WorldWideScience

Sample records for hierarchical mass storage

  1. Functional units and lead topologies: a hierarchical framework for observing and modeling the interplay of structures, storage dynamics and integral mass and energy flows in lower mesoscale catchments

    Science.gov (United States)

    Zehe, Erwin; Jackisch, Conrad; Blume, Theresa; Haßler, Sibylle; Allroggen, Niklas; Tronicke, Jens

    2013-04-01

    The CAOS Research Unit recently proposed a hierarchical classification scheme to subdivide a catchment into what we vaguely name classes of functional entities that puts the gradients driving mass and energy flows and their controls on top of the hierarchy and the arrangement of landscape attributes controlling flow resistances along these driving gradients (for instance soil types and apparent preferential pathways) at the second level. We name these functional entities lead topology classes, to highlight that they are characterized by a spatially ordered arrangement of landscape elements along a superordinate driving gradient. Our idea is that these lead topology classes have a distinct way how their structural and textural architecture controls the interplay of storage dynamics and integral response behavior that is typical for all members of a class, but is dissimilar between different classes. This implies that we might gain exemplary understanding of the typical dynamic behavior of the class, when thoroughly studying a few class members. We propose that the main integral catchment functions mass export and drainage, mass redistribution and storage, energy exchange with the atmosphere, as well as energy redistribution and storage - result from spatially organized interactions of processes within lead topologies that operate at different scale levels and partly dominate during different conditions. We distinguish: 1) Lead topologies controlling the land surface energy balance during radiation driven conditions at the plot/pedon scale level. In this case energy fluxes dominate and deplete a vertical temperature gradient that is build up by depleting a gradient in radiation fluxes. Water is a facilitator in this concert due to the high specific heat of vaporization. Slow vertical water fluxes in soil dominate, which are driven by vertical gradients in atmospheric water potential, chemical potential in the plant and in soil hydraulic potentials. 2) Lead topologies

  2. Hierarchical majorana neutrinos from democratic mass matrices

    Science.gov (United States)

    Yang, Masaki J. S.

    2016-09-01

    In this paper, we obtain the light neutrino masses and mixings consistent with the experiments, in the democratic texture approach. The essential ansatz is that νRi are assumed to transform as "right-handed fields" 2R +1R under the S3L ×S3R symmetry. The symmetry breaking terms are assumed to be diagonal and hierarchical. This setup only allows the normal hierarchy of the neutrino mass, and excludes both of inverted hierarchical and degenerated neutrinos. Although the neutrino sector has nine free parameters, several predictions are obtained at the leading order. When we neglect the smallest parameters ζν and ζR, all components of the mixing matrix UPMNS are expressed by the masses of light neutrinos and charged leptons. From the consistency between predicted and observed UPMNS, we obtain the lightest neutrino masses m1 = (1.1 → 1.4) meV, and the effective mass for the double beta decay ≃ 4.5 meV.

  3. Quark flavor mixings from hierarchical mass matrices

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Rohit [Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China); Rayat Institute of Engineering and Information Technology, Ropar (India); Zhou, Shun [Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China); Peking University, Center for High Energy Physics, Beijing (China)

    2016-05-15

    In this paper, we extend the Fritzsch ansatz of quark mass matrices while retaining their hierarchical structures and show that the main features of the Cabibbo-Kobayashi-Maskawa (CKM) matrix V, including vertical stroke V{sub us} vertical stroke ≅ vertical stroke V{sub cd} vertical stroke, vertical stroke V{sub cb} vertical stroke ≅ vertical stroke V{sub ts} vertical stroke and vertical stroke V{sub ub} vertical stroke / vertical stroke V{sub cb} vertical stroke < vertical stroke V{sub td} vertical stroke / vertical stroke V{sub ts} vertical stroke can be well understood. This agreement is observed especially when the mass matrices have non-vanishing (1, 3) and (3, 1) off-diagonal elements. The phenomenological consequences of these for the allowed texture content and gross structural features of 'hierarchical' quark mass matrices are addressed from a model-independent prospective under the assumption of factorizable phases in these. The approximate and analytical expressions of the CKM matrix elements are derived and a detailed analysis reveals that such structures are in good agreement with the observed quark flavor mixing angles and the CP-violating phase at the 1σ level and call upon a further investigation of the realization of these structures from a top-down prospective. (orig.)

  4. Memory mass storage

    CERN Document Server

    Campardo, Giovanni; Iaculo, Massimo

    2011-01-01

    Covering all the fundamental storage technologies such as semiconductor, magnetic, optical and uncommon, this volume details their core characteristics. In addition, it includes an overview of the 'biological memory' of the human brain and its organization.

  5. HIERARCHICAL METHODOLOGY FOR MODELING HYDROGEN STORAGE SYSTEMS PART II: DETAILED MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, B; Donald L. Anton, D

    2008-12-22

    There is significant interest in hydrogen storage systems that employ a media which either adsorbs, absorbs or reacts with hydrogen in a nearly reversible manner. In any media based storage system the rate of hydrogen uptake and the system capacity is governed by a number of complex, coupled physical processes. To design and evaluate such storage systems, a comprehensive methodology was developed, consisting of a hierarchical sequence of models that range from scoping calculations to numerical models that couple reaction kinetics with heat and mass transfer for both the hydrogen charging and discharging phases. The scoping models were presented in Part I [1] of this two part series of papers. This paper describes a detailed numerical model that integrates the phenomena occurring when hydrogen is charged and discharged. A specific application of the methodology is made to a system using NaAlH{sub 4} as the storage media.

  6. Mass storage technology in networks

    Science.gov (United States)

    Ishii, Katsunori; Takeda, Toru; Itao, Kiyoshi; Kaneko, Reizo

    1990-08-01

    Trends and features of mass storage subsystems in network are surveyed and their key technologies spotlighted. Storage subsystems are becoming increasingly important in new network systems in which communications and data processing are systematically combined. These systems require a new class of high-performance mass-information storage in order to effectively utilize their processing power. The requirements of high transfer rates, high transactional rates and large storage capacities, coupled with high functionality, fault tolerance and flexibility in configuration, are major challenges in storage subsystems. Recent progress in optical disk technology has resulted in improved performance of on-line external memories to optical disk drives, which are competing with mid-range magnetic disks. Optical disks are more effective than magnetic disks in using low-traffic random-access file storing multimedia data that requires large capacity, such as in archive use and in information distribution use by ROM disks. Finally, it demonstrates image coded document file servers for local area network use that employ 130mm rewritable magneto-optical disk subsystems.

  7. Dynamic Non-Hierarchical File Systems for Exascale Storage

    Energy Technology Data Exchange (ETDEWEB)

    Long, Darrell E. [PI; Miller, Ethan L [Co PI

    2015-02-24

    This constitutes the final report for “Dynamic Non-Hierarchical File Systems for Exascale Storage”. The ultimate goal of this project was to improve data management in scientific computing and high-end computing (HEC) applications, and to achieve this goal we proposed: to develop the first, HEC-targeted, file system featuring rich metadata and provenance collection, extreme scalability, and future storage hardware integration as core design goals, and to evaluate and develop a flexible non-hierarchical file system interface suitable for providing more powerful and intuitive data management interfaces to HEC and scientific computing users. Data management is swiftly becoming a serious problem in the scientific community – while copious amounts of data are good for obtaining results, finding the right data is often daunting and sometimes impossible. Scientists participating in a Department of Energy workshop noted that most of their time was spent “...finding, processing, organizing, and moving data and it’s going to get much worse”. Scientists should not be forced to become data mining experts in order to retrieve the data they want, nor should they be expected to remember the naming convention they used several years ago for a set of experiments they now wish to revisit. Ideally, locating the data you need would be as easy as browsing the web. Unfortunately, existing data management approaches are usually based on hierarchical naming, a 40 year-old technology designed to manage thousands of files, not exabytes of data. Today’s systems do not take advantage of the rich array of metadata that current high-end computing (HEC) file systems can gather, including content-based metadata and provenance1 information. As a result, current metadata search approaches are typically ad hoc and often work by providing a parallel management system to the “main” file system, as is done in Linux (the locate utility), personal computers, and enterprise search

  8. Hierarchical neutrino masses and mixing in flipped-SU(5)

    Energy Technology Data Exchange (ETDEWEB)

    Rizos, J. [Physics Department, University of Ioannina, 45110 Ioannina (Greece); Tamvakis, K., E-mail: tamvakis@uoi.g [Physics Department, University of Ioannina, 45110 Ioannina (Greece); Physics Department, CERN, CH-1211, Geneva 23 (Switzerland)

    2010-02-22

    We consider the problem of neutrino masses and mixing in the framework of flipped SU(5). The right-handed neutrino mass, generated through the operation of a seesaw mechanism by a sector of gauge singlets, leads naturally, at a subsequent level, to the standard seesaw mechanism resulting into three light neutrino states with masses of the desired phenomenological order of magnitude. In this framework we study simple Ansaetze for the singlet couplings for which hierarchical neutrino masses emerge naturally as lambda{sup n}:lambda:1 or lambda{sup n}:lambda{sup 2}:1, parametrized in terms of the Cabbibo parameter. The resulting neutrino mixing matrices are characterized by a hierarchical structure, in which theta{sub 13} is always predicted to be the smallest. Finally, we discuss a possible factorized parametrization of the neutrino mass that, in addition to Cabbibo mixing, encodes also mixing due to the singlet sector.

  9. Quark Masses and Mixings with Hierarchical Friedberg-Lee Symmetry

    CERN Document Server

    Araki, T

    2010-01-01

    We propose the hierarchically translating Friedberg-Lee (FL) symmetry for the quark sector and show that the symmetry closely relates to both quark masses and mixings angles. We also extend our scheme to the fourth generation quark model and find the relation $|V_{tb^{'}}| \\simeq |V_{t^{'}b}| \\simeq m_b/m_{b^{'}}199 \\gev$.

  10. Data Acquisition and Mass Storage

    Science.gov (United States)

    Vande Vyvre, P.

    2004-08-01

    The experiments performed at supercolliders will constitute a new challenge in several disciplines of High Energy Physics and Information Technology. This will definitely be the case for data acquisition and mass storage. The microelectronics, communication, and computing industries are maintaining an exponential increase of the performance of their products. The market of commodity products remains the largest and the most competitive market of technology products. This constitutes a strong incentive to use these commodity products extensively as components to build the data acquisition and computing infrastructures of the future generation of experiments. The present generation of experiments in Europe and in the US already constitutes an important step in this direction. The experience acquired in the design and the construction of the present experiments has to be complemented by a large R&D effort executed with good awareness of industry developments. The future experiments will also be expected to follow major trends of our present world: deliver physics results faster and become more and more visible and accessible. The present evolution of the technologies and the burgeoning of GRID projects indicate that these trends will be made possible. This paper includes a brief overview of the technologies currently used for the different tasks of the experimental data chain: data acquisition, selection, storage, processing, and analysis. The major trends of the computing and networking technologies are then indicated with particular attention paid to their influence on the future experiments. Finally, the vision of future data acquisition and processing systems and their promise for future supercolliders is presented.

  11. ICI optical data storage tape: An archival mass storage media

    Science.gov (United States)

    Ruddick, Andrew J.

    1993-01-01

    At the 1991 Conference on Mass Storage Systems and Technologies, ICI Imagedata presented a paper which introduced ICI Optical Data Storage Tape. This paper placed specific emphasis on the media characteristics and initial data was presented which illustrated the archival stability of the media. More exhaustive analysis that was carried out on the chemical stability of the media is covered. Equally important, it also addresses archive management issues associated with, for example, the benefits of reduced rewind requirements to accommodate tape relaxation effects that result from careful tribology control in ICI Optical Tape media. ICI Optical Tape media was designed to meet the most demanding requirements of archival mass storage. It is envisaged that the volumetric data capacity, long term stability and low maintenance characteristics demonstrated will have major benefits in increasing reliability and reducing the costs associated with archival storage of large data volumes.

  12. Origin of Hierarchical Structures of Quark and Lepton Mass Matrices

    CERN Document Server

    Koide, Yoshio

    2015-01-01

    It is shown that the so-called "Yukawaon" model can give a unified description of masses, mixing and $CP$ violation parameters of quarks and leptons without using any hierarchical (family number-dependent) parameters besides the charged lepton masses. Here, we have introduced a phase matrix $P={\\rm daig}(e^{i \\phi_1}, e^{i \\phi_2}, e^{i \\phi_3})$ with the phase parameters $(\\phi_1, \\phi_2, \\phi_3)$ which are described in terms of family number-independent parameters, together with using only the charged lepton mass parameters as the family number-dependent parameters. In this paper, the $CP$ violating phase parameters $\\delta_{CP}^q$ and $\\delta_{CP}^\\ell$ in the standard expression of $V_{CKM}$ and $U_{PMNS}$ are predicted as $\\delta_{CP}^q \\simeq 72^\\circ$ and $\\delta_{CP}^\\ell \\simeq -76^\\circ$, respectively, i.e. $\\delta_{CP}^\\ell \\sim - \\delta_{CP}^q$.

  13. Hierarchical predictive control scheme for distributed energy storage integrated with residential demand and photovoltaic generation

    NARCIS (Netherlands)

    Lampropoulos, I.; Garoufalis, P.; van den Bosch, P.P.J.; Kling, W.L.

    2015-01-01

    A hierarchical control scheme is defined for the energy management of a battery energy storage system which is integrated in a low-voltage distribution grid with residential customers and photovoltaic installations. The scope is the economic optimisation of the integrated system by employing predict

  14. Storage and retrieval of mass spectral information

    Science.gov (United States)

    Hohn, M. E.; Humberston, M. J.; Eglinton, G.

    1977-01-01

    Computer handling of mass spectra serves two main purposes: the interpretation of the occasional, problematic mass spectrum, and the identification of the large number of spectra generated in the gas-chromatographic-mass spectrometric (GC-MS) analysis of complex natural and synthetic mixtures. Methods available fall into the three categories of library search, artificial intelligence, and learning machine. Optional procedures for coding, abbreviating and filtering a library of spectra minimize time and storage requirements. Newer techniques make increasing use of probability and information theory in accessing files of mass spectral information.

  15. Hierarchical electrode architectures for electrical energy storage & conversion.

    Energy Technology Data Exchange (ETDEWEB)

    Zavadil, Kevin Robert; Missert, Nancy A.; Shelnutt, John Allen; van Swol, Frank B.

    2012-01-01

    The integration and stability of electrocatalytic nanostructures, which represent one level of porosity in a hierarchical structural scheme when combined with a three-dimensional support scaffold, has been studied using a combination of synthetic processes, characterization techniques, and computational methods. Dendritic platinum nanostructures have been covalently linked to common electrode surfaces using a newly developed chemical route; a chemical route equally applicable to a range of metals, oxides, and semiconductive materials. Characterization of the resulting bound nanostructure system confirms successful binding, while electrochemistry and microscopy demonstrate the viability of these electroactive particles. Scanning tunneling microscopy has been used to image and validate the short-term stability of several electrode-bound platinum dendritic sheet structures toward Oswald ripening. Kinetic Monte Carlo methods have been applied to develop an understanding of the stability of the basic nano-scale porous platinum sheets as they transform from an initial dendrite to hole containing sheets. Alternate synthetic strategies were pursued to grow dendritic platinum structures directly onto subunits (graphitic particles) of the electrode scaffold. A two-step photocatalytic seeding process proved successful at generating desirable nano-scale porous structures. Growth in-place is an alternate strategy to the covalent linking of the electrocatalytic nanostructures.

  16. Modernizing the monitoring of Mass Storage systems

    CERN Document Server

    Terrien, Alexandre

    2016-01-01

    The monitoring of a system is essential to ensure its efficiency. On a computer system, this monitoring is partly done via the analysis of log messages. The monitoring of CASTOR, a mass-storage system responsible for the storage of 150Pb of scientific data at CERN, was being done with tools developed by the IT-ST-FDO section. Those tools recently encountered some performance limitations due to the increase in the quantity of data produced by CERN's experiments. In this paper, I will describe how I managed to modernize CASTOR's monitoring tools by leveraging services centrally managed by CERN's IT department.

  17. Leptogenesis beyond the limit of hierarchical heavy neutrino masses

    CERN Document Server

    Blanchet, S; Blanchet, Steve; Bari, Pasquale Di

    2006-01-01

    We calculate the baryon asymmetry of the Universe in thermal leptogenesis beyond the usual lightest right-handed (RH) neutrino dominated scenario (N_1DS) and in particular beyond the hierarchical limit (HL), M_1 << M_2 << M_3, for the RH neutrino mass spectrum. After providing some orientation among the large variety of models, we first revisit the central role of the N_1DS, with new insights on the dynamics of the asymmetry generation and then discuss the main routes departing from it, focusing on models beyond the HL. We study in detail two examples of `strong-strong' wash-out scenarios: one with `maximal phase' and the limit of very large M_3, studying the effects arising when delta_2=(M_2-M_1)/M_1 is small. We extend analytical methods already applied to the N_1DS showing, for example, that, in the degenerate limit (DL), the efficiency factors of the RH neutrinos become equal with the single decay parameter replaced by the sum. Both cases disprove the misconception that close RH neutrino masse...

  18. Hierarchical MoS2@RGO nanosheets for high performance sodium storage

    Science.gov (United States)

    Che, Zongzhou; Li, Yafeng; Chen, Kaixiang; Wei, Mingdeng

    2016-11-01

    The hierarchical MoS2/carbonaceous materials composites have received considerable interest for electrochemical energy storage and conversion. In the present work, the hierarchical MoS2@RGO nanosheets, where ultrathin MoS2 nanosheets perpendicularly anchor on both sides of RGO, are successfully synthesized by a new route. Such hybrid structures not only improve the conductivity of the hybrid structure and effectively prevent the aggregation of MoS2 nanosheets, but also maximize the MoS2 loading in the MoS2@RGO composites to be over 92%. The formation process for the hierarchical MoS2@RGO nanosheets is also investigated. When evaluated as an anode material for sodium-ion batteries, the hierarchical MoS2@RGO nanosheets deliver an excellent cycling performance and a high specific capacity of 420 mA h g-1 at a current density of 100 mA g-1. The strategy can be used to prepare other hierarchical metal sulfides@RGO nanosheets as high performance anode materials for sodium-ion batteries.

  19. Hierarchically structured carbon nanotubes for energy conversion and storage

    Science.gov (United States)

    Du, Feng

    As the world population continues to increase, large amounts of energy are consumed. Reality pushes us to find new energy or use our current energy more efficiently. Researches on energy conversion and storage have become increasingly important and essential. This grand challenge research has led to a recent focus on nanostructured materials. Carbon nanomaterials such as carbon nanotubes (CNTs) play a critical role in all of these nanotechnology challenges. CNTs have a very large surface area, a high electrochemical accessibility, high electronic conductivity and strong mechanical properties. This combination of properties makes them promising materials for energy device applications, such as FETs, supercapacitors, fuel cells, and lithium batteries. This study focuses on exploring the possibility of using vertically aligned carbon nanotubes (VA-CNTs) as the electrode materials in these energy applications. For the application of electrode materials, electrical conductive, vertically aligned CNTs with controllable length and diameter were synthesized. Several CVD methods for VA-CNT growth have been explored, although the iron / aluminum pre-coated catalyst CVD system was the main focus. A systematic study of several factors, including growth time, temperature, gas ratio, catalyst coating was conducted. The mechanism of VA-CNTs was discussed and a model for VA-CNT length / time was proposed to explain the CNT growth rate. Furthermore, the preferential growth of semiconducting (up to 96 atom% carbon) VA-SWNTs by using a plasma enhanced CVD process combined with fast heating was also explored, and these semiconducting materials have been directly used for making FETs using simple dispersion in organic solvent, without any separation and purification. Also, by inserting electron-accepting nitrogen atoms into the conjugated VA-CNT structure during the growth process, we synthesized vertically aligned nitrogen containing carbon nanotubes (VA-NCNTs). After purification of

  20. Rapid Framing Mass Storage System on the Internet

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Mass storage system is now very important for storing huge volume of data in many application system such as VOD systems, electronic library, scientific computation and so on. Besides the storage device and network devices, the real performance of mass storage system is greatly influenced by the connection way between the host and storage system. Here we propose a new design of mass storage system by promoting the storage devices' functions and involving them directly into data delivering. It can easily meet the demands both for capacity and I/O bandwidth in those applications, and has better service quality and performance compared with the traditional system in delivering mass data over network.

  1. Pure Nanoscale Morphology Effect Enhancing the Energy Storage Characteristics of Processable Hierarchical Polypyrrole.

    Science.gov (United States)

    Wannapob, Rodtichoti; Vagin, Mikhail Yu; Jeerapan, Itthipon; Mak, Wing Cheung

    2015-11-03

    We report a new synthesis approach for the precise control of wall morphologies of colloidal polypyrrole microparticles (PPyMPs) based on a time-dependent template-assisted polymerization technique. The resulting PPyMPs are water processable, allowing the simple and direct fabrication of multilevel hierarchical PPyMPs films for energy storage via a self-assembly process, whereas convention methods creating hierarchical conducting films based on electrochemical polymerization are complicated and tedious. This approach allows the rational design and fabrication of PPyMPs with well-defined size and tunable wall morphology, while the chemical composition, zeta potential, and microdiameter of the PPyMPs are well characterized. By precisely controlling the wall morphology of the PPyMPs, we observed a pure nanoscale morphological effect of the materials on the energy storage performance. We demonstrated by controlling purely the wall morphology of PPyMPs to around 100 nm (i.e., thin-walled PPyMPs) that the thin-walled PPyMPs exhibit typical supercapacitor characteristics with a significant enhancement of charge storage performance of up to 290% compared to that of thick-walled PPyMPs confirmed by cyclic voltametry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. We envision that the present design concept could be extended to different conducting polymers as well as other functional organic and inorganic dopants, which provides an innovative model for future study and understanding of the complex physicochemical phenomena of energy-related materials.

  2. Preparation and li storage properties of hierarchical porous carbon fibers derived from alginic acid.

    Science.gov (United States)

    Wu, Xing-Long; Chen, Li-Li; Xin, Sen; Yin, Ya-Xia; Guo, Yu-Guo; Kong, Qing-Shan; Xia, Yan-Zhi

    2010-06-21

    One-dimensional (1D) hierarchical porous carbon fibers (HPCFs) have been prepared by controlled carbonization of alginic acid fibers and investigated with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, nitrogen adsorption-desorption isotherms, and electrochemical tests toward lithium storage. The as-obtained HPCFs consist of a 3D network of nanosized carbon particles with diameters less than 10 nm and exhibit a hierarchical porous architecture composed of both micropores and mesopores. Electrochemical measurements show that HPCFs exhibit excellent rate capability and capacity retention compared with commercial graphite when employed as anode materials for lithium-ion batteries. At the discharge/charge rate of 45 C, the reversible capacity of HPCFs is still as high as 80 mA h g(-1) even after 1500 cycles, which is about five times larger than that of commercial graphite anode. The much improved electrochemical performances could be attributed to the nanosized building blocks, the hierarchical porous structure, and the 1D morphology of HPCFs.

  3. Hierarchical storage and visualization of real-time 3D data

    Science.gov (United States)

    Parry, Mitchell; Hannigan, Brendan; Ribarsky, William; Shaw, Christopher D.; Faust, Nickolas L.

    2001-08-01

    In this paper 'real-time 3D data' refers to volumetric data that are acquired and used as they are produced. Large scale, real-time data are difficult to store and analyze, either visually or by some other means, within the time frames required. Yet this is often quite important to do when decision-makers must receive and quickly act on new information. An example is weather forecasting, where forecasters must act on information received on severe storm development and movement. To meet the real-time requirements crude heuristics are often used to gather information from the original data. This is in spite of the fact that better and better real-time data are becoming available, the full use of which could significantly improve decisions. The work reported here addresses these issues by providing comprehensive data acquisition, analysis, and storage components with time budgets for the data management of each component. These components are put into a global geospatial hierarchical structure. The volumetric data are placed into this global structure, and it is shown how levels of detail can be derived and used within this structure. A volumetric visualization procedure is developed that conforms to the hierarchical structure and uses the levels of detail. These general methods are focused on the specific case of the VGIS global hierarchical structure and rendering system,. The real-time data considered are from collections of time- dependent 3D Doppler radars although the methods described here apply more generally to time-dependent volumetric data. This paper reports on the design and construction of the above hierarchical structures and volumetric visualizations. It also reports result for the specific application of 3D Doppler radar displayed over photo textured terrain height fields. Results are presented results for the specific application of 3D Doppler radar displayed over photo textured terrain height fields. Results are presented for display of time

  4. Hierarchical transport networks optimizing dynamic response of permeable energy-storage materials.

    Science.gov (United States)

    Nilson, Robert H; Griffiths, Stewart K

    2009-07-01

    Channel widths and spacing in latticelike hierarchical transport networks are optimized to achieve maximum extraction of gas or electrical charge from nanoporous energy-storage materials during charge and discharge cycles of specified duration. To address a range of physics, the effective transport diffusivity is taken to vary as a power, m , of channel width. Optimal channel widths and spacing in all levels of the hierarchy are found to increase in a power-law manner with normalized system size, facilitating the derivation of closed-form approximations for the optimal dimensions. Characteristic response times and ratios of channel width to spacing are both shown to vary by the factor 2/m between successive levels of any optimal hierarchy. This leads to fractal-like self-similar geometry, but only for m=2 . For this case of quadratic dependence of diffusivity on channel width, the introduction of transport channels permits increases in system size on the order of 10;{4} , 10;{8} , and 10;{10} , without any reduction in extraction efficiency, for hierarchies having 1, 2 and, 8 levels, respectively. However, we also find that for a given system size there is an optimum number of hierarchical levels that maximizes extraction efficiency.

  5. Superior lithium storage performance of hierarchical porous vanadium pentoxide nanofibers for lithium ion battery cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Bo [Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); National Key Laboratory of Power Sources, Tianjin Institute of Power Sources, Tianjin 300381 (China); Li, Xifei, E-mail: xfli2011@hotmail.com [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Bai, Zhimin, E-mail: zhimibai@cugb.edu.cn [Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Li, Minsi [Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Dong, Lei; Xiong, Dongbin [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Li, Dejun, E-mail: dejunli@mail.tjnu.edu.cn [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China)

    2015-06-15

    Highlights: • Hierarchical porous vanadium pentoxide nanofibers were synthesized by electrospinning. • V{sub 2}O{sub 5} nanofibers showed much enhanced lithium storage performance. • Kinetics process of electrospinning V{sub 2}O{sub 5} nanofibers was studied by means of EIS for the first time. • Strategies to enhance the electrochemical performance of V{sub 2}O{sub 5} electrode were concluded. - Abstract: The hierarchical V{sub 2}O{sub 5} nanofibers cathode materials with diameter of 200–400 nm are successfully synthesized via an electrospinning followed by annealing. Powder X-ray diffraction (XRD) pattern confirms the formation of phase-pure product. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) obviously display the hierarchical porous nanofibers constructed by attached tiny vanadium oxide nanoplates. Electrochemical behavior of the as-prepared product is systematically studied using galvanostatic charge/discharge testing, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). It turns out that in comparison to the commercial V{sub 2}O{sub 5} and other unique nanostructured materials in the literature, our V{sub 2}O{sub 5} nanofibers show much enhanced lithium storage capacity, improved cyclic stability, and higher rate capability. After 100 cycles at a current density of 800 mA g{sup −1}, the specific capacity of the V{sub 2}O{sub 5} nanofibers retain 133.9 mAh g{sup −1}, corresponding to high capacity retention of 96.05%. More importantly, the EIS at various discharge depths clearly reveal the kinetics process of the V{sub 2}O{sub 5} cathode reaction with lithium. Based on our results, the possible approach to improve the specific capacity and rate capability of the V{sub 2}O{sub 5} cathode material is proposed. It is expected that this study could accelerate the development of V{sub 2}O{sub 5} cathode in rechargeable lithium ion batteries.

  6. The INFN-CNAF Tier-1 GEMSS Mass Storage System and database facility activity

    Science.gov (United States)

    Ricci, Pier Paolo; Cavalli, Alessandro; Dell'Agnello, Luca; Favaro, Matteo; Gregori, Daniele; Prosperini, Andrea; Pezzi, Michele; Sapunenko, Vladimir; Zizzi, Giovanni; Vagnoni, Vincenzo

    2015-05-01

    The consolidation of Mass Storage services at the INFN-CNAF Tier1 Storage department that has occurred during the last 5 years, resulted in a reliable, high performance and moderately easy-to-manage facility that provides data access, archive, backup and database services to several different use cases. At present, the GEMSS Mass Storage System, developed and installed at CNAF and based upon an integration between the IBM GPFS parallel filesystem and the Tivoli Storage Manager (TSM) tape management software, is one of the largest hierarchical storage sites in Europe. It provides storage resources for about 12% of LHC data, as well as for data of other non-LHC experiments. Files are accessed using standard SRM Grid services provided by the Storage Resource Manager (StoRM), also developed at CNAF. Data access is also provided by XRootD and HTTP/WebDaV endpoints. Besides these services, an Oracle database facility is in production characterized by an effective level of parallelism, redundancy and availability. This facility is running databases for storing and accessing relational data objects and for providing database services to the currently active use cases. It takes advantage of several Oracle technologies, like Real Application Cluster (RAC), Automatic Storage Manager (ASM) and Enterprise Manager centralized management tools, together with other technologies for performance optimization, ease of management and downtime reduction. The aim of the present paper is to illustrate the state-of-the-art of the INFN-CNAF Tier1 Storage department infrastructures and software services, and to give a brief outlook to forthcoming projects. A description of the administrative, monitoring and problem-tracking tools that play a primary role in managing the whole storage framework is also given.

  7. Sodium and Lithium Storage Properties of Spray-Dried Molybdenum Disulfide-Graphene Hierarchical Microspheres

    Science.gov (United States)

    Kalluri, Sujith; Seng, Kuok Hau; Guo, Zaiping; Du, Aijun; Konstantinov, Konstantin; Liu, Hua Kun; Dou, Shi Xue

    2015-07-01

    Developing nano/micro-structures which can effectively upgrade the intriguing properties of electrode materials for energy storage devices is always a key research topic. Ultrathin nanosheets were proved to be one of the potential nanostructures due to their high specific surface area, good active contact areas and porous channels. Herein, we report a unique hierarchical micro-spherical morphology of well-stacked and completely miscible molybdenum disulfide (MoS2) nanosheets and graphene sheets, were successfully synthesized via a simple and industrial scale spray-drying technique to take the advantages of both MoS2 and graphene in terms of their high practical capacity values and high electronic conductivity, respectively. Computational studies were performed to understand the interfacial behaviour of MoS2 and graphene, which proves high stability of the composite with high interfacial binding energy (-2.02 eV) among them. Further, the lithium and sodium storage properties have been tested and reveal excellent cyclic stability over 250 and 500 cycles, respectively, with the highest initial capacity values of 1300 mAh g-1 and 640 mAh g-1 at 0.1 A g-1.

  8. StoRM-GPFS-TSM: A new approach to hierarchical storage management for the LHC experiments

    Energy Technology Data Exchange (ETDEWEB)

    Cavalli, A; Dell' Agnello, L; Ghiselli, A; Gregori, D; Magnoni, L; Martelli, B; Mazzucato, M; Prosperini, A; Ricci, P P; Ronchieri, E; Sapunenko, V; Vitlacil, D; Zappi, R [INFN-CNAF, viale Berti-Pichat 6/2, 40127 Bologna (Italy); Vagnoni, V [INFN-Bologna, via Irnerio 46, 40126 Bologna (Italy)

    2010-04-01

    The mass storage challenge for the experiments at the Large Hadron Collider (LHC) is still nowadays a critical issue for the various Tier-1 computing centres and the Tier-0 centre involved in the custodial and analysis of the data produced by the experiments. In particular, the requirements for the tape mass storage systems are quite strong, amounting to about 15 PB of data produced annually that should be available for near-line access at any time. Besides the solutions already widely employed by the High Energy Physics community so far, INFN-CNAF has approched, in the last year, a solution based on the collaboration between the General Parallel File System (GPFS) and the Tivoli Storage Manager (TSM) by IBM and StoRM as Storage Resource Management (SRM) interface, developed at INFN. The new features available in GPFS version 3.2 allow in general to interface GPFS with any tape storage manager. We implemented such an interface for TSM, and we performed various performance studies on a prototype testbed system. The first StoRM/GPFS/TSM based system is already in production at CNAF for T1D1 Storage Class; it is used by the LHCb experiment. Currently we are performing new tests to exploit features implemented in the new versione of TSM 6.1. These features are focused in high performance and optimized access to the tape backend. We will describe the implementation of the interface and details of the prototype testbed for T1D0 SC and we will discuss the results of the LHCb production system.

  9. Bayesian Mass Estimates of the Milky Way: Including measurement uncertainties with hierarchical Bayes

    CERN Document Server

    Eadie, Gwendolyn; Harris, William

    2016-01-01

    We present a hierarchical Bayesian method for estimating the total mass and mass profile of the Milky Way Galaxy. The new hierarchical Bayesian approach further improves the framework presented by Eadie, Harris, & Widrow (2015) and Eadie & Harris (2016) and builds upon the preliminary reports by Eadie et al (2015a,c). The method uses a distribution function $f(\\mathcal{E},L)$ to model the galaxy and kinematic data from satellite objects such as globular clusters to trace the Galaxy's gravitational potential. A major advantage of the method is that it not only includes complete and incomplete data simultaneously in the analysis, but also incorporates measurement uncertainties in a coherent and meaningful way. We first test the hierarchical Bayesian framework, which includes measurement uncertainties, using the same data and power-law model assumed in Eadie & Harris (2016), and find the results are similar but more strongly constrained. Next, we take advantage of the new statistical framework and in...

  10. Quark masses and mixings with hierarchical Friedberg-Lee symmetry

    Science.gov (United States)

    Araki, Takeshi; Geng, C. Q.

    2010-04-01

    We consider the Friedberg-Lee symmetry for the quark sector and show that the symmetry closely relates to both quark masses and mixing angles. We also extend our scheme to the fourth generation quark model and find the relation |Vtb'|≃|Vt'b|≃mb/mb'199GeV.

  11. Building and managing high performance, scalable, commodity mass storage systems

    Science.gov (United States)

    Lekashman, John

    1998-01-01

    The NAS Systems Division has recently embarked on a significant new way of handling the mass storage problem. One of the basic goals of this new development are to build systems at very large capacity and high performance, yet have the advantages of commodity products. The central design philosophy is to build storage systems the way the Internet was built. Competitive, survivable, expandable, and wide open. The thrust of this paper is to describe the motivation for this effort, what we mean by commodity mass storage, what the implications are for a facility that performs such an action, and where we think it will lead.

  12. Hierarchically designed three-dimensional macro/mesoporous carbon frameworks for advanced electrochemical capacitance storage.

    Science.gov (United States)

    Yang, Yanbing; Li, Peixu; Wu, Shiting; Li, Xinyang; Shi, Enzheng; Shen, Qicang; Wu, Dehai; Xu, Wenjing; Cao, Anyuan; Yuan, Quan

    2015-04-13

    Mesoporous carbon (m-C) has potential applications as porous electrodes for electrochemical energy storage, but its applications have been severely limited by the inherent fragility and low electrical conductivity. A rational strategy is presented to construct m-C into hierarchical porous structures with high flexibility by using a carbon nanotube (CNT) sponge as a three-dimensional template, and grafting Pt nanoparticles at the m-C surface. This method involves several controllable steps including solution deposition of a mesoporous silica (m-SiO2 ) layer onto CNTs, chemical vapor deposition of acetylene, and etching of m-SiO2 , resulting in a CNT@m-C core-shell or a CNT@m-C@Pt core-shell hybrid structure after Pt adsorption. The underlying CNT network provides a robust yet flexible support and a high electrical conductivity, whereas the m-C provides large surface area, and the Pt nanoparticles improves interfacial electron and ion diffusion. Consequently, specific capacitances of 203 and 311 F g(-1) have been achieved in these CNT@m-C and CNT@m-C@Pt sponges as supercapacitor electrodes, respectively, which can retain 96 % of original capacitance under large degree compression.

  13. NASA Langley Research Center's distributed mass storage system

    Science.gov (United States)

    Pao, Juliet Z.; Humes, D. Creig

    1993-01-01

    There is a trend in institutions with high performance computing and data management requirements to explore mass storage systems with peripherals directly attached to a high speed network. The Distributed Mass Storage System (DMSS) Project at NASA LaRC is building such a system and expects to put it into production use by the end of 1993. This paper presents the design of the DMSS, some experiences in its development and use, and a performance analysis of its capabilities. The special features of this system are: (1) workstation class file servers running UniTree software; (2) third party I/O; (3) HIPPI network; (4) HIPPI/IPI3 disk array systems; (5) Storage Technology Corporation (STK) ACS 4400 automatic cartridge system; (6) CRAY Research Incorporated (CRI) CRAY Y-MP and CRAY-2 clients; (7) file server redundancy provision; and (8) a transition mechanism from the existent mass storage system to the DMSS.

  14. Scalable synthesis of hierarchically structured carbon nanotube-graphene fibres for capacitive energy storage.

    Science.gov (United States)

    Yu, Dingshan; Goh, Kunli; Wang, Hong; Wei, Li; Jiang, Wenchao; Zhang, Qiang; Dai, Liming; Chen, Yuan

    2014-07-01

    Micro-supercapacitors are promising energy storage devices that can complement or even replace batteries in miniaturized portable electronics and microelectromechanical systems. Their main limitation, however, is the low volumetric energy density when compared with batteries. Here, we describe a hierarchically structured carbon microfibre made of an interconnected network of aligned single-walled carbon nanotubes with interposed nitrogen-doped reduced graphene oxide sheets. The nanomaterials form mesoporous structures of large specific surface area (396 m(2) g(-1)) and high electrical conductivity (102 S cm(-1)). We develop a scalable method to continuously produce the fibres using a silica capillary column functioning as a hydrothermal microreactor. The resultant fibres show a specific volumetric capacity as high as 305 F cm(-3) in sulphuric acid (measured at 73.5 mA cm(-3) in a three-electrode cell) or 300 F cm(-3) in polyvinyl alcohol (PVA)/H(3)PO(4) electrolyte (measured at 26.7 mA cm(-3) in a two-electrode cell). A full micro-supercapacitor with PVA/H(3)PO(4) gel electrolyte, free from binder, current collector and separator, has a volumetric energy density of ∼6.3 mWh cm(-3) (a value comparable to that of 4 V-500 µAh thin-film lithium batteries) while maintaining a power density more than two orders of magnitude higher than that of batteries, as well as a long cycle life. To demonstrate that our fibre-based, all-solid-state micro-supercapacitors can be easily integrated into miniaturized flexible devices, we use them to power an ultraviolet photodetector and a light-emitting diode.

  15. Scalable synthesis of hierarchically structured carbon nanotube-graphene fibres for capacitive energy storage

    Science.gov (United States)

    Yu, Dingshan; Goh, Kunli; Wang, Hong; Wei, Li; Jiang, Wenchao; Zhang, Qiang; Dai, Liming; Chen, Yuan

    2014-07-01

    Micro-supercapacitors are promising energy storage devices that can complement or even replace batteries in miniaturized portable electronics and microelectromechanical systems. Their main limitation, however, is the low volumetric energy density when compared with batteries. Here, we describe a hierarchically structured carbon microfibre made of an interconnected network of aligned single-walled carbon nanotubes with interposed nitrogen-doped reduced graphene oxide sheets. The nanomaterials form mesoporous structures of large specific surface area (396 m2 g-1) and high electrical conductivity (102 S cm-1). We develop a scalable method to continuously produce the fibres using a silica capillary column functioning as a hydrothermal microreactor. The resultant fibres show a specific volumetric capacity as high as 305 F cm-3 in sulphuric acid (measured at 73.5 mA cm-3 in a three-electrode cell) or 300 F cm-3 in polyvinyl alcohol (PVA)/H3PO4 electrolyte (measured at 26.7 mA cm-3 in a two-electrode cell). A full micro-supercapacitor with PVA/H3PO4 gel electrolyte, free from binder, current collector and separator, has a volumetric energy density of ~6.3 mWh cm-3 (a value comparable to that of 4 V-500 µAh thin-film lithium batteries) while maintaining a power density more than two orders of magnitude higher than that of batteries, as well as a long cycle life. To demonstrate that our fibre-based, all-solid-state micro-supercapacitors can be easily integrated into miniaturized flexible devices, we use them to power an ultraviolet photodetector and a light-emitting diode.

  16. GE networked mass storage solutions supporting IEEE network mass storage model

    Science.gov (United States)

    Herzog, Donald

    1993-01-01

    The General Electric Government Communications Systems Department (GE/GCSD) has developed a near real time digital data storage and retrieval system that extends the capabilities currently available in today's marketplace. This system called DuraStore uses commercially available rotary tape drive technology with ANSI/IEEE standards for automated magnetic tape based data storage. It uses a nonproprietary approach to satisfy a wide range of data rates and storage capabilities requirements and is compliant with the IEEE Network Storage Model. Rotary tape drives, standard interfaces, application specific hardware/software, networked automated tape libraries, library administrator, write protection, volume/physical media linkages, and maximum resource utilization are addressed.

  17. Evolution of the Luminosity-Metallicity-Stellar Mass correlation in a hierarchical scenario

    CERN Document Server

    De Rossi, M E; Scannapieco, C; Rossi, Maria Emilia De; Tissera, Patricia Beatriz; Scannapieco, Cecilia

    2006-01-01

    We study the evolution of the Stellar Mass-Metallicity Relation and the Luminosity-Metallicity Relation by performing numerical simulations in a cosmological framework. We find that the slope and the zero point of the Luminosity-Metallicity Relation evolve in such a way that, at a given metallicity, systems were ~3 mag brighter at z=3 compared to galaxies in the local universe, which is consistent with the observational trend. The local Stellar Mass-Metallicity Relation shows also a good agreement with recent observations. We identify a characteristic stellar mass M_c ~ 10^(10.2) M_sun/h at which the slope of the Stellar Mass-Metallicity Relation decreases for larger stellar masses. Our results indicate that M_c arises naturally as a consequence of the hierarchical building up of the structure.

  18. Bayesian Mass Estimates of the Milky Way: Including Measurement Uncertainties with Hierarchical Bayes

    Science.gov (United States)

    Eadie, Gwendolyn M.; Springford, Aaron; Harris, William E.

    2017-02-01

    We present a hierarchical Bayesian method for estimating the total mass and mass profile of the Milky Way Galaxy. The new hierarchical Bayesian approach further improves the framework presented by Eadie et al. and Eadie and Harris and builds upon the preliminary reports by Eadie et al. The method uses a distribution function f({ E },L) to model the Galaxy and kinematic data from satellite objects, such as globular clusters (GCs), to trace the Galaxy’s gravitational potential. A major advantage of the method is that it not only includes complete and incomplete data simultaneously in the analysis, but also incorporates measurement uncertainties in a coherent and meaningful way. We first test the hierarchical Bayesian framework, which includes measurement uncertainties, using the same data and power-law model assumed in Eadie and Harris and find the results are similar but more strongly constrained. Next, we take advantage of the new statistical framework and incorporate all possible GC data, finding a cumulative mass profile with Bayesian credible regions. This profile implies a mass within 125 kpc of 4.8× {10}11{M}ȯ with a 95% Bayesian credible region of (4.0{--}5.8)× {10}11{M}ȯ . Our results also provide estimates of the true specific energies of all the GCs. By comparing these estimated energies to the measured energies of GCs with complete velocity measurements, we observe that (the few) remote tracers with complete measurements may play a large role in determining a total mass estimate of the Galaxy. Thus, our study stresses the need for more remote tracers with complete velocity measurements.

  19. Hierarchical porous nitrogen doped carbon derived from horn comb as anode for sodium-ion storage with high performance

    Science.gov (United States)

    Ou, Junke; Yang, Lin; Xi, Xianghui

    2017-01-01

    Horn comb, an abundant biomass waste, has been successfully converted into a hierarchical porous nitrogen doped carbon (HPNDC) via a simple and costeffective approach. Tested as anode for sodium ion batteries (SIBs), horn comb derived carbon shows good rate capability and cycling stability, delivering a high initial charge capacity of 400 mAh g-1 at 100 mA g-1, retaining a reversible capacity of 112 mAh g-1 at 5 A g-1, and exhibiting a capacity of 241 mAh g-1 at 100 mA g-1 after 100 cycles. These superior electrochemical performances can be ascribed to its unique hierarchical pore structure combined with appropriate nitrogen doping effects. We believe that our works will be helpful in promoting the development of high-rate and low-cost sodium ion batteries for large-scale energy storage systems. [Figure not available: see fulltext.

  20. Identifying rock blocks based on hierarchical rock-mass structure model

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Rock-masses are divided into many closed blocks by deterministic and stochastic discontinuities and engineering interfaces in complex rock-mass engineering. Determining the sizes, shapes, and adjacent relations of blocks is important for stability analysis of fractured rock masses. Here we propose an algorithm for identifying spatial blocks based on a hierarchical 3D Rock-mass Structure Model (RSM). First, a model is built composed of deterministic discontinuities, engineering interfaces, and the earth’s surface, and the deterministic blocks surrounded by these interfaces are traced. Then, in each deter-ministic block, a network model of stochastic discontinuities is built and the stochastic blocks are traced. Building a unitary wire frame that connects all interfaces seamlessly is the key for our algorithm to identify the above two kinds of blocks. Using this algorithm, geometric models can be built for block theory, discrete element method, and discontinuous deformation analysis.

  1. Phase-Controlled Iron Oxide Nanobox Deposited on Hierarchically Structured Graphene Networks for Lithium Ion Storage and Photocatalysis

    Science.gov (United States)

    Yun, Sol; Lee, Young-Chul; Park, Ho Seok

    2016-01-01

    The phase control, hierarchical architecturing and hybridization of iron oxide is important for achieving multifunctional capability for many practical applications. Herein, hierarchically structured reduced graphene oxide (hrGO)/α-Fe2O3 and γ-Fe3O4 nanobox hybrids (hrGO/α-Fe and hrGO/γ-Fe NBhs) are synthesized via a one-pot, hydrothermal process and their functionality controlled by the crystalline phases is adapted for energy storage and photocatalysis. The three-dimensionally (3D) macroporous structure of hrGO/α-Fe NBhs is constructed, while α-Fe2O3 nanoboxes (NBs) in a proximate contact with the hrGO surface are simultaneously grown during a hydrothermal treatment. The discrete α-Fe2O3 NBs are uniformly distributed on the surface of the hrGO/α-Fe and confined in the 3D architecture, thereby inhibiting the restacking of rGO. After the subsequent phase transition into γ-Fe3O4, the hierarchical structure and the uniform distribution of NBs are preserved. Despite lower initial capacity, the hrGO/α-Fe NBhs show better rate and cyclic performances than those of commercial rGO/α-Fe due to the uniform distribution of discrete α-Fe2O3 NBs and electronic conductivity, macroporosity, and buffering effect of the hrGO for lithium ion battery anodes. Moreover, the catalytic activity and kinetics of hrGO/γ-Fe NBhs are enhanced for photo-Fenton reaction because of the uniform distribution of discrete γ-Fe3O4 NBs on the 3D hierarchical architecture.

  2. Elaborately prepared hierarchical structure titanium dioxide for remarkable performance in lithium storage

    Science.gov (United States)

    Tian, Qinghua; Luo, Dong; Li, Xiaowei; Zhang, Zhengxi; Yang, Li; Hirano, Shin-ichi

    2016-05-01

    Titanium dioxide (TiO2) has been considered to be a promisingly alternative anode material for lithium-ion batteries and thus attracted wide research interest. But, its practical application in lithium-ion batteries is seriously impeded by low capacity and poor rate capability. In the present work, the electrochemical performance of TiO2 is significantly improved by elaborately fabricating hierarchical structures. These as-prepared four hierarchical structure TiO2 assembled by different building blocks (TO2-2 h, TO2-6 h, TO2-18 h and TO2-24 h) all exhibit impressed performance. More importantly, the TO2-6 h constructed by curved nanosheets exhibits the best performance, delivering a capacity of 231.6 mAh g-1 at 0.2C after 200 cycles, and capacities of 187.1 and 129.3 mAh g-1 at 1 and 10C after even 1200 cycles, respectively. The results indicated that design and fabrication of hierarchical structure is an effective strategy for significantly improving the electrochemical performance of TiO2 electrodes, and the electrochemical performance of hierarchical structure TiO2 is heavily dependent on its building blocks. It is suggested that thus excellent electrochemical performance may make TiO2-6 h a promising anode material for advanced lithium-ion batteries with high capacity, good rate capability and long life.

  3. Blocking Probability Based Hierarchical Storage Design in VoD Systems

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, we discuss the relationship between the blocking probability and the configuration of storage hierarchy in a Video on Demand (VoD) server using the queueing model we propose. With this model , the optimal configuration of the storage system can be obtained.

  4. Direct evidence of hierarchical assembly at low masses from isolated dwarf galaxy groups

    Science.gov (United States)

    Stierwalt, S.; Liss, S. E.; Johnson, K. E.; Patton, D. R.; Privon, G. C.; Besla, G.; Kallivayalil, N.; Putman, M.

    2017-01-01

    The demographics of dwarf galaxy populations have long been in tension with predictions from the Λ cold dark matter (ΛCDM) paradigm 1-4 . If primordial density fluctuations were scale-free as predicted, dwarf galaxies should themselves host dark-matter subhaloes 5 , the most massive of which may have undergone star formation resulting in dwarf galaxy groups. Ensembles of dwarf galaxies are observed as sate­llites of more massive galaxies 6-9 , and there is observational 10 and theoretical 11 evidence to suggest that these satellites at redshift z = 0 were captured by the massive host halo as a group. However, the evolution of dwarf galaxies is highly susceptible to environment 12-14 , making these satellite groups imperfect probes of ΛCDM in the low-mass regime. Here we report one of the clearest examples yet of hierarchical structure formation at low masses: using deep multi-wavelength data, we identify seven isolated, spectroscopically confirmed groups of only dwarf galaxies. Each group hosts three to five known members, has a baryonic mass of ~4.4 × 109 to 2 × 1010 solar masses (M ⊙), and requires a mass-to-light ratio of <100 to be gravitationally bound. Such groups are predicted to be rare theoretically and found to be rare observationally at the current epoch, and thus provide a unique window into the possible formation mechanism of more massive, isolated galaxies.

  5. KOI-126: A Triply-Eclipsing Hierarchical Triple with Two Low-Mass Stars

    CERN Document Server

    Carter, Joshua A; Ragozzine, Darin; Holman, Matthew J; Quinn, Samuel N; Latham, David W; Buchhave, Lars A; Van Cleve, Jeffrey; Cochran, William D; Cote, Miles T; Endl, Michael; Ford, Eric B; Haas, Michael R; Jenkins, Jon M; Koch, David G; Li, Jie; Lissauer, Jack J; MacQueen, Phillip J; Middour, Christopher K; Orosz, Jerome A; Rowe, Jason F; Steffen, Jason H; Welsh, William F; 10.1126/science.1201274

    2011-01-01

    The Kepler spacecraft has been monitoring the light from 150,000 stars in its primary quest to detect transiting exoplanets. Here we report on the detection of an eclipsing stellar hierarchical triple, identified in the Kepler photometry. KOI-126 (A,(B, C)), is composed of a low-mass binary (masses M_B = 0.2413+/-0.0030 M_Sun, M_C = 0.2127+/-0.0026 M_Sun; radii R_B = 0.2543+/-0.0014 R_Sun, R_C = 0.2318+/-0.0013 R_Sun; orbital period P_1 = 1.76713+/-0.00019 days) on an eccentric orbit about a third star (mass M_A = 1.347+/-0.032 M_Sun; radius R_A = 2.0254+/-0.0098 R_Sun; period of orbit around the low-mass binary P_2 = 33.9214+/-0.0013 days; eccentricity of that orbit e_2 = 0.3043+/-0.0024). The low-mass pair probe the poorly sampled fully-convective stellar domain offering a crucial benchmark for theoretical stellar models.

  6. Simulation of mass storage systems operating in a large data processing facility

    Science.gov (United States)

    Holmes, R.

    1972-01-01

    A mass storage simulation program was written to aid system designers in the design of a data processing facility. It acts as a tool for measuring the overall effect on the facility of on-line mass storage systems, and it provides the means of measuring and comparing the performance of competing mass storage systems. The performance of the simulation program is demonstrated.

  7. 3D hierarchical porous graphene aerogel with tunable meso-pores on graphene nanosheets for high-performance energy storage

    Science.gov (United States)

    Ren, Long; Hui, K. N.; Hui, K. S.; Liu, Yundan; Qi, Xiang; Zhong, Jianxin; Du, Yi; Yang, Jianping

    2015-09-01

    New and novel 3D hierarchical porous graphene aerogels (HPGA) with uniform and tunable meso-pores (e.g., 21 and 53 nm) on graphene nanosheets (GNS) were prepared by a hydrothermal self-assembly process and an in-situ carbothermal reaction. The size and distribution of the meso-pores on the individual GNS were uniform and could be tuned by controlling the sizes of the Co3O4 NPs used in the hydrothermal reaction. This unique architecture of HPGA prevents the stacking of GNS and promises more electrochemically active sites that enhance the electrochemical storage level significantly. HPGA, as a lithium-ion battery anode, exhibited superior electrochemical performance, including a high reversible specific capacity of 1100 mAh/g at a current density of 0.1 A/g, outstanding cycling stability and excellent rate performance. Even at a large current density of 20 A/g, the reversible capacity was retained at 300 mAh/g, which is larger than that of most porous carbon-based anodes reported, suggesting it to be a promising candidate for energy storage. The proposed 3D HPGA is expected to provide an important platform that can promote the development of 3D topological porous systems in a range of energy storage and generation fields.

  8. A hierarchical Bayesian approach for reconstructing the Initial Mass Function of Single Stellar Populations

    CERN Document Server

    Dries, M; Koopmans, L V E

    2016-01-01

    Recent studies based on the integrated light of distant galaxies suggest that the initial mass function (IMF) might not be universal. Variations of the IMF with galaxy type and/or formation time may have important consequences for our understanding of galaxy evolution. We have developed a new stellar population synthesis (SPS) code specifically designed to reconstruct the IMF. We implement a novel approach combining regularization with hierarchical Bayesian inference. Within this approach we use a parametrized IMF prior to regulate a direct inference of the IMF. This direct inference gives more freedom to the IMF and allows the model to deviate from parametrized models when demanded by the data. We use Markov Chain Monte Carlo sampling techniques to reconstruct the best parameters for the IMF prior, the age, and the metallicity of a single stellar population. We present our code and apply our model to a number of mock single stellar populations with different ages, metallicities, and IMFs. When systematic unc...

  9. Differential changes in body mass index after retirement by occupation: hierarchical models.

    Science.gov (United States)

    Gueorguieva, Ralitza; Sindelar, Jody L; Wu, Ran; Gallo, William T

    2011-02-01

    This paper examines whether retirement differentially affects body mass index (BMI) patterns by occupation; occupation embodies differences in on-the-job physical demands as well as socioeconomic characteristics that could lead to variation in post-retirement BMI. We use 12 years of national data from the US and hierarchical linear models to compare BMI trajectories among four broad occupational classes. We find that those in service and other blue-collar occupations have significant increases in the slopes of their BMI trajectories after retirement, whereas participants in white-collar occupations exhibit no change. This may be due to differences in the physical requirements across blue and white collar jobs or differences in health habits post-retirement. Retirement may provide an opportunity to help prevent obesity in older individuals, especially blue collar workers.

  10. Facile preparation of hierarchically porous carbons from metal-organic gels and their application in energy storage

    Science.gov (United States)

    Xia, Wei; Qiu, Bin; Xia, Dingguo; Zou, Ruqiang

    2013-06-01

    Porous carbon materials have numerous applications due to their thermal and chemical stability, high surface area and low densities. However, conventional preparing porous carbon through zeolite or silica templates casting has been criticized by the costly and/or toxic procedure. Creating three-dimensional (3D) carbon products is another challenge. Here, we report a facile way to prepare porous carbons from metal-organic gel (MOG) template, an extended metal-organic framework (MOF) structure. We surprisingly found that the carbon products inherit the highly porous nature of MOF and combine with gel's integrated character, which results in hierarchical porous architectures with ultrahigh surface areas and quite large pore volumes. They exhibit considerable hydrogen uptake and excellent electrochemical performance as cathode material for lithium-sulfur battery. This work provides a general method to fast and clean synthesis of porous carbon materials and opens new avenues for the application of metal-organic gel in energy storage.

  11. Hierarchically structured carbonaceous foams generation and their use as electrochemical energy storage devices

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Nicolas [Centre de Recherche Paul Pascal, Pessac (France); Institut des Sciences Moleculaires, Talence (France); Prabaharan, Savari R.S.; Morcrette, Mathieu [Laboratoire de Reactivite et de Chimie des Solides, Amiens (France); Pecastaing, Gilles [Laboratoire de Chimie des Polymeres Organiques, Pessac (France); Birot, Marc; Deleuze, Herve [Institut des Sciences Moleculaires, Talence (France); Backov, Renal [Centre de Recherche Paul Pascal, Pessac (France)

    2010-07-01

    Hierarchically structured carbonaceous foams with a high control over macro-meso-microporous structures have been synthesized, using silica as inorganic exotemplate and phenolic resin as carbon precursor. These monolithic foams have been thoroughly characterized over all length scales. The applications of this new series of macrocellular carbonaceous monoliths as negative electrodes for Lithium-ion batteries devices (stable capacity of 200 mAh.g{sup -1}, during 50 cycles) and electrochemical capacitors (specific capacitance of 30 F.g{sup -1} at a scan rate of 10 mV.s{sup -1}) have been checked and will be discussed. (orig.)

  12. RAID-M: A high performance RAID Matrix mass storage

    Institute of Scientific and Technical Information of China (English)

    LIU Peng; LI Sanli; Francis C.M.Lau; SHI Yao; HUANG Feng

    2005-01-01

    In the light of the increasingly serious I/O bottleneck problem, the paper puts forward a method named RAID-M (RAID Matrix) to build high performance mass storage from cheap PC components based on the idea of multi-channel I/O and parallel access.Theoretical analyses prove that different RAID-M configurations vary their performance,space utilization and reliability, meeting various application goals. Experiments show that both the sequential read performance and sequential write performance of a RAID-M prototype machine have broken through the limitation of 32 bit/33 MHz PCI bus.

  13. Hierarchical fragmentation and collapse signatures in a high-mass starless region

    CERN Document Server

    Beuther, H; Linz, H; Feng, S; Ragan, S E; Smith, R J; Bihr, S; Sakai, T; Kuiper, R

    2015-01-01

    Aims: Understanding the fragmentation and collapse properties of the dense gas during the onset of high-mass star formation. Methods: We observed the massive (~800M_sun) starless gas clump IRDC18310-4 with the Plateau de Bure Interferometer (PdBI) at sub-arcsecond resolution in the 1.07mm continuum andN2H+(3-2) line emission. Results: Zooming from a single-dish low-resolution map to previous 3mm PdBI data, and now the new 1.07mm continuum observations, the sub-structures hierarchically fragment on the increasingly smaller spatial scales. While the fragment separations may still be roughly consistent with pure thermal Jeans fragmentation, the derived core masses are almost two orders of magnitude larger than the typical Jeans mass at the given densities and temperatures. However, the data can be reconciled with models using non-homogeneous initial density structures, turbulence and/or magnetic fields. While most sub-cores remain (far-)infrared dark even at 70mum, we identify weak 70mum emission toward one core...

  14. Enhanced Lithium Storage in Hierarchically Porous Carbon Derived from Waste Tea Leaves

    Science.gov (United States)

    Choi, Changhoon; Seo, Seung-Deok; Kim, Byung-Kook; Kim, Dong-Wan

    2016-12-01

    In this study, highly nanoporous carbon (HCl-TW-Car) was successfully synthesized using a facile procedure combining acid treatment with a carbonization process that uses waste tea leaves from spent tea bags as raw materials. The acid treatment not only promotes the efficient removal of unnecessary inorganic impurities but also increases the product porosity to enable synthesis of hierarchically porous carbon materials with various micro-, meso-, and macropores. When used as an anode material for lithium-ion batteries, HCl-TW-Car demonstrated a much higher discharge capacity than is theoretically possible using graphite [479 mAh g-1 after the 200th cycle at a rate of 0.2C (1C = 372 mA g-1)] and exhibited greater rate capabilities compared with those of carbonated products from tea waste without acid treatment. It was shown that the good electrochemical properties of HCl-TW-Car can be ascribed to large Brunauer-Emmett-Teller (BET) surface area, well-formed hierarchical pores, and the prevention of unexpected electrochemical reactions from the reduction of metallic atoms.

  15. Jefferson Lab Mass Storage and File Replication Services

    Institute of Scientific and Technical Information of China (English)

    IanBird; YingChen; 等

    2001-01-01

    Jefferson Lab has implemented a scalable,distributed,high performance mass storage system-JASMine.The system is entirely implemented in Java,provides access to robotic tape storage and includes disk cache and stage manager components.The disk manager subsystem may be used independently to manage stand-alone disk pools.The system includes a scheduler to provide policy-based access to the storage systems.Security is provided by pluggable authentication modules and is implemented at the network socket level.The tape and disk cache systems have well defined interfaces in order to provids integration with grid-based services.The system is in production and being used to archive 1 TB per day from the experiments.and currently moves over 2 TB per day total.This paper will describe the architecture of JASMine;discuss the rationale for building the system,and present a transparent 3rd party file replication service to move data to collab-orating institutes using JASMine,XML,and servlet technology interfacing to grid-based file transfer mechanisms.

  16. Facile solid-state synthesis of Ni@C nanosheet-assembled hierarchical network for high-performance lithium storage

    Science.gov (United States)

    Gu, Jinghe; Li, Qiyun; Zeng, Pan; Meng, Yulin; Zhang, Xiukui; Wu, Ping; Zhou, Yiming

    2017-08-01

    Micro/nano-architectured transition-metal@C hybrids possess unique structural and compositional features toward lithium storage, and are thus expected to manifest ideal anodic performances in advanced lithium-ion batteries (LIBs). Herein, we propose a facile and scalable solid-state coordination and subsequent pyrolysis route for the formation of a novel type of micro/nano-architectured transition-metal@C hybrid (i.e., Ni@C nanosheet-assembled hierarchical network, Ni@C network). Moreover, this coordination-pyrolysis route has also been applied for the construction of bare carbon network using zinc salts instead of nickel salts as precursors. When applied as potential anodic materials in LIBs, the Ni@C network exhibits Ni-content-dependent electrochemical performances, and the partially-etched Ni@C network manifests markedly enhanced Li-storage performances in terms of specific capacities, cycle life, and rate capability than the pristine Ni@C network and carbon network. The proposed solid-state coordination and pyrolysis strategy would open up new opportunities for constructing micro/nano-architectured transition-metal@C hybrids as advanced anode materials for LIBs.

  17. Hierarchically-Porous Carbon Derived from a Large-Scale Iron-based Organometallic Complex for Versatile Energy Storage.

    Science.gov (United States)

    Fan, Chao-Ying; Li, Huan-Huan; Wang, Hai-Feng; Sun, Hai-Zhu; Wu, Xing-Long; Zhang, Jing-Ping

    2016-06-22

    Inspired by the preparation of the hierarchically-porous carbon (HPC) derived from metal organic frameworks (MOFs) for energy storage, in this work, a simple iron-based metal- organic complex (MOC), which was simpler and cheaper compared with the MOF, was selected to achieve versatile energy storage. The intertwined 1 D nanospindles and enriched-oxygen doping of the HPC was obtained after one-step carbonization of the MOC. When employed in lithium-ion batteries, the HPC exhibited reversible capacity of 778 mA h g(-1) after 60 cycles at 50 mA g(-1) . Moreover, the HPC maintained a capacity of 188 mA h g(-1) after 400 cycles at 100 mA g(-1) as the anode material in a sodium-ion battery. In addition, the HPC served as the cathode matrix for evaluation of a lithium-sulfur battery. The general preparation process of the HPC is commercial, which is responsible for the large-scale production for its practical application. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Thermal energy storage system combining mass and PCM

    Energy Technology Data Exchange (ETDEWEB)

    1982-11-01

    The intent of this project was to construct several concrete blocks with PCM (Phase Change Material) encapsulated and to test these blocks as to heat transfer rate with and without a highly conductive matrix cast within the PCM core. The tests were to be conducted on commercially available PCM's being sold for solar applications. Unfortunately, one of the three PCM's was no longer produced commercially for sale and another would not crystallize as claimed by the manufacturer. This left one PCM, paraffin wax (the most critical to this work), to be tested. The testing showed that substantial improvement (18.5%) of heat conduction to the center of the paraffin core was obtainable with only a 2% loss of latent heat storage capacity. This finding may have a significant impact on the container designs for hydrocarbon heat storage system by showing that reduced surface to volume ratios can produce adequate heat transfer rates to the center of the PCM mass, without significant loss of performance.

  19. Fault-tolerant distributed mass storage for LHC computing

    CERN Document Server

    Wiebalck, A; Lindenstruth, V; Stinbeck, T M

    2003-01-01

    In this paper we present the concept and first prototyping results of a modular fault-tolerant distributed mass storage architecture for large Linux PC clusters as they are deployed by the upcoming particle physics experiments. The device masquerading technique using an Enhanced Network Block Device (ENBD) enables local RAID over remote disks as the key concept of the ClusterRAID system. The block level interface to remote files, partitions or disks provided by the ENBD makes it possible to use the standard Linux software RAID to add fault-tolerance to the system. Preliminary performance measurements indicate that the latency is comparable to a local hard drive. With four disks throughput rates of up to 55MB/s were achieved with first prototypes for a RAIDO setup, and about 40M/s for a RAID5 setup. (29 refs).

  20. Deviation from tri-bimaximal mixings through flavour twisters in inverted and normal hierarchical neutrino mass models

    Indian Academy of Sciences (India)

    N Nimai Singh; Monisa Rajkhowa; Abhijit Borah

    2007-10-01

    We explore a novel possibility for lowering the solar mixing angle (12) from tri-bimaximal mixings, without sacrificing the predictions of maximal atmospheric mixing angle (23 = 45°) and zero reactor angle (13 = 0°) in the inverted and normal hierarchical neutrino mass models having 2-3 symmetry. This can be done through the identification of a flavour twister term in the texture of neutrino mass matrix and the variation of such term leads to lowering of solar mixing angle. For the observed ranges of $ m_{21}^{2}$ and $ m_{23}^{2}$, we calculate the predictions on tan2 12 = 0.5, 0.45, 0.35 for different input values of the parameters in the neutrino mass matrix. We also observe a possible transition from inverted hierarchical model having even CP parity (Type-IHA) to inverted hierarchical model having odd CP parity (Type-IHB) in the first two mass eigenvalues, when there is a change in input values of parameters in the same mass matrix. The present work differs from the conventional approaches for the deviations from tri-bimaximal mixing, where the 2-3 symmetry is broken, leading to 23 ≠ 45° and 13 ≠ 0°.

  1. Point-Mass Aircraft Trajectory Prediction Using a Hierarchical, Highly-Adaptable Software Design

    Science.gov (United States)

    Karr, David A.; Vivona, Robert A.; Woods, Sharon E.; Wing, David J.

    2017-01-01

    A highly adaptable and extensible method for predicting four-dimensional trajectories of civil aircraft has been developed. This method, Behavior-Based Trajectory Prediction, is based on taxonomic concepts developed for the description and comparison of trajectory prediction software. A hierarchical approach to the "behavioral" layer of a point-mass model of aircraft flight, a clear separation between the "behavioral" and "mathematical" layers of the model, and an abstraction of the methods of integrating differential equations in the "mathematical" layer have been demonstrated to support aircraft models of different types (in particular, turbojet vs. turboprop aircraft) using performance models at different levels of detail and in different formats, and promise to be easily extensible to other aircraft types and sources of data. The resulting trajectories predict location, altitude, lateral and vertical speeds, and fuel consumption along the flight path of the subject aircraft accurately and quickly, accounting for local conditions of wind and outside air temperature. The Behavior-Based Trajectory Prediction concept was implemented in NASA's Traffic Aware Planner (TAP) flight-optimizing cockpit software application.

  2. A hierarchical Bayesian approach for reconstructing the initial mass function of single stellar populations

    Science.gov (United States)

    Dries, M.; Trager, S. C.; Koopmans, L. V. E.

    2016-11-01

    Recent studies based on the integrated light of distant galaxies suggest that the initial mass function (IMF) might not be universal. Variations of the IMF with galaxy type and/or formation time may have important consequences for our understanding of galaxy evolution. We have developed a new stellar population synthesis (SPS) code specifically designed to reconstruct the IMF. We implement a novel approach combining regularization with hierarchical Bayesian inference. Within this approach, we use a parametrized IMF prior to regulate a direct inference of the IMF. This direct inference gives more freedom to the IMF and allows the model to deviate from parametrized models when demanded by the data. We use Markov chain Monte Carlo sampling techniques to reconstruct the best parameters for the IMF prior, the age and the metallicity of a single stellar population. We present our code and apply our model to a number of mock single stellar populations with different ages, metallicities and IMFs. When systematic uncertainties are not significant, we are able to reconstruct the input parameters that were used to create the mock populations. Our results show that if systematic uncertainties do play a role, this may introduce a bias on the results. Therefore, it is important to objectively compare different ingredients of SPS models. Through its Bayesian framework, our model is well suited for this.

  3. In-situ observation for growth of hierarchical metal-organic frameworks and their self-sequestering mechanism for gas storage

    Science.gov (United States)

    Hyo Park, Jung; Min Choi, Kyung; Joon Jeon, Hyung; Jung Choi, Yoon; Ku Kang, Jeung

    2015-07-01

    Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature. Herein, we report in-situ growth observation of hierarchical pores in pomegranate metal-organic frameworks (pmg-MOFs) and their self-sequestering storage mechanism, not observed for pristine MOFs. Direct observation of hierarchical pores inside the pmg-MOF was evident by in-situ growth X-ray measurements while self-sequestering storage mechanism was revealed by in-situ gas sorption X-ray analysis and molecular dynamics simulations. The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage. This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption.

  4. Mass Storage System Upgrades at the NASA Center for Computational Sciences

    Science.gov (United States)

    Tarshish, Adina; Salmon, Ellen; Macie, Medora; Saletta, Marty

    2000-01-01

    The NASA Center for Computational Sciences (NCCS) provides supercomputing and mass storage services to over 1200 Earth and space scientists. During the past two years, the mass storage system at the NCCS went through a great deal of changes both major and minor. Tape drives, silo control software, and the mass storage software itself were upgraded, and the mass storage platform was upgraded twice. Some of these upgrades were aimed at achieving year-2000 compliance, while others were simply upgrades to newer and better technologies. In this paper we will describe these upgrades.

  5. Hierarchical porous NiCo2O4 nanosheet arrays directly grown on carbon cloth with superior lithium storage performance.

    Science.gov (United States)

    Zhao, Li; Wang, Lei; Yu, Peng; Tian, Chungui; Feng, He; Diao, Zhongwei; Fu, Honggang

    2017-03-23

    Binary metal oxides have been explored as advanced candidates in lithium-ion battery (LIB) anodes due to their high specific capacity. Herein, the hierarchical structures of porous NiCo2O4 nanosheets directly grown on a conductive carbon cloth substrate (3D NCO-PSA/CC) were obtained by a facile in situ synthetic strategy. When applied as a binder-free LIB anode, it exhibited satisfactory performance with a high discharge capacity (a first discharge capacity of 2090.8 mA h g(-1) and a stable capacity of 1687.6 mA h g(-1) at 500 mA g(-1)), superior rate capacity (discharge capacity of 375.5 mA h g(-1) at 6000 mA g(-1)) and excellent reversibility (coulombic efficiency of approximately 100%). The outstanding performances should be attributed to the 3D porous structures, nanosheets and good conductivity of NCO-PSA/CC that could not only ensure the rapid transport of Li(+) ions and electrons but also remit the huge volume change during lithiation/delithiation processes. Undoubtedly, the present facile and effective strategy can be extended to other binary metal-oxide materials for use as high-performance energy storage and conversion devices.

  6. Hierarchical cellulose-derived CNF/CNT composites for electrostatic energy storage

    Science.gov (United States)

    Kuzmenko, V.; Saleem, A. M.; Staaf, H.; Haque, M.; Bhaskar, A.; Flygare, M.; Svensson, K.; Desmaris, V.; Enoksson, P.

    2016-12-01

    Today many applications require new effective approaches for energy delivery on demand. Supercapacitors are viewed as essential energy storage devices that can continuously provide quick energy. The performance of supercapacitors is mostly determined by electrode materials that can store energy via electrostatic charge accumulation. This study presents new sustainable cellulose-derived composite electrodes which consist of carbon nanofibrous (CNF) mats covered with vapor-grown carbon nanotubes (CNTs). The CNF/CNT electrodes have high electrical conductivity and surface area: the two most important features that are responsible for good electrochemical performance of supercapacitor electrodes. The results show that the composite electrodes have fairly high values of specific capacitance (101 F g-1 at 5 mV s-1), energy and power density (10.28 W h kg-1 and 1.99 kW kg-1, respectively, at 1 A g-1) and can retain excellent performance over at least 2000 cycles (96.6% retention). These results indicate that sustainable cellulose-derived composites can be extensively used in the future as supercapacitor electrodes.

  7. Hierarchical Storage Management at the NASA Center for Computational Sciences: From UniTree to SAM-QFS

    Science.gov (United States)

    Salmon, Ellen; Tarshish, Adina; Palm, Nancy; Patel, Sanjay; Saletta, Marty; Vanderlan, Ed; Rouch, Mike; Burns, Lisa; Duffy, Daniel; Caine, Robert

    2004-01-01

    This paper presents the data management issues associated with a large center like the NCCS and how these issues are addressed. More specifically, the focus of this paper is on the recent transition from a legacy UniTree (Legato) system to a SAM-QFS (Sun) system. Therefore, this paper will describe the motivations, from both a hardware and software perspective, for migrating from one system to another. Coupled with the migration from UniTree into SAM-QFS, the complete mass storage environment was upgraded to provide high availability, redundancy, and enhanced performance. This paper will describe the resulting solution and lessons learned throughout the migration process.

  8. Evaluation and Optimization of Porous and Hierarchically Porous Materials for Applications in Energy Storage and Conversion

    Science.gov (United States)

    Petkovich, Nicholas Daniel

    Materials with nm- and mum-scale pores are important in the design of efficient, safe, and versatile energy conversion and storage systems. In the research detailed in this thesis, the synthesis and testing of porous materials for lithium-ion battery anodes and for thermochemical fuel production are explored. The preparation, modification, and performance of various carbon and transition metal oxide composite materials for lithium-ion battery electrodes are discussed in the first part of this work. Of particular interest are TiO 2/carbon composites that possess a three-dimensionally ordered macroporous (3DOM) structure, and, in some instances, additional mesoporosity. By changing the chelating agent used to stabilize the precursor for TiO2, crystallites of TiO2 can either be localized on the surface of the 3DOM structure or buried within the carbon matrix. This positioning has important ramifications for the electrochemical properties of the materials. In addition, the content of carbon in the composite materials can be altered. For carbon-rich composites, improved Li+ insertion/extraction capacities are attained by changing the voltage window used for cycling. Carbon can also be removed altogether, allowing for the formation 3DOM TiO¬2 with good electrochemical properties Conversion of the 3DOM TiO2 to sodium titanate is demonstrated via the ambient pressure treatment of the 3DOM material in sodium hydroxide. Subsequent ion-exchange with H+ results in the formation of hydrogen titanate materials with extremely high surface areas. A remnant of the 3DOM structure remains in these materials. Cerium oxide, praseodymium oxide and perovskite oxide-based catalysts for the thermochemical conversion of solar energy and abundant feedstocks (H2O and CO2) into useable fuels (H2 and CO) are investigated in the second part of this work. All of these materials possess a 3DOM structure and have moderate surface areas intended to improve reaction kinetics. Mixed oxides containing

  9. Low Mass Printable Devices for Energy Capture, Storage, and Use

    Science.gov (United States)

    Frazier, Donald O.; Singer, Christopher E.; Rogers, Jan R.; Schramm, Harry F.; Fabisinski, Leo L.; Lowenthal, Mark; Ray, William J.; Fuller, Kirk A.

    2010-01-01

    The energy-efficient, environmentally friendly technology that will be presented is the result of a Space Act Agreement between NthDegree Technologies Worldwide, Inc., and the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center (MSFC). The work combines semiconductor and printing technologies to advance lightweight electronic and photonic devices having excellent potential for commercial and exploration applications. Device development involves three projects that relate to energy generation and consumption: (1) a low-mass efficient (low power, low heat emission) micro light-emitting diode (LED) area lighting device; (2) a low-mass omni-directional efficient photovoltaic (PV) device with significantly improved energy capture; and (3) a new approach to building super-capacitors. These three technologies, energy capture, storage, and usage (e.g., lighting), represent a systematic approach for building efficient local micro-grids that are commercially feasible; furthermore, these same technologies, appropriately replacing lighting with lightweight power generation, will be useful for enabling inner planetary missions using smaller launch vehicles and to facilitate surface operations during lunar and planetary surface missions. The PV device model is a two sphere, light trapped sheet approximately 2-mm thick. The model suggests a significant improvement over current thin film systems. For lighting applications, all three technology components are printable in-line by printing sequential layers on a standard screen or flexographic direct impact press using the three-dimensional printing technique (3DFM) patented by NthDegree. One primary contribution to this work in the near term by the MSFC is to test the robustness of prototype devices in the harsh environments that prevail in space and on the lunar surface. It is anticipated that this composite device, of which the lighting component has passed off-gassing testing, will function

  10. Microscale Enhancement of Heat and Mass Transfer for Hydrogen Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Drost, Kevin [Oregon State Univ., Corvallis, OR (United States); Jovanovic, Goran [Oregon State Univ., Corvallis, OR (United States); Paul, Brian [Oregon State Univ., Corvallis, OR (United States)

    2015-09-30

    The document summarized the technical progress associated with OSU’s involvement in the Hydrogen Storage Engineering Center of Excellence. OSU focused on the development of microscale enhancement technologies for improving heat and mass transfer in automotive hydrogen storage systems. OSU’s key contributions included the development of an extremely compact microchannel combustion system for discharging hydrogen storage systems and a thermal management system for adsorption based hydrogen storage using microchannel cooling (the Modular Adsorption Tank Insert or MATI).

  11. Synergistic, ultrafast mass storage and removal in artificial mixed conductors

    Science.gov (United States)

    Chen, Chia-Chin; Fu, Lijun; Maier, Joachim

    2016-08-01

    Mixed conductors—single phases that conduct electronically and ionically—enable stoichiometric variations in a material and, therefore, mass storage and redistribution, for example, in battery electrodes. We have considered how such properties may be achieved synergistically in solid two-phase systems, forming artificial mixed conductors. Previously investigated composites suffered from poor kinetics and did not allow for a clear determination of such stoichiometric variations. Here we show, using electrochemical and chemical methods, that a melt-processed composite of the ‘super-ionic’ conductor RbAg4I5 and the electronic conductor graphite exhibits both a remarkable silver excess and a silver deficiency, similar to those found in single-phase mixed conductors, even though such behaviour is not possible in the individual phases. Furthermore, the kinetics of silver uptake and release is very fast. Evaluating the upper limit set by interfacial ambipolar diffusion reveals chemical diffusion coefficients that are even higher than those achieved for sodium chloride in bulk liquid water. These results could potentially stimulate systematic research into powerful, even mesoscopic, artificial mixed conductors.

  12. Excellent Li-ion storage performances of hierarchical SnO-SnO2 composite powders and SnO nanoplates prepared by one-pot spray pyrolysis

    Science.gov (United States)

    Kim, Jung Hyun; Jeon, Kyung Min; Park, Jin-Sung; Kang, Yun Chan

    2017-08-01

    Hierarchical-structured SnO-SnO2 composite powders and SnO nanoplates with some SnO2 nanorods are prepared by one-pot spray pyrolysis. Dicyandiamide dissolved in the spray solution plays a key role in the preparation of the hierarchical-structured SnO-SnO2 composite powder and SnO nanoplates. The hierarchical-structured SnO-SnO2 composite powders, in which the SnO nanoplates are trapped in the porous SnO2 nanosphere, are prepared by spray pyrolysis at 800 °C. Sufficient conversion of the porous SnO2 nanospheres to SnO at 900 °C results in aggregation-free SnO2 nanoplates. SnO2 nanorods with a spherical nanodroplet at the tip are formed by Ostwald ripening. The hierarchical-structured SnO-SnO2 composite powder having high structural stability during repeated lithium alloying and dealloying reactions, shows superior discharge capacities and rate performances for lithium-ion storage compared to those of the dense-structured SnO2 powders. The discharge capacities of the hierarchical-structured SnO-SnO2 composite powders, SnO nanoplates with SnO2 nanorods, and dense-structured SnO2 powders at a current density of 1 A g-1 for the 300th cycle are 561, 504, and 416 mA h g-1, respectively. The SnO nanoplates with SnO2 nanorods and hierarchical-structured SnO-SnO2 powders deliver high reversible discharge capacities of 433 and 379 mA h g-1 at an extremely high current density of 10 A g-1, respectively.

  13. Study of the Origin of the Luminosity-Metallicity and the Stellar Mass-Metallicity Relations in Hierarchical Universes

    CERN Document Server

    De Rossi, M E; Scannapieco, C; Rossi, Maria Emilia De; Tissera, Patricia Beatriz; Scannapieco, Cecilia

    2005-01-01

    In this work, we study the Luminosity-Metallicity relation (LMR) and the Stellar Mass -Metallicity relation (MMR) of galactic systems in a hierarhical clustering scenario. We performed numerical hydrodynamical simulations with the chemical GADGET-2 of Scannapieco et al.(2005) in a LCDM universe. We found that our simulated galactic systems reproduce the observed local LMR and its evolution in zero point and slope. The simulated MMR is also in agreement with recent observational results. From the analysis of the evolution of the MMR, we found a characteristic mass at ~10^(10.2) M_sun / h which separates two galactic populations with different astrophysical properties. More massive systems tend to have their stars formed at z > 2 and show less evolution than smaller systems. Hence, this characteristic mass is determined by the formation of the structure in a hierarchical scenario. Our results also suggest the need for important supernova feedback.

  14. Metadata distribution algorithm based on directory hash in mass storage system

    Science.gov (United States)

    Wu, Wei; Luo, Dong-jian; Pei, Can-hao

    2008-12-01

    The distribution of metadata is very important in mass storage system. Many storage systems use subtree partition or hash algorithm to distribute the metadata among metadata server cluster. Although the system access performance is improved, the scalability problem is remarkable in most of these algorithms. This paper proposes a new directory hash (DH) algorithm. It treats directory as hash key value, implements a concentrated storage of metadata, and take a dynamic load balance strategy. It improves the efficiency of metadata distribution and access in mass storage system by hashing to directory and placing metadata together with directory granularity. DH algorithm has solved the scalable problems existing in file hash algorithm such as changing directory name or permission, adding or removing MDS from the cluster, and so on. DH algorithm reduces the additional request amount and the scale of each data migration in scalable operations. It enhances the scalability of mass storage system remarkably.

  15. A media maniac's guide to removable mass storage media

    Science.gov (United States)

    Kempster, Linda S.

    1996-01-01

    This paper addresses at a high level, the many individual technologies available today in the removable storage arena including removable magnetic tapes, magnetic floppies, optical disks and optical tape. Tape recorders represented below discuss logitudinal, serpantine, logitudinal serpantine,and helical scan technologies. The magnetic floppies discussed will be used for personal electronic in-box applications.Optical disks still fill the role for dense long-term storage. The media capacities quoted are for native data. In some cases, 2 KB ASC2 pages or 50 KB document images will be referenced.

  16. 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.

  17. Hierarchical hollow Fe2O3@MIL-101(Fe)/C derived from metal-organic frameworks for superior sodium storage

    Science.gov (United States)

    Li, Chengping; Hu, Qian; Li, Yan; Zhou, Hang; Lv, Zhaolin; Yang, Xiangjun; Liu, Lixiang; Guo, Hong

    2016-05-01

    A facile generic template-free strategy is employed to prepare hierarchical hollow hybrid Fe2O3@MIL-101(Fe)/C materials derived from metal-organic frameworks as anode materials for Na-ion batteries. The intrinsic hollow nanostructure can shorten the lengths for both electronic and ionic transport, enlarge the surface areas of electrodes, and improve accommodation of the volume change during Na+ insertion/extraction cycling. Therefore, The stable reversible capacity of Fe2O3@MIL-101(Fe)/C electrode is 710 mAhg‑1, and can be retained at 662 mAhg‑1 after 200 cycles with the retention of 93.2%. Especially, its overall rate performance data confirm again the importance of the hierarchical hollow structures and multi-elements characteristics toward high capacities in both low and high current rates. This general strategy may shed light on a new avenue for fast synthesis of hierarchic hollow functional materials for energy storage, catalyst, sensor and other new applications.

  18. Self-assembly synthesis of 3D graphene-encapsulated hierarchical Fe3O4 nano-flower architecture with high lithium storage capacity and excellent rate capability

    Science.gov (United States)

    Ma, Yating; Huang, Jian; Lin, Liang; Xie, Qingshui; Yan, Mengyu; Qu, Baihua; Wang, Laisen; Mai, Liqiang; Peng, Dong-Liang

    2017-10-01

    Graphene-encapsulated hierarchical metal oxides architectures can efficiently combine the merits of graphene and hierarchical metal oxides, which are deemed as the potential anode material candidates for the next-generation lithium-ion batteries due to the synergistic effect between them. Herein, a cationic surfactant induced self-assembly method is developed to construct 3D Fe3O4@reduction graphene oxide (H-Fe3O4@RGO) hybrid architecture in which hierarchical Fe3O4 nano-flowers (H-Fe3O4) are intimately encapsulated by 3D graphene network. Each H-Fe3O4 particle is constituted of rod-shaped skeletons surrounded by petal-like nano-flakes that are made up of enormous nanoparticles. When tested as the anode material in lithium-ion batteries, a high reversible capacity of 2270 mA h g-1 after 460 cycles is achieved under a current density of 0.5 A g-1. More impressively, even tested at a large current density of 10 A g-1, a decent reversible capacity of 490 mA h g-1 can be retained, which is still higher than the theoretical capacity of traditional graphite anode, demonstrating the remarkable lithium storage properties. The reasons for the excellent electrochemical performance of H-Fe3O4@RGO electrode have been discussed in detail.

  19. Cold storage affects mortality, body mass, lifespan, reproduction and flight capacity of Praon volucre (Hymenoptera: Braconidae)

    NARCIS (Netherlands)

    Lins, J.C.; Bueno, V.H.P.; Sidney, L.A.; Silva, D.B.; Sampaio, M.V.; Pereira, J.M.; Nomelini, Q.S.S.; Lenteren, van J.C.

    2013-01-01

    The possibility of storing natural enemies at low temperatures is important for the mass production of biological control agents. We evaluated the effect of different periods of cold storage on immature mortality, mummy body mass, lifespan, reproduction and flight capacity of the parasitoid Praon vo

  20. Cold storage affects mortality, body mass, lifespan, reproduction and flight capacity of Praon volucre (Hymenoptera: Braconidae)

    NARCIS (Netherlands)

    Lins, J.C.; Bueno, V.H.P.; Sidney, L.A.; Silva, D.B.; Sampaio, M.V.; Pereira, J.M.; Nomelini, Q.S.S.; Lenteren, van J.C.

    2013-01-01

    The possibility of storing natural enemies at low temperatures is important for the mass production of biological control agents. We evaluated the effect of different periods of cold storage on immature mortality, mummy body mass, lifespan, reproduction and flight capacity of the parasitoid Praon

  1. Improved Estimates of the Milky Way's Stellar Mass and Star Formation Rate from Hierarchical Bayesian Meta-Analysis

    CERN Document Server

    Licquia, Timothy C

    2014-01-01

    We present improved estimates of several global properties of the Milky Way, including its current star formation rate (SFR), the stellar mass contained in its disk and bulge+bar components, as well as its total stellar mass. We do so by combining previous measurements from the literature using a hierarchical Bayesian (HB) statistical method that allows us to account for the possibility that any value may be incorrect or have underestimated errors. We show that this method is robust to a wide variety of assumptions about the nature of problems in individual measurements or error estimates. Ultimately, our analysis yields a SFR for the Galaxy of $\\dot{\\rm M}_\\star=1.65\\pm0.19$ ${\\rm M}_\\odot$ yr$^{-1}$. By combining HB methods with Monte Carlo simulations that incorporate the latest estimates of the Galactocentric radius of the Sun, $R_0$, the exponential scale-length of the disk, $L_d$, and the local surface density of stellar mass, $\\Sigma_\\star(R_0)$, we show that the mass of the Galactic bulge+bar is ${\\rm...

  2. Measuring neutrino mass with radioactive ions in a storage ring

    CERN Document Server

    Lindroos, Mats; Orme, Christopher; Schwetz, Thomas

    2009-01-01

    We propose a method to measure the neutrino mass kinematically using beams of ions which undergo beta decay. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. Then, by counting the backward moving electrons one can observe the effect of neutrino mass on the beta spectrum close to the endpoint. In order to reach sensitivities for $m_\

  3. The Design and Evolution of Jefferson Lab's Jasmine Mass Storage System

    Energy Technology Data Exchange (ETDEWEB)

    Bryan Hess; M. Andrew Kowalski; Michael Haddox-Schatz

    2005-04-01

    We describe the Jasmine mass storage system, in operation since 2001. Jasmine has scaled to meet the challenges of grid applications, petabyte class storage, and hundreds of MB/sec throughput using commodity hardware, Java technologies, and a small but focused development team. The evolution of the integrated disk cache system, which provides a managed online subset of the tape contents, is examined in detail. We describe how the storage system has grown to meet the special needs of the batch farm, grid clients, and new performance demands.

  4. Measuring Neutrino Mass with Radioactive Ions in a Storage Ring

    Science.gov (United States)

    Lindroos, Mats; McElrath, Bob; Orme, Christopher; Schwetz, Thomas

    2010-03-01

    A method to measure the neutrino mass kinematically using beams of ions which undergo beta decay is proposed. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. By counting the backward moving electrons one can observe the effect of neutrino mass on the beta spectrum close to the endpoint. In order to reach sensitivities for mν<0.2 eV, it is necessary to control the ion momentum with a precision better than δp/p<10-5, identify suitable nuclei with low Q-values (in the few to ten keV range), and one must be able to observe at least O(1018) decays.

  5. Updating of the hierarchical rock mass rating (HRMR) system and a new subsystem developed for weathered granite formations

    Institute of Scientific and Technical Information of China (English)

    Miranda Tiago; e Sousa L. Ribeiro; Tinoco Joaquim

    2014-01-01

    The RMR system is still very much applied in rock mechanics engineering context. It is based on the eval-uation of six weights to obtain a final rating. To obtain the final rating a considerable amount of informa-tion is needed concerning the rock mass which can be difficult to obtain in some projects or project stages at least with accuracy. In 2007 an alternative classification scheme based on the RMR, the Hierarchical Rock Mass Rating (HRMR) was presented. The main feature of this system was the adaptation to the level of knowledge existent about the rock mass to obtain the classification of the rock mass since it followed a decision tree approach. However, the HRMR was only valid for hard rock granites with low fracturing degrees. In this work, the database was enlarged with approximately 40%more cases considering other types of granite rock masses including weathered granites and based on this increased database the sys-tem was updated. Granite formations existent in the north of Portugal including Porto city are predom-inantly granites. Some years ago a light rail infrastructure was built in the city of Porto and surrounding municipalities which involved considerable challenges due to the high heterogeneity levels of the granite formations and the difficulties involved in their geomechanical characterization. In this work it is intended to provide also a contribution to improve the characterization of these formations with special emphasis to the weathered horizons. A specific subsystem applicable to the weathered formations was developed. The results of the validation of these systems are presented and show acceptable perfor-mances in identifying the correct class using less information than with the RMR system.

  6. The SWELLS survey - VI. Hierarchical inference of the initial mass functions of bulges and discs

    DEFF Research Database (Denmark)

    Brewer, Brendon J.; Marshal, Philip J.; Auger, Matthew W.

    2014-01-01

    The long-standing assumption that the stellar initial mass function (IMF) is universal has recently been challenged by a number of observations. Several studies have shown that a 'heavy' IMF (e.g. with a Salpeter-like abundance of low-mass stars and thus normalization) is preferred for massive...... early-type galaxies, while this IMF is inconsistent with the properties of less massive, later-type galaxies. These discoveries motivate the hypothesis that the IMF may vary (possibly very slightly) across galaxies and across components of individual galaxies (e.g. bulges versus discs). In this paper......, we use a sample of 19 late-type strong gravitational lenses from the Sloan WFC Edge-on Late-type Lens Survey (SWELLS) to investigate the IMFs of the bulges and discs in late-type galaxies. We perform a joint analysis of the galaxies' total masses (constrained by strong gravitational lensing...

  7. High interfacial storage capability of porous NiMn2O4/C hierarchical tremella-like nanostructures as the lithium ion battery anode.

    Science.gov (United States)

    Kang, Wenpei; Tang, Yongbing; Li, Wenyue; Yang, Xia; Xue, Hongtao; Yang, Qingdan; Lee, Chun-Sing

    2015-01-07

    Porous hierarchical NiMn2O4/C tremella-like nanostructures are obtained through a simple solvothermal and calcination method. As the anode of lithium ion batteries (LIBs), porous NiMn2O4/C nanostructures exhibit a superior specific capacity and an excellent long-term cycling performance even at a high current density. The discharge capacity can stabilize at 2130 mA h g(-1) within 350 cycles at a current density of 1000 mA g(-1). After a long-term cycling of 1500 cycles, the capacity is still as high as 1773 mA h g(-1) at a high current density of 4000 mA g(-1), which is almost five times higher than the theoretical capacity of graphite. The porous NiMn2O4/C hierarchical nanostructure provides sufficient contact with the electrolyte and fast three-dimensional Li(+) diffusion channels, and dramatically improves the capacity of NiMn2O4/C via interfacial storage.

  8. Synthesis of hierarchical NiO microsphere with waxberry-like structure and its enhanced lithium storage performance

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qi; Xu, Yue-Feng; Xu, Gui-Liang [Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen, 361005 (China); Su, Hang [College of Energy, Xiamen University, Xiamen 361005 (China); Shen, Shou-Yu; Tu, Ting-Ting [Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen, 361005 (China); Huang, Ling, E-mail: huangl@xmu.edu.cn [Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen, 361005 (China); Li, Jun-Tao [College of Energy, Xiamen University, Xiamen 361005 (China); Sun, Shi-Gang [Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen, 361005 (China); College of Energy, Xiamen University, Xiamen 361005 (China)

    2015-11-05

    This work reports a facile synthesis of hierarchical NiO microspheres with a waxberry-like structure by one-pot hydrothermal reaction followed by thermal annealing. We detected the composition of precursor by using two-dimensional detector X-ray diffractometer (XRD{sup 2}). In addition, XRD, TG, SEM, TEM and BET measurement were used to characterize the structural properties of the as-prepared materials. The XRD result showed that the precursor has been completely transformed into NiO materials by calcination at 300 °C (denoted as NiO-300). Moreover, thanks to the well conservation of hierarchical structure consisting of needle-like nanoparticles in NiO-300 sample, the charge capacity can be stabilized at 597.8 mAh g{sup −1} reversibly when cycled 100 times at a relatively high current density of 0.7C which show a very competitive capacity compared with other nano-structure NiO materials and commercial NiO material. It also showed high rate capability, the reversible charge capacity is still retained to 370.3 mAh g{sup −1}, even for the condition of 4.46C (high rate). This NiO-300 material's superior electrochemical performance should be exclusively attributed to the well conserved hierarchical waxberry-like structures, which shortens the diffusion pathways of lithium ions and electrons transfer as well as accommodate the drastic volume change during electrochemical charge/discharge process. - Highlights: • Hierarchical waxberry-like NiO has been synthesized by hydrothermal reaction. • Two-dimensional XRD (XRD{sup 2}) was used to ensure the composition of precursor. • The NiO-300 delivers a charge capacity of 597.8 mAh g{sup −1} cycled 100 weeks at 0.7C. • The superior electrochemical performance should be owed to waxberry-like structure.

  9. Evaluation of the hierarchical control of distributed Energy Storage Systems in islanded Microgrids based on Std IEC/ISO 62264

    DEFF Research Database (Denmark)

    Palizban, Omid; Kauhaniemi, Kimmo; Guerrero, Josep M.

    2016-01-01

    In this paper, a decentralized control methodology based on hierarchical control levels is investigated. In recent years, efforts have been made to standardize microgrids (MGs), and the decentralized control method evaluated here is based on the IEC/ISO 62264 standard. Since the main challenge...... proportionally and directly proportionally, respectively, to the state of charge (SoC) of each battery unit during discharging and charging mode. To evaluate this decentralized method based on the IEC/ISO 62264 standard, PSCAD/EMTDC software is used....

  10. Accurate correction of magnetic field instabilities for high-resolution isochronous mass measurements in storage rings

    CERN Document Server

    Shuai, P; Zhang, Y H; Litvinov, Yu A; Wang, M; Tu, X L; Blaum, K; Zhou, X H; Yuan, Y J; Audi, G; Yan, X L; Chen, X C; Xu, X; Zhang, W; Sun, B H; Yamaguchi, T; Chen, R J; Fu, C Y; Ge, Z; Huang, W J; Liu, D W; Xing, Y M; Zeng, Q

    2014-01-01

    Isochronous mass spectrometry (IMS) in storage rings is a successful technique for accurate mass measurements of short-lived nuclides with relative precision of about $10^{-5}-10^{-7}$. Instabilities of the magnetic fields in storage rings are one of the major contributions limiting the achievable mass resolving power, which is directly related to the precision of the obtained mass values. A new data analysis method is proposed allowing one to minimise the effect of such instabilities. The masses of the previously measured at the CSRe $^{41}$Ti, $^{43}$V, $^{47}$Mn, $^{49}$Fe, $^{53}$Ni and $^{55}$Cu nuclides were re-determined with this method. An improvement of the mass precision by a factor of $\\sim 1.7$ has been achieved for $^{41}$Ti and $^{43}$V. The method can be applied to any isochronous mass experiment irrespective of the accelerator facility. Furthermore, the method can be used as an on-line tool for checking the isochronous conditions of the storage ring.

  11. Assembly of tin oxide/graphene nanosheets into 3D hierarchical frameworks for high-performance lithium storage.

    Science.gov (United States)

    Huang, Yanshan; Wu, Dongqing; Han, Sheng; Li, Shuang; Xiao, Li; Zhang, Fan; Feng, Xinliang

    2013-08-01

    3D hierarchical tin oxide/graphene frameworks (SnO2 /GFs) were built up by the in situ synthesis of 2D SnO2 /graphene nanosheets followed by hydrothermal assembly. These SnO2 /GFs exhibited a 3D hierarchical porous architecture with mesopores (≈3 nm), macropores (3-6 μm), and a large surface area (244 m(2) g(-1) ), which not only effectively prevented the agglomeration of SnO2 nanoparticles, but also facilitated fast ion and electron transport in 3D pathways. As a consequence, the SnO2 /GFs exhibited a high capacity of 830 mAh g(-1) for up to 70 charge-discharge cycles at 100 mA g(-1) . Even at a high current density of 500 mA g(-1) , a reversible capacity of 621 mAh g(-1) could be maintained for SnO2 /GFs with excellent cycling stability. Such performance is superior to that of previously reported SnO2 /graphene and other SnO2 /carbon composites with similar weight contents of SnO2 .

  12. Graphene Oxide Templated Growth and Superior Lithium Storage Performance of Novel Hierarchical Co2V2O7 Nanosheets.

    Science.gov (United States)

    Luo, Yanzhu; Xu, Xu; Zhang, Yuxiang; Chen, Chih-Yen; Zhou, Liang; Yan, Mengyu; Wei, Qiulong; Tian, Xiaocong; Mai, Liqiang

    2016-02-01

    Hierarchical Co2V2O7 nanosheets consisted of interconnected nanoparticles are synthesized by a facile method using graphene oxide as the template. The electrochemical reaction mechanism of the Co2V2O7 nanosheets is thoroughly investigated by in situ XRD and ex situ TEM. The initial Co2V2O7 transforms into CoO nanoparticles and vanadium oxides in the first cycle, and the following reversible conversion reaction mainly occurs between CoO and Co and lithiation/delithiation of the vanadium oxides. The Co2V2O7 nanosheet displays a high reversible capacity (962 mAh/g at 0.5 A/g) and remarkable high rate capability. When cycled at 5.0 A/g, a reversible capacity of 441 mAh/g can be retained after 900 cycles. The stable high capacity and excellent rate capability make the hierarchical Co2V2O7 nanosheets a promising anode material for lithium-ion batteries.

  13. Chemical Evolution in Hierarchical Models Of Cosmic Structure I: Constraints on the Early Stellar Initial Mass Function

    CERN Document Server

    Tumlinson, J

    2006-01-01

    I present a new Galactic chemical evolution model motivated by and grounded in the hierarchical theory of galaxy formation, as expressed by a halo merger history of the Galaxy. This model accurately reproduces the "metallicity distribution function" (MDF) for Population II stars residing today in the Galactic halo. The observed MDF and the apparent absence of true Population III stars from the halo strongly imply that there is some critical metallicity, Z_crit = 8 - 42 Msun. This mass range is similar to the masses predicted by models of primordial star formation that account for formation feedback. The model also implies that metal-poor halo stars below [Fe/H] <~ -3 had only 1 - 10 metal-free stars as their supernova precursors, such that the relative abundances in these halo stars exhibit IMF-weighted averages over the intrinsic yields of the first supernovae. This paper is the first part of a long term project to connect the high-redshift in situ indicators of early star formation with the low-z, old r...

  14. Limits on $T_{\\rm reh}$ for thermal leptogenesis with hierarchical neutrino masses

    CERN Document Server

    Chankowski, P H

    2003-01-01

    We make a simple observation that if one of the right-chiral neutrinos is very heavy or its Yukawa couplings to the standard lepton doublets are negligible, so that it effectively decouples from the see-saw mechanism, the prediction for the baryon asymmetry of the Universe resulting from leptogenesis depends apart from the masses $M_1$ and $M_2$ of the remaining two right-chiral neutrinos only on the element $\\YY{22}$ of the neutrino Yukawa coupling. For $M_2\\simgt10M_1$ the lower bound on $M_1$ and also on $T_{\\rm reh}$, resulting from the requirement of 'successful leptogenesis' is then significantly increased compared to the one computed recently by Buchm\\"uller {\\it et al.} in the most general case. Within the framework of thermal leptogenesis, the only way to lower this limit is then to allow for sufficiently small mass difference $M_2-M_1$.

  15. Numerical analysis of added mass and damping of floating production,storage and offloading system

    Institute of Scientific and Technical Information of China (English)

    Ke Wang; Xi Zhang; Zhi-Qiang Zhang; Wang Xu

    2012-01-01

    An integral equation approach is utilized to investigate the added mass and damping of floating production,storage and offloading system (FPSO system).Finite water depth Green function and higher-order boundary element method are used to solve integral equation.Numerical results about added mass and damping are presented for odd and even mode motions of FPSO.The results show robust convergence in high frequency range and can be used in wave load analysis for FPSO designing and operation.

  16. Fermilab's multi-petabyte scalable mass storage system

    Energy Technology Data Exchange (ETDEWEB)

    Oleynik, Gene; Alcorn, Bonnie; Baisley, Wayne; Bakken, Jon; Berg, David; Berman, Eileen; Huang, Chih-Hao; Jones, Terry; Kennedy, Robert D.; Kulyavtsev, Alexander; Moibenko, Alexander; Perelmutov, Timur; Petravick, Don; Podstavkov, Vladimir; Szmuksta, George; Zalokar, Michael; /Fermilab

    2005-01-01

    Fermilab provides a multi-Petabyte scale mass storage system for High Energy Physics (HEP) Experiments and other scientific endeavors. We describe the scalability aspects of the hardware and software architecture that were designed into the Mass Storage System to permit us to scale to multiple petabytes of storage capacity, manage tens of terabytes per day in data transfers, support hundreds of users, and maintain data integrity. We discuss in detail how we scale the system over time to meet the ever-increasing needs of the scientific community, and relate our experiences with many of the technical and economic issues related to scaling the system. Since the 2003 MSST conference, the experiments at Fermilab have generated more than 1.9 PB of additional data. We present results on how this system has scaled and performed for the Fermilab CDF and D0 Run II experiments as well as other HEP experiments and scientific endeavors.

  17. Effect of water storage on ultimate tensile strength and mass changes of universal adhesives.

    Science.gov (United States)

    Bahrololumi, Nazanin; Beglou, Amirreza; Najafi-Abrandabadi, Ahmad; Sadr, Alireza; Sheikh-Al-Eslamian, Seyedeh-Mahsa; Ghasemi, Amir

    2017-01-01

    The aim of the present study was to evaluate the influence of water storage on micro tensile strength (µTS) and mass changes (MC) of two universal adhesives. 10 disk-shaped specimens were prepared for each adhesive; Scotchbond Universal (SCU) All-Bond Universal (ABU) and Adper Single Bond 2 (SB2). At the baseline and after 1 day and 28 days of water storage, their mass were measured and compared to estimate water sorption and solubility. For µTS test, 20 dumbbell shaped specimens were also prepared for each adhesive in two subgroups of 1 day and 28 days water storage. MC was significantly lower for SCU and ABU than SB2 (P water; both universal adhesives showed less water sorption and higher values of µTS than the control group. Key words:Absorption, dental adhesives, dentin-bonding agents, solubility, tensile strength.

  18. Effects of storage period and mass on seed germination of the Carabao mango

    Directory of Open Access Journals (Sweden)

    Juliana Altafin Galli

    2012-09-01

    Full Text Available The mango is a species that produces recalcitrant seeds, which can be difficult to store. The objective of this work was to evaluate the effect of storage period and mass on the germination of Carabao mango seeds. The fruits were picked and the pits were dried. The seeds were weighed and separated in two classes: I with a mass up to 19.0g, and II above 19.0g. The seeds were treated with 60% thiabendazol, wrapped in perforated transparent polyethylene bags, maintained in a laboratory, and germinated directly in the plastic bags. The statistical analysis used a randomized block design, with four repetitions, that consisted of five storage periods: 0 (zero, 7, 14, 21 and 28 days. A regression analysis was made. Due to the small number of seeds with a mass less than 19.0g, the germination tests using two classes were done only for the periods of zero and the first seven days of storage. It was found that the seeds of Carabao mango, when treated with fungicide, performed best when sown after seven days of storage in polyethylene bags, and that the mass of the seeds positively influenced germination.

  19. A Note on Interfacing Object Warehouses and Mass Storage Systems for Data Mining Applications

    Science.gov (United States)

    Grossman, Robert L.; Northcutt, Dave

    1996-01-01

    Data mining is the automatic discovery of patterns, associations, and anomalies in data sets. Data mining requires numerically and statistically intensive queries. Our assumption is that data mining requires a specialized data management infrastructure to support the aforementioned intensive queries, but because of the sizes of data involved, this infrastructure is layered over a hierarchical storage system. In this paper, we discuss the architecture of a system which is layered for modularity, but exploits specialized lightweight services to maintain efficiency. Rather than use a full functioned database for example, we use light weight object services specialized for data mining. We propose using information repositories between layers so that components on either side of the layer can access information in the repositories to assist in making decisions about data layout, the caching and migration of data, the scheduling of queries, and related matters.

  20. Frequency-Division Power Sharing and Hierarchical Control Design for DC Shipboard Microgrids with Hybrid Energy Storage Systems

    DEFF Research Database (Denmark)

    Jin, Zheming; Meng, Lexuan; Quintero, Juan Carlos Vasquez

    2017-01-01

    Due to the increasing need to reduce the cost and emission of ships, shipboard applications are calling advanced technologies to go onboard. Recently, cleaner power sources (i.e. gas turbines, fuel cell, solar and wind power), energy storage, advanced control and power/energy management are intro......Due to the increasing need to reduce the cost and emission of ships, shipboard applications are calling advanced technologies to go onboard. Recently, cleaner power sources (i.e. gas turbines, fuel cell, solar and wind power), energy storage, advanced control and power/energy management...... are introduced to meet the new requirement, and therefore, making shipboard power system more like a microgrid. In this paper, a frequency-division based power sharing method is proposed to solve the contradiction between fuel efficiency and dynamic load conditions of marine vessels. With effective design...

  1. Diagnosing lysosomal storage diseases in a Brazilian non-newborn population by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Guilherme Dotto Brand

    2013-11-01

    Full Text Available OBJECTIVES: High-throughput mass spectrometry methods have been developed to screen newborns for lysosomal storage disorders, allowing the implementation of newborn screening pilot studies in North America and Europe. It is currently feasible to diagnose Pompe, Fabry, Gaucher, Krabbe, and Niemann-Pick A/B diseases, as well as mucopolysaccharidosis I, by tandem mass spectrometry in dried blood spots, which offers considerable technical advantages compared with standard methodologies. We aimed to investigate whether the mass spectrometry methodology for lysosomal storage disease screening, originally developed for newborns, can also discriminate between affected patients and controls of various ages. METHODS: A total of 205 control individuals were grouped according to age and subjected to mass spectrometry quantification of lysosomal α-glucosidase, β-glucocerebrosidase, α-galactosidase, acid sphingomyelinase, galactocerebrosidase, and α−L-iduronidase activities. Additionally, 13 affected patients were analyzed. RESULTS: The median activities for each enzyme and each age group were determined. Enzyme activities were significantly lower in individuals aged older than 18 years compared with those in newborns. Affected patients presented enzymatic activities corresponding to less than 20% of the age-matched controls. CONCLUSIONS: Our data indicate that the mass spectrometry methodology can be used for the screening of lysosomal storage diseases in non-newborn patients. However, for some diseases, such as Fabry and mucopolysaccharidosis I, a combination of biochemical and clinical data may be necessary to achieve accurate diagnoses.

  2. Load balancing prediction method of cloud storage based on analytic hierarchy process and hybrid hierarchical genetic algorithm.

    Science.gov (United States)

    Zhou, Xiuze; Lin, Fan; Yang, Lvqing; Nie, Jing; Tan, Qian; Zeng, Wenhua; Zhang, Nian

    2016-01-01

    With the continuous expansion of the cloud computing platform scale and rapid growth of users and applications, how to efficiently use system resources to improve the overall performance of cloud computing has become a crucial issue. To address this issue, this paper proposes a method that uses an analytic hierarchy process group decision (AHPGD) to evaluate the load state of server nodes. Training was carried out by using a hybrid hierarchical genetic algorithm (HHGA) for optimizing a radial basis function neural network (RBFNN). The AHPGD makes the aggregative indicator of virtual machines in cloud, and become input parameters of predicted RBFNN. Also, this paper proposes a new dynamic load balancing scheduling algorithm combined with a weighted round-robin algorithm, which uses the predictive periodical load value of nodes based on AHPPGD and RBFNN optimized by HHGA, then calculates the corresponding weight values of nodes and makes constant updates. Meanwhile, it keeps the advantages and avoids the shortcomings of static weighted round-robin algorithm.

  3. Hierarchical networks of redox-active reduced crumpled graphene oxide and functionalized few-walled carbon nanotubes for rapid electrochemical energy storage

    Science.gov (United States)

    Lee, Byeongyong; Lee, Chongmin; Liu, Tianyuan; Eom, Kwangsup; Chen, Zhongming; Noda, Suguru; Fuller, Thomas F.; Jang, Hee Dong; Lee, Seung Woo

    2016-06-01

    Crumpled graphene is known to have a strong aggregation-resistive property due to its unique 3D morphology, providing a promising solution to prevent the restacking issue of graphene based electrode materials. Here, we demonstrate the utilization of redox-active oxygen functional groups on the partially reduced crumpled graphene oxide (r-CGO) for electrochemical energy storage applications. To effectively utilize the surface redox reactions of the functional groups, hierarchical networks of electrodes including r-CGO and functionalized few-walled carbon nanotubes (f-FWNTs) are assembled via a vacuum-filtration process, resulting in a 3D porous structure. These composite electrodes are employed as positive electrodes in Li-cells, delivering high gravimetric capacities of up to ~170 mA h g-1 with significantly enhanced rate-capability compared to the electrodes consisting of conventional 2D reduced graphene oxide and f-FWNTs. These results highlight the importance of microstructure design coupled with oxygen chemistry control, to maximize the surface redox reactions on functionalized graphene based electrodes.Crumpled graphene is known to have a strong aggregation-resistive property due to its unique 3D morphology, providing a promising solution to prevent the restacking issue of graphene based electrode materials. Here, we demonstrate the utilization of redox-active oxygen functional groups on the partially reduced crumpled graphene oxide (r-CGO) for electrochemical energy storage applications. To effectively utilize the surface redox reactions of the functional groups, hierarchical networks of electrodes including r-CGO and functionalized few-walled carbon nanotubes (f-FWNTs) are assembled via a vacuum-filtration process, resulting in a 3D porous structure. These composite electrodes are employed as positive electrodes in Li-cells, delivering high gravimetric capacities of up to ~170 mA h g-1 with significantly enhanced rate-capability compared to the electrodes

  4. Accurate hierarchical control of hollow crossed NiCo2O4 nanocubes for superior lithium storage

    Science.gov (United States)

    Guo, Hong; Liu, Lixiang; Li, Tingting; Chen, Weiwei; Liu, Jiajia; Guo, Yuanyuan; Guo, Yicheng

    2014-04-01

    An effective approach of simultaneously coordinating etching and precipitation reactions is employed to prepare hollow crossed NiCo2O4 nanocubes as anode materials for lithium-ion batteries. Firstly, amorphous hollow (NiCox)O(OH) nanoboxes form uniformly, and subsequent calcination results in the formation of NiCo2O4 nanocubes that exhibit a stable reversible capacity of 1160 mA h g-1 at constant current density of 200 mA g-1 with capacity retention of over 91.1% after 200 cycles. The unique hollow structure can shorten the Li-ion diffusion path, which benefits the rate of performance. Furthermore, the hollow structure offers a sufficient void space to alleviate the mechanical stress caused by volume change. Additionally, the multi-element characteristics of active materials allow the volume change to take place in a stepwise manner. Therefore, hollow crossed NiCo2O4 nanocube electrodes exhibit excellent electrochemical performance. This method is simple and of low cost, which may open a new avenue for fast synthesis of hollow crossed structural nano-functional materials for energy storage, catalysts, sensors and other new applications.An effective approach of simultaneously coordinating etching and precipitation reactions is employed to prepare hollow crossed NiCo2O4 nanocubes as anode materials for lithium-ion batteries. Firstly, amorphous hollow (NiCox)O(OH) nanoboxes form uniformly, and subsequent calcination results in the formation of NiCo2O4 nanocubes that exhibit a stable reversible capacity of 1160 mA h g-1 at constant current density of 200 mA g-1 with capacity retention of over 91.1% after 200 cycles. The unique hollow structure can shorten the Li-ion diffusion path, which benefits the rate of performance. Furthermore, the hollow structure offers a sufficient void space to alleviate the mechanical stress caused by volume change. Additionally, the multi-element characteristics of active materials allow the volume change to take place in a stepwise manner

  5. Mass minimization of a discrete regenerative fuel cell (RFC) system for on-board energy storage

    Science.gov (United States)

    Li, Xiaojin; Xiao, Yu; Shao, Zhigang; Yi, Baolian

    RFC combined with solar photovoltaic (PV) array is the advanced technologic solution for on-board energy storage, e.g. land, sky, stratosphere and aerospace applications, due to its potential of achieving high specific energy. This paper focuses on mass modeling and calculation for a RFC system consisting of discrete electrochemical cell stacks (fuel cell and electrolyzer), together with fuel storage, a PV array, and a radiator. A nonlinear constrained optimization procedure is used to minimize the entire system mass, as well as to study the effect of operating conditions (e.g. current densities of fuel cell and electrolyzer) on the system mass. According to the state-of-the-art specific power of both electrochemical stacks, an energy storage system has been designed for the conditions of stratosphere applications and a rated power output of 12 kW. The calculation results show that the optimization of the current density of both stacks is of importance in designing the light weight on-board energy system.

  6. Facile synthesis of Co{sub 3}O{sub 4} hierarchical microspheres with improved lithium storage performances

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xiaojuan, E-mail: houxiaojuan@nuc.edu.cn; He, Jian; An, Kun; Mu, Jiliang; Chou, Xiujian; Xue, Chenyang

    2016-10-15

    Highlights: • The Co{sub 3}O{sub 4} microspheres were first fabricated without any surfactant. • The Co{sub 3}O{sub 4} microspheres present excellent electrochemical performances. • The excellent performances result from porous nanosheets assembled architectures. • The microspheres exhibit a high specific capacity of 1000 mA h g at 100 mA g. - Abstract: Porous nanosheets-assembled Co{sub 3}O{sub 4} microspheres have been first successfully fabricated by a facile solvothermal method without any surfactant followed by a relatively low annealing temperature (400 °C) with a higher specific surface area compared to the annealing temperature of 600 °C. The nanosheets-assembled microspheres exhibit a high discharge capacity of 1000 mA h g{sup −1} at a current density of 100 mA g{sup −1} after 50 cycles and 850 mA h g{sup −1} at a current density of 500 mA g{sup −1} after 80 cycles, even at a high current density of 1.6 A g{sup −1} the cycling reversible capacity can still keep 750 mA h g{sup −1}, the representative capacities are relatively higher than most of reports about pure Co{sub 3}O{sub 4}. We attribute the excellent electrochemical performances to the porous nanosheets structure and architectures, which can provide more effective electrode/electrolyte contact area and direct ion transmission path, then lead to faster lithium-ion diffusion, confirmed by EIS measurements. The high specific capacity, excellent cycling and rate performances demonstrate that the porous nanosheets assembled microspheres present promising application in lithium storage.

  7. Implications of rate-limited mass transfer for aquifer storage and recovery.

    Science.gov (United States)

    Culkin, Sean L; Singha, Kamini; Day-Lewis, Frederick D

    2008-01-01

    Pressure to decrease reliance on surface water storage has led to increased interest in aquifer storage and recovery (ASR) systems. Recovery efficiency, which is the ratio of the volume of recovered water that meets a predefined standard to total volume of injected fluid, is a common criterion of ASR viability. Recovery efficiency can be degraded by a number of physical and geochemical processes, including rate-limited mass transfer (RLMT), which describes the exchange of solutes between mobile and immobile pore fluids. RLMT may control transport behavior that cannot be explained by advection and dispersion. We present data from a pilot-scale ASR study in Charleston, South Carolina, and develop a three-dimensional finite-difference model to evaluate the impact of RLMT processes on ASR efficiency. The modeling shows that RLMT can explain a rebound in salinity during fresh water storage in a brackish aquifer. Multicycle model results show low efficiencies over one to three ASR cycles due to RLMT degrading water quality during storage; efficiencies can evolve and improve markedly, however, over multiple cycles, even exceeding efficiencies generated by advection-dispersion only models. For an idealized ASR model where RLMT is active, our simulations show a discrete range of diffusive length scales over which the viability of ASR schemes in brackish aquifers would be hindered.

  8. Present and future developments of SPM systems as mass storage devices

    Science.gov (United States)

    Born, A.; Wiesendanger, R.

    SPM technology offers a great potential to increase storage data density. The use of magnetic force microscopy (MFM) and scanning capacitance microscopy (SCM) as possible methods for a future ultrahigh-density-storage (UHDS) device has been explored. Two methods to create parallel large areas of nanometer-scale magnetic dots have been developed. The first technique is based on nanometer latex balls that serve as a mask. For the second method the mask is produced by means of interferometric lithography. The MFM allows the imaging and manipulation of these magnetic dots with full width at half maximum (FWHM) of 150 nm and smaller. Furthermore we have explored the possibility of using a scanning capacitance microscope (SCM) for charge storage. A metallic cantilever was positioned over a nitride-oxide-silicon (NOS) heterostructure. The SCM measures the capacitance as a function of the bias voltage and can detect the stored charge by the displacement of the CV curve. This technique allows a data density of more than 180 bit/μm2. Besides a high data density, a high data rate is an important requirement for a mass storage device. To overcome the problem of the low relative velocity between tip and sample for all commercial scanning probe microscopy (SPM) devices, we have developed a high speed SCM prototype which has the potential to reach data rates of Mbit/s.

  9. Effect of water storage on ultimate tensile strength and mass changes of universal adhesives

    Science.gov (United States)

    Bahrololumi, Nazanin; Najafi-Abrandabadi, Ahmad; Sadr, Alireza; Sheikh-Al-Eslamian, Seyedeh-Mahsa; Ghasemi, Amir

    2017-01-01

    Background The aim of the present study was to evaluate the influence of water storage on micro tensile strength (µTS) and mass changes (MC) of two universal adhesives. Material and Methods 10 disk-shaped specimens were prepared for each adhesive; Scotchbond Universal (SCU) All-Bond Universal (ABU) and Adper Single Bond 2 (SB2). At the baseline and after 1 day and 28 days of water storage, their mass were measured and compared to estimate water sorption and solubility. For µTS test, 20 dumbbell shaped specimens were also prepared for each adhesive in two subgroups of 1 day and 28 days water storage. Results MC was significantly lower for SCU and ABU than SB2 (P adhesives, the MC was significantly lower at 28 days compared to that at 1 day (P adhesives (P adhesives were both material and time dependent when stored in water; both universal adhesives showed less water sorption and higher values of µTS than the control group. Key words:Absorption, dental adhesives, dentin-bonding agents, solubility, tensile strength. PMID:28149468

  10. Porous V2O5/RGO/CNT hierarchical architecture as a cathode material: Emphasis on the contribution of surface lithium storage

    Science.gov (United States)

    Palanisamy, Kowsalya; Um, Ji Hyun; Jeong, Mihee; Yoon, Won-Sub

    2016-08-01

    A three dimensional vanadium pentoxide/reduced graphene oxide/carbon nanotube (3D V2O5/RGO/CNT) composite is synthesized by microwave-assisted hydrothermal method. The combination of 2D RGO and 1D CNT establishes continuous 3D conductive network, and most notably, the 1D CNT is designed to form hierarchically porous structure by penetrating into V2O5 microsphere assembly constituted of numerous V2O5 nanoparticles. The highly porous V2O5 microsphere enhances electrolyte contact and shortens Li+ diffusion path as a consequence of its developed surface area and mesoporosity. The successive phase transformations of 3D V2O5/RGO/CNT from α-phase to ε-, δ-, γ-, and ω-phase and its structural reversibility upon Li+ intercalation/de-intercalation are investigated by in situ XRD analysis, and the electronic and local structure reversibility around vanadium atom in 3D V2O5/RGO/CNT is observed by in situ XANES analysis. The 3D V2O5/RGO/CNT achieves a high capacity of 220 mAh g‑1 at 1 C after 80 cycles and an excellent rate capability of 100 mAh g‑1 even at a considerably high rate of 20 C. The porous 3D V2O5/RGO/CNT structure not only provides facile Li+ diffusion into bulk but contributes to surface Li+ storage as well, which enables the design of 3D V2O5/RGO/CNT composite to become a promising cathode architecture for high performance LIBs.

  11. Total Land Water Storage Change over 2003 - 2013 Estimated from a Global Mass Budget Approach

    Science.gov (United States)

    Dieng, H. B.; Champollion, N.; Cazenave, A.; Wada, Y.; Schrama, E.; Meyssignac, B.

    2015-01-01

    We estimate the total land water storage (LWS) change between 2003 and 2013 using a global water mass budget approach. Hereby we compare the ocean mass change (estimated from GRACE space gravimetry on the one hand, and from the satellite altimetry-based global mean sea level corrected for steric effects on the other hand) to the sum of the main water mass components of the climate system: glaciers, Greenland and Antarctica ice sheets, atmospheric water and LWS (the latter being the unknown quantity to be estimated). For glaciers and ice sheets, we use published estimates of ice mass trends based on various types of observations covering different time spans between 2003 and 2013. From the mass budget equation, we derive a net LWS trend over the study period. The mean trend amounts to +0.30 +/- 0.18 mm/yr in sea level equivalent. This corresponds to a net decrease of -108 +/- 64 cu km/yr in LWS over the 2003-2013 decade. We also estimate the rate of change in LWS and find no significant acceleration over the study period. The computed mean global LWS trend over the study period is shown to be explained mainly by direct anthropogenic effects on land hydrology, i.e. the net effect of groundwater depletion and impoundment of water in man-made reservoirs, and to a lesser extent the effect of naturally-forced land hydrology variability. Our results compare well with independent estimates of human-induced changes in global land hydrology.

  12. Numerical models of mass transfer during ripening and storage of salami

    Directory of Open Access Journals (Sweden)

    Angelo Fabbri

    2013-09-01

    Full Text Available Ripening, in the dry sausages manufacturing process, has an influence over the main physical, chemical and microbiological transformations that take place inside these products and that define the final organoleptic properties of dry sausages. A number of study about the influence of ripening conditions on the main chemical and microbiological characteristics of dry sausages is available today. All these studies indicate that the final quality and safety standards achieved by the sausage manufacturing process can be considered to be strictly dependent from the specific ripening conditions. The water diffusion inside a seasoned sausage is surely an aspect of primary importance with regard to the quality of final product. As a consequence the aim of this research was to develop two parametric numerical models, concerning the moisture diffusion physics, describing salami ripening and storage. Mass transfer equations inside the sausage volume were numerically solved using a finite element technique. A first model describes diffusion phenomena occurring inside the salami and the exchange phenomena involving the surface of the product and the environment. After the ripening, the salami are stored in waterproof packaging, consequently an additional model able to describe also the evaporation and condensation phenomena occurring between the salami surface and the air in the package, was developed. The moisture equilibrium between salami surface and conservation atmosphere is mainly ruled by the temperature changes during storage. Both models allow to analyze the history of the moisture content inside the salami and are parametrised on product size and maturation/storage conditions. The models were experimentally validated, comparing the numerical outputs of the simulations with experimental data, showing a good agreement.

  13. Typing of unknown microorganisms based on quantitative analysis of fatty acids by mass spectrometry and hierarchical clustering

    Energy Technology Data Exchange (ETDEWEB)

    Li Tingting; Dai Ling; Li Lun; Hu Xuejiao; Dong Linjie; Li Jianjian; Salim, Sule Khalfan; Fu Jieying [Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079 (China); Zhong Hongying, E-mail: hyzhong@mail.ccnu.edu.cn [Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079 (China)

    2011-01-17

    Rapid identification of unknown microorganisms of clinical and agricultural importance is not only critical for accurate diagnosis of infections but also essential for appropriate and prompt treatment. We describe here a rapid method for microorganisms typing based on quantitative analysis of fatty acids by iFAT approach (Isotope-coded Fatty Acid Transmethylation). In this work, lyophilized cell lysates were directly mixed with 0.5 M NaOH solution in d3-methanol and n-hexane. After 1 min of ultrasonication, the top n-hexane layer was combined with a mixture of standard d0-methanol derived fatty acid methylesters with known concentration. Measurement of intensity ratios of d3/d0 labeled fragment ion and molecular ion pairs at the corresponding target fatty acids provides a quantitative basis for hierarchical clustering. In the resultant dendrogram, the Euclidean distance between unknown species and known species quantitatively reveals their differences or shared similarities in fatty acid related pathways. It is of particular interest to apply this method for typing fungal species because fungi has distinguished lipid biosynthetic pathways that have been targeted for lots of drugs or fungicides compared with bacteria and animals. The proposed method has no dependence on the availability of genome or proteome databases. Therefore, it is can be applicable for a broad range of unknown microorganisms or mutant species.

  14. The growth of the UniTree mass storage system at the NASA Center for Computational Sciences

    Science.gov (United States)

    Tarshish, Adina; Salmon, Ellen

    1993-01-01

    In October 1992, the NASA Center for Computational Sciences made its Convex-based UniTree system generally available to users. The ensuing months saw the growth of near-online data from nil to nearly three terabytes, a doubling of the number of CPU's on the facility's Cray YMP (the primary data source for UniTree), and the necessity for an aggressive regimen for repacking sparse tapes and hierarchical 'vaulting' of old files to freestanding tape. Connectivity was enhanced as well with the addition of UltraNet HiPPI. This paper describes the increasing demands placed on the storage system's performance and throughput that resulted from the significant augmentation of compute-server processor power and network speed.

  15. 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).

  16. Avoiding progenitor bias: The structural and mass evolution of Brightest Group and Cluster Galaxies in Hierarchical models since z~1

    CERN Document Server

    Shankar, Francesco; Rettura, Alessandro; Bouillot, Vincent; Moreno, Jorge; Licitra, Rossella; Bernardi, Mariangela; Huertas-Company, Marc; Mei, Simona; Ascaso, Begoña; Sheth, Ravi; Delaye, Lauriane; Raichoor, Anand

    2015-01-01

    The mass and structural evolution of massive galaxies is one of the hottest topics in galaxy formation. This is because it may reveal invaluable insights into the still debated evolutionary processes governing the growth and assembly of spheroids. However, direct comparison between models and observations is usually prevented by the so-called "progenitor bias", i.e., new galaxies entering the observational selection at later epochs, thus eluding a precise study of how pre-existing galaxies actually evolve in size. To limit this effect, we here gather data on high-redshift brightest group and cluster galaxies, evolve their (mean) host halo masses down to z=0 along their main progenitors, and assign as their "descendants" local SDSS central galaxies matched in host halo mass. At face value, the comparison between high redshift and local data suggests a noticeable increase in stellar mass of a factor of >2 since z~1, and of >2.5 in mean effective radius. We then compare the inferred stellar mass and size growth ...

  17. Low Mass Printable Devices for Energy Capture, Storage, and Use for Space Exploration Missions

    Science.gov (United States)

    Frazier, Donald O.; Singer, Christopher E.; Ray, William J.; Fuller, Kirk A.

    2010-01-01

    The energy-efficient, environmentally friendly technology that will be presented is the result of a Space Act Agreement between -Technologies Worldwide, Inc., and the National Aeronautics and Space Administration s (NASA s) Marshall Space Flight Center (MSFC). This work combines semiconductor and printing technologies to advance lightweight electronic and photonic devices having excellent potential for commercial and exploration applications, and is an example of industry and government cooperation that leads to novel inventions. Device development involves three energy generation and consumption projects: 1) a low mass efficient (low power, low heat emission) micro light-emitting diode (LED) area lighting device; 2) a low-mass omni-directional efficient photovoltaic (PV) device with significantly improved energy capture; and 3) a new approach to building supercapacitors. These three technologies - energy capture, storage, and usage (e.g., lighting) - represent a systematic approach for building efficient local micro-grids that are commercially feasible; furthermore, these same technologies will be useful for lightweight power generation that enables inner planetary missions using smaller launch vehicles and facilitates surface operations. The PV device model is a two-sphere, light-trapped sheet approximately 2-mm thick. The model suggests a significant improvement over current thin film systems. All three components may be printed in line by printing sequential layers on a standard screen or flexographic direct impact press using the threedimensional printing technique (3DFM) patented by NthDegree. MSFC is testing the robustness of prototype devices in the harsh space and lunar surface environments, and available results will be reported. Unlike many traditional light sources, this device does not contain toxic compounds, and the LED component has passed stringent off-gassing tests required for potential manifesting on spacecraft such as the International Space

  18. 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.

  19. Estimation of root zone storage capacity at the catchment scale using improved Mass Curve Technique

    Science.gov (United States)

    Zhao, Jie; Xu, Zongxue; Singh, Vijay P.

    2016-09-01

    The root zone storage capacity (Sr) greatly influences runoff generation, soil water movement, and vegetation growth and is hence an important variable for ecological and hydrological modelling. However, due to the great heterogeneity in soil texture and structure, there seems to be no effective approach to monitor or estimate Sr at the catchment scale presently. To fill the gap, in this study the Mass Curve Technique (MCT) was improved by incorporating a snowmelt module for the estimation of Sr at the catchment scale in different climatic regions. The "range of perturbation" method was also used to generate different scenarios for determining the sensitivity of the improved MCT-derived Sr to its influencing factors after the evaluation of plausibility of Sr derived from the improved MCT. Results can be showed as: (i) Sr estimates of different catchments varied greatly from ∼10 mm to ∼200 mm with the changes of climatic conditions and underlying surface characteristics. (ii) The improved MCT is a simple but powerful tool for the Sr estimation in different climatic regions of China, and incorporation of more catchments into Sr comparisons can further improve our knowledge on the variability of Sr. (iii) Variation of Sr values is an integrated consequence of variations in rainfall, snowmelt water and evapotranspiration. Sr values are most sensitive to variations in evapotranspiration of ecosystems. Besides, Sr values with a longer return period are more stable than those with a shorter return period when affected by fluctuations in its influencing factors.

  20. Template-Engaged Synthesis of 1D Hierarchical Chainlike LiCoO2 Cathode Materials with Enhanced High-Voltage Lithium Storage Capabilities.

    Science.gov (United States)

    Wu, Naiteng; Zhang, Yun; Wei, Yunhong; Liu, Heng; Wu, Hao

    2016-09-28

    A novel 1D hierarchical chainlike LiCoO2 organized by flake-shaped primary particles is synthesized via a facile template-engaged strategy by using CoC2O4·2H2O as a self-sacrificial template obtained from a simple coprecipitation method. The resultant LiCoO2 has a well-built hierarchical structure, consisting of secondary micrometer-sized chains and sub-micrometer-sized primary flakes, while these primary LiCoO2 flakes have specifically exposed fast-Li(+)-diffused active {010} facets. Owing to this unique hierarchical structure, the chainlike LiCoO2 serves as a stable cathode material for lithium-ion batteries (LIBs) operated at a high cutoff voltage up to 4.5 V, enabling highly reversible capacity, remarkable rate performance, and long-term cycle life. Specifically, the chainlike LiCoO2 can deliver a reversible discharge capacity as high as 168, 156, 150, and 120 mAh g(-1) under the current density of 0.1, 0.5, 1, and 5 C, respectively, while about 85% retention of the initial capacity can be retained after 200 cycles under 1 C at room temperature. Moreover, the chainlike LiCoO2 also shows an excellent cycling stability at a wide operating temperature range, showing the capacity retention of ∼73% after 200 cycles at 55 °C and of ∼68% after 50 cycles at -10 °C, respectively. The work described here suggests the great potential of the hierarchical chainlike LiCoO2 as high-voltage cathode materials aimed toward developing advanced LIBs with high energy density and power density.

  1. WASP-34b: a near-grazing transiting sub-Jupiter-mass exoplanet in a hierarchical triple system

    Science.gov (United States)

    Smalley, B.; Anderson, D. R.; Collier Cameron, A.; Hellier, C.; Lendl, M.; Maxted, P. F. L.; Queloz, D.; Triaud, A. H. M. J.; West, R. G.; Bentley, S. J.; Enoch, B.; Gillon, M.; Lister, T. A.; Pepe, F.; Pollacco, D.; Segransan, D.; Smith, A. M. S.; Southworth, J.; Udry, S.; Wheatley, P. J.; Wood, P. L.; Bento, J.

    2011-02-01

    We report the discovery of WASP-34b, a sub-Jupiter-mass exoplanet transiting its 10.4-magnitude solar-type host star (1SWASP J110135.89-235138.4; TYC 6636-540-1) every 4.3177 days in a slightly eccentric orbit (e = 0.038±0.012). We find a planetary mass of 0.59±0.01 MJup and radius of 1.22-0.08+0.11 RJup. There is a linear trend in the radial velocities of 55±4 m s-1 y-1 indicating the presence of a long-period third body in the system with a mass ⪆0.45 MJup at a distance of ⪆1.2 AU from the host star. This third-body is either a low-mass star, a white dwarf, or another planet. The transit depth ((RP/Rstar)2 = 0.0126) and high impact parameter (b = 0.90) suggest that this could be the first known transiting exoplanet expected to undergo grazing transits, but with a confidence of only 80%. Radial velocity and photometric data are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/526/A130

  2. WASP-34b: a near-grazing transiting sub-Jupiter-mass exoplanet in a hierarchical triple system

    CERN Document Server

    Smalley, B; Cameron, A Collier; Hellier, C; Lendl, M; Maxted, P F L; Queloz, D; Triaud, A H M J; West, R G; Bentley, S J; Enoch, B; Gillon, M; Lister, T A; Pepe, F; Pollacco, D; Segransan, D; Smith, A M S; Southworth, J; Udry, S; Wheatley, P J; Wood, P L; Bento, J

    2010-01-01

    We report the discovery of WASP-34b, a sub-Jupiter-mass exoplanet transiting its 10.4-magnitude solar-type host star (1SWASP J110135.89-235138.4; TYC 6636-540-1) every 4.3177 days in a slightly eccentric orbit (e = 0.038 +/- 0.012). We find a planetary mass of 0.59 +/- 0.01 M_Jup and radius of 1.22 ^{+0.11}_{-0.08} R_Jup. There is a linear trend in the radial velocities of 55+/-4 m/s/y indicating the presence of a long-period third body in the system with a mass > 0.45 M_Jup at a distance of >1.2 AU from the host star. This third-body is either a low-mass star, white dwarf, or another planet. The transit depth ((R_P/R_*)^2 = 0.0126) and high impact parameter (b = 0.90) suggest that this could be the first known transiting exoplanet expected to undergo grazing transits, but with a confidence of only ~80%.

  3. Application of Hierarchical Storage Technology in Paperless Electronic Medical Records Storing%分级存储技术在电子病历无纸化存储中的应用

    Institute of Scientific and Technical Information of China (English)

    苏韶生; 程敏婷; 何远源

    2011-01-01

    为解决电子病历无纸化存储的空间、效率、效益问题,提出一种基于分级存储技术的解决方案。介绍分级存储技术的概念、存储方式、必要性、存储策略、设备及技术优势,并以中山市人民医院为例对上述方法的有效性和实用性进行验证。%In order to solve the space, efficiency and benefit problems of the paperless electronic medical records (EMR) storing, the paper proposes solutions based on hierarchical storage technology. It introduces the concept, storage method, necessity, storage strategy, equipments, technology advantages, taking Zhongshan People's Hospital as an example, verifies the effectiveness and practicality of the above methods.

  4. Charge and frequency resolved isochronous mass spectrometry in storage rings: First direct mass measurement of the short-lived neutron-deficient $^{51}$Co nuclide

    CERN Document Server

    Shuai, P; Tu, X L; Zhang, Y H; Sun, B H; Litvinov, Yu A; Yan, X L; Blaum, K; Wang, M; Zhou, X H; He, J J; Sun, Y; Kaneko, K; Yuan, Y J; Xia, J W; Yang, J C; Audi, G; Chen, X C; Jia, G B; Hu, Z G; Ma, X W; Mao, R S; Mei, B; Sun, Z Y; Wang, S T; Xiao, G Q; Xu, X; Yamaguchi, T; Yamaguchi, Y; Zang, Y D; Zhao, H W; Zhao, T C; Zhang, W; Zhan, W L

    2014-01-01

    Revolution frequency measurements of individual ions in storage rings require sophisticated timing detectors. One of common approaches for such detectors is the detection of secondary electrons released from a thin foil due to penetration of the stored ions. A new method based on the analysis of intensities of secondary electrons was developed which enables determination of the charge of each ion simultaneously with the measurement of its revolution frequency. Although the mass-over-charge ratios of $^{51}$Co$^{27+}$ and $^{34}$Ar$^{18+}$ ions are almost identical, and therefore, the ions can not be resolved in a storage ring, by applying the new method the mass excess of the short-lived $^{51}$Co is determined for the first time to be ME($^{51}$Co)=-27342(48) keV. Shell-model calculations in the $fp$-shell nuclei compared to the new data indicate the need to include isospin-nonconserving forces.

  5. Engineering 3D bicontinuous hierarchically macro-mesoporous LiFePO4/C nanocomposite for lithium storage with high rate capability and long cycle stability

    Science.gov (United States)

    Zhang, Qian; Huang, Shao-Zhuan; Jin, Jun; Liu, Jing; Li, Yu; Wang, Hong-En; Chen, Li-Hua; Wang, Bin-Jie; Su, Bao-Lian

    2016-05-01

    A highly crystalline three dimensional (3D) bicontinuous hierarchically macro-mesoporous LiFePO4/C nanocomposite constructed by nanoparticles in the range of 50~100 nm via a rapid microwave assisted solvothermal process followed by carbon coating have been synthesized as cathode material for high performance lithium-ion batteries. The abundant 3D macropores allow better penetration of electrolyte to promote Li+ diffusion, the mesopores provide more electrochemical reaction sites and the carbon layers outside LiFePO4 nanoparticles increase the electrical conductivity, thus ultimately facilitating reverse reaction of Fe3+ to Fe2+ and alleviating electrode polarization. In addition, the particle size in nanoscale can provide short diffusion lengths for the Li+ intercalation-deintercalation. As a result, the 3D macro-mesoporous nanosized LiFePO4/C electrode exhibits excellent rate capability (129.1 mA h/g at 2 C; 110.9 mA h/g at 10 C) and cycling stability (87.2% capacity retention at 2 C after 1000 cycles, 76.3% at 5 C after 500 cycles and 87.8% at 10 C after 500 cycles, respectively), which are much better than many reported LiFePO4/C structures. Our demonstration here offers the opportunity to develop nanoscaled hierarchically porous LiFePO4/C structures for high performance lithium-ion batteries through microwave assisted solvothermal method.

  6. Ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry coupled with hierarchical cluster analysis to evaluate Wikstroemia indica (L.) C. A. Mey. from different geographical regions.

    Science.gov (United States)

    Wei, Lan; Wang, Xiaobo; Mu, Shanxue; Sun, Lixin; Yu, Zhiguo

    2015-06-01

    A sensitive, rapid and simple ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry method was developed to determine seven constituents (umbelliferone, apigenin, triumbelletin, daphnoretin, arctigenin, genkwanin and emodin) in Wikstroemia indica (L.) C. A. Mey. The chromatographic analysis was performed on an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm, 1.7 μm) by gradient elution with the mobile phase of 0.05% formic acid aqueous solution (A) and acetonitrile (B). Multiple reaction monitoring mode with positive and negative electrospray ionization interface was carried out to detect the components. This method was validated in terms of specificity, linearity, accuracy, precision and stability. Excellent linear behavior was observed over the certain concentration ranges with the correlation coefficient values higher than 0.999. The intraday and innerday precisions were within 2.0%. The recoveries of seven analytes were 99.4-101.1% with relative standard deviation less than 1.2%. The 18 Wikstroemia indica samples from different origins were classified by hierarchical clustering analysis according to the contents of seven components. The results demonstrated that the developed method could successfully be used to quantify simultaneously of seven components in Wikstroemia indica and could be a helpful tool for the detection and confirmation of the quality of traditional Chinese medicines.

  7. Modeling of thermal mass energy storage in buildings with phase change materials

    Science.gov (United States)

    Delcroix, Benoit

    Building thermal mass is a key parameter defining the ability of a building to mitigate inside temperature variations and to maintain a better thermal comfort. Increasing the thermal mass of a lightweight building can be achieved by using Phase Change Materials (PCMs). These materials offer a high energy storage capacity (using latent energy) and a nearly constant temperature phase change. They can be integrated conveniently in net-zero energy buildings. The current interest for these buildings and for better power demand management strategies requires accurate transient simulation of heavy and highly insulated slabs or walls with short time-steps (lower than or equal to 5 minutes). This represents a challenge for codes that were mainly developed for yearly energy load calculations with a time-step of 1 hour. It is the case of the TRNSYS building model (called Type 56) which presents limitations when modeling heavy and highly insulated slabs with short time-steps. These limitations come from the method used by TRNSYS for modeling conduction heat transfer through walls which is known as the Conduction Transfer Function (CTF) method. In particular, problems have been identified in the generation of CTF coefficients used to model the walls thermal response. This method is also unable to define layers with variable thermophysical properties, as displayed by PCMs. PCM modeling is further hindered by the limited information provided by manufacturers: physical properties are often incomplete or incorrect. Finally, current models are unable to represent the whole complexity of PCM thermal behavior: they rarely include different properties for melting and solidification (hysteresis); they sometimes take into account variable thermal conductivity; but they never model subcooling effects. All these challenges are tackled in this thesis and solutions are proposed. The first part (chapter 4) focuses on improving the CTF method in TRNSYS through state-space modeling

  8. submitter Simulation-Based Performance Analysis of the ALICE Mass Storage System

    CERN Document Server

    Vickovic, L; Celar, S

    2016-01-01

    CERN – the European Organization for Nuclear Research today, in the era of big data, is one of the biggest data generators in the world. Especially interesting is transient data storage system in the ALICE experiment. With the goal to optimize its performance this paper discusses a dynamic, discrete event simulation model of disk based Storage Area Network (SAN) and its usage for the performance analyses. Storage system model is based on modular, bottom up approach and the differences between measured and simulated values vary between 1.5 % and 4 % depending on the simulated component. Once finished, simulation model was used for detailed performance analyses. Among other findings it showed that system performances can be seriously affected if the array stripe size is larger than the size of cache on individual disks in the array, which so far has been completely ignored in the literature.

  9. 基于混合储能的并网光伏电站有功分级控制策略%Active Power Hierarchical Control Strategy of Interconnected Photovoltaic Station Based on Hybrid Energy Storage

    Institute of Scientific and Technical Information of China (English)

    鲍雪娜; 张建成; 徐明; 刘汉民

    2013-01-01

    针对自然条件下光伏电源有功出力的波动性,以超级电容器和磷酸铁锂电池组成的混合储能系统为基础,制定了有功分级控制策略.首先分析了光伏电站整体结构及混合储能装置的接入方式,然后考虑电网需求利用指数平滑法来实时更新光伏电站整体出力参考值,实现第1级控制.根据储能元件能量存储与功率吞吐特性,提出了以超级电容器为充放电主体的混合储能系统能量管理策略,实现第2级控制,并设计了脉宽调制的控制原理电路.编程计算结果证实了所述方法的有效性.%In view of the active power fluctuation of large capacity photovoltaic (PV) power systems, based on a hybrid energy storage system consisting of supercapacitors and lithium-ion ferrous phosphate batteries, an active power hierarchical control strategy is formulated to optimize the output power of PV source. First, the overall structure of photovoltaic power station and the way of accessing the hybrid energy storage system are analyzed. Then, by considering the power grid needs, the exponential smoothing method is used to real-time update the reference values of output power to realize the first level control. The energy management strategy is put forward according to the storage characteristics of energy storage components and power throughput so as to realize the second level control of the hybrid energy storage system. In addition, an energy management strategy is put forward with supercapacitors as the principal part of charge and discharge. Finally, a control circuit of pulse width modulation (PWM) is designed. Programming results demonstrate the effectiveness of the proposed method.

  10. MOF-derived, N-doped, hierarchically porous carbon sponges as immobilizers to confine selenium as cathodes for Li-Se batteries with superior storage capacity and perfect cycling stability

    Science.gov (United States)

    Li, Zhaoqiang; Yin, Longwei

    2015-05-01

    Nitrogen-doped carbon sponges (NCS) composed of hierarchical microporous carbon layers are derived from metal organic frameworks (MOFs) via carbonization at high temperatures under Ar and NH3 flow. Se is impregnated into 0.4-0.55 nm micropores by melting-diffusion and infiltration methods. The confinement of Se within small-sized micropores of NCS efficiently prevents Se loss, and mesopores between carbon layers absorb a sufficient amount of electrolyte, as well as serve as cushion spaces for large volume changes during delithiation-lithiation processes. Nitrogen doping improves the electrical conductivity of carbon matrix and facilitates rapid charge transfer, making the carbon sponge a highway for charges involved in redox reactions. When serving as cathode materials for Li-Se batteries, the NCS/Se-50 composite with 50 wt% Se exhibits excellent cycling stability, superior rate capability and high coulombic efficiency. The cathode can exhibit 443.2 mA h g-1 at the 200th cycle with a coulombic efficiency of up to 99.9% at 0.5C (C = 675 mA h g-1), which leads to 0.031% capacity loss per cycle from 5th to 200th cycles. Even at a high rate of 5C, it can still retain 286.6 mA h g-1. The unique, large surface rod-like MOF-derived, N-doped carbon sponges with hierarchical porosity could be potential candidates in the related energy-storage systems.Nitrogen-doped carbon sponges (NCS) composed of hierarchical microporous carbon layers are derived from metal organic frameworks (MOFs) via carbonization at high temperatures under Ar and NH3 flow. Se is impregnated into 0.4-0.55 nm micropores by melting-diffusion and infiltration methods. The confinement of Se within small-sized micropores of NCS efficiently prevents Se loss, and mesopores between carbon layers absorb a sufficient amount of electrolyte, as well as serve as cushion spaces for large volume changes during delithiation-lithiation processes. Nitrogen doping improves the electrical conductivity of carbon matrix and

  11. Hierarchically constructed NiCo2S4@Ni(1-x)Co x (OH)2 core/shell nanoarrays and their application in energy storage

    Science.gov (United States)

    Zhou, Weiwei; Yu, Kun; Wang, Dong; Chu, Jing; Li, Jieying; Zhao, Limin; Ding, Chunyan; Du, Yu; Jia, Xingtao; Wang, Huatao; Wen, Guangwu

    2016-06-01

    We report a new type of core-shell heterostructure consisting of a rod-like NiCo2S4 (NCS) core and an urchin-like Ni(1-x)Co x (OH)2 (NCOH) shell via a simple hydrothermal route coupled with a facile electrodeposition. NCS nanorod arrays (NRAs) can not only act as excellent electrochemically active materials by themselves, but they can also serve as hierarchical porous scaffolds capable of fast electron conduction and ion diffusion for loading a large amount of additional active materials. Moreover, it is observed that the urchin-like NCOH nanosheets coating could bind the inner NCS nanorods together and thereby reinforce the whole structure mechanically. Meanwhile, more effective pathways for electrons are available in the NCS@NCOH hybrids than an individual NCS nanorod. Benefiting from both structural and compositional features, the NCS@NCOH electrode exhibits greatly improved electrochemical performance with high capacity (3.54 C cm-2 at 1 mA cm-2) and excellent cycling stability (78% capacity retention after 4000 cycles). Moreover, a battery-type device is also fabricated by using NCS@NCOH as a positive electrode and activated carbon (AC) as a negative electrode, displaying high capacity (2.51 C cm-2 at 2 mA cm-2) and good durability (88.8% capacity retention after 4000 cycles) as well.

  12. NASA/IEEE MSST 2004 Twelfth NASA Goddard Conference on Mass Storage Systems and Technologies in cooperation with the Twenty-First IEEE Conference on Mass Storage Systems and Technologies

    Science.gov (United States)

    Kobler, Ben (Editor); Hariharan, P. C. (Editor)

    2004-01-01

    MSST2004, the Twelfth NASA Goddard / Twenty-first IEEE Conference on Mass Storage Systems and Technologies has as its focus long-term stewardship of globally-distributed storage. The increasing prevalence of e-anything brought about by widespread use of applications based, among others, on the World Wide Web, has contributed to rapid growth of online data holdings. A study released by the School of Information Management and Systems at the University of California, Berkeley, estimates that over 5 exabytes of data was created in 2002. Almost 99 percent of this information originally appeared on magnetic media. The theme for MSST2004 is therefore both timely and appropriate. There have been many discussions about rapid technological obsolescence, incompatible formats and inadequate attention to the permanent preservation of knowledge committed to digital storage. Tutorial sessions at MSST2004 detail some of these concerns, and steps being taken to alleviate them. Over 30 papers deal with topics as diverse as performance, file systems, and stewardship and preservation. A number of short papers, extemporaneous presentations, and works in progress will detail current and relevant research on the MSST2004 theme.

  13. Seed Storage Proteins as a System for Teaching Protein Identification by Mass Spectrometry in Biochemistry Laboratory

    Science.gov (United States)

    Wilson, Karl A.; Tan-Wilson, Anna

    2013-01-01

    Mass spectrometry (MS) has become an important tool in studying biological systems. One application is the identification of proteins and peptides by the matching of peptide and peptide fragment masses to the sequences of proteins in protein sequence databases. Often prior protein separation of complex protein mixtures by 2D-PAGE is needed,…

  14. Seed Storage Proteins as a System for Teaching Protein Identification by Mass Spectrometry in Biochemistry Laboratory

    Science.gov (United States)

    Wilson, Karl A.; Tan-Wilson, Anna

    2013-01-01

    Mass spectrometry (MS) has become an important tool in studying biological systems. One application is the identification of proteins and peptides by the matching of peptide and peptide fragment masses to the sequences of proteins in protein sequence databases. Often prior protein separation of complex protein mixtures by 2D-PAGE is needed,…

  15. Direct Chemical Analysis of Solids by Laser Ablation in an Ion-Storage Time-of-Flight Mass Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Klunder, G L; Grant, P M; Andresen, B D; Russo, R E

    2003-09-29

    A laser ablation/ionization mass spectrometer system is described for the direct analysis of solids, particles, and fibers. The system uses a quadrupole ion trap operated in an ion-storage (IS) mode, coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). The sample is inserted radially into the ring electrode and an imaging system allows direct viewing and selected analysis of the sample. Measurements identified trace contaminants of Ag, Sn, and Sb in a Pb target with single laser-shot experiments. Resolution (m/{micro}m) of 1500 and detection limits of approximately 10 pg have been achieved with a single laser pulse. The system configuration and related operating principles for accurately measuring low concentrations of isotopes are described.

  16. A database application for pre-processing, storage and comparison of mass spectra derived from patients and controls

    Directory of Open Access Journals (Sweden)

    Sillevis Smitt Peter A

    2006-09-01

    Full Text Available Abstract Background Statistical comparison of peptide profiles in biomarker discovery requires fast, user-friendly software for high throughput data analysis. Important features are flexibility in changing input variables and statistical analysis of peptides that are differentially expressed between patient and control groups. In addition, integration the mass spectrometry data with the results of other experiments, such as microarray analysis, and information from other databases requires a central storage of the profile matrix, where protein id's can be added to peptide masses of interest. Results A new database application is presented, to detect and identify significantly differentially expressed peptides in peptide profiles obtained from body fluids of patient and control groups. The presented modular software is capable of central storage of mass spectra and results in fast analysis. The software architecture consists of 4 pillars, 1 a Graphical User Interface written in Java, 2 a MySQL database, which contains all metadata, such as experiment numbers and sample codes, 3 a FTP (File Transport Protocol server to store all raw mass spectrometry files and processed data, and 4 the software package R, which is used for modular statistical calculations, such as the Wilcoxon-Mann-Whitney rank sum test. Statistic analysis by the Wilcoxon-Mann-Whitney test in R demonstrates that peptide-profiles of two patient groups 1 breast cancer patients with leptomeningeal metastases and 2 prostate cancer patients in end stage disease can be distinguished from those of control groups. Conclusion The database application is capable to distinguish patient Matrix Assisted Laser Desorption Ionization (MALDI-TOF peptide profiles from control groups using large size datasets. The modular architecture of the application makes it possible to adapt the application to handle also large sized data from MS/MS- and Fourier Transform Ion Cyclotron Resonance (FT-ICR mass

  17. Effective representation and storage of mass spectrometry-based proteomic data sets for the scientific community

    DEFF Research Database (Denmark)

    Olsen, Jesper V; Mann, Matthias

    2011-01-01

    Mass spectrometry-based proteomics has emerged as a technology of choice for global analysis of cell signaling networks. However, reporting and sharing of MS data are often haphazard, limiting the usefulness of proteomics to the signaling community. We argue that raw data should always be provided...... mechanisms for community-wide sharing of these data....

  18. MASS CHANGES IN MIGRATING BIRDS - THE EVIDENCE FOR FAT AND PROTEIN STORAGE REEXAMINED

    NARCIS (Netherlands)

    PIERSMA, T

    1993-01-01

    The fact that one cannot kill a bird twice makes it very difficult to determine the relative contributions of fat and non-fat components to increases in body mass before migratory flights in individual birds. Knowing the relative contributions of these components is of obvious energetic interest sin

  19. MASS CHANGES IN MIGRATING BIRDS - THE EVIDENCE FOR FAT AND PROTEIN STORAGE REEXAMINED

    NARCIS (Netherlands)

    PIERSMA, T

    The fact that one cannot kill a bird twice makes it very difficult to determine the relative contributions of fat and non-fat components to increases in body mass before migratory flights in individual birds. Knowing the relative contributions of these components is of obvious energetic interest

  20. Turbulent coherent-structure dynamics in a natural surface storage zone: Mechanisms of mass and momentum transport in rivers

    Science.gov (United States)

    Escauriaza, Cristian; Sandoval, Jorge; Mignot, Emmanuel; Mao, Luca

    2016-11-01

    Turbulent flows developed in surface storage zones (SSZ) in rivers control many physical and biogeochemical processes of contaminants in the water. These regions are characterized by low velocities and long residence times, which favor particle deposition, nutrient uptake, and flow interactions with reactive sediments. The dynamics of the flow in SSZ is driven by a shear layer that induces multiple vortical structures with a wide range of temporal and spatial scales. In this work we study the flow in a lateral SSZ of the Lluta River, a high-altitude Andean stream (4,000 masl), with a Re=45,800. We describe the large-scale turbulent coherent structures using field measurements and 3D numerical simulations. We measure the bed topography, instantaneous 3D velocities at selected points, the mean 2D free-surface velocity field, and arsenic concentration in the sediment. Numerical simulations of the flow are also performed using a DES turbulence model. We focus on the mass and momentum transport processes, analyzing the statistics of mass exchange and residence times in the SSZ. With this information we provide new insights on the flow and transport processes between the main channel and the recirculating region in natural conditions. Supported by Fondecyt 1130940.

  1. 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.

  2. Study on seafood volatile profile characteristics during storage and its potential use for freshness evaluation by headspace solid phase microextraction coupled with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Zhang, Zhuomin; Li, Gongke; Luo, Lin; Chen, Guonan

    2010-02-05

    Seafood volatile profile characteristics at different storage phases are various and can be used for freshness evaluation during storage. It is imperative to obtain the full volatile information prior to the further study of seafood volatile profile characteristics during storage. Also, the efficient data-processing method is another important factor for the interpretation of seafood volatile profile characteristics during storage and related potential volatile markers. In this work, a new analytical strategy, including the efficient sampling technique, sensitive detection and suitable data-processing method, for seafood freshness evaluation was developed based on the volatile profile characteristics during storage. First, the study of volatiles of seafood samples including razor clam, redspot swimming crab and prawn at different storage phases were conducted by headspace solid phase microextraction (HSSPME) followed by gas chromatography-mass spectrometry (GC-MS) detection. Then, seafood volatile profile characteristics at different storage phases were statistically interpreted by a combination data-processing method including normalization, principle component analysis (PCA) and common model strategy. The different seafood volatile profile characteristics and potential volatile markers were attempted to be distilled. The results tentatively suggested that the different seafood volatile profile characteristics during storage could reflect the transitional changing seafood freshness and provide more precise warning information for seafood spoilage during storage than any single chemical markers. This work developed an analytical method for study of seafood volatile profile characteristics and tentatively proposed a new idea of using seafood volatile profile characteristics during storage for the freshness evaluation from the point of view of analytical chemistry.

  3. MASS SMALL-FILE STORAGE FILE SYSTEM RESEARCH OVERVIEW%海量小文件存储文件系统研究综述

    Institute of Scientific and Technical Information of China (English)

    王铃惠; 李小勇; 张轶彬

    2012-01-01

    With the development of Internet, the small file storage size shows a geometric growth too. Therefore traditional file systems no longer meet the requirements for storage performance. For small file storage, especially mass small-file storage, optimization is becoming more and more important. The paper first of all explains the necessity for small file storage system optimization; then analyzes problems existing in present small file storage and expounds optimization approaches. Afterward it introduces three representative file systems for small file storage. In the end there is a summary.%随着互联网的发展,存储的小文件数量也呈几何级的增长.传统文件系统已不能满足存储性能的需求,对于小文件存储,尤其是海量小文件存储的优化已变得越来越重要.首先提出对小文件存储的系统进行优化的必要性,然后对小文件存储中存在的问题进行分析并阐述优化的方式,并介绍三种具有代表性的适合小文件存储的文件系统,最后总结归纳.

  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. 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

  6. A novel approach to quantifying the sensitivity of current and future cosmological datasets to the neutrino mass ordering through Bayesian hierarchical modeling

    CERN Document Server

    Gerbino, Martina; Mena, Olga; Freese, Katherine

    2016-01-01

    We present a novel approach to derive constraints on neutrino masses from cosmological data, while taking into account our ignorance of the neutrino mass ordering. We derive constraints from a combination of current and future cosmological datasets on the total neutrino mass $M_\

  7. Nanostructured conducting polymer hydrogels for energy storage applications.

    Science.gov (United States)

    Shi, Ye; Peng, Lele; Yu, Guihua

    2015-08-14

    Conducting polymer hydrogels are emerging as a promising class of polymeric materials for various technological applications, especially for energy storage devices due to their unique combination of advantageous features of conventional polymers and organic conductors. To overcome the drawbacks of conventional synthesis, new synthetic routes in which acid molecules are adopted as both crosslinkers and dopants have been developed for conducting polymer hydrogels with unique 3D hierarchical porous nanostructures, resulting in high electrical conductivity, large surface area, structural tunability and hierarchical porosity for rapid mass/charge transport. The newly developed conducting polymer hydrogels exhibit high performance when applied as active electrode materials for electrochemical capacitors or as functional binder materials for high-energy lithium-ion batteries. This feature article summarizes the synthesis of conducting polymer hydrogels, presents their applications in energy storage, and discusses further opportunities and challenges.

  8. High-Speed Transmission and Mass Data Storage Solutions for Large-Area and Arbitrarily Structured Fabrication through Maskless Lithography

    Directory of Open Access Journals (Sweden)

    Yu Lu

    2016-01-01

    Full Text Available This paper presents the implementation aspects and design of high-speed data transmission in laser direct-writing lithography. With a single field programmable gate array (FPGA chip, mass data storage management, transmission, and synchronization of each part in real-time were implemented. To store a massive amount of data and transmit data with high bandwidth, a serial advanced technology attachment (SATA intellectual property (IP was developed on Xilinx Virtex-6 FPGA. In addition, control of laser beam power, collection of status read back data of the lithography laser through an analog-to-digital converter, and synchronization of the positioning signal were implemented on the same FPGA. A data structure for each unit with a unique exposure dose and other necessary information was established. Results showed that the maximum read bandwidth (240 MB/s and maximum write bandwidth (200 MB/s of a single solid-state drive conform to the data transmission requirement. The total amount of data meets the requirement of a large-area diffractive element approximately 102 cm2. The throughput has been greatly improved at meters per second or square centimeter per second. And test results showed that data transmission meets the requirement of the experiment.

  9. Validation of a Multiplex Tandem Mass Spectrometry Method for the Detection of Selected Lysosomal Storage Diseases in Dried Blood Spots

    Directory of Open Access Journals (Sweden)

    Graziela Schmitt Ribas PhD

    2017-02-01

    Full Text Available Background: Interest in screening methods for lysosomal storage diseases (LSDs has increased in recent years, since early diagnosis and treatment are essential to prevent or attenuate the onset of symptoms and the complications of these diseases. In the current work, we evaluated the performance of tandem mass spectrometry (MS/MS for the detection of some LSDs, aiming the future use of this methodology for the screening of these disorders. Methods: Standard curves and quality control dried blood spots were assayed to evaluate the precision, linearity, and accuracy. A total of 150 controls were grouped according to age and subjected to measurement of lysosomal enzymes deficient in Niemann-Pick A/B, Krabbe, Gaucher, Fabry, Pompe, and Mucopolysaccharidosis type I diseases. Samples from 59 affected patients with a diagnosis of LSDs previously confirmed by fluorimetric methods were analyzed. Results: Data from standard calibration demonstrated good linearity and accuracy and the intra- and interassay precisions varied from 1.17% to 11.60% and 5.39% to 31.24%, respectively. Except for galactocerebrosidase and α- l -iduronidase, enzyme activities were significantly higher in newborns compared to children and adult controls. Affected patients presented enzymatic activities significantly lower compared to all control participants. Conclusion: Our results show that MS/MS is a promising methodology, suitable for the screening of LSDs, but accurate diagnoses will depend on its correlation with other biochemical and/or molecular analyses.

  10. Dynamic headspace gas chromatography/mass spectrometry characterization of volatiles produced in fish oil enriched mayonnaise during storage.

    Science.gov (United States)

    Hartvigsen, K; Lund, P; Hansen, L F; Holmer, G

    2000-10-01

    Protection against lipid oxidation and formation of unpleasant fishy and rancid off-flavors in oil-in-water food emulsions, such as fish oil enriched mayonnaise, is difficult to achieve. Volatile profiles from stored mayonnaises with different oil phase compositions were collected using a developed dynamic headspace sampling technique, in which interfering acetic acid was removed in situ with potassium hydroxide, and subsequently 148 volatiles were characterized and monitored by gas chromatography/mass spectrometry. Multivariate statistics showed correlation between the concentration of 62 volatiles and the fish oil and storage parameters, indicating the formation of lipid oxidation products, which impose fishy off-flavors. Further verification was obtained by gas chromatography/olfactometry, by which, among 78 odors, cis-4-heptenal and trans,cis-2,4-heptadienal were detected as distinct fishy notes. In total, 27 volatiles, including 1-penten-3-one, cis-2-penten-1-ol, cis-3-hexenal, cis-4-heptenal, 1-octen-3-one, 1,cis-5-octadien-3-one, 1-octen-3-ol, trans,cis-2, 4-heptadienal, and trans,cis-2,6-nonadienal, were suggested to contribute to the developed unpleasant fishy and rancid off-flavors.

  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. Hierarchical nanostructured carbons with meso-macroporosity: design, characterization, and applications.

    Science.gov (United States)

    Fang, Baizeng; Kim, Jung Ho; Kim, Min-Sik; Yu, Jong-Sung

    2013-07-16

    Nanostructured porous carbon materials have diverse applications including sorbents, catalyst supports for fuel cells, electrode materials for capacitors, and hydrogen storage systems. When these materials have hierarchical porosity, interconnected pores of different dimensions, their potential application is increased. Hierarchical nanostructured carbons (HNCs) that contain 3D-interconnected macroporous/mesoporous and mesoporous/microporous structures have enhanced properties compared with single-sized porous carbon materials, because they have improved mass transport through the macropores/mesopores and enhanced selectivity and increased specific surface area on the level of fine pore systems through mesopores/micropores. The HNCs with macro/mesoporosity are of particular interest because chemists can tailor specific applications through controllable synthesis of HNCs with designed nanostructures. An efficient and commonly used technique for creating HNCs is "nanocasting", a technique that first involves the creation of a sacrificial silica template with hierarchical porous nanostructure and then the impregnation of the silica template with an appropriate carbon source. This is followed by carbonization of the filled carbon precursor, and subsequent removal of the silica template. The resulting HNC is an inverse replica of its parent hierarchical nanostructured silica (HNS). Through such nanocasting, scientists can create different HNC frameworks with tailored pore structures and narrow pore size distribution. Generally, HNSs with specific structure and 3D-interconnected porosity are needed to fabricate HNCs using the nanocasting strategy. However, how can we fabricate a HNS framework with tailored structure and hierarchical porosity of meso-macropores? This Account reports on our recent work in the development of novel HNCs and their interesting applications. We have explored a series of strategies to address the challenges in synthesis of HNSs and HNCs. Through

  13. Fluorocarbon adsorption in hierarchical porous frameworks

    Science.gov (United States)

    Motkuri, Radha Kishan; Annapureddy, Harsha V. R.; Vijaykumar, M.; Schaef, H. Todd; Martin, Paul F.; McGrail, B. Peter; Dang, Liem X.; Krishna, Rajamani; Thallapally, Praveen K.

    2014-07-01

    Metal-organic frameworks comprise an important class of solid-state materials and have potential for many emerging applications such as energy storage, separation, catalysis and bio-medical. Here we report the adsorption behaviour of a series of fluorocarbon derivatives on a set of microporous and hierarchical mesoporous frameworks. The microporous frameworks show a saturation uptake capacity for dichlorodifluoromethane of >4 mmol g-1 at a very low relative saturation pressure (P/Po) of 0.02. In contrast, the mesoporous framework shows an exceptionally high uptake capacity reaching >14 mmol g-1 at P/Po of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption is found to generally correlate with the polarizability and boiling point of the refrigerant, with dichlorodifluoromethane >chlorodifluoromethane >chlorotrifluoromethane >tetrafluoromethane >methane. These results suggest the possibility of exploiting these sorbents for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling.

  14. Stationary centrifugal mass energy storage at the Hamburg subway; Stationaerer Schwungmassen-Energiespeicher bei der Hamburger U-Bahn

    Energy Technology Data Exchange (ETDEWEB)

    Steinhorst, F. [Hamburger Hochbahn AG, Hamburg (Germany). Abt. Energieanlagen; Jonassen, I.; Peters, A. [Hamburger Hochbahn AG, Hamburg (Germany). Fachbereich Energieversorgung

    2008-07-01

    A stationary energy storage is to be used as a model in a substation of the Hamburg subway network with a view to the environmentally compatible and technically proper use of the brake energy available in electrified local public transport systems. A further question to be reviewed is whether the use of other energy storages in the subway network is a reasonable solution. (orig.)

  15. Effect of salinity and pressure on the rate of mass transfer in aquifer storage of CO2

    NARCIS (Netherlands)

    Khosrokhavar, R.; Eftekhari, A.A.; Farajzadeh, R.; Wolf, K.H.A.A.; Bruining, J.

    2015-01-01

    The growing concern about global warming has increased interest in improving the technology for the geological storage of CO2 in aquifers. One important aspect for aquifer storage is the rate of transfer between the overlying gas layer and the aquifer below. It is generally accepted that density dri

  16. Liquid chromatography/mass spectrometry investigation of the impact of thermal processing and storage on peach procyanidins.

    Science.gov (United States)

    Hong, Yun-Jeong; Barrett, Diane M; Mitchell, Alyson E

    2004-04-21

    Normal-phase liquid chromatography/mass spectrometry (LC/MS) was used to determine the levels and fate of procyanidins in frozen and canned Ross clingstone peaches as well as in the syrup used in the canning over a 3 month period. Procyanidin oligomers, monomers through undecamers, were identified in Ross clingstone peaches. Optimized methods allowed for the quantitation of oligomers through octamers. The profile of procyanidins in peaches is similar to profiles found in grapes, chocolate, and beverages linked to health benefits such as tea and wine. The monomer content in frozen peeled peaches was found to be 19.59 mg/kg. Dimers (39.59 mg/kg) and trimers (38.81 mg/kg) constituted the largest percent composition of oligomers in the peaches. Tetramers through octamers were present in levels of 17.81, 12.43, 10.62, 3.94 and 1.75 mg/kg, respectively. Thermal processing resulted in an 11% reduction in monomers, a 9% reduction in dimers, a 12% reduction in trimers, a 6% reduction in tetramers, and a 5% reduction in pentamers. Hexamers and heptamers demonstrated an approximate 30% loss, and octamers were no longer detected. Analysis of the syrup after thermal processing indicates that there is a migration of procyanidin monomers through hexamers into the syrup that can account for the losses observed during the canning process. Storage of canned peaches for 3 months demonstrated a time-related loss in higher oligomers and that by 3 months oligomers larger than tetramers are not observed. At 3 months postcanning, levels of monomers had decreased by 10%, dimers by 16%, trimers by 45%, and tetramers by 80%. A similar trend was observed in the canning syrup.

  17. Numerical Investigations of Mixed Convection of Incompressible Viscous Fluid in LNG Storage with a Various Locations of Input and Output Mass

    Directory of Open Access Journals (Sweden)

    Sklyarenko Kristina A.

    2015-01-01

    Full Text Available The article shows the results of mathematical simulation of mixed convection in the low-temperature storage of liquefied natural gas with a regenerative cooling. The regimes of mixed convection in a closed area with the different arrangement of the input and output sections of the masses are investigated. Two-dimensional nonstationary problem in the model of the Navier-Stokes in dimensionless variables “vorticity - stream function - temperature” was examined. Are obtained distributions of the hydrodynamic parameters and temperatures, characteristic basic laws governing the processes being investigated. Detailed circulating currents and carried out analysis of the mechanism of vortices formation and the temperature distribution in the solution for mixed convection mode with low Reynolds and Grashof numbers (Gr = 106, 100 mass sections and input stream velocity on the structure of liquid flow and temperature in the low temperature LNG storage tanks.

  18. 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

  19. 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.

  20. 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.

  1. 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...

  2. Effective Hierarchical Information Management in Mobile Environment

    Directory of Open Access Journals (Sweden)

    Hanmin Jung

    2012-01-01

    Full Text Available Problem statement: As the performance of mobile devices is developed highly, several kinds of data is stored on mobile devices. For effective data management and information retrieval, some researches applying ontology concept to mobile devices are progressed. However, in conventional researches, they apply conventional ontology storage structure used in PC environment to mobile platform. Conclusion/Recommendations: Therefore, performance of search about data is low and not effective. Therefore, we suggested new ontology storage schema with ontology path for effective hierarchical information in mobile environment.

  3. From hierarchical radiative quark mass matrices and mixing to FCNC in SU(2)$_{L}$ x U(1)$_{Y}$ x U(1)$_{H}$

    CERN Document Server

    Restrepo, D A

    1996-01-01

    We present an extension of the Standard Model (SM) without supersymmetry, wich we use to calculate order of magnitude values for the elements of the quark mass matrices in the SM. Our model have the following characteristics a) give only tree level mass to top quark, b) generates approximately, using the top quark as seed, the RRR-textures correspondent to the solution wich have tree texture zeroes in $M_u$ and two texture zeroes in $M_d$, c) fixes one horizontal scale of ${\\cal O}(10 {\\rm Tev})$. The specific model described here is one horizontal extension of the SM $SU(3)_c\\times SU(2)_L\\times U(1)_Y\\times Z_{11}$ with $Z_{11}$ a subset of an anomaly free abelian extension of the standard model already presented by Mira et al.

  4. Storage stability studies for tributyltin determination in human urine samples using headspace solid-phase microextraction and gas chromatography mass spectrometry.

    Science.gov (United States)

    Zachariadis, G A; Tzollas, N M; Nikolaou, M; Rosenberg, E

    2013-03-01

    A headspace solid-phase micro-extraction (HS-SPME) method was employed in order to study the effect of storage conditions of human urine samples spiked with tributyltin (TBT) using gas chromatography and mass spectrometry. To render the analyte more volatile, the derivatization (ethylation) was made in situ by sodium tetraethylborate (NaBEt(4) ), which was added directly to dilute unpreserved urine samples and in buffers of similar acidity. The stability of TBT in human urine matrix was compared with the stability of TBT in buffer solutions of similar pH value. Critical parameters of storage conditions such as temperature and time, which affect the stability of TBT in this kind of matrix, were examined extensively. The tests showed that the stability of TBT remains practically satisfactory for a maximum of 2 days of storage either at +4 or 20°C. Greater variations were observed in the concentration of TBT in human urine samples at +4°C and lower ones at -20°C over a month's storage. The freeze-thaw cycles have negative effect on the stability and should be kept to a minimum. The results from spiked urine samples are also discussed in comparison to those acquired from buffer solutions of equal TBT concentration.

  5. Impact of Denture Cleaning Method and Overnight Storage Condition on Denture Biofilm Mass and Composition: A Cross-Over Randomized Clinical Trial.

    Directory of Open Access Journals (Sweden)

    Joke Duyck

    Full Text Available Appropriate oral hygiene is required to maintain oral health in denture wearers. This study aims to compare the role of denture cleaning methods in combination with overnight storage conditions on biofilm mass and composition on acrylic removable dentures.In a cross-over randomized controlled trial in 13 older people, 4 conditions with 2 different mechanical cleaning methods and 2 overnight storage conditions were considered: (i brushing and immersion in water without a cleansing tablet, (ii brushing and immersion in water with a cleansing tablet, (iii ultrasonic cleaning and immersion in water without a cleansing tablet, and (iv ultrasonic cleaning and immersion in water with a cleansing tablet. Each test condition was performed for 5 consecutive days, preceded by a 2-days wash-out period. Biofilm samples were taken at baseline (control and at the end of each test period from a standardized region. Total and individual levels of selected oral bacteria (n = 20, and of Candida albicans were identified using the Polymerase Chain Reaction (PCR technique. Denture biofilm coverage was scored using an analogue denture plaque score. Paired t-tests and Wilcoxon-signed rank tests were used to compare the test conditions. The level of significance was set at α< 5%.Overnight denture storage in water with a cleansing tablet significantly reduced the total bacterial count (p<0.01. The difference in total bacterial level between the two mechanical cleaning methods was not statistically significant. No significant effect was observed on the amount of Candida albicans nor on the analogue plaque scores.The use of cleansing tablets during overnight denture storage in addition to mechanical denture cleaning did not affect Candida albicans count, but reduced the total bacterial count on acrylic removable dentures compared to overnight storage in water. This effect was more pronounced when combined with ultrasonic cleaning compared to brushing

  6. 1000-TeV in the Center-Of-Mass: Introduction to High-Energy Storage Rings

    Energy Technology Data Exchange (ETDEWEB)

    Bjorken, J D

    1982-09-01

    The lecture discusses, in a pedagogic way, a hypothetical 500 TeV proton storage ring accelerator. It gives machine parameters, discusses linear optics and betatron motions, surveys questions of errors, tolerances and nonlinear resonances, and discusses some of the demands on the detection apparatus, especially the apparent inevitability of multiple interactions per bunch crossing. (GHT)

  7. 1000-TeV in the Center-Of-Mass: Introduction to High-Energy Storage Rings

    Energy Technology Data Exchange (ETDEWEB)

    Bjorken, J D

    1982-09-01

    The lecture discusses, in a pedagogic way, a hypothetical 500 TeV proton storage ring accelerator. It gives machine parameters, discusses linear optics and betatron motions, surveys questions of errors, tolerances and nonlinear resonances, and discusses some of the demands on the detection apparatus, especially the apparent inevitability of multiple interactions per bunch crossing. (GHT)

  8. Quality change and mass loss of paddy during airtight storage in a ferro-cement bin in Sri Lanka

    NARCIS (Netherlands)

    Adhikarinayake, T.B.; Palipane, K.B.; Müller, J.

    2006-01-01

    In Sri Lanka, prices for paddy fluctuate severely showing a minimum price at harvest. To benefit from higher prices, farmers strive to store paddy, but lack of facilities and poor storage management cause quantitative and qualitative losses by rodents, insects and microbial deterioration. To overcom

  9. Lower hepatic iron storage associated with obesity in mice can be restored by decreasing body fat mass through feeding a low-fat diet.

    Science.gov (United States)

    Chung, Hak; Wu, Dayong; Smith, Donald; Meydani, Simin Nikbin; Han, Sung Nim

    2016-09-01

    High-fat diet (HFD)-induced obesity has been reported to result in low hepatic iron storage. In the current study, we tested the hypothesis that these obesity-related changes in hepatic iron status could be reversed by decreasing adiposity by feeding a low-fat diet. Five-week-old C57BL/6 mice were assigned to 3 groups: the LL group was fed a control diet for 31 weeks, the HH group was fed a HFD for 31 weeks, and the HL group was fed the HFD for 15 weeks and then switched to the control diet for 16 weeks. The fat mass of the HL group decreased by 3.2 g from the 14th to the 30th weeks. Fat mass was significantly different among the groups (11.4, 15.8, and 37.5 g in the LL, HH, and HL groups, respectively; Pfat mass through feeding a lower-fat diet to HFD-induced obese mice restores liver iron storage.

  10. 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...

  11. 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.

  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.

    2015-02-01

    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.

  13. 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.

  14. 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....

  15. 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...

  16. 嵌入式USB主机Mass Storage类的实现%Realization of Mass Storage item of embedded host computer

    Institute of Scientific and Technical Information of China (English)

    张建华

    2006-01-01

    研究分析嵌入式USB主机发展的必要性,从嵌入式USB主机Mass Storage类的实现过程出发,介绍了嵌入式USB主机硬件系统是由SM5964单片机加上USB主从芯片SL811HS组成,软件上实现USB1.1主机协议和USB Mass Storage类.

  17. Delineation of Stenotrophomonas maltophilia isolates from cystic fibrosis patients by fatty acid methyl ester profiles and matrix-assisted laser desorption/ionization time-of-flight mass spectra using hierarchical cluster analysis and principal component analysis.

    Science.gov (United States)

    Vidigal, Pedrina Gonçalves; Mosel, Frank; Koehling, Hedda Luise; Mueller, Karl Dieter; Buer, Jan; Rath, Peter Michael; Steinmann, Joerg

    2014-12-01

    Stenotrophomonas maltophilia is an opportunist multidrug-resistant pathogen that causes a wide range of nosocomial infections. Various cystic fibrosis (CF) centres have reported an increasing prevalence of S. maltophilia colonization/infection among patients with this disease. The purpose of this study was to assess specific fingerprints of S. maltophilia isolates from CF patients (n = 71) by investigating fatty acid methyl esters (FAMEs) through gas chromatography (GC) and highly abundant proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and to compare them with isolates obtained from intensive care unit (ICU) patients (n = 20) and the environment (n = 11). Principal component analysis (PCA) of GC-FAME patterns did not reveal a clustering corresponding to distinct CF, ICU or environmental types. Based on the peak area index, it was observed that S. maltophilia isolates from CF patients produced significantly higher amounts of fatty acids in comparison with ICU patients and the environmental isolates. Hierarchical cluster analysis (HCA) based on the MALDI-TOF MS peak profiles of S. maltophilia revealed the presence of five large clusters, suggesting a high phenotypic diversity. Although HCA of MALDI-TOF mass spectra did not result in distinct clusters predominantly composed of CF isolates, PCA revealed the presence of a distinct cluster composed of S. maltophilia isolates from CF patients. Our data suggest that S. maltophilia colonizing CF patients tend to modify not only their fatty acid patterns but also their protein patterns as a response to adaptation in the unfavourable environment of the CF lung. © 2014 The Authors.

  18. Axino mass

    CERN Document Server

    Kim, Jihn E

    2012-01-01

    I will talk on my recent works. Axino, related to the SUSY transformation of axion, can mix with Goldstino in principle. In this short talk, I would like to explain what is the axino mass and its plausible mass range. The axino mass is known to have a hierarchical mass structure depending on accidental symmetries. With only one axino, if G_A=0 where G=K+ 2ln|W|, we obtain axino mass= gravitino mass. For G_A nonzero, the axino mass depends on the details of the Kaehler potential. I also comment on the usefulness of a new parametrization of the CKM matrix.

  19. Study of coupled heat and mass transfer during absorption of hydrogen in MmNi4·6Al0·4 based hydrogen storage device

    Indian Academy of Sciences (India)

    P Muthukumar; Manvendra M Umekar

    2009-04-01

    A two-dimensional numerical analysis of coupled heat and mass transfer processes in a cylindrical metal hydride reactor containing MmNi4·6Al0·4 is presented. To understand the hydrogen absorption mechanism the governing equations for energy, momentum and mass conservation and reaction kinetic equations are solved simultaneously using the finite volume method (FVM). Performance studies on MmNi4·6Al0·4 based hydrogen storage device are carried out by varying the hydrogen supply pressure, absorption (cooling fluid) temperature, overall heat transfer coefficient and hydride bed thickness. Effect of convection terms in the energy equation on hydrogen storage performance is found to be negligible. The results obtained from the computer simulation showed good agreement with the available experimental data. At the supply conditions of 30 bar and 298 K, MmNi4·6Al0·4 stores about 1·28 wt%, which is very close to the experimental value of 1·3 wt%. Overall high heat transfer coefficients are found to reduce the absorption time significantly.

  20. Screening of lysosomal storage disorders: application of the online trapping-and-cleanup liquid chromatography/mass spectrometry method for mucopolysaccharidosis I.

    Science.gov (United States)

    Ombrone, Daniela; Malvagia, Sabrina; Funghini, Silvia; Giocaliere, Elisa; Della Bona, Maria Luisa; Forni, Giulia; De Luca, Alessio; Villanelli, Fabio; Casetta, Bruno; Guerrini, Renzo; la Marca, Giancarlo

    2013-01-01

    In recent years, new treatments have become available to treat some lysosomal storage disorders (LSDs) and many studies suggest that there is a benefit with starting therapy early. Newborn screening should detect diseases early enough for prompt treatment. Some countries include additional conditions, such as some LSDs, into their newborn screening panels. Mucopolysaccharidosis Type I (MPS I) is an autosomal recessive disorder caused by the deficiency of α-L-iduronidase (IDUA) activity. Currently, enzyme replacement therapy (ERT) or bone marrow transplantation is available and this has raised a growing interest for the development of a newborn screening test. In 2009, we reported a new fast and simplified tandem mass spectrometry-based method for quantifying five enzyme activities on dried blood spots. Here, we describe the inclusion of IDUA activity determination for the simultaneous detection of six lysosomal storage diseases. We have defined reference normal ranges by testing 680 healthy newborns and 240 adults. The assay was checked through three confirmed MPS I patients whose IDUA activity was below the normal range. Reproducibility of the assays has been established by assessing the intra-day and inter-day assay imprecisions. This quick assay has been devised to be implemented in newborn screening by liquid chromatography tandem mass spectrometry.

  1. 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.

  2. Finnigan BASIC Computer Programs for the Entry, Display and Compact Storage of Mass Spectra in a Finnigan 6115 Data System.

    Science.gov (United States)

    1981-03-01

    program. ., N(I) - A one-dimensional array containing ion abundance for m/e of 12-999 of a mass spectrum and other special information in N(O) - N(11) and N...ion abutkdances for m/e of 12-999 of a mass spectrum and other special information for N(O) - N(11) and N(1O00). C,D Variables to indicate range of...A one-dimensional array containing ion abundances for m/e of 12-999 of a mass spectrum and other special information for N(O)-N(9) and N(1000). A

  3. Storage Area Networks and The High Performance Storage System

    Energy Technology Data Exchange (ETDEWEB)

    Hulen, H; Graf, O; Fitzgerald, K; Watson, R W

    2002-03-04

    The High Performance Storage System (HPSS) is a mature Hierarchical Storage Management (HSM) system that was developed around a network-centered architecture, with client access to storage provided through third-party controls. Because of this design, HPSS is able to leverage today's Storage Area Network (SAN) infrastructures to provide cost effective, large-scale storage systems and high performance global file access for clients. Key attributes of SAN file systems are found in HPSS today, and more complete SAN file system capabilities are being added. This paper traces the HPSS storage network architecture from the original implementation using HIPPI and IPI-3 technology, through today's local area network (LAN) capabilities, and to SAN file system capabilities now in development. At each stage, HPSS capabilities are compared with capabilities generally accepted today as characteristic of storage area networks and SAN file systems.

  4. Facile synthesis of hierarchical micro/nanostructured MnO material and its excellent lithium storage property and high performance as anode in a MnO/LiNi0.5Mn1.5O(4-δ) lithium ion battery.

    Science.gov (United States)

    Xu, Gui-Liang; Xu, Yue-Feng; Fang, Jun-Chuan; Fu, Fang; Sun, Hui; Huang, Ling; Yang, Shihe; Sun, Shi-Gang

    2013-07-10

    Hierarchical micro/nanostructured MnO material is synthesized from a precursor of MnCO3 with olive shape that is obtained through a facile one-pot hydrothermal procedure. The hierarchical micro/nanostructured MnO is served as anode of lithium ion battery together with a cathode of spinel LiNi0.5Mn1.5O(4-δ) material, which is synthesized also from the precursor of MnCO3 with olive shape through a different calcination process. The structures and compositions of the as-prepared materials are characterized by TGA, XRD, BET, SEM, and TEM. Electrochemical tests of the MnO materials demonstrate that it exhibit excellent lithium storage property. The MnO material in a MnO/Li half cell can deliver a reversible capacity of 782.8 mAh g(-1) after 200 cycles at a rate of 0.13 C, and a stable discharge capacity of 350 mAh g(-1) at a high rate of 2.08 C. Based on the outstanding electrochemical property of the MnO material and the LiNi0.5Mn1.5O(4-δ) as well, the MnO/LiNi0.5Mn1.5O(4-δ) full cell has demonstrated a high discharge specific energy ca. 350 Wh kg(-1) after 30 cycles at 0.1 C with an average high working voltage at 3.5 V and a long cycle stability. It can release a discharge specific energy of 227 Wh kg(-1) after 300 cycles at a higher rate of 0.5 C. Even at a much higher rate of 20 C, the MnO/LiNi0.5Mn1.5O(4-δ) full cell can still deliver a discharge specific energy of 145.5 Wh kg(-1). The excellent lithium storage property of the MnO material and its high performance as anode in the MnO/LiNi0.5Mn1.5O(4-δ) lithium ion battery is mainly attributed to its hierarchical micro/nanostructure, which could buffer the volume change and shorten the diffusion length of Li(+) during the charge/discharge processes.

  5. 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.

  6. Toyota's heat management system - coolant heat storage for mass production today, new technologies for the future

    Energy Technology Data Exchange (ETDEWEB)

    Ichinose, Hiroki; Takaoka, Toshifumi; Kobayashi, Hideo [Toyota Motor Corporation (Japan)

    2004-07-01

    There has been pressing needs for the protection of metropolitan environment and the challenge of global warming. A heat management system prevails to meet such requirements. In actual driving condition, only about 30% of the total fuel energy is consumed for propulsion and air conditioner. At the same time 60% of fuel energy is wasted as exhaust gas, thermal loss and warm up loss. It is important to manage total thermal energy as a whole vehicle to improve thermal efficiency. The principle is to reduce heat loss in order to increase exhaust gas temperature and recover heat energy for pre-heating at the next cold start. Further developed versions may include thermal management strategies including turbocharger and thermal exchanger using exhaust gas heat energy. Toyota has developed the Coolant Heat Storage system (CHSS) for one of heat management systems to reduce cold emission and improve cabin comfort. The system enables to store hot coolant at the warmed up condition in a heat storage tank. At the next cold start, it is possible for CHSS to reduce unburned hydrocarbon by preheating intake port quickly with the hot coolant in the tank. CHSS was adopted in hybrid vehicle Prius for the US model in 2003. This vehicle achieved to meet the ATPZEV,the most stringent emission regulation in the US. This paper describes a total heat management focusing on the newly developed CHSS.

  7. Melamine-assisted one-pot synthesis of hierarchical nitrogen-doped carbon@MoS2 nanowalled core-shell microspheres and their enhanced Li-storage performances

    Science.gov (United States)

    Sun, Fugen; Wei, Yanju; Chen, Jianzhuang; Long, Donghui; Ling, Licheng; Li, Yongsheng; Shi, Jianlin

    2015-07-01

    A facile and scalable one-pot approach has been developed to synthesize carbon@MoS2 core-shell microspheres by a hydrothermal method, which involves the fast formation of melamine-resorcinol-formaldehyde polymeric microspheres in situ, followed by direct growth of the MoS2 nanowalls on them. The results give unequivocal proof that melamine could be the key to forming the core-shell microspherical morphology, and the contents of MoS2 shells can be easily tuned by initial ratios of the precursors. After a simple heat treatment, the obtained carbon@MoS2 microspheres simultaneously integrate the nitrogen-doped carbon cores and the hierarchical shells which consist of few-layered MoS2 nanowalls with an expanded interlayer spacing. Their unique architectures are favourable for high electronic/ionic conductivity and accommodate volume strain during the electrochemical reaction of the MoS2 anodes in lithium-ion batteries. Thus, a very high reversibility capacity of 771 mA h g-1 at 100 mA g-1 after 100 cycles, and a rate capacity of 598 mA h g-1 at 2000 mA g-1 could be achieved for the carbon@MoS2 core-shell microspheres with the optimal composition. Furthermore, a thin carbon coating on the carbon@MoS2 microspheres could further increase the reversible capacity to 856 mA h g-1 after 100 cycles at 100 mA g-1. These encouraging results suggest that such a facile and efficient protocol can provide a new pathway to produce hierarchical core-shell microspheres which integrate the structural, morphological and compositional design rationales for advanced lithium-ion batteries.A facile and scalable one-pot approach has been developed to synthesize carbon@MoS2 core-shell microspheres by a hydrothermal method, which involves the fast formation of melamine-resorcinol-formaldehyde polymeric microspheres in situ, followed by direct growth of the MoS2 nanowalls on them. The results give unequivocal proof that melamine could be the key to forming the core-shell microspherical morphology

  8. Natural sisal fibers derived hierarchical porous activated carbon as capacitive material in lithium ion capacitor

    Science.gov (United States)

    Yang, Zhewei; Guo, Huajun; Li, Xinhai; Wang, Zhixing; Yan, Zhiliang; Wang, Yansen

    2016-10-01

    Lithium-ion capacitor (LIC) is a novel advanced electrochemical energy storage (EES) system bridging gap between lithium ion battery (LIB) and electrochemical capacitor (ECC). In this work, we report that sisal fiber activated carbon (SFAC) was synthesized by hydrothermal treatment followed by KOH activation and served as capacitive material in LIC for the first time. Different particle structure, morphology, specific surface area and heteroatoms affected the electrochemical performance of as-prepared materials and corresponding LICs. When the mass ratio of KOH to char precursor was 2, hierarchical porous structured SFAC-2 was prepared and exhibited moderate specific capacitance (103 F g-1 at 0.1 A g-1), superior rate capability and cyclic stability (88% capacity retention after 5000 cycles at 1 A g-1). The corresponding assembled LIC (LIC-SC2) with optimal comprehensive electrochemical performance, displayed the energy density of 83 Wh kg-1, the power density of 5718 W kg-1 and superior cyclic stability (92% energy density retention after 1000 cycles at 0.5 A g-1). It is worthwhile that the source for activated carbon is a natural and renewable one and the synthesis method is eco-friendly, which facilitate that hierarchical porous activated carbon has potential applications in the field of LIC and other energy storage systems.

  9. Energy Storage.

    Science.gov (United States)

    Eaton, William W.

    Described are technological considerations affecting storage of energy, particularly electrical energy. The background and present status of energy storage by batteries, water storage, compressed air storage, flywheels, magnetic storage, hydrogen storage, and thermal storage are discussed followed by a review of development trends. Included are…

  10. 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.

  11. Pharmaceutical residues in rivers: Quantification of transient storage and travel times by tracer experiments as key parameters for the determination of mass balances

    Science.gov (United States)

    Kunkel, U.; Clemens, C.; Radke, M.

    2009-04-01

    Pharmaceutical residues are commonly detected micropollutants in the aquatic environment. To derive mass balances of these substances in river stretches and to quantify their elimination, besides highly sophisticated analytical methods precise discharge measurements are inevitable. Two additional key parameters are the travel time of water along a river stretch and the hyporheic exchange of water and solutes. Knowledge of travel times is essential to compare concentrations at the upstream and downstream end of an investigated site. As biodegradation in sediments is assumed to be a potentially significant removal process for organic micropollutants in rivers, flow of water and solutes across the sediment-water boundary and their transient storage in the hyporheic zone are also pivotal processes. To determine these river characteristics, tracer experiments using the fluorescent dye uranine were conducted at a 15 km stretch of a small river in Northern Bavaria (Roter Main) in summer 2008. Three sub-reaches were studied in separate tracer tests, and river discharge was simultaneously determined using the ultrasonic doppler technique. The travel time of uranine for the total stretch amounted to almost 1.5 days, corresponding to a mean flow velocity of about 0.4 km/h. Strong tailing of the breakthrough curves could indicate significant transient storage in the hyporheic zone. However, we tentatively attribute this tailing to the merging of two river channels having different flow characteristics and not to transient storage, and thus the hyporheic exchange is expected to be small along the river stretch. The results of the experiments are currently being analyzed by the OTIS model in order to report the exchange rates of surface and pore water on a quantitative basis.

  12. Terrestrial Water Storage in African Hydrological Regimes Derived from GRACE Mission Data: Intercomparison of Spherical Harmonics, Mass Concentration, and Scalar Slepian Methods

    Directory of Open Access Journals (Sweden)

    Ashraf Rateb

    2017-03-01

    Full Text Available Spherical harmonics (SH and mascon solutions are the two most common types of solutions for Gravity Recovery and Climate Experiment (GRACE mass flux observations. However, SH signals are degraded by measurement and leakage errors. Mascon solutions (the Jet Propulsion Laboratory (JPL release, herein exhibit weakened signals at submascon resolutions. Both solutions require a scale factor examined by the CLM4.0 model to obtain the actual water storage signal. The Slepian localization method can avoid the SH leakage errors when applied to the basin scale. In this study, we estimate SH errors and scale factors for African hydrological regimes. Then, terrestrial water storage (TWS in Africa is determined based on Slepian localization and compared with JPL-mascon and SH solutions. The three TWS estimates show good agreement for the TWS of large-sized and humid regimes but present discrepancies for the TWS of medium and small-sized regimes. Slepian localization is an effective method for deriving the TWS of arid zones. The TWS behavior in African regimes and its spatiotemporal variations are then examined. The negative TWS trends in the lower Nile and Sahara at −1.08 and −6.92 Gt/year, respectively, are higher than those previously reported.

  13. Evaluation of volatile profiles obtained for minimally-processed pineapple fruit samples during storage by headspace-solid phase microextraction gas chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Francielle Crocetta TURAZZI

    Full Text Available Abstract This paper describes the application of the solid-phase microextraction (SPME technique for the determination and monitoring of the volatile profile of minimally-processed pineapple fruit stored at various temperatures (-12 °C, 4 °C and 25 °C for different periods (1, 4 and 10 days. The SPME fiber coating composed of Car/PDMS presented the best performance. The optimal extraction conditions obtained through a Doehlert design were 60 min at 35 °C. The profiles for the volatile compounds content of the fruit at each stage of storage were determined by gas chromatography-mass spectrometry (GC-MS. The variation in the volatile profile over time was greater when the fruit samples were stored at 25 °C and at -12 °C compared to 4 °C. Thus, according to the volatile profiles associated with the storage conditions evaluated in this study, packaged pineapple retains best its fresh fruit aroma when stored at 4 °C.

  14. Predicting protein aggregation during storage in lyophilized solids using solid state amide hydrogen/deuterium exchange with mass spectrometric analysis (ssHDX-MS).

    Science.gov (United States)

    Moorthy, Balakrishnan S; Schultz, Steven G; Kim, Sherry G; Topp, Elizabeth M

    2014-06-02

    Solid state amide hydrogen/deuterium exchange with mass spectrometric analysis (ssHDX-MS) was used to assess the conformation of myoglobin (Mb) in lyophilized formulations, and the results correlated with the extent of aggregation during storage. Mb was colyophilized with sucrose (1:1 or 1:8 w/w), mannitol (1:1 w/w), or NaCl (1:1 w/w) or in the absence of excipients. Immediately after lyophilization, samples of each formulation were analyzed by ssHDX-MS and Fourier transform infrared spectroscopy (FTIR) to assess Mb conformation, and by dynamic light scattering (DLS) and size exclusion chromatography (SEC) to determine the extent of aggregation. The remaining samples were then placed on stability at 25 °C and 60% RH or 40 °C and 75% RH for up to 1 year, withdrawn at intervals, and analyzed for aggregate content by SEC and DLS. In ssHDX-MS of samples immediately after lyophilization (t = 0), Mb was less deuterated in solids containing sucrose (1:1 and 1:8 w/w) than in those containing mannitol (1:1 w/w), NaCl (1:1 w/w), or Mb alone. Deuterium uptake kinetics and peptide mass envelopes also indicated greater Mb structural perturbation in mannitol, NaCl, or Mb-alone samples at t = 0. The extent of deuterium incorporation and kinetic parameters related to rapidly and slowly exchanging amide pools (Nfast, Nslow), measured at t = 0, were highly correlated with the extent of aggregation on storage as measured by SEC. In contrast, the extent of aggregation was weakly correlated with FTIR band intensity and peak position measured at t = 0. The results support the use of ssHDX-MS as a formulation screening tool in developing lyophilized protein drug products.

  15. 2DB: a Proteomics database for storage, analysis, presentation, and retrieval of information from mass spectrometric experiments

    Directory of Open Access Journals (Sweden)

    Hippler Michael

    2008-07-01

    Full Text Available Abstract Background The amount of information stemming from proteomics experiments involving (multi dimensional separation techniques, mass spectrometric analysis, and computational analysis is ever-increasing. Data from such an experimental workflow needs to be captured, related and analyzed. Biological experiments within this scope produce heterogenic data ranging from pictures of one or two-dimensional protein maps and spectra recorded by tandem mass spectrometry to text-based identifications made by algorithms which analyze these spectra. Additionally, peptide and corresponding protein information needs to be displayed. Results In order to handle the large amount of data from computational processing of mass spectrometric experiments, automatic import scripts are available and the necessity for manual input to the database has been minimized. Information is in a generic format which abstracts from specific software tools typically used in such an experimental workflow. The software is therefore capable of storing and cross analysing results from many algorithms. A novel feature and a focus of this database is to facilitate protein identification by using peptides identified from mass spectrometry and link this information directly to respective protein maps. Additionally, our application employs spectral counting for quantitative presentation of the data. All information can be linked to hot spots on images to place the results into an experimental context. A summary of identified proteins, containing all relevant information per hot spot, is automatically generated, usually upon either a change in the underlying protein models or due to newly imported identifications. The supporting information for this report can be accessed in multiple ways using the user interface provided by the application. Conclusion We present a proteomics database which aims to greatly reduce evaluation time of results from mass spectrometric experiments and enhance

  16. Recommendations for the generation, quantification, storage and handling of peptides used for mass spectrometry-based assays

    Energy Technology Data Exchange (ETDEWEB)

    Hoofnagle, Andrew N.; Whiteaker, Jeffrey R.; Carr, Steven A.; Kuhn, Eric; Liu, Tao; Massoni, Sam A.; Thomas, Stefani N.; Townsend, Reid; Zimmerman, Lisa J.; Boja, Emily; Chen, Jing; Crimmins, Daniel L.; Davies, Sherri; Gao, Yuqian; Hiltke, Tara R.; Ketchum, Karen; Kinsinger, Christopher; Mesri, Mehdi; Meyer, Matthew R.; Qian, Weijun; Schoenherr, Regine M.; Scott, Mitchell; Shi, Tujin; Whiteley, Gordon; Wrobel, John; Wu, Chaochao; Ackermann, Bradley L.; Aebersold, Ruedi; Barnidge, David R.; Bunk, David M.; Clarke, Nigel; Fishman, Jordan B.; Grant, Russ P.; Kusebauch, Ulrike; Kushnir, Mark M.; Lowenthal, Mark S.; Moritz, Robert; Neubert, Hendrik; Patterson, Scott D.; Rockwood, Alan L.; Rogers, John; Singh, Ravinder J.; Van Eyk, Jennifer; Wong, Steven H.; Zhang, Shucha; Chan, Daniel W.; Chen, Xian; Ellis, Matthew J.; Liebler, Daniel; Rodland, Karin D.; Rodriguez, Henry; Smith, Richard D.; Zhang, Zhen; Zhang, Hui; Paulovich, Amanda G.

    2015-12-30

    The Clinical Proteomic Tumor Analysis Consortium (1) (CPTAC) of the National Cancer Institute (NCI) is a comprehensive and coordinated effort to accelerate the understanding of the molecular basis of cancer through the application of robust technologies and workflows for the quantitative measurements of proteins. The Assay Development Working Group of the CPTAC Program aims to foster broad uptake of targeted mass spectrometry-based assays employing isotopically labeled peptides for confident assignment and quantification, including multiple reaction monitoring (MRM; also referred to as Selected Reaction Monitoring), parallel reaction monitoring (PRM), and other targeted methods.

  17. Convenient and large-scale synthesis of nitrogen-rich hierarchical porous carbon spheres for supercapacitors and CO2 capture

    Science.gov (United States)

    Chang, Binbin; Zhang, Shouren; Yin, Hang; Yang, Baocheng

    2017-08-01

    Herein, considering the great potential of nitrogen-doped hierarchical porous carbons in energy storage and CO2 capture, we designed a convenient and easily large-scale production strategy for preparing nitrogen-doped hierarchical porous carbon sphere (NHPCS) materials. In this synthesis route, spherical resorcinol-formaldehyde (RF) resins were selected as carbon precursor, and then the ZnCl2-impregnated RF resin spheres were carbonized in a NH3 atmosphere at a temperature range of 600-800 °C. During the one-step heat-treatment process, nitrogen atom could be efficiently incorporated into the carbon skeleton, and the interconnected and hierarchical pore structure with different micro/mesopore proportion could be generated and tuned by adjusting the activating agent ZnCl2 dosage and carbonization temperature. The resultant nitrogen-doped hierarchical porous carbon sphere materials exhibited a satisfactory charge storage capacity, and the optimal sample of NHPCS-2-8 with a high mesopore proportion obtained at 800 °C with a ZnCl2/RF mass ratio of 2:1 presented a specific capacitance of 273.8 F g-1 at a current density of 0.5 A g-1. More importantly, the assembled NHPCS-2-8-based symmetric capacitor displayed a high energy density of 17.2 Wh kg-1 at a power density of 178.9 W kg-1 within a voltage window of 0 ∼ 1.8 V in 0.5 M Na2SO4 aqueous electrolyte. In addition, the CO2 capture application of these NHPCS materials was also explored, and the optimal sample of NHPCS-0-8 with a large micropore proportion prepared at 800 °C exhibited an exceptional CO2 uptake capacity at ambient pressures of up to 4.23 mmol g-1 at 0 °C.

  18. 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...

  19. 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,

  20. 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.

  1. 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.

  2. 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.

  3. 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....

  4. 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.

  5. 基于P2P分布式开放资源管理服务的云存储方案研究%Research on Mass Data Cloud Storage System

    Institute of Scientific and Technical Information of China (English)

    陈敏

    2014-01-01

    Because able to provide users with safety and mass data storage function, cloud storage technology developed very rapidly in recent years. This paper introduces the basic principle of cloud storage technology and analyzes the present situation of the cloud storage technology, introduces the use of existing natural distribution network around the world plenty of free storage service, such as disc, FTP, email and other forms of storage. These services will be held together, so as to provide users with low price and reliable storage systems. This paper introduces the design of a kind of low cost,quick speed,high availability,can be expanded cloud storage topology system. By means of the system to expanding other function,finally achieves the purpose of distributed storage resources sharing.%云存储技术因其能为用户提供了安全、海量、随时随地的数据存储功能而得以快速发展。提出了利用网络上现存的自然分布于世界各地的大量免费存储服务,如网盘、ftp、email以及其他形式等存储空间,将这些服务集中起来,为用户提供价廉、可靠的存储系统。介绍了一种低开销、快速度、高可用、可扩展的云存储拓扑系统,以期在该拓扑架构下实现以文件存储和共享服务为基础,不断扩展其他功能,最终形成P2P分布式存储资源共享的目的。

  6. Correlating excipient effects on conformational and storage stability of an IgG1 monoclonal antibody with local dynamics as measured by hydrogen/deuterium-exchange mass spectrometry.

    Science.gov (United States)

    Manikwar, Prakash; Majumdar, Ranajoy; Hickey, John M; Thakkar, Santosh V; Samra, Hardeep S; Sathish, Hasige A; Bishop, Steven M; Middaugh, C Russell; Weis, David D; Volkin, David B

    2013-07-01

    The effects of sucrose and arginine on the conformational and storage stability of an IgG1 monoclonal antibody (mAb) were monitored by differential scanning calorimetry (DSC) and size-exclusion chromatography (SEC), respectively. Excipient effects on protein physical stability were then compared with their effects on the local flexibility of the mAb in solution at pH 6, 25°C using hydrogen/deuterium-exchange mass spectrometry (H/D-MS). Compared with a 0.1 M NaCl control, sucrose (0.5 M) increased conformational stability (T(m) values), slowed the rate of monomer loss, reduced the formation of insoluble aggregates, and resulted in a global trend of small decreases in local flexibility across most regions of the mAb. In contrast, the addition of arginine (0.5 M) decreased the mAb's conformational stability, increased the rate of loss of monomer with elevated levels of soluble and insoluble aggregates, and led to significant increases in the local flexibility in specific regions of the mAb, most notably within the constant domain 2 of the heavy chain (C(H)2). These results provide new insights into the effect of sucrose and arginine on the local dynamics of IgG1 domains as well as preliminary correlations between local flexibility within specific segments of the C(H)2 domain (notably heavy chain 241-251) and the mAb's overall physical stability.

  7. Highly scalable metadata distribution algorithm in mass storage system%海量存储系统中高扩展性元数据分布算法的研究

    Institute of Scientific and Technical Information of China (English)

    吴伟; 谢长生; 黄建忠; 张成峰

    2008-01-01

    Distribution of metadata in a metadata server cluster is important in mass storage system. A good distribution algorithm has a significant influence on the system performance, availability and scalability. Subtree partition and hash are two traditional metadata distribution algorithms used in distributed file systems. They both have a defect in system scalability. This paper proposes a new directory hash (DH) algorithm. By treating directory as the key value of hash function, implementing concentrated storage of metadata, pipelining operations and prefetching technology, DH algorithm can enhance the system scalability on the premise without sacrificing system performance.

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Hierarchical Codebook Design for Massive MIMO

    Directory of Open Access Journals (Sweden)

    Xin Su

    2015-02-01

    Full Text Available The Research of Massive MIMO is an emerging area, since the more antennas the transmitters or receivers equipped with, the higher spectral efficiency and link reliability the system can provide. Due to the limited feedback channel, precoding and codebook design are important to exploit the performance of massive MIMO. To improve the precoding performance, we propose a novel hierarchical codebook with the Fourier-based perturbation matrices as the subcodebook and the Kerdock codebook as the main codebook, which could reduce storage and search complexity due to the finite a lphabet. Moreover, t o f urther r educe t he search complexity and feedback overhead without noticeable performance degradation, we use an adaptive selection algorithm to decide whether to use the subcodebook. Simulation results show that the proposed codebook has remarkable performance gain compared to the conventional Kerdock codebook, without significant increase in feedback overhead and search complexity.

  17. 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...

  18. 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...

  19. 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

  20. Constrained hierarchical least square nonlinear equation solvers. [for indefinite stiffness and large structural deformations

    Science.gov (United States)

    Padovan, J.; Lackney, J.

    1986-01-01

    The current paper develops a constrained hierarchical least square nonlinear equation solver. The procedure can handle the response behavior of systems which possess indefinite tangent stiffness characteristics. Due to the generality of the scheme, this can be achieved at various hierarchical application levels. For instance, in the case of finite element simulations, various combinations of either degree of freedom, nodal, elemental, substructural, and global level iterations are possible. Overall, this enables a solution methodology which is highly stable and storage efficient. To demonstrate the capability of the constrained hierarchical least square methodology, benchmarking examples are presented which treat structure exhibiting highly nonlinear pre- and postbuckling behavior wherein several indefinite stiffness transitions occur.

  1. 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...

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. Ripening and storage conditions of Chétoui and Arbequina olives: Part II. Effect on olive endogenous enzymes and virgin olive oil secoiridoid profile determined by high resolution mass spectrometry.

    Science.gov (United States)

    Hachicha Hbaieb, Rim; Kotti, Faten; Cortes-Francisco, Nuria; Caixach, Josep; Gargouri, Mohamed; Vichi, Stefania

    2016-11-01

    Several factors affect virgin olive oil (VOO) phenolic profile. The aim of this study was to monitor olive hydrolytic (β-glucosidase) and oxidative (peroxydase, POX, and polyphenoloxydase, PPO) enzymes during olive ripening and storage and to determine their capacity to shape VOO phenolic profile. To this end, olives from the cultivars Chétoui and Arbequina were stored at 4°C or 25°C for 4weeks and their enzymatic activities and oil phenolic profiles were compared to those of ripening olives. We observed different trends in enzymes activities according to cultivar and storage temperature. Secoiridoid compounds, determined by high resolution mass spectrometry (HRMS), and their deacetoxylated, oxygenated, and deacetoxy-oxygenated derivatives were identified and their contents differed between the cultivars according to olive ripening degree and storage conditions. These differences could be due to β-glucosidase, POX and PPO activities changes during olive ripening and storage. Results also show that oxidised phenolic compounds could be a marker of VOO ''freshness". Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. 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.

  9. Determination of Nonanthocyanin Phenolic Compounds Using High-Resolution Mass Spectrometry (UHPLC-Orbitrap-MS/MS) and Impact of Storage Conditions in a Beverage Made from Strawberry by Fermentation.

    Science.gov (United States)

    Álvarez-Fernández, M Antonia; Hornedo-Ortega, Ruth; Cerezo, Ana B; Troncoso, Ana M; García-Parrilla, M Carmen

    2016-02-17

    Overproduction of strawberry leads to food waste, as it is very perishable. Therefore, strategies to transform it into new products are appreciated. This research focuses on characterization of the nonanthocyanin phenolic content of a beverage obtained from strawberry by gluconic and acetic fermentation and subsequently monitored for 90 days of storage, at two temperatures. Sixty-four nonanthocyanin (poly)phenols were identified by high-resolution mass spectrometry (UHPLC coupled with linear trap quadrupole and Orbitrap mass analyzer) and, for the first time, four compounds were reported in beverages fermented from strawberry: aromadendrin hexoside, phloretin 2'-O-xylosyl glucoside, dihydroferulic acid 4-O-glucuronide, and kaempferol hexosyl hexoside. During the storage time the increase in protocatechuic acid content was 13 times and condensed tannins diminished, especially procyanidin trimer. Statistical analysis showed that the composition remains unchanged until day 15 of storage at room temperature (27-30 °C) and until day 30 under refrigerated conditions (4 °C).

  10. Hierarchical Bayesian sparse image reconstruction with application to MRFM

    CERN Document Server

    Dobigeon, Nicolas; Tourneret, Jean-Yves

    2008-01-01

    This paper presents a hierarchical Bayesian model to reconstruct sparse images when the observations are obtained from linear transformations and corrupted by an additive white Gaussian noise. Our hierarchical Bayes model is well suited to such naturally sparse image applications as it seamlessly accounts for properties such as sparsity and positivity of the image via appropriate Bayes priors. We propose a prior that is based on a weighted mixture of a positive exponential distribution and a mass at zero. The prior has hyperparameters that are tuned automatically by marginalization over the hierarchical Bayesian model. To overcome the complexity of the posterior distribution, a Gibbs sampling strategy is proposed. The Gibbs samples can be used to estimate the image to be recovered, e.g. by maximizing the estimated posterior distribution. In our fully Bayesian approach the posteriors of all the parameters are available. Thus our algorithm provides more information than other previously proposed sparse reconstr...

  11. Parallel hierarchical global illumination

    Energy Technology Data Exchange (ETDEWEB)

    Snell, Quinn O. [Iowa State Univ., Ames, IA (United States)

    1997-10-08

    Solving the global illumination problem is equivalent to determining the intensity of every wavelength of light in all directions at every point in a given scene. The complexity of the problem has led researchers to use approximation methods for solving the problem on serial computers. Rather than using an approximation method, such as backward ray tracing or radiosity, the authors have chosen to solve the Rendering Equation by direct simulation of light transport from the light sources. This paper presents an algorithm that solves the Rendering Equation to any desired accuracy, and can be run in parallel on distributed memory or shared memory computer systems with excellent scaling properties. It appears superior in both speed and physical correctness to recent published methods involving bidirectional ray tracing or hybrid treatments of diffuse and specular surfaces. Like progressive radiosity methods, it dynamically refines the geometry decomposition where required, but does so without the excessive storage requirements for ray histories. The algorithm, called Photon, produces a scene which converges to the global illumination solution. This amounts to a huge task for a 1997-vintage serial computer, but using the power of a parallel supercomputer significantly reduces the time required to generate a solution. Currently, Photon can be run on most parallel environments from a shared memory multiprocessor to a parallel supercomputer, as well as on clusters of heterogeneous workstations.

  12. Detection of changes in fuel quality during storage of sawdust from pine and spruce by using gas chromatography - Mass spectrometry (GC-MS) and VIS-NIR-spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Arshadi, Mehrdad; Nilsson, David; Geladi, Paul (Unit of Biomass Technology and Chemistry, Swedish Univ. of Agricultural Sciences, SE-904 03 Umeaa (Sweden)). e-mail: mehrdad.arshadi@btk.slu.se

    2008-10-15

    Fuel pellets made of sawdust represent a renewable energy source for heat production. The raw material comes from sawmills and sawdust is used in the pellet mills and for reasons of logistics there is a need for storage of large quantities of the raw material. Long-term storage induces changes in the sawdust and therefore processing parameters for pellets production have to be adapted. This makes knowledge of storage time or maturity necessary. Two examples of experimental studies are presented: An industrial storage of pine and spruce sawdust was carried out over a period of 16 weeks in order to monitor the changes in the quality of sawdust during storage. Samples were taken out every week and all samples were analysed by VIS-NIR spectroscopy while some samples were analysed by GC-MS for their composition of fatty- and resin acids. The resulting data were subjected to multivariate data analysis. GC-MS data showed the difference between pine and spruce sawdust and the influence of maturity. This maturity effect could be associated with the decrease in fatty- and resin acids due to auto oxidative reactions. Multivariate analysis of the VIS-NIR data showed a major effect due to maturity associated with a colour change and also weaker effects of fatty- and resin acids differences. PLS regression was used to predict the storage time with RMSEP values between 10 and 15 days. However, since weather conditions, precipitation and seasonal variation have high influence on the speed of maturing of sawdust it will be necessary to continuously determine the degree of maturity. A second similar study is used as a complementary way of corroborating the results of the first one

  13. Perubahan suhu transisi kaca dan massa resin akrilik heat cured akibat kelembaban dan lama penyimpanan (Changes in glass transition temperature and heat cured acrylic resin mass due to moisture and storage time

    Directory of Open Access Journals (Sweden)

    Sherman Salim

    2014-09-01

    Full Text Available Background: Acrylic resins, especially poly methyl methacrylate (PMMA was introduced in 1937. Acrylic resin has favorable properties, among others, aesthetic, color and texture similar to that of the gingival aesthetic in the mouth, relatively low water absorption and dimensional changes. However, some studies suggest that the duration of storage of acrylic resin will affect the changes in the glass transition temperature and the mass of acrylic resin. Purpose: The objective of this research was to study the effect of humidity and storage time led to changes in the glass transition temperature and the mass of the acrylic resin. Methods: The research method is experimental laboratory. Acrylic resin specimens are kept in conditions of humidity of 90%, 70%, 40% and 30% for 24 hours, one week, one month and two months. In this study used three methods of curing, namely conventional JIs, 24-hour curing at 70 °C and using the microwave. Results: Low humidity causes changes in the glass transition temperature and the mass of acrylic resin. Longer storage of acrylic resins in low humidity, can affect change greater than the glass transition temperature and the mass of acrylic resin. Conclusion: It can be concluded that the humidity and longer storage of acrylic resins can affect the glass transition temperature and a change in mass.Latar belakang: Resin akrilik terutama poli metil metakrilat (PMMA telah diperkenalkan pada tahun 1937. Resin akrilik memiliki sifat yang menguntungkan antara lain estetis, warna dan tekstur mirip dengan gingiva sehingga estetik di dalam mulut baik, daya serap air relatif rendah dan perubahan dimensi kecil. Akan tetapi, dari beberapa penelitian menyatakan bahwa lamanya waktu penyimpanan resin akrilik akan berpengaruh pada perubahan suhu transisi kaca dan massa resin akrilik. Tujuan: Tujuan dari penelitian ini adalah untuk mempelajari pengaruh kelembaban dan waktu penyimpanan yang menyebabkan perubahan suhu transisi kaca dan

  14. The structure of dust aggregates in hierarchical coagulation

    CERN Document Server

    Dominik, Carsten; Borel, Herman

    2016-01-01

    Dust coagulation in interstellar space and protoplanetary disks is usually treated as one of 2 extreme cases: Particle-Cluster Aggregation and Cluster-Cluster Aggregation. In this paper we study the process of hierarchical growth, where aggregates are built from significantly smaller aggregates (but not monomers). We show that this process can be understood as a modified, PCA-like process that produces porous, but non-fractal particles whose filling factor is chiefly determined by the porosity of the building blocks. We also show that in a coagulation environment where relative velocities are driven by turbulence, a logarithmically flat mass distribution (equal mass per mass decade) as it is typically found in environments where fragmentation replenishes small grains, leads to a situation where small particles and aggregates dominate the growth of large ones. Therefore, in such environments, hierarchical growth should be seen as the norm. Consequently, we predict that the aggregates in such environments are n...

  15. 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...

  16. 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...

  17. 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...

  18. 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

  19. Energy storage

    CERN Document Server

    Brunet, Yves

    2013-01-01

    Energy storage examines different applications such as electric power generation, transmission and distribution systems, pulsed systems, transportation, buildings and mobile applications. For each of these applications, proper energy storage technologies are foreseen, with their advantages, disadvantages and limits. As electricity cannot be stored cheaply in large quantities, energy has to be stored in another form (chemical, thermal, electromagnetic, mechanical) and then converted back into electric power and/or energy using conversion systems. Most of the storage technologies are examined: b

  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. Fluorocarbon Adsorption in Hierarchical Porous Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Motkuri, Radha K.; Annapureddy, Harsha V.; Vijayakumar, M.; Schaef, Herbert T.; Martin, P F.; McGrail, B. Peter; Dang, Liem X.; Krishna, Rajamani; Thallapally, Praveen K.

    2014-07-09

    The adsorption behavior of a series of fluorocarbon derivatives was examined on a set of microporous metal organic framework (MOF) sorbents and another set of hierarchical mesoporous MOFs. The microporous M-DOBDC (M = Ni, Co) showed a saturation uptake capacity for R12 of over 4 mmol/g at a very low relative saturation pressure (P/Po) of 0.02. In contrast, the mesoporous MOF MIL-101 showed an exceptionally high uptake capacity reaching over 14 mmol/g at P/Po of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption were found to generally correlate with the polarizability of the refrigerant with R12 > R22 > R13 > R14 > methane. These results suggest the possibility of exploiting MOFs for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling and refrigeration applications.

  3. Probe Storage

    NARCIS (Netherlands)

    Gemelli, Marcellino; Abelmann, Leon; Engelen, Johan B.C.; Khatib, Mohammed G.; Koelmans, Wabe W.; Zaboronski, Olog; Campardo, Giovanni; Tiziani, Federico; Laculo, Massimo

    2011-01-01

    This chapter gives an overview of probe-based data storage research over the last three decades, encompassing all aspects of a probe recording system. Following the division found in all mechanically addressed storage systems, the different subsystems (media, read/write heads, positioning, data chan

  4. Atomic storage

    CERN Multimedia

    Ricadela, A

    2003-01-01

    IBM is supplying CERN, the European Organization for Nuclear Research, with its Storage Tank file system virtualization software, 20 terabytes of storage capacity, and services under a three-year deal to build computer systems that will support the Large Hadron Collider accelerator (1 paragraph).

  5. Comparison of volatiles of cultured and wild sea bream (Sparus aurata) during storage in ice by dynamic headspace analysis/gas chromatography-mass spectrometry.

    Science.gov (United States)

    Alasalvar, Cesarettin; Taylor, K D Anthony; Shahidi, Fereidoon

    2005-04-06

    Cultured and wild sea bream were compared for differences in their volatile components over a 23 day storage period in ice. A total of 60 compounds in cultured and 78 compounds in wild sea bream were tentatively identified (in addition to this, there were 23 unknowns in cultured and 29 unknowns in wild sea bream volatiles). These included aldehydes, ketones, alcohols, aromatics, terpenes, furans, sulfur-containing compounds, an acid, and miscellaneous compounds. Although selection of best fish is a subjective matter, more aldehydes, ketones, aromatics, and terpenes were found in wild sea bream as compared to that of its cultured counterpart. Both sea bream samples exhibited complex volatile profiles over the entire storage period. The combination of several classes of volatile compounds, dependent upon their concentrations and odor thresholds, is responsible for the distinctive and unique flavor of fresh cultured and wild sea bream. Relative concentrations of several compounds (trimethylamine, piperidine, methanethiol, dimethyl disulfide, dimethyl trisulfide, 1-penten-3-ol, 3-methyl-1-butanol, and acetic acid) increased continually throughout the storage period, and these may have the potential to be used as indicators of sea bream quality.

  6. 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...

  7. 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.

  8. 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 ...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Final Report of Optimization Algorithms for Hierarchical Problems, with Applications to Nanoporous Materials

    Energy Technology Data Exchange (ETDEWEB)

    Nash, Stephen G.

    2013-11-11

    The research focuses on the modeling and optimization of nanoporous materials. In systems with hierarchical structure that we consider, the physics changes as the scale of the problem is reduced and it can be important to account for physics at the fine level to obtain accurate approximations at coarser levels. For example, nanoporous materials hold promise for energy production and storage. A significant issue is the fabrication of channels within these materials to allow rapid diffusion through the material. One goal of our research is to apply optimization methods to the design of nanoporous materials. Such problems are large and challenging, with hierarchical structure that we believe can be exploited, and with a large range of important scales, down to atomistic. This requires research on large-scale optimization for systems that exhibit different physics at different scales, and the development of algorithms applicable to designing nanoporous materials for many important applications in energy production, storage, distribution, and use. Our research has two major research thrusts. The first is hierarchical modeling. We plan to develop and study hierarchical optimization models for nanoporous materials. The models have hierarchical structure, and attempt to balance the conflicting aims of model fidelity and computational tractability. In addition, we analyze the general hierarchical model, as well as the specific application models, to determine their properties, particularly those properties that are relevant to the hierarchical optimization algorithms. The second thrust was to develop, analyze, and implement a class of hierarchical optimization algorithms, and apply them to the hierarchical models we have developed. We adapted and extended the optimization-based multigrid algorithms of Lewis and Nash to the optimization models exemplified by the hierarchical optimization model. This class of multigrid algorithms has been shown to be a powerful tool for

  14. The Hierarchical Nature of the Spin Alignment of Dark Matter Haloes in Filaments

    CERN Document Server

    Aragon-Calvo, Miguel A

    2013-01-01

    Dark matter haloes in cosmological filaments and walls have their spin vector aligned (in average) with their host structure. While haloes in walls are aligned with the plane of the wall independently of their mass, haloes in filaments present a mass dependent two-regime orientation. Here we show that the transition mass determining the change in the alignment regime (from parallel to perpendicular) depends on the hierarchical level in which the halo is located, reflecting the hierarchical nature of the Cosmic Web. By explicitly exposing this hierarchy we are able to identify the contributions of different components of the filament network to the spin alignment signal. We discuss a unifying picture to describe the alignment of haloes in filaments and walls consistent with previous results and our findings based on a two-phase angular momentum acquisition, first via tidal torquening and later via anisotropic mass accretion. The hierarchical identification and characterization of cosmic structures was done wit...

  15. Recent results on the hierarchical triple system HD 150136

    Science.gov (United States)

    Gosset, E.; Berger, J. P.; Absil, O.; Le Bouquin, J. B.; Sana, H.; Mahy, L.; De Becker, M.

    2013-06-01

    HD 150136 is a hierarchical triple system, non-thermal radio emitter, made of three O stars totalling some 130 solar masses. The 2.67-day inner orbit is rather well-known. Recent works derived a good approximation for the outer orbit with a period of 3000 days. We report here on interferometric observations that allow us to angularly resolve the outer orbit. First evidences for an astrometric displacement are given. The determination of the outer system orbit gives access to the inclinations of the systems and to the masses, including the one of the O3-O3.5 primary star.

  16. Sparsey™: event recognition via deep hierarchical sparse distributed codes.

    Science.gov (United States)

    Rinkus, Gerard J

    2014-01-01

    The visual cortex's hierarchical, multi-level organization is captured in many biologically inspired computational vision models, the general idea being that progressively larger scale (spatially/temporally) and more complex visual features are represented in progressively higher areas. However, most earlier models use localist representations (codes) in each representational field (which we equate with the cortical macrocolumn, "mac"), at each level. In localism, each represented feature/concept/event (hereinafter "item") is coded by a single unit. The model we describe, Sparsey, is hierarchical as well but crucially, it uses sparse distributed coding (SDC) in every mac in all levels. In SDC, each represented item is coded by a small subset of the mac's units. The SDCs of different items can overlap and the size of overlap between items can be used to represent their similarity. The difference between localism and SDC is crucial because SDC allows the two essential operations of associative memory, storing a new item and retrieving the best-matching stored item, to be done in fixed time for the life of the model. Since the model's core algorithm, which does both storage and retrieval (inference), makes a single pass over all macs on each time step, the overall model's storage/retrieval operation is also fixed-time, a criterion we consider essential for scalability to the huge ("Big Data") problems. A 2010 paper described a nonhierarchical version of this model in the context of purely spatial pattern processing. Here, we elaborate a fully hierarchical model (arbitrary numbers of levels and macs per level), describing novel model principles like progressive critical periods, dynamic modulation of principal cells' activation functions based on a mac-level familiarity measure, representation of multiple simultaneously active hypotheses, a novel method of time warp invariant recognition, and we report results showing learning/recognition of spatiotemporal patterns.

  17. Stability and Degradation of Caffeoylquinic Acids under Different Storage Conditions Studied by High-Performance Liquid Chromatography with Photo Diode Array Detection and High-Performance Liquid Chromatography with Electrospray Ionization Collision-Induced Dissociation Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Meng Xue

    2016-07-01

    Full Text Available Caffeoylquinic acids (CQAs are main constituents in many herbal medicines with various biological and pharmacological effects. However, CQAs will degrade or isomerize when affected by temperature, pH, light, etc. In this study, high-performance liquid chromatography with photodiode array detection (HPLC-PDA and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS was utilized to study the stability and degradation of CQAs (three mono-acyl CQAs and four di-acyl CQAs under various ordinary storage conditions (involving different temperatures, solvents, and light irradiation. The results indicated that the stability of CQAs was mainly affected by temperature and light irradiation, while solvents did not affect it in any obvious way under the conditions studied. Mono-acyl CQAs were generally much more stable than di-acyl CQAs under the same conditions. Meanwhile, the chemical structures of 30 degradation products were also characterized by HPLC-MSn, inferring that isomerization, methylation, and hydrolysis were three major degradation pathways. The result provides a meaningful clue for the storage conditions of CQAs standard substances and samples.

  18. 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...

  19. Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-30

    Energy storage technology is critical if the U.S. is to achieve more than 25% penetration of renewable electrical energy, given the intermittency of wind and solar. Energy density is a critical parameter in the economic viability of any energy storage system with liquid fuels being 10 to 100 times better than batteries. However, the economical conversion of electricity to fuel still presents significant technical challenges. This project addressed these challenges by focusing on a specific approach: efficient processes to convert electricity, water and nitrogen to ammonia. Ammonia has many attributes that make it the ideal energy storage compound. The feed stocks are plentiful, ammonia is easily liquefied and routinely stored in large volumes in cheap containers, and it has exceptional energy density for grid scale electrical energy storage. Ammonia can be oxidized efficiently in fuel cells or advanced Carnot cycle engines yielding water and nitrogen as end products. Because of the high energy density and low reactivity of ammonia, the capital cost for grid storage will be lower than any other storage application. This project developed the theoretical foundations of N2 catalysis on specific catalysts and provided for the first time experimental evidence for activation of Mo 2N based catalysts. Theory also revealed that the N atom adsorbed in the bridging position between two metal atoms is the critical step for catalysis. Simple electrochemical ammonia production reactors were designed and built in this project using two novel electrolyte systems. The first one demonstrated the use of ionic liquid electrolytes at room temperature and the second the use of pyrophosphate based electrolytes at intermediate temperatures (200 – 300 ºC). The mechanism of high proton conduction in the pyrophosphate materials was found to be associated with a polyphosphate second phase contrary to literature claims and ammonia production rates as high as 5X 10

  20. 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.

  1. Hierarchy concepts: classification and preparation strategies for zeolite containing materials with hierarchical porosity.

    Science.gov (United States)

    Schwieger, Wilhelm; Machoke, Albert Gonche; Weissenberger, Tobias; Inayat, Amer; Selvam, Thangaraj; Klumpp, Michael; Inayat, Alexandra

    2016-06-13

    'Hierarchy' is a property which can be attributed to a manifold of different immaterial systems, such as ideas, items and organisations or material ones like biological systems within living organisms or artificial, man-made constructions. The property 'hierarchy' is mainly characterised by a certain ordering of individual elements relative to each other, often in combination with a certain degree of branching. Especially mass-flow related systems in the natural environment feature special hierarchically branched patterns. This review is a survey into the world of hierarchical systems with special focus on hierarchically porous zeolite materials. A classification of hierarchical porosity is proposed based on the flow distribution pattern within the respective pore systems. In addition, this review might serve as a toolbox providing several synthetic and post-synthetic strategies to prepare zeolitic or zeolite containing material with tailored hierarchical porosity. Very often, such strategies with their underlying principles were developed for improving the performance of the final materials in different technical applications like adsorptive or catalytic processes. In the present review, besides on the hierarchically porous all-zeolite material, special focus is laid on the preparation of zeolitic composite materials with hierarchical porosity capable to face the demands of industrial application.

  2. Hierarchical model-based interferometric synthetic aperture radar image registration

    Science.gov (United States)

    Wang, Yang; Huang, Haifeng; Dong, Zhen; Wu, Manqing

    2014-01-01

    With the rapid development of spaceborne interferometric synthetic aperture radar technology, classical image registration methods are incompetent for high-efficiency and high-accuracy masses of real data processing. Based on this fact, we propose a new method. This method consists of two steps: coarse registration that is realized by cross-correlation algorithm and fine registration that is realized by hierarchical model-based algorithm. Hierarchical model-based algorithm is a high-efficiency optimization algorithm. The key features of this algorithm are a global model that constrains the overall structure of the motion estimated, a local model that is used in the estimation process, and a coarse-to-fine refinement strategy. Experimental results from different kinds of simulated and real data have confirmed that the proposed method is very fast and has high accuracy. Comparing with a conventional cross-correlation method, the proposed method provides markedly improved performance.

  3. 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.

  4. Properties of disk galaxies in a hierarchical formation scenario

    CERN Document Server

    Avila-Reese, V

    2000-01-01

    We used galaxy evolutionary models in a hierarchical inside-out formation scenario to study the origin of the main properties and correlations of disk galaxies. We found that most of these properties and correlations are the result of three (cosmological) initial factors and their dispersions: the virial mass, the halo mass aggregation history (MAH), and the angular momentum given through the spin parameter \\lambda. The MAH determines mainly the halo structure and the color indexes while \\lambda determines mainly the surface brightness and the bulge-to-disk ratio. We calculated star formation (SF) using a gravitational instability criterion and a self-regulation mechanism in the turbulent ISM. The efficiency of SF in this model is almost independent from the mass. We show that the luminosity-dependent dust absorption empirically determined by Wang & Heckman explains the observed color-magnitude and color Tully-Fisher (TF) relations without the necessity of introducing a mass-dependent SF efficiency. The d...

  5. Hydrogen storage

    NARCIS (Netherlands)

    Peters, C.J.; Sloan, E.D.

    2005-01-01

    The invention relates to the storage of hydrogen. The invention relates especially to storing hydrogen in a clathrate hydrate. The clathrate hydrate according to the present invention originates from a composition, which comprises water and hydrogen, as well as a promotor compound. The promotor comp

  6. Armazenamento refrigerado de ameixas 'Laetitia' com uso de 1-MCP e indução de perda de massa fresca Cold storage of 'Laetitia' plums treated with 1-MCP and induced to loss of fresh mass

    Directory of Open Access Journals (Sweden)

    Erlani de Oliveira Alves

    2010-02-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da temperatura de armazenamento, do uso de 1-metilciclopropeno (1-MCP e da indução de perda de massa fresca (IPMF na qualidade de ameixas 'Laetitia'. Os tratamentos utilizados foram: -0,5°C; 0,5°C; 0,5°C em combinação com a indução de perda de massa fresca (IPMF; e 0,5°C após tratamento com aplicação de 1-MCP (1,0µL L-1. Frutos armazenados a 0,5°C e tratados com 1-MCP apresentaram os menores valores da taxa respiratória e da taxa de produção de etileno após quatro dias de exposição em condição ambiente (23°C / 60% de UR. Na saída da câmara fria não houve diferença entre tratamentos. Os frutos armazenados por 30 dias a 0,5°C, em combinação com a IPMF ou 1-MCP, apresentaram na saída da câmara maior firmeza de polpa. Porém, após quatro dias, apenas os frutos armazenados a 0,5°C e tratados com 1-MCP apresentaram maior firmeza de polpa. O índice de cor vermelha, na saída da câmara, foi menor nos frutos armazenados a -0,5°C e a 0,5°C após tratamento com 1-MCP, não sendo observada diferença entre os tratamentos após quatro dias de exposição dos frutos em temperatura ambiente. O armazenamento a -0,5°C proporcionou melhor preservação dos atributos de textura dos frutos do que a 0,5°C, e nesta temperatura o tratamento com 1-MCP proporcionou os melhores resultados. O armazenamento a 0,5°C em relação a -0,5°C causou incremento na incidência de degenerescência da polpa após quatro dias de exposição dos frutos em condição ambiente. A melhor temperatura para o armazenamento refrigerado de ameixas 'Laetitia' é de -0,5°C. O uso do 1-MCP e a IPMF contribuem para a manutenção da qualidade dos frutos durante o armazenamento, e o efeito do 1-MCP persiste após o armazenamento.This research was carried out to study the effects of storage temperature, treatment with 1-methycyclopropene (1-MCP, and induction of fresh mass loss (IFML on quality of 'Laetitia

  7. Charge variants characterization of a monoclonal antibody by ion exchange chromatography coupled on-line to native mass spectrometry: Case study after a long-term storage at +5°C.

    Science.gov (United States)

    Leblanc, Y; Ramon, C; Bihoreau, N; Chevreux, G

    2017-03-24

    Numerous putative post-translational modifications may induce variations of monoclonal antibodies charge distribution that can potentially affect their biological activity. The characterization and the monitoring of these charge variants are critical quality requirements to ensure stability and process consistency. Charge variants are usually characterized by preparative ion exchange chromatography, collection of fractions and subsequent reverse-phase liquid chromatography with mass spectrometry analysis. While this process can be automatized by on-line two-dimensional chromatography, it remains often complex and time consuming. For this reason, a straightforward on-line charge variant analysis method is highly desirable and analytical laboratories are actively pursuing efforts to overcome this challenge. In this study, a mixed mode ion exchange chromatographic method using volatile salts and coupled on-line to native mass spectrometry was developed in association with a middle-up approach for a detailed characterization of monoclonal antibodies charge variants. An aged monoclonal antibody, presenting a complex charge variant profile was successfully investigated by this methodology as a case study. Results demonstrate that deamidation of the heavy chain was the major degradation pathway after long-term storage at 5°C while oxidation was rather low. The method was also very useful to identify all the clipped forms of the antibody. Copyright © 2017 LFB Biotechnologies. Published by Elsevier B.V. All rights reserved.

  8. Storage modulus and internal friction variations in a Fe-28 Mn-6Si-5Cr (mass. %) shape memory alloy analyzed by three-point-bending DMA

    Science.gov (United States)

    Popa, M.; Pricop, B.; Mihalache, E.; Bujoreanu, L. G.

    2017-08-01

    An Fe-28Mn-6Si-5Cr (mass. %) shape memory alloy (SMA) was investigated, observing the behavior of the material when subjected to dynamic mechanical analysis (DMA) cycling performed as a function of temperature and as a function of amplitude. Strain sweeps were performed at three temperatures: T1 = RT, T2 = A50 ε and T3 = TN, where A50 and TN are the critical temperatures for the middle of reverse transformation of martensite to austenite and for antiferromagnetic-paramagnetic transition. During temperature scans, a modulus increase, with several GPa, and two internal friction maxima were observed on heating. The temperature scans revealed that internal friction increased with increasing the frequency as compared to similar data presented by other authors where a decreasing tendency was noticed.

  9. Underground Storage Tanks - Storage Tank Locations

    Data.gov (United States)

    NSGIC Education | GIS Inventory — A Storage Tank Location is a DEP primary facility type, and its sole sub-facility is the storage tank itself. Storage tanks are aboveground or underground, and are...

  10. Oil Storage Facilities - Storage Tank Locations

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — A Storage Tank Location is a DEP primary facility type, and its sole sub-facility is the storage tank itself. Storage tanks are aboveground or underground, and are...

  11. Connectivity of Discontinuities of Deep Rock Mass in Water Sealed Underground Storage Cavern%地下水封洞库深部岩体结构面连通性研究

    Institute of Scientific and Technical Information of China (English)

    季惠彬; 宋琨; 吕坤

    2013-01-01

    Water sealed underground storage cavern is the key project of strategic petroleum storage which is ongoing in China. The connectivity of fractured rock mass is the critical issue of oil containment evaluation. Combination of rock mass characteristics of the underground storage cavern, the location and geological characteristics of discontinuities were analyzed by the Borehole Television (BHTV) image. The connective conditions among different boreholes were established. And the geometry connectivity of metamor-phic discontinuities was researched between borehole of ZK11 and ZK12, ZK12 and ZK14. After the relationship of groundwater dropped steeply in boreholes and construction tunnels excavation analyzed, the hydraulic contact of groundwater discharge in tunnels and decline in boreholes was established. And the hydraulic connectivity of the discontinuities was studied. By the comprehensive analysis of the geometry and hydraulic connectivity, the discontinuities connectivity of deep rock mass was determined. The results show that the excavation of construction tunnels caused the groundwater declining significantly, and the hydraulic connection was obvious. The metamorphic discontinuity, J, is satisfied the location, geological feature and hydraulic connectivity in borehole of ZK12, ZK11 and 0 + 379. 424 m of the construction tunnel of NO.1, which is the connective discontinuity. However, the discontinuity, J', is satisfied the location and geological feature, but not fit the hydraulic connectivity in borehole of ZK12 and ZK14. And that is non-connective discontinuity. It has reference value to discontinuities connectivity of deep rock mass in underground engineering projects.%地下水封洞库工程是我国正在大力实施的战略石油储备重点工程,研究建库裂隙岩体的连通性是评价水封效果的关键.结合地下水封洞库工程的岩体特征,以钻孔电视成像技术为手段,通过分析影像中结构面位置、地质特征等,建

  12. 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...

  13. 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.…

  14. 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.

  15. Electrospun zeolite-templated carbon composite fibres for hydrogen storage applications

    CSIR Research Space (South Africa)

    Annamalai, Perushini

    2017-01-01

    Full Text Available -defined hierarchical pore structure. The study involved encapsulation of highly porous zeolite-templated carbon (ZTC) into electrospun fibres and testing of the resulting composites for hydrogen storage. The hydrogen storage capacity of the composite fibres was 1...

  16. 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.

  17. 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.

  18. 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.

  19. 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 ...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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

  6. 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.

  7. 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...

  8. 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 ...

  9. 3D Networked Tin Oxide/Graphene Aerogel with a Hierarchically Porous Architecture for High-Rate Performance Sodium-Ion Batteries.

    Science.gov (United States)

    Xie, Xiuqiang; Chen, Shuangqiang; Sun, Bing; Wang, Chengyin; Wang, Guoxiu

    2015-09-07

    Low-cost and sustainable sodium-ion batteries are regarded as a promising technology for large-scale energy storage and conversion. The development of high-rate anode materials is highly desirable for sodium-ion batteries. The optimization of mass transport and electron transfer is crucial in the discovery of electrode materials with good high-rate performances. Herein, we report the synthesis of 3 D interconnected SnO2 /graphene aerogels with a hierarchically porous structure as anode materials for sodium-ion batteries. The unique 3 D architecture was prepared by a facile in situ process, during which cross-linked 3 D conductive graphene networks with macro-/meso-sized hierarchical pores were formed and SnO2 nanoparticles were dispersed uniformly on the graphene surface simultaneously. Such a 3 D functional architecture not only facilitates the electrode-electrolyte interaction but also provides an efficient electron pathway within the graphene networks. When applied as anode materials in sodium-ion batteries, the as-prepared SnO2 /graphene aerogel exhibited high reversible capacity, improved cycling performance compared to SnO2 , and promising high-rate capability.

  10. Cost of Multicast Logical Key Tree Based on Hierarchical Data Processing

    Institute of Scientific and Technical Information of China (English)

    ZHOU Fucai; XU Jian; LI Ting

    2006-01-01

    How to design a multicast key management system with high performance is a hot issue now. This paper will apply the idea of hierarchical data processing to construct a common analytic model based on directed logical key tree and supply two important metrics to this problem: re-keying cost and key storage cost. The paper gives the basic theory to the hierarchical data processing and the analyzing model to multicast key management based on logical key tree. It has been proved that the 4-ray tree has the best performance in using these metrics. The key management problem is also investigated based on user probability model, and gives two evaluating parameters to re-keying and key storage cost.

  11. Object naming at multiple hierarchical levels: a comparison of preschoolers with and without word-finding deficits.

    Science.gov (United States)

    McGregor, K K; Waxman, S R

    1998-06-01

    According to the storage hypothesis (Kail & Leonard, 1986), word-finding deficits in young children are not the direct results of deficient retrieval strategies; they are a manifestation of a general delay in language development that affects lexical storage. In the current study, we explored one aspect of lexical storage, the hierarchical organization of the semantic system, in 13 preschoolers with word-finding deficits (WF) and 13 preschoolers with normal language abilities (ND), ranging in age from 3;3 to 6;7. The children named a series of objects at multiple levels of the noun hierarchy in response to contrast questions (e.g. for rose they were asked, 'Is this an animal?' to elicit plant [superordinate]; 'Is this a tree?' to elicit flower [basic]; 'Is this a dandelion?' to elicit rose [subordinate]). Both groups readily named at multiple levels, providing evidence of hierarchical organization of the lexicon. However, there were several differences between WF and ND groups that suggested that WF children did not have enough stored information to discriminate between similar semantic neighbours. We conclude (1) that hierarchical organization of the semantic lexicon is a robust developmental phenomenon, apparent in both ND and WF preschoolers and (2) that the word-finding deficits of preschoolers appear to reflect insufficient depth and breadth of storage elaboration rather than deficits in hierarchical semantic organization.

  12. Gas-Chromatography Mass-Spectrometry (GC-MS Based Metabolite Profiling Reveals Mannitol as a Major Storage Carbohydrate in the Coccolithophorid Alga Emiliania huxleyi

    Directory of Open Access Journals (Sweden)

    Alisdair R. Fernie

    2013-03-01

    Full Text Available Algae are divergent organisms having a wide variety of evolutional histories. Although most of them share photosynthetic activity, their pathways of primary carbon metabolism are rather diverse among species. Here we developed a method for gas chromatography-mass spectroscopy (GC-MS based metabolite profiling for the coccolithophorid alga Emiliania huxleyi, which is one of the most abundant microalgae in the ocean, in order to gain an overview of the pathway of primary metabolism within this alga. Following method optimization, twenty-six metabolites could be detected by this method. Whilst most proteogenic amino acids were detected, no peaks corresponding to malate and fumarate were found. The metabolite profile of E. huxleyi was, however, characterized by a prominent accumulation of mannitol reaching in excess of 14 nmol 106 cells−1. Similarly, the accumulation of the 13C label during short term H13CO3− feeding revealed a massive redistribution of label into mannitol as well as rapid but saturating label accumulation into glucose and several amino acids including aspartate, glycine and serine. These results provide support to previous work suggesting that this species adopts C3 photosynthesis and that mannitol functions as a carbon store in E. huxleyi.

  13. Secular Evolution of Hierarchical Triple Star Systems

    Science.gov (United States)

    Ford, Eric B.; Kozinsky, Boris; Rasio, Frederic A.

    2000-05-01

    We derive octupole-level secular perturbation equations for hierarchical triple systems, using classical Hamiltonian perturbation techniques. Our equations describe the secular evolution of the orbital eccentricities and inclinations over timescales that are long compared to the orbital periods. By extending previous work done to leading (quadrupole) order to octupole level (i.e., including terms of order α3, where α≡a1/a2quadrupole-level theory of Kozai gives a vanishing result in the limit of zero relative inclination. The classical planetary perturbation theory, while valid to all orders in α, applies only to orbits of low-mass objects orbiting a common central mass, with low eccentricities and low relative inclinations. For triple systems containing a close inner binary, we also discuss the possible interaction between the classical Newtonian perturbations and the general relativistic precession of the inner orbit. In some cases we show that this interaction can lead to resonances and a significant increase in the maximum amplitude of eccentricity perturbations. We establish the validity of our analytic expressions by providing detailed comparisons with the results of direct numerical integrations of the three-body problem obtained for a large number of representative cases. In addition, we show that our expressions reduce correctly to previously published analytic results obtained in various limiting regimes. We also discuss applications of the theory in the context of several observed triple systems of current interest, including the millisecond pulsar PSR B1620-26 in M4, the giant planet in 16 Cygni, and the protostellar binary TMR-1.

  14. 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.

  15. Microgrids: Hierarchical Control and an Overview of the Control and Reserve Management Strategies

    DEFF Research Database (Denmark)

    Vandoorn, T.L.; Vasquez, Juan Carlos; de Kooning, D.M.

    2013-01-01

    in the network, allowing the DG units to actively contribute in the frequency and voltage regulation. Microgrids can provide such coordination by aggregating DG, (controllable) loads and storage in small-scale networks, that can operate both in grid-connected and islanded mode. Here, the islanded operating...... as either local or centralized. In this article, the hierarchical control for application in microgrids is discussed and an overview of the control strategies is given with respect to the reserve provision by the DG units, loads and storage equipment....

  16. 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

  17. Hierarchical Model for the Evolution of Cloud Complexes

    CERN Document Server

    Sánchez, N; Sanchez, Nestor; Parravano, Antonio

    1999-01-01

    The structure of cloud complexes appears to be well described by a "tree structure" representation when the image is partitioned into "clouds". In this representation, the parent-child relationships are assigned according to containment. Based on this picture, a hierarchical model for the evolution of Cloud Complexes, including star formation, is constructed, that follows the mass evolution of each sub-structure by computing its mass exchange (evaporation or condensation) with its parent and children, which depends on the radiation density at the interphase. For the set of parameters used as a reference model, the system produces IMFs with a maximum at too high mass (~2 M_sun) and the characteristic times for evolution seem too long. We show that these properties can be improved by adjusting model parameters. However, the emphasis here is to illustrate some general properties of this nonlinear model for the star formation process. Notwithstanding the simplifications involved, the model reveals an essential fe...

  18. The structure of dark matter halos in hierarchical clustering theories

    CERN Document Server

    Subramanian, K; Ostriker, J P; Subramanian, Kandaswamy; Cen, Renyue; Ostriker, Jeremiah P.

    1999-01-01

    During hierarchical clustering, smaller masses generally collapse earlier than larger masses and so are denser on the average. The core of a small mass halo could be dense enough to resist disruption and survive undigested, when it is incorporated into a bigger object. We explore the possibility that a nested sequence of undigested cores in the center of the halo, which have survived the hierarchical, inhomogeneous collapse to form larger and larger objects, determines the halo structure in the inner regions. For a flat universe with $P(k) \\propto k^n$, scaling arguments then suggest that the core density profile is, $\\rho \\propto r^{-\\alpha}$ with $\\alpha = (9+3n)/(5+n)$. But whether such behaviour obtains depends on detailed dynamics. We first examine the dynamics using a fluid approach to the self-similar collapse solutions for the dark matter phase space density, including the effect of velocity dispersions. We highlight the importance of tangential velocity dispersions to obtain density profiles shallowe...

  19. Multi-dimensional optical storage

    CERN Document Server

    Xu, Duanyi

    2016-01-01

    This book presents principles and applications to expand the storage space from 2-D to 3-D and even multi-D, including gray scale, color (light with different wavelength), polarization and coherence of light. These actualize the improvements of density, capacity and data transfer rate for optical data storage. Moreover, the applied implementation technologies to make mass data storage devices are described systematically. Some new mediums, which have linear absorption characteristics for different wavelength and intensity to light with high sensitivity, are introduced for multi-wavelength and multi-level optical storage. This book can serve as a useful reference for researchers, engineers, graduate and undergraduate students in material science, information science and optics. .

  20. 一种采用声学指纹去重的海量MP3文件存储架构%Storage architecture of mass MP3 files using acoustic fingerprint deduplication

    Institute of Scientific and Technical Information of China (English)

    赵晓永; 杨扬; 孙莉莉

    2013-01-01

    Due to the Hadoop itself is not suitable for processing of the mass of small files. And current data de-duplication methods are mainly based on the binary characteristics of the file, so it cannot recognize the same song after the signal processing and also cannot meet the requirements of the online processing of massive data. This paper presented a de-duplication storage architecture of the mass of the MP3 file based on the acoustic fingerprint. It combined with music files on the acoustic characteristics and the meta-information of MR files, de-duplication by index, merge online and NAF, solved the memory bottleneck problem effectively in the face of too many small files. At the same time it provided a better de-duplication effect. Offline merge and the replication place module optimized storage continually according to the operating conditions of the system. The experimental results show that the architecture can achieve a good balance on performance, the rate of de-duplication, manageability and scalability.%由于Hadoop自身并不适合海量小文件处理,目前的重复数据删除方法主要基于文件的二进制特征,无法识别经过信号处理后的同一首歌曲,也不能满足海量数据在线处理的要求.提出一种采用声学指纹去重的海量MP3文件存储架构,结合音乐文件自身的声学特性和MP3文件包含的元信息,通过索引、在线归并和NAF去重,很好地解决了小文件过多时内存瓶颈问题,同时提供了更好的去重效果;离线归并和副本调整模块根据系统的运行状况不断优化存储.实验结果表明,该架构在性能、去重率、可管理性和可扩展性方面达到了良好的平衡,极大地提高了去重率,与可变分块CDC相比,去重率提高了100%,具有良好的实用价值.

  1. 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.

  2. Eccentricity evolution in hierarchical triple systems with eccentric outer binaries

    CERN Document Server

    Georgakarakos, Nikolaos

    2014-01-01

    We develop a technique for estimating the inner eccentricity in hierarchical triple systems, with the inner orbit being initially circular, while the outer one is eccentric. We consider coplanar systems with well separated components and comparable masses. The derivation of short period terms is based on an expansion of the rate of change of the Runge-Lenz vector. Then, the short period terms are combined with secular terms, obtained by means of canonical perturbation theory. The validity of the theoretical equations is tested by numerical integrations of the full equations of motion.

  3. Hierarchical porous carbon aerogel derived from bagasse for high performance supercapacitor electrode.

    Science.gov (United States)

    Hao, Pin; Zhao, Zhenhuan; Tian, Jian; Li, Haidong; Sang, Yuanhua; Yu, Guangwei; Cai, Huaqiang; Liu, Hong; Wong, C P; Umar, Ahmad

    2014-10-21

    Renewable, cost-effective and eco-friendly electrode materials have attracted much attention in the energy conversion and storage fields. Bagasse, the waste product from sugarcane that mainly contains cellulose derivatives, can be a promising candidate to manufacture supercapacitor electrode materials. This study demonstrates the fabrication and characterization of highly porous carbon aerogels by using bagasse as a raw material. Macro and mesoporous carbon was first prepared by carbonizing the freeze-dried bagasse aerogel; consequently, microporous structure was created on the walls of the mesoporous carbon by chemical activation. Interestingly, it was observed that the specific surface area, the pore size and distribution of the hierarchical porous carbon were affected by the activation temperature. In order to evaluate the ability of the hierarchical porous carbon towards the supercapacitor electrode performance, solid state symmetric supercapacitors were assembled, and a comparable high specific capacitance of 142.1 F g(-1) at a discharge current density of 0.5 A g(-1) was demonstrated. The fabricated solid state supercapacitor displayed excellent capacitance retention of 93.9% over 5000 cycles. The high energy storage ability of the hierarchical porous carbon was attributed to the specially designed pore structures, i.e., co-existence of the micropores and mesopores. This research has demonstrated that utilization of sustainable biopolymers as the raw materials for high performance supercapacitor electrode materials is an effective way to fabricate low-cost energy storage devices.

  4. A hierarchically nanostructured composite of MnO{sub 2}/conjugated polymer/graphene for high-performance lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Chun Xian; Chen, Tao; Li, Chang Ming [Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing 400715 (China); School of Chemical and Biomedical Engineering, Nanyang Technological University (Singapore); Wang, Min; Lou, Xiong Wen [School of Chemical and Biomedical Engineering, Nanyang Technological University (Singapore)

    2011-10-15

    A hierarchically nanostructured composite of MnO{sub 2}/conjugated polymer/graphene is designed and fabricated for lithium ion batteries. The composite can produce a reversible capacity more than ten times that of plain MnO{sub 2}-based devices. The described approach can be used to create desired hierarchically nanostructured composite electrodes for broad applications in energy conversion/storage systems. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Hierarchical energy management mechanisms for an electricity market with microgrids

    Directory of Open Access Journals (Sweden)

    Hong-Tzer Yang

    2014-08-01

    Full Text Available This study addresses a micro-grid electricity market (MGEM with day-ahead (DA and real-time market mechanisms integrated. The bidding mechanisms for the market are described in this study, considering the generation cost of different distributed energy resources (DERs, like distributed generator, energy storage system and demand response. Including load and renewable generation forecasting systems and a fuzzy decision supporting system, a hierarchical micro-grid energy management system (MG-EMS is then proposed to ensure the benefits of involved micro-grid central controller, DER owners and customers. To verify the feasibility of the proposed system, the whole-year historical pricing and load data for New England independent system operator are employed. The numerical results show that the proposed MG-EMS is promising and effective for the operations of MGEM.

  6. Scalable Hierarchical Algorithms for stochastic PDEs and UQ

    KAUST Repository

    Litvinenko, Alexander

    2015-01-07

    H-matrices and Fast Multipole (FMM) are powerful methods to approximate linear operators coming from partial differential and integral equations as well as speed up computational cost from quadratic or cubic to log-linear (O(n log n)), where n number of degrees of freedom in the discretization. The storage is reduced to the log-linear as well. This hierarchical structure is a good starting point for parallel algorithms. Parallelization on shared and distributed memory systems was pioneered by Kriemann [1,2]. Since 2005, the area of parallel architectures and software is developing very fast. Progress in GPUs and Many-Core Systems (e.g. XeonPhi with 64 cores) motivated us to extend work started in [1,2,7,8].

  7. Likelihood Approximation With Hierarchical Matrices For Large Spatial Datasets

    KAUST Repository

    Litvinenko, Alexander

    2017-09-03

    We use available measurements to estimate the unknown parameters (variance, smoothness parameter, and covariance length) of a covariance function by maximizing the joint Gaussian log-likelihood function. To overcome cubic complexity in the linear algebra, we approximate the discretized covariance function in the hierarchical (H-) matrix format. The H-matrix format has a log-linear computational cost and storage O(kn log n), where the rank k is a small integer and n is the number of locations. The H-matrix technique allows us to work with general covariance matrices in an efficient way, since H-matrices can approximate inhomogeneous covariance functions, with a fairly general mesh that is not necessarily axes-parallel, and neither the covariance matrix itself nor its inverse have to be sparse. We demonstrate our method with Monte Carlo simulations and an application to soil moisture data. The C, C++ codes and data are freely available.

  8. Scalable Hierarchical Algorithms for stochastic PDEs and Uncertainty Quantification

    KAUST Repository

    Litvinenko, Alexander

    2015-01-05

    H-matrices and Fast Multipole (FMM) are powerful methods to approximate linear operators coming from partial differential and integral equations as well as speed up computational cost from quadratic or cubic to log-linear (O(n log n)), where n number of degrees of freedom in the discretization. The storage is reduced to the log-linear as well. This hierarchical structure is a good starting point for parallel algorithms. Parallelization on shared and distributed memory systems was pioneered by R. Kriemann, 2005. Since 2005, the area of parallel architectures and software is developing very fast. Progress in GPUs and Many-Core Systems (e.g. XeonPhi with 64 cores) motivated us to extend work started in [1,2,7,8].

  9. A lattice for a lead storage battery

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, S.; Fukunaga, K.; Kumano, Y.

    1983-07-13

    Lattices for a lead storage cell are made of a lead alloy which contains (in percent by mass): 0.05 to 0.3 strontium; 0.02 to 0.1 aluminum; 0.05 to 3.0 tin and 0.01 to 3.0 cadmium. The storage cell has low autodischarge and a long service life.

  10. Cobalt silicate hierarchical hollow spheres for lithium-ion batteries

    Science.gov (United States)

    Yang, Jun; Guo, Yuanyuan; Zhang, Yufei; Sun, Chencheng; Yan, Qingyu; Dong, Xiaochen

    2016-09-01

    In this paper, the synthesis of cobalt silicate novel hierarchical hollow spheres via a facile hydrothermal method is presented. With a unique hollow structure, the Co2SiO4 provides a large surface area, which can shorten the lithium ions diffusion length and effectively accommodate the volumetic variation during the lithiation/de-lithiation process. Serving as an anode material in lithium-ion battery application, the Co2SiO4 electrode demonstrates a high reversible specific capacity (first-cycle charge capacity of 948.6 mAh g-1 at 100 mA g-1), a cycling durability (specific capacity of 791.4 mAh g-1 after 100 cycles at 100 mA g-1), and a good rate capability (specific capacity of 349.4 mAh g-1 at 10 A g-1). The results indicate that the cobalt silicate hierarchical hollow sphere holds the potential applications in energy storage electrodes.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. 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 ...

  2. 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.

  3. 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....

  4. 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...

  5. 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...

  6. 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.

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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

  12. 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...

  13. Energy Storage Project

    Science.gov (United States)

    Mercer, Carolyn R.; Jankovsky, Amy L.; Reid, Concha M.; Miller, Thomas B.; Hoberecht, Mark A.

    2011-01-01

    NASA's Exploration Technology Development Program funded the Energy Storage Project to develop battery and fuel cell technology to meet the expected energy storage needs of the Constellation Program for human exploration. Technology needs were determined by architecture studies and risk assessments conducted by the Constellation Program, focused on a mission for a long-duration lunar outpost. Critical energy storage needs were identified as batteries for EVA suits, surface mobility systems, and a lander ascent stage; fuel cells for the lander and mobility systems; and a regenerative fuel cell for surface power. To address these needs, the Energy Storage Project developed advanced lithium-ion battery technology, targeting cell-level safety and very high specific energy and energy density. Key accomplishments include the development of silicon composite anodes, lithiated-mixed-metal-oxide cathodes, low-flammability electrolytes, and cell-incorporated safety devices that promise to substantially improve battery performance while providing a high level of safety. The project also developed "non-flow-through" proton-exchange-membrane fuel cell stacks. The primary advantage of this technology set is the reduction of ancillary parts in the balance-of-plant--fewer pumps, separators and related components should result in fewer failure modes and hence a higher probability of achieving very reliable operation, and reduced parasitic power losses enable smaller reactant tanks and therefore systems with lower mass and volume. Key accomplishments include the fabrication and testing of several robust, small-scale nonflow-through fuel cell stacks that have demonstrated proof-of-concept. This report summarizes the project s goals, objectives, technical accomplishments, and risk assessments. A bibliography spanning the life of the project is also included.

  14. 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.

  15. 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.

  16. 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.

  17. Methanol wetting enthalpy on few-layer graphene decorated hierarchical carbon foam for cooling applications

    Energy Technology Data Exchange (ETDEWEB)

    Paul, R., E-mail: paul24@purdue.edu [Birck Nanotechnolgy Center, Purdue University, West Lafayette, IN 47907 (United States); Zemlyanov, D. [Birck Nanotechnolgy Center, Purdue University, West Lafayette, IN 47907 (United States); Voevodin, A.A.; Roy, A.K. [Materials and Manufacturing Directorate, Air Force Research Laboratory, WPAFB, OH 45433 (United States); Fisher, T.S. [Birck Nanotechnolgy Center, Purdue University, West Lafayette, IN 47907 (United States); Department of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 (United States)

    2014-12-01

    Vertical few-layer thick graphene petals are grown on macro-porous carbon foam surfaces having an intrinsic open porosity of 75%. This provides a hierarchical porous structure with a potential for surface adsorption/desorption or wetting/dewetting based thermal energy storage applications. Carbon foams have a combined advantage of large surface area and high thermal conductivity critical for thermal energy storage, but they are prone to oxidation and exhibit low adsorption enthalpies for lightweight hydrocarbons. Here we report graphene petal decoration of carbon foam surfaces and subsequent chemical modification through boron nitride incorporation in hexagonal carbon planes of both carbon foams and graphene petals. This chemically reactive hierarchical structure is characterized with FESEM, Raman, XRD, and XPS measurements. Methanol wetting enthalpy of this three-dimensional hierarchical material was measured with a solution calorimeter, and had shown a six fold increase (from 78 to 522 J/g of foam) as compared to the carbon foam prior to the surface modification. Influences of petal decoration on the surface morphology of carbon foam, BN chemical modification, structure and stoichiometry of the hierarchical material surface, and methanol wetting enthalpy improvement are discussed in detail. The applicability of this hierarchical porous material for thermal energy applications is established. - Highlights: • 500 nm thick few layer graphene petals decoration vertically on macroporous carbon foam surface. • Microwave heating assisted chemical treatment for boron-nitride modification. • Defective petals edges due to boron nitride domain formation. • 20 at. % boron and nitrogen incorporation. • Six fold increase in methanol wetting enthalpy on boron-nitride modification.

  18. 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.

  19. Hydrogen Storage for Aircraft Applications Overview

    Science.gov (United States)

    Colozza, Anthony J.; Kohout, Lisa (Technical Monitor)

    2002-01-01

    Advances in fuel cell technology have brought about their consideration as sources of power for aircraft. This power can be utilized to run aircraft systems or even provide propulsion power. One of the key obstacles to utilizing fuel cells on aircraft is the storage of hydrogen. An overview of the potential methods of hydrogen storage was compiled. This overview identifies various methods of hydrogen storage and points out their advantages and disadvantages relative to aircraft applications. Minimizing weight and volume are the key aspects to storing hydrogen within an aircraft. An analysis was performed to show how changes in certain parameters of a given storage system affect its mass and volume.

  20. SnO2 nanosheet hollow spheres with improved lithium storage capabilities

    Science.gov (United States)

    Ding, Shujiang; Wen (David) Lou, Xiong

    2011-09-01

    In this work, we employ new chemistry to grow tin oxide nanosheets in the gel matrix of sulfonated polystyrene hollow spheres. After calcination in air, hierarchical hollow spheres assembled from SnO2 nanosheets can be obtained. In virtue of the porous shell structure and internal voids, these SnO2 hierarchical nanosheet hollow spheres exhibit improved lithium storage capability.In this work, we employ new chemistry to grow tin oxide nanosheets in the gel matrix of sulfonated polystyrene hollow spheres. After calcination in air, hierarchical hollow spheres assembled from SnO2 nanosheets can be obtained. In virtue of the porous shell structure and internal voids, these SnO2 hierarchical nanosheet hollow spheres exhibit improved lithium storage capability. Electronic supplementary information (ESI) available: Detailed experimental procedures, more SEM and TEM images, XRD patterns, and TGA results. See DOI: 10.1039/c1nr10581g

  1. Spatial Information Storage

    Directory of Open Access Journals (Sweden)

    Vladimir Markelov

    2013-01-01

    Full Text Available The article describes the spatial information storage, shows the features of spatial information and of such storage systems formation. Requirements for information storage technologies and for the data management in storage systems are determined. Cartographic information storage and updating features are shown. The article proves that intelligent solutions are the most efficient means of working with large amounts of spatial data.

  2. Properties of Disk Galaxies in a Hierarchical Formation Scenario

    Science.gov (United States)

    Avila-Reese, Vladimir; Firmani, Claudio

    2000-04-01

    We used galaxy evolutionary models in a hierarchical inside-out disk formation scenario to study the origin of the main local and global properties of disk galaxies as well as their correlations. We found that most of these properties and correlations are the result of three (cosmological) initial factors and their dispersions: the virial mass, the halo mass aggregation history (MAH), and the angular momentum given through the spin parameter lambda. The MAH determines mainly the halo structure and the integral color indexes while Lambda determines mainly the surface brightness and the bulge-to-disk ratio. We calculated star formation (SF) using a gravitational instability criterion and a self-regulation mechanism in the disk turbulent ISM. The efficiency of SF in this model is almost independent from the mass. We show that the luminosity- dependent dust absorption empirically determined by Wang & Heckman explains the observed color-magnitude and color Tully-Fisher (TF) relations without the necessity of introducing a mass-dependent SF efficiency. The disks in centrifugal equilibrium form within growing cold dark matter halos with a gas accretion rate proportional to the rate of the MAH. The disks present exponential surface density and brightness profiles, negative radial color index gradients, and nearly flat rotation curves. We also calculated the secular formation of a bulge due to gravitational instabilities in the stellar disk. The intensive properties of our models agree with the observational data and the trends of the Hubble sequence are reproduced. The predicted infrared TF and luminosity-radius relations also agree with observations. The main shortcomings of our inside-out hierarchical models are the excessive radial color gradients and the dark halo dominion in the rotation curve decompositions.

  3. Flexible Transparent Supercapacitors Based on Hierarchical Nanocomposite Films.

    Science.gov (United States)

    Chen, Fanhong; Wan, Pengbo; Xu, Haijun; Sun, Xiaoming

    2017-05-31

    Flexible transparent electronic devices have recently gained immense popularity in smart wearable electronics and touch screen devices, which accelerates the development of the portable power sources with reliable flexibility, robust transparency and integration to couple these electronic devices. For potentially coupled as energy storage modules in various flexible, transparent and portable electronics, the flexible transparent supercapacitors are developed and assembled from hierarchical nanocomposite films of reduced graphene oxide (rGO) and aligned polyaniline (PANI) nanoarrays upon their synergistic advantages. The nanocomposite films are fabricated from in situ PANI nanoarrays preparation in a blended solution of aniline monomers and rGO onto the flexible, transparent, and stably conducting film (FTCF) substrate, which is obtained by coating silver nanowires (Ag NWs) layer with Meyer rod and then coating of rGO layer on polyethylene terephthalate (PET) substrate. Optimization of the transparency, the specific capacitance, and the flexibility resulted in the obtained all-solid state nanocomposite supercapacitors exhibiting enhanced capacitance performance, good cycling stability, excellent flexibility, and superior transparency. It provides promising application prospects for exploiting flexible, low-cost, transparent, and high-performance energy storage devices to be coupled into various flexible, transparent, and wearable electronic devices.

  4. Biomarker for Glycogen Storage Diseases

    Science.gov (United States)

    2017-07-03

    Fructose Metabolism, Inborn Errors; Glycogen Storage Disease; Glycogen Storage Disease Type I; Glycogen Storage Disease Type II; Glycogen Storage Disease Type III; Glycogen Storage Disease Type IV; Glycogen Storage Disease Type V; Glycogen Storage Disease Type VI; Glycogen Storage Disease Type VII; Glycogen Storage Disease Type VIII

  5. 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.

  6. Enhancing the Color Set Partitioning in Hierarchical Tree (SPIHT Algorithm Using Correlation Theory

    Directory of Open Access Journals (Sweden)

    a a a

    2011-01-01

    Full Text Available Problem statement: Efficient color image compression algorithm is essential for mass storage and the transmission of the image. The compression efficiency of the Set Partitioning in Hierarchical Tree (SPIHT coding algorithm for color images is improved by using correlation theory. Approach: In this study the correlation between the color channels are used to propose the new algorithm. The correlation between the color channels are analyzed in various color spaces and the color space CIE-UVW in which the color channels are highly correlated is taken. The most correlated U channel is considered as base color and compressed by using the wavelet filter and the SPIHT algorithm. The linear approximation of the two of the color components (V and W based on the primary color component U is used to code subordinate color components. The image is divided into N*N blocks in each color channels. The linear approximation coefficients are calculated for each block of the subordinate colors V and W as functions of the base color. Only these coefficients of each block are coded and send to the receiver along with the SPIHT coding of the base color. Results: By using this algorithm, a significant (4 dB mean value Peak Signal to Noise Ratio (PSNR improvement is obtained compared to the traditional coding scheme for the same compression rate and reduces the coding and decoding time. Also the proposed compression algorithm reduces the complexity in coding and decoding algorithms. Conclusion: This algorithm allows the reduction of complexity for both coding and decoding of color images. It is concluded that a significant PSNR gain and visual quality improvement is obtained. It is found that in color image coding, this algorithm is superior to the traditional de-correlation based methods and reduces the coding and decoding time.

  7. Hierarchical MnO2 nanowire/graphene hybrid fibers with excellent electrochemical performance for flexible solid-state supercapacitors

    Science.gov (United States)

    Ma, Wujun; Chen, Shaohua; Yang, Shengyuan; Chen, Wenping; Cheng, Yanhua; Guo, Yiwei; Peng, Shengjie; Ramakrishna, Seeram; Zhu, Meifang

    2016-02-01

    Towards rapid development of lightweight, flexible, and even wearable electronics, a highly efficient energy-storage device is required for their energy supply management. Graphene fiber-based supercapacitor is considered as one of the promising candidates because of the remarkable mechanical and electrical properties of graphene fibers. However, supercapacitors based on bare graphene fibers generally suffer a low capacitance, which certainly restricts their potentially wide applications. In this work, hierarchically structured MnO2 nanowire/graphene hybrid fibers are fabricated through a simple, scalable wet-spinning method. The hybrid fibers form mesoporous structure with large specific surface area of 139.9 m2 g-1. The mass loading of MnO2 can be as high as 40 wt%. Due to the synergistic effect between MnO2 nanowires and graphene, the main pseudocapacitance of MnO2 and the electric double-layer capacitance of graphene are improved simultaneously. In view of the practical demonstration, a highly flexible solid-state supercapacitor is fabricated by twisting of two MnO2/graphene fibers coated by polyvinyl alcohol/H3PO4 electrolyte. The supercapacitor exhibits a high volumetric capacitance (66.1 F cm-3, normalized by the total volume of two fiber electrodes), excellent cycling stability (96% capacitance retention over 10,000 cycles), high energy and power density (5.8 mWh cm-3 and 0.51 W cm-3, respectively).

  8. Overview of Probe-based Storage Technologies

    Science.gov (United States)

    Wang, Lei; Yang, Ci Hui; Wen, Jing; Gong, Si Di; Peng, Yuan Xiu

    2016-07-01

    The current world is in the age of big data where the total amount of global digital data is growing up at an incredible rate. This indeed necessitates a drastic enhancement on the capacity of conventional data storage devices that are, however, suffering from their respective physical drawbacks. Under this circumstance, it is essential to aggressively explore and develop alternative promising mass storage devices, leading to the presence of probe-based storage devices. In this paper, the physical principles and the current status of several different probe storage devices, including thermo-mechanical probe memory, magnetic probe memory, ferroelectric probe memory, and phase-change probe memory, are reviewed in details, as well as their respective merits and weakness. This paper provides an overview of the emerging probe memories potentially for next generation storage device so as to motivate the exploration of more innovative technologies to push forward the development of the probe storage devices.

  9. Seasonal thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  10. Enhanced methods for conditioning, storage, and extraction of liquid and solid samples of manure for determination of steroid hormones by solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Combalbert, Sarah; Pype, Marie-Laure; Bernet, Nicolas; Hernandez-Raquet, Guillermina

    2010-09-01

    Hormones are among the highest-impact endocrine disrupters affecting living organisms in aquatic environments. These molecules have been measured in both wastewater and sewage sludge. Analytical techniques for such matrices are well described in the literature. In contrast, there is little information about the analysis of hormones in animal waste. The objectives of this study were, first, to propose a method for conditioning swine manure samples (addition of formaldehyde, separation of the solid and liquid phases, and duration of storage) in order to determine hormones in the liquid fraction of manure by solid-phase extraction (SPE) coupled with gas chromatography-mass spectrometry (GC-MS). Our results showed that analysis of hormones was affected by matrix changes which occurred during freezing and thawing and after addition of formaldehyde, an additive frequently used to preserve environmental samples. Thus, our results argue for the conditioning of samples without formaldehyde and for separating the solid and liquid fractions of manure before freezing. Second, this study reports on the use of a liquid extraction method coupled with SPE and GC-MS analysis for determination of hormones in the solid fraction of manure. Under the conditions selected, hormone recoveries were between 80 and 100%. Finally, the optimized method was used to quantify hormones in both liquid and solid fractions of swine manure from different breeding units. High levels of estrone and α-estradiol were found in samples whereas β-estradiol was detected in smaller amounts. Estriol and progesterone were mainly found in manure from the gestating sow building whereas testosterone was detected in manure from male breeding buildings.

  11. Simultaneous determination of propofol and its glucuronide in whole blood by liquid chromatography-electrospray tandem mass spectrometry and the influence of sample storage conditions on the reliability of the test results.

    Science.gov (United States)

    Sørensen, Lambert K; Hasselstrøm, Jørgen B

    2015-05-10

    Propofol (2,6-diisopropylphenol) is commonly used as an anaesthetic agent but is also abused for recreational purposes. Several cases of fatalities involving self-administered propofol have been reported. For rapid quantification of propofol and propofol β-d-glucuronide (propofol G) in clinical and forensic cases, an ultra-performance liquid chromatography-tandem mass spectrometry method using pneumatically assisted electrospray ionisation has been developed. The technique has been validated on both ante-mortem and post-mortem human whole blood. The proteins in the blood samples were removed by the addition of a mixture of methanol and acetonitrile, and the extract was cleaned up by solid phase extraction. The extract was concentrated in dimethyl sulphoxide. The system was calibrated using matrix-matched calibrants combined with isotope dilution. The lower limits of quantification were 0.01 and 0.02mg/L for propofol and 0.02 and 0.04mg/L for propofol G in ante-mortem and post-mortem whole blood, respectively. The relative intra-laboratory reproducibility standard deviation was less than 10% at concentrations of 0.2mg/L or higher. The mean true extraction recovery was 85% for propofol and 81% for propofol G. The trueness of the propofol determination expressed as the relative bias of the test results was within ±6% at concentration levels of 0.01-8.5mg/L. Propofol was less stable in blood stabilised with a citrate-EDTA-fluoride mixture than in blood stabilised with an oxalate-fluoride mixture. The stability was lower at -20°C than at 5°C and -80°C. Propofol G did not show instability under the storage conditions tested.

  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. Enhanced Electrocatalytic Activity of Pt/3D Hierarchical Bimodal Macroporous Carbon Nanospheres.

    Science.gov (United States)

    Balgis, Ratna; Widiyastuti, W; Ogi, Takashi; Okuyama, Kikuo

    2017-07-19

    Proton exchange membrane fuel cells require electrocatalysts with a high platinum (Pt) loading, large active surface area, and favorable hydrodynamic profile for practical applications. Here, we report the design of three-dimensional hierarchical bimodal macroporous carbon nanospheres with an interconnected pore system, which are applied as an electrocatalyst support. Carbon-supported Pt (Pt/C) catalysts were prepared by aerosol spray pyrolysis followed by microwave chemical deposition. The hierarchical porous structures not only increased the dispersion of Pt nanoparticles but also improved catalytic performance. A hierarchical bimodal macroporous Pt/C catalyst with a mixture of 30 and 120 nm size pores showed the best performance. The electrochemical surface area and mass activity values of this support were 96 m(2) g(-1)-Pt and 378 mA mg(-1)-Pt, respectively at a Pt loading of 15 wt %.

  16. Hierarchical porous carbon toward effective cathode in advanced zinc-cerium redox flow battery

    Institute of Scientific and Technical Information of China (English)

    谢志鹏; 杨斌; 蔡定建; 杨亮

    2014-01-01

    Advanced zinc-cerium redox flow battery (ZCRFB) is a large-scale energy storage system which plays a significant role in the application of new energy sources. The requirement of superior cathode with high acitivity and fast ion diffusion is a hierarchical porous structure, which was synthesized in this work by a method in which both hard template and soft template were used. The structure and the performance of the cathode prepared here were characterized and evaluated by a variety of techniques such as scan-ning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), cyclic voltam-metry (CV), linear sweep voltammetry (LSV), and chronoamperometry (CA). There were mainly three types of pore size within the hierarchical porous carbon:2μm, 80 nm, and 10 nm. The charge capacity of the cell using hierarchical porous carbon (HPC) as posi-tive electrode was obviously larger than that using carbon felt;the former was 665.5 mAh with a coulombic efficiency of 89.0%and an energy efficiency of 79.0%, whereas the latter was 611.1 mAh with a coulombic efficiency of 81.5%and an energy efficiency of 68.6%. In addition, performance of the ZCRFB using HPC as positive electrode showed a good stability over 50 cycles. These results showed that the hierarchical porous carbon was superior over the carbon felt for application in ZCRFB.

  17. Graphene--nanotube--iron hierarchical nanostructure as lithium ion battery anode.

    Science.gov (United States)

    Lee, Si-Hwa; Sridhar, Vadahanambi; Jung, Jung-Hwan; Karthikeyan, Kaliyappan; Lee, Yun-Sung; Mukherjee, Rahul; Koratkar, Nikhil; Oh, Il-Kwon

    2013-05-28

    In this study, we report a novel route via microwave irradiation to synthesize a bio-inspired hierarchical graphene--nanotube--iron three-dimensional nanostructure as an anode material in lithium-ion batteries. The nanostructure comprises vertically aligned carbon nanotubes grown directly on graphene sheets along with shorter branches of carbon nanotubes stemming out from both the graphene sheets and the vertically aligned carbon nanotubes. This bio-inspired hierarchical structure provides a three-dimensional conductive network for efficient charge-transfer and prevents the agglomeration and restacking of the graphene sheets enabling Li-ions to have greater access to the electrode material. In addition, functional iron-oxide nanoparticles decorated within the three-dimensional hierarchical structure provides outstanding lithium storage characteristics, resulting in very high specific capacities. The anode material delivers a reversible capacity of ~1024 mA · h · g(-1) even after prolonged cycling along with a Coulombic efficiency in excess of 99%, which reflects the ability of the hierarchical network to prevent agglomeration of the iron-oxide nanoparticles.

  18. 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.

  19. 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.

  20. 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...

  1. 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.

  2. 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.

  3. 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...

  4. 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.

  5. 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...

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. 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.

  14. Hierarchical process memory: memory as an integral component of information processing

    Science.gov (United States)

    Hasson, Uri; Chen, Janice; Honey, Christopher J.

    2015-01-01

    Models of working memory commonly focus on how information is encoded into and retrieved from storage at specific moments. However, in the majority of real-life processes, past information is used continuously to process incoming information across multiple timescales. Considering single unit, electrocorticography, and functional imaging data, we argue that (i) virtually all cortical circuits can accumulate information over time, and (ii) the timescales of accumulation vary hierarchically, from early sensory areas with short processing timescales (tens to hundreds of milliseconds) to higher-order areas with long processing timescales (many seconds to minutes). In this hierarchical systems perspective, memory is not restricted to a few localized stores, but is intrinsic to information processing that unfolds throughout the brain on multiple timescales. “The present contains nothing more than the past, and what is found in the effect was already in the cause.”Henri L Bergson PMID:25980649

  15. Hierarchically Structured Graphene Coupled Microporous Organic Polymers for Superior CO2 Capture.

    Science.gov (United States)

    Liu, Fa-Qian; Wang, Li-Li; Li, Guo-Hua; Li, Wei; Li, Chao-Qin

    2017-10-04

    Hierarchically porous materials containing interconnected macro-/meso-/micropores are promising candidates for energy storage, catalysis, and gas separation. Here, we present an effective approach for synthesizing three-dimensional (3D) sulfonated graphene coupled microporous organic polymers (SG-MOPs). The resulting SG-MOPs possess uniform macropores with an average size of ca. 350 nm, abundant mesopores, and micropores with an average size of ca. 0.6 nm. The SG-supported adsorbents exhibit a high nitrogen content (more than 38.1 wt %), high adsorption capacity (up to 3.37 mmol CO2 g(-1)), high CO2/N2 selectivity from 42 to 51, moderate heat of adsorption, as well as good stability because of the hierarchical porous structure and excellent thermal conductivity of the SG scaffold. Thus, these nitrogen-enriched adsorbents allow the overall CO2 capture process to be promising and sustainable.

  16. Controlled Synthesis and Magnetic Properties of Uniform Hierarchical Polyhedral α-Fe2O3 Particles

    Science.gov (United States)

    Long, Nguyen Viet; Yang, Yong; Thi, Cao Minh; Phuc, Le Hong; Nogami, Masayuki

    2017-02-01

    The controlled synthesis of uniform hierarchical polyhedral iron (Fe) micro-/nanoscale oxide particles with the α-Fe2O3 structure is presented. The hierarchical polyhedral iron oxide particles were synthesized by modified polyol methods with sodium borohydride as a powerful and efficient reducing agent. A critical heat treatment process used during the synthesis allowed for the interesting formation of α-Fe2O3 hematite with a micro-/nanoscale structure. The structure and weak ferromagnetism of the α-Fe2O3 particles were investigated by x-ray diffraction with whole pattern fitting and Rietveld refinement, scanning electron microscopy, and by vibrating sample magnetometry. The as-prepared α-Fe2O3 particles and the three dimensional models presented have promising practical applications for energy storage and conversion in batteries, capacitors, and fuel cells, and related spintronic devices and technologies.

  17. Hierarchical mesoporous/microporous carbon with graphitized frameworks for high-performance lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Yingying Lv

    2014-11-01

    Full Text Available A hierarchical meso-/micro-porous graphitized carbon with uniform mesopores and ordered micropores, graphitized frameworks, and extra-high surface area of ∼2200 m2/g, was successfully synthesized through a simple one-step chemical vapor deposition process. The commercial mesoporous zeolite Y was utilized as a meso-/ micro-porous template, and the small-molecule methane was employed as a carbon precursor. The as-prepared hierarchical meso-/micro-porous carbons have homogeneously distributed mesopores as a host for electrolyte, which facilitate Li+ ions transport to the large-area micropores, resulting a high reversible lithium ion storage of 1000 mA h/g and a high columbic efficiency of 65% at the first cycle.

  18. Anterior insula coordinates hierarchical processing of tactile mismatch responses

    Science.gov (United States)

    Allen, Micah; Fardo, Francesca; Dietz, Martin J.; Hillebrandt, Hauke; Friston, Karl J.; Rees, Geraint; Roepstorff, Andreas

    2016-01-01

    The body underlies our sense of self, emotion, and agency. Signals arising from the skin convey warmth, social touch, and the physical characteristics of external stimuli. Surprising or unexpected tactile sensations can herald events of motivational salience, including imminent threats (e.g., an insect bite) and hedonic rewards (e.g., a caressing touch). Awareness of such events is thought to depend upon the hierarchical integration of body-related mismatch responses by the anterior insula. To investigate this possibility, we measured brain activity using functional magnetic resonance imaging, while healthy participants performed a roving tactile oddball task. Mass-univariate analysis demonstrated robust activations in limbic, somatosensory, and prefrontal cortical areas previously implicated in tactile deviancy, body awareness, and cognitive control. Dynamic Causal Modelling revealed that unexpected stimuli increased the strength of forward connections along a caudal to rostral hierarchy—projecting from thalamic and somatosensory regions towards insula, cingulate and prefrontal cortices. Within this ascending flow of sensory information, the AIC was the only region to show increased backwards connectivity to the somatosensory cortex, augmenting a reciprocal exchange of neuronal signals. Further, participants who rated stimulus changes as easier to detect showed stronger modulation of descending PFC to AIC connections by deviance. These results suggest that the AIC coordinates hierarchical processing of tactile prediction error. They are interpreted in support of an embodied predictive coding model where AIC mediated body awareness is involved in anchoring a global neuronal workspace. PMID:26584870

  19. Case histories in scientific and pseudo-scientific mass-media communication in energy/heat production from underground (geogas storage, geothermics, hydrocarbons), in the frame of Nimby Sindrome enhancement in Europe: the proposal of a new European Direct

    Science.gov (United States)

    Quattrocchi, Fedora; Boschi, Enzo

    2014-05-01

    In the frame of energy/heat production from underground, the paper considers some European case histories and the needs of a complex and motley stakeholders community, made by scientific-industry-institutions, involved in the difficult task to study and accept (or refuse) projects strongly impacting the lived territory & underground, in densely populate countries, as Italy, in terms of appropriate public communication and sound deontological behaviour. Successively, the paper recalls years of "scientific" communication within the mass-media, highlighting the positive and negative messages, in comparison to the true and objective experimental data gathered by the real scientific work, as perceived by citizens of medium scholastic culture, which not delve the geologic disciplines, but receive simply the journalistic front-end, very often as sensationalist scoop. The authors retrace case histories of heuristic-participatory communication with the citizenship about the scientific results on challenges raised by certain technologies. The objective and rational communication is often impeded by local interests and by local journalism, which prefers to create sensationalist news more than scientific truths. This path progressively tangles as a consequence of the complex and with conflicting use of underground to produce energy (heat as gas storage, geothermical, unconventional gas exploitation, mining, etc…). Even the chain of renewables meets by now serious issues, exacerbated also by the need to start mining and drilling for the smart grids materials too (metals, rare Earths, etc..). A new text for a smart and innovative European Directivity is discussed, starting from the Italian regulatory issue. The review efforts for a "paper" on both a newspaper or a blog could be more difficult than the review a scientific paper, as a consequence of the peculiar situations behind the scenes and the conflicts of interests staying in the nest in a newspaper article or in a blog

  20. Mass measurement of radioactive isotopes

    CERN Document Server

    Kluge, H J; Scheidenberger, C

    2004-01-01

    The highest precision in mass measurements on short-lived radionuclides is obtained using trapping and cooling techniques. Here, the experimental storage ring (ESR) at GSI/Darmstadt and the tandem Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN play an important role. Status and recent results on mass measurements of radioactive nuclides with ESR and ISOLTRAP are summarized.

  1. Sparsey^TM: Spatiotemporal Event Recognition via Deep Hierarchical Sparse Distributed Codes

    Directory of Open Access Journals (Sweden)

    Gerard J Rinkus

    2014-12-01

    Full Text Available The visual cortex’s hierarchical, multi-level organization is captured in many biologically inspired computational vision models, the general idea being that progressively larger scale (spatially/temporally and more complex visual features are represented in progressively higher areas. However, most earlier models use localist representations (codes in each representational field (which we equate with the cortical macrocolumn, mac, at each level. In localism, each represented feature/concept/event (hereinafter item is coded by a single unit. The model we describe, Sparsey, is hierarchical as well but crucially, it uses sparse distributed coding (SDC in every mac in all levels. In SDC, each represented item is coded by a small subset of the mac’s units. The SDCs of different items can overlap and the size of overlap between items can be used to represent their similarity. The difference between localism and SDC is crucial because SDC allows the two essential operations of associative memory, storing a new item and retrieving the best-matching stored item, to be done in fixed time for the life of the model. Since the model’s core algorithm, which does both storage and retrieval (inference, makes a single pass over all macs on each time step, the overall model’s storage/retrieval operation is also fixed-time, a criterion we consider essential for scalability to the huge (Big Data problems. A 2010 paper described a non-hierarchical version of this model in the context of purely spatial pattern processing. Here, we elaborate a fully hierarchical model (arbitrary numbers of levels and macs per level, describing novel model principles like progressive critical periods, dynamic modulation of principal cells’ activation functions based on a mac-level familiarity measure, representation of multiple simultaneously active hypotheses, a novel method of time warp invariant recognition, and we report results showing learning/recognition of

  2. 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...

  3. 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....

  4. 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.

  5. 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...

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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…

  11. 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.

  12. 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

  13. 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.

  14. 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,…

  15. 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.

  16. 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.

  17. 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.

  18. 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…

  19. 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....

  20. Hierarchical porous carbon aerogel derived from bagasse for high performance supercapacitor electrode

    Science.gov (United States)

    Hao, Pin; Zhao, Zhenhuan; Tian, Jian; Li, Haidong; Sang, Yuanhua; Yu, Guangwei; Cai, Huaqiang; Liu, Hong; Wong, C. P.; Umar, Ahmad

    2014-09-01

    Renewable, cost-effective and eco-friendly electrode materials have attracted much attention in the energy conversion and storage fields. Bagasse, the waste product from sugarcane that mainly contains cellulose derivatives, can be a promising candidate to manufacture supercapacitor electrode materials. This study demonstrates the fabrication and characterization of highly porous carbon aerogels by using bagasse as a raw material. Macro and mesoporous carbon was first prepared by carbonizing the freeze-dried bagasse aerogel; consequently, microporous structure was created on the walls of the mesoporous carbon by chemical activation. Interestingly, it was observed that the specific surface area, the pore size and distribution of the hierarchical porous carbon were affected by the activation temperature. In order to evaluate the ability of the hierarchical porous carbon towards the supercapacitor electrode performance, solid state symmetric supercapacitors were assembled, and a comparable high specific capacitance of 142.1 F g-1 at a discharge current density of 0.5 A g-1 was demonstrated. The fabricated solid state supercapacitor displayed excellent capacitance retention of 93.9% over 5000 cycles. The high energy storage ability of the hierarchical porous carbon was attributed to the specially designed pore structures, i.e., co-existence of the micropores and mesopores. This research has demonstrated that utilization of sustainable biopolymers as the raw materials for high performance supercapacitor electrode materials is an effective way to fabricate low-cost energy storage devices.Renewable, cost-effective and eco-friendly electrode materials have attracted much attention in the energy conversion and storage fields. Bagasse, the waste product from sugarcane that mainly contains cellulose derivatives, can be a promising candidate to manufacture supercapacitor electrode materials. This study demonstrates the fabrication and characterization of highly porous carbon

  1. High temperature thermal storage for solar gas turbines using encapsulated phase change materials

    CSIR Research Space (South Africa)

    Klein, P

    2014-01-01

    Full Text Available to compare the storage system with sensible heat storage in ceramic media. The results show that the discharge time of EPCM storage is comparable (<10 % improvement) with a packed bed of alumina particles, while the total storage mass is reduced by up to 31...

  2. 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.

  3. 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

  4. A Propellant Mass Gauge Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Technologies Group, Inc. proposes the development of a Liquid-Oxygen Mass Gauge, (LMG) for In-Space cryogenic storage capable of continuous monitoring of...

  5. A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure

    OpenAIRE

    Yingzhi Li; Qinghua Zhang; Junxian Zhang; Lei Jin; Xin Zhao; Ting Xu

    2015-01-01

    Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific ca...

  6. 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.

  7. The evolution of hierarchical triple star-systems

    Science.gov (United States)

    Toonen, Silvia; Hamers, Adrian; Portegies Zwart, Simon

    2016-12-01

    Field stars are frequently formed in pairs, and many of these binaries are part of triples or even higher-order systems. Even though, the principles of single stellar evolution and binary evolution, have been accepted for a long time, the long-term evolution of stellar triples is poorly understood. The presence of a third star in an orbit around a binary system can significantly alter the evolution of those stars and the binary system. The rich dynamical behaviour in three-body systems can give rise to Lidov-Kozai cycles, in which the eccentricity of the inner orbit and the inclination between the inner and outer orbit vary periodically. In turn, this can lead to an enhancement of tidal effects (tidal friction), gravitational-wave emission and stellar interactions such as mass transfer and collisions. The lack of a self-consistent treatment of triple evolution, including both three-body dynamics as well as stellar evolution, hinders the systematic study and general understanding of the long-term evolution of triple systems. In this paper, we aim to address some of these hiatus, by discussing the dominant physical processes of hierarchical triple evolution, and presenting heuristic recipes for these processes. To improve our understanding on hierarchical stellar triples, these descriptions are implemented in a public source code TrES, which combines three-body dynamics (based on the secular approach) with stellar evolution and their mutual influences. Note that modelling through a phase of stable mass transfer in an eccentric orbit is currently not implemented in TrES, but can be implemented with the appropriate methodology at a later stage.

  8. Hierarchical star cluster assembly in globally collapsing molecular clouds

    Science.gov (United States)

    Vázquez-Semadeni, Enrique; González-Samaniego, Alejandro; Colín, Pedro

    2017-05-01

    We discuss the mechanism of cluster formation in a numerical simulation of a molecular cloud (MC) undergoing global hierarchical collapse, focusing on how the gas motions in the parent cloud control the assembly of the cluster. The global collapse implies that the star formation rate (SFR) increases over time. The collapse is hierarchical because it consists of small-scale collapses within larger scale ones. The latter culminate a few Myr later than the first small-scale ones and consist of filamentary flows that accrete on to massive central clumps. The small-scale collapses consist of clumps that are embedded in the filaments and falling on to the large-scale collapse centres. The stars formed in the early, small-scale collapses share the infall motion of their parent clumps, so that the filaments feed both gas and stars to the massive central clump. This process leads to the presence of a few older stars in a region where new protostars are forming, and also to a self-similar structure, in which each unit is composed of smaller scale subunits that approach each other and may merge. Because the older stars formed in the filaments share the infall motion of the gas on to the central clump, they tend to have larger velocities and to be distributed over larger areas than the younger stars formed in the central clump. Finally, interpreting the initial mass function (IMF) simply as a probability distribution implies that massive stars only form once the local SFR is large enough to sample the IMF up to high masses. In combination with the increase of the SFR, this implies that massive stars tend to appear late in the evolution of the MC, and only in the central massive clumps. We discuss the correspondence of these features with observed properties of young stellar clusters, finding very good qualitative agreement.

  9. The Triply Eclipsing Hierarchical Triple Star KIC002856960

    Science.gov (United States)

    Lee, Jae Woo; Kim, Seung-Lee; Lee, Chung-Uk; Lee, Byeong-Cheol; Park, Byeong-Gon; Hinse, Tobias Cornelius

    2013-02-01

    In a recent study, Armstrong et al. presented an eclipsing binary star of about 6.2 hr period with transit-like tertiary signals occurring every 204.2 days in the Kepler public data of KIC002856960 and proposed three possible hierarchical structures: (AB)b, (AB)C, and A(BC). We analyzed the Kepler light curve by including a third light source and one starspot on each binary component. The results represent that the close eclipsing pair is in a low-mass eccentric-orbit, detached configuration. Based on 123 eclipse timings calculated from the Wilson-Devinney binary model, a period study of the close binary reveals that the orbital period has experienced a sinusoidal variation with a period and a semi-amplitude of 205 ± 2 days and 0.0021 ± 0.0002 days, respectively. The period variation would be produced by the light-travel-time effect due to a gravitationally bound third body with a minimum mass of M 3sin i 3 = 0.76 M ⊙ in an eccentric orbit of e 3 = 0.61. This is consistent with the presence of third light found in our light curve solution and the tertiary signal of 204.2 day period most likely arises from the K-type star crossed by the close eclipsing binary. Then, KIC002856960 is a triply eclipsing hierarchical system, A(BC), consisting of a close binary with two M-type dwarfs and a more massive K-type component. The presence of the third star may have played an important role in the formation and evolution of the close pair, which may ultimately evolve into a contact system by angular momentum loss.

  10. Removal of Pertechnetate-Related Oxyanions from Solution Using Functionalized Hierarchical Porous Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Debasis [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; Elsaidi, Sameh K. [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; Chemistry Department, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia Alexandria 21321 Egypt; Aguila, Briana [Department of Chemistry, University of South Florida, USA; Li, Baiyan [Department of Chemistry, University of South Florida, USA; Kim, Dongsang [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Schweiger, Michael J. [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Kruger, Albert A. [US Department of Energy, Office of River Protection, Richland WA 99352 USA; Doonan, Christian J. [Department of Chemistry, The University of Adelaide, Adelaide South Australia 5005 Australia; Ma, Shengqian [Department of Chemistry, University of South Florida, USA; Thallapally, Praveen K. [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA

    2016-10-20

    Efficient and cost-effective removal of radioactive pertechnetate anions from nuclear waste is a key challenge to mitigate long-term nuclear waste storage issues. Traditional materials such as resins and layered double hydroxides (LDHs) were evaluated for their pertechnetate or perrhenate (the non-radioactive surrogate) removal capacity, but there is room for improvement in terms of capacity, selectivity and kinetics. A series of functionalized hierarchical porous frameworks were evaluated for their perrhenate removal capacity in the presence of other competing anions.

  11. Hierarchical Control of Droop-Controlled DC and AC Microgrids - A General Approach Towards Standardization

    DEFF Research Database (Denmark)

    Guerrero, Josep M.; Vásquez, Juan V.; Teodorescu, Remus

    2009-01-01

    DC and AC Microgrids are key elements to integrate renewable and distributed energy resources as well as distributed energy storage systems. In the last years, efforts toward the standardization of these Microgrids have been made. In this sense, this paper present the hierarchical control derived...... the deviations produced by the primary control; and iii) the tertiary control manage the power flow between the microgrid and the external electrical distribution system. Results from a hierarchicalcontrolled microgrid are provided to show the feasibility of the proposed approach....

  12. Storage and flood routing

    Science.gov (United States)

    Carter, R.W.; Godfrey, R.G.

    1960-01-01

    The basic equations used in flood routing are developed from the law of continuity. In each method the assumptions are discussed to enable the user to select an appropriate technique. In the stage-storage method the storage is related to the mean gage height in the reach under consideration. In the discharge-storage method the storage is determined, from weighted values of inflow and outflow discharge. In the reservoir-storage method the storage is considered as a function of outflow discharge alone. A detailed example is given for each method to illustrate that particular technique.

  13. Massive Storage Systems

    Institute of Scientific and Technical Information of China (English)

    Dan Feng; Hai Jin

    2006-01-01

    To accommodate the explosively increasing amount of data in many areas such as scientific computing and e-Business, physical storage devices and control components have been separated from traditional computing systems to become a scalable, intelligent storage subsystem that, when appropriately designed, should provide transparent storage interface, effective data allocation, flexible and efficient storage management, and other impressive features. The design goals and desirable features of such a storage subsystem include high performance, high scalability, high availability, high reliability and high security. Extensive research has been conducted in this field by researchers all over the world, yet many issues still remain open and challenging. This paper studies five different online massive storage systems and one offline storage system that we have developed with the research grant support from China. The storage pool with multiple network-attached RAIDs avoids expensive store-and-forward data copying between the server and storage system, improving data transfer rate by a factor of 2-3 over a traditional disk array. Two types of high performance distributed storage systems for local-area network storage are introduced in the paper. One of them is the Virtual Interface Storage Architecture (VISA) where VI as a communication protocol replaces the TCP/IP protocol in the system. VISA's performance is shown to achieve better than that of IP SAN by designing and implementing the vSCSI (VI-attached SCSI) protocol to support SCSI commands in the VI network. The other is a fault-tolerant parallel virtual file system that is designed and implemented to provide high I/O performance and high reliability. A global distributed storage system for wide-area network storage is discussed in detail in the paper, where a Storage Service Provider is added to provide storage service and plays the role of user agent for the storage system. Object based Storage Systems not only

  14. 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

  15. INTEGRATED HYDROGEN STORAGE SYSTEM MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, B

    2007-11-16

    Hydrogen storage is recognized as a key technical hurdle that must be overcome for the realization of hydrogen powered vehicles. Metal hydrides and their doped variants have shown great promise as a storage material and significant advances have been made with this technology. In any practical storage system the rate of H2 uptake will be governed by all processes that affect the rate of mass transport through the bed and into the particles. These coupled processes include heat and mass transfer as well as chemical kinetics and equilibrium. However, with few exceptions, studies of metal hydrides have focused primarily on fundamental properties associated with hydrogen storage capacity and kinetics. A full understanding of the complex interplay of physical processes that occur during the charging and discharging of a practical storage system requires models that integrate the salient phenomena. For example, in the case of sodium alanate, the size of NaAlH4 crystals is on the order of 300nm and the size of polycrystalline particles may be approximately 10 times larger ({approx}3,000nm). For the bed volume to be as small as possible, it is necessary to densely pack the hydride particles. Even so, in packed beds composed of NaAlH{sub 4} particles alone, it has been observed that the void fraction is still approximately 50-60%. Because of the large void fraction and particle to particle thermal contact resistance, the thermal conductivity of the hydride is very low, on the order of 0.2 W/m-{sup o}C, Gross, Majzoub, Thomas and Sandrock [2002]. The chemical reaction for hydrogen loading is exothermic. Based on the data in Gross [2003], on the order of 10{sup 8}J of heat of is released for the uptake of 5 kg of H{sub 2}2 and complete conversion of NaH to NaAlH{sub 4}. Since the hydride reaction transitions from hydrogen loading to discharge at elevated temperatures, it is essential to control the temperature of the bed. However, the low thermal conductivity of the hydride

  16. Performance of hydrogen storage of carbon nanotubes decorated with palladium

    Institute of Scientific and Technical Information of China (English)

    木士春; 唐浩林; 钱胜浩; 潘牧; 袁润章

    2004-01-01

    Carbon nanotubes(CNTs) decorated with palladium were synthesized and applied to hydrogen storage of gas phase. The results show that the amount of hydrogen storage of the decorated CNTs is up to 3.9 % (mass fraction), of which, almost 85% H2 can be desorbed at ambient temperature and pressure, while the non-decorated CNTs has a poor performance of hydrogen storage(only about 0.5% H2, mass fraction). These indicate that it is feasible to enhance the performance of hydrogen storage of CNTs by further decoration with hydrogen-storing metals or alloys.

  17. A Framework for Hierarchical Clustering Based Indexing in Search Engines

    Directory of Open Access Journals (Sweden)

    Parul Gupta

    2011-01-01

    Full Text Available Granting efficient and fast accesses to the index is a key issuefor performances of Web Search Engines. In order to enhancememory utilization and favor fast query resolution, WSEs useInverted File (IF indexes that consist of an array of theposting lists where each posting list is associated with a termand contains the term as well as the identifiers of the documentscontaining the term. Since the document identifiers are stored insorted order, they can be stored as the difference between thesuccessive documents so as to reduce the size of the index. Thispaper describes a clustering algorithm that aims atpartitioning the set of documents into ordered clusters so thatthe documents within the same cluster are similar and are beingassigned the closer document identifiers. Thus the averagevalue of the differences between the successive documents willbe minimized and hence storage space would be saved. Thepaper further presents the extension of this clustering algorithmto be applied for the hierarchical clustering in which similarclusters are clubbed to form a mega cluster and similar megaclusters are then combined to form super cluster. Thus thepaper describes the different levels of clustering whichoptimizes the search process by directing the searchto a specific path from higher levels of clustering to the lowerlevels i.e. from super clusters to mega clusters, then to clustersand finally to the individual documents so that the user gets thebest possible matching results in minimum possible time.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Fuel storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Donakowski, T.D.; Tison, R.R.

    1979-08-01

    Storage technologies are characterized for solid, liquid, and gaseous fuels. Emphasis is placed on storage methods applicable to Integrated Community Energy Systems based on coal. Items discussed here include standard practice, materials and energy losses, environmental effects, operating requirements, maintenance and reliability, and cost considerations. All storage systems were found to be well-developed and to represent mature technologies; an exception may exist for low-Btu gas storage, which could have materials incompatability.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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...

  20. Thermal energy storage

    Science.gov (United States)

    1980-01-01

    The planning and implementation of activities associated with lead center management role and the technical accomplishments pertaining to high temperature thermal energy storage subsystems are described. Major elements reported are: (1) program definition and assessment; (2) research and technology development; (3) industrial storage applications; (4) solar thermal power storage applications; and (5) building heating and cooling applications.

  1. Pit Water Storage Ottrupgaard

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    The pit water storage, a seasonal thermal storage, was built in 1993 with floating lid and hybrid clay-polymer for pit lining. The storage was leaking severe and solutions were to be found. In the paper solutions for pit lining and floating lids are discussed, cost estimations given and coming...

  2. Pit Water Storage Ottrupgaard

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    The pit water storage, a seasonal thermal storage, was built in 1993 with floating lid and hybrid clay-polymer for pit lining. The storage was leaking severe and solutions were to be found. In the paper solutions for pit lining and floating lids are discussed, cost estimations given and coming...

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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.

  8. 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.

  9. 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...

  10. 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).

  11. Correlation Between Hierarchical Bayesian and Aerosol Optical Depth PM2.5 Data and Respiratory-Cardiovascular Chronic Diseases

    Science.gov (United States)

    Tools to estimate PM2.5 mass have expanded in recent years, and now include: 1) stationary monitor readings, 2) Community Multi-Scale Air Quality (CMAQ) model estimates, 3) Hierarchical Bayesian (HB) estimates from combined stationary monitor readings and CMAQ model output; and, ...

  12. Unleashed Microactuators electrostatic wireless actuation for probe-based data storage

    NARCIS (Netherlands)

    Hoexum, A.M.

    2007-01-01

    Summary A hierarchical overview of the currently available data storage systems for desktop computer systems can be visualised as a pyramid in which the height represents both the price per bit and the access rate. The width of the pyramid represents the capacity of the medium. At the bottom slow,

  13. Unleashed Microactuators electrostatic wireless actuation for probe-based data storage

    NARCIS (Netherlands)

    Hoexum, A.M.

    2007-01-01

    Summary A hierarchical overview of the currently available data storage systems for desktop computer systems can be visualised as a pyramid in which the height represents both the price per bit and the access rate. The width of the pyramid represents the capacity of the medium. At the bottom slow, c

  14. A Wireless Power Sharing Control Strategy for Hybrid Energy Storage Systems in DC Microgrids

    DEFF Research Database (Denmark)

    Yang, Jie; Jin, Xinmin; Wu, Xuezhi

    2017-01-01

    In order to compensate multiple time scales power fluctuation resulted from distributed energy resources and loads, hybrid energy storage systems are employed as the buffer unit in DC microgrid. In this paper, a wireless hierarchical control strategy is proposed to realize power sharing between...

  15. Multi-Organ Contribution to the Metabolic Plasma Profile Using Hierarchical Modelling.

    Directory of Open Access Journals (Sweden)

    Frida Torell

    Full Text Available Hierarchical modelling was applied in order to identify the organs that contribute to the levels of metabolites in plasma. Plasma and organ samples from gut, kidney, liver, muscle and pancreas were obtained from mice. The samples were analysed using gas chromatography time-of-flight mass spectrometry (GC TOF-MS at the Swedish Metabolomics centre, Umeå University, Sweden. The multivariate analysis was performed by means of principal component analysis (PCA and orthogonal projections to latent structures (OPLS. The main goal of this study was to investigate how each organ contributes to the metabolic plasma profile. This was performed using hierarchical modelling. Each organ was found to have a unique metabolic profile. The hierarchical modelling showed that the gut, kidney and liver demonstrated the greatest contribution to the metabolic pattern of plasma. For example, we found that metabolites were absorbed in the gut and transported to the plasma. The kidneys excrete branched chain amino acids (BCAAs and fatty acids are transported in the plasma to the muscles and liver. Lactic acid was also found to be transported from the pancreas to plasma. The results indicated that hierarchical modelling can be utilized to identify the organ contribution of unknown metabolites to the metabolic profile of plasma.

  16. Hierarchically structured composites for ultrafast liquid sensing and smart leak-plugging.

    Science.gov (United States)

    Wu, Xiaodong; Han, Yangyang; Zhang, Xinxing; Lu, Canhui

    2017-06-21

    Conductive polymer composites (CPCs) have been intensively exploited as remarkable liquid sensing materials based on variations in their conductivity under liquid stimuli. However, most advances in liquid sensing CPCs are limited to bulk materials. Due to the slow permeation of liquids into the compact CPCs, sluggish responses are inevitable for most existing CPC-based liquid sensing materials. Here, we developed a new class of liquid sensing materials via a hierarchical structure design. Specifically, a thin CPC layer with a segregated conductive network was coated on porous polyurethane (PU) skeletons by layer-by-layer assembly, forming an elaborately designed hierarchical structure in the prepared CPC@PU composites. With this hierarchical structure, the CPC@PU composites exhibited ultrafast responses (0.05-0.15 s) to solvent stimuli, which are ∼3 orders of magnitude faster than the state-of-the-art composites. After liquid sensing, quick regeneration (within 10 s) could be achieved under hot-air. Accordingly, organic liquid and gas sensors and liquid-sensing electronic skins were fabricated. Furthermore, we prepared smart and fast leak-plugging materials using the CPC@PU composites based on the swelling-induced blocking of micropores in the materials. This structural strategy proposed here opens up exciting avenues towards manufacturing real-time liquid sensing and plugging materials, revealing potential applications in oilfield exploitation, solvent storage/transportation, environmental monitoring, etc.

  17. Cloud storage for dummies

    CERN Document Server

    Xu, Linda; Loughlin, Tanya

    2010-01-01

    Understand cloud computing and save your organization time and money! Cloud computing is taking IT by storm, but what is it and what are the benefits to your organization? Hitachi Data Systems' Cloud Storage For Dummies provides all the answers, With this book, you discover a clear explanation of cloud storage, and tips for how to choose the right type of cloud storage for your organization's needs. You also find out how cloud storage can free up valuable IT resources, saving time and money. Cloud Storage For Dummies presents useful information on setting up a

  18. A Novel Dynamic Physical Storage Model for Vehicle Navigation Maps

    Directory of Open Access Journals (Sweden)

    Shaohua Wang

    2016-04-01

    Full Text Available The physical storage model is one of the key technologies for vehicle navigation maps used in a navigation system. However, the performance of most traditional storage models is limited in dynamic navigation due to the static storage format they use. In this paper, we proposed a new physical storage model, China Navigation Data Format (CNDF, which helped access and update the navigation data. The CNDF model used the reach-based hierarchy method to build a road hierarchal network, which enhanced the efficiency of data compression. It also adopted the Linear Link Coding method, in which the start position was combined with the end position as the identification code for multi-level links, and each link traced up-level links consistently without recording the array of identifications. The navigation map of East China (including Beijing, Tianjin, Shandong, Hebei, and Jiangsu at 1:10,000, generated using the CNDF model, and the real time traffic information in Beijing were combined to test the performance of a navigation system using an embedded navigation device. Results showed that it cost less than 1 second each time to refresh the navigation map, and the accuracy of the hierarchal shortest-path algorithm was 99.9%. Our work implied that the CNDF model is efficient in vehicle navigation applications.

  19. DCMDSM: a DICOM decomposed storage model.

    Science.gov (United States)

    Savaris, Alexandre; Härder, Theo; von Wangenheim, Aldo

    2014-01-01

    To design, build, and evaluate a storage model able to manage heterogeneous digital imaging and communications in medicine (DICOM) images. The model must be simple, but flexible enough to accommodate variable content without structural modifications; must be effective on answering query/retrieval operations according to the DICOM standard; and must provide performance gains on querying/retrieving content to justify its adoption by image-related projects. The proposal adapts the original decomposed storage model, incorporating structural and organizational characteristics present in DICOM image files. Tag values are stored according to their data types/domains, in a schema built on top of a standard relational database management system (RDBMS). Evaluation includes storing heterogeneous DICOM images, querying metadata using a variable number of predicates, and retrieving full-content images for different hierarchical levels. When compared to a well established DICOM image archive, the proposal is 0.6-7.2 times slower in storing content; however, in querying individual tags, it is about 48.0% faster. In querying groups of tags, DICOM decomposed storage model (DCMDSM) is outperformed in scenarios with a large number of tags and low selectivity (being 66.5% slower); however, when the number of tags is balanced with better selectivity predicates, the performance gains are up to 79.1%. In executing full-content retrieval, in turn, the proposal is about 48.3% faster. DCMDSM is a model built for the storage of heterogeneous DICOM content, based on a straightforward database design. The results obtained through its evaluation attest its suitability as a storage layer for projects where DICOM images are stored once, and queried/retrieved whenever necessary. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  20. The Triply Eclipsing Hierarchical Triple Star KIC002856960

    CERN Document Server

    Lee, Jae Woo; Lee, Chung-Uk; Lee, Byeong-Cheol; Park, Byeong-Gon; Hinse, Tobias Cornelius

    2012-01-01

    In a recent study, Armstrong et al. presented an eclipsing binary star of about 6.2 h period with transit-like tertiary signals occurring every 204.2 d in the {\\it Kepler} public data of KIC002856960 and proposed three possible hierarchical structures: (AB)b, (AB)C, and A(BC). We analyzed the {\\it Kepler} light curve by including a third light source and one starspot on each binary component. The results represent that the close eclipsing pair is in a low-mass eccentric-orbit, detached configuration. Based on 123 eclipse timings calculated from the Wilson-Devinney binary model, a period study of the close binary reveals that the orbital period has experienced a sinusoidal variation with a period and a semi-amplitude of 205$\\pm$2 d and 0.0021$\\pm$0.0002 d, respectively. The period variation would be produced by the light-travel-time effect due to a gravitationally-bound third body with a minimum mass of $M_3 \\sin i_3$=0.76 M$_\\odot$ in an eccentric orbit of $e_3$=0.61. This is consistent with the presence of t...

  1. The fragmentation and stability of hierarchical structure in Serpens South

    CERN Document Server

    Friesen, R K; Di Francesco, J; Gutermuth, R; Myers, P C

    2016-01-01

    Filamentary structures are ubiquitous in molecular clouds, and have been recently argued to play an important role in regulating the size and mass of embedded clumps through fragmentation and mass accretion. Here, we reveal the dynamical state and fragmentation of filamentary molecular gas associated with the Serpens South protocluster through analysis of wide (~4 x 4 pc) observations of NH3 (1,1) and (2,2) inversion transitions with the Green Bank Telescope. Detailed modeling of the NH3 lines reveals that the kinematics of the cluster and surrounding filaments are complex. We identify hierarchical structure using a dendrogram analysis of the NH3 emission. The distance between neighbour structures that are embedded within the same parent structure is generally greater than expected from a spherical Jeans analysis, and is in better agreement with cylindrical fragmentation models. The NH3 line width-size relation is flat, and average gas motions are sub- or trans-sonic over all physical scales observed. Subsoni...

  2. 物联网感知层一种分层访问控制方案%A Hierarchical Access Control Scheme for Perceptual Layer of IoT

    Institute of Scientific and Technical Information of China (English)

    马骏; 郭渊博; 马建峰; 熊金波; 张涛

    2013-01-01

    在物联网感知层中,用于信息采集的感知层节点需要根据隐私、安全或定制消费等需要,按不同级别提供授权用户的数据访问,这导致传统的访问控制方案无法满足用户安全高效的按需访问需求.为此,提出了一种分层访问控制方案.将同安全级别感知节点划分为一个层次节点,由层次节点之间形成的偏序关系构成一个分层的访问控制模型.本方案的优势体现在:每个用户和分层节点仅存储单个密钥材料,通过密钥推导获得访问当前及下层所有资源的密钥值,减少存储开销的同时提高了系统的安全强度;支持层次节点的动态扩展及密钥材料的动态更新;满足标准模型下的可证明安全及其他扩展安全.分析表明,方案能很好地满足物联网感知层的访问控制需求.%The perceptual layer is at the most front-end of information collection,which plays a fundamental role in the Internet of Things (IoT).In the perceptual layer,mass perceptual nodes are required to sense a vast range of different data types for authorized users in accordance with privacy,security,and customization.This leads to the problem that traditional access control schemes (IBAC,RBAC etc.) fail to meet the requirements of users who want secure and efficient access resources ondemand.In this paper,a hierarchical access control scheme for perceptual layer of the IoT is presented.In the scheme,every hierarchical node,representing a class in the access hierarchy,is composed of perceptual nodes which provide information with the same levels of security.More hierarchical nodes can be modeled as a set of partially ordered classes.Besides,the scheme considers the limited computational and storage capacity of mass perceptual nodes.Compared with previous proposals,the scheme has the following advantages:Every user and perceptual node possesses a single key material to get some keys by a deterministic key derivation algorithm

  3. Facile Carbonization of Microporous Organic Polymers into Hierarchically Porous Carbons Targeted for Effective CO2 Uptake at Low Pressures.

    Science.gov (United States)

    Gu, Shuai; He, Jianqiao; Zhu, Yunlong; Wang, Zhiqiang; Chen, Dongyang; Yu, Guipeng; Pan, Chunyue; Guan, Jianguo; Tao, Kai

    2016-07-20

    The advent of microporous organic polymers (MOPs) has delivered great potential in gas storage and separation (CCS). However, the presence of only micropores in these polymers often imposes diffusion limitations, which has resulted in the low utilization of MOPs in CCS. Herein, facile chemical activation of the single microporous organic polymers (MOPs) resulted in a series of hierarchically porous carbons with hierarchically meso-microporous structures and high CO2 uptake capacities at low pressures. The MOPs precursors (termed as MOP-7-10) with a simple narrow micropore structure obtained in this work possess moderate apparent BET surface areas ranging from 479 to 819 m(2) g(-1). By comparing different activating agents for the carbonization of these MOPs matrials, we found the optimized carbon matrials MOPs-C activated by KOH show unique hierarchically porous structures with a significant expansion of dominant pore size from micropores to mesopores, whereas their microporosity is also significantly improved, which was evidenced by a significant increase in the micropore volume (from 0.27 to 0.68 cm(3) g(-1)). This maybe related to the collapse and the structural rearrangement of the polymer farmeworks resulted from the activation of the activating agent KOH at high temperature. The as-made hierarchically porous carbons MOPs-C show an obvious increase in the BET surface area (from 819 to 1824 m(2) g(-1)). And the unique hierarchically porous structures of MOPs-C significantly contributed to the enhancement of the CO2 capture capacities, which are up to 214 mg g(-1) (at 273 K and 1 bar) and 52 mg g(-1) (at 273 K and 0.15 bar), superior to those of the most known MOPs and porous carbons. The high physicochemical stabilities and appropriate isosteric adsorption heats as well as high CO2/N2 ideal selectivities endow these hierarchically porous carbon materials great potential in gas sorption and separation.

  4. Dependable Benchmarking for Storage Systems in High-Energy Physics

    CERN Document Server

    Fleri Soler, Edward

    2017-01-01

    In high-energy physics, storage systems play a crucial role to store and secure very valuable data produced by complex experiments. The effectiveness and efficiency of data acquisition systems of such experiments depends directly on those of these storage systems. Coping with present day rates and reliability requirements of such experiments implies operating high-performance hardware under the best possible conditions, with a broad set of hardware and software parameters existing along the hierarchical levels, from networks down to drives. An extensive number of tests are required for the tuning of parameters to achieve optimised I/O operations. Current approaches to I/O optimisation generally consist of manual test execution and result taking. This approach lacks appropriate modularity, durability and reproducibility, attainable through dedicated testing facilities. The aim of this project is to conceive a user-friendly, dedicated storage benchmarking tool for the improved comparison of I/O parameters in re...

  5. Hydrogen Storage Properties of Ti1.2Fe+xCa Hydrogen Storage Alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The hydrogen storage properties of Ti1.2Fe+xCa (x=1%, 3% and 5% in mass fraction) alloys was investigated. Results show that the modified alloys can be activated without any thermal treatment at room temperature due to the addition of Ca and excess Ti in the alloys. Hydrogen storage properties of these modified alloys vary with Ca amount and reaction temperature. In addition, the influence mechanism of the addition of Ca and excessive Ti on the activation behavior and hydrogen storage capacity of the alloys was discussed.

  6. 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.

  7. 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

  8. Generation of Hierarchically Ordered Structures on a Polymer Film by Electrohydrodynamic Structure Formation.

    Science.gov (United States)

    Tian, Hongmiao; Shao, Jinyou; Hu, Hong; Wang, Li; Ding, Yucheng

    2016-06-29

    The extensive applications of hierarchical structures in optoelectronics, micro/nanofluidics, energy conservation, etc., have led to the development of a variety of approaches for their fabrication, which can be categorized as bottom-up or top-down strategies. Current bottom-up and top-down strategies bear a complementary relationship to each other due to their processing characteristics, i.e., the advantages of one method correspond to the disadvantages of the other, and vice versa. Here we propose a novel method based on electrohydrodynamic structure formation, aimed at combining the main advantages of the two strategies. The method allows the fabrication of a hierarchically ordered structure with well-defined geometry and high mechanical durability on a polymer film, through a simple and low-cost process also suitable for mass-production. In this approach, upon application of an electric field between a template and a substrate sandwiching an air gap and a polymer film, the polymer is pulled toward the template and further flows into the template cavities, resulting in a hierarchical structure with primary and secondary patterns determined by electrohydrodynamic instability and by the template features, respectively. In this work, the fabrication of a hierarchical structure by electrohydrodynamic structure formation is studied using numerical simulations and experimental tests. The proposed method is then employed for the one-step fabrication of a hierarchical structure exhibiting a gradual transition in the periodicity of the primary structure using a slant template and a flat polymer film, which presents an excellent performance on controllable wettability.

  9. 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.

  10. 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.

  11. 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.

  12. Hierarchical Control for Multiple DC Microgrids Clusters

    DEFF Research Database (Denmark)

    Shafiee, Qobad; Dragicevic, Tomislav; Vasquez, Juan Carlos;

    2014-01-01

    This paper presents a distributed hierarchical control framework to ensure reliable operation of dc Microgrid (MG) clusters. In this hierarchy, primary control is used to regulate the common bus voltage inside each MG locally. An adaptive droop method is proposed for this level which determines....... Another distributed policy is employed then to regulate the power flow among the MGs according to their local SOCs. The proposed distributed controllers on each MG communicate with only the neighbor MGs through a communication infrastructure. Finally, the small signal model is expanded for dc MG clusters...

  13. A Hierarchical Framework for Facial Age Estimation

    Directory of Open Access Journals (Sweden)

    Yuyu Liang

    2014-01-01

    Full Text Available Age estimation is a complex issue of multiclassification or regression. To address the problems of uneven distribution of age database and ignorance of ordinal information, this paper shows a hierarchic age estimation system, comprising age group and specific age estimation. In our system, two novel classifiers, sequence k-nearest neighbor (SKNN and ranking-KNN, are introduced to predict age group and value, respectively. Notably, ranking-KNN utilizes the ordinal information between samples in estimation process rather than regards samples as separate individuals. Tested on FG-NET database, our system achieves 4.97 evaluated by MAE (mean absolute error for age estimation.

  14. A hierarchical classification scheme of psoriasis images

    DEFF Research Database (Denmark)

    Maletti, Gabriela Mariel; Ersbøll, Bjarne Kjær

    2003-01-01

    the normal skin in the second stage. These tools are the Expectation-Maximization Algorithm, the quadratic discrimination function and a classification window of optimal size. Extrapolation of classification parameters of a given image to other images of the set is evaluated by means of Cohen's Kappa......A two-stage hierarchical classification scheme of psoriasis lesion images is proposed. These images are basically composed of three classes: normal skin, lesion and background. The scheme combines conventional tools to separate the skin from the background in the first stage, and the lesion from...

  15. Renormalization of Hierarchically Interacting Isotropic Diffusions

    Science.gov (United States)

    den Hollander, F.; Swart, J. M.

    1998-10-01

    We study a renormalization transformation arising in an infinite system of interacting diffusions. The components of the system are labeled by the N-dimensional hierarchical lattice ( N≥2) and take values in the closure of a compact convex set bar D subset {R}^d (d ≥slant 1). Each component starts at some θ ∈ D and is subject to two motions: (1) an isotropic diffusion according to a local diffusion rate g: bar D to [0,infty ] chosen from an appropriate class; (2) a linear drift toward an average of the surrounding components weighted according to their hierarchical distance. In the local mean-field limit N→∞, block averages of diffusions within a hierarchical distance k, on an appropriate time scale, are expected to perform a diffusion with local diffusion rate F ( k) g, where F^{(k)} g = (F_{c_k } circ ... circ F_{c_1 } ) g is the kth iterate of renormalization transformations F c ( c>0) applied to g. Here the c k measure the strength of the interaction at hierarchical distance k. We identify F c and study its orbit ( F ( k) g) k≥0. We show that there exists a "fixed shape" g* such that lim k→∞ σk F ( k) g = g* for all g, where the σ k are normalizing constants. In terms of the infinite system, this property means that there is complete universal behavior on large space-time scales. Our results extend earlier work for d = 1 and bar D = [0,1], resp. [0, ∞). The renormalization transformation F c is defined in terms of the ergodic measure of a d-dimensional diffusion. In d = 1 this diffusion allows a Yamada-Watanabe-type coupling, its ergodic measure is reversible, and the renormalization transformation F c is given by an explicit formula. All this breaks down in d≥2, which complicates the analysis considerably and forces us to new methods. Part of our results depend on a certain martingale problem being well-posed.

  16. Hierarchical silica particles by dynamic multicomponent assembly

    DEFF Research Database (Denmark)

    Wu, Z. W.; Hu, Q. Y.; Pang, J. B.

    2005-01-01

    Abstract: Aerosol-assisted assembly of mesoporous silica particles with hierarchically controllable pore structure has been prepared using cetyltrimethylammonium bromide (CTAB) and poly(propylene oxide) (PPO, H[OCH(CH3)CH2],OH) as co-templates. Addition of the hydrophobic PPO significantly influe......-silicate assembling system was discussed. The mesostructure of these particles was characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), and N-2 sorption. (c) 2005 Elsevier Inc. All rights reserved....

  17. Constructing storyboards based on hierarchical clustering analysis

    Science.gov (United States)

    Hasebe, Satoshi; Sami, Mustafa M.; Muramatsu, Shogo; Kikuchi, Hisakazu

    2005-07-01

    There are growing needs for quick preview of video contents for the purpose of improving accessibility of video archives as well as reducing network traffics. In this paper, a storyboard that contains a user-specified number of keyframes is produced from a given video sequence. It is based on hierarchical cluster analysis of feature vectors that are derived from wavelet coefficients of video frames. Consistent use of extracted feature vectors is the key to avoid a repetition of computationally-intensive parsing of the same video sequence. Experimental results suggest that a significant reduction in computational time is gained by this strategy.

  18. Technique for fast and efficient hierarchical clustering

    Science.gov (United States)

    Stork, Christopher

    2013-10-08

    A fast and efficient technique for hierarchical clustering of samples in a dataset includes compressing the dataset to reduce a number of variables within each of the samples of the dataset. A nearest neighbor matrix is generated to identify nearest neighbor pairs between the samples based on differences between the variables of the samples. The samples are arranged into a hierarchy that groups the samples based on the nearest neighbor matrix. The hierarchy is rendered to a display to graphically illustrate similarities or differences between the samples.

  19. Robust Pseudo-Hierarchical Support Vector Clustering

    DEFF Research Database (Denmark)

    Hansen, Michael Sass; Sjöstrand, Karl; Olafsdóttir, Hildur

    2007-01-01

    Support vector clustering (SVC) has proven an efficient algorithm for clustering of noisy and high-dimensional data sets, with applications within many fields of research. An inherent problem, however, has been setting the parameters of the SVC algorithm. Using the recent emergence of a method...... for calculating the entire regularization path of the support vector domain description, we propose a fast method for robust pseudo-hierarchical support vector clustering (HSVC). The method is demonstrated to work well on generated data, as well as for detecting ischemic segments from multidimensional myocardial...

  20. Additive Manufacturing of Hierarchical Porous Structures

    Energy Technology Data Exchange (ETDEWEB)

    Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division. Polymers and Coatings

    2016-08-30

    Additive manufacturing has become a tool of choice for the development of customizable components. Developments in this technology have led to a powerful array of printers that t serve a variety of needs. However, resin development plays a crucial role in leading the technology forward. This paper addresses the development and application of printing hierarchical porous structures. Beginning with the development of a porous scaffold, which can be functionalized with a variety of materials, and concluding with customized resins for metal, ceramic, and carbon structures.

  1. An introduction to hierarchical linear modeling

    Directory of Open Access Journals (Sweden)

    Heather Woltman

    2012-02-01

    Full Text Available 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. The first section of the tutorial defines HLM, clarifies its purpose, and states its advantages. The second section explains the mathematical theory, equations, and conditions underlying HLM. HLM hypothesis testing is performed in the third section. Finally, the fourth section provides a practical example of running HLM, with which readers can follow along. Throughout this tutorial, emphasis is placed on providing a straightforward overview of the basic principles of HLM.

  2. Magnetic susceptibilities of cluster-hierarchical models

    Science.gov (United States)

    McKay, Susan R.; Berker, A. Nihat

    1984-02-01

    The exact magnetic susceptibilities of hierarchical models are calculated near and away from criticality, in both the ordered and disordered phases. The mechanism and phenomenology are discussed for models with susceptibilities that are physically sensible, e.g., nondivergent away from criticality. Such models are found based upon the Niemeijer-van Leeuwen cluster renormalization. A recursion-matrix method is presented for the renormalization-group evaluation of response functions. Diagonalization of this matrix at fixed points provides simple criteria for well-behaved densities and response functions.

  3. Universality: Accurate Checks in Dyson's Hierarchical Model

    Science.gov (United States)

    Godina, J. J.; Meurice, Y.; Oktay, M. B.

    2003-06-01

    In this talk we present high-accuracy calculations of the susceptibility near βc for Dyson's hierarchical model in D = 3. Using linear fitting, we estimate the leading (γ) and subleading (Δ) exponents. Independent estimates are obtained by calculating the first two eigenvalues of the linearized renormalization group transformation. We found γ = 1.29914073 ± 10 -8 and, Δ = 0.4259469 ± 10-7 independently of the choice of local integration measure (Ising or Landau-Ginzburg). After a suitable rescaling, the approximate fixed points for a large class of local measure coincide accurately with a fixed point constructed by Koch and Wittwer.

  4. Hierarchical Classification of Chinese Documents Based on N-grams

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We explore the techniques of utilizing N-gram informatio n tocategorize Chinese text documents hierarchically so that the classifier can shak e off the burden of large dictionaries and complex segmentation processing, and subsequently be domain and time independent. A hierarchical Chinese text classif ier is implemented. Experimental results show that hierarchically classifying Chinese text documents based N-grams can achieve satisfactory performance and outperforms the other traditional Chinese text classifiers.

  5. Freestanding hierarchically porous carbon framework decorated by polyaniline as binder-free electrodes for high performance supercapacitors

    Science.gov (United States)

    Miao, Fujun; Shao, Changlu; Li, Xinghua; Wang, Kexin; Lu, Na; Liu, Yichun

    2016-10-01

    Freestanding hierarchically porous carbon electrode materials with favorable features of large surface areas, hierarchical porosity and continuous conducting pathways are very attractive for practical applications in electrochemical devices. Herein, three-dimensional freestanding hierarchically porous carbon (HPC) materials have been fabricated successfully mainly by the facile phase separation method. In order to further improve the energy storage ability, polyaniline (PANI) with high pseudocapacitance has been decorated on HPC through in situ chemical polymerization of aniline monomers. Benefiting from the synergistic effects between HPC and PANI, the resulting HPC/PANI composites as electrode materials present dramatic electrochemical performance with high specific capacitance up to 290 F g-1 at 0.5 A g-1 and good rate capability with ∼86% (248 F g-1) capacitance retention at 64 A g-1 of initial capacitance in three-electrode configuration. Moreover, the as-assembled symmetric supercapacitor based on HPC/PANI composites also demonstrates good capacitive properties with high energy density of 9.6 Wh kg-1 at 223 W kg-1 and long-term cycling stability with 78% capacitance retention after 10 000 cycles. Therefore, this work provides a new approach for designing high-performance electrodes with exceptional electrochemical performance, which are very promising for practical application in the energy storage field.

  6. Nanosheet-based hierarchical Ni(2)(CO(3))(OH)(2) microspheres with weak crystallinity for high-performance supercapacitor.

    Science.gov (United States)

    Zhu, Guoxing; Xi, Chunyan; Shen, Mengqi; Bao, Chunlin; Zhu, Jun

    2014-10-08

    Three-dimensionally hierarchical oxide/hydroxide materials have recently attracted increasing interest by virtue of their exciting potential in electrochemical energy conversion and storage. Herein, hierarchical Ni2(CO3)(OH)2 microspheres assembled from ultrathin nanosheets were successfully synthesized by a one-pot/one-step hydrothermal route. In this method, common nickel salts and urea were selected as raw materials. The influence of urea concentration on the final product was studied. The hierarchical Ni2(CO3)(OH)2 microspheres show weak crystallinity and contain crystalline water. It was found that they exhibit excellent rate capacity when used as supercapacitor electrode. Under current density of 0.5 and 10 A/g, the optimized Ni2(CO3)(OH)2 electrode with loading density of 5.3 mg/cm(2) exhibited specific capacitances of 1178 and 613 F/g with excellent cycling stability. The excellent electrochemical property is possibly attributed to the intrinsic nature of Ni2(CO3)(OH)2, the ultrathin thickness of nanosheet units, and the sufficient space available to interact with the electrolyte. This facile synthesis strategy and the good electrochemical properties indicate that hydroxycarbonates are promising materials for supercapacitor application. This study suggests a large library of materials for potential application in energy storage systems.

  7. Preparation of hierarchical porous carbon from waste printed circuit boards for high performance electric double-layer capacitors

    Science.gov (United States)

    Du, Xuan; Wang, Li; Zhao, Wei; Wang, Yi; Qi, Tao; Li, Chang Ming

    2016-08-01

    Renewable clean energy and resources recycling have become inevitable choices to solve worldwide energy shortages and environmental pollution problems. It is a great challenge to recycle tons of waste printed circuit boards (PCB) produced every year for clean environment while creating values. In this work, low cost, high quality activated carbons (ACs) were synthesized from non-metallic fractions (NMF) of waste PCB to offer a great potential for applications of electrochemical double-layer capacitors (EDLCs). After recovering metal from waste PCB, hierarchical porous carbons were produced from NMF by carbonization and activation processes. The experimental results exhibit that some pores were formed after carbonization due to the escape of impurity atoms introduced by additives in NMF. Then the pore structure was further tailored by adjusting the activation parameters. Roles of micropores and non-micropores in charge storage were investigated when the hierarchical porous carbons were applied as electrode of EDLCs. The highest specific capacitance of 210 F g-1 (at 50 mA g-1) and excellent rate capability were achieved when the ACs possessing a proper micropores/non-micropores ratio. This work not only provides a promising method to recycle PCB, but also investigates the structure tailoring arts for a rational hierarchical porous structure in energy storage/conversion.

  8. Hierarchical Porous ZSM-5 Zeolite Synthesized by in situ Zeolitization and Its Coke Deposition Resistance in Aromatization Reaction

    Institute of Scientific and Technical Information of China (English)

    张珂; 柳云骐; 赵晋翀; 刘晨光

    2012-01-01

    Hierarchical ZSM-5 zeolites with micro-, meso- and macroporosity were prepared from diatomite zeolitization through a vapor-phase transport process on solid surfaces. The aromatization performance of the catalysts was in- vestigated on a fixed bed reactor by using FCC gasoline as feedstock. The crystal phase, morphology, pore struc- tures, acidity and coke depositions of the hierarchical ZSM-5 zeolites were characterized by means of X-ray diffrac- tion (XRD), scanning electron microscope (SEM), N2 adsorption/desorption, Fourier transform infrared (FT-IR) and thermogravimetry-mass spectrogram (TG-MS), respectively. The results show that the prepared hierarchical ZSM-5 zeolite possesses excellent porosity and high crystallinity, displaying an improved aromatization performance and carbon deposition resistance due to its meso- and macroporous structures.

  9. Fractal image perception provides novel insights into hierarchical cognition.

    Science.gov (United States)

    Martins, M J; Fischmeister, F P; Puig-Waldmüller, E; Oh, J; Geissler, A; Robinson, S; Fitch, W T; Beisteiner, R

    2014-08-01

    Hierarchical structures play a central role in many aspects of human cognition, prominently including both language and music. In this study we addressed hierarchy in the visual domain, using a novel paradigm based on fractal images. Fractals are self-similar patterns generated by repeating the same simple rule at multiple hierarchical levels. Our hypothesis was that the brain uses different resources for processing hierarchies depending on whether it applies a "fractal" or a "non-fractal" cognitive strategy. We analyzed the neural circuits activated by these complex hierarchical patterns in an event-related fMRI study of 40 healthy subjects. Brain activation was compared across three different tasks: a similarity task, and two hierarchical tasks in which subjects were asked to recognize the repetition of a rule operating transformations either within an existing hierarchical level, or generating new hierarchical levels. Similar hierarchical images were generated by both rules and target images were identical. We found that when processing visual hierarchies, engagement in both hierarchical tasks activated the visual dorsal stream (occipito-parietal cortex, intraparietal sulcus and dorsolateral prefrontal cortex). In addition, the level-generating task specifically activated circuits related to the integration of spatial and categorical information, and with the integration of items in contexts (posterior cingulate cortex, retrosplenial cortex, and medial, ventral and anterior regions of temporal cortex). These findings provide interesting new clues about the cognitive mechanisms involved in the generation of new hierarchical levels as required for fractals.

  10. Geometrical phase transitions on hierarchical lattices and universality

    Science.gov (United States)

    Hauser, P. R.; Saxena, V. K.

    1986-12-01

    In order to examine the validity of the principle of universality for phase transitions on hierarchical lattices, we have studied percolation on a variety of hierarchical lattices, within exact position-space renormalization-group schemes. It is observed that the percolation critical exponent νp strongly depends on the topology of the lattices, even for lattices with the same intrinsic dimensions and connectivities. These results support some recent similar results on thermal phase transitions on hierarchical lattices and point out the possible violation of universality in phase transitions on hierarchical lattices.

  11. Atomic Storage States

    Institute of Scientific and Technical Information of China (English)

    汪凯戈; 朱诗尧

    2002-01-01

    We present a complete description of atomic storage states which may appear in the electromagnetically induced transparency (EIT). The result shows that the spatial coherence has been included in the atomic collective operators and the atomic storage states. In some limits, a set of multimode atomic storage states has been established in correspondence with the multimode Fock states of the electromagnetic field. This gives a better understanding of the fact that, in BIT, the optical coherent information can be preserved and recovered.

  12. Spacecraft Energy Storage Systems

    OpenAIRE

    Robinson, Wilf; Hanks, James; Spina, Len; Havenhill, Doug; Gisler, Gary; Ginter, Steve; Brault, Sharon

    1997-01-01

    Flywheel Energy Storage Systems represent an exciting alternative to traditional battery storage systems used to power satellites during periods of eclipse. The increasing demand for reliable communication and data access is driving explosive growth in the number of satellite systems being developed as well as their performance requirements. Power on orbit is the key to this performance, and batteries are becoming increasingly unattractive as an energy storage media. Flywheel systems offer ve...

  13. Carbon wrapped hierarchical Li3V2(PO4)3 microspheres for high performance lithium ion batteries.

    Science.gov (United States)

    Liang, Shuquan; Tan, Qinguang; Xiong, Wei; Tang, Yan; Tan, Xiaoping; Huang, Linjun; Pan, Anqiang; Cao, Guozhong

    2016-09-21

    Nanomaterials are extensively studied in electrochemical energy storage and conversion systems because of their structural advantages. However, their volumetric energy density still needs improvement due to the high surface area, especially the carbon based nanocomposites. Constructing hierarchical micro-scaled materials from closely stacked subunits is proposed as an effective way to solve the problem. In this work, Li3V2(PO4)3@carbon hierarchical microspheres are prepared by a solvothermal reaction and subsequent annealing. Hierarchical Li3V2(PO4)3 structures with different subunits are obtained with the aid of polyvinyl pyrrolidone (PVP). Moreover, excessive PVP interconnect and form PVP-based hydrogels, which later convert into conductive carbon layer on the surface of Li3V2(PO4)3 microspheres during the annealing process. As a cathode material for lithium ion batteries, the 3D carbon wrapped Li3V2(PO4)3 hierarchical microspheres exhibit high rate capability and excellent cycling stability. The electrode has the capacity retention of 80% after 5000 cycles even at 50C.

  14. Carbon wrapped hierarchical Li3V2(PO4)3 microspheres for high performance lithium ion batteries

    Science.gov (United States)

    Liang, Shuquan; Tan, Qinguang; Xiong, Wei; Tang, Yan; Tan, Xiaoping; Huang, Linjun; Pan, Anqiang; Cao, Guozhong

    2016-01-01

    Nanomaterials are extensively studied in electrochemical energy storage and conversion systems because of their structural advantages. However, their volumetric energy density still needs improvement due to the high surface area, especially the carbon based nanocomposites. Constructing hierarchical micro-scaled materials from closely stacked subunits is proposed as an effective way to solve the problem. In this work, Li3V2(PO4)3@carbon hierarchical microspheres are prepared by a solvothermal reaction and subsequent annealing. Hierarchical Li3V2(PO4)3 structures with different subunits are obtained with the aid of polyvinyl pyrrolidone (PVP). Moreover, excessive PVP interconnect and form PVP-based hydrogels, which later convert into conductive carbon layer on the surface of Li3V2(PO4)3 microspheres during the annealing process. As a cathode material for lithium ion batteries, the 3D carbon wrapped Li3V2(PO4)3 hierarchical microspheres exhibit high rate capability and excellent cycling stability. The electrode has the capacity retention of 80% after 5000 cycles even at 50C. PMID:27649860

  15. Energy Storage Flywheels on Spacecraft

    Science.gov (United States)

    Bartlett, Robert O.; Brown, Gary; Levinthal, Joel; Brodeur, Stephen (Technical Monitor)

    2002-01-01

    With advances in carbon composite material, magnetic bearings, microprocessors, and high-speed power switching devices, work has begun on a space qualifiable Energy Momentum Wheel (EMW). An EMW is a device that can be used on a satellite to store energy, like a chemical battery, and manage angular momentum, like a reaction wheel. These combined functions are achieved by the simultaneous and balanced operation of two or more energy storage flywheels. An energy storage flywheel typically consists of a carbon composite rotor driven by a brushless DC motor/generator. Each rotor has a relatively large angular moment of inertia and is suspended on magnetic bearings to minimize energy loss. The use of flywheel batteries on spacecraft will increase system efficiencies (mass and power), while reducing design-production time and life-cycle cost. This paper will present a discussion of flywheel battery design considerations and a simulation of spacecraft system performance utilizing four flywheel batteries to combine energy storage and momentum management for a typical LEO satellite. A proposed set of control laws and an engineering animation will also be presented. Once flight qualified and demonstrated, space flywheel batteries may alter the architecture of most medium and high-powered spacecraft.

  16. Regenerators with cellulose as storage material. Regeneratoren mit Cellulose als Speichermaterial

    Energy Technology Data Exchange (ETDEWEB)

    Schenk, J. (Inst. fuer Luft- und Kaeltetechnik, Dresden (Germany))

    1994-02-01

    Regenerators for heat and mass transfer are mostly based on storage materials made of aluminium or glass and ceramic fibres. For about 15 years, experience with storage masses made of cellulose paper has been available. A development carried out at the Institute for Air and Refrigeration Technology in Dresden led to the production of more than 1000 regenerative energy transfer units in the variant of heat exchanger as well as of enthalpy transfer units. At present, an advanced line of products of cellulose storage masses is prepared. The relations to be observed between microgeometry of the storage mass and performance data, such as transmission level and pressure loss, are presented. (orig.)

  17. Hierarchical prisoner’s dilemma in hierarchical game for resource competition

    Science.gov (United States)

    Fujimoto, Yuma; Sagawa, Takahiro; Kaneko, Kunihiko

    2017-07-01

    Dilemmas in cooperation are one of the major concerns in game theory. In a public goods game, each individual cooperates by paying a cost or defecting without paying it, and receives a reward from the group out of the collected cost. Thus, defecting is beneficial for each individual, while cooperation is beneficial for the group. Now, groups (say, countries) consisting of individuals also play games. To study such a multi-level game, we introduce a hierarchical game in which multiple groups compete for limited resources by utilizing the collected cost in each group, where the power to appropriate resources increases with the population of the group. Analyzing this hierarchical game, we found a hierarchical prisoner’s dilemma, in which groups choose the defecting policy (say, armament) as a Nash strategy to optimize each group’s benefit, while cooperation optimizes the total benefit. On the other hand, for each individual, refusing to pay the cost (say, tax) is a Nash strategy, which turns out to be a cooperation policy for the group, thus leading to a hierarchical dilemma. Here the group reward increases with the group size. However, we find that there exists an optimal group size that maximizes the individual payoff. Furthermore, when the population asymmetry between two groups is large, the smaller group will choose a cooperation policy (say, disarmament) to avoid excessive response from the larger group, and the prisoner’s dilemma between the groups is resolved. Accordingly, the relevance of this hierarchical game on policy selection in society and the optimal size of human or animal groups are discussed.

  18. Hierarchical Star Formation in Nearby LEGUS Galaxies

    CERN Document Server

    Elmegreen, Debra Meloy; Adamo, Angela; Aloisi, Alessandra; Andrews, Jennifer; Annibali, Francesca; Bright, Stacey N; Calzetti, Daniela; Cignoni, Michele; Evans, Aaron S; Gallagher, John S; Gouliermis, Dimitrios A; Grebel, Eva K; Hunter, Deidre A; Johnson, Kelsey; Kim, Hwi; Lee, Janice; Sabbi, Elena; Smith, Linda; Thilker, David; Tosi, Monica; Ubeda, Leonardo

    2014-01-01

    Hierarchical structure in ultraviolet images of 12 late-type LEGUS galaxies is studied by determining the numbers and fluxes of nested regions as a function of size from ~1 to ~200 pc, and the number as a function of flux. Two starburst dwarfs, NGC 1705 and NGC 5253, have steeper number-size and flux-size distributions than the others, indicating high fractions of the projected areas filled with star formation. Nine subregions in 7 galaxies have similarly steep number-size slopes, even when the whole galaxies have shallower slopes. The results suggest that hierarchically structured star-forming regions several hundred parsecs or larger represent common unit structures. Small galaxies dominated by only a few of these units tend to be starbursts. The self-similarity of young stellar structures down to parsec scales suggests that star clusters form in the densest parts of a turbulent medium that also forms loose stellar groupings on larger scales. The presence of super star clusters in two of our starburst dwarf...

  19. PERFORMANCE OF SELECTED AGGLOMERATIVE HIERARCHICAL CLUSTERING METHODS

    Directory of Open Access Journals (Sweden)

    Nusa Erman

    2015-01-01

    Full Text Available A broad variety of different methods of agglomerative hierarchical clustering brings along problems how to choose the most appropriate method for the given data. It is well known that some methods outperform others if the analysed data have a specific structure. In the presented study we have observed the behaviour of the centroid, the median (Gower median method, and the average method (unweighted pair-group method with arithmetic mean – UPGMA; average linkage between groups. We have compared them with mostly used methods of hierarchical clustering: the minimum (single linkage clustering, the maximum (complete linkage clustering, the Ward, and the McQuitty (groups method average, weighted pair-group method using arithmetic averages - WPGMA methods. We have applied the comparison of these methods on spherical, ellipsoid, umbrella-like, “core-and-sphere”, ring-like and intertwined three-dimensional data structures. To generate the data and execute the analysis, we have used R statistical software. Results show that all seven methods are successful in finding compact, ball-shaped or ellipsoid structures when they are enough separated. Conversely, all methods except the minimum perform poor on non-homogenous, irregular and elongated ones. Especially challenging is a circular double helix structure; it is being correctly revealed only by the minimum method. We can also confirm formerly published results of other simulation studies, which usually favour average method (besides Ward method in cases when data is assumed to be fairly compact and well separated.

  20. Bimodal Color Distribution in Hierarchical Galaxy Formation

    CERN Document Server

    Menci, N; Giallongo, E; Salimbeni, S

    2005-01-01

    We show how the observed bimodality in the color distribution of galaxies can be explained in the framework of the hierarchical clustering picture in terms of the interplay between the properties of the merging histories and the feedback/star-formation processes in the progenitors of local galaxies. Using a semi-analytic model of hierarchical galaxy formation, we compute the color distributions of galaxies with different luminosities and compare them with the observations. Our fiducial model matches the fundamental properties of the observed distributions, namely: 1) the distribution of objects brighter than M_r = -18 is clearly bimodal, with a fraction of red objects increasing with luminosity; 2) for objects brighter than M_r = -21 the color distribution is dominated by red objects with color u-r = 2.2-2.4; 3) the spread on the distribution of the red population is smaller than that of the blue population; 4) the fraction of red galaxies is larger in denser environments, even for low-luminosity objects; 5) ...