WorldWideScience

Sample records for rank superstructure bcc

  1. Nanoparticle assemblies and superstructures

    National Research Council Canada - National Science Library

    Kotov, Nicholas A

    2006-01-01

    ... building blocks of larger and more complex systems. Therefore, the present challenge of nanoscale science is to shift from making certain building blocks to organizing them in one-, two-, and three-dimensional structures. Such assemblies and superstructures are the next logical step in the development of nanoscience and nanotechnology. In this re...

  2. On Weak-BCC-Algebras

    Science.gov (United States)

    Thomys, Janus; Zhang, Xiaohong

    2013-01-01

    We describe weak-BCC-algebras (also called BZ-algebras) in which the condition (x∗y)∗z = (x∗z)∗y is satisfied only in the case when elements x, y belong to the same branch. We also characterize ideals, nilradicals, and nilpotent elements of such algebras. PMID:24311983

  3. BCC and Childhood Low Dose Radiation

    OpenAIRE

    Arash Beiraghi Toosi; Hamed Shariat Razavi

    2014-01-01

    Skin cancer is a late complication of ionizing radiation. Two skin neoplasms prominent Basal Cell Carcinoma (BCC) and Squamous Cell Carcinoma (SCC) are the most famous complications of radiotherapy. Basal Cell Carcinoma (BCC) is the most common human malignant neoplasm. Many genetic and environmental factors are involved in its onset. BCC is observed in sun-exposed areas of skin. Some patients with scalp BCC have had a history of scalp radiation for the treatment of tinea capitis in childhood...

  4. Atomic displacements in bcc dilute alloys

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 68; Issue 4. Atomic displacements in bcc ... metal (TM) dilute alloys. We have calculated the atomic displacements in bcc (V, Cr, Fe, Nb, Mo, Ta and W) transition metals (TMs) due to 3d, 4d and 5d TMs at the substitutional site using the Kanzaki lattice static method.

  5. Implementing Composite Superstructures in Large Passenger Ships

    DEFF Research Database (Denmark)

    Karatzas, Vasileios; Berggreen, Christian; Jensen, Jørgen Juncher

    2015-01-01

    This study focuses on the structural response of the part of the superstructure of a RoPax ferry that has been redesigned using composite materials. The composite superstructure is presented and subsequently compared to the existing steel design considering different loading conditions by the use...... of FE modelling.Results indicate that it is not the structural response of the superstructure that inhibits the implementation of composites in the superstructures of large passenger ships but the complicated design procedure and the acceptance of such solutions by the regulatory bodies....

  6. BCC and Childhood Low Dose Radiation

    Directory of Open Access Journals (Sweden)

    Arash Beiraghi Toosi

    2014-10-01

    Full Text Available Skin cancer is a late complication of ionizing radiation. Two skin neoplasms prominent Basal Cell Carcinoma (BCC and Squamous Cell Carcinoma (SCC are the most famous complications of radiotherapy. Basal Cell Carcinoma (BCC is the most common human malignant neoplasm. Many genetic and environmental factors are involved in its onset. BCC is observed in sun-exposed areas of skin. Some patients with scalp BCC have had a history of scalp radiation for the treatment of tinea capitis in childhood. Evidence that ionizing radiation is carcinogenic first came from past reports of nonmelanoma skin cancers on the hands of workers using radiation devices. The total dose of radiation and irradiated site exposed to sunlight can lead to a short incubation period. It is not clear whether BCC in these cases has a more aggressive nature and requires a more aggressive resection of the lesion. The aim of this review was to evaluate the differences between BCC specification and treatment results between irradiated and nonirradiated patients.

  7. Arsenic poisoning of magnetism in bcc cobalt

    Science.gov (United States)

    Singh, David J.

    1992-04-01

    Highly converged local spin-density approximation calculations are used to determine the effectiveness of As as a poisoning agent for the magnetism of bcc Co films grown on GaAs. To do this, supercell calculations of the magnetization were performed using an extension of the general potential linearized augmented plane-wave method for Co7As, Co15As, and Co31As. The effect of the nearest-neighbor relaxation around As impurities, calculated using total energy techniques, was included. It is found that substitutional As is moderately effective as a poisoning agent, each As atom contributes a moment of -3.8μB, and this may be important in explaining the discrepancy of 0.2-0.3μB between the calculated magnetization of bcc Co and the measured magnetization of bcc Co films on GaAs.

  8. Cascade morphology transition in bcc metals.

    Science.gov (United States)

    Setyawan, Wahyu; Selby, Aaron P; Juslin, Niklas; Stoller, Roger E; Wirth, Brian D; Kurtz, Richard J

    2015-06-10

    Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent, b, in the defect production curve as a function of cascade energy (N(F) ~ E(MD)(b)). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, μ, between the high- and the low-energy regime. Using Cr, Fe, Mo and W data, an empirical formula of μ as a function of displacement threshold energy, E(d), is presented for bcc metals.

  9. Microbiological assessment of Burkholderia cepacia complex (Bcc ...

    African Journals Online (AJOL)

    Nancy Omar

    2014-09-18

    Sep 18, 2014 ... The highest rate of isolation of Bcc isolates was from pus (85.7%) isolated from patients in the burn unit. Antibiotic susceptibility tests .... strain of Pseudomonas aeruginosa ATCC 27853 was also cul- tured on BCSA as .... 5 strains were of intermediate sensitivity (16 lg/ml) and the remaining 14 strains were ...

  10. Atomic displacements in bcc dilute alloys

    Indian Academy of Sciences (India)

    Keywords. Atomic displacements; crystal defects; crystalline solids. PACS Nos 63.43.j; 63.43.Dq; 61.66.Dk; 61.72.Ji. 1. Introduction. The transition metal dilute alloys are studied for their unique properties such as high strength ...... Even the recent techniques like EXAFS are inadequate for bcc alloys because in the EXAFS ...

  11. Cascade morphology transition in bcc metals

    Energy Technology Data Exchange (ETDEWEB)

    Setyawan, Wahyu; Selby, A.; Juslin, Niklas; Stoller, Roger E.; Wirth, Brian D.; Kurtz, Richard J.

    2015-06-10

    Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent, $b$, in the defect production curve as a function of cascade energy ($N_F$$ \\sim$$E_{MD}^b$). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, $\\mu$, between the high- and the low-energy regime. Using Cr, Fe, Mo and W data, an empirical formula of $\\mu$ as a function of displacement threshold energy, $E_d$, is presented for bcc metals.

  12. Cascade morphology transition in bcc metals

    OpenAIRE

    Setyawan, Wahyu; Selby, Aaron P.; Juslin, Niklas; Stoller, Roger E; Wirth, Brian D.; Kurtz, Richard J.

    2014-01-01

    Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent, $b$, in the defect production curve as a function of cascade energy ($N_F \\sim E_{MD}^b$). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, $\\mu$, between the high- and the l...

  13. Superstructure of stapes. An analysis by HRCT

    Energy Technology Data Exchange (ETDEWEB)

    Horiuchi, Yasuharu; Hunai, Hiroaki; Ichimura; Keiiti; Iinuma, Toshitaka; Oyama, Kazuyuki

    1989-03-01

    High-resolution Computed Tomography (HRCT) of the temporal bone has now become a routine test for the diagnosis of various temporal bone lesions. Correct assessment of such minute structures as ossicles, especially stapes, is important in the pre-operative HRCT evaluation. On the other hand, analysis for the reliability of HRCT findings has not been done, including the superstructure of the stapes. A retrospectively study was done in order to assess the availability of HRCT findings in axial overlapping scans in 226 ears, with respect to the superstructures of stapes. The study was concerned with the analysis of HRCTs of 148 normal ears, 71 ears of chronic otitis media and 7 ears of ossicular abnormalities. HRCT findings were compared to those of surgeries in pathological cases. The present study revealed that the superstructures of stapes are noted in 70% when the stapes is surrounded by air. The major limitations in the proper analysis of stapes by HRCT are partial volume averaging and effects of soft tissue silhouetting, this is especially so when the stapes is surrounded by soft tissue density.

  14. Dental implant superstructures by superplastic forming

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, R.V.; Garriga-Majo, D.; Soo, S.; Pagliaria, D. [Kings Coll., London (United Kingdom). Dept. of Dental Biomaterials Science; Juszczyk, A.S.; Walter, J.D. [Kings Coll., London (United Kingdom). Dept. of Prosthetic Dentistry

    2001-07-01

    A novel application of superplastic forming is described for the production of fixed-bridge dental implant superstructures. Finite element analysis (FEA) has shown that Ti-6Al-4V sheet would be a suitable candidate material for the design of a fixed-bridge dental implant superstructure. Traditionally superstructures are cast in gold alloy onto pre-machined gold alloy cylinders but castings are often quite bulky and 25% of castings do not fit accurately (1) which means that sectioning and soldering is required to obtain a fit that is clinically acceptable and will not prejudice the integrity of the commercially pure cp-titanium implants osseointegrated with the bone. Superplastic forming is shown to be a forming technique that would allow the production of strong, light-weight components of thin section with low residual stress that could be suitable for such applications. Considerable cost savings over traditional dental techniques can be achieved using a low-cost ceramic die material. The properties of these die materials are optimised so that suitable components can be produced. Satisfactory hot strength is demonstrated and thermal properties are matched to those of the titanium alloy for accurate fit of the prosthesis. (orig.)

  15. Tensor Rank

    OpenAIRE

    Erdtman, Elias; Jönsson, Carl

    2012-01-01

    This master's thesis addresses numerical methods of computing the typical ranks of tensors over the real numbers and explores some properties of tensors over finite fields. We present three numerical methods to compute typical tensor rank. Two of these have already been published and can be used to calculate the lowest typical ranks of tensors and an approximate percentage of how many tensors have the lowest typical ranks (for some tensor formats), respectively. The third method was developed...

  16. Vibrational properties of vacancy in bcc transition metals using ...

    Indian Academy of Sciences (India)

    quasi atom concept and density functional theory. Adams and Foiles [3] developed a model for bcc metal V with the Morse form as pair-potential between atoms, and this model was successfully applied to calculate many-body potentials. Johnson and Oh [4] have presented an analytic EAM model for the bcc metals in which ...

  17. Lattice dynamical calculations for bcc caesium chloride | Taura ...

    African Journals Online (AJOL)

    In general, the obtained results agree reasonably well with the experimental data of the bcc Caesium Chloride. Keywords: Bcc caesium chloride; Lattice dynamics; Phonon dispersion; Density of state; Specific heat. Journal of the Nigerian Association of Mathematical Physics, Volume 20 (March, 2012), pp 261 – 266 ...

  18. Rank Dynamics

    Science.gov (United States)

    Gershenson, Carlos

    Studies of rank distributions have been popular for decades, especially since the work of Zipf. For example, if we rank words of a given language by use frequency (most used word in English is 'the', rank 1; second most common word is 'of', rank 2), the distribution can be approximated roughly with a power law. The same applies for cities (most populated city in a country ranks first), earthquakes, metabolism, the Internet, and dozens of other phenomena. We recently proposed ``rank diversity'' to measure how ranks change in time, using the Google Books Ngram dataset. Studying six languages between 1800 and 2009, we found that the rank diversity curves of languages are universal, adjusted with a sigmoid on log-normal scale. We are studying several other datasets (sports, economies, social systems, urban systems, earthquakes, artificial life). Rank diversity seems to be universal, independently of the shape of the rank distribution. I will present our work in progress towards a general description of the features of rank change in time, along with simple models which reproduce it

  19. A critical consideration of magnetism and composition of (bcc) Cu precipitates in (bcc) Fe

    Energy Technology Data Exchange (ETDEWEB)

    Schober, M. [University of Leoben, Department of Physical Metallurgy and Materials Testing, Leoben (Austria); Montanuniversitaet Leoben, Department Metallkunde und Werkstoffpruefung, Leoben (Austria); Eidenberger, E.; Leitner, H. [University of Leoben, Department of Physical Metallurgy and Materials Testing, Leoben (Austria); Staron, P. [GKSS Research Centre, Institute of Materials Research, Geesthacht (Germany); Reith, D.; Podloucky, R. [University of Vienna, Department for Physical Chemistry, Vienna (Austria)

    2010-06-15

    Atom probe and small-angle neutron scattering (SANS) measurements were carried out in order to investigate the chemical composition of (bcc) Cu precipitates in a (bcc) Fe matrix. The ratio of nuclear and magnetic integrated intensities (R-value) found by SANS is compared to a theoretical model which is based on the chemical composition obtained from the atom probe data. Furthermore, density functional theory calculations were performed to derive the magnetic moment per atom and the lattice parameters of the Cu alloys modeled in terms of supercells. The calculated and measured R-values agree rather well suggesting that Fe atoms are incorporated in the Cu precipitates up to concentrations of about 50 at.%. (orig.)

  20. Hydrothermal synthesis and photoluminescent properties of stacked indium sulfide superstructures.

    Science.gov (United States)

    Xing, Yan; Zhang, Hongjie; Song, Shuyan; Feng, Jing; Lei, Yongqian; Zhao, Lijun; Li, Meiye

    2008-03-28

    Unusual hierarchical stacked superstructures of cubic beta-In2S3 were fabricated via a facile hydrothermal process in the presence of a surfactant cetyltrimethylammonium bromide CTAB; the 3D superstructures were developed by helical propagation of surface steps from microflakes of 10-20 nm thickness.

  1. Metastable bcc phase formation in the Nb-Cr system

    Energy Technology Data Exchange (ETDEWEB)

    Thoma, D.J.; Schwarz, R.B. [Los Alamos National Lab., NM (United States); Perepezko, J.H. [Wisconsin Univ., Madison, WI (United States). Dept. of Materials Science and Engineering; Plantz, D.H. [Coast Guard Academy, New London, CT (United States). Dept. of Engineering

    1993-08-01

    Extended metastable bcc solid solutions of Nb-Xat.%Cr (X = 35, 50, 57, 77, 82, and 94) were synthesized by two-anvil splat-quenching. In addition, bcc (Nb-67at.%Cr) was prepared by mechanically alloying mixtures of niobium and chromium powders. The lattice parameters were measured by X-ray diffraction and the Young`s moduli were measured by low-load microindentation. The composition dependence of the lattice parameters and elastic moduli show a positive deviation with respect to a rule of mixtures. During continuous heating at 15C/min., the metastable precursor bcc phases decomposed at temperatures above 750C to uniformly refined microstructures.

  2. Inert gas bubbles in bcc Fe

    Energy Technology Data Exchange (ETDEWEB)

    Gai, Xiao, E-mail: windgx22@hotmail.com; Smith, Roger, E-mail: r.smith@lboro.ac.uk; Kenny, S.D., E-mail: masdk@lboro.ac.uk

    2016-03-15

    The properties of inert gas bubbles in bcc Fe is examined using a combination of static energy minimisation, molecular dynamics and barrier searching methods with empirical potentials. Static energy minimisation techniques indicate that for small Ar and Xe bubbles, the preferred gas to vacancy ratio at 0 K is about 1:1 for Ar and varies between 0.5:1 and 0.9:1 for Xe. In contrast to interstitial He atoms and small He interstitial clusters, which are highly mobile in the lattice, Ar and Xe atoms prefer to occupy substitutional sites and any interstitials present in the lattice soon displace Fe atoms and become substitutional. If a pre-existing bubble is present then there is a capture radius around a bubble which extends up to the 6th neighbour position. Collision cascades can also enlarge an existing bubble by the capture of vacancies. Ar and Xe can diffuse through the lattice through vacancy driven mechanisms but with relatively high energy barriers of 1.8 and 2.0 eV respectively. This indicates that Ar and Xe bubbles are much harder to form than bubbles of He and that such gases produced in a nuclear reaction would more likely be dispersed at substitutional sites without the help of increased temperature or radiation-driven mechanisms.

  3. Non covalent assembly of coordination superstructures

    CERN Document Server

    Khlobystov, A N

    2002-01-01

    The main topic of this work is the design of discrete and polymeric multi-component coordination structures using non-covalent interactions between organic and inorganic molecular components. All of the structures described herein are based on transition metal cations and N-donor heterocyclic bis-exodentate ligands with different geometries and various spacer functionalities. The predominant method used for the structural characterisation of the complexes was single crystal X-ray crystallography. X-ray powder diffraction, IR and NMR spectroscopies and TEM and AFM imaging were used to characterise the bulk products from the reactions. Chapter 1 is a comparative review of non-covalent interactions relevant to coordination superstructures and covers the latest developments in the area of crystal engineering and supramolecular chemistry. The nature, geometry and relative energy of the non-covalent interactions are considered in detail in order to reveal their influence on the structure and properties of complexes...

  4. Enhanced thermophysical properties via PAO superstructure

    Science.gov (United States)

    Pournorouz, Zahra; Mostafavi, Amirhossein; Pinto, Aditya; Bokka, Apparao; Jeon, Junha; Shin, Donghyun

    2017-01-01

    For the last few years, molten salt nanomaterials have attracted many scientists for their enhanced specific heat by doping a minute concentration of nanoparticles (up to 1% by weight). Likewise, enhancing the specific heat of liquid media is important in many aspects of engineering such as engine oil, coolant, and lubricant. However, such enhancement in specific heat was only observed for molten salts, yet other engineering fluids such as water, ethylene glycol, and oil have shown a decrease of specific heat with doped nanoparticles. Recent studies have shown that the observed specific heat enhancement resulted from unique nanostructures that were formed by molten salt molecules when interacting with nanoparticles. Thus, such enhancement in specific heat is only possible for molten salts because other fluids may not naturally form such nanostructures. In this study, we hypothesized such nanostructures can be mimicked through in situ formation of fabricated nano-additives, which are putative nanoparticles coated with useful organic materials (e.g., polar-group-ended organic molecules) leading to superstructures, and thus can be directly used for other engineering fluids. We first applied this approach to polyalphaolefin (PAO). A differential scanning calorimeter (DSC), a rheometer, and a customized setup were employed to characterize the heat capacity, viscosity, and thermal conductivity of PAO and PAO with fabricated nano-additives. Results showed 44.5% enhanced heat capacity and 19.8 and 22.98% enhancement for thermal conductivity and viscosity, respectively, by an addition of only 2% of fabricated nanostructures in comparison with pure PAO. Moreover, a partial melting of the polar-group-ended organic molecules was observed in the first thermal cycle and the peak disappeared in the following cycles. This indicates that the in situ formation of fabricated nano-additives spontaneously occurs in the thermal cycle to form nanostructures. Figure of merit analyses have

  5. ELABORATION OF THE SUPERSTRUCTURE OF THE BULGARIAN HOTEL INDUSTRY

    Directory of Open Access Journals (Sweden)

    Tanya Dabeva

    2010-12-01

    Full Text Available The purpose of the paper is to suggest some terms of reference for the elaboration of the superstructure of the Bulgarian hotel industry. The suggestions are based on the analysis of the superstructure at present. Its capacity, main types of accommodation establishments and their distribution by categories and territory are examined. An analysis is made of some resulting indices such as overnight stays and average stay. The main positive, respectively negative features of the superstructure have been analyzed. Concrete terms of reference have been given in order to overcome the problems specified.

  6. Pivotal ERIVANCE basal cell carcinoma (BCC) study: 12-month update of efficacy and safety of vismodegib in advanced BCC.

    Science.gov (United States)

    Sekulic, Aleksandar; Migden, Michael R; Lewis, Karl; Hainsworth, John D; Solomon, James A; Yoo, Simon; Arron, Sarah T; Friedlander, Philip A; Marmur, Ellen; Rudin, Charles M; Chang, Anne Lynn S; Dirix, Luc; Hou, Jeannie; Yue, Huibin; Hauschild, Axel

    2015-06-01

    Primary analysis from the pivotal ERIVANCE BCC study resulted in approval of vismodegib, a Hedgehog pathway inhibitor indicated for treatment of adults with metastatic or locally advanced basal cell carcinoma (BCC) that has recurred after surgery or for patients who are not candidates for surgery or radiation. An efficacy and safety analysis was conducted 12 months after primary analysis. This was a multinational, multicenter, nonrandomized, 2-cohort study in patients with measurable and histologically confirmed locally advanced or metastatic BCC taking oral vismodegib (150 mg/d). Primary outcome measure was objective response rate (complete and partial responses) assessed by independent review facility. After 12 months of additional follow-up, median duration of exposure to vismodegib was 12.9 months. Objective response rate increased from 30.3% to 33.3% in patients with metastatic disease, and from 42.9% to 47.6% in patients with the locally advanced form. Median duration of response in patients with locally advanced BCC increased from 7.6 to 9.5 months. No new safety signals emerged with extended treatment duration. Limitations include low prevalence of advanced BCC and challenges of designing a study with heterogenous manifestations. The 12-month update of the study confirms the efficacy and safety of vismodegib in management of advanced BCC. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  7. Calculation Of Phonon Dispersion Frequencies For Bcc Tantalum ...

    African Journals Online (AJOL)

    The phonon dispersion frequencies are calculated from first principles for bcc Tantalum using a resonance pseudopotential model. It was also possible, using this scheme, to account for the anomalous feature of the Ta dispersion curve observed experimentally in the (ε,o,o,) direction where the frequencies of the transverse ...

  8. Perturbation theory of solid-liquid interfacial free energies of bcc metals

    Energy Technology Data Exchange (ETDEWEB)

    Warshavsky, Vadim B.; Song, Xueyu

    2012-09-18

    A perturbation theory is used to calculate bcc solid-liquid interfacial free energies of metallic systems with embedded-atom model potentials. As a reference system for bcc crystals we used a single-occupancy cell, hard-sphere bcc system. Good agreements between the perturbation theory results and the corresponding results from simulations are found. The strategy to extract hard-sphere bcc solid-liquid interfacial free energies may have broader applications for other crystal lattices.

  9. Atomistic Simulations of Dislocations in a Model BCC Multicomponent Concentrated Solid Solution Alloy (Postprint)

    Science.gov (United States)

    2016-12-19

    Dislocations ; Atomistic simulations; Concentrated multicomponent solid solution alloy; BCC crystal 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...This has implications for higher-scale modeling ( dislocation dynamics or crystal plasticity) of HEA alloys, relative to elemental BCC metals, which...AFRL-RX-WP-JA-2017-0302 ATOMISTIC SIMULATIONS OF DISLOCATIONS IN A MODEL BCC MULTICOMPONENT CONCENTRATED SOLID SOLUTION ALLOY

  10. Imprint of DES superstructures on the cosmic microwave background

    Science.gov (United States)

    Kovács, A.; Sánchez, C.; García-Bellido, J.; Nadathur, S.; Crittenden, R.; Gruen, D.; Huterer, D.; Bacon, D.; Clampitt, J.; DeRose, J.; Dodelson, S.; Gaztañaga, E.; Jain, B.; Kirk, D.; Lahav, O.; Miquel, R.; Naidoo, K.; Peacock, J. A.; Soergel, B.; Whiteway, L.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Rosell, A. Carnero; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Eifler, T. F.; Finley, D. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Giannantonio, T.; Goldstein, D. A.; Gruendl, R. A.; Gutierrez, G.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Nord, B.; Ogando, R.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Sobreira, F.; Suchyta, E.; Swanson, M.; Tarle, G.; Thomas, D.; Walker, A. R.; DES Collaboration

    2017-03-01

    Small temperature anisotropies in the cosmic microwave background (CMB) can be sourced by density perturbations via the late-time integrated Sachs-Wolfe (ISW) effect. Large voids and superclusters are excellent environments to make a localized measurement of this tiny imprint. In some cases excess signals have been reported. We probed these claims with an independent data set, using the first year data of the Dark Energy Survey (DES) in a different footprint, and using a different superstructure finding strategy. We identified 52 large voids and 102 superclusters at redshifts 0.2 Digital Sky Survey superstructure data.

  11. Superstructure optimization of biodiesel production from microalgal biomass

    DEFF Research Database (Denmark)

    Rizwan, Muhammad; Lee, Jay H.; Gani, Rafiqul

    2013-01-01

    In this study, we propose a mixed integer nonlinear programming (MINLP) model for superstructure based optimization of biodiesel production from microalgal biomass. The proposed superstructure includes a number of major processing steps for the production of biodiesel from microalgal biomass...... for the production of biodiesel from microalgae. The proposed methodology is tested by implementing on a specific case study. The MINLP model is implemented and solved in GAMS using a database built in Excel. The results from the optimization are analyzed and their significances are discussed....

  12. Construction of prestressed concrete single-tee bridge superstructures.

    Science.gov (United States)

    1977-01-01

    This report discusses in detail the construction of the first five precast, prestressed concrete, single-tee beam bridge superstructures to be let to contract in Virginia. The data suggest that this single-tee beam enables efficient construction of t...

  13. Templated and template-free fabrication strategies for zero-dimensional hollow MOF superstructures.

    Science.gov (United States)

    Kim, Hyehyun; Lah, Myoung Soo

    2017-05-16

    Various fabrication strategies for hollow metal-organic framework (MOF) superstructures are reviewed and classified using various types of external templates and their properties. Hollow MOF superstructures have also been prepared without external templates, wherein unstable intermediates obtained during reactions convert to the final hollow MOF superstructures. Many hollow MOF superstructures have been fabricated using hard templates. After the core-shell core@MOF structure was prepared using a hard template, the core was selectively etched to generate a hollow MOF superstructure. Another approach for generating hollow superstructures is to use a solid reactant as a sacrificial template; this method requires no additional etching process. Soft templates such as discontinuous liquid/emulsion droplets and gas bubbles in a continuous soft phase have also been employed to prepare hollow MOF superstructures.

  14. Hook-up between a main body and a superstructure. Systeme de liaison entre un corps principal et une superstructure

    Energy Technology Data Exchange (ETDEWEB)

    Berthet, H.; Laugier, N.

    1988-12-20

    The system of this invention comprises means for displacing a principal body relative to the superstructure and guide means cooperating with the said displacement means. The invention is especially suitably for installing platforms, buoys, or columns intended for offshore petroleum production.

  15. Quartic Box-Spline Reconstruction on the BCC Lattice.

    Science.gov (United States)

    Kim, Minho

    2013-02-01

    This paper presents an alternative box-spline filter for the body-centered cubic (BCC) lattice, the seven-direction quartic box-spline M7 that has the same approximation order as the eight-direction quintic box-spline M8 but a lower polynomial degree, smaller support, and is computationally more efficient. When applied to reconstruction with quasi-interpolation prefilters, M7 shows less aliasing, which is verified quantitatively by integral filter metrics and frequency error kernels. To visualize and analyze distributional aliasing characteristics, each spectrum is evaluated on the planes and lines with various orientations.

  16. SELF-ORGANIZATION OF LEAD SULFIDE QUANTUM DOTS INTO SUPERSTRUCTURES

    Directory of Open Access Journals (Sweden)

    Elena V. Ushakova

    2014-11-01

    Full Text Available The method of X-ray structural analysis (X-ray scattering at small angles is used to show that the structures obtained by self-organization on a substrate of lead sulfide (PbS quantum dots are ordered arrays. Self-organization of quantum dots occurs at slow evaporation of solvent from a cuvette. The cuvette is a thin layer of mica with teflon ring on it. The positions of peaks in SAXS pattern are used to calculate crystal lattice of obtained ordered structures. Such structures have a primitive orthorhombic crystal lattice. Calculated lattice parameters are: a = 21,1 (nm; b = 36,2 (nm; c = 62,5 (nm. Dimensions of structures are tens of micrometers. The spectral properties of PbS QDs superstructures and kinetic parameters of their luminescence are investigated. Absorption band of superstructures is broadened as compared to the absorption band of the quantum dots in solution; the luminescence band is slightly shifted to the red region of the spectrum, while its bandwidth is not changed much. Luminescence lifetime of obtained structures has been significantly decreased in comparison with the isolated quantum dots in solution, but remained the same for the lead sulfide quantum dots close-packed ensembles. Such superstructures can be used to produce solar cells with improved characteristics.

  17. Ranking library materials

    OpenAIRE

    Lewandowski, Dirk

    2015-01-01

    Purpose: This paper discusses ranking factors suitable for library materials and shows that ranking in general is a complex process and that ranking for library materials requires a variety of techniques. Design/methodology/approach: The relevant literature is reviewed to provide a systematic overview of suitable ranking factors. The discussion is based on an overview of ranking factors used in Web search engines. Findings: While there are a wide variety of ranking factors appl...

  18. Influence of mandibular superstructure shape on implant stresses during simulated posterior biting.

    Science.gov (United States)

    Korioth, T W; Johann, A R

    1999-07-01

    Theoretical considerations on the ideal implant-supported prosthetic superstructure shape lack the effect of complex mandibular deformation patterns during function. This study compared implant abutment stresses for idealized superstructures with different cross-sectional shapes and material properties during a simulated, complex biting task. A simplified and idealized 3-dimensional finite element computer model was built, which consisted of a sectioned mandible rehabilitated with 5 titanium implants and an attached superstructure beam composed of metal alloy and acrylic resin. The model was submitted to loads mimicking simultaneous bending and (to a lesser degree) torsion of the mandibular corpus during a bilateral posterior bite. Maximum and minimum principal stresses were calculated at implant abutment sites for each of 6 beam cross sections of the prosthetic superstructure and 2 types of materials. Predicted implant stresses varied significantly between implant sites for different superstructure shapes. The lowest principal stresses were obtained by using a superstructure with a rectangular-shaped beam oriented vertically. Contrary to former theoretical considerations, the ideal "I-beam" superstructure cross section did not yield the lowest stresses. Superstructure materials with a lower modulus of elasticity seem to not only increase implant abutment stresses overall but also slightly reduce the tensile stresses on the most anterior implants. Simulated implant abutment stresses may be significantly affected by the shape of the prosthetic superstructure, by diverse mandibular loading conditions, and to a lesser extent, by the prosthetic material properties.

  19. Synthesis, permeability resonance and microwave absorption of flake-assembled cobalt superstructure

    Energy Technology Data Exchange (ETDEWEB)

    Wen, S.L. [School of Materials Science and Engineering, Beijing Institute of Technology (China); Liu, Y., E-mail: yingliu@bit.edu.cn [School of Materials Science and Engineering, Beijing Institute of Technology (China); Zhao, X.C. [School of Materials Science and Engineering, Beijing Institute of Technology (China); Fan, Z.Z. [AVIC Beijing Institute of Aeronautical Materials, Beijing 100081 (China)

    2015-07-01

    To meet the demands of high-efficient microwave absorption materials, cobalt superstructure was synthesized and characterized. As SEM confirmed, the cobalt superstructure was assembled by flakes. The size of cobalt superstructure was about 10 μm, and the thickness of the flake was about 500 nm. The permittivity and permeability were investigated as a function of frequency in the microwave range of 1–18 GHz. Based on the LLG equation and exchange resonance mode, three magnetic resonances, including one natural resonance and two exchange resonances were discussed. The calculated reflection loss (RL) indicated the cobalt superstructure indicated the cobalt superstructure has potential application as a promising candidate for microwave absorption. The maximum RL reached as high as −77.29 dB with a matching thickness of 1.5 mm, and the effective bandwidth with a reflection loss less than −10 dB was 3.6 GHz from 9.85 to 13.45 GHz. For cobalt superstructure, magnetic loss mainly contributed even more than dielectric loss to the microwave absorption. - Highlights: • The cobalt superstructure were synthesized and characterized. • The multiple magnetic resonances were studied for cobalt superstructure based on the LLG equation and exchange resonance mode. • The maximum reflection loss of cobalt superstructure reaches to −77.29 dB.

  20. Experimental Determination of Pass-By Noise Contributions from the Bogies and Superstructure of a Freight Wagon

    Science.gov (United States)

    DE BEER, F. G.; VERHEIJ, J. W.

    2000-03-01

    Pass-by noise from freight trains on straight tracks is dominated by rolling noise. The main contributions are generally accepted to originate from vibrations of the track and the wheels. However, there is uncertainty about the contributions from the bogie and the wagon superstructure. This article describes experimental methods to determine these. The methods combine vibration measurements on a rolling wagon and measurements of structural and of vibro-acoustical transfer functions under static conditions. Firstly, an inverse method is used to determine the equivalent structural excitation of a wagon. Secondly, two reciprocity methods are described for detailed vibro-acoustic transmission path analysis, with the wagon parts excited by the equivalent forces. As an example, some data will be shown from experiments on a widely used freight wagon. It appears that the contributions from two bogies and from the wagon superstructure are respectively 20 and 30dB(A) lower than the measured pass-by noise levels. Detailed information is obtained about the ranking of sub-areas which contribute to the sound radiation. The results illustrate the practical value of the methods even in the case of weak partial sources.

  1. Towards true 3-dimensional BCC colloidal crystals with controlled lattice orientation

    NARCIS (Netherlands)

    Dziomkina, N.; Hempenius, Mark A.; Vancso, Gyula J.

    2009-01-01

    A fabrication method of colloidal crystals possessing the BCC crystal structure is described. BCC colloidal crystals with a thickness of up to seven colloidal layers were grown in the direction of the (100) crystal plane. Defect free colloidal crystals with a homogeneous surface coverage were

  2. Long-ranged interactions in bcc NbMoTaW high-entropy alloys

    NARCIS (Netherlands)

    Kormann, F.H.W.; Ruban, A.V.; Sluiter, M.H.F.

    2017-01-01

    We reveal that in a prototypical bcc high-entropy alloy NbMoTaW chemical interactions are long ranged and highly frustrated. We show that this is the reason that bcc solid solutions in NbMoTaW can persist to low temperatures. The ab initio-computed long-ranged interactions strongly impact

  3. Calculation of Crystallographic Texture of BCC Steels During Cold Rolling

    Science.gov (United States)

    Das, Arpan

    2017-05-01

    BCC alloys commonly tend to develop strong fibre textures and often represent as isointensity diagrams in φ 1 sections or by fibre diagrams. Alpha fibre in bcc steels is generally characterised by crystallographic axis parallel to the rolling direction. The objective of present research is to correlate carbon content, carbide dispersion, rolling reduction, Euler angles (ϕ) (when φ 1 = 0° and φ 2 = 45° along alpha fibre) and the resulting alpha fibre texture orientation intensity. In the present research, Bayesian neural computation has been employed to correlate these and compare with the existing feed-forward neural network model comprehensively. Excellent match to the measured texture data within the bounding box of texture training data set has been already predicted through the feed-forward neural network model by other researchers. Feed-forward neural network prediction outside the bounds of training texture data showed deviations from the expected values. Currently, Bayesian computation has been similarly applied to confirm that the predictions are reasonable in the context of basic metallurgical principles, and matched better outside the bounds of training texture data set than the reported feed-forward neural network. Bayesian computation puts error bars on predicted values and allows significance of each individual parameters to be estimated. Additionally, it is also possible by Bayesian computation to estimate the isolated influence of particular variable such as carbon concentration, which exactly cannot in practice be varied independently. This shows the ability of the Bayesian neural network to examine the new phenomenon in situations where the data cannot be accessed through experiments.

  4. Garden-like perovskite superstructures with enhanced photocatalytic activity.

    Science.gov (United States)

    Ye, Meidan; Wang, Mengye; Zheng, Dajiang; Zhang, Nan; Lin, Changjian; Lin, Zhiqun

    2014-04-07

    By subjecting amorphous flower-like TiO2 to a facile hydrothermal synthesis in the presence of Sr(2+), garden-like perovskite SrTiO3 superstructures were achieved. The amorphous TiO2 was preformed using ZnO flowers as templates. Different three-dimensional SrTiO3 architectures were coexisted in the garden, including SrTiO3 flowers composed of several hollow sword-shaped petals, many sheet-shaped petals or numerous flake-shaped petals, and SrTiO3 grass consisting of a number of long blades. These SrTiO3 superstructures were simultaneously grown on fluorine-doped tin oxide (FTO) substrates. On the basis of a comprehensive study on the effects of growth time, temperature, initial concentrations of precursor, and pH, the formation of these various hierarchical architectures was attributed primarily to the dissolution of amorphous TiO2 and precipitation of perovskite crystals, followed by the Ostwald ripening process of perovskite nanocrystals and self-organization of perovskite building blocks. Interestingly, this approach can be readily extended to create other perovskite structures, including dendritic BaTiO3 and nest-like CaTiO3, as well as PbTiO3 transformed from plate-like pyrochlore Pb2Ti2O6 after post-thermal treatment. Garden-like SrTiO3 superstructures showed a superior photocatalytic performance when compared to other as-prepared semiconductors and perovskite materials (i.e., ZnO, TiO2, BaTiO3, CaTiO3 and PbTiO3), probably due to their intrinsic photocatalytic activity and special garden-like features with a coexistence of various structures that significantly facilitated the adsorption and diffusion of methyl blue (MB) molecules and oxygen species in the photochemical reaction of MB degradation.

  5. Vismodegib for the treatment of basal cell carcinoma: results and implications of the ERIVANCE BCC trial.

    Science.gov (United States)

    Dessinioti, Clio; Plaka, Michaela; Stratigos, Alexander J

    2014-05-01

    The need for effective treatment of patients with locally advanced or metastatic basal cell carcinoma (BCC), in conjunction with major advances in the elucidation of the molecular basis of this tumor has led to the advent of new targeted therapies - namely, hedgehog inhibitors. The rationale for their use in patients with advanced BCC is based on their inhibitory effect on the hedgehog pathway, which is aberrantly activated in BCCs due to mutations of its primary components, PTCH1 and SMO genes. Vismodegib (GDC-0449) is an orally bioavailable hedgehog pathway inhibitor that selectively inhibits SMO. The ERIVANCE BCC study is a Phase II, international, multicenter clinical trial evaluating the efficacy and safety of vismodegib 150 mg once daily in patients with locally advanced or metastatic BCC. Vismodegib has been approved for the treatment of adult patients with metastatic BCC, or with locally advanced BCC that has recurred following surgery or who are not candidates for surgery or radiation therapy. This article will outline the rationale, design and available results from the ERIVANCE BCC study and discuss the clinical implications of vismodegib in the management of patients with BCC. Challenges regarding vismodegib use include the recurrence of BCC after drug discontinuation, the development of acquired resistance, the dramatic efficacy in patients with Gorlin syndrome, and class-related drug toxicity. Ongoing clinical trials aim to explore the role of vismodegib in the neoadjuvant setting prior to surgery, the potential use of alternate dosing regimens in order to limit chronic adverse events, as well as the identification of patients with BCC that are more likely to respond to this targeted therapy based on genotypic and/or phenotypic characteristics.

  6. A Generic Methodology for Superstructure Optimization of Different Processing Networks

    DEFF Research Database (Denmark)

    Bertran, Maria-Ona; Frauzem, Rebecca; Zhang, Lei

    2016-01-01

    In this paper, we propose a generic computer-aided methodology for synthesis of different processing networks using superstructure optimization. The methodology can handle different network optimization problems of various application fields. It integrates databases with a common data architecture......, a generic model to represent the processing steps, and appropriate optimization tools. A special software interface has been created to automate the steps in the methodology workflow, allow the transfer of data between tools and obtain the mathematical representation of the problem as required...

  7. Reduced Rank Regression

    DEFF Research Database (Denmark)

    Johansen, Søren

    2008-01-01

    The reduced rank regression model is a multivariate regression model with a coefficient matrix with reduced rank. The reduced rank regression algorithm is an estimation procedure, which estimates the reduced rank regression model. It is related to canonical correlations and involves calculating e...... eigenvalues and eigenvectors. We give a number of different applications to regression and time series analysis, and show how the reduced rank regression estimator can be derived as a Gaussian maximum likelihood estimator. We briefly mention asymptotic results......The reduced rank regression model is a multivariate regression model with a coefficient matrix with reduced rank. The reduced rank regression algorithm is an estimation procedure, which estimates the reduced rank regression model. It is related to canonical correlations and involves calculating...

  8. Voids and superstructures: correlations and induced large-scale velocity flows

    Science.gov (United States)

    Lares, Marcelo; Luparello, Heliana E.; Maldonado, Victoria; Ruiz, Andrés N.; Paz, Dante J.; Ceccarelli, Laura; Garcia Lambas, Diego

    2017-09-01

    The expanding complex pattern of filaments, walls and voids build the evolving cosmic web with material flowing from underdense on to high density regions. Here, we explore the dynamical behaviour of voids and galaxies in void shells relative to neighbouring overdense superstructures, using the Millenium simulation and the main galaxy catalogue in Sloan Digital Sky Survey data. We define a correlation measure to estimate the tendency of voids to be located at a given distance from a superstructure. We find voids-in-clouds (S-types) preferentially located closer to superstructures than voids-in-voids (R-types) although we obtain that voids within ˜40 h-1 Mpc of superstructures are infalling in a similar fashion independently of void type. Galaxies residing in void shells show infall towards the closest superstructure, along with the void global motion, with a differential velocity component depending on their relative position in the shell with respect to the direction to the superstructure. This effect is produced by void expansion and therefore is stronger for R-types. We also find that galaxies in void shells facing the superstructure flow towards the overdensities faster than galaxies elsewhere at the same relative distance to the superstructure. The results obtained for the simulation are also reproduced for the Sky Survey Data Release data with a linearized velocity field implementation.

  9. 40 CFR 745.228 - Accreditation of training programs: public and commercial buildings, bridges and superstructures...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Accreditation of training programs: public and commercial buildings, bridges and superstructures. 745.228 Section 745.228 Protection of... of training programs: public and commercial buildings, bridges and superstructures. ...

  10. Ranking Operations Management conferences

    NARCIS (Netherlands)

    Steenhuis, H.J.; de Bruijn, E.J.; Gupta, Sushil; Laptaned, U

    2007-01-01

    Several publications have appeared in the field of Operations Management which rank Operations Management related journals. Several ranking systems exist for journals based on , for example, perceived relevance and quality, citation, and author affiliation. Many academics also publish at conferences

  11. The incidence of metastatic basal cell carcinoma (mBCC) in Denmark, 1997-2010.

    Science.gov (United States)

    Nguyen-Nielsen, Mary; Wang, Lisa; Pedersen, Lars; Olesen, Anne Braae; Hou, Jeannie; Mackey, Howard; McCusker, Margaret; Basset-Seguin, Nicole; Fryzek, Jon; Vyberg, Mogens

    2015-01-01

    Few data exist on the occurrence of metastatic basal cell carcinoma (mBCC). To identify all cases of mBCC in Denmark over a 14-year period. We searched the Danish National Patient Registry covering all Danish hospitals, the Danish Cancer Registry, the National Pathology Registry and the Causes of Death Registry during the period 1997 to 2010 for potential cases of mBCC registered according to the International classification of diseases ICD-10 and the International Systemized Nomenclature of Medicine (SNOMED). We identified 126,627 patients with a history of primary basal cell carcinoma (BCC) in the registries during the 14-year study period. Using case identifications from the four registries, a total of 170 potential mBCC cases were identified. However, after a pathology review, only five cases could be confirmed, of which three were basosquamous carcinomas. The 14-year cumulative incidence proportion of mBCC was 0.0039% (95% CI 0.0016-0.0083) among individuals with a history of previous BCC (n = 126,627) and 0.0001% (95% CI 0.0000-0.0002) in the general population. MBCC is a rare disease and only a small proportion of potential cases identified in automated clinical databases or registries can be confirmed by pathology and medical record review.

  12. Sparse structure regularized ranking

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-04-17

    Learning ranking scores is critical for the multimedia database retrieval problem. In this paper, we propose a novel ranking score learning algorithm by exploring the sparse structure and using it to regularize ranking scores. To explore the sparse structure, we assume that each multimedia object could be represented as a sparse linear combination of all other objects, and combination coefficients are regarded as a similarity measure between objects and used to regularize their ranking scores. Moreover, we propose to learn the sparse combination coefficients and the ranking scores simultaneously. A unified objective function is constructed with regard to both the combination coefficients and the ranking scores, and is optimized by an iterative algorithm. Experiments on two multimedia database retrieval data sets demonstrate the significant improvements of the propose algorithm over state-of-the-art ranking score learning algorithms.

  13. Single crystalline superstructured stable single domain magnetite nanoparticles.

    Science.gov (United States)

    Reichel, Victoria; Kovács, András; Kumari, Monika; Bereczk-Tompa, Éva; Schneck, Emanuel; Diehle, Patrick; Pósfai, Mihály; Hirt, Ann M; Duchamp, Martial; Dunin-Borkowski, Rafal E; Faivre, Damien

    2017-03-30

    Magnetite nanoparticles exhibit magnetic properties that are size and organization dependent and, for applications that rely on their magnetic state, they usually have to be monodisperse. Forming such particles, however, has remained a challenge. Here, we synthesize 40 nm particles of magnetite in the presence of polyarginine and show that they are composed of 10 nm building blocks, yet diffract like single crystals. We use both bulk magnetic measurements and magnetic induction maps recorded from individual particles using off-axis electron holography to show that each 40 nm particle typically contains a single magnetic domain. The magnetic state is therefore determined primarily by the size of the superstructure and not by the sizes of the constituent sub-units. Our results fundamentally demonstrate the structure - property relationship in a magnetic mesoparticle.

  14. In situ lattice measurement of the bcc phase boundary in Mg on the principal shock Hugoniot

    Science.gov (United States)

    Milathianaki, D.; Swift, D. C.; Hawreliak, J.; El-Dasher, B. S.; McNaney, J. M.; Lorenzana, H. E.; Ditmire, T.

    2012-07-01

    We report on nanosecond resolution lattice measurements of shock-compressed Mg in the hcp and bcc phases between 12 and 45 GPa. X-ray diffraction signals consistent with a compressed bcc lattice were captured above a shock pressure of 26.2 ± 1.3 GPa. Our results are in agreement with the phase boundary calculated by Moriarty and Althoff using the generalized pseudopotential theory in the pressure and temperature region intersected by the principal shock Hugoniot.

  15. Plasticity and Failure in Nanocrystalline BCC Metals via MD Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, R E

    2010-02-12

    Advances in the ability to generate extremely high pressures in dynamic experiments such as at the National Ignition Facility has motivated the need for special materials optimized for those conditions as well as ways to probe the response of these materials as they are deformed. We need to develop a much deeper understanding of the behavior of materials subjected to high pressure, especially the effect of rate at the extremely high rates encountered in those experiments. Here we use large-scale molecular dynamics (MD) simulations of the high-rate deformation of nanocrystalline tantalum at pressures less than 100 GPa to investigate the processes associated with plastic deformation for strains up to 100%. We focus on 3D polycrystalline systems with typical grain sizes of 10-20 nm. We also study a rapidly quenched liquid (amorphous solid) tantalum. We apply a constant volume (isochoric), constant temperature (isothermal) shear deformation over a range of strain rates, and compute the resulting stress-strain curves to large strains for both uniaxial and biaxial compression. We study the rate dependence and identify plastic deformation mechanisms. The identification of the mechanisms is facilitated through a novel technique that computes the local grain orientation, returning it as a quaternion for each atom. This analysis technique is robust and fast, and has been used to compute the orientations on the fly during our parallel MD simulations on supercomputers. We find both dislocation and twinning processes are important, and they interact in the weak strain hardening in these extremely fine-grained microstructures. We also present some results on void growth in nanocrystalline BCC metals under tension.

  16. Maximum Waring ranks of monomials

    OpenAIRE

    Holmes, Erik; Plummer, Paul; Siegert, Jeremy; Teitler, Zach

    2013-01-01

    We show that monomials and sums of pairwise coprime monomials in four or more variables have Waring rank less than the generic rank, with a short list of exceptions. We asymptotically compare their ranks with the generic rank.

  17. How to Rank Journals.

    Science.gov (United States)

    Bradshaw, Corey J A; Brook, Barry W

    2016-01-01

    There are now many methods available to assess the relative citation performance of peer-reviewed journals. Regardless of their individual faults and advantages, citation-based metrics are used by researchers to maximize the citation potential of their articles, and by employers to rank academic track records. The absolute value of any particular index is arguably meaningless unless compared to other journals, and different metrics result in divergent rankings. To provide a simple yet more objective way to rank journals within and among disciplines, we developed a κ-resampled composite journal rank incorporating five popular citation indices: Impact Factor, Immediacy Index, Source-Normalized Impact Per Paper, SCImago Journal Rank and Google 5-year h-index; this approach provides an index of relative rank uncertainty. We applied the approach to six sample sets of scientific journals from Ecology (n = 100 journals), Medicine (n = 100), Multidisciplinary (n = 50); Ecology + Multidisciplinary (n = 25), Obstetrics & Gynaecology (n = 25) and Marine Biology & Fisheries (n = 25). We then cross-compared the κ-resampled ranking for the Ecology + Multidisciplinary journal set to the results of a survey of 188 publishing ecologists who were asked to rank the same journals, and found a 0.68-0.84 Spearman's ρ correlation between the two rankings datasets. Our composite index approach therefore approximates relative journal reputation, at least for that discipline. Agglomerative and divisive clustering and multi-dimensional scaling techniques applied to the Ecology + Multidisciplinary journal set identified specific clusters of similarly ranked journals, with only Nature & Science separating out from the others. When comparing a selection of journals within or among disciplines, we recommend collecting multiple citation-based metrics for a sample of relevant and realistic journals to calculate the composite rankings and their relative uncertainty windows.

  18. Chirality control for in situ preparation of gold nanoparticle superstructures directed by a coordinatable organogelator.

    Science.gov (United States)

    Zhu, Liangliang; Li, Xin; Wu, Shaojue; Nguyen, Kim Truc; Yan, Hong; Ågren, Hans; Zhao, Yanli

    2013-06-19

    Imposing chirality into nanoscale superstructures is a major step forward toward systematic understanding and utilization of nanomaterials. In an attempt to achieve tunable chirality during in situ preparation of hybrid nanomaterials, we here report a novel unimolecular strategy of employing a coordinatable organogelator for the realization of chirality control in the formation of gold nanoparticle superstructures. The work takes advantage of thermally reversible sol-gel transition of the chiral dispersion as template, which causes different micelle properties that can influence the coordination ability between the organogelator and Au(III) ions. Followed by a reduction reaction, gold nanoparticle superstructures with P-helicity were prepared from the sol form of the template through a coordination-induced chiral inversion, whereas those with M-helicity were obtained from the gel form with chiral holding. Such superstructures are solvent-stable and the chirality difference between them could be observed in many solvent environments.

  19. Feasibility of fiber reinforced composite materials used in highway bridge superstructures

    OpenAIRE

    Lin, Shih-Yung

    1988-01-01

    Composite materials are considered here as structural materials of highway bridge superstructures. Bridge deck designs can be done according to AASHTO1 specification and elastic design concepts. In order to evaluate the feasibility of composites as structural materials of highway bridge superstructures, composite materials are compared not only to composite materials themselves but also to the most popular bridge structural materials, which are reinforced concrete and struc...

  20. Synthesis, permeability resonance and microwave absorption of flake-assembled cobalt superstructure

    Science.gov (United States)

    Wen, S. L.; Liu, Y.; Zhao, X. C.; Fan, Z. Z.

    2015-07-01

    To meet the demands of high-efficient microwave absorption materials, cobalt superstructure was synthesized and characterized. As SEM confirmed, the cobalt superstructure was assembled by flakes. The size of cobalt superstructure was about 10 μm, and the thickness of the flake was about 500 nm. The permittivity and permeability were investigated as a function of frequency in the microwave range of 1-18 GHz. Based on the LLG equation and exchange resonance mode, three magnetic resonances, including one natural resonance and two exchange resonances were discussed. The calculated reflection loss (RL) indicated the cobalt superstructure indicated the cobalt superstructure has potential application as a promising candidate for microwave absorption. The maximum RL reached as high as -77.29 dB with a matching thickness of 1.5 mm, and the effective bandwidth with a reflection loss less than -10 dB was 3.6 GHz from 9.85 to 13.45 GHz. For cobalt superstructure, magnetic loss mainly contributed even more than dielectric loss to the microwave absorption.

  1. Use of Polycrystalline Ice for Assembly of Large Area Au Nanoparticle Superstructures as SERS Substrates.

    Science.gov (United States)

    Bekana, Deribachew; Liu, Rui; Amde, Meseret; Liu, Jing-Fu

    2017-01-11

    It is still a great challenge to develop simple and low-cost methods for preparation of surface-enhanced Raman scattering (SERS) substrates with high sensitivity and reproducibility. Taking advantage of the microstructure of polycrystalline ice, we developed a new method to assemble large area gold nanoparticle (AuNP) superstructures as SERS substrates without external templating and aggregating agent. The assembly was conducted by freezing AuNP colloid at -20 °C, which concentrated AuNPs in the ice veins and produced an AuNP superstructure upon thawing the ice. The AuNP superstructures exhibited high SERS activity with enhancement factors on the order of 7.63 × 107 owing to the high-density hot spots throughout the superstructures. The SERS activity was found to increase with particle size and aggregate size of AuNP superstructures. Besides, the substrates showed good uniformity and reproducibility with relative standard deviations of 11.9% and 12.4%, respectively. The substrates showed long-term stability, maintaining SERS activity over a period of five months without noticeable change in morphology of the superstructures. The substrates was further used for label-free detection of trace Thiram on apple fruit with high sensitivity down to the concentration of 0.28 ng/cm2, offering great potential to monitor Thiram levels in foodstuffs and environmental samples.

  2. Academic rankings: an approach to a Portuguese ranking

    OpenAIRE

    Bernardino, Pedro; Marques,Rui

    2009-01-01

    The academic rankings are a controversial subject in higher education. However, despite all the criticism, academic rankings are here to stay and more and more different stakeholders use rankings to obtain information about the institutions’ performance. The two most well-known rankings, The Times and the Shanghai Jiao Tong University rankings have different methodologies. The Times ranking is based on peer review, whereas the Shanghai ranking has only quantitative indicators and is mainly ba...

  3. Ranking Economic History Journals

    DEFF Research Database (Denmark)

    Di Vaio, Gianfranco; Weisdorf, Jacob Louis

    This study ranks - for the first time - 12 international academic journals that have economic history as their main topic. The ranking is based on data collected for the year 2007. Journals are ranked using standard citation analysis where we adjust for age, size and self-citation of journals. We...... also compare the leading economic history journals with the leading journals in economics in order to measure the influence on economics of economic history, and vice versa. With a few exceptions, our results confirm the general idea about what economic history journals are the most influential...

  4. Ranking economic history journals

    DEFF Research Database (Denmark)

    Di Vaio, Gianfranco; Weisdorf, Jacob Louis

    2010-01-01

    This study ranks-for the first time-12 international academic journals that have economic history as their main topic. The ranking is based on data collected for the year 2007. Journals are ranked using standard citation analysis where we adjust for age, size and self-citation of journals. We also...... compare the leading economic history journals with the leading journals in economics in order to measure the influence on economics of economic history, and vice versa. With a few exceptions, our results confirm the general idea about what economic history journals are the most influential for economic...

  5. Recurrent fuzzy ranking methods

    Science.gov (United States)

    Hajjari, Tayebeh

    2012-11-01

    With the increasing development of fuzzy set theory in various scientific fields and the need to compare fuzzy numbers in different areas. Therefore, Ranking of fuzzy numbers plays a very important role in linguistic decision-making, engineering, business and some other fuzzy application systems. Several strategies have been proposed for ranking of fuzzy numbers. Each of these techniques has been shown to produce non-intuitive results in certain case. In this paper, we reviewed some recent ranking methods, which will be useful for the researchers who are interested in this area.

  6. Bilateral Congenital Absence of the Stapes Superstructure in Two Siblings

    Directory of Open Access Journals (Sweden)

    Jose Ignacio Undabeitia

    2014-01-01

    Full Text Available Middle ear ossicle malformations are an uncommon event. Among them, the congenital absence of the stapes is a very rare condition that is seldom described in the literature. We report the cases of two women, aged 19 and 22 , who presented with a long history of conductive deafness. An exploratory tympanotomy was performed and the absence of the stapes superstructure and an abnormal position of the facial nerve could be observed. A bone anchored hearing aid (BAHA was implanted in both patients with good results. It is believed that stapes agenesis is related to an abnormal development of the facial nerve, which by the 5th to 6th week of gestation would interpose between the otic capsule and the stapes blastema, preventing these structures from contacting. A long history of nonprogressive hearing loss from birth or early childhood is the key to reach a diagnosis. Several treatment options have been described. The authors opted for a hearing aid due to the high risk of facial nerve lesion, with good functional results.

  7. Elemental moment variation of bcc FexMn1-x on MgO(001)

    Science.gov (United States)

    Bhatkar, H.; Snow, R. J.; Arenholz, E.; Idzerda, Y. U.

    2017-02-01

    We report the growth, structural characterization, and electronic structure evolution of epitaxially grown bcc FexMn1-x on MgO(001). It is observed that the 20 nm thick FexMn1-x alloy films remained bcc from 0.65≤x≤1, much beyond the bulk stability range of 0.88≤x≤1. X-ray absorption spectroscopy and X-ray magnetic circular dichroism show that both the Fe and Mn L3 binding energies slightly increase with Mn incorporation and that the elemental moment of Fe in the 20 nm crystalline bcc alloy film remain nearly constant, then shows a dramatic collapse near x 0.84. The Mn MCD intensity is found to be small at all compositions that exhibit ferromagnetism

  8. Asset ranking manager (ranking index of components)

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, S.M.; Engle, A.M.; Morgan, T.A. [Applied Reliability, Maracor Software and Engineering (United States)

    2004-07-01

    The Ranking Index of Components (RIC) is an Asset Reliability Manager (ARM), which itself is a Web Enabled front end where plant database information fields from several disparate databases are combined. That information is used to create a specific weighted number (Ranking Index) relating to that components health and risk to the site. The higher the number, the higher priority that any work associated with that component receives. ARM provides site Engineering, Maintenance and Work Control personnel with a composite real time - (current condition) look at the components 'risk of not working' to the plant. Information is extracted from the existing Computerized Maintenance management System (CMMS) and specific site applications and processed nightly. ARM helps to ensure that the most important work is placed into the workweeks and the non value added work is either deferred, frequency changed or deleted. This information is on the web, updated each night, and available for all employees to use. This effort assists the work management specialist when allocating limited resources to the most important work. The use of this tool has maximized resource usage, performing the most critical work with available resources. The ARM numbers are valued inputs into work scoping for the workweek managers. System and Component Engineers are using ARM to identify the components that are at 'risk of failure' and therefore should be placed into the appropriate work week schedule.

  9. First-principles study of interactions between substitutional solutes in bcc iron

    Energy Technology Data Exchange (ETDEWEB)

    Gorbatov, O.I., E-mail: o.i.gorbatov@gmail.com [Department of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm SE-100 44 (Sweden); Institute of Quantum Materials Science, Ekaterinburg 620107 (Russian Federation); Nosov Magnitogorsk State Technical University, Magnitogorsk 455000 (Russian Federation); Delandar, A. Hosseinzadeh [Department of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm SE-100 44 (Sweden); Gornostyrev, Yu N. [Institute of Quantum Materials Science, Ekaterinburg 620107 (Russian Federation); Institute of Metal Physics, Ural Division RAS, Ekaterinburg 620219 (Russian Federation); Ruban, A.V. [Department of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm SE-100 44 (Sweden); Materials Center Leoben, Leoben 8700 (Austria); Korzhavyi, P.A. [Department of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm SE-100 44 (Sweden); Institute of Metal Physics, Ural Division RAS, Ekaterinburg 620219 (Russian Federation)

    2016-07-15

    Using density functional theory based calculations, employing the locally self-consistent Green's function method and the projected augmented wave method, we develop a database of solute–solute interactions in dilute alloys of bcc Fe. Interactions within the first three coordination shells are computed for the ferromagnetic state as well as for the paramagnetic (disordered local moment) state of the iron matrix. The contribution of lattice relaxations to the defect interaction energy is investigated in the ferromagnetic state. Implications of the obtained results for modeling the phenomena of point defect clustering and phase precipitation in bcc Fe-based alloys and steel are discussed.

  10. Multiplex PageRank.

    Directory of Open Access Journals (Sweden)

    Arda Halu

    Full Text Available Many complex systems can be described as multiplex networks in which the same nodes can interact with one another in different layers, thus forming a set of interacting and co-evolving networks. Examples of such multiplex systems are social networks where people are involved in different types of relationships and interact through various forms of communication media. The ranking of nodes in multiplex networks is one of the most pressing and challenging tasks that research on complex networks is currently facing. When pairs of nodes can be connected through multiple links and in multiple layers, the ranking of nodes should necessarily reflect the importance of nodes in one layer as well as their importance in other interdependent layers. In this paper, we draw on the idea of biased random walks to define the Multiplex PageRank centrality measure in which the effects of the interplay between networks on the centrality of nodes are directly taken into account. In particular, depending on the intensity of the interaction between layers, we define the Additive, Multiplicative, Combined, and Neutral versions of Multiplex PageRank, and show how each version reflects the extent to which the importance of a node in one layer affects the importance the node can gain in another layer. We discuss these measures and apply them to an online multiplex social network. Findings indicate that taking the multiplex nature of the network into account helps uncover the emergence of rankings of nodes that differ from the rankings obtained from one single layer. Results provide support in favor of the salience of multiplex centrality measures, like Multiplex PageRank, for assessing the prominence of nodes embedded in multiple interacting networks, and for shedding a new light on structural properties that would otherwise remain undetected if each of the interacting networks were analyzed in isolation.

  11. Multiplex PageRank.

    Science.gov (United States)

    Halu, Arda; Mondragón, Raúl J; Panzarasa, Pietro; Bianconi, Ginestra

    2013-01-01

    Many complex systems can be described as multiplex networks in which the same nodes can interact with one another in different layers, thus forming a set of interacting and co-evolving networks. Examples of such multiplex systems are social networks where people are involved in different types of relationships and interact through various forms of communication media. The ranking of nodes in multiplex networks is one of the most pressing and challenging tasks that research on complex networks is currently facing. When pairs of nodes can be connected through multiple links and in multiple layers, the ranking of nodes should necessarily reflect the importance of nodes in one layer as well as their importance in other interdependent layers. In this paper, we draw on the idea of biased random walks to define the Multiplex PageRank centrality measure in which the effects of the interplay between networks on the centrality of nodes are directly taken into account. In particular, depending on the intensity of the interaction between layers, we define the Additive, Multiplicative, Combined, and Neutral versions of Multiplex PageRank, and show how each version reflects the extent to which the importance of a node in one layer affects the importance the node can gain in another layer. We discuss these measures and apply them to an online multiplex social network. Findings indicate that taking the multiplex nature of the network into account helps uncover the emergence of rankings of nodes that differ from the rankings obtained from one single layer. Results provide support in favor of the salience of multiplex centrality measures, like Multiplex PageRank, for assessing the prominence of nodes embedded in multiple interacting networks, and for shedding a new light on structural properties that would otherwise remain undetected if each of the interacting networks were analyzed in isolation.

  12. Ranking of Rankings: Benchmarking Twenty-Five Higher Education Ranking Systems in Europe

    Science.gov (United States)

    Stolz, Ingo; Hendel, Darwin D.; Horn, Aaron S.

    2010-01-01

    The purpose of this study is to evaluate the ranking practices of 25 European higher education ranking systems (HERSs). Ranking practices were assessed with 14 quantitative measures derived from the Berlin Principles on Ranking of Higher Education Institutions (BPs). HERSs were then ranked according to their degree of congruence with the BPs.…

  13. Influence of superstructure geometry on the mechanical behavior of zirconia implant abutments: a finite element analysis.

    Science.gov (United States)

    Geringer, Alexander; Diebels, Stefan; Nothdurft, Frank P

    2014-12-01

    To predict the clinical performance of zirconia abutments, it is crucial to examine the mechanical behavior of different dental implant-abutment connection configurations. The international standard protocol for dynamic fatigue tests of dental implants (ISO 14801) allows comparing these configurations using standardized superstructure geometries. However, from a mechanical point of view, the geometry of clinical crowns causes modified boundary conditions. The purpose of this finite element (FE) study was to evaluate the influence of the superstructure geometry on the maximum stress values of zirconia abutments with a conical implant-abutment connection. Geometry models of the experimental setup described in ISO 14801 were generated using CAD software following the reconstruction of computerized tomography scans from all relevant components. These models served as a basis for an FE simulation. To reduce the numerical complexity of the FE model, the interaction between loading stamp and superstructure geometry was taken into account by defining the boundary conditions with regard to the frictional force. The results of the FE simulations performed on standardized superstructure geometry and anatomically shaped crowns showed a strong influence of the superstructure geometry and related surface orientations on the mechanical behavior of the underlying zirconia abutments. In conclusion, ISO testing of zirconia abutments should be accompanied by load-bearing capacity testing under simulated clinical conditions to predict clinical performance.

  14. From rankings to mission.

    Science.gov (United States)

    Kirch, Darrell G; Prescott, John E

    2013-08-01

    Since the 1980s, school ranking systems have been a topic of discussion among leaders of higher education. Various ranking systems are based on inadequate data that fail to illustrate the complex nature and special contributions of the institutions they purport to rank, including U.S. medical schools, each of which contributes uniquely to meeting national health care needs. A study by Tancredi and colleagues in this issue of Academic Medicine illustrates the limitations of rankings specific to primary care training programs. This commentary discusses, first, how each school's mission and strengths, as well as the impact it has on the community it serves, are distinct, and, second, how these schools, which are each unique, are poorly represented by overly subjective ranking methodologies. Because academic leaders need data that are more objective to guide institutional development, the Association of American Medical Colleges (AAMC) has been developing tools to provide valid data that are applicable to each medical school. Specifically, the AAMC's Medical School Admissions Requirements and its Missions Management Tool each provide a comprehensive assessment of medical schools that leaders are using to drive institutional capacity building. This commentary affirms the importance of mission while challenging the leaders of medical schools, teaching hospitals, and universities to use reliable data to continually improve the quality of their training programs to improve the health of all.

  15. Dynamic Matrix Rank

    DEFF Research Database (Denmark)

    Frandsen, Gudmund Skovbjerg; Frandsen, Peter Frands

    2009-01-01

    We consider maintaining information about the rank of a matrix under changes of the entries. For n×n matrices, we show an upper bound of O(n1.575) arithmetic operations and a lower bound of Ω(n) arithmetic operations per element change. The upper bound is valid when changing up to O(n0.575) entries...... in a single column of the matrix. We also give an algorithm that maintains the rank using O(n2) arithmetic operations per rank one update. These bounds appear to be the first nontrivial bounds for the problem. The upper bounds are valid for arbitrary fields, whereas the lower bound is valid for algebraically...... closed fields. The upper bound for element updates uses fast rectangular matrix multiplication, and the lower bound involves further development of an earlier technique for proving lower bounds for dynamic computation of rational functions....

  16. Towards an unbiased comparison of CC, BCC, and FCC lattices in terms of prealiasing

    KAUST Repository

    Vad, Viktor

    2014-06-01

    In the literature on optimal regular volume sampling, the Body-Centered Cubic (BCC) lattice has been proven to be optimal for sampling spherically band-limited signals above the Nyquist limit. On the other hand, if the sampling frequency is below the Nyquist limit, the Face-Centered Cubic (FCC) lattice was demonstrated to be optimal in reducing the prealiasing effect. In this paper, we confirm that the FCC lattice is indeed optimal in this sense in a certain interval of the sampling frequency. By theoretically estimating the prealiasing error in a realistic range of the sampling frequency, we show that in other frequency intervals, the BCC lattice and even the traditional Cartesian Cubic (CC) lattice are expected to minimize the prealiasing. The BCC lattice is superior over the FCC lattice if the sampling frequency is not significantly below the Nyquist limit. Interestingly, if the original signal is drastically undersampled, the CC lattice is expected to provide the lowest prealiasing error. Additionally, we give a comprehensible clarification that the sampling efficiency of the FCC lattice is lower than that of the BCC lattice. Although this is a well-known fact, the exact percentage has been erroneously reported in the literature. Furthermore, for the sake of an unbiased comparison, we propose to rotate the Marschner-Lobb test signal such that an undue advantage is not given to either lattice. © 2014 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  17. Experimental observations elucidating the mechanisms of structural bcc-hcp transformations in ?-Ti alloys

    NARCIS (Netherlands)

    Van Bohemen, S.M.C.; Sietsma, J.; Van der Zwaag, S.

    2006-01-01

    The formation mechanisms of two hcp ? phase morphologies in Ti-4.5Fe-6.8Mo-1.5Al have been investigated by optical microscopy (OM), atomic force microscopy (AFM), electron probe microanalysis (EPMA) and dilatometry. At relatively high temperatures primary ? forms predominantly on prior bcc ? grain

  18. Hirsutane Sesquiterpenes from Cultures of the Basidiomycete Marasmiellus sp. BCC 22389

    Directory of Open Access Journals (Sweden)

    Masahiko Isaka

    2016-08-01

    Full Text Available Abstract Two new hirsutane sesquiterpenes, marasmiellins A (1 and B (2, were isolated from cultures of the basidiomycete Marasmiellus sp. BCC 22389. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. The absolute configuration of marasmiellin B was determined by application of the modified Mosher’s method. Graphical Abstract

  19. Molecular dynamics simulations of fcc-to-bcc transformation in pure iron : a review

    NARCIS (Netherlands)

    Ou, X.

    2017-01-01

    Molecular dynamics (MD) simulation has been used to study the martensitic transformation in iron at the atomic scale. The paper reviews the available interatomic interaction potentials for iron, which describe the properties of different phases present in that system. Cases on the fcc-to-bcc

  20. Segregation-induced ordered superstructures at general grain boundaries in a nickel-bismuth alloy

    Science.gov (United States)

    Yu, Zhiyang; Cantwell, Patrick R.; Gao, Qin; Yin, Denise; Zhang, Yuanyao; Zhou, Naixie; Rohrer, Gregory S.; Widom, Michael; Luo, Jian; Harmer, Martin P.

    2017-10-01

    The properties of materials change, sometimes catastrophically, as alloying elements and impurities accumulate preferentially at grain boundaries. Studies of bicrystals show that regular atomic patterns often arise as a result of this solute segregation at high-symmetry boundaries, but it is not known whether superstructures exist at general grain boundaries in polycrystals. In bismuth-doped polycrystalline nickel, we found that ordered, segregation-induced grain boundary superstructures occur at randomly selected general grain boundaries, and that these reconstructions are driven by the orientation of the terminating grain surfaces rather than by lattice matching between grains. This discovery shows that adsorbate-induced superstructures are not limited to special grain boundaries but may exist at a variety of general grain boundaries, and hence they can affect the performance of polycrystalline engineering alloys.

  1. Linking experiment and theory for three-dimensional networked binary metal nanoparticle–triblock terpolymer superstructures

    KAUST Repository

    Li, Zihui

    2014-02-21

    © 2014 Macmillan Publishers Limited. Controlling superstructure of binary nanoparticle mixtures in three dimensions from self-assembly opens enormous opportunities for the design of materials with unique properties. Here we report on how the intimate coupling of synthesis, in-depth electron tomographic characterization and theory enables exquisite control of superstructure in highly ordered porous three-dimensional continuous networks from single and binary mixtures of metal nanoparticles with a triblock terpolymer. Poly(isoprene-block-styrene-block-(N,N-dimethylamino)ethyl methacrylate) is synthesized and used as structure-directing agent for ligand-stabilized platinum and gold nanoparticles. Quantitative analysis provides insights into short-and long-range nanoparticle-nanoparticle correlations, and local and global contributions to structural chirality in the networks. Results provide synthesis criteria for next-generation mesoporous network superstructures from binary nanoparticle mixtures for potential applications in areas including catalysis.

  2. Diversifying customer review rankings.

    Science.gov (United States)

    Krestel, Ralf; Dokoohaki, Nima

    2015-06-01

    E-commerce Web sites owe much of their popularity to consumer reviews accompanying product descriptions. On-line customers spend hours and hours going through heaps of textual reviews to decide which products to buy. At the same time, each popular product has thousands of user-generated reviews, making it impossible for a buyer to read everything. Current approaches to display reviews to users or recommend an individual review for a product are based on the recency or helpfulness of each review. In this paper, we present a framework to rank product reviews by optimizing the coverage of the ranking with respect to sentiment or aspects, or by summarizing all reviews with the top-K reviews in the ranking. To accomplish this, we make use of the assigned star rating for a product as an indicator for a review's sentiment polarity and compare bag-of-words (language model) with topic models (latent Dirichlet allocation) as a mean to represent aspects. Our evaluation on manually annotated review data from a commercial review Web site demonstrates the effectiveness of our approach, outperforming plain recency ranking by 30% and obtaining best results by combining language and topic model representations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. OutRank

    DEFF Research Database (Denmark)

    Müller, Emmanuel; Assent, Ira; Steinhausen, Uwe

    2008-01-01

    Outlier detection is an important data mining task for consistency checks, fraud detection, etc. Binary decision making on whether or not an object is an outlier is not appropriate in many applications and moreover hard to parametrize. Thus, recently, methods for outlier ranking have been proposed...

  4. Experimental Study of Properties of Pervious Concrete used for Bridge Superstructure

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard; Hertz, Kristian Dahl

    2014-01-01

    around freezing point are exposed to a harsh freeze-thaw impact, since bridges are not only cooled from the topside, as a normal road bed, but also from underneath. Hence, the demands to the moisture properties of the superstructure are strict in order to ensure the necessary durability. Pearl......One of the main advantages of pervious concrete is its ability to drain water easily. Moreover, ear-lier studies on pervious concrete have shown that it can be designed to perform well in freeze-thaw regions. Bridge superstructures placed in regions where the temperature during winter time varies...

  5. Optimal processing pathway for the production of biodiesel from microalgal biomass: A superstructure based approach

    DEFF Research Database (Denmark)

    Rizwan, Muhammad; Lee, Jay H.; Gani, Rafiqul

    2013-01-01

    In this study, we propose a mixed integer nonlinear programming (MINLP) model for superstructure based optimization of biodiesel production from microalgal biomass. The proposed superstructure includes a number of major processing steps for the production of biodiesel from microalgal biomass...... for the production of biodiesel from microalgae. The proposed methodology is tested by implementing on a specific case with different choices of objective functions. The MINLP model is implemented and solved in GAMS using a database built in Excel. The results from the optimization are analyzed...

  6. Ab initio study of long-period superstructures in close-packed A3B compounds

    DEFF Research Database (Denmark)

    Rosengaard, N. M.; Skriver, Hans Lomholt

    1994-01-01

    We have performed ab initio calculations of the stability of one-dimensional long-period superstructures in Cu3Pd, Cu3Al, and Ag3Mg by means of an interface Green's function technique based on the linear-muffin-tin-orbitals method within the tight-binding and atomic-sphere approximations. The ene......We have performed ab initio calculations of the stability of one-dimensional long-period superstructures in Cu3Pd, Cu3Al, and Ag3Mg by means of an interface Green's function technique based on the linear-muffin-tin-orbitals method within the tight-binding and atomic-sphere approximations...

  7. Improving Ranking Using Quantum Probability

    OpenAIRE

    Melucci, Massimo

    2011-01-01

    The paper shows that ranking information units by quantum probability differs from ranking them by classical probability provided the same data used for parameter estimation. As probability of detection (also known as recall or power) and probability of false alarm (also known as fallout or size) measure the quality of ranking, we point out and show that ranking by quantum probability yields higher probability of detection than ranking by classical probability provided a given probability of ...

  8. In vivo assessment of optical properties of basal cell carcinoma and differentiation of BCC subtypes by high-definition optical coherence tomography

    DEFF Research Database (Denmark)

    Boone, Marc; Suppa, Mariano; Miyamoto, Makiko

    2016-01-01

    High-definition optical coherence tomography (HD-OCT) features of basal cell carcinoma (BCC) have recently been defined. We assessed in vivo optical properties (IV-OP) of BCC, by HD-OCT. Moreover their critical values for BCC subtype differentiation were determined. The technique of semi-log plot...

  9. Fractional cointegration rank estimation

    DEFF Research Database (Denmark)

    Lasak, Katarzyna; Velasco, Carlos

    We consider cointegration rank estimation for a p-dimensional Fractional Vector Error Correction Model. We propose a new two-step procedure which allows testing for further long-run equilibrium relations with possibly different persistence levels. The fi…rst step consists in estimating the parame......We consider cointegration rank estimation for a p-dimensional Fractional Vector Error Correction Model. We propose a new two-step procedure which allows testing for further long-run equilibrium relations with possibly different persistence levels. The fi…rst step consists in estimating...... to control for stochastic trend estimation effects from the first step. The critical values of the tests proposed depend only on the number of common trends under the null, p - r, and on the interval of the cointegration degrees b allowed, but not on the true cointegration degree b0. Hence, no additional...

  10. Cryo-transmission electron microscopy of a superstructure of fluid dioleoylphosphatidylcholine (DOPC) membranes

    DEFF Research Database (Denmark)

    Klösgen, B; Helfrich, W

    1997-01-01

    Using cryo-transmission electron microscopy, we have obtained abundant and reproducible evidence for a superstructure of dioleoylphosphatidylcholine (DOPC) bilayers. Dispersions of vesicles were prepared by gentle shaking of a 2% suspension of DOPC in water followed in part by extrusion through a...

  11. A generic methodology for processing route synthesis and design based on superstructure optimization

    DEFF Research Database (Denmark)

    Bertran, Maria-Ona; Frauzem, Rebecca; Sanchez-Arcilla, Ana Sofia

    2017-01-01

    In this paper, a systematic framework for novel and sustainable synthesis-design of processing routes is presented along with the associated computer-aided methods and tools. In Stage 1, superstructure optimization is used to determine the optimal processing route(s). In Stage 2, the design issue...

  12. Globalisation in Africa: Reflecting on Peter Jarvis's Superstructure and Substructure Model

    Science.gov (United States)

    Preece, Julia

    2017-01-01

    This paper reflects on Peter Jarvis' book "Globalisation, lifelong learning and the learning society," volume 2--in which he describes human learning within a global context and factors contributing to globalisation. He describes the relationship of power between countries manifested as the superstructure and sub structure. The paper…

  13. Surface orientation dependence of the activation energy of S diffusion in bcc Fe

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, P.E., E-mail: Pieter.Barnard@sasol.com; Terblans, J.J., E-mail: terblansjj@ufs.ac.za; Swart, H.C., E-mail: swarthc@ufs.ac.za

    2015-11-30

    Graphical abstract: - Highlights: • The formation of vacancies in bcc Fe was studied. • DFT was combined with AES, TOF-SIMS and XRD. • Activation energies for segregation of S in Fe(1 0 0), (1 1 0) and (1 1 1) were calculated. • Simulations revealed variation in the segregation kinetics due to surface orientation. • Experimental data confirmed this variation in the segregation kinetics of S. - Abstract: The formation of vacancies in the low-index orientations of bcc Fe was studied by a combined computational modelling and experimental investigation by making use of density functional theory (DFT), Auger electron spectroscopy (AES), time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray diffraction (XRD). Vacancies were considered to occur as a result of a Schottky defect forming in the bcc Fe lattice. This predicted a surface orientation dependence on the vacancy formation energy and consequently also on the activation energy of diffusion. Activation energies for the segregation of S in the Fe(1 0 0), Fe(1 1 0) and Fe(1 1 1) surface orientations were calculated by DFT modelling as 2.75 eV, 2.86 eV and 1.94 eV respectively. Simulations furthermore revealed a variation in the segregation kinetics of S as a result of the activation energy dependence on the surface orientation. Experimental data obtained by AES, TOF-SIMS and XRD confirmed this variation in the segregation kinetics of S segregation in different Fe orientations. This article provides compelling evidence for the formation of vacancies in bcc Fe to occur via the Schottky defect mechanism, which results in the orientation dependence for the activation energy of diffusion.

  14. Assessment of Atomic Mobility for the Bcc Phase of the Ti-Al-Mo System

    Science.gov (United States)

    Chen, Yi; Cheng, Liang; Zhang, Yunlong

    2017-09-01

    The atomic mobility for the bcc phase of the Ti-Al-Mo ternary system was developed by critical assessment of the experimental diffusion data by using the DICTRA software. The results shown the calculated diffusion coefficients presented the good agreements by the comprehensive comparisons with the experimental diffusion coefficients. The developed Ti-Al-Mo ternary atomic mobility was then subsequently validated by appropriate prediction of the interdiffusion behavior with comparison of the diffusion-couple experiments in the literature.

  15. [A microstructural approach to fatigue crack processes in poly crystalline BCC materials]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Gerberich, W.W.

    1992-12-31

    Objective was to study fatigue where a combination of low temperature and cyclic loading produced cyclic cleavage in bcc Fe-base systems. Both dislocation dynamics and quasi-statics of crack growth were probed. This document reviews progress over the past 6 years: hydrogen embrittlement and cleavage, computations (stress near crack tip), dislocation emission from grain boundaries, fracture process zones, and understanding brittle fracture at the atomistic/dislocation scales and at the microscopic/macroscopic scale.

  16. [A microstructural approach to fatigue crack processes in poly crystalline BCC materials

    Energy Technology Data Exchange (ETDEWEB)

    Gerberich, W.W.

    1992-01-01

    Objective was to study fatigue where a combination of low temperature and cyclic loading produced cyclic cleavage in bcc Fe-base systems. Both dislocation dynamics and quasi-statics of crack growth were probed. This document reviews progress over the past 6 years: hydrogen embrittlement and cleavage, computations (stress near crack tip), dislocation emission from grain boundaries, fracture process zones, and understanding brittle fracture at the atomistic/dislocation scales and at the microscopic/macroscopic scale.

  17. Molecular dynamics simulation of grain-boundary diffusion of vacancies in bcc iron

    Science.gov (United States)

    Kwok, T.; Ho, P. S.; Yip, S.; Balluffi, R.; Brokman, A. W.; Bristowe, P. D.

    1981-06-01

    The jumping of vacancies in a bcc iron sigma = 5 tilt boundary was simulated by computer molecular dynamics. The data yielded a reasonable value of the activation energy for migration and showed that the jump processes are highly structure dependent. The use of a temperature dependent transition probability matrix to describe the diffusion of the vacancies in the grain boundary is suggested. Formation of one type of boundary interstitial was observed which was found to be immobile.

  18. Molecular dynamics simulation of grain-boundary diffusion of vacancies in bcc iron

    Energy Technology Data Exchange (ETDEWEB)

    Kwok, T.; Ho, P. S.; Yip, S.; Balluffi, R. W.; Bristowe, P. D.; Brokman, A.

    1981-06-01

    The jumping of vacancies in a bcc iron ..sigma.. = 5 tilt boundary was simulated by computer molecular dynamics. The data yielded a reasonable value of the activation energy for migration and showed that the jump processes are highly structure-dependent. The use of a temperature dependent transition probability matrix to describe the diffusion of the vacancies in the grain boundary is suggested. Formation of one type of boundary interstitial was observed which was found to be immobile.

  19. Diffusion behavior of Cr diluted in bcc and fcc Fe: Classical and quantum simulation methods

    Energy Technology Data Exchange (ETDEWEB)

    Ramunni, Viviana P., E-mail: vpram@cnea.gov.ar [CONICET, Avda. Rivadavia 1917, Cdad. de Buenos Aires C.P. 1033 (Argentina); Comisión Nacional de Energía Atómica, Gerencia Materiales, Av. Del Libertador 8250, C1429BNP Ciudad de Buenos Aires (Argentina); Rivas, Alejandro M.F. [CONICET, Avda. Rivadavia 1917, Cdad. de Buenos Aires C.P. 1033 (Argentina); Comisión Nacional de Energía Atómica, Departamento de Física Teórica, Tandar, Av. Del Libertador 8250, C1429BNP Ciudad de Buenos Aires (Argentina)

    2015-07-15

    We characterize the atomic mobility behavior driven by vacancies, in bcc and fcc Fe−Cr diluted alloys, using a multi-frequency model. We calculate the full set of the Onsager coefficients and the tracer self and solute diffusion coefficients in terms of the mean jump frequencies. The involved jump frequencies are calculated using a classical molecular static (CMS) technique. For the bcc case, we also perform quantum calculations based on the density functional theory (DFT). There, we show that, in accordance with Bohr's correspondence principle, as the size of the atomic cell (total number of atoms) is increased, quantum results with DFT recover the classical ones obtained with CMS calculations. This last ones, are in perfect agreement with available experimental data for both, solute and solvent diffusion coefficients. For high temperatures, in the fcc phase where no experimental data are yet available, our CMS calculations predict the expected solute and solvent diffusion coefficients. - Graphical abstract: Display Omitted - Highlights: • Comparison of diffusion coefficients obtained from classical and quantum methods. • We perform our calculations in diluted bcc/fcc Fe–Cr alloy. • Magnetic and phonon effects must be taken into account. • Classical calculations are in perfect agreement with experimental data.

  20. Shear induced order in SEP diblock copolymer micelles: multiple BCC slip systems

    Science.gov (United States)

    Torija, Maria A.; Choi, Soohyung; Bates, Frank S.; Lodge, Timothy P.

    2010-03-01

    Poly(styrene-b-ethylene-alt-propylene) (SEP) diblock copolymers are solvated by squalane leading to glassy poly(styrene) domains dispersed in a viscoelastic medium. For diblocks containing less than about 50% by weight poly(styrene) and at SEP concentrations greater than 6 w. % these mixtures self-assemble into glassy spherical microdomains that order on a body centered cubic (BCC) lattice. We have investigated how polycrystalline configurations respond to large amplitude oscillatory shear as a function of shear rate, strain amplitude and block copolymer composition. Structure was characterized by small-angle X-ray scattering measurements while simultaneously deforming the mixtures with an in-situ rheometer. All three slip systems associated with plastic deformation in BCC metals110,211,321, were identified with the x-ray beam oriented perpendicular to the shear plane. Higher shear rates and larger strain amplitudes produced more slip within the 211 system. These results represent one of the most comprehensive assessments of BCC structure in solvated copolymers and will be discussed within the context of the associated linear viscoelastic behavior.

  1. Can College Rankings Be Believed?

    Directory of Open Access Journals (Sweden)

    Meredith Davis

    Full Text Available The article summarizes literature on college and university rankings worldwide and the strategies used by various ranking organizations, including those of government and popular media. It traces the history of national and global rankings, indicators used by ranking systems, and the effect of rankings on academic programs and their institutions. Although ranking systems employ diverse criteria and most weight certain indicators over others, there is considerable skepticism that most actually measure educational quality. At the same time, students and their families increasingly consult these evaluations when making college decisions, and sponsors of faculty research consider reputation when forming academic partnerships. While there are serious concerns regarding the validity of ranking institutions when so little data can support differences between one institution and another, college rankings appear to be here to stay.

  2. Ranking Baltic States Researchers

    Directory of Open Access Journals (Sweden)

    Gyula Mester

    2017-10-01

    Full Text Available In this article, using the h-index and the total number of citations, the best 10 Lithuanian, Latvian and Estonian researchers from several disciplines are ranked. The list may be formed based on the h-index and the total number of citations, given in Web of Science, Scopus, Publish or Perish Program and Google Scholar database. Data for the first 10 researchers are presented. Google Scholar is the most complete. Therefore, to define a single indicator, h-index calculated by Google Scholar may be a good and simple one. The author chooses the Google Scholar database as it is the broadest one.

  3. Sync-rank: Robust Ranking, Constrained Ranking and Rank Aggregation via Eigenvector and SDP Synchronization

    Science.gov (United States)

    2015-04-28

    eigenvector of the associated Laplacian matrix (i.e., the Fiedler vector) matches that of the variables. In other words, this approach (reminiscent of...S1), i.e., Dii = ∑n j=1Gi,j is the degree of node i in the measurement graph G. 3: Compute the Fiedler vector of S (eigenvector corresponding to the...smallest nonzero eigenvalue of LS). 4: Output the ranking induced by sorting the Fiedler vector of S, with the global ordering (increasing or decreasing

  4. Rankings from Fuzzy Pairwise Comparisons

    NARCIS (Netherlands)

    van den Broek, P.M.; Noppen, J.A.R.; Mohammadian, M.

    2006-01-01

    We propose a new method for deriving rankings from fuzzy pairwise comparisons. It is based on the observation that quantification of the uncertainty of the pairwise comparisons should be used to obtain a better crisp ranking, instead of a fuzzified version of the ranking obtained from crisp pairwise

  5. PageRank (II): Mathematics

    African Journals Online (AJOL)

    maths/stats

    INTRODUCTION. PageRank is Google's system for ranking web pages. A page with a higher PageRank is deemed more important and is more likely to be listed above a ... Felix U. Ogban, Department of Mathematics/Statistics and Computer Science, Faculty of Science, University of ..... probability, 2004, 41, (3): 721-734.

  6. University Rankings and Social Science

    Science.gov (United States)

    Marginson, Simon

    2014-01-01

    University rankings widely affect the behaviours of prospective students and their families, university executive leaders, academic faculty, governments and investors in higher education. Yet the social science foundations of global rankings receive little scrutiny. Rankings that simply recycle reputation without any necessary connection to real…

  7. Sequential rank agreement methods for comparison of ranked lists

    DEFF Research Database (Denmark)

    Ekstrøm, Claus Thorn; Gerds, Thomas Alexander; Jensen, Andreas Kryger

    2015-01-01

    The comparison of alternative rankings of a set of items is a general and prominent task in applied statistics. Predictor variables are ranked according to magnitude of association with an outcome, prediction models rank subjects according to the personalized risk of an event, and genetic studies...... are illustrated using gene rankings, and using data from two Danish ovarian cancer studies where we assess the within and between agreement of different statistical classification methods.......The comparison of alternative rankings of a set of items is a general and prominent task in applied statistics. Predictor variables are ranked according to magnitude of association with an outcome, prediction models rank subjects according to the personalized risk of an event, and genetic studies...

  8. Limitations of BCC_CSM's ability to predict summer precipitation over East Asia and the Northwestern Pacific

    KAUST Repository

    Gong, Zhiqiang

    2017-04-05

    This study examines the ability of the Beijing Climate Center Climate System Model (BCC_CSM) to predict the meridional pattern of summer precipitation over East Asia-Northwest Pacific (EA-NWP) and its East Asia-Pacific (EAP) teleconnection. The differences of summer precipitation modes of the empirical orthogonal function and the bias of atmospheric circulations over EA-NWP are analyzed to determine the reason for the precipitation prediction errors. Results indicate that the BCC_CSM could not reproduce the positive-negative-positive meridional tripole pattern from south to north that differs markedly from that observed over the last 20 years. This failure can be attributed to the bias of the BCC_CSM hindcasts of the summer EAP teleconnection and the low predictability of 500 hPa at the mid-high latitude lobe of the EAP. Meanwhile, the BCC_CSM hindcasts\\' deficiencies of atmospheric responses to SST anomalies over the Indonesia maritime continent (IMC) resulted in opposite and geographically shifted geopotential anomalies at 500 hPa as well as wind and vorticity anomalies at 850 hPa, rendering the BCC_CSM unable to correctly reproduce the EAP teleconnection pattern. Understanding these two problems will help further improve BCC_CSM\\'s summer precipitation forecasting ability over EA-NWP.

  9. Highly Ordered Single Crystalline Nanowire Array Assembled Three-Dimensional Nb3O7(OH) and Nb2O5 Superstructures for Energy Storage and Conversion Applications.

    Science.gov (United States)

    Zhang, Haimin; Wang, Yun; Liu, Porun; Chou, Shu Lei; Wang, Jia Zhao; Liu, Hongwei; Wang, Guozhong; Zhao, Huijun

    2016-01-26

    Three-dimensional (3D) metal oxide superstructures have demonstrated great potentials for structure-dependent energy storage and conversion applications. Here, we reported a facile hydrothermal method for direct growth of highly ordered single crystalline nanowire array assembled 3D orthorhombic Nb3O7(OH) superstructures and their subsequent thermal transformation into monoclinic Nb2O5 with well preserved 3D nanowire superstructures. The performance of resultant 3D Nb3O7(OH) and Nb2O5 superstructures differed remarkably when used for energy conversion and storage applications. The thermally converted Nb2O5 superstructures as anode material of lithium-ion batteries (LiBs) showed higher capacity and excellent cycling stability compared to the Nb3O7(OH) superstructures, while directly hydrothermal grown Nb3O7(OH) nanowire superstructure film on FTO substrate as photoanode of dye-sensitized solar cells (DSSCs) without the need for further calcination exhibited an overall light conversion efficiency of 6.38%, higher than that (5.87%) of DSSCs made from the thermally converted Nb2O5 film. The high energy application performance of the niobium-based nanowire superstructures with different chemical compositions can be attributed to their large surface area, superior electron transport property, and high light utilization efficiency resulting from a 3D superstructure, high crystallinity, and large sizes. The formation process of 3D nanowire superstructures before and after thermal treatment was investigated and discussed based on our theoretical and experimental results.

  10. RE{sub 13}Pd{sub 25+x}Zn{sub 28-x} (RE = Y, Ho-Lu). A 4 x 4 x 4 tungsten superstructure with short Pd/Zn dumbbells as structural motif

    Energy Technology Data Exchange (ETDEWEB)

    Gerke, Birgit; Hoffmann, Rolf-Dieter; Niehaus, Oliver; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

    2016-08-01

    The rare earth-based zinc compounds RE{sub 13}Pd{sub 25+x}Zn{sub 28-x} (RE = Y, Ho-Lu) were synthesized from the elements in sealed niobium ampoules with a maximum reaction temperature of 1470 K followed by different annealing sequences. The structures of all compounds were refined from single crystal X-ray diffraction data, indicating substantial Zn/Pd mixing on one 8c and one 24g zinc site. Exemplarily, the homogeneity range of the solid solution Yb{sub 13}Pd{sub 25+x}Zn{sub 28-x} was manifested from samples of different starting compositions and five single crystal data sets. The RE{sub 13}Pd{sub 25+x}Zn{sub 28-x} structures are cubic, space group I anti 43m with lattice parameters ranging from 1295 to 1307 pm, as a function of the rare earth element and the Zn/Pd mixing. Hierarchically, one can derive the RE{sub 13}Pd{sub 25+x}Zn{sub 28-x} structures from the simple bcc packing. A group-subgroup scheme was developed for this new 4 x 4 x 4 tungsten superstructure which shows vacancy ordering and dumbbell formation. Temperature dependent magnetic susceptibility measurements show diamagnetism for a Lu{sub 13}Pd{sub 29}Zn{sub 24} sample and Curie-Weiss paramagnetism for Tm{sub 13}Pd{sub 29}Zn{sub 24} down to 3 K.

  11. Ranking nodes in growing networks: When PageRank fails.

    Science.gov (United States)

    Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng

    2015-11-10

    PageRank is arguably the most popular ranking algorithm which is being applied in real systems ranging from information to biological and infrastructure networks. Despite its outstanding popularity and broad use in different areas of science, the relation between the algorithm's efficacy and properties of the network on which it acts has not yet been fully understood. We study here PageRank's performance on a network model supported by real data, and show that realistic temporal effects make PageRank fail in individuating the most valuable nodes for a broad range of model parameters. Results on real data are in qualitative agreement with our model-based findings. This failure of PageRank reveals that the static approach to information filtering is inappropriate for a broad class of growing systems, and suggest that time-dependent algorithms that are based on the temporal linking patterns of these systems are needed to better rank the nodes.

  12. Neophilia Ranking of Scientific Journals

    Science.gov (United States)

    Packalen, Mikko; Bhattacharya, Jay

    2017-01-01

    The ranking of scientific journals is important because of the signal it sends to scientists about what is considered most vital for scientific progress. Existing ranking systems focus on measuring the influence of a scientific paper (citations)—these rankings do not reward journals for publishing innovative work that builds on new ideas. We propose an alternative ranking based on the proclivity of journals to publish papers that build on new ideas, and we implement this ranking via a text-based analysis of all published biomedical papers dating back to 1946. In addition, we compare our neophilia ranking to citation-based (impact factor) rankings; this comparison shows that the two ranking approaches are distinct. Prior theoretical work suggests an active role for our neophilia index in science policy. Absent an explicit incentive to pursue novel science, scientists underinvest in innovative work because of a coordination problem: for work on a new idea to flourish, many scientists must decide to adopt it in their work. Rankings that are based purely on influence thus do not provide sufficient incentives for publishing innovative work. By contrast, adoption of the neophilia index as part of journal-ranking procedures by funding agencies and university administrators would provide an explicit incentive for journals to publish innovative work and thus help solve the coordination problem by increasing scientists' incentives to pursue innovative work. PMID:28713181

  13. Enigmatic cranial superstructures among Chamorro ancestors from the Mariana Islands: gross anatomy and microanatomy.

    Science.gov (United States)

    Heathcote, Gary M; Bromage, Timothy G; Sava, Vincent J; Hanson, Douglas B; Anderson, Bruce E

    2014-06-01

    This study focuses on the gross anatomy, anatomic relations, microanatomy, and the meaning of three enigmatic, geographically patterned, and quasi-continuous superstructures of the posterior cranium. Collectively known as occipital superstructures (OSSs), these traits are the occipital torus tubercle (TOT), retromastoid process (PR), and posterior supramastoid tubercle (TSP). When present, TOT, PR, and TSP develop at posterior cranial attachment sites of the upper trapezius, superior oblique, and sternocleidomastoid muscles, respectively. Marked expression and co-occurrence of these OSSs are virtually circumscribed within Oceania and reach highest recorded frequencies in protohistoric Chamorros (CHamoru) of the Mariana Islands. Prior to undertaking scanning electron microscopy (SEM) work, our working multifactorial model for OSS development was that early-onset, long-term, and chronic activity-related microtrauma at enthesis sites led to exuberant reactive or reparative responses in a substantial minority of genetically predisposed (and mostly male) individuals. SEM imaging, however, reveals topographic patterning that questions, but does not negate, activity induction of these superstructures. Although OSSs appear macroscopically as relatively large and discrete phenomena, SEM findings reveal a unique, widespread, and seemingly systemic distribution of structures over the occipital surface that have the appearance of OSS microforms. Nevertheless, apparent genetic underpinnings, anatomic relationships with muscle entheses, and positive correlation of OSS development with humeral robusticity continue to suggest that these superstructures have potential to at once bear witness to Chamorro population history and inform osteobiographical constructions of chronic activity patterns in individuals bearing them. Further work is outlined that would illuminate the proximate and ultimate meanings of OSS. Copyright © 2014 Wiley Periodicals, Inc.

  14. Z-contrast imaging and ab initio study on "d" superstructure in sedimentary dolomite

    CERN Document Server

    Shen, Zhizhang; Szlufarska, Izabela; Brown, Philip E; Xu, Huifang

    2016-01-01

    Nano-precipitates with tripled periodicity along the c-axis are observed in a Ca-rich dolomite sample from Proterozoic carbonate rocks with "molar tooth" structure. This observation is consistent with previous description of d reflections. High-angle annular dark-field STEM imaging (or Z-contrast imaging) that avoids dynamic diffraction as seen in electron diffraction and high-resolution TEM imaging modes, confirms that d reflections correspond to nanoscale precipitates aligned parallel to (001) of the host dolomite. The lamellae precipitates have a cation ordering sequence of Ca-Ca-Mg-Ca-Ca- Mg along the c direction resulting in a chemical composition of Ca0.67Mg0.33CO3. This superstructure is attributed to the extra or d reflections, thus is referred to as the d superstructure in this study. The structure can be simply described as interstratified calcite/dolomite. The crystal structure of the d superstructure calculated from density functional theory (DFT) has a space group of P31c and has a and c unit-cel...

  15. A ROBUST COMBINATORIAL APPROACH BASED ON P-GRAPH FOR SUPERSTRUCTURE GENERATION IN DOWNSTREAM BIOPROCESSES

    Directory of Open Access Journals (Sweden)

    Xiaohui Xu

    2015-03-01

    Full Text Available Abstract In the production of chemicals from fermentation, the cost of downstream purification constitutes the major portion of the total production cost. Since the bioprocess generally contains a large amount of biochemical separation units, its flowsheets are complex. How to generate the rigorous superstructure of the downstream bioprocess is a primary problem and key step. In this work, a robust combined approach based on the P-graph was proposed to generate the rigorous superstructure of the downstream process of fermentation. This method integrates the hierarchical decomposition of the heuristics with P-graph-based algorithm MSG with the advantages including: (1 Different design flowsheets could be evaluated simultaneously; (2 An unique bipartite graph, P-graph, was introduced, which could represent the maximum structure clearly and intuitively; (3 The rigorous superstructure could be automatically generated. The validity of the present method was verified with two practical bioprocesses. Results show that the effective processes and the adequate operation units could be determined in the beginning stage of the design, and the tedious reforming steps during process synthesis could be avoided.

  16. Superstructure-based Design and Optimization of Batch Biodiesel Production Using Heterogeneous Catalysts

    Science.gov (United States)

    Nuh, M. Z.; Nasir, N. F.

    2017-08-01

    Biodiesel as a fuel comprised of mono alkyl esters of long chain fatty acids derived from renewable lipid feedstock, such as vegetable oil and animal fat. Biodiesel production is complex process which need systematic design and optimization. However, no case study using the process system engineering (PSE) elements which are superstructure optimization of batch process, it involves complex problems and uses mixed-integer nonlinear programming (MINLP). The PSE offers a solution to complex engineering system by enabling the use of viable tools and techniques to better manage and comprehend the complexity of the system. This study is aimed to apply the PSE tools for the simulation of biodiesel process and optimization and to develop mathematical models for component of the plant for case A, B, C by using published kinetic data. Secondly, to determine economic analysis for biodiesel production, focusing on heterogeneous catalyst. Finally, the objective of this study is to develop the superstructure for biodiesel production by using heterogeneous catalyst. The mathematical models are developed by the superstructure and solving the resulting mixed integer non-linear model and estimation economic analysis by using MATLAB software. The results of the optimization process with the objective function of minimizing the annual production cost by batch process from case C is 23.2587 million USD. Overall, the implementation a study of process system engineering (PSE) has optimized the process of modelling, design and cost estimation. By optimizing the process, it results in solving the complex production and processing of biodiesel by batch.

  17. Wikipedia ranking of world universities

    Science.gov (United States)

    Lages, José; Patt, Antoine; Shepelyansky, Dima L.

    2016-03-01

    We use the directed networks between articles of 24 Wikipedia language editions for producing the wikipedia ranking of world Universities (WRWU) using PageRank, 2DRank and CheiRank algorithms. This approach allows to incorporate various cultural views on world universities using the mathematical statistical analysis independent of cultural preferences. The Wikipedia ranking of top 100 universities provides about 60% overlap with the Shanghai university ranking demonstrating the reliable features of this approach. At the same time WRWU incorporates all knowledge accumulated at 24 Wikipedia editions giving stronger highlights for historically important universities leading to a different estimation of efficiency of world countries in university education. The historical development of university ranking is analyzed during ten centuries of their history.

  18. Low-rank coal research

    Energy Technology Data Exchange (ETDEWEB)

    Weber, G. F.; Laudal, D. L.

    1989-01-01

    This work is a compilation of reports on ongoing research at the University of North Dakota. Topics include: Control Technology and Coal Preparation Research (SO{sub x}/NO{sub x} control, waste management), Advanced Research and Technology Development (turbine combustion phenomena, combustion inorganic transformation, coal/char reactivity, liquefaction reactivity of low-rank coals, gasification ash and slag characterization, fine particulate emissions), Combustion Research (fluidized bed combustion, beneficiation of low-rank coals, combustion characterization of low-rank coal fuels, diesel utilization of low-rank coals), Liquefaction Research (low-rank coal direct liquefaction), and Gasification Research (hydrogen production from low-rank coals, advanced wastewater treatment, mild gasification, color and residual COD removal from Synfuel wastewaters, Great Plains Gasification Plant, gasifier optimization).

  19. Defect-induced change of temperature-dependent elastic constants in BCC iron

    Energy Technology Data Exchange (ETDEWEB)

    Gao, N.; Setyawan, W.; Zhang, S. H.; Wang, Z. G.

    2017-07-01

    The effects of radiation-induced defects (randomly distributed vacancies, voids, and interstitial dislocation loops) on temperature-dependent elastic constants, C11, C12, and C44 in BCC iron, are studied with molecular dynamics method. The elastic constants are found to decrease with increasing temperatures for all cases containing different defects. The presence of vacancies, voids, or interstitial loops further decreases the elastic constants. For a given number of point defects, the randomly distributed vacancies show the strongest effect compared to voids or interstitial loops. All these results are expected to provide useful information to combine with experimental results for further understanding of radiation damage.

  20. Evidence for Vacancy Mechanism in Grain Boundary Diffusion in bcc Iron: A Molecular-Dynamics Study

    Science.gov (United States)

    Kwok, Thomas; Ho, P. S.; Yip, Sidney; Balluffi, R. W.; Bristowe, P. D.; Brokman, A.

    1981-10-01

    The dominance of vacancy migration in grain boundary self-diffusion has been established by molecular-dynamics simulation of a bcc iron Σ=5 tilt boundary. The data yielded a reasonable value of the activation energy for migration and showed that the jump processes are highly structure dependent. The use of a temperature-dependent transition-probability matrix to describe the diffusion of the vacancies in the grain boundary is suggested. Formation of one type of boundary interstitial was observed, and the interstitial was found to be immobile during its lifetime.

  1. Statistical methods for ranking data

    CERN Document Server

    Alvo, Mayer

    2014-01-01

    This book introduces advanced undergraduate, graduate students and practitioners to statistical methods for ranking data. An important aspect of nonparametric statistics is oriented towards the use of ranking data. Rank correlation is defined through the notion of distance functions and the notion of compatibility is introduced to deal with incomplete data. Ranking data are also modeled using a variety of modern tools such as CART, MCMC, EM algorithm and factor analysis. This book deals with statistical methods used for analyzing such data and provides a novel and unifying approach for hypotheses testing. The techniques described in the book are illustrated with examples and the statistical software is provided on the authors’ website.

  2. In vivo assessment of optical properties of basal cell carcinoma and differentiation of BCC subtypes by high-definition optical coherence tomography

    DEFF Research Database (Denmark)

    Boone, Marc; Suppa, Mariano; Miyamoto, Makiko

    2016-01-01

    part of epidermis and (ii) increased epidermal thickness (E-T). IV-OP of nodular BCC with good to high DA and NPV were (i) less negative µraf in papillary dermis compared to normal adjacent skin and (ii) significantly decreased E-T and papillary dermal thickness (PD-T). In infiltrative BCC (i) high......High-definition optical coherence tomography (HD-OCT) features of basal cell carcinoma (BCC) have recently been defined. We assessed in vivo optical properties (IV-OP) of BCC, by HD-OCT. Moreover their critical values for BCC subtype differentiation were determined. The technique of semi-log plot...... whereby an exponential function becomes linear has been implemented on HD-OCT signals. The relative attenuation factor (µraf ) at different skin layers could be assessed.. IV-OP of superficial BCC with high diagnostic accuracy (DA) and high negative predictive values (NPV) were (i) decreased µraf in lower...

  3. Ranking nodes in growing networks: When PageRank fails

    Science.gov (United States)

    Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng

    2015-11-01

    PageRank is arguably the most popular ranking algorithm which is being applied in real systems ranging from information to biological and infrastructure networks. Despite its outstanding popularity and broad use in different areas of science, the relation between the algorithm’s efficacy and properties of the network on which it acts has not yet been fully understood. We study here PageRank’s performance on a network model supported by real data, and show that realistic temporal effects make PageRank fail in individuating the most valuable nodes for a broad range of model parameters. Results on real data are in qualitative agreement with our model-based findings. This failure of PageRank reveals that the static approach to information filtering is inappropriate for a broad class of growing systems, and suggest that time-dependent algorithms that are based on the temporal linking patterns of these systems are needed to better rank the nodes.

  4. Classification of different kinds of pesticide residues on lettuce based on fluorescence spectra and WT-BCC-SVM algorithm

    Science.gov (United States)

    Zhou, Xin; Jun, Sun; Zhang, Bing; Jun, Wu

    2017-07-01

    In order to improve the reliability of the spectrum feature extracted by wavelet transform, a method combining wavelet transform (WT) with bacterial colony chemotaxis algorithm and support vector machine (BCC-SVM) algorithm (WT-BCC-SVM) was proposed in this paper. Besides, we aimed to identify different kinds of pesticide residues on lettuce leaves in a novel and rapid non-destructive way by using fluorescence spectra technology. The fluorescence spectral data of 150 lettuce leaf samples of five different kinds of pesticide residues on the surface of lettuce were obtained using Cary Eclipse fluorescence spectrometer. Standard normalized variable detrending (SNV detrending), Savitzky-Golay coupled with Standard normalized variable detrending (SG-SNV detrending) were used to preprocess the raw spectra, respectively. Bacterial colony chemotaxis combined with support vector machine (BCC-SVM) and support vector machine (SVM) classification models were established based on full spectra (FS) and wavelet transform characteristics (WTC), respectively. Moreover, WTC were selected by WT. The results showed that the accuracy of training set, calibration set and the prediction set of the best optimal classification model (SG-SNV detrending-WT-BCC-SVM) were 100%, 98% and 93.33%, respectively. In addition, the results indicated that it was feasible to use WT-BCC-SVM to establish diagnostic model of different kinds of pesticide residues on lettuce leaves.

  5. Enhanced moments in bcc Co{sub 1−x}Mn{sub x} on MgO(001)

    Energy Technology Data Exchange (ETDEWEB)

    Snow, R.J.; Bhatkar, H. [Department of Physics, Montana State University, Bozeman, MT 59715 (United States); N' Diaye, A.T.; Arenholz, E. [Advanced Light Source, Lawrence Berkeley Nat. Labs, Berkeley, CA 94720 (United States); Idzerda, Y.U., E-mail: Idzerda@montana.edu [Department of Physics, Montana State University, Bozeman, MT 59715 (United States)

    2016-12-01

    A 40% enhancement of the Co magnetic moment has been found for thin films of bcc Co{sub 1−x}Mn{sub x} grown by molecular beam epitaxy on a 2 nm bcc Fe buffer layer on MgO(001). Although the bcc phase cannot be stabilized in the bulk, we confirm that it is stable as an epitaxial film in the composition range x=0–0.7. Using X-ray absorption spectroscopy and X-ray magnetic circular dichroism, we show that the Co moment is a maximum of 2.38 μ{sub B} at x=0.24, while the net Mn moment remains roughly constant until x=0.24, then drops steadily. Mn is found to align parallel with Co for all ferromagnetic concentrations, up to x=0.7, where the total moment of the film abruptly collapses to zero, most likely due to the onset of the observed structural instability. - Highlights: • Stabilization of bcc Co{sub 1−x}Mn{sub x} films in the composition range of x=0 to 0.7. • Enhancement of Co moment by 40% from pure bcc Co. • Parallel alignment of Mn moment and Co moment. • Measured the elemental moment of Co and Mn as a function of composition.

  6. Isolation and Characterization of a Hybrid Respiratory Supercomplex Consisting of Mycobacterium tuberculosis Cytochrome bcc and Mycobacterium smegmatis Cytochrome aa3.

    Science.gov (United States)

    Kim, Mi-Sun; Jang, Jichan; Ab Rahman, Nurlilah Binte; Pethe, Kevin; Berry, Edward A; Huang, Li-Shar

    2015-06-05

    Recently, energy production pathways have been shown to be viable antitubercular drug targets to combat multidrug-resistant tuberculosis and eliminate pathogen in the dormant state. One family of drugs currently under development, the imidazo[1,2-a]pyridine derivatives, is believed to target the pathogen's homolog of the mitochondrial bc1 complex. This complex, denoted cytochrome bcc, is highly divergent from mitochondrial Complex III both in subunit structure and inhibitor sensitivity, making it a good target for drug development. There is no soluble cytochrome c in mycobacteria to transport electrons from the bcc complex to cytochrome oxidase. Instead, the bcc complex exists in a "supercomplex" with a cytochrome aa3-type cytochrome oxidase, presumably allowing direct electron transfer. We describe here purification and initial characterization of the mycobacterial cytochrome bcc-aa3 supercomplex using a strain of M. smegmatis that has been engineered to express the M. tuberculosis cytochrome bcc. The resulting hybrid supercomplex is stable during extraction and purification in the presence of dodecyl maltoside detergent. It is hoped that this purification procedure will potentiate functional studies of the complex as well as crystallographic studies of drug binding and provide structural insight into a third class of the bc complex superfamily. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Structure and creep of Russian reactor steels with a BCC structure

    Science.gov (United States)

    Sagaradze, V. V.; Kochetkova, T. N.; Kataeva, N. V.; Kozlov, K. A.; Zavalishin, V. A.; Vil'danova, N. F.; Ageev, V. S.; Leont'eva-Smirnova, M. V.; Nikitina, A. A.

    2017-05-01

    The structural phase transformations have been revealed and the characteristics of the creep and long-term strength at 650, 670, and 700°C and 60-140 MPa have been determined in six Russian reactor steels with a bcc structure after quenching and high-temperature tempering. Creep tests were carried out using specially designed longitudinal and transverse microsamples, which were fabricated from the shells of the fuel elements used in the BN-600 fast neutron reactor. It has been found that the creep rate of the reactor bcc steels is determined by the stability of the lath martensitic and ferritic structures in relation to the diffusion processes of recovery and recrystallization. The highest-temperature oxide-free steel contains the maximum amount of the refractory elements and carbides. The steel strengthened by the thermally stable Y-Ti nanooxides has a record high-temperature strength. The creep rate at 700°C and 100 MPa in the samples of this steel is lower by an order of magnitude and the time to fracture is 100 times greater than that in the oxide-free reactor steels.

  8. Interaction of Ti and Cr atoms with point defects in bcc vanadium: A DFT study

    Science.gov (United States)

    Boev, A. O.; Aksyonov, D. A.; Kartamyshev, A. I.; Maksimenko, V. N.; Nelasov, I. V.; Lipnitskii, A. G.

    2017-08-01

    The development of low-swelling radiation-resistant alloys is vital for the creation of reliable fusion reactors. In this article, we revisit the long-standing problem of very low radiation swelling in V-Ti-Cr alloys by means of DFT calculations. In particular, we study double and triple interactions of point defects such as solutes, vacancies and self-interstitial atoms in bcc V. According to our results titanium atom and vacancy are strongly attracted and in addition to pairs form highly stable triple Ti-Vacancy-Ti complexes, which are absent in the case of chromium. By using an analytic model of void growth and using calculated binding energies of point defect complexes in bcc vanadium we obtain three orders of magnitude reduction of swelling rate due to the formation of Ti-Vacancy-Ti complexes, which allows to explain experimental observations. Finally, we explain the causes of the strong attraction between titanium and vacancy using geometry and electronic structure analysis.

  9. Co thin film with metastable bcc structure formed on GaAs(111 substrate

    Directory of Open Access Journals (Sweden)

    Minakawa Shigeyuki

    2014-07-01

    Full Text Available Co thin films are prepared on GaAs(111 substrates at temperatures ranging from room temperature to 600 ºC by radio-frequency magnetron sputtering. The growth behavior and the detailed resulting film structure are investigated by in-situ reflection high-energy electron diffraction and X-ray diffraction. In early stages of film growth at temperatures lower than 200 ºC, Co crystals with metastable A2 (bcc structure are formed, where the crystal structure is stabilized through hetero-epitaxial growth. With increasing the film thickness beyond 2 nm, the metastable structure starts to transform into more stable A1 (fcc structure through atomic displacements parallel to the A2{110} close-packed planes. The crystallographic orientation relationship between the A2 and the transformed A1 crystals is A1{111} || A2{110}. When the substrate temperature is higher than 400 ºC, Ga atoms of substrate diffuse into the Co films and a Co-Ga alloy with bcc-based ordered structure of B2 is formed.

  10. Nanoscale Twinning and Martensitic Transformation in Shock-Deformed BCC Metals

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, L L

    2005-03-22

    Shock-induced twinning and martensitic transformation in BCC-based polycrystalline metals (Ta and U-6wt%Nb) have been observed and studied using transmission electron microscopy (TEM). The length-scale of domain thickness for both twin lamella and martensite phase is found to be smaller than 100 nm. While deformation twinning of {l_brace}112{r_brace}<111>-type is found in Ta when shock-deformed at 15 GPa, both twinning and martensitic transformation are found in Ta when shock-deformed at 45 GPa. Similar phenomena of nanoscale twinning and martensitic transformation are also found in U6Nb shock-deformed at 30 GPa. Since both deformation twinning and martensitic transformation occurred along the {l_brace}211{r_brace}{sub b} planes associated with high resolved shear stresses, it is suggested that both can be regarded as alternative paths for shear transformations to occur in shock-deformed BCC metals. Heterogeneous nucleation mechanisms for shock-induced twinning and martensitic transformation are proposed and discussed.

  11. bcc-to-hcp transformation pathways for iron versus hydrostatic pressure: Coupled shuffle and shear modes

    Science.gov (United States)

    Liu, J. B.; Johnson, D. D.

    2009-04-01

    Using density-functional theory, we calculate the potential-energy surface (PES), minimum-energy pathway (MEP), and transition state (TS) versus hydrostatic pressure σhyd for the reconstructive transformation in Fe from body-centered cubic (bcc) to hexagonal closed-packed (hcp). At fixed σhyd , the PES is described by coupled shear (γ) and shuffle (η) modes and is determined from structurally minimized hcp-bcc energy differences at a set of (η,γ) . We fit the PES using symmetry-adapted polynomials, permitting the MEP to be found analytically. The MEP is continuous and fully explains the transformation and its associated magnetization and volume discontinuity at TS. We show that σhyd (while not able to induce shear) dramatically alters the MEP to drive reconstruction by a shuffle-only mode at ≤30GPa , as observed. Finally, we relate our polynomial-based results to Landau and nudge-elastic-band approaches and show they yield incorrect MEP in general.

  12. University Rankings in Critical Perspective

    Science.gov (United States)

    Pusser, Brian; Marginson, Simon

    2013-01-01

    This article addresses global postsecondary ranking systems by using critical-theoretical perspectives on power. This research suggests rankings are at once a useful lens for studying power in higher education and an important instrument for the exercise of power in service of dominant norms in global higher education. (Contains 1 table and 1…

  13. University Ranking as Social Exclusion

    Science.gov (United States)

    Amsler, Sarah S.; Bolsmann, Chris

    2012-01-01

    In this article we explore the dual role of global university rankings in the creation of a new, knowledge-identified, transnational capitalist class and in facilitating new forms of social exclusion. We examine how and why the practice of ranking universities has become widely defined by national and international organisations as an important…

  14. PageRank tracker: from ranking to tracking.

    Science.gov (United States)

    Gong, Chen; Fu, Keren; Loza, Artur; Wu, Qiang; Liu, Jia; Yang, Jie

    2014-06-01

    Video object tracking is widely used in many real-world applications, and it has been extensively studied for over two decades. However, tracking robustness is still an issue in most existing methods, due to the difficulties with adaptation to environmental or target changes. In order to improve adaptability, this paper formulates the tracking process as a ranking problem, and the PageRank algorithm, which is a well-known webpage ranking algorithm used by Google, is applied. Labeled and unlabeled samples in tracking application are analogous to query webpages and the webpages to be ranked, respectively. Therefore, determining the target is equivalent to finding the unlabeled sample that is the most associated with existing labeled set. We modify the conventional PageRank algorithm in three aspects for tracking application, including graph construction, PageRank vector acquisition and target filtering. Our simulations with the use of various challenging public-domain video sequences reveal that the proposed PageRank tracker outperforms mean-shift tracker, co-tracker, semiboosting and beyond semiboosting trackers in terms of accuracy, robustness and stability.

  15. LatticeLibrary and BccFccRaycaster: Software for processing and viewing 3D data on optimal sampling lattices

    Directory of Open Access Journals (Sweden)

    Elisabeth Schold Linnér

    2016-01-01

    Full Text Available In this paper, we present LatticeLibrary, a C++ library for general processing of 2D and 3D images sampled on arbitrary lattices. The current implementation supports the Cartesian Cubic (CC, Body-Centered Cubic (BCC and Face-Centered Cubic (FCC lattices, and is designed to facilitate addition of other sampling lattices. We also introduce BccFccRaycaster, a plugin for the existing volume renderer Voreen, making it possible to view CC, BCC and FCC data, using different interpolation methods, with the same application. The plugin supports nearest neighbor and trilinear interpolation at interactive frame rates. These tools will enable further studies of the possible advantages of non-Cartesian lattices in a wide range of research areas.

  16. Assessment and correction of BCC_CSM's performance in capturing leading modes of summer precipitation over North Asia

    KAUST Repository

    Gong, Zhiqiang

    2017-11-07

    This article examines the ability of Beijing Climate Center Climate System Model (BCC_CSM) in demonstrating the prediction accuracy and the leading modes of the summer precipitation over North Asia (NA). A dynamic-statistic combined approach for improving the prediction accuracy and the prediction of the leading modes of the summer precipitation over NA is proposed. Our results show that the BCC_CSM can capture part of the spatial anomaly features of the first two leading modes of NA summer precipitation. Moreover, BCC_CSM regains relationships such that the first and second mode of the empirical orthogonal function (EOF1 and EOF2) of NA summer precipitation, respectively, corresponds to the development of the El Niño and La Niña conditions in the tropical East Pacific. Nevertheless, BCC_CSM exhibits limited prediction skill over most part of NA and presents a deficiency in reproducing the EOF1\\'s and EOF2\\'s spatial pattern over central NA and EOF2\\'s interannual variability. This can be attributed as the possible reasons why the model is unable to capture the correct relationships among the basic climate elements over the central NA, lacks in its ability to reproduce a consistent zonal atmospheric pattern over NA, and has bias in predicting the relevant Sea Surface Temperature (SST) modes over the tropical Pacific and Indian Ocean regions. Based on the proposed dynamic-statistic combined correction approach, compared with the leading modes of BCC_CSM\\'s original prediction, anomaly correlation coefficients of corrected EOF1/EOF2 with the tropical Indian Ocean SST are improved from 0.18/0.36 to 0.51/0.62. Hence, the proposed correction approach suggests that the BCC_CSM\\'s prediction skill for the summer precipitation prediction over NA and its ability to capture the dominant modes could be certainly improved by choosing proper historical analogue information.

  17. A spray-drying strategy for synthesis of nanoscale metal-organic frameworks and their assembly into hollow superstructures

    Science.gov (United States)

    Carné-Sánchez, Arnau; Imaz, Inhar; Cano-Sarabia, Mary; Maspoch, Daniel

    2013-03-01

    Metal-organic frameworks (MOFs) are among the most attractive porous materials known today. Their miniaturization to the nanoscale—into nanoMOFs—is expected to serve myriad applications from drug delivery to membranes, to open up novel avenues to more traditional storage and catalysis applications, and to enable the creation of sophisticated superstructures. Here, we report the use of spray-drying as a versatile methodology to assemble nanoMOFs, yielding spherical hollow superstructures with diameters smaller than 5 µm. This strategy conceptually mimics the emulsions used by chemists to confine the synthesis of materials, but does not require secondary immiscible solvents or surfactants. We demonstrate that the resulting spherical, hollow superstructures can be processed into stable colloids, whose disassembly by sonication affords discrete, homogeneous nanoMOFs. This spray-drying strategy enables the construction of multicomponent MOF superstructures, and the encapsulation of guest species within these superstructures. We anticipate that this will provide new routes to capsules, reactors and composite materials.

  18. Preparation of flowerlike BiOBr/Bi2MoO6 composite superstructures and the adsorption behavior to dyes

    Science.gov (United States)

    He, Qiong; Ni, Yonghong; Ye, Shiyong

    2017-05-01

    Flowerlike BiOBr/Bi2MoO6 composite superstructures were synthesized by a simple solvothermal route with subsequent direct precipitation at room temperature, employing bismuth nitrate, sodium molybdate, and cetyltrimethylammonium bromide (CTAB) as the raw materials. The phase and the morphology of the as-prepared products were characterized by SEM, TEM, SAED, XRD and EDS. BET investigation proved the mesoporous structure of flowerlike BiOBr/Bi2MoO6 composite superstructures. It was found that the composite superstructures exhibited higher adsorption ability to methylene blue (MB) and pyronine B (PB) dyes from their solutions than single component (BiOBr or Bi2MoO6). As a case, the adsorption behavior of MB aqueous solution on BiOBr/Bi2MoO6 composite superstructures was detailedly studied, including the adsorption isotherm, kinetics and thermodynamic parameters. The results indicated that flowerlike BiOBr/Bi2MoO6 composite superstructures have potential applications in the field of wastewater treatment.

  19. Universal scaling in sports ranking

    Science.gov (United States)

    Deng, Weibing; Li, Wei; Cai, Xu; Bulou, Alain; Wang, Qiuping A.

    2012-09-01

    Ranking is a ubiquitous phenomenon in human society. On the web pages of Forbes, one may find all kinds of rankings, such as the world's most powerful people, the world's richest people, the highest-earning tennis players, and so on and so forth. Herewith, we study a specific kind—sports ranking systems in which players' scores and/or prize money are accrued based on their performances in different matches. By investigating 40 data samples which span 12 different sports, we find that the distributions of scores and/or prize money follow universal power laws, with exponents nearly identical for most sports. In order to understand the origin of this universal scaling we focus on the tennis ranking systems. By checking the data we find that, for any pair of players, the probability that the higher-ranked player tops the lower-ranked opponent is proportional to the rank difference between the pair. Such a dependence can be well fitted to a sigmoidal function. By using this feature, we propose a simple toy model which can simulate the competition of players in different matches. The simulations yield results consistent with the empirical findings. Extensive simulation studies indicate that the model is quite robust with respect to the modifications of some parameters.

  20. Universal scaling in sports ranking

    CERN Document Server

    Deng, Weibing; Cai, Xu; Bulou, Alain; Wang, Qiuping A

    2011-01-01

    Ranking is a ubiquitous phenomenon in the human society. By clicking the web pages of Forbes, you may find all kinds of rankings, such as world's most powerful people, world's richest people, top-paid tennis stars, and so on and so forth. Herewith, we study a specific kind, sports ranking systems in which players' scores and prize money are calculated based on their performances in attending various tournaments. A typical example is tennis. It is found that the distributions of both scores and prize money follow universal power laws, with exponents nearly identical for most sports fields. In order to understand the origin of this universal scaling we focus on the tennis ranking systems. By checking the data we find that, for any pair of players, the probability that the higher-ranked player will top the lower-ranked opponent is proportional to the rank difference between the pair. Such a dependence can be well fitted to a sigmoidal function. By using this feature, we propose a simple toy model which can simul...

  1. Grain-scale characterization of FCC/BCC correspondence relations and variant selection

    Science.gov (United States)

    He, Youliang

    The misorientations between FCC and BCC crystals are characterized according to the common lattice correspondence relationships in terms of their parallelism conditions. Individual variants of the six models, namely the Bain, Kurdjumov-Sachs, Nishiyama-Wassermann, Pitsch, Greninger-Troiano and inverse Greninger-Troiano relations, are identified and represented in both pole figure form and in Rodrigues-Frank space with respect to various coordinate frames. In this way, the relations between the variants of these models are clarified. The orientations of the kamacite (BCC) lamellae transformed from a single prior-taenite (FCC) grain in the Gibeon meteorite were measured by analyzing the electron backscatter diffraction patterns. The local misorientations between individual FCC and BCC crystals along their common interfaces were computed and are compared with the common lattice correspondence relationships. The orientation relations between the alpha and gamma phases in the plessite regions are also characterized. The Neumann bands (mechanical twins) and their orientation variations within individual kamacite lamellae were studied and analyzed. A Nb-bearing TRIP steel was control rolled and a certain amount of austenite was retained through appropriate heat treatment. EBSD measurements were conducted on specimens deformed to various reductions and the textures (ODF's) of both the gamma and alpha phases were obtained from the measured data points. The orientations of the bainite formed within individual prior-austenite grains are compared to those expected from the common correspondence relationships and the average orientation of the prior-austenite grain. The crystallography of the bainite laths within a single packet is also characterized. The orientations of the bainite formed from individual prior-austenite grains are analyzed with respect to their parent orientations. The occurrence of variant selection at the grain scale was examined using a dislocation

  2. Comparative analysis of different joining techniques to improve the passive fit of cobalt-chromium superstructures.

    Science.gov (United States)

    Barbi, Francisco C L; Camarini, Edevaldo T; Silva, Rafael S; Endo, Eliana H; Pereira, Jefferson R

    2012-12-01

    The influence of different joining techniques on passive fit at the interface structure/abutment of cobalt-chromium (Co-Cr) superstructures has not yet been clearly established. The purpose of this study was to compare 3 different techniques of joining Co-Cr superstructures by measuring the resulting marginal misfit in a simulated prosthetic assembly. A specially designed metal model was used for casting, sectioning, joining, and measuring marginal misfit. Forty-five cast bar-type superstructures were fabricated in a Co-Cr alloy and randomly assigned by drawing lots to 3 groups (n=15) according to the joining method used: conventional gas-torch brazing (G-TB), laser welding (LW), and tungsten inert gas welding (TIG). Joined specimens were assembled onto abutment analogs in the metal model with the 1-screw method. The resulting marginal misfit was measured with scanning electron microscopy (SEM) at 3 different points: distal (D), central (C), and mesial (M) along the buccal aspect of both abutments: A (tightened) and B (without screw). The Levene test was used to evaluate variance homogeneity and then the Welsch ANOVA for heteroscedastic data (α=.05). Significant differences were found on abutment A between groups G-TB and LW (P=.013) measured mesially and between groups G-TB and TIG (P=.037) measured centrally. On abutment B, significant differences were found between groups G-TB and LW (PTIG (PTIG (P=.007) measured distally; and groups G-TB and TIG (P=.001) and LW and TIG (P=.007) measured centrally. The method used for joining Co-Cr prosthetic structures had an influence on the level of resulting passive fit. Structures joined by the tungsten inert gas method produced better mean results than did the brazing or laser method. Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  3. System design optimization for stand-alone photovoltaic systems sizing by using superstructure model

    Science.gov (United States)

    Azau, M. A. M.; Jaafar, S.; Samsudin, K.

    2013-06-01

    Although the photovoltaic (PV) systems have been increasingly installed as an alternative and renewable green power generation, the initial set up cost, maintenance cost and equipment mismatch are some of the key issues that slows down the installation in small household. This paper presents the design optimization of stand-alone photovoltaic systems using superstructure model where all possible types of technology of the equipment are captured and life cycle cost analysis is formulated as a mixed integer programming (MIP). A model for investment planning of power generation and long-term decision model are developed in order to help the system engineer to build a cost effective system.

  4. Polymersomes with asymmetric membranes and self-assembled superstructures using pentablock quintopolymers resolved by electron tomography

    KAUST Repository

    Haataja, J. S.

    2018-01-09

    Polystyrene-block-poly(1,4-isoprene)-block-poly(dimethyl siloxane)-block-poly(tert-butyl methacrylate)-block-poly(2-vinyl pyridine), PS-b-PI-b-PDMS-b-PtBMA-b-P2VP, self-assembles in acetone into polymersomes with asymmetric (directional) PI-b-PDMS membranes. The polymersomes, in turn, self-assemble into superstructures. Analogically to supravesicular structures at a smaller length scale, we refer to them as suprapolymersome structures. Electron tomograms are shown to be invaluable in the structural assessment of such complex self-assemblies.

  5. PageRank of integers

    Science.gov (United States)

    Frahm, K. M.; Chepelianskii, A. D.; Shepelyansky, D. L.

    2012-10-01

    We up a directed network tracing links from a given integer to its divisors and analyze the properties of the Google matrix of this network. The PageRank vector of this matrix is computed numerically and it is shown that its probability is approximately inversely proportional to the PageRank index thus being similar to the Zipf law and the dependence established for the World Wide Web. The spectrum of the Google matrix of integers is characterized by a large gap and a relatively small number of nonzero eigenvalues. A simple semi-analytical expression for the PageRank of integers is derived that allows us to find this vector for matrices of billion size. This network provides a new PageRank order of integers.

  6. Combined molecular and spin dynamics simulation of bcc iron with lattice vacancies

    Science.gov (United States)

    Mudrick, Mark; Eisenbach, Markus; Perera, Dilina; Stocks, G. Malcolm; Landau, David P.

    2017-11-01

    Using an atomistic model that treats both translational and spin degrees of freedom, we have performed combined molecular and spin dynamics simulations to study dynamic properties of BCC iron with varying vacancy concentrations. Atomic interactions are described by an empirical many-body potential while spin interactions are handled with a Heisenberg-like Hamiltonian with a coordinate dependent exchange interaction. By calculating the Fourier transform of spatial and temporal correlation functions, vibrational and magnetic excitations have been studied. The creation of vacancies in the material has shown splitting of the characteristic transverse spin-wave excitations, indicating the production of additional excitation modes. By merging two vacancies to form a nearest neighbor pair, we find that these modes become more distinct. Investigation of longitudinal spin-wave excitations reveals interactions between constituent components of the split transverse excitations.

  7. Properties of grain boundaries in BCC iron and iron-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Terentyev, D.; He, Xinfu

    2010-08-15

    The report contains a summary of work done within the collaboration established between SCK-CEN and CIEA, performed during the internship of Xinfu He (CIAE) in the period of September 2009 to June 2010. In this work, we have carried out an atomistic study addressing the properties of grain boundaries in BCC Fe and Fe-Cr alloys. Throughout this work we report on the structural and cohesive properties of grain boundaries; thermal stability; interaction of grain boundaries with He and diffusivity of He in the core of the grain boundaries; equilibrium segregation of Cr near the grain boundary zone; cleavage fracture of grain boundaries; influence of the Cr precipitates, voids and He bubbles on the structure and strength of grain boundaries.

  8. Solute/impurity diffusivities in bcc Fe: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chong [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian 116024 (China); School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Fu, Jie; Li, Ruihuan [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian 116024 (China); Zhang, Pengbo [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Zhao, Jijun, E-mail: zhaojj@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian 116024 (China); Dong, Chuang [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian 116024 (China); School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2014-12-15

    Chinese low activation martensitic steel (CLAM) has been designed with decreased W content and increased Ta content to improve performance. We performed first-principles calculations to investigate the diffusion properties of solute element (Cr, W, Mn, V, Ta) and C diffusion with a nearby solute element inside bcc Fe. The self-diffusion coefficients and solute diffusion coefficients in Fe host were derived using the nine-frequency model. A relatively lower diffusivity was observed for W in paramagnetic state, implying enriched W concentration inside Fe host. The solute atom interacts strongly with C impurity, depending on the interatomic distance. According to our calculations, formation of Ta carbide precipitates is energetically preferred by trapping C impurity around Ta atom. Our theoretical results are helpful for investigating the evolution of microstructure of steels for engineering applications.

  9. Effects of applied strain on nanoscale self-interstitial cluster formation in BCC iron

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Ning; Setyawan, Wahyu; Kurtz, Richard J.; Wang, Zhiguang

    2017-09-01

    The effect of applied strains on the configurational evolution of self-interstitial clusters in BCC iron (Fe) is explored with atomistic simulations. A novel cluster configuration is discovered at low temperatures (<600 K), which consists of <110> dumbbells and <111> crowdions in a specific configuration, resulting in an immobile defect. The stability and diffusion of this cluster at higher temperatures is explored. In addition, an anisotropy distribution factor of a particular [hkl] interstitial loop within the family of loops is calculated as a function of strain. The results show that loop anisotropy is governed by the angle between the stress direction and the orientation of the <111> crowdions in the loop, and directly linked to the stress induced preferred nucleation of self-interstitial atoms.

  10. Study of loop-loop and loop-edge dislocation interactions in bcc iron

    DEFF Research Database (Denmark)

    Osetsky, Y.N.; Bacon, D.J.; Gao, F.

    2000-01-01

    that the evolution of heterogeneities such as dislocation decoration and rafts has serious impacts on the mechanical properties on neutron-irradiated metals. In the present work, atomic-scale computer modelling (ASCM) has been applied to study the mechanisms for the formation of such microstructure in bcc iron....... It is shown that glissile clusters with parallel Burgers vectors interact strongly and can form extended immobile complexes, i.e., rafts. Similar attractive interaction exists between dislocation loops and an edge dislocation. These two mechanisms may be responsible for the formation of extended complexes...... of dislocation loops below the extra half-plane of edge dislocations. The interaction energies between loops and between an edge dislocation and loops has been calculated as a function of distance using ASCM and the results for long-range interactions are in good agreement with the results of isotropic...

  11. Paramagnetic atom number and paramagnetic critical pressure of the sc, bcc and fcc Ising nanolattices

    Energy Technology Data Exchange (ETDEWEB)

    Şarlı, Numan, E-mail: numansarli82@gmail.com

    2015-01-15

    The effects of the magnetic atom number in the unit volume on the magnetic properties are investigated by using sc (n=8), bcc (n=9) and fcc (n=14) Ising NLs within the effective field theory with correlations. We find that the magnetic properties expand as the magnetic atom number increases in the unit volume and this expanding constitutes an elliptical path at T{sub C}. The effect of the magnetic atom number (n) in the unit volume on the magnetic properties (mp) appear as n{sub sc}bcc}bcc}bcc and fcc Ising

  12. Ranking in evolving complex networks

    Science.gov (United States)

    Liao, Hao; Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng; Zhou, Ming-Yang

    2017-05-01

    Complex networks have emerged as a simple yet powerful framework to represent and analyze a wide range of complex systems. The problem of ranking the nodes and the edges in complex networks is critical for a broad range of real-world problems because it affects how we access online information and products, how success and talent are evaluated in human activities, and how scarce resources are allocated by companies and policymakers, among others. This calls for a deep understanding of how existing ranking algorithms perform, and which are their possible biases that may impair their effectiveness. Many popular ranking algorithms (such as Google's PageRank) are static in nature and, as a consequence, they exhibit important shortcomings when applied to real networks that rapidly evolve in time. At the same time, recent advances in the understanding and modeling of evolving networks have enabled the development of a wide and diverse range of ranking algorithms that take the temporal dimension into account. The aim of this review is to survey the existing ranking algorithms, both static and time-aware, and their applications to evolving networks. We emphasize both the impact of network evolution on well-established static algorithms and the benefits from including the temporal dimension for tasks such as prediction of network traffic, prediction of future links, and identification of significant nodes.

  13. Comparison of interface structure of BCC metallic (Fe, V and Nb) films on MgO (100) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Du, J.L. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Zhang, L.Y. [State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an, 710049 (China); Fu, E.G., E-mail: efu@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Ding, X., E-mail: dingxd@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an, 710049 (China); Yu, K.Y., E-mail: kyyu@cup.edu.cn [Department of Materials Science and Engineering, China University of Petroleum, Beijing 102249 (China); Wang, Y.G. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Wang, Y.Q.; Baldwin, J.K. [Experimental Physical Sciences Directorate, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Wang, X.J. [State Key Laboratory of Advanced Optical Communication Systems and Networks, Peking University, Beijing 100871 (China); Xu, P. [Department of Chemistry, Harbin Institute of Technology, Harbin, Heilongjiang, 150001 (China)

    2017-07-15

    Highlights: • The difference of BCC metal/MgO(100) interface configuration with various lattice mismatches is identified by experiments and simulations in terms of dislocations and work of separation. • The strength of bonds along interface is found to be the fundamental factor to determine the interface configurations between BCC metal and MgO substrate. • The combination of experiments and simulations shows that the O-atop model is the actual match type between BCC metal and MgO substrate. - Abstract: This study systematically investigates the interface structure of three body-centered-cubic (BCC) metallic (Fe, V and Nb) films grown on MgO(100) substrates through experiments and simulations. Orientation relationships of their interfaces with the different lattice mismatches exhibit cube-on-cube configurations. The misfit dislocations at these three interfaces exhibit different characteristics. High resolution TEM (HRTEM), combined with first principle calculations, demonstrates the O-atop match type between metal atoms and MgO substrates for the first time. The fundamental mechanism in determining the interface configuration is discussed in terms of the work of separation and delocalization of atomic charge density.

  14. Evaluation of the biphasic calcium composite (BCC), a novel bone cement, in a minipig model of pulmonary embolism.

    Science.gov (United States)

    Qin, Yi; Ye, Jichao; Wang, Peng; Gao, Liangbin; Jiang, Jianming; Wang, Suwei; Shen, Huiyong

    2016-01-01

    Polymethylmethacrylate (PMMA) bone cement, which is used as a filler material in vertebroplasty, is one of the major sources of pulmonary embolism in patients who have undergone vertebroplasty. In the present study, we established and evaluated two animal models of pulmonary embolism by injecting PMMA or biphasic calcium composite (BCC) bone cement with a negative surface charge. A total of 12 adults and healthy Wuzhishan minipigs were randomly divided into two groups, the PMMA and BBC groups, which received injection of PMMA bone cement and BBC bone cement with a negative surface charge in the circulation system through the pulmonary trunk, respectively, to construct animal models of pulmonary embolism. The hemodynamics, arterial blood gas, and plasma coagulation were compared between these two groups. In addition, morphological changes of the lung were examined using three-dimensional computed tomography. The results showed that both PMMA and BCC injections induced pulmonary embolisms in minipigs. Compared to the PMMA group, the BCC group exhibited significantly lower levels of arterial pressure, pulmonary artery pressure, blood oxygen pressure, blood carbon dioxide pressure, blood bicarbonate, base excess, antithrombin III and D-dimer. In conclusion, BCC bone cement with a negative surface charge is a promising filler material for vertebroplasty.

  15. Photodynamic Therapy Using Indolines-Fused-Triazoles Induces Mitochondrial Apoptosis in Human Non-Melanoma BCC Cells.

    Science.gov (United States)

    Hu, Wan-Ping; Kuo, Kung-Kai; Senadi, Gopal Chandru; Chang, Long-Sen; Wang, Jeh-Jeng

    2017-10-01

    Cancer is one of the most dreadful diseases in humans and among them non-melanoma skin cancer (NMSC) is an increasing problem in the world, that occurs more frequently in people with fair skin. Photodynamic therapy (PDT), a non-invasive treatment is widely used for the prevention and treatment of BCC cells. We previously reported an efficient synthesis of novel indolines-fused-triazoles and studied their photophysical studies. This study delineated the signaling pathways involved in the PDT effect of triazoles on BCC cells under UVA irradiation. Cell survival was evaluated by the MTT assay. The uptake of 1j in BCC cells was determined by using its fluorescence properties. Intracellular ROS and mitochondrial membrane potential (ΔΨmt) were measured using DCFH-DA probe and DiOC6 dye, respectively. Cytochrome c release was determined using immunofluorescent staining. Our data disclosed that treatment of BCC cells with 1j-UVA resulted in increased ROS generation, loss of mmp (ΔΨmt), decreased levels of Bcl-2 and Bcl-xL, increased levels of Bax and Bad, cytochrome c release, and caspase-3/PARP degradation to identify apoptotic cell death. The present study suggest that 1j-PDT may serve as a potential ancillary modality for the treatment of NMSC. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  16. RANK and RANK ligand expression in primary human osteosarcoma

    Directory of Open Access Journals (Sweden)

    Daniel Branstetter

    2015-09-01

    Our results demonstrate RANKL expression was observed in the tumor element in 68% of human OS using IHC. However, the staining intensity was relatively low and only 37% (29/79 of samples exhibited≥10% RANKL positive tumor cells. RANK expression was not observed in OS tumor cells. In contrast, RANK expression was clearly observed in other cells within OS samples, including the myeloid osteoclast precursor compartment, osteoclasts and in giant osteoclast cells. The intensity and frequency of RANKL and RANK staining in OS samples were substantially less than that observed in GCTB samples. The observation that RANKL is expressed in OS cells themselves suggests that these tumors may mediate an osteoclastic response, and anti-RANKL therapy may potentially be protective against bone pathologies in OS. However, the absence of RANK expression in primary human OS cells suggests that any autocrine RANKL/RANK signaling in human OS tumor cells is not operative, and anti-RANKL therapy would not directly affect the tumor.

  17. Historical Development and Applications of Unconventional Structure of Railway Superstructure of the Railway Infrastructure of the Slovak Republic

    Directory of Open Access Journals (Sweden)

    Ižvolt Libor

    2014-05-01

    Full Text Available In the first part, the paper deals with the origin and reasons to construct an unconventional type of the structure of railway superstructure, which is referred to as a slab track, it is shortly characterized by its development and the possible application of the railway tracks. The second part of the paper deals with the historical development of unconventional structure of railway superstructure in the Slovak Republic, characteristics of the developed and tested structures, and then in the third part of this paper, there are characterized specific structures of slab track applied in the ongoing modernization of the railway infrastructure in the Slovak Republic

  18. Evolution of Dislocation Subsystem Components During Plastic Deformation Depending on Parameters of Strengthening Phase with L12 Superstructure

    Science.gov (United States)

    Daneyko, O. I.; Kovalevskaya, T. A.; Kulaeva, N. A.; Kolupaeva, S. N.; Shalygina, T. A.

    2017-09-01

    The paper presents results of mathematical modelling of plastic deformation in dispersion-hardened materials with FCC crystal system and L12 superstructure particles. Research results show that the size and the distance between particles of the strengthening phase affect the strain hardening and the evolution of the dislocation subsystem of the FCC alloy hardened with coherent L12 superstructure particles. It is found that increased size of ordered particles or decreased distance between them enhances the abnormal growth in the flow stress and the density of the dislocation subsystem components. Investigations show that prismatic dislocation loops predominate in the dislocation subsystem of materials having a nano-dispersion strengthening phase.

  19. On-Particle Rolling Circle Amplification-Based Core-Satellite Magnetic Superstructures for MicroRNA Detection

    DEFF Research Database (Denmark)

    Tian, Bo; Qiu, Zhen; Ma, Jing

    2017-01-01

    Benefiting from the specially tailored properties of the building blocks as well as of the scaffolds, DNA-assembled core-satellite superstructures have gained increasing interest in drug delivery, imaging, and biosensing. The load of satellites plays a vital role in core-satellite superstructures......-specific nuclease in the presence of target microRNA, resulting in a release of MNPs that can be quantified in an optomagnetic sensor. The proposed biosensor has a simple mix-separate-measure strategy. For let-7b detection, the proposed biosensor offers a wide linear detection range of approximately 5 orders...

  20. The Effects on the Operating Condition of a Passenger Ship Retro-fitted with a Composite Superstructure

    DEFF Research Database (Denmark)

    Karatzas, Vasileios; Hjørnet, N. K.; Kristensen, Hans Otto Holmegaard

    2016-01-01

    As sustainability and climate change have come on the politi-cal agenda, the shipping industry will have to be operating energy efficient ships. An appealing step to achieve this goal is by designing superstructures made out of Fiber Reinforced Plastics (FRP) aiming at the reduction of the ship...... the stability of the ship. In this work, the superstructure of a RoPax ferry has been redesigned using composite materials emphasizing the effects on the ship from an operational per-spective. The weight reduction has been calculated for a real-istic average operating condition quantifying the effects...

  1. Ranking structures and Rank-Rank Correlations of Countries. The FIFA and UEFA cases

    CERN Document Server

    Ausloos, Marcel; Gadomski, Adam; Vitanov, Nikolay K

    2014-01-01

    Ranking of agents competing with each other in complex systems may lead to paradoxes according to the pre-chosen different measures. A discussion is presented on such rank-rank, similar or not, correlations based on the case of European countries ranked by UEFA and FIFA from different soccer competitions. The first question to be answered is whether an empirical and simple law is obtained for such (self-) organizations of complex sociological systems with such different measuring schemes. It is found that the power law form is not the best description contrary to many modern expectations. The stretched exponential is much more adequate. Moreover, it is found that the measuring rules lead to some inner structures, in both cases.

  2. Ranking structures and rank-rank correlations of countries: The FIFA and UEFA cases

    Science.gov (United States)

    Ausloos, Marcel; Cloots, Rudi; Gadomski, Adam; Vitanov, Nikolay K.

    2014-04-01

    Ranking of agents competing with each other in complex systems may lead to paradoxes according to the pre-chosen different measures. A discussion is presented on such rank-rank, similar or not, correlations based on the case of European countries ranked by UEFA and FIFA from different soccer competitions. The first question to be answered is whether an empirical and simple law is obtained for such (self-) organizations of complex sociological systems with such different measuring schemes. It is found that the power law form is not the best description contrary to many modern expectations. The stretched exponential is much more adequate. Moreover, it is found that the measuring rules lead to some inner structures in both cases.

  3. Fracture behavior of zirconia implant abutments is influenced by superstructure-geometry.

    Science.gov (United States)

    Nothdurft, Frank P; Neumann, Konrad; Knauber, Andreas W

    2014-01-01

    The purpose of this in vitro study was to evaluate the influence of the superstructure-geometry on the fracture behavior of zirconia abutments (Compartis, DeguDent GmbH, Hanau, G). Four different groups (n = 8) representing anterior single crown replacement were prepared. In groups 1 and 2, the implants were restored with customized all-ceramic abutments and anatomically shaped crowns (chromium cobalt alloy). Groups 3 and 4 received crowns with a geometry according to the international standard ISO 14801 (dynamic fatigue test for endosseous dental implants) with a spherical contact area. Groups 2 and 4 were subjected to mechanical aging in a chewing simulator (50 N × 1,200,000 cycles). Static loading until fracture was performed using a universal testing device at an angle of 30° to the implant axis. Fracture patterns were analyzed using SEM. In group 2, only one specimen survived mechanical aging. In group 4, one specimen fractured during the chewing simulation. Groups 1 and 2 showed significantly lower load-bearing capacity than groups 3 and 4. Artificial aging did not influence the fracture resistance. The SEM analysis revealed fatigue-related fracture patterns in those specimens, which failed during artificial aging. Drawing conclusions from ISO testing concerning clinical performance appears to be critical as anatomic superstructure geometries induce different fracture behaviors. ISO testing of zirconia abutments should be accompanied by load-bearing capacity testing under simulated clinical conditions to predict clinical performance.

  4. Dynamic cholesteric liquid crystal superstructures photoaligned by one-step polarization holography

    Science.gov (United States)

    Li, Sen-Sen; Shen, Yuan; Chang, Zhen-Ni; Li, Wen-Song; Xu, Yan-Chao; Fan, Xing-Yu; Chen, Lu-Jian

    2017-12-01

    A convenient approach to modulate the fingerprint textures of methyl red (MR) doped cholesteric liquid crystals by asymmetric photoalignment in the green-light waveband is presented, resulting in the generation of voltage-controllable helical superstructures. The interaction between the MR molecules and the incident light polarization determines the initial twisted planar geometry, providing a multivariant control over the stripe directions of fingerprint textures by applying a proper electric field. The key factors for precise manipulation of fingerprint stripes in a predictable and rewritable manner are analyzed theoretically and investigated experimentally, which involves the alignment asymmetry, the ratio of cell gap to natural pitch length, and the chirality of chiral dopant. Dynamic periodic fingerprint textures in shapes of dashed curve and dashed line are further demonstrated by utilizing a facile one-step polarization holography process using two beams with orthogonal circular and orthogonal linear polarizations, respectively. It is believed that the practical approach described in this study would enrich the research contents of self-assembled hierarchical superstructures using soft liquid crystal building blocks.

  5. Comparative analysis of cogeneration power plants optimization based on stochastic method using superstructure and process simulator

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Leonardo Rodrigues de [Instituto Federal do Espirito Santo, Vitoria, ES (Brazil)], E-mail: leoaraujo@ifes.edu.br; Donatelli, Joao Luiz Marcon [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil)], E-mail: joaoluiz@npd.ufes.br; Silva, Edmar Alino da Cruz [Instituto Tecnologico de Aeronautica (ITA/CTA), Sao Jose dos Campos, SP (Brazil); Azevedo, Joao Luiz F. [Instituto de Aeronautica e Espaco (CTA/IAE/ALA), Sao Jose dos Campos, SP (Brazil)

    2010-07-01

    Thermal systems are essential in facilities such as thermoelectric plants, cogeneration plants, refrigeration systems and air conditioning, among others, in which much of the energy consumed by humanity is processed. In a world with finite natural sources of fuels and growing energy demand, issues related with thermal system design, such as cost estimative, design complexity, environmental protection and optimization are becoming increasingly important. Therefore the need to understand the mechanisms that degrade energy, improve energy sources use, reduce environmental impacts and also reduce project, operation and maintenance costs. In recent years, a consistent development of procedures and techniques for computational design of thermal systems has occurred. In this context, the fundamental objective of this study is a performance comparative analysis of structural and parametric optimization of a cogeneration system using stochastic methods: genetic algorithm and simulated annealing. This research work uses a superstructure, modelled in a process simulator, IPSEpro of SimTech, in which the appropriate design case studied options are included. Accordingly, the cogeneration system optimal configuration is determined as a consequence of the optimization process, restricted within the configuration options included in the superstructure. The optimization routines are written in MsExcel Visual Basic, in order to work perfectly coupled to the simulator process. At the end of the optimization process, the system optimal configuration, given the characteristics of each specific problem, should be defined. (author)

  6. University Ranking Systems; Criteria and Critiques

    OpenAIRE

    Saka, Yavuz; YAMAN, Süleyman

    2011-01-01

    The purpose of this paper is to explore international university ranking systems. As a compilation study this paper provides specific criteria that each ranking system uses and main critiques regarding these ranking systems. Since there are many ranking systems in this area of research, this study focused on only most cited and referred ranking systems. As there is no consensus in terms of the criteria that these systems use, this paper has no intention of identifying the best ranking system ...

  7. Ranking species in mutualistic networks.

    Science.gov (United States)

    Domínguez-García, Virginia; Muñoz, Miguel A

    2015-02-02

    Understanding the architectural subtleties of ecological networks, believed to confer them enhanced stability and robustness, is a subject of outmost relevance. Mutualistic interactions have been profusely studied and their corresponding bipartite networks, such as plant-pollinator networks, have been reported to exhibit a characteristic "nested" structure. Assessing the importance of any given species in mutualistic networks is a key task when evaluating extinction risks and possible cascade effects. Inspired in a recently introduced algorithm--similar in spirit to Google's PageRank but with a built-in non-linearity--here we propose a method which--by exploiting their nested architecture--allows us to derive a sound ranking of species importance in mutualistic networks. This method clearly outperforms other existing ranking schemes and can become very useful for ecosystem management and biodiversity preservation, where decisions on what aspects of ecosystems to explicitly protect need to be made.

  8. University rankings in computer science

    DEFF Research Database (Denmark)

    Ehret, Philip; Zuccala, Alesia Ann; Gipp, Bela

    2017-01-01

    This is a research-in-progress paper concerning two types of institutional rankings, the Leiden and QS World ranking, and their relationship to a list of universities’ ‘geo-based’ impact scores, and Computing Research and Education Conference (CORE) participation scores in the field of computer...... science. A ‘geo-based’ impact measure examines the geographical distribution of incoming citations to a particular university’s journal articles for a specific period of time. It takes into account both the number of citations and the geographical variability in these citations. The CORE participation...... score is calculated on the basis of the number of weighted proceedings papers that a university has contributed to either an A*, A, B, or C conference as ranked by the Computing Research and Education Association of Australasia. In addition to calculating the correlations between the distinct university...

  9. Morphology-controlled hydrothermal synthesis of MnCO{sub 3} hierarchical superstructures with Schiff base as stabilizer

    Energy Technology Data Exchange (ETDEWEB)

    Hu, He; Xu, Jie-yan; Yang, Hong; Liang, Jie [Department of Chemistry, Shanghai Normal University, No. 100, Guilin Road, Shanghai 200234 (China); Yang, Shiping, E-mail: shipingy@shnu.edu.cn [Department of Chemistry, Shanghai Normal University, No. 100, Guilin Road, Shanghai 200234 (China); Wu, Huixia [Department of Chemistry, Shanghai Normal University, No. 100, Guilin Road, Shanghai 200234 (China)

    2011-11-15

    Graphical abstract: MnCO3 microcrystals with hierarchical superstructures were synthesized by using the CO2 in atmosphere as carbonate ions source and Schiff base as shape guiding-agent in water/ethanol system under hydrothermal condition. Highlights: {yields} The most interesting in this work is the use of the greenhouse gases CO{sub 2} in atmosphere as carbonate ions source to precipitate with Mn{sup 2+} for producing MnCO{sub 3} crystals. {yields} This work is the first report related to the small organic molecule Schiff base as shape guiding-agent to produce different MnCO{sub 3} hierarchical superstructures. {yields} We are controllable synthesis of the MnCO{sub 3} hierarchical superstructures such as chrysanthemum, straw-bundle, dumbbell and sphere-like microcrystals. {yields} The as-prepared MnCO{sub 3} could be used precursor to fabricate the Mn{sub 2}O{sub 3} hierarchical superstructures after thermal decomposition at high temperature. -- Abstract: MnCO{sub 3} with hierarchical superstructures such as chrysanthemum, straw-bundle, dumbbell and sphere-like were synthesized in water/ethanol system under environment-friendly hydrothermal condition. In the synthesis process, the CO{sub 2} in atmosphere was used as the source of carbonate ions and Schiff base was used as shape guiding-agent. The different superstructures of MnCO{sub 3} could be obtained by controlling the hydrothermal temperature, the molar ratio of manganous ions to the Schiff base, or the volume ratio of water to ethanol. A tentative growth mechanism for the generation of MnCO{sub 3} superstructures was proposed based on the rod-dumbbell-sphere model. Furthermore, the MnCO{sub 3} as precursor could be further successfully transferred to Mn{sub 2}O{sub 3} microstructure after heating in the atmosphere at 500 {sup o}C, and the morphology of the Mn{sub 2}O{sub 3} was directly determined by that of the MnCO{sub 3} precursor.

  10. Rank distributions: Frequency vs. magnitude.

    Science.gov (United States)

    Velarde, Carlos; Robledo, Alberto

    2017-01-01

    We examine the relationship between two different types of ranked data, frequencies and magnitudes. We consider data that can be sorted out either way, through numbers of occurrences or size of the measures, as it is the case, say, of moon craters, earthquakes, billionaires, etc. We indicate that these two types of distributions are functional inverses of each other, and specify this link, first in terms of the assumed parent probability distribution that generates the data samples, and then in terms of an analog (deterministic) nonlinear iterated map that reproduces them. For the particular case of hyperbolic decay with rank the distributions are identical, that is, the classical Zipf plot, a pure power law. But their difference is largest when one displays logarithmic decay and its counterpart shows the inverse exponential decay, as it is the case of Benford law, or viceversa. For all intermediate decay rates generic differences appear not only between the power-law exponents for the midway rank decline but also for small and large rank. We extend the theoretical framework to include thermodynamic and statistical-mechanical concepts, such as entropies and configuration.

  11. Rankings Methodology Hurts Public Institutions

    Science.gov (United States)

    Van Der Werf, Martin

    2007-01-01

    In the 1980s, when the "U.S. News & World Report" rankings of colleges were based solely on reputation, the nation's public universities were well represented at the top. However, as soon as the magazine began including its "measures of excellence," statistics intended to define quality, public universities nearly disappeared from the top. As the…

  12. Let Us Rank Journalism Programs

    Science.gov (United States)

    Weber, Joseph

    2014-01-01

    Unlike law, business, and medical schools, as well as universities in general, journalism schools and journalism programs have rarely been ranked. Publishers such as "U.S. News & World Report," "Forbes," "Bloomberg Businessweek," and "Washington Monthly" do not pay them much mind. What is the best…

  13. Multiple graph regularized protein domain ranking

    Directory of Open Access Journals (Sweden)

    Wang Jim

    2012-11-01

    Full Text Available Abstract Background Protein domain ranking is a fundamental task in structural biology. Most protein domain ranking methods rely on the pairwise comparison of protein domains while neglecting the global manifold structure of the protein domain database. Recently, graph regularized ranking that exploits the global structure of the graph defined by the pairwise similarities has been proposed. However, the existing graph regularized ranking methods are very sensitive to the choice of the graph model and parameters, and this remains a difficult problem for most of the protein domain ranking methods. Results To tackle this problem, we have developed the Multiple Graph regularized Ranking algorithm, MultiG-Rank. Instead of using a single graph to regularize the ranking scores, MultiG-Rank approximates the intrinsic manifold of protein domain distribution by combining multiple initial graphs for the regularization. Graph weights are learned with ranking scores jointly and automatically, by alternately minimizing an objective function in an iterative algorithm. Experimental results on a subset of the ASTRAL SCOP protein domain database demonstrate that MultiG-Rank achieves a better ranking performance than single graph regularized ranking methods and pairwise similarity based ranking methods. Conclusion The problem of graph model and parameter selection in graph regularized protein domain ranking can be solved effectively by combining multiple graphs. This aspect of generalization introduces a new frontier in applying multiple graphs to solving protein domain ranking applications.

  14. Multiple graph regularized protein domain ranking

    KAUST Repository

    Wang, Jim Jing-Yan

    2012-11-19

    Background: Protein domain ranking is a fundamental task in structural biology. Most protein domain ranking methods rely on the pairwise comparison of protein domains while neglecting the global manifold structure of the protein domain database. Recently, graph regularized ranking that exploits the global structure of the graph defined by the pairwise similarities has been proposed. However, the existing graph regularized ranking methods are very sensitive to the choice of the graph model and parameters, and this remains a difficult problem for most of the protein domain ranking methods.Results: To tackle this problem, we have developed the Multiple Graph regularized Ranking algorithm, MultiG-Rank. Instead of using a single graph to regularize the ranking scores, MultiG-Rank approximates the intrinsic manifold of protein domain distribution by combining multiple initial graphs for the regularization. Graph weights are learned with ranking scores jointly and automatically, by alternately minimizing an objective function in an iterative algorithm. Experimental results on a subset of the ASTRAL SCOP protein domain database demonstrate that MultiG-Rank achieves a better ranking performance than single graph regularized ranking methods and pairwise similarity based ranking methods.Conclusion: The problem of graph model and parameter selection in graph regularized protein domain ranking can be solved effectively by combining multiple graphs. This aspect of generalization introduces a new frontier in applying multiple graphs to solving protein domain ranking applications. 2012 Wang et al; licensee BioMed Central Ltd.

  15. The Globalization of College and University Rankings

    Science.gov (United States)

    Altbach, Philip G.

    2012-01-01

    In the era of globalization, accountability, and benchmarking, university rankings have achieved a kind of iconic status. The major ones--the Academic Ranking of World Universities (ARWU, or the "Shanghai rankings"), the QS (Quacquarelli Symonds Limited) World University Rankings, and the "Times Higher Education" World…

  16. Time evolution of Wikipedia network ranking

    Science.gov (United States)

    Eom, Young-Ho; Frahm, Klaus M.; Benczúr, András; Shepelyansky, Dima L.

    2013-12-01

    We study the time evolution of ranking and spectral properties of the Google matrix of English Wikipedia hyperlink network during years 2003-2011. The statistical properties of ranking of Wikipedia articles via PageRank and CheiRank probabilities, as well as the matrix spectrum, are shown to be stabilized for 2007-2011. A special emphasis is done on ranking of Wikipedia personalities and universities. We show that PageRank selection is dominated by politicians while 2DRank, which combines PageRank and CheiRank, gives more accent on personalities of arts. The Wikipedia PageRank of universities recovers 80% of top universities of Shanghai ranking during the considered time period.

  17. Trends in exchange interactions for bcc Fe/TaW(001)

    Energy Technology Data Exchange (ETDEWEB)

    Ondracek, Martin; Kudrnovsky, Josef; Maca, Frantisek [Institute of Physics, ASCR, Prague (Czech Republic); Bengone, Olivier [University of Strasbourg, IPCM, Strasbourg (France); Turek, Ilja [Institute of Physics of Materials, ASCR, Brno (Czech Republic); Department of Condensed Matter Physics, Charles University, Prague (Czech Republic)

    2009-07-01

    A recent study of Ferriani et al. investigated the possibility of tuning the magnetic order of the Fe monolayer on the disordered bcc-Ta(x)W(1-x)[001] surface. We will further extend this study by constructing the effective two-dimensional Heisenberg Hamiltonian, which describes exchange interactions in the iron monolayer in detail. We investigate the behavior of exchange integrals as a function of the composition of the alloy substrate, but also as a function of distance (damping due to disorder) and the dependence on the crystallographic directions in the overlayer. The calculated exchange integrals allow us to estimate the spin stiffness and the corresponding critical temperatures. We also wish to investigate the crossover between the ferromagnetic and antiferromagnetic state from the point of view of the stability of the Heisenberg Hamiltonian with respect to magnon excitations. The present study will help us to deeper understand the character of magnetic phase transition of the Fe overlayer due to disorder in the alloy substrate.

  18. Influence of point defects on grain boundary mobility in bcc tungsten.

    Science.gov (United States)

    Borovikov, Valery; Tang, Xian-Zhu; Perez, Danny; Bai, Xian-Ming; Uberuaga, Blas P; Voter, Arthur F

    2013-01-23

    Atomistic computer simulations were performed to study the influence of radiation-induced damage on grain boundary (GB) sliding processes in bcc tungsten (W), the divertor material in the ITER tokamak and the leading candidate for the first wall material in future fusion reactors. In particular, we calculated the average sliding-friction force as a function of the number of point defects introduced into the GB for a number of symmetric tilt GBs. In all cases the average sliding-friction force at fixed shear strain rate depends on the number of point defects introduced into the GB, and in many cases introduction of these defects reduces the average sliding-friction force by roughly an order of magnitude. We have also observed that as the number of interstitials in the GB is varied, the direction of the coupled GB motion sometimes reverses, causing the GB to migrate in the opposite direction under the same applied shear stress. This could be important in the microstructural evolution of polycrystalline W under the harsh radiation environment in a fusion reactor, in which high internal stresses are present and frequent collision cascades generate interstitials and vacancies.

  19. Ginzburg-Landau theory of crystalline anisotropy for bcc-liquid interfaces

    Science.gov (United States)

    Wu, Kuo-An; Karma, Alain; Hoyt, Jeffrey J.; Asta, Mark

    2006-03-01

    The weak anisotropy of the interfacial free energy γ is a crucial parameter influencing dendritic crystal growth morphologies in systems with atomically rough solid-liquid interfaces. The physical origin and quantitative prediction of this anisotropy are investigated for body-centered-cubic (bcc) forming systems using a Ginzburg-Landau theory where the order parameters are the amplitudes of density waves corresponding to principal reciprocal lattice vectors. We find that this theory predicts the correct sign γ100 > γ110 and magnitude ( γ100 - γ110 ) / ( γ100 + γ110 ) ≈1% of this anisotropy in good agreement with the results of molecular dynamics (MD) simulations for Fe. The results show that the directional dependence of the rate of spatial decay of solid density waves into the liquid, imposed by the crystal structure, is a main determinant of anisotropy. This directional dependence is validated by MD computations of density wave profiles for different reciprocal lattice vectors for {110} crystal faces. Our results are contrasted with the prediction of the reverse ordering γ100 < γ110 from an earlier formulation of Ginzburg-Landau theory [Shih et al., Phys. Rev. A 35, 2611 (1987)].

  20. Ginzburg-Landau theory of the bcc-liquid interface kinetic coefficient

    Science.gov (United States)

    Wu, Kuo-An; Hoyt, Jeffrey; Karma, Alain

    2015-03-01

    We extend the Ginzburg-Landau (GL) theory of atomically rough bcc-liquid interfaces outside of equilibrium to derive an analytical expression for the kinetic coefficient μ (n& circ;) . The kinetic coefficient is expressed as a spatial integral along the normal direction of a sum of gradient square terms corresponding to different nonlinear density wave profiles. Anisotropy arises naturally from the dependence of those profiles on the angles between the principal reciprocal lattice vectors K-->i and n& circ;. Values of the kinetic coefficient for the (100) , (110) and (111) interfaces are compared quantitatively to the prediction of linear Mikheev-Chernov (MC) theory and previous MD simulation studies of crystallization kinetics for a classical model of Fe. The GL theory predicts a similar expression for μ as the MC theory but yields a better agreement with MD simulations for both its magnitude and anisotropy due to a fully nonlinear description of density wave profiles across the solid-liquid interface. In particular, the overall magnitude of μ predicted by GL theory is an order of magnitude larger than predicted by the MC theory. GL theory is also used to derive an inverse relation between μ and the solid-liquid interfacial free-energy.

  1. Phase-field crystal modeling of equilibrium bcc-liquid interfaces

    Science.gov (United States)

    Wu, Kuo-An; Karma, Alain

    2007-11-01

    We investigate the equilibrium properties of bcc-liquid interfaces modeled with a continuum phase-field crystal (PFC) approach [K. R. Elder and M. Grant, Phys. Rev. E 70, 051605 (2004)]. A multiscale analysis of the PFC model is carried out which exploits the fact that the amplitudes of crystal density waves decay slowly into the liquid in the physically relevant limit where the freezing transition is weakly first order. This analysis yields a set of coupled equations for these amplitudes that is similar to the set of equations derived from Ginzburg-Landau (GL) theory [K.-A. Wu , Phys. Rev. B 73, 094101 (2006)]. The two sets only differ in the details of higher order nonlinear couplings between different density waves, which is determined by the form of the nonlinearity assumed in the PFC model and by the ansatz that all polygons with the same number of sides have equal weight in GL theory. Despite these differences, for parameters (liquid structure factor and solid density wave amplitude) of Fe determined from molecular dynamics (MD) simulations, the PFC and GL amplitude equations yield very similar predictions for the overall magnitude and anisotropy of the interfacial free-energy and density wave profiles. These predictions are compared with MD simulations as well as numerical solutions of the PFC model.

  2. Identifying self-interstitials of bcc and fcc crystals in molecular dynamics

    Science.gov (United States)

    Bukkuru, S.; Bhardwaj, U.; Warrier, M.; Rao, A. D. P.; Valsakumar, M. C.

    2017-02-01

    Identification of self-interstitials in molecular dynamics (MD) simulations is of critical importance. There exist several criteria for identifying the self-interstitial. Most of the existing methods use an assumed cut-off value for the displacement of an atom from its lattice position to identify the self-interstitial. The results obtained are affected by the chosen cut-off value. Moreover, these chosen cut-off values are independent of temperature. We have developed a novel unsupervised learning algorithm called Max-Space Clustering (MSC) to identify an appropriate cut-off value and its dependence on temperature. This method is compared with some widely used methods such as effective sphere (ES) method and nearest neighbor sphere (NNS) method. The cut-off radius obtained using our method shows a linear variation with temperature. The value of cut-off radius and its temperature dependence is derived for five bcc (Cr, Fe, Mo, Nb, W) and six fcc (Ag, Au, Cu, Ni, Pd, Pt) crystals. It is seen that the ratio of the cut-off values "r" to the lattice constant "a" lies between 0.23 and 0.3 at 300 K and this ratio is on an average smaller for the fcc crystals. Collision cascade simulations are carried out for Primary knock-on Atom (PKA) energies of 5 keV in Fe (at 300 K and 1000 K) and W (at 300 K and 2500 K) and the results are compared using the various methods.

  3. Amylase Production from Thermophilic Bacillus sp. BCC 021-50 Isolated from a Marine Environment

    Directory of Open Access Journals (Sweden)

    Altaf Ahmed Simair

    2017-06-01

    Full Text Available The high cost of fermentation media is one of the technical barriers in amylase production from microbial sources. Amylase is used in several industrial processes or industries, for example, in the food industry, the saccharification of starchy materials, and in the detergent and textile industry. In this study, marine microorganisms were isolated to identify unique amylase-producing microbes in starch agar medium. More than 50 bacterial strains with positive amylase activity, isolated from marine water and soil, were screened for amylase production in starch agar medium. Bacillus sp. BCC 021-50 was found to be the best amylase-producing strain in starch agar medium and under submerged fermentation conditions. Next, fermentation conditions were optimized for bacterial growth and enzyme production. The highest amylase concentration of 5211 U/mL was obtained after 36 h of incubation at 50 °C, pH 8.0, using 20 g/L molasses as an energy source and 10 g/L peptone as a nitrogen source. From an application perspective, crude amylase was characterized in terms of temperature and pH. Maximum amylase activity was noted at 70 °C and pH 7.50. However, our results show clear advantages for enzyme stability in alkaline pH, high-temperature, and stability in the presence of surfactant, oxidizing, and bleaching agents. This research contributes towards the development of an economical amylase production process using agro-industrial residues.

  4. On the Secrecy Capacity Region of the Block-Fading BCC with Limited CSI Feedback

    KAUST Repository

    Hyadi, Amal

    2017-02-07

    In this work, we examine the secrecy capacity region of the block-fading broadcast channel with confidential messages (BCC) when the transmitter has limited knowledge of the channel. In particular, we consider a two-user communication system where the transmitter has one common message to be transmitted to both users and one confidential message intended to only one of them. The confidential message has to be kept secret from the other user to whom the information is not intended. The transmitter is not aware of the channel state information (CSI) of neither channel and is only provided by limited CSI feedback sent at the beginning of each fading block. Assuming an error-free feedback link, we characterize the secrecy capacity region of this channel and show that even with a 1-bit CSI feedback, a positive secrecy rate can still be achieved. Then, we look at the case where the feedback link is not error- free and is rather a binary erasure channel (BEC). In the latter case, we provide an achievable secrecy rate region and show that as long as the erasure event is not a probability 1 event, the transmitter can still transmit the confidential information with a positive secrecy rate.

  5. Grain Size Dependence of Uniform Elongation in Single-Phase FCC/BCC Metals

    Science.gov (United States)

    Liu, Haiting; Shen, Yao; Ma, Jiawei; Zheng, Pengfei; Zhang, Lei

    2016-09-01

    We studied the dependence of uniform elongation on grain size in the range of submicron to millimeter for single-phase FCC/BCC metals by reviewing recent experimental results and applying crystal plasticity finite element method simulation. In the order of increasing grain size, uniform elongation can be divided into three stages, namely low elongation stage, nearly constant elongation stage, and decreased elongation with large scatters stage. Low elongation stage features a dramatic increase near the critical grain size at the end of the stage, which is primarily attributed to the emergence of dislocation cell size transition from ultrafine to mid-size grain. Other factors can be neglected due to their negligible influence on overall variation trend. In nearly constant elongation stage, uniform elongation remains unchanged at a high level in general. As grain size keeps growing, uniform elongation starts decreasing and becomes scattered upon a certain grain size, indicating the initiation of decreased elongation with large scatters stage. It is shown that the increase is not linear or smooth but rather sharp at the end of low elongation stage, leading to a wider range in nearly constant elongation stage. The grain size dependence of uniform elongation can serve as a guiding principle for designing small uniaxial tensile specimens for mechanical testing, where size effect matters in most cases.

  6. Free energy calculation of mechanically unstable but dynamically stabilized bcc titanium

    Science.gov (United States)

    Kadkhodaei, Sara; Hong, Qi-Jun; van de Walle, Axel

    2017-02-01

    The phase diagram of numerous materials of technological importance features high-symmetry high-temperature phases that exhibit phonon instabilities. Leading examples include shape-memory alloys, as well as ferroelectric, refractory, and structural materials. The thermodynamics of these phases have proven challenging to handle by atomistic computational thermodynamic techniques due to the occurrence of constant anharmonicity-driven hopping between local low-symmetry distortions, while maintaining a high-symmetry time-averaged structure. To compute the free energy in such phases, we propose to explore the system's potential-energy surface by discrete sampling of local minima by means of a lattice gas Monte Carlo approach and by continuous sampling by means of a lattice dynamics approach in the vicinity of each local minimum. Given the proximity of the local minima, it is necessary to carefully partition phase space by using a Voronoi tessellation to constrain the domain of integration of the partition function in order to avoid double counting artifacts and enable an accurate harmonic treatment near each local minima. We consider the bcc phase of titanium as a prototypical example to illustrate our approach.

  7. Statistical theory of diffusion in concentrated bcc and fcc alloys and concentration dependencies of diffusion coefficients in bcc alloys FeCu, FeMn, FeNi, and FeCr

    Energy Technology Data Exchange (ETDEWEB)

    Vaks, V. G.; Khromov, K. Yu., E-mail: khromov-ky@nrcki.ru; Pankratov, I. R. [National Research Center “Kurchatov Institute,” (Russian Federation); Popov, V. V. [Russian Academy of Sciences, Mikheev Institute of Metal Physics, Ural Branch (Russian Federation)

    2016-07-15

    The statistical theory of diffusion in concentrated bcc and fcc alloys with arbitrary pairwise interatomic interactions based on the master equation approach is developed. Vacancy–atom correlations are described using both the second-shell-jump and the nearest-neighbor-jump approximations which are shown to be usually sufficiently accurate. General expressions for Onsager coefficients in terms of microscopic interatomic interactions and some statistical averages are given. Both the analytical kinetic mean-field and the Monte Carlo methods for finding these averages are described. The theory developed is used to describe sharp concentration dependencies of diffusion coefficients in several iron-based alloy systems. For the bcc alloys FeCu, FeMn, and FeNi, we predict the notable increase of the iron self-diffusion coefficient with solute concentration c, up to several times, even though values of c possible for these alloys do not exceed some percent. For the bcc alloys FeCr at high temperatures T ≳ 1400 K, we show that the very strong and peculiar concentration dependencies of both tracer and chemical diffusion coefficients observed in these alloys can be naturally explained by the theory, without invoking exotic models discussed earlier.

  8. Template-free synthesis of beta-In2S3 superstructures and their photocatalytic activity.

    Science.gov (United States)

    Amutha, R; Akilandeswari, S; Ahmmad, Bashir; Muruganandham, M; Sillanpää, Mika

    2010-12-01

    In this article, we have successfully fabricated various morphological beta-Indium sulfide (In2S3) superstructures by using indium thiocyanate complex at acidic pH. All the synthesis has been performed by a template-free, hydrothermal method at 195 degrees C for 3 h. The photocatalytic activity of synthesized In2S3 have been investigated by using UV-B (lamda = 365 nm) light with Methyl Orange dye as a model pollutant. The synthesized photocatalyst was characterized by using XRD, FE-SEM, HR-TEM, DRS spectra and nitrogen adsorption analysis. The influence of indium precursors and solvents on the morphology as well as the surface properties has also been discussed. The XRD result shows that cubic phase beta-In2S3 formed under all experimental conditions. A plausible mechanism of the In2S3 microsphere formation has been discussed based on experimental observations.

  9. Experimental and theoretical study of the operation of longitudinal sidewalls in reinforced concrete superstructures

    Science.gov (United States)

    Bokarev, Sergey; Efimov, Stefan

    2017-11-01

    In the present article, we report results of a laboratory experimental study of reinforced-concrete superstructure fragments with extended longitudinal boxing sidewalls. The study included laboratory tests and numerical experiments performed using a finite element model of fragments generated in specialized simulation software. The distribution of horizontal pressures over the height of longitudinal boxing sidewalls, the dependence of the bending moment in the root section of the sidewalls on the ballast-bed thickness under sleepers, and some other characteristics were examined. The results of the experimental and theoretical study have shown a good convergence of obtained data to each other and to the data obtained by an improved engineering calculation procedure proposed by the present authors.

  10. Synthesis of noble metal nanoparticles and their superstructures; Darstellung von Edelmetallnanopartikeln und deren Ueberstrukturen

    Energy Technology Data Exchange (ETDEWEB)

    Bigall, Nadja-Carola

    2009-08-18

    A modified synthesis procedure for citrate-stabilized gold nanoparticles in aqueous solution is transferred under application of equal concentrations to the systems silver, platinum, and palladium. The nanoparticles are analyzed by means of absorption spectroscopy and electron microscopy. Ordered superstructures of the noble-metal nanoparticles can be synthesized by infiltration of templates of block-copolymer films with aqueous nanoparticle solution. In dependence on the pre-treatment of the polymer films either two-dimensional periodical arrangements with a periodicity of less than 30 nm or fingerprint-like arrangements with a groove distance in the same order of magnitude. By removal of the polymer one- respectively two-dimensional arrangements of platinum nanowires respectively nanoparticles on a silicon waver arise.

  11. Growth and Transfer of Monolithic Horizontal ZnO Nanowire Superstructures onto Flexible Substrates

    KAUST Repository

    Xu, Sheng

    2010-04-28

    A method of fabricating horizontally aligned ZnO nanowire (NW) arrays with full control over the width and length is demonstrated. A cross-sectional view of the NWs by transmission electron microscopy shows a "mushroom-like" structure. Novel monolithic multisegment superstructures are fabricated by making use of the lateral overgrowth. Ultralong horizontal ZnO NWs of an aspect ratio on the order often thousand are also demonstrated. These horizontal NWs are lifted off and transferred onto a flexible polymer substrate, which may have many great applications in horizontal ZnO NW-based nanosensor arrays, light-emitting diodes, optical gratings, integrated circuit interconnects, and high-output-power alternating-current nanogenerators. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.

  12. Tendencies in the development of operational quality of ballasted and ballastless track superstructure and transition areas

    Science.gov (United States)

    Ižvolt, Libor; Šestáková, Janka; Šmalo, Michal

    2017-09-01

    Department of Railway Engineering and Track Management is cooperating with Slovak Railways (Železnice Slovenskej republiky - ŽSR) on assessment of quality of railway tracks, structures of railway tracks and parts of these structures. One of diagnostics methods is monitoring of track geometry focused on durability of ballastless track quality and its transition area to ballasted track. The diagnostics is carried out by continuous method and results are used for prediction of future degradation of construction. The first part of the paper deals with a brief recapitulation of information about the experimental sections and the methods of diagnostics of track geometry. The second part of the paper is carrying out the analysis and prognosis of development of the quality of construction of the experimental sections, which is a tool for the track superstructure maintenance planning.

  13. Extended and quasi-continuous tuning of quantum cascade lasers using superstructure gratings and integrated heaters

    Energy Technology Data Exchange (ETDEWEB)

    Bidaux, Yves, E-mail: yves.bidaux@alpeslasers.ch [Alpes Lasers SA, 1-3 Passsage Max Meuron, CH-2001 Neuchâtel (Switzerland); Institute for Quantum Electronics, ETH-Zurich, CH-8093 Zurich (Switzerland); Bismuto, Alfredo, E-mail: alfredo.bismuto@alpeslasers.ch; Tardy, Camille; Terazzi, Romain; Gresch, Tobias; Blaser, Stéphane; Muller, Antoine [Alpes Lasers SA, 1-3 Passsage Max Meuron, CH-2001 Neuchâtel (Switzerland); Faist, Jerome [Institute for Quantum Electronics, ETH-Zurich, CH-8093 Zurich (Switzerland)

    2015-11-30

    In this work, we demonstrate broad electrical tuning of quantum cascade lasers at 9.25 μm, 8.5 μm, and 4.4 μm in continuous wave operation using Vernier-effect distributed Bragg reflectors based on superstructure gratings. Integrated micro-heaters allow to switch from one Vernier channel to the other, while predictable and mode-hop free tuning can be obtained in each channel modulating the laser current with a side mode suppression ratio as high as 30 dB. The resulting device behaves effectively as a switchable multicolour tunable source. Tuning up to 6.5% of the central wavelength is observed. To prove the importance of the developed devices for high resolution molecular spectroscopy, a N{sub 2}O absorption spectrum has been measured.

  14. Prevention of Cutaneous Tissue Contracture During Removal of Craniofacial Implant Superstructures for CT and MRI Studies

    Directory of Open Access Journals (Sweden)

    Maureen Sullivan

    2010-04-01

    Full Text Available Objectives: Head and neck cancer patients who have lost facial parts following surgical intervention frequently require craniofacial implant retained facial prostheses for restoration. Many craniofacial implant patients require computed tomography and magnetic resonance imaging scans as part of their long-term follow-up care. Consequently removal of implant superstructures and peri-abutment tissue management is required for those studies. The purpose of the present paper was to describe a method for eliminating cranial imaging artifacts in patients with craniofacial implants.Material and Methods: Three patients wearing extraoral implant retained facial prostheses needing either computed tomography or magnetic resonance imaging studies were discussed. Peri-implant soft tissues contracture after removal of percutaneous craniofacial implant abutments during computed tomography and magnetic resonance imaging studies was prevented using a method proposed by authors. The procedure involves temporary removal of the supra-implant components prior to imaging and filling of the tissue openings with polyvinyl siloxane dental impression material.Results: Immediately after filling of the tissue openings with polyvinyl siloxane dental impression material patients were sent for the imaging studies, and were asked to return for removal of the silicone plugs and reconnection of all superstructure hardware after imaging procedures were complete. The silicone plugs were easily removed with a dental explorer. The percutaneous abutments were immediately replaced and screwed into the implants which were at the bone level.Conclusions: Presented herein method eliminates the source of artifacts and prevents contracture of percutaneous tissues upon removal of the implant abutments during imaging.

  15. Impact of Intragranular Substructure Parameters on the Forming Limit Diagrams of Single-Phase B.C.C. Steels

    Directory of Open Access Journals (Sweden)

    Gérald Franz

    2013-11-01

    Full Text Available An advanced elastic-plastic self-consistent polycrystalline model, accounting for intragranular microstructure development and evolution, is coupled with a bifurcation-based localization criterion and applied to the numerical investigation of the impact of microstructural patterns on ductility of single-phase steels. The proposed multiscale model, taking into account essential microstructural aspects, such as initial and induced textures, dislocation densities, and softening mechanisms, allows us to emphasize the relationship between intragranular microstructure of B.C.C. steels and their ductility. A qualitative study in terms of forming limit diagrams for various dislocation networks, during monotonic loading tests, is conducted in order to analyze the impact of intragranular substructure parameters on the formability of single-phase B.C.C. steels.

  16. SCC, Bowen's disease and BCC arising on chronic radiation dermatitis due to radiation therapy for tinea pedis

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Eri; Aoki, Mikako; Ikemura, Akiko; Igarashi, Tsukasa; Suzuki, Kayano; Kawana, Seiji [Nippon Medical School, Tokyo (Japan). Hospital

    2000-05-01

    We reported a case who developed three different types of skin cancers: SCC, BCC, and Bowen's disease, on the chronic radiation dermatitis. He had been treated for his tinea pedis et palmaris with radiotherapy in 1940's. It is very ratre that three different types of skin cancers arise in the same patient. This is a second case reported in Japan. (author)

  17. The fcc-bcc crystallographic orientation relationship in AlxCoCrFeNi high-entropy alloys

    NARCIS (Netherlands)

    Rao, J. C.; Ocelik, V.; Vainchtein, D.; Tang, Z.; Liaw, P. K.; De Hosson, J. Th. M.

    2016-01-01

    This paper concentrates on the crystallographic-orientation relationship between the various phases in the Al-Co-Cr-Fe-Ni high-entropy alloys. Two types of orientation relationships of bcc phases (some with ordered B2 structures) and fcc matrix were observed in Al0.5CoCrFeNi and Al0.7CoCrFeNi alloys

  18. Dynamical feedback between synoptic eddy and low-frequency flow as simulated by BCC_CSM1.1(m)

    Science.gov (United States)

    Zhou, Fang; Ren, Hong-Li

    2017-11-01

    Since the interaction between atmospheric synoptic eddy (SE) (2-8 days) activity and low-frequency (LF) (monthly) flow (referred to as SELF) plays an essential role in generating and maintaining dominant climate modes, an evaluation of the performance of BCC_CSM1.1(m) in simulating the SE feedback onto the LF flow is given in this paper. The model captures well the major spatial features of climatological eddy vorticity forcing, eddy-induced growth rate, and patterns of SELF feedback for the climate modes with large magnitudes in cold seasons and small magnitudes in warm seasons for both the Northern and Southern Hemisphere. As in observations, the eddy-induced growth rate and SELF feedback patterns in the model also show positive SE feedback. Overall, the relationships between SE and LF flow show that BCC_CSM1.1(m) satisfactorily captures the basic features of positive SE feedback, which demonstrates the simulation skill of the model for LF variability. Specifically, such an evaluation can help to find model biases of BCC_CSM1.1(m) in simulating SE feedback, which will provide a reference for the model's application.

  19. Performance evaluation and ranking of participation Asian countries in 2012 London Olympic Games through Data Envelopment Analysis

    Directory of Open Access Journals (Sweden)

    Hadi Shirouyehzad

    2014-07-01

    Full Text Available The Olympic Games ranking is done through lexicographic multi criteria method in each period. According to this method, the country receiving the most gold medals will have the highest score, and in case of having equal silver medals, comparison will be done according to bronze ones. The problem of this method is to pay the most attention merely to gold medals. Using data envelopment analysis, some studies have recently suggested various ranking for the Olympic Games. The present research uses DEA to rank the participating Asian countries in London Olympic that have at least won one medal. As an output-oriented BCC model, this one considers the number of male and female athletes, received medals in two previous Olympic as well as the number of their presence in the Olympic games as the inputs. Gold, silver and bronze medals are the only output of the model. This model is solved in two forms of female and male athlete combination and their separation. Solving this model makes this opportunity to present a new rankings model for participating Asian countries in the Olympic Games that can be compared with the ranking used by Olympic committee.

  20. Validating rankings in soccer championships

    Directory of Open Access Journals (Sweden)

    Annibal Parracho Sant'Anna

    2012-08-01

    Full Text Available The final ranking of a championship is determined by quality attributes combined with other factors which should be filtered out of any decision on relegation or draft for upper level tournaments. Factors like referees' mistakes and difficulty of certain matches due to its accidental importance to the opponents should have their influence reduced. This work tests approaches to combine classification rules considering the imprecision of the number of points as a measure of quality and of the variables that provide reliable explanation for it. Two home-advantage variables are tested and shown to be apt to enter as explanatory variables. Independence between the criteria is checked against the hypothesis of maximal correlation. The importance of factors and of composition rules is evaluated on the basis of correlation between rank vectors, number of classes and number of clubs in tail classes. Data from five years of the Brazilian Soccer Championship are analyzed.

  1. Minkowski metrics in creating universal ranking algorithms

    Directory of Open Access Journals (Sweden)

    Andrzej Ameljańczyk

    2014-06-01

    Full Text Available The paper presents a general procedure for creating the rankings of a set of objects, while the relation of preference based on any ranking function. The analysis was possible to use the ranking functions began by showing the fundamental drawbacks of commonly used functions in the form of a weighted sum. As a special case of the ranking procedure in the space of a relation, the procedure based on the notion of an ideal element and generalized Minkowski distance from the element was proposed. This procedure, presented as universal ranking algorithm, eliminates most of the disadvantages of ranking functions in the form of a weighted sum.[b]Keywords[/b]: ranking functions, preference relation, ranking clusters, categories, ideal point, universal ranking algorithm

  2. Combined Reduced-Rank Transform

    Directory of Open Access Journals (Sweden)

    Anatoli Torokhti

    2006-04-01

    Full Text Available We propose and justify a new approach to constructing optimal nonlinear transforms of random vectors. We show that the proposed transform improves such characteristics of {rank-reduced} transforms as compression ratio, accuracy of decompression and reduces required computational work. The proposed transform ${mathcal T}_p$ is presented in the form of a sum with $p$ terms where each term is interpreted as a particular rank-reduced transform. Moreover, terms in ${mathcal T}_p$ are represented as a combination of three operations ${mathcal F}_k$, ${mathcal Q}_k$ and ${oldsymbol{varphi}}_k$ with $k=1,ldots,p$. The prime idea is to determine ${mathcal F}_k$ separately, for each $k=1,ldots,p$, from an associated rank-constrained minimization problem similar to that used in the Karhunen--Lo`{e}ve transform. The operations ${mathcal Q}_k$ and ${oldsymbol{varphi}}_k$ are auxiliary for f/inding ${mathcal F}_k$. The contribution of each term in ${mathcal T}_p$ improves the entire transform performance. A corresponding unconstrained nonlinear optimal transform is also considered. Such a transform is important in its own right because it is treated as an optimal filter without signal compression. A rigorous analysis of errors associated with the proposed transforms is given.

  3. Functional Multiplex PageRank

    Science.gov (United States)

    Iacovacci, Jacopo; Rahmede, Christoph; Arenas, Alex; Bianconi, Ginestra

    2016-10-01

    Recently it has been recognized that many complex social, technological and biological networks have a multilayer nature and can be described by multiplex networks. Multiplex networks are formed by a set of nodes connected by links having different connotations forming the different layers of the multiplex. Characterizing the centrality of the nodes in a multiplex network is a challenging task since the centrality of the node naturally depends on the importance associated to links of a certain type. Here we propose to assign to each node of a multiplex network a centrality called Functional Multiplex PageRank that is a function of the weights given to every different pattern of connections (multilinks) existent in the multiplex network between any two nodes. Since multilinks distinguish all the possible ways in which the links in different layers can overlap, the Functional Multiplex PageRank can describe important non-linear effects when large relevance or small relevance is assigned to multilinks with overlap. Here we apply the Functional Page Rank to the multiplex airport networks, to the neuronal network of the nematode C. elegans, and to social collaboration and citation networks between scientists. This analysis reveals important differences existing between the most central nodes of these networks, and the correlations between their so-called pattern to success.

  4. Ranking Support Vector Machine with Kernel Approximation.

    Science.gov (United States)

    Chen, Kai; Li, Rongchun; Dou, Yong; Liang, Zhengfa; Lv, Qi

    2017-01-01

    Learning to rank algorithm has become important in recent years due to its successful application in information retrieval, recommender system, and computational biology, and so forth. Ranking support vector machine (RankSVM) is one of the state-of-art ranking models and has been favorably used. Nonlinear RankSVM (RankSVM with nonlinear kernels) can give higher accuracy than linear RankSVM (RankSVM with a linear kernel) for complex nonlinear ranking problem. However, the learning methods for nonlinear RankSVM are still time-consuming because of the calculation of kernel matrix. In this paper, we propose a fast ranking algorithm based on kernel approximation to avoid computing the kernel matrix. We explore two types of kernel approximation methods, namely, the Nyström method and random Fourier features. Primal truncated Newton method is used to optimize the pairwise L2-loss (squared Hinge-loss) objective function of the ranking model after the nonlinear kernel approximation. Experimental results demonstrate that our proposed method gets a much faster training speed than kernel RankSVM and achieves comparable or better performance over state-of-the-art ranking algorithms.

  5. Plasticity and Failure in Nanocrystalline BCC Metals via Molecular Dynamics Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, R E

    2010-09-29

    Advances in the ability to generate extremely high pressures in dynamic experiments such as at the National Ignition Facility has motivated the need for special materials optimized for those conditions as well as ways to probe the response of these materials as they are deformed. We need to develop a much deeper understanding of the behavior of materials subjected to high pressure, especially the effect of rate at the extremely high rates encountered in those experiments. Here we use large-scale molecular dynamics (MD) simulations of the high-rate deformation of nanocrystalline tantalum at pressures less than 100 GPa to investigate the processes associated with plastic deformation for strains up to 100%. We focus on 3D polycrystalline systems with typical grain sizes of 10-20 nm. We also study a rapidly quenched liquid (amorphous solid) tantalum. We apply a constant volume (isochoric), constant temperature (isothermal) shear deformation over a range of strain rates, and compute the resulting stress-strain curves to large strains for both uniaxial and biaxial compression. We study the rate dependence and identify plastic deformation mechanisms. The identification of the mechanisms is facilitated through a novel technique that computes the local grain orientation, returning it as a quaternion for each atom. This analysis technique is robust and fast, and has been used to compute the orientations on the fly during our parallel MD simulations on supercomputers. We find both dislocation and twinning processes are important, and they interact in the weak strain hardening in these extremely fine-grained microstructures. We also present some results on void growth in nanocrystalline BCC metals under tension.

  6. Development of a new formulation of interferons (HEBERPAG for BCC treatment

    Directory of Open Access Journals (Sweden)

    Bello-Rivero I

    2013-12-01

    Full Text Available Purpose: This work is aimed to show briefly, the clinical development of a new pharmaceutical formulation of interferons for the treatment of basal cell carcinoma. Methods: A rationale design of the combination of IFN-α2b and -γ based in their anti-proliferative synergism on several tumors cell lines identified adequate proportions to be combined to obtain the best clinical results. The potential mechanism of antitumoral effect was studied by qPCR mRNA quantification. HEBERPAG (anti-proliferative synergistic combination of co-formulated recombinant interferons-α2b and –γ was used in clinical trials in adult patients with non-melanoma skin cancer. Trials were conducted after approval by the ethics review boards of the institutions participating in trials; and the patients gave their written informed consent to be enrolled in the studies and receive HEBERPAG. Results: HEBERPAG inhibits the proliferation of several tumor cell lines in vitro and in vivo. The combination has improved pharmacodinamic properties. Several clinical trials have demonstrated the efficacy of HEBERPAG in BCC, with excellent cosmetic effect and well tolerable, mild side effects. HEBERPAG was approved by State Control Center for Drug, Medical Equipment and Devises in Cuba, for the treatment of basal cell carcinoma of any subtype, size and localization, and adjuvant to other treatments, surgical or not. After 3-year follow-up, a recurrence rate of 0.03% was detected in treated patients. Conclusions: HEBERPAG is a novel formulation of IFNs, more potent than separated IFNs for the treatment of basal cell carcinoma, with more rapid and prolonged clinical effect and excellent cosmetic effect and safety profile.

  7. Energetic stability of solute–carbon–vacancy complexes in bcc iron

    Energy Technology Data Exchange (ETDEWEB)

    Bakaev, Alexander, E-mail: alexander.bakaev@ugent.be [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, Mol B2400 (Belgium); Department of Experimental Nuclear Physics K-89, Institute of Physics, Nanotechnology and Telecommunications, St. Petersburg State Polytechnical University, 29 Polytekhnicheskaya str., 195251 St. Petersburg (Russian Federation); Center for Molecular Modeling, Department of Physics and Astronomy, Ghent University, Technologiepark 903, 9052 Zwijnaarde (Belgium); Terentyev, Dmitry [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, Mol B2400 (Belgium); Zhurkin, Evgeny E. [Department of Experimental Nuclear Physics K-89, Institute of Physics, Nanotechnology and Telecommunications, St. Petersburg State Polytechnical University, 29 Polytekhnicheskaya str., 195251 St. Petersburg (Russian Federation); Van Neck, Dimitri [Center for Molecular Modeling, Department of Physics and Astronomy, Ghent University, Technologiepark 903, 9052 Zwijnaarde (Belgium)

    2015-06-01

    The strong binding between a vacancy and carbon in bcc iron plays an important role in the evolution of radiation-induced microstructure. Our previous ab initio study points to the fact that the vacancy–carbon (V–C) pair can serve as a nucleus for the solute-rich clusters. Here, we continue the ab initio study by considering the interaction of mixed solute clusters (Mn, Ni and Si) with the V–C pair, and the interaction of typical alloying elements of Fe-based steels (i.e., Mn, Ni, Cu, Si, Cr and P) with di-carbon–vacancy pair (V–C{sub 2}). We have identified the sequence of growth of Ni, Si and Mn solute-rich clusters nucleating on the V–C pair. The mixed-solute–V–C configurations are found to be less stable clusters than pure-solute–V–C clusters with the energy difference up to 0.22 eV per four atoms. The V–C{sub 2} pair is found to be as strong nucleation site for the solute-rich clusters as the V–C pair. Only Si solute atom stands out from the trend showing a weaker affinity to the V–C{sub 2} complex by 0.09 eV compared to the attraction to the V–C pair. The overall results point to the importance of taking into account the existence of both V–C and V–C{sub 2} complexes in studying the formation of solute-rich clusters in Fe-based steels for nuclear applications.

  8. Optomagnetic Detection of MicroRNA Based on Duplex-Specific Nuclease-Assisted Target Recycling and Multilayer Core-Satellite Magnetic Superstructures

    DEFF Research Database (Denmark)

    Tian, Bo; Ma, Jing; Qiu, Zhen

    2017-01-01

    RNA and DSN-assisted target recycling, the core-satellite magnetic superstructures release their "satellites" to the suspension, which subsequently can be quantified accurately in a low-cost and user-friendly optomagnetic setup. Target miRNAs are preserved in the cleaving reaction and can thereby trigger more......Superstructural assembly of magnetic nanoparticles enables approaches to biosensing by combining specially tailored properties of superstructures and the particular advantages associated with a magnetic or optomagnetic read-out such as low background signal, easy manipulation, cost......-efficiency, and potential for bioresponsive multiplexing. Herein, we demonstrate a sensitive and rapid miRNA detection method based on optomagnetic read-out, duplex-specific nuclease (DSN)-assisted target recycling, and the use of multilayer core-satellite magnetic superstructures. Triggered by the presence of target mi...

  9. Egg albumin-assisted preparation, characterization and influencing factors of Dumbbell-shaped BaCO{sub 3} superstructures

    Energy Technology Data Exchange (ETDEWEB)

    Ni Yonghong, E-mail: niyh@mail.ahnu.edu.cn [College of Chemistry and Materials Science, Anhui Key Laboratory of Functional Molecular Solids, Anhui Normal University, Wuhu 241000 (China); Li Xiaolong [College of Chemistry and Materials Science, Anhui Key Laboratory of Functional Molecular Solids, Anhui Normal University, Wuhu 241000 (China); Hong Jianming; Ma Xiang [Centers of Modern Analysis, Nanjing University, Nanjing 210093 (China)

    2010-03-15

    Dumbbell-shaped barium carbonate superstructures were successfully synthesized in the aqueous system containing egg albumin and ethylenediaminetetraacetate disodium (EDTA-2Na), employing BaCl{sub 2}, NaHCO{sub 3} and NH{sub 3}.H{sub 2}O as the starting reagents. The as-prepared product was characterized by X-ray powder diffraction (XRD), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Some factors influencing the morphology of BaCO{sub 3} crystals, such as the time, the amounts of egg albumin and EDTA-2Na, were studied. Experimental facts showed that a proper amount of egg albumin and EDTA-2Na played crucial roles in the formation of dumbbell-shaped BaCO{sub 3} superstructures.

  10. The line shape of the Ortho-II superstructure reflection in YBa2Cu3O6.5

    DEFF Research Database (Denmark)

    Schleger, P.; Hadfield, R.; Casalta, H.

    1994-01-01

    Neutron and synchrotron x-ray measurements of the Ortho-II superstructure reflections on a high quality single crystal of YBa2Cu3O6.5 revealed that the intrinsic line shape is a Lorentzian to the power 5/2. It is argued that such a line shape implies late-stage domain coarsening of a quenched...... system ordering in three dimensions (d=3) with a two component order parameter (n=2)....

  11. Environmental Impacts of Fiber Composite Materials : Study on Life Cycle Assessment of Materials used forShip Superstructure

    OpenAIRE

    Umair, Shakila

    2006-01-01

    This thesis was conducted to investigate the impacts of fiber composites on theenvironment. Composition, properties and application of fiber compositeswere also studied. On the basis of its application, taking into account previousstudies information was gathered related to impacts of these fiber composites.In order to study impacts of fiber composites in marine application a detailstudy was conducted where using the LCA method and Sima Pro softwarethree ship superstructures of the ship Stena...

  12. Assessment of Superstructure Ice Protection as Applied to Offshore Oil Operations Safety: Ice Protection Technologies, Safety Enhancements, and Development Needs

    Science.gov (United States)

    2009-04-01

    away from the surface. Frost forms in two circumstances. On wind- less nights with clear skies frost often forms on surfaces facing the sky. On...Cable icing is also a problem for communication tower operators on guy wires, ski lift operators on lift cables, and catenary wires of bridges and...on northern New England mountains. U.S A. Arctic and Alpine Research 22(13:90-97. Ryerson, C. C. 2008. Assessment of superstructure ice protection

  13. Understanding the formation of CuS concave superstructures with peroxidase-like activity

    Science.gov (United States)

    He, Weiwei; Jia, Huimin; Li, Xiaoxiao; Lei, Yan; Li, Jing; Zhao, Hongxiao; Mi, Liwei; Zhang, Lizhi; Zheng, Zhi

    2012-05-01

    Copper sulfide (CuS) concave polyhedral superstructures (CPSs) have been successfully prepared in an ethanolic solution by a simple solvothermal reaction without the use of surfactants or templates. Two typical well defined, high symmetry CuS concave polyhedrons, forming a concave truncated cuboctahedron and icosahedron were prepared. The effect of the reaction time, temperature and different Cu ion and sulfur sources on the formation of CuS CPSs were investigated and a possible formation mechanism was proposed and discussed based on gas chromatography-mass spectrometry. More importantly, we found, for the first time, that the CuS CPSs exhibit intrinsic peroxidase-like activity, as they can quickly catalyze the oxidation of typical horseradish peroxidase (HRP) substrates, 3,3',5,5'-tetramethylbenzidine (TMB) and o-phenylenediamine (OPD), in the presence of hydrogen peroxide. In addition to the recent discoveries regarding peroxidase mimetics on Fe3O4 NPs and carbon nanostructures, our findings suggest a new kind of candidate for peroxidase mimics. This may open up a new application field of CuS micro-nano structures in biodetection, biocatalysis and environmental monitoring.Copper sulfide (CuS) concave polyhedral superstructures (CPSs) have been successfully prepared in an ethanolic solution by a simple solvothermal reaction without the use of surfactants or templates. Two typical well defined, high symmetry CuS concave polyhedrons, forming a concave truncated cuboctahedron and icosahedron were prepared. The effect of the reaction time, temperature and different Cu ion and sulfur sources on the formation of CuS CPSs were investigated and a possible formation mechanism was proposed and discussed based on gas chromatography-mass spectrometry. More importantly, we found, for the first time, that the CuS CPSs exhibit intrinsic peroxidase-like activity, as they can quickly catalyze the oxidation of typical horseradish peroxidase (HRP) substrates, 3

  14. The Privilege of Ranking: Google Plays Ball.

    Science.gov (United States)

    Wiggins, Richard

    2003-01-01

    Discussion of ranking systems used in various settings, including college football and academic admissions, focuses on the Google search engine. Explains the PageRank mathematical formula that scores Web pages by connecting the number of links; limitations, including authenticity and accuracy of ranked Web pages; relevancy; adjusting algorithms;…

  15. Methodology, Meaning and Usefulness of Rankings

    Science.gov (United States)

    Williams, Ross

    2008-01-01

    University rankings are having a profound effect on both higher education systems and individual universities. In this paper we outline these effects, discuss the desirable characteristics of a good ranking methodology and document existing practice, with an emphasis on the two main international rankings (Shanghai Jiao Tong and THES-QS). We take…

  16. "Dual-template" synthesis of one-dimensional conductive nanoparticle superstructures from coordination metal-peptide polymer crystals.

    Science.gov (United States)

    Rubio-Martínez, Marta; Puigmartí-Luis, Josep; Imaz, Inhar; Dittrich, Petra S; Maspoch, Daniel

    2013-12-20

    Bottom-up fabrication of self-assembled structures made of nanoparticles may lead to new materials, arrays and devices with great promise for myriad applications. Here a new class of metal-peptide scaffolds is reported: coordination polymer Ag(I)-DLL belt-like crystals, which enable the dual-template synthesis of more sophisticated nanoparticle superstructures. In these biorelated scaffolds, the self-assembly and recognition capacities of peptides and the selective reduction of Ag(I) ions to Ag are simultaneously exploited to control the growth and assembly of inorganic nanoparticles: first on their surfaces, and then inside the structures themselves. The templated internal Ag nanoparticles are well confined and closely packed, conditions that favour electrical conductivity in the superstructures. It is anticipated that these Ag(I)-DLL belts could be applied to create long (>100 μm) conductive Ag@Ag nanoparticle superstructures and polymetallic, multifunctional Fe3 O4 @Ag nanoparticle composites that marry the magnetic and conductive properties of the two nanoparticle types. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Tool for Ranking Research Options

    Science.gov (United States)

    Ortiz, James N.; Scott, Kelly; Smith, Harold

    2005-01-01

    Tool for Research Enhancement Decision Support (TREDS) is a computer program developed to assist managers in ranking options for research aboard the International Space Station (ISS). It could likely also be adapted to perform similar decision-support functions in industrial and academic settings. TREDS provides a ranking of the options, based on a quantifiable assessment of all the relevant programmatic decision factors of benefit, cost, and risk. The computation of the benefit for each option is based on a figure of merit (FOM) for ISS research capacity that incorporates both quantitative and qualitative inputs. Qualitative inputs are gathered and partly quantified by use of the time-tested analytical hierarchical process and used to set weighting factors in the FOM corresponding to priorities determined by the cognizant decision maker(s). Then by use of algorithms developed specifically for this application, TREDS adjusts the projected benefit for each option on the basis of levels of technical implementation, cost, and schedule risk. Based partly on Excel spreadsheets, TREDS provides screens for entering cost, benefit, and risk information. Drop-down boxes are provided for entry of qualitative information. TREDS produces graphical output in multiple formats that can be tailored by users.

  18. Issue Management Risk Ranking Systems

    Energy Technology Data Exchange (ETDEWEB)

    Novack, Steven David; Marshall, Frances Mc Clellan; Stromberg, Howard Merion; Grant, Gary Michael

    1999-06-01

    Thousands of safety issues have been collected on-line at the Idaho National Engineering and Environmental Laboratory (INEEL) as part of the Issue Management Plan. However, there has been no established approach to prioritize collected and future issues. The authors developed a methodology, based on hazards assessment, to identify and risk rank over 5000 safety issues collected at INEEL. This approach required that it was easily applied and understandable for site adaptation and commensurate with the Integrated Safety Plan. High-risk issues were investigated and mitigative/preventive measures were suggested and ranked based on a cost-benefit scheme to provide risk-informed safety measures. This methodology was consistent with other integrated safety management goals and tasks providing a site-wide risk informed decision tool to reduce hazardous conditions and focus resources on high-risk safety issues. As part of the issue management plan, this methodology was incorporated at the issue collection level and training was provided to management to better familiarize decision-makers with concepts of safety and risk. This prioritization methodology and issue dissemination procedure will be discussed. Results of issue prioritization and training efforts will be summarized. Difficulties and advantages of the process will be reported. Development and incorporation of this process into INEELs lessons learned reporting and the site-wide integrated safety management program will be shown with an emphasis on establishing self reliance and ownership of safety issues.

  19. Phase-field-crystal study of grain boundary premelting and shearing in bcc iron

    Science.gov (United States)

    Adland, Ari; Karma, Alain; Spatschek, Robert; Buta, Dorel; Asta, Mark

    2013-01-01

    We use the phase-field-crystal (PFC) method to investigate the equilibrium premelting and nonequilibrium shearing behaviors of [001] symmetric tilt grain boundaries (GBs) at high homologous temperature over the complete range of misorientation 0<θ<90∘ in classical models of bcc Fe. We characterize the dependence of the premelted layer width W as a function of temperature and misorientation. In addition, we compute the thermodynamic disjoining potential whose derivative with respect to W represents the structural force between crystal-melt interfaces due to the spatial overlap of density waves. The disjoining potential is also computed by molecular dynamics (MD) simulations, for quantitative comparison with PFC simulations, and coarse-grained amplitude equations (AE) derived from PFC that provide additional analytical insights. We find that, for GBs over an intermediate range of misorientation (θmin<θ<θmax), W diverges as the melting temperature is approached from below, corresponding to a purely repulsive disjoining potential, while for GBs outside this range (θ<θmin or θmax<θ<90∘) W remains finite at the melting point. In the latter case, W corresponds to a shallow attractive minimum of the disjoining potential. The misorientation range where W diverges predicted by PFC simulations is much smaller than the range predicted by MD simulations when the small dimensionless parameter ɛ of the PFC model is matched to liquid structure factor properties. However, it agrees well with MD simulations with a lower ɛ value chosen to match the ratio of bulk modulus and solid-liquid interfacial free energy, consistent with the amplitude-equation prediction that θmin and 90∘-θmax scale as ˜ɛ1/2. The incorporation of thermal fluctuations in PFC is found to have a negligible effect on this range. In response to a shear stress parallel to the GB plane, GBs in PFC simulations exhibit coupled motion normal to this plane or sliding. Furthermore, the coupling factor

  20. Efficient construction of the motorway and highway bridge superstructure (experimental studies

    Directory of Open Access Journals (Sweden)

    Babayev Vladimir

    2017-01-01

    Full Text Available The design of the span structure of the bridge was presented. Its structure was formed by the creation of a composite steel and concrete element consisting spatial steel perforated boxlike-section blocks, a system of shear links of a special type and a monolithic reinforced concrete slab containing inside emptiness-formers The novelty of the design and methods of its creation predetermined the need for experimental testing. It was implemented in full-scale conditions and had, in addition to research, acceptance nature. In this connection, the article presents the results of tests of the composite steel and concrete structure of the superstructure of the bridge over Sukhoy Torets in Barvenkovo. The nature of its deformation under the static and dynamic loads is shown. During the tests, the components of the stress-strain state were determined at the distinguished points of the structure, fixed under static load. The amplitude and frequency response of the bridge unit were established for various dynamic impact options. Based on the obtained data, the structural resistance features under load impacts was analyzed, the design model of the bridge was verified, and the compliance of the accepted design parameters with the limitations of the applicable reference documents was confirmed.

  1. Presenting a Multi-level Superstructure Optimization Approach for Mechatronic System Design

    DEFF Research Database (Denmark)

    Pedersen, Henrik C.; Andersen, Torben Ole; Bech, Michael Møller

    2010-01-01

    Synergism and integration in the design process is what sets apart a Mechatronic System from a traditional, multidisciplinary system. However the typical design approach has been to divide the design problem into sub problems for each technology area (mechanics, electronics and control) and descr......Synergism and integration in the design process is what sets apart a Mechatronic System from a traditional, multidisciplinary system. However the typical design approach has been to divide the design problem into sub problems for each technology area (mechanics, electronics and control......) and describe the interface between the technologies, whereas the lack of well-established, systematic engineering methods to form the basic set-off in analysis and design of complete mechatronic systems has been obvious. The focus of the current paper is therefore to present an integrated design approach...... for mechatronic system design, utilizing a multi-level superstructure optimization based approach. Finally two design examples are presented and the possibilities and limitations of the approach are outlined....

  2. Superstructure spray and ice accretion on a large U.S. Coast Guard cutter

    Science.gov (United States)

    Ryerson, C. C.

    Superstructure spray flux and ice accretion were measured on a 115-m Coast Guard cutter in the North Pacific Ocean and the Bering Sea during February and March 1990. This was the first such measurement cruise on a large ship; all previous measurements were on trawlers and patrol boats. Spray event duration averaged 2.73 s, somewhat longer than events measured on a 35-m Soviet trawler. The drop number concentration of most spray clouds was high, ranging from 2.0 × 10 5 to 3.0 × 10 5 drops m -3. Spray cloud drop sizes ranged from 14 to 7700 μm, with a geometric median of 234 μm. Spray cloud liquid water contents had a very large range with a mean of 64.1 g · m -3. Ice accretion rates were low, but sufficient for observing greater ice thicknesses on decks than on bulkheads. The ice accretion process was also found to be extremely dynamic, alternately accreting and ablating several times before reaching maximum thickness. No simple relationships were found between time-series of ice thickness during two icing events and controlling environmental parameters.

  3. Influence of plasma-treatments on the structure, superstructure, and function of membrane lipids

    Science.gov (United States)

    Hammer, Malte U.; Forbrig, Enrico; Weltmann, Klaus-Dieter; Reuter, Stephan

    2012-10-01

    Every cell, eu- or prokaryotic, has a membrane as an interface to the environment. Every substance that is applied from outside the cell has to interact with it. This includes plasma-generated reactive species in the liquid cell environment created by plasma-treatment. By the Singer and Nicolson model, proteins are embedded in a lipid bilayer. Proteins are the functional elements, lipids are the structural elements. Due to the amphiphilic nature of the lipids, they form (super-) structures in an aqueous environment. The exact superstructure is determined by a structural parameter of the lipid, its shape. Here, we show experiments on lipids by fluorophore-based liposome assays and raman spectroscopy. The results show a membrane-activity of plasma-born reactive species against lipids and lipid structures. Based on this results and literature, we propose a model for a lesion-forming mechanism in membranes of some reactive species created by plasma-treatment. It is based on a hydrophobic-hydrophilic mismatch due to lipid peroxidization induced by reactive species generated in liquids by plasma-treatment.

  4. Two-dimensional ranking of Wikipedia articles

    Science.gov (United States)

    Zhirov, A. O.; Zhirov, O. V.; Shepelyansky, D. L.

    2010-10-01

    The Library of Babel, described by Jorge Luis Borges, stores an enormous amount of information. The Library exists ab aeterno. Wikipedia, a free online encyclopaedia, becomes a modern analogue of such a Library. Information retrieval and ranking of Wikipedia articles become the challenge of modern society. While PageRank highlights very well known nodes with many ingoing links, CheiRank highlights very communicative nodes with many outgoing links. In this way the ranking becomes two-dimensional. Using CheiRank and PageRank we analyze the properties of two-dimensional ranking of all Wikipedia English articles and show that it gives their reliable classification with rich and nontrivial features. Detailed studies are done for countries, universities, personalities, physicists, chess players, Dow-Jones companies and other categories.

  5. Anharmonic correlated Debye model high-order expanded interatomic effective potential and Debye-Waller factors of bcc crystals

    Energy Technology Data Exchange (ETDEWEB)

    Van Hung, Nguyen, E-mail: hungnv@vnu.edu.vn [Department of Physics, Hanoi University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi (Viet Nam); Hue, Trinh Thi [Department of Physics, Hanoi University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi (Viet Nam); Khoa, Ha Dang [School of Engineering Physics, Hanoi University of Science and Technology, 1 Dai Co Viet, Hanoi (Viet Nam); Vuong, Dinh Quoc [Quang Ninh Education & Training Department, Nguyen Van Cu, Ha Long, Quang Ninh (Viet Nam)

    2016-12-15

    High-order expanded interatomic effective potential and Debye-Waller factors (DWFs) for local vibrational amplitudes in X-ray absorption fine structure (XAFS) of bcc crystals have been studied based on the anharmonic correlated Debye model. DWFs are presented in terms of cumulant expansion up to the fourth order and the many-body effects are taken into account in the present one-dimensional model based on the first shell near neighbor contribution approach used in the derivations of the anharmonic effective potential and XAFS cumulants where Morse potential is assumed to describe the single-pair atomic interaction. Analytical expressions for the dispersion relation, correlated Debye frequency and temperature and four first temperature-dependent XAFS cumulants have been derived based on the many-body perturbation approach. Thermodynamic properties and anharmonic effects in XAFS of bcc crystals described by the obtained cumulants have been in detail discussed. The advantage and efficiency of the present theory are illustrated by good agreement of the numerical results for Mo, Fe and W with experiment.

  6. First principles calculations of thermodynamic and mechanical properties of high temperature bcc Ta-W and Mo-Ta alloys

    Energy Technology Data Exchange (ETDEWEB)

    Masuda-Jindo, K. [Department of Materials Science and Engineering, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8503 (Japan)], E-mail: kmjindo@issp.u-tokyo.ac.jp; Vu Van Hung; Hoa, N.T. [Department of Physics, Hanoi National Pedagogic University, km8 Hanoi-Sontay Highway, Hanoi (Viet Nam); Turchi, P.E.A. [Lawrence Livermore National Laboratory, PO Box 808, L-353 LLNL, Livermore, CA 94551 (United States)

    2008-03-06

    The thermodynamic quantities of high temperature metals and alloys are studied using the statistical moment method, going beyond the quasi-harmonic approximations. Including the power moments of the atomic displacements up to the fourth order, the Helmholtz free energies and the related thermodynamic quantities are derived explicitly in closed analytic forms. The configurational entropy term is taken into account by using the tetrahedron cluster approximation of the cluster variation method (CVM). The energetics of the binary (Ta-W and Mo-Ta) alloys are treated within the framework of the first-principles TB-LMTO (tight-binding linear muffin tin orbital) method coupled to CPA (coherent potential approximation) and GPM (generalized perturbation method). The equilibrium phase diagrams are calculated for the refractory Ta-W and Mo-Ta bcc alloys. In addition, the mechanical properties, i.e., temperature dependence of the elastic moduli C{sub 11}, C{sub 12} and C{sub 44} and those of the ideal tensile and shear strengths of the bcc Ta-W and Ta-Mo alloys have been also studied.

  7. SIMS as a new methodology to depth profile helium in as-implanted and annealed pure bcc metals?

    Energy Technology Data Exchange (ETDEWEB)

    Gorondy-Novak, S. [CEA, DEN, Service de Recherches de Métallurgie Physique, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France); Jomard, F. [Groupe d' Etude de la Matière Condensée, CNRS, UVSQ, 45 avenue des Etats-Unis, 78035 Versailles cedex (France); Prima, F. [PSL Research University, Chimie ParisTech – CNRS, Institut de Recherche de Chimie Paris, 75005 Paris (France); Lefaix-Jeuland, H., E-mail: helene.lefaix@cea.fr [CEA, DEN, Service de Recherches de Métallurgie Physique, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-05-01

    Reliable He profiles are highly desirable for better understanding helium behavior in materials for future nuclear applications. Recently, Secondary Ions Mass Spectrometry (SIMS) allowed the characterization of helium distribution in as-implanted metallic systems. The Cs{sup +} primary ion beam coupled with CsHe{sup +} molecular detector appeared to be a promising technique which overcomes the very high He ionization potential. In this study, {sup 4}He depth profiles in pure body centered cubic (bcc) metals (V, Fe, Ta, Nb and Mo) as-implanted and annealed, were obtained by SIMS. All as-implanted samples exhibited a projected range of around 200 nm, in agreement with SRIM theoretical calculations. After annealing treatment, SIMS measurements evidenced the evolution of helium depth profile with temperature. The latter SIMS results were compared to the helium bubble distribution obtained by Transmission Electron Microscopy (TEM). This study confirmed the great potential of this experimental procedure as a He-depth profiling technique in bcc metals. Indeed, the methodology described in this work could be extended to other materials including metallic and non-metallic compounds. Nevertheless, the quantification of helium concentration after annealing treatment by SIMS remains uncertain probably due to the non-uniform ionization efficiency in samples containing large bubbles.

  8. Bone-repair properties of biodegradable hydroxyapatite nano-rod superstructures

    Science.gov (United States)

    D'Elía, Noelia L.; Mathieu, Colleen; Hoemann, Caroline D.; Laiuppa, Juan A.; Santillán, Graciela E.; Messina, Paula V.

    2015-11-01

    Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures for the in vitro conditions of bone-repair. Experiments are underway to investigate the effects of the material microstructure, surface roughness and hydrophilicity on their osseo-integration, osteo-conduction and osteo-induction abilities. Materials were tested in the presence of both, rat primary osteoblasts and rabbit mesenchymal stem cells. The following aspects are discussed: (i) cytotoxicity and material degradation; (ii) rat osteoblast spreading, proliferation and differentiation; and (iii) rabbit mesenchymal stem cell adhesion on nano-HAp and nano-HAp/collagen type I coatings. We effectively prepared a material based on biomimetic HAp nano-rods displaying the appropriate surface topography, hydrophilicity and degradation properties to induce the in vitro desired cellular responses for bone bonding and healing. Cells seeded on the selected material readily attached, proliferated and differentiated, as confirmed by cell viability, mitochondrial metabolic activity, alkaline phosphatase (ALP) activity and cytoskeletal integrity analysis by immunofluorescence localization of alpha-smooth muscle actin (α-SMA) protein. These results highlight the influence of material's surface characteristics to determine their tissue regeneration potential and their future use in engineering osteogenic scaffolds for orthopedic implants.Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures

  9. Rank Modulation for Translocation Error Correction

    CERN Document Server

    Farnoud, Farzad; Milenkovic, Olgica

    2012-01-01

    We consider rank modulation codes for flash memories that allow for handling arbitrary charge drop errors. Unlike classical rank modulation codes used for correcting errors that manifest themselves as swaps of two adjacently ranked elements, the proposed \\emph{translocation rank codes} account for more general forms of errors that arise in storage systems. Translocations represent a natural extension of the notion of adjacent transpositions and as such may be analyzed using related concepts in combinatorics and rank modulation coding. Our results include tight bounds on the capacity of translocation rank codes, construction techniques for asymptotically good codes, as well as simple decoding methods for one class of structured codes. As part of our exposition, we also highlight the close connections between the new code family and permutations with short common subsequences, deletion and insertion error-correcting codes for permutations and permutation arrays.

  10. Dynamics of Ranking Processes in Complex Systems

    Science.gov (United States)

    Blumm, Nicholas; Ghoshal, Gourab; Forró, Zalán; Schich, Maximilian; Bianconi, Ginestra; Bouchaud, Jean-Philippe; Barabási, Albert-László

    2012-09-01

    The world is addicted to ranking: everything, from the reputation of scientists, journals, and universities to purchasing decisions is driven by measured or perceived differences between them. Here, we analyze empirical data capturing real time ranking in a number of systems, helping to identify the universal characteristics of ranking dynamics. We develop a continuum theory that not only predicts the stability of the ranking process, but shows that a noise-induced phase transition is at the heart of the observed differences in ranking regimes. The key parameters of the continuum theory can be explicitly measured from data, allowing us to predict and experimentally document the existence of three phases that govern ranking stability.

  11. Error analysis of stochastic gradient descent ranking.

    Science.gov (United States)

    Chen, Hong; Tang, Yi; Li, Luoqing; Yuan, Yuan; Li, Xuelong; Tang, Yuanyan

    2013-06-01

    Ranking is always an important task in machine learning and information retrieval, e.g., collaborative filtering, recommender systems, drug discovery, etc. A kernel-based stochastic gradient descent algorithm with the least squares loss is proposed for ranking in this paper. The implementation of this algorithm is simple, and an expression of the solution is derived via a sampling operator and an integral operator. An explicit convergence rate for leaning a ranking function is given in terms of the suitable choices of the step size and the regularization parameter. The analysis technique used here is capacity independent and is novel in error analysis of ranking learning. Experimental results on real-world data have shown the effectiveness of the proposed algorithm in ranking tasks, which verifies the theoretical analysis in ranking error.

  12. Ranking in Swiss system chess team tournaments

    OpenAIRE

    Csató, László

    2015-01-01

    The paper uses paired comparison-based scoring procedures for ranking the participants of a Swiss system chess team tournament. We present the main challenges of ranking in Swiss system, the features of individual and team competitions as well as the failures of official lexicographical orders. The tournament is represented as a ranking problem, our model is discussed with respect to the properties of the score, generalized row sum and least squares methods. The proposed procedure is illustra...

  13. A universal rank-size law

    CERN Document Server

    Ausloos, Marcel

    2016-01-01

    A mere hyperbolic law, like the Zipf's law power function, is often inadequate to describe rank-size relationships. An alternative theoretical distribution is proposed based on theoretical physics arguments starting from the Yule-Simon distribution. A modeling is proposed leading to a universal form. A theoretical suggestion for the "best (or optimal) distribution", is provided through an entropy argument. The ranking of areas through the number of cities in various countries and some sport competition ranking serves for the present illustrations.

  14. Methodology for ranking restoration options

    Energy Technology Data Exchange (ETDEWEB)

    Hedemann Jensen, Per

    1999-04-01

    The work described in this report has been performed as a part of the RESTRAT Project FI4P-CT95-0021a (PL 950128) co-funded by the Nuclear Fission Safety Programme of the European Commission. The RESTRAT project has the overall objective of developing generic methodologies for ranking restoration techniques as a function of contamination and site characteristics. The project includes analyses of existing remediation methodologies and contaminated sites, and is structured in the following steps: characterisation of relevant contaminated sites; identification and characterisation of relevant restoration techniques; assessment of the radiological impact; development and application of a selection methodology for restoration options; formulation of generic conclusions and development of a manual. The project is intended to apply to situations in which sites with nuclear installations have been contaminated with radioactive materials as a result of the operation of these installations. The areas considered for remedial measures include contaminated land areas, rivers and sediments in rivers, lakes, and sea areas. Five contaminated European sites have been studied. Various remedial measures have been envisaged with respect to the optimisation of the protection of the populations being exposed to the radionuclides at the sites. Cost-benefit analysis and multi-attribute utility analysis have been applied for optimisation. Health, economic and social attributes have been included and weighting factors for the different attributes have been determined by the use of scaling constants. (au)

  15. Ranking documents with a thesaurus.

    Science.gov (United States)

    Rada, R; Bicknell, E

    1989-09-01

    This article reports on exploratory experiments in evaluating and improving a thesaurus through studying its effect on retrieval. A formula called DISTANCE was developed to measure the conceptual distance between queries and documents encoded as sets of thesaurus terms. DISTANCE references MeSH (Medical Subject Headings) and assesses the degree of match between a MeSH-encoded query and document. The performance of DISTANCE on MeSH is compared to the performance of people in the assessment of conceptual distance between queries and documents, and is found to simulate with surprising accuracy the human performance. The power of the computer simulation stems both from the tendency of people to rely heavily on broader-than (BT) relations in making decisions about conceptual distance and from the thousands of accurate BT relations in MeSH. One source for discrepancy between the algorithms' measurement of closeness between query and document and people's measurement of closeness between query and document is occasional inconsistency in the BT relations. Our experiments with adding non-BT relations to MeSH showed how these non-BT non-BT relations to MeSH showed how these non-BT relations could improve document ranking, if DISTANCE were also appropriately revised to treat these relations differently from BT relations.

  16. Communities in Large Networks: Identification and Ranking

    DEFF Research Database (Denmark)

    Olsen, Martin

    2008-01-01

    We study the problem of identifying and ranking the members of a community in a very large network with link analysis only, given a set of representatives of the community. We define the concept of a community justified by a formal analysis of a simple model of the evolution of a directed graph. ...... and its immediate surroundings. The members are ranked with a “local” variant of the PageRank algorithm. Results are reported from successful experiments on identifying and ranking Danish Computer Science sites and Danish Chess pages using only a few representatives....

  17. Citation graph based ranking in Invenio

    CERN Document Server

    Marian, Ludmila; Rajman, Martin; Vesely, Martin

    2010-01-01

    Invenio is the web-based integrated digital library system developed at CERN. Within this framework, we present four types of ranking models based on the citation graph that complement the simple approach based on citation counts: time-dependent citation counts, a relevancy ranking which extends the PageRank model, a time-dependent ranking which combines the freshness of citations with PageRank and a ranking that takes into consideration the external citations. We present our analysis and results obtained on two main data sets: Inspire and CERN Document Server. Our main contributions are: (i) a study of the currently available ranking methods based on the citation graph; (ii) the development of new ranking methods that correct some of the identified limitations of the current methods such as treating all citations of equal importance, not taking time into account or considering the citation graph complete; (iii) a detailed study of the key parameters for these ranking methods. (The original publication is ava...

  18. Ranked Conservation Opportunity Areas for Region 7 (ECO_RES.RANKED_OAS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The RANKED_OAS are all the Conservation Opportunity Areas identified by MoRAP that have subsequently been ranked by patch size, landform representation, and the...

  19. Ranking scientific publications: the effect of nonlinearity.

    Science.gov (United States)

    Yao, Liyang; Wei, Tian; Zeng, An; Fan, Ying; Di, Zengru

    2014-10-17

    Ranking the significance of scientific publications is a long-standing challenge. The network-based analysis is a natural and common approach for evaluating the scientific credit of papers. Although the number of citations has been widely used as a metric to rank papers, recently some iterative processes such as the well-known PageRank algorithm have been applied to the citation networks to address this problem. In this paper, we introduce nonlinearity to the PageRank algorithm when aggregating resources from different nodes to further enhance the effect of important papers. The validation of our method is performed on the data of American Physical Society (APS) journals. The results indicate that the nonlinearity improves the performance of the PageRank algorithm in terms of ranking effectiveness, as well as robustness against malicious manipulations. Although the nonlinearity analysis is based on the PageRank algorithm, it can be easily extended to other iterative ranking algorithms and similar improvements are expected.

  20. Ranking scientific publications: the effect of nonlinearity

    Science.gov (United States)

    Yao, Liyang; Wei, Tian; Zeng, An; Fan, Ying; di, Zengru

    2014-10-01

    Ranking the significance of scientific publications is a long-standing challenge. The network-based analysis is a natural and common approach for evaluating the scientific credit of papers. Although the number of citations has been widely used as a metric to rank papers, recently some iterative processes such as the well-known PageRank algorithm have been applied to the citation networks to address this problem. In this paper, we introduce nonlinearity to the PageRank algorithm when aggregating resources from different nodes to further enhance the effect of important papers. The validation of our method is performed on the data of American Physical Society (APS) journals. The results indicate that the nonlinearity improves the performance of the PageRank algorithm in terms of ranking effectiveness, as well as robustness against malicious manipulations. Although the nonlinearity analysis is based on the PageRank algorithm, it can be easily extended to other iterative ranking algorithms and similar improvements are expected.

  1. Entity Ranking using Wikipedia as a Pivot

    NARCIS (Netherlands)

    R. Kaptein; P. Serdyukov; A.P. de Vries (Arjen); J. Kamps

    2010-01-01

    htmlabstractIn this paper we investigate the task of Entity Ranking on the Web. Searchers looking for entities are arguably better served by presenting a ranked list of entities directly, rather than a list of web pages with relevant but also potentially redundant information about

  2. Entity ranking using Wikipedia as a pivot

    NARCIS (Netherlands)

    Kaptein, R.; Serdyukov, P.; de Vries, A.; Kamps, J.; Huang, X.J.; Jones, G.; Koudas, N.; Wu, X.; Collins-Thompson, K.

    2010-01-01

    In this paper we investigate the task of Entity Ranking on the Web. Searchers looking for entities are arguably better served by presenting a ranked list of entities directly, rather than a list of web pages with relevant but also potentially redundant information about these entities. Since

  3. Biplots in Reduced-Rank Regression

    NARCIS (Netherlands)

    Braak, ter C.J.F.; Looman, C.W.N.

    1994-01-01

    Regression problems with a number of related response variables are typically analyzed by separate multiple regressions. This paper shows how these regressions can be visualized jointly in a biplot based on reduced-rank regression. Reduced-rank regression combines multiple regression and principal

  4. Mining Feedback in Ranking and Recommendation Systems

    Science.gov (United States)

    Zhuang, Ziming

    2009-01-01

    The amount of online information has grown exponentially over the past few decades, and users become more and more dependent on ranking and recommendation systems to address their information seeking needs. The advance in information technologies has enabled users to provide feedback on the utilities of the underlying ranking and recommendation…

  5. Using centrality to rank web snippets

    NARCIS (Netherlands)

    Jijkoun, V.; de Rijke, M.; Peters, C.; Jijkoun, V.; Mandl, T.; Müller, H.; Oard, D.W.; Peñas, A.; Petras, V.; Santos, D.

    2008-01-01

    We describe our participation in the WebCLEF 2007 task, targeted at snippet retrieval from web data. Our system ranks snippets based on a simple similarity-based centrality, inspired by the web page ranking algorithms. We experimented with retrieval units (sentences and paragraphs) and with the

  6. Generating and ranking of Dyck words

    CERN Document Server

    Kasa, Zoltan

    2010-01-01

    A new algorithm to generate all Dyck words is presented, which is used in ranking and unranking Dyck words. We emphasize the importance of using Dyck words in encoding objects related to Catalan numbers. As a consequence of formulas used in the ranking algorithm we can obtain a recursive formula for the nth Catalan number.

  7. University ranking methodologies. An interview with Ben Sowter about the Quacquarelli Symonds World University Ranking

    OpenAIRE

    Alberto Baccini; Antono Banfi; Giuseppe De Nicolao; Paola Galimberti

    2015-01-01

    University rankings represent a controversial issue in the debate about higher education policy. One of the best known university ranking is the Quacquarelli Symonds World University Rankings (QS), published annually since 2004 by Quacquarelli Symonds ltd, a company founded in 1990 and headquartered in London. QS provides a ranking based on a score calculated by weighting six different indicators. The 2015 edition, published in October 2015, introduced major methodological innovations and, as...

  8. Universal emergence of PageRank

    Energy Technology Data Exchange (ETDEWEB)

    Frahm, K M; Georgeot, B; Shepelyansky, D L, E-mail: frahm@irsamc.ups-tlse.fr, E-mail: georgeot@irsamc.ups-tlse.fr, E-mail: dima@irsamc.ups-tlse.fr [Laboratoire de Physique Theorique du CNRS, IRSAMC, Universite de Toulouse, UPS, 31062 Toulouse (France)

    2011-11-18

    The PageRank algorithm enables us to rank the nodes of a network through a specific eigenvector of the Google matrix, using a damping parameter {alpha} Element-Of ]0, 1[. Using extensive numerical simulations of large web networks, with a special accent on British University networks, we determine numerically and analytically the universal features of the PageRank vector at its emergence when {alpha} {yields} 1. The whole network can be divided into a core part and a group of invariant subspaces. For {alpha} {yields} 1, PageRank converges to a universal power-law distribution on the invariant subspaces whose size distribution also follows a universal power law. The convergence of PageRank at {alpha} {yields} 1 is controlled by eigenvalues of the core part of the Google matrix, which are extremely close to unity, leading to large relaxation times as, for example, in spin glasses. (paper)

  9. Comparing classical and quantum PageRanks

    Science.gov (United States)

    Loke, T.; Tang, J. W.; Rodriguez, J.; Small, M.; Wang, J. B.

    2017-01-01

    Following recent developments in quantum PageRanking, we present a comparative analysis of discrete-time and continuous-time quantum-walk-based PageRank algorithms. Relative to classical PageRank and to different extents, the quantum measures better highlight secondary hubs and resolve ranking degeneracy among peripheral nodes for all networks we studied in this paper. For the discrete-time case, we investigated the periodic nature of the walker's probability distribution for a wide range of networks and found that the dominant period does not grow with the size of these networks. Based on this observation, we introduce a new quantum measure using the maximum probabilities of the associated walker during the first couple of periods. This is particularly important, since it leads to a quantum PageRanking scheme that is scalable with respect to network size.

  10. Reliability of journal impact factor rankings

    Science.gov (United States)

    Greenwood, Darren C

    2007-01-01

    Background Journal impact factors and their ranks are used widely by journals, researchers, and research assessment exercises. Methods Based on citations to journals in research and experimental medicine in 2005, Bayesian Markov chain Monte Carlo methods were used to estimate the uncertainty associated with these journal performance indicators. Results Intervals representing plausible ranges of values for journal impact factor ranks indicated that most journals cannot be ranked with great precision. Only the top and bottom few journals could place any confidence in their rank position. Intervals were wider and overlapping for most journals. Conclusion Decisions placed on journal impact factors are potentially misleading where the uncertainty associated with the measure is ignored. This article proposes that caution should be exercised in the interpretation of journal impact factors and their ranks, and specifically that a measure of uncertainty should be routinely presented alongside the point estimate. PMID:18005435

  11. Reliability of journal impact factor rankings

    Directory of Open Access Journals (Sweden)

    Greenwood Darren C

    2007-11-01

    Full Text Available Abstract Background Journal impact factors and their ranks are used widely by journals, researchers, and research assessment exercises. Methods Based on citations to journals in research and experimental medicine in 2005, Bayesian Markov chain Monte Carlo methods were used to estimate the uncertainty associated with these journal performance indicators. Results Intervals representing plausible ranges of values for journal impact factor ranks indicated that most journals cannot be ranked with great precision. Only the top and bottom few journals could place any confidence in their rank position. Intervals were wider and overlapping for most journals. Conclusion Decisions placed on journal impact factors are potentially misleading where the uncertainty associated with the measure is ignored. This article proposes that caution should be exercised in the interpretation of journal impact factors and their ranks, and specifically that a measure of uncertainty should be routinely presented alongside the point estimate.

  12. Cointegration rank testing under conditional heteroskedasticity

    DEFF Research Database (Denmark)

    Cavaliere, Giuseppe; Rahbek, Anders Christian; Taylor, Robert M.

    2010-01-01

    (martingale difference) innovations. We first demonstrate that the limiting null distributions of the rank statistics coincide with those derived by previous authors who assume either independent and identically distributed (i.i.d.) or (strict and covariance) stationary martingale difference innovations. We...... then propose wild bootstrap implementations of the cointegrating rank tests and demonstrate that the associated bootstrap rank statistics replicate the first-order asymptotic null distributions of the rank statistics. We show that the same is also true of the corresponding rank tests based on the i.......i.d. bootstrap of Swensen (2006, Econometrica 74, 1699-1714). The wild bootstrap, however, has the important property that, unlike the i.i.d. bootstrap, it preserves in the resampled data the pattern of heteroskedasticity present in the original shocks. Consistent with this, numerical evidence suggests that...

  13. PageRank and rank-reversal dependence on the damping factor

    Science.gov (United States)

    Son, S.-W.; Christensen, C.; Grassberger, P.; Paczuski, M.

    2012-12-01

    PageRank (PR) is an algorithm originally developed by Google to evaluate the importance of web pages. Considering how deeply rooted Google's PR algorithm is to gathering relevant information or to the success of modern businesses, the question of rank stability and choice of the damping factor (a parameter in the algorithm) is clearly important. We investigate PR as a function of the damping factor d on a network obtained from a domain of the World Wide Web, finding that rank reversal happens frequently over a broad range of PR (and of d). We use three different correlation measures, Pearson, Spearman, and Kendall, to study rank reversal as d changes, and we show that the correlation of PR vectors drops rapidly as d changes from its frequently cited value, d0=0.85. Rank reversal is also observed by measuring the Spearman and Kendall rank correlation, which evaluate relative ranks rather than absolute PR. Rank reversal happens not only in directed networks containing rank sinks but also in a single strongly connected component, which by definition does not contain any sinks. We relate rank reversals to rank pockets and bottlenecks in the directed network structure. For the network studied, the relative rank is more stable by our measures around d=0.65 than at d=d0.

  14. PageRank and rank-reversal dependence on the damping factor.

    Science.gov (United States)

    Son, S-W; Christensen, C; Grassberger, P; Paczuski, M

    2012-12-01

    PageRank (PR) is an algorithm originally developed by Google to evaluate the importance of web pages. Considering how deeply rooted Google's PR algorithm is to gathering relevant information or to the success of modern businesses, the question of rank stability and choice of the damping factor (a parameter in the algorithm) is clearly important. We investigate PR as a function of the damping factor d on a network obtained from a domain of the World Wide Web, finding that rank reversal happens frequently over a broad range of PR (and of d). We use three different correlation measures, Pearson, Spearman, and Kendall, to study rank reversal as d changes, and we show that the correlation of PR vectors drops rapidly as d changes from its frequently cited value, d_{0}=0.85. Rank reversal is also observed by measuring the Spearman and Kendall rank correlation, which evaluate relative ranks rather than absolute PR. Rank reversal happens not only in directed networks containing rank sinks but also in a single strongly connected component, which by definition does not contain any sinks. We relate rank reversals to rank pockets and bottlenecks in the directed network structure. For the network studied, the relative rank is more stable by our measures around d=0.65 than at d=d_{0}.

  15. A tilting approach to ranking influence

    KAUST Repository

    Genton, Marc G.

    2014-12-01

    We suggest a new approach, which is applicable for general statistics computed from random samples of univariate or vector-valued or functional data, to assessing the influence that individual data have on the value of a statistic, and to ranking the data in terms of that influence. Our method is based on, first, perturbing the value of the statistic by ‘tilting’, or reweighting, each data value, where the total amount of tilt is constrained to be the least possible, subject to achieving a given small perturbation of the statistic, and, then, taking the ranking of the influence of data values to be that which corresponds to ranking the changes in data weights. It is shown, both theoretically and numerically, that this ranking does not depend on the size of the perturbation, provided that the perturbation is sufficiently small. That simple result leads directly to an elegant geometric interpretation of the ranks; they are the ranks of the lengths of projections of the weights onto a ‘line’ determined by the first empirical principal component function in a generalized measure of covariance. To illustrate the generality of the method we introduce and explore it in the case of functional data, where (for example) it leads to generalized boxplots. The method has the advantage of providing an interpretable ranking that depends on the statistic under consideration. For example, the ranking of data, in terms of their influence on the value of a statistic, is different for a measure of location and for a measure of scale. This is as it should be; a ranking of data in terms of their influence should depend on the manner in which the data are used. Additionally, the ranking recognizes, rather than ignores, sign, and in particular can identify left- and right-hand ‘tails’ of the distribution of a random function or vector.

  16. A New Approach to Reducing Search Space and Increasing Efficiency in Simulation Optimization Problems via the Fuzzy-DEA-BCC

    Directory of Open Access Journals (Sweden)

    Rafael de Carvalho Miranda

    2014-01-01

    Full Text Available The development of discrete-event simulation software was one of the most successful interfaces in operational research with computation. As a result, research has been focused on the development of new methods and algorithms with the purpose of increasing simulation optimization efficiency and reliability. This study aims to define optimum variation intervals for each decision variable through a proposed approach which combines the data envelopment analysis with the Fuzzy logic (Fuzzy-DEA-BCC, seeking to improve the decision-making units’ distinction in the face of uncertainty. In this study, Taguchi’s orthogonal arrays were used to generate the necessary quantity of DMUs, and the output variables were generated by the simulation. Two study objects were utilized as examples of mono- and multiobjective problems. Results confirmed the reliability and applicability of the proposed method, as it enabled a significant reduction in search space and computational demand when compared to conventional simulation optimization techniques.

  17. Layer texture of hot-rolled BCC metals and its significance for stress-corrosion cracking of main gas pipelines

    Science.gov (United States)

    Perlovich, Yu. A.; Isaenkova, M. G.; Krymskaya, O. A.; Morozov, N. S.

    2016-10-01

    Based on data of X-ray texture analysis of hot-rolled BCC materials it was shown that the layerwise texture inhomogeneity of products is formed during their manufacturing. The effect can be explained by saturation with interstitial impurities of the surface layer, resulting in dynamical deformation aging (DDA). DDA prevents the dislocation slip under rolling and leads to an increase of lattice parameters in the external layer. The degree of arising inhomogeneity correlates with the tendency of hot-rolled sheets and obtained therefrom tubes to stress-corrosion cracking under exploitation, since internal layers have a compressive effect on external layers, and prevents opening of corrosion cracks at the tube surface.

  18. Controllable topological transformation from BiOCl hierarchical microspheres to Bi{sub 2}WO{sub 6} superstructures in the Bi–W–Cl–O system

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jiao [National Engineering Research Center for Manufacturing Equipment Digitization, Department of Mechanical Science and Engineering, Huazhong University of Science and Technology (HUST), No. 1037, Luoyu Road, Wuhan 430074 (China); State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, No. 1037, Luoyu Road, Wuhan 430074 (China); Shi, Songxin, E-mail: shisx@hust.edu.cn [National Engineering Research Center for Manufacturing Equipment Digitization, Department of Mechanical Science and Engineering, Huazhong University of Science and Technology (HUST), No. 1037, Luoyu Road, Wuhan 430074 (China); Tang, Tengteng [State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, No. 1037, Luoyu Road, Wuhan 430074 (China); Tian, Shouqin [State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, No. 1037, Luoyu Road, Wuhan 430074 (China); Nanomaterials and Smart Sensors Research Laboratory, Department of Materials Science and Engineering, Huazhong University of Science and Technology, No. 1037, Luoyu Road, Wuhan 430074 (China); Yang, Wenjuan [State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, No. 1037, Luoyu Road, Wuhan 430074 (China); Zeng, Dawen [Nanomaterials and Smart Sensors Research Laboratory, Department of Materials Science and Engineering, Huazhong University of Science and Technology, No. 1037, Luoyu Road, Wuhan 430074 (China)

    2015-09-15

    Graphical abstract: The three-dimensional (3D) Bi{sub 2}WO{sub 6} superstructures assembled by nanosheets were directly transformed topologically from BiOCl hierarchical microspheres via a facile one-pot solvothermal method. Furthermore, the crystal growth of Bi{sub 2}WO{sub 6} superstructure was confirmed to occur at the exposed plane (0 0 1) of BiOCl nanosheets with WO{sub 6}{sup 6−} units replacing the interlaminar Cl atoms. Their similar layered structures favored the controllable transformation of BiOCl to Bi{sub 2}WO{sub 6} through the substitution process. And this topological transformation may provide a new prospective to the synthesis of other 3D compounds. - Highlights: • Bi{sub 2}WO{sub 6} superstructures were prepared by topological transformation of BiOCl assembly. • Transformation process experienced three stages of BiOCl, BiOCl/Bi{sub 2}WO{sub 6} and Bi{sub 2}WO{sub 6}. • Bi{sub 2}WO{sub 6} superstructures grew at the exposed (0 0 1) facets of BiOCl nanosheets. • The growth mechanism was revealed from thermodynamic and kinetic dynamic aspects. - Abstract: In this work, three-dimensional (3D) Bi{sub 2}WO{sub 6} superstructures assembled by nanosheets were prepared using the topological transformation of BiOCl hierarchical microspheres via a facile one-pot solvothermal method. Interestingly, it was found that the transformation process experienced three stages including BiOCl, BiOCl/Bi{sub 2}WO{sub 6} composites and Bi{sub 2}WO{sub 6} with increasing solvothermal time at 150 °C, which was confirmed by X-Ray Diffraction (XRD), Raman spectrometer and Transmission Electron Microscopy (TEM) results. Importantly, the crystal growth of Bi{sub 2}WO{sub 6} superstructures occurred at the exposed (0 0 1) facets of BiOCl nanosheets with WO{sub 6}{sup 6−} units replacing the interlaminar Cl atoms. Also, the growth mechanism was revealed and discussed in the thermodynamic and kinetic dynamic aspects. Compared with BiOCl superstructures, the Bi

  19. Fermentation RS3 derived from sago and rice starch with Clostridium butyricum BCC B2571 or Eubacterium rectale DSM 17629.

    Science.gov (United States)

    Purwani, Endang Yuli; Purwadaria, Tresnawati; Suhartono, Maggy Thenawidjaja

    2012-02-01

    Resistant starch type 3 (RS3) is retrograded starch which is not digested by human starch degrading enzyme, and will thus undergo bacterial degradation in the colon. The main fermentation products are the Short Chain Fatty Acid (SCFA): acetate, propionate and butyrate. SCFA has significant benefit impact on the metabolism of the host. The objectives of this research were to study the SCFA profile produced by colonic butyrate producing bacteria grown in medium containing RS3. RS3 was made from sago or rice starch treated with amylase, pullulanase and the combination of amylase and pullulanase. Fermentation study was performed by using Clostridium butyricum BCC B2571 or Eubacterium rectale DSM 17629, which has been identified as capable of degradation of starch residue and also regarded as beneficial bacteria. Experimental result revealed that enzyme hydrolysis of retrograded sago or rice starch was beneficial to RS formation. RS3 derived from sago contained higher RS (31-38%) than those derived from rice starch (21-26%). This study indicated that C. butyricum BCC B2571 produced acetate, propionate and butyrate at molar ratio of 1.8 : 1 : 1, when the medium was supplemented with RSSA at concentration 1%. In the medium containing similar substrate, E. rectale DSM 17629 produced acetate, propionate and butyrate at molar ratio of 1.7 : 1 : 1.2. High levels of acetate, propionate and butyrate at molar ratio of 1.8 : 1 : 1.1 was also produced by E. rectale DSM 17629 in medium supplemented with RSSP at concentration 1%. The results showed that both bacteria responded differently to the RS3 supplementation. Such result provided insight into the possibility of designing RS3 as prebiotic with featured regarding SCFA released in the human colon with potential health implication. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. On the critical temperature discontinuity at the theoretical bcc-fcc phase transition in compressed selenium and tellurium superconductors

    Science.gov (United States)

    Szczęśniak, D.; Wrona, I. A.; Drzazga, E. A.; Kaczmarek, A. Z.; Szewczyk, K. A.

    2017-11-01

    Recent hydrides-driven advent in the high-pressure phonon-mediated superconductivity motivates research on chemical elements which compound with hydrogen. It is desired that such elements should allow chemical pre-compression of hydrogen to assure the induction of the superconducting phase with the high transition temperature (T C). Herein, we present detailed theoretical insight into the properties of the superconducting state induced under pressure (p) in two of such component elements, namely selenium (Se) and tellurium (Te) at p=250 GPa and p=70 GPa, respectively. The assumed external pressure conditions allow us to conduct our analysis just above previously theoretically predicted bcc-fcc structural phase transition of Se and Te, and identify the possible associated discontinuity effect of the critical temperature. In particular, our numerical analysis is conducted within Migdal-Eliashberg formalism, due to the confirmed electron-phonon pairing mechanism and relatively high electron-phonon coupling constant in the materials of interest. We predict that T C values in Se and Te equal 8.13 K and 5.96 K, respectively, and mark the highest critical temperature values for these elements within the postulated fcc phase. Additionally, we supplement these results by the estimated maximum values of the superconducting energy band gap and the effective mass of electrons. We predict that all these parameters can be used as a guidelines for experimental observation of the critical temperature discontinuity and the corresponding bcc-fcc phase transition in Se and Te superconductors. Moreover, we show that the thermodynamics of superconducting phase in both elements may exhibit deviations from the conventional estimates of the Bardeen-Cooper-Schrieffer theory, and suggest existence of the strong-coupling and retardation effects. Finally, we note that our results can be also instructive for future screening of chemical elements for applications in superconducting hydrides.

  1. The observation of formation and annihilation of solitons and standing strain wave superstructures in a two-dimensional colloidal crystal.

    Science.gov (United States)

    Chui, Yu-Hang; Sengupta, Surajit; Snook, Ian K; Binder, Kurt

    2010-02-21

    Confining a colloidal crystal within a long narrow channel produced by two parallel walls can be used to impose a mesoscale superstructure of a predominantly mechanical elastic character [Chui et al., EPL 83, 58004 (2008)]. When the crystal is compressed in the direction perpendicular to the walls, we obtain a structural transition when the number of rows of particles parallel to the walls decreases by one. All the particles of this vanishing row are distributed throughout the crystal. If the confining walls are structured (say with a corrugation along the length of the walls), then these extra particles are distributed neither uniformly nor randomly; rather, defect structures are created along the boundaries resembling "soliton staircases," inducing a nonuniform strain pattern within the crystal. Here, we study the conditions of stability, formation, and annihilation of these solitons using a coarse grained description of the dynamics. The processes are shown by comparing superimposed configurations as well as molecular animations obtained from our simulations. Also, the corresponding normal and shear stresses during the transformation are calculated. A study of these dynamical processes should be useful for controlling strain wave superstructures in the self-assembly of various nano- and mesoscaled particles.

  2. Failure behavior of concrete pile and super-structure dynamic response as a result of soil liquefaction during earthquake

    Science.gov (United States)

    Kaneda, Shogo; Hayashi, Kazuhiro; Hachimori, Wataru; Tamura, Shuji; Saito, Taiki

    2017-10-01

    In past earthquake disasters, numerous building structure piles were damaged by soil liquefaction occurring during the earthquake. Damage to these piles, because they are underground, is difficult to find. The authors aim to develop a monitoring method of pile damage based on superstructure dynamic response. This paper investigated the relationship between the damage of large cross section cementitious piles and the dynamic response of the super structure using a centrifuge test apparatus. A dynamic specimen used simple cross section pile models consisting of aluminum rod and mortar, a saturated soil (Toyoura sand) of a relative density of 40% and a super structure model of a natural period of 0.63sec. In the shaking table test under a 50G field (length scale of 1/50), excitation was a total of 3 motions scaled from the Rinkai wave at different amplitudes. The maximum acceleration of each of the excitations was 602gal, 336gal and 299gal. The centrifuge test demonstrated the liquefaction of saturated soil and the failure behavior of piles. In the test result, the damage of piles affected the predominant period of acceleration response spectrum on the footing of the superstructure.

  3. Curvature aided efficient axial field emission from carbon nanofiber–reduced graphene oxide superstructures on tungsten wire substrate

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Arunava [School of Materials Science and Nanotechnology, Jadavpur University, Kolkata 700032 (India); Roy, Rajarshi; Sen, Dipayan [Thin Film and Nanoscience Laboratory, Department of Physics, Jadavpur University, Kolkata 700032 (India); Chattopadhyay, Kalyan K., E-mail: kalyan_chattopadhyay@yahoo.com [School of Materials Science and Nanotechnology, Jadavpur University, Kolkata 700032 (India); Thin Film and Nanoscience Laboratory, Department of Physics, Jadavpur University, Kolkata 700032 (India)

    2016-03-15

    Graphical abstract: - Highlights: • Efficient axial field emitter was fabricated through deposition of thin RGO layer by Langmuir–Blodgett method. • Tungsten wire substrate was used. • The CNF–RGO superstructure produced better field emission characteristics compared to bare CNF. - Abstract: Field emission characteristics found in reduced graphene oxide (RGO) and RGO based composite systems have always been an area of research interest mainly due to presence of prolific quasi aligned edges working as emitter sites. However, the specific role and extent of edge curvature geometry in RGO systems in regards to the enhancement of field emission has not discussed thoroughly prior to this work. In this work we demonstrate enhanced axial field emission due to top assembly of thin RGO layer over a quasi-vertically aligned carbon nanofiber thin film supported on a tungsten wire substrate. Furthermore, simulation analysis for our RGO based hybrid system using finite element modeling showed that two-stage local field amplification in RGO is responsible for the overall improvement of field emission characteristics. In support of our findings, a tentative explanation has been proposed based on the additional emission from RGO edges in between the CNF network resulting to the enhancement of axial field emission in the nanocomposite superstructure.

  4. Self-organization of nickel nanoparticles dispersed in acetone: From separate nanoparticles to three-dimensional superstructures

    Directory of Open Access Journals (Sweden)

    I. Hernández-Pérez

    2017-02-01

    Full Text Available Sonochemical synthesis of monodisperse nickel nanoparticles (Ni-NPs by reduction of Ni acetylacetonate in the presence of polyvinylpyrrolidone stabilizer is reported. The Ni-NPs size is readily controlled to 5 nanometer diameter with a standard deviation of less than 5%. The as-prepared Ni-NPs sample was dispersed in acetone, for 4 weeks. For structural analysis was not applied to a magnetic field or heat treatment as key methods to direct the assembly. The transition from separate Ni-NPs into self-organization of three dimensions (3D superstructures was studied by electron microscopy. Experimental analysis suggests that the translation and rotation movement of the Ni-NPs are governed by magnetic frustration which promotes the formation of different geometric arrangements in two dimensions (2D. The formation of 3D superstructures is confirmed from scanning electron microscopy revealing a layered domain that consists of staking of several monolayers having multiple well-defined supercrystalline domains, enabling their use for optical, electronic and sensor applications.

  5. Superstructures with diverse morphologies and highly ordered fullerene C60 arrays from 1 : 1 and 2 : 1 adamantane-C60 hybrid molecules.

    Science.gov (United States)

    Zhou, Shengju; Wang, Lin; Chen, Mengjun; Liu, Baoyong; Sun, Xiaofeng; Cai, Meirong; Li, Hongguang

    2017-11-02

    Superstructures from fullerene C60-containing compounds, especially those tethered to rigid functional groups with defined shapes, remain largely unexplored. Being the smallest diamondoid, adamantane (Ad) can be viewed as a promising building block for the construction of well-defined superstructures. Here, we report the syntheses of 1 : 1 (4a) and 2 : 1 (4b) Ad-C60 hybrid molecules, which were then used to construct superstructures in binary solvent mixtures via a modified liquid/liquid interfacial precipitation (LLIP) method using CHCl3 as a good solvent. Typically in the combination of DMSO/CHCl3 with a final concentration (cf) of 1.0 mmol L-1, 4a successively forms spheres, plates, nanoflowers and plicated particles with increasing content of DMSO while 4b forms cuboid blocks and microparticles with hierarchically organized surfaces. Changing from DMSO to other poor solvents including acetone, MeOH and EtOAc leads to variations of the morphology of the superstructures for both 4a and 4b. At the nanometer length scale, 4a and 4b adopt different organizations within the superstructures. While 4a tends to self-organize into lamellae with highly ordered C60 layers, the hexagonal phase is dominant in the superstructures formed by 4b. Wettability tests indicate that films formed by the superstructures of 4a and 4b show anti-wetting properties. Besides the solvent effect, the morphology of the superstructures can be also tuned by concentration. For example, when cf is lowered to 0.5 mmol L-1, a new form of superstructure, i.e., fibers, was detected for 4a. Our results also indicate that besides the solvent-induced aggregate transition, gravity-induced sedimentation and subsequent structure ripening can have a significant influence on the final morphology of the superstructures and the aggregate transition pathways.

  6. University ranking methodologies. An interview with Ben Sowter about the Quacquarelli Symonds World University Ranking

    Directory of Open Access Journals (Sweden)

    Alberto Baccini

    2015-10-01

    Full Text Available University rankings represent a controversial issue in the debate about higher education policy. One of the best known university ranking is the Quacquarelli Symonds World University Rankings (QS, published annually since 2004 by Quacquarelli Symonds ltd, a company founded in 1990 and headquartered in London. QS provides a ranking based on a score calculated by weighting six different indicators. The 2015 edition, published in October 2015, introduced major methodological innovations and, as a consequence, many universities worldwide underwent major changes of their scores and ranks. Ben Sowter, head of division of intelligence unit of Quacquarelli Symonds, responds to 15 questions about the new QS methodology.

  7. On a common generalization of Shelah's 2-rank, dp-rank, and o-minimal dimension

    OpenAIRE

    Guingona, Vincent; Hill, Cameron Donnay

    2013-01-01

    In this paper, we build a dimension theory related to Shelah's 2-rank, dp-rank, and o-minimal dimension. We call this dimension op-dimension. We exhibit the notion of the n-multi-order property, generalizing the order property, and use this to create op-rank, which generalizes 2-rank. From this we build op-dimension. We show that op-dimension bounds dp-rank, that op-dimension is sub-additive, and op-dimension generalizes o-minimal dimension in o-minimal theories.

  8. Academic rankings: an approach to rank portuguese universities Rankings académicos: un abordaje para clasificar las universidades portuguesas Rankings acadêmicos: uma abordagem ao ranking das universidades portuguesas

    Directory of Open Access Journals (Sweden)

    Pedro Bernardino

    2010-03-01

    Full Text Available The academic rankings are a controversial subject in higher education. However, despite all the criticism, academic rankings are here to stay and more and more different stakeholders use rankings to obtain information about the institutions' performance. The two most well-known rankings, The Times and the Shanghai Jiao Tong University rankings have different methodologies. The Times ranking is based on peer review, whereas the Shanghai ranking has only quantitative indicators and is mainly based on research outputs. In Germany, the CHE ranking uses a different methodology from the traditional rankings, allowing the users to choose criteria and weights. The Portuguese higher education institutions are performing below their European peers, and the Government believes that an academic ranking could improve both performance and competitiveness between institutions. The purpose of this paper is to analyse the advantages and problems of academic rankings and provide guidance to a new Portuguese ranking.Los rankings académicos son un tema muy contradictorio en la enseñanza superior. Todavía, además de todas las críticas los rankings están para quedarse entre nosotros. Y cada vez más, diferentes stakeholders utilizan los rankings para obtener información sobre el desempeño de las instituciones. Dos de los rankings más conocidos, el The Times y el ranking de la universidad de Shangai Jiao Tong tienen métodos distintos. El The Times se basa en la opinión de expertos mientras el ranking de la universidad de Shangai presenta solamente indicadores cuantitativos y mayoritariamente basados en los resultados de actividades de investigación. En Alemania el ranking CHE usa un método distinto permitiendo al utilizador elegir los criterios y su importancia. Las instituciones de enseñanza superior portuguesas tienen un desempeño abajo de las europeas y el gobierno cree que un ranking académico podría contribuir para mejorar su desempeño y

  9. Adiabatic quantum algorithm for search engine ranking.

    Science.gov (United States)

    Garnerone, Silvano; Zanardi, Paolo; Lidar, Daniel A

    2012-06-08

    We propose an adiabatic quantum algorithm for generating a quantum pure state encoding of the PageRank vector, the most widely used tool in ranking the relative importance of internet pages. We present extensive numerical simulations which provide evidence that this algorithm can prepare the quantum PageRank state in a time which, on average, scales polylogarithmically in the number of web pages. We argue that the main topological feature of the underlying web graph allowing for such a scaling is the out-degree distribution. The top-ranked log(n) entries of the quantum PageRank state can then be estimated with a polynomial quantum speed-up. Moreover, the quantum PageRank state can be used in "q-sampling" protocols for testing properties of distributions, which require exponentially fewer measurements than all classical schemes designed for the same task. This can be used to decide whether to run a classical update of the PageRank.

  10. Ranking Adverse Drug Reactions With Crowdsourcing

    KAUST Repository

    Gottlieb, Assaf

    2015-03-23

    Background: There is no publicly available resource that provides the relative severity of adverse drug reactions (ADRs). Such a resource would be useful for several applications, including assessment of the risks and benefits of drugs and improvement of patient-centered care. It could also be used to triage predictions of drug adverse events. Objective: The intent of the study was to rank ADRs according to severity. Methods: We used Internet-based crowdsourcing to rank ADRs according to severity. We assigned 126,512 pairwise comparisons of ADRs to 2589 Amazon Mechanical Turk workers and used these comparisons to rank order 2929 ADRs. Results: There is good correlation (rho=.53) between the mortality rates associated with ADRs and their rank. Our ranking highlights severe drug-ADR predictions, such as cardiovascular ADRs for raloxifene and celecoxib. It also triages genes associated with severe ADRs such as epidermal growth-factor receptor (EGFR), associated with glioblastoma multiforme, and SCN1A, associated with epilepsy. Conclusions: ADR ranking lays a first stepping stone in personalized drug risk assessment. Ranking of ADRs using crowdsourcing may have useful clinical and financial implications, and should be further investigated in the context of health care decision making.

  11. Adiabatic Quantum Algorithm for Search Engine Ranking

    Science.gov (United States)

    Garnerone, Silvano; Zanardi, Paolo; Lidar, Daniel A.

    2012-06-01

    We propose an adiabatic quantum algorithm for generating a quantum pure state encoding of the PageRank vector, the most widely used tool in ranking the relative importance of internet pages. We present extensive numerical simulations which provide evidence that this algorithm can prepare the quantum PageRank state in a time which, on average, scales polylogarithmically in the number of web pages. We argue that the main topological feature of the underlying web graph allowing for such a scaling is the out-degree distribution. The top-ranked log⁡(n) entries of the quantum PageRank state can then be estimated with a polynomial quantum speed-up. Moreover, the quantum PageRank state can be used in “q-sampling” protocols for testing properties of distributions, which require exponentially fewer measurements than all classical schemes designed for the same task. This can be used to decide whether to run a classical update of the PageRank.

  12. Ranking adverse drug reactions with crowdsourcing.

    Science.gov (United States)

    Gottlieb, Assaf; Hoehndorf, Robert; Dumontier, Michel; Altman, Russ B

    2015-03-23

    There is no publicly available resource that provides the relative severity of adverse drug reactions (ADRs). Such a resource would be useful for several applications, including assessment of the risks and benefits of drugs and improvement of patient-centered care. It could also be used to triage predictions of drug adverse events. The intent of the study was to rank ADRs according to severity. We used Internet-based crowdsourcing to rank ADRs according to severity. We assigned 126,512 pairwise comparisons of ADRs to 2589 Amazon Mechanical Turk workers and used these comparisons to rank order 2929 ADRs. There is good correlation (rho=.53) between the mortality rates associated with ADRs and their rank. Our ranking highlights severe drug-ADR predictions, such as cardiovascular ADRs for raloxifene and celecoxib. It also triages genes associated with severe ADRs such as epidermal growth-factor receptor (EGFR), associated with glioblastoma multiforme, and SCN1A, associated with epilepsy. ADR ranking lays a first stepping stone in personalized drug risk assessment. Ranking of ADRs using crowdsourcing may have useful clinical and financial implications, and should be further investigated in the context of health care decision making.

  13. Augmenting the Deliberative Method for Ranking Risks.

    Science.gov (United States)

    Susel, Irving; Lasley, Trace; Montezemolo, Mark; Piper, Joel

    2016-01-01

    The Department of Homeland Security (DHS) characterized and prioritized the physical cross-border threats and hazards to the nation stemming from terrorism, market-driven illicit flows of people and goods (illegal immigration, narcotics, funds, counterfeits, and weaponry), and other nonmarket concerns (movement of diseases, pests, and invasive species). These threats and hazards pose a wide diversity of consequences with very different combinations of magnitudes and likelihoods, making it very challenging to prioritize them. This article presents the approach that was used at DHS to arrive at a consensus regarding the threats and hazards that stand out from the rest based on the overall risk they pose. Due to time constraints for the decision analysis, it was not feasible to apply multiattribute methodologies like multiattribute utility theory or the analytic hierarchy process. Using a holistic approach was considered, such as the deliberative method for ranking risks first published in this journal. However, an ordinal ranking alone does not indicate relative or absolute magnitude differences among the risks. Therefore, the use of the deliberative method for ranking risks is not sufficient for deciding whether there is a material difference between the top-ranked and bottom-ranked risks, let alone deciding what the stand-out risks are. To address this limitation of ordinal rankings, the deliberative method for ranking risks was augmented by adding an additional step to transform the ordinal ranking into a ratio scale ranking. This additional step enabled the selection of stand-out risks to help prioritize further analysis. © 2015 Society for Risk Analysis.

  14. Evaluation of treatment effects by ranking

    DEFF Research Database (Denmark)

    Halekoh, U; Kristensen, K

    2008-01-01

    In crop experiments measurements are often made by a judge evaluating the crops' conditions after treatment. In the present paper an analysis is proposed for experiments where plots of crops treated differently are mutually ranked. In the experimental layout the crops are treated on consecutive...... plots usually placed side by side in one or more rows. In the proposed method a judge ranks several neighbouring plots, say three, by ranking them from best to worst. For the next observation the judge moves on by no more than two plots, such that up to two plots will be re-evaluated again...

  15. FCC Fe{sub 2}NiSi prepared by mechanical alloying and stabilization effect of L2{sub 1}B disorder on BCC Heusler structure

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hongzhi, E-mail: luo_hongzhi@163.com [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Xin, Yuepeng; Ma, Yuexing; Liu, Bohua; Meng, Fanbin; Liu, Heyan [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Liu, Enke; Wu, Guangheng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2016-12-01

    Fe{sub 2}NiSi FCC phase has been prepared by ball-milling successfully, which is different from the BCC Heusler phase prepared by arc-melting in previous literatures. The FCC Fe{sub 2}NiSi is a ferromagnet with a lattice constant of 3.58 Å. The phase stability of the FCC and BCC Fe{sub 2}NiSi has been compared by first-principles calculations. It has been found that the FCC structure has a lower total energy compared with the highly-ordered Heusler structures XA and L2{sub 1}, that is the reason why the FCC phase can be prepared by ball-milling. However, the Fe (A)–Ni (C) disorder in the BCC XA structure can lower its total energy further and make it smaller than the FCC phase. So the most stable structure in Fe{sub 2}NiSi is L2{sub 1}B, as has been observed in the arc-melting sample. This can be explained from their DOS structures. The calculated total moments for the FCC and BCC phases agree with their M{sub s} at 5 K quite well. - Highlights: • FCC Fe{sub 2}NiSi has been prepared by ball-milling successfully. • Phase stability of Fe{sub 2}NiSi with different structures has been investigated. • The BCC Heusler structure in Fe{sub 2}NiSi is stabilized by L2{sub 1}B disorder.

  16. About oxide dispersion particles chemical compatibility with areas coherent dissipation/sub-grains of bcc-alloys in Fe - (Cr, V, Mo, W systems

    Directory of Open Access Journals (Sweden)

    Udovsky A.

    2016-01-01

    Full Text Available A concept of partial magnetic moments (PMM of the iron atoms located in the first ч four coordination spheres (1÷4 CS for bcc lattice have been introduced based on analysis of results obtained by quantum-mechanical calculations (QMC for volume dependence of the average magnetic moment ferromagnetic (FM Fe. The values of these moments have been calculated for pure bcc Fe and bcc - Fe-Cr alloys. This concept has been used to formulate a three sub-lattice model for binary FM alloys of the Fe-M systems (M is an alloying paramagnetic element. Physical reason for sign change dependence of the short-range order and mixing enthalpy obtained by QMCs for Fe-(Cr, V bcc phases has been found. Using this model it has been predicted that static displacements of Fe - atoms in alloy matrix increase with increasing the of CS number and result in reducing of the area of coherent dissipation (ACD size with growth of the dimension factor (DF in the Fe-(Cr, V, Mo, W systems in agreement with the X-ray experiments. It has been shown theoretically that anisotropy of spin- density in bcc lattice Fe and DF in binary Fe - (Cr, V, Mo, W systems is main factor for origins of segregations on small angle boundaries of ACD and sub-grains boundaries To prevent the coagulation of both ACD and sub-grains, and to increase the strength of alloys, it is advisable to add oxide dispersion particles into ferrite steel taking into account their chemical compatibility and coherent interfacing with the crystalline lattice of a ferrite matrix. Application of phase diagrams for binary and ternary the Fe-(Y, Zr-O systems to verify chemical compatibility of oxide dispersion particles with ferrite matrix have been discussed

  17. Subseasonal prediction of the heat wave of December 2013 in Southern South America by the POAMA and BCC-CPS models

    Science.gov (United States)

    Osman, Marisol; Alvarez, Mariano S.

    2017-03-01

    The prediction skill of subseasonal forecast models is evaluated for a strong and long-lasting heat wave occurred in December 2013 over Southern South America. Reforecasts from two models participating in the WCRP/WWRP Subseasonal to Seasonal project, the Bureau of Meteorology POAMA and Beijing Climate Center model BCC-CPS were considered to evaluate their skill in forecasting temperature and circulation anomalies during that event. The POAMA reforecast of 32-member ensemble size, initialized every five days, and BCC-CPS reforecast of 4-member ensemble size for the same date of POAMA plus the previous 4 days were considered. Weekly ensemble-mean forecasts were computed with leadtimes from 2 days up to 24 days every 5 days. Weekly anomalies were calculated for observations from 13th of December to 31st of December 2013. Anomalies for both observations and reforecast were calculated with respect to their own climatology. Results show that the ensemble mean warm anomalies forecasted for week 1 and 2 of the heat wave resulted more similar to the observations for the POAMA model, especially for longer leads. The BCC-CPS performed better for leads shorter than 7 (14) for week 1 (2). For week 3 the BCC-CPS outperformed the POAMA model, particularly at shorter leads, locating more accurately the maxima of the anomalies. In a probabilistic approach, POAMA predicted with a higher chance than BCC-CPS the excess of the upper tercile of temperature anomalies for almost every week and lead time. The forecast of the circulation anomalies over South America could be used to explain the location of the highest temperature anomalies. In summary, for this case, models skill in forecasting surface temperature in a context of a heat wave resulted moderate at lead times longer than the fortnight. However, this study is limited to model-to-model analysis and a multi-model ensemble strategy might increase the skill.

  18. Analysis of connection element classes and locations and of some structural requirements for the mounting of different superstructure types on transport vehicles

    Directory of Open Access Journals (Sweden)

    Zoran Đ. Majkić

    2011-04-01

    Full Text Available The paper presents the basic requirements for transport vehicles. A special request regarding the adaptation of transport vehicles for the transport of various types of cargo was taken into consideration. Superstructures and the situation arising after mounting superstructures on wheeled transport vehicles were analyzed and the following was described: console coupling, stirrups, simplex elastic coupling, two-way elastic and rigid connection elements. Vehicle torsional elasticity is provided by a proper choice of the type of connection between the superstructure and the vehicle chassis. Applying the instructions of vehicle manufacturers for using appropriate connections between the truck superstructure and the vehicle chassis provides positive torsional elasticity of the vehicle. The paper gives the general recommendations of the Volvo, Mercedes and Renault transport vehicle producers for the use of particular connection types of locations as well as structural requirements for the mounting of concrete mixers, tippers and truck tanks on their vehicles. Introduction Achieving a high level of transport effectiveness depends on a number of factors. One of the most important ones is the possibility to increase the payload share in the gross vehicle weight. This share depends on the net vehicle weight, a method of coupling the truck superstructure with the chassis frame as well as on the truck superstructure construction. Realization of this requirement is of significant importance, particularly for large business systems since it results in the reduction of number of necessary vehicles, more economic fleet maintenance and the fleet capacity increase. It is also relatively easy to adapt the vehicle for the transportation of other loads, depending on user's current needs. The adaptation is correctly performed if manufacturer's recommendations are followed during the mounting of the superstructure on the chassis. This paper gives the analysis of the

  19. Block models and personalized PageRank

    National Research Council Canada - National Science Library

    Kloumann, Isabel M; Ugander, Johan; Kleinberg, Jon

    2017-01-01

    ...? We start from the observation that the most widely used techniques for this problem, personalized PageRank and heat kernel methods, operate in the space of "landing probabilities" of a random walk...

  20. Who's bigger? where historical figures really rank

    CERN Document Server

    Skiena, Steven

    2014-01-01

    Is Hitler bigger than Napoleon? Washington bigger than Lincoln? Picasso bigger than Einstein? Quantitative analysts are rapidly finding homes in social and cultural domains, from finance to politics. What about history? In this fascinating book, Steve Skiena and Charles Ward bring quantitative analysis to bear on ranking and comparing historical reputations. They evaluate each person by aggregating the traces of millions of opinions, just as Google ranks webpages. The book includes a technical discussion for readers interested in the details of the methods, but no mathematical or computational background is necessary to understand the rankings or conclusions. Along the way, the authors present the rankings of more than one thousand of history's most significant people in science, politics, entertainment, and all areas of human endeavor. Anyone interested in history or biography can see where their favorite figures place in the grand scheme of things.

  1. Ranking Forestry Investments With Parametric Linear Programming

    Science.gov (United States)

    Paul A. Murphy

    1976-01-01

    Parametric linear programming is introduced as a technique for ranking forestry investments under multiple constraints; it combines the advantages of simple tanking and linear programming as capital budgeting tools.

  2. Superfund Hazard Ranking System Training Course

    Science.gov (United States)

    The Hazard Ranking System (HRS) training course is a four and ½ day, intermediate-level course designed for personnel who are required to compile, draft, and review preliminary assessments (PAs), site inspections (SIs), and HRS documentation records/packag

  3. A cognitive model for aggregating people's rankings

    National Research Council Canada - National Science Library

    Lee, Michael D; Steyvers, Mark; Miller, Brent

    2014-01-01

    .... Applications of the model to 23 data sets, dealing with general knowledge and prediction tasks, show that the model performs well in producing an aggregate ranking that is often close to the ground...

  4. Block models and personalized PageRank.

    Science.gov (United States)

    Kloumann, Isabel M; Ugander, Johan; Kleinberg, Jon

    2017-01-03

    Methods for ranking the importance of nodes in a network have a rich history in machine learning and across domains that analyze structured data. Recent work has evaluated these methods through the "seed set expansion problem": given a subset [Formula: see text] of nodes from a community of interest in an underlying graph, can we reliably identify the rest of the community? We start from the observation that the most widely used techniques for this problem, personalized PageRank and heat kernel methods, operate in the space of "landing probabilities" of a random walk rooted at the seed set, ranking nodes according to weighted sums of landing probabilities of different length walks. Both schemes, however, lack an a priori relationship to the seed set objective. In this work, we develop a principled framework for evaluating ranking methods by studying seed set expansion applied to the stochastic block model. We derive the optimal gradient for separating the landing probabilities of two classes in a stochastic block model and find, surprisingly, that under reasonable assumptions the gradient is asymptotically equivalent to personalized PageRank for a specific choice of the PageRank parameter [Formula: see text] that depends on the block model parameters. This connection provides a formal motivation for the success of personalized PageRank in seed set expansion and node ranking generally. We use this connection to propose more advanced techniques incorporating higher moments of landing probabilities; our advanced methods exhibit greatly improved performance, despite being simple linear classification rules, and are even competitive with belief propagation.

  5. Rank rigidity for CAT(0) cube complexes

    OpenAIRE

    Caprace, Pierre-Emmanuel; Sageev, Michah

    2010-01-01

    We prove that any group acting essentially without a fixed point at infinity on an irreducible finite-dimensional CAT(0) cube complex contains a rank one isometry. This implies that the Rank Rigidity Conjecture holds for CAT(0) cube complexes. We derive a number of other consequences for CAT(0) cube complexes, including a purely geometric proof of the Tits Alternative, an existence result for regular elements in (possibly non-uniform) lattices acting on cube complexes, and a characterization ...

  6. NUCLEAR POWER PLANTS SAFETY IMPROVEMENT PROJECTS RANKING

    OpenAIRE

    Григорян, Анна Сергеевна; Тигран Георгиевич ГРИГОРЯН; Квасневский, Евгений Анатольевич

    2013-01-01

    The ranking nuclear power plants safety improvement projects is the most important task for ensuring the efficiency of NPP project management office work. Total amount of projects in NPP portfolio may reach more than 400. Features of the nuclear power plants safety improvement projects ranking in NPP portfolio determine the choice of the decision verbal analysis as a method of decision-making, as it allows to quickly compare the number of alternatives that are not available at the time of con...

  7. Ranking Music Data by Relevance and Importance

    DEFF Research Database (Denmark)

    Ruxanda, Maria Magdalena; Nanopoulos, Alexandros; Jensen, Christian Søndergaard

    2008-01-01

    Due to the rapidly increasing availability of audio files on the Web, it is relevant to augment search engines with advanced audio search functionality. In this context, the ranking of the retrieved music is an important issue. This paper proposes a music ranking method capable of flexibly fusing...... the relevance and importance of music. The proposed method may support users with diverse needs when searching for music....

  8. Ag on Ge(111): 2D x-ray structure analysis of the #sq root#3 x #sq root#3 superstructure

    DEFF Research Database (Denmark)

    Dornisch, D.; Moritz, W.; Schulz, H.

    1992-01-01

    We have studied the Ag/Ge(111) square-root 3 x square-root 3 superstructure by grazing-incidence X-ray diffraction. In our structural analysis we find striking similarities to the geometry of Au on Si(111). The Ag atoms form trimer clusters with an Ag-Ag distance of 2.94 +/- 0.04 angstrom...

  9. Rank distributions: A panoramic macroscopic outlook

    Science.gov (United States)

    Eliazar, Iddo I.; Cohen, Morrel H.

    2014-01-01

    This paper presents a panoramic macroscopic outlook of rank distributions. We establish a general framework for the analysis of rank distributions, which classifies them into five macroscopic "socioeconomic" states: monarchy, oligarchy-feudalism, criticality, socialism-capitalism, and communism. Oligarchy-feudalism is shown to be characterized by discrete macroscopic rank distributions, and socialism-capitalism is shown to be characterized by continuous macroscopic size distributions. Criticality is a transition state between oligarchy-feudalism and socialism-capitalism, which can manifest allometric scaling with multifractal spectra. Monarchy and communism are extreme forms of oligarchy-feudalism and socialism-capitalism, respectively, in which the intrinsic randomness vanishes. The general framework is applied to three different models of rank distributions—top-down, bottom-up, and global—and unveils each model's macroscopic universality and versatility. The global model yields a macroscopic classification of the generalized Zipf law, an omnipresent form of rank distributions observed across the sciences. An amalgamation of the three models establishes a universal rank-distribution explanation for the macroscopic emergence of a prevalent class of continuous size distributions, ones governed by unimodal densities with both Pareto and inverse-Pareto power-law tails.

  10. Hierarchical Rank Aggregation with Applications to Nanotoxicology.

    Science.gov (United States)

    Patel, Trina; Telesca, Donatello; Rallo, Robert; George, Saji; Xia, Tian; Nel, André E

    2013-06-01

    The development of high throughput screening (HTS) assays in the field of nanotoxicology provide new opportunities for the hazard assessment and ranking of engineered nanomaterials (ENMs). It is often necessary to rank lists of materials based on multiple risk assessment parameters, often aggregated across several measures of toxicity and possibly spanning an array of experimental platforms. Bayesian models coupled with the optimization of loss functions have been shown to provide an effective framework for conducting inference on ranks. In this article we present various loss-function-based ranking approaches for comparing ENM within experiments and toxicity parameters. Additionally, we propose a framework for the aggregation of ranks across different sources of evidence while allowing for differential weighting of this evidence based on its reliability and importance in risk ranking. We apply these methods to high throughput toxicity data on two human cell-lines, exposed to eight different nanomaterials, and measured in relation to four cytotoxicity outcomes. This article has supplementary material online.

  11. Pr{sub 1.33}Pt{sub 4}Ga{sub 10}: Superstructure and magnetism

    Energy Technology Data Exchange (ETDEWEB)

    Doan Nguyen, Sau; Ryan, Kevin [Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, CO 80639 (United States); Chai, Ping [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306 (United States); Shatruk, Michael [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306 (United States); National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310 (United States); Xin, Yan [National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310 (United States); Chapman, Karena W.; Chupas, Peter J. [X-Ray Science Division, The Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439 (United States); Fronczek, Frank R. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Macaluso, Robin T., E-mail: robin.macaluso@unco.edu [Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, CO 80639 (United States)

    2014-12-15

    Pr{sub 1.33}Pt{sub 4}Ga{sub 10} crystals were prepared by Ga-flux method. The superstructure of this compound was studied by single-crystal X-ray diffraction (XRD), transmission electron microscopy (TEM), and diffuse X-ray scattering. Pr{sub 1.33}Pt{sub 4}Ga{sub 10} adopts the P6{sub 3}/mmc space group with a=b=4.3227(5) Å, c=16.485(3) Å: the structure features Pr{sub 2}Ga{sub 3} layers alternating with Pt{sub 2}Ga{sub 4} layers along the c-axis. TEM studies and pair distribution function (PDF) analysis of X-ray total scattering data show that Pr{sub 2}Ga{sub 3} layers possess an ordered superstructure (of dimension a′=a√(3)) in which Pr vacancies and Ga atoms are ordered within the ab-plane but disordered along the c-direction. PDF analysis also shows temperature-dependent structural features local to the Pr{sup 3+} ion. Magnetic measurements reveal that Pr{sup 3+} ions order ferrimagnetically below 12.5(2) K. - Graphical abstract: Left: Crystal structure of Pr{sub 1.33}Pt{sub 4}Ga{sub 10} showing Pr and Ga vacancies in the Pr{sub 2}Ga{sub 3} plane. Right: Tunneling electron microscopy (TEM) image of Pr{sub 1.33}Pt{sub 4}Ga{sub 10}. These vacancies have been studied using TEM and pair distribution function analysis. Magnetic measurements reveal that Pr{sup 3+} ions order ferrimagnetically below 7.8(2) K. - Highlights: • TEM studies indicate a superstructure from Pr and Ga vacancies. • Pair distribution function analyses may point to structural relaxation of vacancies. • Pr{sub 1.33}Pt{sub 4}Ga{sub 10} behaves as a ferromagnet and exhibits a metamagnetic transition.

  12. ARWU vs. Alternative ARWU Ranking: What are the Consequences for Lower Ranked Universities?

    Directory of Open Access Journals (Sweden)

    Milica Maričić

    2017-05-01

    Full Text Available The ARWU ranking has been a source of academic debate since its development in 2003, but the same does not account for the Alternative ARWU ranking. Namely, the Alternative ARWU ranking attempts to reduce the influence of the prestigious indicators Alumni and Award which are based on the number of received Nobel Prizes and Fields Medals by alumni or university staff. However, the consequences of the reduction of the two indicators have not been scrutinized in detail. Therefore, we propose a statistical approach to the comparison of the two rankings and an in-depth analysis of the Alternative ARWU groups. The obtained results, which are based on the official data, can provide new insights into the nature of the Alternative ARWU ranking. The presented approach might initiate further research on the Alternative ARWU ranking and on the impact of university ranking’s list length. JEL Classification: C10, C38, I23

  13. Controlling superstructural ordering in the clathrate-I Ba8M16P30 (M = Cu, Zn) through the formation of metal-metal bonds.

    Science.gov (United States)

    Dolyniuk, J; Whitfield, P S; Lee, K; Lebedev, O I; Kovnir, K

    2017-05-01

    Order-disorder-order phase transitions in the clathrate-I Ba8Cu16P30 were induced and controlled by aliovalent substitutions of Zn into the framework. Unaltered Ba8Cu16P30 crystallizes in an ordered orthorhombic (Pbcn) clathrate-I superstructure that maintains complete segregation of metal and phosphorus atoms over 23 different crystallographic positions in the clathrate framework. The driving force for the formation of this Pbcn superstructure is the avoidance of Cu-Cu bonds. This superstructure is preserved upon aliovalent substitution of Zn for Cu in Ba8Cu16-x Zn x P30 with 0 Cu-Zn bonds in the framework, leading to a collapse of the orthorhombic superstructure into the more common cubic subcell of clathrate-I (Pm3n). In the resulting cubic phases, each clathrate framework position is jointly occupied by three different elements: Cu, Zn, and P. Detailed structural characterization of the Ba-Cu-Zn-P clathrates-I via single crystal X-ray diffraction, joint synchrotron X-ray and neutron powder diffractions, pair distribution function analysis, electron diffraction and high-resolution electron microscopy, along with elemental analysis, indicates that local ordering is present in the cubic clathrate framework, suggesting the evolution of Cu-Zn bonds. For the compounds with the highest Zn content, a disorder-order transformation is detected due to the formation of another superstructure with trigonal symmetry and Cu-Zn bonds in the clathrate-I framework. It is shown that small changes in the composition, synthesis, and crystal structure have significant impacts on the structural and transport properties of Zn-substituted Ba8Cu16P30.

  14. The anisotropic quantum spin-1/2 Heisenberg antiferromagnet in the presence of a longitudinal field on a bcc lattice

    Energy Technology Data Exchange (ETDEWEB)

    Neto, Minos A., E-mail: minos@pq.cnpq.br [Departamento de Fisica, Universidade Federal do Amazonas, 3000, Japiim, Manaus, 69077-000 AM (Brazil); Roberto Viana, J., E-mail: vianafisica@bol.com.br [Departamento de Fisica, Universidade Federal do Amazonas, 3000, Japiim, Manaus, 69077-000 AM (Brazil); Ricardo de Sousa, J., E-mail: jsousa@edu.ufam.br [Departamento de Fisica, Universidade Federal do Amazonas, 3000, Japiim, Manaus, 69077-000 AM (Brazil); National Institute of Science and Technology for Complex Systems, 3000, Japiim, Manaus, 69077-000 AM (Brazil)

    2012-08-15

    In this work we study the critical behavior of the quantum spin-1/2 anisotropic Heisenberg antiferromagnet in the presence of a longitudinal field on a body centered cubic (bcc) lattice as a function of temperature, anisotropy parameter ({Delta}) and magnetic field (H), where {Delta}=0 and 1 correspond the isotropic Heisenberg and Ising models, respectively. We use the framework of the differential operator technique in the effective-field theory with finite cluster of N=4 spins (EFT-4). The staggered m{sub s}=(m{sub A}-m{sub B})/2 and total m=(m{sub A}+m{sub B})/2 magnetizations are numerically calculated, where in the limit of m{sub s}{yields}0 the critical line T{sub N}(H,{Delta}) is obtained. The phase diagram in the T-H plane is discussed as a function of the parameter {Delta} for all values of H Element-Of [0,H{sub c}({Delta})], where H{sub c}({Delta}) correspond the critical field (T{sub N}=0). Special focus is given in the low temperature region, where a reentrant behavior is observed around of H=H{sub c}({Delta}){>=}H{sub c}({Delta}=1)=8J in the Ising limit, results in accordance with Monte Carlo simulation, and also was observed for all values of {Delta} Element-Of [0,1]. This reentrant behavior increases with increase of the anisotropy parameter {Delta}. In the limit of low field, our results for the Heisenberg limit are compared with series expansion values. - Highlights: Black-Right-Pointing-Pointer In the lat decade there has been a great interest in the physics of the quantum phase transition in spins system. Black-Right-Pointing-Pointer Effective-field theory in cluster with N=4 spins is generalized to treat the quantum spin-1/2 Heisenberg model. Black-Right-Pointing-Pointer We have obtained phase diagram at finite temperature for the quantum spin-1/2 antiferromagnet Heisenberg model as a bcc lattice.

  15. Growth and investigation of the Slater-Pauling behavior by X-ray characterization of single crystal bcc FexMn1-x on MgO(001)

    Science.gov (United States)

    Bhatkar, Harshawardhan Ramesh

    Magnetic memory storage industry is always searching for materials that can store, read, and write data ever so faster, with lower power, with accuracy and on denser packaging. The material research was spurred with discovery and successful implementation of Giant Magnetoresistance phenomena into critical components of devices. GMR devices essentially were multilayered thin films of a set of magnetically ordered metals. Fe-Mn thin films were used to create one of its moment pinning layers. Fcc Fe-Mn thin films were studied enthusiastically for their AFM properties but very little was known about the rare bcc structured single crystals. Bcc Fe-Mn was found to be ferromagnetic in parts of phase diagram of Fe-Mn. The magnetic moment of alloys usually follows a regular linear trend based upon electronic configuration of constituent elements, known as Slater-Pauling curve. While most alloys follow the trend, bcc Fe-Mn binary alloys show a dramatic collapse in the bulk magnetic moment, as concentration of Mn is varied. In this work, we successfully fabricate bcc single crystal thin film of Fe-Mn on MgO(001) substrate by Molecular Beam Epitaxy method. We confirm using Reflection High Energy Electron Diffraction that, the bcc phase of Fe-Mn thin film is achieved, albeit being a forced structure, stable up to 35% of Mn concentration. X-ray absorption spectra of individual elements were used to confirm the compositions of Fe-Mn films and x-ray magnetic circular dichroism was used to track the elemental magnetic moment as the composition was varied. We found that the magnetic moment of Fe drops faster than expected and Mn has very small identical moment in all compositions. We also successfully created a compositionally graded Fe-Mn sample in MBE and spatially mapped its Fe moment by around the critical composition. The mechanism for collapse of magnetic moment over a spread of composition of Mn is a very complex problem yet we provide our experimental findings of

  16. Efficient Top-k Search for PageRank

    National Research Council Canada - National Science Library

    Fujiwara, Yasuhiro; Nakatsuji, Makoto; Shiokawa, Hiroaki; Mishima, Takeshi; Onizuka, Makoto

    2015-01-01

      In AI communities, many applications utilize PageRank. To obtain high PageRank score nodes, the original approach iteratively computes the PageRank score of each node until convergence from the whole graph...

  17. Topotactic epitaxy of SrTiO{sub 3} mesocrystal superstructures with anisotropic construction for efficient overall water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Peng; Fujitsuka, Mamoru; Majima, Tetsuro [The Institute of Scientific and Industrial Research (SANKEN), Osaka University (Japan); Ochi, Tomoya [Department of Chemistry, Graduate School of Science, Kobe University (Japan); Kobori, Yasuhiro [Department of Chemistry, Graduate School of Science, Kobe University (Japan); Molecular Photoscience Research Center, Kobe University (Japan); Tachikawa, Takashi [Department of Chemistry, Graduate School of Science, Kobe University (Japan); Molecular Photoscience Research Center, Kobe University (Japan); PRESTO, Science and Technology Agency (JST), Saitama (Japan)

    2017-05-02

    The higher-order structures of semiconductor-based photocatalysts play crucial roles in their physicochemical properties for efficient light-to-energy conversion. A novel perovskite SrTiO{sub 3} mesocrystal superstructure with well-defined orientation of assembled cubic nanocrystals was synthesized by topotactic epitaxy from TiO{sub 2} mesocrystals through a facile hydrothermal treatment. The SrTiO{sub 3} mesocrystal exhibits three times the efficiency for the hydrogen evolution of conventional disordered systems in alkaline aqueous solution. It also exhibits a high quantum yield of 6.7 % at 360 nm in overall water splitting and even good durability up to 1 day. Temporal and spatial spectroscopic observations revealed that the synergy of the efficient electron flow along the internal nanocube network and efficient collection at the larger external cubes produces remarkably long-lived charges for enhanced photocatalysis. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. PageRank as a method to rank biomedical literature by importance.

    Science.gov (United States)

    Yates, Elliot J; Dixon, Louise C

    2015-01-01

    Optimal ranking of literature importance is vital in overcoming article overload. Existing ranking methods are typically based on raw citation counts, giving a sum of 'inbound' links with no consideration of citation importance. PageRank, an algorithm originally developed for ranking webpages at the search engine, Google, could potentially be adapted to bibliometrics to quantify the relative importance weightings of a citation network. This article seeks to validate such an approach on the freely available, PubMed Central open access subset (PMC-OAS) of biomedical literature. On-demand cloud computing infrastructure was used to extract a citation network from over 600,000 full-text PMC-OAS articles. PageRanks and citation counts were calculated for each node in this network. PageRank is highly correlated with citation count (R = 0.905, P PageRank can be trivially computed on commodity cluster hardware and is linearly correlated with citation count. Given its putative benefits in quantifying relative importance, we suggest it may enrich the citation network, thereby overcoming the existing inadequacy of citation counts alone. We thus suggest PageRank as a feasible supplement to, or replacement of, existing bibliometric ranking methods.

  19. RANK/RANK-Ligand/OPG: Ein neuer Therapieansatz in der Osteoporosebehandlung

    Directory of Open Access Journals (Sweden)

    Preisinger E

    2007-01-01

    Full Text Available Die Erforschung der Kopplungsmechanismen zur Osteoklastogenese, Knochenresorption und Remodellierung eröffnete neue mögliche Therapieansätze in der Behandlung der Osteoporose. Eine Schlüsselrolle beim Knochenabbau spielt der RANK- ("receptor activator of nuclear factor (NF- κB"- Ligand (RANKL. Durch die Bindung von RANKL an den Rezeptor RANK wird die Knochenresorption eingeleitet. OPG (Osteoprotegerin sowie der für den klinischen Gebrauch entwickelte humane monoklonale Antikörper (IgG2 Denosumab blockieren die Bindung von RANK-Ligand an RANK und verhindern den Knochenabbau.

  20. Hybrid framework with cobalt-chromium alloy and gold cylinder for implant superstructure: Bond strength and corrosion resistance.

    Science.gov (United States)

    Yoshinari, Masao; Uzawa, Shinobu; Komiyama, Yataro

    2016-10-01

    The aim of this in vitro study was to evaluate tensile bond strengths and corrosion resistance of CoCr alloys joined with gold cylinder by a soldering system in comparison with the conventional cast-joining system. CoCr alloys joined with gold cylinder by a soldering system using a high-fusing gold solder (CoCr/Solder/Gold cylinder), gold alloy joined with gold cylinder by a cast joining system (Gold alloy/Gold cylinder) and CoCr castings were fabricated. The tensile bond strength and corrosion resistance in 0.9% NaCl solution (pH 7.4 and pH 2.3) were evaluated. Scanning electron microscopy (SEM) of the fractured surface and electron probe microanalysis (EPMA) of the joined interfaces were also performed. The tensile bond strengths of the CoCr/Solder/Gold cylinder specimens showed similar values as the Gold alloy/Gold cylinder specimens. SEM observation and EPMA analyses suggested firm bonding between the CoCr alloy and gold cylinder. The released elements from the CoCr/Solder/Gold cylinder specimens were similar to ones from CoCr castings. Results showed that superstructures made of CoCr alloys joined with the gold cylinder using a high-fusing gold solder had sufficient bond strength and high corrosion resistance. These hybrid frameworks with cobalt-chromium alloy and gold cylinder are promising prosthesis for implant superstructures with the low cost and favorable mechanical properties instead of conventional high-gold alloys. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  1. Diamondlike carbon coating as a galvanic corrosion barrier between dental implant abutments and nickel-chromium superstructures.

    Science.gov (United States)

    Ozkomur, Ahmet; Erbil, Mehmet; Akova, Tolga

    2013-01-01

    The objectives of this study were to evaluate the galvanic corrosion behavior between titanium and nickel-chromium (Ni-Cr) alloy, to investigate the effect of diamondlike carbon (DLC) coating over titanium on galvanic corrosion behavior between titanium and Ni-Cr alloy, and to evaluate the effect of DLC coating over titanium abutments on the fit and integrity of prosthetic assemblies by scanning electron microcopy (SEM). Five Ni-Cr and 10 titanium disks with a diameter of 5 mm and thickness of 3 mm were prepared. DLC coating was applied to five titanium disks. Electrode samples were prepared, and open circuit potential measurements, galvanic current measurements over platinum electrodes, and potentiodynamic polarization tests were carried out. For the SEM evaluation, 20 Ni-Cr alloy and 10 gold alloy superstructures were cast and prepared over 30 abutments. DLC coating was applied to 10 of the abutments. Following the fixation of prosthetic assemblies, the samples were embedded in acrylic resin and cross sectioned longitudinally. Internal fit evaluations were carried out through examination of the SEM images. Titanium showed more noble and electrochemically stable properties than Ni-Cr alloy. DLC coating over the cathode electrode served as an insulating film layer over the surface and prevented galvanic coupling. Results of the SEM evaluations indicated that the DLC-coated and titanium abutments showed no statistically significant difference in fit. Hence, no adverse effects on the adaptation of prosthetic components were found with the application of DLC coating over abutment surfaces. DLC coating might serve as a galvanic corrosion barrier between titanium abutments and Ni-Cr superstructures.

  2. Ranking Fuzzy Numbers and Its Application to Products Attributes Preferences

    OpenAIRE

    Abdullah, Lazim; Fauzee, Nor Nashrah Ahmad

    2011-01-01

    Ranking is one of the widely used methods in fuzzy decision making environment. The recent ranking fuzzy numbers proposed by Wang and Li is claimed to be the improved version in ranking. However, the method was never been simplified and tested in real life application. This paper presents a four-step computation of ranking fuzzy numbers and its application in ranking attributes of selected chocolate products. The four steps algorithm was formulated to rank fuzzy numbers and followed by a tes...

  3. Social class rank, essentialism, and punitive judgment.

    Science.gov (United States)

    Kraus, Michael W; Keltner, Dacher

    2013-08-01

    Recent evidence suggests that perceptions of social class rank influence a variety of social cognitive tendencies, from patterns of causal attribution to moral judgment. In the present studies we tested the hypotheses that upper-class rank individuals would be more likely to endorse essentialist lay theories of social class categories (i.e., that social class is founded in genetically based, biological differences) than would lower-class rank individuals and that these beliefs would decrease support for restorative justice--which seeks to rehabilitate offenders, rather than punish unlawful action. Across studies, higher social class rank was associated with increased essentialism of social class categories (Studies 1, 2, and 4) and decreased support for restorative justice (Study 4). Moreover, manipulated essentialist beliefs decreased preferences for restorative justice (Study 3), and the association between social class rank and class-based essentialist theories was explained by the tendency to endorse beliefs in a just world (Study 2). Implications for how class-based essentialist beliefs potentially constrain social opportunity and mobility are discussed.

  4. A network-based dynamical ranking system

    CERN Document Server

    Motegi, Shun

    2012-01-01

    Ranking players or teams in sports is of practical interests. From the viewpoint of networks, a ranking system is equivalent a centrality measure for sports networks, whereby a directed link represents the result of a single game. Previously proposed network-based ranking systems are derived from static networks, i.e., aggregation of the results of games over time. However, the score (i.e., strength) of a player, for example, depends on time. Defeating a renowned player in the peak performance is intuitively more rewarding than defeating the same player in other periods. To account for this factor, we propose a dynamic variant of such a network-based ranking system and apply it to professional men's tennis data. Our ranking system, also interpreted as a centrality measure for directed temporal networks, has two parameters. One parameter represents the exponential decay rate of the past score, and the other parameter controls the effect of indirect wins on the score. We derive a set of linear online update equ...

  5. Global network centrality of university rankings

    Science.gov (United States)

    Guo, Weisi; Del Vecchio, Marco; Pogrebna, Ganna

    2017-10-01

    Universities and higher education institutions form an integral part of the national infrastructure and prestige. As academic research benefits increasingly from international exchange and cooperation, many universities have increased investment in improving and enabling their global connectivity. Yet, the relationship of university performance and its global physical connectedness has not been explored in detail. We conduct, to our knowledge, the first large-scale data-driven analysis into whether there is a correlation between university relative ranking performance and its global connectivity via the air transport network. The results show that local access to global hubs (as measured by air transport network betweenness) strongly and positively correlates with the ranking growth (statistical significance in different models ranges between 5% and 1% level). We also found that the local airport's aggregate flight paths (degree) and capacity (weighted degree) has no effect on university ranking, further showing that global connectivity distance is more important than the capacity of flight connections. We also examined the effect of local city economic development as a confounding variable and no effect was observed suggesting that access to global transportation hubs outweighs economic performance as a determinant of university ranking. The impact of this research is that we have determined the importance of the centrality of global connectivity and, hence, established initial evidence for further exploring potential connections between university ranking and regional investment policies on improving global connectivity.

  6. A Cognitive Model for Aggregating People's Rankings

    Science.gov (United States)

    Lee, Michael D.; Steyvers, Mark; Miller, Brent

    2014-01-01

    We develop a cognitive modeling approach, motivated by classic theories of knowledge representation and judgment from psychology, for combining people's rankings of items. The model makes simple assumptions about how individual differences in knowledge lead to observed ranking data in behavioral tasks. We implement the cognitive model as a Bayesian graphical model, and use computational sampling to infer an aggregate ranking and measures of the individual expertise. Applications of the model to 23 data sets, dealing with general knowledge and prediction tasks, show that the model performs well in producing an aggregate ranking that is often close to the ground truth and, as in the “wisdom of the crowd” effect, usually performs better than most of individuals. We also present some evidence that the model outperforms the traditional statistical Borda count method, and that the model is able to infer people's relative expertise surprisingly well without knowing the ground truth. We discuss the advantages of the cognitive modeling approach to combining ranking data, and in wisdom of the crowd research generally, as well as highlighting a number of potential directions for future model development. PMID:24816733

  7. A Review of Outcomes of Seven World University Ranking Systems

    National Research Council Canada - National Science Library

    Mahmood Khosrowjerdi; Neda Zeraatkar

    2012-01-01

    There are many national and international ranking systems rank the universities and higher education institutions of the world, nationally or internationally, based on the same or different criteria...

  8. Magnetic properties and atomic ordering of BCC Heusler alloy Fe{sub 2}MnGa ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Yuepeng; Ma, Yuexing; Luo, Hongzhi, E-mail: luo_hongzhi@163.com; Meng, Fanbin; Liu, Heyan

    2016-05-15

    The electronic structure, atomic disorder and magnetic properties of the Heusler alloy Fe{sub 2}MnGa have been investigated experimentally and theoretically. BCC Fe{sub 2}MnGa ribbon samples were prepared. Experimentally, a saturation magnetic moment (3.68 μ{sub B} at 5 K) much larger than the theoretical value (2.04 μ{sub B}) has been reported. First-principles calculations indicate that the difference is related to the Fe–Mn disorder between A, B sites, as can also be deduced from the XRD pattern. L2{sub 1} type Fe{sub 2}MnGa is a ferrimagnet with antiparallel Fe and Mn spin moments. However, when Fe–Mn disorder occurs, part of Mn moments will be parallel to Fe moments, and the Fe moments also clearly increase simultaneously. All this results in a total moment of 3.74 μ{sub B}, close to the experimental value.

  9. Positron studies of interaction between yttrium atoms and vacancies in bcc iron with relevance for ODS nanoparticles formation

    Energy Technology Data Exchange (ETDEWEB)

    He, C.W., E-mail: chenwei.he@cnrs-orleans.fr [CNRS, CEMHTI UPR3079, Univ. Orléans, F-45071 Orléans (France); Barthe, M.F.; Desgardin, P. [CNRS, CEMHTI UPR3079, Univ. Orléans, F-45071 Orléans (France); Akhmadaliev, S. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, BautznerLandstr. 400, D-01328 Dresden (Germany); Behar, M. [Instituto de Fisica, Av. Bento Gonçalves 9500, Agronomia, Porto Alegre (Brazil); Jomard, F. [GEMac, Univ. Versailles, 45 avenue des Etats Unis, 78035 Versailles cedex (France)

    2014-12-15

    The very high calculated binding energy of vacancy (V)–Y{sub sub} (1.45 eV) in Fe makes it be one possible earliest formation stage of (Y, Ti, O) nanoclusters in ODS alloy. Our direct slow positrons annihilation observations are used to valid the interaction between V and Y. The pure bcc iron samples have been implanted by 1.2 MeV Y ions at three fluences from 1 × 10{sup 14} to 3 × 10{sup 15} cm{sup −2}. Vacancy clusters are observed for all these three fluences. Their size and concentration decrease with Y concentration measured by using SIMS. Two hypotheses are proposed to explain the results, including the formation of complexes V{sub m}–Y{sub n} and/or of precipitates Y{sub m}–X{sub n} (X = Y, O, etc.). In addition, vacancy clusters are detected deeper than predicted by SRIM calculation due to, at least for a part, channelling which is confirmed by Marlowe calculation and SIMS measurements.

  10. Atomistic simulations of screw dislocations in bcc tungsten: From core structures and static properties to interaction with vacancies

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ke [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China); Niu, Liang-Liang [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China); Department of Nuclear Engineering and Radiological Science, University of Michigan, Ann Arbor, MI 48109 (United States); Jin, Shuo, E-mail: jinshuo@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China); Shu, Xiaolin [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China); Xie, Hongxian [School of Mechanical Engineering, Hebei University of Technology, Tianjin 300132 (China); Wang, Lifang; Lu, Guang-Hong [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China)

    2017-02-15

    Atomistic simulations have been used to investigate the core structures, static properties of isolated 1/2 <1 1 1> screw dislocations, and their interaction with vacancies in bcc tungsten (W) based on three empirical interatomic potentials. Differential displacement maps show that only one embedded atom method potential is able to reproduce the compact non-degenerate core as evidenced by ab initio calculations. The obtained strain energy and stress distribution from atomistic simulations are, in general, consistent with elasticity theory predictions. In particular, one component of the calculated shear stress, which is not present according to elasticity theory, is non-negligible in the core region of our dislocation model. The differences between the results calculated from three interatomic potentials are in details, such as the specific value and the symmetry, but the trend of spatial distributions of static properties in the long range are close to each other. By calculating the binding energies between the dislocations and vacancies, we demonstrate that the dislocations act as vacancy sinks, which may be important for the nucleation and growth of hydrogen bubbles in W under irradiation.

  11. Ranking schools on external knowledge tests results

    Directory of Open Access Journals (Sweden)

    Gašper Cankar

    2007-01-01

    Full Text Available The paper discusses the use of external knowledge test results for school ranking and the implicit effect of such ranking. A question of validity is raised and a review of research literature and main known problems are presented. In many western countries publication of school results is a common practice and a similar trend can be observed in Slovenia. Experiences of other countries help to predict positive and negative aspects of such publication. Results of external knowledge tests produce very limited information about school quality—if we use other sources of information our ranking of schools can be very different. Nevertheless, external knowledge tests can yield useful information. If we want to improve quality in schools, we must allow schools to use this information themselves and improve from within. Broad public scrutiny is unnecessary and problematic—it moves the focus of school efforts from real improvement of quality to mere improvement of the school public image.

  12. Resolution of ranking hierarchies in directed networks

    Science.gov (United States)

    Barucca, Paolo; Lillo, Fabrizio

    2018-01-01

    Identifying hierarchies and rankings of nodes in directed graphs is fundamental in many applications such as social network analysis, biology, economics, and finance. A recently proposed method identifies the hierarchy by finding the ordered partition of nodes which minimises a score function, termed agony. This function penalises the links violating the hierarchy in a way depending on the strength of the violation. To investigate the resolution of ranking hierarchies we introduce an ensemble of random graphs, the Ranked Stochastic Block Model. We find that agony may fail to identify hierarchies when the structure is not strong enough and the size of the classes is small with respect to the whole network. We analytically characterise the resolution threshold and we show that an iterated version of agony can partly overcome this resolution limit. PMID:29394278

  13. Ranking beta sheet topologies of proteins

    DEFF Research Database (Denmark)

    Fonseca, Rasmus; Helles, Glennie; Winter, Pawel

    2010-01-01

    One of the challenges of protein structure prediction is to identify long-range interactions between amino acids. To reliably predict such interactions, we enumerate, score and rank all beta-topologies (partitions of beta-strands into sheets, orderings of strands within sheets and orientations...... of paired strands) of a given protein. We show that the beta-topology corresponding to the native structure is, with high probability, among the top-ranked. Since full enumeration is very time-consuming, we also suggest a method to deal with proteins with many beta-strands. The results reported...... in this paper are highly relevant for ab initio protein structure prediction methods based on decoy generation. The top-ranked beta-topologies can be used to find initial conformations from which conformational searches can be started. They can also be used to filter decoys by removing those with poorly...

  14. Low Rank Approximation Algorithms, Implementation, Applications

    CERN Document Server

    Markovsky, Ivan

    2012-01-01

    Matrix low-rank approximation is intimately related to data modelling; a problem that arises frequently in many different fields. Low Rank Approximation: Algorithms, Implementation, Applications is a comprehensive exposition of the theory, algorithms, and applications of structured low-rank approximation. Local optimization methods and effective suboptimal convex relaxations for Toeplitz, Hankel, and Sylvester structured problems are presented. A major part of the text is devoted to application of the theory. Applications described include: system and control theory: approximate realization, model reduction, output error, and errors-in-variables identification; signal processing: harmonic retrieval, sum-of-damped exponentials, finite impulse response modeling, and array processing; machine learning: multidimensional scaling and recommender system; computer vision: algebraic curve fitting and fundamental matrix estimation; bioinformatics for microarray data analysis; chemometrics for multivariate calibration; ...

  15. Adaptive distributional extensions to DFR ranking

    DEFF Research Database (Denmark)

    Petersen, Casper; Simonsen, Jakob Grue; Järvelin, Kalervo

    2016-01-01

    Divergence From Randomness (DFR) ranking models assume that informative terms are distributed in a corpus differently than non-informative terms. Different statistical models (e.g. Poisson, geometric) are used to model the distribution of non-informative terms, producing different DFR models....... An informative term is then detected by measuring the divergence of its distribution from the distribution of non-informative terms. However, there is little empirical evidence that the distributions of non-informative terms used in DFR actually fit current datasets. Practically this risks providing a poor...... separation between informative and non-informative terms, thus compromising the discriminative power of the ranking model. We present a novel extension to DFR, which first detects the best-fitting distribution of non-informative terms in a collection, and then adapts the ranking computation to this best...

  16. Sign rank versus Vapnik-Chervonenkis dimension

    Science.gov (United States)

    Alon, N.; Moran, Sh; Yehudayoff, A.

    2017-12-01

    This work studies the maximum possible sign rank of sign (N × N)-matrices with a given Vapnik-Chervonenkis dimension d. For d=1, this maximum is three. For d=2, this maximum is \\widetilde{\\Theta}(N1/2). For d >2, similar but slightly less accurate statements hold. The lower bounds improve on previous ones by Ben-David et al., and the upper bounds are novel. The lower bounds are obtained by probabilistic constructions, using a theorem of Warren in real algebraic topology. The upper bounds are obtained using a result of Welzl about spanning trees with low stabbing number, and using the moment curve. The upper bound technique is also used to: (i) provide estimates on the number of classes of a given Vapnik-Chervonenkis dimension, and the number of maximum classes of a given Vapnik-Chervonenkis dimension--answering a question of Frankl from 1989, and (ii) design an efficient algorithm that provides an O(N/log(N)) multiplicative approximation for the sign rank. We also observe a general connection between sign rank and spectral gaps which is based on Forster's argument. Consider the adjacency (N × N)-matrix of a Δ-regular graph with a second eigenvalue of absolute value λ and Δ ≤ N/2. We show that the sign rank of the signed version of this matrix is at least Δ/λ. We use this connection to prove the existence of a maximum class C\\subseteq\\{+/- 1\\}^N with Vapnik-Chervonenkis dimension 2 and sign rank \\widetilde{\\Theta}(N1/2). This answers a question of Ben-David et al. regarding the sign rank of large Vapnik-Chervonenkis classes. We also describe limitations of this approach, in the spirit of the Alon-Boppana theorem. We further describe connections to communication complexity, geometry, learning theory, and combinatorics. Bibliography: 69 titles.

  17. Pulling Rank: A Plan to Help Students with College Choice in an Age of Rankings

    Science.gov (United States)

    Thacker, Lloyd

    2008-01-01

    Colleges and universities are "ranksteering"--driving under the influence of popular college rankings systems like "U.S. News and World Report's" Best Colleges. This article examines the criticisms of college rankings and describes how a group of education leaders is honing a plan to end the tyranny of the ratings game and better help students and…

  18. When sparse coding meets ranking: a joint framework for learning sparse codes and ranking scores

    KAUST Repository

    Wang, Jim Jing-Yan

    2017-06-28

    Sparse coding, which represents a data point as a sparse reconstruction code with regard to a dictionary, has been a popular data representation method. Meanwhile, in database retrieval problems, learning the ranking scores from data points plays an important role. Up to now, these two problems have always been considered separately, assuming that data coding and ranking are two independent and irrelevant problems. However, is there any internal relationship between sparse coding and ranking score learning? If yes, how to explore and make use of this internal relationship? In this paper, we try to answer these questions by developing the first joint sparse coding and ranking score learning algorithm. To explore the local distribution in the sparse code space, and also to bridge coding and ranking problems, we assume that in the neighborhood of each data point, the ranking scores can be approximated from the corresponding sparse codes by a local linear function. By considering the local approximation error of ranking scores, the reconstruction error and sparsity of sparse coding, and the query information provided by the user, we construct a unified objective function for learning of sparse codes, the dictionary and ranking scores. We further develop an iterative algorithm to solve this optimization problem.

  19. Comparison of Therapeutic and Cosmetic Results of Curettage, Surgical Excision and Combined Curettage and Cauterization in Lesions of Basal Cell Carcinoma (BCC

    Directory of Open Access Journals (Sweden)

    F Rad

    2006-07-01

    Full Text Available Introduction & Objective: Skin cancers are the most common malignancies of the mankind. Basal call carcinoma (BCC constitutes the most prevalent skin cancer in human beings. This study aimed to evaluate the therapeutic and cosmetic results of three methods of treatment of BCC i.e. curettage, surgical excision and combined curettage and cauterization. Materials & Methods: This is an interventional study, through which 79 lesions of BCC on the faces and scalps of 64 patients in Besat hospital of Sanandaj city in 2001-2003 were treated by curettage, surgical excision and combined curettage and cauterization. Collected data were recorded in frequency tables. Results: 69 (87.3% of tumors were papulonodular type, 61 of them had an ulcer on their surface. 26 tumors were treated by surgery which had a cure rate of 91.7%. 45 (57% tumors were of solid type. During the follow–up period, an overall recurrence rate of 11.4% (9 tumors was noticed. Two of the tumors that were treated by surgery, 5 of the tumors treated by curettage, and 2 of those which were treated by combined curettage and cauterization recurred. The cosmetic result in the patients who had been treated by curettage was quite promising, only a small scar or a slight hyper pigmentation was left at the site of the lesions. Conclusion: Curettage is more suitable for the treatment of small lesions of B.C, but it is not recommended for the treatment of the tumors having aggressive behavior or rapid growth. The cosmetic result in the patients treated by combined curettage and cauterization of the lesions was also excellent and in most cases scar was minimal or absent. Combined curettage and cauterization is a cheap and suitable method for the treatment of BCC and it can easily be accomplished.

  20. Comparison of Therapeutic and Cosmetic Results of Curettage, Surgical Excision and Combined Curettage and Cauterization in Lesions of Basal Cell Carcinoma (BCC

    Directory of Open Access Journals (Sweden)

    F Rad

    2006-10-01

    Full Text Available Introduction & Objective: Skin cancers are the most common malignancies of the mankind. Basal call carcinoma (BCC constitutes the most prevalent skin cancer in human beings. This study aimed to evaluate the therapeutic and cosmetic results of three methods of treatment of BCC i.e. curettage, surgical excision and combined curettage and cauterization. Materials & Methods: This is an interventional study, through which 79 lesions of BCC on the faces and scalps of 64 patients in Besat hospital of Sanandaj city in 2001-2003 were treated by curettage, surgical excision and combined curettage and cauterization. Collected data were recorded in frequency tables. Results: 69 (87.3% of tumors were papulonodular type, 61 of them had an ulcer on their surface. 26 tumors were treated by surgery which had a cure rate of 91.7%. 45 (57% tumors were of solid type. During the follow–up period, an overall recurrence rate of 11.4% (9 tumors was noticed. Two of the tumors that were treated by surgery, 5 of the tumors treated by curettage, and 2 of those which were treated by combined curettage and cauterization recurred. The cosmetic result in the patients who had been treated by curettage was quite promising, only a small scar or a slight hyper pigmentation was left at the site of the lesions. Conclusion: Curettage is more suitable for the treatment of small lesions of B.C, but it is not recommended for the treatment of the tumors having aggressive behavior or rapid growth. The cosmetic result in the patients treated by combined curettage and cauterization of the lesions was also excellent and in most cases scar was minimal or absent. Combined curettage and cauterization is a cheap and suitable method for the treatment of BCC and it can easily be accomplished.

  1. Ranking Entities in Networks via Lefschetz Duality

    DEFF Research Database (Denmark)

    Aabrandt, Andreas; Hansen, Vagn Lundsgaard; Poulsen, Bjarne

    2014-01-01

    In the theory of communication it is essential that agents are able to exchange information. This fact is closely related to the study of connected spaces in topology. A communication network may be modelled as a topological space such that agents can communicate if and only if they belong...... then be ranked according to how essential their positions are in the network by considering the effect of their respective absences. Defining a ranking of a network which takes the individual position of each entity into account has the purpose of assigning different roles to the entities, e.g. agents...

  2. Compressed Sensing with Rank Deficient Dictionaries

    DEFF Research Database (Denmark)

    Hansen, Thomas Lundgaard; Johansen, Daniel Højrup; Jørgensen, Peter Bjørn

    2012-01-01

    In compressed sensing it is generally assumed that the dictionary matrix constitutes a (possibly overcomplete) basis of the signal space. In this paper we consider dictionaries that do not span the signal space, i.e. rank deficient dictionaries. We show that in this case the signal-to-noise ratio...... (SNR) in the compressed samples can be increased by selecting the rows of the measurement matrix from the column space of the dictionary. As an example application of compressed sensing with a rank deficient dictionary, we present a case study of compressed sensing applied to the Coarse Acquisition (C...

  3. Research of Subgraph Estimation Page Rank Algorithm for Web Page Rank

    Directory of Open Access Journals (Sweden)

    LI Lan-yin

    2017-04-01

    Full Text Available The traditional PageRank algorithm can not efficiently perform large data Webpage scheduling problem. This paper proposes an accelerated algorithm named topK-Rank,which is based on PageRank on the MapReduce platform. It can find top k nodes efficiently for a given graph without sacrificing accuracy. In order to identify top k nodes,topK-Rank algorithm prunes unnecessary nodes and edges in each iteration to dynamically construct subgraphs,and iteratively estimates lower/upper bounds of PageRank scores through subgraphs. Theoretical analysis shows that this method guarantees result exactness. Experiments show that topK-Rank algorithm can find k nodes much faster than the existing approaches.

  4. Evaluate and Analysis Efficiency of Safaga Port Using DEA-CCR, BCC and SBM Models–Comparison with DP World Sokhna

    Science.gov (United States)

    Elsayed, Ayman; Shabaan Khalil, Nabil

    2017-10-01

    The competition among maritime ports is increasing continuously; the main purpose of Safaga port is to become the best option for companies to carry out their trading activities, particularly importing and exporting The main objective of this research is to evaluate and analyze factors that may significantly affect the levels of Safaga port efficiency in Egypt (particularly the infrastructural capacity). The assessment of such efficiency is a task that must play an important role in the management of Safaga port in order to improve the possibility of development and success in commercial activities. Drawing on Data Envelopment Analysis(DEA)models, this paper develops a manner of assessing the comparative efficiency of Safaga port in Egypt during the study period 2004-2013. Previous research for port efficiencies measurement usually using radial DEA models (DEA-CCR), (DEA-BCC), but not using non radial DEA model. The research applying radial - output oriented (DEA-CCR), (DEA-BCC) and non-radial (DEA-SBM) model with ten inputs and four outputs. The results were obtained from the analysis input and output variables based on DEA-CCR, DEA-BCC and SBM models, by software Max DEA Pro 6.3. DP World Sokhna port higher efficiency for all outputs were compared to Safaga port. DP World Sokhna position is below the southern entrance to the Suez Canal, on the Red Sea, Egypt, makes it strategically located to handle cargo transiting through one of the world's busiest commercial waterways.

  5. Hierarchical super-structure identified by polarized light microscopy, electron microscopy and nanoindentation: Implications for the limits of biological control over the growth mode of abalone sea shells

    Directory of Open Access Journals (Sweden)

    Schneider Andreas S

    2012-09-01

    Full Text Available Abstract Background Mollusc shells are commonly investigated using high-resolution imaging techniques based on cryo-fixation. Less detailed information is available regarding the light-optical properties. Sea shells of Haliotis pulcherina were embedded for polishing in defined orientations in order to investigate the interface between prismatic calcite and nacreous aragonite by standard materialographic methods. A polished thin section of the interface was prepared with a defined thickness of 60 μm for quantitative birefringence analysis using polarized light and LC-PolScope microscopy. Scanning electron microscopy images were obtained for comparison. In order to study structural-mechanical relationships, nanoindentation experiments were performed. Results Incident light microscopy revealed a super-structure in semi-transparent regions of the polished cross-section under a defined angle. This super-structure is not visible in transmitted birefringence analysis due to the blurred polarization of small nacre platelets and numerous organic interfaces. The relative orientation and homogeneity of calcite prisms was directly identified, some of them with their optical axes exactly normal to the imaging plane. Co-oriented "prism colonies" were identified by polarized light analyses. The nacreous super-structure was also visualized by secondary electron imaging under defined angles. The domains of the super-structure were interpreted to consist of crystallographically aligned platelet stacks. Nanoindentation experiments showed that mechanical properties changed with the same periodicity as the domain size. Conclusions In this study, we have demonstrated that insights into the growth mechanisms of nacre can be obtained by conventional light-optical methods. For example, we observed super-structures formed by co-oriented nacre platelets as previously identified using X-ray Photo-electron Emission Microscopy (X-PEEM [Gilbert et al., Journal of the

  6. SOUTH AFRICAN ARMY RANKS AND INSIGNIA

    African Journals Online (AJOL)

    major, cap- tain, lieutenant;. Other Ranks : Warrant officer, staff sergeant, sergeant, corporal, lance-cor- poral, private.' We apparently had no need for second lieuten- ants at that time, and they were introduced only .... Army warrant officers can also hold the cmmon serv- ice posts of Sergeant-Major of Special Forces.

  7. Kinesiology Faculty Citations across Academic Rank

    Science.gov (United States)

    Knudson, Duane

    2015-01-01

    Citations to research reports are used as a measure for the influence of a scholar's research line when seeking promotion, grants, and awards. The current study documented the distributions of citations to kinesiology scholars of various academic ranks. Google Scholar Citations was searched for user profiles using five research interest areas…

  8. Biomechanics Scholar Citations across Academic Ranks

    Directory of Open Access Journals (Sweden)

    Knudson Duane

    2015-11-01

    Full Text Available Study aim: citations to the publications of a scholar have been used as a measure of the quality or influence of their research record. A world-wide descriptive study of the citations to the publications of biomechanics scholars of various academic ranks was conducted.

  9. Ranking Workplace Competencies: Student and Graduate Perceptions.

    Science.gov (United States)

    Rainsbury, Elizabeth; Hodges, Dave; Burchell, Noel; Lay, Mark

    2002-01-01

    New Zealand business students and graduates made similar rankings of the five most important workplace competencies: computer literacy, customer service orientation, teamwork and cooperation, self-confidence, and willingness to learn. Graduates placed greater importance on most of the 24 competencies, resulting in a statistically significant…

  10. Subject Gateway Sites and Search Engine Ranking.

    Science.gov (United States)

    Thelwall, Mike

    2002-01-01

    Discusses subject gateway sites and commercial search engines for the Web and presents an explanation of Google's PageRank algorithm. The principle question addressed is the conditions under which a gateway site will increase the likelihood that a target page is found in search engines. (LRW)

  11. Ranking related entities: components and analyses

    NARCIS (Netherlands)

    Bron, M.; Balog, K.; de Rijke, M.

    2010-01-01

    Related entity finding is the task of returning a ranked list of homepages of relevant entities of a specified type that need to engage in a given relationship with a given source entity. We propose a framework for addressing this task and perform a detailed analysis of four core components;

  12. Low-rank coal oil agglomeration

    Science.gov (United States)

    Knudson, C.L.; Timpe, R.C.

    1991-07-16

    A low-rank coal oil agglomeration process is described. High mineral content, a high ash content subbituminous coals are effectively agglomerated with a bridging oil which is partially water soluble and capable of entering the pore structure, and is usually coal-derived.

  13. An evaluation and critique of current rankings

    NARCIS (Netherlands)

    Federkeil, Gero; Westerheijden, Donald F.; van Vught, Franciscus A.; Ziegele, Frank

    2012-01-01

    This chapter raises the question of whether university league tables deliver relevant information to one of their key target groups – students. It examines the inherent biases and weaknesses in the methodologies of the major rankings and argues that the concentration on a single indicator of

  14. World University Ranking Methodologies: Stability and Variability

    Science.gov (United States)

    Fidler, Brian; Parsons, Christine

    2008-01-01

    There has been a steady growth in the number of national university league tables over the last 25 years. By contrast, "World University Rankings" are a more recent development and have received little serious academic scrutiny in peer-reviewed publications. Few researchers have evaluated the sources of data and the statistical…

  15. Alternative Class Ranks Using Z-Scores

    Science.gov (United States)

    Brown, Philip H.; Van Niel, Nicholas

    2012-01-01

    Grades at US colleges and universities have increased precipitously over the last 50 years, suggesting that their signalling power has become attenuated. Moreover, average grades have risen disproportionately in some departments, implying that weak students in departments with high grades may obtain better class ranks than strong students in…

  16. Statistical inference of Minimum Rank Factor Analysis

    NARCIS (Netherlands)

    Shapiro, A; Ten Berge, JMF

    For any given number of factors, Minimum Rank Factor Analysis yields optimal communalities for an observed covariance matrix in the sense that the unexplained common variance with that number of factors is minimized, subject to the constraint that both the diagonal matrix of unique variances and the

  17. City Life: Rankings (Livability) versus Perceptions (Satisfaction)

    Science.gov (United States)

    Okulicz-Kozaryn, Adam

    2013-01-01

    I investigate the relationship between the popular Mercer city ranking (livability) and survey data (satisfactions). Livability aims to capture "objective" quality of life such as infrastructure. Survey items capture "subjective" quality of life such as satisfaction with city. The relationship between objective measures of quality of life and…

  18. Matrices with high completely positive semidefinite rank

    NARCIS (Netherlands)

    de Laat, David; Gribling, Sander; Laurent, Monique

    2017-01-01

    A real symmetric matrix M is completely positive semidefinite if it admits a Gram representation by (Hermitian) positive semidefinite matrices of any size d. The smallest such d is called the (complex) completely positive semidefinite rank of M , and it is an open question whether there exists an

  19. Ranking health between countries in international comparisons

    DEFF Research Database (Denmark)

    Brønnum-Hansen, Henrik

    2014-01-01

    Cross-national comparisons and ranking of summary measures of population health sometimes give rise to inconsistent and diverging conclusions. In order to minimise confusion, international comparative studies ought to be based on well-harmonised data with common standards of definitions...

  20. Comparing survival curves using rank tests

    NARCIS (Netherlands)

    Albers, Willem/Wim

    1990-01-01

    Survival times of patients can be compared using rank tests in various experimental setups, including the two-sample case and the case of paired data. Attention is focussed on two frequently occurring complications in medical applications: censoring and tail alternatives. A review is given of the

  1. Smooth rank one perturbations of selfadjoint operators

    NARCIS (Netherlands)

    Hassi, Seppo; Snoo, H.S.V. de; Willemsma, A.D.I.

    Let A be a selfadjoint operator in a Hilbert space aleph with inner product [.,.]. The rank one perturbations of A have the form A+tau [.,omega]omega, tau epsilon R, for some element omega epsilon aleph. In this paper we consider smooth perturbations, i.e. we consider omega epsilon dom \\A\\(k/2) for

  2. Primate Innovation: Sex, Age and Social Rank

    NARCIS (Netherlands)

    Reader, S.M.; Laland, K.N.

    2001-01-01

    Analysis of an exhaustive survey of primate behavior collated from the published literature revealed significant variation in rates of innovation among individuals of different sex, age and social rank. We searched approximately 1,000 articles in four primatology journals, together with other

  3. An algorithm for ranking assignments using reoptimization

    DEFF Research Database (Denmark)

    Pedersen, Christian Roed; Nielsen, Lars Relund; Andersen, Kim Allan

    2008-01-01

    We consider the problem of ranking assignments according to cost in the classical linear assignment problem. An algorithm partitioning the set of possible assignments, as suggested by Murty, is presented where, for each partition, the optimal assignment is calculated using a new reoptimization...... technique. Computational results for the new algorithm are presented...

  4. Ouderdom, omvang en citatiescores: rankings nader bekeken

    NARCIS (Netherlands)

    van Rooij, Jules

    2017-01-01

    By comparing the Top-300 lists of four global university rankings (ARWU, THE, QS, Leiden), three hypotheses are tested: 1) position correlates with size in the ARWU more than in the THE and QS; 2) given their strong dependency on reputation scores, position will be correlated more with a

  5. Returns to Tenure: Time or Rank?

    DEFF Research Database (Denmark)

    Buhai, Ioan Sebastian

    -specific investment, efficiency-wages or adverse-selection models. However, rent extracting arguments as suggested by the theory of internal labor markets, indicate that the relative position of the worker in the seniority hierarchy of the firm, her 'seniority rank', may also explain part of the observed returns...

  6. Probabilistic relation between In-Degree and PageRank

    NARCIS (Netherlands)

    Litvak, Nelli; Scheinhardt, Willem R.W.; Volkovich, Y.

    2008-01-01

    This paper presents a novel stochastic model that explains the relation between power laws of In-Degree and PageRank. PageRank is a popularity measure designed by Google to rank Web pages. We model the relation between PageRank and In-Degree through a stochastic equation, which is inspired by the

  7. The effect of new links on Google PageRank

    NARCIS (Netherlands)

    Avrachenkov, Konstatin; Litvak, Nelli

    2004-01-01

    PageRank is one of the principle criteria according to which Google ranks Web pages. PageRank can be interpreted as a frequency of visiting a Web page by a random surfer and thus it reflects the popularity of a Web page. We study the effect of newly created links on Google PageRank. We discuss to

  8. World University Rankings: Take with a Large Pinch of Salt

    Science.gov (United States)

    Cheng, Soh Kay

    2011-01-01

    Equating the unequal is misleading, and this happens consistently in comparing rankings from different university ranking systems, as the NUT saga shows. This article illustrates the problem by analyzing the 2011 rankings of the top 100 universities in the AWUR, QSWUR and THEWUR ranking results. It also discusses the reasons why the rankings…

  9. Generalized Reduced Rank Tests using the Singular Value Decomposition

    NARCIS (Netherlands)

    Kleibergen, F.R.; Paap, R.

    2006-01-01

    We propose a novel statistic to test the rank of a matrix. The rank statistic overcomes deficiencies of existing rank statistics, like: a Kronecker covariance matrix for the canonical correlation rank statistic of Anderson [Annals of Mathematical Statistics (1951), 22, 327-351] sensitivity to the

  10. Some upper and lower bounds on PSD-rank

    NARCIS (Netherlands)

    T. J. Lee (Troy); Z. Wei (Zhaohui); R. M. de Wolf (Ronald)

    2014-01-01

    textabstractPositive semidefinite rank (PSD-rank) is a relatively new quantity with applications to combinatorial optimization and communication complexity. We first study several basic properties of PSD-rank, and then develop new techniques for showing lower bounds on the PSD-rank. All of these

  11. Some upper and lower bounds on PSD-rank

    NARCIS (Netherlands)

    Lee, T.; Wei, Z.; de Wolf, R.

    Positive semidefinite rank (PSD-rank) is a relatively new complexity measure on matrices, with applications to combinatorial optimization and communication complexity. We first study several basic properties of PSD-rank, and then develop new techniques for showing lower bounds on the PSD-rank. All

  12. Biology of RANK, RANKL, and osteoprotegerin

    Science.gov (United States)

    Boyce, Brendan F; Xing, Lianping

    2007-01-01

    The discovery of the receptor activator of nuclear factor-κB ligand (RANKL)/RANK/osteoprotegerin (OPG) system and its role in the regulation of bone resorption exemplifies how both serendipity and a logic-based approach can identify factors that regulate cell function. Before this discovery in the mid to late 1990s, it had long been recognized that osteoclast formation was regulated by factors expressed by osteoblast/stromal cells, but it had not been anticipated that members of the tumor necrosis factor superfamily of ligands and receptors would be involved or that the factors involved would have extensive functions beyond bone remodeling. RANKL/RANK signaling regulates the formation of multinucleated osteoclasts from their precursors as well as their activation and survival in normal bone remodeling and in a variety of pathologic conditions. OPG protects the skeleton from excessive bone resorption by binding to RANKL and preventing it from binding to its receptor, RANK. Thus, RANKL/OPG ratio is an important determinant of bone mass and skeletal integrity. Genetic studies in mice indicate that RANKL/RANK signaling is also required for lymph node formation and mammary gland lactational hyperplasia, and that OPG also protects arteries from medial calcification. Thus, these tumor necrosis factor superfamily members have important functions outside bone. Although our understanding of the mechanisms whereby they regulate osteoclast formation has advanced rapidly during the past 10 years, many questions remain about their roles in health and disease. Here we review our current understanding of the role of the RANKL/RANK/OPG system in bone and other tissues. PMID:17634140

  13. VaRank: a simple and powerful tool for ranking genetic variants

    Directory of Open Access Journals (Sweden)

    Véronique Geoffroy

    2015-03-01

    Full Text Available Background. Most genetic disorders are caused by single nucleotide variations (SNVs or small insertion/deletions (indels. High throughput sequencing has broadened the catalogue of human variation, including common polymorphisms, rare variations or disease causing mutations. However, identifying one variation among hundreds or thousands of others is still a complex task for biologists, geneticists and clinicians.Results. We have developed VaRank, a command-line tool for the ranking of genetic variants detected by high-throughput sequencing. VaRank scores and prioritizes variants annotated either by Alamut Batch or SnpEff. A barcode allows users to quickly view the presence/absence of variants (with homozygote/heterozygote status in analyzed samples. VaRank supports the commonly used VCF input format for variants analysis thus allowing it to be easily integrated into NGS bioinformatics analysis pipelines. VaRank has been successfully applied to disease-gene identification as well as to molecular diagnostics setup for several hundred patients.Conclusions. VaRank is implemented in Tcl/Tk, a scripting language which is platform-independent but has been tested only on Unix environment. The source code is available under the GNU GPL, and together with sample data and detailed documentation can be downloaded from http://www.lbgi.fr/VaRank/.

  14. Boron doped bcc-W films: Achieving excellent mechanical properties and tribological performance by regulating substrate bias voltage

    Science.gov (United States)

    Yang, Lina; Zhang, Kan; Zeng, Yi; Wang, Xin; Du, Suxuan; Tao, Chuanying; Ren, Ping; Cui, Xiaoqiang; Wen, Mao

    2017-11-01

    Boron doped bcc-W (WBx, x = B/W) films were deposited on Si(100) substrates by magnetron co-sputtering pure W and B targets. Our results reveal that when the absolute value of substrate bias voltage (Vb) increases from floating to 240 V, the value of x monotonously decreases from 0.18 to 0.04, accompanied by a phase transition from a mixture of tetragonal γ-W2B and body-centered cubic α-W(B) phase (-Vb ≤ 60 V) to α-W(B) single phase (-Vb > 60 V). Hardness, depending on Vb, increases first and then drops, where the maximum hardness of 30.8 GPa was obtained at -Vb = 60 V and far higher than pure W and W2B theoretical value. In the mixed phase structure, the grain boundaries strengthening, Hall-Petch effect and solid-solution strengthening induced by B dominate the strengthening mechanism. Astonishingly, the film grown at -Vb = 120 V still possesses twice higher hardness than pure W, wherein unexpectedly low (6.7 at.%) B concentration and only the single α-W(B) phase can be identified. In this case, both Hall-Petch effect and solid-solution strengthening work. Besides, low friction coefficient of ∼0.18 can be obtained for the films with α-W(B) phase, which is competitive to that of reported B-rich transition-metal borides, such as TiB2, CrB and CrB2.

  15. Microstructural Characterization of Dislocation Networks During Harper-Dorn Creep of fcc, bcc, and hcp Metals and Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Przystupa, Marek A.

    2007-12-13

    Harper-Dorn (H-D) creep is observed in metals and geological materials exposed to very low stresses at temperatures close to the melting point. It is one of several types of creep processes wherein the steady-state strain rate is proportional to the applied stress, Nabarro-Herring creep and Coble creep being two other important processes. H-D creep can be somewhat insidious because the creep rates are much larger than those expected for Nabarro-Herring or Coble creep. Since the working conditions of structural components of power plants and propulsion systems, as well as the motion of the earth’s mantle all involve very low stresses, an understanding of the factors controlling H-D creep is critical in preventing failures associated with those higher-than-expected creep rates. The purpose of this investigation was to obtain missing microstructural information on the evolution of the dislocation structures during static annealing of materials with fcc, bcc and hcp structure and use obtained results to test predictive capabilities of the dislocation network theory of H-D creep. In our view the evolutionary processes during static annealing and during Harper-Dorn creep are intimately related. The materials used in this study were fcc aluminum, hcp zinc and bcc tin. All characterizations of dislocation structures, densities and dislocation link length distributions were carried out using the etch pit method. To obtain quantitative information on the evolution of the dislocation networks during annealing the pure fcc aluminum samples were pre-deformed by creep at 913 and 620 K and then annealed. The higher deformation temperature was selected to generate starting dislocation networks similar to those forming during Harper-Dorn creep and the lower, to obtain higher dislocation densities suitable for reliable estimates of the parameters of the network growth law. The measured experimental link length distribution were, after scaling, (1) the same for all annealing

  16. Ranked Conservation Opportunity Areas for Region 7 (ECO_RES.RANKED_OAS)

    Science.gov (United States)

    The RANKED_OAS are all the Conservation Opportunity Areas identified by MoRAP that have subsequently been ranked by patch size, landform representation, and the targeted land cover class (highest rank for conservation management = 1 [LFRANK_NOR]). The OAs designate areas with potential for forest or grassland conservation because they are areas of natural or semi-natural land cover that are at least 75 meters away from roads and away from patch edges. The OAs were modeled by creating distance grids using the National Land Cover Database and the Census Bureau's TIGER roads files.

  17. UNIVERSITY RANKINGS BY COST OF LIVING ADJUSTED FACULTY COMPENSATION

    OpenAIRE

    Terrance Jalbert; Mercedes Jalbert; Karla Hayashi

    2010-01-01

    In this paper we rank 574 universities based on compensation paid to their faculty. The analysis examines universities both on a raw basis and on a cost of living adjusted basis. Rankings based on salary data and benefit data are presented. In addition rankings based on total compensation are presented. Separate rankings are provided for universities offering different degrees. The results indicate that rankings of universities based on raw and cost of living adjusted data are markedly differ...

  18. The Impact of Implant Design, Defect Size, and Type of Superstructure on the Accessibility of Nonsurgical and Surgical Approaches for the Treatment of Peri-implantitis.

    Science.gov (United States)

    Polak, David; Maayan, Efrat; Chackartchi, Tali

    The success of nonsurgical or surgical treatments of peri-implantitis is unpredictable, often without a clear reason. The aim of this study was to investigate the efficacy of nonsurgical and surgical cleaning, focusing on the impact of implant design, defect size, type of superstructure, and experience of the operator. Conical and straight implants were coated with a biofilm-like material and placed in shallow/deep defects in an artificial jaw model. Treatment was done by three operators and included either healing abutments or crowns as superstructures. Analysis was done using stereomicroscopy and ImageJ software. Nonsurgical treatment of peri-implantitis defects was inefficient in removing all biofilm areas, regardless of the depth of the defect. The type of implant, experience of the operator, or type of superstructure did not have a significant impact. Surgical treatment was more efficient than a nonsurgical approach with regard to biofilm residues. However, the surgical approach failed to clean the apical portion of the exposed part of the implants. Nonsurgical and surgical treatment were found to be ineffective in cleaning the exposed portion of implants with peri-implantitis. Treatment of peri-implantitis should therefore also include other approaches, such as chemical or biological modalities.

  19. Large-scale room-temperature aqueous synthesis of Co superstructures with controlled morphology, and their application to electromagnetic wave absorption

    Science.gov (United States)

    Kuchi, Rambabu; Dongquoc, Viet; Kim, Dojin; Yoon, Soon-Gil; Park, Seung-Young; Jeong, Jong-Ryul

    2017-03-01

    In this work, we report on the large-scale room-temperature synthesis of Co superstructures using a facile liquid phase reduction method in an aqueous medium. This method yielded pure Co powders within a short period of time without the use of any surfactants. The morphological changes in the Co superstructures could be controlled simply by varying the amounts of reducing agent (hydrazine hydrate). The morphology of the Co powders systematically controlled from aggregated foliage to isolated microfoliage by increasing the hydrazine hydrate addition from 4 ml to 8 ml. The morphology-dependent electromagnetic properties, including the electric permittivity, and magnetic permeability, were investigated over the microwave frequency range, 2-18 GHz. Co isolated microfoliage showed a maximum reflection loss (RL) of -32 dB at 9 GHz with a matching thickness of 2.5 mm, whereas the aggregated foliage Co superstructures displayed a maximum RL of -17 dB at 11 GHz with a matching thickness of 2.5 mm. The stronger absorption for isolated microfoliage was ascribed to a continuous micro networks and vibrating microcurrent dissipation arise from size and shape of the isolated microfoliage. The calculated RL suggested that the as-prepared samples were potential microwave absorption candidates in the X-band region.

  20. Giant reversible magnetocaloric effect in flower-like β-Co(OH){sub 2} hierarchical superstructures self-assembled by nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xianguo; Feng, Chao; Xiao, Feng; Jin, Chuangui; Xia, Ailin, E-mail: liuxianguohugh@gmail.com, E-mail: eeswor@polyu.edu.hk [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Ma' anshan, PR (China); Or, Siu Wing [Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Sun, Yuping [Center for Engineering Practice and Innovation Education, Anhui University of Technology, Ma' anshan, PR (China)

    2014-01-15

    A facile hydrothermal strategy is proposed to synthesize flower-like β- Co(OH){sub 2} hierarchical microspherical superstructures with a diameter of 0.5-1.5 µm, which are self-assembled by β - Co(OH){sub 2} nano sheets with the average thickness ranging between 20 and 40 nm. The magnetocaloric effect associated with magnetic phase transitions in Co(OH){sub 2} superstructures has been investigated. A sign change in the magnetocaloric effect is induced by a magnetic field, which is related to a filed-induced transition from the antiferromagnetic to the ferromagnetic state below the Néel temperature. The large reversible magnetic-entropy change –ΔS{sub m} (13.4 J/kg K at 15 K for a field change of 5 T) indicates that flower-like Co(OH){sub 2} superstructures is a potential candidate for application in magnetic refrigeration in the low-temperature range. (author)

  1. Kriging for Simulation Metamodeling: Experimental Design, Reduced Rank Kriging, and Omni-Rank Kriging

    Science.gov (United States)

    Hosking, Michael Robert

    This dissertation improves an analyst's use of simulation by offering improvements in the utilization of kriging metamodels. There are three main contributions. First an analysis is performed of what comprises good experimental designs for practical (non-toy) problems when using a kriging metamodel. Second is an explanation and demonstration of how reduced rank decompositions can improve the performance of kriging, now referred to as reduced rank kriging. Third is the development of an extension of reduced rank kriging which solves an open question regarding the usage of reduced rank kriging in practice. This extension is called omni-rank kriging. Finally these results are demonstrated on two case studies. The first contribution focuses on experimental design. Sequential designs are generally known to be more efficient than "one shot" designs. However, sequential designs require some sort of pilot design from which the sequential stage can be based. We seek to find good initial designs for these pilot studies, as well as designs which will be effective if there is no following sequential stage. We test a wide variety of designs over a small set of test-bed problems. Our findings indicate that analysts should take advantage of any prior information they have about their problem's shape and/or their goals in metamodeling. In the event of a total lack of information we find that Latin hypercube designs are robust default choices. Our work is most distinguished by its attention to the higher levels of dimensionality. The second contribution introduces and explains an alternative method for kriging when there is noise in the data, which we call reduced rank kriging. Reduced rank kriging is based on using a reduced rank decomposition which artificially smoothes the kriging weights similar to a nugget effect. Our primary focus will be showing how the reduced rank decomposition propagates through kriging empirically. In addition, we show further evidence for our

  2. Pulling Rank: Military Rank Affects Hormone Levels and Fairness in an Allocation Experiment

    Directory of Open Access Journals (Sweden)

    Benjamin Siart

    2016-11-01

    Full Text Available Status within social hierarchies has great effects on the lives of socially organized mammals. Its effects on human behavior and related physiology however is relatively little studied. The present study investigated the impact of military rank on fairness and behavior in relation to salivary cortisol (C and testosterone (T levels in male soldiers. For this purpose 180 members of the Austrian Armed Forces belonging to two distinct rank groups participated in two variations of a computer-based guard duty allocation experiment. The rank groups were 1 warrant officers (High Rank, HR and 2 enlisted men (Low Rank, LR. One soldier from each rank group participated in every experiment. At the beginning of the experiment, one participant was assigned to start standing guard and the other participant at rest. The participant who started at rest could choose if and when to relieve his fellow soldier and therefore had control over the experiment. In order to trigger perception of unfair behavior, an additional experiment was conducted which was manipulated by the experimenter. In the manipulated version both soldiers started in the standing guard position and were never relieved, believing that their opponent was at rest, not relieving them. Our aim was to test whether unfair behavior causes a physiological reaction. Saliva samples for hormone analysis were collected at regular intervals throughout the experiment.We found that in the un-manipulated setup high-ranking soldiers spent less time standing guard than lower ranking individuals. Rank was a significant predictor for C but not for T levels during the experiment. C levels in the HR group were higher than in LR group. C levels were also elevated in the manipulated experiment compared to the un-manipulated experiment, especially in LR. We assume that the elevated C levels in HR were caused by HR feeling their status challenged by the situation of having to negotiate with an individual of lower military

  3. Pulling Rank: Military Rank Affects Hormone Levels and Fairness in an Allocation Experiment.

    Science.gov (United States)

    Siart, Benjamin; Pflüger, Lena S; Wallner, Bernard

    2016-01-01

    Status within social hierarchies has great effects on the lives of socially organized mammals. Its effects on human behavior and related physiology, however, is relatively little studied. The present study investigated the impact of military rank on fairness and behavior in relation to salivary cortisol (C) and testosterone (T) levels in male soldiers. For this purpose 180 members of the Austrian Armed Forces belonging to two distinct rank groups participated in two variations of a computer-based guard duty allocation experiment. The rank groups were (1) warrant officers (high rank, HR) and (2) enlisted men (low rank, LR). One soldier from each rank group participated in every experiment. At the beginning of the experiment, one participant was assigned to start standing guard and the other participant at rest. The participant who started at rest could choose if and when to relieve his fellow soldier and therefore had control over the experiment. In order to trigger perception of unfair behavior, an additional experiment was conducted which was manipulated by the experimenter. In the manipulated version both soldiers started in the standing guard position and were never relieved, believing that their opponent was at rest, not relieving them. Our aim was to test whether unfair behavior causes a physiological reaction. Saliva samples for hormone analysis were collected at regular intervals throughout the experiment. We found that in the un-manipulated setup high-ranking soldiers spent less time standing guard than lower ranking individuals. Rank was a significant predictor for C but not for T levels during the experiment. C levels in the HR group were higher than in the LR group. C levels were also elevated in the manipulated experiment compared to the un-manipulated experiment, especially in LR. We assume that the elevated C levels in HR were caused by HR feeling their status challenged by the situation of having to negotiate with an individual of lower military rank

  4. Social Bookmarking Induced Active Page Ranking

    Science.gov (United States)

    Takahashi, Tsubasa; Kitagawa, Hiroyuki; Watanabe, Keita

    Social bookmarking services have recently made it possible for us to register and share our own bookmarks on the web and are attracting attention. The services let us get structured data: (URL, Username, Timestamp, Tag Set). And these data represent user interest in web pages. The number of bookmarks is a barometer of web page value. Some web pages have many bookmarks, but most of those bookmarks may have been posted far in the past. Therefore, even if a web page has many bookmarks, their value is not guaranteed. If most of the bookmarks are very old, the page may be obsolete. In this paper, by focusing on the timestamp sequence of social bookmarkings on web pages, we model their activation levels representing current values. Further, we improve our previously proposed ranking method for web search by introducing the activation level concept. Finally, through experiments, we show effectiveness of the proposed ranking method.

  5. Regression Estimator Using Double Ranked Set Sampling

    Directory of Open Access Journals (Sweden)

    Hani M. Samawi

    2002-06-01

    Full Text Available The performance of a regression estimator based on the double ranked set sample (DRSS scheme, introduced by Al-Saleh and Al-Kadiri (2000, is investigated when the mean of the auxiliary variable X is unknown. Our primary analysis and simulation indicates that using the DRSS regression estimator for estimating the population mean substantially increases relative efficiency compared to using regression estimator based on simple random sampling (SRS or ranked set sampling (RSS (Yu and Lam, 1997 regression estimator.  Moreover, the regression estimator using DRSS is also more efficient than the naïve estimators of the population mean using SRS, RSS (when the correlation coefficient is at least 0.4 and DRSS for high correlation coefficient (at least 0.91. The theory is illustrated using a real data set of trees.

  6. Low-rank quadratic semidefinite programming

    KAUST Repository

    Yuan, Ganzhao

    2013-04-01

    Low rank matrix approximation is an attractive model in large scale machine learning problems, because it can not only reduce the memory and runtime complexity, but also provide a natural way to regularize parameters while preserving learning accuracy. In this paper, we address a special class of nonconvex quadratic matrix optimization problems, which require a low rank positive semidefinite solution. Despite their non-convexity, we exploit the structure of these problems to derive an efficient solver that converges to their local optima. Furthermore, we show that the proposed solution is capable of dramatically enhancing the efficiency and scalability of a variety of concrete problems, which are of significant interest to the machine learning community. These problems include the Top-k Eigenvalue problem, Distance learning and Kernel learning. Extensive experiments on UCI benchmarks have shown the effectiveness and efficiency of our proposed method. © 2012.

  7. Classification of rank 2 cluster varieties

    DEFF Research Database (Denmark)

    Mandel, Travis

    We classify rank 2 cluster varieties (those whose corresponding skew-form has rank 2) according to the deformation type of a generic fiber U of their X-spaces, as defined by Fock and Goncharov. Our approach is based on the work of Gross, Hacking, and Keel for cluster varieties and log Calabi......-Yau surfaces. We find, for example, that U is "positive" (i.e., nearly affine) and either finite-type or non-acyclic (in the cluster sense) if and only if the monodromy of the tropicalization of U is one of Kodaira's matrices for the monodromy of an ellpitic fibration. In the positive cases, we also describe...... the action of the cluster modular group on the tropicalization of U....

  8. Deep Impact: Unintended consequences of journal rank

    CERN Document Server

    Brembs, Björn

    2013-01-01

    Much has been said about the increasing bureaucracy in science, stifling innovation, hampering the creativity of researchers and incentivizing misconduct, even outright fraud. Many anecdotes have been recounted, observations described and conclusions drawn about the negative impact of impact assessment on scientists and science. However, few of these accounts have drawn their conclusions from data, and those that have typically relied on a few studies. In this review, we present the most recent and pertinent data on the consequences that our current scholarly communication system has had on various measures of scientific quality (such as utility/citations, methodological soundness, expert ratings and retractions). These data confirm previous suspicions: using journal rank as an assessment tool is bad scientific practice. Moreover, the data lead us to argue that any journal rank (not only the currently-favored Impact Factor) would have this negative impact. Therefore, we suggest that abandoning journals altoge...

  9. Probabilistic Low-Rank Multitask Learning.

    Science.gov (United States)

    Kong, Yu; Shao, Ming; Li, Kang; Fu, Yun

    2017-01-04

    In this paper, we consider the problem of learning multiple related tasks simultaneously with the goal of improving the generalization performance of individual tasks. The key challenge is to effectively exploit the shared information across multiple tasks as well as preserve the discriminative information for each individual task. To address this, we propose a novel probabilistic model for multitask learning (MTL) that can automatically balance between low-rank and sparsity constraints. The former assumes a low-rank structure of the underlying predictive hypothesis space to explicitly capture the relationship of different tasks and the latter learns the incoherent sparse patterns private to each task. We derive and perform inference via variational Bayesian methods. Experimental results on both regression and classification tasks on real-world applications demonstrate the effectiveness of the proposed method in dealing with the MTL problems.

  10. Ranking agility factors affecting hospitals in Iran

    OpenAIRE

    M. Abdi Talarposht; GH. Mahmodi; MA. Jahani

    2017-01-01

    Background: Agility is an effective response to the changing and unpredictable environment and using these changes as opportunities for organizational improvement. Objective: The aim of the present study was to rank the factors affecting agile supply chain of hospitals of Iran. Methods: This applied study was conducted by cross sectional-descriptive method at some point of 2015 for one year. The research population included managers, administrators, faculty members and experts were sele...

  11. Ranking images based on aesthetic qualities.

    OpenAIRE

    Gaur, Aarushi

    2015-01-01

    The qualitative assessment of image content and aesthetic impression is affected by various image attributes and relations between the attributes. Modelling of such assessments in the form of objective rankings and learning image representations based on them is not a straightforward problem. The criteria can be varied with different levels of complexity for various applications. A highly-complex problem could involve a large number of interrelated attributes and features alongside varied rul...

  12. Homological characterisation of Lambda-ranks

    OpenAIRE

    Howson, Susan

    1999-01-01

    If G is a pro-p, p-adic, Lie group and if $\\Lambda(G)$ denotes the Iwasawa algebra of G then we present a formula for determining the $\\Lambda(G)$-rank of a finitely generated $\\Lambda(G)$-module. This is given in terms of the G homology groups of the module. We explore some consequences of this for the structure of $\\Lambda(G)$-modules.

  13. Citation ranking versus peer evaluation of senior faculty research performance

    DEFF Research Database (Denmark)

    Meho, Lokman I.; Sonnenwald, Diane H.

    2000-01-01

    indicator of research performance of senior faculty members? Citation data, book reviews, and peer ranking were compiled and examined for faculty members specializing in Kurdish studies. Analysis shows that normalized citation ranking and citation content analysis data yield identical ranking results....... Analysis also shows that normalized citation ranking and citation content analysis, book reviews, and peer ranking perform similarly (i.e., are highly correlated) for high-ranked and low-ranked senior scholars. Additional evaluation methods and measures that take into account the context and content......The purpose of this study is to analyze the relationship between citation ranking and peer evaluation in assessing senior faculty research performance. Other studies typically derive their peer evaluation data directly from referees, often in the form of ranking. This study uses two additional...

  14. Estimation of rank correlation for clustered data.

    Science.gov (United States)

    Rosner, Bernard; Glynn, Robert J

    2017-06-30

    It is well known that the sample correlation coefficient (Rxy ) is the maximum likelihood estimator of the Pearson correlation (ρxy ) for independent and identically distributed (i.i.d.) bivariate normal data. However, this is not true for ophthalmologic data where X (e.g., visual acuity) and Y (e.g., visual field) are available for each eye and there is positive intraclass correlation for both X and Y in fellow eyes. In this paper, we provide a regression-based approach for obtaining the maximum likelihood estimator of ρxy for clustered data, which can be implemented using standard mixed effects model software. This method is also extended to allow for estimation of partial correlation by controlling both X and Y for a vector U_ of other covariates. In addition, these methods can be extended to allow for estimation of rank correlation for clustered data by (i) converting ranks of both X and Y to the probit scale, (ii) estimating the Pearson correlation between probit scores for X and Y, and (iii) using the relationship between Pearson and rank correlation for bivariate normally distributed data. The validity of the methods in finite-sized samples is supported by simulation studies. Finally, two examples from ophthalmology and analgesic abuse are used to illustrate the methods. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Higher-rank fields and currents

    Energy Technology Data Exchange (ETDEWEB)

    Gelfond, O.A. [Institute of System Research of Russian Academy of Sciences,Nakhimovsky prospect 36-1, 117218, Moscow (Russian Federation); I.E.Tamm Department of Theoretical Physics, Lebedev Physical Institute,Leninsky prospect 53, 119991, Moscow (Russian Federation); Vasiliev, M.A. [I.E.Tamm Department of Theoretical Physics, Lebedev Physical Institute,Leninsky prospect 53, 119991, Moscow (Russian Federation)

    2016-10-13

    Sp(2M) invariant field equations in the space M{sub M} with symmetric matrix coordinates are classified. Analogous results are obtained for Minkowski-like subspaces of M{sub M} which include usual 4d Minkowski space as a particular case. The constructed equations are associated with the tensor products of the Fock (singleton) representation of Sp(2M) of any rank r. The infinite set of higher-spin conserved currents multilinear in rank-one fields in M{sub M} is found. The associated conserved charges are supported by (rM−((r(r−1))/2))-dimensional differential forms in M{sub M}, that are closed by virtue of the rank-2r field equations. The cohomology groups H{sup p}(σ{sub −}{sup r}) with all p and r, which determine the form of appropriate gauge fields and their field equations, are found both for M{sub M} and for its Minkowski-like subspace.

  16. Association between Metabolic Syndrome and Job Rank.

    Science.gov (United States)

    Mehrdad, Ramin; Pouryaghoub, Gholamreza; Moradi, Mahboubeh

    2018-01-01

    The occupation of the people can influence the development of metabolic syndrome. To determine the association between metabolic syndrome and its determinants with the job rank in workers of a large car factory in Iran. 3989 male workers at a large car manufacturing company were invited to participate in this cross-sectional study. Demographic and anthropometric data of the participants, including age, height, weight, and abdominal circumference were measured. Blood samples were taken to measure lipid profile and blood glucose level. Metabolic syndrome was diagnosed in each participant based on ATPIII 2001 criteria. The workers were categorized based on their job rank into 3 groups of (1) office workers, (2) workers with physical exertion, and (3) workers with chemical exposure. The study characteristics, particularly the frequency of metabolic syndrome and its determinants were compared among the study groups. The prevalence of metabolic syndrome in our study was 7.7% (95% CI 6.9 to 8.5). HDL levels were significantly lower in those who had chemical exposure (p=0.045). Diastolic blood pressure was significantly higher in those who had mechanical exertion (p=0.026). The frequency of metabolic syndrome in the office workers, workers with physical exertion, and workers with chemical exposure was 7.3%, 7.9%, and 7.8%, respectively (p=0.836). Seemingly, there is no association between metabolic syndrome and job rank.

  17. [Ranke and modern surgery in Groningen].

    Science.gov (United States)

    van Gijn, Jan; Gijselhart, Joost P

    2012-01-01

    Hans Rudolph Ranke (1849-1887) studied medicine in Halle, located in the eastern part of Germany, where he also trained as a surgeon under Richard von Volkmann (1830-1889), during which time he became familiar with the new antiseptic technique that had been introduced by Joseph Lister (1827-1912). In 1878 he was appointed head of the department of surgery in Groningen, the Netherlands, where his predecessor had been chronically indisposed and developments were flagging. Within a few months, Ranke had introduced disinfection by using carbolic acid both before and during operations. For the disinfection of wound dressings, he replaced carbolic acid with thymol as this was less pungent and foul-smelling. The rate of postoperative infections dropped to a minimum despite the inadequate housing and living conditions of the patients with infectious diseases. In 1887, at the age of 37, Ranke died after a brief illness - possibly glomerulonephritis - only eight years after he had assumed office. A street in the city of Groningen near its present-day University Medical Centre has been named after him.

  18. Ranking agility factors affecting hospitals in Iran

    Directory of Open Access Journals (Sweden)

    M. Abdi Talarposht

    2017-04-01

    Full Text Available Background: Agility is an effective response to the changing and unpredictable environment and using these changes as opportunities for organizational improvement. Objective: The aim of the present study was to rank the factors affecting agile supply chain of hospitals of Iran. Methods: This applied study was conducted by cross sectional-descriptive method at some point of 2015 for one year. The research population included managers, administrators, faculty members and experts were selected hospitals. A total of 260 people were selected as sample from the health centers. The construct validity of the questionnaire was approved by confirmatory factor analysis test and its reliability was approved by Cronbach's alpha (α=0.97. All data were analyzed by Kolmogorov-Smirnov, Chi-square and Friedman tests. Findings: The development of staff skills, the use of information technology, the integration of processes, appropriate planning, and customer satisfaction and product quality had a significant impact on the agility of public hospitals of Iran (P<0.001. New product introductions had earned the highest ranking and the development of staff skills earned the lowest ranking. Conclusion: The new product introduction, market responsiveness and sensitivity, reduce costs, and the integration of organizational processes, ratings better to have acquired agility hospitals in Iran. Therefore, planners and officials of hospitals have to, through the promotion quality and variety of services customer-oriented, providing a basis for investing in the hospital and etc to apply for agility supply chain public hospitals of Iran.

  19. Preparation and high-performance microwave absorption of hierarchical dendrite-like Co superstructures self-assembly of nanoflakes

    Science.gov (United States)

    Yu, Miao; Wang, Lirui; Yang, Pingan; Fu, Jie

    2017-12-01

    Dendritic-like Co superstructures based on the self-assembly of nanoflakes that could efficiently suppress the eddy current were successfully synthesized via a facile, rapid, and energy-saving chemical reduction method. Since crystal structure, size, and special geometrical morphology, magnetism have a vital influence on microwave absorption properties, the as-obtained products were characterized by x-ray diffraction, scanning electron microscopy, vibrating sample magnetometry, and vector network analysis. The prepared dendritic Co possesses abundant secondary branches that extend to the 3D space. Their dimensions, spacing, sheet-like blocks, and high-ordering microstructures all contribute to the penetration, scattering, and attenuation of EM waves. The composites present attractive microwave absorption performances in the X band, as well as in the whole S band (2–4 GHz). This work investigates the mechanism of absorption for the as-obtained Co, offers a promising strategy for the fabrication of hierarchical Co microstructure assemblies by multi-leaf flakes and introduces the application of dendritic-like Co as a highly efficient absorber in the S band and X band.

  20. Ranking Fuzzy Numbers and Its Application to Products Attributes Preferences

    OpenAIRE

    Lazim Abdullah; Nor Nashrah Ahmad Fauzee

    2011-01-01

    Ranking is one of the widely used methods in fuzzy decision making environment. The recent ranking fuzzy numbers proposed by Wang and Li is claimed to be the improved version in ranking. However, the method was never been simplified and tested in real life application. This paper presents a four-step computation of ranking fuzzy numbers and its application in ranking attributes of selected chocolate products.  The four steps algorithm was formulated to rank fuzzy numbers and followed by a tes...

  1. Electronic structure of metastable bcc Cu-Cr alloy thin films: Comparison of electron energy-loss spectroscopy and first-principles calculations.

    Science.gov (United States)

    Liebscher, C H; Freysoldt, C; Dennenwaldt, T; Harzer, T P; Dehm, G

    2017-07-01

    Metastable Cu-Cr alloy thin films with nominal thickness of 300nm and composition of Cu67Cr33 (at%) are obtained by co-evaporation using molecular beam epitaxy. The microstructure, chemical phase separation and electronic structure are investigated by transmission electron microscopy (TEM). The thin film adopts the body-centered cubic crystal structure and consists of columnar grains with ~50nm diameter. Aberration-corrected scanning TEM in combination with energy dispersive X-ray spectroscopy confirms compositional fluctuations within the grains. Cu- and Cr-rich domains with composition of Cu85Cr15 (at%) and Cu42Cr58 (at%) and domain size of 1-5nm are observed. The alignment of the interface between the Cu- and Cr-rich domains shows a preference for {110}-type habit plane. The electronic structure of the Cu-Cr thin films is investigated by electron energy loss spectroscopy (EELS) and is contrasted to an fcc-Cu reference sample. The experimental EEL spectra are compared to spectra computed by density functional theory. The main differences between bcc-and fcc-Cu are related to differences in van Hove singularities in the electron density of states. In Cu-Cr solid solutions with bcc crystal structure a single peak after the L3-edge, corresponding to a van Hove singularity at the N-point of the first Brillouin zone is observed. Spectra computed for pure bcc-Cu and random Cu-Cr solid solutions with 10at% Cr confirm the experimental observations. The calculated spectrum for a perfect Cu50Cr50 (at%) random structure shows a shift in the van Hove singularity towards higher energy by developing a Cu-Cr d-band that lies between the delocalized d-bands of Cu and Cr. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Ranking U-Sapiens 2010-2

    Directory of Open Access Journals (Sweden)

    Carlos-Roberto Peña-Barrera

    2011-08-01

    Full Text Available Los principales objetivos de esta investigación son los siguientes: (1 que la comunidad científica nacional e internacional y la sociedad en general co-nozcan los resultados del Ranking U-Sapiens Colombia 2010_2, el cual clasifica a cada institución de educación superior colombiana según puntaje, posición y cuartil; (2 destacar los movimientos más importantes al comparar los resultados del ranking 2010_1 con los del 2010_2; (3 publicar las respuestas de algunos actores de la academia nacional con respecto a la dinámica de la investigación en el país; (4 reconocer algunas instituciones, medios de comunicación e investigadores que se han interesado a modo de reflexión, referenciación o citación por esta investigación; y (5 dar a conocer el «Sello Ranking U-Sapiens Colombia» para las IES clasificadas. El alcance de este estudio en cuanto a actores abordó todas y cada una de las IES nacionales (aunque solo algunas lograran entrar al ranking y en cuanto a tiempo, un periodo referido al primer semestre de 2010 con respecto a: (1 los resultados 2010-1 de revistas indexadas en Publindex, (2 los programas de maestrías y doctorados activos durante 2010-1 según el Ministerio de Educación Nacional, y (3 los resultados de grupos de investigación clasificados para 2010 según Colciencias. El método empleado para esta investigación es el mismo que para el ranking 2010_1, salvo por una especificación aún más detallada en uno de los pasos del modelo (las variables α, β, γ; es completamente cuantitativo y los datos de las variables que fundamentan sus resultados provienen de Colciencias y el Ministerio de Educación Nacional; y en esta ocasión se darán a conocer los resultados por variable para 2010_1 y 2010_2. Los resultados más relevantes son estos: (1 entraron 8 IES al ranking y salieron 3; (2 las 3 primeras IES son públicas; (3 en total hay 6 instituciones universitarias en el ranking; (4 7 de las 10 primeras IES son

  3. Surface reconstruction of clean bcc-Fe{1 1 0}: A quasi-hexagonal top-layer with periodic height modulation

    Science.gov (United States)

    Yamada, T. K.; Tamura, H.; Shishido, M.; Irisawa, T.; Mizoguchi, T.

    2009-01-01

    Hexagonal-pillar shaped pure Fe single crystal whiskers with six {1 1 0} side planes were obtained by means of chemical vapor deposition. Atomically resolved scanning tunneling microscopy images obtained on the {1 1 0} surface showed a quasi-hexagonal atomic array with mesoscopic-range periodic height modulation of about 1/3 of an atomic step. This height modulation was found to be a result of an interference between the quasi-hexagonal top-layer and the sub-surface bcc-Fe{1 1 0} layer. Unit vectors of the mesoscopic-range modulation turned out to be expressed as

  4. Effects of PEO-PPO diblock impurities on the cubic structure of aqueous PEO-PPO-PEO pluronics micelles: fcc and bcc ordered structures in F127

    DEFF Research Database (Denmark)

    Mortensen, Kell; Pedersen, Walther Batsberg; Hvidt, S.

    2008-01-01

    We report on structural properties of PEO-PPO-PEO type of triblock block copolymers (Pluronics F127) with special emphasis on the effect of diblock PEO-PPO impurities on the ordered gel phase. Commercial F127 polymers contain as received roughly 20% PEO-PPO diblock and 80% PEO-PPO-PEO triblock...... copolymers. Aqueous solutions of F127 copolymers used as received form fee ordered micellar structure. Copolymers depleted with respect to the diblock impurity, resulting in a pure PEO-PPO-PEO triblock copolymer system, form bcc ordered micelles within the major parts of the gel phase. However, close...

  5. Electronic structure of metastable bcc Cu–Cr alloy thin films: Comparison of electron energy-loss spectroscopy and first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Liebscher, C.H.; Freysoldt, C. [Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf (Germany); Dennenwaldt, T. [Institute of Condensed Matter Physics and Interdisciplinary Center for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland); Harzer, T.P.; Dehm, G. [Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf (Germany)

    2017-07-15

    Metastable Cu–Cr alloy thin films with nominal thickness of 300 nm and composition of Cu{sub 67}Cr{sub 33} (at%) are obtained by co-evaporation using molecular beam epitaxy. The microstructure, chemical phase separation and electronic structure are investigated by transmission electron microscopy (TEM). The thin film adopts the body-centered cubic crystal structure and consists of columnar grains with ~50 nm diameter. Aberration-corrected scanning TEM in combination with energy dispersive X-ray spectroscopy confirms compositional fluctuations within the grains. Cu- and Cr-rich domains with composition of Cu{sub 85}Cr{sub 15} (at%) and Cu{sub 42}Cr{sub 58} (at%) and domain size of 1–5 nm are observed. The alignment of the interface between the Cu- and Cr-rich domains shows a preference for {110}-type habit plane. The electronic structure of the Cu–Cr thin films is investigated by electron energy loss spectroscopy (EELS) and is contrasted to an fcc-Cu reference sample. The experimental EEL spectra are compared to spectra computed by density functional theory. The main differences between bcc-and fcc-Cu are related to differences in van Hove singularities in the electron density of states. In Cu–Cr solid solutions with bcc crystal structure a single peak after the L{sub 3}-edge, corresponding to a van Hove singularity at the N-point of the first Brillouin zone is observed. Spectra computed for pure bcc-Cu and random Cu–Cr solid solutions with 10 at% Cr confirm the experimental observations. The calculated spectrum for a perfect Cu{sub 50}Cr{sub 50} (at%) random structure shows a shift in the van Hove singularity towards higher energy by developing a Cu–Cr d-band that lies between the delocalized d-bands of Cu and Cr. - Highlights: • Compositional fluctuations on the order of 1–5 nm in Cu- and Cr-rich domains are observed. • EELS determines a single van Hove singularity for bcc Cu–Cr solid solutions. • The electronic structure is dominated by d

  6. Ranking the Online Documents Based on Relative Credibility Measures

    Directory of Open Access Journals (Sweden)

    Ahmad Dahlan

    2009-05-01

    Full Text Available Information searching is the most popular activity in Internet. Usually the search engine provides the search results ranked by the relevance. However, for a certain purpose that concerns with information credibility, particularly citing information for scientific works, another approach of ranking the search engine results is required. This paper presents a study on developing a new ranking method based on the credibility of information. The method is built up upon two well-known algorithms, PageRank and Citation Analysis. The result of the experiment that used Spearman Rank Correlation Coefficient to compare the proposed rank (generated by the method with the standard rank (generated manually by a group of experts showed that the average Spearman 0 < rS < critical value. It means that the correlation was proven but it was not significant. Hence the proposed rank does not satisfy the standard but the performance could be improved.

  7. Ranking the Online Documents Based on Relative Credibility Measures

    Directory of Open Access Journals (Sweden)

    Ahmad Dahlan

    2013-09-01

    Full Text Available Information searching is the most popular activity in Internet. Usually the search engine provides the search results ranked by the relevance. However, for a certain purpose that concerns with information credibility, particularly citing information for scientific works, another approach of ranking the search engine results is required. This paper presents a study on developing a new ranking method based on the credibility of information. The method is built up upon two well-known algorithms, PageRank and Citation Analysis. The result of the experiment that used Spearman Rank Correlation Coefficient to compare the proposed rank (generated by the method with the standard rank (generated manually by a group of experts showed that the average Spearman 0 < rS < critical value. It means that the correlation was proven but it was not significant. Hence the proposed rank does not satisfy the standard but the performance could be improved.

  8. On the Nonnegative Rank of Euclidean Distance Matrices.

    Science.gov (United States)

    Lin, Matthew M; Chu, Moody T

    2010-09-01

    The Euclidean distance matrix for n distinct points in ℝ r is generically of rank r + 2. It is shown in this paper via a geometric argument that its nonnegative rank for the case r = 1 is generically n.

  9. Global Low-Rank Image Restoration With Gaussian Mixture Model.

    Science.gov (United States)

    Zhang, Sibo; Jiao, Licheng; Liu, Fang; Wang, Shuang

    2017-06-27

    Low-rank restoration has recently attracted a lot of attention in the research of computer vision. Empirical studies show that exploring the low-rank property of the patch groups can lead to superior restoration performance, however, there is limited achievement on the global low-rank restoration because the rank minimization at image level is too strong for the natural images which seldom match the low-rank condition. In this paper, we describe a flexible global low-rank restoration model which introduces the local statistical properties into the rank minimization. The proposed model can effectively recover the latent global low-rank structure via nuclear norm, as well as the fine details via Gaussian mixture model. An alternating scheme is developed to estimate the Gaussian parameters and the restored image, and it shows excellent convergence and stability. Besides, experiments on image and video sequence datasets show the effectiveness of the proposed method in image inpainting problems.

  10. Algebraic and computational aspects of real tensor ranks

    CERN Document Server

    Sakata, Toshio; Miyazaki, Mitsuhiro

    2016-01-01

    This book provides comprehensive summaries of theoretical (algebraic) and computational aspects of tensor ranks, maximal ranks, and typical ranks, over the real number field. Although tensor ranks have been often argued in the complex number field, it should be emphasized that this book treats real tensor ranks, which have direct applications in statistics. The book provides several interesting ideas, including determinant polynomials, determinantal ideals, absolutely nonsingular tensors, absolutely full column rank tensors, and their connection to bilinear maps and Hurwitz-Radon numbers. In addition to reviews of methods to determine real tensor ranks in details, global theories such as the Jacobian method are also reviewed in details. The book includes as well an accessible and comprehensive introduction of mathematical backgrounds, with basics of positive polynomials and calculations by using the Groebner basis. Furthermore, this book provides insights into numerical methods of finding tensor ranks through...

  11. Implicit Block Diagonal Low-Rank Representation.

    Science.gov (United States)

    Xie, Xingyu; Guo, Xianglin; Liu, Guangcan; Wang, Jun

    2017-10-17

    While current block diagonal constrained subspace clustering methods are performed explicitly on the original data space, in practice it is often more desirable to embed the block diagonal prior into the reproducing kernel Hilbert feature space by kernelization techniques, as the underlying data structure in reality is usually nonlinear. However, it is still unknown how to carry out the embedding and kernelization in the models with block diagonal constraints. In this work, we shall take a step in this direction. First, we establish a novel model termed Implicit Block Diagonal Low-Rank Representation (IBDLR), by incorporating the implicit feature representation and block diagonal prior into the prevalent Low-Rank Representation (LRR) method. Second, mostly important, we show that the model in IBDLR could be kernelized by making use of a smoothed dual representation and the specifics of a proximal gradient based optimization algorithm. Finally, we provide some theoretical analyses for the convergence of our optimization algorithm. Comprehensive experiments on synthetic and realworld datasets demonstrate the superiorities of our IBDLR over state-of-the-art methods.While current block diagonal constrained subspace clustering methods are performed explicitly on the original data space, in practice it is often more desirable to embed the block diagonal prior into the reproducing kernel Hilbert feature space by kernelization techniques, as the underlying data structure in reality is usually nonlinear. However, it is still unknown how to carry out the embedding and kernelization in the models with block diagonal constraints. In this work, we shall take a step in this direction. First, we establish a novel model termed Implicit Block Diagonal Low-Rank Representation (IBDLR), by incorporating the implicit feature representation and block diagonal prior into the prevalent Low-Rank Representation (LRR) method. Second, mostly important, we show that the model in IBDLR could be

  12. Tecer sobe no ranking da Capes

    Directory of Open Access Journals (Sweden)

    José Aparecido

    2013-11-01

    Full Text Available Surpresa ainda maior foi verificar que prosseguimos no rumo da consolidação, crescendo no ranking – chegando a B3 em alguns campos, como pode ser visto no portal de buscas do Qualis Capes http://qualis.capes.gov.br/webqualis/principal.seamhttp://qualis.capes.gov, que apresenta nossa classificação abaixo:   B3 ADMINISTRAÇÃO, CIÊNCIAS CONTÁBEIS E TURISMO B4 CIÊNCIAS SOCIAIS APLICADAS I B4 EDUCAÇÃO B4 INTERDISCIPLINAR B5 DIREITO B5 HISTÓRIA C CIÊNCIA DA COMPUTAÇÃO

  13. On Stein's unbiased risk estimate for reduced rank estimators

    DEFF Research Database (Denmark)

    Hansen, Niels Richard

    2018-01-01

    Stein's unbiased risk estimate (SURE) is considered for matrix valued observables with low rank means. It is shown that SURE is applicable to a class of spectral function estimators including the reduced rank estimator.......Stein's unbiased risk estimate (SURE) is considered for matrix valued observables with low rank means. It is shown that SURE is applicable to a class of spectral function estimators including the reduced rank estimator....

  14. A study of serial ranks via random graphs

    OpenAIRE

    Haeusler, Erich; Mason, David M.; Turova, Tatyana S.

    2000-01-01

    Serial ranks have long been used as the basis for nonparametric tests of independence in time series analysis. We shall study the underlying graph structure of serial ranks. This will lead us to a basic martingale which will allow us to construct a weighted approximation to a serial rank process. To show the applicability of this approximation, we will use it to prove two very general central limit theorems for Wald-Wolfowitz-type serial rank statistics.

  15. Do PageRank-based author rankings outperform simple citation counts?

    CERN Document Server

    Fiala, Dalibor; Žitnik, Slavko; Bajec, Marko

    2015-01-01

    The basic indicators of a researcher's productivity and impact are still the number of publications and their citation counts. These metrics are clear, straightforward, and easy to obtain. When a ranking of scholars is needed, for instance in grant, award, or promotion procedures, their use is the fastest and cheapest way of prioritizing some scientists over others. However, due to their nature, there is a danger of oversimplifying scientific achievements. Therefore, many other indicators have been proposed including the usage of the PageRank algorithm known for the ranking of webpages and its modifications suited to citation networks. Nevertheless, this recursive method is computationally expensive and even if it has the advantage of favouring prestige over popularity, its application should be well justified, particularly when compared to the standard citation counts. In this study, we analyze three large datasets of computer science papers in the categories of artificial intelligence, software engineering,...

  16. Tumor thickness and adnexal extension of superficial basal cell carcinoma (sBCC) as determinants of treatment failure for methylaminolevulinate (MAL)-photodynamic therapy (PDT), imiquimod, and 5-fluorouracil (FU).

    Science.gov (United States)

    Roozeboom, Marieke H; van Kleef, Lotte; Arits, Aimee H M M; Mosterd, Klara; Winnepenninckx, Veronique J L; van Marion, Arienne M W; Nelemans, Patty J; Kelleners-Smeets, Nicole W J

    2015-07-01

    Noninvasive treatments are frequently used in treatment of superficial basal cell carcinoma (sBCC) because of better cosmetic results, lower costs, and less burden on health care services when compared with surgical excision. However, probability of treatment failure is higher after noninvasive therapies and may depend on histologic tumor characteristics. We sought to investigate whether tumor thickness and adnexal extension are determinants of treatment failure in sBCC treated with topical methylaminolevulinate-photodynamic therapy, imiquimod, or 5-fluorouracil. Data were derived from a randomized controlled trial on the effectiveness of methylaminolevulinate photodynamic therapy, imiquimod, and 5-fluorouracil for treatment of sBCC (ISRCTN79701845). For tumors with treatment failure (n = 112) and a randomly selected control group of tumors without treatment failure (n = 224) data on tumor thickness and adnexal extension were retrospectively collected. Treatment failure was defined as a clinically and histologically persistent or recurrent tumor within 1-year posttreatment. Tumor thickness of included patients ranged from 0.2 to 1.0 mm. Tumor thickness and adnexal extension of sBCC were not significantly associated with treatment failure of methylaminolevulinate photodynamic therapy, imiquimod, or 5-fluorouracil. Follow-up period of 1 year is a limitation. There seems to be no need to determine tumor thickness or adnexal extension in sBCC before treatment. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  17. an investigation into n investigation into index ranking technique for ...

    African Journals Online (AJOL)

    eobe

    The study shows that the utility of the ranking technique may be limited by em. Therefore users of the technique for ranking fuzzy numbers have to maker, risk attitude, critical path, total float ranking s usually faced with a ully managing projects. The th project management is vities in the project have the activity times in the.

  18. Variation in rank abundance replicate samples and impact of clustering

    NARCIS (Netherlands)

    Neuteboom, J.H.; Struik, P.C.

    2005-01-01

    Calculating a single-sample rank abundance curve by using the negative-binomial distribution provides a way to investigate the variability within rank abundance replicate samples and yields a measure of the degree of heterogeneity of the sampled community. The calculation of the single-sample rank

  19. PageRank in scale-free random graphs

    NARCIS (Netherlands)

    Chen, Ningyuan; Litvak, Nelli; Olvera-Cravioto, Mariana; Bonata, Anthony; Chung, Fan; Pralat, Paweł

    2014-01-01

    We analyze the distribution of PageRank on a directed configuration model and show that as the size of the graph grows to infinity, the PageRank of a randomly chosen node can be closely approximated by the PageRank of the root node of an appropriately constructed tree. This tree approximation is in

  20. Tutorial: Calculating Percentile Rank and Percentile Norms Using SPSS

    Science.gov (United States)

    Baumgartner, Ted A.

    2009-01-01

    Practitioners can benefit from using norms, but they often have to develop their own percentile rank and percentile norms. This article is a tutorial on how to quickly and easily calculate percentile rank and percentile norms using SPSS, and this information is presented for a data set. Some issues in calculating percentile rank and percentile…

  1. University Rankings 2.0: New Frontiers in Institutional Comparisons

    Science.gov (United States)

    Usher, Alex

    2009-01-01

    The number of university rankings systems in use around the world has increased dramatically over the last decade. As they have spread, they have mutated; no longer are ranking systems simply clones of the original ranking systems such as "US News" and "World Report". A number of different types of "mutation" have occurred, so that there are now…

  2. Ranking Scholarly Publishers in Political Science: An Alternative Approach

    Science.gov (United States)

    Garand, James C.; Giles, Micheal W.

    2011-01-01

    Previous research has documented how political scientists evaluate and rank scholarly journals, but the evaluation and ranking of scholarly book publishers has drawn less attention. In this article, we use data from a survey of 603 American political scientists to generate a ranking of scholarly publishers in political science. We used open-ended…

  3. Ranking Quality in Higher Education: Guiding or Misleading?

    Science.gov (United States)

    Bergseth, Brita; Petocz, Peter; Abrandt Dahlgren, Madeleine

    2014-01-01

    The study examines two different models of measuring, assessing and ranking quality in higher education. Do different systems of quality assessment lead to equivalent conclusions about the quality of education? This comparative study is based on the rankings of 24 Swedish higher education institutions. Two ranking actors have independently…

  4. Cardinal priority ranking based decision making for economic ...

    African Journals Online (AJOL)

    To access the indifference band, interaction with the decision maker is obtained via cardinal priority ranking (CPR) of the objectives. The cardinal priority ranking is constructed in the functional space and then transformed into the decision space, so the cardinal priority ranking of objectives relate the decision maker's ...

  5. A Fast Algorithm for Generating Permutation Distribution of Ranks in ...

    African Journals Online (AJOL)

    ... function of the distribution of the ranks. This further gives insight into the permutation distribution of a rank statistics. The algorithm is implemented with the aid of the computer algebra system Mathematica. Key words: Combinatorics, generating function, permutation distribution, rank statistics, partitions, computer algebra.

  6. Calibrating Canadian Universities: Rankings for Sale Once Again

    Science.gov (United States)

    Cramer, Kenneth M.; Page, Stewart

    2007-01-01

    A summary and update on recent research by the authors and others concerning rankings of Canadian universities is presented. Some specific data are reported in regard to the 2005 and 2006 ranking data published by "Maclean's" magazine. Some criticisms and difficulties with the use of rank-based data are outlined with regard to the issues…

  7. Higher Education Ranking and Leagues Tables: Lessons Learned from Benchmarking

    Science.gov (United States)

    Proulx, Roland

    2007-01-01

    The paper intends to contribute to the debate on ranking and league tables by adopting a critical approach to ranking methodologies from the point of view of a university benchmarking exercise. The absence of a strict benchmarking exercise in the ranking process has been, in the opinion of the author, one of the major problems encountered in the…

  8. Synthesis of Partial Rankings of Points of Interest Using Crowdsourcing

    DEFF Research Database (Denmark)

    Keles, Ilkcan; Saltenis, Simonas; Jensen, Christian Søndergaard

    2015-01-01

    to the query keywords and the query location. A key challenge in being able to make progress on the design of ranking functions is to be able to assess the quality of the results returned by ranking functions. We propose a model that synthesizes a ranking of points of interest from answers to crowdsourced...

  9. Fuzzy Multicriteria Ranking of Aluminium Coating Methods

    Science.gov (United States)

    Batzias, A. F.

    2007-12-01

    This work deals with multicriteria ranking of aluminium coating methods. The alternatives used are: sulfuric acid anodization, A1; oxalic acid anodization, A2; chromic acid anodization, A3; phosphoric acid anodization, A4; integral color anodizing, A5; chemical conversion coating, A6; electrostatic powder deposition, A7. The criteria used are: cost of production, f1; environmental friendliness of production process, f2; appearance (texture), f3; reflectivity, f4; response to coloring, f5; corrosion resistance, f6; abrasion resistance, f7; fatigue resistance, f8. Five experts coming from relevant industrial units set grades to the criteria vector and the preference matrix according to a properly modified Delphi method. Sensitivity analysis of the ranked first alternative A1 against the `second best', which was A3 at low and A7 at high resolution levels proved that the solution is robust. The dependence of anodized products quality on upstream processes is presented and the impact of energy price increase on industrial cost is discussed.

  10. Rank order scaling of pictorial depth.

    Science.gov (United States)

    van Doorn, Andrea; Koenderink, Jan; Wagemans, Johan

    2011-01-01

    We address the topic of "pictorial depth" in cases of pictures that are unlike photographic renderings. The most basic measure of "depth" is no doubt that of depth order. We establish depth order through the pairwise depth-comparison method, involving all pairs from a set of 49 fiducial points. The pictorial space for this study was evoked by a capriccio (imaginary landscape) by Francesco Guardi (1712-1793). In such a drawing pictorial space is suggested by the artist through a small set of conventional depth cues. As a result typical Western observers tend to agree largely in their visual awareness when looking at such art. We rank depths for locations that are not on a single surface and far apart in pictorial space. We find that observers resolve about 40 distinct depth layers and agree largely in this. From a previous experiment we have metrical data for the same observers. The rank correlations between the results are high. Perhaps surprisingly, we find no correlation between the number of distinct depth layers and the total metrical depth range. Thus, the relation between subjective magnitude and discrimination threshold fails to hold for pictorial depth.

  11. Condensing biomedical journal texts through paragraph ranking.

    Science.gov (United States)

    Chiang, Jung-Hsien; Liu, Heng-Hui; Huang, Yi-Ting

    2011-04-15

    The growing availability of full-text scientific articles raises the important issue of how to most efficiently digest full-text content. Although article titles and abstracts provide accurate and concise information on an article's contents, their brevity inevitably entails the loss of detail. Full-text articles provide those details, but require more time to read. The primary goal of this study is to combine the advantages of concise abstracts and detail-rich full-texts to ease the burden of reading. We retrieved abstract-related paragraphs from full-text articles through shared keywords between the abstract and paragraphs from the main text. Significant paragraphs were then recommended by applying a proposed paragraph ranking approach. Finally, the user was provided with a condensed text consisting of these significant paragraphs, allowing the user to save time from perusing the whole article. We compared the performance of the proposed approach with a keyword counting approach and a PageRank-like approach. Evaluation was conducted in two aspects: the importance of each retrieved paragraph and the information coverage of a set of retrieved paragraphs. In both evaluations, the proposed approach outperformed the other approaches. jchiang@mail.ncku.edu.tw.

  12. Rank hypocrisies the insult of the REF

    CERN Document Server

    Sayer, Derek

    2015-01-01

    "The REF is right out of Havel's and Kundera's Eastern Europe: a state-administered exercise to rank academic research like hotel chains dependent on the active collaboration of the UK professoriate. In crystalline text steeped in cold rage, Sayer takes aim at the REF's central claim, that it is a legitimate process of expert peer review. He critiques university and national-level REF processes against actual practices of scholarly review as found in academic journals, university presses, and North American tenure procedures. His analysis is damning. If the REF fails as scholarly review, how can academics and universities continue to participate? And how can government use its rankings as a basis for public policy?" - Tarak Barkawi, Reader in the Department of International Relations, London School of Economics "Many academics across the world have come to see the REF as an arrogant attempt to raise national research standards that has resulted in a variety of self-inflicted wounds to UK higher education. Der...

  13. Ginzburg-Landau theory for the solid-liquid interface of bcc elements. II - Application to the classical one-component plasma, the Wigner crystal, and He-4

    Science.gov (United States)

    Zeng, X. C.; Stroud, D.

    1989-01-01

    The previously developed Ginzburg-Landau theory for calculating the crystal-melt interfacial tension of bcc elements to treat the classical one-component plasma (OCP), the charged fermion system, and the Bose crystal. For the OCP, a direct application of the theory of Shih et al. (1987) yields for the surface tension 0.0012(Z-squared e-squared/a-cubed), where Ze is the ionic charge and a is the radius of the ionic sphere. Bose crystal-melt interface is treated by a quantum extension of the classical density-functional theory, using the Feynman formalism to estimate the relevant correlation functions. The theory is applied to the metastable He-4 solid-superfluid interface at T = 0, with a resulting surface tension of 0.085 erg/sq cm, in reasonable agreement with the value extrapolated from the measured surface tension of the bcc solid in the range 1.46-1.76 K. These results suggest that the density-functional approach is a satisfactory mean-field theory for estimating the equilibrium properties of liquid-solid interfaces, given knowledge of the uniform phases.

  14. Modification of culture conditions for production of the anti-tubercular hirsutellones by the insect pathogenic fungus Hirsutella nivea BCC 2594.

    Science.gov (United States)

    Madla, S; Isaka, M; Wongsa, P

    2008-08-01

    This work aimed to improve the production of anti-tubercular hirsutellones by the insect pathogenic fungus Hirsutella nivea BCC 2594. The fungus was cultivated under different carbon/nitrogen sources and aerations (shake vs static flasks) to improve the production of the anti-tubercular alkaloids, hirsutellones A-D. Under the basal conditions, static cultivation at 25 degrees C in minimum salt medium, only hirsutellone B and C were detected with maximum concentrations of 139.00 and 18.27 mg l(-1). Substitution of fructose for glucose and peptone for yeast extract increased the titres of hirsutellones A, B and C about two- to threefold. However, hirsutellone D was not detected in this medium. Culture agitation induced the production of hirsutellone D. As a result, the significant amounts of hirsutellones A-D were obtained with the concentration of 29.93, 169.63, 22.65 and 15.71 mg l(-1) within 15 days. Improved titres of hirsutellones in H. nivea BCC 2549 were achieved with an agitated (200 rev min(-1)) fructose-peptone medium at 25 degrees C. Improved yields of hirsutellones B-D will enable medicinal chemistry modifications leading to a development of a potential candidate for tuberculosis therapy.

  15. Partial Kernelization for Rank Aggregation: Theory and Experiments

    Science.gov (United States)

    Betzler, Nadja; Bredereck, Robert; Niedermeier, Rolf

    Rank Aggregation is important in many areas ranging from web search over databases to bioinformatics. The underlying decision problem Kemeny Score is NP-complete even in case of four input rankings to be aggregated into a "median ranking". We study efficient polynomial-time data reduction rules that allow us to find optimal median rankings. On the theoretical side, we improve a result for a "partial problem kernel" from quadratic to linear size. On the practical side, we provide encouraging experimental results with data based on web search and sport competitions, e.g., computing optimal median rankings for real-world instances with more than 100 candidates within milliseconds.

  16. Efficient visible light photocatalytic NO{sub x} removal with cationic Ag clusters-grafted (BiO){sub 2}CO{sub 3} hierarchical superstructures

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xin [Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, College of Environment and Resources, Engineering Research Center for Waste Oil Recovery Technology and Equipment of Ministry of Education, College of Environment and Resources, Chongqing Technology and Business University, Chongqing 40067 (China); Zhang, Wendong [Department of Scientific Research Management, Chongqing Normal University, Chongqing 401331 (China); Deng, Hua [State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Ni, Zilin [Department of Scientific Research Management, Chongqing Normal University, Chongqing 401331 (China); Dong, Fan, E-mail: dfctbu@126.com [Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, College of Environment and Resources, Engineering Research Center for Waste Oil Recovery Technology and Equipment of Ministry of Education, College of Environment and Resources, Chongqing Technology and Business University, Chongqing 40067 (China); Zhang, Yuxin, E-mail: zhangyuxin@cqu.edu.cn [College of Materials Science and Engineering, National Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology, Chongqing University, Chongqing 400044 (China)

    2017-01-15

    Graphical abstract: The cationic Ag clusters-grafted (BiO){sub 2}CO{sub 3} hierarchical superstructures exhibits highly enhanced visible light photocatalytic air purification through an interfacial charge transfer process induced by Ag clusters. - Highlights: • Microstructural optimization and surface cluster-grafting were firstly combined. • Cationic Ag clusters were grafted on the surface of (BiO){sub 2}CO{sub 3} superstructures. • The Ag clusters-grafted BHS displayed enhanced visible light photocatalysis. • Direct interfacial charge transfer (IFCT) from BHS to Ag clusters was proposed. • The charge transfer process and the dominant reactive species were revealed. - Abstract: A facile method was developed to graft cationic Ag clusters on (BiO){sub 2}CO{sub 3} hierarchical superstructures (BHS) surface to improve their visible light activity. Significantly, the resultant Ag clusters-grafted BHS displayed a highly enhanced visible light photocatalytic performance for NOx removal due to the direct interfacial charge transfer (IFCT) from BHS to Ag clusters. The chemical and coordination state of the cationic Ag clusters was determined with the extended X-ray absorption fine structure (EXAFS) and a theoretical structure model was proposed for this unique Ag clusters. The charge transfer process and the dominant reactive species (·OH) were revealed on the basis of electron spin resonance (ESR) trapping. A new photocatalysis mechanism of Ag clusters-grafted BHS under visible light involving IFCT process was uncovered. In addition, the cationic Ag clusters-grafted BHS also demonstrated high photochemical and structural stability under repeated photocatalysis runs. The perspective of enhancing photocatalysis through combination of microstructural optimization and IFCT could provide a new avenue for the developing efficient visible light photocatalysts.

  17. In-Situ Synchrotron X-ray Diffraction Studies on Effects of Plastic and Elastic Loading on bcc Phase Transformations of a 3rd Generation 1 GPa Advanced High Strength Steel

    Science.gov (United States)

    Eftekharimilani, P.; Huizenga, R. M.; Kim, B.; Bernasconi, A.; Hermans, M. J. M.

    2018-01-01

    In this paper, we describe the effects of mechanical loading on bcc-to-bcc phase transformations of an Advanced High Strength Steel during cooling. In-situ synchrotron diffraction was employed to measure time-temperature-load diffraction patterns. Calculations were made of the volume fractions of the phases, the transformation kinetics, and the austenite lattice parameter during cooling and simultaneous loading. In addition, volume fractions and lattice parameters of retained austenite at room temperature under different loading conditions were obtained. The results show that applying a load during cooling of the fcc phase significantly increases the volume fraction of a bcc phase before the start of the martensitic transformation. The kinetics of phase transformations were affected by the applied loads. The volume fraction and lattice parameter of retained austenite at room temperature vary in different samples and the highest retained austenite and the largest lattice parameter were obtained in the sample subjected to the highest load.

  18. Ranking de universidades chilenas: un análisis multivariado

    Directory of Open Access Journals (Sweden)

    Firinguetti Limone, Luis

    2015-06-01

    Full Text Available In this work a ranking of Chilean universities on the basis of publicly available information is developed. This ranking takes into account the multivariate character of these institutions. Also, it is noted that the results are consistent with those of a well-known international ranking that uses a different set of data, as well as with several multivariate analyses of the data considered in this study.En este trabajo se elabora un ranking de las universidades chilenas en base a información pública disponible. Dicho ranking toma en cuenta el carácter multivariado de estas instituciones. Además, se ha comprobado que los resultados del ranking son consistentes con un conocido ranking internacional construido a partir de un conjunto diferente de datos y con varios análisis multivariados realizados de la información tratada en este estudio.

  19. EU Country Rankings' Sensitivity to the Choice of Welfare Indicators

    DEFF Research Database (Denmark)

    Hussain, M. Azhar

    2016-01-01

    are particularly volatile for countries in the middle of the ranking distribution, while countries with either high or low welfare generally have lower volatility. A multidimensional poverty index has the highest correlation with the latent welfare measure. It is concluded that the observed rankings do not tell......Ranking of countries with respect to some welfare measure is highly popular and takes places with high frequency. Ranking of a country can change over time given the same welfare measure is applied. Rankings can also change depending on which welfare measure is applied in a given year. To what...... extent do we see ranking changes and which existing welfare measures best captures an unobserved, yet existing, notion of welfare in society? To investigate this we apply seven welfare indicators for fifteen EU countries covering the years from 2005 until 2011. The results indicate that rankings...

  20. Inhibition of osteoclastogenesis by RNA interference targeting RANK

    Directory of Open Access Journals (Sweden)

    Ma Ruofan

    2012-08-01

    Full Text Available Abstract Background Osteoclasts and osteoblasts regulate bone resorption and formation to allow bone remodeling and homeostasis. The balance between bone resorption and formation is disturbed by abnormal recruitment of osteoclasts. Osteoclast differentiation is dependent on the receptor activator of nuclear factor NF-kappa B (RANK ligand (RANKL as well as the macrophage colony-stimulating factor (M-CSF. The RANKL/RANK system and RANK signaling induce osteoclast formation mediated by various cytokines. The RANK/RANKL pathway has been primarily implicated in metabolic, degenerative and neoplastic bone disorders or osteolysis. The central role of RANK/RANKL interaction in osteoclastogenesis makes RANK an attractive target for potential therapies in treatment of osteolysis. The purpose of this study was to assess the effect of inhibition of RANK expression in mouse bone marrow macrophages on osteoclast differentiation and bone resorption. Methods Three pairs of short hairpin RNAs (shRNA targeting RANK were designed and synthesized. The optimal shRNA was selected among three pairs of shRNAs by RANK expression analyzed by Western blot and Real-time PCR. We investigated suppression of osteoclastogenesis of mouse bone marrow macrophages (BMMs using the optimal shRNA by targeting RANK. Results Among the three shRANKs examined, shRANK-3 significantly suppressed [88.3%] the RANK expression (p Conclusions These findings suggest that retrovirus-mediated shRNA targeting RANK inhibits osteoclast differentiation and osteolysis. It may appear an attractive target for preventing osteolysis in humans with a potential clinical application.

  1. Asynchronous Gossip for Averaging and Spectral Ranking

    Science.gov (United States)

    Borkar, Vivek S.; Makhijani, Rahul; Sundaresan, Rajesh

    2014-08-01

    We consider two variants of the classical gossip algorithm. The first variant is a version of asynchronous stochastic approximation. We highlight a fundamental difficulty associated with the classical asynchronous gossip scheme, viz., that it may not converge to a desired average, and suggest an alternative scheme based on reinforcement learning that has guaranteed convergence to the desired average. We then discuss a potential application to a wireless network setting with simultaneous link activation constraints. The second variant is a gossip algorithm for distributed computation of the Perron-Frobenius eigenvector of a nonnegative matrix. While the first variant draws upon a reinforcement learning algorithm for an average cost controlled Markov decision problem, the second variant draws upon a reinforcement learning algorithm for risk-sensitive control. We then discuss potential applications of the second variant to ranking schemes, reputation networks, and principal component analysis.

  2. Ranking Visualizations of Correlation Using Weber's Law.

    Science.gov (United States)

    Harrison, Lane; Yang, Fumeng; Franconeri, Steven; Chang, Remco

    2014-12-01

    Despite years of research yielding systems and guidelines to aid visualization design, practitioners still face the challenge of identifying the best visualization for a given dataset and task. One promising approach to circumvent this problem is to leverage perceptual laws to quantitatively evaluate the effectiveness of a visualization design. Following previously established methodologies, we conduct a large scale (n=1687) crowdsourced experiment to investigate whether the perception of correlation in nine commonly used visualizations can be modeled using Weber's law. The results of this experiment contribute to our understanding of information visualization by establishing that: (1) for all tested visualizations, the precision of correlation judgment could be modeled by Weber's law, (2) correlation judgment precision showed striking variation between negatively and positively correlated data, and (3) Weber models provide a concise means to quantify, compare, and rank the perceptual precision afforded by a visualization.

  3. Motif discovery in ranked lists of sequences

    DEFF Research Database (Denmark)

    Nielsen, Morten Muhlig; Tataru, Paula; Madsen, Tobias

    2016-01-01

    . These features make Regmex well suited for a range of biological sequence analysis problems related to motif discovery, exemplified by microRNA seed enrichment, but also including enrichment problems involving complex motifs and combinations of motifs. We demonstrate a number of usage scenarios that take......Motif analysis has long been an important method to characterize biological functionality and the current growth of sequencing-based genomics experiments further extends its potential. These diverse experiments often generate sequence lists ranked by some functional property. There is therefore...... a growing need for motif analysis methods that can exploit this coupled data structure and be tailored for specific biological questions. Here, we present an exploratory motif analysis tool, Regmex (REGular expression Motif EXplorer), which offers several methods to evaluate the correlation of motifs...

  4. Ranking different factors influencing flight delay

    Directory of Open Access Journals (Sweden)

    Meysam Kazemi Asfe

    2014-07-01

    Full Text Available Flight interruption is one of the most important issues in today’s airline industry. Every year, most airlines spend significant amount of money to compensate flight delays. Therefore, it is important to detect important factors influencing on flight delays. This paper presents an empirical investigation to determine important factors on this issue. The study also asks some decision makers to make pairwise comparison and ranks various factors using the art of analytical hierarchy process. The study determines that technical defects and delayed entry were among the most important factors to blame for flight delays. In addition, announcing the postponement, replacement aircraft and path replacement are among the most important decisions facing managers in the aviation industry during the disruption of the flight.

  5. Image Registration based on Low Rank Matrix: Rank-Regularized SSD.

    Science.gov (United States)

    Ghaffari, Aboozar; Fatemizadeh, Emad

    2017-08-25

    Similarity measure is a main core of image registration algorithms. Spatially varying intensity distortion is an important challenge which affects the performance of similarity measures. Correlation among pixels is the main characteristic of this distortion. Similarity measures such as sum-of-squareddifferences (SSD) and mutual information (MI) ignore this correlation; Hence, perfect registration cannot be achieved in the presence of this distortion. In this paper, we model this correlation with the aid of the low rank matrix theory. Based on this model, we compensate this distortion analytically and introduce Rank-Regularized SSD (RRSSD). This new similarity measure is a modified SSD based on singular values of difference image in mono-modal imaging. In fact, image registration and distortion correction are performed simultaneously in the proposed model. Based on our experiments, the RRSSD similarity measure achieves clinically acceptable registration results, and outperforms other state-of-the-art similarity measures such as the well-known method of residual complexity.

  6. Large-scale preparation of porous ultrathin Ga-doped ZnO nanoneedles from 3D basic zinc carbonate superstructures

    Energy Technology Data Exchange (ETDEWEB)

    Du Shangfeng [Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Liu Haidi; Chen Yunfa [State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China)], E-mail: s.du@bham.ac.uk

    2009-02-25

    A facile procedure for large-scale preparation of porous ZnO 1D nanomaterials with good electrical conductivity has been demonstrated for the first time. Porous ultrathin Ga-doped ZnO nanoneedles can be prepared by calcining the precursor of ultrathin Ga-doped basic zinc carbonate (BZC) nanoneedles obtained from BZC 3D superstructures, which are synthesized by a simple chemical co-precipitation method at room temperature, without using any catalyst, template or surfactant. There is evidence that the growth mechanisms of the BZC 3D superstructures and nanoneedles are correlated with the concentrations of ammonium ions and ethanol in the synthesis solution. The as-prepared porous Ga-doped ZnO nanoneedles have a thickness of only a couple of nanometers, consisting of many fine nanoparticles in a few nanometers. Electrical conductivity measurements indicate that porous ultrathin ZnO nanoneedles have a volume resistivity similar to that of the spherical Ga-doped ZnO nanoparticles. The porous nanostructures and good electrical conductivity make the porous ultrathin ZnO 1D nanoneedles promising candidates for applications in electrochemical fields.

  7. Photochemically and Thermally Driven Full-Color Reflection in a Self-Organized Helical Superstructure Enabled by a Halogen-Bonded Chiral Molecular Switch.

    Science.gov (United States)

    Wang, Hao; Bisoyi, Hari Krishna; Wang, Ling; Urbas, Augustine M; Bunning, Timothy J; Li, Quan

    2018-02-05

    Supramolecular approaches toward the fabrication of functional materials and systems have been an enabling endeavor. Recently, halogen bonding has been harnessed as a promising supramolecular tool. Herein we report the synthesis and characterization of a novel halogen-bonded light-driven axially chiral molecular switch. The photoactive halogen-bonded chiral switch is able to induce a self-organized, tunable helical superstructure, that is, cholesteric liquid crystal (CLC), when doped into an achiral liquid crystal (LC) host. The halogen-bonded switch as a chiral dopant has a high helical twisting power (HTP) and shows a large change of its HTP upon photoisomerization. This light-driven dynamic modulation enables reversible selective reflection color tuning across the entire visible spectrum. The chiral switch also displays a temperature-dependent HTP change that enables thermally driven red, green, and blue (RGB) reflection colors in the self-organized helical superstructure. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Novel EGCG assisted ultrasound synthesis of self-assembled Ca2SiO4:Eu(3+) hierarchical superstructures: Photometric characteristics and LED applications.

    Science.gov (United States)

    Venkataravanappa, M; Nagabhushana, H; Darshan, G P; Daruka Prasad, B; Vijayakumar, G R; Premkumar, H B; Udayabhanu

    2016-11-01

    This paper reports for the first time ultrasound, EGCG assisted synthesis of pure and Eu(3+) (1-5mol%) activated Ca2SiO4 nanophosphors having self-assembled superstructures with high purity. The shape, size and morphology of the product were tuned by controlling influential parameters. It was found that morphology was highly dependent on EGCG concentration, sonication time, pH and sonication power. The probable formation mechanism for various hierarchical superstructures was proposed. The PL studies of Ca2SiO4:Eu(3+) phosphors can be effectively excited by the near ultraviolet (UV) (396nm) light and exhibited strong red emission around 613nm, which was attributed to the Eu(3+) ((5)D0→(7)F2) transition. The concentration quenching phenomenon was explained based on energy transfer between defect and Eu(3+) ions, electron-phonon coupling and Eu(3+)-Eu(3+) interaction. The Judd-Ofelt intensity parameters and radiative properties were estimated by using PL emission spectra. The photometric studies indicate that the obtained phosphors could be a promising red component for possible applications in the field of white light emitting diodes. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Rankings matter: nurse graduates from higher-ranked institutions have higher productivity.

    Science.gov (United States)

    Yakusheva, Olga; Weiss, Marianne

    2017-02-13

    Increasing demand for baccalaureate-prepared nurses has led to rapid growth in the number of baccalaureate-granting programs, and to concerns about educational quality and potential effects on productivity of the graduating nursing workforce. We examined the association of individual productivity of a baccalaureate-prepared nurse with the ranking of the degree-granting institution. For a sample of 691 nurses from general medical-surgical units at a large magnet urban hospital between 6/1/2011-12/31/2011, we conducted multivariate regression analysis of nurse productivity on the ranking of the degree-granting institution, adjusted for age, hospital tenure, gender, and unit-specific effects. Nurse productivity was coded as "top"/"average"/"bottom" based on a computation of individual nurse value-added to patient outcomes. Ranking of the baccalaureate-granting institution was derived from the US News and World Report Best Colleges Rankings' categorization of the nurse's institution as the "first tier" or the "second tier", with diploma or associate degree as the reference category. Relative to diploma or associate degree nurses, nurses who had attended first-tier universities had three-times the odds of being in the top productivity category (OR = 3.18, p productivity (OR = 1.73, p = 0.11). Being in the bottom productivity category was not associated with having a baccalaureate degree or the quality tier. The productivity boost from a nursing baccalaureate degree depends on the quality of the educational institution. Recognizing differences in educational outcomes, initiatives to build a baccalaureate-educated nursing workforce should be accompanied by improved access to high-quality educational institutions.

  10. Using incomplete citation data for MEDLINE results ranking.

    Science.gov (United States)

    Herskovic, Jorge R; Bernstam, Elmer V

    2005-01-01

    Information overload is a significant problem for modern medicine. Searching MEDLINE for common topics often retrieves more relevant documents than users can review. Therefore, we must identify documents that are not only relevant, but also important. Our system ranks articles using citation counts and the PageRank algorithm, incorporating data from the Science Citation Index. However, citation data is usually incomplete. Therefore, we explore the relationship between the quantity of citation information available to the system and the quality of the result ranking. Specifically, we test the ability of citation count and PageRank to identify "important articles" as defined by experts from large result sets with decreasing citation information. We found that PageRank performs better than simple citation counts, but both algorithms are surprisingly robust to information loss. We conclude that even an incomplete citation database is likely to be effective for importance ranking.

  11. Improving the Incoherence of a Learned Dictionary via Rank Shrinkage.

    Science.gov (United States)

    Ubaru, Shashanka; Seghouane, Abd-Krim; Saad, Yousef

    2017-01-01

    This letter considers the problem of dictionary learning for sparse signal representation whose atoms have low mutual coherence. To learn such dictionaries, at each step, we first update the dictionary using the method of optimal directions (MOD) and then apply a dictionary rank shrinkage step to decrease its mutual coherence. In the rank shrinkage step, we first compute a rank 1 decomposition of the column-normalized least squares estimate of the dictionary obtained from the MOD step. We then shrink the rank of this learned dictionary by transforming the problem of reducing the rank to a nonnegative garrotte estimation problem and solving it using a path-wise coordinate descent approach. We establish theoretical results that show that the rank shrinkage step included will reduce the coherence of the dictionary, which is further validated by experimental results. Numerical experiments illustrating the performance of the proposed algorithm in comparison to various other well-known dictionary learning algorithms are also presented.

  12. LogDet Rank Minimization with Application to Subspace Clustering.

    Science.gov (United States)

    Kang, Zhao; Peng, Chong; Cheng, Jie; Cheng, Qiang

    2015-01-01

    Low-rank matrix is desired in many machine learning and computer vision problems. Most of the recent studies use the nuclear norm as a convex surrogate of the rank operator. However, all singular values are simply added together by the nuclear norm, and thus the rank may not be well approximated in practical problems. In this paper, we propose using a log-determinant (LogDet) function as a smooth and closer, though nonconvex, approximation to rank for obtaining a low-rank representation in subspace clustering. Augmented Lagrange multipliers strategy is applied to iteratively optimize the LogDet-based nonconvex objective function on potentially large-scale data. By making use of the angular information of principal directions of the resultant low-rank representation, an affinity graph matrix is constructed for spectral clustering. Experimental results on motion segmentation and face clustering data demonstrate that the proposed method often outperforms state-of-the-art subspace clustering algorithms.

  13. RANK/RANK-L/OPG in Patients with Bone Metastases Treated with Anticancer Agents and Zoledronic Acid: A Prospective Study

    Directory of Open Access Journals (Sweden)

    Laura Mercatali

    2013-05-01

    Full Text Available Patients with solid cancer frequently develop bone metastases (BM. Zoledronic acid (Zometa®, ZA, routinely used to treat patients with BM, acts on osteoclasts and also has antitumor properties. We aimed to assess the effect of ZA over time in novel bone turnover markers (RANK/receptor activator of nuclear factor-k B ligand (RANK-L/ Osteoprotegerin (OPG and to correlate these with serum N-terminal telopeptide (NTX. The study prospectively evaluated levels of RANK, RANK-L and OPG transcripts by real-time PCR and NTX expression by ELISA in the peripheral blood of 49 consecutive patients with advanced breast, lung or prostate cancer. All patients received the standard ZA schedule and were monitored for 12 months. Median baseline values of RANK, RANK-L and OPG were 78.28 (range 7.34–620.64, 319.06 (21.42–1884.41 and 1.52 (0.10–58.02, respectively. At 12 months, the median RANK-L value had decreased by 22% with respect to the baseline, whereas median OPG levels had increased by about 96%. Consequently, the RANK-L/OPG ratio decreased by 56% from the baseline. Median serum NTX levels decreased over the 12-month period, reaching statistical significance (p < 0.0001. Our results would seem to indicate that ZA modulates RANK, RANK-L and OPG expression, thus decreasing osteoclast activity.

  14. RANK/RANKL/OPG Signalization Implication in Periodontitis: New Evidence from a RANK Transgenic Mouse Model

    Directory of Open Access Journals (Sweden)

    Bouchra Sojod

    2017-05-01

    Full Text Available Periodontitis is based on a complex inflammatory over-response combined with possible genetic predisposition factors. The RANKL/RANK/OPG signaling pathway is implicated in bone resorption through its key function in osteoclast differentiation and activation, as well as in the inflammatory response. This central element of osteo-immunology has been suggested to be perturbed in several diseases, including periodontitis, as it is a predisposing factor for this disease. The aim of the present study was to validate this hypothesis using a transgenic mouse line, which over-expresses RANK (RTg and develops a periodontitis-like phenotype at 5 months of age. RTg mice exhibited severe alveolar bone loss, an increased number of TRAP positive cells, and disorganization of periodontal ligaments. This phenotype was more pronounced in females. We also observed dental root resorption lacunas. Hyperplasia of the gingival epithelium, including Malassez epithelial rests, was visible as early as 25 days, preceding any other symptoms. These results demonstrate that perturbations of the RANKL/RANK/OPG system constitute a core element of periodontitis, and more globally, osteo-immune diseases.

  15. A review of the irradiation evolution of dispersed oxide nanoparticles in the b.c.c. Fe-Cr system: Current understanding and future directions

    Science.gov (United States)

    Wharry, Janelle P.; Swenson, Matthew J.; Yano, Kayla H.

    2017-04-01

    Thus far, a number of studies have investigated the irradiation evolution of oxide nanoparticles in b.c.c. Fe-Cr based oxide dispersion strengthened (ODS) alloys. But given the inconsistent experimental conditions, results have been widely variable and inconclusive. Crystal structure and chemistry changes differ from experiment to experiment, and the total nanoparticle volume fraction has been observed to both increase and decrease. Furthermore, there has not yet been a comprehensive review of the archival literature. In this paper, we summarize the existing studies on nanoparticle irradiation evolution. We note significant observations with respect to oxide nanoparticle crystallinity, composition, size, and number density. We discuss four possible contributing mechanisms for nanoparticle evolution: ballistic dissolution, Ostwald ripening, irradiation-enhanced diffusion, and homogeneous nucleation. Finally, we propose future directions to achieve a more comprehensive understanding of irradiation effects on oxide nanoparticles in ODS alloys.

  16. Photo Aesthetics Ranking Network with Attributes and Content Adaptation

    OpenAIRE

    Kong, Shu; Shen, Xiaohui; Lin, Zhe; Mech, Radomir; Fowlkes, Charless

    2016-01-01

    Real-world applications could benefit from the ability to automatically generate a fine-grained ranking of photo aesthetics. However, previous methods for image aesthetics analysis have primarily focused on the coarse, binary categorization of images into high- or low-aesthetic categories. In this work, we propose to learn a deep convolutional neural network to rank photo aesthetics in which the relative ranking of photo aesthetics are directly modeled in the loss function. Our model incorpor...

  17. A Review of Ranking Models in Data Envelopment Analysis

    OpenAIRE

    Hosseinzadeh Lotfi, F.; Jahanshahloo, G.R.; M. Khodabakhshi; Rostamy-Malkhlifeh, M.; Moghaddas, Z.; Vaez-Ghasemi, M.

    2013-01-01

    In the course of improving various abilities of data envelopment analysis (DEA) models, many investigations have been carried out for ranking decision-making units (DMUs). This is an important issue both in theory and practice. There exist a variety of papers which apply different ranking methods to a real data set. Here the ranking methods are divided into seven groups. As each of the existing methods can be viewed from different aspects, it is possible that somewhat these groups have an ove...

  18. International ranking systems for universities and institutions: a critical appraisal

    Science.gov (United States)

    Ioannidis, John PA; Patsopoulos, Nikolaos A; Kavvoura, Fotini K; Tatsioni, Athina; Evangelou, Evangelos; Kouri, Ioanna; Contopoulos-Ioannidis, Despina G; Liberopoulos, George

    2007-01-01

    Background Ranking of universities and institutions has attracted wide attention recently. Several systems have been proposed that attempt to rank academic institutions worldwide. Methods We review the two most publicly visible ranking systems, the Shanghai Jiao Tong University 'Academic Ranking of World Universities' and the Times Higher Education Supplement 'World University Rankings' and also briefly review other ranking systems that use different criteria. We assess the construct validity for educational and research excellence and the measurement validity of each of the proposed ranking criteria, and try to identify generic challenges in international ranking of universities and institutions. Results None of the reviewed criteria for international ranking seems to have very good construct validity for both educational and research excellence, and most don't have very good construct validity even for just one of these two aspects of excellence. Measurement error for many items is also considerable or is not possible to determine due to lack of publication of the relevant data and methodology details. The concordance between the 2006 rankings by Shanghai and Times is modest at best, with only 133 universities shared in their top 200 lists. The examination of the existing international ranking systems suggests that generic challenges include adjustment for institutional size, definition of institutions, implications of average measurements of excellence versus measurements of extremes, adjustments for scientific field, time frame of measurement and allocation of credit for excellence. Conclusion Naïve lists of international institutional rankings that do not address these fundamental challenges with transparent methods are misleading and should be abandoned. We make some suggestions on how focused and standardized evaluations of excellence could be improved and placed in proper context. PMID:17961208

  19. Asian top universities in six world university ranking systems

    OpenAIRE

    Mahmood Khosrowjerdi; Zahra Seif Kashani

    2013-01-01

    There are a variety of ranking systems for universities throughout the different continents of the world. The majority of the world ranking systems have paid special attention toward evaluation of universities and higher education institutions at the national and international level. This paper tries to study the similarities and status of top Asian universities in the list of top 200 universities by these world ranking systems. Findings show that there are some parallelisms among the...

  20. International ranking systems for universities and institutions: a critical appraisal

    Directory of Open Access Journals (Sweden)

    Tatsioni Athina

    2007-10-01

    Full Text Available Abstract Background Ranking of universities and institutions has attracted wide attention recently. Several systems have been proposed that attempt to rank academic institutions worldwide. Methods We review the two most publicly visible ranking systems, the Shanghai Jiao Tong University 'Academic Ranking of World Universities' and the Times Higher Education Supplement 'World University Rankings' and also briefly review other ranking systems that use different criteria. We assess the construct validity for educational and research excellence and the measurement validity of each of the proposed ranking criteria, and try to identify generic challenges in international ranking of universities and institutions. Results None of the reviewed criteria for international ranking seems to have very good construct validity for both educational and research excellence, and most don't have very good construct validity even for just one of these two aspects of excellence. Measurement error for many items is also considerable or is not possible to determine due to lack of publication of the relevant data and methodology details. The concordance between the 2006 rankings by Shanghai and Times is modest at best, with only 133 universities shared in their top 200 lists. The examination of the existing international ranking systems suggests that generic challenges include adjustment for institutional size, definition of institutions, implications of average measurements of excellence versus measurements of extremes, adjustments for scientific field, time frame of measurement and allocation of credit for excellence. Conclusion Naïve lists of international institutional rankings that do not address these fundamental challenges with transparent methods are misleading and should be abandoned. We make some suggestions on how focused and standardized evaluations of excellence could be improved and placed in proper context.

  1. Ranking agricultural, environmental and natural resource economics journals: A note

    OpenAIRE

    Halkos, George; Tzeremes, Nickolaos

    2012-01-01

    This paper by applying Data Envelopment Analysis (DEA) ranks for the first time Economics journals in the field of Agricultural, Environmental and Natural Resource. Specifically, by using one composite input and one composite output the paper ranks 32 journals. In addition for the first time three different quality ranking reports have been incorporated to the DEA modelling problem in order to classify the journals into four categories (‘A’ to ‘D’). The results reveal that the journals with t...

  2. Reduced Rank Adaptive Filtering in Impulsive Noise Environments

    KAUST Repository

    Soury, Hamza

    2014-01-06

    An impulsive noise environment is used in this paper. A new aspect of signal truncation is deployed to reduce the harmful effect of the impulsive noise to the signal. A full rank direct solution is derived followed by an iterative solution. The reduced rank adaptive filter is presented in this environment by using two methods for rank reduction. The minimized objective function is defined using the Lp norm. The results are presented and the efficiency of each algorithm is discussed.

  3. Diffusion of scientific credits and the ranking of scientists

    OpenAIRE

    Radicchi, Filippo; Fortunato, Santo; Markines, Benjamin; Vespignani, Alessandro

    2009-01-01

    Recently, the abundance of digital data enabled the implementation of graph based ranking algorithms that provide system level analysis for ranking publications and authors. Here we take advantage of the entire Physical Review publication archive (1893-2006) to construct authors' networks where weighted edges, as measured from opportunely normalized citation counts, define a proxy for the mechanism of scientific credit transfer. On this network we define a ranking method based on a diffusion ...

  4. Social ranking effects on tooth-brushing behaviour

    OpenAIRE

    Maltby, John; Paterson, Kevin; Day, Liz; Jones, Ceri; Kinnear, Hayley; Buchanan, Heather

    2016-01-01

    Objective: A tooth-brushing social rank hypothesis is tested suggesting tooth-brushing duration is influenced when individuals position their behaviour in a rank when comparing their behaviour with other individuals.\\ud Design: Study 1 used a correlation design, Study 2 used a semi-experimental design, and Study 3 used a randomized intervention design to examine the tooth-brushing social rank hypothesis in terms of self-reported attitudes, cognitions, and behaviour towards tooth-brushing dura...

  5. Production and secretion of naphthoquinones is mediated by the MFS transporter MFS1 in the entomopathogenic fungus Ophiocordyceps sp. BCC1869.

    Science.gov (United States)

    Khaokhajorn, Pratoomporn; Samipak, Sompid; Nithithanasilp, Sutichai; Tanticharoen, Morakot; Amnuaykanjanasin, Alongkorn

    2015-10-01

    Naphthoquinones are deep red polyketide pigments produced by the ant-pathogenic fungus Ophiocordyceps sp. BCC1869. In culture, biosynthesis of these naphthoquinones remains at a low level during the first 20 days and reaches its maximum production level at approximately 50 days. The MFS transporter gene MFS1 was previously identified in Ophiocordyceps sp. BCC1869 from a subtractive EST library between the fungus grown under naphthoquinone-inductive and naphthoquinone-repressive conditions. We cloned and sequenced this transporter gene, which has an open reading frame of 1505 bp and three introns (48, 52, and 58 bp). Phylogenetic analysis showed this MFS transporter was tightly clustered with fungal riboflavin transporters. Functional analysis of this gene was performed by overexpression of MFS1 under the control of a strong, constitutive promoter. We successfully transformed the fungus with this overexpression plasmid using PEG-protoplast transformation, which generated nine transformants per µg of plasmid. RT-PCR indicated that the MFS1 expression level in the overexpressing strains increased 3- to 10-fold compared to the wild type. HPLC analysis of crude extracts of mutants and wild type demonstrated that four naphthoquinone derivatives, erythrostominone, epierythrostominol, deoxyerythrostominone, and deoxyerythrostominol, were the major naphthoquinones produced and excreted in staggering quantities (20- to 2300-fold) in 7-day old liquid cultures by the mutant C7, compared to the wild type. High resolution electrospray ionization mass spectrometry verified mass spectra of these purified metabolites. Three other naphthoquinone derivatives, whose structures have not been identified, were also detected in high amount in the mutant liquid cultures.

  6. A scale for ranking volcanoes by risk

    Science.gov (United States)

    Scandone, Roberto; Bartolini, Stefania; Martí, Joan

    2016-01-01

    We propose a simple volcanic risk coefficient (VRC) useful for comparing the degree of risk arising from different volcanoes, which may be used by civil protection agencies and volcano observatories to rapidly allocate limited resources even without a detailed knowledge of each volcano. Volcanic risk coefficient is given by the sum of the volcanic explosivity index (VEI) of the maximum expected eruption from the volcano, the logarithm of the eruption rate, and the logarithm of the population that may be affected by the maximum expected eruption. We show how to apply the method to rank the risk using as examples the volcanoes of Italy and in the Canary Islands. Moreover, we demonstrate that the maximum theoretical volcanic risk coefficient is 17 and pertains to the large caldera-forming volcanoes like Toba or Yellowstone that may affect the life of the entire planet. We develop also a simple plugin for a dedicated Quantum Geographic Information System (QGIS) software to graphically display the VRC of different volcanoes in a region.

  7. Relevancy Ranking of Satellite Dataset Search Results

    Science.gov (United States)

    Lynnes, Christopher; Quinn, Patrick; Norton, James

    2017-01-01

    As the Variety of Earth science datasets increases, science researchers find it more challenging to discover and select the datasets that best fit their needs. The most common way of search providers to address this problem is to rank the datasets returned for a query by their likely relevance to the user. Large web page search engines typically use text matching supplemented with reverse link counts, semantic annotations and user intent modeling. However, this produces uneven results when applied to dataset metadata records simply externalized as a web page. Fortunately, data and search provides have decades of experience in serving data user communities, allowing them to form heuristics that leverage the structure in the metadata together with knowledge about the user community. Some of these heuristics include specific ways of matching the user input to the essential measurements in the dataset and determining overlaps of time range and spatial areas. Heuristics based on the novelty of the datasets can prioritize later, better versions of data over similar predecessors. And knowledge of how different user types and communities use data can be brought to bear in cases where characteristics of the user (discipline, expertise) or their intent (applications, research) can be divined. The Earth Observing System Data and Information System has begun implementing some of these heuristics in the relevancy algorithm of its Common Metadata Repository search engine.

  8. Multirelational Social Recommendations via Multigraph Ranking.

    Science.gov (United States)

    Mao, Mingsong; Lu, Jie; Zhang, Guangquan; Zhang, Jinlong

    2017-12-01

    Recommender systems aim to identify relevant items for particular users in large-scale online applications. The historical rating data of users is a valuable input resource for many recommendation models such as collaborative filtering (CF), but these models are known to suffer from the rating sparsity problem when the users or items under consideration have insufficient rating records. With the continued growth of online social networks, the increased user-to-user relationships are reported to be helpful and can alleviate the CF rating sparsity problem. Although researchers have developed a range of social network-based recommender systems, there is no unified model to handle multirelational social networks. To address this challenge, this paper represents different user relationships in a multigraph and develops a multigraph ranking model to identify and recommend the nearest neighbors of particular users in high-order environments. We conduct empirical experiments on two real-world datasets: 1) Epinions and 2) Last.fm, and the comprehensive comparison with other approaches demonstrates that our model improves recommendation performance in terms of both recommendation coverage and accuracy, especially when the rating data are sparse.

  9. Grades and Ranking: When Tenure Affects Assessment

    Directory of Open Access Journals (Sweden)

    Jean Filetti

    2010-10-01

    Full Text Available This article examines how a faculty member's status-'either tenured or tenure-track-'might affect the grades assigned to students in a writing class. We begin with a brief review of the research surrounding faculty to student assessment practices and follow with specific controversies regarding faculty motivation pertaining to grading practices. We interpret the grade distributions of tenured and tenure-track faculty members teaching a sophomore-level writing course in an English Department at a small, public liberal arts university in Virginia, examine the relationship between grade distributions and faculty rank, and conclude that tenure-track faculty grade more leniently than their tenured colleagues, primarily in the number of - A- grades assigned. The results of this study suggest that tenured professors tend to award fewer - As- than tenure-track professors. We posit that at universities where emphasis is placed upon teaching, two specific patterns emerge: reciprocity may be an unspoken agreement between some faculty and students with regard to the exchange of good grades for good evaluations, or with experience comes rigor.

  10. Improving CBIR Systems Using Automated Ranking

    Directory of Open Access Journals (Sweden)

    B. D. Reljin

    2012-11-01

    Full Text Available The most common way of searching images on the Internet and in private collections is based on a similarity measuring of a series of text words that are assigned to each image with users query series. This method imposes strong constraints (the number of words to describe the image, the time necessary to thoroughly describe the subjective experience of images, the level of details in the picture, language barrier, etc., and is therefore very inefficient. Modern researches in this area are focused on the contentbased searching images (CBIR. In this way, all described disadvantages are overcome and the quality of searching results is improved. This paper presents a solution for CBIR systems where the search procedure is enhanced using sophisticated extraction and ranking of extracted images. The searching procedure is based on extraction and preprocessing of a large number of low level image features. Thus, when the user defines a query image, the proposed algorithm based on artificial intelligence, shows to the user a group of images which are most similar to a query image by content. The proposed algorithm is iterative, so the user can direct the searching procedure to an expected outcome and get a set of images that are more similar to the query one.

  11. Rank diversity of languages: generic behavior in computational linguistics.

    Science.gov (United States)

    Cocho, Germinal; Flores, Jorge; Gershenson, Carlos; Pineda, Carlos; Sánchez, Sergio

    2015-01-01

    Statistical studies of languages have focused on the rank-frequency distribution of words. Instead, we introduce here a measure of how word ranks change in time and call this distribution rank diversity. We calculate this diversity for books published in six European languages since 1800, and find that it follows a universal lognormal distribution. Based on the mean and standard deviation associated with the lognormal distribution, we define three different word regimes of languages: "heads" consist of words which almost do not change their rank in time, "bodies" are words of general use, while "tails" are comprised by context-specific words and vary their rank considerably in time. The heads and bodies reflect the size of language cores identified by linguists for basic communication. We propose a Gaussian random walk model which reproduces the rank variation of words in time and thus the diversity. Rank diversity of words can be understood as the result of random variations in rank, where the size of the variation depends on the rank itself. We find that the core size is similar for all languages studied.

  12. Econophysics of a ranked demand and supply resource allocation problem

    Science.gov (United States)

    Priel, Avner; Tamir, Boaz

    2018-01-01

    We present a two sided resource allocation problem, between demands and supplies, where both parties are ranked. For example, in Big Data problems where a set of different computational tasks is divided between a set of computers each with its own resources, or between employees and employers where both parties are ranked, the employees by their fitness and the employers by their package benefits. The allocation process can be viewed as a repeated game where in each iteration the strategy is decided by a meta-rule, based on the ranks of both parties and the results of the previous games. We show the existence of a phase transition between an absorbing state, where all demands are satisfied, and an active one where part of the demands are always left unsatisfied. The phase transition is governed by the ratio between supplies and demand. In a job allocation problem we find positive correlation between the rank of the workers and the rank of the factories; higher rank workers are usually allocated to higher ranked factories. These all suggest global emergent properties stemming from local variables. To demonstrate the global versus local relations, we introduce a local inertial force that increases the rank of employees in proportion to their persistence time in the same factory. We show that such a local force induces non trivial global effects, mostly to benefit the lower ranked employees.

  13. Proceedings of the sixteenth biennial low-rank fuels symposium

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    Low-rank coals represent a major energy resource for the world. The Low-Rank Fuels Symposium, building on the traditions established by the Lignite Symposium, focuses on the key opportunities for this resource. This conference offers a forum for leaders from industry, government, and academia to gather to share current information on the opportunities represented by low-rank coals. In the United States and throughout the world, the utility industry is the primary user of low-rank coals. As such, current experiences and future opportunities for new technologies in this industry were the primary focuses of the symposium.

  14. Multidimensional ranking the design and development of U-Multirank

    CERN Document Server

    Ziegele, Frank

    2012-01-01

    During the last decades ranking has become one of the most controversial issues in higher education and research. It is widely recognized now that, although some of the current rankings can be severely criticized, they seem to be here to stay. In addition, rankings appear to have a great impact on decision-makers at all levels of higher education and research systems worldwide, including in universities. Rankings reflect a growing international competition among universities for talent and resources; at the same time they reinforce competition by their very results. Yet major concerns remain a

  15. Quantum probability ranking principle for ligand-based virtual screening.

    Science.gov (United States)

    Al-Dabbagh, Mohammed Mumtaz; Salim, Naomie; Himmat, Mubarak; Ahmed, Ali; Saeed, Faisal

    2017-04-01

    Chemical libraries contain thousands of compounds that need screening, which increases the need for computational methods that can rank or prioritize compounds. The tools of virtual screening are widely exploited to enhance the cost effectiveness of lead drug discovery programs by ranking chemical compounds databases in decreasing probability of biological activity based upon probability ranking principle (PRP). In this paper, we developed a novel ranking approach for molecular compounds inspired by quantum mechanics, called quantum probability ranking principle (QPRP). The QPRP ranking criteria would make an attempt to draw an analogy between the physical experiment and molecular structure ranking process for 2D fingerprints in ligand based virtual screening (LBVS). The development of QPRP criteria in LBVS has employed the concepts of quantum at three different levels, firstly at representation level, this model makes an effort to develop a new framework of molecular representation by connecting the molecular compounds with mathematical quantum space. Secondly, estimate the similarity between chemical libraries and references based on quantum-based similarity searching method. Finally, rank the molecules using QPRP approach. Simulated virtual screening experiments with MDL drug data report (MDDR) data sets showed that QPRP outperformed the classical ranking principle (PRP) for molecular chemical compounds.

  16. Quantum probability ranking principle for ligand-based virtual screening

    Science.gov (United States)

    Al-Dabbagh, Mohammed Mumtaz; Salim, Naomie; Himmat, Mubarak; Ahmed, Ali; Saeed, Faisal

    2017-04-01

    Chemical libraries contain thousands of compounds that need screening, which increases the need for computational methods that can rank or prioritize compounds. The tools of virtual screening are widely exploited to enhance the cost effectiveness of lead drug discovery programs by ranking chemical compounds databases in decreasing probability of biological activity based upon probability ranking principle (PRP). In this paper, we developed a novel ranking approach for molecular compounds inspired by quantum mechanics, called quantum probability ranking principle (QPRP). The QPRP ranking criteria would make an attempt to draw an analogy between the physical experiment and molecular structure ranking process for 2D fingerprints in ligand based virtual screening (LBVS). The development of QPRP criteria in LBVS has employed the concepts of quantum at three different levels, firstly at representation level, this model makes an effort to develop a new framework of molecular representation by connecting the molecular compounds with mathematical quantum space. Secondly, estimate the similarity between chemical libraries and references based on quantum-based similarity searching method. Finally, rank the molecules using QPRP approach. Simulated virtual screening experiments with MDL drug data report (MDDR) data sets showed that QPRP outperformed the classical ranking principle (PRP) for molecular chemical compounds.

  17. A Modification on the Hesitant Fuzzy Set Lexicographical Ranking Method

    Directory of Open Access Journals (Sweden)

    Xiaodi Liu

    2016-12-01

    Full Text Available Recently, a novel hesitant fuzzy set (HFS ranking technique based on the idea of lexicographical ordering is proposed and an example is presented to demonstrate that the proposed ranking method is invariant with multiple occurrences of any element of a hesitant fuzzy element (HFE. In this paper, we show by examples that the HFS lexicographical ordering method is sometimes invalid, and a modified ranking method is presented. In comparison with the HFS lexicographical ordering method, the modified ranking method is more reasonable in more general cases.

  18. Extreme learning machine for ranking: generalization analysis and applications.

    Science.gov (United States)

    Chen, Hong; Peng, Jiangtao; Zhou, Yicong; Li, Luoqing; Pan, Zhibin

    2014-05-01

    The extreme learning machine (ELM) has attracted increasing attention recently with its successful applications in classification and regression. In this paper, we investigate the generalization performance of ELM-based ranking. A new regularized ranking algorithm is proposed based on the combinations of activation functions in ELM. The generalization analysis is established for the ELM-based ranking (ELMRank) in terms of the covering numbers of hypothesis space. Empirical results on the benchmark datasets show the competitive performance of the ELMRank over the state-of-the-art ranking methods. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Severe language effect in university rankings: particularly Germany and France are wronged in citation-based rankings.

    Science.gov (United States)

    van Raan, Anthony F J; van Leeuwen, Thed N; Visser, Martijn S

    2011-08-01

    We applied a set of standard bibliometric indicators to monitor the scientific state-of-arte of 500 universities worldwide and constructed a ranking on the basis of these indicators (Leiden Ranking 2010). We find a dramatic and hitherto largely underestimated language effect in the bibliometric, citation-based measurements of research performance when comparing the ranking based on all Web of Science (WoS) covered publications and on only English WoS covered publications, particularly for Germany and France.

  20. Effect of Doximity Residency Rankings on Residency Applicants’ Program Choices

    Directory of Open Access Journals (Sweden)

    Aimee M. Rolston

    2015-11-01

    Full Text Available Introduction: Choosing a residency program is a stressful and important decision. Doximity released residency program rankings by specialty in September 2014. This study sought to investigate the impact of those rankings on residency application choices made by fourth year medical students. Methods: A 12-item survey was administered in October 2014 to fourth year medical students at three schools. Students indicated their specialty, awareness of and perceived accuracy of the rankings, and the rankings’ impact on the programs to which they chose to apply. Descriptive statistics were reported for all students and those applying to Emergency Medicine (EM. Results: A total of 461 (75.8% students responded, with 425 applying in one of the 20 Doximity ranked specialties. Of the 425, 247 (58% were aware of the rankings and 177 looked at them. On a 1-100 scale (100=very accurate, students reported a mean ranking accuracy rating of 56.7 (SD 20.3. Forty-five percent of students who looked at the rankings modified the number of programs to which they applied. The majority added programs. Of the 47 students applying to EM, 18 looked at the rankings and 33% changed their application list with most adding programs. Conclusion: The Doximity rankings had real effects on students applying to residencies as almost half of students who looked at the rankings modified their program list. Additionally, students found the rankings to be moderately accurate. Graduating students might benefit from emphasis on more objective characterization of programs to assess in light of their own interests and personal/career goals

  1. Ranking production units according to marginal efficiency contribution

    DEFF Research Database (Denmark)

    Ghiyasi, Mojtaba; Hougaard, Jens Leth

    League tables associated with various forms of service activities from schools to hospitals illustrate the public need for ranking institutions by their productive performance. We present a new method for ranking production units which is based on each units marginal contribution to the technical...

  2. WISER ranking of the African national libraries' websites | Gupta ...

    African Journals Online (AJOL)

    Data collection has been done with the help of Google search engine and Check Page Rank tool. This study highlighted the fact that the ranking based on web impact factor was not much reliable and it is biased towards the small number of webpages and in-links. In the present study WISER, a combined web indicator was ...

  3. Monte Carlo methods of PageRank computation

    NARCIS (Netherlands)

    Litvak, Nelli

    2004-01-01

    We describe and analyze an on-line Monte Carlo method of PageRank computation. The PageRank is being estimated basing on results of a large number of short independent simulation runs initiated from each page that contains outgoing hyperlinks. The method does not require any storage of the hyperlink

  4. Co-integration Rank Testing under Conditional Heteroskedasticity

    DEFF Research Database (Denmark)

    Cavaliere, Guiseppe; Rahbæk, Anders; Taylor, A.M. Robert

    null distributions of the rank statistics coincide with those derived by previous authors who assume either i.i.d. or (strict and covariance) stationary martingale difference innovations. We then propose wild bootstrap implementations of the co-integrating rank tests and demonstrate that the associated...

  5. The Ranking Phenomenon and the Experience of Academics in Taiwan

    Science.gov (United States)

    Lo, William Yat Wai

    2014-01-01

    The primary aim of the paper is to examine how global university rankings have influenced the higher education sector in Taiwan from the perspective of academics. A qualitative case study method was used to examine how university ranking influenced the Taiwanese higher education at institutional and individual levels, respectively, thereby…

  6. Relying on topic subsets for system ranking estimation

    NARCIS (Netherlands)

    Hauff, C.; Hiemstra, Djoerd; de Jong, Franciska M.G.; Azzopardi, Leif

    2009-01-01

    Ranking a number of retrieval systems according to their retrieval effectiveness without relying on costly relevance judgments was first explored by Soboroff et al [6]. Over the years, a number of alternative approaches have been proposed. We perform a comprehensive analysis of system ranking

  7. Who Should Rank Our Journals...And Based on What?

    Science.gov (United States)

    Cherkowski, Sabre; Currie, Russell; Hilton, Sandy

    2012-01-01

    Purpose: This study aims to establish the use of active scholar assessment (ASA) in the field of education leadership as a new methodology in ranking administration and leadership journals. The secondary purpose of this study is to respond to the paucity of research on journal ranking in educational administration and leadership.…

  8. A Comparative Analysis of Higher Education Ranking Systems in Europe

    Science.gov (United States)

    Hendel, Darwin D.; Stolz, Ingo

    2008-01-01

    According to Altbach in 2004, "everyone wants a world-class university". Corresponding developmental efforts undertaken by higher education institutions are very often referenced to improvements in ranking results. Surprisingly, there is relatively little analysis of variations in higher education ranking systems across countries…

  9. International University Ranking Systems and the Idea of University Excellence

    Science.gov (United States)

    Taylor, Paul; Braddock, Richard

    2007-01-01

    We look at some of the theoretical and methodological issues underlying international university ranking systems and, in particular, their conceptual connection with the idea of excellence. We then turn to a critical examination of the two best-known international university ranking systems--the "Times Higher Education Supplement (THES)" World…

  10. How Do European Pharmacy Students Rank Competences for Practice?

    NARCIS (Netherlands)

    Atkinson, Jeffrey; De Paepe, Kristien; Sánchez Pozo, Antonio; Rekkas, Dimitrios; Volmer, Daisy; Hirvonen, Jouni; Bozic, Borut; Skowron, Agnieska; Mircioiu, Constantin; Marcincal, Annie; Koster, Andries; Wilson, Keith; van Schravendijk, Chris; Hočevar, Sandra

    2016-01-01

    European students (n = 370), academics (n = 241) and community pharmacists (n = 258) ranked 13 clusters of 68 personal and patient care competences for pharmacy practice. The results show that ranking profiles for all three groups as a rule were similar. This was especially true of the comparison

  11. The Distribution of the Sum of Signed Ranks

    Science.gov (United States)

    Albright, Brian

    2012-01-01

    We describe the calculation of the distribution of the sum of signed ranks and develop an exact recursive algorithm for the distribution as well as an approximation of the distribution using the normal. The results have applications to the non-parametric Wilcoxon signed-rank test.

  12. Online learning to rank for information retrieval: SIGIR 2016 tutorial

    NARCIS (Netherlands)

    Grotov, A.; de Rijke, M.

    2016-01-01

    During the past 10--15 years offline learning to rank has had a tremendous influence on information retrieval, both scientifically and in practice. Recently, as the limitations of offline learning to rank for information retrieval have become apparent, there is increased attention for online

  13. A generative language modeling approach for ranking entities

    NARCIS (Netherlands)

    Weerkamp, W.; Balog, K.; Meij, E.

    2009-01-01

    We describe our participation in the INEX 2008 Entity Ranking track. We develop a generative language modeling approach for the entity ranking and list completion tasks. Our framework comprises the following components: (i) entity and (ii) query language models, (iii) entity prior, (iv) the

  14. Estimating Independent Locally Shifted Random Utility Models for Ranking Data

    Science.gov (United States)

    Lam, Kar Yin; Koning, Alex J.; Franses, Philip Hans

    2011-01-01

    We consider the estimation of probabilistic ranking models in the context of conjoint experiments. By using approximate rather than exact ranking probabilities, we avoided the computation of high-dimensional integrals. We extended the approximation technique proposed by Henery (1981) in the context of the Thurstone-Mosteller-Daniels model to any…

  15. A Global Comparison of Business Journal Ranking Systems

    Science.gov (United States)

    Alexander, Jennifer K.; Scherer, Robert F.; Lecoutre, Marc

    2007-01-01

    The authors compared business journal ranking systems from 6 countries. Results revealed a low degree of agreement among the systems, and a low to moderate relationship between pairs of systems. In addition, the French and United Kingdom ranking systems were different from each other and from the systems in Australia, Germany, Hong Kong, and the…

  16. Trachomatous Scar Ranking: A Novel Outcome for Trachoma Studies.

    Science.gov (United States)

    Baldwin, Angela; Ryner, Alexander M; Tadesse, Zerihun; Shiferaw, Ayalew; Callahan, Kelly; Fry, Dionna M; Zhou, Zhaoxia; Lietman, Thomas M; Keenan, Jeremy D

    2017-06-01

    AbstractWe evaluated a new trachoma scarring ranking system with potential use in clinical research. The upper right tarsal conjunctivas of 427 individuals from Ethiopian villages with hyperendemic trachoma were photographed. An expert grader first assigned a scar grade to each photograph using the 1981 World Health Organization (WHO) grading system. Then, all photographs were ranked from least (rank = 1) to most scarring (rank = 427). Photographic grading found 79 (18.5%) conjunctivae without scarring (C0), 191 (44.7%) with minimal scarring (C1), 105 (24.6%) with moderate scarring (C2), and 52 (12.2%) with severe scarring (C3). The ranking method demonstrated good internal validity, exhibiting a monotonic increase in the median rank across the levels of the 1981 WHO grading system. Intrarater repeatability was better for the ranking method (intraclass correlation coefficient = 0.84, 95% CI = 0.74-0.94). Exhibiting better internal and external validity, this ranking method may be useful for evaluating the difference in scarring between groups of individuals.

  17. Combining Document-and Paragraph-Based Entity Ranking

    NARCIS (Netherlands)

    Rode, H.; Serdyukov, Pavel; Hiemstra, Djoerd

    2008-01-01

    We study entity ranking on the INEX entity track and pro- pose a simple graph-based ranking approach that enables to combine scores on document and paragraph level. The com- bined approach improves the retrieval results not only on the INEX testset, but similarly on TREC’s expert finding task.

  18. University Rankings: How Well Do They Measure Library Service Quality?

    Science.gov (United States)

    Jackson, Brian

    2015-01-01

    University rankings play an increasingly large role in shaping the goals of academic institutions and departments, while removing universities themselves from the evaluation process. This study compares the library-related results of two university ranking publications with scores on the LibQUAL+™ survey to identify if library service quality--as…

  19. What Parameters Do Students Value in Business School Rankings?

    Science.gov (United States)

    Mårtensson, Pär; Richtnér, Anders

    2015-01-01

    The starting point of this paper is the question: Which issues do students think are important when choosing a higher education institution, and how are they related to the factors taken into consideration in ranking institutions? The aim is to identify and rank the parameters students perceive as important when choosing their place of education.…

  20. Positioning Open Access Journals in a LIS Journal Ranking

    Science.gov (United States)

    Xia, Jingfeng

    2012-01-01

    This research uses the h-index to rank the quality of library and information science journals between 2004 and 2008. Selected open access (OA) journals are included in the ranking to assess current OA development in support of scholarly communication. It is found that OA journals have gained momentum supporting high-quality research and…

  1. Information Theoretic Bounds for Low-Rank Matrix Completion

    CERN Document Server

    Vishwanath, Sriram

    2010-01-01

    This paper studies the low-rank matrix completion problem from an information theoretic perspective. The completion problem is rephrased as a communication problem of an (uncoded) low-rank matrix source over an erasure channel. The paper then uses achievability and converse arguments to present order-wise optimal bounds for the completion problem.

  2. Balancing exploration and exploitation in learning to rank online

    NARCIS (Netherlands)

    Hofmann, K.; Whiteson, S.; de Rijke, M.

    2011-01-01

    As retrieval systems become more complex, learning to rank approaches are being developed to automatically tune their parameters. Using online learning to rank approaches, retrieval systems can learn directly from implicit feedback, while they are running. In such an online setting, algorithms need

  3. On the classification of complex vector bundles of stable rank

    Indian Academy of Sciences (India)

    According to previous observations, this would imply (under the above torsion conditions) a classification of all rank r complex vector bundles on X, for stable rank r ≥ n/2. A few partial answers to this question are known. For instance, a classical result of. Wu asserts that any couple of cohomology classes (c1,c2) ∈ H2(X, ...

  4. Economic Research at National Liberal Arts Colleges: School Rankings.

    Science.gov (United States)

    Hartley, James E.; Robinson, Michael D.

    1997-01-01

    Presents a comprehensive ranking of all national liberal arts colleges based on publications cataloged by the "Journal of Economic Literature" (JEL) from 1989-1994. Concludes that, although economics research is important at the highest ranked colleges, it remains a secondary consideration at the rest. Briefly discusses previous rankings…

  5. Rank range test for equality of dispersion | Odiase | Journal of ...

    African Journals Online (AJOL)

    This paper exploits the computational simplicity of the range of a set of data to formulate a twosample scale test called the Rank Range test. The performance of the test statistic is compared with other tests of scale. The exact distribution of the Rank Range test statistic is generated empirically through the unconditional ...

  6. Social ranking effects on tooth-brushing behaviour.

    Science.gov (United States)

    Maltby, John; Paterson, Kevin; Day, Liz; Jones, Ceri; Kinnear, Hayley; Buchanan, Heather

    2016-05-01

    A tooth-brushing social rank hypothesis is tested suggesting tooth-brushing duration is influenced when individuals position their behaviour in a rank when comparing their behaviour with other individuals. Study 1 used a correlation design, Study 2 used a semi-experimental design, and Study 3 used a randomized intervention design to examine the tooth-brushing social rank hypothesis in terms of self-reported attitudes, cognitions, and behaviour towards tooth-brushing duration. Study 1 surveyed participants to examine whether the perceived health benefits of tooth-brushing duration could be predicted from the ranking of each person's tooth-brushing duration. Study 2 tested whether manipulating the rank position of the tooth-brushing duration influenced participant-perceived health benefits of tooth-brushing duration. Study 3 used a longitudinal intervention method to examine whether messages relating to the rank positions of tooth-brushing durations causally influenced the self-report tooth-brushing duration. Study 1 demonstrates that perceptions of the health benefits from tooth-brushing duration are predicted by the perceptions of how that behaviour ranks in comparison to other people's behaviour. Study 2 demonstrates that the perceptions of the health benefits of tooth-brushing duration can be manipulated experimentally by changing the ranked position of a person's tooth-brushing duration. Study 3 experimentally demonstrates the possibility of increasing the length of time for which individuals clean their teeth by focusing on how they rank among their peers in terms of tooth-brushing duration. The effectiveness of interventions using social-ranking methods relative to those that emphasize comparisons made against group averages or normative guidelines are discussed. What is already known on this subject? Individual make judgements based on social rank information. Social rank information has been shown to influence positive health behaviours such as exercise

  7. PageRank model of opinion formation on social networks

    Science.gov (United States)

    Kandiah, Vivek; Shepelyansky, Dima L.

    2012-11-01

    We propose the PageRank model of opinion formation and investigate its rich properties on real directed networks of the Universities of Cambridge and Oxford, LiveJournal, and Twitter. In this model, the opinion formation of linked electors is weighted with their PageRank probability. Such a probability is used by the Google search engine for ranking of web pages. We find that the society elite, corresponding to the top PageRank nodes, can impose its opinion on a significant fraction of the society. However, for a homogeneous distribution of two opinions, there exists a bistability range of opinions which depends on a conformist parameter characterizing the opinion formation. We find that the LiveJournal and Twitter networks have a stronger tendency to a totalitarian opinion formation than the university networks. We also analyze the Sznajd model generalized for scale-free networks with the weighted PageRank vote of electors.

  8. CNN-based ranking for biomedical entity normalization.

    Science.gov (United States)

    Li, Haodi; Chen, Qingcai; Tang, Buzhou; Wang, Xiaolong; Xu, Hua; Wang, Baohua; Huang, Dong

    2017-10-03

    Most state-of-the-art biomedical entity normalization systems, such as rule-based systems, merely rely on morphological information of entity mentions, but rarely consider their semantic information. In this paper, we introduce a novel convolutional neural network (CNN) architecture that regards biomedical entity normalization as a ranking problem and benefits from semantic information of biomedical entities. The CNN-based ranking method first generates candidates using handcrafted rules, and then ranks the candidates according to their semantic information modeled by CNN as well as their morphological information. Experiments on two benchmark datasets for biomedical entity normalization show that our proposed CNN-based ranking method outperforms traditional rule-based method with state-of-the-art performance. We propose a CNN architecture that regards biomedical entity normalization as a ranking problem. Comparison results show that semantic information is beneficial to biomedical entity normalization and can be well combined with morphological information in our CNN architecture for further improvement.

  9. Rankings Scientists, Journals and Countries using h-Index

    Directory of Open Access Journals (Sweden)

    Gyula Mester

    2016-01-01

    Full Text Available Indexes in scientometrics are based on citations. However, in contrast to the journal impact factor, which gives only the ranking of the scientific journals, ordered by impact factor, indexes in scientometrics are suitable for ranking of scientists, scientific journals and countries. In this paper the h-index, h5-index, the World ranking the top of 25 Highly Cited Researchers (h > 100 and the ranking of 25 scientists in Hungarian Institutions according to their Google Scholar Citations public profiles are considered. These indexes (h5-index are applied for making of the list of top 20 publications (journals and proceedings in the field of Robotics. The World ranking is done of the best 50 countries according to h-index in year 2014. Data are obtained from the portal Scimago.

  10. Sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants.

    Science.gov (United States)

    Gerner, Nadine V; Cailleaud, Kevin; Bassères, Anne; Liess, Matthias; Beketov, Mikhail A

    2017-11-01

    Hydrocarbons have an utmost economical importance but may also cause substantial ecological impacts due to accidents or inadequate transportation and use. Currently, freshwater biomonitoring methods lack an indicator that can unequivocally reflect the impacts caused by hydrocarbons while being independent from effects of other stressors. The aim of the present study was to develop a sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants, which can be used in hydrocarbon-specific bioindicators. We employed the Relative Sensitivity method and developed the sensitivity ranking S hydrocarbons based on literature ecotoxicological data supplemented with rapid and mesocosm test results. A first validation of the sensitivity ranking based on an earlier field study has been conducted and revealed the S hydrocarbons ranking to be promising for application in sensitivity based indicators. Thus, the first results indicate that the ranking can serve as the core component of future hydrocarbon-specific and sensitivity trait based bioindicators.

  11. Rank Protein Immunolabeling during Bone-Implant Interface Healing Process

    Directory of Open Access Journals (Sweden)

    Francisley Ávila Souza

    2010-01-01

    Full Text Available The purpose of this paper was to evaluate the expression of RANK protein during bone-healing process around machined surface implants. Twenty male Wistar rats, 90 days old, after having had a 2 mm diameter and 6 mm long implant inserted in their right tibias, were evaluated at 7, 14, 21, and 42 days after healing. After obtaining the histological samples, slides were subjected to RANK immunostaining reaction. Results were quantitatively evaluated. Results. Immunolabeling analysis showed expressions of RANK in osteoclast and osteoblast lineage cells. The statistical analysis showed an increase in the expression of RANK in osteoblasts at 7 postoperative days and a gradual decrease during the chronology of the healing process demonstrated by mild cellular activity in the final stage (P<.05. Conclusion. RANK immunolabeling was observed especially in osteoclast and osteoblast cells in primary bone during the initial periods of bone-healing/implant interface.

  12. Rank Protein Immunolabeling during Bone-Implant Interface Healing Process

    Science.gov (United States)

    Ávila Souza, Francisley; Pereira Queiroz, Thallita; Rodrigues Luvizuto, Eloá; Nishioka, Renato Sussumu; Garcia-JR, Idelmo Rangel; de Carvalho, Paulo Sérgio Perri; Okamoto, Roberta

    2010-01-01

    The purpose of this paper was to evaluate the expression of RANK protein during bone-healing process around machined surface implants. Twenty male Wistar rats, 90 days old, after having had a 2 mm diameter and 6 mm long implant inserted in their right tibias, were evaluated at 7, 14, 21, and 42 days after healing. After obtaining the histological samples, slides were subjected to RANK immunostaining reaction. Results were quantitatively evaluated. Results. Immunolabeling analysis showed expressions of RANK in osteoclast and osteoblast lineage cells. The statistical analysis showed an increase in the expression of RANK in osteoblasts at 7 postoperative days and a gradual decrease during the chronology of the healing process demonstrated by mild cellular activity in the final stage (P < .05). Conclusion. RANK immunolabeling was observed especially in osteoclast and osteoblast cells in primary bone during the initial periods of bone-healing/implant interface. PMID:20706673

  13. Beyond Zipf's Law: The Lavalette Rank Function and its Properties

    CERN Document Server

    Fontanelli, Oscar; Yang, Yaning; Cocho, Germinal; Li, Wentian

    2016-01-01

    Although Zipf's law is widespread in natural and social data, one often encounters situations where one or both ends of the ranked data deviate from the power-law function. Previously we proposed the Beta rank function to improve the fitting of data which does not follow a perfect Zipf's law. Here we show that when the two parameters in the Beta rank function have the same value, the Lavalette rank function, the probability density function can be derived analytically. We also show both computationally and analytically that Lavalette distribution is approximately equal, though not identical, to the lognormal distribution. We illustrate the utility of Lavalette rank function in several datasets. We also address three analysis issues on the statistical testing of Lavalette fitting function, comparison between Zipf's law and lognormal distribution through Lavalette function, and comparison between lognormal distribution and Lavalette distribution.

  14. VisualRank: applying PageRank to large-scale image search.

    Science.gov (United States)

    Jing, Yushi; Baluja, Shumeet

    2008-11-01

    Because of the relative ease in understanding and processing text, commercial image-search systems often rely on techniques that are largely indistinguishable from text-search. Recently, academic studies have demonstrated the effectiveness of employing image-based features to provide alternative or additional signals. However, it remains uncertain whether such techniques will generalize to a large number of popular web queries, and whether the potential improvement to search quality warrants the additional computational cost. In this work, we cast the image-ranking problem into the task of identifying "authority" nodes on an inferred visual similarity graph and propose VisualRank to analyze the visual link structures among images. The images found to be "authorities" are chosen as those that answer the image-queries well. To understand the performance of such an approach in a real system, we conducted a series of large-scale experiments based on the task of retrieving images for 2000 of the most popular products queries. Our experimental results show significant improvement, in terms of user satisfaction and relevancy, in comparison to the most recent Google Image Search results. Maintaining modest computational cost is vital to ensuring that this procedure can be used in practice; we describe the techniques required to make this system practical for large scale deployment in commercial search engines.

  15. Journal Rankings by Health Management Faculty Members: Are There Differences by Rank, Leadership Status, or Area of Expertise?

    Science.gov (United States)

    Menachemi, Nir; Hogan, Tory H; DelliFraine, Jami L

    2015-01-01

    Health administration (HA) faculty members publish in a variety of journals, including journals focused on management, economics, policy, and information technology. HA faculty members are evaluated on the basis of the quality and quantity of their journal publications. However, it is unclear how perceptions of these journals vary by subdiscipline, department leadership role, or faculty rank. It is also not clear how perceptions of journals may have changed over the past decade since the last evaluation of journal rankings in the field was published. The purpose of the current study is to examine how respondents rank journals in the field of HA, as well as the variation in perception by academic rank, department leadership status, and area of expertise. Data were drawn from a survey of HA faculty members at U.S. universities, which was completed in 2012. Different journal ranking patterns were noted for faculty members of different subdisciplines. The health management-oriented journals (Health Care Management Review and Journal of Healthcare Management) were ranked higher than in previous research, suggesting that journal ranking perceptions may have changed over the intervening decade. Few differences in perceptions were noted by academic rank, but we found that department chairs were more likely than others to select Health Affairs in their top three most prestigious journals (β = 0.768; p different disciplines, and this perceived difference could have implications for promotion and tenure decisions.

  16. The Times Higher Education Supplement and Quacquarelli Symonds (THES - QS) World University Rankings: New Developments in Ranking Methodology

    Science.gov (United States)

    Sowter, Ben

    2008-01-01

    This paper presents key new developments in the THES - QS World University Rankings in 2007, related to enhancements to the "Peer Review", "Data Collection" and "Statistical Aggregation" utilised in this ranking as well as discussing the decision to utilise Full-Time Equivalent (FTE) figures for personnel statistics. Indicator correlation is also…

  17. The structure of completely positive matrices according to their CP-rank and CP-plus-rank

    NARCIS (Netherlands)

    Dickinson, Peter James Clair; Bomze, Immanuel M.; Still, Georg J.

    2015-01-01

    We study the topological properties of the cp-rank operator $\\mathrm{cp}(A)$ and the related cp-plus-rank operator $\\mathrm{cp}^+(A)$ (which is introduced in this paper) in the set $\\mathcal{S}^n$ of symmetric $n\\times n$-matrices. For the set of completely positive matrices, $\\mathcal{CP}^n$, we

  18. Genetic-Algorithm Discovery of a Direct-Gap and Optically Allowed Superstructure from Indirect-Gap Si and Ge Semiconductors

    Science.gov (United States)

    D'Avezac, Mayeul; Luo, Jun-Wei; Chanier, Thomas; Zunger, Alex

    2012-01-01

    Combining two indirect-gap materials—with different electronic and optical gaps—to create a direct gap material represents an ongoing theoretical challenge with potentially rewarding practical implications, such as optoelectronics integration on a single wafer. We provide an unexpected solution to this classic problem, by spatially melding two indirect-gap materials (Si and Ge) into one strongly dipole-allowed direct-gap material. We leverage a combination of genetic algorithms with a pseudopotential Hamiltonian to search through the astronomic number of variants of Sin/Gem/…/Sip/Geq superstructures grown on (001) Si1-xGex. The search reveals a robust configurational motif—SiGe2Si2Ge2SiGen on (001) SixGe1-x substrate (x≤0.4) presenting a direct and dipole-allowed gap resulting from an enhanced Γ-X coupling at the band edges.

  19. Superstructure formation in PrNi{sub 2}Al{sub 3} and ErPd{sub 2}Al{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Eustermann, Fabian; Hoffmann, Rolf-Dieter [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Janka, Oliver [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Oldenburg Univ. (Germany). Inst. fuer Chemie

    2017-09-01

    The intermetallic phase ErPd{sub 2}Al{sub 3} was obtained by arc-melting of the elements and subsequent annealing for crystal growth. The sample was studied by X-ray diffraction on powders and single crystals. The structure of ErPd{sub 2}Al{sub 3} was refined from X-ray diffraction data and revealed a superstructure of PrNi{sub 2}Al{sub 3} - a CaCu{sub 5} derivative (P6/m, a=1414.3(1), c=418.87(3) pm wR=0.0820, 1060 F{sup 2} values, 48 variables). The same superstructure was subsequently found for PrNi{sub 2}Al{sub 3} (P6/m, a=1407.87(4), c=406.19(2) pm, wR=0.0499, 904 F{sup 2} values, 47 variables). In the crystal structure, the aluminium and transition metal atoms form a polyanionic network according to [T{sub 2}Al{sub 3}]{sup δ-}, while rare earth atoms fill cavities within the networks. They are coordinated by six transition metal and twelve aluminum atoms. In contrast to the PrNi{sub 2}Al{sub 3} type structure reported so far, two crystallographic independent rare-earth sites are found of which one (1b) is shifted by 1/2 z, causing a distortion in the structure along with a recoloring of the T and Al atoms in the network.

  20. AptRank: an adaptive PageRank model for protein function prediction on   bi-relational graphs.

    Science.gov (United States)

    Jiang, Biaobin; Kloster, Kyle; Gleich, David F; Gribskov, Michael

    2017-06-15

    Diffusion-based network models are widely used for protein function prediction using protein network data and have been shown to outperform neighborhood-based and module-based methods. Recent studies have shown that integrating the hierarchical structure of the Gene Ontology (GO) data dramatically improves prediction accuracy. However, previous methods usually either used the GO hierarchy to refine the prediction results of multiple classifiers, or flattened the hierarchy into a function-function similarity kernel. No study has taken the GO hierarchy into account together with the protein network as a two-layer network model. We first construct a Bi-relational graph (Birg) model comprised of both protein-protein association and function-function hierarchical networks. We then propose two diffusion-based methods, BirgRank and AptRank, both of which use PageRank to diffuse information on this two-layer graph model. BirgRank is a direct application of traditional PageRank with fixed decay parameters. In contrast, AptRank utilizes an adaptive diffusion mechanism to improve the performance of BirgRank. We evaluate the ability of both methods to predict protein function on yeast, fly and human protein datasets, and compare with four previous methods: GeneMANIA, TMC, ProteinRank and clusDCA. We design four different validation strategies: missing function prediction, de novo function prediction, guided function prediction and newly discovered function prediction to comprehensively evaluate predictability of all six methods. We find that both BirgRank and AptRank outperform the previous methods, especially in missing function prediction when using only 10% of the data for training. The MATLAB code is available at https://github.rcac.purdue.edu/mgribsko/aptrank . gribskov@purdue.edu. Supplementary data are available at Bioinformatics online.