WorldWideScience

Sample records for hierarchical caustic maps

  1. Programming with Hierarchical Maps

    DEFF Research Database (Denmark)

    Ørbæk, Peter

    This report desribes the hierarchical maps used as a central data structure in the Corundum framework. We describe its most prominent features, ague for its usefulness and briefly describe some of the software prototypes implemented using the technology....

  2. Hierarchical Reverberation Mapping

    CERN Document Server

    Brewer, Brendon J

    2013-01-01

    Reverberation mapping (RM) is an important technique in studies of active galactic nuclei (AGN). The key idea of RM is to measure the time lag $\\tau$ between variations in the continuum emission from the accretion disc and subsequent response of the broad line region (BLR). The measurement of $\\tau$ is typically used to estimate the physical size of the BLR and is combined with other measurements to estimate the black hole mass $M_{\\rm BH}$. A major difficulty with RM campaigns is the large amount of data needed to measure $\\tau$. Recently, Fine et al (2012) introduced a new approach to RM where the BLR light curve is sparsely sampled, but this is counteracted by observing a large sample of AGN, rather than a single system. The results are combined to infer properties of the sample of AGN. In this letter we implement this method using a hierarchical Bayesian model and contrast this with the results from the previous stacked cross-correlation technique. We find that our inferences are more precise and allow fo...

  3. Hierarchical Reverberation Mapping

    OpenAIRE

    Brendon J. Brewer; Elliott, Tom M.

    2013-01-01

    Reverberation mapping (RM) is an important technique in studies of active galactic nuclei (AGN). The key idea of RM is to measure the time lag $\\tau$ between variations in the continuum emission from the accretion disc and subsequent response of the broad line region (BLR). The measurement of $\\tau$ is typically used to estimate the physical size of the BLR and is combined with other measurements to estimate the black hole mass $M_{\\rm BH}$. A major difficulty with RM campaigns is the large a...

  4. [Caustic ingestions].

    Science.gov (United States)

    Adukauskiene, Dalia; Mazeikiene, Sandra; Rumba, Arvydas; Vizgirdaite, Venta

    2009-01-01

    Caustic ingestions (alkalis, acids) may cause severe chemical burns and lifelong complications, which worsen life quality. Approximately 80% of caustic ingestions occur in children. They mostly intoxicate because of chemical substances kept insecurely or in inappropriate containers. Until now, there is no general opinion about diagnostics and management of caustic ingestions. Therefore, the main aim of this article is accurately represent diagnostic and treatment options believing that this information would help physicians to diagnose caustic ingestions easier and faster, to provide emergency management correctly, and to avoid acute and chronic complications.

  5. Hierarchical Gompertzian growth maps with application in astrophysics

    CERN Document Server

    De Martino, S

    2010-01-01

    The Gompertz model describes the growth in time of the size of significant quantities associated to a large number of systems, taking into account nonlinearity features by a linear equation satisfied by a nonlinear function of the size. Following this scheme, we introduce a class of hierarchical maps which describe discrete sequences of intermediate characteristic scales. We find the general solutions of the maps, which account for a rich set of possible phenomena. Eventually, we provide an important application, by showing that a map belonging to the class so introduced generates all the observed astrophysical length and mass scales.

  6. Mobile Robot Hierarchical Simultaneous Localization and Mapping Using Monocular Vision

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A hierarchical mobile robot simultaneous localization and mapping (SLAM) method that allows us to obtain accurate maps was presented. The local map level is composed of a set of local metric feature maps that are guaranteed to be statistically independent. The global level is a topological graph whose arcs are labeled with the relative location between local maps. An estimation of these relative locations is maintained with local map alignment algorithm, and more accurate estimation is calculated through a global minimization procedure using the loop closure constraint. The local map is built with Rao-Blackwellised particle filter (RBPF), where the particle filter is used to extending the path posterior by sampling new poses. The landmark position estimation and update is implemented through extended Kalman filter (EKF). Monocular vision mounted on the robot tracks the 3D natural point landmarks, which are structured with matching scale invariant feature transform (SIFT) feature pairs. The matching for multi-dimension SIFT features is implemented with a KD-tree in the time cost of O(lbN). Experiment results on Pioneer mobile robot in a real indoor environment show the superior performance of our proposed method.

  7. Controlling light in Airy and higher-order caustic photonic structures

    Science.gov (United States)

    Zannotti, Alessandro; Diebel, Falko; Rüschenbaum, Matthias; Denz, Cornelia

    2017-06-01

    Caustics form geometrically stable structures in light and are hierarchically categorized by the catastrophe theory. We embed higher-order cusp and swallowtail catastrophes in paraxial beams and investigate their dynamics. Utilizing high-intensity caustics that propagate on curved trajectories, we realize photonic caustic lattices in photosensitive media, and demonstrate waveguiding with a rich diversity of light guiding paths.

  8. Rendering Caustics on Non-Lambertian Surfaces

    DEFF Research Database (Denmark)

    Jensen, Henrik Wann

    1997-01-01

    This paper presents a new technique for rendering caustics on non-Lambertian surfaces. The method is based on an extension of the photon map which removes previous restrictions limiting the usage to Lambertian surfaces. We add information about the incoming direction to the photons and this allow...... reduces the rendering time. We have used the method to render caustics on surfaces with reflectance functions varying from Lambertian to glossy specular....

  9. Caustics for Spherical Waves

    CERN Document Server

    de Rham, Claudia

    2016-01-01

    We study the development of caustics in shift-symmetric scalar field theories by focusing on simple waves with an $SO(p)$-symmetry in an arbitrary number of space dimensions. We show that the Galileon and the DBI-Galileon naturally emerge as the unique set of caustic-free theories, highlighting a link between the caustic-free condition for simple $SO(p)$-waves and the existence of either a global galilean symmetry or a global relativistic galilean symmetry.

  10. Electron caustic lithography

    Directory of Open Access Journals (Sweden)

    S. M. Kennedy

    2012-06-01

    Full Text Available A maskless method of electron beam lithography is described which uses the reflection of an electron beam from an electrostatic mirror to produce caustics in the demagnified image projected onto a resist–coated wafer. By varying the electron optics, e.g. via objective lens defocus, both the morphology and dimensions of the caustic features may be controlled, producing a range of bright and tightly focused projected features. The method is illustrated for line and fold caustics and is complementary to other methods of reflective electron beam lithography.

  11. Space-time caustics

    Directory of Open Access Journals (Sweden)

    Arthur D. Gorman

    1986-01-01

    Full Text Available The Lagrange manifold (WKB formalism enables the determination of the asymptotic series solution of linear differential equations modelling wave propagation in spatially inhomogeneous media at caustic (turning points. Here the formalism is adapted to determine a class of asymptotic solutions at caustic points for those equations modelling wave propagation in media with both spatial and temporal inhomogeneities. The analogous Schrodinger equation is also considered.

  12. A Privacy Data-Oriented Hierarchical MapReduce Programming Model

    Directory of Open Access Journals (Sweden)

    Haiwen Han

    2013-08-01

    Full Text Available To realize privacy data protection efficiently in hybrid cloud service, a hierarchical control architecture based multi-cluster MapReduce programming model (the Hierarchical MapReduce Model,HMR is presented. Under this hierarchical control architecture,  data isolation and placement among private cloud and public clouds according to the data privacy characteristic is implemented by the control center in private cloud.  And then, to perform the corresponding distributed parallel computation correctly under the multi-clusters mode that is different to the conventional single-cluster mode, the Map-Reduce-GlobalReduce three stage scheduling process is designed. Limiting the computation about privacy data in private cloud while outsourcing the computation about non-privacy data to public clouds as much as possible, HMR reaches the performance of both security and low cost.  

  13. A Hierarchical and Distributed Approach for Mapping Large Applications to Heterogeneous Grids using Genetic Algorithms

    Science.gov (United States)

    Sanyal, Soumya; Jain, Amit; Das, Sajal K.; Biswas, Rupak

    2003-01-01

    In this paper, we propose a distributed approach for mapping a single large application to a heterogeneous grid environment. To minimize the execution time of the parallel application, we distribute the mapping overhead to the available nodes of the grid. This approach not only provides a fast mapping of tasks to resources but is also scalable. We adopt a hierarchical grid model and accomplish the job of mapping tasks to this topology using a scheduler tree. Results show that our three-phase algorithm provides high quality mappings, and is fast and scalable.

  14. Spatio-temporal map generalizations with the hierarchical Voronoi data structure

    DEFF Research Database (Denmark)

    Mioc, Darka; Anton, François; Gold, Christopher M.

    of map objects, together with their temporal and spatial adjacency relationships. In this paper, we present new solutions to the problems of spatio-temporal generalizations using the hierarchical Voronoi spatio-temporal data structure. The application of the hierarchical Voronoi data structure presented...... in this research is in spatio-temporal map generalization, which is needed for reasoning about dynamic aspects of the world, primarily about actions, events and processes. This provides an advance in the domain of map generalization as we are able to deal not only with the cartographic objects, but also...... implemented in commercial GIS systems. In this research, we used the Voronoi spatial data model for map generalizations. We were able to demonstrate that the map generalization does not affect only spatial objects (points, lines or polygons), but also the events corresponding to the creation and modification...

  15. Mapping informative clusters in a hierarchical [corrected] framework of FMRI multivariate analysis.

    Directory of Open Access Journals (Sweden)

    Rui Xu

    Full Text Available Pattern recognition methods have become increasingly popular in fMRI data analysis, which are powerful in discriminating between multi-voxel patterns of brain activities associated with different mental states. However, when they are used in functional brain mapping, the location of discriminative voxels varies significantly, raising difficulties in interpreting the locus of the effect. Here we proposed a hierarchical framework of multivariate approach that maps informative clusters rather than voxels to achieve reliable functional brain mapping without compromising the discriminative power. In particular, we first searched for local homogeneous clusters that consisted of voxels with similar response profiles. Then, a multi-voxel classifier was built for each cluster to extract discriminative information from the multi-voxel patterns. Finally, through multivariate ranking, outputs from the classifiers were served as a multi-cluster pattern to identify informative clusters by examining interactions among clusters. Results from both simulated and real fMRI data demonstrated that this hierarchical approach showed better performance in the robustness of functional brain mapping than traditional voxel-based multivariate methods. In addition, the mapped clusters were highly overlapped for two perceptually equivalent object categories, further confirming the validity of our approach. In short, the hierarchical framework of multivariate approach is suitable for both pattern classification and brain mapping in fMRI studies.

  16. Caustics in dark matter haloes

    CERN Document Server

    Mohayaee, R; Mohayaee, Roya; Colombi, Stephane; Fort, Bernard; Gavazzi, Raphael; Shandarin, Sergei; Touma, Jihad

    2005-01-01

    Cold dark matter haloes are populated by high-density structures with sharply-peaked profiles known as caustics which have not yet been resolved by 3-dimensional numerical simulations. Here, we derive semi-analytic expressions for the density profiles near caustics in haloes which form by self-similar accretions of dark matter with infinitesimal velocity dispersion. A simple rescaling shows that these profiles are universal: they are valid for all caustics and irrespective of physical parameters of the halo. We derive the maximum density of the caustics and show that it depends on the velocity dispersion and the caustic location. Finally, we demonstrate that there can be a significant contribution to the emission measure from dark matter particle annihilation in the caustics.

  17. Disparity map generation from illumination variant stereo images using efficient hierarchical dynamic programming.

    Science.gov (United States)

    Borisagar, Viral H; Zaveri, Mukesh A

    2014-01-01

    A novel hierarchical stereo matching algorithm is presented which gives disparity map as output from illumination variant stereo pair. Illumination difference between two stereo images can lead to undesirable output. Stereo image pair often experience illumination variations due to many factors like real and practical situation, spatially and temporally separated camera positions, environmental illumination fluctuation, and the change in the strength or position of the light sources. Window matching and dynamic programming techniques are employed for disparity map estimation. Good quality disparity map is obtained with the optimized path. Homomorphic filtering is used as a preprocessing step to lessen illumination variation between the stereo images. Anisotropic diffusion is used to refine disparity map to give high quality disparity map as a final output. The robust performance of the proposed approach is suitable for real life circumstances where there will be always illumination variation between the images. The matching is carried out in a sequence of images representing the same scene, however in different resolutions. The hierarchical approach adopted decreases the computation time of the stereo matching problem. This algorithm can be helpful in applications like robot navigation, extraction of information from aerial surveys, 3D scene reconstruction, and military and security applications. Similarity measure SAD is often sensitive to illumination variation. It produces unacceptable disparity map results for illumination variant left and right images. Experimental results show that our proposed algorithm produces quality disparity maps for both wide range of illumination variant and invariant stereo image pair.

  18. Disparity Map Generation from Illumination Variant Stereo Images Using Efficient Hierarchical Dynamic Programming

    Directory of Open Access Journals (Sweden)

    Viral H. Borisagar

    2014-01-01

    Full Text Available A novel hierarchical stereo matching algorithm is presented which gives disparity map as output from illumination variant stereo pair. Illumination difference between two stereo images can lead to undesirable output. Stereo image pair often experience illumination variations due to many factors like real and practical situation, spatially and temporally separated camera positions, environmental illumination fluctuation, and the change in the strength or position of the light sources. Window matching and dynamic programming techniques are employed for disparity map estimation. Good quality disparity map is obtained with the optimized path. Homomorphic filtering is used as a preprocessing step to lessen illumination variation between the stereo images. Anisotropic diffusion is used to refine disparity map to give high quality disparity map as a final output. The robust performance of the proposed approach is suitable for real life circumstances where there will be always illumination variation between the images. The matching is carried out in a sequence of images representing the same scene, however in different resolutions. The hierarchical approach adopted decreases the computation time of the stereo matching problem. This algorithm can be helpful in applications like robot navigation, extraction of information from aerial surveys, 3D scene reconstruction, and military and security applications. Similarity measure SAD is often sensitive to illumination variation. It produces unacceptable disparity map results for illumination variant left and right images. Experimental results show that our proposed algorithm produces quality disparity maps for both wide range of illumination variant and invariant stereo image pair.

  19. Intrusion Detection Method Based on Improved Growing Hierarchical Self-Organizing Map

    Institute of Scientific and Technical Information of China (English)

    张亚平; 布文秀; 苏畅; 王璐瑶; 许涵

    2016-01-01

    Considering that growing hierarchical self-organizing map(GHSOM) ignores the influence of individ-ual component in sample vector analysis, and its accurate rate in detecting unknown network attacks is relatively lower, an improved GHSOM method combined with mutual information is proposed. After theoretical analysis, experiments are conducted to illustrate the effectiveness of the proposed method by accurately clustering the input data. Based on different clusters, the complex relationship within the data can be revealed effectively.

  20. A hierarchical Bayesian-MAP approach to inverse problems in imaging

    Science.gov (United States)

    Raj, Raghu G.

    2016-07-01

    We present a novel approach to inverse problems in imaging based on a hierarchical Bayesian-MAP (HB-MAP) formulation. In this paper we specifically focus on the difficult and basic inverse problem of multi-sensor (tomographic) imaging wherein the source object of interest is viewed from multiple directions by independent sensors. Given the measurements recorded by these sensors, the problem is to reconstruct the image (of the object) with a high degree of fidelity. We employ a probabilistic graphical modeling extension of the compound Gaussian distribution as a global image prior into a hierarchical Bayesian inference procedure. Since the prior employed by our HB-MAP algorithm is general enough to subsume a wide class of priors including those typically employed in compressive sensing (CS) algorithms, HB-MAP algorithm offers a vehicle to extend the capabilities of current CS algorithms to include truly global priors. After rigorously deriving the regression algorithm for solving our inverse problem from first principles, we demonstrate the performance of the HB-MAP algorithm on Monte Carlo trials and on real empirical data (natural scenes). In all cases we find that our algorithm outperforms previous approaches in the literature including filtered back-projection and a variety of state-of-the-art CS algorithms. We conclude with directions of future research emanating from this work.

  1. A Sparse Hierarchical Map Representation for Mars Science Laboratory Science Operations

    Science.gov (United States)

    Nefian, A. V.; Edwards, L. J.; Keely, L.; Lees, D. S.; Fluckinger, L.; Malin, M. C.; Parker, T. J.

    2015-12-01

    We describe a solution for multi-scale Mars terrain modeling and mapping with Digital Elevation Models (DEMs) and co-registered orthogonally projected imagery (ortho-images). High resolution DEMs and ortho-images derived from Mars Science Laboratory (MSL) rover science and navigation cameras are represented in context with lower resolution, wide coverage DEMs and ortho-images derived from Mars Reconnaissance Orbiter (MRO) HiRISE and CTX camera images and Mars Express (MEX) mission HRSC images. Merging MSL rover image derived terrain models with those from orbital images at a uniform high resolution would require super-sampling of the orbital data across a large area to maintain significant context. This solution is not practical, and would result in a mapping product of enormous size. Instead, we choose a sparse hierarchical map representation. Each level in this hierarchical representation is a map described by a set of tiles with fixed number of samples and fixed resolution. The number of samples in a tile is fixed for all levels and each level is associated with a specific resolution. In this work, the resolution ratio between two adjacent levels is set to two. The map at each level is sparse and it contains only the tiles for which data is available at the resolution of the given level. For example, at the highest resolution level only MSL science camera models are available and only a small set of tiles are generated in a sparse map. At the lowest resolution, the map contains the complete set of tiles. The reference level of the representation is chosen to be the HiRISE terrain model and CTX, HRSC and MSL data are projected onto this model before being mapped. While our terrain representation was developed for use in "Antares", a visual planning and sequencing tool for MSL science cameras developed at NASA Ames Research Center, it is general purpose and has a number of potential geo-science visualization applications.

  2. Wavefield extrapolation in caustic-free normal ray coordinates

    KAUST Repository

    Ma, Xuxin

    2012-11-04

    Normal ray coordinates are conventionally constructed from ray tracing, which inherently requires smooth velocity profiles. To use rays as coordinates, the velocities have to be smoothed further to avoid caustics, which is detrimental to the mapping process. Solving the eikonal equation numerically for a line source at the surface provides a platform to map normal rays in complex unsmoothed velocity models and avoid caustics. We implement reverse-time migration (RTM) and downward continuation in the new ray coordinate system, which allows us to obtain efficient images and avoid some of the dip limitations of downward continuation.

  3. Full hierarchic versus non-hierarchic classification approaches for mapping sealed surfaces at the rural-urban fringe using high-resolution satellite data.

    Science.gov (United States)

    De Roeck, Tim; Van de Voorde, Tim; Canters, Frank

    2009-01-01

    Since 2008 more than half of the world population is living in cities and urban sprawl is continuing. Because of these developments, the mapping and monitoring of urban environments and their surroundings is becoming increasingly important. In this study two object-oriented approaches for high-resolution mapping of sealed surfaces are compared: a standard non-hierarchic approach and a full hierarchic approach using both multi-layer perceptrons and decision trees as learning algorithms. Both methods outperform the standard nearest neighbour classifier, which is used as a benchmark scenario. For the multi-layer perceptron approach, applying a hierarchic classification strategy substantially increases the accuracy of the classification. For the decision tree approach a one-against-all hierarchic classification strategy does not lead to an improvement of classification accuracy compared to the standard all-against-all approach. Best results are obtained with the hierarchic multi-layer perceptron classification strategy, producing a kappa value of 0.77. A simple shadow reclassification procedure based on characteristics of neighbouring objects further increases the kappa value to 0.84.

  4. Causticizing for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Scott Sinquefeld; James Cantrell; Xiaoyan Zeng; Alan Ball; Jeff Empie

    2009-01-07

    The cost-benefit outlook of black liquor gasification (BLG) could be greatly improved if the smelt causticization step could be achieved in situ during the gasification step. Or, at a minimum, the increase in causticizing load associated with BLG could be mitigated. A number of chemistries have been proven successful during black liquor combustion. In this project, three in situ causticizing processes (titanate, manganate, and borate) were evaluated under conditions suitable for high temperature entrained flow BLG, and low temperature steam reforming of black liquor. The evaluation included both thermodynamic modeling and lab experimentation. Titanate and manganate were tested for complete direct causticizing (to thus eliminate the lime cycle), and borates were evaluated for partial causticizing (to mitigate the load increase associated with BLG). Criteria included high carbonate conversion, corresponding hydroxide recovery upon hydrolysis, non process element (NPE) removal, and economics. Of the six cases (three chemistries at two BLG conditions), only two were found to be industrially viable: titanates for complete causticizing during high temperature BLG, and borates for partial causticizing during high temperature BLG. These two cases were evaluated for integration into a gasification-based recovery island. The Larsen [28] BLG cost-benefit study was used as a reference case for economic forecasting (i.e. a 1500 tpd pulp mill using BLG and upgrading the lime cycle). By comparison, using the titanate direct causticizing process yielded a net present value (NPV) of $25M over the NPV of BLG with conventional lime cycle. Using the existing lime cycle plus borate autocausticizing for extra capacity yielded a NPV of $16M.

  5. Critical Curves and Caustics of Triple-lens Models

    Science.gov (United States)

    Daněk, Kamil; Heyrovský, David

    2015-06-01

    Among the 25 planetary systems detected up to now by gravitational microlensing, there are two cases of a star with two planets, and two cases of a binary star with a planet. Other, yet undetected types of triple lenses include triple stars or stars with a planet with a moon. The analysis and interpretation of such events is hindered by the lack of understanding of essential characteristics of triple lenses, such as their critical curves and caustics. We present here analytical and numerical methods for mapping the critical-curve topology and caustic cusp number in the parameter space of n-point-mass lenses. We apply the methods to the analysis of four symmetric triple-lens models, and obtain altogether 9 different critical-curve topologies and 32 caustic structures. While these results include various generic types, they represent just a subset of all possible triple-lens critical curves and caustics. Using the analyzed models, we demonstrate interesting features of triple lenses that do not occur in two-point-mass lenses. We show an example of a lens that cannot be described by the Chang-Refsdal model in the wide limit. In the close limit we demonstrate unusual structures of primary and secondary caustic loops, and explain the conditions for their occurrence. In the planetary limit we find that the presence of a planet may lead to a whole sequence of additional caustic metamorphoses. We show that a pair of planets may change the structure of the primary caustic even when placed far from their resonant position at the Einstein radius.

  6. Multi-scale hierarchical approach for parametric mapping: assessment on multi-compartmental models.

    Science.gov (United States)

    Rizzo, G; Turkheimer, F E; Bertoldo, A

    2013-02-15

    This paper investigates a new hierarchical method to apply basis function to mono- and multi-compartmental models (Hierarchical-Basis Function Method, H-BFM) at a voxel level. This method identifies the parameters of the compartmental model in its nonlinearized version, integrating information derived at the region of interest (ROI) level by segmenting the cerebral volume based on anatomical definition or functional clustering. We present the results obtained by using a two tissue-four rate constant model with two different tracers ([(11)C]FLB457 and [carbonyl-(11)C]WAY100635), one of the most complex models used in receptor studies, especially at the voxel level. H-BFM is robust and its application on both [(11)C]FLB457 and [carbonyl-(11)C]WAY100635 allows accurate and precise parameter estimates, good quality parametric maps and a low percentage of voxels out of physiological bound (approach for PET quantification by using compartmental modeling at the voxel level. In particular, different from other proposed approaches, this method can also be used when the linearization of the model is not appropriate. We expect that applying it to clinical data will generate reliable parametric maps. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Cosmological parameters, shear maps and power spectra from CFHTLenS using Bayesian hierarchical inference

    CERN Document Server

    Alsing, Justin; Jaffe, Andrew H

    2016-01-01

    We apply two Bayesian hierarchical inference schemes to infer shear power spectra, shear maps and cosmological parameters from the CFHTLenS weak lensing survey - the first application of this method to data. In the first approach, we sample the joint posterior distribution of the shear maps and power spectra by Gibbs sampling, with minimal model assumptions. In the second approach, we sample the joint posterior of the shear maps and cosmological parameters, providing a new, accurate and principled approach to cosmological parameter inference from cosmic shear data. As a first demonstration on data we perform a 2-bin tomographic analysis to constrain cosmological parameters and investigate the possibility of photometric redshift bias in the CFHTLenS data. Under the baseline $\\Lambda$CDM model we constrain $S_8 = \\sigma_8(\\Omega_\\mathrm{m}/0.3)^{0.5} = 0.67 ^{\\scriptscriptstyle+ 0.03 }_{\\scriptscriptstyle- 0.03 }$ $(68\\%)$, consistent with previous CFHTLenS analysis but in tension with Planck. Adding neutrino m...

  8. Marginality: a numerical mapping for enhanced treatment of nominal and hierarchical attributes

    CERN Document Server

    Domingo-Ferrer, Josep

    2012-01-01

    The purpose of statistical disclosure control (SDC) of microdata, a.k.a. data anonymization or privacy-preserving data mining, is to publish data sets containing the answers of individual respondents in such a way that the respondents corresponding to the released records cannot be re-identified and the released data are analytically useful. SDC methods are either based on masking the original data, generating synthetic versions of them or creating hybrid versions by combining original and synthetic data. The choice of SDC methods for categorical data, especially nominal data, is much smaller than the choice of methods for numerical data. We mitigate this problem by introducing a numerical mapping for hierarchical nominal data which allows computing means, variances and covariances on them.

  9. MAP-Based Underdetermined Blind Source Separation of Convolutive Mixtures by Hierarchical Clustering and -Norm Minimization

    Directory of Open Access Journals (Sweden)

    Kellermann Walter

    2007-01-01

    Full Text Available We address the problem of underdetermined BSS. While most previous approaches are designed for instantaneous mixtures, we propose a time-frequency-domain algorithm for convolutive mixtures. We adopt a two-step method based on a general maximum a posteriori (MAP approach. In the first step, we estimate the mixing matrix based on hierarchical clustering, assuming that the source signals are sufficiently sparse. The algorithm works directly on the complex-valued data in the time-frequency domain and shows better convergence than algorithms based on self-organizing maps. The assumption of Laplacian priors for the source signals in the second step leads to an algorithm for estimating the source signals. It involves the -norm minimization of complex numbers because of the use of the time-frequency-domain approach. We compare a combinatorial approach initially designed for real numbers with a second-order cone programming (SOCP approach designed for complex numbers. We found that although the former approach is not theoretically justified for complex numbers, its results are comparable to, or even better than, the SOCP solution. The advantage is a lower computational cost for problems with low input/output dimensions.

  10. Studying the microlenses mass function from statistical analysis of the caustic concentration

    Energy Technology Data Exchange (ETDEWEB)

    Mediavilla, T; Ariza, O [Departamento de Estadistica e Investigacion Operativa, Universidad de Cadiz, Avda de Ramon Puyol, s/n 11202 Algeciras (Spain); Mediavilla, E [Instituto de Astrofisica de Canarias, Avda Via Lactea s/n, La Laguna (Spain); Munoz, J A, E-mail: teresa.mediavilla@ca.uca.es, E-mail: octavio.ariza@uca.es, E-mail: emg@iac.es [Departamento de Astrofisica y Astronomia, Universidad de Valencia, Burjassot, Valencia (Spain)

    2011-09-22

    The statistical distribution of caustic crossings by the images of a lensed quasar depends on the properties of the distribution of microlenses in the lens galaxy. We use a procedure based in Inverse Polygon Mapping to easily identify the critical and caustic curves generated by a distribution of stars in the lens galaxy. We analyze the statistical distributions of the number of caustic crossings by a pixel size source for several projected mass densities and different mass distributions. We compare the results of simulations with theoretical binomial distributions. Finally we apply this method to the study of the stellar mass distribution in the lens galaxy of QSO 2237+0305.

  11. Hierarchical Bayesian approach for estimating physical properties in spiral galaxies: Age Maps for M74

    Science.gov (United States)

    Sánchez Gil, M. Carmen; Berihuete, Angel; Alfaro, Emilio J.; Pérez, Enrique; Sarro, Luis M.

    2015-09-01

    One of the fundamental goals of modern Astronomy is to estimate the physical parameters of galaxies from images in different spectral bands. We present a hierarchical Bayesian model for obtaining age maps from images in the Ha line (taken with Taurus Tunable Filter (TTF)), ultraviolet band (far UV or FUV, from GALEX) and infrared bands (24, 70 and 160 microns (μm), from Spitzer). As shown in [1], we present the burst ages for young stellar populations in the nearby and nearly face on galaxy M74. As it is shown in the previous work, the Hα to FUV flux ratio gives a good relative indicator of very recent star formation history (SFH). As a nascent star-forming region evolves, the Ha line emission declines earlier than the UV continuum, leading to a decrease in the HαFUV ratio. Through a specific star-forming galaxy model (Starburst 99, SB99), we can obtain the corresponding theoretical ratio Hα / FUV to compare with our observed flux ratios, and thus to estimate the ages of the observed regions. Due to the nature of the problem, it is necessary to propose a model of high complexity to take into account the mean uncertainties, and the interrelationship between parameters when the Hα / FUV flux ratio mentioned above is obtained. To address the complexity of the model, we propose a Bayesian hierarchical model, where a joint probability distribution is defined to determine the parameters (age, metallicity, IMF), from the observed data, in this case the observed flux ratios Hα / FUV. The joint distribution of the parameters is described through an i.i.d. (independent and identically distributed random variables), generated through MCMC (Markov Chain Monte Carlo) techniques.

  12. Cosmological parameters, shear maps and power spectra from CFHTLenS using Bayesian hierarchical inference

    Science.gov (United States)

    Alsing, Justin; Heavens, Alan; Jaffe, Andrew H.

    2017-04-01

    We apply two Bayesian hierarchical inference schemes to infer shear power spectra, shear maps and cosmological parameters from the Canada-France-Hawaii Telescope (CFHTLenS) weak lensing survey - the first application of this method to data. In the first approach, we sample the joint posterior distribution of the shear maps and power spectra by Gibbs sampling, with minimal model assumptions. In the second approach, we sample the joint posterior of the shear maps and cosmological parameters, providing a new, accurate and principled approach to cosmological parameter inference from cosmic shear data. As a first demonstration on data, we perform a two-bin tomographic analysis to constrain cosmological parameters and investigate the possibility of photometric redshift bias in the CFHTLenS data. Under the baseline ΛCDM (Λ cold dark matter) model, we constrain S_8 = σ _8(Ω _m/0.3)^{0.5} = 0.67+0.03-0.03 (68 per cent), consistent with previous CFHTLenS analyses but in tension with Planck. Adding neutrino mass as a free parameter, we are able to constrain ∑mν linear redshift-dependent photo-z bias Δz = p2(z - p1), we find p_1=-0.25+0.53-0.60 and p_2 = -0.15+0.17-0.15, and tension with Planck is only alleviated under very conservative prior assumptions. Neither the non-minimal neutrino mass nor photo-z bias models are significantly preferred by the CFHTLenS (two-bin tomography) data.

  13. Mapping local microstructure and mechanical performance around carbon nanotube grafted silica fibres: Methodologies for hierarchical composites

    Science.gov (United States)

    Qian, Hui; Kalinka, Gerhard; Chan, K. L. Andrew; Kazarian, Sergei G.; Greenhalgh, Emile S.; Bismarck, Alexander; Shaffer, Milo S. P.

    2011-11-01

    The introduction of carbon nanotubes (CNTs) modifies bulk polymer properties, depending on intrinsic quality, dispersion, alignment, interfacial chemistry and mechanical properties of the nanofiller. These effects can be exploited to enhance the matrices of conventional microscale fibre-reinforced polymer composites, by using primary reinforcing fibres grafted with CNTs. This paper presents a methodology that combines atomic force microscopy, polarised Raman spectroscopy, and nanoindentation techniques, to study the distribution, alignment and orientation of CNTs in the vicinity of epoxy-embedded micrometre-scale silica fibres, as well as, the resulting local mechanical properties of the matrix. Raman maps of key features in the CNT spectra clearly show the CNT distribution and orientation, including a `parted' morphology associated with long grafted CNTs. The hardness and indentation modulus of the epoxy matrix were improved locally by 28% and 24%, respectively, due to the reinforcing effects of CNTs. Moreover, a slower stress relaxation was observed in the epoxy region containing CNTs, which may be due to restricted molecular mobility of the matrix. The proposed methodology is likely to be relevant to further studies of nanocomposites and hierarchical composites.The introduction of carbon nanotubes (CNTs) modifies bulk polymer properties, depending on intrinsic quality, dispersion, alignment, interfacial chemistry and mechanical properties of the nanofiller. These effects can be exploited to enhance the matrices of conventional microscale fibre-reinforced polymer composites, by using primary reinforcing fibres grafted with CNTs. This paper presents a methodology that combines atomic force microscopy, polarised Raman spectroscopy, and nanoindentation techniques, to study the distribution, alignment and orientation of CNTs in the vicinity of epoxy-embedded micrometre-scale silica fibres, as well as, the resulting local mechanical properties of the matrix. Raman

  14. Critical Curves and Caustics of Triple-lens Models

    CERN Document Server

    Danek, Kamil

    2015-01-01

    Among the 25 planetary systems detected up to now by gravitational microlensing, there are two cases of a star with two planets, and two cases of a binary star with a planet. Other, yet undetected types of triple lenses include triple stars or stars with a planet with a moon. The analysis and interpretation of such events is hindered by the lack of understanding of essential characteristics of triple lenses, such as their critical curves and caustics. We present here analytical and numerical methods for mapping the critical-curve topology and caustic cusp number in the parameter space of $n$-point-mass lenses. We apply the methods to the analysis of four symmetric triple-lens models, and obtain altogether 9 different critical-curve topologies and 32 caustic structures. While these results include various generic types, they represent just a subset of all possible triple-lens critical curves and caustics. Using the analyzed models, we demonstrate interesting features of triple lenses that do not occur in two-p...

  15. Photon Differential Splatting for Rendering Caustics

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Schjøth, Lars; Erleben, Kenny;

    2014-01-01

    We present a photon splatting technique which reduces noise and blur in the rendering of caustics. Blurring of illumination edges is an inherent problem in photon splatting, as each photon is unaware of its neighbours when being splatted. This means that the splat size is usually based...... on heuristics rather than knowledge of the local flux density. We use photon differentials to determine the size and shape of the splats such that we achieve adaptive anisotropic flux density estimation in photon splatting. As compared to previous work that uses photon differentials, we present the first method...... where no photons or beams or differentials need to be stored in a map. We also present improvements in the theory of photon differentials, which give more accurate results and a faster implementation. Our technique has good potential for GPU acceleration, and we limit the number of parameters requiring...

  16. Hierarchical Bayesian approach for estimating physical properties in spiral galaxies: Age Maps for M74

    CERN Document Server

    Gil, M Carmen Sánchez; Alfaro, Emilio J; Pérez, Enrique; Sarro, Luis M

    2015-01-01

    One of the fundamental goals of modern Astronomy is to estimate the physical parameters of galaxies from images in different spectral bands. We present a hierarchical Bayesian model for obtaining age maps from images in the \\Ha\\ line (taken with Taurus Tunable Filter (TTF)), ultraviolet band (far UV or FUV, from GALEX) and infrared bands (24, 70 and 160 microns ($\\mu$m), from Spitzer). As shown in S\\'anchez-Gil et al. (2011), we present the burst ages for young stellar populations in the nearby and nearly face on galaxy M74. As it is shown in the previous work, the \\Ha\\ to FUV flux ratio gives a good relative indicator of very recent star formation history (SFH). As a nascent star-forming region evolves, the \\Ha\\ line emission declines earlier than the UV continuum, leading to a decrease in the \\Ha\\/FUV ratio. Through a specific star-forming galaxy model (Starburst 99, SB99), we can obtain the corresponding theoretical ratio \\Ha\\ / FUV to compare with our observed flux ratios, and thus to estimate the ages of...

  17. Mapping local microstructure and mechanical performance around carbon nanotube grafted silica fibres: methodologies for hierarchical composites.

    Science.gov (United States)

    Qian, Hui; Kalinka, Gerhard; Chan, K L Andrew; Kazarian, Sergei G; Greenhalgh, Emile S; Bismarck, Alexander; Shaffer, Milo S P

    2011-11-01

    The introduction of carbon nanotubes (CNTs) modifies bulk polymer properties, depending on intrinsic quality, dispersion, alignment, interfacial chemistry and mechanical properties of the nanofiller. These effects can be exploited to enhance the matrices of conventional microscale fibre-reinforced polymer composites, by using primary reinforcing fibres grafted with CNTs. This paper presents a methodology that combines atomic force microscopy, polarised Raman spectroscopy, and nanoindentation techniques, to study the distribution, alignment and orientation of CNTs in the vicinity of epoxy-embedded micrometre-scale silica fibres, as well as, the resulting local mechanical properties of the matrix. Raman maps of key features in the CNT spectra clearly show the CNT distribution and orientation, including a 'parted' morphology associated with long grafted CNTs. The hardness and indentation modulus of the epoxy matrix were improved locally by 28% and 24%, respectively, due to the reinforcing effects of CNTs. Moreover, a slower stress relaxation was observed in the epoxy region containing CNTs, which may be due to restricted molecular mobility of the matrix. The proposed methodology is likely to be relevant to further studies of nanocomposites and hierarchical composites.

  18. Hierarchical Structure of the Eysenck Personality Inventory in a Large Population Sample: Goldberg's Trait-Tier Mapping Procedure.

    Science.gov (United States)

    Chapman, Benjamin P; Weiss, Alexander; Barrett, Paul; Duberstein, Paul

    2013-03-01

    The structure of the Eysenck Personality Inventory (EPI) is poorly understood, and applications have mostly been confined to the broad Neuroticism, Extraversion, and Lie scales. Using a hierarchical factoring procedure, we mapped the sequential differentiation of EPI scales from broad, molar factors to more specific, molecular factors, in a UK population sample of over 6500 persons. Replicable facets at the lowest tier of Neuroticism included emotional fragility, mood lability, nervous tension, and rumination. The lowest order set of replicable Extraversion facets consisted of social dynamism, sociotropy, decisiveness, jocularity, social information seeking, and impulsivity. The Lie scale consisted of an interpersonal virtue and a behavioral diligence facet. Users of the EPI may be well served in some circumstances by considering its broad Neuroticism, Extraversion, and Lie scales as multifactorial, a feature that was explicitly incorporated into subsequent Eysenck inventories and is consistent with other hierarchical trait structures.

  19. In-situ caustic generation from sewage: the impact of caustic strength and sewage composition.

    Science.gov (United States)

    Pikaar, Ilje; Rozendal, René A; Rabaey, Korneel; Yuan, Zhiguo

    2013-10-01

    Periodic caustic dosage is a commonly used method by the water industry to elevate pH levels and deactivate sewer biofilms responsible for hydrogen sulfide generation. Caustic (NaOH) can be generated in-situ from sewage using a divided electrochemical cell, which avoids the need for transport, handling and storage of concentrated caustic solutions. In this study, we investigated the impact of caustic strength in the cathode compartment and the impact of sodium concentration in sewage on the Coulombic efficiency (CE) for caustic generation. The CE was found to be independent of the caustic strength produced in the range of up to ~3 wt%. Results showed that a caustic solution of ~3 wt% could be produced directly from sewage at a CE of up to 75 ± 0.5%. The sodium concentration in sewage had a significant impact on the CE for caustic generation as well as on the energy requirements of the system, with a higher sodium concentration leading to a higher CE and lower energy consumption. The proton, calcium, magnesium and ammonium concentrations in sewage affected the CE for caustic generation, especially at low sodium concentrations. Economical assessment based on the experimental results indicated that sulfide control in sewers using electrochemically-generated caustic from sewage is an economically attractive strategy.

  20. Mapping the hierarchical layout of the structural network of the macaque prefrontal cortex.

    Science.gov (United States)

    Goulas, Alexandros; Uylings, Harry B M; Stiers, Peter

    2014-05-01

    A consensus on the prefrontal cortex (PFC) holds that it is pivotal for flexible behavior and the integration of the cognitive, affective, and motivational domains. Certain models have been put forth and a dominant model postulates a hierarchical anterior-posterior gradient. The structural connectivity principles of this model dictate that increasingly anterior PFC regions exhibit more efferent connections toward posterior ones than vice versa. Such hierarchical asymmetry principles are thought to pertain to the macaque PFC. Additionally, the laminar patterns of the connectivity of PFC regions can be used for defining hierarchies. In the current study, we formally tested the asymmetry-based hierarchical principles of the anterior-posterior model by employing an exhaustive dataset on macaque PFC connectivity and tools from network science. On the one hand, the asymmetry-based principles and predictions of the hierarchical anterior-posterior model were not confirmed. The wiring of the macaque PFC does not fully correspond to the principles of the model, and its asymmetry-based hierarchical layout does not follow a strict anterior-posterior gradient. On the other hand, our results suggest that the laminar-based hierarchy seems a more tenable working hypothesis for models advocating an anterior-posterior gradient. Our results can inform models of the human PFC.

  1. 27 CFR 21.102 - Caustic soda, liquid.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Caustic soda, liquid. 21....102 Caustic soda, liquid. (a) The liquid caustic soda may consist of either 50 percent or 73 percent by weight sodium hydroxide in aqueous solution. The amount of caustic soda used shall be such...

  2. Caustic ingestion and esophageal function

    Energy Technology Data Exchange (ETDEWEB)

    Cadranel, S.; Di Lorenzo, C.; Rodesch, P.; Piepsz, A.; Ham, H.R. (Children University Hospital, Brussels (Belgium))

    1990-02-01

    The aim of the present study was to investigate esophageal motor function by means of krypton-81m esophageal transit scintigraphy and to compare the results with the functional and morphological data obtained by means of triple lumen manometry and endoscopy. In acute and subacute stages of the disease, all clinical, anatomical, and functional parameters were in good agreement, revealing significant impairment. In chronic stages, the severity of the dysphagia was not correlated to the importance of the residual stenosis. Conversely, 81mKr esophageal transit and manometric's findings were in good agreement with the clinical symptoms, during the entire follow-up period ranging between 3 months to 7 years. The 81mKr test is undoubtedly the easiest and probably the most physiological technique currently available for long-term functional evaluation of caustic esophagitis.

  3. Caustic Soda Will Be Oversupply in 2007

    Institute of Scientific and Technical Information of China (English)

    Yao Liqin

    2007-01-01

    @@ Rapid output increase There are more than 220 caustic soda producers in China today. At the end of 2006 the capacity of caustic soda in China was 17.61 million t/a. The output of caustic soda was 15.118 million tons in 2006, an increase of 19.0% over 2005 and 1.331 million tons were exported, an increase of 55.8%. Production increased fastest in Northwest China, with growth 51.9% faster than 2005. The output in East China grew 22.9% and 22.3% in Southwest China, both higher than the national average level.

  4. Classifying airborne radiometry data with Agglomerative Hierarchical Clustering: A tool for geological mapping in context of rainforest (French Guiana)

    Science.gov (United States)

    Martelet, G.; Truffert, C.; Tourlière, B.; Ledru, P.; Perrin, J.

    2006-09-01

    In highly weathered environments, it is crucial that geological maps provide information concerning both the regolith and the bedrock, for societal needs, such as land-use, mineral or water resources management. Often, geologists are facing the challenge of upgrading existing maps, as relevant information concerning weathering processes and pedogenesis is currently missing. In rugged areas in particular, where access to the field is difficult, ground observations are sparsely available, and need therefore to be complemented using methods based on remotely sensed data. For this purpose, we discuss the use of Agglomerative Hierarchical Clustering (AHC) on eU, K and eTh airborne gamma-ray spectrometry grids. The AHC process allows primarily to segment the geophysical maps into zones having coherent U, K and Th contents. The analysis of these contents are discussed in terms of geochemical signature for lithological attribution of classes, as well as the use of a dendrogram, which gives indications on the hierarchical relations between classes. Unsupervised classification maps resulting from AHC can be considered as spatial models of the distribution of the radioelement content in surface and sub-surface formations. The source of gamma rays emanating from the ground is primarily related to the geochemistry of the bedrock and secondarily to modifications of the radioelement distribution by weathering and other secondary mechanisms, such as mobilisation by wind or water. The interpretation of the obtained predictive classified maps, their U, K, Th contents, and the dendrogram, in light of available geological knowledge, allows to separate signatures related to regolith and solid geology. Consequently, classification maps can be integrated within a GIS environment and used by the geologist as a support for mapping bedrock lithologies and their alteration. We illustrate the AHC classification method in the region of Cayenne using high-resolution airborne radiometric data

  5. Tunable caustic phenomena in electron wavefields

    Energy Technology Data Exchange (ETDEWEB)

    Tavabi, Amir Hossein, E-mail: a.tavabi@fz-juelich.de [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Migunov, Vadim; Dwyer, Christian; Dunin-Borkowski, Rafal E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Pozzi, Giulio [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Department of Physics and Astronomy, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna (Italy)

    2015-10-15

    Novel caustic phenomena, which contain fold, butterfly and elliptic umbilic catastrophes, are observed in defocused images of two approximately collinear oppositely biased metallic tips in a transmission electron microscope. The observed patterns depend sensitively on defocus, on the applied voltage between the tips and on their separation and lateral offset. Their main features are interpreted on the basis of a projected electrostatic potential model for the electron-optical phase shift. - Highlights: • Electron-optical caustics are observed in defocused images of biased metallic tips. • The caustics depend on defocus, on the bias between the tips and on their separation. • The setup offers the flexibility to study a wide variety of caustic phenomena.

  6. Caustic graphene plasmons with Kelvin angle

    CERN Document Server

    Shi, Xihang; Gao, Fei; Xu, Hongyi; Yang, Zhaoju; Zhang, Baile

    2015-01-01

    A century-long argument made by Lord Kelvin that all swimming objects have an effective Mach number of 3, corresponding to the Kelvin angle of 19.5 degree for ship waves, has been recently challenged with the conclusion that the Kelvin angle should gradually transit to the Mach angle as the ship velocity increases. Here we show that a similar phenomenon can happen for graphene plasmons. By analyzing the caustic wave pattern of graphene plasmons stimulated by a swift charged particle moving uniformly above graphene, we show that at low velocities of the charged particle, the caustics of graphene plasmons form the Kelvin angle. At large velocities of the particle, the caustics disappear and the effective semi-angle of the wave pattern approaches the Mach angle. Our study introduces caustic wave theory to the field of graphene plasmonics, and reveals a novel physical picture of graphene plasmon excitation during electron energy-loss spectroscopy measurement.

  7. Classification of cancer cell lines using an automated two-dimensional liquid mapping method with hierarchical clustering techniques.

    Science.gov (United States)

    Wang, Yanfei; Wu, Rong; Cho, Kathleen R; Shedden, Kerby A; Barder, Timothy J; Lubman, David M

    2006-01-01

    A two-dimensional liquid mapping method was used to map the protein expression of eight ovarian serous carcinoma cell lines and three immortalized ovarian surface epithelial cell lines. Maps were produced using pI as the separation parameter in the first dimension and hydrophobicity based upon reversed-phase HPLC separation in the second dimension. The method can be reproducibly used to produce protein expression maps over a pH range from 4.0 to 8.5. A dynamic programming method was used to correct for minor shifts in peaks during the HPLC gradient between sample runs. The resulting corrected maps can then be compared using hierarchical clustering to produce dendrograms indicating the relationship between different cell lines. It was found that several of the ovarian surface epithelial cell lines clustered together, whereas specific groups of serous carcinoma cell lines clustered with each other. Although there is limited information on the current biology of these cell lines, it was shown that the protein expression of certain cell lines is closely related to each other. Other cell lines, including one ovarian clear cell carcinoma cell line, two endometrioid carcinoma cell lines, and three breast epithelial cell lines, were also mapped for comparison to show that their protein profiles cluster differently than the serous samples and to study how they cluster relative to each other. In addition, comparisons can be made between proteins differentially expressed between cell lines that may serve as markers of ovarian serous carcinomas. The automation of the method allows reproducible comparison of many samples, and the use of differential analysis limits the number of proteins that might require further analysis by mass spectrometry techniques.

  8. Iterative Maps with Hierarchical Clustering for the Observed Scales of Astrophysical and Cosmological Structures

    CERN Document Server

    Capozziello, S; De Siena, S; Guerra, F; Illuminati, F

    2000-01-01

    We derive, in order of magnitude, the observed astrophysical and cosmologicalscales in the Universe, from neutron stars to superclusters of galaxies, up to,asymptotically, the observed radius of the Universe. This result is obtained byintroducing a recursive scheme of alternating hierachical mechanisms ofthree-dimensional and two-dimensional close packings of gravitationallyinteracting objects. The iterative scheme yields a rapidly converging geometricsequence, which can be described as a hierarchical clustering of aggregates,having the observed radius of the Universe as its fixed point.

  9. Pigging ends freezeups in caustic piping system

    Energy Technology Data Exchange (ETDEWEB)

    Gros, R.; Gaines, A.

    1985-03-01

    Convent Chemical Corporation in Convent, LA produces and ships bulk quantities of chlorine and caustic soda (NaOH). The caustic soda is available in various grades, including a 50% aqueous solution that freezes at 56/sup 0/F. An extensive network of chemical-resistant polypropylene-lined steel pipe (without heat tracing) is used to transfer the caustic soda from the production area to storage tanks and to the loading facilities for tank trucks, rail tank cars and barges. A sudden drop in ambient temperature can cause freezeup of the caustic transfer pipes which may result in downtime of as much as a week. Convent plant engineers designed a pigging system for the outdoor caustic transfer lines in the tank farm and to the loading stations. The patented design pig, (internal pipeline cleaner) consists of a flexible, bullet-shaped cylinder of chemical-resistant polyurethane foam with strips of urethane rubber on the surface, or with a solid coating of the tough material. Fluid or gas pressure on the sealed concave base propels the flexible pig through the pipe, valves, elbows, and other fittings, and material ahead of the pig is discharged into an appropriate receiver. The pigging system has eliminated the caustic freezing and plugging problems since it was installed in the summer of 1981. The flexible pig, propelled by 80 psi air, is used to clear the pipelines whenever caustic is transferred during the winter months. The air-propelled pig is designed and sized to easily pass through restrictions in the piping system, such as reduced port plug valves, but was once stuck when it reached a section of pipe that had collapsed. A pig containing the Cobalt 60 nuclear element was inserted into the line to quickly locate the stuck pig with the Geiger counter. The faulty section of pipe was replaced with a new polypropylene lined spool piece.

  10. INTER-CONTACT FORCE ANALYSIS OF IMPACTED DISK ASSEMBLY BY DYNAMIC CAUSTICS

    Institute of Scientific and Technical Information of China (English)

    LI Ming(李明); ZHANG Jue; FANG Jing(方竞)

    2003-01-01

    The caustic method was utilized to study the contact force transmission in disk assemblies under impact load. The mapping equations were obtained based on the first invariant of the stress components in the disk subject to a normal concentrated force, and a characteristic dimension of the maximum size in the caustic curve was proposed to evaluate the contact force between the disks.Transient patterns of the caustic shadows were recorded by means of a high-speed camera of off-focus imaging, then the histories of the inter-contact forces among the disks were obtained with respect to the conditions of different masses and heights of the falling hammers. The influence of the impact loading and impulsive velocity was analyzed with respect to the force responses of the disk assembly,the double-peak phenomenon with comparison to the initial masses, and the energy dissipation of the systems under impact of different momentums.

  11. Line Caustic Microlensing and Limb Darkening

    CERN Document Server

    Rhie, S H; Rhie, Sun Hong; Bennett, David P.

    1999-01-01

    In a line caustic crossing microlensing event, the caustic line moving across the surface of the source star provides a direct method to measure the integrated luminosity profile of the star. Combined with the enormous brightening at the caustic crossings, microlensing offers a promising tool for studying stellar luminosity profiles. We derive the amplification behavior of the two extra images that become partial images conjoined across the critical curve at a line caustic crossing. We identify the multiplicative factors that depend on the caustic crossing point and the relative size of the star, and the shape function that depends on the stellar luminosity profile. We examine the analytic limb-darkening models -- linear, square root, and square -- using the analytic form of the shape function. We find that the microlensing lightcurves must be determined to an accuracy of better than 0.3-0.8% in order to be able to determine the linear limb-darkening parameter $c_1$ with precision of binaries as reported by P...

  12. Probing dark matter caustics with weak lensing

    CERN Document Server

    Gavazzi, R; Fort, B; Gavazzi, Raphael; Mohayaee, Roya; Fort, Bernard

    2006-01-01

    Caustics are high-density structures that form frequently in collisionless media. Under self-gravity, cold dark matter flows focus onto caustics which are yet to be resolved in numerical simulations and or observed in the real world. If detected, caustics would provide a strong evidence for dark matter and would rule out alternative models such as those with modified dynamics. Here, we demonstrate how they might be observed in the weak lensing data. We evaluate the shear distortion and show that its radial profile is marked by a characteristic sawtooth pattern due to the caustics in dark matter haloes that form by selfsimilar accretion. We discuss the observational complications, mainly due to the poor knowledge of the virial radii of the haloes and demonstrate that a superposition of about 600 cluster-size haloes would give a signal-to-noise ratio which is sufficiently large for the detection of caustics with ground-based observations. This number is reduced to 200 for space-based observations. These bounds ...

  13. Large Scale Hierarchical K-Means Based Image Retrieval With MapReduce

    Science.gov (United States)

    2014-03-27

    version of Hadoop at the time of this research. Hadoop is the open-source implementation of MapReduce and HDFS. • OpenCV [10]: C++ library for Computer...Boost.Python[1]: Allows for wrapping C++ code to create Python modules. Exposes full C++ OpenCV libraries, as well as native speeds for computation intensive...Yield (′0′, (ImageName, f eature)) end for end function Figure 3.3: MapReduce Feature Extraction Algorithm C++ using the OpenCV libraby. The C

  14. Mapping Plant Functional Types over Broad Mountainous Regions: A Hierarchical Soft Time-Space Classification Applied to the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Danlu Cai

    2014-04-01

    Full Text Available Research on global climate change requires plant functional type (PFT products. Although several PFT mapping procedures for remote sensing imagery are being used, none of them appears to be specifically designed to map and evaluate PFTs over broad mountainous areas which are highly relevant regions to identify and analyze the response of natural ecosystems. We present a methodology for generating soft classifications of PFTs from remotely sensed time series that are based on a hierarchical strategy by integrating time varying integrated NDVI and phenological information with topography: (i Temporal variability: a Fourier transform of a vegetation index (MODIS NDVI, 2006 to 2010. (ii Spatial partitioning: a primary image segmentation based on a small number of thresholds applied to the Fourier amplitude. (iii Classification by a supervised soft classification step is based on a normalized distance metric constructed from a subset of Fourier coefficients and complimentary altitude data from a digital elevation model. Applicability and effectiveness is tested for the eastern Tibetan Plateau. A classification nomenclature is determined from temporally stable pixels in the MCD12Q1 time series. Overall accuracy statistics of the resulting classification reveal a gain of about 7% from 64.4% compared to 57.7% by the MODIS PFT products.

  15. Mapping brucellosis increases relative to elk density using hierarchical Bayesian models

    Science.gov (United States)

    Cross, Paul C.; Heisey, Dennis M.; Scurlock, Brandon M.; Edwards, William H.; Brennan, Angela; Ebinger, Michael R.

    2010-01-01

    The relationship between host density and parasite transmission is central to the effectiveness of many disease management strategies. Few studies, however, have empirically estimated this relationship particularly in large mammals. We applied hierarchical Bayesian methods to a 19-year dataset of over 6400 brucellosis tests of adult female elk (Cervus elaphus) in northwestern Wyoming. Management captures that occurred from January to March were over two times more likely to be seropositive than hunted elk that were killed in September to December, while accounting for site and year effects. Areas with supplemental feeding grounds for elk had higher seroprevalence in 1991 than other regions, but by 2009 many areas distant from the feeding grounds were of comparable seroprevalence. The increases in brucellosis seroprevalence were correlated with elk densities at the elk management unit, or hunt area, scale (mean 2070 km2; range = [95–10237]). The data, however, could not differentiate among linear and non-linear effects of host density. Therefore, control efforts that focus on reducing elk densities at a broad spatial scale were only weakly supported. Additional research on how a few, large groups within a region may be driving disease dynamics is needed for more targeted and effective management interventions. Brucellosis appears to be expanding its range into new regions and elk populations, which is likely to further complicate the United States brucellosis eradication program. This study is an example of how the dynamics of host populations can affect their ability to serve as disease reservoirs.

  16. Mapping brucellosis increases relative to elk density using hierarchical Bayesian models.

    Directory of Open Access Journals (Sweden)

    Paul C Cross

    Full Text Available The relationship between host density and parasite transmission is central to the effectiveness of many disease management strategies. Few studies, however, have empirically estimated this relationship particularly in large mammals. We applied hierarchical Bayesian methods to a 19-year dataset of over 6400 brucellosis tests of adult female elk (Cervus elaphus in northwestern Wyoming. Management captures that occurred from January to March were over two times more likely to be seropositive than hunted elk that were killed in September to December, while accounting for site and year effects. Areas with supplemental feeding grounds for elk had higher seroprevalence in 1991 than other regions, but by 2009 many areas distant from the feeding grounds were of comparable seroprevalence. The increases in brucellosis seroprevalence were correlated with elk densities at the elk management unit, or hunt area, scale (mean 2070 km(2; range = [95-10237]. The data, however, could not differentiate among linear and non-linear effects of host density. Therefore, control efforts that focus on reducing elk densities at a broad spatial scale were only weakly supported. Additional research on how a few, large groups within a region may be driving disease dynamics is needed for more targeted and effective management interventions. Brucellosis appears to be expanding its range into new regions and elk populations, which is likely to further complicate the United States brucellosis eradication program. This study is an example of how the dynamics of host populations can affect their ability to serve as disease reservoirs.

  17. Principal component analysis vs. self-organizing maps combined with hierarchical clustering for pattern recognition in volcano seismic spectra

    Science.gov (United States)

    Unglert, K.; Radić, V.; Jellinek, A. M.

    2016-06-01

    Variations in the spectral content of volcano seismicity related to changes in volcanic activity are commonly identified manually in spectrograms. However, long time series of monitoring data at volcano observatories require tools to facilitate automated and rapid processing. Techniques such as self-organizing maps (SOM) and principal component analysis (PCA) can help to quickly and automatically identify important patterns related to impending eruptions. For the first time, we evaluate the performance of SOM and PCA on synthetic volcano seismic spectra constructed from observations during two well-studied eruptions at Klauea Volcano, Hawai'i, that include features observed in many volcanic settings. In particular, our objective is to test which of the techniques can best retrieve a set of three spectral patterns that we used to compose a synthetic spectrogram. We find that, without a priori knowledge of the given set of patterns, neither SOM nor PCA can directly recover the spectra. We thus test hierarchical clustering, a commonly used method, to investigate whether clustering in the space of the principal components and on the SOM, respectively, can retrieve the known patterns. Our clustering method applied to the SOM fails to detect the correct number and shape of the known input spectra. In contrast, clustering of the data reconstructed by the first three PCA modes reproduces these patterns and their occurrence in time more consistently. This result suggests that PCA in combination with hierarchical clustering is a powerful practical tool for automated identification of characteristic patterns in volcano seismic spectra. Our results indicate that, in contrast to PCA, common clustering algorithms may not be ideal to group patterns on the SOM and that it is crucial to evaluate the performance of these tools on a control dataset prior to their application to real data.

  18. Does the process map influence the outcome of quality improvement work? A comparison of a sequential flow diagram and a hierarchical task analysis diagram

    Directory of Open Access Journals (Sweden)

    Potts Henry WW

    2010-01-01

    Full Text Available Abstract Background Many quality and safety improvement methods in healthcare rely on a complete and accurate map of the process. Process mapping in healthcare is often achieved using a sequential flow diagram, but there is little guidance available in the literature about the most effective type of process map to use. Moreover there is evidence that the organisation of information in an external representation affects reasoning and decision making. This exploratory study examined whether the type of process map - sequential or hierarchical - affects healthcare practitioners' judgments. Methods A sequential and a hierarchical process map of a community-based anti coagulation clinic were produced based on data obtained from interviews, talk-throughs, attendance at a training session and examination of protocols and policies. Clinic practitioners were asked to specify the parts of the process that they judged to contain quality and safety concerns. The process maps were then shown to them in counter-balanced order and they were asked to circle on the diagrams the parts of the process where they had the greatest quality and safety concerns. A structured interview was then conducted, in which they were asked about various aspects of the diagrams. Results Quality and safety concerns cited by practitioners differed depending on whether they were or were not looking at a process map, and whether they were looking at a sequential diagram or a hierarchical diagram. More concerns were identified using the hierarchical diagram compared with the sequential diagram and more concerns were identified in relation to clinical work than administrative work. Participants' preference for the sequential or hierarchical diagram depended on the context in which they would be using it. The difficulties of determining the boundaries for the analysis and the granularity required were highlighted. Conclusions The results indicated that the layout of a process map does

  19. Does the process map influence the outcome of quality improvement work? A comparison of a sequential flow diagram and a hierarchical task analysis diagram.

    Science.gov (United States)

    Colligan, Lacey; Anderson, Janet E; Potts, Henry W W; Berman, Jonathan

    2010-01-07

    Many quality and safety improvement methods in healthcare rely on a complete and accurate map of the process. Process mapping in healthcare is often achieved using a sequential flow diagram, but there is little guidance available in the literature about the most effective type of process map to use. Moreover there is evidence that the organisation of information in an external representation affects reasoning and decision making. This exploratory study examined whether the type of process map - sequential or hierarchical - affects healthcare practitioners' judgments. A sequential and a hierarchical process map of a community-based anti coagulation clinic were produced based on data obtained from interviews, talk-throughs, attendance at a training session and examination of protocols and policies. Clinic practitioners were asked to specify the parts of the process that they judged to contain quality and safety concerns. The process maps were then shown to them in counter-balanced order and they were asked to circle on the diagrams the parts of the process where they had the greatest quality and safety concerns. A structured interview was then conducted, in which they were asked about various aspects of the diagrams. Quality and safety concerns cited by practitioners differed depending on whether they were or were not looking at a process map, and whether they were looking at a sequential diagram or a hierarchical diagram. More concerns were identified using the hierarchical diagram compared with the sequential diagram and more concerns were identified in relation to clinical work than administrative work. Participants' preference for the sequential or hierarchical diagram depended on the context in which they would be using it. The difficulties of determining the boundaries for the analysis and the granularity required were highlighted. The results indicated that the layout of a process map does influence perceptions of quality and safety problems in a process. In

  20. Caustic echoes from a Schwarzschild black hole

    CERN Document Server

    Zenginoğlu, Anıl

    2012-01-01

    We present the first numerical construction of the scalar Schwarzschild Green function in the time-domain, which reveals several universal features of wave propagation in black hole spacetimes. We demonstrate the trapping of energy near the photon sphere and confirm its exponential decay. The trapped wavefront propagates through caustics resulting in echoes that propagate to infinity. The arrival times and the decay rate of these caustic echoes are consistent with propagation along null geodesics and the large l-limit of quasinormal modes. We show that the four-fold singularity structure of the retarded Green function is due to the well-known action of a Hilbert transform on the trapped wavefront at caustics. A two-fold cycle is obtained for degenerate source-observer configurations along the caustic line, where the energy amplification increases with an inverse power of the scale of the source. Finally, we discuss the tail piece of the solution due to propagation within the light cone, up to and including nu...

  1. Hierarchical multivariate mixture generalized linear models for the analysis of spatial data: An application to disease mapping.

    Science.gov (United States)

    Torabi, Mahmoud

    2016-09-01

    Disease mapping of a single disease has been widely studied in the public health setup. Simultaneous modeling of related diseases can also be a valuable tool both from the epidemiological and from the statistical point of view. In particular, when we have several measurements recorded at each spatial location, we need to consider multivariate models in order to handle the dependence among the multivariate components as well as the spatial dependence between locations. It is then customary to use multivariate spatial models assuming the same distribution through the entire population density. However, in many circumstances, it is a very strong assumption to have the same distribution for all the areas of population density. To overcome this issue, we propose a hierarchical multivariate mixture generalized linear model to simultaneously analyze spatial Normal and non-Normal outcomes. As an application of our proposed approach, esophageal and lung cancer deaths in Minnesota are used to show the outperformance of assuming different distributions for different counties of Minnesota rather than assuming a single distribution for the population density. Performance of the proposed approach is also evaluated through a simulation study. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Interaction of aqueous caustic with acidic oils

    Energy Technology Data Exchange (ETDEWEB)

    Chiwetelu, C.I.; Hornof, V.; Neale, G.H. (Univ. of Ottawa, Ottawa, ON (Canada))

    High content of native carboxylic acids make heavy oils acidic. It is generally accepted that these acids react with caustic reagents present in floodwater, resulting in the in-situ formation of surface active soap anions. When these adsorb at the oil-water interface, they can drastically lower the interfacial tension to the point where residual oil is mobilized. The most intriguing aspect of these acid/caustic interactions is the dynamic nature of the interfacial tension. Given a sufficiently long time, the dynamic tension would attain an equilibrium state. Measurements were made of the equilibrium interfacial tensions of acidified oleic phases contacted with a wide range of caustic concentrations in the aqueous phase. A novel measurement technique (photomicropendography) was used, and data analysis was carried out by nonlinear regression. The present approach utilizes pre-selected fatty acids in a defined oleic phase, enabling quantification of relevant model parameters and facilitating evaluation of key variables influencing interfacial activity. The acid ionization constant and the equilibrium constant governing the formation of inactive soap species were found to be the most important parameters for systems of oleic and lauric acids dissolved in hexadecane. Regression analysis showed that the acid dissociation constant (pKa) of oleic acid ranged from 6.2 to 6.9 and was dependent on the working acid concentration. For lauric acid, the pKa values were in the range of 9 to 11 depending on the caustic concentration of the aqueous phase. Species aggregation in both the oleic and aqueous phases is mostly responsible for the variations in pKa values. 30 refs., 10 figs., 4 tabs.

  3. In Situ Causticizing for Black Liquor Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Scott Alan Sinquefield

    2005-10-01

    Black liquor gasification offers a number of attractive incentives to replace Tomlinson boilers but it also leads to an increase in the causticizing load. Reasons for this have been described in previous reports (FY04 ERC, et.al.). The chemistries have also been covered but will be reviewed here briefly. Experimental results of the causticizing reactions with black liquor are presented here. Results of the modeling work were presented in detail in the Phase 1 report. They are included in Table 2 for comparison but will not be discussed in detail. The causticizing agents were added to black liquor in the ratios shown in Table 1, mixed, and then spray-dried. The mixture ratios (doping levels) reflect amount calculated from the stoichiometry above to achieve specified conversions shown in the table. The solids were sieved to 63-90 microns for use in the entrained flow reactors. The firing conditions are shown in Table 2. Pictures and descriptions of the reactors can be found in the Phase 1 annual report. Following gasification, the solids (char) was collected and analyzed by coulometric titration (for carbonate and total carbon), and by inductively coupled plasma emission spectroscopy (ICP) for a wide array of metals.

  4. Prioritizing the risk of plant pests by clustering methods; self-organising maps, k-means and hierarchical clustering

    Directory of Open Access Journals (Sweden)

    Susan Worner

    2013-09-01

    Full Text Available For greater preparedness, pest risk assessors are required to prioritise long lists of pest species with potential to establish and cause significant impact in an endangered area. Such prioritization is often qualitative, subjective, and sometimes biased, relying mostly on expert and stakeholder consultation. In recent years, cluster based analyses have been used to investigate regional pest species assemblages or pest profiles to indicate the risk of new organism establishment. Such an approach is based on the premise that the co-occurrence of well-known global invasive pest species in a region is not random, and that the pest species profile or assemblage integrates complex functional relationships that are difficult to tease apart. In other words, the assemblage can help identify and prioritise species that pose a threat in a target region. A computational intelligence method called a Kohonen self-organizing map (SOM, a type of artificial neural network, was the first clustering method applied to analyse assemblages of invasive pests. The SOM is a well known dimension reduction and visualization method especially useful for high dimensional data that more conventional clustering methods may not analyse suitably. Like all clustering algorithms, the SOM can give details of clusters that identify regions with similar pest assemblages, possible donor and recipient regions. More important, however SOM connection weights that result from the analysis can be used to rank the strength of association of each species within each regional assemblage. Species with high weights that are not already established in the target region are identified as high risk. However, the SOM analysis is only the first step in a process to assess risk to be used alongside or incorporated within other measures. Here we illustrate the application of SOM analyses in a range of contexts in invasive species risk assessment, and discuss other clustering methods such as k

  5. Caustics and Caustic-Diffraction in Laser Shadowgraphy of a Sessile Drop and Identification of Profile Near Contact Line

    Science.gov (United States)

    Zhang, Neng-Li; Chao, David F.

    2003-01-01

    This paper presents an optical method based on the caustics and caustic-difraction in laser shadowgaphy of a sessile drop to identify and estimate the drop profile near the contact line. A parallel laser beam passes through a liquid sessile drop placed on a transparent substrate to produce a shadowgraphic image of the drop on the screen far from the substrate. Along the inflection line of the drop the Gaussian curvature of the wavefront deformed by the drop vanishes, and therefore the inflection line gives caustics in the far field of the wave, which can be seen on the screen. The neighboring light rays at both sides of the inflection line interfere with each other to form interference fringes at the inner side of the caustics. According to the pattern of the caustics, the drop-profile shape can be identified and estimated.

  6. Caustic ingestion-a forensic overview.

    Science.gov (United States)

    Byard, Roger W

    2015-05-01

    The ingestion of corrosive substances may produce severe burns to the upper aerodigestive tract and stomach, particularly if the pH is greater than 12 or less than two. There is a biphasic age grouping with adult cases most often involving self-harm and pediatric cases accidental ingestion. Three cases are reported to demonstrate characteristic features following the ingestion of potassium hydroxide, glacial acetic acid and Lysol(®) , respectively. All deaths were due to the effects of caustic burns to the upper aerodigestive tract, esophagus and stomach with perforation and/or hemorrhage. The extent of injuries in these cases depends on the nature, amount, and concentration of the agent and on the exposure time. A point to note at autopsy is that tissue damage may also occur from postmortem exposure. Typical injuries involve perioral, limb, and trunk burns, with extensive aerodigestive liquefactive/coagulative necrosis causing hemorrhage and perforation.

  7. Preconceptual Design Description for Caustic Recycle Facility

    Energy Technology Data Exchange (ETDEWEB)

    Sevigny, Gary J.; Poloski, Adam P.; Fountain, Matthew S.; Kurath, Dean E.

    2008-04-12

    The U.S. Department of Energy plans to vitrify both high-level and low-activity waste at the Hanford Site in southeastern Washington State. One aspect of the planning includes a need for a caustic recycle process to separate sodium hydroxide for recycle. Sodium is already a major limitation to the waste-oxide loading in the low-activity waste glass to be vitrified at the Waste Treatment Plant, and additional sodium hydroxide will be added to remove aluminum and to control precipitation in the process equipment. Aluminum is being removed from the high level sludge to reduce the number of high level waste canisters produced. A sodium recycle process would reduce the volume of low-activity waste glass produced and minimize the need to purchase new sodium hydroxide, so there is a renewed interest in investigating sodium recycle. This document describes an electrochemical facility for recycling sodium for the WTP.

  8. Design Method of the Semantic-driven Hierarchical Map Symbols%语义驱动的层次化地图符号设计方法

    Institute of Scientific and Technical Information of China (English)

    田江鹏; 贾奋励; 夏青; 吴金兵

    2012-01-01

    Research of map symbols is an important part of cartography. Currently, the main research of map symbols was focused on the visual graphics but paying little attention to the semantic. This paper puts forward a method of semantic-driven hierarchical map symbols design. In this method the semantic relation of map symbols is as a benchmark to the construction of symbol graphics, and the symbol graphics is controlled by semantic model. So we can fully exploit the intrinsic value of the semantic components of the map symbols in its design activities. We mainly focused on such four key steps of the method. The first one is semantic feature extraction. We systematically summarized the semantic feature of the map symbols by using ontological level concept. Second step is about morphemes design. The concept, design principles of morphemes and its important role in map symbols design was discussed. The third is about modeling of the associative semantic relation. In this step the modeling methods was discussed and a practice that show how to construct an associative semantic model based on common map symbols for the public geographical information was conducted. The fourth is semantics-driven generation of map symbols. The processes and characteristics of a symbol's generation was analyzed. An existing map symbol standard was improved by using our symbol design method. And a group of cognitive experiments have been done which show that the propound method has a superior performance in cognitive efficiency and relatively stable and high transmission efficiency in the analog process of information transmission. In conclusion, the semantic relation of the geospatial objects is the core of the method of semantic-driven hierarchical map symbols design, which is aimed to improve the graphic design and understanding of map symbols. Characterized by the symbol design oriented ontology domain, this method makes the map symbols more semantic-evident for better recognition

  9. Multicusp caustics formed from reflections of warped surfaces.

    Science.gov (United States)

    Theocaris, P S

    1988-02-15

    The optical method of caustics developed mainly for studying singularities in stress fields was extended to define quantitatively the slope variation of warped surfaces. The existing theory was concerned with the study of infinitesimal but abrupt variations of thickness in elastic and plastic stress fields containing stress singularities due to either loading or geometry. In this paper the theory of caustics was extended to study the warping of any surface due mainly to twisting loads- While the caustics developed in previous uses were generalized epicycloid surfaces with or without a single cusp line, in the cases studied in this paper multicusp surfaces were developed. The quantitative interrelationship between the shape and size of the caustic and the respective mode of twisting of the surface was established, and interesting properties of these surfaces were disclosed. Applications to twisted elliptic, triangular, and square elastic bars clearly illustrate the importance of the method.

  10. Formation of caustics in k-essence and Horndeski theory

    CERN Document Server

    Babichev, Eugeny

    2016-01-01

    We study propagation of waves and appearance of caustics in k-essence and galileon theories. First we show that previously known solutions for travelling waves in k-essence and galileon models correspond to very specific fine-tuned initial conditions. On the contrary, as we demonstrate by the method of characteristics, a generic wave in k-essence ends up with formation of caustics. Finally, we find that any wave solution in pure k-essence is also a solution for a galileon theory with the same k-essence term. Thus in the Horndeski theory formation of caustics is generic. We discuss physical consequences of the caustics formation and possible ways to cure the problem.

  11. Formation of caustics in k-essence and Horndeski theory

    Energy Technology Data Exchange (ETDEWEB)

    Babichev, Eugeny [Laboratoire de Physique Théorique, CNRS, University Paris-Sud, Université Paris-Saclay,91405 Orsay (France)

    2016-04-20

    We study propagation of waves and appearance of caustics in k-essence and galileon theories. First we show that previously known solutions for travelling waves in k-essence and galileon models correspond to very specific fine-tuned initial conditions. On the contrary, as we demonstrate by the method of characteristics, generic initial conditions leads to a wave in k-essence which ends up with formation of caustics. Finally, we find that any wave solution in pure k-essence is also a solution for a galileon theory with the same k-essence term. Thus in the Horndeski theory with a k-essence term formation of caustics is generic. We discuss physical consequences of the caustics formation and possible ways to cure the problem.

  12. Test report - 241-AN-274 Caustic Pump Control Building

    Energy Technology Data Exchange (ETDEWEB)

    Paintner, G.P.

    1995-05-01

    This Acceptance Test Report documents the test results of test procedure WHC-SD-WM-ATP-135 `Acceptance Test Procedure for the 241-AN- 274 Caustic Pump Control Building.` The objective of the test was to verify that the 241-AN-274 Caustic Pump Control Building functions properly based on design specifications per applicable H-2-85573 drawings and associated ECN`s. The objective of the test was met.

  13. Tracking nanoparticles in an optical microscope using caustics

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Eann A [Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824 (United States); Whelan, Maurice P [Nanotechnology and Molecular Imaging Unit, Institute for Health and Consumer Protection, European Commission DG Joint Research Center, 21021 Ispra (Vatican City State, Holy See,) (Italy)

    2008-03-12

    An elegant method is proposed and demonstrated for tracking the location and movement of nanoparticles in an optical microscope using the optical phenomenon of caustics. A simple and reversible adjustment to the microscope generates caustics several orders of magnitude larger than the particles. The method offers a simple and relatively inexpensive method for visualizing such phenomena as the formation of self-assembled monolayers and the interaction of nanoparticles with chemically functionalized surfaces.

  14. Engineering wavefront caustics trajectories in ${\\cal PT}$-symmetric lattices

    CERN Document Server

    Bender, Nicholas; Kottos, Tsampikos

    2015-01-01

    We utilize caustic theory in ${\\cal PT}-$symmetric lattices to design focusing and curved beam dynamics. We show that the gain and loss parameter in these systems provides an addition degree of freedom which allows for the design of the same caustics trajectories with different intensity distribution in the individual waveguides. Moreover we can create aberration-free focal points at any paraxial distance $z_f$, with anomalously large focal intensity.

  15. Illuminating Hot Jupiters in caustic crossing

    CERN Document Server

    Sajadian, Sedighe

    2010-01-01

    In recent years a large number of Hot Jupiters orbiting in a very close orbit around the parent stars have been explored with the transit and doppler effect methods. Here in this work we study the gravitational microlensing effect of a binary lens on a parent star with a Hot Jupiter revolving around it. Caustic crossing of the planet makes enhancements on the light curve of the parent star in which the signature of the planet can be detected by high precision photometric observations. We use the inverse ray shooting method with tree code algorithm to generate the combined light curve of the parent star and the planet. In order to investigate the probability of observing the planet signal, we do a Monte-Carlo simulation and obtain the observational optical depth of $\\tau \\sim 10^{-8}$. We show that about ten years observations of Galactic Bulge with a network of telescopes will enable us detecting about ten Hot Jupiter with this method. Finally we show that the observation of the microlensing event in infra-re...

  16. booc.io: An Education System with Hierarchical Concept Maps and Dynamic Non-linear Learning Plans.

    Science.gov (United States)

    Schwab, Michail; Strobelt, Hendrik; Tompkin, James; Fredericks, Colin; Huff, Connor; Higgins, Dana; Strezhnev, Anton; Komisarchik, Mayya; King, Gary; Pfister, Hanspeter

    2017-01-01

    Information hierarchies are difficult to express when real-world space or time constraints force traversing the hierarchy in linear presentations, such as in educational books and classroom courses. We present booc.io, which allows linear and non-linear presentation and navigation of educational concepts and material. To support a breadth of material for each concept, booc.io is Web based, which allows adding material such as lecture slides, book chapters, videos, and LTIs. A visual interface assists the creation of the needed hierarchical structures. The goals of our system were formed in expert interviews, and we explain how our design meets these goals. We adapt a real-world course into booc.io, and perform introductory qualitative evaluation with students.

  17. Hierarchical classification approach for mapping rubber tree growth using per-pixel and object-oriented classifiers with SPOT-5 imagery

    Directory of Open Access Journals (Sweden)

    Hayder Dibs

    2017-06-01

    Full Text Available There has been growing interest in Malaysia to increase the productivity of latex. This made accurate knowledge of rubber tree growth and age distribution a helpful decision making tool for the government, rubber plantation managers, and harvesters. Gathering this information using conventional methods is difficult, time consuming, and limited in spatial coverage. This paper presents hierarchical classification approach to obtain accurate map of rubber tree growth age distribution using SPOT-5 satellite imagery. The objective of the study is to evaluate the performance of pixel-based and object-oriented classifiers for rubber growth classification. At the first level, the general land cover was classified into eight land cover classes (soil, water body, rubber, mature oil palm, young oil palm, forest, urban area, and other vegetation using Mahalanobis distance (MD, k-nearest neighbor (k-NN, and Support Vector Machine (SVM classifiers. Thereafter, the best classification map, k-NN output, was used to select only pixels that belong to the rubber class from the SPOT-5 image. The extracted pixels served as input into the next classification hierarchy where four classifiers, MD, k-NN, SVM, and decision tree (DT, were implemented to map rubber trees into three intra-classes (mature, middle-aged, and young rubbers. The result produced overall accuracy of 97.48%, 96.90%, 96.25%, and 80.80% for k-NN, SVM, MD, and DT respectively. The result indicates that object-oriented classifiers are better than pixel-based methods mapping rubber tree growth.

  18. Effect of asphericity in caustic mass estimates of galaxy clusters

    CERN Document Server

    Svensmark, Jacob; Hansen, Steen H

    2014-01-01

    The caustic technique of mass estimation of galaxy clusters relies on the assumption of spherical symmetry, which is not always a valid assumption. Here we demonstrate the effect of spatial anisotropy of galaxy clusters on the inferred caustic mass profiles by considering particle data from dark matter N-body simulations. We find a factor of ~3 discrepancy between major and minor axis mass estimates in ellipsoidal clusters within the virial radius Rv, and up to ~5 within 3 Rv. We also find filaments to influence caustic mass estimates at a comparable magnitude. By stacking halos to align their principal axes we find that a line of sight along the major axis overestimates the caustic mass of galaxy clusters, as well as a line of sight along the minor axis underestimates it. The mass discrepancy between the major and minor axis is a factor of 2.47, 2.97 and 3.95 at 1, 2 and 3 Rv for virial masses Mv = [1,2] x 10^{14} Msun/h, and $(30-35)\\%$ larger for Mv > 2 x 10^{14} Msun/h. Furthermore, the caustic mass is ov...

  19. Wavefronts and caustic associated with Durnin’s beams

    Science.gov (United States)

    de Jesús Cabrera-Rosas, Omar; Espíndola-Ramos, Ernesto; Alejandro Juárez-Reyes, Salvador; Julián-Macías, Israel; Ortega-Vidals, Paula; Silva-Ortigoza, Gilberto; Silva-Ortigoza, Ramón; Sosa-Sánchez, Citlalli Teresa

    2017-01-01

    The aim of the present work is to give a geometrical characterization of Durnin’s beams. That is, we compute the wavefronts and caustic associated with the nondiffracting solutions to the scalar wave equation introduced by Durnin. To this end, first we show that in an isotropic optical medium \\psi ({r},t)={{{e}}}{{i}[{k}0S({r})-ω t]} is an exact solution of the wave equation, if and only if, S is a solution of both the eikonal and Laplace equations, then from one and two-parameter families of this type of solution and the superposition principle we define new solutions of the wave equation, in particular we show that the ideal nondiffracting beams are one example of this type of construction in free space. Using this fact, the wavefronts and caustic associated with those beams are computed. We find that their caustic has only one branch, which is invariant under translations along the direction of evolution of the beam. Finally, the Bessel beam of order m is worked out explicitly and we find that it is characterized by wavefronts that are deformations of conical ones and the caustic is an infinite cylinder of radius proportional to m. In the case m = 0, the wavefronts are cones and the caustic degenerates into an infinite line.

  20. Parallel hierarchical radiosity rendering

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.

    1993-07-01

    In this dissertation, the step-by-step development of a scalable parallel hierarchical radiosity renderer is documented. First, a new look is taken at the traditional radiosity equation, and a new form is presented in which the matrix of linear system coefficients is transformed into a symmetric matrix, thereby simplifying the problem and enabling a new solution technique to be applied. Next, the state-of-the-art hierarchical radiosity methods are examined for their suitability to parallel implementation, and scalability. Significant enhancements are also discovered which both improve their theoretical foundations and improve the images they generate. The resultant hierarchical radiosity algorithm is then examined for sources of parallelism, and for an architectural mapping. Several architectural mappings are discussed. A few key algorithmic changes are suggested during the process of making the algorithm parallel. Next, the performance, efficiency, and scalability of the algorithm are analyzed. The dissertation closes with a discussion of several ideas which have the potential to further enhance the hierarchical radiosity method, or provide an entirely new forum for the application of hierarchical methods.

  1. Map Building Method Based on Hierarchical Temporal Memory%基于层级实时记忆的地图创建方法∗

    Institute of Scientific and Technical Information of China (English)

    张新征; 麦晓春; 张建芬

    2015-01-01

    提出基于层级实现记忆( HTM)网络的地图创建方法。该方法利用层级实时记忆将制图问题等效为场景识别问题,环境地图由一系列HTM模型输出的场景构成。首先从获取图像中提取位置不变鲁棒特征( PIRF)。并利用PIRF构建视觉词汇表,根据词汇表将图像的PIRF描述符映射为视觉单词频率矢量。多个视觉单词频率矢量构成的序列输入HTM网络,用于实现环境地图的学习与创建及环路场景的推断识别。采用两组实验数据验证文中方法,结果表明基于HTM的制图策略能成功建立环境地图,并能高效处理环路检测问题。%A map building method based on hierarchical temporal memory ( HTM) is proposed. The mapping problem is treated as scene recognition. The map is composed of a series of scenes being the outputs of HTM network. Firstly, the position invariant robust feature ( PIRF) is extracted from the obtained images and then the PIRFs are applied to build the visual vocabulary. Secondly, according to the visual vocabulary PIRF descriptors of an image are projected to the vector of visual word occurrences. Multiple visual word occurrences vectors are formed as a sequence of visual word occurrences. This sequence is inputted to HTM to implement the environment map learning and building and closed loop scenes recognition. The performance of the proposed mapping method is evaluated by two experiments. The results show that the proposed strategy based on HTM is effective for map building and closed loop detection.

  2. Hierarchical object-based mapping of riverscape units and in-stream mesohabitats using LiDAR and VHR imagery

    OpenAIRE

    Luca Demarchi; Simone Bizzi; Hervé Piégay

    2015-01-01

    In this paper, we present a new, semi-automated methodology for mapping hydromorphological indicators of rivers at a regional scale using multisource remote sensing (RS) data. This novel approach is based on the integration of spectral and topographic information within a multilevel, geographic, object-based image analysis (GEOBIA). Different segmentation levels were generated based on the two sources of Remote Sensing (RS) data, namely very-high spatial resolution, near-infrared imagery (VHR...

  3. Caustics and Rogue Waves in an Optical Sea

    CERN Document Server

    Mathis, Amaury; Toenger, Shanti; Dias, Frederic; Genty, Goery; Dudley, John M

    2015-01-01

    There are many examples in physics of systems showing rogue wave behaviour, the generation of high amplitude events at low probability. Although initially studied in oceanography, rogue waves have now been seen in many other domains, with particular recent interest in optics. Although most studies in optics have focussed on how nonlinearity can drive rogue wave emergence, purely linear effects have also been shown to induce extreme wave amplitudes. In this paper, we report a detailed experimental study of linear rogue waves in an optical system, using a spatial light modulator to impose random phase structure on a coherent optical field. After free space propagation, different random intensity patterns are generated, including partially-developed speckle, a broadband caustic network, and an intermediate pattern with characteristics of both speckle and caustic structures. Intensity peaks satisfying statistical criteria for rogue waves are seen especially in the case of the caustic network, and are associated w...

  4. Incorporating Endmember Variability into Linear Unmixing of Coarse Resolution Imagery: Mapping Large-Scale Impervious Surface Abundance Using a Hierarchically Object-Based Spectral Mixture Analysis

    Directory of Open Access Journals (Sweden)

    Chengbin Deng

    2015-07-01

    Full Text Available As an important indicator of anthropogenic impacts on the Earth’s surface, it is of great necessity to accurately map large-scale urbanized areas for various science and policy applications. Although spectral mixture analysis (SMA can provide spatial distribution and quantitative fractions for better representations of urban areas, this technique is rarely explored with 1-km resolution imagery. This is due mainly to the absence of image endmembers associated with the mixed pixel problem. Consequently, as the most profound source of error in SMA, endmember variability has rarely been considered with coarse resolution imagery. These issues can be acute for fractional land cover mapping due to the significant spectral variations of numerous land covers across a large study area. To solve these two problems, a hierarchically object-based SMA (HOBSMA was developed (1 to extrapolate local endmembers for regional spectral library construction; and (2 to incorporate endmember variability into linear spectral unmixing of MODIS 1-km imagery for large-scale impervious surface abundance mapping. Results show that by integrating spatial constraints from object-based image segments and endmember extrapolation techniques into multiple endmember SMA (MESMA of coarse resolution imagery, HOBSMA improves the discriminations between urban impervious surfaces and other land covers with well-known spectral confusions (e.g., bare soil and water, and particularly provides satisfactory representations of urban fringe areas and small settlements. HOBSMA yields promising abundance results at the km-level scale with relatively high precision and small bias, which considerably outperforms the traditional simple mixing model and the aggregated MODIS land cover classification product.

  5. Electrochemical generation of Fenton's reagent to treat spent caustic wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, H. K.; Nunez, P.; Rodriguez, N.; Guzman, J.

    2009-07-01

    An important wastewater stream from oil refineries is the spent caustic. Caustic solutions are used as scrubbing agent during the desulphurization process to eliminate sulphur an mercaptans from oil and gasses. Spent caustic is classified as DOO3 (reactive sulphide) hazardous waste under the US Resource Conservation and Recovery Act (RCRA). (Author)

  6. 21 CFR 2.110 - Definition of ammonia under Federal Caustic Poison Act.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Definition of ammonia under Federal Caustic Poison... SERVICES GENERAL GENERAL ADMINISTRATIVE RULINGS AND DECISIONS Caustic Poisons § 2.110 Definition of ammonia under Federal Caustic Poison Act. For the purpose of determining whether an article containing...

  7. Mapping disability-adjusted life years: a Bayesian hierarchical model framework for burden of disease and injury assessment.

    Science.gov (United States)

    MacNab, Ying C

    2007-11-20

    This paper presents a Bayesian disability-adjusted life year (DALY) methodology for spatial and spatiotemporal analyses of disease and/or injury burden. A Bayesian disease mapping model framework, which blends together spatial modelling, shared-component modelling (SCM), temporal modelling, ecological modelling, and non-linear modelling, is developed for small-area DALY estimation and inference. In particular, we develop a model framework that enables SCM as well as multivariate CAR modelling of non-fatal and fatal disease or injury rates and facilitates spline smoothing for non-linear modelling of temporal rate and risk trends. Using British Columbia (Canada) hospital admission-separation data and vital statistics mortality data on non-fatal and fatal road traffic injuries to male population age 20-39 for year 1991-2000 and for 84 local health areas and 16 health service delivery areas, spatial and spatiotemporal estimation and inference on years of life lost due to premature death, years lived with disability, and DALYs are presented. Fully Bayesian estimation and inference, with Markov chain Monte Carlo implementation, are illustrated. We present a methodological framework within which the DALY and the Bayesian disease mapping methodologies interface and intersect. Its development brings the relative importance of premature mortality and disability into the assessment of community health and health needs in order to provide reliable information and evidence for community-based public health surveillance and evaluation, disease and injury prevention, and resource provision.

  8. Hierarchical state space partitioning with a network self-organising map for the recognition of ST-T segment changes.

    Science.gov (United States)

    Bezerianos, A; Vladutu, L; Papadimitriou, S

    2000-07-01

    The problem of maximising the performance of ST-T segment automatic recognition for ischaemia detection is a difficult pattern classification problem. The paper proposes the network self-organising map (NetSOM) model as an enhancement to the Kohonen self-organised map (SOM) model. This model is capable of effectively decomposing complex large-scale pattern classification problems into a number of partitions, each of which is more manageable with a local classification device. The NetSOM attempts to generalize the regularization and ordering potential of the basic SOM from the space of vectors to the space of approximating functions. It becomes a device for the ordering of local experts (i.e. independent neural networks) over its lattice of neurons and for their selection and co-ordination. Each local expert is an independent neural network that is trained and activated under the control of the NetSOM. This method is evaluated with examples from the European ST-T database. The first results obtained after the application of NetSOM to ST-T segment change recognition show a significant improvement in the performance compared with that obtained with monolithic approaches, i.e. with single network types. The basic SOM model has attained an average ischaemic beat sensitivity of 73.6% and an average ischaemic beat predictivity of 68.3%. The work reports and discusses the improvements that have been obtained from the implementation of a NetSOM classification system with both multilayer perceptrons and radial basis function (RBF) networks as local experts for the ST-T segment change problem. Specifically, the NetSOM with multilayer perceptrons (radial basis functions) as local experts has improved the results over the basic SOM to an average ischaemic beat sensitivity of 75.9% (77.7%) and an average ischaemic beat predictivity of 72.5% (74.1%).

  9. Hierarchical Object-Based Mapping of Riverscape Units and in-Stream Mesohabitats Using LiDAR and VHR Imagery

    Directory of Open Access Journals (Sweden)

    Luca Demarchi

    2016-01-01

    Full Text Available In this paper, we present a new, semi-automated methodology for mapping hydromorphological indicators of rivers at a regional scale using multisource remote sensing (RS data. This novel approach is based on the integration of spectral and topographic information within a multilevel, geographic, object-based image analysis (GEOBIA. Different segmentation levels were generated based on the two sources of Remote Sensing (RS data, namely very-high spatial resolution, near-infrared imagery (VHR and high-resolution LiDAR topography. At each level, different input object features were tested with Machine Learning classifiers for mapping riverscape units and in-stream mesohabitats. The GEOBIA approach proved to be a powerful tool for analyzing the river system at different levels of detail and for coupling spectral and topographic datasets, allowing for the delineation of the natural fluvial corridor with its primary riverscape units (e.g., water channel, unvegetated sediment bars, riparian densely-vegetated units, etc. and in-stream mesohabitats with a high level of accuracy, respectively of K = 0.91 and K = 0.83. This method is flexible and can be adapted to different sources of data, with the potential to be implemented at regional scales in the future. The analyzed dataset, composed of VHR imagery and LiDAR data, is nowadays increasingly available at larger scales, notably through European Member States. At the same time, this methodology provides a tool for monitoring and characterizing the hydromorphological status of river systems continuously along the entire channel network and coherently through time, opening novel and significant perspectives to river science and management, notably for planning and targeting actions.

  10. Ingestion of Caustic Substances in Adults: A Review Article

    Directory of Open Access Journals (Sweden)

    Andon Chibishev

    2013-02-01

    Full Text Available Background: Ingestion of caustic agents can cause serious damages of the upper gastrointestinal tract and in some cases this kind of poisoning may have fatal outcomes. Acute caustic intoxications are one of the main problems in the modern clinical toxicology since they mainly affect young people with psychic disorders, suicidal intent, and alcohol addiction. Text: In diagnostic evaluation of this kind of poisoning, different procedures are used. Today’s golden standard for determination of the grade and extent of the lesion is esophagogastroduodenoscopy (EGD performed in the first 12-24 hours following corrosive ingestion. In some patients, some late complications, such as esophageal stenosis and gastric stenosis, which are the most common, as well as carcinoma of the upper gastrointestinal tract, which is rarely seen, can be detected. Acute caustic poisonings are treated with specific kinds of protocols. According to them, first, an attempt is made to neutralize the poison. Combinations of antibiotics, anti-secretory drugs, and collagen synthesis inhibitors are used. As a support therapy, nutritional liquids can be utilized, and in the most unmanageable cases, esophageal dilatation, stent placement and surgery are used. Conclusion: In the future, caustic poisonings will remain a serious socio-medical issue, due to the difficult clinical presentation, expensive diagnostic protocol, extended hospitalization, and possible permanent disability.

  11. Laser Beam Caustic Measurement with Focal Spot Analyser

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Gong, Hui; Bagger, Claus

    2005-01-01

    In industrial applications of high power CO2-lasers the caustic characteristics of the laser beam have great effects on the performance of the lasers. A welldefined high intense focused spot is essential for reliable production results. This paper presents a focal spot analyser that is developed...... for measuring the beam profiles of focused high power CO2-lasers....

  12. Genome-Wide Mapping of Collier In Vivo Binding Sites Highlights Its Hierarchical Position in Different Transcription Regulatory Networks.

    Directory of Open Access Journals (Sweden)

    Mathilde de Taffin

    Full Text Available Collier, the single Drosophila COE (Collier/EBF/Olf-1 transcription factor, is required in several developmental processes, including head patterning and specification of muscle and neuron identity during embryogenesis. To identify direct Collier (Col targets in different cell types, we used ChIP-seq to map Col binding sites throughout the genome, at mid-embryogenesis. In vivo Col binding peaks were associated to 415 potential direct target genes. Gene Ontology analysis revealed a strong enrichment in proteins with DNA binding and/or transcription-regulatory properties. Characterization of a selection of candidates, using transgenic CRM-reporter assays, identified direct Col targets in dorso-lateral somatic muscles and specific neuron types in the central nervous system. These data brought new evidence that Col direct control of the expression of the transcription regulators apterous and eyes-absent (eya is critical to specifying neuronal identities. They also showed that cross-regulation between col and eya in muscle progenitor cells is required for specification of muscle identity, revealing a new parallel between the myogenic regulatory networks operating in Drosophila and vertebrates. Col regulation of eya, both in specific muscle and neuronal lineages, may illustrate one mechanism behind the evolutionary diversification of Col biological roles.

  13. Hierarchical photocatalysts.

    Science.gov (United States)

    Li, Xin; Yu, Jiaguo; Jaroniec, Mietek

    2016-05-01

    As a green and sustainable technology, semiconductor-based heterogeneous photocatalysis has received much attention in the last few decades because it has potential to solve both energy and environmental problems. To achieve efficient photocatalysts, various hierarchical semiconductors have been designed and fabricated at the micro/nanometer scale in recent years. This review presents a critical appraisal of fabrication methods, growth mechanisms and applications of advanced hierarchical photocatalysts. Especially, the different synthesis strategies such as two-step templating, in situ template-sacrificial dissolution, self-templating method, in situ template-free assembly, chemically induced self-transformation and post-synthesis treatment are highlighted. Finally, some important applications including photocatalytic degradation of pollutants, photocatalytic H2 production and photocatalytic CO2 reduction are reviewed. A thorough assessment of the progress made in photocatalysis may open new opportunities in designing highly effective hierarchical photocatalysts for advanced applications ranging from thermal catalysis, separation and purification processes to solar cells.

  14. Determination Of Caustic Drain Out Period Of Glass Bottle Washerand Impact Of Total And Effective Caustic Strengths For Glass Bottle Washing In Soft Drink Plant

    Directory of Open Access Journals (Sweden)

    B.M.MJ. Harshani

    2015-08-01

    Full Text Available One of the most important processes in soft drink production is bottle washing high quality of the product depends on that. A main objective of the present study is to determine the impact of total caustic and effective caustic strength on the washing performance of glass bottles. Total and effective caustic strength in samples were measured based on titration results. Four parameters were considered on the washing performance of glass bottles such as Microbiological Tests APC and Yeast amp Molds Methylene blue test Phenolphthalein test and Physical inspection. Ten samples were tested for every test per each time and three times were considered for a day and conduct for 43 days within two caustic drains out periods. Negative correlations in between total effective caustic strengths with time Days indicate from 29 days onward in tanks. There is a Positive correlation P 0.05 in between Carbonates gml and time Days onward. Positive correlations P 0.05 indicate from 35 days onward for the number of algae present bottles number of dirty bottles and APC too. Twenty nine days from the initial charge of caustic soda can be taken as the most suitable day for the caustic discharge. Under the practical scenario mean differences of total and effective caustic strengths are negligible compared to the standard value and not significantly difference P 0.05.

  15. Statistics of Caustics in Large-Scale Structure Formation

    Science.gov (United States)

    Feldbrugge, Job L.; Hidding, Johan; van de Weygaert, Rien

    2016-10-01

    The cosmic web is a complex spatial pattern of walls, filaments, cluster nodes and underdense void regions. It emerged through gravitational amplification from the Gaussian primordial density field. Here we infer analytical expressions for the spatial statistics of caustics in the evolving large-scale mass distribution. In our analysis, following the quasi-linear Zel'dovich formalism and confined to the 1D and 2D situation, we compute number density and correlation properties of caustics in cosmic density fields that evolve from Gaussian primordial conditions. The analysis can be straightforwardly extended to the 3D situation. We moreover, are currently extending the approach to the non-linear regime of structure formation by including higher order Lagrangian approximations and Lagrangian effective field theory.

  16. Statistics of Caustics in Large-Scale Structure Formation

    CERN Document Server

    Feldbrugge, Job; van de Weygaert, Rien

    2014-01-01

    The cosmic web is a complex spatial pattern of walls, filaments, cluster nodes and underdense void regions. It emerged through gravitational amplification from the Gaussian primordial density field. Here we infer analytical expressions for the spatial statistics of caustics in the evolving large-scale mass distribution. In our analysis, following the quasi-linear Zeldovich formalism and confined to the 1D and 2D situation, we compute number density and correlation properties of caustics in cosmic density fields that evolve from Gaussian primordial conditions. The analysis can be straightforwardly extended to the 3D situation. We moreover, are currently extending the approach to the non-linear regime of structure formation by including higher order Lagrangian approximations and Lagrangian effective field theory.

  17. Spectral caustics in laser assisted Breit–Wheeler process

    OpenAIRE

    Nousch, T.; Seipt, D.; Kämpfer, B.; Titov, A. I.

    2016-01-01

    Electron–positron pair production by the Breit–Wheeler process embedded in a strong laser pulse is analyzed. The transverse momentum spectrum displays prominent peaks which are interpreted as caustics, the positions of which are accessible by the stationary phases. Examples are given for the superposition of an XFEL beam with an optical high-intensity laser beam. Such a configuration is available, e.g., at LCLS at present and at European XFEL in near future. It requires a counter propagating ...

  18. Epidemiology and prevention of caustic ingestion in children

    DEFF Research Database (Denmark)

    Christesen, H B

    1994-01-01

    significantly during the period studied. The cause of this decrease is not clear, but a change in the spectrum of household products and the gradual introduction of child-proof caps are possible explanations. To minimize the frequency of accidents, an information campaign directed specifically at parents...... of toddlers is recommended. Information material should stress that caustics should always be inaccessible to children and stored separately, and should never be decanted....

  19. Caustics in Tachyon Matter and Other Born-Infeld Scalars

    CERN Document Server

    Felder, G; Starobinsky, A A; Felder, Gary; Kofman, Lev; Starobinsky, Alexei

    2002-01-01

    We consider scalar Born-Infeld type theories with arbitrary potentials V(T) of a scalar field T. We find that for models with runaway potentials V(T) the generic inhomogeneous solutions after a short transient stage can be very well approximated by the solutions of a Hamilton-Jacobi equation that describes free streaming wave front propagation. The analytic solution for this wave propagation shows the formation of caustics with multi-valued regions beyond them. We verified that these caustics appear in numerical solutions of the original scalar BI non-linear equations. Our results include the scalar BI model with an exponential potential, which was recently proposed as an effective action for the string theory tachyon in the approximation where high-order spacetime derivatives of T are truncated. Since the actual string tachyon dynamics contain derivatives of all orders, the tachyon BI model with an exponential potential becomes inadequate when the caustics develop because high order spatial derivatives of T ...

  20. A middle age addicted man with caustic stomach

    Directory of Open Access Journals (Sweden)

    Gholamreza Nouri Broujerdi

    2014-06-01

    Full Text Available Background: The term caustic generally refers to alkaline and the term corrosive generally refers to acidic agents' injury; however, in medical literature caustic is frequently a term applied to both substances. Ingested alkali typically damage the esophagus more than stomach or duodenum, whereas acids usually cause more severe gastric injury. Since esophagus has a slightly alkaline pH, its epithelium is more resistant to acids, so that only 6 to 20% of those who ingest these substances present lesions in this organ. Case : A middle-aged addicted man who drunk hydrochloric acid accidentally had extensive necrosis of the stomach with remarkable sparing of the esophagus on second look exploration. A total gastrectomy with a Roux-en-Y esophago-jejunostomy with feeding jejunostomy was performed. Conclusion : In caustic GI injury, patients who are operated on and found to have no evidence of extensive esophago-gastric necrosis, a biopsy of the posterior gastric wall should be performed to exclude occult injury. If histologically there is a question of viability, a second look operation should be performed within 36 hours.

  1. Caustics and Rogue Waves in an Optical Sea.

    Science.gov (United States)

    Mathis, Amaury; Froehly, Luc; Toenger, Shanti; Dias, Frédéric; Genty, Goëry; Dudley, John M

    2015-08-06

    There are many examples in physics of systems showing rogue wave behaviour, the generation of high amplitude events at low probability. Although initially studied in oceanography, rogue waves have now been seen in many other domains, with particular recent interest in optics. Although most studies in optics have focussed on how nonlinearity can drive rogue wave emergence, purely linear effects have also been shown to induce extreme wave amplitudes. In this paper, we report a detailed experimental study of linear rogue waves in an optical system, using a spatial light modulator to impose random phase structure on a coherent optical field. After free space propagation, different random intensity patterns are generated, including partially-developed speckle, a broadband caustic network, and an intermediate pattern with characteristics of both speckle and caustic structures. Intensity peaks satisfying statistical criteria for rogue waves are seen especially in the case of the caustic network, and are associated with broader spatial spectra. In addition, the electric field statistics of the intermediate pattern shows properties of an "optical sea" with near-Gaussian statistics in elevation amplitude, and trough-to-crest statistics that are near-Rayleigh distributed but with an extended tail where a number of rogue wave events are observed.

  2. Analysis of ray stability and caustic formation in a layered moving fluid medium

    CERN Document Server

    Bergman, David R

    2015-01-01

    Caustic formation occurs within a ray skeleton as optical or acoustic fields propagate in a medium with variable refractive properties and are unphysical, their presence being an artifact of the ray approximation of the field, and methods of correcting the field near a caustic are well known. Differential geometry provides a novel approach to calculating acoustic intensity, assessing ray stability and locating caustics in acoustic ray traces when the properties of medium are completely arbitrary by identifying points on the caustic with conjugate points along various rays. The method of geodesic deviation is applied to the problem of determining ray stability and locating caustics in 2-dimensional acoustic ray traces in a layered moving medium. Specifically, a general treatment of caustic formation in sound ducts and in piecewise continuous media is presented and applied to various idealized and realistic scenarios.

  3. Effects of an expanding caustic ring on a distribution of stars

    Science.gov (United States)

    Chakrabarty, Sankha Subhra; Sikivie, Pierre

    2017-01-01

    In self-similar axially symmetric model of galactic halo, caustic rings lie on the galactic disk and expand on cosmological time scale. We study the motion of a distribution of stars under the gravitational field of an expanding caustic ring. We investigate how the bulk velocities of the stars are affected by the caustic. This work was supported in part by the Heising-Simons Foundation.

  4. Spectral caustics in laser assisted Breit–Wheeler process

    Directory of Open Access Journals (Sweden)

    T. Nousch

    2016-04-01

    Full Text Available Electron–positron pair production by the Breit–Wheeler process embedded in a strong laser pulse is analyzed. The transverse momentum spectrum displays prominent peaks which are interpreted as caustics, the positions of which are accessible by the stationary phases. Examples are given for the superposition of an XFEL beam with an optical high-intensity laser beam. Such a configuration is available, e.g., at LCLS at present and at European XFEL in near future. It requires a counter propagating probe photon beam with high energy which can be generated by synchronized inverse Compton backscattering.

  5. Spectral caustics in laser assisted Breit-Wheeler process

    Science.gov (United States)

    Nousch, T.; Seipt, D.; Kämpfer, B.; Titov, A. I.

    2016-04-01

    Electron-positron pair production by the Breit-Wheeler process embedded in a strong laser pulse is analyzed. The transverse momentum spectrum displays prominent peaks which are interpreted as caustics, the positions of which are accessible by the stationary phases. Examples are given for the superposition of an XFEL beam with an optical high-intensity laser beam. Such a configuration is available, e.g., at LCLS at present and at European XFEL in near future. It requires a counter propagating probe photon beam with high energy which can be generated by synchronized inverse Compton backscattering.

  6. A systematic fitting scheme for caustic-crossing microlensing events

    DEFF Research Database (Denmark)

    Kains ...[et al], N.; Jørgensen, Uffe Gråe

    2009-01-01

    in the parameter space, which lead to several distinct competitive best models. We examine the parameters for each of them, and estimate their physical properties. We find that our fitting strategy locates several minima that are difficult to find with other modelling strategies and is therefore a more appropriate......We outline a method for fitting binary-lens caustic-crossing microlensing events based on the alternative model parametrization proposed and detailed by Cassan. As an illustration of our methodology, we present an analysis of OGLE-2007-BLG-472, a double-peaked Galactic microlensing event...... method to fit this type of event....

  7. Spectral caustics in laser assisted Breit-Wheeler process

    CERN Document Server

    Nousch, T; Kämpfer, B; Titov, A I

    2015-01-01

    Electron-positron pair production by the Breit-Wheeler process embedded in a strong laser pulse is analyzed. The transverse momentum spectrum displays prominent peaks which are interpreted as caustics, the positions of which are accessible by the stationary phases. Examples are given for the superposition of an XFEL beam with an optical high-intensity laser beam. Such a configuration is available, e.g., at LCLS at present and at European XFEL in near future. It requires a counter propagating probe photon beam with high energy which can be generated by synchronized inverse Compton backscattering.

  8. Adaptive mobility management scheme in hierarchical mobile IPv6

    Science.gov (United States)

    Fang, Bo; Song, Junde

    2004-04-01

    Hierarchical mobile IPv6 makes the mobility management localized. Registration with HA is only needed while MN moving between MAP domains. This paper proposed an adaptive mobility management scheme based on the hierarchical mobile IPv6. The scheme focuses on the MN operation as well as MAP operation during the handoff. Adaptive MAP selection algorithm can be used to select a suitable MAP to register with once MN moves into a new subnet while MAP can thus adaptively changing his management domain. Furthermore, MAP can also adaptively changes its level in the hierarchical referring on the service load or other related information. Detailed handoff algorithm is also discussed in this paper.

  9. Biological treatment of sulfidic spent caustics under haloalkaline conditions using soda lake bacteria

    NARCIS (Netherlands)

    Graaff, de C.M.

    2012-01-01

    In this thesis, the development of a newbiotechnological process for the treatment of undiluted sulfidic spent caustics (SSC’s) using soda lake bacteria is described. SSC’s are waste solutions that are formed in the oil and gas industry due to the caustic (NaOH) scrubbing of hydrocarbon

  10. Caustic-based approach to understanding bunching dynamics and current spike formation in particle bunches

    Science.gov (United States)

    Charles, T. K.; Paganin, D. M.; Dowd, R. T.

    2016-10-01

    Current modulations, current spikes, and current horns, are observed in a range of accelerator physics applications including strong bunch compression in Free Electron Lasers and linear colliders, trains of microbunching for terahertz radiation, microbunching instability and many others. This paper considers the fundamental mechanism that drives intense current modulations in dispersive regions, beyond the common explanation of nonlinear and higher-order effects. Under certain conditions, neighboring electron trajectories merge to form caustics, and often result in characteristic current spikes. Caustic lines and surfaces are regions of maximum electron density, and are witnessed in accelerator physics as folds in phase space of accelerated bunches. We identify the caustic phenomenon resulting in cusplike current profiles and derive an expression which describes the conditions needed for particle-bunch caustic formation in dispersive regions. The caustic expression not only reveals the conditions necessary for caustics to form but also where in longitudinal space the caustics will form. Particle-tracking simulations are used to verify these findings. We discuss the broader implications of this work including how to utilize the caustic expression for manipulation of the longitudinal phase space to achieve a desired current profile shape.

  11. Hydrogen peroxide and caustic soda: Dancing with a dragon while bleaching

    Science.gov (United States)

    Peter W. Hart; Carl Houtman; Kolby Hirth

    2013-01-01

    When hydrogen peroxide is mixed with caustic soda, an auto-accelerating reaction can lead to generation of significant amounts of heat and oxygen. On the basis of experiments using typical pulp mill process concentration and temperatures, a relatively simple kinetic model has been developed. Evaluation of these model results reveals that hydrogen peroxide-caustic soda...

  12. Regeneration and treatment of sulfidic spent caustic using analytic hierarchy process

    Directory of Open Access Journals (Sweden)

    Asadollah Karimi

    2016-10-01

    Full Text Available Background: Sulfur compounds must be removed from petroleum because they contribute to environmental pollution. A strong alkaline solution such as caustic soda is used to remove these compounds. This spent caustic has high values for chemical oxygen demand (COD concentration, pH and total sulfur. In this study, the regeneration and treatment methodology of sulfidic spent caustic was investigated by applying the analytic hierarchy process (AHP. Methods: The evaluation index system developed was based on group decision-improved AHP. Expert Choice software was used to simplify decision-making when choosing a practical method and prioritizing treatment of spent caustic. Cost, environmental considerations, availability and scale-up were chosen as criteria and wet air oxidation and biological and catalytic methods were selected as alternative methods. The treatment and regeneration of spent caustic was carried out in a batch bubble column reactor loaded with IVKAZ catalyst and the effluent was treated in a precipitation-stirred tank reactor. Results: Evaluation indicated that cost ranked first among criteria at 40.9%. The results showed that the proposed process produced about 13% (wt of caustic, 50 g/L of COD and 36 g/L of S2-. Conclusion: The results indicate that the catalytic method was more effective (0.45 than wet air oxidation and the biological method. This process regenerated more than 85% of initial caustic and the economy of the process improved by the recycling of the stream of caustic.

  13. 16 CFR 1500.129 - Substances named in the Federal Caustic Poison Act.

    Science.gov (United States)

    2010-01-01

    ... Poison Act. 1500.129 Section 1500.129 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL... REGULATIONS § 1500.129 Substances named in the Federal Caustic Poison Act. The Commission finds that for those substances covered by the Federal Caustic Poison Act (44 Stat. 1406), the requirements of section 2(p)(1)...

  14. Weather regimes over Senegal during the summer monsoon season using self-organizing maps and hierarchical ascendant classification. Part II: interannual time scale

    Energy Technology Data Exchange (ETDEWEB)

    Gueye, A.K. [ESP, UCAD, Dakar (Senegal); Janicot, Serge; Sultan, Benjamin [LOCEAN/IPSL, IRD, Universite Pierre et Marie Curie, Paris cedex 05 (France); Niang, A. [LTI, ESP/UCAD, Dakar (Senegal); Sawadogo, S. [LTI, EPT, Thies (Senegal); Diongue-Niang, A. [ANACIM, Dakar (Senegal); Thiria, S. [LOCEAN/IPSL, UPMC, Paris (France)

    2012-11-15

    The aim of this work is to define over the period 1979-2002 the main synoptic weather regimes relevant for understanding the daily variability of rainfall during the summer monsoon season over Senegal. ''Interannual'' synoptic weather regimes are defined by removing the influence of the mean 1979-2002 seasonal cycle. This is different from Part I where the seasonal evolution of each year was removed, then removing also the contribution of interannual variability. As in Part I, the self-organizing maps approach, a clustering methodology based on non-linear artificial neural network, is combined with a hierarchical ascendant classification to compute these regimes. Nine weather regimes are identified using the mean sea level pressure and 850 hPa wind field as variables. The composite circulation patterns of all these nine weather regimes are very consistent with the associated anomaly patterns of precipitable water, mid-troposphere vertical velocity and rainfall. They are also consistent with the distribution of rainfall extremes. These regimes have been then gathered into different groups. A first group of four regimes is included in an inner circuit and is characterized by a modulation of the semi-permanent trough located along the western coast of West Africa and an opposite modulation on the east. This circuit is important because it associates the two wettest and highly persistent weather regimes over Senegal with the driest and the most persistent one. One derivation of this circuit is highlighted, including the two driest regimes and the most persistent one, what can provide important dry sequences occurrence. An exit of this circuit is characterised by a filling of the Saharan heat low. An entry into the main circuit includes a southward location of the Saharan heat low followed by its deepening. The last weather regime is isolated from the other ones and it has no significant impact on Senegal. It is present in June and September, and

  15. Does the process map influence the outcome of quality improvement work? A comparison of a sequential flow diagram and a hierarchical task analysis diagram

    OpenAIRE

    Potts Henry WW; Anderson Janet E; Colligan Lacey; Berman Jonathan

    2010-01-01

    Abstract Background Many quality and safety improvement methods in healthcare rely on a complete and accurate map of the process. Process mapping in healthcare is often achieved using a sequential flow diagram, but there is little guidance available in the literature about the most effective type of process map to use. Moreover there is evidence that the organisation of information in an external representation affects reasoning and decision making. This exploratory study examined whether the...

  16. 基于层次MAP的虚拟试验系统互操作协议研究%Interoperability Protocol Study of Virtual Test System Based on Hierarchical MAP

    Institute of Scientific and Technical Information of China (English)

    李雨江; 杜承烈; 尤涛

    2011-01-01

    Aiming at the problem that Ethernet and VMIC rellective memory network cannot communicate directly in virtual test system, an interoperability protocol scheme based on hierarchical MAP is proposed .BAsed on the introduction of gateway node which connects Ethernet and VWIC reflective memory network, we propose three-tier memory division scheme of VMIC refective memory, achieve the distribution and release algorithms of reflective memory by hierarchical MAP, complete the mutual mapping between Ethernet data and reflective memory data, thus achieving interoperability protocol of virtual test system. Tests show the the interoperability protocol can effectively exchanges and shares data between Ethernet and VMIC real-time metwor,and satisfies the real-time request of virtual test system.%在虚拟试验系统中,针对以太网和VMIC反射内存网不能直接通信的问题,提出了一种基于层次MAP的互操作协议方案;在引入网关节点连接以太网和VMIC反射内存网的基础上,提出了VMIC反射内存的三层内存划分方案,利用层次MAP实现了反射内存的分配和释放算法,完成了以太网数据和反射内存网数据的相互映射,从而实现了虚拟试验系统的互操作;试验表明,该互操作协议方案能够有效实现以太网和VMIC实时网之间的数据交换和共享,较好地满足了虚拟试验系统的实时性要求.

  17. Testing the Caustic Ring Dark Matter Halo Model Against Observations in the Milky Way

    Science.gov (United States)

    Dumas, Julie; Newberg, Heidi Jo; Niedzielski, Bethany; Susser, Adam; Thompson, Jeffery M.; Weiss, Jake; Lewis, Kim M.

    2016-06-01

    One prediction of axion dark matter models is they can form Bose-Einstein condensates and rigid caustic rings as a halo collapses in the non-linear regime. In this thesis, we undertake the first study of a caustic ring model for the Milky Way halo (Duffy & Sikivie 2008), paying particular attention to observational consequences. We first present the formalism for calculating the gravitational acceleration of a caustic ring halo. The caustic ring dark matter theory reproduces a roughly logarithmic halo, with large perturbations near the rings. We show that this halo can reasonably match the known Galactic rotation curve. We are not able to confirm or rule out an association between the positions of the caustic rings and oscillations in the observed rotation curve, due to insufficient rotation curve data. We explore the effects of dark matter caustic rings on dwarf galaxy tidal disruption with N-body simulations. Simulations of the Sagittarius (Sgr) dwarf galaxy in a caustic ring halo potential, with disk and bulge parameters that are tuned to match the Galactic rotation curve, match observations of the Sgr trailing tidal tails as far as 90 kpc from the Galactic center. Like the Navarro-Frenk-White (NFW) halo, they are, however, unable to match the leading tidal tail. None of the caustic, NFW, or triaxial logarithmic halos are able to simultaneously match observations of the leading and trailing arms of the Sagittarius stream. We further show that simulations of dwarf galaxies that move through caustic rings are qualitatively similar to those moving in a logarithmic halo. This research was funded by NSF grant AST 10-09670, the NASA-NY Space Grant, and the American Fellowship from AAUW.

  18. Industrial Experience on the Caustic Cracking of Stainless Steels and Nickel Alloys - A Review

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B

    2005-10-09

    Caustic environments are present in several industries, from nuclear power generation to the fabrication of alkalis and alumina. The most common material of construction is carbon steel but its application is limited to a maximum temperature of approximately 80 C. The use of Nickel (Ni) alloys is recommended at higher temperatures. Commercially pure Ni is the most resistant material for caustic applications both from the general corrosion and the stress corrosion cracking (SCC) perspectives. Nickel rich alloys also offer a good performance. The most important alloying elements are Ni and chromium (Cr). Molybdenum (Mo) is not a beneficial alloying element and it dissolves preferentially from the alloy in presence of caustic environments. Austenitic stainless steels such as type 304 and 316 seem less resistant to caustic conditions than even plain carbon steel. Experimental evidence shows that the most likely mechanism for SCC is anodic dissolution.

  19. Novel Electrochemical Treatment of Spent Caustic from the Hydrocarbon Industry Using Ti/BDD

    National Research Council Canada - National Science Library

    Medel, Alejandro; Méndez, Erika; Hernández-López, José L; Ramírez, José A; Cárdenas, Jesús; Frausto, Roberto F; Godínez, Luis A; Bustos, Erika; Meas, Yunny

    2015-01-01

    .... In this study, the use of electrochemical technology (ET), using BDD with Ti as substrate (Ti/BDD), is evaluated in electrolysis of spent caustic mixtures, obtained through individual samples from different refineries...

  20. About supersaturation and growth rates of hydrargillite Al(OH) 3 in alumina caustic solutions

    Science.gov (United States)

    Veesler, Stéphane; Boistelle, Roland

    1993-06-01

    Growth rates of hydrargillite crystals, Al(OH) 3, growing from concentrated caustic solutions, are traditionally plotted and discussed as a function of the difference between actual concentration and solubility of alumina. This way to express supersaturation is probably due to practical or technical reasons, as hydrargillite is mainly grown in industrial plants. However, as the solubility of hydrargillite is greatly affected by the presence of caustic soda there are as many growth rate curves as there are solutions at different soda concentrations, if supersaturation is expressed as a concentration difference. In the present paper we show that all growth rates, measured in different caustic solutions, lie on a single curve if supersaturation is normalized with respect to solubility, i.e. expressed as a ratio of actual concentration over solubility. Accordingly, growth rates become independent of the caustic concentrations when growth takes place at the same supersaturation.

  1. Industrial Experience on the Caustic Cracking of Stainless Steels and Nickel Alloys - A Review

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B

    2005-10-09

    Caustic environments are present in several industries, from nuclear power generation to the fabrication of alkalis and alumina. The most common material of construction is carbon steel but its application is limited to a maximum temperature of approximately 80 C. The use of Nickel (Ni) alloys is recommended at higher temperatures. Commercially pure Ni is the most resistant material for caustic applications both from the general corrosion and the stress corrosion cracking (SCC) perspectives. Nickel rich alloys also offer a good performance. The most important alloying elements are Ni and chromium (Cr). Molybdenum (Mo) is not a beneficial alloying element and it dissolves preferentially from the alloy in presence of caustic environments. Austenitic stainless steels such as type 304 and 316 seem less resistant to caustic conditions than even plain carbon steel. Experimental evidence shows that the most likely mechanism for SCC is anodic dissolution.

  2. Caustics, pseudocaustics and the related illuminated and dark regions with the computational method of quantifier elimination

    Science.gov (United States)

    Ioakimidis, Nikolaos I.

    2017-01-01

    The method of caustics is a powerful experimental method in elasticity and particularly in fracture mechanics for crack problems. The related method of pseudocaustics is also of interest. Here we apply the computational method of quantifier elimination implemented in the computer algebra system Mathematica in order to determine (i) the non-parametric equation and two properties of the caustic at a crack tip and especially (ii) the illuminated and the dark regions related to caustics and pseudocaustics in plane elasticity and plate problems. The present computations concern: (i) The derivation of the non-parametric equation of the classical caustic about a crack tip through the elimination of the parameter involved (here the polar angle) as well as two geometrical properties of this caustic. (ii) The derivation of the inequalities defining the illuminated region on the screen in the problem of an elastic half-plane loaded normally by a concentrated load with the boundary of this illuminated region related to some extent to the caustic formed. (iii) Similarly for the problem of a clamped circular plate under a uniform loading with respect to the caustic and the pseudocaustic formed. (iv) Analogously for the problem of an equilateral triangular plate loaded by uniformly distributed moments along its whole boundary, which defines the related pseudocaustic. (v) The determination of quantities of interest in mechanics from the obtained caustics or pseudocaustics. The kind of computations in the applications (ii) to (iv), i.e. the derivation of inequalities defining the illuminated region on the screen, seems to be completely new independently of the use here of the method of quantifier elimination. Additional applications are also possible, but some of them require the expansion of the present somewhat limited power of the quantifier elimination algorithms in Mathematica. This is expected to take place in the future.

  3. Structured caustic vector vortex optical field: manipulating optical angular momentum flux and polarization rotation.

    Science.gov (United States)

    Chen, Rui-Pin; Chen, Zhaozhong; Chew, Khian-Hooi; Li, Pei-Gang; Yu, Zhongliang; Ding, Jianping; He, Sailing

    2015-05-29

    A caustic vector vortex optical field is experimentally generated and demonstrated by a caustic-based approach. The desired caustic with arbitrary acceleration trajectories, as well as the structured states of polarization (SoP) and vortex orders located in different positions in the field cross-section, is generated by imposing the corresponding spatial phase function in a vector vortex optical field. Our study reveals that different spin and orbital angular momentum flux distributions (including opposite directions) in different positions in the cross-section of a caustic vector vortex optical field can be dynamically managed during propagation by intentionally choosing the initial polarization and vortex topological charges, as a result of the modulation of the caustic phase. We find that the SoP in the field cross-section rotates during propagation due to the existence of the vortex. The unique structured feature of the caustic vector vortex optical field opens the possibility of multi-manipulation of optical angular momentum fluxes and SoP, leading to more complex manipulation of the optical field scenarios. Thus this approach further expands the functionality of an optical system.

  4. Hierarchical Network Design

    DEFF Research Database (Denmark)

    Thomadsen, Tommy

    2005-01-01

    of different types of hierarchical networks. This is supplemented by a review of ring network design problems and a presentation of a model allowing for modeling most hierarchical networks. We use methods based on linear programming to design the hierarchical networks. Thus, a brief introduction to the various....... The thesis investigates models for hierarchical network design and methods used to design such networks. In addition, ring network design is considered, since ring networks commonly appear in the design of hierarchical networks. The thesis introduces hierarchical networks, including a classification scheme...... linear programming based methods is included. The thesis is thus suitable as a foundation for study of design of hierarchical networks. The major contribution of the thesis consists of seven papers which are included in the appendix. The papers address hierarchical network design and/or ring network...

  5. 应用生长、分级的自组织映射模型进行意识任务分类%GROWING HIERARCHICAL SELF-ORGANIZING MAP MODELS FOR MENTAL TASK CLASSIFICATION

    Institute of Scientific and Technical Information of China (English)

    刘海龙; 王珏; 郑崇勋

    2005-01-01

    提出一种使用生长、分级的自组织映射(growing hierarchical self-organizing map,GHSOM)模型进行基于EEG信号的意识任务分类来实现脑机接口技术的方法.GHSOM模型是自组织映射(self-organizing map,SOM)的一种变体,由多层的SOM组成,具有一定的分级结构,能够表达数据中不同层次的信息.同时研究了使用平均量化误差(mean quantization error,mqe)和量化误差(quantization error,qe)两种方法实现的GHSOM模型对意识任务分类的作用.结果表明,GHSOM模型对于意识任务的可分性能够提供可视化的信息,并且发现使用量化误差方法实现的GHSOM模型提供较多的数据信息和较高的分类精度.使用GHSOM模型进行了5类意识任务的分类,平均分类精度可达80%.

  6. Hierarchical Multiagent Reinforcement Learning

    Science.gov (United States)

    2004-01-25

    In this paper, we investigate the use of hierarchical reinforcement learning (HRL) to speed up the acquisition of cooperative multiagent tasks. We...introduce a hierarchical multiagent reinforcement learning (RL) framework and propose a hierarchical multiagent RL algorithm called Cooperative HRL. In

  7. Incorporating Endmember Variability into Linear Unmixing of Coarse Resolution Imagery: Mapping Large-Scale Impervious Surface Abundance Using a Hierarchically Object-Based Spectral Mixture Analysis

    OpenAIRE

    Chengbin Deng

    2015-01-01

    As an important indicator of anthropogenic impacts on the Earth’s surface, it is of great necessity to accurately map large-scale urbanized areas for various science and policy applications. Although spectral mixture analysis (SMA) can provide spatial distribution and quantitative fractions for better representations of urban areas, this technique is rarely explored with 1-km resolution imagery. This is due mainly to the absence of image endmembers associated with the mixed pixel problem. Con...

  8. Spiking neurons in a hierarchical self-organizing map model can learn to develop spatial and temporal properties of entorhinal grid cells and hippocampal place cells.

    Directory of Open Access Journals (Sweden)

    Praveen K Pilly

    Full Text Available Medial entorhinal grid cells and hippocampal place cells provide neural correlates of spatial representation in the brain. A place cell typically fires whenever an animal is present in one or more spatial regions, or places, of an environment. A grid cell typically fires in multiple spatial regions that form a regular hexagonal grid structure extending throughout the environment. Different grid and place cells prefer spatially offset regions, with their firing fields increasing in size along the dorsoventral axes of the medial entorhinal cortex and hippocampus. The spacing between neighboring fields for a grid cell also increases along the dorsoventral axis. This article presents a neural model whose spiking neurons operate in a hierarchy of self-organizing maps, each obeying the same laws. This spiking GridPlaceMap model simulates how grid cells and place cells may develop. It responds to realistic rat navigational trajectories by learning grid cells with hexagonal grid firing fields of multiple spatial scales and place cells with one or more firing fields that match neurophysiological data about these cells and their development in juvenile rats. The place cells represent much larger spaces than the grid cells, which enable them to support navigational behaviors. Both self-organizing maps amplify and learn to categorize the most frequent and energetic co-occurrences of their inputs. The current results build upon a previous rate-based model of grid and place cell learning, and thus illustrate a general method for converting rate-based adaptive neural models, without the loss of any of their analog properties, into models whose cells obey spiking dynamics. New properties of the spiking GridPlaceMap model include the appearance of theta band modulation. The spiking model also opens a path for implementation in brain-emulating nanochips comprised of networks of noisy spiking neurons with multiple-level adaptive weights for controlling autonomous

  9. Associative Hierarchical Random Fields.

    Science.gov (United States)

    Ladický, L'ubor; Russell, Chris; Kohli, Pushmeet; Torr, Philip H S

    2014-06-01

    This paper makes two contributions: the first is the proposal of a new model-The associative hierarchical random field (AHRF), and a novel algorithm for its optimization; the second is the application of this model to the problem of semantic segmentation. Most methods for semantic segmentation are formulated as a labeling problem for variables that might correspond to either pixels or segments such as super-pixels. It is well known that the generation of super pixel segmentations is not unique. This has motivated many researchers to use multiple super pixel segmentations for problems such as semantic segmentation or single view reconstruction. These super-pixels have not yet been combined in a principled manner, this is a difficult problem, as they may overlap, or be nested in such a way that the segmentations form a segmentation tree. Our new hierarchical random field model allows information from all of the multiple segmentations to contribute to a global energy. MAP inference in this model can be performed efficiently using powerful graph cut based move making algorithms. Our framework generalizes much of the previous work based on pixels or segments, and the resulting labelings can be viewed both as a detailed segmentation at the pixel level, or at the other extreme, as a segment selector that pieces together a solution like a jigsaw, selecting the best segments from different segmentations as pieces. We evaluate its performance on some of the most challenging data sets for object class segmentation, and show that this ability to perform inference using multiple overlapping segmentations leads to state-of-the-art results.

  10. Wavefields Near Transverse Cusp Caustics Produced by Reflecting Ultrasonic Transients and Tone Bursts from Curved Surfaces.

    Science.gov (United States)

    Frederickson, Carl King

    Ultrasonic wavefields reflected from curved surfaces were studied in the vicinity of caustics. Acoustical and optical transverse cusp diffraction catastrophes produced by reflections from a curved metal surface in water were imaged by displaying the amplitude or intensity in an observation plane transverse to the general direction of propagation. The optical image was used to locate the cusp point in the observation plane. Acoustical diffraction patterns for sine waves, described by the Pearcey function, were calculated with the parameters determined by the experimental setup leaving no adjustable scaling parameters. The calculated and experimental acoustical diffraction patterns showed good agreement near the cusp point. The acoustical diffraction pattern showed the expected mirror symmetry about an axis. The pattern was shown to scale properly with frequency. The transverse cusp caustic separates space into a region with three rays and a region with one ray. Inside the caustic there are three rays, on the curve two of the rays merge and disappear leaving one ray outside. Transient signals reflected from curved surfaces exhibited the merging and disappearance of rays on the caustic. Relative arrival times for signals in calculated and recorded time traces agree well. The relation to the wavefront parameters of the temporal orientation of the travel time surface is discussed. The general shape of the travel time surface is that of the swallow tail caustic surface. The temporal shape of the transient echoes was seen to be generally that of the incident signal or of its Hilbert transform. The Hilbert transform shape identifies the signals that have touched the caustic. The observed arrival sequence of the transient signals was shh inside the caustic and one h outside, where s stands for a signal with the general shape of the incident signal and h for its Hilbert transform. The relation between the surface and wavefront parameters and the arrival sequence is given.

  11. Hierarchical Network Design

    DEFF Research Database (Denmark)

    Thomadsen, Tommy

    2005-01-01

    Communication networks are immensely important today, since both companies and individuals use numerous services that rely on them. This thesis considers the design of hierarchical (communication) networks. Hierarchical networks consist of layers of networks and are well-suited for coping...... the clusters. The design of hierarchical networks involves clustering of nodes, hub selection, and network design, i.e. selection of links and routing of ows. Hierarchical networks have been in use for decades, but integrated design of these networks has only been considered for very special types of networks....... The thesis investigates models for hierarchical network design and methods used to design such networks. In addition, ring network design is considered, since ring networks commonly appear in the design of hierarchical networks. The thesis introduces hierarchical networks, including a classification scheme...

  12. MECHANISTIC UNDERSTANDING OF CAUSTIC CRACKING OF CARBON STEELS

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Diaz, B.; Roy, A.

    2009-10-19

    Liquid waste generated by the PUREX process for separation of nuclear materials is concentrated and stored in Type IV single-shell carbon steel tanks at the Savannah River Site (SRS). The Type IV tanks for this waste do not have cooling coils and have not undergone heat treatment to stress-relieve the tanks. After the waste is concentrated by evaporation, it becomes very alkaline and can cause stress corrosion cracking (SCC) and pitting corrosion of the tank materials. SRS has experienced leakage from non-stress-relieved waste tanks constructed of A285 carbon steel and pitting of A212 carbon steel tanks in the vapor space. An investigation of tank materials has been undertaken at SRS to develop a basic understanding of caustic SCC of A285 and A212 grade carbon steels exposed to aqueous solutions, primarily containing sodium hydroxide (NaOH), sodium nitrate (NaNO{sub 3}), and sodium nitrite (NaNO{sub 2}) at temperatures relevant to the operating conditions of both the F and H area plants. This report presents the results of this corrosion testing program. Electrochemical tests were designed using unstressed coupons in a simulated tank environment. The purpose of this testing was to determine the corrosion susceptibility of the tank materials as a function of chemical concentration, pH, and temperature. A285 and A516 (simulates A212 carbon steel) coupons were used to investigate differences in the corrosion of these carbon steels. Electrochemical testing included measurement of the corrosion potential and polarization resistance as well as cyclic potentiodynamic polarization (CPP) testing of coupons. From the CPP experiments, corrosion characteristics were determined including: corrosion potential (E{sub corr}), pitting or breakdown potential (E{sub pit}), and repassivation potential (E{sub prot}). CPP results showed no indications of localized corrosion, such as pitting, and all samples showed the formation of a stable passive layer as evidenced by the positive

  13. Mapping urban and peri-urban breeding habitats of Aedes mosquitoes using a fuzzy analytical hierarchical process based on climatic and physical parameters

    Directory of Open Access Journals (Sweden)

    Muhammad Shahzad Sarfraz

    2014-12-01

    Full Text Available The spread of dengue fever depends mainly on the availability of favourable breeding sites for its mosquito vectors around human dwellings. To investigate if the various factors influencing breeding habitats can be mapped from space, dengue indices, such as the container index, the house index and the Breteau index, were calculated from Ministry of Public health data collected three times annually in Phitsanulok, Thailand between 2009 and 2011. The most influential factors were found to be temperature, humidity, rainfall, population density, elevation and land cover. Models were worked out using parameters mostly derived from freely available satellite images and fuzzy logic software with parameter synchronisation and a predication algorithm based on data mining and the Decision Tree method. The models developed were found to be sufficiently flexible to accommodate additional parameters and sampling data that might improve prediction of favourable breeding hotspots. The algorithm applied can not only be used for the prediction of near real-time scenarios with respect to dengue, but can also be applied for monitoring other diseases influenced by environmental and climatic factors. The multi-criteria model presented is a cost-effective way of identifying outbreak hotspots and early warning systems lend themselves for development based on this strategy. The proposed approach demonstrates the successful utilisation of remotely sensed images to map mosquito breeding habitats.

  14. Mapping urban and peri-urban breeding habitats of Aedes mosquitoes using a fuzzy analytical hierarchical process based on climatic and physical parameters.

    Science.gov (United States)

    Sarfraz, Muhammad Shahzad; Tripathi, Nagesh K; Faruque, Fazlay S; Bajwa, Usama Ijaz; Kitamoto, Asanobu; Souris, Marc

    2014-12-01

    The spread of dengue fever depends mainly on the availability of favourable breeding sites for its mosquito vectors around human dwellings. To investigate if the various factors influencing breeding habitats can be mapped from space, dengue indices, such as the container index, the house index and the Breteau index, were calculated from Ministry of Public health data collected three times annually in Phitsanulok, Thailand between 2009 and 2011. The most influential factors were found to be temperature, humidity, rainfall, population density, elevation and land cover. Models were worked out using parameters mostly derived from freely available satellite images and fuzzy logic software with parameter synchronisation and a predication algorithm based on data mining and the Decision Tree method. The models developed were found to be sufficiently flexible to accommodate additional parameters and sampling data that might improve prediction of favourable breeding hotspots. The algorithm applied can not only be used for the prediction of near real-time scenarios with respect to dengue, but can also be applied for monitoring other diseases influenced by environmental and climatic factors. The multi-criteria model presented is a cost-effective way of identifying outbreak hotspots and early warning systems lend themselves for development based on this strategy. The proposed approach demonstrates the successful utilisation of remotely sensed images to map mosquito breeding habitats.

  15. Faraday caustics: Singularities in the Faraday spectrum and their utility as probes of magnetic field properties

    CERN Document Server

    Bell, M R; Enßlin, T A

    2011-01-01

    We describe singularities in the distribution of polarized intensity as a function of Faraday depth (i.e. the Faraday spectrum) that arise due to line of sight (LOS) magnetic field reversals. We call these features Faraday caustics due to their similarity to optical caustics. They appear sharply spiked in the Faraday spectrum with a tail that extends to one side. The direction in which the tail extends depends on the way in which the LOS magnetic field reversal occurs (either changing from oncoming to retreating or vice versa). We describe how surfaces of Faraday caustics relate to boundaries between regions where the LOS magnetic field has opposite polarity. Examples from simulations of the polarized synchrotron emission from the Milky Way are provided. We derive the probability or luminosity distribution of Faraday caustics produced in a Gaussian magnetic field distribution as a function of their strength, F, and find that for strong Faraday caustics P(F) ~ F^(-3). If fully resolved, this distribution is al...

  16. Caustic Ingestion in Children: a Systematic Review and Meta-Analysis

    Science.gov (United States)

    Rafeey, Mandana; Ghojazadeh, Morteza; Sheikhi, Saeede; Vahedi, Leila

    2016-01-01

    Introduction:Caustic ingestion that occurs accidently is one of the most common problems in children. Methods: This systematic review has been performed by searching the databases including Science Direct, ProQuest, Google Scholar, and PubMed. A strategic search was performed with keywords including caustic, corrosive, ingestion, and children, and was limited to articles in English and Persian. Data were analyzed using Comprehensive Meta-Analysis2 and PASW Statistics 18. Results: We selected 64 articles regarding caustic ingestion with a total sample of 11,345 cases. The data analysis indicated a higher consumption in young boys (age range 2.78 (2.02) years (OR=0.53 with a 95% confidence interval of 0.49-0.57 (P=0.08)). The most common caustic substances were household cleaning agents, particularly bleaches and cleaners. Esophageal cancer and death were reported as well as digestive and respiratory complications. Invasive and expensive techniques are frequently used for diagnosis, treatment and follow up. Conclusion: The results demonstrated that although caustic ingestion is a serious problem among children, it is a preventable and manageable issue. Therefore, appropriate efforts by families, government, factories, health team and media should be made to handle adequately this matter.

  17. A hierarchical framework of aquatic ecological units in North America (Nearctic Zone).

    Science.gov (United States)

    James R. Maxwell; Clayton J. Edwards; Mark E. Jensen; Steven J. Paustian; Harry Parrott; Donley M. Hill

    1995-01-01

    Proposes a framework for classifying and mapping aquatic systems at various scales using ecologically significant physical and biological criteria. Classification and mapping concepts follow tenets of hierarchical theory, pattern recognition, and driving variables. Criteria are provided for the hierarchical classification and mapping of aquatic ecological units of...

  18. Topology-based hierarchical scheduling using deficit round robin

    DEFF Research Database (Denmark)

    Yu, Hao; Yan, Ying; Berger, Michael Stubert

    2009-01-01

    This paper proposes a topology-based hierarchical scheduling scheme using Deficit Round Robin (DRR). The main idea of the topology-based hierarchical scheduling is to map the topology of the connected network into the logical structure of the scheduler, and combine several token schedulers...

  19. New strategies for treatment and reuse of spent sulfidic caustic stream from petroleum industry

    Directory of Open Access Journals (Sweden)

    Jéssica Frontino Paulino

    2012-01-01

    Full Text Available This work examines traditional and new routes for removal of H2S and other sulfur compounds from spent sufidic caustic (SSC. SH- (hydrogenosulfide and S2- (sulfide ions were quantitatively oxidized at 25 ºC using H2O2, NaOCl or a spent sulfochromic mixture. SH-/S2- ions were also removed via reaction with freshly prepared iron or manganese hydroxides, or after passing the SSC through strong basic anion exchange resins (OH- form. The treated caustic solution, as well as iron/manganese hydroxides, removed H2S from diesel samples at 25 ºC. SSC treatment via strong basic anion-exchange resins produced the treated caustic solution with the highest free alkalinity.

  20. Superboom Caustic Analysis and Measurement Program (SCAMP) Final Report

    Science.gov (United States)

    Page, Juliet; Plotkin, Ken; Hobbs, Chris; Sparrow, Vic; Salamone, Joe; Cowart, Robbie; Elmer, Kevin; Welge, H. Robert; Ladd, John; Maglieri, Domenic; Piacsek, Andrew

    2015-01-01

    The objectives of the Superboom Caustic Analysis and Measurement (SCAMP) Program were to develop and validate, via flight-test measurements, analytical models for sonic boom signatures in and around focal zones as they are expected to occur during commercial aircraft transition from subsonic to supersonic flight, and to apply these models to focus boom prediction of low-boom aircraft designs. The SCAMP program has successfully investigated sonic boom focusing both analytically and experimentally, while gathering a comprehensive empirical flight test and acoustic dataset, and developing a suite of focused sonic boom prediction tools. An experimental flight and acoustic measurement test was designed during the initial year of the SCAMP program, with execution of the SCAMP flight test occurring in May 2011. The current SCAMP team, led by Wyle, includes partners from the Boeing Company, Pennsylvania State University, Gulfstream Aerospace, Eagle Aeronautics, and Central Washington University. Numerous collaborators have also participated by supporting the experiment with human and equipment resources at their own expense. The experiment involved precision flight of a McDonnell Douglas (now Boeing) F-18B executing different maneuvers that created focused sonic booms. The maneuvers were designed to center on the flight regime expected for commercial supersonic aircraft transonic transition, and also span a range of caustic curvatures in order to provide a variety of conditions for code validations. The SCAMP experiment was designed to capture concurrent F-18B on-board flight instrumentation data, high-fidelity ground-based and airborne acoustic data, and surface and upper air meteorological data. Close coordination with NASA Dryden resulted in the development of new experimental instrumentation and techniques to facilitate the SCAMP flight-test execution, including the development of an F-18B Mach rate cockpit display, TG-14 powered glider in-flight sonic boom measurement

  1. Biological treatment of refinery spent caustics under halo-alkaline conditions

    NARCIS (Netherlands)

    Graaff, de M.; Bijmans, M.F.M.; Abbas, B.; Euverink, G.J.W.; Muyzer, G.; Janssen, A.J.H.

    2011-01-01

    The present research demonstrates the biological treatment of refinery sulfidic spent caustics in a continuously fed system under halo-alkaline conditions (i.e. pH 9.5; Na(+)= 0.8M). Experiments were performed in identical gas-lift bioreactors operated under aerobic conditions (80-90% saturation) at

  2. Safety basis for the 241-AN-107 mixer pump installation and caustic addition

    Energy Technology Data Exchange (ETDEWEB)

    Van Vleet, R.J. [Westinghouse Hanford Co., Richland, WA (United States)

    1994-10-05

    This safety Basis was prepared to determine whether or not the proposed activities of installing a 76 HP jet mixer pump and the addition of approximately 50,000 gallons of 19 M (50:50 wt %) aqueous caustic are within the safety envelope as described by Tank Farms (chapter six of WHC-SD-WM-ISB-001, Rev. 0). The safety basis covers the components, structures and systems for the caustic addition and mixer pump installation. These include: installation of the mixer pump and monitoring equipment; operation of the mixer pump, process monitoring equipment and caustic addition; the pump stand, caustic addition skid, the electrical skid, the video camera system and the two densitometers. Also covered is the removal and decontamination of the mixer pump and process monitoring system. Authority for this safety basis is WHC-IP-0842 (Waste Tank Administration). Section 15.9, Rev. 2 (Unreviewed Safety Questions) of WHC-IP-0842 requires that an evaluation be performed for all physical modifications.

  3. Epidemiologic Features and Outcomes of Caustic Ingestions; a 10-Year Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Athena Alipour Faz

    2017-01-01

    Full Text Available Introduction: Caustic ingestions are among the most prevalent causes of toxic exposure. The present 10-year survey aimed to evaluate the epidemiologic features and outcomes of caustic ingestion cases presenting to emergency department.Methods: This is a retrospective cross-sectional study on patients who were admitted to a referral toxicology center during 2004 to 2014, following caustic ingestion. Baseline characteristics, presenting chief complaint, severity of mucosal injury, complications, imaging and laboratory findings as well as outcomes (need for ICU admission, need for surgery, mortality were recorded, reviewing patients’ medical profile, and analyzed using SPSS 22.Results: 348 patients with mean age of 37.76 ± 17.62 years were studied (55.6% male. The mean amount of ingested caustic agent was 106.69 ± 100.24 mL (59.2 % intentional. Intentional ingestions (p < 0.0001, acidic substance (p = 0.054, and higher volume of ingestion (p = 0.021 were significantly associated with higher severity of mucosal damage. 28 (8% cases had died, 53 (15.2% were admitted to ICU, and 115 (33% cases underwent surgery.Conclusion: It seems that, suicidal intention, higher grade of mucosal injury, higher volume of ingestion, lower level of consciousness, lower serum pH, and higher respiratory rate are among the most important predictors of need for ICU admission, need for surgery, and mortality.

  4. Structural evaluation of mixer pump installed in Tank 241-AN-107 for caustic addition project

    Energy Technology Data Exchange (ETDEWEB)

    Leshikar, G.A.

    1995-06-16

    This report documents the structural analysis and evaluation of a mixer pump and caustic addition system to be used in Tank 107-AN. This pump will be installed in the central pump pit of this double- shell tank for the purpose of bringing the hydroxide ion concentration into compliance with Tank Farm operating specifications.

  5. Design and implementation of a caustic flooding EOR pilot at Court Bakken heavy oil reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Xie, J.; Chung, B.; Leung, L. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Nexen Inc., Calgary, AB (Canada)

    2008-10-15

    Successful waterflooding has been ongoing since 1988 at the Court Bakken heavy oil field in west central Saskatchewan. There are currently 20 injectors and 28 active oil producers in the Court main unit which is owned by Nexen and Pengrowth. The Court pool has an estimated 103.8 mmbbl of original oil in place (OOIP), of which 24 per cent has been successfully recovered after 20 years of waterflooding. A high-level enhanced oil recovery (EOR) screening study was conducted to evaluate other EOR technologies for a heavy oil reservoir of this viscosity range (17 degrees API). Laboratory studies showed that caustic flooding may enhance oil recovery after waterflooding at the Court Bakken heavy oil pool. A single well test demonstrated that caustic injection effectively reduced residual oil saturation. A sector model reservoir simulation revealed that caustic flood could achieve 9 per cent incremental oil recovery in the pilot area. Following the promising laboratory results, a successful caustic flood pilot was implemented at Court heavy oil pool where the major challenges encountered were low reservoir pressure and water channeling. 6 refs., 2 tabs., 6 figs.

  6. Curvilinear wave-equation angle transform: Caustics, turning rays, absence of kinematic artifacts

    NARCIS (Netherlands)

    Stolk, C.C.; De Hoop, M.V.

    2007-01-01

    Migration of seismic reflection data to common image-point gathers is an integral part of both migration velocity analysis (MVA) and amplitude (AVA) analysis. Its applicability in complex geology depends on whether these gathers will be artifact free, and is related to the formation of caustics and

  7. Novel Electrochemical Treatment of Spent Caustic from the Hydrocarbon Industry Using Ti/BDD

    Directory of Open Access Journals (Sweden)

    Alejandro Medel

    2015-01-01

    Full Text Available During the crude oil refining process, NaOH solutions are used to remove H2S, H2Saq, and sulfur compounds from different hydrocarbon streams. The residues obtained are called “spent caustics.” These residues can be mixed with those obtained in other processes, adding to its chemical composition naphthenic acids and phenolic compounds, resulting in one of the most dangerous industrial residues. In this study, the use of electrochemical technology (ET, using BDD with Ti as substrate (Ti/BDD, is evaluated in electrolysis of spent caustic mixtures, obtained through individual samples from different refineries. In this way, the Ti/BDD’s capability of carrying out the electrochemical destruction of spent caustics in an acidic medium is evaluated having as key process a chemical pretreatment phase. The potential production of •OHs, as the main reactive oxygen species electrogenerated over Ti/BDD surface, was evaluated in HCl and H2SO4 through fluorescence spectroscopy, demonstrating the reaction medium’s influence on its production. The results show that the hydrocarbon industry spent caustics can be mineralized to CO2 and water, driving the use of ET and of the Ti/BDD to solve a real problem, whose potential and negative impact on the environment and on human health is and has been the environmental agencies’ main focus.

  8. Topical mitomycin C can effectively alleviate dysphagia in children with long-segment caustic esophageal strictures.

    Science.gov (United States)

    El-Asmar, K M; Hassan, M A; Abdelkader, H M; Hamza, A F

    2015-07-01

    Caustic ingestion in children and the resulting long esophageal strictures are usually difficult to be managed, and eventually, esophageal replacement was required for cases refractory to frequent dilatation sessions. Topical mitomycin C (MMC) application has been used recently to improve the results of endoscopic dilatation for short esophageal strictures. The study aims to assess the role of MMC application in management of long-segment caustic esophageal strictures. From January 2009 to June December 2013, patients presented with long caustic esophageal stricture (>3 cm in length) were included in this study and subjected to topical MMC application after endoscopic esophageal dilatation on multiple sessions. Regular follow-up and re-evaluation were done. A dysphagia score was used for close follow-up clinically; verification was done radiologically and endoscopically. During the specified follow-up period, 21 patients with long caustic esophageal stricture were subjected to topical MMC application sessions. Clinical, radiological, and endoscopic resolution of strictures occurred in 18 patients (85.7% cure rate). Number of dilatation sessions to achieve resolution of dysphagia was (n = 14.3 ± 5.7) with application of mitomycin two to six times. There was no recurrence in short- and mid-term follow-up. No complications were encountered related to topical MMC application. MMC is a promising agent in management of long-segment caustic esophageal strictures. Long-term follow-up is needed to prove its efficacy and to evaluate potential long-term side-effects of MMC application.

  9. Direct Causticizing for Black Liquor Gasification in a Circulating Fluidized Bed

    Energy Technology Data Exchange (ETDEWEB)

    Scott Sinquefield; Xiaoyan Zeng, Alan Ball

    2010-03-02

    Gasification of black liquor (BLG) has distinct advantages over direct combustion in Tomlinson recovery boilers. In this project we seek to resolve causticizing issues in order to make pressurized BLG even more efficient and cost-effective. One advantage of BLG is that the inherent partial separation of sulfur and sodium during gasification lends itself to the use of proven high yield variants to conventional kraft pulping which require just such a separation. Processes such as polysulfide, split sulfidity, ASAQ, and MSSAQ can increase pulp yield from 1% to 10% over conventional kraft but require varying degrees of sulfur/sodium separation, which requires additional [and costly] processing in a conventional Tomlinson recovery process. However during gasification, the sulfur is partitioned between the gas and smelt phases, while the sodium all leaves in the smelt; thus creating the opportunity to produce sulfur-rich and sulfur-lean white liquors for specialty pulping processes. A second major incentive of BLG is the production of a combustible product gas, rich in H2 and CO. This product gas (a.k.a. “syngas”) can be used in gas turbines for combined cycle power generation (which is twice as efficient as the steam cycle alone), or it can be used as a precursor to form liquid fuels, such as dimethyl ether or Fischer Tropsh diesel. There is drawback to BLG, which has the potential to become a third major incentive if this work is successful. The causticizing load is greater for gasification of black liquor than for combustion in a Tomlinson boiler. So implementing BLG in an existing mill would require costly increases to the causticizing capacity. In situ causticizing [within the gasifier] would handle the entire causticizing load and therefore eliminate the lime cycle entirely. Previous work by the author and others has shown that titanate direct causticizing (i.e. in situ) works quite well for high-temperature BLG (950°C), but was limited to pressures below

  10. EFRT M-12 Issue Resolution: Caustic Leach Rate Constants from PEP and Laboratory-Scale Tests

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A.; Rassat, Scot D.; Eslinger, Paul W.; Aaberg, Rosanne L.; Aker, Pamela M.; Golovich, Elizabeth C.; Hanson, Brady D.; Hausmann, Tom S.; Huckaby, James L.; Kurath, Dean E.; Minette, Michael J.; Sundaram, S. K.; Yokuda, Satoru T.

    2009-08-14

    Testing Summary Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed and constructed and is to be operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes.” The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP; vessels UFP-VSL-00001A and B in the WTP PTF). In both scenarios, 19-M sodium hydroxide solution (NaOH, caustic) is added to the waste slurry in the vessels to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by a heating step that uses direct injection of steam to accelerate the leaching process. Following the caustic leach, the vessel contents are cooled using vessel cooling jackets and/or external heat exchangers. The main difference between the two scenarios is that for leaching in UFP-1, the 19-M NaOH is added to un-concentrated waste slurry (3 to 8 wt% solids), while for leaching in UFP-2, the slurry is

  11. Micromechanics of hierarchical materials

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon, Jr.

    2012-01-01

    A short overview of micromechanical models of hierarchical materials (hybrid composites, biomaterials, fractal materials, etc.) is given. Several examples of the modeling of strength and damage in hierarchical materials are summarized, among them, 3D FE model of hybrid composites...... with nanoengineered matrix, fiber bundle model of UD composites with hierarchically clustered fibers and 3D multilevel model of wood considered as a gradient, cellular material with layered composite cell walls. The main areas of research in micromechanics of hierarchical materials are identified, among them......, the investigations of the effects of load redistribution between reinforcing elements at different scale levels, of the possibilities to control different material properties and to ensure synergy of strengthening effects at different scale levels and using the nanoreinforcement effects. The main future directions...

  12. Hierarchical auxetic mechanical metamaterials.

    Science.gov (United States)

    Gatt, Ruben; Mizzi, Luke; Azzopardi, Joseph I; Azzopardi, Keith M; Attard, Daphne; Casha, Aaron; Briffa, Joseph; Grima, Joseph N

    2015-02-11

    Auxetic mechanical metamaterials are engineered systems that exhibit the unusual macroscopic property of a negative Poisson's ratio due to sub-unit structure rather than chemical composition. Although their unique behaviour makes them superior to conventional materials in many practical applications, they are limited in availability. Here, we propose a new class of hierarchical auxetics based on the rotating rigid units mechanism. These systems retain the enhanced properties from having a negative Poisson's ratio with the added benefits of being a hierarchical system. Using simulations on typical hierarchical multi-level rotating squares, we show that, through design, one can control the extent of auxeticity, degree of aperture and size of the different pores in the system. This makes the system more versatile than similar non-hierarchical ones, making them promising candidates for industrial and biomedical applications, such as stents and skin grafts.

  13. Introduction into Hierarchical Matrices

    KAUST Repository

    Litvinenko, Alexander

    2013-12-05

    Hierarchical matrices allow us to reduce computational storage and cost from cubic to almost linear. This technique can be applied for solving PDEs, integral equations, matrix equations and approximation of large covariance and precision matrices.

  14. Hierarchical Auxetic Mechanical Metamaterials

    Science.gov (United States)

    Gatt, Ruben; Mizzi, Luke; Azzopardi, Joseph I.; Azzopardi, Keith M.; Attard, Daphne; Casha, Aaron; Briffa, Joseph; Grima, Joseph N.

    2015-02-01

    Auxetic mechanical metamaterials are engineered systems that exhibit the unusual macroscopic property of a negative Poisson's ratio due to sub-unit structure rather than chemical composition. Although their unique behaviour makes them superior to conventional materials in many practical applications, they are limited in availability. Here, we propose a new class of hierarchical auxetics based on the rotating rigid units mechanism. These systems retain the enhanced properties from having a negative Poisson's ratio with the added benefits of being a hierarchical system. Using simulations on typical hierarchical multi-level rotating squares, we show that, through design, one can control the extent of auxeticity, degree of aperture and size of the different pores in the system. This makes the system more versatile than similar non-hierarchical ones, making them promising candidates for industrial and biomedical applications, such as stents and skin grafts.

  15. Applied Bayesian Hierarchical Methods

    CERN Document Server

    Congdon, Peter D

    2010-01-01

    Bayesian methods facilitate the analysis of complex models and data structures. Emphasizing data applications, alternative modeling specifications, and computer implementation, this book provides a practical overview of methods for Bayesian analysis of hierarchical models.

  16. Catalysis with hierarchical zeolites

    DEFF Research Database (Denmark)

    Holm, Martin Spangsberg; Taarning, Esben; Egeblad, Kresten

    2011-01-01

    Hierarchical (or mesoporous) zeolites have attracted significant attention during the first decade of the 21st century, and so far this interest continues to increase. There have already been several reviews giving detailed accounts of the developments emphasizing different aspects of this research...... topic. Until now, the main reason for developing hierarchical zeolites has been to achieve heterogeneous catalysts with improved performance but this particular facet has not yet been reviewed in detail. Thus, the present paper summaries and categorizes the catalytic studies utilizing hierarchical...... zeolites that have been reported hitherto. Prototypical examples from some of the different categories of catalytic reactions that have been studied using hierarchical zeolite catalysts are highlighted. This clearly illustrates the different ways that improved performance can be achieved with this family...

  17. Caustic Recycling Pilot Unit to Separate Sodium from LLW at Hanford Site - 12279

    Energy Technology Data Exchange (ETDEWEB)

    Pendleton, Justin; Bhavaraju, Sai; Priday, George; Desai, Aditya; Duffey, Kean; Balagopal, Shekar [Ceramatec Inc., Salt Lake City, UT 84119 (United States)

    2012-07-01

    As part of the Department of Energy (DOE) sponsored Advanced Remediation Technologies initiative, a scheme was developed to combine Continuous Sludge Leaching (CSL), Near-Tank Cesium Removal (NTCR), and Caustic Recycling Unit (CRU) using Ceramatec technology, into a single system known as the Pilot Near-Tank Treatment System (PNTTS). The Cesium (Cs) decontaminated effluent from the NTCR process will be sent to the caustic recycle process for recovery of the caustic which will be reused in another cycle of caustic leaching in the CSL process. Such an integrated mobile technology demonstration will give DOE the option to insert this process for sodium management at various sites in Hanford, and will minimize the addition of further sodium into the waste tanks. This allows for recycling of the caustic used to remove aluminum during sludge washing as a pretreatment step in the vitrification of radioactive waste which will decrease the Low Level Waste (LLW) volume by as much as 39%. The CRU pilot process was designed to recycle sodium in the form of pure sodium hydroxide. The basis for the design of the 1/4 scale pilot caustic recycling unit was to demonstrate the efficient operation of a larger scale system to recycle caustic from the NTCR effluent stream from the Parsons process. The CRU was designed to process 0.28 liter/minute of NTCR effluent, and generate 10 M concentration of 'usable' sodium hydroxide. The proposed process operates at 40 deg. C to provide additional aluminum solubility and then recover the sodium hydroxide to the point where the aluminum is saturated at 40 deg. C. A system was developed to safely separate and vent the gases generated during operation of the CRU with the production of 10 M sodium hydroxide. Caustic was produced at a rate between 1.9 to 9.3 kg/hr. The CRU was located inside an ISO container to allow for moving of the unit close to tank locations to process the LLW stream. Actual tests were conducted with the NTCR effluent

  18. Results Of Routine Strip Effluent Hold Tank, Decontaminated Salt Solution Hold Tank, Caustic Wash Tank And Caustic Storage Tank Samples From Modular Caustic-Side Solvent Extraction Unit During Macrobatch 6 Operations

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T. B.

    2014-01-02

    Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), Caustic Wash Tank (CWT) and Caustic Storage Tank (CST) samples from the Interim Salt Disposition Project (ISDP) Salt Batch (“Macrobatch”) 6 have been analyzed for 238Pu, 90Sr, 137Cs, and by Inductively Coupled Plasma Emission Spectroscopy (ICPES). The Pu, Sr, and Cs results from the current Macrobatch 6 samples are similar to those from comparable samples in previous Macrobatch 5. In addition the SEHT and DSSHT heel samples (i.e. ‘preliminary’) have been analyzed and reported to meet NGS Demonstration Plan requirements. From a bulk chemical point of view, the ICPES results do not vary considerably between this and the previous samples. The titanium results in the DSSHT samples continue to indicate the presence of Ti, when the feed material does not have detectable levels. This most likely indicates that leaching of Ti from MST has increased in ARP at the higher free hydroxide concentrations in the current feed.

  19. K-Area Acid/Caustic Basin groundwater monitoring report: First quarter 1992

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, C.Y.

    1992-06-01

    During first quarter 1992, samples from the seven KAC monitoring wells at the K-Area Acid/Caustic Basin of Savannah River Plant were analyzed for herbicides, indicator parameters, major ions, pesticides, radionuclides, turbidity, volatile organic compounds, and other constituents. Monitoring results that exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) and the Savannah River Site (SRS) flagging criteria and turbidity standards during the quarter are discussed in this report. No constituent exceeded the PDWS in the KAC wells at the K-Area Acid/Caustic Basin during first quarter 1992. Total organic halogens exceeded the Flag 2 criterion in wells KAC 6, and 7, and iron exceeded the Flag 2 criterion in well KAC 6. Well KAC 2 was the only well in the KAC well series to exceed the SRS turbidity standard.

  20. K-Area Acid/Caustic Basin groundwater monitoring report. Second quarter 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    During second quarter 1994, samples from the KAC-monitoring wells at the K-Area Acid/Caustic Basin were collected and analyzed for herbicides/pesticides, indicator parameters, metals, nitrate, radionuclide indicators, and other constituents. Monitoring results that exceeded the final Primary Drinking Water Standards (PDWS), other Savannah River Site (SRS) Flag 2 criteria, of the SRS turbidity standard are provided in this report. No constituents exceeded the final PDWS in the KAC wells. Aluminum, iron, and specific conductance exceeded other SRS flagging criteria in one or more of the downgradient wells. Total organic halogens was elevated in upgradient well KAC 3. Groundwater flow direction and rate in the water table beneath the K-Area Acid/Caustic Basin were similar to past quarters.

  1. Detecting stellar spots through polarimetry observations of microlensing events in caustic-crossing

    CERN Document Server

    Sajadian, Sedighe

    2015-01-01

    In this work, we investigate if gravitational microlensing can magnify the polarization signal of a stellar spot and make it be observable. A stellar spot on a source star of microlensing makes polarization signal through two channels of Zeeman effect and breaking circular symmetry of the source surface brightness due to its temperature contrast. We first explore the characteristics of perturbations in polarimetric microlensing during caustic-crossing of a binary lensing as follows: (a) The cooler spots over the Galactic bulge sources have the smaller contributions in the total flux, although they have stronger magnetic fields. (b) The maximum deviation in the polarimetry curve due to the spot happens when the spot is located near the source edge and the source spot is first entering the caustic whereas the maximum photometric deviation occurs for the spots located at the source center. (c) There is a (partial) degeneracy for indicating spot's size, its temperature contrast and its magnetic induction from the...

  2. Galaxy And Mass Assembly: Estimating galaxy group masses via caustic analysis

    CERN Document Server

    Alpaslan, Mehmet; Driver, Simon; Norberg, Peder; Peacock, John A; Baldry, Ivan; Bland-Hawthorn, Joss; Brough, Sarah; Hopkins, Andrew M; Kelvin, Lee S; Liske, Jochen; Loveday, Jon; Merson, Alexander; Nichol, Robert C; Pimbblet, Kevin

    2012-01-01

    We have generated complementary halo mass estimates for all groups in the Galaxy And Mass Assembly Galaxy Group Catalogue (GAMA G3Cv1) using a modified caustic mass estimation algorithm, originally developed by Diaferio & Geller (1997). We calibrate the algorithm by applying it on a series of 9 GAMA mock galaxy light cones and investigate the effects of using different definitions for group centre and size. We select the set of parameters that provide median-unbiased mass estimates when tested on mocks, and generate mass estimates for the real group catalogue. We find that on average, the caustic mass estimates agree with dynamical mass estimates within a factor of 2 in 90.8 +/- 6.1% groups and compares equally well to velocity dispersion based mass estimates for both high and low multiplicity groups over the full range of masses probed by the G3Cv1.

  3. SPHERICAL NONLINEAR PULSES FOR THE SOLUTIONS OF NONLINEAR WAVE EQUATIONS Ⅱ, NONLINEAR CAUSTIC

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This article discusses spherical pulse like solutions of the system of semilinear wave equations with the pulses focusing at a point and emerging outgoing in three space variables. In small initial data case, it shows that the nonlinearities have a strong effect at the focal point. Scattering operator is introduced to describe the caustic crossing. With the aid of the L∞ norms, it analyzes the relative errors in approximate solutions.

  4. Caustic Injury In Adults – A Study For 3 Year Period

    OpenAIRE

    2016-01-01

    The aim of the study is to present the results of a 3-year clinico-epidemiological investigation of caustic injury in adults. The study includes 43 patients with acute corrosive ingestion, hospitalized in the Toxicology Clinic, University Hospital “N. I. Pirogov”, Sofia, Bulgaria, for the period 01.01. 2010-31.12.2012. The methods used include: clinical observation and examination, clinical laboratory, imaging, and psychiatric methods and tests. 43 patients between the ages of 22 and 82 with ...

  5. The Efficacy of Mesenchymal Stem Cell Transplantation in Caustic Esophagus Injury: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Murat Kantarcioglu

    2014-01-01

    Full Text Available Introduction. Ingestion of corrosive substances may lead to stricture formation in esophagus as a late complication. Full thickness injury seems to exterminate tissue stem cells of esophagus. Mesenchymal stem cells (MSCs can differentiate into specific cell lineages and have the capacity of homing in sites of injury. Aim and Methods. We aimed to investigate the efficacy of MSC transplantation, on prevention of esophageal damage and stricture formation after caustic esophagus injury in rats. 54 rats were allocated into four groups; 4 rats were sacrificed for MSC production. Group 1, untreated controls (n: 10. Group 2, membrane labeled MSCs-treated rats (n: 20. Group 3, biodistribution of fluorodeoxyglucose labeled MSCs via positron emission tomography (PET imaging (n: 10. Group 4, sham operated (n: 10. Standard caustic esophageal burns were created and MSCs were transplanted 24 hours after. All rats were sacrificed at the 21st days. Results. PET scan images revealed the homing behavior of MSCs to the injury site. The histopathology damage score was not significantly different from controls. However, we demonstrated Dil labeled epithelial and muscle cells which were originating from transplanted MSCs. Conclusion. MSC transplantation after caustic esophageal injury may be a helpful treatment modality; however, probably repeated infusions are needed.

  6. Washing and caustic leaching of Hanford tank sludge: Results of FY 1997 studies

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, G.J.; Burgeson, I.E.; Wagner, M.J.; Liu, J.; Chen, Y.L.

    1997-08-01

    The current plan for remediating the Hanford tank farms consists of waste retrieval, pretreatment, treatment (immobilization), and disposal. The tank wastes will be partitioned into high-level and low-level fractions. The HLW will be immobilized in a borosilicate glass matrix; the resulting glass canisters will then be disposed of in a geologic repository. Because of the expected high cost of HLW vitrification and geologic disposal, pretreatment processes will be implemented to reduce the volume of immobilized high-level waste (IHLW). Caustic leaching (sometimes referred to as enhanced sludge washing or ESW) represents the baseline method for pretreating Hanford tank sludges. Caustic leaching is expected to remove a large fraction of the Al, which is present in large quantities in Hanford tank sludges. A significant portion of the P is also expected to be removed from the sludge by metathesis of water-insoluble metal phosphates to insoluble hydroxides and soluble Na{sub 3}PO{sub 4}. Similar metathesis reactions can occur for insoluble sulfate salts, allowing the removal of sulfate from the HLW stream. This report describes the sludge washing and caustic leaching tests performed at the Pacific Northwest National Laboratory in FY 1996. The sludges used in this study were taken from Hanford tanks AN-104, BY-108, S-101, and S-111.

  7. Neutrosophic Hierarchical Clustering Algoritms

    Directory of Open Access Journals (Sweden)

    Rıdvan Şahin

    2014-03-01

    Full Text Available Interval neutrosophic set (INS is a generalization of interval valued intuitionistic fuzzy set (IVIFS, whose the membership and non-membership values of elements consist of fuzzy range, while single valued neutrosophic set (SVNS is regarded as extension of intuitionistic fuzzy set (IFS. In this paper, we extend the hierarchical clustering techniques proposed for IFSs and IVIFSs to SVNSs and INSs respectively. Based on the traditional hierarchical clustering procedure, the single valued neutrosophic aggregation operator, and the basic distance measures between SVNSs, we define a single valued neutrosophic hierarchical clustering algorithm for clustering SVNSs. Then we extend the algorithm to classify an interval neutrosophic data. Finally, we present some numerical examples in order to show the effectiveness and availability of the developed clustering algorithms.

  8. Caustic ingestion in adults: The role of endoscopic classification in predicting outcome

    Directory of Open Access Journals (Sweden)

    Tang Jui-Hsiang

    2008-07-01

    Full Text Available Abstract Background The ingestion of caustic substances induces an extensive spectrum of injuries to the aerodigestive tract which include extensive necrosis and perforation of the esophagus and stomach. The gold standard of safely assessing depth, extent of injury, and appropriate therapeutic regimen is esophagogastroduodenoscopy (EGD. The objective of this study was to report our clinical experience and to evaluate the role of a 6-point EGD classification system of injury in predicting outcomes in adult patients diagnosed with caustic agent ingestion. Methods The study was a retrospective medical chart review from 273 patients admitted to the Chang Gung Memorial Hospital in Tao-Yuan, Taiwan between June 1999 and July 2006 for treatment of caustic ingestion. The patients underwent EGD within 24 hours of admission and mucosal damage was graded using Zagar's modified endoscopic classification scheme. After treatment, patients were followed in the outpatient clinic for a minimum of 6 months. Results A total of 273 patients were included for analysis. Grade 3b injury was the most common caustic injury (n = 82, 30.03%, followed by grade 2b injuries (n = 62, 22.71%. Stricture was the most common complication (n = 66, 24.18%, followed by aspiration pneumonia (n = 31, 11.36%, and respiratory failure (n = 21, 7.69%. Compared to grade 3a mucosal injury, grade 3b mucosal injuries were at greater risk of prolonged hospital stay (odds ratio [OR]: 2.44; 95% confidence interval [CI]: 1.25–4.80, ICU admission (OR: 10.82; 95% CI: 2.05–200.39, and gastrointestinal (OR: 4.15; 95% CI: 1.55–13.29 and systemic complications (OR: 4.07; 95% CI: 1.81–14.07. Conclusion In patients with caustic ingestion, EGD should be performed within 12 to 24 hours and categorized according to a 6-point scale. Patients with grade 3b burns identified on endoscopy have high rates of morbidity. The 6-point scale is useful for predicting immediate and long-term complications, and

  9. Hierarchical image segmentation for learning object priors

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.; Li, Nan [TEMPLE UNIV.

    2010-11-10

    The proposed segmentation approach naturally combines experience based and image based information. The experience based information is obtained by training a classifier for each object class. For a given test image, the result of each classifier is represented as a probability map. The final segmentation is obtained with a hierarchial image segmentation algorithm that considers both the probability maps and the image features such as color and edge strength. We also utilize image region hierarchy to obtain not only local but also semi-global features as input to the classifiers. Moreover, to get robust probability maps, we take into account the region context information by averaging the probability maps over different levels of the hierarchical segmentation algorithm. The obtained segmentation results are superior to the state-of-the-art supervised image segmentation algorithms.

  10. Mill Integration-Pulping, Stream Reforming and Direct Causticization for Black Liquor Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Adriaan van Heiningen

    2007-06-30

    MTCI/StoneChem developed a steam reforming, fluidized bed gasification technology for biomass. DOE supported the demonstration of this technology for gasification of spent wood pulping liquor (or 'black liquor') at Georgia-Pacific's Big Island, Virginia mill. The present pre-commercial R&D project addressed the opportunities as well as identified negative aspects when the MTCI/StoneChem gasification technology is integrated in a pulp mill production facility. The opportunities arise because black liquor gasification produces sulfur (as H{sub 2}S) and sodium (as Na{sub 2}CO{sub 3}) in separate streams which may be used beneficially for improved pulp yield and properties. The negative aspect of kraft black liquor gasification is that the amount of Na{sub 2}CO{sub 3} which must be converted to NaOH (the so called causticizing requirement) is increased. This arises because sulfur is released as Na{sub 2}S during conventional kraft black liquor recovery, while during gasification the sodium associated Na{sub 2}S is partly or fully converted to Na{sub 2}CO{sub 3}. The causticizing requirement can be eliminated by including a TiO{sub 2} based cyclic process called direct causticization. In this process black liquor is gasified in the presence of (low sodium content) titanates which convert Na{sub 2}CO{sub 3} to (high sodium content) titanates. NaOH is formed when contacting the latter titanates with water, thereby eliminating the causticizing requirement entirely. The leached and low sodium titanates are returned to the gasification process. The project team comprised the University of Maine (UM), North Carolina State University (NCSU) and MTCI/ThermoChem. NCSU and MTCI are subcontractors to UM. The principal organization for the contract is UM. NCSU investigated the techno-economics of using advanced pulping techniques which fully utilize the unique cooking liquors produced by steam reforming of black liquor (Task 1). UM studied the kinetics and

  11. Hierarchical Porous Structures

    Energy Technology Data Exchange (ETDEWEB)

    Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-07

    Materials Design is often at the forefront of technological innovation. While there has always been a push to generate increasingly low density materials, such as aero or hydrogels, more recently the idea of bicontinuous structures has gone more into play. This review will cover some of the methods and applications for generating both porous, and hierarchically porous structures.

  12. Test Results for Caustic Demand Measurements on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples

    Energy Technology Data Exchange (ETDEWEB)

    Doll, Stephanie R. [Washington River Protection Solutions, Richland, WA (United States); Bolling, Stacie D. [Washington River Protection Solutions, Richland, WA (United States)

    2016-07-14

    Caustic demand testing is used to determine the necessary amount of caustic required to neutralize species present in the Hanford tank waste and obtain a target molarity of free hydroxide for tank corrosion control. The presence and quantity of hydroxide-consuming analytes are just as important in determining the caustic demand as is the amount of free hydroxide present. No single data point can accurately predict whether a satisfactory hydroxide level is being met, as it is dependent on multiple factors (e.g., free hydroxide, buffers, amphoteric metal hydroxides, bicarbonate, etc.). This enclosure contains the caustic demand, scanning electron microscopy (SEM), polarized light microscopy (PLM), and X-ray diffraction (XRD) analysis for the tank 241-AX-101 (AX-101) and 241-AX-103 (AX-103) samples. The work was completed to fulfill a customer request outlined in the test plan, WRPS-1505529, “Test Plan and Procedure for Caustic Demand Testing on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples.” The work results will provide a baseline to support planned retrieval of AX-101 and AX-103.

  13. Test Results for Caustic Demand Measurements on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples

    Energy Technology Data Exchange (ETDEWEB)

    Doll, Stephanie R. [Washington River Protection Solutions, Richland, WA (United States); Bolling, Stacie D. [Washington River Protection Solutions, Richland, WA (United States)

    2016-07-14

    Caustic demand testing is used to determine the necessary amount of caustic required to neutralize species present in the Hanford tank waste and obtain a target molarity of free hydroxide for tank corrosion control. The presence and quantity of hydroxide-consuming analytes are just as important in determining the caustic demand as is the amount of free hydroxide present. No single data point can accurately predict whether a satisfactory hydroxide level is being met as it is dependent on multiple factors (e.g., free hydroxide, buffers, amphoteric metal hydroxides, bicarbonate, etc.). This enclosure contains the caustic demand, scanning electron microscopy (SEM), polarized light microscopy (PLM), and X-ray diffraction (XRD) analysis for the tank 241-AX-101 (AX-101) and 241-AX-103 (AX-103) samples. The work was completed to fulfill a customer request outlined in the test plan, WRPS-1505529, “Test Plan and Procedure for Caustic Demand Testing on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples.” The work results will provide a baseline to support planned retrieval of AX-101 and AX-103.

  14. Collaborative Hierarchical Sparse Modeling

    CERN Document Server

    Sprechmann, Pablo; Sapiro, Guillermo; Eldar, Yonina C

    2010-01-01

    Sparse modeling is a powerful framework for data analysis and processing. Traditionally, encoding in this framework is done by solving an l_1-regularized linear regression problem, usually called Lasso. In this work we first combine the sparsity-inducing property of the Lasso model, at the individual feature level, with the block-sparsity property of the group Lasso model, where sparse groups of features are jointly encoded, obtaining a sparsity pattern hierarchically structured. This results in the hierarchical Lasso, which shows important practical modeling advantages. We then extend this approach to the collaborative case, where a set of simultaneously coded signals share the same sparsity pattern at the higher (group) level but not necessarily at the lower one. Signals then share the same active groups, or classes, but not necessarily the same active set. This is very well suited for applications such as source separation. An efficient optimization procedure, which guarantees convergence to the global opt...

  15. Hierarchical manifold learning.

    Science.gov (United States)

    Bhatia, Kanwal K; Rao, Anil; Price, Anthony N; Wolz, Robin; Hajnal, Jo; Rueckert, Daniel

    2012-01-01

    We present a novel method of hierarchical manifold learning which aims to automatically discover regional variations within images. This involves constructing manifolds in a hierarchy of image patches of increasing granularity, while ensuring consistency between hierarchy levels. We demonstrate its utility in two very different settings: (1) to learn the regional correlations in motion within a sequence of time-resolved images of the thoracic cavity; (2) to find discriminative regions of 3D brain images in the classification of neurodegenerative disease,

  16. Process for converting sodium nitrate-containing, caustic liquid radioactive wastes to solid insoluble products

    Science.gov (United States)

    Barney, Gary S.; Brownell, Lloyd E.

    1977-01-01

    A method for converting sodium nitrate-containing, caustic, radioactive wastes to a solid, relatively insoluble, thermally stable form is provided and comprises the steps of reacting powdered aluminum silicate clay, e.g., kaolin, bentonite, dickite, halloysite, pyrophyllite, etc., with the sodium nitrate-containing radioactive wastes which have a caustic concentration of about 3 to 7 M at a temperature of 30.degree. C to 100.degree. C to thereby entrap the dissolved radioactive salts in the aluminosilicate matrix. In one embodiment the sodium nitrate-containing, caustic, radioactive liquid waste, such as neutralized Purex-type waste, or salts or oxide produced by evaporation or calcination of these liquid wastes (e.g., anhydrous salt cake) is converted at a temperature within the range of 30.degree. C to 100.degree. C to the solid mineral form-cancrinite having an approximate chemical formula 2(NaAlSiO.sub.4) .sup.. xSalt.sup.. y H.sub.2 O with x = 0.52 and y = 0.68 when the entrapped salt is NaNO.sub.3. In another embodiment the sodium nitrate-containing, caustic, radioactive liquid is reacted with the powdered aluminum silicate clay at a temperature within the range of 30.degree. C to 100.degree. C, the resulting reaction product is air dried eitheras loose powder or molded shapes (e.g., bricks) and then fired at a temperature of at least 600.degree. C to form the solid mineral form-nepheline which has the approximate chemical formula of NaAlSiO.sub.4. The leach rate of the entrapped radioactive salts with distilled water is reduced essentially to that of the aluminosilicate lattice which is very low, e.g., in the range of 10.sup.-.sup.2 to 10.sup.-.sup.4 g/cm.sup.2 -- day for cancrinite and 10.sup.-.sup.3 to 10.sup.-.sup.5 g/cm.sup.2 -- day for nepheline.

  17. Demonstration of Caustic-Side Solvent Extraction with Savannah River Site High Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.D.

    2001-08-27

    Researchers successfully demonstrated the chemistry and process equipment of the Caustic-Side Solvent Extraction (CSSX) flowsheet for the decontamination of high level waste using a 33-stage, 2-cm centrifugal contactor apparatus at the Savannah River Technology Center. This represents the first CSSX process demonstration using Savannah River Site (SRS) high level waste. Three tests lasting 6, 12, and 48 hours processed simulated average SRS waste, simulated Tank 37H/44F composite waste, and Tank 37H/44F high level waste, respectively.

  18. Characterization of irregular seeds on gibbsites precipitated from caustic aluminate solutions

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-hui; CHEN Qi-yuan; YIN Zhou-lan; YIN Zhi-min

    2006-01-01

    The irregular surface of seeds on which gibbsites are precipitated from caustic aluminate solutions, was investigated according to the fractal theory. Two kinds of fractal dimensions were used to characterize these irregularity. Box-dimension and spectral dimension are based on the SEM images of seeds and diffusive dynamic equation ofthe precipitation respectively. Both these two dimensions are affected by the reaction temperature, evolved with different reaction conditions and can reflect the influence of irregularity of seeds on the precipitation rate. Box dimension is fit for the characterization of the irregular morphology of seeds, while spectral dimension can explain the fractal dynamic behavior.

  19. Caustic leaching of high-level radioactive tank sludge: A critical literature review

    Energy Technology Data Exchange (ETDEWEB)

    McGinnis, C.P.; Welch, T.D.; Hunt, R.D.

    1998-08-01

    The Department of Energy (DOE) must treat and safely dispose of its radioactive tank contents, which can be separated into high-level waste (HLW) and low-level waste (LLW) fractions. Since the unit costs of treatment and disposal are much higher for HLW than for LLW, technologies to reduce the amount of HLW are being developed. A key process currently being studied to reduce the volume of HLW sludges is called enhanced sludge washing (ESW). This process removes, by water washes, soluble constituents such as sodium salts, and the washed sludge is then leached with 2--3 M NaOH at 60--100 C to remove nonradioactive metals such as aluminum. The remaining solids are considered to be HLW while the solutions are LLW after radionuclides such as {sup 137}Cs have been removed. Results of bench-scale tests have shown that the ESW will probably remove the required amounts of inert constituents. While both experimental and theoretical results have shown that leaching efficiency increases as the time and temperature of the leach are increased, increases in the caustic concentration above 2--3 M will only marginally improve the leach factors. However, these tests were not designed to validate the assumption that the caustic used in the ESW process will generate only a small increase (10 Mkg) in the amount of LLW; instead the test conditions were selected to maximize leaching in a short period and used more water and caustic than is planned during full-scale operations. Even though calculations indicate that the estimate for the amount of LLW generated by the ESW process appears to be reasonable, a detailed study of the amount of LLW from the ESW process is still required. If the LLW analysis indicates that sodium management is critical, then a more comprehensive evaluation of the clean salt process or caustic recycle would be needed. Finally, experimental and theoretical studies have clearly demonstrated the need for the control of solids formation during and after leaching.

  20. Caustic leaching of high-level radioactive tank sludge: A critical literature review

    Energy Technology Data Exchange (ETDEWEB)

    McGinnis, C.P.; Welch, T.D.; Hunt, R.D.

    1997-12-31

    The Department of Energy (DOE) must treat and safely dispose of its radioactive tank contents, which can be separated into high-level waste (HLW) and low-level waste (LLW) fractions. Since the unit costs of treatment and disposal are much higher for HLW than for LLW, technologies to reduce the amount of HLW are being developed. A key process currently being studied to reduce the volume of HLW sludges is called enhanced sludge washing (ESW). This process removes, by water washes, soluble constituents such as sodium salts, and the washed sludge is then leached with 2--3 M NaOH at 60--100 C to remove nonradioactive metals such as aluminum. The remaining solids are considered to be HLW while the solutions are LLW after radionuclides such as {sup 137}Cs have been removed. Results of bench-scale tests have shown that the ESW will probably remove the required amounts of inert constituents. While both experimental and theoretical results have shown that leaching efficiency increases as the time and temperature of the leach are increased, increases in the caustic concentration above 2--3 M will only marginally improve the leach factors. However, these tests were not designed to validate the assumption that the caustic used in the ESW process will generate only a small increase (10 Mkg) in the amount of LLW; instead, the test conditions were selected to maximize leaching in a short period and used more water and caustic than is planned during full-scale operations. Even though calculations indicate that the estimate for the amount of LLW generated by the ESW process appears to be reasonable, a detailed study of the amount of LLW from the ESW process is still required. If the LLW analysis indicates that sodium management is critical, then a more comprehensive evaluation of the clean salt process or caustic recycle would be needed. Finally, experimental and theoretical studies have clearly demonstrated the need for the control of solids formation during and after leaching.

  1. Hierarchically Structured Electrospun Fibers

    Directory of Open Access Journals (Sweden)

    Nicole E. Zander

    2013-01-01

    Full Text Available Traditional electrospun nanofibers have a myriad of applications ranging from scaffolds for tissue engineering to components of biosensors and energy harvesting devices. The generally smooth one-dimensional structure of the fibers has stood as a limitation to several interesting novel applications. Control of fiber diameter, porosity and collector geometry will be briefly discussed, as will more traditional methods for controlling fiber morphology and fiber mat architecture. The remainder of the review will focus on new techniques to prepare hierarchically structured fibers. Fibers with hierarchical primary structures—including helical, buckled, and beads-on-a-string fibers, as well as fibers with secondary structures, such as nanopores, nanopillars, nanorods, and internally structured fibers and their applications—will be discussed. These new materials with helical/buckled morphology are expected to possess unique optical and mechanical properties with possible applications for negative refractive index materials, highly stretchable/high-tensile-strength materials, and components in microelectromechanical devices. Core-shell type fibers enable a much wider variety of materials to be electrospun and are expected to be widely applied in the sensing, drug delivery/controlled release fields, and in the encapsulation of live cells for biological applications. Materials with a hierarchical secondary structure are expected to provide new superhydrophobic and self-cleaning materials.

  2. HDS: Hierarchical Data System

    Science.gov (United States)

    Pearce, Dave; Walter, Anton; Lupton, W. F.; Warren-Smith, Rodney F.; Lawden, Mike; McIlwrath, Brian; Peden, J. C. M.; Jenness, Tim; Draper, Peter W.

    2015-02-01

    The Hierarchical Data System (HDS) is a file-based hierarchical data system designed for the storage of a wide variety of information. It is particularly suited to the storage of large multi-dimensional arrays (with their ancillary data) where efficient access is needed. It is a key component of the Starlink software collection (ascl:1110.012) and is used by the Starlink N-Dimensional Data Format (NDF) library (ascl:1411.023). HDS organizes data into hierarchies, broadly similar to the directory structure of a hierarchical filing system, but contained within a single HDS container file. The structures stored in these files are self-describing and flexible; HDS supports modification and extension of structures previously created, as well as functions such as deletion, copying, and renaming. All information stored in HDS files is portable between the machines on which HDS is implemented. Thus, there are no format conversion problems when moving between machines. HDS can write files in a private binary format (version 4), or be layered on top of HDF5 (version 5).

  3. Hierarchical video summarization

    Science.gov (United States)

    Ratakonda, Krishna; Sezan, M. Ibrahim; Crinon, Regis J.

    1998-12-01

    We address the problem of key-frame summarization of vide in the absence of any a priori information about its content. This is a common problem that is encountered in home videos. We propose a hierarchical key-frame summarization algorithm where a coarse-to-fine key-frame summary is generated. A hierarchical key-frame summary facilitates multi-level browsing where the user can quickly discover the content of the video by accessing its coarsest but most compact summary and then view a desired segment of the video with increasingly more detail. At the finest level, the summary is generated on the basis of color features of video frames, using an extension of a recently proposed key-frame extraction algorithm. The finest level key-frames are recursively clustered using a novel pairwise K-means clustering approach with temporal consecutiveness constraint. We also address summarization of MPEG-2 compressed video without fully decoding the bitstream. We also propose efficient mechanisms that facilitate decoding the video when the hierarchical summary is utilized in browsing and playback of video segments starting at selected key-frames.

  4. Caustic waterflooding demonstration project: Ranger Zone, Long Beach Unit, Wilmington Field, California. Third annual report, June 1978-May 1979

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, E.H.

    1979-12-01

    A caustic-enhanced waterflooding pilot test is being conducted in the Ranger Reservoir of the Long Beach Unit, Wilmington Field, California. Evaluation of entrapment and entrainment caustic flooding in Ranger Zone cores was continued. The caustic-only (entrapment) core floods failed to demonstrate improved behavior. Based on the unfavorable results of all tests of the entrapment mechanism, further laboratory work and flooding in the pilot with caustic alone have been eliminated from the project's plans. Some of the year's caustic-salt (entrainment) core floods in contrast showed both substantial recovery and WOR improvement. The poorer overall entrainment core flood results obtained in the year may be due to the core material, a smaller preflush volume used or the crude oil employed. Core flood testing where sodium silicate is substituted for some of the sodium hydroxide, was continued. The primary set of caustic water-oil dehydration tests was completed. The test softening of produced waters was completed and the results evaluated; produced water softening was found to be an economically feasible alternative to the use of fresh water. The preflush injection facilities became operational in January 1979 with the pilot's preflush officially begun April 15, 1979. The alkaline injection facility was expanded in scope to permit use of both sodium silicate and sodium hydroxide; its completion in late 1979 is anticipated with the alkaline-salt injection scheduled to begin at that time. The base case reservoir simulator prediction of the pilot under continued waterflooding was completed. This prediction provided the base line from which incremental alkaline flood production will be determined, as the test has now been declared a qualified tertiary enhanced recovery project by DOE's Economic Regulatory Administration. Major well repair/redrill work continued to be necessary exceeding earlier increased cost estimates.

  5. An Analysis of Prospective Teachers' Knowledge for Constructing Concept Maps

    Science.gov (United States)

    Subramaniam, Karthigeyan; Esprívalo Harrell, Pamela

    2015-01-01

    Background: Literature contends that a teacher's knowledge of concept map-based tasks influence how their students perceive the task and execute the creation of acceptable concept maps. Teachers who are skilled concept mappers are able to (1) understand and apply the operational terms to construct a hierarchical/non-hierarchical concept map; (2)…

  6. Additives effects on crystallization and morphology in a novel caustic aluminate solution decomposition process

    Institute of Scientific and Technical Information of China (English)

    Ying ZHANG; Sbili ZHENG; Yifei ZHANG; Hongbin XU; Yi ZHANG

    2009-01-01

    A novel process of caustic aluminate solution decomposition by alcohol medium was developed by the Institute of Process Engineering, Chinese Academy of Sciences in order to solve the problem of low decomposi-tion ratio in the traditional Bayer seeded hydrolysis process. In this research, effects of additives on the crystallization ratio, secondary particle size and morphol-ogy of aluminum hydroxide in the new process were studied to obtain high-quality products. On the basis of primary selection of additives, an orthogonal design L9(34)was used as a chemometric method to investigate the effects of additives. The studied parameters include the reaction style, quantity of additives, caustic soda concen-tration, as well as the combination manner. The crystal-lization ratios of sodium aluminate solution and crystal size of aluminum hydroxide, determined by ICP-OES, SEM and MLPSA (Malvern Laser Particle Size Analyzer), were used to evaluate the effects of the additives. The results showed that different combination manners could promote agglomeration or dispersion. An additive composed by Tween 80 and PEG 200 could promote agglomeration,while a spot of PEG species had a relatively strong dispersion effect. However, the additives had little effects on the crystallization ratios. According to the Raman spectra result, the added alcohol medium might serve as a kind of solvent.

  7. Direct anodic hydrochloric acid and cathodic caustic production during water electrolysis

    Science.gov (United States)

    Lin, Hui-Wen; Cejudo-Marín, Rocío; Jeremiasse, Adriaan W.; Rabaey, Korneel; Yuan, Zhiguo; Pikaar, Ilje

    2016-02-01

    Hydrochloric acid (HCl) and caustic (NaOH) are among the most widely used chemicals by the water industry. Direct anodic electrochemical HCl production by water electrolysis has not been successful as current commercially available electrodes are prone to chlorine formation. This study presents an innovative technology simultaneously generating HCl and NaOH from NaCl using a Mn0.84Mo0.16O2.23 oxygen evolution electrode during water electrolysis. The results showed that protons could be anodically generated at a high Coulombic efficiency (i.e. ≥ 95%) with chlorine formation accounting for 3 ~ 5% of the charge supplied. HCl was anodically produced at moderate strengths at a CE of 65 ± 4% together with a CE of 89 ± 1% for cathodic caustic production. The reduction in CE for HCl generation was caused by proton cross-over from the anode to the middle compartment. Overall, this study showed the potential of simultaneous HCl and NaOH generation from NaCl and represents a major step forward for the water industry towards on-site production of HCl and NaOH. In this study, artificial brine was used as a source of sodium and chloride ions. In theory, artificial brine could be replaced by saline waste streams such as Reverse Osmosis Concentrate (ROC), turning ROC into a valuable resource.

  8. F-Area Acid/Caustic Basin groundwater monitoring report. First quarter 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    During first quarter 1995, samples from the FAC monitoring wells at the F-Area Acid/Caustic Basin were collected and analyzed for herbicides/pesticides, indicator parameters, metals, nitrate, radionuclide indicators, volatile organic compounds, and other constituents. Piezometer FAC 5P and monitoring well FAC 6 were dry and could not be sampled. New monitoring wells FAC 9C, 10C, 11C, and 12C were completed in the Barnwell/McBean aquifer and were sampled for the first time during third quarter 1994 (first quarter 1995 is the third of four quarters of data required to support the closure of the basin). Analytical results that exceeded final Primary Drinking Water Standards (PDWS), other Savannah River Site (SRS) Flag 2 criteria, or the SRS turbidity standard of 50 NTU during the quarter were as follows: gross alpha exceeded the final PDWS and aluminum, iron, manganese, and total alpha-emitting radium exceeded the SRS Flag 2 criteria in one or more of the FAC wells. Turbidity exceeded the SRS standard (50 NTU) in wells FAC 3 and 11C. Groundwater flow direction and rate in the water table beneath the F-Area Acid/Caustic Basin were similar to past quarters.

  9. Origami constraints on the initial-conditions arrangement of dark-matter caustics and streams

    CERN Document Server

    Neyrinck, Mark C

    2012-01-01

    In a cold-dark-matter universe, cosmological structure formation proceeds in rough analogy to origami folding. Dark matter occupies a three-dimensional 'sheet,' non-intersecting in six-dimensional velocity-position phase space. At early times, the sheet was flat like an origami sheet, i.e. velocities were essentially zero. The present paper further illustrates this analogy, and identifies a result of origami mathematics that applies to cosmology. We define caustics in the initial conditions Lagrangian space) as surfaces in this sheet, along which the sheet has folded. The regions outlined by these caustics, which we call streams, may be colored according to the two possible orientations of initial basis vectors, a two-coloring such that adjacent streams are not colored the same. While this may not have clear observational consequences, it is a severe restriction on connectivity, since there are no bounds on the number of colors required to color a general arrangement of three-dimensional regions. Then, measur...

  10. Detecting Hierarchical Structure in Networks

    DEFF Research Database (Denmark)

    Herlau, Tue; Mørup, Morten; Schmidt, Mikkel Nørgaard;

    2012-01-01

    a generative Bayesian model that is able to infer whether hierarchies are present or not from a hypothesis space encompassing all types of hierarchical tree structures. For efficient inference we propose a collapsed Gibbs sampling procedure that jointly infers a partition and its hierarchical structure......Many real-world networks exhibit hierarchical organization. Previous models of hierarchies within relational data has focused on binary trees; however, for many networks it is unknown whether there is hierarchical structure, and if there is, a binary tree might not account well for it. We propose....... On synthetic and real data we demonstrate that our model can detect hierarchical structure leading to better link-prediction than competing models. Our model can be used to detect if a network exhibits hierarchical structure, thereby leading to a better comprehension and statistical account the network....

  11. Context updates are hierarchical

    Directory of Open Access Journals (Sweden)

    Anton Karl Ingason

    2016-10-01

    Full Text Available This squib studies the order in which elements are added to the shared context of interlocutors in a conversation. It focuses on context updates within one hierarchical structure and argues that structurally higher elements are entered into the context before lower elements, even if the structurally higher elements are pronounced after the lower elements. The crucial data are drawn from a comparison of relative clauses in two head-initial languages, English and Icelandic, and two head-final languages, Korean and Japanese. The findings have consequences for any theory of a dynamic semantics.

  12. Hierarchical Fixed Point Problems in Uniformly Smooth Banach Spaces

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available We propose some relaxed implicit and explicit viscosity approximation methods for hierarchical fixed point problems for a countable family of nonexpansive mappings in uniformly smooth Banach spaces. These relaxed viscosity approximation methods are based on the well-known viscosity approximation method and hybrid steepest-descent method. We obtain some strong convergence theorems under mild conditions.

  13. Cuspidal caustic and focusing of acoustical waves generated by a parametric array onto a concave reflecting surface

    Science.gov (United States)

    Castagnède, Bernard; Sahraoui, Sohbi; Tournat, Vincent; Tahani, Najat

    2009-09-01

    The present Note is devoted to the study of the so-called cuspidal caustic at the surface of a hemi-cylindrical reflector illuminated with plane waves. In order to generate low frequency (e.g. in the range of 4 kHz) acoustical plane waves, a commercially available parametric array has been used. It produces powerful ultrasonic carrier waves at 40 kHz which can be electronically modulated between 200 Hz and 10 kHz. Further self-demodulation process during propagation in air generates an ultra-directive acoustical field (i.e. quasi-planar wavefronts) enabling to accurately study the focusing process occurring along the cuspidal caustic. The focusing coefficient can be computed locally by using two numerical tools, on one hand by computing the density of tangent rays to the caustic, and on the other hand by using some numerical results provided by a ray tracing algorithm. Some preliminary experimental data are then provided in order to validate the numerical predictions (spatial position of the caustic and focusing coefficient). To cite this article: B. Castagnède et al., C. R. Mecanique 337 (2009).

  14. Hierarchical Neural Regression Models for Customer Churn Prediction

    Directory of Open Access Journals (Sweden)

    Golshan Mohammadi

    2013-01-01

    Full Text Available As customers are the main assets of each industry, customer churn prediction is becoming a major task for companies to remain in competition with competitors. In the literature, the better applicability and efficiency of hierarchical data mining techniques has been reported. This paper considers three hierarchical models by combining four different data mining techniques for churn prediction, which are backpropagation artificial neural networks (ANN, self-organizing maps (SOM, alpha-cut fuzzy c-means (α-FCM, and Cox proportional hazards regression model. The hierarchical models are ANN + ANN + Cox, SOM + ANN + Cox, and α-FCM + ANN + Cox. In particular, the first component of the models aims to cluster data in two churner and nonchurner groups and also filter out unrepresentative data or outliers. Then, the clustered data as the outputs are used to assign customers to churner and nonchurner groups by the second technique. Finally, the correctly classified data are used to create Cox proportional hazards model. To evaluate the performance of the hierarchical models, an Iranian mobile dataset is considered. The experimental results show that the hierarchical models outperform the single Cox regression baseline model in terms of prediction accuracy, Types I and II errors, RMSE, and MAD metrics. In addition, the α-FCM + ANN + Cox model significantly performs better than the two other hierarchical models.

  15. THE CHEMICAL AND RADIATION RESISTANCE OF POLYPHENYLENE SULFIIDE AS ENCOUNTERED IN THE MODULAR CAUSTIC SIDE SOLVENT EXTRACTION PROCESSES

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Herman, D.; Poirier, M.; Fink, S.

    2011-06-30

    Polyphenylene sulfide (PPS) is a semicrystalline polymer with excellent engineering plastic properties and suitable processing temperatures. PPS can also be made containing branches (using a trifunctional monomer) and with crosslinked microstructure (when curing the monomer at high temperature in the presence of oxygen). PPS is made from the condensation reaction between para-dichlorobenzene and sodium sulfide with the assistance of a catalyst (to lower the activation barrier). The synthesis conditions for making PPS has evolved since its invention in the 1960's to the optimal conditions developed by the Philips Corporation in the 1970's. The resulting polymer consists of chemically stable molecular moieties such as benzene rings and ether like sulfur linkages between the aromatic rings. Polyphenylene sulfide (PPS) is extremely resistant to gamma irradiation, caustic solution, and dilute nitric acid. PPS is the material of construction for the coalescers used in the Modular Caustic-Side Solvent Extraction Unit (MCU). After applying the equivalent of 3.3 E8 rad (330 Mrad), or the equivalent of 11 years of gamma irradiation (assuming a stripping solution concentration of 7.5 Ci/gal), and several months of exposures to 3M caustic solution and caustic salt simulant, no dimensional changes nor chemical changes were detected in PPS whether the PPS was in fiber form or in a composite with E-glass fibers. However, PPS acts as a media for heterogeneous nucleation. In particular, PPS appears to favor aluminosilicate formation in saturated solutions of aluminum and silicon in caustic environments. Parallel testing, in progress, is examining the stability of PPS when exposed to the new solvent formulation under development for MCU. Preliminary data, after two months of exposure, demonstrates PPS is stable to the new solvent.

  16. EFRT M-12 Issue Resolution: Caustic-Leach Rate Constants from PEP and Laboratory-Scale Tests

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A.; Rassat, Scot D.; Eslinger, Paul W.; Aaberg, Rosanne L.; Aker, Pamela M.; Golovich, Elizabeth C.; Hanson, Brady D.; Hausmann, Tom S.; Huckaby, James L.; Kurath, Dean E.; Minette, Michael J.; Sundaram, S. K.; Yokuda, Satoru T.

    2010-01-01

    Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes” of the External Flowsheet Review Team (EFRT) issue response plan.( ) The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. The work described in this report addresses caustic leaching under WTP conditions, based on tests performed with a Hanford waste simulant. Because gibbsite leaching kinetics are rapid (gibbsite is expected to be dissolved by the time the final leach temperature is reached), boehmite leach kinetics are the main focus of the caustic-leach tests. The tests were completed at the laboratory-scale and in the PEP, which is a 1/4.5-scale mock-up of key PTF process equipment. Two laboratory-scale caustic-leach tests were performed for each of the PEP runs. For each PEP run, unleached slurry was taken from the PEP caustic-leach vessel for one batch and used as feed for both of the corresponding laboratory-scale tests.

  17. Simulating Photon Mapping for Real-time Applications

    DEFF Research Database (Denmark)

    Larsen, Bent Dalgaard; Christensen, Niels Jørgen

    2004-01-01

    GPU accelerated final gathering method and the illumination is then stored in light maps. Caustic photons are traced on the CPU and then drawn using points in the framebuffer, and finally filtered using the GPU. Both diffuse and non-diffuse surfaces can be handled by calculating the direct...... illumination on the GPU and the photon tracing on the CPU. We achieve real-time frame rates for dynamic scenes....

  18. Hierarchical partial order ranking.

    Science.gov (United States)

    Carlsen, Lars

    2008-09-01

    Assessing the potential impact on environmental and human health from the production and use of chemicals or from polluted sites involves a multi-criteria evaluation scheme. A priori several parameters are to address, e.g., production tonnage, specific release scenarios, geographical and site-specific factors in addition to various substance dependent parameters. Further socio-economic factors may be taken into consideration. The number of parameters to be included may well appear to be prohibitive for developing a sensible model. The study introduces hierarchical partial order ranking (HPOR) that remedies this problem. By HPOR the original parameters are initially grouped based on their mutual connection and a set of meta-descriptors is derived representing the ranking corresponding to the single groups of descriptors, respectively. A second partial order ranking is carried out based on the meta-descriptors, the final ranking being disclosed though average ranks. An illustrative example on the prioritization of polluted sites is given.

  19. Trees and Hierarchical Structures

    CERN Document Server

    Haeseler, Arndt

    1990-01-01

    The "raison d'etre" of hierarchical dustering theory stems from one basic phe­ nomenon: This is the notorious non-transitivity of similarity relations. In spite of the fact that very often two objects may be quite similar to a third without being that similar to each other, one still wants to dassify objects according to their similarity. This should be achieved by grouping them into a hierarchy of non-overlapping dusters such that any two objects in ~ne duster appear to be more related to each other than they are to objects outside this duster. In everyday life, as well as in essentially every field of scientific investigation, there is an urge to reduce complexity by recognizing and establishing reasonable das­ sification schemes. Unfortunately, this is counterbalanced by the experience of seemingly unavoidable deadlocks caused by the existence of sequences of objects, each comparatively similar to the next, but the last rather different from the first.

  20. Hierarchical Affinity Propagation

    CERN Document Server

    Givoni, Inmar; Frey, Brendan J

    2012-01-01

    Affinity propagation is an exemplar-based clustering algorithm that finds a set of data-points that best exemplify the data, and associates each datapoint with one exemplar. We extend affinity propagation in a principled way to solve the hierarchical clustering problem, which arises in a variety of domains including biology, sensor networks and decision making in operational research. We derive an inference algorithm that operates by propagating information up and down the hierarchy, and is efficient despite the high-order potentials required for the graphical model formulation. We demonstrate that our method outperforms greedy techniques that cluster one layer at a time. We show that on an artificial dataset designed to mimic the HIV-strain mutation dynamics, our method outperforms related methods. For real HIV sequences, where the ground truth is not available, we show our method achieves better results, in terms of the underlying objective function, and show the results correspond meaningfully to geographi...

  1. Optimisation by hierarchical search

    Science.gov (United States)

    Zintchenko, Ilia; Hastings, Matthew; Troyer, Matthias

    2015-03-01

    Finding optimal values for a set of variables relative to a cost function gives rise to some of the hardest problems in physics, computer science and applied mathematics. Although often very simple in their formulation, these problems have a complex cost function landscape which prevents currently known algorithms from efficiently finding the global optimum. Countless techniques have been proposed to partially circumvent this problem, but an efficient method is yet to be found. We present a heuristic, general purpose approach to potentially improve the performance of conventional algorithms or special purpose hardware devices by optimising groups of variables in a hierarchical way. We apply this approach to problems in combinatorial optimisation, machine learning and other fields.

  2. How hierarchical is language use?

    Science.gov (United States)

    Frank, Stefan L.; Bod, Rens; Christiansen, Morten H.

    2012-01-01

    It is generally assumed that hierarchical phrase structure plays a central role in human language. However, considerations of simplicity and evolutionary continuity suggest that hierarchical structure should not be invoked too hastily. Indeed, recent neurophysiological, behavioural and computational studies show that sequential sentence structure has considerable explanatory power and that hierarchical processing is often not involved. In this paper, we review evidence from the recent literature supporting the hypothesis that sequential structure may be fundamental to the comprehension, production and acquisition of human language. Moreover, we provide a preliminary sketch outlining a non-hierarchical model of language use and discuss its implications and testable predictions. If linguistic phenomena can be explained by sequential rather than hierarchical structure, this will have considerable impact in a wide range of fields, such as linguistics, ethology, cognitive neuroscience, psychology and computer science. PMID:22977157

  3. How hierarchical is language use?

    Science.gov (United States)

    Frank, Stefan L; Bod, Rens; Christiansen, Morten H

    2012-11-22

    It is generally assumed that hierarchical phrase structure plays a central role in human language. However, considerations of simplicity and evolutionary continuity suggest that hierarchical structure should not be invoked too hastily. Indeed, recent neurophysiological, behavioural and computational studies show that sequential sentence structure has considerable explanatory power and that hierarchical processing is often not involved. In this paper, we review evidence from the recent literature supporting the hypothesis that sequential structure may be fundamental to the comprehension, production and acquisition of human language. Moreover, we provide a preliminary sketch outlining a non-hierarchical model of language use and discuss its implications and testable predictions. If linguistic phenomena can be explained by sequential rather than hierarchical structure, this will have considerable impact in a wide range of fields, such as linguistics, ethology, cognitive neuroscience, psychology and computer science.

  4. Effect of solvent addition sequence on lycopene extraction efficiency from membrane neutralized caustic peeled tomato waste.

    Science.gov (United States)

    Phinney, David M; Frelka, John C; Cooperstone, Jessica L; Schwartz, Steven J; Heldman, Dennis R

    2017-01-15

    Lycopene is a high value nutraceutical and its isolation from waste streams is often desirable to maximize profits. This research investigated solvent addition order and composition on lycopene extraction efficiency from a commercial tomato waste stream (pH 12.5, solids ∼5%) that was neutralized using membrane filtration. Constant volume dilution (CVD) was used to desalinate the caustic salt to neutralize the waste. Acetone, ethanol and hexane were used as direct or blended additions. Extraction efficiency was defined as the amount of lycopene extracted divided by the total lycopene in the sample. The CVD operation reduced the active alkali of the waste from 0.66 to lycopene efficiently from tomato processing byproducts.

  5. K-Area/Caustic Basin Groundwater Monitoring Report. Second quarter 1993

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, C.Y.

    1993-09-01

    During second quarter 1993, samples from the KAC monitoring wells at the K-Area Acid/Caustic Basin were collected and analyzed for indicator parameters, groundwater quality parameters, parameters indicating suitability as drinking water, and other constituents. Monitoring results that exceeded the final Primary Drinking Water Standards (PDWS) or the Savannah River Site (SRS) flagging criteria or turbidity standard during the quarter are discussed in this report. No analytes exceeded the final PDWS during second quarter 1993. Aluminum exceeded its Flag 2 criterion in wells KAC 6, 7, and 9. Iron exceeded the Flag 2 criterion in wells KAC 6 and 7, and specific conductance exceeded the Flag 2 criterion in well KAC 9. No samples exceeded the SRS turbidity standard.

  6. Ultrasound rays in droplets: The role of viscosity and caustics in acoustic streaming

    DEFF Research Database (Denmark)

    Bruus, Henrik

    2017-01-01

    When an acoustic wave propagates through a viscous fluid, it progressively transfers momentum to the fluid through viscous dissipation, which results in the formation of a steady vortical flow called acoustic streaming. Although spawned by viscous effects, the magnitude of the streaming does...... not depend on the viscosity in most simple geometries. However, viscosity has a profound influence on the acoustic streaming as demonstrated by Riaud et al. (J. Fluid Mech., vol. 821, 2017, pp. 384-420) in their study of sessile mm-sized water-glycerol droplets placed on a piezoelectric substrate with a 20......-MHz ultrasound surface acoustic wave propagating along its surface. A detailed experimental and numerical analysis reveals that streaming dynamics is driven by a few ultrasound ray caustics inside the droplet....

  7. Probe of Multi-electron Dynamics in Xenon by Caustics in High Order Harmonic Generation

    CERN Document Server

    Faccialà, Davide; Bruner, Barry D; Ciriolo, Anna G; De Silvestri, Sandro; Devetta, Michele; Negro, Matteo; Soifer, Hadas; Stagira, Salvatore; Dudovich, Nirit; Vozzi, Caterina

    2016-01-01

    We investigated the giant resonance in Xenon by high-order harmonic generation spectroscopy driven by a two-color field. The addition of a non-perturbative second harmonic component parallel to the driving field breaks the symmetry between neighboring sub-cycles resulting in the appearance of spectral caustics at two distinct cut-off energies. By controlling the phase delay between the two color components it is possible to tailor the harmonic emission in order to amplify and isolate the spectral feature of interest. In this paper we demonstrate how this control scheme can be used to investigate the role of electron correlations that give birth to the giant resonance in Xenon. The collective excitations of the giant dipole resonance in Xenon combined with the spectral manipulation associated with the two color driving field allow to see features that are normally not accessible and to obtain a quantitative good agreement between the experimental results and the theoretical predictions.

  8. Free-fall accretion and emitting caustics in wind-fed X-ray sources

    Science.gov (United States)

    Illarionov, Andrei F.; Beloborodov, Andrei M.

    2001-05-01

    In wind-fed X-ray binaries the accreting matter is Compton-cooled and falls freely on to the compact object. The matter has a modest angular momentum l and accretion is quasi-spherical at large distances from the compact object. Initially small non-radial velocities grow in the converging supersonic flow and become substantial in the vicinity of the accretor. The streamlines with l>(GMR*)1/2 (where M and R* are the mass and radius of the compact object) intersect outside R* and form a two-dimensional caustic which emits X-rays. The streamlines with low angular momentum, lorbital phase of the binary. The accretor then appears as a `Moon-like' X-ray source.

  9. Prediction of complications following unintentional caustic ingestion in children. Is endoscopy always necessary?

    DEFF Research Database (Denmark)

    Christesen, H B

    1995-01-01

    The records of 115 children hospitalized following caustic ingestion over an 18.5-year period from 1976 to 1994 were reviewed. The relationship between types of product ingested, signs and symptoms, degree of esophageal injury and complications was analyzed. All complications were the result...... of strong alkali ingestion (sensitivity = 1.0). Among the 102 incident patients, 36.8% of lye ingestions resulted in complications, whereas only 2.7% (one) of automatic dishwasher detergent (ADD) ingestions caused any complications (p ... or identifying complications in all types of strong alkali ingestions. In lye ingestions, endoscopy was not superior to the test, "one or more signs or symptoms" in predicting complications (predictivity = 1.0). Endoscopy is recommended to establish or confirm a prognosis, or to identify acute respiratory...

  10. [Clinical aspects of the post-caustic esophageal stenosis on 116 cases].

    Science.gov (United States)

    Mihalache, Carmen; Mihalache, S

    2006-01-01

    116 cases of post-caustic esophageal stenosis hospitalized in the Emergency Surgical Clinic of Iaşi during the period 1982-2004 have been analyzed. The patients' ages, the 4th decade of age (24.13%) prevailed. The alkaline substances prevailed (84.48%). Eight patients benefited from an endoscopic examination in the 15th day from the injury, and presented lesion degree 1-2 C. Progressive dysphagia, retrosternal pain and weight loss-symptoms were in all cases. The most of the patients (65.50%) came for a medical consultation within the first 6 months. The diagnosis and localizing the esophageal stenosis were based on the endoscopic examination and radiology. The single or double stenosis esophagus prevailed. The corrosive substances represent a frequent cause of benign esophageal stenosis.

  11. The Caustic Alkali-free Water Extraction Agents for Treating Inner Mongolia Oil Sands

    Institute of Scientific and Technical Information of China (English)

    Shen Zhibing; Zhang Juntao; Zhang Jie; Liang Shengrong

    2014-01-01

    The caustic alkali-free water extraction agents were studied for treating the oil sands excavated from Inner Mon-golia, China. Several kinds of chemical reagents were evaluated, among which sodium carbonate (SC), sodium dodecyl benzene sulfonate (SD) and sodium chloride were conifrmed as composite solutes. Their proportion was optimized by an orthogonal test. The optimum proportion of the composite agent covered 0.03%of SD, 0.50%of sodium chloride, 3.00%of SC, with the rest composed of water. The optimal operating condition was also conifrmed. The oil sands were extracted at the following optimized conditions:a treating time of 15 min, a temperature of 80℃and an extraction agent/feed ratio of 1:1, with the bitumen yield reaching more than 96%. The extraction agent after separation from the bitumen product can be recycled for reuse to carve out a good environmentally friendly route.

  12. Probe of Multielectron Dynamics in Xenon by Caustics in High-Order Harmonic Generation

    Science.gov (United States)

    Faccialà, D.; Pabst, S.; Bruner, B. D.; Ciriolo, A. G.; De Silvestri, S.; Devetta, M.; Negro, M.; Soifer, H.; Stagira, S.; Dudovich, N.; Vozzi, C.

    2016-08-01

    We investigated the giant resonance in xenon by high-order harmonic generation spectroscopy driven by a two-color field. The addition of a nonperturbative second harmonic component parallel to the driving field breaks the symmetry between neighboring subcycles resulting in the appearance of spectral caustics at two distinct cutoff energies. By controlling the phase delay between the two color components it is possible to tailor the harmonic emission in order to amplify and isolate the spectral feature of interest. In this Letter we demonstrate how this control scheme can be used to investigate the role of electron correlations that give birth to the giant resonance in xenon. The collective excitations of the giant dipole resonance in xenon combined with the spectral manipulation associated with the two-color driving field allow us to see features that are normally not accessible and to obtain a good agreement between the experimental results and the theoretical predictions.

  13. Predictive Factors of Gastrointestinal Caustic Injury According to Clinical and Endoscopic Findings

    Directory of Open Access Journals (Sweden)

    Cherie Quingking

    2013-03-01

    Full Text Available Background: Ingestion of caustic substances is the main reason for referral to Philippines National Poison Management and Control Center among other causes of acute poisoning. Rapid assessment of severity of injury is important for treatment and prognosis of these cases. This study was aimed to investigate the correlation of clinical factors with severity of gastrointestinal (GI mucosal injury. Methods: In this retrospective study, a total of 105 patients were included. Patients were categorized into two groups including 35 patients with low grade and 70 patients with high grade GI injury to compare the predictive value of clinical findings. Results: Mean (SD age of patients was 27 (10 and 47% of patients were male. Oral burns (P

  14. Next Generation Solvent Development for Caustic-Side Solvent Extraction of Cesium

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Birdwell, Joseph F. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Bonnesen, Peter V. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

    2014-03-01

    This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Inter laboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

  15. Next Generation Solvent Performance in the Modular Caustic Side Solvent Extraction Process - 15495

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Tara E. [Savannah River Remediation, LLC., Aiken, SC (United States); Scherman, Carl [Savannah River Remediation, LLC., Aiken, SC (United States); Martin, David [Savannah River Remediation, LLC., Aiken, SC (United States); Suggs, Patricia [Savannah River Site (SRS), Aiken, SC (United States)

    2015-01-14

    Changes to the Modular Caustic Side Solvent Extraction Unit (MCU) flow-sheet were implemented in the facility. Implementation included changing the scrub and strip chemicals and concentrations, modifying the O/A ratios for the strip, scrub, and extraction contactor banks, and blending the current BoBCalixC6 extractant-based solvent in MCU with clean MaxCalix extractant-based solvent. During the successful demonstration period, the MCU process was subject to rigorous oversight to ensure hydraulic stability and chemical/radionuclide analysis of the key process tanks (caustic wash tank, solvent hold tank, strip effluent hold tank, and decontaminated salt solution hold tank) to evaluate solvent carryover to downstream facilities and the effectiveness of cesium removal from the liquid salt waste. Results indicated the extraction of cesium was significantly more effective with an average Decontamination Factor (DF) of 1,129 (range was 107 to 1,824) and that stripping was effective. The contactor hydraulic performance was stable and satisfactory, as indicated by contactor vibration, contactor rotational speed, and flow stability; all of which remained at or near target values. Furthermore, the Solvent Hold Tank (SHT) level and specific gravity was as expected, indicating that solvent integrity and organic hydraulic stability were maintained. The coalescer performances were in the range of processing results under the BOBCalixC6 flow sheet, indicating negligible adverse impact of NGS deployment. After the Demonstration period, MCU began processing via routine operations. Results to date reiterate the enhanced cesium extraction and stripping capability of the Next Generation Solvent (NGS) flow sheet. This paper presents process performance results of the NGS Demonstration and continued operations of MCU utilizing the blended BobCalixC6-MaxCalix solvent under the NGS flowsheet.

  16. Next Generation Solvent (NGS): Development for Caustic-Side Solvent Extraction of Cesium

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Birdwell, Jr, Joseph F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bonnesen, Peter V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Delmau, Laetitia Helene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Duncan, Nathan C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ensor, Dale [Tennessee Technological Univ., Cookeville, TN (United States); Hill, Talon G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Denise L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rajbanshi, Arbin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Roach, Benjamin D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Szczygiel, Patricia L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sloop, Jr., Frederick V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stoner, Erica L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Neil J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-03-01

    This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Interlaboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

  17. Synthesis of ZnS thin films from aqueous caustic of trisodium citrate and their properties

    Directory of Open Access Journals (Sweden)

    Martyn A. Sozanskyi

    2015-12-01

    Full Text Available Zinc sulfide (ZnS thin films due to their properties are widely used in various electronic optical devices. They are produced by several methods, among which – vacuum sublimation, high frequency sputtering method, quasiclosed volume method, sol-gel method, electrodeposition. These methods have high energy consumption which increases the price of ZnS thin films. Aim: The aim of this work is to establish the optimal parameters of the synthesis of ZnS thin films of the aqueous caustic and the correlation between content of zinc in the synthesized films determined by the method of stripping voltammetry and thickness, structural, morphological and optical parameters. Materials and Methods: The ZnS thin films were obtained from aqueous caustics of zinc-containing salt using chemical deposition. Fresh solution of zinc-containing salt, trisodium citrate (Na3C6H5O7 as a complexing agent, thiourea ((NH22CS and ammonium hydroxide (NH4OH was used for the synthesis of ZnS films by chemical deposition. The deposition was performed on prepared glass substrates with the area of 5,76 cm2. Results: The phase mixture of the films has been determined. It showed the presence of ZnS compounds in the cubic modification (sphalerite. Stripping voltammetry was used to determine the mass of zinc in the ZnS films on various conditions of synthesis, namely on the concentration of the initial zinc-containing salt, trisodium citrate, thiourea, deposition time and temperature. The surface morphology, optical properties, the thickness of the ZnS resulting films have been studied. Conclusions: The optimal conditions for the synthesis of ZnS films were found based on these data. Three-dimensional surface morphology of ZnS film studies showed its smoothness, uniformity, integrity and confirmed the correctness of determining the optimal synthesis parameters.

  18. Modeling hierarchical structures - Hierarchical Linear Modeling using MPlus

    CERN Document Server

    Jelonek, M

    2006-01-01

    The aim of this paper is to present the technique (and its linkage with physics) of overcoming problems connected to modeling social structures, which are typically hierarchical. Hierarchical Linear Models provide a conceptual and statistical mechanism for drawing conclusions regarding the influence of phenomena at different levels of analysis. In the social sciences it is used to analyze many problems such as educational, organizational or market dilemma. This paper introduces the logic of modeling hierarchical linear equations and estimation based on MPlus software. I present my own model to illustrate the impact of different factors on school acceptation level.

  19. PEP Integrated Test D Run Report Caustic and Oxidative Leaching in UFP-VSL-T02A

    Energy Technology Data Exchange (ETDEWEB)

    Sevigny, Gary J.; Bredt, Ofelia P.; Burns, Carolyn A.; Kurath, Dean E.; Geeting, John GH; Golovich, Elizabeth C.; Guzman-Leong, Consuelo E.; Josephson, Gary B.

    2009-12-11

    Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, "Undemonstrated Leaching Processes" of the External Flowsheet Review Team (EFRT) issue response plan. The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario (Test B and D) has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario (Test A) has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP and vessels UFP VSL-00001A and B in the WTP PTF). In Test D, 19M sodium hydroxide (NaOH, caustic) was added to the waste slurry in the UFP VSL T02 vessel after the solids were concentrated to ~20% undissolved solids. The NaOH was added to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by heating to 85°C using direct injection of steam to accelerate the leach process. The main difference of Test D compared to Test B is that the leach temperature is 85°C for 24 hrs as compared to 100°C for 12 hours. The other difference is the Test D simulant had Cr in the

  20. Hierarchical Design Method for Micro Device

    Directory of Open Access Journals (Sweden)

    Zheng Liu

    2013-05-01

    Full Text Available Traditional mask-beginning design flow of micro device is unintuitive and fussy for designers. A hierarchical design method and involved key technologies for features mapping procedure are presented. With the feature-based design framework, the model of micro device is organized by various features in different designing stages, which can be converted into each other based on the mapping rules. The feature technology is the foundation of the three-level design flow that provides a more efficient design way. In system level, functional features provide the top level of schematic and functional description. After the functional mapping procedure, on the other hand, parametric design features construct the 3D model of micro device in device level, which is based on Hybird Model representation. By means of constraint features, the corresponding revision rules are applied to the rough model to optimize the original structure. As a result, the model reconstruction algorithm makes benefit for the model revision and constraint features mapping process. Moreover, the formulating description of manufacturing features derivation provides the automatic way for model conversion.

  1. Modeling hierarchical structures - Hierarchical Linear Modeling using MPlus

    OpenAIRE

    Jelonek, Magdalena

    2006-01-01

    The aim of this paper is to present the technique (and its linkage with physics) of overcoming problems connected to modeling social structures, which are typically hierarchical. Hierarchical Linear Models provide a conceptual and statistical mechanism for drawing conclusions regarding the influence of phenomena at different levels of analysis. In the social sciences it is used to analyze many problems such as educational, organizational or market dilemma. This paper introduces the logic of m...

  2. Quality Assurance Project Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System - 1997 Notice of Violation Consent Order

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Susan Kay; Orchard, B. J.

    2002-01-01

    This Quality Assurance Project Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System is one of two documents that comprise the Sampling and Analysis Plan for the HWMA/RCRA closure certification of the TRA-731 caustic and acid storage tank system at the Idaho National Engineering and Environmental Laboratory. This plan, which provides information about the project description, project organization, and quality assurance and quality control procedures, is to be used in conjunction with the Field Sampling Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System. This Quality Assurance Project Plan specifies the procedures for obtaining the data of known quality required by the closure activities for the TRA-731 caustic and acid storage tank system.

  3. Quality Assurance Project Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System - 1997 Notice of Violation Consent Order

    Energy Technology Data Exchange (ETDEWEB)

    Evans, S.K.

    2002-01-31

    This Quality Assurance Project Plan for the HWMA/RCRA Closure Certification of the TRA- 731 Caustic and Acid Storage Tank System is one of two documents that comprise the Sampling and Analysis Plan for the HWMA/RCRA closure certification of the TRA-731 caustic and acid storage tank system at the Idaho National Engineering and Environmental Laboratory. This plan, which provides information about the project description, project organization, and quality assurance and quality control procedures, is to be used in conjunction with the Field Sampling Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System. This Quality Assurance Project Plan specifies the procedures for obtaining the data of known quality required by the closure activities for the TRA-731 caustic and acid storage tank system.

  4. Hierarchical fringe tracking

    CERN Document Server

    Petrov, Romain G; Boskri, Abdelkarim; Folcher, Jean-Pierre; Lagarde, Stephane; Bresson, Yves; Benkhaldoum, Zouhair; Lazrek, Mohamed; Rakshit, Suvendu

    2014-01-01

    The limiting magnitude is a key issue for optical interferometry. Pairwise fringe trackers based on the integrated optics concepts used for example in GRAVITY seem limited to about K=10.5 with the 8m Unit Telescopes of the VLTI, and there is a general "common sense" statement that the efficiency of fringe tracking, and hence the sensitivity of optical interferometry, must decrease as the number of apertures increases, at least in the near infrared where we are still limited by detector readout noise. Here we present a Hierarchical Fringe Tracking (HFT) concept with sensitivity at least equal to this of a two apertures fringe trackers. HFT is based of the combination of the apertures in pairs, then in pairs of pairs then in pairs of groups. The key HFT module is a device that behaves like a spatial filter for two telescopes (2TSF) and transmits all or most of the flux of a cophased pair in a single mode beam. We give an example of such an achromatic 2TSF, based on very broadband dispersed fringes analyzed by g...

  5. Onboard hierarchical network

    Science.gov (United States)

    Tunesi, Luca; Armbruster, Philippe

    2004-02-01

    The objective of this paper is to demonstrate a suitable hierarchical networking solution to improve capabilities and performances of space systems, with significant recurrent costs saving and more efficient design & manufacturing flows. Classically, a satellite can be split in two functional sub-systems: the platform and the payload complement. The platform is in charge of providing power, attitude & orbit control and up/down-link services, whereas the payload represents the scientific and/or operational instruments/transponders and embodies the objectives of the mission. One major possibility to improve the performance of payloads, by limiting the data return to pertinent information, is to process data on board thanks to a proper implementation of the payload data system. In this way, it is possible to share non-recurring development costs by exploiting a system that can be adopted by the majority of space missions. It is believed that the Modular and Scalable Payload Data System, under development by ESA, provides a suitable solution to fulfil a large range of future mission requirements. The backbone of the system is the standardised high data rate SpaceWire network http://www.ecss.nl/. As complement, a lower speed command and control bus connecting peripherals is required. For instance, at instrument level, there is a need for a "local" low complexity bus, which gives the possibility to command and control sensors and actuators. Moreover, most of the connections at sub-system level are related to discrete signals management or simple telemetry acquisitions, which can easily and efficiently be handled by a local bus. An on-board hierarchical network can therefore be defined by interconnecting high-speed links and local buses. Additionally, it is worth stressing another important aspect of the design process: Agencies and ESA in particular are frequently confronted with a big consortium of geographically spread companies located in different countries, each one

  6. Adaptive Photon Mapping Based on Gradient

    Institute of Scientific and Technical Information of China (English)

    Chun-Meng Kang; Lu Wang; Yan-Ning Xu; Xiang-Xu Meng; Yuan-Jie Song

    2016-01-01

    Photon mapping can simulate some special effects efficiently such as shadows and caustics. Photon mapping runs in two phases: the photon map generating phase and the radiance estimation phase. In this paper, we focus on the bandwidth selection process in the second phase, as it can affect the final quality significantly. Poor results with noise arise if few photons are collected, while bias appears if a large number of photons are collected. In order to solve this issue, we propose an adaptive radiance estimation solution to obtain trade-offs between noise and bias by changing the number of neighboring photons and the shape of the collected area according to the radiance gradient. Our approach can be applied in both the direct and the indirect illumination computation. Finally, experimental results show that our approach can produce smoother quality while keeping the high frequency features perfectly compared with the original photon mapping algorithm.

  7. Hierarchical materials: Background and perspectives

    DEFF Research Database (Denmark)

    2016-01-01

    Hierarchical design draws inspiration from analysis of biological materials and has opened new possibilities for enhancing performance and enabling new functionalities and extraordinary properties. With the development of nanotechnology, the necessary technological requirements for the manufactur...

  8. Hierarchical clustering for graph visualization

    CERN Document Server

    Clémençon, Stéphan; Rossi, Fabrice; Tran, Viet Chi

    2012-01-01

    This paper describes a graph visualization methodology based on hierarchical maximal modularity clustering, with interactive and significant coarsening and refining possibilities. An application of this method to HIV epidemic analysis in Cuba is outlined.

  9. Direct hierarchical assembly of nanoparticles

    Science.gov (United States)

    Xu, Ting; Zhao, Yue; Thorkelsson, Kari

    2014-07-22

    The present invention provides hierarchical assemblies of a block copolymer, a bifunctional linking compound and a nanoparticle. The block copolymers form one micro-domain and the nanoparticles another micro-domain.

  10. Functional annotation of hierarchical modularity.

    Directory of Open Access Journals (Sweden)

    Kanchana Padmanabhan

    Full Text Available In biological networks of molecular interactions in a cell, network motifs that are biologically relevant are also functionally coherent, or form functional modules. These functionally coherent modules combine in a hierarchical manner into larger, less cohesive subsystems, thus revealing one of the essential design principles of system-level cellular organization and function-hierarchical modularity. Arguably, hierarchical modularity has not been explicitly taken into consideration by most, if not all, functional annotation systems. As a result, the existing methods would often fail to assign a statistically significant functional coherence score to biologically relevant molecular machines. We developed a methodology for hierarchical functional annotation. Given the hierarchical taxonomy of functional concepts (e.g., Gene Ontology and the association of individual genes or proteins with these concepts (e.g., GO terms, our method will assign a Hierarchical Modularity Score (HMS to each node in the hierarchy of functional modules; the HMS score and its p-value measure functional coherence of each module in the hierarchy. While existing methods annotate each module with a set of "enriched" functional terms in a bag of genes, our complementary method provides the hierarchical functional annotation of the modules and their hierarchically organized components. A hierarchical organization of functional modules often comes as a bi-product of cluster analysis of gene expression data or protein interaction data. Otherwise, our method will automatically build such a hierarchy by directly incorporating the functional taxonomy information into the hierarchy search process and by allowing multi-functional genes to be part of more than one component in the hierarchy. In addition, its underlying HMS scoring metric ensures that functional specificity of the terms across different levels of the hierarchical taxonomy is properly treated. We have evaluated our

  11. Hierarchical architecture of active knits

    Science.gov (United States)

    Abel, Julianna; Luntz, Jonathan; Brei, Diann

    2013-12-01

    Nature eloquently utilizes hierarchical structures to form the world around us. Applying the hierarchical architecture paradigm to smart materials can provide a basis for a new genre of actuators which produce complex actuation motions. One promising example of cellular architecture—active knits—provides complex three-dimensional distributed actuation motions with expanded operational performance through a hierarchically organized structure. The hierarchical structure arranges a single fiber of active material, such as shape memory alloys (SMAs), into a cellular network of interlacing adjacent loops according to a knitting grid. This paper defines a four-level hierarchical classification of knit structures: the basic knit loop, knit patterns, grid patterns, and restructured grids. Each level of the hierarchy provides increased architectural complexity, resulting in expanded kinematic actuation motions of active knits. The range of kinematic actuation motions are displayed through experimental examples of different SMA active knits. The results from this paper illustrate and classify the ways in which each level of the hierarchical knit architecture leverages the performance of the base smart material to generate unique actuation motions, providing necessary insight to best exploit this new actuation paradigm.

  12. Advanced hierarchical distance sampling

    Science.gov (United States)

    Royle, Andy

    2016-01-01

    In this chapter, we cover a number of important extensions of the basic hierarchical distance-sampling (HDS) framework from Chapter 8. First, we discuss the inclusion of “individual covariates,” such as group size, in the HDS model. This is important in many surveys where animals form natural groups that are the primary observation unit, with the size of the group expected to have some influence on detectability. We also discuss HDS integrated with time-removal and double-observer or capture-recapture sampling. These “combined protocols” can be formulated as HDS models with individual covariates, and thus they have a commonality with HDS models involving group structure (group size being just another individual covariate). We cover several varieties of open-population HDS models that accommodate population dynamics. On one end of the spectrum, we cover models that allow replicate distance sampling surveys within a year, which estimate abundance relative to availability and temporary emigration through time. We consider a robust design version of that model. We then consider models with explicit dynamics based on the Dail and Madsen (2011) model and the work of Sollmann et al. (2015). The final major theme of this chapter is relatively newly developed spatial distance sampling models that accommodate explicit models describing the spatial distribution of individuals known as Point Process models. We provide novel formulations of spatial DS and HDS models in this chapter, including implementations of those models in the unmarked package using a hack of the pcount function for N-mixture models.

  13. Synthesis and characterization of TiO2 from ilmenite by caustic fusion process for photocatalytic application

    Science.gov (United States)

    Mulyono, J. E.; Soepriyanto, S.

    2017-01-01

    In this research, the use of TiO2 from Indonesian ilmenite will be developed using caustic fusion process and made into photocatalyst product that will be applied for water treatment applications. The research procedures include caustic fusion process involving the mixing of NaOH and ilmenite with a ratio of 1 : 4 at 650°C for 120 minutes. The result from this caustic fusion process, i.e. frit, was then washed with water and followed by acid leaching using sulfuric acid 45% to obtain precursor TiOSO4. This precursor was then hydrolyzed to produce white precipitates in the form of sol TiO(OH)2 which was then condensed for 24 hours. The precipitate was washed and dried before calcined at a temperature of 500°C for 1 hour. X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX) analysis is included to show the phases, morphology and the final composition of the synthesized TiO2 powder. UV-Vis Spectrometry was also used to calculate the band-gap energy and the photocatalytic ability of the synthesized TiO2 in the purification process of rhodamin-B.

  14. Simulations of sonic boom ray tube area fluctuations for propagation through atmospheric turbulence including caustics via a Monte Carlo method

    Science.gov (United States)

    Sparrow, Victor W.; Pierce, Allan D.

    1992-01-01

    A theory which gives statistical predictions for how often sonic booms propagating through the earth's turbulent boundary layer will encounter caustics, given the spectral properties of the atmospheric turbulence, is outlined. The theory is simple but approximately accounts for the variation of ray tube areas along ray paths. This theory predicts that the variation of ray tube areas is determined by the product of two similar area factors, psi (x) and phi (x), each satisfying a generic harmonic oscillator equation. If an area factor increases the peak acoustic pressure decreases, and if the factor decreases the peak acoustic pressure increases. Additionally, if an area factor decreases to zero and becomes negative, the ray has propagated through a caustic, which contributes a phase change of 90 degrees to the wave. Thus, it is clear that the number of times that a sonic boom wave passes through a caustic should be related to the distorted boom waveform received on the ground. Examples are given based on a characterization of atmospheric turbulence due to the structure function of Tatarski as modified by Crow.

  15. Effect of competing ions and causticization on the ammonia adsorption by a novel poly ligand exchanger (PLE) ammonia adsorption reagent.

    Science.gov (United States)

    Chen, Quanzhou; Zhou, Kanggen; Hu, Yuanjuan; Liu, Fang; Wang, Aihe

    2017-03-01

    In this paper, a poly ligand exchanger, Cu(II)-loaded chelating resin named ammonia adsorption reagent (AMAR), bearing the functional group of weak iminodiacetate acid, was prepared to efficiently remove ammonia from solutions. Batch adsorption equilibrium experiments were conducted under a range of conditions. The effects of pH on the removal of ammonia by AMAR were investigated at 25 °C. The copper loaded on the resin forms a complex with NH3 in solution under alkaline condition. The effect of alkaline dosage (AD) on the ammonia adsorption was investigated. The maximum breakthrough bed volumes were obtained when the AD was set as 0.75 mmol OH(-)/mL. The higher AD did not guarantee the better ammonia removal efficiency due to the forming of Cu(OH)2 precipitate between OH(-) in solutions and Cu(II) on the resin. The effect of competing ions on the adsorption breakthrough curve of virgin AMAR and causticized AMAR was also investigated. The results demonstrated that the existence of competing ions had a negative impact on the adsorption capacity for both virgin AMAR and causticized AMAR. After causticization, the AMAR was more resistant to the competing ions comparing with virgin AMAR. The bivalent Ca(2+) affects the ammonia adsorption more than does the monovalent Na(+).

  16. A Hierarchical Bayesian Model for Crowd Emotions

    Science.gov (United States)

    Urizar, Oscar J.; Baig, Mirza S.; Barakova, Emilia I.; Regazzoni, Carlo S.; Marcenaro, Lucio; Rauterberg, Matthias

    2016-01-01

    Estimation of emotions is an essential aspect in developing intelligent systems intended for crowded environments. However, emotion estimation in crowds remains a challenging problem due to the complexity in which human emotions are manifested and the capability of a system to perceive them in such conditions. This paper proposes a hierarchical Bayesian model to learn in unsupervised manner the behavior of individuals and of the crowd as a single entity, and explore the relation between behavior and emotions to infer emotional states. Information about the motion patterns of individuals are described using a self-organizing map, and a hierarchical Bayesian network builds probabilistic models to identify behaviors and infer the emotional state of individuals and the crowd. This model is trained and tested using data produced from simulated scenarios that resemble real-life environments. The conducted experiments tested the efficiency of our method to learn, detect and associate behaviors with emotional states yielding accuracy levels of 74% for individuals and 81% for the crowd, similar in performance with existing methods for pedestrian behavior detection but with novel concepts regarding the analysis of crowds. PMID:27458366

  17. Hierarchical topic modeling with nested hierarchical Dirichlet process

    Institute of Scientific and Technical Information of China (English)

    Yi-qun DING; Shan-ping LI; Zhen ZHANG; Bin SHEN

    2009-01-01

    This paper deals with the statistical modeling of latent topic hierarchies in text corpora. The height of the topic tree is assumed as fixed, while the number of topics on each level as unknown a priori and to be inferred from data. Taking a nonparametric Bayesian approach to this problem, we propose a new probabilistic generative model based on the nested hierarchical Dirichlet process (nHDP) and present a Markov chain Monte Carlo sampling algorithm for the inference of the topic tree structure as welt as the word distribution of each topic and topic distribution of each document. Our theoretical analysis and experiment results show that this model can produce a more compact hierarchical topic structure and captures more free-grained topic relationships compared to the hierarchical latent Dirichlet allocation model.

  18. STATISTICS OF MICROLENSING CAUSTIC CROSSINGS IN Q 2237+0305: PECULIAR VELOCITY OF THE LENS GALAXY AND ACCRETION DISK SIZE

    Energy Technology Data Exchange (ETDEWEB)

    Mediavilla, E. [Instituto de Astrofísica de Canarias, Vía Láctea S/N, La Laguna E-38200 Tenerife (Spain); Jimenez-Vicente, J. [Departamento de Física Teórica y del Cosmos, Universidad de Granada, Campus de Fuentenueva E-18071 Granada (Spain); Muñoz, J. A. [Departamento de Astronomía y Astrofísica, Universidad de Valencia E-46100 Burjassot, Valencia (Spain); Mediavilla, T.; Ariza, O. [Departamento de Estadística e Investigación Operativa, Universidad de Cádiz, Avda Ramón Puyol s/n E-11202, Algeciras, Cádiz (Spain)

    2015-01-10

    We use the statistics of caustic crossings induced by microlensing in the lens system Q 2237+0305 to study the lens galaxy peculiar velocity. We calculate the caustic crossing rates for a comprehensive family of stellar mass functions and find a dependence of the average number of caustic crossings with the effective transverse velocity and the average mass, 〈n〉∝v{sub eff}/√(〈m〉), equivalent to the theoretical prediction for the case of microlenses with identical masses. We explore the possibilities of the method to measure v {sub eff} using the ∼12 yr of Optical Gravitational Lensing Experiment monitoring of the four images of Q 2237+0305. To determine a lower limit for v {sub eff}, we count, conservatively, a single caustic crossing for each one of the four high magnification events identified in the literature (plus one additional proposed by us) obtaining v{sub eff}≳240√(〈m〉/0.17 M{sub ⊙}) km s{sup −1} at 68% of confidence. From this value and the average FWHM of the four high magnification events, we obtain a lower limit of r{sub s}≳1.4√(〈m〉/0.17 M{sub ⊙}) light-days for the radius of the source (r{sub s} = FWHM/2.35). Tentative identification of three additional caustic crossing events leads to estimates of v{sub eff}≃(493±246)√(〈m〉/0.17 M{sub ⊙}) km s{sup −1} for the effective transverse velocity and of r{sub s}≃(2.7±1.3)√(〈m〉/0.17 M{sub ⊙}) light-days for the source size. The estimated transverse peculiar velocity of the galaxy is v{sub t}≃(429±246)√(〈m〉/0.17 M{sub ⊙}) km s{sup −1}.

  19. CHEMICAL STABILITY OF POLYPHENYLENE SULFIDE IN THE NEXT GENERATION SOLVENT FOR CAUSTIC-SIDE SOLVENT EXTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Fink, S.

    2011-12-08

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. For simplicity, this solvent is referred to as the Next Generation Solvent (NGS). The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The initial deployment target envisioned for the technology was within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with polyphenylene sulfide (PPS), the polymer used in the coalescers within MCU. This report provides the data from exposing PPS polymer to NGS. The test was conducted over a three month period. PPS is remarkably stable in the presence of the next generation solvent. Testing showed no indication of swelling or significant leaching. Preferential sorption of the Modifier on PPS was observed but the same behavior occurs with the baseline solvent. Therefore, PPS coalescers exposed to the NGS are expected to perform comparably to those in contact with the baseline solvent.

  20. MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT GAMMA MONITORS SYSTEM FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Casella, V

    2007-06-25

    The Department of Energy (DOE) selected Caustic-Side Solvent Extraction (CSSX) as the preferred technology for the removal of radioactive cesium from High-Level Waste (HLW) at the Savannah River Site (SRS). Before the full-scale Salt Waste Processing Facility (SWPF) becomes operational, the liquid Waste Organization (LWO) plans to process a portion of dissolved saltcake waste through a Modular CSSX Unit (MCU). This work was derived from Technical Task Request SP-TTR-2004-00013, ''Gamma Monitor for MCU.'' The deliverables for this task are the hardware and software for the gamma monitors and a report summarizing the testing and acceptance of this equipment for use in the MCU. Revision of this report is a deliverable in Technical Task Report SP-TTR-2006-00010, ''NaI Shield Box Testing.'' Gamma-ray monitors were developed to: {lg_bullet} Measure the Cs-137 concentration in the decontaminated salt solution before entering the DSS (Decontaminated Salt Solution) Hold Tank, {lg_bullet} Measure the Cs-137 concentration in the strip effluent before entering the Strip Effluent Hold Tank, {lg_bullet} Verify proper operation of the solvent extraction system by verifying material balance within the process (The DSS Hold Tank Cs-137 concentration will be very low and the Cs-137 concentration in the Strip Effluent Hold Tank will be approximately fifteen times higher than the Cs-137 concentration in the Feed Tank.)

  1. Laboratory Demonstration of the Pretreatment Process with Caustic and Oxidative Leaching Using Actual Hanford Tank Waste

    Energy Technology Data Exchange (ETDEWEB)

    Fiskum, Sandra K.; Billing, Justin M.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Shimskey, Rick W.; Snow, Lanee A.

    2009-01-01

    This report describes the bench-scale pretreatment processing of actual tank waste materials through the entire baseline WTP pretreatment flowsheet in an effort to demonstrate the efficacy of the defined leaching processes on actual Hanford tank waste sludge and the potential impacts on downstream pretreatment processing. The test material was a combination of reduction oxidation (REDOX) tank waste composited materials containing aluminum primarily in the form of boehmite and dissolved S saltcake containing Cr(III)-rich entrained solids. The pretreatment processing steps tested included • caustic leaching for Al removal • solids crossflow filtration through the cell unit filter (CUF) • stepwise solids washing using decreasing concentrations of sodium hydroxide with filtration through the CUF • oxidative leaching using sodium permanganate for removing Cr • solids filtration with the CUF • follow-on solids washing and filtration through the CUF • ion exchange processing for Cs removal • evaporation processing of waste stream recycle for volume reduction • combination of the evaporated product with dissolved saltcake. The effectiveness of each process step was evaluated by following the mass balance of key components (such as Al, B, Cd, Cr, Pu, Ni, Mn, and Fe), demonstrating component (Al, Cr, Cs) removal, demonstrating filterability by evaluating filter flux rates under various processing conditions (transmembrane pressure, crossflow velocities, wt% undissolved solids, and PSD) and filter fouling, and identifying potential issues for WTP. The filterability was reported separately (Shimskey et al. 2008) and is not repeated herein.

  2. Recommended Guanidine Suppressor for the Next-Generation Caustic-Side Solvent Extraction Process

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A [ORNL; Delmau, Laetitia Helene [ORNL; Duncan, Nathan C [ORNL; Ensor, Dale [Tennessee Technological University; Hill, Talon G [ORNL; Lee, Denise L [ORNL; Roach, Benjamin D [ORNL; Sloop Jr, Frederick {Fred} V [ORNL; Williams, Neil J [ORNL

    2013-01-01

    The guanidine recommended for the Next-Generation Caustic-Side is N,N ,N -tris(3,7-dimethyloctyl)guanidine (TiDG). Systematic testing has shown that it is significantly more lipophilic than the previously recommended guanidine DCiTG, the active extractant in the commercial guanidine product LIX -79, while not otherwise changing the solvent performance. Previous testing indicated that the extent of partitioning of the DCiTG suppressor to the aqueous strip solution is significantly greater than expected, potentially leading to rapid depletion of the suppressor from the solvent and unwanted organic concentrations in process effluents. Five candidate guanidines were tested as potential replacements for DCiTG. The tests included batch extraction with simulated waste and flowsheet solutions, third-phase formation, emulsion formation, and partition ratios of the guanidine between the solvent and aqueous strip solution. Preliminary results of a thermal stability test of the TiDG solvent at one month duration indicated performance approximately equivalent to DCiTG. Two of the guanidines proved adequate in all respects, and the choice of TiDG was deemed slightly preferable vs the next best guanidine BiTABG.

  3. Washing and caustic leaching of Hanford tank sludges: Results of FY 1995 studies

    Energy Technology Data Exchange (ETDEWEB)

    Rapko, B.M.; Lumetta, G.J.; Wagner, M.J.

    1995-08-11

    During the past few years, the primary mission at the US Department of Energy`s Hanford Site has changed from producing plutonium to environmental restoration. Large volumes of high-level radioactive wastes (HLW), generated during past Pu production and other operations, are stored in underground tanks on site. The current plan for remediating the Hanford tank farms consists of waste retrieval, pretreatment, treatment (immobilization), and disposal. The HLW will be immobilized in a borosilicate glass matrix; the resulting glass canisters will then be disposed of in a geologic repository. Because of the expected high cost of HLW immobilization and disposal, pretreatment processes will be implemented to reduce the volume of borosilicate glass produced in processing the tank wastes. This document describes sludge washing and caustic leaching tests conducted in FY 1995 at the Pacific Northwest Laboratory (PNL) at the request of Westinghouse Hanford Company. These tests were performed using sludges from seven Hanford waste tanks -- B-111, BX-107, C-103, S-104, SY-103, T-104, and T-111. The primary and secondary types of waste stored in each of these tanks are given in Table 1. 1. The data collected in this effort will be used to support the March 1998 Tri-Party Agreement decision on the extent of pretreatment to be performed on the Hanford tank sludges (Ecology, EPA, and DOE 1994).

  4. Free-fall accretion and emitting caustics in wind-fed X-ray sources

    CERN Document Server

    Illarionov, A F; Illarionov, Andrei F.; Beloborodov, Andrei M.

    2000-01-01

    In wind-fed X-ray binaries, the accreting matter is Compton cooled and falls freely onto the compact object. The matter has a modest angular momentum, $l$, and accretion is quasi-spherical at large distances from the compact object. Initially small non-radial velocities grow in the converging supersonic flow and become substantial in the vicinity of the accretor. The streamlines with $l>(GMR_*)^{1/2}$ (where $M$ and $R_*$ are the mass and radius of the compact object) intersect outside $R_*$ and form a two-dimensional caustic which emits X-rays. The streamlines with low angular momentum, $l<(GMR_*)^{1/2}$, run into the accretor. If the accretor is a neutron star, a large X-ray luminosity results. We show that the distribution of accretion rate/luminosity over the star surface is sensitive to the angular momentum distribution of the accreting matter. The apparent luminosity depends on the side from which the star is observed and can change periodically with the orbital phase of the binary. The accretor then...

  5. Caustic Injury In Adults – A Study For 3 Year Period

    Directory of Open Access Journals (Sweden)

    Radenkova-Saeva J.

    2016-10-01

    Full Text Available The aim of the study is to present the results of a 3-year clinico-epidemiological investigation of caustic injury in adults. The study includes 43 patients with acute corrosive ingestion, hospitalized in the Toxicology Clinic, University Hospital “N. I. Pirogov”, Sofia, Bulgaria, for the period 01.01. 2010-31.12.2012. The methods used include: clinical observation and examination, clinical laboratory, imaging, and psychiatric methods and tests. 43 patients between the ages of 22 and 82 with acute corrosive ingestions have been observed. Eleven were male (25.6% and 32 female (74.4%. All ingestions were intentional. Alkaline agents were used by all of the patients. The severity of poisonings varied from moderate to extremely severe. Different complications were seen in 82% of the cases - severe bleeding, perforation, fistula or/and stricture formation. Two of the patients have undergone surgical intervention - coloesophagoplastic - and have recovered completely. The motivation in different age groups was also studied. Psychiatric comorbidity occurred in patients as depressive and schizoaffective disorder, as well as existential crises. Acute corrosive ingestions by alkaline agents cause severe pathology. The severity and complex character of the injuries require good coordination between different medical specialists.

  6. Caustic Hydrogen Peroxide Treatment of Effluent from Cassava Processing Industry: Prospects and Limitations

    Directory of Open Access Journals (Sweden)

    Olayinka Omotosho

    2015-04-01

    Full Text Available Cassava has been described as a major part of diet in most African countries. Its processing usually requires the release of polluted effluent which has been found to be toxic, carcinogenic as well as mutagenic to some extent. In this study, the treatment process comprised of a combination of peroxide oxidation at caustic range and filtration which ensured that the key pollutant, Cyanide was converted to cyanate. Metal and other non-metal pollutants were filtered off with the aid of a graded sand filter after undergoing hydroxide formation and precipitation. Results from the study shows that an optimum dosage of 0.3mg/l was adequate for Cyanide destruction and hydroxide precipitation reactions. A comparison of the effluent from the treatment process with FEPA standards for waste water discharge shows that most of the pollutant parameters were within acceptable limits after the treatment with the exception of PO4 and BOD5. However when compared with Canadian Water Quality Guidelines for Irrigation the only parameter outstanding was the BOD5. As a result of the inadequacy of the process in handling the phosphate and biological load content of the wastewater, It is proposed that an additional treatment method such as sorption using activated carbon or use of a combined baffle flocculation and aeration techniques will be appropriate if the water is to be discharged safely into water courses or even for irrigation purposes.

  7. CHEMICAL STABILITY OF POLYPHENYLENE SULFIDE IN THE NEXT GENERATION SOLVENT FOR CAUSTIC-SIDE SOLVENT EXTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Fink, S.

    2011-12-08

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. For simplicity, this solvent is referred to as the Next Generation Solvent (NGS). The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The initial deployment target envisioned for the technology was within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with polyphenylene sulfide (PPS), the polymer used in the coalescers within MCU. This report provides the data from exposing PPS polymer to NGS. The test was conducted over a three month period. PPS is remarkably stable in the presence of the next generation solvent. Testing showed no indication of swelling or significant leaching. Preferential sorption of the Modifier on PPS was observed but the same behavior occurs with the baseline solvent. Therefore, PPS coalescers exposed to the NGS are expected to perform comparably to those in contact with the baseline solvent.

  8. Electrochemical studies on stress corrosion cracking of incoloy-800 in caustic solution. Part II: Precracking samples

    Directory of Open Access Journals (Sweden)

    Dinu Alice

    2006-01-01

    Full Text Available Stress corrosion cracking (SCC in a caustic medium may affect the secondary circuit tubing of a CANDU NPP cooled with river water, due to an accidental formation of a concentrated alkaline environment in the areas with restricted circulation, as a result of a leakage of cooling water from the condenser. To evaluate the susceptibility of Incoloy-800 (used to manufacture steam generator tubes for CANDU NPP to SCC, some accelerated corrosion tests were conducted in an alkaline solution (10% NaOH, pH = 13. These experiments were performed at ambient temperature and 85 °C. We used the potentiodynamic method and the potentiostatic method, simultaneously monitoring the variation of the open circuit potential during a time period (E corr/time curve. The C-ring method was used to stress the samples. In order to create stress concentrations, mechanical precracks with a depth of 100 or 250 μm were made on the outer side of the C-rings. Experimental results showed that the stressed samples were more susceptible to SCC than the unstressed samples whereas the increase in temperature and crack depth lead to an increase in SCC susceptibility. Incipient micro cracks of a depth of 30 μm were detected in the area of the highest peak of the mechanical precrack.

  9. Organizing Search Results with a Reference Map.

    Science.gov (United States)

    Nocaj, A; Brandes, U

    2012-12-01

    We propose a method to highlight query hits in hierarchically clustered collections of interrelated items such as digital libraries or knowledge bases. The method is based on the idea that organizing search results similarly to their arrangement on a fixed reference map facilitates orientation and assessment by preserving a user's mental map. Here, the reference map is built from an MDS layout of the items in a Voronoi treemap representing their hierarchical clustering, and we use techniques from dynamic graph layout to align query results with the map. The approach is illustrated on an archive of newspaper articles.

  10. Deliberate change without hierarchical influence?

    DEFF Research Database (Denmark)

    Nørskov, Sladjana; Kesting, Peter; Ulhøi, John Parm

    2017-01-01

    Purpose This paper aims to present that deliberate change is strongly associated with formal structures and top-down influence. Hierarchical configurations have been used to structure processes, overcome resistance and get things done. But is deliberate change also possible without formal...... reveals that deliberate change is indeed achievable in a non-hierarchical collaborative OSS community context. However, it presupposes the presence and active involvement of informal change agents. The paper identifies and specifies four key drivers for change agents’ influence. Originality....../value The findings contribute to organisational analysis by providing a deeper understanding of the importance of leadership in making deliberate change possible in non-hierarchical settings. It points to the importance of “change-by-conviction”, essentially based on voluntary behaviour. This can open the door...

  11. Static Correctness of Hierarchical Procedures

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff

    1990-01-01

    A system of hierarchical, fully recursive types in a truly imperative language allows program fragments written for small types to be reused for all larger types. To exploit this property to enable type-safe hierarchical procedures, it is necessary to impose a static requirement on procedure calls....... We introduce an example language and prove the existence of a sound requirement which preserves static correctness while allowing hierarchical procedures. This requirement is further shown to be optimal, in the sense that it imposes as few restrictions as possible. This establishes the theoretical...... basis for a general type hierarchy with static type checking, which enables first-order polymorphism combined with multiple inheritance and specialization in a language with assignments. We extend the results to include opaque types. An opaque version of a type is different from the original but has...

  12. Hierarchical fractal Weyl laws for chaotic resonance states in open mixed systems.

    Science.gov (United States)

    Körber, M J; Michler, M; Bäcker, A; Ketzmerick, R

    2013-09-13

    In open chaotic systems the number of long-lived resonance states obeys a fractal Weyl law, which depends on the fractal dimension of the chaotic saddle. We study the generic case of a mixed phase space with regular and chaotic dynamics. We find a hierarchy of fractal Weyl laws, one for each region of the hierarchical decomposition of the chaotic phase-space component. This is based on our observation of hierarchical resonance states localizing on these regions. Numerically this is verified for the standard map and a hierarchical model system.

  13. Structural integrity of hierarchical composites

    Directory of Open Access Journals (Sweden)

    Marco Paggi

    2012-01-01

    Full Text Available Interface mechanical problems are of paramount importance in engineering and materials science. Traditionally, due to the complexity of modelling their mechanical behaviour, interfaces are often treated as defects and their features are not explored. In this study, a different approach is illustrated, where the interfaces play an active role in the design of innovative hierarchical composites and are fundamental for their structural integrity. Numerical examples regarding cutting tools made of hierarchical cellular polycrystalline materials are proposed, showing that tailoring of interface properties at the different scales is the way to achieve superior mechanical responses that cannot be obtained using standard materials

  14. A network of topographic numerosity maps in human association cortex.

    NARCIS (Netherlands)

    Harvey, Ben M.; Dumoulin, Serge O.

    2017-01-01

    Sensory and motor cortices each contain multiple topographic maps with the structure of sensory organs (such as the retina or cochlea) mapped onto the cortical surface. These sensory maps are hierarchically organized. For example, visual field maps contain neurons that represent increasingly large

  15. A network of topographic numerosity maps in human association cortex.

    NARCIS (Netherlands)

    Harvey, Ben M.; Dumoulin, Serge O.

    2017-01-01

    Sensory and motor cortices each contain multiple topographic maps with the structure of sensory organs (such as the retina or cochlea) mapped onto the cortical surface. These sensory maps are hierarchically organized. For example, visual field maps contain neurons that represent increasingly large p

  16. Hierarchical resource analysis for land use planning through remote sensing

    Science.gov (United States)

    Byrnes, B. H.; Frazee, C. J.; Cox, T. L.

    1976-01-01

    A hierarchical resource analysis was applied to remote sensing data to provide maps at Planning Levels I and III (Anderson et al., U.S. Geological Survey Circular 671) for Meade County, S. Dak. Level I land use and general soil maps were prepared by visual interpretation of imagery from a false color composite of Landsat MSS bands 4, 5, and 7 and single bands (5 and 7). A modified Level III land use map was prepared for the Black Hills area from RB-57 photography enlarged to a scale of 1:24,000. Level III land use data were used together with computer-generated interpretive soil maps to analyze relationships between developed and developing areas and soil criteria.

  17. A comparative study between the use of artificial neural networks and multiple linear regression for caustic concentration prediction in a stage of alumina production

    Directory of Open Access Journals (Sweden)

    Giovanni Leopoldo Rozza

    2015-09-01

    Full Text Available With world becoming each day a global village, enterprises continuously seek to optimize their internal processes to hold or improve their competitiveness and make better use of natural resources. In this context, decision support tools are an underlying requirement. Such tools are helpful on predicting operational issues, avoiding cost risings, loss of productivity, work-related accident leaves or environmental disasters. This paper has its focus on the prediction of spent liquor caustic concentration of Bayer process for alumina production. Caustic concentration measuring is essential to keep it at expected levels, otherwise quality issues might arise. The organization requests caustic concentration by chemical analysis laboratory once a day, such information is not enough to issue preventive actions to handle process inefficiencies that will be known only after new measurement on the next day. Thereby, this paper proposes using Multiple Linear Regression and Artificial Neural Networks techniques a mathematical model to predict the spent liquor´s caustic concentration. Hence preventive actions will occur in real time. Such models were built using software tool for numerical computation (MATLAB and a statistical analysis software package (SPSS. The models output (predicted caustic concentration were compared with the real lab data. We found evidence suggesting superior results with use of Artificial Neural Networks over Multiple Linear Regression model. The results demonstrate that replacing laboratorial analysis by the forecasting model to support technical staff on decision making could be feasible.

  18. Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Delmau, L.H.

    2002-10-08

    This work was undertaken to optimize the solvent used in the Caustic Side Solvent Extraction (CSSX) process and to measure key chemical and physical properties related to its performance in the removal of cesium from the alkaline high-level salt waste stored in tanks at the Savannah River Site. The need to adjust the solvent composition arose from the prior discovery that the previous baseline solvent was supersaturated with respect to the calixarene extractant. The following solvent-component concentrations in Isopar{reg_sign} L diluent are recommended: 0.007 M calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) extractant, 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) phase modifier, and 0.003 M tri-n-octylamine (TOA) stripping aid. Criteria for this selection included BOBCalixC6 solubility, batch cesium distribution ratios (D{sub Cs}), calculated flowsheet robustness, third-phase formation, coalescence rate (dispersion numbers), and solvent density. Although minor compromises within acceptable limits were made in flowsheet robustness and solvent density, significant benefits were gained in lower risk of third-phase formation and lower solvent cost. Data are also reported for the optimized solvent regarding the temperature dependence of D{sub Cs} in extraction, scrubbing, and stripping (ESS); ESS performance on recycle; partitioning of BOBCalixC6, Cs-7SB, and TOA to aqueous process solutions; partitioning of organic anions; distribution of metals; solvent phase separation at low temperatures; solvent stability to elevated temperatures; and solvent density and viscosity. Overall, the technical risk of the CSSX process has been reduced by resolving previously identified issues and raising no new issues.

  19. Caustic-Side Solvent Extraction Chemical and Physical Properties Progress in FY 2000 and FY 2001.

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, BA

    2002-04-17

    The purpose of this work was to provide chemical- and physical-property data addressing the technical risks of the Caustic-Side Solvent Extraction (CSSX) process as applied specifically to the removal of cesium from alkaline high-level salt waste stored at the US Department of Energy Savannah River Site. As part of the overall Salt Processing Project, this effort supported decision-making in regards to selecting a preferred technology among three alternatives: (1) CSSX, (2) nonelutable ion-exchange with an inorganic silicotitanate material and (3) precipitation with tetraphenylborate. High risks, innate to CSSX, that needed specific attention included: (1) chemical stability of the solvent matrix, (2) radiolytic stability of the solvent matrix, (3) proof-of-concept performance of the proposed process flowsheet with simulated waste, and (4) performance of the CSSX flowsheet with actual SRS high-level waste. This body of work directly addressed the chemical-stability risk and additionally provided supporting information that served to plan, carry out, and evaluate experiments conducted by other CSSX investigators addressing the other high risks. Information on cesium distribution in extraction, scrubbing, and stripping served as input for flowsheet design, provided a baseline for evaluating solvent performance under numerous stresses, and contributed to a broad understanding of the effects of expected process variables. In parallel, other measurements were directed toward learning how other system components distribute in the flowsheet. Such components include the solvent components themselves, constituents of the waste, and solvent-degradation products. Upon understanding which components influence flowsheet performance, it was then possible to address in a rational fashion how to clean up the solvent and maintain its stable function.

  20. Sensory Hierarchical Organization and Reading.

    Science.gov (United States)

    Skapof, Jerome

    The purpose of this study was to judge the viability of an operational approach aimed at assessing response styles in reading using the hypothesis of sensory hierarchical organization. A sample of 103 middle-class children from a New York City public school, between the ages of five and seven, took part in a three phase experiment. Phase one…

  1. Memory Stacking in Hierarchical Networks.

    Science.gov (United States)

    Westö, Johan; May, Patrick J C; Tiitinen, Hannu

    2016-02-01

    Robust representations of sounds with a complex spectrotemporal structure are thought to emerge in hierarchically organized auditory cortex, but the computational advantage of this hierarchy remains unknown. Here, we used computational models to study how such hierarchical structures affect temporal binding in neural networks. We equipped individual units in different types of feedforward networks with local memory mechanisms storing recent inputs and observed how this affected the ability of the networks to process stimuli context dependently. Our findings illustrate that these local memories stack up in hierarchical structures and hence allow network units to exhibit selectivity to spectral sequences longer than the time spans of the local memories. We also illustrate that short-term synaptic plasticity is a potential local memory mechanism within the auditory cortex, and we show that it can bring robustness to context dependence against variation in the temporal rate of stimuli, while introducing nonlinearities to response profiles that are not well captured by standard linear spectrotemporal receptive field models. The results therefore indicate that short-term synaptic plasticity might provide hierarchically structured auditory cortex with computational capabilities important for robust representations of spectrotemporal patterns.

  2. Accuracy of Endoscopy in Predicting the Depth of Mucosal Injury Following Caustic Ingestion; a Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Athena Alipour-Faz

    2017-01-01

    Full Text Available Introduction: Esophagogastroduodenoscopy (EGD is currently considered as the primary method of determining the degree of mucosal injury following caustic ingestion. The present study aimed to evaluate the screening performance characteristics of EGD in predicting the depth of gastrointestinal mucosal injuries following caustic ingestion.Methods: Adult patients who were referred to emergency department due to ingestion of corrosive materials, over a 7-year period, were enrolled to this diagnostic accuracy study. Sensitivity, specificity, positive and negative predictive values as well as negative and positive likelihood ratios of EGD in predicting the depth of mucosal injury was calculated using pathologic findings as the gold standard.Results: 54 cases with the mean age of 35 ± 11.2 years were enrolled (59.25% male. Primary endoscopic results defined 28 (51.85% cases as second grade and 26 (48.14% as third grade of mucosal injury. On the other hand, pathologic findings reported 21 (38.88% patients as first grade, 14 (25.92% as second, and 19 patients (35.18% as third grade. Sensitivity and specificity of endoscopy for determining grade II tissue injury were 50.00 (23.04-76.96 and 47.50 (31.51-63.87, respectively. These measures were 100.00 (82.35-100 and 80.00 (63.06-91.56, respectively for grade III. Accuracy of EGD was 87.03% for grade III and 48.14% for grade II.Conclusion: Based on the findings of the present study, endoscopic grading of caustic related mucosal injury based on the Zargar’s classification has good accuracy in predicting grade III (87% and fail accuracy in grade II injuries (48%. It seems that we should be cautious in planning treatment for these patients solely based on endoscopic results. 

  3. 离子膜法烧碱工艺改进%Process improvement of exchange membrane caustic soda production

    Institute of Scientific and Technical Information of China (English)

    许琼武

    2012-01-01

    Through addition of titanium heat exchanger, the steam condensed water recovery and utilization, vacuum dechlorination pipe renovation measures,the ionic membrane caustic soda device stable operation. Reduces energy consumption, improves the economic benefit.%通过新增钛换热器、蒸汽冷凝水回收利用、真空脱氯氯水管改造等措施,保证了离子膜烧碱生产装置的平稳运行,降低了能耗,提高了经济效益。

  4. Mobile Node Speed Detection Mechanism in Hierarchical Mobile Internet Protocol (IPv6

    Directory of Open Access Journals (Sweden)

    Zulkeflee Kusin

    2011-01-01

    Full Text Available Problem statement: IETF has introduced Hierarchical Mobile IPv6 (HMIPv6 to support mobility problem in the next generation Internet Protocol (IPv6. The key concept behind this protocol is the usage of Mobility Anchor Point (MAP located at any level router of network to support hierarchical mobility management and seamless handover. The distance MAP selection in HMIPv6 causes MAP overloaded as the network grows. Approach: To address the issue in designing MAP selection scheme, we proposed a dynamic speed detection mechanism that integrates with the load control mechanism. Results: From the experimental results we obtained that the proposed scheme gives better distribution in MAP load and reduced binding update cost. Conclusion/Recommendations: The Next Generation Networks (NGN is expected to provide seamless handover in high speed wireless network environment. There is crucial need of very sophisticated protocols to support NGN QoS requirements.

  5. Hierarchical Prisoner's Dilemma in Hierarchical Public-Goods Game

    CERN Document Server

    Fujimoto, Yuma; Kaneko, Kunihiko

    2016-01-01

    The dilemma in cooperation is one of the major concerns in game theory. In a public-goods game, each individual pays a cost for cooperation, or to prevent defection, and receives a reward from the collected cost in a group. Thus, defection is beneficial for each individual, while cooperation is beneficial for the group. Now, groups (say, countries) consisting of individual players also play games. To study such a multi-level game, we introduce a hierarchical public-goods (HPG) game in which two groups compete for finite resources by utilizing costs collected from individuals in each group. Analyzing this HPG game, we found a hierarchical prisoner's dilemma, in which groups choose the defection policy (say, armaments) as a Nash strategy to optimize each group's benefit, while cooperation optimizes the total benefit. On the other hand, for each individual within a group, refusing to pay the cost (say, tax) is a Nash strategy, which turns to be a cooperation policy for the group, thus leading to a hierarchical d...

  6. Hierarchical structure of biological systems

    Science.gov (United States)

    Alcocer-Cuarón, Carlos; Rivera, Ana L; Castaño, Victor M

    2014-01-01

    A general theory of biological systems, based on few fundamental propositions, allows a generalization of both Wierner and Berthalanffy approaches to theoretical biology. Here, a biological system is defined as a set of self-organized, differentiated elements that interact pair-wise through various networks and media, isolated from other sets by boundaries. Their relation to other systems can be described as a closed loop in a steady-state, which leads to a hierarchical structure and functioning of the biological system. Our thermodynamical approach of hierarchical character can be applied to biological systems of varying sizes through some general principles, based on the exchange of energy information and/or mass from and within the systems. PMID:24145961

  7. Automatic Hierarchical Color Image Classification

    Directory of Open Access Journals (Sweden)

    Jing Huang

    2003-02-01

    Full Text Available Organizing images into semantic categories can be extremely useful for content-based image retrieval and image annotation. Grouping images into semantic classes is a difficult problem, however. Image classification attempts to solve this hard problem by using low-level image features. In this paper, we propose a method for hierarchical classification of images via supervised learning. This scheme relies on using a good low-level feature and subsequently performing feature-space reconfiguration using singular value decomposition to reduce noise and dimensionality. We use the training data to obtain a hierarchical classification tree that can be used to categorize new images. Our experimental results suggest that this scheme not only performs better than standard nearest-neighbor techniques, but also has both storage and computational advantages.

  8. Intuitionistic fuzzy hierarchical clustering algorithms

    Institute of Scientific and Technical Information of China (English)

    Xu Zeshui

    2009-01-01

    Intuitionistic fuzzy set (IFS) is a set of 2-tuple arguments, each of which is characterized by a mem-bership degree and a nonmembership degree. The generalized form of IFS is interval-valued intuitionistic fuzzy set (IVIFS), whose components are intervals rather than exact numbers. IFSs and IVIFSs have been found to be very useful to describe vagueness and uncertainty. However, it seems that little attention has been focused on the clus-tering analysis of IFSs and IVIFSs. An intuitionistic fuzzy hierarchical algorithm is introduced for clustering IFSs, which is based on the traditional hierarchical clustering procedure, the intuitionistic fuzzy aggregation operator, and the basic distance measures between IFSs: the Hamming distance, normalized Hamming, weighted Hamming, the Euclidean distance, the normalized Euclidean distance, and the weighted Euclidean distance. Subsequently, the algorithm is extended for clustering IVIFSs. Finally the algorithm and its extended form are applied to the classifications of building materials and enterprises respectively.

  9. Hierarchical Formation of Galactic Clusters

    CERN Document Server

    Elmegreen, B G

    2006-01-01

    Young stellar groupings and clusters have hierarchical patterns ranging from flocculent spiral arms and star complexes on the largest scale to OB associations, OB subgroups, small loose groups, clusters and cluster subclumps on the smallest scales. There is no obvious transition in morphology at the cluster boundary, suggesting that clusters are only the inner parts of the hierarchy where stars have had enough time to mix. The power-law cluster mass function follows from this hierarchical structure: n(M_cl) M_cl^-b for b~2. This value of b is independently required by the observation that the summed IMFs from many clusters in a galaxy equals approximately the IMF of each cluster.

  10. Hierarchical matrices algorithms and analysis

    CERN Document Server

    Hackbusch, Wolfgang

    2015-01-01

    This self-contained monograph presents matrix algorithms and their analysis. The new technique enables not only the solution of linear systems but also the approximation of matrix functions, e.g., the matrix exponential. Other applications include the solution of matrix equations, e.g., the Lyapunov or Riccati equation. The required mathematical background can be found in the appendix. The numerical treatment of fully populated large-scale matrices is usually rather costly. However, the technique of hierarchical matrices makes it possible to store matrices and to perform matrix operations approximately with almost linear cost and a controllable degree of approximation error. For important classes of matrices, the computational cost increases only logarithmically with the approximation error. The operations provided include the matrix inversion and LU decomposition. Since large-scale linear algebra problems are standard in scientific computing, the subject of hierarchical matrices is of interest to scientists ...

  11. Hierarchical Cont-Bouchaud model

    CERN Document Server

    Paluch, Robert; Holyst, Janusz A

    2015-01-01

    We extend the well-known Cont-Bouchaud model to include a hierarchical topology of agent's interactions. The influence of hierarchy on system dynamics is investigated by two models. The first one is based on a multi-level, nested Erdos-Renyi random graph and individual decisions by agents according to Potts dynamics. This approach does not lead to a broad return distribution outside a parameter regime close to the original Cont-Bouchaud model. In the second model we introduce a limited hierarchical Erdos-Renyi graph, where merging of clusters at a level h+1 involves only clusters that have merged at the previous level h and we use the original Cont-Bouchaud agent dynamics on resulting clusters. The second model leads to a heavy-tail distribution of cluster sizes and relative price changes in a wide range of connection densities, not only close to the percolation threshold.

  12. Optimising steel production schedules via a hierarchical genetic algorithm

    Directory of Open Access Journals (Sweden)

    Worapradya, Kiatkajohn

    2014-08-01

    Full Text Available This paper presents an effective scheduling in a steel-making continuous casting (SCC plant. The main contribution of this paper is the formulation of a new optimisation model that more closely represents real-world situations, and a hierarchical genetic algorithm (HGA tailored particularly for searching for an optimal SCC schedule. The optimisation model is developed by integrating two main planning phases of traditional scheduling: (1 planning cast sequence, and (2 scheduling of steel-making and timing of all jobs. A novel procedure is given for genetic algorithm (GA chromosome coding that maps Gantt chart and hierarchical chromosomes. The performance of the proposed methodology is illustrated and compared with a two-phase traditional scheduling and a standard GA toolbox. Both qualitative and quantitative performance measures are investigated.

  13. Analysis and Optimisation of Hierarchically Scheduled Multiprocessor Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Traian; Pop, Paul; Eles, Petru;

    2008-01-01

    , they are organised in a hierarchy. In this paper, we first develop a holistic scheduling and schedulability analysis that determines the timing properties of a hierarchically scheduled system. Second, we address design problems that are characteristic to such hierarchically scheduled systems: assignment......We present an approach to the analysis and optimisation of heterogeneous multiprocessor embedded systems. The systems are heterogeneous not only in terms of hardware components, but also in terms of communication protocols and scheduling policies. When several scheduling policies share a resource...... of scheduling policies to tasks, mapping of tasks to hardware components, and the scheduling of the activities. We also present several algorithms for solving these problems. Our heuristics are able to find schedulable implementations under limited resources, achieving an efficient utilisation of the system...

  14. Nonlinear robust hierarchical control for nonlinear uncertain systems

    Directory of Open Access Journals (Sweden)

    Leonessa Alexander

    1999-01-01

    Full Text Available A nonlinear robust control-system design framework predicated on a hierarchical switching controller architecture parameterized over a set of moving nominal system equilibria is developed. Specifically, using equilibria-dependent Lyapunov functions, a hierarchical nonlinear robust control strategy is developed that robustly stabilizes a given nonlinear system over a prescribed range of system uncertainty by robustly stabilizing a collection of nonlinear controlled uncertain subsystems. The robust switching nonlinear controller architecture is designed based on a generalized (lower semicontinuous Lyapunov function obtained by minimizing a potential function over a given switching set induced by the parameterized nominal system equilibria. The proposed framework robustly stabilizes a compact positively invariant set of a given nonlinear uncertain dynamical system with structured parametric uncertainty. Finally, the efficacy of the proposed approach is demonstrated on a jet engine propulsion control problem with uncertain pressure-flow map data.

  15. Hybrid Steepest-Descent Methods for Triple Hierarchical Variational Inequalities

    Directory of Open Access Journals (Sweden)

    L. C. Ceng

    2015-01-01

    Full Text Available We introduce and analyze a relaxed iterative algorithm by combining Korpelevich’s extragradient method, hybrid steepest-descent method, and Mann’s iteration method. We prove that, under appropriate assumptions, the proposed algorithm converges strongly to a common element of the fixed point set of infinitely many nonexpansive mappings, the solution set of finitely many generalized mixed equilibrium problems (GMEPs, the solution set of finitely many variational inclusions, and the solution set of general system of variational inequalities (GSVI, which is just a unique solution of a triple hierarchical variational inequality (THVI in a real Hilbert space. In addition, we also consider the application of the proposed algorithm for solving a hierarchical variational inequality problem with constraints of finitely many GMEPs, finitely many variational inclusions, and the GSVI. The results obtained in this paper improve and extend the corresponding results announced by many others.

  16. MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT (MCU) GAMMA MONITORS SYSTEM FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Casella, V

    2005-12-15

    The Department of Energy (DOE) selected Caustic-Side Solvent Extraction (CSSX) as the preferred technology for the removal of radioactive cesium from High-Level Waste (HLW) at the Savannah River Site (SRS). Before the full-scale Salt Waste Processing Facility (SWPF) becomes operational, the Closure Business Unit (CBU) plans to process a portion of dissolved saltcake waste through a Modular CSSX Unit (MCU). This work was derived from Technical Task Request SP-TTR-2004-00013, ''Gamma Monitor for MCU''. The deliverables for this task are the hardware and software for the gamma monitors and a report summarizing the testing and acceptance of this equipment for use in the MCU. Gamma-ray monitors are required to: (1) Measure the Cs-137 concentration in the decontaminated salt solution before entering the DSS (Decontaminated Salt Solution) Hold Tank, (2) Measure the Cs-137 concentration in the strip effluent before entering the Strip Effluent Hold Tank, (3) Verify proper operation of the solvent extraction system by verifying material balance within the process (The DSS Hold Tank Cs-137 concentration will be very low and the Cs-137 concentration in the Strip Effluent Hold Tank will be fifteen times higher than the Cs-137 concentration in the Feed Tank.) Sodium iodide monitors are used to measure the Cs-137 concentration in the piping before the DSS Hold tank, while GM monitors are used for Cs-137 measurements before the Strip Effluent Hold Tank. Tungsten shields were designed using Monte Carlo calculations and fabricated to reduce the process background radiation at the detector positions. These monitors were calibrated with NIST traceable standards that were specially made to be the same as the piping being monitored. Since this gamma ray monitoring system is unique, specially designed software was written and acceptance tested by Savannah River National Laboratory personnel. The software is a LabView-based application that serves as a unified

  17. Caustic-Side Solvent-Extraction Modeling for Hanford Interim Pretreatment System

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, B.A.; Birdwell, J.F.; Delmau, L. H.; McFarlane, J.

    2008-06-01

    The purpose of this work is to examine the applicability of the Caustic-Side Solvent Extraction (CSSX) process for the removal of cesium from Hanford tank-waste supernatant solutions in support of the Hanford Interim Pretreatment System (IPS). The Hanford waste types are more challenging than those at the Savannah River Site (SRS) in that they contain significantly higher levels of potassium, the chief competing ion in the extraction of cesium. It was confirmed by use of the CSSX model that the higher levels of potassium depress the cesium distribution ratio (DCs), as validated by measurement of DCs values for four of eight specified Hanford waste-simulant compositions. The model predictions were good to an apparent standard error of ±11%. It is concluded from batch distribution experiments, physical-property measurements, equilibrium modeling, flowsheet calculations, and contactor sizing that the CSSX process as currently employed for cesium removal from alkaline salt waste at the SRS is capable of treating similar Hanford tank feeds. For the most challenging waste composition, 41 stages would be required to provide a cesium decontamination factor (DF) of 5000 and a concentration factor (CF) of 5. Commercial contacting equipment with rotor diameters of 10 in. for extraction and 5 in. for stripping should have the capacity to meet throughput requirements, but testing will be required to confirm that the needed efficiency and hydraulic performance are actually obtainable. Markedly improved flowsheet performance was calculated for a new solvent formulation employing the more soluble cesium extractant BEHBCalixC6 used with alternative scrub and strip solutions, respectively 0.1 M NaOH and 10 mM boric acid. The improved system can meet minimum requirements (DF = 5000 and CF = 5) with 17 stages or more ambitious goals (DF = 40,000 and CF = 15) with 19 stages. Potential benefits of further research and development are identified that would lead to reduced costs, greater

  18. Using Concept Maps in Teaching Microbiology

    OpenAIRE

    Gary E. Kaiser

    2010-01-01

    This article is intended for faculty teaching microbiology and other biological science courses, and is applicable to both the classroom and the laboratory. Concept maps are graphical tools for presenting knowledge concepts and the relationship between these concepts in a graphical, hierarchical fashion. Cross-links are further used to illustrate the relationships between the various segments of the concept map.

  19. Using Concept Maps in Teaching Microbiology

    Directory of Open Access Journals (Sweden)

    Gary E. Kaiser

    2010-04-01

    Full Text Available This article is intended for faculty teaching microbiology and other biological science courses, and is applicable to both the classroom and the laboratory. Concept maps are graphical tools for presenting knowledge concepts and the relationship between these concepts in a graphical, hierarchical fashion. Cross-links are further used to illustrate the relationships between the various segments of the concept map.

  20. Hierarchical Clustering and Active Galaxies

    CERN Document Server

    Hatziminaoglou, E; Manrique, A

    2000-01-01

    The growth of Super Massive Black Holes and the parallel development of activity in galactic nuclei are implemented in an analytic code of hierarchical clustering. The evolution of the luminosity function of quasars and AGN will be computed with special attention paid to the connection between quasars and Seyfert galaxies. One of the major interests of the model is the parallel study of quasar formation and evolution and the History of Star Formation.

  1. Hybrid and hierarchical composite materials

    CERN Document Server

    Kim, Chang-Soo; Sano, Tomoko

    2015-01-01

    This book addresses a broad spectrum of areas in both hybrid materials and hierarchical composites, including recent development of processing technologies, structural designs, modern computer simulation techniques, and the relationships between the processing-structure-property-performance. Each topic is introduced at length with numerous  and detailed examples and over 150 illustrations.   In addition, the authors present a method of categorizing these materials, so that representative examples of all material classes are discussed.

  2. Treatment Protocols as Hierarchical Structures

    Science.gov (United States)

    Ben-Bassat, Moshe; Carlson, Richard W.; Puri, Vinod K.; Weil, Max Harry

    1978-01-01

    We view a treatment protocol as a hierarchical structure of therapeutic modules. The lowest level of this structure consists of individual therapeutic actions. Combinations of individual actions define higher level modules, which we call routines. Routines are designed to manage limited clinical problems, such as the routine for fluid loading to correct hypovolemia. Combinations of routines and additional actions, together with comments, questions, or precautions organized in a branching logic, in turn, define the treatment protocol for a given disorder. Adoption of this modular approach may facilitate the formulation of treatment protocols, since the physician is not required to prepare complex flowcharts. This hierarchical approach also allows protocols to be updated and modified in a flexible manner. By use of such a standard format, individual components may be fitted together to create protocols for multiple disorders. The technique is suited for computer implementation. We believe that this hierarchical approach may facilitate standarization of patient care as well as aid in clinical teaching. A protocol for acute pancreatitis is used to illustrate this technique.

  3. CHARACTERIZATION AND EVALUATION OF CAUSTIC WASH TANK AND SOLVENT HOLD TANK SAMPLES FROM MCU FROM AUGUST TO SEPTEMBER 2011

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Fink, S.

    2012-08-01

    During processing of Salt Batches 3 and 4 in the Modular Caustic-Side Solvent Extraction Unit (MCU), the decontamination efficiency for cesium declined from historical values and from expectations based on laboratory testing. This report documents efforts to analyze samples of solvent and process solutions from MCU in an attempt to understand the cause of the reduced performance and to recommend mitigations. CWT Solutions from MCU from the time period of variable decontamination factor (DF) performance which covers from April 2011 to September 2011 (during processing of Salt Batch 4) were examined for impurities using chromatography and spectroscopy. The results indicate that impurities were found to be of two types: aromatic containing impurities most likely from Modifier degradation and aliphatic type impurities most likely from Isopar{reg_sign} L and tri-n-octylamine (TOA) degradation. Caustic washing the Solvent Hold Tank (SHT) solution with 1M NaOH improved its extraction ability as determined from {sup 22}Na uptake tests. Evidence from this work showed that pH variance in the aqueous solutions within the range of 1M nitric acid to 1.91M NaOH that contacted the solvent samples does not influence the analytical determination of the TOA concentration by GC-MS.

  4. Energy conversion performance of black liquor gasification to hydrogen production using direct causticization with CO(2) capture.

    Science.gov (United States)

    Naqvi, M; Yan, J; Dahlquist, E

    2012-04-01

    This paper estimates potential hydrogen production via dry black liquor gasification system with direct causticization integrated with a reference pulp mill. The advantage of using direct causticization is elimination of energy intensive lime kiln. Pressure swing adsorption is integrated in the carbon capture process for hydrogen upgrading. The energy conversion performance of the integrated system is compared with other bio-fuel alternatives and evaluated based on system performance indicators. The results indicated a significant hydrogen production potential (about 141MW) with an energy ratio of about 0.74 from the reference black liquor capacity (about 243.5MW) and extra biomass import (about 50MW) to compensate total energy deficit. About 867,000tonnes of CO(2) abatement per year is estimated i.e. combining CO(2) capture and CO(2) offset from hydrogen replacing motor gasoline. The hydrogen production offers a substantial motor fuel replacement especially in regions with large pulp and paper industry e.g. about 63% of domestic gasoline replacement in Sweden. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. HIERARCHICAL FRAGMENTATION OF THE ORION MOLECULAR FILAMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Satoko; Ho, Paul T. P.; Su, Yu-Nung [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Teixeira, Paula S. [Institut fuer Astrophysik, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180, Wien (Austria); Zapata, Luis A., E-mail: satoko_t@asiaa.sinica.edu.tw [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Morelia, Michoacan 58090 (Mexico)

    2013-01-20

    We present a high angular resolution map of the 850 {mu}m continuum emission of the Orion Molecular Cloud-3 (OMC 3) obtained with the Submillimeter Array (SMA); the map is a mosaic of 85 pointings covering an approximate area of 6.'5 Multiplication-Sign 2.'0 (0.88 Multiplication-Sign 0.27 pc). We detect 12 spatially resolved continuum sources, each with an H{sub 2} mass between 0.3-5.7 M {sub Sun} and a projected source size between 1400-8200 AU. All the detected sources are on the filamentary main ridge (n{sub H{sub 2}}{>=}10{sup 6} cm{sup -3}), and analysis based on the Jeans theorem suggests that they are most likely gravitationally unstable. Comparison of multi-wavelength data sets indicates that of the continuum sources, 6/12 (50%) are associated with molecular outflows, 8/12 (67%) are associated with infrared sources, and 3/12 (25%) are associated with ionized jets. The evolutionary status of these sources ranges from prestellar cores to protostar phase, confirming that OMC-3 is an active region with ongoing embedded star formation. We detect quasi-periodical separations between the OMC-3 sources of Almost-Equal-To 17''/0.035 pc. This spatial distribution is part of a large hierarchical structure that also includes fragmentation scales of giant molecular cloud ( Almost-Equal-To 35 pc), large-scale clumps ( Almost-Equal-To 1.3 pc), and small-scale clumps ( Almost-Equal-To 0.3 pc), suggesting that hierarchical fragmentation operates within the Orion A molecular cloud. The fragmentation spacings are roughly consistent with the thermal fragmentation length in large-scale clumps, while for small-scale cores it is smaller than the local fragmentation length. These smaller spacings observed with the SMA can be explained by either a helical magnetic field, cloud rotation, or/and global filament collapse. Finally, possible evidence for sequential fragmentation is suggested in the northern part of the OMC-3 filament.

  6. Rectifying systems of ionic membrane caustic soda synchronized debugging%离子膜烧碱整流系统同步调试

    Institute of Scientific and Technical Information of China (English)

    朱琦; 孔强; 王小红

    2011-01-01

    论述了离子膜烧碱整流系统同步调试的原理、步骤和注意事项。%Discusses of rectifying systems for ionic membrane caustic soda synchronized debugging principles, steps and considerations.

  7. Hierarchical structure and biomineralization in cricket tooth

    CERN Document Server

    Xing, Xueqing; Cai, Quan; Mo, Guang; Du, Rong; Chen, Zhongjun; Wu, Zhonghua

    2012-01-01

    Cricket is a truculent insect with stiff and sharp teeth as a fighting weapon. The structure and possible biomineralization of the cricket teeth are always interested. Synchrotron radiation X-ray fluorescence, X-ray diffraction and small angle X-ray scattering techniques were used to probe the element distribution, possible crystalline structures and size distribution of scatterers in cricket teeth. Scanning electron microscope was used to observe the nanoscaled structure. The results demonstrate that Zn is the main heavy element in cricket teeth. The surface of the cricket teeth has a crystalline compound like ZnFe2(AsO4)2(OH)2(H2O)4. While, the interior of the teeth has a crystalline compound like ZnCl2, which is from the biomineralization. The ZnCl2-like biomineral forms nanoscaled microfibrils and their axial direction points at the top of tooth cusp. The microfibrils aggregate random into intermediate filaments, forming a hierarchical structure. A sketch map of the cricket tooth cusp was proposed and a d...

  8. Application of injection of spent caustic sludge into sour water stripper%酸性水汽提塔注废碱渣工艺技术应用

    Institute of Scientific and Technical Information of China (English)

    刘静翔; 黄占修; 耿庆光; 孙宁飞

    2013-01-01

    中国石油化工股份有限公司洛阳分公司液态烃脱硫醇装置废碱渣年产量超过1 kt,原采用碱渣湿式氧化装置脱硫、浓硫酸中和、酸性水限流排放至炼油污水处理场处理工艺.该工艺存在浓硫酸中和碱渣作业风险大、酸性水低温盐结晶堵塞管线,作业过程恶臭气体环境污染大等问题.通过实施酸性水汽提塔注废碱渣技术改造,停用了碱渣湿式氧化装置,不再进行碱渣酸化处理.工业实践表明:废碱渣注入汽提塔后,净化水中约70%的固定铵可去除,酸性水汽提塔蒸汽单耗下降约10 kg/t,对总外排水水质几乎没有影响,取得了良好的经济效益和社会效益.%The liquid hydrocarbon sweetening unit in Sinopec Luoyang Company produced more than 1000 tons of caustic sludge each year.In the original design,the process of wet oxidation desulfurization,sulfuric acid neutralization and controlled sour water drainage to refinery waste water plant for treatment was applied to treat the caustic sludge.This process had the problems of higher operating risk in neutralization of caustic sludge by sulfuric acid and easy plugging of pipelines by low-temperature salt crystallization of sour water and air pollution by foul gas from operation,etc.To solve these problems,the injection of spent caustic sludge was implemented,caustic sludge wet oxidation unit was shutdown and caustic sludge acidification operation was stopped.The above practices in commercial operation show that,after injection of spent caustic sludge into the sour water stripper,70% of fixed ammonium is removed,steam consumption of sour water stripper is reduced by 10 kg/t,there is no impact on the quality of discharge water,and good economic and social benefits have been achieved.

  9. Hierarchical Control for Smart Grids

    DEFF Research Database (Denmark)

    Trangbæk, K; Bendtsen, Jan Dimon; Stoustrup, Jakob

    2011-01-01

    This paper deals with hierarchical model predictive control (MPC) of smart grid systems. The design consists of a high level MPC controller, a second level of so-called aggregators, which reduces the computational and communication-related load on the high-level control, and a lower level...... of autonomous consumers. The control system is tasked with balancing electric power production and consumption within the smart grid, and makes active use of the flexibility of a large number of power producing and/or power consuming units. The objective is to accommodate the load variation on the grid, arising...

  10. POTENTIAL FOR STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS CONTAINING HIGHLY CAUSTIC SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.; Stripling, C.; Fisher, D.; Elder, J.

    2010-04-26

    The evaporator recycle streams of nuclear waste tanks may contain waste in a chemistry and temperature regime that exceeds the current corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history found that two of these A537 carbon steel tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved tanks of similar construction. Therefore, it appears that the efficacy of stress relief of welding residual stress is the primary corrosion-limiting mechanism. The objective of this experimental program is to test A537 carbon steel small scale welded U-bend specimens and large welded plates (30.48 x 30.38 x 2.54 cm) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 C). These conditions simulate worst-case situations in these nuclear waste tanks. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test was completed after 12 weeks of immersion in a similar solution at 125 C except that the aluminate concentration was reduced to 0.3 M. Visual inspection of the plate revealed that stress corrosion cracking had not initiated from the machined crack tips in the weld or in the heat affected zone. NDE ultrasonic testing also confirmed subsurface cracking did not occur. Based on these results, it can be concluded that the environmental condition of these tests was unable to develop stress corrosion cracking within the test periods for the small welded U-bends and for the large plates, which were welded with an identical procedure as used in the construction of the actual nuclear waste tanks in the 1960s. The

  11. Fish Springs National Wildlife Refuge National Vegetation Classification (NVC) map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — National Vegetation Classification (NVC) map for Fish Springs National Wildlife Refuge. NVC provides a standardized hierarchical approach to classifying vegetation...

  12. Hierarchical Structures in Hypertext Learning Environments

    NARCIS (Netherlands)

    Bezdan, Eniko; Kester, Liesbeth; Kirschner, Paul A.

    2011-01-01

    Bezdan, E., Kester, L., & Kirschner, P. A. (2011, 9 September). Hierarchical Structures in Hypertext Learning Environments. Presentation for the visit of KU Leuven, Open University, Heerlen, The Netherlands.

  13. How Hierarchical Topics Evolve in Large Text Corpora.

    Science.gov (United States)

    Cui, Weiwei; Liu, Shixia; Wu, Zhuofeng; Wei, Hao

    2014-12-01

    Using a sequence of topic trees to organize documents is a popular way to represent hierarchical and evolving topics in text corpora. However, following evolving topics in the context of topic trees remains difficult for users. To address this issue, we present an interactive visual text analysis approach to allow users to progressively explore and analyze the complex evolutionary patterns of hierarchical topics. The key idea behind our approach is to exploit a tree cut to approximate each tree and allow users to interactively modify the tree cuts based on their interests. In particular, we propose an incremental evolutionary tree cut algorithm with the goal of balancing 1) the fitness of each tree cut and the smoothness between adjacent tree cuts; 2) the historical and new information related to user interests. A time-based visualization is designed to illustrate the evolving topics over time. To preserve the mental map, we develop a stable layout algorithm. As a result, our approach can quickly guide users to progressively gain profound insights into evolving hierarchical topics. We evaluate the effectiveness of the proposed method on Amazon's Mechanical Turk and real-world news data. The results show that users are able to successfully analyze evolving topics in text data.

  14. Power margin improvement for OFDMA-PON using hierarchical modulation.

    Science.gov (United States)

    Cao, Pan; Hu, Xiaofeng; Zhuang, Zhiming; Zhang, Liang; Chang, Qingjiang; Yang, Qi; Hu, Rong; Su, Yikai

    2013-04-08

    We propose and experimentally demonstrate a hierarchical modulation scheme to improve power margin for orthogonal frequency division multiple access-passive optical networks (OFDMA-PONs). In a PON system, under the same launched optical power, optical network units (ONUs) have different power margins due to unequal distribution fiber lengths. The power margin of the PON system is determined by the ONU with the lowest power margin. In our proposed scheme, ONUs with long and short distribution fibers are grouped together, and downstream signals for the paired ONUs are mapped onto the same OFDM subcarriers using hierarchical modulation. In a pair of ONUs, part of the power margin of the ONU with short distribution fiber is re-allocated to the ONU with long distribution fiber. Therefore, the power margin of the ONU with the longest distribution fiber can be increased, leading to the power margin improvement of the PON system. Experimental results show that the hierarchical modulation scheme improves the power margin by 2.7 dB for an OFDMA-PON system, which can be used to support more users or extend transmission distance.

  15. Dynamic Organization of Hierarchical Memories.

    Science.gov (United States)

    Kurikawa, Tomoki; Kaneko, Kunihiko

    2016-01-01

    In the brain, external objects are categorized in a hierarchical way. Although it is widely accepted that objects are represented as static attractors in neural state space, this view does not take account interaction between intrinsic neural dynamics and external input, which is essential to understand how neural system responds to inputs. Indeed, structured spontaneous neural activity without external inputs is known to exist, and its relationship with evoked activities is discussed. Then, how categorical representation is embedded into the spontaneous and evoked activities has to be uncovered. To address this question, we studied bifurcation process with increasing input after hierarchically clustered associative memories are learned. We found a "dynamic categorization"; neural activity without input wanders globally over the state space including all memories. Then with the increase of input strength, diffuse representation of higher category exhibits transitions to focused ones specific to each object. The hierarchy of memories is embedded in the transition probability from one memory to another during the spontaneous dynamics. With increased input strength, neural activity wanders over a narrower state space including a smaller set of memories, showing more specific category or memory corresponding to the applied input. Moreover, such coarse-to-fine transitions are also observed temporally during transient process under constant input, which agrees with experimental findings in the temporal cortex. These results suggest the hierarchy emerging through interaction with an external input underlies hierarchy during transient process, as well as in the spontaneous activity.

  16. Extraction, scrub, and strip test results for the salt waste processing facility caustic side solvent extraction solvent example

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-08-01

    An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(Cs) measured 12.9, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges.

  17. A comparative study of the treatment of ethylene plant spent caustic by neutralization and classical and advanced oxidation.

    Science.gov (United States)

    Hawari, Alaa; Ramadan, Hasanat; Abu-Reesh, Ibrahim; Ouederni, Mabrouk

    2015-03-15

    The treatment of spent caustic produced from an ethylene plant was investigated. In the case of neutralization alone it was found that the maximum removal of sulfide was at pH values below 5.5. The higher percentage removal of sulfides (99% at pH = 1.5) was accompanied with the highest COD removal (88%). For classical oxidation using H2O2 the maximum COD removal percentage reached 89% at pH = 2.5 and at a hydrogen peroxide concentration of 19 mM/L. For the advanced oxidation using Fenton's process it was found that the maximum COD removal of 96.5% was achieved at a hydrogen peroxide/ferrous sulfate ratio of (7:1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. INVESTIGATION OF THE POTENTIAL FOR CAUSTIC STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.

    2009-10-15

    The evaporator recycle streams contain waste in a chemistry and temperature regime that may be outside of the current waste tank corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history (1998-2008) of Tanks 30 and 32 showed that these tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved F-Area tanks. Therefore, for the Type III/IIIA waste tanks the efficacy of the stress relief of welding residual stress is the only corrosion-limiting mechanism. The objective of this experimental program is to test carbon steel small scale welded U-bend specimens and large welded plates (12 x 12 x 1 in.) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 C). These conditions simulate worst-case situations in Tanks 30 and 32. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test is currently in progress, but no cracking has been observed after 9 weeks of immersion. Based on the preliminary results, it appears that the environmental conditions of the tests are unable to develop stress corrosion cracking within the duration of these tests.

  19. Discovering hierarchical structure in normal relational data

    DEFF Research Database (Denmark)

    Schmidt, Mikkel Nørgaard; Herlau, Tue; Mørup, Morten

    2014-01-01

    Hierarchical clustering is a widely used tool for structuring and visualizing complex data using similarity. Traditionally, hierarchical clustering is based on local heuristics that do not explicitly provide assessment of the statistical saliency of the extracted hierarchy. We propose a non-param...

  20. Discursive Hierarchical Patterning in Economics Cases

    Science.gov (United States)

    Lung, Jane

    2011-01-01

    This paper attempts to apply Lung's (2008) model of the discursive hierarchical patterning of cases to a closer and more specific study of Economics cases and proposes a model of the distinct discursive hierarchical patterning of the same. It examines a corpus of 150 Economics cases with a view to uncovering the patterns of discourse construction.…

  1. A Model of Hierarchical Key Assignment Scheme

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhigang; ZHAO Jing; XU Maozhi

    2006-01-01

    A model of the hierarchical key assignment scheme is approached in this paper, which can be used with any cryptography algorithm. Besides, the optimal dynamic control property of a hierarchical key assignment scheme will be defined in this paper. Also, our scheme model will meet this property.

  2. Galaxy formation through hierarchical clustering

    Science.gov (United States)

    White, Simon D. M.; Frenk, Carlos S.

    1991-01-01

    Analytic methods for studying the formation of galaxies by gas condensation within massive dark halos are presented. The present scheme applies to cosmogonies where structure grows through hierarchical clustering of a mixture of gas and dissipationless dark matter. The simplest models consistent with the current understanding of N-body work on dissipationless clustering, and that of numerical and analytic work on gas evolution and cooling are adopted. Standard models for the evolution of the stellar population are also employed, and new models for the way star formation heats and enriches the surrounding gas are constructed. Detailed results are presented for a cold dark matter universe with Omega = 1 and H(0) = 50 km/s/Mpc, but the present methods are applicable to other models. The present luminosity functions contain significantly more faint galaxies than are observed.

  3. Groups possessing extensive hierarchical decompositions

    CERN Document Server

    Januszkiewicz, T; Leary, I J

    2009-01-01

    Kropholler's class of groups is the smallest class of groups which contains all finite groups and is closed under the following operator: whenever $G$ admits a finite-dimensional contractible $G$-CW-complex in which all stabilizer groups are in the class, then $G$ is itself in the class. Kropholler's class admits a hierarchical structure, i.e., a natural filtration indexed by the ordinals. For example, stage 0 of the hierarchy is the class of all finite groups, and stage 1 contains all groups of finite virtual cohomological dimension. We show that for each countable ordinal $\\alpha$, there is a countable group that is in Kropholler's class which does not appear until the $\\alpha+1$st stage of the hierarchy. Previously this was known only for $\\alpha= 0$, 1 and 2. The groups that we construct contain torsion. We also review the construction of a torsion-free group that lies in the third stage of the hierarchy.

  4. Quantum transport through hierarchical structures.

    Science.gov (United States)

    Boettcher, S; Varghese, C; Novotny, M A

    2011-04-01

    The transport of quantum electrons through hierarchical lattices is of interest because such lattices have some properties of both regular lattices and random systems. We calculate the electron transmission as a function of energy in the tight-binding approximation for two related Hanoi networks. HN3 is a Hanoi network with every site having three bonds. HN5 has additional bonds added to HN3 to make the average number of bonds per site equal to five. We present a renormalization group approach to solve the matrix equation involved in this quantum transport calculation. We observe band gaps in HN3, while no such band gaps are observed in linear networks or in HN5. We provide a detailed scaling analysis near the edges of these band gaps.

  5. Hierarchical networks of scientific journals

    CERN Document Server

    Palla, Gergely; Mones, Enys; Pollner, Péter; Vicsek, Tamás

    2015-01-01

    Scientific journals are the repositories of the gradually accumulating knowledge of mankind about the world surrounding us. Just as our knowledge is organised into classes ranging from major disciplines, subjects and fields to increasingly specific topics, journals can also be categorised into groups using various metrics. In addition to the set of topics characteristic for a journal, they can also be ranked regarding their relevance from the point of overall influence. One widespread measure is impact factor, but in the present paper we intend to reconstruct a much more detailed description by studying the hierarchical relations between the journals based on citation data. We use a measure related to the notion of m-reaching centrality and find a network which shows the level of influence of a journal from the point of the direction and efficiency with which information spreads through the network. We can also obtain an alternative network using a suitably modified nested hierarchy extraction method applied ...

  6. Adaptive Sampling in Hierarchical Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Knap, J; Barton, N R; Hornung, R D; Arsenlis, A; Becker, R; Jefferson, D R

    2007-07-09

    We propose an adaptive sampling methodology for hierarchical multi-scale simulation. The method utilizes a moving kriging interpolation to significantly reduce the number of evaluations of finer-scale response functions to provide essential constitutive information to a coarser-scale simulation model. The underlying interpolation scheme is unstructured and adaptive to handle the transient nature of a simulation. To handle the dynamic construction and searching of a potentially large set of finer-scale response data, we employ a dynamic metric tree database. We study the performance of our adaptive sampling methodology for a two-level multi-scale model involving a coarse-scale finite element simulation and a finer-scale crystal plasticity based constitutive law.

  7. Multicollinearity in hierarchical linear models.

    Science.gov (United States)

    Yu, Han; Jiang, Shanhe; Land, Kenneth C

    2015-09-01

    This study investigates an ill-posed problem (multicollinearity) in Hierarchical Linear Models from both the data and the model perspectives. We propose an intuitive, effective approach to diagnosing the presence of multicollinearity and its remedies in this class of models. A simulation study demonstrates the impacts of multicollinearity on coefficient estimates, associated standard errors, and variance components at various levels of multicollinearity for finite sample sizes typical in social science studies. We further investigate the role multicollinearity plays at each level for estimation of coefficient parameters in terms of shrinkage. Based on these analyses, we recommend a top-down method for assessing multicollinearity in HLMs that first examines the contextual predictors (Level-2 in a two-level model) and then the individual predictors (Level-1) and uses the results for data collection, research problem redefinition, model re-specification, variable selection and estimation of a final model.

  8. Hierarchically Nanostructured Materials for Sustainable Environmental Applications

    Science.gov (United States)

    Ren, Zheng; Guo, Yanbing; Liu, Cai-Hong; Gao, Pu-Xian

    2013-11-01

    This article presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions and multiple functionalities towards water remediation, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

  9. A neural signature of hierarchical reinforcement learning.

    Science.gov (United States)

    Ribas-Fernandes, José J F; Solway, Alec; Diuk, Carlos; McGuire, Joseph T; Barto, Andrew G; Niv, Yael; Botvinick, Matthew M

    2011-07-28

    Human behavior displays hierarchical structure: simple actions cohere into subtask sequences, which work together to accomplish overall task goals. Although the neural substrates of such hierarchy have been the target of increasing research, they remain poorly understood. We propose that the computations supporting hierarchical behavior may relate to those in hierarchical reinforcement learning (HRL), a machine-learning framework that extends reinforcement-learning mechanisms into hierarchical domains. To test this, we leveraged a distinctive prediction arising from HRL. In ordinary reinforcement learning, reward prediction errors are computed when there is an unanticipated change in the prospects for accomplishing overall task goals. HRL entails that prediction errors should also occur in relation to task subgoals. In three neuroimaging studies we observed neural responses consistent with such subgoal-related reward prediction errors, within structures previously implicated in reinforcement learning. The results reported support the relevance of HRL to the neural processes underlying hierarchical behavior.

  10. Hierarchical Identity-Based Lossy Trapdoor Functions

    CERN Document Server

    Escala, Alex; Libert, Benoit; Rafols, Carla

    2012-01-01

    Lossy trapdoor functions, introduced by Peikert and Waters (STOC'08), have received a lot of attention in the last years, because of their wide range of applications in theoretical cryptography. The notion has been recently extended to the identity-based scenario by Bellare et al. (Eurocrypt'12). We provide one more step in this direction, by considering the notion of hierarchical identity-based lossy trapdoor functions (HIB-LTDFs). Hierarchical identity-based cryptography generalizes identitybased cryptography in the sense that identities are organized in a hierarchical way; a parent identity has more power than its descendants, because it can generate valid secret keys for them. Hierarchical identity-based cryptography has been proved very useful both for practical applications and to establish theoretical relations with other cryptographic primitives. In order to realize HIB-LTDFs, we first build a weakly secure hierarchical predicate encryption scheme. This scheme, which may be of independent interest, is...

  11. Hierarchically nanostructured materials for sustainable environmental applications

    Science.gov (United States)

    Ren, Zheng; Guo, Yanbing; Liu, Cai-Hong; Gao, Pu-Xian

    2013-01-01

    This review presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions, and multiple functionalities toward water remediation, biosensing, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing, and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology. PMID:24790946

  12. Hierarchically Nanostructured Materials for Sustainable Environmental Applications

    Directory of Open Access Journals (Sweden)

    Zheng eRen

    2013-11-01

    Full Text Available This article presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions and multiple functionalities towards water remediation, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

  13. Hierarchically Nanoporous Bioactive Glasses for High Efficiency Immobilization of Enzymes

    DEFF Research Database (Denmark)

    He, W.; Min, D.D.; Zhang, X.D.

    2014-01-01

    Bioactive glasses with hierarchical nanoporosity and structures have been heavily involved in immobilization of enzymes. Because of meticulous design and ingenious hierarchical nanostructuration of porosities from yeast cell biotemplates, hierarchically nanostructured porous bioactive glasses can...

  14. Hierarchical mutual information for the comparison of hierarchical community structures in complex networks

    CERN Document Server

    Perotti, Juan Ignacio; Caldarelli, Guido

    2015-01-01

    The quest for a quantitative characterization of community and modular structure of complex networks produced a variety of methods and algorithms to classify different networks. However, it is not clear if such methods provide consistent, robust and meaningful results when considering hierarchies as a whole. Part of the problem is the lack of a similarity measure for the comparison of hierarchical community structures. In this work we give a contribution by introducing the {\\it hierarchical mutual information}, which is a generalization of the traditional mutual information, and allows to compare hierarchical partitions and hierarchical community structures. The {\\it normalized} version of the hierarchical mutual information should behave analogously to the traditional normalized mutual information. Here, the correct behavior of the hierarchical mutual information is corroborated on an extensive battery of numerical experiments. The experiments are performed on artificial hierarchies, and on the hierarchical ...

  15. A Mirroring Theorem and its Application to a New Method of Unsupervised Hierarchical Pattern Classification

    CERN Document Server

    Deepthi, Dasika Ratna

    2009-01-01

    In this paper, we prove a crucial theorem called Mirroring Theorem which affirms that given a collection of samples with enough information in it such that it can be classified into classes and subclasses then (i) There exists a mapping which classifies and subclassifies these samples (ii) There exists a hierarchical classifier which can be constructed by using Mirroring Neural Networks (MNNs) in combination with a clustering algorithm that can approximate this mapping. Thus, the proof of the Mirroring theorem provides a theoretical basis for the existence and a practical feasibility of constructing hierarchical classifiers, given the maps. Our proposed Mirroring Theorem can also be considered as an extension to Kolmogrovs theorem in providing a realistic solution for unsupervised classification. The techniques we develop, are general in nature and have led to the construction of learning machines which are (i) tree like in structure, (ii) modular (iii) with each module running on a common algorithm (tandem a...

  16. Triple Hierarchical Variational Inequalities with Constraints of Mixed Equilibria, Variational Inequalities, Convex Minimization, and Hierarchical Fixed Point Problems

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available We introduce and analyze a hybrid iterative algorithm by virtue of Korpelevich's extragradient method, viscosity approximation method, hybrid steepest-descent method, and averaged mapping approach to the gradient-projection algorithm. It is proven that under appropriate assumptions, the proposed algorithm converges strongly to a common element of the fixed point set of infinitely many nonexpansive mappings, the solution set of finitely many generalized mixed equilibrium problems (GMEPs, the solution set of finitely many variational inequality problems (VIPs, the solution set of general system of variational inequalities (GSVI, and the set of minimizers of convex minimization problem (CMP, which is just a unique solution of a triple hierarchical variational inequality (THVI in a real Hilbert space. In addition, we also consider the application of the proposed algorithm to solve a hierarchical fixed point problem with constraints of finitely many GMEPs, finitely many VIPs, GSVI, and CMP. The results obtained in this paper improve and extend the corresponding results announced by many others.

  17. Point Diffraction Interferometry to Measure Local Curvatures and Caustics of Noisy Wave Fronts: Application for Determining Optical Properties of Fish Lenses

    Science.gov (United States)

    Vallmitjana, S.; Ricart, I.; Bosch, S.; Gargallo, A.; Acosta, E.

    2015-02-01

    The study of caustics is important because they contain information about the image formation properties of optical systems. In this work we use the concept of caustic as a set of focal points, and we have developed a second order approach theory to determine local slopes and curvatures of a wavefront emerging from an optical system. The method is based on the use of a point diffraction interferometer, and the analysis of the interferograms allows us to compute the focal region. Experimental results obtained with a plano-convex lens demonstrate the accuracy of the combined theoretical-experimental method here developed. Application to noisy wavefronts such as those produced by biological samples, specifically in crystalline lenses of fish eyes, are also exposed.

  18. Hierarchically structured, nitrogen-doped carbon membranes

    KAUST Repository

    Wang, Hong

    2017-08-03

    The present invention is a structure, method of making and method of use for a novel macroscopic hierarchically structured, nitrogen-doped, nano-porous carbon membrane (HNDCMs) with asymmetric and hierarchical pore architecture that can be produced on a large-scale approach. The unique HNDCM holds great promise as components in separation and advanced carbon devices because they could offer unconventional fluidic transport phenomena on the nanoscale. Overall, the invention set forth herein covers a hierarchically structured, nitrogen-doped carbon membranes and methods of making and using such a membranes.

  19. A Model for Slicing JAVA Programs Hierarchically

    Institute of Scientific and Technical Information of China (English)

    Bi-Xin Li; Xiao-Cong Fan; Jun Pang; Jian-Jun Zhao

    2004-01-01

    Program slicing can be effectively used to debug, test, analyze, understand and maintain objectoriented software. In this paper, a new slicing model is proposed to slice Java programs based on their inherent hierarchical feature. The main idea of hierarchical slicing is to slice programs in a stepwise way, from package level, to class level, method level, and finally up to statement level. The stepwise slicing algorithm and the related graph reachability algorithms are presented, the architecture of the Java program Analyzing Tool (JATO) based on hierarchical slicing model is provided, the applications and a small case study are also discussed.

  20. Hierarchical analysis of acceptable use policies

    Directory of Open Access Journals (Sweden)

    P. A. Laughton

    2008-01-01

    Full Text Available Acceptable use policies (AUPs are vital tools for organizations to protect themselves and their employees from misuse of computer facilities provided. A well structured, thorough AUP is essential for any organization. It is impossible for an effective AUP to deal with every clause and remain readable. For this reason, some sections of an AUP carry more weight than others, denoting importance. The methodology used to develop the hierarchical analysis is a literature review, where various sources were consulted. This hierarchical approach to AUP analysis attempts to highlight important sections and clauses dealt with in an AUP. The emphasis of the hierarchal analysis is to prioritize the objectives of an AUP.

  1. Hierarchical modeling and analysis for spatial data

    CERN Document Server

    Banerjee, Sudipto; Gelfand, Alan E

    2003-01-01

    Among the many uses of hierarchical modeling, their application to the statistical analysis of spatial and spatio-temporal data from areas such as epidemiology And environmental science has proven particularly fruitful. Yet to date, the few books that address the subject have been either too narrowly focused on specific aspects of spatial analysis, or written at a level often inaccessible to those lacking a strong background in mathematical statistics.Hierarchical Modeling and Analysis for Spatial Data is the first accessible, self-contained treatment of hierarchical methods, modeling, and dat

  2. Hierarchical Route Optimization By Using Memetic Algorithm In A Mobile Networks

    Directory of Open Access Journals (Sweden)

    K .K. Gautam

    2011-02-01

    Full Text Available The networks Mobility (NEMO Protocol is a way of managing the mobility of an entire network, and mobile internet protocol is the basic solution for networks Mobility. A hierarchical route optimization system for mobile network is proposed to solve management of hierarchical route optimization problems. In present paper we study hierarchical Route Optimization scheme using memetic algorithm(HROSMA The concept of optimization- finding the extreme of a function that maps candidate ‘solution’ to scalar values of ‘quality’ – is an extremely general and useful idea. For solving this problem, we use a few salient adaptations, and we also extend HROSMA perform routing between the mobile networks.

  3. Multilevel compression of random walks on networks reveals hierarchical organization in large integrated systems

    CERN Document Server

    Rosvall, M

    2010-01-01

    To comprehend the hierarchical organization of large integrated systems, we introduce the hierarchical map equation that reveals multilevel structures in networks. In this information-theoretic approach, we exploit the duality between compression and pattern detection; by compressing a description of a random walker as a proxy for real flow on a network, we find regularities in the network that induce this system-wide flow. Finding the shortest multilevel description of the random walker therefore gives us the best hierarchical clustering of the network, the optimal number of levels and modular partition at each level, with respect to the dynamics on the network. With a novel search algorithm, we extract and illustrate the rich multilevel organization of several large social and biological networks. For example, from the global air traffic network we uncover countries and continents, and from the pattern of scientific communication we reveal more than 100 scientific fields organized in four major disciplines:...

  4. Image meshing via hierarchical optimization

    Institute of Scientific and Technical Information of China (English)

    Hao XIE; Ruo-feng TONG‡

    2016-01-01

    Vector graphic, as a kind of geometric representation of raster images, has many advantages, e.g., defi nition independence and editing facility. A popular way to convert raster images into vector graphics is image meshing, the aim of which is to fi nd a mesh to represent an image as faithfully as possible. For traditional meshing algorithms, the crux of the problem resides mainly in the high non-linearity and non-smoothness of the objective, which makes it difficult to fi nd a desirable optimal solution. To ameliorate this situation, we present a hierarchical optimization algorithm solving the problem from coarser levels to fi ner ones, providing initialization for each level with its coarser ascent. To further simplify the problem, the original non-convex problem is converted to a linear least squares one, and thus becomes convex, which makes the problem much easier to solve. A dictionary learning framework is used to combine geometry and topology elegantly. Then an alternating scheme is employed to solve both parts. Experiments show that our algorithm runs fast and achieves better results than existing ones for most images.

  5. Image meshing via hierarchical optimization*

    Institute of Scientific and Technical Information of China (English)

    Hao XIE; Ruo-feng TONGS

    2016-01-01

    Vector graphic, as a kind of geometric representation of raster images, has many advantages, e.g., definition independence and editing facility. A popular way to convert raster images into vector graphics is image meshing, the aim of which is to find a mesh to represent an image as faithfully as possible. For traditional meshing algorithms, the crux of the problem resides mainly in the high non-linearity and non-smoothness of the objective, which makes it difficult to find a desirable optimal solution. To ameliorate this situation, we present a hierarchical optimization algorithm solving the problem from coarser levels to finer ones, providing initialization for each level with its coarser ascent. To further simplify the problem, the original non-convex problem is converted to a linear least squares one, and thus becomes convex, which makes the problem much easier to solve. A dictionary learning framework is used to combine geometry and topology elegantly. Then an alternating scheme is employed to solve both parts. Experiments show that our algorithm runs fast and achieves better results than existing ones for most images.

  6. Hierarchical Bayes Ensemble Kalman Filtering

    CERN Document Server

    Tsyrulnikov, Michael

    2015-01-01

    Ensemble Kalman filtering (EnKF), when applied to high-dimensional systems, suffers from an inevitably small affordable ensemble size, which results in poor estimates of the background error covariance matrix ${\\bf B}$. The common remedy is a kind of regularization, usually an ad-hoc spatial covariance localization (tapering) combined with artificial covariance inflation. Instead of using an ad-hoc regularization, we adopt the idea by Myrseth and Omre (2010) and explicitly admit that the ${\\bf B}$ matrix is unknown and random and estimate it along with the state (${\\bf x}$) in an optimal hierarchical Bayes analysis scheme. We separate forecast errors into predictability errors (i.e. forecast errors due to uncertainties in the initial data) and model errors (forecast errors due to imperfections in the forecast model) and include the two respective components ${\\bf P}$ and ${\\bf Q}$ of the ${\\bf B}$ matrix into the extended control vector $({\\bf x},{\\bf P},{\\bf Q})$. Similarly, we break the traditional backgrou...

  7. Water washes and caustic leaches of sludge from Hanford Tank S-101 and water washes of sludge from Hanford Tank C-103

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, R.D.; Collins, J.L.; Chase, C.W.

    1998-07-01

    In 1993, the Department of Energy (DOE) selected the enhanced sludge washing (ESW) process as the baseline for pretreatment of Hanford tank sludges. The ESW process uses a series of water washes and caustic leaches to separate nonradioactive components such as aluminum, chromium, and phosphate from the high-level waste sludges. If the ESW process is successful, the volume of immobilized high-level waste will be significantly reduced. The tests on the sludge from Hanford Tank S-101 focused on the effects of process variables such as sodium hydroxide concentration (1 and 3 M), temperature (70 and 95 C), and leaching time (5, 24, 72, and 168 h) on the efficacy of the ESW process with realistic liquid-to-solid ratios. Another goal of this study was to evaluate the effectiveness of water washes on a sludge sample from hanford Tank C-103. The final objective of this study was to test potential process control monitors during the water washes and caustic leaches with actual sludge. Both {sup 137}Cs activity and conductance were measured for each of the water washes and caustic leaches. Experimental procedures, a discussion of results, conclusions and recommendations are included in this report.

  8. An Automatic Hierarchical Delay Analysis Tool

    Institute of Scientific and Technical Information of China (English)

    FaridMheir-El-Saadi; BozenaKaminska

    1994-01-01

    The performance analysis of VLSI integrated circuits(ICs) with flat tools is slow and even sometimes impossible to complete.Some hierarchical tools have been developed to speed up the analysis of these large ICs.However,these hierarchical tools suffer from a poor interaction with the CAD database and poorly automatized operations.We introduce a general hierarchical framework for performance analysis to solve these problems.The circuit analysis is automatic under the proposed framework.Information that has been automatically abstracted in the hierarchy is kept in database properties along with the topological information.A limited software implementation of the framework,PREDICT,has also been developed to analyze the delay performance.Experimental results show that hierarchical analysis CPU time and memory requirements are low if heuristics are used during the abstraction process.

  9. Packaging glass with hierarchically nanostructured surface

    KAUST Repository

    He, Jr-Hau

    2017-08-03

    An optical device includes an active region and packaging glass located on top of the active region. A top surface of the packaging glass includes hierarchical nanostructures comprised of honeycombed nanowalls (HNWs) and nanorod (NR) structures extending from the HNWs.

  10. Generation of hierarchically correlated multivariate symbolic sequences

    CERN Document Server

    Tumminello, Mi; Mantegna, R N

    2008-01-01

    We introduce an algorithm to generate multivariate series of symbols from a finite alphabet with a given hierarchical structure of similarities. The target hierarchical structure of similarities is arbitrary, for instance the one obtained by some hierarchical clustering procedure as applied to an empirical matrix of Hamming distances. The algorithm can be interpreted as the finite alphabet equivalent of the recently introduced hierarchically nested factor model (M. Tumminello et al. EPL 78 (3) 30006 (2007)). The algorithm is based on a generating mechanism that is different from the one used in the mutation rate approach. We apply the proposed methodology for investigating the relationship between the bootstrap value associated with a node of a phylogeny and the probability of finding that node in the true phylogeny.

  11. Hierarchical modularity in human brain functional networks

    CERN Document Server

    Meunier, D; Fornito, A; Ersche, K D; Bullmore, E T; 10.3389/neuro.11.037.2009

    2010-01-01

    The idea that complex systems have a hierarchical modular organization originates in the early 1960s and has recently attracted fresh support from quantitative studies of large scale, real-life networks. Here we investigate the hierarchical modular (or "modules-within-modules") decomposition of human brain functional networks, measured using functional magnetic resonance imaging (fMRI) in 18 healthy volunteers under no-task or resting conditions. We used a customized template to extract networks with more than 1800 regional nodes, and we applied a fast algorithm to identify nested modular structure at several hierarchical levels. We used mutual information, 0 < I < 1, to estimate the similarity of community structure of networks in different subjects, and to identify the individual network that is most representative of the group. Results show that human brain functional networks have a hierarchical modular organization with a fair degree of similarity between subjects, I=0.63. The largest 5 modules at ...

  12. HIERARCHICAL ORGANIZATION OF INFORMATION, IN RELATIONAL DATABASES

    Directory of Open Access Journals (Sweden)

    Demian Horia

    2008-05-01

    Full Text Available In this paper I will present different types of representation, of hierarchical information inside a relational database. I also will compare them to find the best organization for specific scenarios.

  13. Hierarchical Network Design Using Simulated Annealing

    DEFF Research Database (Denmark)

    Thomadsen, Tommy; Clausen, Jens

    2002-01-01

    The hierarchical network problem is the problem of finding the least cost network, with nodes divided into groups, edges connecting nodes in each groups and groups ordered in a hierarchy. The idea of hierarchical networks comes from telecommunication networks where hierarchies exist. Hierarchical...... networks are described and a mathematical model is proposed for a two level version of the hierarchical network problem. The problem is to determine which edges should connect nodes, and how demand is routed in the network. The problem is solved heuristically using simulated annealing which as a sub......-algorithm uses a construction algorithm to determine edges and route the demand. Performance for different versions of the algorithm are reported in terms of runtime and quality of the solutions. The algorithm is able to find solutions of reasonable quality in approximately 1 hour for networks with 100 nodes....

  14. When to Use Hierarchical Linear Modeling

    National Research Council Canada - National Science Library

    Veronika Huta

    2014-01-01

    Previous publications on hierarchical linear modeling (HLM) have provided guidance on how to perform the analysis, yet there is relatively little information on two questions that arise even before analysis...

  15. An introduction to hierarchical linear modeling

    National Research Council Canada - National Science Library

    Woltman, Heather; Feldstain, Andrea; MacKay, J. Christine; Rocchi, Meredith

    2012-01-01

    This tutorial aims to introduce Hierarchical Linear Modeling (HLM). A simple explanation of HLM is provided that describes when to use this statistical technique and identifies key factors to consider before conducting this analysis...

  16. Conservation Laws in the Hierarchical Model

    NARCIS (Netherlands)

    Beijeren, H. van; Gallavotti, G.; Knops, H.

    1974-01-01

    An exposition of the renormalization-group equations for the hierarchical model is given. Attention is drawn to some properties of the spin distribution functions which are conserved under the action of the renormalization group.

  17. Hierarchical DSE for multi-ASIP platforms

    DEFF Research Database (Denmark)

    Micconi, Laura; Corvino, Rosilde; Gangadharan, Deepak;

    2013-01-01

    This work proposes a hierarchical Design Space Exploration (DSE) for the design of multi-processor platforms targeted to specific applications with strict timing and area constraints. In particular, it considers platforms integrating multiple Application Specific Instruction Set Processors (ASIPs...

  18. Nanodesigning of Hierarchical Multifunctional Ceramics

    Science.gov (United States)

    1993-09-28

    conditions by reacting nanosized titanium oxide or titanium alkoxides with a solution of barium hydroxide. The powders produced by this approach range in...14 1.2.5 Density of Colloidal Aggregated Network Near a Hard Wall ...... 15 1.2.6 Synthesis of Lead- Zirconium -Titanate (Pb(Zr0.5 2Tio.4 8)0 3 ) (PZT...6 Figure 4: Spinnability map for poly(ethylene oxide )-based a-A120 3 suspensions ......... 9 Figure 5: High

  19. Hierarchical organization versus self-organization

    OpenAIRE

    Busseniers, Evo

    2014-01-01

    In this paper we try to define the difference between hierarchical organization and self-organization. Organization is defined as a structure with a function. So we can define the difference between hierarchical organization and self-organization both on the structure as on the function. In the next two chapters these two definitions are given. For the structure we will use some existing definitions in graph theory, for the function we will use existing theory on (self-)organization. In the t...

  20. Hierarchical decision making for flood risk reduction

    DEFF Research Database (Denmark)

    Custer, Rocco; Nishijima, Kazuyoshi

    2013-01-01

    . In current practice, structures are often optimized individually without considering benefits of having a hierarchy of protection structures. It is here argued, that the joint consideration of hierarchically integrated protection structures is beneficial. A hierarchical decision model is utilized to analyze...... and compare the benefit of large upstream protection structures and local downstream protection structures in regard to epistemic uncertainty parameters. Results suggest that epistemic uncertainty influences the outcome of the decision model and that, depending on the magnitude of epistemic uncertainty...

  1. Hierarchical self-organization of tectonic plates

    OpenAIRE

    2010-01-01

    The Earth's surface is subdivided into eight large tectonic plates and many smaller ones. We reconstruct the plate tessellation history and demonstrate that both large and small plates display two distinct hierarchical patterns, described by different power-law size-relationships. While small plates display little organisational change through time, the structure of the large plates oscillate between minimum and maximum hierarchical tessellations. The organization of large plates rapidly chan...

  2. Angelic Hierarchical Planning: Optimal and Online Algorithms

    Science.gov (United States)

    2008-12-06

    restrict our attention to plans in I∗(Act, s0). Definition 2. ( Parr and Russell , 1998) A plan ah∗ is hierarchically optimal iff ah∗ = argmina∈I∗(Act,s0):T...Murdock, Dan Wu, and Fusun Yaman. SHOP2: An HTN planning system. JAIR, 20:379–404, 2003. Ronald Parr and Stuart Russell . Reinforcement Learning with...Angelic Hierarchical Planning: Optimal and Online Algorithms Bhaskara Marthi Stuart J. Russell Jason Wolfe Electrical Engineering and Computer

  3. Hierarchical Needs, Income Comparisons and Happiness Levels

    OpenAIRE

    Drakopoulos, Stavros

    2011-01-01

    The cornerstone of the hierarchical approach is that there are some basic human needs which must be satisfied before non-basic needs come into the picture. The hierarchical structure of needs implies that the satisfaction of primary needs provides substantial increases to individual happiness compared to the subsequent satisfaction of secondary needs. This idea can be combined with the concept of comparison income which means that individuals compare rewards with individuals with similar char...

  4. Evaluating Hierarchical Structure in Music Annotations.

    Science.gov (United States)

    McFee, Brian; Nieto, Oriol; Farbood, Morwaread M; Bello, Juan Pablo

    2017-01-01

    Music exhibits structure at multiple scales, ranging from motifs to large-scale functional components. When inferring the structure of a piece, different listeners may attend to different temporal scales, which can result in disagreements when they describe the same piece. In the field of music informatics research (MIR), it is common to use corpora annotated with structural boundaries at different levels. By quantifying disagreements between multiple annotators, previous research has yielded several insights relevant to the study of music cognition. First, annotators tend to agree when structural boundaries are ambiguous. Second, this ambiguity seems to depend on musical features, time scale, and genre. Furthermore, it is possible to tune current annotation evaluation metrics to better align with these perceptual differences. However, previous work has not directly analyzed the effects of hierarchical structure because the existing methods for comparing structural annotations are designed for "flat" descriptions, and do not readily generalize to hierarchical annotations. In this paper, we extend and generalize previous work on the evaluation of hierarchical descriptions of musical structure. We derive an evaluation metric which can compare hierarchical annotations holistically across multiple levels. sing this metric, we investigate inter-annotator agreement on the multilevel annotations of two different music corpora, investigate the influence of acoustic properties on hierarchical annotations, and evaluate existing hierarchical segmentation algorithms against the distribution of inter-annotator agreement.

  5. Evaluating Hierarchical Structure in Music Annotations

    Directory of Open Access Journals (Sweden)

    Brian McFee

    2017-08-01

    Full Text Available Music exhibits structure at multiple scales, ranging from motifs to large-scale functional components. When inferring the structure of a piece, different listeners may attend to different temporal scales, which can result in disagreements when they describe the same piece. In the field of music informatics research (MIR, it is common to use corpora annotated with structural boundaries at different levels. By quantifying disagreements between multiple annotators, previous research has yielded several insights relevant to the study of music cognition. First, annotators tend to agree when structural boundaries are ambiguous. Second, this ambiguity seems to depend on musical features, time scale, and genre. Furthermore, it is possible to tune current annotation evaluation metrics to better align with these perceptual differences. However, previous work has not directly analyzed the effects of hierarchical structure because the existing methods for comparing structural annotations are designed for “flat” descriptions, and do not readily generalize to hierarchical annotations. In this paper, we extend and generalize previous work on the evaluation of hierarchical descriptions of musical structure. We derive an evaluation metric which can compare hierarchical annotations holistically across multiple levels. sing this metric, we investigate inter-annotator agreement on the multilevel annotations of two different music corpora, investigate the influence of acoustic properties on hierarchical annotations, and evaluate existing hierarchical segmentation algorithms against the distribution of inter-annotator agreement.

  6. Hierarchical Nanoceramics for Industrial Process Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ruud, James, A.; Brosnan, Kristen, H.; Striker, Todd; Ramaswamy, Vidya; Aceto, Steven, C.; Gao, Yan; Willson, Patrick, D.; Manoharan, Mohan; Armstrong, Eric, N., Wachsman, Eric, D.; Kao, Chi-Chang

    2011-07-15

    This project developed a robust, tunable, hierarchical nanoceramics materials platform for industrial process sensors in harsh-environments. Control of material structure at multiple length scales from nano to macro increased the sensing response of the materials to combustion gases. These materials operated at relatively high temperatures, enabling detection close to the source of combustion. It is anticipated that these materials can form the basis for a new class of sensors enabling widespread use of efficient combustion processes with closed loop feedback control in the energy-intensive industries. The first phase of the project focused on materials selection and process development, leading to hierarchical nanoceramics that were evaluated for sensing performance. The second phase focused on optimizing the materials processes and microstructures, followed by validation of performance of a prototype sensor in a laboratory combustion environment. The objectives of this project were achieved by: (1) synthesizing and optimizing hierarchical nanostructures; (2) synthesizing and optimizing sensing nanomaterials; (3) integrating sensing functionality into hierarchical nanostructures; (4) demonstrating material performance in a sensing element; and (5) validating material performance in a simulated service environment. The project developed hierarchical nanoceramic electrodes for mixed potential zirconia gas sensors with increased surface area and demonstrated tailored electrocatalytic activity operable at high temperatures enabling detection of products of combustion such as NOx close to the source of combustion. Methods were developed for synthesis of hierarchical nanostructures with high, stable surface area, integrated catalytic functionality within the structures for gas sensing, and demonstrated materials performance in harsh lab and combustion gas environments.

  7. Hierarchical trie packet classification algorithm based on expectation-maximization clustering

    Science.gov (United States)

    Bi, Xia-an; Zhao, Junxia

    2017-01-01

    With the development of computer network bandwidth, packet classification algorithms which are able to deal with large-scale rule sets are in urgent need. Among the existing algorithms, researches on packet classification algorithms based on hierarchical trie have become an important packet classification research branch because of their widely practical use. Although hierarchical trie is beneficial to save large storage space, it has several shortcomings such as the existence of backtracking and empty nodes. This paper proposes a new packet classification algorithm, Hierarchical Trie Algorithm Based on Expectation-Maximization Clustering (HTEMC). Firstly, this paper uses the formalization method to deal with the packet classification problem by means of mapping the rules and data packets into a two-dimensional space. Secondly, this paper uses expectation-maximization algorithm to cluster the rules based on their aggregate characteristics, and thereby diversified clusters are formed. Thirdly, this paper proposes a hierarchical trie based on the results of expectation-maximization clustering. Finally, this paper respectively conducts simulation experiments and real-environment experiments to compare the performances of our algorithm with other typical algorithms, and analyzes the results of the experiments. The hierarchical trie structure in our algorithm not only adopts trie path compression to eliminate backtracking, but also solves the problem of low efficiency of trie updates, which greatly improves the performance of the algorithm. PMID:28704476

  8. Characterizing Low-Mass Binaries From Observation of Long Time-scale Caustic-crossing Gravitational Microlensing Events

    CERN Document Server

    Shin, I -G; Choi, J -Y; Udalski, A; Sumi, T; Gould, A; Bozza, V; Dominik, M; Fouqué, P; Horne, K; \\, M; Szymański, K; Kubiak, M; Soszyński, I; Pietrzyński, G; Poleski, R; Ulaczyk, K; Pietrukowicz, P; Kozłowski, S; Skowron, J; Wyrzykowski, Ł; Abe, F; Bennett, D P; Bond, I A; Botzler, C S; Chote, P; Freeman, M; Fukui, A; Furusawa, K; Itow, Y; Kobara, S; Ling, C H; Masuda, K; Matsubara, Y; Miyake, N; Muraki, Y; Ohmori, K; Ohnishi, K; Rattenbury, N J; Saito, To; Sullivan, D J; Suzuki, D; Suzuki, K; Sweatman, W L; Takino, S; Tristram, P J; Wada, K; Yock, P C M; Bramich, D M; Snodgrass, C; Steele, I A; Street, R A; Tsapras, Y; Alsubai, K A; Browne, P; Burgdorf, M J; Novati, S Calchi; Dodds, P; Dreizler, S; Fang, X -S; Grundahl, F; Gu, C -H; Hardis, S; Harpsøe, K; Hinse, T C; Hornstrup, A; Hundertmark, M; Jessen-Hansen, J; Jørgensen, U G; Kains, N; Kerins, E; Liebig, C; Lund, M; Lunkkvist, M; Mancini, L; Mathiasen, M; Penny, M T; Rahvar, S; Ricci, D; Scarpetta, G; Skottfelt, J; Southworth, J; Surdej, J; Tregloan-Reed, J; Wambsganss, J; Wertz, O; Almeida, L A; Batista, V; Christie, G; DePoy, D L; Dong, Subo; Gaudi, B S; Henderson, C; Jablonski, F; Lee, C -U; McCormick, J; McGregor, D; Moorhouse, D; Natusch, T; Ngan, H; Park, S -Y; Pogge, R W; Tan, T -G; Thornley, G; Yee, J C; Albrow, M D; Bachelet, E; Beaulieu, J -P; Brillant, S; Cassan, A; Cole, A A; Corrales, E; Coutures, C; Dieters, S; Prester, D Dominis; Donatowicz, J; Greenhill, J; Kubas, D; Marquette, J -B; Menzies, J W; Sahu, K C; Zub, M

    2012-01-01

    Despite astrophysical importance of binary star systems, detections are limited to those located in small ranges of separations, distances, and masses and thus it is necessary to use a variety of observational techniques for a complete view of stellar multiplicity across a broad range of physical parameters. In this paper, we report the detections and measurements of 2 binaries discovered from observations of microlensing events MOA-2011-BLG-090 and OGLE-2011-BLG-0417. Determinations of the binary masses are possible by simultaneously measuring the Einstein radius and the lens parallax from analyses of the well-resolved caustic-crossing parts of the light curve and the long-term deviation induced by the orbital motion of the Earth around the Sun, respectively. The measured masses of the binary components are 0.43 $M_{\\odot}$ and 0.39 $M_{\\odot}$ for MOA-2011-BLG-090 and 0.57 $M_{\\odot}$ and 0.17 $M_{\\odot}$ for OGLE-2011-BLG-0417 and thus both lens components of MOA-2011-BLG-090 and one component of OGLE-2011...

  9. A study of the electrochemical behavior in tungsten and caustic solutions and platinum/iridium in chloride solutions, informal report

    Energy Technology Data Exchange (ETDEWEB)

    Vitus, C.M.; Isaacs, H.S. [Brookhaven National Lab., Upton, NY (United States); Schroeder, V. [Univ. of California, Berkeley, CA (United States). College of Engineering

    1994-11-22

    Platinum/iridium and tungsten wires were electronically etched in chloride and caustic solution, respectively, to produce tips with high aspect ratio. A direct relationship between the meniscus and the aspect ratio of etched tips was established. Scanning electron micrographs indicated that higher aspect ratios were obtained by changing the geometry of the meniscus during the etch either by an increase in the applied a.c. voltage or with the addition of a nonpolar layer above the electrolytic solution during the etching process. Above the breakdown voltage, two possible mechanisms appeared to control the etching process by expediting chemical dissolution: cavitation and sparking. Cavitation caused erosion due to the force of evolved gases against the electrode and sparking attacked the surface by vaporizing the metal. Sparking commenced on both wires near 24V. This voltage corresponded to a minimum in the plot of total etch time versus voltage. From light emission studies, sparking on Pt/Ir was associated with the ionization of Pt, Ir, Ca, and Cl. A compositional analysis of insoluble black particles produced during a.c. and d.c. etching of Pt/Ir revealed Pt and Ir as the major constituents of the product. The sparking process was shown to have a potential use in micromachining.

  10. Electro chemical studies on stress corrosion cracking of Incoloy-800 in caustic solution, part I: As received samples

    Directory of Open Access Journals (Sweden)

    Dinu Alice

    2005-01-01

    Full Text Available Many non-volatile impurities accidentally introduced into the steam generator tend to Concentrate on its surface in restricted flow areas. In this way these impurities can lead to stress corrosion cracking (SCC on stressed tubes of the steam generator. Such impurities can be strong alkaline or acid solutions. To evaluate the effect of alkaline concentrated environments on SCC of steam generator tubes, the tests were con ducted on stressed samples of Incoloy-800 in 10% NaOH solution. To accelerate the SCC process, stressed specimens were anodically polarised in a caustic solution in an electro chemical cell. The method of stressing of Incoloy-800 tubes used in our experiments was the C-ring. Using the cathodic zone of the potentiodynamic curves it was possible to calculate the most important electrochemical parameters: the corrosion current, the corrosion rate, and the polarization resistance. We found that the value of the corrosion potential to initiate the SCC microcracks was -100 mV. The tested samples were examined using the metallographic method. The main experimental results showed that the in crease of the stress state promoted the in crease of the SCC susceptibility of Incoloy-800 samples tested under the same conditions, and that the length of the SCC-type microcracks in creased with the growth of the stress value.

  11. Experimental Study on Wing Crack Behaviours in Dynamic-Static Superimposed Stress Field Using Caustics and High-Speed Photography

    Directory of Open Access Journals (Sweden)

    L.Y. Yang

    2014-07-01

    Full Text Available During the drill-and-blast progress in rock tunnel excavation of great deep mine, rock fracture is evaluated by both blasting load and pre-exiting earth stress (pre-compression. Many pre-existing flaws in the rock mass, like micro-crack, also seriously affect the rock fracture pattern. Under blasting load with pre-compression, micro-cracks initiate, propagate and grow to be wing cracks. With an autonomous design of static-dynamic loading system, dynamic and static loads were applied on some PMMA plate specimen with pre-existing crack, and the behaviour of the wing crack was tested by caustics corroding with a high-speed photography. Four programs with different static loading modes that generate different pre-compression fields were executed, and the length, velocity of the blasting wing crack and dynamic stress intensity factor (SIF at the wing crack tip were analyzed and discussed. It is found that the behaviour of blasting-induced wing crack is affected obviously by blasting and pre-compression. And pre-compression, which is vertical to the direction of the wing crack propagation, hinders the crack propagation. Furthermore, the boundary constraint condition plays an important role on the behaviour of blasting induced crack during the experiment.

  12. HIERARCHICAL OPTIMIZATION MODEL ON GEONETWORK

    Directory of Open Access Journals (Sweden)

    Z. Zha

    2012-07-01

    Full Text Available In existing construction experience of Spatial Data Infrastructure (SDI, GeoNetwork, as the geographical information integrated solution, is an effective way of building SDI. During GeoNetwork serving as an internet application, several shortcomings are exposed. The first one is that the time consuming of data loading has been considerately increasing with the growth of metadata count. Consequently, the efficiency of query and search service becomes lower. Another problem is that stability and robustness are both ruined since huge amount of metadata. The final flaw is that the requirements of multi-user concurrent accessing based on massive data are not effectively satisfied on the internet. A novel approach, Hierarchical Optimization Model (HOM, is presented to solve the incapability of GeoNetwork working with massive data in this paper. HOM optimizes the GeoNetwork from these aspects: internal procedure, external deployment strategies, etc. This model builds an efficient index for accessing huge metadata and supporting concurrent processes. In this way, the services based on GeoNetwork can maintain stable while running massive metadata. As an experiment, we deployed more than 30 GeoNetwork nodes, and harvest nearly 1.1 million metadata. From the contrast between the HOM-improved software and the original one, the model makes indexing and retrieval processes more quickly and keeps the speed stable on metadata amount increasing. It also shows stable on multi-user concurrent accessing to system services, the experiment achieved good results and proved that our optimization model is efficient and reliable.

  13. Global Considerations in Hierarchical Clustering Reveal Meaningful Patterns in Data

    Science.gov (United States)

    Varshavsky, Roy; Horn, David; Linial, Michal

    2008-01-01

    Background A hierarchy, characterized by tree-like relationships, is a natural method of organizing data in various domains. When considering an unsupervised machine learning routine, such as clustering, a bottom-up hierarchical (BU, agglomerative) algorithm is used as a default and is often the only method applied. Methodology/Principal Findings We show that hierarchical clustering that involve global considerations, such as top-down (TD, divisive), or glocal (global-local) algorithms are better suited to reveal meaningful patterns in the data. This is demonstrated, by testing the correspondence between the results of several algorithms (TD, glocal and BU) and the correct annotations provided by experts. The correspondence was tested in multiple domains including gene expression experiments, stock trade records and functional protein families. The performance of each of the algorithms is evaluated by statistical criteria that are assigned to clusters (nodes of the hierarchy tree) based on expert-labeled data. Whereas TD algorithms perform better on global patterns, BU algorithms perform well and are advantageous when finer granularity of the data is sought. In addition, a novel TD algorithm that is based on genuine density of the data points is presented and is shown to outperform other divisive and agglomerative methods. Application of the algorithm to more than 500 protein sequences belonging to ion-channels illustrates the potential of the method for inferring overlooked functional annotations. ClustTree, a graphical Matlab toolbox for applying various hierarchical clustering algorithms and testing their quality is made available. Conclusions Although currently rarely used, global approaches, in particular, TD or glocal algorithms, should be considered in the exploratory process of clustering. In general, applying unsupervised clustering methods can leverage the quality of manually-created mapping of proteins families. As demonstrated, it can also provide

  14. Application of growing hierarchical SOM for visualisation of network forensics traffic data.

    Science.gov (United States)

    Palomo, E J; North, J; Elizondo, D; Luque, R M; Watson, T

    2012-08-01

    Digital investigation methods are becoming more and more important due to the proliferation of digital crimes and crimes involving digital evidence. Network forensics is a research area that gathers evidence by collecting and analysing network traffic data logs. This analysis can be a difficult process, especially because of the high variability of these attacks and large amount of data. Therefore, software tools that can help with these digital investigations are in great demand. In this paper, a novel approach to analysing and visualising network traffic data based on growing hierarchical self-organising maps (GHSOM) is presented. The self-organising map (SOM) has been shown to be successful for the analysis of highly-dimensional input data in data mining applications as well as for data visualisation in a more intuitive and understandable manner. However, the SOM has some problems related to its static topology and its inability to represent hierarchical relationships in the input data. The GHSOM tries to overcome these limitations by generating a hierarchical architecture that is automatically determined according to the input data and reflects the inherent hierarchical relationships among them. Moreover, the proposed GHSOM has been modified to correctly treat the qualitative features that are present in the traffic data in addition to the quantitative features. Experimental results show that this approach can be very useful for a better understanding of network traffic data, making it easier to search for evidence of attacks or anomalous behaviour in a network environment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Simulating Photon Mapping for Real-time Applications

    DEFF Research Database (Denmark)

    Larsen, Bent Dalgaard; Christensen, Niels Jørgen

    2004-01-01

    This paper introduces a novel method for simulating photon mapping for real-time applications. First we introduce a new method for selectively redistributing photons. Then we describe a method for selectively updating the indirect illumination. The indirect illumination is calculated using a new...... GPU accelerated final gathering method and the illumination is then stored in light maps. Caustic photons are traced on the CPU and then drawn using points in the framebuffer, and finally filtered using the GPU. Both diffuse and non-diffuse surfaces can be handled by calculating the direct...... illumination on the GPU and the photon tracing on the CPU. We achieve real-time frame rates for dynamic scenes....

  16. A hierarchical model of the evolution of human brain specializations.

    Science.gov (United States)

    Barrett, H Clark

    2012-06-26

    The study of information-processing adaptations in the brain is controversial, in part because of disputes about the form such adaptations might take. Many psychologists assume that adaptations come in two kinds, specialized and general-purpose. Specialized mechanisms are typically thought of as innate, domain-specific, and isolated from other brain systems, whereas generalized mechanisms are developmentally plastic, domain-general, and interactive. However, if brain mechanisms evolve through processes of descent with modification, they are likely to be heterogeneous, rather than coming in just two kinds. They are likely to be hierarchically organized, with some design features widely shared across brain systems and others specific to particular processes. Also, they are likely to be largely developmentally plastic and interactive with other brain systems, rather than canalized and isolated. This article presents a hierarchical model of brain specialization, reviewing evidence for the model from evolutionary developmental biology, genetics, brain mapping, and comparative studies. Implications for the search for uniquely human traits are discussed, along with ways in which conventional views of modularity in psychology may need to be revised.

  17. UNCERTAINTY HANDLING IN DISASTER MANAGEMENT USING HIERARCHICAL ROUGH SET GRANULATION

    Directory of Open Access Journals (Sweden)

    H. Sheikhian

    2015-08-01

    Full Text Available Uncertainty is one of the main concerns in geospatial data analysis. It affects different parts of decision making based on such data. In this paper, a new methodology to handle uncertainty for multi-criteria decision making problems is proposed. It integrates hierarchical rough granulation and rule extraction to build an accurate classifier. Rough granulation provides information granules with a detailed quality assessment. The granules are the basis for the rule extraction in granular computing, which applies quality measures on the rules to obtain the best set of classification rules. The proposed methodology is applied to assess seismic physical vulnerability in Tehran. Six effective criteria reflecting building age, height and material, topographic slope and earthquake intensity of the North Tehran fault have been tested. The criteria were discretized and the data set was granulated using a hierarchical rough method, where the best describing granules are determined according to the quality measures. The granules are fed into the granular computing algorithm resulting in classification rules that provide the highest prediction quality. This detailed uncertainty management resulted in 84% accuracy in prediction in a training data set. It was applied next to the whole study area to obtain the seismic vulnerability map of Tehran. A sensitivity analysis proved that earthquake intensity is the most effective criterion in the seismic vulnerability assessment of Tehran.

  18. Architecture of the parallel hierarchical network for fast image recognition

    Science.gov (United States)

    Timchenko, Leonid; Wójcik, Waldemar; Kokriatskaia, Natalia; Kutaev, Yuriy; Ivasyuk, Igor; Kotyra, Andrzej; Smailova, Saule

    2016-09-01

    Multistage integration of visual information in the brain allows humans to respond quickly to most significant stimuli while maintaining their ability to recognize small details in the image. Implementation of this principle in technical systems can lead to more efficient processing procedures. The multistage approach to image processing includes main types of cortical multistage convergence. The input images are mapped into a flexible hierarchy that reflects complexity of image data. Procedures of the temporal image decomposition and hierarchy formation are described in mathematical expressions. The multistage system highlights spatial regularities, which are passed through a number of transformational levels to generate a coded representation of the image that encapsulates a structure on different hierarchical levels in the image. At each processing stage a single output result is computed to allow a quick response of the system. The result is presented as an activity pattern, which can be compared with previously computed patterns on the basis of the closest match. With regard to the forecasting method, its idea lies in the following. In the results synchronization block, network-processed data arrive to the database where a sample of most correlated data is drawn using service parameters of the parallel-hierarchical network.

  19. Hierarchical Compressed Sensing for Cluster Based Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Vishal Krishna Singh

    2016-02-01

    Full Text Available Data transmission consumes significant amount of energy in large scale wireless sensor networks (WSNs. In such an environment, reducing the in-network communication and distributing the load evenly over the network can reduce the overall energy consumption and maximize the network lifetime significantly. In this work, the aforementioned problem of network lifetime and uneven energy consumption in large scale wireless sensor networks is addressed. This work proposes a hierarchical compressed sensing (HCS scheme to reduce the in-network communication during the data gathering process. Co-related sensor readings are collected via a hierarchical clustering scheme. A compressed sensing (CS based data processing scheme is devised to transmit the data from the source to the sink. The proposed HCS is able to identify the optimal position for the application of CS to achieve reduced and similar number of transmissions on all the nodes in the network. An activity map is generated to validate the reduced and uniformly distributed communication load of the WSN. Based on the number of transmissions per data gathering round, the bit-hop metric model is used to analyse the overall energy consumption. Simulation results validate the efficiency of the proposed method over the existing CS based approaches.

  20. Hybrid Iterative Scheme for Triple Hierarchical Variational Inequalities with Mixed Equilibrium, Variational Inclusion, and Minimization Constraints

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available We introduce and analyze a hybrid iterative algorithm by combining Korpelevich's extragradient method, the hybrid steepest-descent method, and the averaged mapping approach to the gradient-projection algorithm. It is proven that, under appropriate assumptions, the proposed algorithm converges strongly to a common element of the fixed point set of finitely many nonexpansive mappings, the solution set of a generalized mixed equilibrium problem (GMEP, the solution set of finitely many variational inclusions, and the solution set of a convex minimization problem (CMP, which is also a unique solution of a triple hierarchical variational inequality (THVI in a real Hilbert space. In addition, we also consider the application of the proposed algorithm to solving a hierarchical variational inequality problem with constraints of the GMEP, the CMP, and finitely many variational inclusions.

  1. Limitations of Passively Mapping Logical Network Topologies

    Directory of Open Access Journals (Sweden)

    Ayodeji J. Akande

    2017-02-01

    Full Text Available Understanding logical network connectivity is essential in network topology mapping especially in a fast growing network where knowing what is happening on the network is critical for security purposes and where knowing how network resources are being used is highly important. Mapping logical communication topology is important for network auditing, network maintenance and governance, network optimization, and network security. However, the process of capturing network traffic to generate the logical network topology may have a great influence on the operation of the network. In hierarchically structured networks such as control systems, typical active network mapping techniques are not employable as they can affect time-sensitive cyber-physical processes, hence, passive network mapping is required. Though passive network mapping does not modify or disrupt existing traffic, current passive mapping techniques ignore many practical issues when used to generate logical communication topologies. In this paper, we present a methodology which compares topologies from an idealized mapping process with what is actually achievable using passive network mapping and identify some of the factors that can cause inaccuracies in logical maps derived from passively monitored network traffic. We illustrate these factors using a case study involving a hierarchical control network.

  2. Hierarchical linear regression models for conditional quantiles

    Institute of Scientific and Technical Information of China (English)

    TIAN Maozai; CHEN Gemai

    2006-01-01

    The quantile regression has several useful features and therefore is gradually developing into a comprehensive approach to the statistical analysis of linear and nonlinear response models,but it cannot deal effectively with the data with a hierarchical structure.In practice,the existence of such data hierarchies is neither accidental nor ignorable,it is a common phenomenon.To ignore this hierarchical data structure risks overlooking the importance of group effects,and may also render many of the traditional statistical analysis techniques used for studying data relationships invalid.On the other hand,the hierarchical models take a hierarchical data structure into account and have also many applications in statistics,ranging from overdispersion to constructing min-max estimators.However,the hierarchical models are virtually the mean regression,therefore,they cannot be used to characterize the entire conditional distribution of a dependent variable given high-dimensional covariates.Furthermore,the estimated coefficient vector (marginal effects)is sensitive to an outlier observation on the dependent variable.In this article,a new approach,which is based on the Gauss-Seidel iteration and taking a full advantage of the quantile regression and hierarchical models,is developed.On the theoretical front,we also consider the asymptotic properties of the new method,obtaining the simple conditions for an n1/2-convergence and an asymptotic normality.We also illustrate the use of the technique with the real educational data which is hierarchical and how the results can be explained.

  3. QHNS: QoS-aware Hierarchical Name System

    Directory of Open Access Journals (Sweden)

    Fuhong Lin

    2011-10-01

    Full Text Available Naming and name resolution mapping are playing extremely important roles in Internet applications. Currently, naming is constructed by the combination of the location of host and the location of resource in the host, and name resolution mapping system is constructed by a tree-like domain name system (DNS. To overcome the shortcomings of DNS, such as not supporting data migration and replication, vulnerable to Denial of Service (DoS attacks and not supporting quality of service (QoS, researchers have proposed a DHT-based flat structure to achieve naming and name resolution mapping. This system deals with the shortcomings of DNS above very well except supporting QoS, but it introduces a new problem that the resolution time cost is so large that users often can not tolerate this long delay. In this paper, we present an improved structure called QoS-aware Hierarchical Name System (QHNS by combining the advantages of DNS and DHT. The architecture of QHNS is a two-layer’s structure, namely top-layer which maintains the global information and bottom-layer which maintains local information. Owning to the location information, the resolution delay is greatly reduced while the shortcomings of DNS have been eliminated. And this design can also can do well with the shortcomings of the above two approaches that they can not provide QoS. Finally, theoretical analysis and numerical experiments show that our system is feasible in the practical use.

  4. Spatial Bayesian hierarchical modelling of extreme sea states

    Science.gov (United States)

    Clancy, Colm; O'Sullivan, John; Sweeney, Conor; Dias, Frédéric; Parnell, Andrew C.

    2016-11-01

    A Bayesian hierarchical framework is used to model extreme sea states, incorporating a latent spatial process to more effectively capture the spatial variation of the extremes. The model is applied to a 34-year hindcast of significant wave height off the west coast of Ireland. The generalised Pareto distribution is fitted to declustered peaks over a threshold given by the 99.8th percentile of the data. Return levels of significant wave height are computed and compared against those from a model based on the commonly-used maximum likelihood inference method. The Bayesian spatial model produces smoother maps of return levels. Furthermore, this approach greatly reduces the uncertainty in the estimates, thus providing information on extremes which is more useful for practical applications.

  5. Hierarchically Clustered Star Formation in the Magellanic Clouds

    CERN Document Server

    Gouliermis, Dimitrios A; Ossenkopf, Volker; Klessen, Ralf S; Dolphin, Andrew E

    2012-01-01

    We present a cluster analysis of the bright main-sequence and faint pre--main-sequence stellar populations of a field ~ 90 x 90 pc centered on the HII region NGC 346/N66 in the Small Magellanic Cloud, from imaging with HST/ACS. We extend our earlier analysis on the stellar cluster population in the region to characterize the structuring behavior of young stars in the region as a whole with the use of stellar density maps interpreted through techniques designed for the study of the ISM structuring. In particular, we demonstrate with Cartwrigth & Whitworth's Q parameter, dendrograms, and the Delta-variance wavelet transform technique that the young stellar populations in the region NGC 346/N66 are hierarchically clustered, in agreement with other regions in the Magellanic Clouds observed with HST. The origin of this hierarchy is currently under investigation.

  6. [A medical image semantic modeling based on hierarchical Bayesian networks].

    Science.gov (United States)

    Lin, Chunyi; Ma, Lihong; Yin, Junxun; Chen, Jianyu

    2009-04-01

    A semantic modeling approach for medical image semantic retrieval based on hierarchical Bayesian networks was proposed, in allusion to characters of medical images. It used GMM (Gaussian mixture models) to map low-level image features into object semantics with probabilities, then it captured high-level semantics through fusing these object semantics using a Bayesian network, so that it built a multi-layer medical image semantic model, aiming to enable automatic image annotation and semantic retrieval by using various keywords at different semantic levels. As for the validity of this method, we have built a multi-level semantic model from a small set of astrocytoma MRI (magnetic resonance imaging) samples, in order to extract semantics of astrocytoma in malignant degree. Experiment results show that this is a superior approach.

  7. Hierarchical CodeBook for background subtraction in MRF

    Science.gov (United States)

    Shao, Quan; Tang, Zhixing; Han, Songchen

    2013-11-01

    Foreground detection is the key low-level fundamental work in intelligent video surveillance. This paper proposed a hierarchical background subtraction algorithm consisted of block-based stage and pixel-based stage for it. In block-based stage, obvious backgrounds got detected via block-based CodeBook, leaving spatial relations among suspicious foreground pixels undestroyed. Pixel-based stage further eliminated the left background pixels with the introduction of spatial and temporal relations in a MRF-MAP framework. Then comparative experiments were conducted to evaluate the performance of the scheme in three dimensions - detection accuracy, update speed and memory consumption. Proposed approach possesses the highest detection precision and consumes the second least memories. And the update speed is of real-time level.

  8. Real-time Global Illumination by Simulating Photon Mapping

    DEFF Research Database (Denmark)

    Larsen, Bent Dalgaard

    2004-01-01

    This thesis introduces a new method for simulating photon mapping in realtime. The method uses a variety of both CPU and GPU based algorithms for speeding up the different elements in global illumination. The idea behind the method is to calculate each illumination element individually in a progr......This thesis introduces a new method for simulating photon mapping in realtime. The method uses a variety of both CPU and GPU based algorithms for speeding up the different elements in global illumination. The idea behind the method is to calculate each illumination element individually...... in a progressive and efficient manner. This has been done by analyzing the photon mapping method and by selecting efficient methods, either CPU based or GPU based, which replaces the original photon mapping algorithms. We have chosen to focus on the indirect illumination and the caustics. In our method we first...... divide the photon map into several photon maps in order to make local updates possible. Then indirect illumination is added using light maps that are selectively updated by using selective photon tracing on the CPU. The final gathering step is calculated by using fragment programs and GPU based...

  9. SOFM Neural Network Based Hierarchical Topology Control for Wireless Sensor Networks

    OpenAIRE

    2014-01-01

    Well-designed network topology provides vital support for routing, data fusion, and target tracking in wireless sensor networks (WSNs). Self-organization feature map (SOFM) neural network is a major branch of artificial neural networks, which has self-organizing and self-learning features. In this paper, we propose a cluster-based topology control algorithm for WSNs, named SOFMHTC, which uses SOFM neural network to form a hierarchical network structure, completes cluster head selection by the...

  10. Julia sets and complex singularities in diamond-like hierarchical Potts models

    Institute of Scientific and Technical Information of China (English)

    QIAO; Jianyong

    2005-01-01

    We study the phase transition of the Potts model on diamond-like hierarchical lattices. It is shown that the set of the complex singularities is the Julia set of a rational mapping. An interesting problem is how are these singularities continued to the complex plane. In this paper, by the method of complex dynamics, we give a complete description about the connectivity of the set of the complex singularities.

  11. Hierarchical Temporal Memory Based on Spin-Neurons and Resistive Memory for Energy-Efficient Brain-Inspired Computing

    OpenAIRE

    Fan, Deliang; Sharad, Mrigank; Sengupta, Abhronil; Roy, Kaushik

    2014-01-01

    Hierarchical temporal memory (HTM) tries to mimic the computing in cerebral-neocortex. It identifies spatial and temporal patterns in the input for making inferences. This may require large number of computationally expensive tasks like, dot-product evaluations. Nano-devices that can provide direct mapping for such primitives are of great interest. In this work we show that the computing blocks for HTM can be mapped using low-voltage, fast-switching, magneto-metallic spin-neurons combined wit...

  12. Self-assembled biomimetic superhydrophobic hierarchical arrays.

    Science.gov (United States)

    Yang, Hongta; Dou, Xuan; Fang, Yin; Jiang, Peng

    2013-09-01

    Here, we report a simple and inexpensive bottom-up technology for fabricating superhydrophobic coatings with hierarchical micro-/nano-structures, which are inspired by the binary periodic structure found on the superhydrophobic compound eyes of some insects (e.g., mosquitoes and moths). Binary colloidal arrays consisting of exemplary large (4 and 30 μm) and small (300 nm) silica spheres are first assembled by a scalable Langmuir-Blodgett (LB) technology in a layer-by-layer manner. After surface modification with fluorosilanes, the self-assembled hierarchical particle arrays become superhydrophobic with an apparent water contact angle (CA) larger than 150°. The throughput of the resulting superhydrophobic coatings with hierarchical structures can be significantly improved by templating the binary periodic structures of the LB-assembled colloidal arrays into UV-curable fluoropolymers by a soft lithography approach. Superhydrophobic perfluoroether acrylate hierarchical arrays with large CAs and small CA hysteresis can be faithfully replicated onto various substrates. Both experiments and theoretical calculations based on the Cassie's dewetting model demonstrate the importance of the hierarchical structure in achieving the final superhydrophobic surface states. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Analysis hierarchical model for discrete event systems

    Science.gov (United States)

    Ciortea, E. M.

    2015-11-01

    The This paper presents the hierarchical model based on discrete event network for robotic systems. Based on the hierarchical approach, Petri network is analysed as a network of the highest conceptual level and the lowest level of local control. For modelling and control of complex robotic systems using extended Petri nets. Such a system is structured, controlled and analysed in this paper by using Visual Object Net ++ package that is relatively simple and easy to use, and the results are shown as representations easy to interpret. The hierarchical structure of the robotic system is implemented on computers analysed using specialized programs. Implementation of hierarchical model discrete event systems, as a real-time operating system on a computer network connected via a serial bus is possible, where each computer is dedicated to local and Petri model of a subsystem global robotic system. Since Petri models are simplified to apply general computers, analysis, modelling, complex manufacturing systems control can be achieved using Petri nets. Discrete event systems is a pragmatic tool for modelling industrial systems. For system modelling using Petri nets because we have our system where discrete event. To highlight the auxiliary time Petri model using transport stream divided into hierarchical levels and sections are analysed successively. Proposed robotic system simulation using timed Petri, offers the opportunity to view the robotic time. Application of goods or robotic and transmission times obtained by measuring spot is obtained graphics showing the average time for transport activity, using the parameters sets of finished products. individually.

  14. Hierarchical models and chaotic spin glasses

    Science.gov (United States)

    Berker, A. Nihat; McKay, Susan R.

    1984-09-01

    Renormalization-group studies in position space have led to the discovery of hierarchical models which are exactly solvable, exhibiting nonclassical critical behavior at finite temperature. Position-space renormalization-group approximations that had been widely and successfully used are in fact alternatively applicable as exact solutions of hierarchical models, this realizability guaranteeing important physical requirements. For example, a hierarchized version of the Sierpiriski gasket is presented, corresponding to a renormalization-group approximation which has quantitatively yielded the multicritical phase diagrams of submonolayers on graphite. Hierarchical models are now being studied directly as a testing ground for new concepts. For example, with the introduction of frustration, chaotic renormalization-group trajectories were obtained for the first time. Thus, strong and weak correlations are randomly intermingled at successive length scales, and a new microscopic picture and mechanism for a spin glass emerges. An upper critical dimension occurs via a boundary crisis mechanism in cluster-hierarchical variants developed to have well-behaved susceptibilities.

  15. A Mirroring Theorem and its Application to a New Method of Unsupervised Hierarchical Pattern Classification

    Directory of Open Access Journals (Sweden)

    Dasika Ratna Deepthi

    2009-10-01

    Full Text Available In this paper, we prove a crucial theorem called “Mirroring Theorem” which affirms that given a collection of samples with enough information in it such that it can be classified into classes and sub-classes then (i There exists a mapping which classifies and subclassifies these samples (ii There exists a hierarchical classifier which can be constructed by using Mirroring Neural Networks (MNNs in combination with a clustering algorithm that can approximate this mapping. Thus, the proof of the Mirroring theorem provides a theoretical basis for the existence and a practical feasibility of constructing hierarchical classifiers, given the maps. Our proposed Mirroring Theorem can also be considered as an extension to Kolmogrov’s theorem in providing a realistic solution for unsupervised classification. The techniques we develop, are general in nature and have led to the construction of learning machines which are (i tree like in structure, (ii modular (iii with each module running on a common algorithm (tandem algorithm and (iv self-supervised. We have actually built the architecture, developed the tandem algorithm of such a hierarchical classifier and demonstrated it on an example problem.

  16. Review:A survey of photon mapping state-of-the-art research and future challenges

    Institute of Scientific and Technical Information of China (English)

    Chun-meng KANG; Lu WANG; Yan-ning XU; Xiang-xu MENG

    2016-01-01

    Global illumination is the core part of photo-realistic rendering. The photon mapping algorithm is an effective method for computing global illumination with its obvious advantage of caustic and color bleeding rendering. It is an active research fi eld that has been developed over the past two decades. The defi ciency of precise details and efficient rendering are still the main challenges of photon mapping. This report reviews recent work and classifi es it into a set of categories including radiance estimation, photon relaxation, photon tracing, progressive photon mapping, and parallel methods. The goals of our report are giving readers an overall introduction to photon mapping and motivating further research to address the limitations of existing methods.

  17. Final Report: Caustic Waste-Soil Weathering Reactions and Their Impacts on Trace Contaminant Migration and Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    O' Day, Peggy A.; Chorover, J.; Mueller, K.T.; Serne, R.J.

    2006-12-11

    The principal goal of this project was to assess the molecular nature and stability of radionuclide (137-Cs, 90-Sr, and 129-I) immobilization during weathering reactions in bulk Hanford sediments and their high surface area clay mineral constituents. We focused on the unique aqueous geochemical conditions that are representative of waste-impacted locations in the Hanford site vadose zone: high ionic strength, high pH and high Al concentrations. The specific objectives of the work were to (i) measure the coupling of clay mineral weathering and contaminant uptake kinetics of Cs+, Sr2+ and I-; (ii) determine the molecular structure of contaminant binding sites and their change with weathering time during and after exposure to synthetic tank waste leachate (STWL); (iii) establish the stability of neoformed weathering products and their sequestered contaminants upon exposure of the solids to more “natural” soil solutions (i.e., after removal of the caustic waste source); and (iv) integrate macroscopic, microscopic and spectroscopic data to distinguish labile from non-labile contaminant binding environments, including their dependence on system composition and weathering time. During this funding period, we completed a large set of bench-scale collaborative experiments and product characterization aimed at elucidating the coupling between mineral transformation reactions and contaminant sequestration/stabilization. Our experiments included three representative Hanford sediments: course and fine sediments collected from the Hanford Formation and Ringold Silt, in addition to investigations with specimen clay minerals illite, vermiculite, smectite and kaolinite. These experiments combined macroscopic measurements of element release, contaminant uptake and subsequent neoformed mineral dissolution behavior, with detailed studies of solid phase products using SEM and TEM microscopy, NMR, XAS and FTIR spectroscopy. Our studies have shown direct coupling between mineral

  18. Irradiation Effects on Phase-Separation Performance Using a Centrifugal Contactor in a Caustic-Side Solvent Extraction Process

    Energy Technology Data Exchange (ETDEWEB)

    Birdwell, J.F.

    2001-09-12

    A test program has been conducted to determine the extent to which irradiation of a calixarene-based cesium extractant affects-separation of the organic (solvent) phase from aqueous solutions with which it is contacted in a prototype extraction flowsheet. A caustic-side solvent extraction process, known as CSSX, has been developed for the selective removal of cesium from wastes generated by the processing of irradiated nuclear reactor fuels. This process consists of a cascade of mass transfer stages in which cesium is transferred from an aqueous feed into the CSSX extractant (BOBCalixC6), the extract is scrubbed with 0.05 M nitric acid to remove coextracted elements, and the solvated cesium is stripped (or back-extracted) into 0.001 M HNO{sub 3}. Removal of cesium from stored waste supernatants is desirable as a means of segregating high-activity cesium-137 ({sup 137}Cs) from the solution, thereby reducing the volume of material that must be processed and disposed of as high-level waste. The CSSX process is one of three cesium removal technologies currently being considered for deployment for treatment of wastes that are stored at the U. S. Department of Energy's (USDOE's) Savannah River Site (SRS). The irradiation tests described in this report were designed to simulate the effect of 2 years of continuous solvent irradiation under conditions present in the stripping and extraction sections of the CSSX cascade. Stated simply, the irradiation tests consisted of continuously mixing an aqueous process solution (either simulated SRS waste supernatant or dilute nitric acid) with the CSSX solvent. The aqueous solutions used in testing were spiked with {sup 137}Cs at known activity levels. Test durations were determined based on the activity levels in the experiment and the estimated solvent exposures to radionuclides in a full-scale CSSX facility.

  19. Biased trapping issue on weighted hierarchical networks

    Indian Academy of Sciences (India)

    Meifeng Dai; Jie Liu; Feng Zhu

    2014-10-01

    In this paper, we present trapping issues of weight-dependent walks on weighted hierarchical networks which are based on the classic scale-free hierarchical networks. Assuming that edge’s weight is used as local information by a random walker, we introduce a biased walk. The biased walk is that a walker, at each step, chooses one of its neighbours with a probability proportional to the weight of the edge. We focus on a particular case with the immobile trap positioned at the hub node which has the largest degree in the weighted hierarchical networks. Using a method based on generating functions, we determine explicitly the mean first-passage time (MFPT) for the trapping issue. Let parameter (0 < < 1) be the weight factor. We show that the efficiency of the trapping process depends on the parameter a; the smaller the value of a, the more efficient is the trapping process.

  20. Improving broadcast channel rate using hierarchical modulation

    CERN Document Server

    Meric, Hugo; Arnal, Fabrice; Lesthievent, Guy; Boucheret, Marie-Laure

    2011-01-01

    We investigate the design of a broadcast system where the aim is to maximise the throughput. This task is usually challenging due to the channel variability. Forty years ago, Cover introduced and compared two schemes: time sharing and superposition coding. The second scheme was proved to be optimal for some channels. Modern satellite communications systems such as DVB-SH and DVB-S2 mainly rely on time sharing strategy to optimize throughput. They consider hierarchical modulation, a practical implementation of superposition coding, but only for unequal error protection or backward compatibility purposes. We propose in this article to combine time sharing and hierarchical modulation together and show how this scheme can improve the performance in terms of available rate. We present the gain on a simple channel modeling the broadcasting area of a satellite. Our work is applied to the DVB-SH standard, which considers hierarchical modulation as an optional feature.

  1. Incentive Mechanisms for Hierarchical Spectrum Markets

    CERN Document Server

    Iosifidis, George; Alpcan, Tansu; Koutsopoulos, Iordanis

    2011-01-01

    We study spectrum allocation mechanisms in hierarchical multi-layer markets which are expected to proliferate in the near future based on the current spectrum policy reform proposals. We consider a setting where a state agency sells spectrum to Primary Operators (POs) and in turn these resell it to Secondary Operators (SOs) through auctions. We show that these hierarchical markets do not result in a socially efficient spectrum allocation which is aimed by the agency, due to lack of coordination among the entities in different layers and the inherently selfish revenue-maximizing strategy of POs. In order to reconcile these opposing objectives, we propose an incentive mechanism which aligns the strategy and the actions of the POs with the objective of the agency, and thus it leads to system performance improvement in terms of social welfare. This pricing based mechanism constitutes a method for hierarchical market regulation and requires the feedback provision from SOs. A basic component of the proposed incenti...

  2. Hierarchical self-organization of tectonic plates

    CERN Document Server

    Morra, Gabriele; Müller, R Dietmar

    2010-01-01

    The Earth's surface is subdivided into eight large tectonic plates and many smaller ones. We reconstruct the plate tessellation history and demonstrate that both large and small plates display two distinct hierarchical patterns, described by different power-law size-relationships. While small plates display little organisational change through time, the structure of the large plates oscillate between minimum and maximum hierarchical tessellations. The organization of large plates rapidly changes from a weak hierarchy at 120-100 million years ago (Ma) towards a strong hierarchy, which peaked at 65-50, Ma subsequently relaxing back towards a minimum hierarchical structure. We suggest that this fluctuation reflects an alternation between top and bottom driven plate tectonics, revealing a previously undiscovered tectonic cyclicity at a timescale of 100 million years.

  3. Towards a sustainable manufacture of hierarchical zeolites.

    Science.gov (United States)

    Verboekend, Danny; Pérez-Ramírez, Javier

    2014-03-01

    Hierarchical zeolites have been established as a superior type of aluminosilicate catalysts compared to their conventional (purely microporous) counterparts. An impressive array of bottom-up and top-down approaches has been developed during the last decade to design and subsequently exploit these exciting materials catalytically. However, the sustainability of the developed synthetic methods has rarely been addressed. This paper highlights important criteria to ensure the ecological and economic viability of the manufacture of hierarchical zeolites. Moreover, by using base leaching as a promising case study, we verify a variety of approaches to increase reactor productivity, recycle waste streams, prevent the combustion of organic compounds, and minimize separation efforts. By reducing their synthetic footprint, hierarchical zeolites are positioned as an integral part of sustainable chemistry. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Classification using Hierarchical Naive Bayes models

    DEFF Research Database (Denmark)

    Langseth, Helge; Dyhre Nielsen, Thomas

    2006-01-01

    Classification problems have a long history in the machine learning literature. One of the simplest, and yet most consistently well-performing set of classifiers is the Naïve Bayes models. However, an inherent problem with these classifiers is the assumption that all attributes used to describe...... an instance are conditionally independent given the class of that instance. When this assumption is violated (which is often the case in practice) it can reduce classification accuracy due to “information double-counting” and interaction omission. In this paper we focus on a relatively new set of models......, termed Hierarchical Naïve Bayes models. Hierarchical Naïve Bayes models extend the modeling flexibility of Naïve Bayes models by introducing latent variables to relax some of the independence statements in these models. We propose a simple algorithm for learning Hierarchical Naïve Bayes models...

  5. Hierarchical Neural Network Structures for Phoneme Recognition

    CERN Document Server

    Vasquez, Daniel; Minker, Wolfgang

    2013-01-01

    In this book, hierarchical structures based on neural networks are investigated for automatic speech recognition. These structures are evaluated on the phoneme recognition task where a  Hybrid Hidden Markov Model/Artificial Neural Network paradigm is used. The baseline hierarchical scheme consists of two levels each which is based on a Multilayered Perceptron. Additionally, the output of the first level serves as a second level input. The computational speed of the phoneme recognizer can be substantially increased by removing redundant information still contained at the first level output. Several techniques based on temporal and phonetic criteria have been investigated to remove this redundant information. The computational time could be reduced by 57% whilst keeping the system accuracy comparable to the baseline hierarchical approach.

  6. Universal hierarchical behavior of citation networks

    CERN Document Server

    Mones, Enys; Vicsek, Tamás

    2014-01-01

    Many of the essential features of the evolution of scientific research are imprinted in the structure of citation networks. Connections in these networks imply information about the transfer of knowledge among papers, or in other words, edges describe the impact of papers on other publications. This inherent meaning of the edges infers that citation networks can exhibit hierarchical features, that is typical of networks based on decision-making. In this paper, we investigate the hierarchical structure of citation networks consisting of papers in the same field. We find that the majority of the networks follow a universal trend towards a highly hierarchical state, and i) the various fields display differences only concerning their phase in life (distance from the "birth" of a field) or ii) the characteristic time according to which they are approaching the stationary state. We also show by a simple argument that the alterations in the behavior are related to and can be understood by the degree of specializatio...

  7. Static and dynamic friction of hierarchical surfaces

    Science.gov (United States)

    Costagliola, Gianluca; Bosia, Federico; Pugno, Nicola M.

    2016-12-01

    Hierarchical structures are very common in nature, but only recently have they been systematically studied in materials science, in order to understand the specific effects they can have on the mechanical properties of various systems. Structural hierarchy provides a way to tune and optimize macroscopic mechanical properties starting from simple base constituents and new materials are nowadays designed exploiting this possibility. This can be true also in the field of tribology. In this paper we study the effect of hierarchical patterned surfaces on the static and dynamic friction coefficients of an elastic material. Our results are obtained by means of numerical simulations using a one-dimensional spring-block model, which has previously been used to investigate various aspects of friction. Despite the simplicity of the model, we highlight some possible mechanisms that explain how hierarchical structures can significantly modify the friction coefficients of a material, providing a means to achieve tunability.

  8. Variability of surfer circulation and Kuroshio intrusion in northern South China Sea using growing hierarchical self-organizing maps%应用GHSOM网络分析南海北部表层环流模态与黑潮入侵

    Institute of Scientific and Technical Information of China (English)

    徐晓华; 廖光洪; 杨成浩; 袁耀初; 黄韦艮

    2013-01-01

    基于1992年10月至2009年11月卫星观测的海表高度(SSH)时间序列数据,应用增长型分级自组织映射(GHSOM)人工神经网络方法研究南海北部和西太平洋 SSH和中尺度涡旋的变化,识别出该海域 SSH的季节和年际变化信号。分析表明,流经吕宋海峡的黑潮分支在冷季入侵南海北部,同时在吕宋岛西北海域出现一个强烈的气旋式涡旋,表层黑潮的入侵与跨过吕宋海峡南北的经向压力梯度密切相关。黑潮的非入侵事件主要出现在暖季。春秋季节作为两个事件的过渡期,环流结构复杂,由 GHSOM的第2层特征图进一步进行分类识别。黑潮入侵事件和非入侵事件发生的百分比分别为24.57%和27.53%,过渡模态的百分比为47.87%。当入侵南海事件发生时,南海北部表层环流流态相对简单,主要为气旋环流控制南海北部,吕宋海峡表层海流是否入侵南海,与南海北部中尺度涡旋特别是吕宋岛西北的气旋式涡的变化关系密切;反之,在非入侵事件发生时,南海北部出现多涡结构,环流流态复杂,表明吕宋海峡海流入侵南海对南海北部环流也有重要调整作用。除季节尺度变化外,年际时间尺度变化信号也十分显著。在1994-1995、1997-1998和2002-2003年期间,表层黑潮入侵南海北部的事件要显著多于其他年份,然而入侵事件在1998-2001年和2006-2009年时间段明显减少,非入侵事件增加。应用欧氏距离定义的模态2的时间发展序列与Niño3.4指数序列延迟相关。%Sea surface height (SSH) variations and eddies on both sides of the Luzon Strait are examined from the merged satellite altimeter data from October 1992 to November 2009. The neural network analyses based on the growing hierarchical self-organizing map (GHSOM) are used to extract feature patterns of the circulation variability. The evolution of the characteristic circulation patterns

  9. Genetic Mapping

    Science.gov (United States)

    ... Fact Sheets Fact Sheets En Español: Mapeo Genético Genetic Mapping What is genetic mapping? How do researchers create ... genetic map? What are genetic markers? What is genetic mapping? Among the main goals of the Human Genome ...

  10. Terapia nutricional en pacientes adultos con quemaduras del tracto gastrointestinal por cáusticos Nutrition therapy for adult patients with caustic injuries to gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    N. A. Muñoz Botero

    2010-04-01

    Full Text Available Objetivos: Presentar la experiencia del Grupo de Terapia Nutricional del Hospital El Tunal, en el manejo nutricional de pacientes adultos con quemaduras por cáusticos del tracto gastrointestinal. Materiales y métodos: Es un estudio retrospectivo, descriptivo de pacientes manejados por el Grupo de Terapia Nutricional por quemaduras por cáusticos del tracto gastrointestinal en un periodo comprendido entre Enero de 2000 y Diciembre de 2007. Se revisaron las historias clínicas de los pacientes que tenían diagnóstico de quemaduras por cáusticos. Se analizaron los datos pertinentes al manejo nutricional, la evolución y el resultado final dedichos pacientes. Resultados: Se atendieron 30 pacientes, 17 hombres y 13 mujeres con edad promedio 34,4 ± 17,2 años. La ingesta del cáustico fue por intento de suicidio en 22 (73,3% pacientes y accidental en 8 (26,7%. La mortalidad global fue alta (43,3%. El 46,9% de los pacientes mostró perdida de peso y balance nitrogenado negativo el 62,5%. Diez y siete pacientes (53,12% recibieron nutrición mixta (enteral y/o parenteral por un tiempo promedio de 24 ± 22 días. Al comparar dos grupos clasificados como quemadura del TGI Grave vs Moderada se encontró que fue significativamente diferente la mortalidad, la estancia hospitalaria y el valor final de albúmina. Conclusiones: La quemadura del tracto gastrointestinal por cáusticos es una entidad poco frecuente, sucede principalmente en jóvenes por intento de suicidio y se asocia a alta mortalidad, sobre todo en quemaduras graves. Esta agresión lleva a catabolismo importante que produce balance nitrogenado negativo y perdida de peso. Estos pacientes requieren intervención nutricional temprana que puede extenderse por varios meses.Objectives: To present here the experience of our Nutrition Therapy Team of the Hospital El Tunal, for the nutritional management of adult patients with caustic injuries to gastrointestinal tract. Materials and methods: This is

  11. MOC - HEALPix Multi-Order Coverage map Version 1.0

    CERN Document Server

    Fernique, Pierre; Donaldson, Tom; Durand, Daniel; O'Mullane, Wil; Reinecke, Martin; Taylor, Mark

    2015-01-01

    This document describes the Multi-Order Coverage map method (MOC) to specify arbitrary sky regions. The goal is to be able to provide a very fast comparison mechanism between coverage maps. The mechanism is based on the HEALPix sky tessellation algorithm. It is essentially a simple way to map regions of the sky into hierarchically grouped predefined cells.

  12. Hierarchical control of electron-transfer

    DEFF Research Database (Denmark)

    Westerhoff, Hans V.; Jensen, Peter Ruhdal; Egger, Louis;

    1997-01-01

    In this chapter the role of electron transfer in determining the behaviour of the ATP synthesising enzyme in E. coli is analysed. It is concluded that the latter enzyme lacks control because of special properties of the electron transfer components. These properties range from absence of a strong...... back pressure by the protonmotive force on the rate of electron transfer to hierarchical regulation of the expression of the gens that encode the electron transfer proteins as a response to changes in the bioenergetic properties of the cell.The discussion uses Hierarchical Control Analysis...

  13. Genetic Algorithm for Hierarchical Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sajid Hussain

    2007-09-01

    Full Text Available Large scale wireless sensor networks (WSNs can be used for various pervasive and ubiquitous applications such as security, health-care, industry automation, agriculture, environment and habitat monitoring. As hierarchical clusters can reduce the energy consumption requirements for WSNs, we investigate intelligent techniques for cluster formation and management. A genetic algorithm (GA is used to create energy efficient clusters for data dissemination in wireless sensor networks. The simulation results show that the proposed intelligent hierarchical clustering technique can extend the network lifetime for different network deployment environments.

  14. DC Hierarchical Control System for Microgrid Applications

    OpenAIRE

    Lu, Xiaonan; Sun, Kai; Guerrero, Josep M.; Huang, Lipei

    2013-01-01

    In order to enhance the DC side performance of AC-DC hybrid microgrid,a DC hierarchical control system is proposed in this paper.To meet the requirement of DC load sharing between the parallel power interfaces,droop method is adopted.Meanwhile,DC voltage secondary control is employed to restore the deviation in the DC bus voltage.The hierarchical control system is composed of two levels.DC voltage and AC current controllers are achieved in the primary control level.

  15. Hierarchical social networks and information flow

    Science.gov (United States)

    López, Luis; F. F. Mendes, Jose; Sanjuán, Miguel A. F.

    2002-12-01

    Using a simple model for the information flow on social networks, we show that the traditional hierarchical topologies frequently used by companies and organizations, are poorly designed in terms of efficiency. Moreover, we prove that this type of structures are the result of the individual aim of monopolizing as much information as possible within the network. As the information is an appropriate measurement of centrality, we conclude that this kind of topology is so attractive for leaders, because the global influence each actor has within the network is completely determined by the hierarchical level occupied.

  16. Analyzing security protocols in hierarchical networks

    DEFF Research Database (Denmark)

    Zhang, Ye; Nielson, Hanne Riis

    2006-01-01

    Validating security protocols is a well-known hard problem even in a simple setting of a single global network. But a real network often consists of, besides the public-accessed part, several sub-networks and thereby forms a hierarchical structure. In this paper we first present a process calculus...... capturing the characteristics of hierarchical networks and describe the behavior of protocols on such networks. We then develop a static analysis to automate the validation. Finally we demonstrate how the technique can benefit the protocol development and the design of network systems by presenting a series...

  17. Hierarchic Models of Turbulence, Superfluidity and Superconductivity

    CERN Document Server

    Kaivarainen, A

    2000-01-01

    New models of Turbulence, Superfluidity and Superconductivity, based on new Hierarchic theory, general for liquids and solids (physics/0102086), have been proposed. CONTENTS: 1 Turbulence. General description; 2 Mesoscopic mechanism of turbulence; 3 Superfluidity. General description; 4 Mesoscopic scenario of fluidity; 5 Superfluidity as a hierarchic self-organization process; 6 Superfluidity in 3He; 7 Superconductivity: General properties of metals and semiconductors; Plasma oscillations; Cyclotron resonance; Electroconductivity; 8. Microscopic theory of superconductivity (BCS); 9. Mesoscopic scenario of superconductivity: Interpretation of experimental data in the framework of mesoscopic model of superconductivity.

  18. Hierarchical Analysis of the Omega Ontology

    Energy Technology Data Exchange (ETDEWEB)

    Joslyn, Cliff A.; Paulson, Patrick R.

    2009-12-01

    Initial delivery for mathematical analysis of the Omega Ontology. We provide an analysis of the hierarchical structure of a version of the Omega Ontology currently in use within the US Government. After providing an initial statistical analysis of the distribution of all link types in the ontology, we then provide a detailed order theoretical analysis of each of the four main hierarchical links present. This order theoretical analysis includes the distribution of components and their properties, their parent/child and multiple inheritance structure, and the distribution of their vertical ranks.

  19. Concept Maps

    OpenAIRE

    Schwendimann, Beat Adrian

    2014-01-01

    A concept map is a node-link diagram showing the semantic relationships among concepts. The technique for constructing concept maps is called "concept mapping". A concept map consists of nodes, arrows as linking lines, and linking phrases that describe the relationship between nodes. Two nodes connected with a labeled arrow are called a proposition. Concept maps are versatile graphic organizers that can represent many different forms of relationships between concepts. The relationship between...

  20. [Evaluating risk of health disorders in workers engaged into polyvinyl chloride, vinyl chloride and caustic soda production (according to data collected by polls)].

    Science.gov (United States)

    D'iakovich, O A

    2014-01-01

    The authors represent data of automated system for quantitative risk evaluation of main pathologic syndromes in workers engaged into polyvinyl chloride, vinyl chloride and caustic soda production. Vinyl chloride and mercury levels at the investigation time corresponded with MAC. Relationship was seen between value of arterial hypertension risk and duration of contact with both vinyl chloride and mercury. Risk values for functional disorders of liver, endocrine system and nervous system were in weak correlation with length of exposure to mercury at work. Workers exposed to mercury appeared to have lower self-estimation of health state and higher dissatisfaction with the work.

  1. The Syntax Model of Mobile Maps Generation

    Directory of Open Access Journals (Sweden)

    TIAN Jiangpeng

    2016-11-01

    Full Text Available Using the method of formal language (FL, the syntax model of mobile map generation is studied. The syntax model is located in the level of logical calculus of map generation based on the analysis of its process. Combined the hierarchical and recursive characteristics of map representation, the simplest form of syntax structure is abstracted as carto-lexicons and syntax-rules. The classification system of carto-lexicons is established as well as the model of the spatial relation predicate system, and the map operation rules and rules of different levels of syntactic units are discussed. The compilation process and key techniques of the syntax model are discussed, and the feasibility of the model is verified through mobile maps generation experiment. The essence of the model is a kind of formal language grammar, which uses finite rules and lexicons to generate maps automatically, as well as a kind of high-level cartography interface of human-computer interactive.

  2. Application of oxidative technique for organic matter remove from a petroleum refinery spent caustic stream; Aplicacao de tecnicas oxidativas para a remocao do teor de materia organica de uma corrente de soda gasta de refinaria de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcante, Aline M.; Sant' Anna Junior, Geraldo L.; Dezzotti, Marcia [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Quimica

    2004-07-01

    Spent caustic is a hazardous wastewater produced in several petroleum refineries. After the specific treatment for toxicity reduction, performed in the industrial site, this stream still presents high organic matter content. Thus, many times a further treatment is required. In this work, the removal of dissolved organic carbon (DOC) from the spent caustic stream, previously submitted to wet air oxidation (WAO), was investigated. This softening process is required to reduce the impact of the spent caustic effluent on the downstream industrial wastewater biological treatment plant. Among the softening techniques tested, Fenton and photo-Fenton processes were the most efficient. The combination of these processes led to 49% of DOC removal in time intervals of 85 min, using molars ratios H{sub 2}O{sub 2}/DOC=1.34 and H{sub 2}O{sub 2}/Fe{sup 2+}=10. (author)

  3. Hierarchical machining materials and their performance

    DEFF Research Database (Denmark)

    Sidorenko, Daria; Loginov, Pavel; Levashov, Evgeny

    2016-01-01

    as nanoparticles in the binder, or polycrystalline, aggregate-like reinforcements, also at several scale levels). Such materials can ensure better productivity, efficiency, and lower costs of drilling, cutting, grinding, and other technological processes. This article reviews the main groups of hierarchical...

  4. Hierarchical Optimization of Material and Structure

    DEFF Research Database (Denmark)

    Rodrigues, Helder C.; Guedes, Jose M.; Bendsøe, Martin P.

    2002-01-01

    This paper describes a hierarchical computational procedure for optimizing material distribution as well as the local material properties of mechanical elements. The local properties are designed using a topology design approach, leading to single scale microstructures, which may be restricted...... in various ways, based on design and manufacturing criteria. Implementation issues are also discussed and computational results illustrate the nature of the procedure....

  5. Hierarchical structure of nanofibers by bubbfil spinning

    Directory of Open Access Journals (Sweden)

    Liu Chang

    2015-01-01

    Full Text Available A polymer bubble is easy to be broken under a small external force, various different fragments are formed, which can be produced to different morphologies of products including nanofibers and plate-like strip. Polyvinyl-alcohol/honey solution is used in the experiment to show hierarchical structure by the bubbfil spinning.

  6. Sharing the proceeds from a hierarchical venture

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moreno-Ternero, Juan D.; Tvede, Mich;

    2017-01-01

    We consider the problem of distributing the proceeds generated from a joint venture in which the participating agents are hierarchically organized. We introduce and characterize a family of allocation rules where revenue ‘bubbles up’ in the hierarchy. The family is flexible enough to accommodate...

  7. Metal oxide nanostructures with hierarchical morphology

    Science.gov (United States)

    Ren, Zhifeng; Lao, Jing Yu; Banerjee, Debasish

    2007-11-13

    The present invention relates generally to metal oxide materials with varied symmetrical nanostructure morphologies. In particular, the present invention provides metal oxide materials comprising one or more metallic oxides with three-dimensionally ordered nanostructural morphologies, including hierarchical morphologies. The present invention also provides methods for producing such metal oxide materials.

  8. Hierarchical Scaling in Systems of Natural Cities

    CERN Document Server

    Chen, Yanguang

    2016-01-01

    Hierarchies can be modeled by a set of exponential functions, from which we can derive a set of power laws indicative of scaling. These scaling laws are followed by many natural and social phenomena such as cities, earthquakes, and rivers. This paper is devoted to revealing the scaling patterns in systems of natural cities by reconstructing the hierarchy with cascade structure. The cities of America, Britain, France, and Germany are taken as examples to make empirical analyses. The hierarchical scaling relations can be well fitted to the data points within the scaling ranges of the size and area of the natural cities. The size-number and area-number scaling exponents are close to 1, and the allometric scaling exponent is slightly less than 1. The results suggest that natural cities follow hierarchical scaling laws and hierarchical conservation law. Zipf's law proved to be one of the indications of the hierarchical scaling, and the primate law of city-size distribution represents a local pattern and can be mer...

  9. Semiparametric Quantile Modelling of Hierarchical Data

    Institute of Scientific and Technical Information of China (English)

    Mao Zai TIAN; Man Lai TANG; Ping Shing CHAN

    2009-01-01

    The classic hierarchical linear model formulation provides a considerable flexibility for modelling the random effects structure and a powerful tool for analyzing nested data that arise in various areas such as biology, economics and education. However, it assumes the within-group errors to be independently and identically distributed (i.i.d.) and models at all levels to be linear. Most importantly, traditional hierarchical models (just like other ordinary mean regression methods) cannot characterize the entire conditional distribution of a dependent variable given a set of covariates and fail to yield robust estimators. In this article, we relax the aforementioned and normality assumptions, and develop a so-called Hierarchical Semiparametric Quantile Regression Models in which the within-group errors could be heteroscedastic and models at some levels are allowed to be nonparametric. We present the ideas with a 2-level model. The level-l model is specified as a nonparametric model whereas level-2 model is set as a parametric model. Under the proposed semiparametric setting the vector of partial derivatives of the nonparametric function in level-1 becomes the response variable vector in level 2. The proposed method allows us to model the fixed effects in the innermost level (i.e., level 2) as a function of the covariates instead of a constant effect. We outline some mild regularity conditions required for convergence and asymptotic normality for our estimators. We illustrate our methodology with a real hierarchical data set from a laboratory study and some simulation studies.

  10. Hierarchical Context Modeling for Video Event Recognition.

    Science.gov (United States)

    Wang, Xiaoyang; Ji, Qiang

    2016-10-11

    Current video event recognition research remains largely target-centered. For real-world surveillance videos, targetcentered event recognition faces great challenges due to large intra-class target variation, limited image resolution, and poor detection and tracking results. To mitigate these challenges, we introduced a context-augmented video event recognition approach. Specifically, we explicitly capture different types of contexts from three levels including image level, semantic level, and prior level. At the image level, we introduce two types of contextual features including the appearance context features and interaction context features to capture the appearance of context objects and their interactions with the target objects. At the semantic level, we propose a deep model based on deep Boltzmann machine to learn event object representations and their interactions. At the prior level, we utilize two types of prior-level contexts including scene priming and dynamic cueing. Finally, we introduce a hierarchical context model that systematically integrates the contextual information at different levels. Through the hierarchical context model, contexts at different levels jointly contribute to the event recognition. We evaluate the hierarchical context model for event recognition on benchmark surveillance video datasets. Results show that incorporating contexts in each level can improve event recognition performance, and jointly integrating three levels of contexts through our hierarchical model achieves the best performance.

  11. Managing Clustered Data Using Hierarchical Linear Modeling

    Science.gov (United States)

    Warne, Russell T.; Li, Yan; McKyer, E. Lisako J.; Condie, Rachel; Diep, Cassandra S.; Murano, Peter S.

    2012-01-01

    Researchers in nutrition research often use cluster or multistage sampling to gather participants for their studies. These sampling methods often produce violations of the assumption of data independence that most traditional statistics share. Hierarchical linear modeling is a statistical method that can overcome violations of the independence…

  12. Strategic games on a hierarchical network model

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Among complex network models, the hierarchical network model is the one most close to such real networks as world trade web, metabolic network, WWW, actor network, and so on. It has not only the property of power-law degree distribution, but growth based on growth and preferential attachment, showing the scale-free degree distribution property. In this paper, we study the evolution of cooperation on a hierarchical network model, adopting the prisoner's dilemma (PD) game and snowdrift game (SG) as metaphors of the interplay between connected nodes. BA model provides a unifying framework for the emergence of cooperation. But interestingly, we found that on hierarchical model, there is no sign of cooperation for PD game, while the frequency of cooperation decreases as the common benefit decreases for SG. By comparing the scaling clustering coefficient properties of the hierarchical network model with that of BA model, we found that the former amplifies the effect of hubs. Considering different performances of PD game and SG on complex network, we also found that common benefit leads to cooperation in the evolution. Thus our study may shed light on the emergence of cooperation in both natural and social environments.

  13. Endogenous Effort Norms in Hierarchical Firms

    NARCIS (Netherlands)

    J. Tichem (Jan)

    2013-01-01

    markdownabstract__Abstract__ This paper studies how a three-layer hierarchical firm (principal-supervisor-agent) optimally creates effort norms for its employees. The key assumption is that effort norms are affected by the example of superiors. In equilibrium, norms are eroded as one moves down

  14. Complex Evaluation of Hierarchically-Network Systems

    CERN Document Server

    Polishchuk, Dmytro; Yadzhak, Mykhailo

    2016-01-01

    Methods of complex evaluation based on local, forecasting, aggregated, and interactive evaluation of the state, function quality, and interaction of complex system's objects on the all hierarchical levels is proposed. Examples of analysis of the structural elements of railway transport system are used for illustration of efficiency of proposed approach.

  15. A Hierarchical Grouping of Great Educators

    Science.gov (United States)

    Barker, Donald G.

    1977-01-01

    Great educators of history were categorized on the basis of their: aims of education, fundamental ideas, and educational theories. They were classed by Ward's method of hierarchical analysis into six groupings: Socrates, Ausonius, Jerome, Abelard; Quintilian, Origen, Melanchthon, Ascham, Loyola; Alciun, Comenius; Vittorino, Basedow, Pestalozzi,…

  16. Ultrafast Hierarchical OTDM/WDM Network

    Directory of Open Access Journals (Sweden)

    Hideyuki Sotobayashi

    2003-12-01

    Full Text Available Ultrafast hierarchical OTDM/WDM network is proposed for the future core-network. We review its enabling technologies: C- and L-wavelength-band generation, OTDM-WDM mutual multiplexing format conversions, and ultrafast OTDM wavelengthband conversions.

  17. Hierarchical fuzzy identification of MR damper

    Science.gov (United States)

    Wang, Hao; Hu, Haiyan

    2009-07-01

    Magneto-rheological (MR) dampers, recently, have found many successful applications in civil engineering and numerous area of mechanical engineering. When an MR damper is to be used for vibration suppression, an inevitable problem is to determine the input voltage so as to gain the desired restoring force determined from the control law. This is the so-called inverse problem of MR dampers and is always an obstacle in the application of MR dampers to vibration control. It is extremely difficult to get the inverse model of MR damper because MR dampers are highly nonlinear and hysteretic. When identifying the inverse model of MR damper with simple fuzzy system, there maybe exists curse of dimensionality of fuzzy system. Therefore, it will take much more time, and even the inverse model may not be identifiable. The paper presents two-layer hierarchical fuzzy system, that is, two-layer hierarchical ANFIS to deal with the curse of dimensionality of the fuzzy identification of MR damper and to identify the inverse model of MR damper. Data used for training the model are generated from numerical simulation of nonlinear differential equations. The numerical simulation proves that the proposed hierarchical fuzzy system can model the inverse model of MR damper much more quickly than simple fuzzy system without any reduction of identification precision. Such hierarchical ANFIS shows the higher priority for the complicated system, and can also be used in system identification and system control for the complicated system.

  18. Statistical theory of hierarchical avalanche ensemble

    OpenAIRE

    Olemskoi, Alexander I.

    1999-01-01

    The statistical ensemble of avalanche intensities is considered to investigate diffusion in ultrametric space of hierarchically subordinated avalanches. The stationary intensity distribution and the steady-state current are obtained. The critical avalanche intensity needed to initiate the global avalanche formation is calculated depending on noise intensity. The large time asymptotic for the probability of the global avalanche appearance is derived.

  19. Managing Clustered Data Using Hierarchical Linear Modeling

    Science.gov (United States)

    Warne, Russell T.; Li, Yan; McKyer, E. Lisako J.; Condie, Rachel; Diep, Cassandra S.; Murano, Peter S.

    2012-01-01

    Researchers in nutrition research often use cluster or multistage sampling to gather participants for their studies. These sampling methods often produce violations of the assumption of data independence that most traditional statistics share. Hierarchical linear modeling is a statistical method that can overcome violations of the independence…

  20. Equivalence Checking of Hierarchical Combinational Circuits

    DEFF Research Database (Denmark)

    Williams, Poul Frederick; Hulgaard, Henrik; Andersen, Henrik Reif

    1999-01-01

    This paper presents a method for verifying that two hierarchical combinational circuits implement the same Boolean functions. The key new feature of the method is its ability to exploit the modularity of circuits to reuse results obtained from one part of the circuits in other parts. We demonstrate...... our method on large adder and multiplier circuits....

  1. Hierarchical Linear Models for Energy Prediction using Inertial Sensors: A Comparative Study for Treadmill Walking.

    Science.gov (United States)

    Vathsangam, Harshvardhan; Emken, B Adar; Schroeder, E Todd; Spruijt-Metz, Donna; Sukhatme, Gaurav S

    2013-12-01

    Walking is a commonly available activity to maintain a healthy lifestyle. Accurately tracking and measuring calories expended during walking can improve user feedback and intervention measures. Inertial sensors are a promising measurement tool to achieve this purpose. An important aspect in mapping inertial sensor data to energy expenditure is the question of normalizing across physiological parameters. Common approaches such as weight scaling require validation for each new population. An alternative is to use a hierarchical approach to model subject-specific parameters at one level and cross-subject parameters connected by physiological variables at a higher level. In this paper, we evaluate an inertial sensor-based hierarchical model to measure energy expenditure across a target population. We first determine the optimal movement and physiological features set to represent data. Periodicity based features are more accurate (phierarchical model with a subject-specific regression model and weight exponent scaled models. Subject-specific models perform significantly better (pmodels at all exponent scales whereas the hierarchical model performed worse than both. However, using an informed prior from the hierarchical model produces similar errors to using a subject-specific model with large amounts of training data (phierarchical modeling is a promising technique for generalized prediction energy expenditure prediction across a target population in a clinical setting.

  2. Multilevel compression of random walks on networks reveals hierarchical organization in large integrated systems.

    Directory of Open Access Journals (Sweden)

    Martin Rosvall

    Full Text Available To comprehend the hierarchical organization of large integrated systems, we introduce the hierarchical map equation, which reveals multilevel structures in networks. In this information-theoretic approach, we exploit the duality between compression and pattern detection; by compressing a description of a random walker as a proxy for real flow on a network, we find regularities in the network that induce this system-wide flow. Finding the shortest multilevel description of the random walker therefore gives us the best hierarchical clustering of the network--the optimal number of levels and modular partition at each level--with respect to the dynamics on the network. With a novel search algorithm, we extract and illustrate the rich multilevel organization of several large social and biological networks. For example, from the global air traffic network we uncover countries and continents, and from the pattern of scientific communication we reveal more than 100 scientific fields organized in four major disciplines: life sciences, physical sciences, ecology and earth sciences, and social sciences. In general, we find shallow hierarchical structures in globally interconnected systems, such as neural networks, and rich multilevel organizations in systems with highly separated regions, such as road networks.

  3. Hierarchical sparse coding in the sensory system of Caenorhabditis elegans.

    Science.gov (United States)

    Zaslaver, Alon; Liani, Idan; Shtangel, Oshrat; Ginzburg, Shira; Yee, Lisa; Sternberg, Paul W

    2015-01-27

    Animals with compact sensory systems face an encoding problem where a small number of sensory neurons are required to encode information about its surrounding complex environment. Using Caenorhabditis elegans worms as a model, we ask how chemical stimuli are encoded by a small and highly connected sensory system. We first generated a comprehensive library of transgenic worms where each animal expresses a genetically encoded calcium indicator in individual sensory neurons. This library includes the vast majority of the sensory system in C. elegans. Imaging from individual sensory neurons while subjecting the worms to various stimuli allowed us to compile a comprehensive functional map of the sensory system at single neuron resolution. The functional map reveals that despite the dense wiring, chemosensory neurons represent the environment using sparse codes. Moreover, although anatomically closely connected, chemo- and mechano-sensory neurons are functionally segregated. In addition, the code is hierarchical, where few neurons participate in encoding multiple cues, whereas other sensory neurons are stimulus specific. This encoding strategy may have evolved to mitigate the constraints of a compact sensory system.

  4. Hierarchical Star Formation across the ring galaxy NGC 6503

    CERN Document Server

    Gouliermis, Dimitrios A; Elmegreen, Bruce G; Elmegreen, Debra M; Calzetti, Daniela; Lee, Janice C; Adamo, Angela; Aloisi, Alessandra; Cignoni, Michele; Cook, David O; Dale, Daniel; Gallagher, John S; Grasha, Kathryn; Grebel, Eva K; Davo, Artemio Herrero; Hunter, Deidre A; Johnson, Kelsey E; Kim, Hwihyun; Nair, Preethi; Nota, Antonella; Pellerin, Anne; Ryon, Jenna; Sabbi, Elena; Sacchi, Elena; Smith, Linda J; Tosi, Monica; Ubeda, Leonardo; Whitmore, Brad

    2015-01-01

    We present a detailed clustering analysis of the young stellar population across the star-forming ring galaxy NGC 6503, based on the deep HST photometry obtained with the Legacy ExtraGalactic UV Survey (LEGUS). We apply a contour-based map analysis technique and identify in the stellar surface density map 244 distinct star-forming structures at various levels of significance. These stellar complexes are found to be organized in a hierarchical fashion with 95% being members of three dominant super-structures located along the star-forming ring. The size distribution of the identified structures and the correlation between their radii and numbers of stellar members show power-law behaviors, as expected from scale-free processes. The self-similar distribution of young stars is further quantified from their autocorrelation function, with a fractal dimension of ~1.7 for length-scales between ~20 pc and 2.5 kpc. The young stellar radial distribution sets the extent of the star-forming ring at radial distances betwe...

  5. Generic hierarchical engine for mask data preparation

    Science.gov (United States)

    Kalus, Christian K.; Roessl, Wolfgang; Schnitker, Uwe; Simecek, Michal

    2002-07-01

    Electronic layouts are usually flattened on their path from the hierarchical source downstream to the wafer. Mask data preparation has certainly been identified as a severe bottleneck since long. Data volumes are not only doubling every year along the ITRS roadmap. With the advent of optical proximity correction and phase-shifting masks data volumes are escalating up to non-manageable heights. Hierarchical treatment is one of the most powerful means to keep memory and CPU consumption in reasonable ranges. Only recently, however, has this technique acquired more public attention. Mask data preparation is the most critical area calling for a sound infrastructure to reduce the handling problem. Gaining more and more attention though, are other applications such as large area simulation and manufacturing rule checking (MRC). They all would profit from a generic engine capable to efficiently treat hierarchical data. In this paper we will present a generic engine for hierarchical treatment which solves the major problem, steady transitions along cell borders. Several alternatives exist how to walk through the hierarchy tree. They have, to date, not been thoroughly investigated. One is a bottom-up attempt to treat cells starting with the most elementary cells. The other one is a top-down approach which lends itself to creating a new hierarchy tree. In addition, since the variety, degree of hierarchy and quality of layouts extends over a wide range a generic engine has to take intelligent decisions when exploding the hierarchy tree. Several applications will be shown, in particular how far the limits can be pushed with the current hierarchical engine.

  6. Hierarchical organisation in perception of orientation.

    Science.gov (United States)

    Spinelli, D; Antonucci, G; Daini, R; Martelli, M L; Zoccolotti, P

    1999-01-01

    According to Rock [1990, in The Legacy of Solomon Asch (Hillsdale, NJ: Lawrence Erlbaum Associates)], hierarchical organisation of perception describes cases in which the orientation of an object is affected by the immediately surrounding elements in the visual field. Various experiments were performed to study the hierarchical organisation of orientation perception. In most of them the rod-and-frame-illusion (RFI: change of the apparent vertical measured on a central rod surrounded by a tilted frame) was measured in the presence/absence of a second inner frame. The first three experiments showed that, when the inner frame is vertical, the direction and size of the illusion are consistent with expectancies based on the hierarchical organisation hypothesis. An analysis of published and unpublished data collected on a large number of subjects showed that orientational hierarchical effects are independent from the absolute size of the RFI. In experiments 4 to 7 we examined the perceptual conditions of the inner stimulus (enclosure, orientation, and presence of luminance borders) critical for obtaining a hierarchical organisation effect. Although an inner vertical square was effective in reducing the illusion (experiment 3), an inner circle enclosing the rod was ineffective (experiment 4). This indicates that definite orientation is necessary to modulate the illusion. However, orientational information provided by a vertical or horizontal rectangle presented near the rod, but not enclosing it, did not modulate the RFI (experiment 5). This suggests that the presence of a figure with oriented contours enclosing the rod is critical. In experiments 6 and 7 we studied whether the presence of luminance borders is important or whether the inner upright square might be effective also if made of subjective contours. When the subjective contour figure was salient and the observers perceived it clearly, its effectiveness in modulating the RFI was comparable to that observed with

  7. Stability of the Caustic-Side Solvent Extraction (CSSX) Process Solvent: Effect of High Nitrite on Solvent Nitration

    Energy Technology Data Exchange (ETDEWEB)

    Bonnesen, P.V.

    2002-06-26

    The purpose of this investigation was to determine whether nitrated organic compounds could be formed during operation of the Caustic-Side Solvent Extraction (CSSX) process, and whether such compounds would present a safety concern. The CSSX process was developed to remove cesium from alkaline high-level salt waste stored at the US Department of Energy Savannah River Site (SRS). The solvent is composed of the cesium extractant calix[4]arene-bis-(4-tert-octylbenzo-crown-6) (BOBCalixC6), a fluorinated alcohol phase modifier, tri-n-octylamine (TOA), and an isoparaffinic diluent (Iospar{reg_sign}). During the CSSX process, the solvent is expected to be exposed to high concentrations of nitrate and nitrite dissolved in the alkaline waste feed. The solvent will also be exposed to dilute (50 mM) nitric acid solutions containing low concentrations of nitrite during scrubbing, followed by stripping with 1 mM nitric acid. The solvent is expected to last for one year of plant operation, and the temperatures the solvent may experience during the process could range from as low as 15 C to as high as 35 C. Excursions from standard process conditions could result in the solvent experiencing higher temperatures, as well as concentrations of nitrate, nitrite, and most importantly nitric acid, that exceed normal operating conditions. Accordingly, conditions may exist where nitration reactions involving the solvent components, possibly leading to other chemical reactions stemming from nitration reactions, could occur. To model such nitration reactions, the solvent was exposed to the types of nitrate- and nitrite-containing solutions that might be expected to be encountered during the process (even under off-normal conditions), as a function of time, temperature, and concentration of nitrate, nitrite, and nitric acid. The experiments conducted as part of this report were designed to examine the more specific effect that high nitrite concentrations could have on forming nitrated

  8. Curious case of gravitational lensing by binary black holes: A tale of two photon spheres, new relativistic images, and caustics

    Science.gov (United States)

    Patil, Mandar; Mishra, Priti; Narasimha, D.

    2017-01-01

    Binary black holes have been in the limelight of late due to the detection of gravitational waves from coalescing compact binaries in the events GW150914 and GW151226. In this paper we study gravitational lensing by the binary black holes modeled as an equal mass Majumdar-Papapetrou dihole metric and show that this system displays features that are quite unprecedented and absent in any other lensing configuration investigated so far in the literature. We restrict our attention to the light rays which move on the plane midway between the two identical black holes, which allows us to employ various techniques developed for the equatorial lensing in the spherically symmetric spacetimes. If distance between the two black holes is below a certain threshold value, then the system admits two photon spheres. As in the case of a single black hole, infinitely many relativistic images are formed due to the light rays which turn back from the region outside the outer (unstable) photon sphere, all of which lie beyond a critical angular radius with respect to the lens. However, in the presence of the inner (stable) photon sphere, the effective potential after admitting minimum turns upwards and blows up for the smaller values of radii and the light rays that enter the outer photon sphere can turn back, leading to the formation of a new set of infinitely many relativistic images, all of which lie below the critical radius from the lens mentioned above. As the distance between the two black holes is increased, two photon spheres approach one another, merge and eventually disappear. In the absence of the photon sphere, apart from the formation of a finite number of discrete relativistic images, the system remarkably admits a radial caustic, which has never been observed in the context of relativistic lensing before. Thus the system of the binary black hole admits novel features both in the presence and absence of photon spheres. We discuss possible observational signatures and

  9. A general strategy to determine the congruence between a hierarchical and a non-hierarchical classification

    Directory of Open Access Journals (Sweden)

    Marín Ignacio

    2007-11-01

    Full Text Available Abstract Background Classification procedures are widely used in phylogenetic inference, the analysis of expression profiles, the study of biological networks, etc. Many algorithms have been proposed to establish the similarity between two different classifications of the same elements. However, methods to determine significant coincidences between hierarchical and non-hierarchical partitions are still poorly developed, in spite of the fact that the search for such coincidences is implicit in many analyses of massive data. Results We describe a novel strategy to compare a hierarchical and a dichotomic non-hierarchical classification of elements, in order to find clusters in a hierarchical tree in which elements of a given "flat" partition are overrepresented. The key improvement of our strategy respect to previous methods is using permutation analyses of ranked clusters to determine whether regions of the dendrograms present a significant enrichment. We show that this method is more sensitive than previously developed strategies and how it can be applied to several real cases, including microarray and interactome data. Particularly, we use it to compare a hierarchical representation of the yeast mitochondrial interactome and a catalogue of known mitochondrial protein complexes, demonstrating a high level of congruence between those two classifications. We also discuss extensions of this method to other cases which are conceptually related. Conclusion Our method is highly sensitive and outperforms previously described strategies. A PERL script that implements it is available at http://www.uv.es/~genomica/treetracker.

  10. Harm of superheated steam to caustic soda evaporation and coutermeasures against it%过热蒸汽对烧碱蒸发的危害及对策

    Institute of Scientific and Technical Information of China (English)

    贺续安; 莫春阳

    2001-01-01

    The harm of super heated steam to caustic soda evaporation wasanalysed. The special methods to increase humidity of steam and decrease its temprature were introduced. Good results were achieved, which included consumption of steam was reduced from 5.1 t/t to 3.8 t/t so that about ten thousand tons of steam can be saved per year and expences of over 0.5 million RMB ¥/a could be reduced, output of caustic soda was increased largely and running condition was improved. Some problems still need to be solved.%概述了过热蒸汽对烧碱蒸发的危害,和采取特殊方式的增湿减温措施取得的良好效果:汽耗由5.1t/t降到3.8t/t,节汽约1万t/a,节约资金50万元/a,产量得到很大提高,使烧碱的运行状态得到改善。但仍存在一定问题尚需改进。

  11. Extraction of Zinc from Electric Arc Furnace Dust by Alkaline Leaching Followed by Fusion of the Leaching Residue with Caustic Soda

    Institute of Scientific and Technical Information of China (English)

    赵由才; R.Stanforth

    2004-01-01

    Extractability of zinc from two types of electric arc furnace (EAF) dusts containing 24.8% and 16.8% of zinc respectively (denoted as Sample A and Sample B) were tested using direct alkaline leaching followed by fusion of the resulting leaching residues with caustic soda. The experimental results show that the extraction of zinc is heavily dependent on the contents of iron in the dusts. The higher iron content, the lower extraction of zinc is obtained. 53% and 38% of zinc can be extracted when both dusts were directly contacted with 5mol·L-1 NaOH solution for 42h. The remaining zinc left in the leaching residues, which supposed to be present as zinc ferrites, can be further leached when the residues were fused with caustic soda. Quantitative extraction of zinc can be obtained from the leaching residue of Sample A while only 85% from Sample B. The extractability of zinc from dusts wit hvarious contents of iron is compared. The production flowsheet for zinc from the dusts using the process proposed is discussed.

  12. 麦草氨法制浆工艺及动力学%Pulping of Wheat Straw with Caustic Potash-Ammonia Aqueous Solutions and Its Kinetics

    Institute of Scientific and Technical Information of China (English)

    黄国林; 张成芳; 陈中胜

    2006-01-01

    A pulping technology of wheat straw with aqueous ammonia and diluent caustic potash was investigated.Because its strong alkalinity, the addition of caustic potash not only reduced the quantity of NH3 consumed and cooking time, but also enriched the black liquor with nutrients such as potassium and nitrogen, which could be used as fertilizer for agriculture. Various pulping conditions including composition of cooking liquor, liquor-to-solid ratio,maximum cooking temperature, time to reach the maximum temperature and time at the maximum temperature were studied systematically to determine the suitable pulping conditions. Results of the cooking course showed that there were three distinct delignification phases, namely, the bulk delignification phase from the beginning of cooking to 100 ℃, the supplementary delignification phase from 100 ℃ to 155 ℃ for 45min and the third delignification phase till the end of cooking. The rate of delignification was found to be first order with respect to residual lignin and 0.34 order with respect to [OH-]. The activation energy of the delignification reaction was 29.75 kJ·mol-1 and the rate equation of delignification was also obtained.

  13. Efficient Hierarchical Algorithm for Mixed Mode Placement in Three Dimensional Integrated Circuit Chip Designs

    Institute of Scientific and Technical Information of China (English)

    YAN Haixia; ZHOU Qiang; HONG Xianlong; LI Zhuoyuan

    2009-01-01

    Hierarchical art was used to solve the mixed mode placement for three dimensional (3-D) inte-grated circuit design. The 3-D placement flow stream includes hierarchical clustering, hierarchical 3-D floor-planning, vertical via mapping, and recursive two dimensional (2-D) global/detailed placement phases. With state-of-the-art clustering and de-clustering phases, the design complexity was reduced to enhance the placement algorithm efficiency and capacity. The 3-D floorplanning phase solved the layer assignment problem and controlled the number of vertical vias. The vertical via mapping transformed the 3-D placement problem to a set of 2-D placement sub-problems, which not only simplifies the original 3-D placement prob-lem, but also generates the vertical via assignment solution for the routing phase. The design optimizes both the wire length and the thermal load in the floorplan and placement phases to improve the performance and reliability of 3-D integrate circuits. Experiments on IBM benchmarks show that the total wire length is reduced from 15% to 35% relative to 2-D placement with two to four stacked layers, with the number of vertical vias minimized to satisfy a pre-defined upper bound constraint. The maximum temperature is reduced by 16% with two-stage optimization on four stacked layers.

  14. Map Projection

    CERN Document Server

    Ghaderpour, Ebrahim

    2014-01-01

    In this paper, we introduce some known map projections from a model of the Earth to a flat sheet of paper or map and derive the plotting equations for these projections. The first fundamental form and the Gaussian fundamental quantities are defined and applied to obtain the plotting equations and distortions in length, shape and size for some of these map projections.

  15. On the geostatistical characterization of hierarchical media

    Science.gov (United States)

    Neuman, Shlomo P.; Riva, Monica; Guadagnini, Alberto

    2008-02-01

    The subsurface consists of porous and fractured materials exhibiting a hierarchical geologic structure, which gives rise to systematic and random spatial and directional variations in hydraulic and transport properties on a multiplicity of scales. Traditional geostatistical moment analysis allows one to infer the spatial covariance structure of such hierarchical, multiscale geologic materials on the basis of numerous measurements on a given support scale across a domain or "window" of a given length scale. The resultant sample variogram often appears to fit a stationary variogram model with constant variance (sill) and integral (spatial correlation) scale. In fact, some authors, who recognize that hierarchical sedimentary architecture and associated log hydraulic conductivity fields tend to be nonstationary, nevertheless associate them with stationary "exponential-like" transition probabilities and variograms, respectively, the latter being a consequence of the former. We propose that (1) the apparent ability of stationary spatial statistics to characterize the covariance structure of nonstationary hierarchical media is an artifact stemming from the finite size of the windows within which geologic and hydrologic variables are ubiquitously sampled, and (2) the artifact is eliminated upon characterizing the covariance structure of such media with the aid of truncated power variograms, which represent stationary random fields obtained upon sampling a nonstationary fractal over finite windows. To support our opinion, we note that truncated power variograms arise formally when a hierarchical medium is sampled jointly across all geologic categories and scales within a window; cite direct evidence that geostatistical parameters (variance and integral scale) inferred on the basis of traditional variograms vary systematically with support and window scales; demonstrate the ability of truncated power models to capture these variations in terms of a few scaling parameters

  16. Topographic mapping

    Science.gov (United States)

    ,

    2008-01-01

    The U.S. Geological Survey (USGS) produced its first topographic map in 1879, the same year it was established. Today, more than 100 years and millions of map copies later, topographic mapping is still a central activity for the USGS. The topographic map remains an indispensable tool for government, science, industry, and leisure. Much has changed since early topographers traveled the unsettled West and carefully plotted the first USGS maps by hand. Advances in survey techniques, instrumentation, and design and printing technologies, as well as the use of aerial photography and satellite data, have dramatically improved mapping coverage, accuracy, and efficiency. Yet cartography, the art and science of mapping, may never before have undergone change more profound than today.

  17. Application of hierarchical matrices for partial inverse

    KAUST Repository

    Litvinenko, Alexander

    2013-11-26

    In this work we combine hierarchical matrix techniques (Hackbusch, 1999) and domain decomposition methods to obtain fast and efficient algorithms for the solution of multiscale problems. This combination results in the hierarchical domain decomposition (HDD) method, which can be applied for solution multi-scale problems. Multiscale problems are problems that require the use of different length scales. Using only the finest scale is very expensive, if not impossible, in computational time and memory. Domain decomposition methods decompose the complete problem into smaller systems of equations corresponding to boundary value problems in subdomains. Then fast solvers can be applied to each subdomain. Subproblems in subdomains are independent, much smaller and require less computational resources as the initial problem.

  18. First-passage phenomena in hierarchical networks

    CERN Document Server

    Tavani, Flavia

    2016-01-01

    In this paper we study Markov processes and related first passage problems on a class of weighted, modular graphs which generalize the Dyson hierarchical model. In these networks, the coupling strength between two nodes depends on their distance and is modulated by a parameter $\\sigma$. We find that, in the thermodynamic limit, ergodicity is lost and the "distant" nodes can not be reached. Moreover, for finite-sized systems, there exists a threshold value for $\\sigma$ such that, when $\\sigma$ is relatively large, the inhomogeneity of the coupling pattern prevails and "distant" nodes are hardly reached. The same analysis is carried on also for generic hierarchical graphs, where interactions are meant to involve $p$-plets ($p>2$) of nodes, finding that ergodicity is still broken in the thermodynamic limit, but no threshold value for $\\sigma$ is evidenced, ultimately due to a slow growth of the network diameter with the size.

  19. An Hierarchical Approach to Big Data

    CERN Document Server

    Allen, M G; Boch, T; Durand, D; Oberto, A; Merin, B; Stoehr, F; Genova, F; Pineau, F-X; Salgado, J

    2016-01-01

    The increasing volumes of astronomical data require practical methods for data exploration, access and visualisation. The Hierarchical Progressive Survey (HiPS) is a HEALPix based scheme that enables a multi-resolution approach to astronomy data from the individual pixels up to the whole sky. We highlight the decisions and approaches that have been taken to make this scheme a practical solution for managing large volumes of heterogeneous data. Early implementors of this system have formed a network of HiPS nodes, with some 250 diverse data sets currently available, with multiple mirror implementations for important data sets. This hierarchical approach can be adapted to expose Big Data in different ways. We describe how the ease of implementation, and local customisation of the Aladin Lite embeddable HiPS visualiser have been keys for promoting collaboration on HiPS.

  20. Non-homogeneous fractal hierarchical weighted networks.

    Science.gov (United States)

    Dong, Yujuan; Dai, Meifeng; Ye, Dandan

    2015-01-01

    A model of fractal hierarchical structures that share the property of non-homogeneous weighted networks is introduced. These networks can be completely and analytically characterized in terms of the involved parameters, i.e., the size of the original graph Nk and the non-homogeneous weight scaling factors r1, r2, · · · rM. We also study the average weighted shortest path (AWSP), the average degree and the average node strength, taking place on the non-homogeneous hierarchical weighted networks. Moreover the AWSP is scrupulously calculated. We show that the AWSP depends on the number of copies and the sum of all non-homogeneous weight scaling factors in the infinite network order limit.

  1. Noise enhances information transfer in hierarchical networks.

    Science.gov (United States)

    Czaplicka, Agnieszka; Holyst, Janusz A; Sloot, Peter M A

    2013-01-01

    We study the influence of noise on information transmission in the form of packages shipped between nodes of hierarchical networks. Numerical simulations are performed for artificial tree networks, scale-free Ravasz-Barabási networks as well for a real network formed by email addresses of former Enron employees. Two types of noise are considered. One is related to packet dynamics and is responsible for a random part of packets paths. The second one originates from random changes in initial network topology. We find that the information transfer can be enhanced by the noise. The system possesses optimal performance when both kinds of noise are tuned to specific values, this corresponds to the Stochastic Resonance phenomenon. There is a non-trivial synergy present for both noisy components. We found also that hierarchical networks built of nodes of various degrees are more efficient in information transfer than trees with a fixed branching factor.

  2. Design of Hierarchical Structures for Synchronized Deformations

    Science.gov (United States)

    Seifi, Hamed; Javan, Anooshe Rezaee; Ghaedizadeh, Arash; Shen, Jianhu; Xu, Shanqing; Xie, Yi Min

    2017-01-01

    In this paper we propose a general method for creating a new type of hierarchical structures at any level in both 2D and 3D. A simple rule based on a rotate-and-mirror procedure is introduced to achieve multi-level hierarchies. These new hierarchical structures have remarkably few degrees of freedom compared to existing designs by other methods. More importantly, these structures exhibit synchronized motions during opening or closure, resulting in uniform and easily-controllable deformations. Furthermore, a simple analytical formula is found which can be used to avoid collision of units of the structure during the closing process. The novel design concept is verified by mathematical analyses, computational simulations and physical experiments.

  3. Hierarchical model of vulnerabilities for emotional disorders.

    Science.gov (United States)

    Norton, Peter J; Mehta, Paras D

    2007-01-01

    Clark and Watson's (1991) tripartite model of anxiety and depression has had a dramatic impact on our understanding of the dispositional variables underlying emotional disorders. More recently, calls have been made to examine not simply the influence of negative affectivity (NA) but also mediating factors that might better explain how NA influences anxious and depressive syndromes (e.g. Taylor, 1998; Watson, 2005). Extending preliminary projects, this study evaluated two hierarchical models of NA, mediating factors of anxiety sensitivity and intolerance of uncertainty, and specific emotional manifestations. Data provided a very good fit to a model elaborated from preliminary studies, lending further support to hierarchical models of emotional vulnerabilities. Implications for classification and diagnosis are discussed.

  4. Hierarchical Self-organization of Complex Systems

    Institute of Scientific and Technical Information of China (English)

    CHAI Li-he; WEN Dong-sheng

    2004-01-01

    Researches on organization and structure in complex systems are academic and industrial fronts in modern sciences. Though many theories are tentatively proposed to analyze complex systems, we still lack a rigorous theory on them. Complex systems possess various degrees of freedom, which means that they should exhibit all kinds of structures. However, complex systems often show similar patterns and structures. Then the question arises why such similar structures appear in all kinds of complex systems. The paper outlines a theory on freedom degree compression and the existence of hierarchical self-organization for all complex systems is found. It is freedom degree compression and hierarchical self-organization that are responsible for the existence of these similar patterns or structures observed in the complex systems.

  5. Bayesian hierarchical modeling of drug stability data.

    Science.gov (United States)

    Chen, Jie; Zhong, Jinglin; Nie, Lei

    2008-06-15

    Stability data are commonly analyzed using linear fixed or random effect model. The linear fixed effect model does not take into account the batch-to-batch variation, whereas the random effect model may suffer from the unreliable shelf-life estimates due to small sample size. Moreover, both methods do not utilize any prior information that might have been available. In this article, we propose a Bayesian hierarchical approach to modeling drug stability data. Under this hierarchical structure, we first use Bayes factor to test the poolability of batches. Given the decision on poolability of batches, we then estimate the shelf-life that applies to all batches. The approach is illustrated with two example data sets and its performance is compared in simulation studies with that of the commonly used frequentist methods. (c) 2008 John Wiley & Sons, Ltd.

  6. Hierarchical Boltzmann simulations and model error estimation

    Science.gov (United States)

    Torrilhon, Manuel; Sarna, Neeraj

    2017-08-01

    A hierarchical simulation approach for Boltzmann's equation should provide a single numerical framework in which a coarse representation can be used to compute gas flows as accurately and efficiently as in computational fluid dynamics, but a subsequent refinement allows to successively improve the result to the complete Boltzmann result. We use Hermite discretization, or moment equations, for the steady linearized Boltzmann equation for a proof-of-concept of such a framework. All representations of the hierarchy are rotationally invariant and the numerical method is formulated on fully unstructured triangular and quadrilateral meshes using a implicit discontinuous Galerkin formulation. We demonstrate the performance of the numerical method on model problems which in particular highlights the relevance of stability of boundary conditions on curved domains. The hierarchical nature of the method allows also to provide model error estimates by comparing subsequent representations. We present various model errors for a flow through a curved channel with obstacles.

  7. Hierarchical State Machines as Modular Horn Clauses

    Directory of Open Access Journals (Sweden)

    Pierre-Loïc Garoche

    2016-07-01

    Full Text Available In model based development, embedded systems are modeled using a mix of dataflow formalism, that capture the flow of computation, and hierarchical state machines, that capture the modal behavior of the system. For safety analysis, existing approaches rely on a compilation scheme that transform the original model (dataflow and state machines into a pure dataflow formalism. Such compilation often result in loss of important structural information that capture the modal behaviour of the system. In previous work we have developed a compilation technique from a dataflow formalism into modular Horn clauses. In this paper, we present a novel technique that faithfully compile hierarchical state machines into modular Horn clauses. Our compilation technique preserves the structural and modal behavior of the system, making the safety analysis of such models more tractable.

  8. Hierarchical community structure in complex (social) networks

    CERN Document Server

    Massaro, Emanuele

    2014-01-01

    The investigation of community structure in networks is a task of great importance in many disciplines, namely physics, sociology, biology and computer science where systems are often represented as graphs. One of the challenges is to find local communities from a local viewpoint in a graph without global information in order to reproduce the subjective hierarchical vision for each vertex. In this paper we present the improvement of an information dynamics algorithm in which the label propagation of nodes is based on the Markovian flow of information in the network under cognitive-inspired constraints \\cite{Massaro2012}. In this framework we have introduced two more complex heuristics that allow the algorithm to detect the multi-resolution hierarchical community structure of networks from a source vertex or communities adopting fixed values of model's parameters. Experimental results show that the proposed methods are efficient and well-behaved in both real-world and synthetic networks.

  9. Object tracking with hierarchical multiview learning

    Science.gov (United States)

    Yang, Jun; Zhang, Shunli; Zhang, Li

    2016-09-01

    Building a robust appearance model is useful to improve tracking performance. We propose a hierarchical multiview learning framework to construct the appearance model, which has two layers for tracking. On the top layer, two different views of features, grayscale value and histogram of oriented gradients, are adopted for representation under the cotraining framework. On the bottom layer, for each view of each feature, three different random subspaces are generated to represent the appearance from multiple views. For each random view submodel, the least squares support vector machine is employed to improve the discriminability for concrete and efficient realization. These two layers are combined to construct the final appearance model for tracking. The proposed hierarchical model assembles two types of multiview learning strategies, in which the appearance can be described more accurately and robustly. Experimental results in the benchmark dataset demonstrate that the proposed method can achieve better performance than many existing state-of-the-art algorithms.

  10. Assembling hierarchical cluster solids with atomic precision.

    Science.gov (United States)

    Turkiewicz, Ari; Paley, Daniel W; Besara, Tiglet; Elbaz, Giselle; Pinkard, Andrew; Siegrist, Theo; Roy, Xavier

    2014-11-12

    Hierarchical solids created from the binary assembly of cobalt chalcogenide and iron oxide molecular clusters are reported. Six different molecular clusters based on the octahedral Co6E8 (E = Se or Te) and the expanded cubane Fe8O4 units are used as superatomic building blocks to construct these crystals. The formation of the solid is driven by the transfer of charge between complementary electron-donating and electron-accepting clusters in solution that crystallize as binary ionic compounds. The hierarchical structures are investigated by single-crystal X-ray diffraction, providing atomic and superatomic resolution. We report two different superstructures: a superatomic relative of the CsCl lattice type and an unusual packing arrangement based on the double-hexagonal close-packed lattice. Within these superstructures, we demonstrate various compositions and orientations of the clusters.

  11. Hierarchical Robot Control In A Multisensor Environment

    Science.gov (United States)

    Bhanu, Bir; Thune, Nils; Lee, Jih Kun; Thune, Mari

    1987-03-01

    Automatic recognition, inspection, manipulation and assembly of objects will be a common denominator in most of tomorrow's highly automated factories. These tasks will be handled by intelligent computer controlled robots with multisensor capabilities which contribute to desired flexibility and adaptability. The control of a robot in such a multisensor environment becomes of crucial importance as the complexity of the problem grows exponentially with the number of sensors, tasks, commands and objects. In this paper we present an approach which uses CAD (Computer-Aided Design) based geometric and functional models of objects together with action oriented neuroschemas to recognize and manipulate objects by a robot in a multisensor environment. The hierarchical robot control system is being implemented on a BBN Butterfly multi processor. Index terms: CAD, Hierarchical Control, Hypothesis Generation and Verification, Parallel Processing, Schemas

  12. Repair approach for DMC images based on hierarchical location using edge curve

    Institute of Scientific and Technical Information of China (English)

    PAN Jun; WANG Mi; LI DeRen; FENG TianTian

    2009-01-01

    The color composite digital mapping camera (DMC) images are produced by the post-processing software of Z/I imaging. But the failure of radiometric correction in post-processing leads to residual radiometric differences between CCD images, which then affect the quality of the images in further applications. This paper, via analyzing the characters and causes of such a phenomenon, proposes a repair approach based on hierarchical location using edge curve. The approach employs a hierarchical strategy to locate the transition area and seam-line automatically and then repair the image through the global reconstruction between CCD images and the local reconstruction in the transition area. Experiments indicate that the approach proposed by this paper is feasible and can improve the quality of images effectively.

  13. Towards an Efficient Hierarchical Codebooks for Content-Based Images Retrieval

    Institute of Scientific and Technical Information of China (English)

    Z.Elleuch; K.Marzouki

    2014-01-01

    In space feature quantization, the most important problem is designing an efficient and compact codebook. The hierarchical clustering approach successfully solves the problem of quantifying the feature space in a large vocabulary size. In this paper we propose to use a tree structure of hierarchical self-organizing-map (H-SOM) with the depth length equal to two and a high size of branch factors (50, 100, 200, 400, and 500). Moreover, an incremental learning process of H-SOM is used to overcome the problem of the curse of the dimensionality of space. The method is evaluated on three public datasets. Results exceed the current state-of-art retrieval performance on Kentucky and Oxford5k dataset. However, it is with less performance on the Holidays dataset. The experiment results indicate that the proposed tree structure shows significant improvement with a large number of branch factors.

  14. Monitoring Post Disturbance Forest Regeneration with Hierarchical Object-Based Image Analysis

    Directory of Open Access Journals (Sweden)

    L. Monika Moskal

    2013-10-01

    Full Text Available The main goal of this exploratory project was to quantify seedling density in post fire regeneration sites, with the following objectives: to evaluate the application of second order image texture (SOIT in image segmentation, and to apply the object-based image analysis (OBIA approach to develop a hierarchical classification. With the utilization of image texture we successfully developed a methodology to classify hyperspatial (high-spatial imagery to fine detail level of tree crowns, shadows and understory, while still allowing discrimination between density classes and mature forest versus burn classes. At the most detailed hierarchical Level I classification accuracies reached 78.8%, a Level II stand density classification produced accuracies of 89.1% and the same accuracy was achieved by the coarse general classification at Level III. Our interpretation of these results suggests hyperspatial imagery can be applied to post-fire forest density and regeneration mapping.

  15. TRANSIMS and the hierarchical data format

    Energy Technology Data Exchange (ETDEWEB)

    Bush, B.W.

    1997-06-12

    The Hierarchical Data Format (HDF) is a general-purposed scientific data format developed at the National Center for Supercomputing Applications. It supports metadata, compression, and a variety of data structures (multidimensional arrays, raster images, tables). FORTRAN 77 and ANSI C programming interfaces are available for it and a wide variety of visualization tools read HDF files. The author discusses the features of this file format and its possible uses in TRANSIMS.

  16. Modular, Hierarchical Learning By Artificial Neural Networks

    Science.gov (United States)

    Baldi, Pierre F.; Toomarian, Nikzad

    1996-01-01

    Modular and hierarchical approach to supervised learning by artificial neural networks leads to neural networks more structured than neural networks in which all neurons fully interconnected. These networks utilize general feedforward flow of information and sparse recurrent connections to achieve dynamical effects. The modular organization, sparsity of modular units and connections, and fact that learning is much more circumscribed are all attractive features for designing neural-network hardware. Learning streamlined by imitating some aspects of biological neural networks.

  17. The Infinite Hierarchical Factor Regression Model

    CERN Document Server

    Rai, Piyush

    2009-01-01

    We propose a nonparametric Bayesian factor regression model that accounts for uncertainty in the number of factors, and the relationship between factors. To accomplish this, we propose a sparse variant of the Indian Buffet Process and couple this with a hierarchical model over factors, based on Kingman's coalescent. We apply this model to two problems (factor analysis and factor regression) in gene-expression data analysis.

  18. Superhydrophobicity of Hierarchical and ZNO Nanowire Coatings

    Science.gov (United States)

    2014-01-01

    KOH (3 wt%), distilled water and isopropyl alcohol (10% vol%) at 95 C for 50 min. Subsequently, a 10 nm ZnO seed layer wasThis journal is © The Royal...ZnO have been widely used in sensors, piezo-nanogenerators, and solar cells. The hierarchical structures of ZnO nanowires grown on Si pyramid surfaces...exhibiting superhydrophobicity in this work will have promising applications in the next generation photovoltaic devices and solar cells

  19. Hierarchical Parallel Evaluation of a Hamming Code

    Directory of Open Access Journals (Sweden)

    Shmuel T. Klein

    2017-04-01

    Full Text Available The Hamming code is a well-known error correction code and can correct a single error in an input vector of size n bits by adding logn parity checks. A new parallel implementation of the code is presented, using a hierarchical structure of n processors in logn layers. All the processors perform similar simple tasks, and need only a few bytes of internal memory.

  20. Hierarchical mixture models for assessing fingerprint individuality

    OpenAIRE

    Dass, Sarat C.; Li, Mingfei

    2009-01-01

    The study of fingerprint individuality aims to determine to what extent a fingerprint uniquely identifies an individual. Recent court cases have highlighted the need for measures of fingerprint individuality when a person is identified based on fingerprint evidence. The main challenge in studies of fingerprint individuality is to adequately capture the variability of fingerprint features in a population. In this paper hierarchical mixture models are introduced to infer the extent of individua...

  1. Sustained Activity in Hierarchical Modular Neural Networks: Self-Organized Criticality and Oscillations

    Science.gov (United States)

    Wang, Sheng-Jun; Hilgetag, Claus C.; Zhou, Changsong

    2010-01-01

    Cerebral cortical brain networks possess a number of conspicuous features of structure and dynamics. First, these networks have an intricate, non-random organization. In particular, they are structured in a hierarchical modular fashion, from large-scale regions of the whole brain, via cortical areas and area subcompartments organized as structural and functional maps to cortical columns, and finally circuits made up of individual neurons. Second, the networks display self-organized sustained activity, which is persistent in the absence of external stimuli. At the systems level, such activity is characterized by complex rhythmical oscillations over a broadband background, while at the cellular level, neuronal discharges have been observed to display avalanches, indicating that cortical networks are at the state of self-organized criticality (SOC). We explored the relationship between hierarchical neural network organization and sustained dynamics using large-scale network modeling. Previously, it was shown that sparse random networks with balanced excitation and inhibition can sustain neural activity without external stimulation. We found that a hierarchical modular architecture can generate sustained activity better than random networks. Moreover, the system can simultaneously support rhythmical oscillations and SOC, which are not present in the respective random networks. The mechanism underlying the sustained activity is that each dense module cannot sustain activity on its own, but displays SOC in the presence of weak perturbations. Therefore, the hierarchical modular networks provide the coupling among subsystems with SOC. These results imply that the hierarchical modular architecture of cortical networks plays an important role in shaping the ongoing spontaneous activity of the brain, potentially allowing the system to take advantage of both the sensitivity of critical states and the predictability and timing of oscillations for efficient information

  2. Sustained activity in hierarchical modular neural networks: self-organized criticality and oscillations

    Directory of Open Access Journals (Sweden)

    Sheng-Jun Wang

    2011-06-01

    Full Text Available Cerebral cortical brain networks possess a number of conspicuous features of structure and dynamics. First, these networks have an intricate, non-random organization. They are structured in a hierarchical modular fashion, from large-scale regions of the whole brain, via cortical areas and area subcompartments organized as structural and functional maps to cortical columns, and finally circuits made up of individual neurons. Second, the networks display self-organized sustained activity, which is persistent in the absence of external stimuli. At the systems level, such activity is characterized by complex rhythmical oscillations over a broadband background, while at the cellular level, neuronal discharges have been observed to display avalanches, indicating that cortical networks are at the state of self-organized criticality. We explored the relationship between hierarchical neural network organization and sustained dynamics using large-scale network modeling. It was shown that sparse random networks with balanced excitation and inhibition can sustain neural activity without external stimulation. We find that a hierarchical modular architecture can generate sustained activity better than random networks. Moreover, the system can simultaneously support rhythmical oscillations and self-organized criticality, which are not present in the respective random networks. The underlying mechanism is that each dense module cannot sustain activity on its own, but displays self-organized criticality in the presence of weak perturbations. The hierarchical modular networks provide the coupling among subsystems with self-organized criticality. These results imply that the hierarchical modular architecture of cortical networks plays an important role in shaping the ongoing spontaneous activity of the brain, potentially allowing the system to take advantage of both the sensitivityof critical state and predictability and timing of oscillations for efficient

  3. Sustained activity in hierarchical modular neural networks: self-organized criticality and oscillations.

    Science.gov (United States)

    Wang, Sheng-Jun; Hilgetag, Claus C; Zhou, Changsong

    2011-01-01

    Cerebral cortical brain networks possess a number of conspicuous features of structure and dynamics. First, these networks have an intricate, non-random organization. In particular, they are structured in a hierarchical modular fashion, from large-scale regions of the whole brain, via cortical areas and area subcompartments organized as structural and functional maps to cortical columns, and finally circuits made up of individual neurons. Second, the networks display self-organized sustained activity, which is persistent in the absence of external stimuli. At the systems level, such activity is characterized by complex rhythmical oscillations over a broadband background, while at the cellular level, neuronal discharges have been observed to display avalanches, indicating that cortical networks are at the state of self-organized criticality (SOC). We explored the relationship between hierarchical neural network organization and sustained dynamics using large-scale network modeling. Previously, it was shown that sparse random networks with balanced excitation and inhibition can sustain neural activity without external stimulation. We found that a hierarchical modular architecture can generate sustained activity better than random networks. Moreover, the system can simultaneously support rhythmical oscillations and SOC, which are not present in the respective random networks. The mechanism underlying the sustained activity is that each dense module cannot sustain activity on its own, but displays SOC in the presence of weak perturbations. Therefore, the hierarchical modular networks provide the coupling among subsystems with SOC. These results imply that the hierarchical modular architecture of cortical networks plays an important role in shaping the ongoing spontaneous activity of the brain, potentially allowing the system to take advantage of both the sensitivity of critical states and the predictability and timing of oscillations for efficient information

  4. Metal hierarchical patterning by direct nanoimprint lithography.

    Science.gov (United States)

    Radha, Boya; Lim, Su Hui; Saifullah, Mohammad S M; Kulkarni, Giridhar U

    2013-01-01

    Three-dimensional hierarchical patterning of metals is of paramount importance in diverse fields involving photonics, controlling surface wettability and wearable electronics. Conventionally, this type of structuring is tedious and usually involves layer-by-layer lithographic patterning. Here, we describe a simple process of direct nanoimprint lithography using palladium benzylthiolate, a versatile metal-organic ink, which not only leads to the formation of hierarchical patterns but also is amenable to layer-by-layer stacking of the metal over large areas. The key to achieving such multi-faceted patterning is hysteretic melting of ink, enabling its shaping. It undergoes transformation to metallic palladium under gentle thermal conditions without affecting the integrity of the hierarchical patterns on micro- as well as nanoscale. A metallic rice leaf structure showing anisotropic wetting behavior and woodpile-like structures were thus fabricated. Furthermore, this method is extendable for transferring imprinted structures to a flexible substrate to make them robust enough to sustain numerous bending cycles.

  5. Hierarchical unilamellar vesicles of controlled compositional heterogeneity.

    Directory of Open Access Journals (Sweden)

    Maik Hadorn

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

  6. A New Metrics for Hierarchical Clustering

    Institute of Scientific and Technical Information of China (English)

    YANGGuangwen; SHIShuming; WANGDingxing

    2003-01-01

    Hierarchical clustering is a popular method of performing unsupervised learning. Some metric must be used to determine the similarity between pairs of clusters in hierarchical clustering. Traditional similarity metrics either can deal with simple shapes (i.e. spherical shapes) only or are very sensitive to outliers (the chaining effect). The main contribution of this paper is to propose some potential-based similarity metrics (APES and AMAPES) between clusters in hierarchical clustering, inspired by the concepts of the electric potential and the gravitational potential in electromagnetics and astronomy. The main features of these metrics are: the first, they have strong antijamming capability; the second, they are capable of finding clusters of different shapes such as spherical, spiral, chain, circle, sigmoid, U shape or other complex irregular shapes; the third, existing algorithms and research fruits for classical metrics can be adopted to deal with these new potential-based metrics with no or little modification. Experiments showed that the new metrics are more superior to traditional ones. Different potential functions are compared, and the sensitivity to parameters is also analyzed in this paper.

  7. A secure solution on hierarchical access control

    CERN Document Server

    Wei, Chuan-Sheng; Huang, Tone-Yau; Ong, Yao Lin

    2011-01-01

    Hierarchical access control is an important and traditional problem in information security. In 2001, Wu et.al. proposed an elegant solution for hierarchical access control by the secure-filter. Jeng and Wang presented an improvement of Wu et. al.'s method by the ECC cryptosystem. However, secure-filter method is insecure in dynaminc access control. Lie, Hsu and Tripathy, Paul pointed out some secure leaks on the secure-filter and presented some improvements to eliminate these secure flaws. In this paper, we revise the secure-filter in Jeng-Wang method and propose another secure solutions in hierarchical access control problem. CA is a super security class (user) in our proposed method and the secure-filter of $u_i$ in our solutions is a polynomial of degree $n_i+1$ in $\\mathbb{Z}_p^*$, $f_i(x)=(x-h_i)(x-a_1)...(x-a_{n_i})+L_{l_i}(K_i)$. Although the degree of our secure-filter is larger than others solutions, our solution is secure and efficient in dynamics access control.

  8. SORM applied to hierarchical parallel system

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager

    2006-01-01

    The old hierarchical stochastic load combination model of Ferry Borges and Castanheta and the corresponding problem of determining the distribution of the extreme random load effect is the inspiration to this paper. The evaluation of the distribution function of the extreme value by use of a part......The old hierarchical stochastic load combination model of Ferry Borges and Castanheta and the corresponding problem of determining the distribution of the extreme random load effect is the inspiration to this paper. The evaluation of the distribution function of the extreme value by use...... of a particular first order reliability method (FORM) was first described in a celebrated paper by Rackwitz and Fiessler more than a quarter of a century ago. The method has become known as the Rackwitz-Fiessler algorithm. The original RF-algorithm as applied to a hierarchical random variable model...... is recapitulated so that a simple but quite effective accuracy improving calculation can be explained. A limit state curvature correction factor on the probability approximation is obtained from the final stop results of the RF-algorithm. This correction factor is based on Breitung’s asymptotic formula for second...

  9. Anisotropic and Hierarchical Porosity in Multifunctional Ceramics

    Science.gov (United States)

    Lichtner, Aaron Zev

    The performance of multifunctional porous ceramics is often hindered by the seemingly contradictory effects of porosity on both mechanical and non-structural properties and yet a sufficient body of knowledge linking microstructure to these properties does not exist. Using a combination of tailored anisotropic and hierarchical materials, these disparate effects may be reconciled. In this project, a systematic investigation of the processing, characterization and properties of anisotropic and isotropic hierarchically porous ceramics was conducted. The system chosen was a composite ceramic intended as the cathode for a solid oxide fuel cell (SOFC). Comprehensive processing investigations led to the development of approaches to make hierarchical, anisotropic porous microstructures using directional freeze-casting of well dispersed slurries. The effect of all the important processing parameters was investigated. This resulted in an ability to tailor and control the important microstructural features including the scale of the microstructure, the macropore size and total porosity. Comparable isotropic porous ceramics were also processed using fugitive pore formers. A suite of characterization techniques including x-ray tomography and 3-D sectional scanning electron micrographs (FIB-SEM) was used to characterize and quantify the green and partially sintered microstructures. The effect of sintering temperature on the microstructure was quantified and discrete element simulations (DEM) were used to explain the experimental observations. Finally, the comprehensive mechanical properties, at room temperature, were investigated, experimentally and using DEM, for the different microstructures.

  10. Resilient 3D hierarchical architected metamaterials.

    Science.gov (United States)

    Meza, Lucas R; Zelhofer, Alex J; Clarke, Nigel; Mateos, Arturo J; Kochmann, Dennis M; Greer, Julia R

    2015-09-15

    Hierarchically designed structures with architectural features that span across multiple length scales are found in numerous hard biomaterials, like bone, wood, and glass sponge skeletons, as well as manmade structures, like the Eiffel Tower. It has been hypothesized that their mechanical robustness and damage tolerance stem from sophisticated ordering within the constituents, but the specific role of hierarchy remains to be fully described and understood. We apply the principles of hierarchical design to create structural metamaterials from three material systems: (i) polymer, (ii) hollow ceramic, and (iii) ceramic-polymer composites that are patterned into self-similar unit cells in a fractal-like geometry. In situ nanomechanical experiments revealed (i) a nearly theoretical scaling of structural strength and stiffness with relative density, which outperforms existing nonhierarchical nanolattices; (ii) recoverability, with hollow alumina samples recovering up to 98% of their original height after compression to ≥ 50% strain; (iii) suppression of brittle failure and structural instabilities in hollow ceramic hierarchical nanolattices; and (iv) a range of deformation mechanisms that can be tuned by changing the slenderness ratios of the beams. Additional levels of hierarchy beyond a second order did not increase the strength or stiffness, which suggests the existence of an optimal degree of hierarchy to amplify resilience. We developed a computational model that captures local stress distributions within the nanolattices under compression and explains some of the underlying deformation mechanisms as well as validates the measured effective stiffness to be interpreted as a metamaterial property.

  11. The Hourglass Effect in Hierarchical Dependency Networks

    CERN Document Server

    Sabrin, Kaeser M

    2016-01-01

    Many hierarchically modular systems are structured in a way that resembles a bow-tie or hourglass. This "hourglass effect" means that the system generates many outputs from many inputs through a relatively small number of intermediate modules that are critical for the operation of the entire system (the waist of the hourglass). We investigate the hourglass effect in general (not necessarily layered) hierarchical dependency networks. Our analysis focuses on the number of source-to-target dependency paths that traverse each vertex, and it identifies the core of a dependency network as the smallest set of vertices that collectively cover almost all dependency paths. We then examine if a given network exhibits the hourglass property or not, comparing its core size with a "flat" (i.e., non-hierarchical) network that preserves the source dependencies of each target in the original network. As a possible explanation for the hourglass effect, we propose the Reuse Preference (RP) model that captures the bias of new mo...

  12. Semantic Image Segmentation with Contextual Hierarchical Models.

    Science.gov (United States)

    Seyedhosseini, Mojtaba; Tasdizen, Tolga

    2016-05-01

    Semantic segmentation is the problem of assigning an object label to each pixel. It unifies the image segmentation and object recognition problems. The importance of using contextual information in semantic segmentation frameworks has been widely realized in the field. We propose a contextual framework, called contextual hierarchical model (CHM), which learns contextual information in a hierarchical framework for semantic segmentation. At each level of the hierarchy, a classifier is trained based on downsampled input images and outputs of previous levels. Our model then incorporates the resulting multi-resolution contextual information into a classifier to segment the input image at original resolution. This training strategy allows for optimization of a joint posterior probability at multiple resolutions through the hierarchy. Contextual hierarchical model is purely based on the input image patches and does not make use of any fragments or shape examples. Hence, it is applicable to a variety of problems such as object segmentation and edge detection. We demonstrate that CHM performs at par with state-of-the-art on Stanford background and Weizmann horse datasets. It also outperforms state-of-the-art edge detection methods on NYU depth dataset and achieves state-of-the-art on Berkeley segmentation dataset (BSDS 500).

  13. 膜法除硝在离子膜烧碱盐水精制中的应用%Application of sulfate removed by membrane method in the ionic membrane caustic soda brine refined

    Institute of Scientific and Technical Information of China (English)

    杨国稳

    2012-01-01

    阐述了MRO膜法除硝的设计原理、除硝生产工艺及其在离子膜烧碱装置中的应用情况。%Described the design principles of sulfate removed by MRO-membrane ,productive process, and its effect in the ionic membrane caustic soda installation.

  14. Estudo comparativo do uso de redes neurais artificiais e regressão linear múltipla para a previsão da concentração cáustica em uma etapa do processo de fabricação de alumina/Comparative study of the use of artificial neural networks and multiple linear regression for the prediction of the caustic concentration in one step of the alumina manufacturing process

    National Research Council Canada - National Science Library

    Giovanni Leopoldo Rozza; Ruy Gomes da Silva; Sonia Isoldi Marty Gama Müller

    2015-01-01

    .... The organization requests caustic concentration by chemical analysis laboratory once a day, such information is not enough to issue preventive actions to handle process inefficiencies that will be...

  15. NEXT GENERATION SOLVENT-MATERIALS COMPATIBILITY WITH POLYMER COMPONENTS WITHIN MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT (FINAL REPORT)

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Peters, T.; Fink, S.

    2012-01-17

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The first deployment target for the technology is within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the facility. This report provides the data from exposing these polymers to the Next Generation Solvent (NGS). The test was conducted over six months. An assessment of the dimensional stability of polymers present in MCU (i.e., PEEK, Grafoil, Tefzel and Isolast) in the modified NGS (where the concentration of LIX{reg_sign}79 and MaxCalix was varied systematically) showed that LIX{reg_sign}79 selectively affected Tefzel and its different grades (by an increase in size and lowering its density). The copolymer structure of Tefzel and possibly its porosity allows for the easier diffusion of LIX{reg_sign}79. Tefzel is used as the seat material in some of the valves at MCU. Long term exposure to LIX{reg_sign}79, may make the valves hard to operate over time due to the seat material (Tefzel) increasing in size. However, since the physical changes of Tefzel in the improved solvent are comparable to the changes in the CSSX baseline solvent, no design changes are needed with respect to the Tefzel seating material. PEEK, Grafoil and Isolast were not affected by LIX{reg_sign}79 and MaxCalix within six months of exposure. The initial rapid weight gain observed in every polymer is assigned to the finite and

  16. Optimization of mathematical models for thematic maps

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The thematic map is a major class of maps designed to demonstrate particular features or concepts,functioning as an indispensable tool in geographical research.The process of thematic mapping is one into which geographical research goes deeply and broadly.The key activity and course of thematic map production is the use of mathematical models to create thematic data layers.Therefore,the selection and optimization of mathematical models is in the forefront of thematic map research.The theoretical foundations,mechanisms and methods of mathematical model optimization are expounded in this paper,including two approaches,the phase by phase mode and the multi-aim scheme balance mode.Case studies in eco-environment mapping and emergency mapping are described and analyzed,with a hierarchical analysis method being used in the model optimization for eco-environment fragility and sensitivity assessment mapping in Beibuwan (Guangxi) District,the dynamic system (DS) method being used in the model optimization for ecological security adjustment mapping in Xishuang Banna,Yunnan province,and the multi-phase mode being used in the models for forest fire and infectious diseases mapping.

  17. Mapping Deeply

    OpenAIRE

    Denis Wood

    2015-01-01

    This is a description of an avant la lettre deep mapping project carried out by a geographer and a number of landscape architecture students in the early 1980s. Although humanists seem to take the “mapping” in deep mapping more metaphorically than cartographically, in this neighborhood mapping project, the mapmaking was taken literally, with the goal of producing an atlas of the neighborhood. In this, the neighborhood was construed as a transformer, turning the stuff of the world (gas, wate...

  18. Hierarchical and Non-Hierarchical Linear and Non-Linear Clustering Methods to “Shakespeare Authorship Question”

    Directory of Open Access Journals (Sweden)

    Refat Aljumily

    2015-09-01

    Full Text Available A few literary scholars have long claimed that Shakespeare did not write some of his best plays (history plays and tragedies and proposed at one time or another various suspect authorship candidates. Most modern-day scholars of Shakespeare have rejected this claim, arguing that strong evidence that Shakespeare wrote the plays and poems being his name appears on them as the author. This has caused and led to an ongoing scholarly academic debate for quite some long time. Stylometry is a fast-growing field often used to attribute authorship to anonymous or disputed texts. Stylometric attempts to resolve this literary puzzle have raised interesting questions over the past few years. The following paper contributes to “the Shakespeare authorship question” by using a mathematically-based methodology to examine the hypothesis that Shakespeare wrote all the disputed plays traditionally attributed to him. More specifically, the mathematically based methodology used here is based on Mean Proximity, as a linear hierarchical clustering method, and on Principal Components Analysis, as a non-hierarchical linear clustering method. It is also based, for the first time in the domain, on Self-Organizing Map U-Matrix and Voronoi Map, as non-linear clustering methods to cover the possibility that our data contains significant non-linearities. Vector Space Model (VSM is used to convert texts into vectors in a high dimensional space. The aim of which is to compare the degrees of similarity within and between limited samples of text (the disputed plays. The various works and plays assumed to have been written by Shakespeare and possible authors notably, Sir Francis Bacon, Christopher Marlowe, John Fletcher, and Thomas Kyd, where “similarity” is defined in terms of correlation/distance coefficient measure based on the frequency of usage profiles of function words, word bi-grams, and character triple-grams. The claim that Shakespeare authored all the disputed

  19. Polynomial mappings

    CERN Document Server

    Narkiewicz, Wŀadysŀaw

    1995-01-01

    The book deals with certain algebraic and arithmetical questions concerning polynomial mappings in one or several variables. Algebraic properties of the ring Int(R) of polynomials mapping a given ring R into itself are presented in the first part, starting with classical results of Polya, Ostrowski and Skolem. The second part deals with fully invariant sets of polynomial mappings F in one or several variables, i.e. sets X satisfying F(X)=X . This includes in particular a study of cyclic points of such mappings in the case of rings of algebrai integers. The text contains several exercises and a list of open problems.

  20. Participatory Maps

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    2016-01-01

    practice. In particular, mapping environmental damage, endangered species, and human-made disasters has become one focal point for environmental knowledge production. This type of digital map has been highlighted as a processual turn in critical cartography, whereas in related computational journalism...... of a geo-visualization within information mapping that enhances embodiment in the experience of the information. InfoAmazonia is defined as a digitally created map-space within which journalistic practice can be seen as dynamic, performative interactions between journalists, ecosystems, space, and species...

  1. Characterization of solids deposited on the modular caustic-side solvent extraction unit (MCU) coalescer media removed in May and October 2014

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-01

    During routine maintenance, the coalescers utilized in the Modular Caustic-Side Solvent Extraction Unit (MCU) processing of Salt Batch 6 and a portion of Salt Batch 7 were sampled and submitted to the Savannah River National Laboratory (SRNL) for characterization, for the purpose of identifying solid phase constituents that may be accumulating in these coalescers. Specifically, two samples were received and characterized: A decontaminated salt solution (DSS) coalescer sample and a strip effluent (SE) coalescer sample. Aliquots of the samples were analyzed by XRD, Fourier Transform Infrared (FTIR) Spectroscopy, SEM, and EDS. Other aliquots of the samples were leached in acid solution, and the leachates were analyzed by ICP-AES. In addition, modeling was performed to provide a basis for comparison of the analytical results.

  2. PEP Run Report for Integrated Test A, Caustic Leaching in UFP-VSL-T01A, Oxidative Leaching in UFP-VSL-T02A

    Energy Technology Data Exchange (ETDEWEB)

    Guzman-Leong, Consuelo E.; Bredt, Ofelia P.; Burns, Carolyn A.; Daniel, Richard C.; Su, Yin-Fong; Geeting, John GH; Golovich, Elizabeth C.; Josephson, Gary B.; Kurath, Dean E.; Sevigny, Gary J.; Smith, Dennese M.; Valdez, Patrick LJ; Yokuda, Satoru T.; Young, Joan K.

    2009-12-04

    Pacific Northwest National Laboratory (PNNL) was tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed and constructed and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes.”(a) The PEP, located in the Process Engineering Laboratory-West (PDLW) located in Richland, Washington, is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing.

  3. Determination of sodium chloride in ion - exchange membrane caustic soda%离子膜碱中氯化钠的测定

    Institute of Scientific and Technical Information of China (English)

    宋昕; 孙士娟; 邱雪松

    2000-01-01

    The determination of sodium chloride in ion- exchange membrane caustic soda by potentiometry and by spectrophotometry are introduced, and the results obtained by the above two methods are compared. It is concluded that potentiometry is suitable to macro analysis with characteristics of simple operation, rapid analysis and accurate measurement.%介绍了用电位滴定法和分光光度法测定离子膜碱中氯化钠含量的方法,并对这2种方法的测试结果进行了比较。电位滴定法适用于常量分析,具有操作简便、分析速度快、测量结果准确等特点。

  4. Pretreatment Engineering Platform (PEP) Integrated Test B Run Report--Caustic and Oxidative Leaching in UFP-VSL-T02A

    Energy Technology Data Exchange (ETDEWEB)

    Geeting, John GH; Bredt, Ofelia P.; Burns, Carolyn A.; Golovich, Elizabeth C.; Guzman-Leong, Consuelo E.; Josephson, Gary B.; Kurath, Dean E.; Sevigny, Gary J.; Aaberg, Rosanne L.

    2009-12-10

    Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes” of the External Flowsheet Review Team (EFRT) issue response plan.( ) The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing.

  5. Deep subspace mapping in hyperspectral imaging

    Science.gov (United States)

    Wadströmer, Niclas; Gustafsson, David; Perersson, Henrik; Bergström, David

    2016-10-01

    We propose a novel Deep learning approach using autoencoders to map spectral bands to a space of lower dimensionality while preserving the information that makes it possible to discriminate different materials. Deep learning is a relatively new pattern recognition approach which has given promising result in many applications. In Deep learning a hierarchical representation of increasing level of abstraction of the features is learned. Autoencoder is an important unsupervised technique frequently used in Deep learning for extracting important properties of the data. The learned latent representation is a non-linear mapping of the original data which potentially preserve the discrimination capacity.

  6. Hybrid Viscosity Approaches to General Systems of Variational Inequalities with Hierarchical Fixed Point Problem Constraints in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available The purpose of this paper is to introduce and analyze hybrid viscosity methods for a general system of variational inequalities (GSVI with hierarchical fixed point problem constraint in the setting of real uniformly convex and 2-uniformly smooth Banach spaces. Here, the hybrid viscosity methods are based on Korpelevich’s extragradient method, viscosity approximation method, and hybrid steepest-descent method. We propose and consider hybrid implicit and explicit viscosity iterative algorithms for solving the GSVI with hierarchical fixed point problem constraint not only for a nonexpansive mapping but also for a countable family of nonexpansive mappings in X, respectively. We derive some strong convergence theorems under appropriate conditions. Our results extend, improve, supplement, and develop the recent results announced by many authors.

  7. RESULTS FROM ANALYSIS OF THE FIRST AND SECOND STRIP EFFLUENT COALESCER ELEMENTS FROM RADIOACTIVE OPERATIONS OF THE MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T.; Fondeur, F.; Fink, S.

    2011-06-28

    The coalescer elements for the Strip Effluent (SE) acid within the Modular Caustic-Side Solvent Extraction Unit (MCU) experienced elevated differential pressure drop during radioactive operations. Following the end of operations for the first Macrobatch campaign and soon after start of the second Macrobatch campaign, personnel removed the coalescer media and provided to Savannah River National Laboratory (SRNL) for diagnostic investigation of the causes of reduced flow. This report summarizes those studies. Two Strip Effluent (SE) coalescers were delivered to the Savannah River National Laboratory (SRNL). One was removed from the Modular Caustic-Side Solvent Extraction Unit (MCU) between processing of Macrobatch 1 and 2 (coalescer 'Alpha'), and the second was removed from MCU after processing of {approx}24,000 gallons of salt solution (coalescer 'Beta'). Both coalescers underwent the same general strip acid flush program to reduce the dose and were delivered to SRNL for analysis of potential occluding solids. Analysis of Coalescer Alpha indicates the presence of aluminum hydroxide solids and aluminosilicate solids, while analysis of Coalescer Beta indicates the presence of aluminum hydroxide solids, but no aluminosilicates. Leaching studies on sections of both coalescers were performed. The results indicate that the coalescers had different amounts of solids present on them at the time of removal. Finally, samples of free liquids retrieved from both coalescers indicate no excessive amounts of CSSX solvent present. Given the strip acid flushing that occurred in the SE coalescers, the solids we detected on the coalescers are probably indicative of a larger quantity of these solids present before the strip acid flushing. Under this scenario, the excessive pressure drops are due to the solids and not from organic fouling.

  8. A Comparison of Hierarchical and Non-Hierarchical Bayesian Approaches for Fitting Allometric Larch (Larix.spp. Biomass Equations

    Directory of Open Access Journals (Sweden)

    Dongsheng Chen

    2016-01-01

    Full Text Available Accurate biomass estimations are important for assessing and monitoring forest carbon storage. Bayesian theory has been widely applied to tree biomass models. Recently, a hierarchical Bayesian approach has received increasing attention for improving biomass models. In this study, tree biomass data were obtained by sampling 310 trees from 209 permanent sample plots from larch plantations in six regions across China. Non-hierarchical and hierarchical Bayesian approaches were used to model allometric biomass equations. We found that the total, root, stem wood, stem bark, branch and foliage biomass model relationships were statistically significant (p-values < 0.001 for both the non-hierarchical and hierarchical Bayesian approaches, but the hierarchical Bayesian approach increased the goodness-of-fit statistics over the non-hierarchical Bayesian approach. The R2 values of the hierarchical approach were higher than those of the non-hierarchical approach by 0.008, 0.018, 0.020, 0.003, 0.088 and 0.116 for the total tree, root, stem wood, stem bark, branch and foliage models, respectively. The hierarchical Bayesian approach significantly improved the accuracy of the biomass model (except for the stem bark and can reflect regional differences by using random parameters to improve the regional scale model accuracy.

  9. Collection Mapping.

    Science.gov (United States)

    Harbour, Denise

    2002-01-01

    Explains collection mapping for library media collections. Discusses purposes for creating collection maps, including helping with selection and weeding decisions, showing how the collection supports the curriculum, and making budget decisions; and methods of data collection, including evaluating a collaboratively taught unit with the classroom…

  10. Causal mapping

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2006-01-01

    The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method......The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method...

  11. Affective Maps

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    of environmental knowledge production. It uses InfoAmazonia, the databased platform on Amazon rainforests, as an example of affective geo-visualization within information mapping that enhances embodiment in the experience of the information. Amazonia is defined as a digitally created affective (map)space within...

  12. Fuzzy/Kalman Hierarchical Horizontal Motion Control of Underactuated ROVs

    Directory of Open Access Journals (Sweden)

    Francesco M. Raimondi

    2010-09-01

    Full Text Available A new closed loop fuzzy motion control system including on-line Kalman's filter (KF for the two dimensional motion of underactuated and underwater Remotely Operated Vehicle (ROV is presented. Since the sway force is unactuated, new continuous and discrete time models are developed using a polar transformation. A new hierarchical control architecture is developed, where the high level fuzzy guidance controller generates the surge speed and the yaw rate needed to achieve the objective of planar motion, while the low level controller gives the thruster surge force and the yaw control signals. The Fuzzy controller ensures robustness with respect to uncertainties due to the marine environment, forward surge speed and saturation of the control signals. Also Lyapunov's stability of the motion errors is proved based on the properties of the fuzzy maps. If Inertial Measurement Unit data (IMU is employed for the feedback directly, aleatory noises due to accelerometers and gyros damage the performances of the motion control. These noises denote a king of non parametric uncertainty which perturbs the model of the ROV. Therefore a KF is inserted in the feedback of the control system to compensate for the above uncertainties and estimate the feedback signals with more precision.

  13. Hierarchical and High-Girth QC LDPC Codes

    CERN Document Server

    Wang, Yige; Yedidia, Jonathan S

    2011-01-01

    We present a general approach to designing capacity-approaching high-girth low-density parity-check (LDPC) codes that are friendly to hardware implementation. Our methodology starts by defining a new class of "hierarchical" quasi-cyclic (HQC) LDPC codes that generalizes the structure of quasi-cyclic (QC) LDPC codes. Whereas the parity check matrices of QC LDPC codes are composed of circulant sub-matrices, those of HQC LDPC codes are composed of a hierarchy of circulant sub-matrices that are in turn constructed from circulant sub-matrices, and so on, through some number of levels. We show how to map any class of codes defined using a protograph into a family of HQC LDPC codes. Next, we present a girth-maximizing algorithm that optimizes the degrees of freedom within the family of codes to yield a high-girth HQC LDPC code. Finally, we discuss how certain characteristics of a code protograph will lead to inevitable short cycles, and show that these short cycles can be eliminated using a "squashing" procedure tha...

  14. Hierarchical approach to diagnosis of electronic circuits using ANNs

    Directory of Open Access Journals (Sweden)

    Andrejević-Stošović Miona

    2010-01-01

    Full Text Available In this paper, we apply artificial neural networks (ANNs to the diagnosis of a mixed-mode electronic circuit. In order to tackle the circuit complexity and to reduce the number of test points hierarchical approach to the diagnosis generation was implemented with two levels of decision: the system level and the circuit level. For every level, using the simulation-before-test (SBT approach, fault dictionary was created first, containing data relating the fault code and the circuit response for a given input signal. Also, hypercomputing was implemented, i.e. we used parallel simulation of large number of replicas of the original circuit with faults inserted to achieve fast creation of the fault dictionary. ANNs were used to model the fault dictionaries. At the topmost level, the fault dictionary was split into parts simplifying the implementation of the concept. During the learning phase, the ANNs were considered as an approximation algorithm to capture the mapping enclosed within the fault dictionary. Later on, in the diagnostic phase, the ANNs were used as an algorithm for searching the fault dictionary. A voting system was created at the topmost level in order to distinguish which ANN output is to be accepted as the final diagnostic statement. The approach was tested on an example of an analog-to-digital converter.

  15. Fuzzy/Kalman Hierarchical Horizontal Motion Control of Underactuated ROVs

    Directory of Open Access Journals (Sweden)

    Francesco M. Raimondi

    2010-06-01

    Full Text Available A new closed loop fuzzy motion control system including on-line Kalman's filter (KF for the two dimensional motion of underactuated and underwater Remotely Operated Vehicle (ROV is presented. Since the sway force is unactuated, new continuous and discrete time models are developed using a polar transformation. A new hierarchical control architecture is developed, where the high level fuzzy guidance controller generates the surge speed and the yaw rate needed to achieve the objective of planar motion, while the low level controller gives the thruster surge force and the yaw torque control signals. The Fuzzy controller ensures robustness with respect to uncertainties due to the marine environment, forward surge speed and saturation of the control signals. Also Lyapunov's stability of the motion errors is proved based on the properties of the fuzzy maps. If Inertial Measurement Unit data (IMU is employed for the feedback directly, aleatory noises due to accelerometers and gyros damage the performances of the motion control. These noises denote a kind of non parametric uncertainty which perturbs the model of the ROV. Therefore a KF is inserted in the feedback of the control system to compensate for the above uncertainties and estimate the feedback signals with more precision.

  16. Hierarchical Parallelization of Gene Differential Association Analysis

    Directory of Open Access Journals (Sweden)

    Dwarkadas Sandhya

    2011-09-01

    Full Text Available Abstract Background Microarray gene differential expression analysis is a widely used technique that deals with high dimensional data and is computationally intensive for permutation-based procedures. Microarray gene differential association analysis is even more computationally demanding and must take advantage of multicore computing technology, which is the driving force behind increasing compute power in recent years. In this paper, we present a two-layer hierarchical parallel implementation of gene differential association analysis. It takes advantage of both fine- and coarse-grain (with granularity defined by the frequency of communication parallelism in order to effectively leverage the non-uniform nature of parallel processing available in the cutting-edge systems of today. Results Our results show that this hierarchical strategy matches data sharing behavior to the properties of the underlying hardware, thereby reducing the memory and bandwidth needs of the application. The resulting improved efficiency reduces computation time and allows the gene differential association analysis code to scale its execution with the number of processors. The code and biological data used in this study are downloadable from http://www.urmc.rochester.edu/biostat/people/faculty/hu.cfm. Conclusions The performance sweet spot occurs when using a number of threads per MPI process that allows the working sets of the corresponding MPI processes running on the multicore to fit within the machine cache. Hence, we suggest that practitioners follow this principle in selecting the appropriate number of MPI processes and threads within each MPI process for their cluster configurations. We believe that the principles of this hierarchical approach to parallelization can be utilized in the parallelization of other computationally demanding kernels.

  17. Three Layer Hierarchical Model for Chord

    Directory of Open Access Journals (Sweden)

    Waqas A. Imtiaz

    2012-12-01

    Full Text Available Increasing popularity of decentralized Peer-to-Peer (P2P architecture emphasizes on the need to come across an overlay structure that can provide efficient content discovery mechanism, accommodate high churn rate and adapt to failures in the presence of heterogeneity among the peers. Traditional p2p systems incorporate distributed client-server communication, which finds the peer efficiently that store a desires data item, with minimum delay and reduced overhead. However traditional models are not able to solve the problems relating scalability and high churn rates. Hierarchical model were introduced to provide better fault isolation, effective bandwidth utilization, a superior adaptation to the underlying physical network and a reduction of the lookup path length as additional advantages. It is more efficient and easier to manage than traditional p2p networks. This paper discusses a further step in p2p hierarchy via 3-layers hierarchical model with distributed database architecture in different layer, each of which is connected through its root. The peers are divided into three categories according to their physical stability and strength. They are Ultra Super-peer, Super-peer and Ordinary Peer and we assign these peers to first, second and third level of hierarchy respectively. Peers in a group in lower layer have their own local database which hold as associated super-peer in middle layer and access the database among the peers through user queries. In our 3-layer hierarchical model for DHT algorithms, we used an advanced Chord algorithm with optimized finger table which can remove the redundant entry in the finger table in upper layer that influences the system to reduce the lookup latency. Our research work finally resulted that our model really provides faster search since the network lookup latency is decreased by reducing the number of hops. The peers in such network then can contribute with improve functionality and can perform well in

  18. Hierarchical bismuth phosphate microspheres with high photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Lizhai; Wei, Tian; Lin, Nan; Yu, Haiyun [Anhui University of Technology, Ma' anshan (China). Key Laboratory of Materials Science and Processing of Anhui Province

    2016-05-15

    Hierarchical bismuth phosphate microspheres have been prepared by a simple hydrothermal process with polyvinyl pyrrolidone. Scanning electron microscopy observations show that the hierarchical bismuth phosphate microspheres consist of nanosheets with a thickness of about 30 nm. The diameter of the microspheres is about 1 - 3 μm. X-ray diffraction analysis shows that the microspheres are comprised of triclinic Bi{sub 23}P{sub 4}O{sub 44.5} phase. The formation of the hierarchical microspheres depends on polyvinyl pyrrolidone concentration, hydrothermal temperature and reaction time. Gentian violet acts as the pollutant model for investigating the photocatalytic activity of the hierarchical bismuth phosphate microspheres under ultraviolet-visible light irradiation. Irradiation time, dosage of the hierarchical microspheres and initial gentian violet concentration on the photocatalytic efficiency are also discussed. The hierarchical bismuth phosphate microspheres show good photocatalytic performance for gentian violet removal in aqueous solution.

  19. Electronic Properties in a Hierarchical Multilayer Structure

    Institute of Scientific and Technical Information of China (English)

    ZHU Chen-Ping; XIONG Shi-Jie

    2001-01-01

    We investigate electronic properties of a hierarchical multilayer structure consisting of stacking of barriers and wells. The structure is formed in a sequence of generations, each of which is constructed with the same pattern but with the previous generation as the basic building blocks. We calculate the transmission spectrum which shows the multifractal behavior for systems with large generation index. From the analysis of the average resistivity and the multifractal structure of the wavefunctions, we show that there exist different types of states exhibiting extended, localized and intermediate characteristics. The degree of localization is sensitive to the variation of the structural parameters.Suggestion of the possible experimental realization is discussed.

  20. Mechanics of hierarchical 3-D nanofoams

    Science.gov (United States)

    Chen, Q.; Pugno, N. M.

    2012-01-01

    In this paper, we study the mechanics of new three-dimensional hierarchical open-cell foams, and, in particular, its Young's modulus and plastic strength. We incorporate the effects of the surface elasticity and surface residual stress in the linear elastic and plastic analyses. The results show that, as the cross-sectional dimension decreases, the influences of the surface effect on Young's modulus and plastic strength increase, and the surface effect makes the solid stiffer and stronger; similarly, as level n increases, these quantities approach to those of the classical theory as lower bounds.