers in the past years. 24 cruise vessels with around 7600 passengers arrived in Muscat in 2005. Seven years later 135 cruise liners carrying 257,000 tourists docked in Muscat. Due to this dramatic rise of international cruise ships, the socio-cultural impacts have increased for local residents, shop vendors/owners and tourists alike. To capture those socio-cultural impacts on Souq Mutrah, a survey of cruise tourists was conducted by a questionnaire. In addition, the researcher used participatory observation, counting, and in-depth interviews with different stakeholders of the local community and different types of tourists during the cruise seasons 2012/13 and 2013/14. Moreover, content analysis of statistics and local media publications were used. Results indicate that the souq has become “the core of a tourist bubble”, where crowding is a major problem and local residents avoid the place. The social carrying capacity of the souq has been reached. Omani vendors are leaving their businesses and renting their shops out to expatriates. Since contemporary cruise tourists are low spenders, expatriate shop sellers have become more aggressive.