Sample records for skew bridges

  1. LOOKING WEST, BETWEEN READING DEPOT BRIDGE AND SKEW ARCH BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOOKING WEST, BETWEEN READING DEPOT BRIDGE AND SKEW ARCH BRIDGE (HAER No. PA-116). - Philadelphia & Reading Railroad, Reading Depot Bridge, North Sixth Street at Woodward Street, Reading, Berks County, PA

  2. TWIN SKEWED TRUSS RAILROAD BRIDGES NEAR BRIDGE STREET AT THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TWIN SKEWED TRUSS RAILROAD BRIDGES NEAR BRIDGE STREET AT THE WEST END OF THE PLANT. THIS VIEW PROBABLY LOOKING NORTHWEST. BRIDGES BUILT OVER ERIE CANAL (WHICH FLOWED RIGHT THROUGH THE MIDDLE OF THE PLANT) BY AMERICAN BRIDGE COMPANY IN 1902. SINCE THIS PHOTO WAS TAKEN, NEAR BRIDGE HAS BEEN DEMOLISHED; FAR BRIDGE IS STILL IN SERVICE. - Solvay Process Company, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  3. Evaluation of dynamic loads on a skew box girder continuous bridge Part I: Field test and modal analysis

    Microsoft Academic Search

    Demeke B. Ashebo; Tommy H. T. Chan; Ling Yu

    2007-01-01

    Field measurements were carried out to evaluate dynamic loads on an existing skew box girder continuous bridge. This paper presents the experimental procedure, the data acquisition system, the calibration test, the modal analysis and the load distribution in a transversal direction. A three-axle heavy truck was hired for use in the test to calibrate the field measurements. The static and

  4. http://rcc.its.psu.edu/hpc Guidelines for analyzing curved and skewed bridges and designing

    E-print Network

    Bjørnstad, Ottar Nordal

    Stage-3 Stage-4 Stage-5 Stage-6 Figure 1: Stage 1 to stage 6 for paired girder (inner girders placed-frame consistent detailing (4) girder and cross-frame erection sequencing along the span and with respect to girder for a curved bridge. Figure 2 shows a representative finite element model for a curved bridge. Stage-1 Stage-2

  5. Bridges

    USGS Multimedia Gallery

    Bridges from top to bottom: Expressway Bridge, Liberty Memorial Bridge, Burlington Northern SantaFe Railway Bridge, and Interstate 94 Grant Marsh Bridge. Photo taken by USGS personnel on a Civil Air Patrol flight....

  6. Skew Distribution

    NSDL National Science Digital Library

    2011-05-26

    In this activity, students adjust the median and standard deviation of a skewed Gaussian distribution. Then they can create a histogram from that distribution. This activity allows students to explore the idea of a skewed distribution. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

  7. Bridges

    NSDL National Science Digital Library

    Leske, Cavin.

    Bridges have been drawing plenty of attention lately, with numerous construction projects around the world and the controversy over the deteriorating bridge infrastructure in the US. They have been an essential part of transportation for hundreds of years, and it is the job of civil engineers to design the safest, most durable bridges possible.Bridge Basics (1) has a large list of different types of bridges with brief explanations. This is a good place for beginners to learn about various bridge designs and parts. The Web site of a nationwide engineering design contest (2) offers free West Point Bridge Designer software. This educational tool allows the user to create a custom virtual bridge model. Although this year's contest is over, another one is planned for next year. Rice University is the home of the Bridges Project (3), a comprehensive database of "all 74 1,000 ft. span bridges in the United States." For each of these, a short description and construction history are given, and some include photos and other interesting facts. The Gibraltar Bridge, a proposed nine mile bridge that connects Europe and Africa, was recently featured on the Discovery Channel's Engineering the Impossible (4). This Web site discusses its specifications, as well as the many challenges that must be overcome for it to be a reality. The Innovative Bridge Research and Construction Program (5) investigates new technologies that can be used in the "repair, rehabilitation, replacement and new construction of bridges" in the US. This is particularly important now, since a large portion of the countries bridges are badly in need of maintenance. A more specific area of research being conducted to protect bridge infrastructure involves the corrosion of steel reinforcements in concrete bridges (6). The material on this site provides an in-depth report on the findings of the Turner-Fairbank Highway Research Center. Technical reports and papers are published in the bimonthly Journal of Bridge Engineering (7). It covers almost any topic related to bridges, and is offered free online by the American Society of Civil Engineers. Fun activities for grade school students are given on this page (8). Separated into three levels of difficulty, the projects give students freedom to learn about and design any kind of bridge structure that interests them. A list of materials and criteria are given, but there are few explicit instructions, allowing for maximum creativity.

  8. Bridges

    NSDL National Science Digital Library

    2014-09-18

    Through a five-lesson series that includes numerous hands-on activities, students are introduced to the importance and pervasiveness of bridges for connecting people to resources, places and other people, with references to many historical and current-day examples. In learning about bridge types—arch, beam, truss and suspension—students explore the effect of tensile and compressive forces. Students investigate the calculations that go into designing bridges; they learn about loads and cross-sectional areas by designing and testing the strength of model piers. Geology and soils are explored as they discover the importance of foundations, bearing pressure and settlement considerations in the creation of dependable bridges and structures. Students learn about brittle and ductile material properties. Students also learn about the many cost factors that comprise the economic considerations of bridge building. Bridges are unique challenges that take advantage of the creative nature of engineering.

  9. Exact Zero Skew

    Microsoft Academic Search

    Ren-song Tsay

    1991-01-01

    An exact zero skew clock routing algorithm using the Elmore delay model is presented. Recursively in a bottom-up fashion, two zero-skewed subtrees are merged into a new tree with zero skew. The algorithm can be applied to single-staged clock trees, multi-staged clock trees, and multi-chip system clock trees. It is ideal for hierarchical methods of constructing large systems. All subsystems

  10. Skew-T Mastery

    NSDL National Science Digital Library

    2014-09-14

    Meteorologists typically examine atmospheric soundings in the course of preparing a weather forecast. The skew-T / log-P diagram provides the preferred method for analyzing these soundings. This module comprehensively examines the use of the skew-T diagram. It explores thermodynamic properties, convective parameters, stability assessment, and several forecast applications. The module is designed for both instruction and reference. It also comes with an interactive Web-based skew-T diagram that calculates several common forecast parameters.

  11. Quantum skew divergence

    NASA Astrophysics Data System (ADS)

    Audenaert, Koenraad M. R.

    2014-11-01

    In this paper, we study the quantum generalisation of the skew divergence, which is a dissimilarity measure between distributions introduced by Lee in the context of natural language processing. We provide an in-depth study of the quantum skew divergence, including its relation to other state distinguishability measures. Finally, we present a number of important applications: new continuity inequalities for the quantum Jensen-Shannon divergence and the Holevo information, and a new and short proof of Bravyi's Small Incremental Mixing conjecture.

  12. Self-dual skew codes and factorization of skew polynomials

    E-print Network

    Ulmer, Felix

    Self-dual skew codes and factorization of skew polynomials Delphine Boucher IRMAR, CNRS, UMR 6625 IRMAR, CNRS, UMR 6625, Universit´e de Rennes 1, Universit´e europ´eenne de Bretagne, Campus de Beaulieu

  13. Zero skew clock net routing

    Microsoft Academic Search

    Ting-Hai Chao; J.-M. Ho; Y.-C. Hsu

    1992-01-01

    The authors present an algorithm, called the zero skew segment tree method (ZSTM), for the clock net routing problem. To eliminate the lock skew and minimize the total wire length, ZSTM recursively partitions the sink nodes into two subsets which have equal loadings and minimum sum of diameters, and then constructs a zero skew segment tree according to the partitioning

  14. Inequalities for quantum skew information

    E-print Network

    Koenraad Audenaert; Liang Cai; Frank Hansen

    2008-07-22

    We study quantum information inequalities and show that the basic inequality between the quantum variance and the metric adjusted skew information generates all the multi-operator matrix inequalities or Robertson type determinant inequalities studied by a number of authors. We introduce an order relation on the set of functions representing quantum Fisher information that renders the set into a lattice with an involution. This order structure generates new inequalities for the metric adjusted skew informations. In particular, the Wigner-Yanase skew information is the maximal skew information with respect to this order structure in the set of Wigner-Yanase-Dyson skew informations. Key words and phrases: Quantum covariance, metric adjusted skew information, Robertson-type uncertainty principle, operator monotone function, Wigner-Yanase-Dyson skew information.

  15. Skewed graph partitioning

    SciTech Connect

    Hendrickson, B.; Leland, R. [Sandia National Labs., Albuquerque, NM (United States); Van Driessche, R. [Alcatel Telecom, Antwerp (Belgium)

    1997-02-01

    Graph partitioning is an important abstraction used in solving many scientific computing problems. Unfortunately, the standard partitioning model does not incorporate considerations that are important in many settings. We address this by describing a generalized partitioning model which incorporates the notion of partition skew and is applicable to a variety of problems. We then develop enhancements to several important partitioning algorithms necessary to solve the generalized partitioning problem. Finally we demonstrate the benefit of employing several of these generalized methods to static decomposition of parallel computing problems.

  16. Skew Killing spinors Georges Habib

    E-print Network

    Paris-Sud XI, Université de

    Skew Killing spinors Georges Habib , Julien Roth Abstract In this paper, we study the existence of a skew Killing spinor (see the definition below) on 2 and 3-dimensional Riemannian spin manifolds. We constructions (see [4, 6] for results in this topic). A -Killing spinor is a smooth section of the spinor

  17. NONNORMAL REGRESSION. I. SKEW DISTRIBUTIONS

    Microsoft Academic Search

    M. Qamarul Islam; Moti L. Tiku; F. Yildirim

    2001-01-01

    In a linear regression model of the type y= ? X+e, it is often assumed that the random error eis normally distributed. In numerous situations, e.g., when ymeasures life times or reaction times, etypically has a skew distribution. We consider two important families of skew distributions, (a) Weibull with support IR: (0, ?) on the real line, and (b) generalised

  18. Skew grids and irrotational flow

    NASA Astrophysics Data System (ADS)

    Bernard, Robert S.

    1988-03-01

    Finite-difference computation of incompressible flow through regions of arbitrary shape often requires the implementation of boundary-fitted coordinates for which the grid lines may be non-orthogonal (skew). When the governing equations are expressed in terms of pressure and velocity, conservation of mass is maintained by the gradient of the pressure. In principle, the gradient is irrotational and should have no effect on the existing circulation in the flow field; but if the grid lines are skew, the discrete representation of the gradient can generate spurious vorticity near the boundaries. In the present work this difficulty is eliminated for uniform skew grids, and markedly reduced for non-uniform skew grids, by adopting a discrete formulation of the pressure gradient that helps maintain irrotationality near boundaries. The procedure is applicable for staggered grids with either Poisson or Chorin equations for pressure.

  19. Skew resisting hydrodynamic seal

    DOEpatents

    Conroy, William T. (Pearland, TX); Dietle, Lannie L. (Sugar Land, TX); Gobeli, Jeffrey D. (Houston, TX); Kalsi, Manmohan S. (Houston, TX)

    2001-01-01

    A novel hydrodynamically lubricated compression type rotary seal that is suitable for lubricant retention and environmental exclusion. Particularly, the seal geometry ensures constraint of a hydrodynamic seal in a manner preventing skew-induced wear and provides adequate room within the seal gland to accommodate thermal expansion. The seal accommodates large as-manufactured variations in the coefficient of thermal expansion of the sealing material, provides a relatively stiff integral spring effect to minimize pressure-induced shuttling of the seal within the gland, and also maintains interfacial contact pressure within the dynamic sealing interface in an optimum range for efficient hydrodynamic lubrication and environment exclusion. The seal geometry also provides for complete support about the circumference of the seal to receive environmental pressure, as compared the interrupted character of seal support set forth in U.S. Pat. Nos. 5,873,576 and 6,036,192 and provides a hydrodynamic seal which is suitable for use with non-Newtonian lubricants.

  20. Is a Brownian motion skew? Anotine Lejay

    E-print Network

    Paris-Sud XI, Université de

    Is a Brownian motion skew? Anotine Lejay Ernesto Mordecki Soledad Torres December 10, 2010 Abstract to the observation of a trajectory of a Skew Brownian motion, through a uniform time discretization. We charac in this case are non-classical, under the null hypothesis of the Skew Brownian motion being an usual Brownian

  1. Factor Analysis for Skewed Data and Skew-Normal Maximum Likelihood Factor Analysis

    E-print Network

    Gaucher, Beverly Jane

    2013-04-04

    Beverly Jane Gaucher ABSTRACT This research explores factor analysis applied to data from skewed distributions for the general skew model, the selection-elliptical model, the selection-normal model, the skew-elliptical model and the skew-normal model... and Main Properties . . . . . . . . . . . . . . . 15 2.4.3 Spherical Distributions and Elliptical Distributions . . . . 16 2.4.4 The Multivariate Elliptically Contoured Distribution . . . 17 2.4.5 The Unified Skew-Elliptical Distribution...

  2. Bridge permeameter

    DOEpatents

    Graf, Darin C. (Edgewood, NM); Warpinski, Norman R. (Albuquerque, NM)

    1996-01-01

    A system for single-phase, steady-state permeability measurements of porous rock utilizes a fluid bridge arrangement analogous to a Wheatstone bridge. The arms of the bridge contain the sample and calibrated flow resistors.

  3. Three Bridge Fryer's Ford Bridge, Nimrod Bridge, and Ward's ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Three Bridge - Fryer's Ford Bridge, Nimrod Bridge, and Ward's Crossing Bridge - Fryer's Ford Bridge, Spanning East Fork of Point Remove Creek at Fryer Bridge Road (CR 67), Solgohachia, Conway County, AR

  4. A New Framework for Join Product Skew

    E-print Network

    Afrati, Foto; Lekeas, Paraskevas V; Souliou, Dora

    2010-01-01

    Different types of data skew can result in load imbalance in the context of parallel joins under the shared nothing architecture. We study one important type of skew, join product skew (JPS). A static approach based on frequency classes is proposed which takes for granted the data distribution of join attribute values. It comes from the observation that the join selectivity can be expressed as a sum of products of frequencies of the join attribute values. As a consequence, an appropriate assignment of join sub-tasks, that takes into consideration the magnitude of the frequency products can alleviate the join product skew. Motivated by the aforementioned remark, we propose an algorithm, called Handling Join Product Skew (HJPS), to handle join product skew.

  5. Associative skew clock routing for difficult instances 

    E-print Network

    Kim, Min-seok

    2006-08-16

    by: Chair of Committee, Jiang Hu Committee Members, Weiping Shi Eun J. Kim Head of Department, Costas N. Georghiades May 2006 Major Subject: Electrical Engineering iii ABSTRACT Associative Skew Clock Routing for Difficult Instances. (May 2006) Min...-seok Kim, B.S., Texas A&M University Chair of Advisory Committee: Dr. Jiang Hu This thesis studies the associative skew clock routing problem, which seeks a clock routing tree such that zero skew is preserved only within identified groups of sinks. Al...

  6. A New Framework for Join Product Skew

    Microsoft Academic Search

    Foto N. Afrati; Victor Kyritsis; Paraskevas V. Lekeas; Dora Souliou

    2010-01-01

    Different types of data skew can result in load imbalance in the context of\\u000aparallel joins under the shared nothing architecture. We study one important\\u000atype of skew, join product skew (JPS). A static approach based on frequency\\u000aclasses is proposed which takes for granted the data distribution of join\\u000aattribute values. It comes from the observation that the join

  7. Straw Bridges

    NSDL National Science Digital Library

    2012-03-20

    Learners design, build and test a model bridge out of straws. The bridge must span 25 cm across a gap between two tables or two chairs. To measure the load, the bridge must securely hold a small cup. Learners test the load by placing as many pennies in the cup as possible and counting how many the bridge can hold.

  8. Flexible Class of Skew-Symmetric Distributions

    E-print Network

    Genton, Marc G.

    1. Introduction A popular approach to achieve departures from normality consists of modifying define flexible skew-normal and skew-t distributions that can have more than one mode. This is an essenti illustrative examples for the fibreglass data, the simulated data from a mixture of two normal distributions

  9. Popsicle Bridge

    NSDL National Science Digital Library

    IEEE

    2013-08-30

    In this activity, learners explore how engineering has impacted the development of bridges over time, including innovative designs and the challenge of creating bridges that become landmarks for a city. Learners work in teams of "engineers" to design and build their own bridge out of glue and popsicle sticks. Learners test their bridges using weights, evaluate their results, and present their findings to the group.

  10. Spaghetti Bridge

    NSDL National Science Digital Library

    COSI

    2009-01-01

    In this engineering activity, learners investigate the differences between the strength of bridges made from flat and round building materials. They construct simple bridges out of linguine, which has a rectangular shape, and spaghetti, which has a circular shape. They then test and compare the weight capacity of the bridges.

  11. Bridge permeameter

    DOEpatents

    Graf, D.C.; Warpinski, N.R.

    1996-08-13

    A system is described for single-phase, steady-state permeability measurements of porous rock which utilizes a fluid bridge arrangement analogous to a Wheatstone bridge. The arms of the bridge contain the sample and calibrated flow resistors. 8 figs.

  12. Spaghetti Bridge

    NSDL National Science Digital Library

    K-12 Outreach Office,

    Civil engineers design structures such as buildings, dams, highways and bridges. Student teams explore the field of engineering by making bridges using spaghetti as their primary building material. Then they test their bridges to see how much weight they can carry before breaking.

  13. Designing Bridges

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program and Laboratory,

    Students learn about the types of possible loads, how to calculate ultimate load combinations, and investigate the different sizes for the beams (girders) and columns (piers) of simple bridge design. Students learn the steps that engineers use to design bridges: understanding the problem, determining the potential bridge loads, calculating the highest possible load, and calculating the amount of material needed to resist the loads.

  14. SKEW QUADRUPOLE FOCUSING LATTICES AND APPLICATIONS.

    SciTech Connect

    PARKER,B.

    2001-06-18

    In this paper we revisit using skew quadrupole fields in place of traditional normal upright quadrupole fields to make beam focusing structures. We illustrate by example skew lattice decoupling, dispersion suppression and chromatic correction using the neutrino factory Study-II muon storage ring design. Ongoing BNL investigation of flat coil magnet structures that allow building a very compact muon storage ring arc and other flat coil configurations that might bring significant magnet cost reduction to a VLHC motivate our study of skew focusing.

  15. COMPUTER VISION FOR INTERACTIVE SKEWED VIDEO PROJECTION

    E-print Network

    Colombo, Carlo

    COMPUTER VISION FOR INTERACTIVE SKEWED VIDEO PROJECTION Alessandro Brazzini Carlo Colombo Dipartimento di Sistemi e Informatica, Via Santa Marta 3, I-50139 Firenze, Italy colombo@dsi.unifi.it Abstract

  16. Modular classes of skew algebroid relations

    E-print Network

    Janusz Grabowski

    2011-08-11

    Skew algebroid is a natural generalization of the concept of Lie algebroid. In this paper, for a skew algebroid E, its modular class mod(E) is defined in the classical as well as in the supergeometric formulation. It is proved that there is a homogeneous nowhere-vanishing 1-density on E* which is invariant with respect to all Hamiltonian vector fields if and only if E is modular, i.e. mod(E)=0. Further, relative modular class of a subalgebroid is introduced and studied together with its application to holonomy, as well as modular class of a skew algebroid relation. These notions provide, in particular, a unified approach to the concepts of a modular class of a Lie algebroid morphism and that of a Poisson map.

  17. Associative skew clock routing for difficult instances

    E-print Network

    Kim, Min-seok

    2006-08-16

    ASSOCIATIVE SKEW CLOCK ROUTING FOR DIFFICULT INSTANCES A Thesis by MIN-SEOK KIM Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 2006 Major Subject...: Electrical Engineering ASSOCIATIVE SKEW CLOCK ROUTING FOR DIFFICULT INSTANCES A Thesis by MIN-SEOK KIM Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved...

  18. Skew chicane based betatron eigenmode exchange module

    DOEpatents

    Douglas, David (Yorktown, VA)

    2010-12-28

    A skewed chicane eigenmode exchange module (SCEEM) that combines in a single beamline segment the separate functionalities of a skew quad eigenmode exchange module and a magnetic chicane. This module allows the exchange of independent betatron eigenmodes, alters electron beam orbit geometry, and provides longitudinal parameter control with dispersion management in a single beamline segment with stable betatron behavior. It thus reduces the spatial requirements for multiple beam dynamic functions, reduces required component counts and thus reduces costs, and allows the use of more compact accelerator configurations than prior art design methods.

  19. Preference patterns for skewed gambles in rhesus monkeys.

    PubMed

    Strait, Caleb E; Hayden, Benjamin Y

    2013-01-01

    While standard models of risky choice account for the first and second statistical moments of reward outcome distributions (mean and variance, respectively), they often ignore the third moment, skewness. Determining a decision-maker's attitude about skewness is useful because it can help constrain process models of the mental steps involved in risky choice. We measured three rhesus monkeys' preferences for gambles whose outcome distributions had almost identical means and variances but differed in skewness. We tested five distributions of skewness: strong negative, weak negative, normal, weak positive and strong positive. Monkeys preferred positively skewed gambles to negatively skewed ones and preferred strongly skewed and normal (i.e. unskewed) gambles to weakly skewed ones. This pattern of preferences cannot be explained solely by monotonic deformations of the utility curve or any other popular single account, but can be accounted for by multiple interacting factors. PMID:24335272

  20. Preference patterns for skewed gambles in rhesus monkeys

    PubMed Central

    Strait, Caleb E.; Hayden, Benjamin Y.

    2013-01-01

    While standard models of risky choice account for the first and second statistical moments of reward outcome distributions (mean and variance, respectively), they often ignore the third moment, skewness. Determining a decision-maker's attitude about skewness is useful because it can help constrain process models of the mental steps involved in risky choice. We measured three rhesus monkeys’ preferences for gambles whose outcome distributions had almost identical means and variances but differed in skewness. We tested five distributions of skewness: strong negative, weak negative, normal, weak positive and strong positive. Monkeys preferred positively skewed gambles to negatively skewed ones and preferred strongly skewed and normal (i.e. unskewed) gambles to weakly skewed ones. This pattern of preferences cannot be explained solely by monotonic deformations of the utility curve or any other popular single account, but can be accounted for by multiple interacting factors. PMID:24335272

  1. Multivariate Skew-t Distributions in Econometrics and Environmetrics 

    E-print Network

    Marchenko, Yulia V.

    2012-02-14

    . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 II A HECKMAN SELECTION-T MODEL . . . . . . . . . . . . . 9 A. Heckman Selection Models . . . . . . . . . . . . . . . . . . 11 1. Classical Heckman sample-selection model . . . . . . . 12 2. Link to extended skew-elliptical distributions... of lean body mass on weight and height. . . . 71 11 Skew-t regression of lean body mass on weight and height. . . . . . . 72 12 Skew-normal regression analysis of the AIS data. . . . . . . . . . . . 85 13 Skew-normal regression of lean body mass...

  2. Volume and skewness in international equity markets

    Microsoft Academic Search

    Elaine Hutson; Colm Kearney; Margaret Lynch

    2008-01-01

    We examine the relation between trading volume and skewness in 11 international stock markets using daily and monthly data from January 1980 to August 2004. We construct single equation and VAR models of the relation between the first three moments of market returns and trading volumes. Our results show hitherto unrecognised channels of influence, and support the investor heterogeneity approach

  3. Irreducible complex skew-Berger algebras

    Microsoft Academic Search

    Anton S. Galaev

    2008-01-01

    Irreducible skew-Berger algebras $\\\\g\\\\subset\\\\gl(n,\\\\Co)$, i.e. algebras spanned by the images of the linear maps $R:\\\\odot^2\\\\Co^n\\\\to\\\\g$ satisfying the Bianchi identity, are classified. These Lie algebras can be interpreted as irreducible complex Berger superalgebras contained in $\\\\gl(0|n,\\\\Co)$.

  4. Irreducible complex skew-Berger algebras

    Microsoft Academic Search

    Anton S. Galaev

    2009-01-01

    Irreducible skew-Berger algebras g?gl(n,C), i.e. algebras spanned by the images of the linear maps R:?2Cn?g satisfying the Bianchi identity, are classified. These Lie algebras can be interpreted as irreducible complex Berger superalgebras contained in gl(0|n,C).

  5. Symmetry detection through local skewed symmetries

    E-print Network

    Cham, Tat Jen

    Symmetry detection through local skewed symmetries Tat-Jen Cham and Roberto Cipolla We explore how global symmetry can be detected prior to segmentation and under noise and occlusion. The definition of local symmetries is extended to affine geometries by consider- ing the tangents and curvatures of local

  6. Fast Seamless Skew and Orientation Detection in Document Images

    Microsoft Academic Search

    Iuliu Vasile Konya; Stefan Eickeler; Christoph Seibert

    2010-01-01

    Reliable and generic methods for skew detection are a necessity for any large-scale digitization projects. As one of the first processing steps, skew detection and correction has a heavy influence on all further document analysis modules, such as geometric and logical layout analysis. This paper introduces a generic, scale-independent algorithm capable of accurately detecting the global skew angle of document

  7. Skewed Bessel Function Distribution with Application to Rainfall Data

    E-print Network

    Sidorov, Nikita

    Skewed Bessel Function Distribution with Application to Rainfall Data S. Nadarajah, H. M and Statistics Group School of Mathematics, The University of Manchester #12;Skewed Bessel Function Distribution attention in the last few years. In this note, a skewed Bessel function distribution with the pdf f(x) = 2g

  8. Fractionfree Row Reduction of Matrices of Skew Polynomials

    E-print Network

    Waterloo, University of

    matri­ ces. These are transformations which convert a matrix of skew polynomials into one where the rank Cheng y and George Labahn z Abstract We present a new algorithm for row reduction of a matrix of skew fraction­free methods. At the same time the method is fast: for an m \\Theta s matrix of input skew

  9. Metric adjusted skew information: Convexity and restricted forms of superadditivity

    E-print Network

    Liang Cai; Frank Hansen

    2009-08-24

    We give a truly elementary proof of the convexity of metric adjusted skew information following an idea of Effros. We extend earlier results of weak forms of superadditivity to general metric adjusted skew informations. Recently, Luo and Zhang introduced the notion of semi-quantum states on a bipartite system and proved superadditivity of the Wigner-Yanase-Dyson skew informations for such states. We extend this result to general metric adjusted skew informations. We finally show that a recently introduced extension to parameter values $ 1skew information.

  10. Basswood Bridges

    NSDL National Science Digital Library

    Abramowitz, Harvey

    The Elementary Engineering Design course for freshmen students at Purdue University Calumet consists of two components: one ME and one EE. Due to the two part structure and in order to expose the students to the faculty, it is also team taught. The course counts as two credits, with the format one hour lecture and three hours lab. The basswood bridge is the major project of the ME half and counts for one quarter of the total course grade. The object, as is usual with bridge projects, is to design, build and test a truss bridge having a high strength to weight ratio. The design process includes statics analysis in combination with the tensile and compressive properties of the basswood. The details of the project from initial design to final testing are provided.

  11. Bridged graphite oxide materials

    NASA Technical Reports Server (NTRS)

    Herrera-Alonso, Margarita (Inventor); McAllister, Michael J. (Inventor); Aksay, Ilhan A. (Inventor); Prud'homme, Robert K. (Inventor)

    2010-01-01

    Bridged graphite oxide material comprising graphite sheets bridged by at least one diamine bridging group. The bridged graphite oxide material may be incorporated in polymer composites or used in adsorption media.

  12. A process capability index sensitive to skewness

    Microsoft Academic Search

    Peter A. Wright

    1995-01-01

    A new process capability indexCs, is proposed which extends the most useful index to date, the Pearn-Kotz-Johnson Cpmk, by not only taking into account that the process mean may not lie midway between the specification limits and incorporating a penalty when the mean deviates from its target, but also incorporating a penalty for skewness. The new index is specifically designed

  13. Bridge Inspector's Training Manual.

    ERIC Educational Resources Information Center

    Federal Highway Administration (DOT), Washington, DC. Bureau of Public Roads.

    A guide for the instruction of bridge inspectors is provided in this manual as well as instructions for conducting and reporting on a bridge inspection. The chapters outline the qualifications necessary to become a bridge inspector. The subject areas covered are: The Bridge Inspector, Bridge Structures, Bridge Inspection Reporting System,…

  14. The Belizean Bridge Activity.

    ERIC Educational Resources Information Center

    Murfin, Brian

    2000-01-01

    Describes the famous swing bridge in Belize. Students build bridges from a variety of materials and answer the questions, What are different types of bridges?, How do bridges work?, How can you tell if a bridge design will be safe?, and What is the best way to build a bridge over a river while still allowing boat traffic? (SAH)

  15. Digital Bridges: Bridges of the Nineteenth Century

    NSDL National Science Digital Library

    2002-01-01

    The collection consists of thirty representative 19th-century American bridge engineering monographs, manuals, and documents from the Lehigh University Libraries' Special Collections. The source documents have been scanned, converted to text, and partially corrected to make all significant terms and personal and proper names retrievable through the site's search engine. Topics include specific bridges (the Brooklyn Bridge, the East River Bridge), bridge types (suspension bridges, wrought iron bridges), bridge components (cabling, foundations), bridge design, bridge disasters, and others. The collection is browseable by title and searchable by keyword. Printable versions of the documents are also available. A glossary is also provided with definitions of terms, short biographies of authors, and descriptions of some of the bridges

  16. Bayesian inference for finite mixtures of univariate and multivariate skew-normal and skew-t distributions.

    PubMed

    Frühwirth-Schnatter, Sylvia; Pyne, Saumyadipta

    2010-04-01

    Skew-normal and skew-t distributions have proved to be useful for capturing skewness and kurtosis in data directly without transformation. Recently, finite mixtures of such distributions have been considered as a more general tool for handling heterogeneous data involving asymmetric behaviors across subpopulations. We consider such mixture models for both univariate as well as multivariate data. This allows robust modeling of high-dimensional multimodal and asymmetric data generated by popular biotechnological platforms such as flow cytometry. We develop Bayesian inference based on data augmentation and Markov chain Monte Carlo (MCMC) sampling. In addition to the latent allocations, data augmentation is based on a stochastic representation of the skew-normal distribution in terms of a random-effects model with truncated normal random effects. For finite mixtures of skew normals, this leads to a Gibbs sampling scheme that draws from standard densities only. This MCMC scheme is extended to mixtures of skew-t distributions based on representing the skew-t distribution as a scale mixture of skew normals. As an important application of our new method, we demonstrate how it provides a new computational framework for automated analysis of high-dimensional flow cytometric data. Using multivariate skew-normal and skew-t mixture models, we could model non-Gaussian cell populations rigorously and directly without transformation or projection to lower dimensions. PMID:20110247

  17. A General Class of Multivariate Skew-Elliptical Distributions

    Microsoft Academic Search

    Márcia D. Branco; Dipak K. Dey

    2001-01-01

    This paper proposes a general class of multivariate skew-elliptical distributions. We extend earlier results on the so-called multivariate skew-normal distribution. This family of distributions contains the multivariate normal, Student's t, exponential power, and Pearson type II, but with an extra parameter to regulate skewness. We also obtain the moment generating functions and study some distributional properties. Several examples are provided.

  18. The additive logistic skew-normal distribution on the simplex

    Microsoft Academic Search

    G. Mateu-Figueras; V. Pawlowsky-Glahn; C. Barceló-Vidal

    2005-01-01

    There is a dearth of suitable models with which to adequately model compositional data sets, especially those which exhibit skewness after additive logratio-transformation. In order to address this deficit we propose the additive logistic skew-normal distribution, an extension to the additive logistic normal model on the simplex derived from the skew-normal distribution in real space. The purpose of this paper

  19. Influence analyses of skew-normal\\/independent linear mixed models

    Microsoft Academic Search

    Camila B. Zeller; Filidor V. Labra; Victor H. Lachos; N. Balakrishnan

    2010-01-01

    A extension of some diagnostic procedures to skew-normal\\/independent linear mixed models is discussed. This class provides a useful generalization of normal (and skew-normal) linear mixed models since it is assumed that the random effects and the random error terms follow jointly a multivariate skew-normal\\/independent distribution. Inspired by the EM algorithm, a local influence analysis for linear mixed models, following Zhu

  20. Building Bridges

    NSDL National Science Digital Library

    Roger Day

    2000-01-01

    In this lesson, students build bridges from arithmetical to algebraic thinking by exploring problems that are not limited to single-solution responses. Values organized into tables and graphs are used to move toward symbolic representations. Problem situations at the middle school level involve linear, quadratic, and exponential models. The site is valuable not only for its problems for students but also for the teaching strategy illustrated here.

  1. Inferring climate variability from skewed proxy records

    NASA Astrophysics Data System (ADS)

    Emile-Geay, J.; Tingley, M.

    2013-12-01

    Many paleoclimate analyses assume a linear relationship between the proxy and the target climate variable, and that both the climate quantity and the errors follow normal distributions. An ever-increasing number of proxy records, however, are better modeled using distributions that are heavy-tailed, skewed, or otherwise non-normal, on account of the proxies reflecting non-normally distributed climate variables, or having non-linear relationships with a normally distributed climate variable. The analysis of such proxies requires a different set of tools, and this work serves as a cautionary tale on the danger of making conclusions about the underlying climate from applications of classic statistical procedures to heavily skewed proxy records. Inspired by runoff proxies, we consider an idealized proxy characterized by a nonlinear, thresholded relationship with climate, and describe three approaches to using such a record to infer past climate: (i) applying standard methods commonly used in the paleoclimate literature, without considering the non-linearities inherent to the proxy record; (ii) applying a power transform prior to using these standard methods; (iii) constructing a Bayesian model to invert the mechanistic relationship between the climate and the proxy. We find that neglecting the skewness in the proxy leads to erroneous conclusions and often exaggerates changes in climate variability between different time intervals. In contrast, an explicit treatment of the skewness, using either power transforms or a Bayesian inversion of the mechanistic model for the proxy, yields significantly better estimates of past climate variations. We apply these insights in two paleoclimate settings: (1) a classical sedimentary record from Laguna Pallcacocha, Ecuador (Moy et al., 2002). Our results agree with the qualitative aspects of previous analyses of this record, but quantitative departures are evident and hold implications for how such records are interpreted, and compared to other proxy records. (2) a multiproxy reconstruction of temperature over the Common Era (Mann et al., 2009), where we find that about one third of the records display significant departures from normality. Accordingly, accounting for skewness in proxy predictors has a notable influence on both reconstructed global mean and spatial patterns of temperature change. Inferring climate variability from skewed proxy records thus requires cares, but can be done with relatively simple tools. References - Mann, M. E., Z. Zhang, S. Rutherford, R. S. Bradley, M. K. Hughes, D. Shindell, C. Ammann, G. Faluvegi, and F. Ni (2009), Global signatures and dynamical origins of the little ice age and medieval climate anomaly, Science, 326(5957), 1256-1260, doi:10.1126/science.1177303. - Moy, C., G. Seltzer, D. Rodbell, and D. Anderson (2002), Variability of El Niño/Southern Oscillation activ- ity at millennial timescales during the Holocene epoch, Nature, 420(6912), 162-165.

  2. Skew quad compensation for SPEAR minibeta optics

    SciTech Connect

    Wille, K.

    1984-06-01

    With the new minibeta insertion for SPEAR the betatron coupling and the perturbations of beam optics caused by the solenoid field of the MARK III detector can't be compensated by the simple coils used so far. Therefore another scheme with four skew quads arranged in two families has been chosen. Even though this scheme doesn't compensate the effect of the solenoid on the beam completely, the residual emittance coupling is much less than 1% which should be sufficient under all running conditions. The major advantage of this concept is its simplicity.

  3. Factor Analysis for Skewed Data and Skew-Normal Maximum Likelihood Factor Analysis 

    E-print Network

    Gaucher, Beverly Jane

    2013-04-04

    . . . . . . . . . . . . . . 33 2.11 Review of Selected Literature for Non-Normal Factor Analysis . . 34 2.11.1 Factor Analysis for Non-Normally Distributed Data . . . . 34 2.11.2 The Skew-Normal Factor Model . . . . . . . . . . . . . . . 41 3. FACTOR ANALYSIS FOR DATA FROM...

  4. Evolution and models for skewed parton distributions

    E-print Network

    Musatov, I V

    2000-01-01

    We discuss the structure of the ``forward visible'' (FW) parts of double and skewed distributions related to usual distributions through reduction relations. We use factorized models for double distributions (DDs) f(x, alpha) in which one factor coincides with the usual (forward) parton distribution and another specifies the profile characterizing the spread of the longitudinal momentum transfer. The model DDs are used to construct skewed parton distributions (SPDs). For small skewedness, the FW parts of SPDs H(x, xi) can be obtained by averaging forward parton densities f(x- xi alpha) with the weight rho (alpha) coinciding with the profile function of the double distribution f(x, alpha) at small x. We show that if the x^n moments f_n (alpha) of DDs have the asymptotic (1-alpha^2)^{n+1} profile, then the alpha-profile of f (x,alpha) for small x is completely determined by small-x behavior of the usual parton distribution. We demonstrate that, for small xi, the model with asymptotic profiles for f_n (alpha) is...

  5. Evolution and models for skewed parton distribution

    SciTech Connect

    Musatov, I.C.; Radyushkin, A.V.

    1999-05-17

    The authors discuss the structure of the ''forward visible'' (FW) parts of double and skewed distributions related to usual distributions through reduction relations. They use factorized models for double distributions (DDs) {tilde f}(x,{alpha}) in which one factor coincides with the usual (forward) parton distribution and another specifies the profile characterizing the spread of the longitudinal momentum transfer. The model DDs are used to construct skewed parton distributions (SPDs). For small skewedness, the FW parts of SPDs H ({tilde x},{xi}) can be obtained by averaging forward parton densities f({tilde x}-{xi}{alpha}) with the weight {rho}({alpha}) coinciding with the profile function of the double distribution {tilde f}(x, {alpha}) at small x. They show that if the x{sup n} moments {tilde f}{sub n}({alpha}) of DDs have the asymptotic (1-{alpha}{sup 2}){sup n+1} profile, then the {alpha}-profile of {tilde f}(x,{alpha}) for small x is completely determined by small-x behavior of the usual parton distribution. They demonstrate that, for small {xi}, the model with asymptotic profiles for {tilde f}{sub n}({alpha}) is equivalent to that proposed recently by Shuvaev et al., in which the Gegenbauer moments of SPDs do not depend on {xi}. They perform a numerical investigation of the evolution patterns of SPDs and give interpretation of the results of these studies within the formalism of double distributions.

  6. Modelling Scalar Skewness in Cloudy Boundary Layers

    NASA Astrophysics Data System (ADS)

    Mironov, Dmitrii; Machulskaya, Ekaterina; Naumann, Ann Kristin; Seifert, Axel; Mellado, Juan Pedro

    2015-04-01

    Following the pioneering work of Sommeria and Deardorff (1977), statistical cloud schemes are widely used in numerical weather prediction (NWP) and climate models to parameterize the effect of shallow clouds on turbulent mixing and radiation fluxes. Statistical cloud schemes compute the cloud fraction, the amount of cloud condensate and the effect clouds on the buoyancy flux in a given atmospheric-model grid box. This is done with due regard for the sub-grid scale (SGS) fluctuations of temperature and humidity (and possibly the vertical velocity), thus providing an important coupling between cloudiness and the SGS mixing processes. The shape of the PDF of fluctuating fields is assumed, whereas the PDF moments should be provided to the cloud scheme as an input. For non-precipitation clouds, the mixing schemes are usually formulated in terms of quasi-conservative variable, e.g. the liquid (total) water potential temperature and the total water specific humidity. Then, the cloud schemes are conveniently cast in terms of the linearized saturation deficit, referred to as the "s" variable (Mellor 1977), that accounts for the combined effect of the two scalars. If a simple two-parameter single-Gaussian PDF is used, the only "turbulence" parameter to be provided to the cloud scheme is the variance of s. The single-Gaussian PDF ignores the skewed nature of SGS motions and fails to describe many important regimes, e.g. shallow cumuli. A number of more flexible skewed PDFs have been proposed to date. A three-parameter PDF, based on a double-Gaussian distribution and diagnostic relations between some PDF parameters derived from LES and observational data (Naumann et al. 2013), appears to be a good compromise between physical realism and computational economy. A crucial point is that the cloud schemes using non-Gaussian PDFs require the scalar skewness as an input. Using rather mild non-restrictive assumptions, we develop a transport equation for the s-variable triple correlation. That equation contains three terms that require closure. A simple relaxation approximation in terms of the turbulence time (length) scale is used for the dissipation term. The third-order and the fourth-order scalar-velocity correlations are parameterized using an advanced advection-diffusion formulation and a generalized Millionschikov hypothesis (Mironov et al. 1999, Gryanik et al. 2005). These formulations satisfy both the Gaussian limit and, importantly, the limit of strong skewness. The equation for the s triple correlation is coupled to the turbulence kinetic energy (TKE) - scalar variance mixing scheme (Machulskaya and Mironov 2013), where not only the TKE but also the scalar variances and covariance are computed from the prognostic transport equations with due regard for the third-order transport. The coupled scheme is tested through single-column numerical experiments. Results compare favourably with large-eddy simulation data from well-documented shallow cloud cases. Some details of the implementation of the s-skewness formulation into NWP models are discussed.

  7. Analysis of horizontally curved post-tensioned segmental concrete box girder bridges

    Microsoft Academic Search

    Rafael Manuel Rojas

    1993-01-01

    This report presents the background and details of a numerical procedure developed specifically for the longitudinal analysis of curved segmentally erected prestressed concrete box girder bridges. It is based on a skew ended thin-wall beam element including the modes of warping and distorsion of the cross section. The cross section must consist of a single cell, may have overhangs, and

  8. Bridge Builders

    NSDL National Science Digital Library

    2010-01-01

    In this interactive game, students build bridges using fractional lengths in the form of fraction bars. Gap length may be known or unknown, entirely empty or partially filled. Fractions to fill the gap must be constructed in specific ways, using the four basic operations. After five tries at one level, the game resets. Note that the game sometimes expects particular answers: students may need to multiply 2/5 by 3 rather than multiplying 3/5 by 2, for example, even though both computations would produce the same result.

  9. Wiener–Hopf Solution for Impenetrable Wedges at Skew Incidence

    Microsoft Academic Search

    Vito G. Daniele; Guido Lombardi

    2006-01-01

    A new Wiener-Hopf approach for the solution of impenetrable wedges at skew incidence is presented. Mathematical aspects are described in a unified and consistent theory for angular region problems. Solutions are obtained using analytical and numerical-analytical approaches. Several numerical tests from the scientific literature validate the new technique, and new solutions for anisotropic surface impedance wedges are solved at skew

  10. ON THE SPECTRUM OF SKEW-SHIFT SCHRODINGER HELGE KRUGER

    E-print Network

    Krueger, Helge

    ON THE SPECTRUM OF SKEW-SHIFT SCHR¨ODINGER OPERATORS HELGE KR¨UGER Abstract. I prove that the spectrum of a skew-shift Schr¨odinger operator contains larges interval in the semi-classical regime-classical regime, that is for h > 0 sufficiently small, I will show that the spectrum of the operator Hh contains

  11. EXPLOSION POINTS IN SKEW MAPS Anne Stefanie Costolanski

    E-print Network

    Sander, Evelyn

    EXPLOSION POINTS IN SKEW MAPS by Anne Stefanie Costolanski A Thesis Submitted to the Graduate: Summer Semester 2007 George Mason University Fairfax, VA #12;Explosion Points in Skew Maps A thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2.7 Crises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2.8 Explosions

  12. Colony nutrition skews reproduction in a social spider

    Microsoft Academic Search

    Mor Salomon; David Mayntz; Yael Lubin

    2008-01-01

    Cooperative breeding societies are characterized by alloparental care and unequal distribution of reproduction (skewed reproduction). Competition for resources among group members may determine the reproductive outcome of each individual. In a spider colony, females feed together on prey and therefore may compete over the extraction of specific nutrients required for reproduction. Here we examined the occurrence of skewed reproduction in

  13. Zero skew clock routing in multiple-clock synchronous systems

    Microsoft Academic Search

    Wasini Khan; M. Hossain; Naveed Sherwani

    1992-01-01

    A clock routing algorithm for two-phase clock systems is presented. The algorithm, which minimizes both intraclock skew and interclock skew, has been implemented on SPARC 1+ in C and has been tested on several industrial benchmarks as well as on randomly generated examples. In particular, the result was tested for a 267 synchronous component circuit at clock rates of 100

  14. Female reproductive synchrony predicts skewed paternity across primates

    Microsoft Academic Search

    Julia Ostner; Charles L. Nunn; Oliver Schülke

    2008-01-01

    Recent studies have uncovered remarkable variation in paternity within primate groups. To date, however, we lack a general understanding of the factors that drive variation in paternity skew among primate groups and across species. Our study focused on hypotheses from reproductive skew theory involving limited control and the use of paternity \\

  15. Investigating the Investigative Task: Testing for Skewness--An Investigation of Different Test Statistics and Their Power to Detect Skewness

    ERIC Educational Resources Information Center

    Tabor, Josh

    2010-01-01

    On the 2009 AP[c] Statistics Exam, students were asked to create a statistic to measure skewness in a distribution. This paper explores several of the most popular student responses and evaluates which statistic performs best when sampling from various skewed populations. (Contains 8 figures, 3 tables, and 4 footnotes.)

  16. Cracked shells under skew-symmetric loading

    NASA Technical Reports Server (NTRS)

    Lelale, F.

    1982-01-01

    A shell containing a through crack in one of the principal planes of curvature and under general skew-symmetric loading is considered. By employing a Reissner type shell theory which takes into account the effect of transverse shear strains, all boundary conditions on the crack surfaces are satisfied separately. Consequently, unlike those obtained from the classical shell theory, the angular distributions of the stress components around the crack tips are shown to be identical to the distributions obtained from the plane and antiplane elasticity solutions. Extensive results are given for axially and circumferentially cracked cylindrical shells, spherical shells, and toroidal shells under uniform inplane shearing, out of plane shearing, and torsion. The effect of orthotropy on the results is also studied.

  17. Incorporating covariates in skewed functional data models.

    PubMed

    Li, Meng; Staicu, Ana-Maria; Bondell, Howard D

    2015-07-01

    We introduce a class of covariate-adjusted skewed functional models (cSFM) designed for functional data exhibiting location-dependent marginal distributions. We propose a semi-parametric copula model for the pointwise marginal distributions, which are allowed to depend on covariates, and the functional dependence, which is assumed covariate invariant. The proposed cSFM framework provides a unifying platform for pointwise quantile estimation and trajectory prediction. We consider a computationally feasible procedure that handles densely as well as sparsely observed functional data. The methods are examined numerically using simulations and is applied to a new tractography study of multiple sclerosis. Furthermore, the methodology is implemented in the R package cSFM, which is publicly available on CRAN. PMID:25527820

  18. Female reproductive synchrony predicts skewed paternity across primates

    PubMed Central

    Nunn, Charles L.; Schülke, Oliver

    2008-01-01

    Recent studies have uncovered remarkable variation in paternity within primate groups. To date, however, we lack a general understanding of the factors that drive variation in paternity skew among primate groups and across species. Our study focused on hypotheses from reproductive skew theory involving limited control and the use of paternity “concessions” by investigating how paternity covaries with the number of males, female estrous synchrony, and rates of extragroup paternity. In multivariate and phylogenetically controlled analyses of data from 27 studies on 19 species, we found strong support for a limited control skew model, with reproductive skew within groups declining as female reproductive synchrony and the number of males per group increase. Of these 2 variables, female reproductive synchrony explained more of the variation in paternity distributions. To test whether dominant males provide incentives to subordinates to resist matings by extragroup males, that is, whether dominants make concessions of paternity, we derived a novel prediction that skew is lower within groups when threat from outside the group exists. This prediction was not supported as a primary factor underlying patterns of reproductive skew among primate species. However, our approach revealed that if concessions occur in primates, they are most likely when female synchrony is low, as these conditions provide alpha male control of paternity that is assumed by concessions models. Collectively, our analyses demonstrate that aspects of male reproductive competition are the primary drivers of reproductive skew in primates. PMID:19018288

  19. The Significance of Edge-Barrier Pinning in Superconducting Bridges

    NASA Astrophysics Data System (ADS)

    Barnes, Paul; Jones, Wesley; Mullins, Matthew; Baca, Francisco; Haugan, Timothy

    2010-03-01

    Edge-barrier pinning in thin superconducting films provides additional pinning over that of the bulk pinning. When using bridges greater than 1 ?m to determine the critical current density (Jc) of films, this additional pinning is typically ignored. However, theoretical and experimental data presented here indicate that this pinning enhancement is non-negligible with bridge widths of less than 100 ?m and on par with the bulk pinning at a few microns. In the present study, bridges in YBa2Cu3O7-? (YBCO) thin films were repeatedly narrowed to avoid issues of sample to sample variation. Bridge widths starting at 500 ?m and 50 ?m were patterned by photolithography with subsequent narrowing performed by photolithography and focused ion beam milling, respectively. Transport Jc was determined after each bridge size. Theoretical analysis follows that of J.R Clem [e.g. Elistratov et al, Phys. Rev. B 66, 220506 (2002)]. Theoretical implications of the narrow bridge effect on Jc(H) and Jc(T) plots are not simple scalar changes. Based on these results presented here, two key points are: 1) Jc data comparison among institutions using different bridge sizes can provide improper conclusions (similarly as not accounting for film thickness), and 2) the Jc(T) and Jc(H) curve shapes are skewed differently for different widths. The implication of these effects will be discussed.

  20. Bayesian QTL mapping using skewed Student-t distributions

    PubMed Central

    von Rohr, Peter; Hoeschele, Ina

    2002-01-01

    In most QTL mapping studies, phenotypes are assumed to follow normal distributions. Deviations from this assumption may lead to detection of false positive QTL. To improve the robustness of Bayesian QTL mapping methods, the normal distribution for residuals is replaced with a skewed Student-t distribution. The latter distribution is able to account for both heavy tails and skewness, and both components are each controlled by a single parameter. The Bayesian QTL mapping method using a skewed Student-t distribution is evaluated with simulated data sets under five different scenarios of residual error distributions and QTL effects. PMID:11929622

  1. Boxed Skew Plane Partition and Integrable Phase Model

    E-print Network

    Keiichi Shigechi; Masaru Uchiyama

    2005-10-02

    We study the relation between the boxed skew plane partition and the integrable phase model. We introduce a generalization of a scalar product of the phase model and calculate it in two ways; the first one in terms of the skew Schur functions, and another one by use of the commutation relations of operators. In both cases, a generalized scalar product is expressed as a determinant. We show that a special choice of the spectral parameters of a generalized scalar product gives the generating function of the boxed skew plane partition.

  2. Quantifying morphology changes in time series data with skew

    E-print Network

    Sung, Phil

    This paper examines strategies to quantify differences in the morphology of time series while accounting for time skew in the observed data. We adapt four measures originally designed for signal shape comparison: Dynamic ...

  3. Summarizing and Mining Skewed Data Streams Graham Cormode

    E-print Network

    Summarizing and Mining Skewed Data Streams Graham Cormode S. Muthukrishnan Abstract Many applications generate massive data streams. Sum- marizing such massive data requires fast, small space algo bounds. Keywords: data stream analysis, data mining, Zipf distribution, power laws, heavy hitters

  4. Arnold-Chiari malformation and nystagmus of skew

    PubMed Central

    Pieh, C.; Gottlob, I.

    2000-01-01

    The Arnold-Chiari malfomation is typically associated with downbeat nystagmus. Eye movement recordings in two patients with Arnold-Chiari malfomation type 1 showed, in addition to downbeat and gaze evoked nystagmus, intermittent nystagmus of skew. To date this finding has not been reported in association with Arnold-Chiari malfomation. Nystagmus of skew should raise the suspicion of Arnold-Chiari malfomation and prompt sagittal head MRI examination.?? PMID:10864619

  5. Skewed exponential pairwise velocities from Gaussian initial conditions

    SciTech Connect

    Juszkiewicz, R. [Warsaw, Copernicus Astron (Poland); Fisher, K. B. [Princeton Univ., Princeton, NJ (United States); Szapudi, I. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    1998-09-01

    Using an Eulerian perturbative calculation, we show that the distribution of relative pairwise velocities which arises from gravitational instability of Gaussian density fluctuations has asymmetric (skewed) exponential tails. The negative skewness is induced by the negative mean streaming velocity of pairs (the infall prevails over expansion), while the exponential tails arise because the relative pairwise velocity is a number, not volume weighted statistic. The derived probability distribution is compared with N-body simulations and shown to provide a reasonable fit.

  6. Derivations and skew derivations of the Grassmann algebras

    E-print Network

    Bavula, V V

    2007-01-01

    Surprisingly, skew derivations rather than ordinary derivations are more basic (important) object in study of the Grassmann algebras. Let $\\L_n = K\\lfloor x_1, ..., x_n\\rfloor$ be the Grassmann algebra over a commutative ring $K$ with ${1/2}\\in K$, and $\\d$ be a skew $K$-derivation of $\\L_n$. It is proved that $\\d$ is a unique sum $\\d = \\d^{ev} +\\d^{od}$ of an even and odd skew derivation. Explicit formulae are given for $\\d^{ev}$ and $\\d^{od}$ via the elements $\\d (x_1), ..., \\d (x_n)$. It is proved that the set of all even skew derivations of $\\L_n$ coincides with the set of all the inner skew derivations. Similar results are proved for derivations of $\\L_n$. In particular, $\\Der_K(\\L_n)$ is a faithful but not simple $\\Aut_K(\\L_n)$-module (where $K$ is reduced and $n\\geq 2$). All differential and skew differential ideals of $\\L_n$ are found. It is proved that the set of generic normal elements of $\\L_n$ that are not units forms a single $\\Aut_K(\\L_n)$-orbit (namely, $\\Aut_K(\\L_n)x_1$) if $n$ is even and two...

  7. Derivations and skew derivations of the Grassmann algebras

    E-print Network

    V. V. Bavula

    2007-04-29

    Surprisingly, skew derivations rather than ordinary derivations are more basic (important) object in study of the Grassmann algebras. Let $\\L_n = K\\lfloor x_1, ..., x_n\\rfloor$ be the Grassmann algebra over a commutative ring $K$ with ${1/2}\\in K$, and $\\d$ be a skew $K$-derivation of $\\L_n$. It is proved that $\\d$ is a unique sum $\\d = \\d^{ev} +\\d^{od}$ of an even and odd skew derivation. Explicit formulae are given for $\\d^{ev}$ and $\\d^{od}$ via the elements $\\d (x_1), ..., \\d (x_n)$. It is proved that the set of all even skew derivations of $\\L_n$ coincides with the set of all the inner skew derivations. Similar results are proved for derivations of $\\L_n$. In particular, $\\Der_K(\\L_n)$ is a faithful but not simple $\\Aut_K(\\L_n)$-module (where $K$ is reduced and $n\\geq 2$). All differential and skew differential ideals of $\\L_n$ are found. It is proved that the set of generic normal elements of $\\L_n$ that are not units forms a single $\\Aut_K(\\L_n)$-orbit (namely, $\\Aut_K(\\L_n)x_1$) if $n$ is even and two orbits (namely, $\\Aut_K(\\L_n)x_1$ and $\\Aut_K(\\L_n)(x_1+x_2... x_n)$) if $n$ is odd.

  8. Extension of EMA to address regional skew and low outliers

    USGS Publications Warehouse

    Griffis, V.W.; Stedinger, J.R.; Cohn, T.A.

    2003-01-01

    The recently developed expected moments algorithm [EMA] (Cohn et al. 1997) does as well as MLEs at estimating LP3 flood quantiles using systematic and historical information. Needed extensions include use of a regional skewness estimator and its precision to be consistent with Bulletin 17B and to make use of such hydrologic information. Another issue addressed by Bulletin 17B is the treatment of low outliers. A Monte Carlo study illustrates the performance of an extended EMA estimator compared to estimators that employ the complete data set with and without use of regional skew, conditional probability adjustment from Bulletin 17B, and an estimator that uses probability plot regression to compute substitute values for low outliers. Estimators that use a regional skew all do better than estimators that fail to use an informative regional skewness estimator. For LP3 data, the low outlier rejection procedure results in no loss of overall accuracy, and the differences between the MSEs of the estimators that used an informative regional skew were generally negligible in the skew range of real interest.

  9. Surfacing of concrete bridges

    Microsoft Academic Search

    Vibeke Wegan

    The estimated life for concrete bridges in Denmark is 100 years. One condition to en- sure this long lifetime is waterproofing of the bridge deck together with a high quality asphalt pavement. The surfacing of the concrete bridge deck is important because the concrete should be protected against water and de-icing salts since these factors can lead to reduction of

  10. Load distribution effects and repair procedures for existing skewed plate girder bridges 

    E-print Network

    Crozier, Allen R

    1992-01-01

    cracking in the web-to-flange weld as well as at the termination of the connection plate to web weldment. While these cracks are not life threatening, they still need to be dealt with. Figure 6 illustrates the locations of these forms of fatigue... of the steels used at that time and not the detail itself. Unfortunately, these gaps were permitted by the design code for many years even as welding technology improved and the metallurgical understanding of steels and brittle fracture increased...

  11. On Optimal Backward Perturbation Analysis for the Linear System with Skew Circulant Coefficient Matrix

    PubMed Central

    Jiang, Zhaolin; Shen, Nuo; Zhou, Jianwei

    2013-01-01

    We first give the style spectral decomposition of a special skew circulant matrix C and then get the style decomposition of arbitrary skew circulant matrix by making use of the Kronecker products between the elements of first row in skew circulant and the special skew circulant C. Besides that, we obtain the singular value of skew circulant matrix as well. Finally, we deal with the optimal backward perturbation analysis for the linear system with skew circulant coefficient matrix on the base of its style spectral decomposition. PMID:24369488

  12. Bayesian partial linear model for skewed longitudinal data.

    PubMed

    Tang, Yuanyuan; Sinha, Debajyoti; Pati, Debdeep; Lipsitz, Stuart; Lipshultz, Steven

    2015-07-01

    Unlike majority of current statistical models and methods focusing on mean response for highly skewed longitudinal data, we present a novel model for such data accommodating a partially linear median regression function, a skewed error distribution and within subject association structures. We provide theoretical justifications for our methods including asymptotic properties of the posterior and associated semiparametric Bayesian estimators. We also provide simulation studies to investigate the finite sample properties of our methods. Several advantages of our method compared with existing methods are demonstrated via analysis of a cardiotoxicity study of children of HIV-infected mothers. PMID:25792623

  13. Skewness and kurtosis of measured raindrop size distributions

    NASA Astrophysics Data System (ADS)

    Yangang, Liu

    Skewness and kurtosis are used to investigate particle size distributions. A quantitative method is introduced to distinguish between a gamma distribution and an exponential (e.g. Marshall-Palmer) distribution. For this method, two "deviation coefficients" are introduced, which are the skewness and the square root of the kurtosis of the measured distributions divided by their values for an exponential distribution. The method is illustrated with data for raindrop size distributions from four case studies and demonstrates that the data are inadequately described by the Marshall-Palmer distribution, although it does appear to be an "equilibrium" distribution toward which steady precipitation appears to tend.

  14. Cluster Rendering of Skewed Datasets via Visualization Keke Chen Ling Liu

    E-print Network

    Liu, Ling

    Cluster Rendering of Skewed Datasets via Visualization Keke Chen Ling Liu College of Computing clustering approach with visualization techniques, aiming at the datasets that have skewed cluster information visualization methods into the clustering process in order to enhance the understanding

  15. Arc voltage distribution skewness as an indicator of electrode gap during vacuum arc remelting

    DOEpatents

    Williamson, R.L.; Zanner, F.J.; Grose, S.M.

    1998-01-13

    The electrode gap of a VAR is monitored by determining the skewness of a distribution of gap voltage measurements. A decrease in skewness indicates an increase in gap and may be used to control the gap. 4 figs.

  16. Arc voltage distribution skewness as an indicator of electrode gap during vacuum arc remelting

    DOEpatents

    Williamson, Rodney L. (Albuquerque, NM); Zanner, Frank J. (Sandia Park, NM); Grose, Stephen M. (Glenwood, WV)

    1998-01-01

    The electrode gap of a VAR is monitored by determining the skewness of a distribution of gap voltage measurements. A decrease in skewness indicates an increase in gap and may be used to control the gap.

  17. Numerical computation of deflating subspaces of skew-Hamiltonian/Hamiltonian pencils

    E-print Network

    Benner, P.; Byers, Ralph; Mehrmann, V.; Xu, Hongguo

    2002-07-09

    to the general case of skew- Hamiltonian/ Hamiltonian pencils. The algorithms circumvent problems with skew- Hamiltonian/ Hamiltonian matrix pencils that lack structured Schur forms by embedding them into matrix pencils that always admit a structured Schur form...

  18. LOOKING WNW, CHEVROLET AVENUE BRIDGE CROSSING FLINT RIVER. BRIDGE CONNECTED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOOKING WNW, CHEVROLET AVENUE BRIDGE CROSSING FLINT RIVER. BRIDGE CONNECTED NORTH AND SOUTH PORTIONS OF FACTORY COMPLEX. DANIEL LUTEN DESIGNED THE BRIDGE, AND ILLINOIS BRIDGE COMPANY BUILT IT IN 1918. THE BRIDGE WAS THE SITE OF THE BATTLE OF RUNNING BULLS IN THE 1936-1937 GM SIT DOWN STRIKE. - Delphi Flint West, 300 Chevrolet Avenue, Flint, Genesee County, MI

  19. Classifying Data Streams with Skewed Class Distributions and Concept Drifts

    Microsoft Academic Search

    Jing Gao; Bolin Ding; Wei Fan; Jiawei Han; Philip S. Yu

    2008-01-01

    Classification is an important data analysis tool that uses a model built from historical data to predict class labels for new observations. More and more applications are featuring data streams, rather than finite stored data sets, which are a challenge for traditional classification algorithms. Concept drifts and skewed distributions, two common properties of data stream applications, make the task of

  20. Integrated Placement and Skew Optimization for Rotary Clocking

    E-print Network

    Hu, Jiang

    issues. Ro- tary clocking is a novel technique which employs untermi- nated rings formed by differential clocking requires latch locations to match pre-designed clock skew on rotary clock rings. This require] is a promising approach. The basic component of a rotary clock is a pair of cross-connected differential trans

  1. Casting with Skewed Ejection Direction Hee-Kap Ahn1

    E-print Network

    Cheng, Siu-Wing

    Casting with Skewed Ejection Direction Hee-Kap Ahn1 Siu-Wing Cheng2 Otfried Cheong3 Abstract Casting is a manufacturing process in which liquid is poured into a cast (mould) that has a cavity with the shape of the object to be manufactured. The liquid then hardens, after which the cast is removed. We

  2. Electronic skewing circuit monitors exact position of object underwater

    NASA Technical Reports Server (NTRS)

    Roller, R.; Yaroshuk, N.

    1967-01-01

    Linear Variable Differential Transformer /LVDT/ electronic skewing circuit guides a long cylindrical capsule underwater into a larger tube so that it does not contact the tube wall. This device detects movement of the capsule from a reference point and provides a continuous signal that is monitored on an oscilloscope.

  3. Thermocline Feedback Influence on Indian Ocean Dipole Skewness

    NASA Astrophysics Data System (ADS)

    Ng, B.; Cai, W.; Walsh, K. J.

    2014-12-01

    A positive Indian Ocean Dipole (IOD) tends to have stronger cold sea surface temperature anomalies (SSTAs) over the eastern Indian Ocean with greater impacts than warm SSTAs that occur during its negative phase. These impacts from positive IODs range from drought over Australia and Indonesia, to flooding over East Africa and India. Two feedbacks have been suggested as the cause of positive IOD skewness, a positive Bjerknes feedback and a negative SST-cloud-radiation (SCR) feedback, but their relative importance is debated. Using models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) and inter-model statistics, we show that the most important process for IOD skewness is an asymmetry in the thermocline feedback, whereby SSTAs respond to thermocline depth anomalies more strongly during the positive phase than negative phase. This asymmetric thermocline feedback drives IOD skewness despite positive IODs receiving greater damping from the SCR feedback. In response to global warming, although the thermocline feedback strengthens, its asymmetry between positive and negative IODs weakens. This behaviour change explains the reduction in IOD skewness that many models display under global warming.

  4. Assistant detection of skewed data streams classification in cloud security

    Microsoft Academic Search

    Qun Song; Jun Zhang; Qian Chi

    2010-01-01

    Data stream in the cloud is characterized by imbalanced distribution and concept drift. To solve the problem of classification of skewed and concept drift data stream in cloud security, we present an one-class classifier dynamic ensemble method which aims at separating virus data, reducing the amount of data analyzed in clouds, improving the efficiency of intrusion detection in cloud security

  5. Default Bayesian Analysis of the Skew-Normal Distribution

    Microsoft Academic Search

    Brunero Liseo; Nicola Loperfido

    Abstract The Skew Normal (SN, hereafter) class of densities has posed several and interesting inferential problems. In particular, the maximum likelihood estimator of the shape parameter ‚ may take infinite values with positive sampling probability. To over- come these problems we propose an objective Bayesian approach, based on reference priors. We show that the reference prior for ‚ is proper

  6. SKEW PRODUCTS, QUANTITATIVE RECURRENCE, SHRINKING TARGETS AND DECAY OF CORRELATIONS

    E-print Network

    Boyer, Edmond

    SKEW PRODUCTS, QUANTITATIVE RECURRENCE, SHRINKING TARGETS AND DECAY OF CORRELATIONS STEFANO examples of systems of this kind having not the shrinking target property, and having a trivial limit.2. Upper bound on decay of correlations 8 4. Quantitative recurrence, shrinking targets and arithmetical

  7. Portfolio optimization for t and skewed-t Quantitative Trader

    E-print Network

    Aluffi, Paolo

    Portfolio optimization for t and skewed-t returns Wenbo Hu Quantitative Trader Bell Trading 111 W distributed, but what should the portfolio manager do about this, and is it worth the effort? As we describe on how much available return can be captured by an optimal portfolio on the efficient frontier. #12

  8. Portfolio optimization for Student t and skewed t returns

    E-print Network

    Portfolio optimization for Student t and skewed t returns Wenbo Hu Quantitative Trader Bell Trading returns are not Normally distributed, but what should the portfolio manager do about this, and is it worth of distribution has a significant effect on how much available return can be captured by an optimal portfolio

  9. Skew reduction for synchronous OE-VLSI receiver applications

    Microsoft Academic Search

    Michael B. Venditti; Joshua D. Schwartz; David V. Plant

    2004-01-01

    A dc photocurrent rejection technique for optically differential receivers is proposed to reduce the sensitivity of receiver latency to variations in average input photocurrent. This is particularly attractive in optoelectronic very large scale integration applications, where array-scale nonuniformity is significant. Using optically enabled ring oscillator experiments, we demonstrate that the technique is capable of removing between 50%-75% of the skew

  10. Properties of the Robinson-Schensted correspondence for oscillating and skew oscillating tableaux

    E-print Network

    Chauve, Cedric

    Properties of the Robinson-Schensted correspondence for oscillating and skew oscillating tableaux, p 141-152, 1999. #12; PROPERTIES OF THE ROBINSON-SCHENSTED CORRESPONDENCE FOR OSCILLATING AND SKEW consider the Robinson-Schensted correspondence for oscillating tableaux and skew oscillating tableaux de#12

  11. A geometric version of the Robinson-Schensted correspondence for skew oscillating tableaux

    E-print Network

    Chauve, Cedric

    A geometric version of the Robinson-Schensted correspondence for skew oscillating tableaux Cedric; A GEOMETRIC VERSION OF THE ROBINSON-SCHENSTED CORRESPONDENCE FOR SKEW OSCILLATING TABLEAUX CEDRIC CHAUVE AND SERGE DULUCQ Abstract. We consider an analogue of the Robinson-Schensted correspondence for skew oscil

  12. Observations of intra-wave suspended sediment transport under acceleration-skewed oscillatory flow

    Microsoft Academic Search

    G. Ruessink; H. Michallet; D. Hurther; P. Silva

    2008-01-01

    In the nearshore, waves transform from skewed shoaling waves to asymmetric breaking waves. Velocity skewness, such as found beneath Stokes second-order waves, generally results in a net onshore sediment transport. Recent numerical studies and limited experimental laboratory data have demonstrated the potential importance of acceleration skewness to onshore sediment transport beneath asymmetric, 'saw- tooth' waves. Here, we investigate new full-scale

  13. Estimation of Time Varying Skewness and Kurtosis with an Application to Value at Risk

    Microsoft Academic Search

    Jonathan Graeme Dark

    2010-01-01

    This paper generalizes the Hyperbolic Asymmetric Power ARCH (HYAPARCH) model to allow for time varying skewness and kurtosis in the conditional distribution. This is done by modeling the conditional skewness and degrees of freedom of the skewed Student's t distribution of Lambert and Laurent (2001) as a function of the conditioning information. The proposed specification nests a large number of

  14. 3-D Analytical and Numerical Modeling of Tubular Actuators With Skewed Permanent Magnets

    Microsoft Academic Search

    B. L. J. Gysen; K. J. Meessen; J. J. H. Paulides; E. A. Lomonova

    2011-01-01

    This paper considers analytical and numerical techniques to model the magnetic field distribution in a tubular actuator with skewed permanent magnets (PMs). A fast 3-D analytical model based on Fourier analysis is developed for calculation of the various field components resulting from the skewed PMs for various skewing topologies. This techniques provides means for validating the assumptions of 2.5-D multilayer

  15. Semiconductor bridge (SCB) detonator

    DOEpatents

    Bickes, R.W. Jr.; Grubelich, M.C.

    1999-01-19

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge (SCB) igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length. 3 figs.

  16. Semiconductor bridge (SCB) detonator

    DOEpatents

    Bickes, Jr., Robert W. (Albuquerque, NM); Grubelich, Mark C. (Albuquerque, NM)

    1999-01-01

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

  17. Root waving and skewing: unexpectedly in micro-g.

    PubMed

    Roux, Stanley J

    2012-01-01

    Gravity has major effects on both the form and overall length of root growth. Numerous papers have documented these effects (over 300 publications in the last 5 years), the most well-studied being gravitropism, which is a growth re-orientation directed by gravity toward the earth's center. Less studied effects of gravity are undulations due to the regular periodic change in the direction root tips grow, called waving, and the slanted angle of growth roots exhibit when they are growing along a nearly-vertical surface, called skewing. Although diverse studies have led to the conclusion that a gravity stimulus is needed for plant roots to show waving and skewing, the novel results just published by Paul et al. (2012) reveal that this conclusion is not correct. In studies carried out in microgravity on the International Space Station, the authors used a new imaging system to collect digital photographs of plants every six hours during 15 days of spaceflight. The imaging system allowed them to observe how roots grew when their orientation was directed not by gravity but by overhead LED lights, which roots grew away from because they are negatively phototropic. Surprisingly, the authors observed both skewing and waving in spaceflight plants, thus demonstrating that both growth phenomena were gravity independent. Touch responses and differential auxin transport would be common features of root waving and skewing at 1-g and micro-g, and the novel results of Paul et al. will focus the attention of cell and molecular biologists more on these features as they try to decipher the signaling pathways that regulate root skewing and waving. PMID:23217095

  18. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM BELOW, SHOWING VALVE TOWER TO RIGHT. VIEW FACING NORTH - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  19. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM ENTRY. VIEW FACING NORTHWEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  20. GOETHALS BRIDGE FROM NORTH SIDE OVER ARTHUR KILL. RAILROAD BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GOETHALS BRIDGE FROM NORTH SIDE OVER ARTHUR KILL. RAILROAD BRIDGE IN FOREGROUND - Goethals Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  1. Plans: Poop Deck, Boat Deck, Housetop, Bridge Deck, Upper Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Plans: Poop Deck, Boat Deck, Housetop, Bridge Deck, Upper Bridge Deck, Navigating Bridge, Forecastle Deck, Upper Deck, Second Deck and Hold - Saugatuck, James River Reserve Fleet, Newport News, Newport News, VA

  2. 1. VIEW OF SWING BRIDGE FROM KEDZIE AVENUE BRIDGE, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF SWING BRIDGE FROM KEDZIE AVENUE BRIDGE, LOOKING EAST. - Chicago, Madison & Northern Railroad, Sanitary & Ship Canal Bridge, Spanning Sanitary & Ship Canal, east of Kedzie Avenue, Chicago, Cook County, IL

  3. A novel bridge scour monitoring and prediction system

    NASA Astrophysics Data System (ADS)

    Valyrakis, Manousos; Michalis, Panagiotis; Zhang, Hanqing

    2015-04-01

    Earth's surface is continuously shaped due to the action of geophysical flows. Erosion due to the flow of water in river systems has been identified as a key problem in preserving ecological health but also a threat to our built environment and critical infrastructure, worldwide. As an example, it has been estimated that a major reason for bridge failure is due to scour. Even though the flow past bridge piers has been investigated both experimentally and numerically, and the mechanisms of scouring are relatively understood, there still lacks a tool that can offer fast and reliable predictions. Most of the existing formulas for prediction of bridge pier scour depth are empirical in nature, based on a limited range of data or for piers of specific shape. In this work, the use of a novel methodology is proposed for the prediction of bridge scour. Specifically, the use of an Adaptive Neuro-Fuzzy Inference System (ANFIS) is proposed to estimate the scour depth around bridge piers. In particular, various complexity architectures are sequentially built, in order to identify the optimal for scour depth predictions, using appropriate training and validation subsets obtained from the USGS database (and pre-processed to remove incomplete records). The model has five variables, namely the effective pier width (b), the approach velocity (v), the approach depth (y), the mean grain diameter (D50) and the skew to flow. Simulations are conducted with data groups (bed material type, pier type and shape) and different number of input variables, to produce reduced complexity and easily interpretable models. Analysis and comparison of the results indicate that the developed ANFIS model has high accuracy and outstanding generalization ability for prediction of scour parameters. The effective pier width (as opposed to skew to flow) is amongst the most relevant input parameters for the estimation. Training of the system to new bridge geometries and flow conditions can be achieved by obtaining real time data, via novel electromagnetic sensors monitoring scour depth. Once the model is trained with data representative of the new system, bridge scour prediction can be performed for high/design flows or floods.

  4. Bryce Canyon Natural Bridge

    USGS Multimedia Gallery

    The Bryce Canyon Natural Bridge. Technically, this is not a natural bridge, which forms when running water erodes a tunnel into a rock formation. Instead, this is a natural arch, similar to the ones in nearby Arches National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is...

  5. Bridge Program Planning Guide

    NSDL National Science Digital Library

    Jenkins, Davis

    This report discusses bridge training programs which are designed to "prepare individuals without the requisite basic skills for postsecondary training leading to career-path employment and further learning in a specific industry or occupational sector." This guide is intended to help those representing community colleges, community organizations, and others plan the development of bridge training programs.

  6. STEM Bridge Scholarship Program

    E-print Network

    Buehrer, R. Michael

    2015-2016 STEM Bridge Scholarship Program Virginia Space Grant Consortium (VSGC) provides renewable STEM Bridge Scholarships of $1,000 to sophomore students from any federally recognized minority group enrolled full-time in a program of study in science, technology, engineering, or math (STEM) at one

  7. Virtual Bridge Design Challenge

    ERIC Educational Resources Information Center

    Mitts, Charles R.

    2013-01-01

    This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

  8. Bridge Monitoring and Loading

    E-print Network

    of a dedicated opera- tional modal analysis suite of hardware and software, and the increasing realisation;2 Bridge-Friendly Truck Suspensions Short-span bridge dynamic responses to heavy vehicle crossing events can be reduced through adjustment of the vehicle suspension damping coefficient just before

  9. Pedestrian excitation of bridges

    Microsoft Academic Search

    D E Newland

    2004-01-01

    This paper reviews the evidence on dynamic bridge loading caused by moving pedestrians. The phenomenon of ' synchronization' by which people respond naturally to an oscillating bridge when this has a frequency close to their natural walking or running frequency is a feature of this phenomenon. By increasing modal damping, synchronization can be prevented, but how much damping is needed

  10. Building Our Bridge to Fun!

    NSDL National Science Digital Library

    AMPS GK-12 Program,

    Students identify different bridge designs and construction materials used in modern day engineering. They work in construction teams to create paper bridges and spaghetti bridges based on existing bridge designs. Students progressively realize the importance of the structural elements in each bridge. They also measure vertical displacements under the center of the spaghetti bridge span when a load is applied. Vertical deflection is measured using a LEGO® MINDSTORMS® NXT intelligent brick and ultrasonic sensor. As they work, students experience tension and compression forces acting on structural elements of the two bridge prototypes. In conclusion, students discuss the material properties of paper and spaghetti and compare bridge designs with performance outcomes.

  11. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007...MARITIME SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge...Bridge-to-bridge radiotelephone installation. Use of the...

  12. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007...MARITIME SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge...Bridge-to-bridge radiotelephone installation. Use of the...

  13. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007...MARITIME SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge...Bridge-to-bridge radiotelephone installation. Use of the...

  14. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007...MARITIME SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge...Bridge-to-bridge radiotelephone installation. Use of the...

  15. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007...MARITIME SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge...Bridge-to-bridge radiotelephone installation. Use of the...

  16. Skewness and Kurtosis Risks of Quality Control in Overlay Inspection

    NASA Astrophysics Data System (ADS)

    Sato, Takashi; Ikeda, Takahiro; Kasa, Kentaro; Asano, Masafumi; Sato, Yasuharu

    2010-06-01

    The population of overlay errors in layer-to-layer structures in semiconductor manufacturing often obeys non-normal distribution functions such as elliptic, rectangular, and skewed distributions. Thus, there can be many wrong diagnoses of quality control that can lead to consumer's risk and producer's risk. In a lot acceptance test, a product should be judged by variables rather than by attributes because of the small sample size. A new acceptance test by variables was introduced for a non-normal population. It included sample skewness and kurtosis as well as mean and standard deviations. Using operating characteristic (OC) curves, it was shown that sampling inspection by variables can be applied safely to a strong non-normal population with new variables.

  17. Skewness and Kurtosis Risks of Quality Control in Overlay Inspection

    NASA Astrophysics Data System (ADS)

    Takashi Sato,; Takahiro Ikeda,; Kentaro Kasa,; Masafumi Asano,; Yasuharu Sato,

    2010-06-01

    The population of overlay errors in layer-to-layer structures in semiconductor manufacturing often obeys non-normal distribution functions such as elliptic, rectangular, and skewed distributions. Thus, there can be many wrong diagnoses of quality control that can lead to consumer’s risk and producer’s risk. In a lot acceptance test, a product should be judged by variables rather than by attributes because of the small sample size. A new acceptance test by variables was introduced for a non-normal population. It included sample skewness and kurtosis as well as mean and standard deviations. Using operating characteristic (OC) curves, it was shown that sampling inspection by variables can be applied safely to a strong non-normal population with new variables.

  18. Newspaper Coverage of Intimate Partner Violence: Skewing Representations of Risk

    PubMed Central

    Carlyle, Kellie E.; Slater, Michael D.; Chakroff, Jennifer L.

    2011-01-01

    How media portray intimate partner violence (IPV) has implications for public perceptions and social policy. Therefore, to better understand these portrayals, this study content analyzes a nationally representative sample of newspaper coverage of IPV over a two-year-period and compares this coverage to epidemiological data in order to examine the implications of the discrepancies between coverage and social reality. Stratified media outlets across the country were used to obtain a representative sample of daily newspapers based on their designated market areas, resulting in 395 IPV-related articles. Results show that newspaper framing of IPV tends to be heavily skewed toward episodic framing. In addition, there are significant differences between our data and epidemiological estimates, particularly in the coverage of homicide and use of alcohol and illegal drugs, which may skew public perceptions of risk. Implications for public perceptions and social policy are discussed. PMID:21297889

  19. SKEW QUADRUPOLES IN RHIC DIPOLE MAGNETS AT HIGH FIELDS.

    SciTech Connect

    JAIN, A.; GUPTA, P.; THOMPSON, P.; WANDERER, P.

    1995-06-11

    In the RHIC arc dipoles, the center of the cold mass lies above the center of the cryostat. At the maximum design field, the magnetic flux lines leak through the yoke to the asymmetrically located cryostat, which provides an additional return path. This introduces a systematic top-bottom asymmetry leading to a skew quadrupole term at high fields. A similar asymmetry is also created by any difference in weights of the upper and the lower yoke halves. Data from measurements of several RHIC dipoles are presented to study this effect. In the current production series of the RDIC dipoles, an attempt is made to compensate the effect of the cryostat by an asymmetry in the iron yoke. Seven dipoles with this type of yoke have been cold tested, and show a reduced saturation in the skew quadrupole term, as expected.

  20. Skew quadrupole in RHIC dipole magnets at high fields

    SciTech Connect

    Jain, A.; Gupta, R.; Thompson, P.; Wanderer, P. [Brookhaven National Lab., Upton, NY (United States)] [Brookhaven National Lab., Upton, NY (United States)

    1996-07-01

    In the RHIC are dipoles, the center of the cold mass lies above the center of the cryostat. At the maximum design field, the magnetic flux lines leak through the yoke to the asymmetrically located cryostat, which provides an additional return path. This introduces a systematic top-bottom asymmetry leading to a skew quadrupole term at high fields. A similar asymmetry is also created by any difference in weights of the upper and the lower yoke halves. Data from measurements of several RHIC dipoles are presented to study this effect. In the current production series of the RHIC dipoles, an attempt is made to compensate the effect of the cryostat by an asymmetry in the iron yoke. Seven dipoles with this type of yoke have been cold tested, and show a reduced saturation in the skew quadrupole term, as expected.

  1. Skew quadrupole in RHIC dipole magnets at high fields

    SciTech Connect

    Jain, A.; Gupta, P.; Thompson, P.; Wanderer, P.

    1995-07-01

    In the RHIC arc dipoles, the center of the cold mass lies above the center of the cryostat. At the maximum design field, the magnetic flux lines leak through the yoke to the asymmetrically located cryostat, which provides an additional return path. This introduces a systematic top-bottom asymmetry leading to a skew quadrupole term at high fields. A similar asymmetry is also created by any difference in weights of the upper and the lower yoke halves. Data from measurements of several RHIC dipoles are presented to study this effect. In the current production series of the RHIC dipoles, an attempt is made to compensate the effect of the cryostat by an asymmetry in the iron yoke. Seven dipoles with this type of yoke have been cold tested, and show a reduced saturation in the skew quadrupole term, as expected.

  2. Universal relation between skewness and kurtosis in complex dynamics

    NASA Astrophysics Data System (ADS)

    Cristelli, Matthieu; Zaccaria, Andrea; Pietronero, Luciano

    2012-06-01

    We identify an important correlation between skewness and kurtosis for a broad class of complex dynamic systems and present a specific analysis of earthquake and financial time series. Two regimes of non-Gaussianity can be identified: a parabolic one, which is common in various fields of physics, and a power law one, with exponent 4/3, which at the moment appears to be specific of earthquakes and financial markets. For this property we propose a model and an interpretation in terms of very rare events dominating the statistics independently on the nature of the events considered. The predicted scaling relation between skewness and kurtosis matches very well the experimental pattern of the second regime. Regarding price fluctuations, this situation characterizes a universal stylized fact.

  3. Identification of spots in rotated and skewed microarray images

    NASA Astrophysics Data System (ADS)

    Le Brese, Christopher; Zou, Ju Jia

    2009-12-01

    DNA microarray image processing has vast potential in the measurement of mass gene expression. A common approach to processing microarrays consists of spot identification, spot segmentation, and information extraction. We are concerned with spot identification. We aim to tackle the problem of identifying spots in rotated and skewed arrays via an automated process. The method proposed is composed of three steps, namely, array orientation calculation based on the Hough transform, affine calculation and correction, and gridding. The method is able to correctly identify spots in a microarray that has been rotated or skewed at an angle between 0 and +/-30 deg and corrupted by various types of noise such as high-intensity streaks, Gaussian noise, and salt-and-pepper noise.

  4. Universal relation between skewness and kurtosis in complex dynamics.

    PubMed

    Cristelli, Matthieu; Zaccaria, Andrea; Pietronero, Luciano

    2012-06-01

    We identify an important correlation between skewness and kurtosis for a broad class of complex dynamic systems and present a specific analysis of earthquake and financial time series. Two regimes of non-Gaussianity can be identified: a parabolic one, which is common in various fields of physics, and a power law one, with exponent 4/3, which at the moment appears to be specific of earthquakes and financial markets. For this property we propose a model and an interpretation in terms of very rare events dominating the statistics independently on the nature of the events considered. The predicted scaling relation between skewness and kurtosis matches very well the experimental pattern of the second regime. Regarding price fluctuations, this situation characterizes a universal stylized fact. PMID:23005163

  5. Skewed brownian fluctuations in single-molecule magnetic tweezers.

    PubMed

    Burnham, Daniel R; De Vlaminck, Iwijn; Henighan, Thomas; Dekker, Cees

    2014-01-01

    Measurements in magnetic tweezers rely upon precise determination of the position of a magnetic microsphere. Fluctuations in the position due to Brownian motion allows calculation of the applied force, enabling deduction of the force-extension response function for a single DNA molecule that is attached to the microsphere. The standard approach relies upon using the mean of position fluctuations, which is valid when the microsphere axial position fluctuations obey a normal distribution. However, here we demonstrate that nearby surfaces and the non-linear elasticity of DNA can skew the distribution. Through experiment and simulations, we show that such a skewing leads to inaccurate position measurements which significantly affect the extracted DNA extension and mechanical properties, leading to up to two-fold errors in measured DNA persistence length. We develop a simple, robust and easily implemented method to correct for such mismeasurements. PMID:25265383

  6. Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers

    PubMed Central

    Burnham, Daniel R.; De Vlaminck, Iwijn; Henighan, Thomas; Dekker, Cees

    2014-01-01

    Measurements in magnetic tweezers rely upon precise determination of the position of a magnetic microsphere. Fluctuations in the position due to Brownian motion allows calculation of the applied force, enabling deduction of the force-extension response function for a single DNA molecule that is attached to the microsphere. The standard approach relies upon using the mean of position fluctuations, which is valid when the microsphere axial position fluctuations obey a normal distribution. However, here we demonstrate that nearby surfaces and the non-linear elasticity of DNA can skew the distribution. Through experiment and simulations, we show that such a skewing leads to inaccurate position measurements which significantly affect the extracted DNA extension and mechanical properties, leading to up to two-fold errors in measured DNA persistence length. We develop a simple, robust and easily implemented method to correct for such mismeasurements. PMID:25265383

  7. Incorporating Skew into RMS Surface Roughness Probability Distribution

    NASA Technical Reports Server (NTRS)

    Stahl, Mark T.; Stahl, H. Philip.

    2013-01-01

    The standard treatment of RMS surface roughness data is the application of a Gaussian probability distribution. This handling of surface roughness ignores the skew present in the surface and overestimates the most probable RMS of the surface, the mode. Using experimental data we confirm the Gaussian distribution overestimates the mode and application of an asymmetric distribution provides a better fit. Implementing the proposed asymmetric distribution into the optical manufacturing process would reduce the polishing time required to meet surface roughness specifications.

  8. Skew and twist resistant hydrodynamic rotary shaft seal

    DOEpatents

    Dietle, L.; Kalsi, M.S.

    1999-02-23

    A hydrodynamically lubricated squeeze packing type rotary shaft seal suitable for lubricant retention and environmental exclusion which incorporates one or more resilient protuberances which cooperate with the gland walls to hold the seal straight in its installation groove in unpressurized and low pressure lubricant retention applications thereby preventing skew-induced wear caused by impingement of abrasive contaminants present in the environment, and which also serve as radial bearings to prevent tipping of the seal within its installation gland. 14 figs.

  9. Mutual impedance of nonplanar-skew sinusoidal dipoles

    NASA Technical Reports Server (NTRS)

    Richmond, J. H.; Geary, N. H.

    1974-01-01

    The mutual impedance of nonplanar-skew sinusoidal dipoles is presented as a summation of several exponential integrals with complex arguments. Mathematical models are developed to show the near-zone field of the sinusoidal dipole. The mutual impedance of coupled dipoles is expressed as the sum of four monopole-mobopole impedances to simplify the analysis procedure. The subroutines for solving the parameters of the dipoles are discussed.

  10. A skew polynomial approach to integro-differential operators

    Microsoft Academic Search

    Georg Regensburger; Markus Rosenkranz; Johannes Middeke

    2009-01-01

    We construct the algebra of integro-differential operators over an ordinary integro-differential algebra directly in terms of normal forms. In the case of polynomial coefficients, we use skew polynomials for defining the integro-differential Weyl algebra as a natural extension of the classical Weyl algebra in one variable. Its normal forms, algebraic properties and its relation to the localization of differential operators

  11. Minority report in fraud detection: classification of skewed data

    Microsoft Academic Search

    Clifton Phua; Damminda Alahakoon; Vincent Lee

    2004-01-01

    This paper proposes an innovative fraud detection method, built upon existing fraud detection research and Minority Report, to deal with the data mining problem of skewed data distributions. This method uses backpropagation (BP), together with naive Bayesian (NB) and C4.5 algorithms, on data partitions derived from minority oversampling with replacement. Its originality lies in the use of a single meta-classifier

  12. SKEW-ADJOINT FINITE DIFFERENCE METHODS ON NONUNIFORM GRIDS

    E-print Network

    McLachlan, Robert

    of design goals which are often in conflict. Many researchers agree that stability is a paramount goal S is a symmetric matrix), then d dt 1 2 u, u S = ut (SD + Dt S)u, which is zero for all u Rn if and only if D. The differentiation matrix D is skew-adjoint with respect to the symmetric bilinear form u, v S := ut Sv (or

  13. Head-position-dependent Adaptation of Nonconcomitant Vertical Skew

    Microsoft Academic Search

    JAMES S. MAXWELL; CLIFTON M. SCHOR

    Vertical phoria can be trained to vary with either head position or orbital eye position. The present experiments show that subjects can simultaneously adapt their eye-position-specific (nonconcomi- tant) vertical phorias in different directions at different head positions. Eye-position-dependent and head-position-dependent adaptive pathways, therefore, are not independent. Rather, the adaptation of vertical skew takes into account both eye and head position.

  14. Head-position-dependent Adaptation of Nonconcomitant Vertical Skew

    Microsoft Academic Search

    JAMES S MAXWELL; CLIFTON M SCHOR

    1997-01-01

    Vertical phoria can be trained to vary with either head position or orbital eye position. The present experiments show that subjects can simultaneously adapt their eye-position-specific (nonconcomitant) vertical phorias in different directions at different head positions. Eye-position-dependent and head-position-dependent adaptive pathways, therefore, are not independent. Rather, the adaptation of vertical skew takes into account both eye and head position. In

  15. A skew-symmetric cantilever accelerometer for automotive airbag applications

    Microsoft Academic Search

    Kyu Hyun Kim; Jong Soo Ko; Young-Ho Cho; Kwyro Lee; Byung Man Kwak

    1995-01-01

    A piezoresistive cantilever-beam microaccelerometer has been designed, fabricated and tested with a hybrid airbag electronic control unit for automobile crash detection. A skew-symmetric accelerometer has been proposed and the associated fabrication process has been developed. A simultaneous etching process for beam-thickness control, fillet-rounding formation and corner compensation is discussed. The microfabricated device shows a flat response with a resonance frequency

  16. Linear Waste of Best Fit Bin Packing on Skewed Distributions

    E-print Network

    Kenyon, Claire

    Linear Waste of Best Fit Bin Packing on Skewed Distributions Claire Kenyon # Universitâ??e Paris that Best Fit bin packing has linear waste on the discrete distri­ bution U{j, k} (where items are drawn; precisely the expected waste of Best Fit is #(n 1/2 log 3/4 n) [15, 11]; here the waste is the total unused

  17. Handling Data Skew in Multiprocessor Database Computers Using Partition Tuning

    Microsoft Academic Search

    Kien A. Hua; Chiang Lee

    1991-01-01

    Shared nothing multiprocessor archit.ecture is known t.o be more scalable to support very large databases. Compared to other join strategies, a hash-ba9ed join algorithm is par- ticularly efficient and easily parallelized for this compu- tation model. However, this hardware structure is very sensitive to the data skew problem. Unless the parallel hash join algorithm includes some load balancing mecha- nism,

  18. Bay Bridge 360

    NSDL National Science Digital Library

    This website was created by the various California transportation agencies that are involved in the enormous job of retrofitting the San Francisco-Oakland Bay Bridge to protect it from being damaged by seismic activity. It is an extremely well thought out website, with an interactive aerial graphic of the Bridge on its homepage that introduces visitors to their work. If you click on the colored circles on the bridge, you can see a slideshow of the construction on that section of the Bridge, and some of the Bridge sections include a time-lapse video of the construction. Additionally, there is a short film visitors can watch to get an overview of the project, by clicking on the blue circle above "Bay Bridge Overview" in the right-hand corner of the homepage. Clicking on the arrow in the left-hand corner of the homepage takes you inside the website where you can find links to "Closures and Detours", "Environmental Issues", for the Final Environmental Impact Statement, detailed explanations of the construction methods under the "Information Center" link, and even "Construction Cams". If you just can't get enough of traffic where you live, just click on "Construction Cams" and see Bay Bridge traffic.

  19. 5. View of Clark Fork Vehicle Bridge facing east. Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View of Clark Fork Vehicle Bridge facing east. Bridge from south shore of Clark Fork River-southernmost span. 1900-era Northern Pacific Railway Bridge in background. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  20. Nonrandom sampling in human genetics: skewness and kurtosis.

    PubMed

    Chakraborty, R; Hanis, C L

    1987-01-01

    When a multivariate normal sample is chosen from a truncated space of one of its components one can no longer make use of the normality assumption for the sample observations or for the estimates derived from them. In this paper, skewness and kurtosis for each component are derived analytically under a broad class of nonrandom sampling. It is shown that the distortions in skewness and kurtosis produced by nonrandomness are negligible, except those for the component with respect to which the selection of sampling regions is based. The usual tests of normality from sample values of skewness and kurtosis measures remain valid under nonrandom sampling, except for the selection variable. The implications of these analytical results in the context of commingling analysis in genetic epidemiology are discussed. It is recommended that when samples of families are obtained through nonrandomly ascertained probands, a commingling analysis should treat each relative class separately, since such analyses based on the pooled sample of individuals may involve unspecified bias in the levels of the test procedure. PMID:3582959

  1. Kurtosis, skewness, and non-Gaussian cosmological density perturbations

    NASA Astrophysics Data System (ADS)

    Luo, Xiaochun; Schramm, David N.

    1993-05-01

    Cosmological topological defects as well as some nonstandard inflation models can give rise to non-Gaussian density perturbations. Skewness and kurtosis are the third and fourth moments that measure the deviation of a distribution from a Gaussian. Measurement of these moments for the cosmological density field and for the microwave background temperature anisotropy can provide a test of the Gaussian nature of the primordial fluctuation spectrum. In the case of the density field, the importance of measuring the kurtosis is stressed since it will be preserved through the weakly nonlinear gravitational evolution epoch. Current constraints on skewness and kurtosis of primeval perturbations are obtained from the observed density contrast on small scales and from recent COBE observations of temperature anisotropies on large scales. It is also shown how, in principle, future microwave anisotropy experiments might be able to reveal the initial skewness and kurtosis. It is shown that present data argue that if the initial spectrum is adiabatic, then it is probably Gaussian, but non-Gaussian isocurvature fluctuations are still allowed, and these are what topological defects provide.

  2. Bridge : an unraveled architecture

    E-print Network

    ElHusseiny, Ahmed

    2006-01-01

    The bridge is an inhabitable structure housing live/work artists studios, galleries and workshops. It is an urban/architectural/personal intervention that strives to explore issues of Iatent/potential narratives within a ...

  3. Build Your Bridge

    NSDL National Science Digital Library

    These interactive learning modules and simulations allow students to explore the science, technology and people involved in building the New Bay Bridge, which is intended as a replacement for the historic San Francisco-Oakland Bay Bridge that was damaged in the 1989 Loma Prieta Earthquake. In the interactive module "Quake Country," students investigate plate tectonics as the driving force behind the faulting and resulting earthquakes in the Bay area. In the "Engineering for Earthquakes" simulation, students act as engineers, design their own bridges, and test them against the Maximum Credible Earthquake (MCE), the worst earthquake that might hit the Bay area every 1500 years. In the module "Two Miles and 2,000 Hands," students learn about the people who perform a large variety of jobs in building the new bridge.

  4. Implant-Supported Bridge

    MedlinePLUS

    ... made by the dental lab. Porcelain-fused-to-metal bridge The restoration (the part that looks like ... porcelain attached and fused to a framework of metal. The Implant Process The time it takes to ...

  5. Bridge Rectifier Animation

    NSDL National Science Digital Library

    This is an animation of a bridge rectifier circuit or diode bridge. Voltages and parts of the circuit of this 3-D animated gif are highlighted with different colors. Current is displayed by green arrows indicating directional flow. The animation requires a Web browser or other video player software capable of displaying gif animations. A link provides an optional Quicktime version of this same animation.Other 3-D Circuit Animations can be seen here.

  6. Valve bridge construction method

    SciTech Connect

    Greene, H.F.

    1987-07-07

    This patent describes an improved method of rebuilding a used valve bridge assembly of the type that actuates the exhaust valves in a cylinder of a diesel locomotive engine, the bridge including a cross-arm with distal ends and lash adjuster sockets adjacent to each of the distal ends. Each of the lash adjuster sockets has an opening adapted to receive a lash adjuster by being press-fit in order to provide smooth, efficient operation of the exhaust valves. The bridge has at least one lash adjuster socket with an inner diameter worn oversized so that a standard size lash adjuster can no longer be properly fitted. The improved method of: maintaining a stock of oversized lash adjusters which each include an outer cylindrical wall having a radially outwardly projecting rib member adapted to be in surface-to-surface contact with the inner surface of the lash adjuster sockets. An outer diameter dimension then is larger in diameter than the outer diameter dimension of the corresponding rib on the standard size lash adjuster; disassembling the used valve bridge, including removing the used lash adjusters from each of the lash adjuster sockets; cleaning the valve bridge, including the lash adjuster sockets formed without machining the lash adjuster sockets in the valve bridge; measuring the inner diameter dimension of each of the oversized lash adjuster sockets in the valve bridge; selecting an oversized lash adjuster from the stock of oversized lash adjusters an outer diameter dimension comparable to the measured inner diameter dimension of each of the oversized lash adjuster sockets; and reassembling the valve bridge, including press-fitting the selected oversized lash adjuster into the measured lash adjuster socket so that the radially outwardly projecting rib member is in surface to surface contact with the inner surface of the measured lash adjuster socket.

  7. Skewness as a Test of Non-Gaussian Primordial Density Fluctuations

    E-print Network

    P. Coles; L. Moscardini; F. Lucchin; S. Matarrese; A. Messina

    1993-02-24

    We investigate the evolution of the skewness of the distribution of density fluctuations in CDM models with both Gaussian and non--Gaussian initial fluctuations. We show that the method proposed by Coles \\& Frenk (1991), which uses the skewness of galaxy counts to test the hypothesis of Gaussian primordial density fluctuations, is a potentially powerful probe of initial conditions. As expected, the mass distribution in models with initially non--Gaussian fluctuations shows systematic departures from the Gaussian behaviour on intermediate to large scales. We investigate the effect of peculiar velocity distortions and normalisation upon the relationship between skewness and variance. These effects are generally small for the models we consider. Comparing our results to the QDOT measurements of the skewness, we find that our initially positive--skew models are clearly excluded by this analysis, but the available data do not rule out the negative--skew models.

  8. Skewed multivariate models related to hidden truncation and\\/or selective reporting

    Microsoft Academic Search

    Barry C. Arnold; Robert J. Beaver; A. Azzalini; N. Balakrishnan; A. Bhaumik; D. K. Dey; C. M. Cuadras; J. M. Sarabia

    2002-01-01

    The univariate skew-normal distribution was introduced by Azzalini in 1985 as a natural extension of the classical normal\\u000a density to accommodate asymmetry. He extensively studied the properties of this distribution and in conjunction with coauthors,\\u000a extended this class to include the multivariate analog of the skew-normal. Arnold et al. (1993) introduced a more general\\u000a skew-normal distribution as the marginal distribution

  9. Severe Skew Foot Deformity in a Patient With Freeman-Sheldon Syndrome

    PubMed Central

    Kaissi, Ali Al; Klaushofer, Klaus; Grill, Franz

    2011-01-01

    We report on a 3-year-old boy with the full phenotypic features of Freeman Sheldon syndrome (FSS). Severe skew foot deformity has been recognized as additional skeletal abnormality. Parents were first degree cousins, raising the possibility of autosomal recessive pattern of inheritance. To the best of our knowledge this is the first report of severe skew foot deformity in a patient with (FSS). Keywords Freeman-Sheldon syndrome; Skew foot deformity; Metatarsus adductus PMID:22383916

  10. Built-in clock skew system for on-line debug and repair

    Microsoft Academic Search

    Atanu Chattopadhyay; Zeljko Zilic

    2008-01-01

    We present a low-cost on-line system for clock skew management in integrated circuits. Our Built-In Clock Skew System (BICSS) uses a centralized approach to identify, quantify and correct skew using a two-step method. The technique assesses the time-of-flight between the central debug circuitry and each region, or tap under test to account for the measurement error due to differences in

  11. Built-in Clock Skew System for On-line Debug and Repair

    Microsoft Academic Search

    Atanu Chattopadhyay; Zeljko Zilic

    2008-01-01

    We present a low-cost on-line system for clock skew management in integrated circuits. Our built-in clock skew system (BICSS) uses a centralized approach to identify, quantify and correct skew using a two-step method. The technique assesses the time-off-light between the central debug circuitry and each region, or tap under test to account for the measurement error due to differences in

  12. Bit error rate performance for head skew angle in shingled magnetic recording using dual reader heads

    NASA Astrophysics Data System (ADS)

    Nakamura, Y.; Osawa, H.; Okamoto, Y.; Kanai, Y.; Muraoaka, H.

    2015-05-01

    The two-dimensional magnetic recording (TDMR) exploits two-dimensional signal processing using the neighboring read-back waveforms. We allocate dual readers for the intended tracks and evaluate the effects of head skew angle on the bit error rate performance in partial response class-I maximum likelihood system with a two-dimensional finite impulse response filter using two read-back waveforms under TDMR R/W channel specifications of 4 Tbit/in.2. The results show that the effect of positive skew angle is larger than that of negative skew angle, and the center of skew angle should be shifted to minus direction.

  13. Techniques to estimate generalized skew coefficients of annual peak streamflow for natural basins in Texas

    USGS Publications Warehouse

    Judd, Linda J.; Asquith, William H.; Slade, Raymond M., Jr.

    1996-01-01

    This report presents two techniques to estimate generalized skew coefficients used for log-Pearson Type III peak-streamflow frequency analysis of natural basins in Texas. A natural basin has less than 10 percent impervious cover, and less than 10 percent of its drainage area is controlled by reservoirs. The estimation of generalized skew coefficients is based on annual peak and historical peak streamflow for all U.S. Geological Survey streamflow-gaging stations having at least 20 years of annual peak-streamflow record from natural basins in Texas. Station skew coefficients calculated for each of 255 Texas stations were used to estimate generalized skew coefficients for Texas. One technique to estimate generalized skew coefficients involved the use of regression equations developed for each of eight regions in Texas, and the other involved development of a statewide map of generalized skew coefficients. The weighted mean of the weighted mean standard errors of the regression equations for the eight regions is 0.36 log10 skew units, and the weighted mean standard error of the map is 0.35 log10 skew units. The technique based on the map is preferred for estimating generalized skew coefficients because of its smooth transition from one region of the State to another.

  14. Which measures of skewness and kurtosis are best?

    PubMed

    Royston, P

    1992-02-15

    Indices of distributional shape based on linear combinations of order statistics have recently been described by Hosking. Their usefulness as tools for practical data analysis is examined. They are found to have several advantages over the conventional indices of skewness and kurtosis (square root of b1 and b2) and no serious drawbacks. It is proposed, therefore, that they should replace square root of b1 and b2 in routine data analysis. To implement this suggestion, action by the developers of standard statistical software is needed. PMID:1609174

  15. Skew And Twist Resistant Hydrodynamic Rotary Shaft Seal

    DOEpatents

    Dietle, Lannie (Sugar Land, TX); Kalsi, Manmohan Singh (Houston, TX)

    2000-03-14

    A hydrodynamically lubricated squeeze packing type rotary shaft seal suitable for lubricant retention and environmental exclusion which incorporates one or more resilient protuberances which and cooperate with the gland walls to hold the seal straight in its installation groove in unpressurized and low pressure lubricant retention applications thereby preventing skew-induced wear caused by impingement of abrasive contaminants present in the environment, and which also serve as radial bearings to prevent tipping of the seal within its installation gland. Compared to prior art, this invention provides a dramatic reduction of seal and shaft wear in abrasive environments and provides a significant increase in seal life.

  16. Generally astigmatic Gaussian beam representation and optimization using skew rays

    NASA Astrophysics Data System (ADS)

    Colbourne, Paul D.

    2014-12-01

    Methods are presented of using skew rays to optimize a generally astigmatic optical system to obtain the desired Gaussian beam focus and minimize aberrations, and to calculate the propagating generally astigmatic Gaussian beam parameters at any point. The optimization method requires very little computation beyond that of a conventional ray optimization, and requires no explicit calculation of the properties of the propagating Gaussian beam. Unlike previous methods, the calculation of beam parameters does not require matrix calculations or the introduction of non-physical concepts such as imaginary rays.

  17. 22. BRIDGE CREEK BRIDGE, AVENUE OF THE GIANTS, OLD HIGHWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. BRIDGE CREEK BRIDGE, AVENUE OF THE GIANTS, OLD HIGHWAY 101. HUMBOLDT COUNTY, CALIFORNIA. LOOKING E. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  18. Dog Bridge, view of the deck of the bridge and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Dog Bridge, view of the deck of the bridge and rails looking from Linden Lane - National Park Seminary, Bounded by Capitol Beltway (I-495), Linden Lane, Woodstove Avenue, & Smith Drive, Silver Spring, Montgomery County, MD

  19. 4. VIEW OF SILVER BRIDGE (ST. MARY'S BRIDGE), CARRYING COUNTY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF SILVER BRIDGE (ST. MARY'S BRIDGE), CARRYING COUNTY ROAD OVER SOURIS RIVER NEAR SOUTH END OF REFUGE, LOOKING NORTHEAST - Upper Souris National Wildlife Refuge Dams, Souris River Basin, Foxholm, Ward County, ND

  20. The Relationship between Skewness and Kurtosis of A Diffusing Scalar

    NASA Astrophysics Data System (ADS)

    Schopflocher, T. P.; Sullivan, P. J.

    It has been demonstrated that in turbulent dispersion, there exists a quadratic relationship between the skewness (S) and kurtosis (K) statistics obtained from continuous, elevated sources of scalar contaminant released into both convective and stable atmospheric boundary layers. Specifically, one observes that where A and B are empirically fitted constants that depend on the flow. For two reasons, this is potentially useful information in regard to modelling the probability density function (PDF) of a diffusing scalar. First, since many PDFs have a signature relationship between their skewness and kurtosis, candidate models can immediately be either accepted or rejected depending upon whether they conform to the quadratic curve that is observed experimentally. Second, if one intends to model the PDF by inverting a limited number of moments, the task is reduced when there is a functional relationship between the standardized third and fourth moments. The aforementioned relationship has been corroborated by others who have examined data over a wide range of experimental configurations. However, from one flow to another, there appears to be a non-negligible variability in the two fitting constants of the quadratic curve. In this paper we put forth a framework to help explain this phenomenon, and we also attempt to predict how these parameters vary in space and/or time. Our point is illustrated with well-resolved data from a wind-tunnel, grid-turbulence, plume experiment.

  1. Skewness and kurtosis in large-scale cosmic fields

    NASA Astrophysics Data System (ADS)

    Bernardeau, Francis

    1994-09-01

    In this paper, I present the calculation of the third and fourth moments of both the distribution function of the large-scale density and the large-scale divergence of the velocity field, theta. These calculations are made by the mean of perturbative calculations assuming Gaussian initial conditions and are expected to be valid in the linear or quasi-linear regime. The moments are derived for a top-hat window function and for any cosmological parameters omega and lambda. It turns out that the dependence with lambda is always very weak, whereas the moments of the distribution function of the divergence are strongly dependent on omega. A method to measure omega using the skewness of this field has already been presented by Bernardeau et al. I show here that the simultaneous measurement of the skewness and the kurtosis allows to test the validity of the gravitational instability scenario hypothesis. Indeed, there is a combination of the first three moments of theta that is almost independent of the cosmological parameters omega and lambda.

  2. Problematic standard errors and confidence intervals for skewness and kurtosis.

    PubMed

    Wright, Daniel B; Herrington, Joshua A

    2011-03-01

    Many statistics packages print skewness and kurtosis statistics with estimates of their standard errors. The function most often used for the standard errors (e.g., in SPSS) assumes that the data are drawn from a normal distribution, an unlikely situation. Some textbooks suggest that if the statistic is more than about 2 standard errors from the hypothesized value (i.e., an approximate value for the critical value from the t distribution for moderate or large sample sizes when ? = 5%), the hypothesized value can be rejected. This is an inappropriate practice unless the standard error estimate is accurate and the sampling distribution is approximately normal. We show distributions where the traditional standard errors provided by the function underestimate the actual values, often being 5 times too small, and distributions where the function overestimates the true values. Bootstrap standard errors and confidence intervals are more accurate than the traditional approach, although still imperfect. The reasons for this are discussed. We recommend that if you are using skewness and kurtosis statistics based on the 3rd and 4th moments, bootstrapping should be used to calculate standard errors and confidence intervals, rather than using the traditional standard. Software in the freeware R for this article provides these estimates. PMID:21298573

  3. Skewed sex ratios in India: "physician, heal thyself".

    PubMed

    Patel, Archana B; Badhoniya, Neetu; Mamtani, Manju; Kulkarni, Hemant

    2013-06-01

    Sex selection, a gender discrimination of the worst kind, is highly prevalent across all strata of Indian society. Physicians have a crucial role in this practice and implementation of the Indian Government's Pre-Natal Diagnostic Techniques Act in 1996 to prevent the misuse of ultrasound techniques for the purpose of prenatal sex determination. Little is known about family preferences, let alone preferences among families of physicians. We investigated the sex ratios in 946 nuclear families with 1,624 children, for which either one or both parents were physicians. The overall child sex ratio was more skewed than the national average of 914. The conditional sex ratios decreased with increasing number of previous female births, and a previous birth of a daughter in the family was associated with a 38 % reduced likelihood of a subsequent female birth. The heavily skewed sex ratios in the families of physicians are indicative of a deeply rooted social malady that could pose a critical challenge in correcting the sex ratios in India. PMID:23322380

  4. Skewness and Kurtosis in Large-Scale Cosmic Fields

    E-print Network

    F. Bernardeau

    1993-12-13

    In this paper, I present the calculation of the third and fourth moments of both the distribution function of the large--scale density and the large--scale divergence of the velocity field, $\\theta$. These calculations are made by the mean of perturbative calculations assuming Gaussian initial conditions and are expected to be valid in the linear or quasi linear regime. The moments are derived for a top--hat window function and for any cosmological parameters $\\Omega$ and $\\Lambda$. It turns out that the dependence with $\\Lambda$ is always very weak whereas the moments of the distribution function of the divergence are strongly dependent on $\\Omega$. A method to measure $\\Omega$ using the skewness of this field has already been presented by Bernardeau et al. (1993). I show here that the simultaneous measurement of the skewness and the kurtosis allows to test the validity of the gravitational instability scenario hypothesis. Indeed there is a combination of the first three moments of $\\theta$ that is almost independent of the cosmological parameters $\\Omega$ and $\\Lambda$, $${(-3^2) \\over ^2}\\approx 1.5,$$ (the value quoted is valid when the index of the power spectrum at the filtering scale is close to -1) so that any cosmic velocity field created by gravitational instabilities should verify such a property.

  5. The floating water bridge The floating water bridge

    E-print Network

    Podgornik, Rudolf

    The floating water bridge The floating water bridge Elmar C. Fuchs1 , Jakob Woisetschläger2 , Karl ____________________________________________ Abstract When high voltage is applied to distilled water filled into two glass beakers which are in contact, a stable water connection forms spontaneously, giving the impression of a floating water bridge. A detailed

  6. SoftBridge: A Multimodal Instant Messaging Bridging System

    E-print Network

    Blake, Edwin

    1 SoftBridge: A Multimodal Instant Messaging Bridging System John Lewis, William Tucker and Edwin}@cs.uct.ac.za Abstract-- Instant Messaging is traditionally a text only affair. However, there are instances when framework that enables this kind of communications bridging us- ing instant messages. Its use of protocols

  7. Retrofitted Bridge Fragility Analysis for Typical Classes of Multispan Bridges

    Microsoft Academic Search

    Jamie E. Padgett; Reginald DesRoches

    2009-01-01

    Retrofitted bridge fragility curves provide a powerful tool for assessing the effect of retrofit measures on the seismic performance of different bridge types under a range of loading levels. Traditional methods for retrofit assessment typically evaluate the effectiveness of retrofit based on the performance of individual components. However, the use of fragility curves for retrofitted bridges has the ability to

  8. Online Load Balancing for MapReduce with Skewed Data Input

    E-print Network

    Liu, Jiangchuan (JC)

    Online Load Balancing for MapReduce with Skewed Data Input Yanfang Le, Jiangchuan Liu, Funda Erg reduce stage or after seeing all the data, we address the skew from the beginning of data input, and make the input in a continuous fashion and adaptively assign tasks with a load-balanced strategy. We show

  9. Online Load Balancing for MapReduce with Skewed Data Input

    E-print Network

    Wang, Dan

    balanced load in the later stages. The real world data, however, are not necessarily uniform, and oftenOnline Load Balancing for MapReduce with Skewed Data Input Yanfang Le, Jiangchuan Liu, Funda Erg reduce stage or after seeing all the data, we address the skew from the beginning of data input, and make

  10. Properties of the Robinson-Schensted correspondence for oscillating and skew oscillating tableaux

    E-print Network

    Chauve, Cedric

    Properties of the Robinson-Schensted correspondence for oscillating and skew oscillating tableauxBRI, Universit#19;e Bordeaux I, 1999. #12; PROPERTIES OF THE ROBINSON-SCHENSTED CORRESPONDENCE FOR OSCILLATING the Robinson-Schensted correspondence for oscillating tab- leaux and skew oscillating tableaux de#12;ned in [15

  11. A Novel Approach to Skew Detection and Character Segmentation for Handwritten Bangla Words

    Microsoft Academic Search

    A. Roy; T. K. Bhowmik; S. K. Parui; U. Roy

    2005-01-01

    Character segmentation is a necessary preprocessing step for character recognition in many handwritten word recognition systems. The most difficult case in character segmentation is the cursive script. Fully cursive nature of Bangla handwriting, the natural skewness in words poses some challenges for automatic character segmentation. In this article a novel approach to skew detection, correction as well as character segmentation

  12. Information Extraction from a Skewed Form Document in the Presence of Crossing Characters

    Microsoft Academic Search

    Jin-yong Yoo; Min-ki Kim; Sang-yong Han; Young-bin Kwon

    1997-01-01

    In this paper, we propose an information extraction method which can restore the handwritten character information from prescribed and skewed form documents. The proposed method include the following aspects: boundary and successive internal line dectection, accurate skew angle measurement, line removal and broken character restoration using morphological analysis model of crossing shape. Using the proposed method, more than 95% of

  13. On Fast and Accurate Detection of Unauthorized Wireless Access Points Using Clock Skews

    Microsoft Academic Search

    Suman Jana; Sneha K. Kasera

    2010-01-01

    We explore the use of clock skew of a wireless local area network access point (AP) as its fingerprint to detect unauthorized APs quickly and accurately. The main goal behind using clock skews is to overcome one of the major limitations of existing solutions - the inability to effectively detect Medium Access Control (MAC) address spoofing. We calculate the clock

  14. On fast and accurate detection of unauthorized wireless access points using clock skews

    Microsoft Academic Search

    Suman Jana; Sneha Kumar Kasera

    2008-01-01

    We explore the use of clock skew of a wireless local area network access point (AP) as its fingerprint to detect unau- thorized APs quickly and accurately. The main goal behind using clock skews is to overcome one of the major limita- tions of existing solutions - the inability to effectively de- tect Medium Access Control (MAC) address spoofing. We

  15. LETTER Communicated by Robert Shapley Sample Skewness as a Statistical Measurement

    E-print Network

    Gupta, Abhinav

    func- tion and parameter. Skewness provides a robust nonparametric measure of tuning curve sharpness, skewness is best used for capturing the Brian Potetz is now at Google, Los Angeles, CA. Neural Computation- ing rates of action potentials to changes in sensory input or motor output characteristics. For many

  16. Interval estimators for the population mean for skewed distributions with a small sample size

    E-print Network

    Meeden, Glen

    Interval estimators for the population mean for skewed distributions with a small sample size Glen for skewed distributions with a small sample size SUMMARY In finite population sampling it has long been developed which is based on the `Polya posterior'. For large sample sizes these methods often closely mimic

  17. The Combined Effect of Process Variations and Power Supply Noise on Clock Skew and Jitter

    E-print Network

    De Micheli, Giovanni

    of skitter, which consists of skew and jitter, is proposed. Clock paths with different buffer insertionThe Combined Effect of Process Variations and Power Supply Noise on Clock Skew and Jitter Hu Xu, a large number of clock buffers are inserted in clock distribution networks, which are significantly

  18. The combined effect of process variations and power supply noise on clock skew and jitter

    Microsoft Academic Search

    Hu Xu; Vasilis F. Pavlidis; Wayne Burleson; Giovanni De Micheli

    2012-01-01

    In modern VLSI circuits, a large number of clock buffers are inserted in clock distribution networks, which are significantly affected by process and power supply noise variations. The combined effect of process variations and power supply noise on clock skew and jitter is investigated in this paper. A statistical model of skitter, which consists of skew and jitter, is proposed.

  19. Buffer sizing for clock power minimization subject to general skew constraints

    Microsoft Academic Search

    Kai Wang; Malgorzata Marek-Sadowska

    2004-01-01

    In this paper, we investigate the problem of buffer sizing for clock power minimization subject to general skew constraints. A novel approach based on sequential linear programming is presented. By taking the first-order Taylor's expansion of clock path delay with respect to buffer widths, the original nonlinear problem is transformed to a sequence of linear programs, which incorporate clock skew

  20. Forecasting Crashes: Trading Volume, Past Returns and Conditional Skewness in Stock Prices

    Microsoft Academic Search

    Joseph S. Chen; Harrison G. Hong; Jeremy C. Stein

    2000-01-01

    This paper is an investigation into the determinants of asymmetries in stock returns. We develop a series of cross-sectional regression specifications which attempt to forecast skewness in the daily returns of individual stocks. Negative skewness is most pronounced in stocks that have experienced: 1) an increase in trading volume relative to trend over the prior six months; and 2) positive

  1. No evidence that skewing of X chromosome inactivation patterns is transmitted to offspring in humans

    PubMed Central

    Bolduc, Véronique; Chagnon, Pierre; Provost, Sylvie; Dubé, Marie-Pierre; Belisle, Claude; Gingras, Marianne; Mollica, Luigina; Busque, Lambert

    2007-01-01

    Skewing of X chromosome inactivation (XCI) can occur in normal females and increases in tissues with age. The mechanisms underlying skewing in normal females, however, remain controversial. To better understand the phenomenon of XCI in nondisease states, we evaluated XCI patterns in epithelial and hematopoietic cells of over 500 healthy female mother-neonate pairs. The incidence of skewing observed in mothers was twice that observed in neonates, and in both cohorts, the incidence of XCI was lower in epithelial cells than hematopoietic cells. These results suggest that XCI incidence varies by tissue type and that age-dependent mechanisms can influence skewing in both epithelial and hematopoietic cells. In both cohorts, a correlation was identified in the direction of skewing in epithelial and hematopoietic cells, suggesting common underlying skewing mechanisms across tissues. However, there was no correlation between the XCI patterns of mothers and their respective neonates, and skewed mothers gave birth to skewed neonates at the same frequency as nonskewed mothers. Taken together, our data suggest that in humans, the XCI pattern observed at birth does not reflect a single heritable genetic locus, but rather corresponds to a complex trait determined, at least in part, by selection biases occurring after XCI. PMID:18097474

  2. Clutch-size adjustments and skew models: effects on reproductive partitioning and group stability

    Microsoft Academic Search

    Ian M. Hamilton; Dik Heg

    2006-01-01

    Reproductive skew theory seeks to integrate social and ecological factors thought to influence the division of reproduction among group-living animals. However, most reproductive skew models only examine interactions between individuals of the same sex. Here, we suggest that females can influence group stability and conflict among males by modifying their clutch size and may do so if they benefit from

  3. POPULATION GENETICS MODELS WITH SKEWED FERTILITIES: A FORWARD AND BACKWARD ANALYSIS

    E-print Network

    Paris-Sud XI, Université de

    POPULATION GENETICS MODELS WITH SKEWED FERTILITIES: A FORWARD AND BACKWARD ANALYSIS THIERRY HUILLET, MARTIN M¨OHLE Abstract. Discrete population genetics models with unequal (skewed) fertil- ities for power law fertilities and for geomet- ric fertilities. This class of models can exhibit a rich variety

  4. FDTD/PBC Algorithm for Skewed Grid Periodic Structures Khaled ElMahgoub1*

    E-print Network

    Elsherbeni, Atef Z.

    FDTD/PBC Algorithm for Skewed Grid Periodic Structures Khaled ElMahgoub1* , Fan Yang1 , Atef Z's worthwhile to point out that most previous PBCs are developed to analyze axial grid periodic structures angle. Figure 1 shows the geometries of both axial and skewed grid structures. The axial periodic

  5. Effects of Trophic Skewing of Species Richness on Ecosystem Functioning in a Diverse Marine Community

    Microsoft Academic Search

    Pamela L. Reynolds; John F. Bruno

    2012-01-01

    Widespread overharvesting of top consumers of the world’s ecosystems has “skewed” food webs, in terms of biomass and species richness, towards a generally greater domination at lower trophic levels. This skewing is exacerbated in locations where exotic species are predominantly low-trophic level consumers such as benthic macrophytes, detritivores, and filter feeders. However, in some systems where numerous exotic predators have

  6. Monitoring Bridge Deterioration Using Sensors

    Microsoft Academic Search

    Bijan Samali; Jianchun Li; Khalid Aboura

    2008-01-01

    Structural health monitoring is a vital part in the management of bridges, particularly as the structures begin to age. Detecting structural faults through the use of sensors is an emerging field that has seen considerable efforts this past decade. Similarly, the use of sensors in bridge management systems provides valuable data on the condition of bridges and external factors affecting

  7. Quantum Bidding in Bridge

    NASA Astrophysics Data System (ADS)

    Muhammad, Sadiq; Tavakoli, Armin; Kurant, Maciej; Paw?owski, Marcin; ?ukowski, Marek; Bourennane, Mohamed

    2014-04-01

    Quantum methods allow us to reduce communication complexity of some computational tasks, with several separated partners, beyond classical constraints. Nevertheless, experimental demonstrations of this have thus far been limited to some abstract problems, far away from real-life tasks. We show here, and demonstrate experimentally, that the power of reduction of communication complexity can be harnessed to gain an advantage in a famous, immensely popular, card game—bridge. The essence of a winning strategy in bridge is efficient communication between the partners. The rules of the game allow only a specific form of communication, of very low complexity (effectively, one has strong limitations on the number of exchanged bits). Surprisingly, our quantum technique does not violate the existing rules of the game (as there is no increase in information flow). We show that our quantum bridge auction corresponds to a biased nonlocal Clauser-Horne-Shimony-Holt game, which is equivalent to a 2?1 quantum random access code. Thus, our experiment is also a realization of such protocols. However, this correspondence is not complete, which enables the bridge players to have efficient strategies regardless of the quality of their detectors.

  8. Building Migratory Bridges

    ERIC Educational Resources Information Center

    Roy, Michael; Doss, Laurie K.

    2007-01-01

    The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

  9. JHU Bridge Designer

    NSDL National Science Digital Library

    Michael Karweit

    The Bridge Designer is a web-based program that allows the user to design and analyze 2-Dimensional statically determinate trusses. The user can specify support types (fixed or rolling) and locations, as well as the locations of various truss nodes and members.

  10. The Bridges Program.

    ERIC Educational Resources Information Center

    Bohnen, Elizabeth; Klie, Judy

    This report describes BRIDGES, an employment equity special measures training program developed by the City of Toronto (Ontario, Canada). It was designed to help women employees move from their traditional jobs into trades, technical or operation (TTO) jobs within their own organization. The program is a combination of classroom sessions, shop…

  11. Bridging the Gap?

    ERIC Educational Resources Information Center

    Salter, Colin

    2009-01-01

    The political context of the conversion of the Historic Tramway Bridge, adjacent to Sandon Point in Bulli (NSW, Australia), and how this was exploited to serve predetermined ends, illustrates that technologies can be designed to have particular social (and political) effects. Through reflection on this relatively small engineering project, this…

  12. DOE Information Bridge

    E-print Network

    United States. Department of Energy. Office of Scientific and Technical Information

    DOE Information Bridge, a component of EnergyFiles, provides free, convenient, and quick access to full-text DOE research and development reports in physics, chemistry, materials, biology, environmental sciences, energy technologies, engineering, computer and information science, renewable energy, and other topics. This vast collection includes over 43,000 reports that have been received and processed by OSTI since January 1995.

  13. A proof for Rhiel's range estimator of the coefficient of variation for skewed distributions.

    PubMed

    Rhiel, G Steven

    2007-02-01

    In this research study is proof that the coefficient of variation (CV(high-low)) calculated from the highest and lowest values in a set of data is applicable to specific skewed distributions with varying means and standard deviations. Earlier Rhiel provided values for d(n), the standardized mean range, and a(n), an adjustment for bias in the range estimator of micro. These values are used in estimating the coefficient of variation from the range for skewed distributions. The d(n) and an values were specified for specific skewed distributions with a fixed mean and standard deviation. In this proof it is shown that the d(n) and an values are applicable for the specific skewed distributions when the mean and standard deviation can take on differing values. This will give the researcher confidence in using this statistic for skewed distributions regardless of the mean and standard deviation. PMID:17451028

  14. Measures of kurtosis and skewness of INGARCH model

    NASA Astrophysics Data System (ADS)

    Mohamad, Nurul Najihah; Mohamed, Ibrahim; Thavaneswaran, A.; Yahya, Mohd Sahar

    2014-07-01

    Recently there has been a growing interest in time series of counts/integer-valued time series. The time series under the hypothesis of homogeneous variance becomes unrealistic in many situations because the variance tend to change with level. Important models such as ACP (autoregressive conditional Poisson) models and integer valued GARCH models have been proposed in the literature. Ghahramani and Thavaneswaran [1] studied the moment properties of ACP models using martingale transformation. However the forecasting for count process has not been studied in the literature. Using a martingale transformation, Thavaneswaran et al. [2] studied the volatility forecasts for GARCH models. In this paper, first we derive closed form expressions for skewness and kurtosis for count processes via martingale transformation then we study the joint forecasts for integer-valued count models with errors following Poisson.

  15. Restoring the skew quadrupole moment in the Tevatron dipoles

    SciTech Connect

    Harding, D.J.; Bauer, P.C.; Blowers, J.N.; DiMarco, J.; Glass, H.D.; Hanft, R.W.; Carson, J.A.; Robotham, W.F.; Tartaglia, M.A.; Tompkins, J.C.; Velev, G.; /Fermilab

    2005-05-01

    In early 2003 it was realized that mechanical changes in the Tevatron dipoles had led to a deterioration of the magnetic field quality that was hindering operation of the accelerator. After extensive study, a remediation program was started in late 2003 that will continue through 2005. The mechanical and magnetic effects are discussed. The readjustment process and experience are reported, along with other observations on aging magnets. In January 2003 two lines of inquiry converged, leading to the recognition that the severe betatron coupling that was hindering operation of the Tevatron could be explained by a systematic shift on the skew quadrupole field in the dipole magnets of the same size expected from observed mechanical movement of the coils inside the magnet yokes [1]. This paper reports on subsequent magnet studies that were conducted in parallel with additional beam studies and accelerator modeling [2] exploring the feasibility of the eventual remediation effort [3].

  16. Evolution of cooperation and skew under imperfect information.

    PubMed

    Akçay, Erol; Meirowitz, Adam; Ramsay, Kristopher W; Levin, Simon A

    2012-09-11

    The evolution of cooperation in nature and human societies depends crucially on how the benefits from cooperation are divided and whether individuals have complete information about their payoffs. We tackle these questions by adopting a methodology from economics called mechanism design. Focusing on reproductive skew as a case study, we show that full cooperation may not be achievable due to private information over individuals' outside options, regardless of the details of the specific biological or social interaction. Further, we consider how the structure of the interaction can evolve to promote the maximum amount of cooperation in the face of the informational constraints. Our results point to a distinct avenue for investigating how cooperation can evolve when the division of benefits is flexible and individuals have private information. PMID:22908269

  17. Guaranteeing Convergence of Iterative Skewed Voting Algorithms for Image Segmentation.

    PubMed

    Balcan, Doru C; Srinivasa, Gowri; Fickus, Matthew; Kova?evi?, Jelena

    2012-09-01

    In this paper we provide rigorous proof for the convergence of an iterative voting-based image segmentation algorithm called Active Masks. Active Masks (AM) was proposed to solve the challenging task of delineating punctate patterns of cells from fluorescence microscope images. Each iteration of AM consists of a linear convolution composed with a nonlinear thresholding; what makes this process special in our case is the presence of additive terms whose role is to "skew" the voting when prior information is available. In real-world implementation, the AM algorithm always converges to a fixed point. We study the behavior of AM rigorously and present a proof of this convergence. The key idea is to formulate AM as a generalized (parallel) majority cellular automaton, adapting proof techniques from discrete dynamical systems. PMID:22984338

  18. Evolution of cooperation and skew under imperfect information

    PubMed Central

    Akçay, Erol; Meirowitz, Adam; Ramsay, Kristopher W.; Levin, Simon A.

    2012-01-01

    The evolution of cooperation in nature and human societies depends crucially on how the benefits from cooperation are divided and whether individuals have complete information about their payoffs. We tackle these questions by adopting a methodology from economics called mechanism design. Focusing on reproductive skew as a case study, we show that full cooperation may not be achievable due to private information over individuals’ outside options, regardless of the details of the specific biological or social interaction. Further, we consider how the structure of the interaction can evolve to promote the maximum amount of cooperation in the face of the informational constraints. Our results point to a distinct avenue for investigating how cooperation can evolve when the division of benefits is flexible and individuals have private information. PMID:22908269

  19. The effect of forward skewed rotor blades on aerodynamic and aeroacoustic performance of axial-flow fan

    Microsoft Academic Search

    Jun Wei; Fangyuan Zhong

    1988-01-01

    Based on comparative experiment, this paper deals with using tangentially skewed rotor blades in axial-flow fan. It is seen from the comparison of the overall performance of the fan with skewed bladed rotor and radial bladed rotor that the skewed blades operate more efficiently than the radial blades, especially at low volume flows. Meanwhile, decrease in pressure rise and flow

  20. Unusually Stable Pyrazolate-Bridged Dialuminum Complexes Containing Bridging Methyl Groups

    E-print Network

    Schlegel, H. Bernhard

    Unusually Stable Pyrazolate-Bridged Dialuminum Complexes Containing Bridging Methyl Groups Zhengkun pyrazoles with excess trimethylaluminum. The bridging methyl groups in these complexes are more stable than

  1. Electrical Actuation Technology Bridging

    NASA Technical Reports Server (NTRS)

    Hammond, Monica (compiler); Sharkey, John (compiler)

    1993-01-01

    This document contains the proceedings of the NASA Electrical Actuation Technology Bridging (ELA-TB) Workshop held in Huntsville, Alabama, September 29-October 1, 1992. The workshop was sponsored by the NASA Office of Space Systems Development and Marshall Space Flight Center (MSFC). The workshop addressed key technologies bridging the entire field of electrical actuation including systems methodology, control electronics, power source systems, reliability, maintainability, and vehicle health management with special emphasis on thrust vector control (TVC) applications on NASA launch vehicles. Speakers were drawn primarily from industry with participation from universities and government. In addition, prototype hardware demonstrations were held at the MSFC Propulsion Laboratory each afternoon. Splinter sessions held on the final day afforded the opportunity to discuss key issues and to provide overall recommendations. Presentations are included in this document.

  2. Rapid bridge deck replacement 

    E-print Network

    Osegueda, Roberto Alejandro

    1983-01-01

    , California . . . Maryland State Highway Administration-Federal Highway Administration Summary . Objectives of Study Scope of Study 2 EXPERIMENTAL WORK General 13 13 17 20 22 22 24 Selection of Prototype Bridge Model Design Design of Model... Distribution . . Comparison of Shear Stress Distribution Comparison of Midspan Deflections Comparison of Full Composite Test Results to Prototype . Flexural Strains 156 156 159 159 161 161 166 168 173 173 Deflections Discussion of Slip Di...

  3. BRIDGE Other Resources

    NSDL National Science Digital Library

    Bridge Ocean Resources provide access to ocean sciences educational materials with particular emphasis on K-12 audiences. The collection emphasizes biological oceanography, aquaria, research institutions, career information, student opportunities and announcements. There is a strong focus on research data and its use in teaching. The collection provides educators with a source of accurate and useful information on global, national, and regional ocean science topics, and gives researchers a contact point for educational outreach.

  4. Enhanced responsivity with skew ray excitation of reflection- and transmission-type refractometric sensors.

    PubMed

    Chen, George Y; Codemard, Christophe A; Lewis, Richard J; Jankowski, Lukasz; Chan, Jaclyn S; Gorman, Philip M; Zervas, Michalis N

    2014-07-01

    The responsivity of optical fibers to refractive index can be enhanced using high-order skew rays compared with using meridional rays. Skew rays can have a much higher number of reflections with increased interaction length along the core-cladding interface, which gives rise to stronger interactions with the external medium. Reflection/transmission-type refractometric sensors based on twin-coupled-core and multimode fibers showed one/two orders of magnitude increase in responsivity with skew ray excitation. The responsivity and sensitivity for the two types are ~2000%/RIU, ~1400%/RIU, and 4.9×10????RIU, 7.0×10????RIU, respectively. PMID:24978746

  5. The active-bridge oscillator

    SciTech Connect

    Wessendorf, K.O.

    1998-07-01

    This paper describes the Active-Bridge Oscillator (ABO), a new concept in high-stability oscillator design. The ABO is ab ridge-type oscillator design that is easly to design and overcomes many of the operational and design difficulties associated with standard bridge oscillator designs. The ABO will oscillate with a very stable output amplitude over a wide range of operating conditions without the use of an automatic-level-control (ALC). A standard bridge oscillator design requires an ALC to maintain the desired amplitude of oscillation. for this and other reasons, bridge oscilaltors are not used in mainstream designs. Bridge oscillators are generally relegated to relatively low-volume, high-performance applications. The Colpitts and Pierce designs are the most popular oscillators but are typically less stable than a bridge-type oscillator.

  6. Foundation Depth for Bridge Piers

    NASA Astrophysics Data System (ADS)

    Veerappadevaru, G.; Gangadharaiah, T.; Jagadeesh, T. R.

    2013-09-01

    The safety of bridge piers built in rivers having the bed is one of the prime aspects in the study of scouring process around bridge piers. The stability of bridge piers depends on the depth of foundation provided below maximum scour level. The stability analysis of bridge piers is carried based on moment of forces acting on the caisson pier when the pier slides and tilts slightly in downstream from its position. The experiments are conducted for three pier shapes on two sediment beds and for different flow conditions. The curves indicating the stability limits are compared with Lacey's recommendations which are used in present day practice in India. The analysis presented here indicates that the Lacey's recommendation for railway bridges is safe and for some cases of the road bridges depends on grip length, angle of tilt and weight of caisson.

  7. Tacoma Narrows Bridge: Extreme History

    NSDL National Science Digital Library

    Stretching across the southern portion of Puget Sound, the elegant Tacoma Narrows bridge is considered one of the finest suspension bridges in the United States. The current bridge is the second on the site, as it was constructed in 1950 to serve as a replacement to the famous "Galloping Gertie" bridge, which collapsed in a windstorm in the fall of 1940. Currently, the Washington State Department of Transportation is building a bridge to replace the existing structure, and it is anticipated that it will be completed in 2007. This site offers a host of materials on all three structures, including ample information on the construction of the bridges and their aesthetic appeal. Along with these materials, the site also provides a glossary of related terms, Weird Facts, and some information about the dog "Tubby", who perished when "Galloping Gertie" collapsed on that fateful fall day back in 1940.

  8. Automatic P - phase picking using skewness and kurtosis

    NASA Astrophysics Data System (ADS)

    Lee, J.; Küperkoch, L.; Meier, T.; Friederich, W.

    2009-04-01

    For near-real time event detection and localization, the automatic arrival time picking plays an important role and its picking uncertainty is essential to measure the accuracy of automatic phase picking. Characteristic functions calculated by STA/LTA algorithms are often used for automated detection of P-waves and the estimation of their arrival times. Here we present procedures for automatic picking of P-wave arrival times using characteristic functions, which are calculated by estimating the skewness and kurtosis in a moving window and compare with the characteristic functions of the conventional STA/LTA. When estimating the automatic arrival times, we take the picking uncertainty into account in order to control the quality of picking. In order to test the accuracy and robustness of these algorithms we apply these to broadband digital waveforms recorded by the German Regional Seismological Network (GRSN) stations from 1996 to 2006. The data set contains recordings from about 500 earthquakes in the region between 0°E and 90°E, and 20°N and 60°N. It includes recordings for earthquakes with magnitudes >= 4 occurring down to 100 km depth. This results in over 6000 vertical component broadband recordings. After estimation of the signal-to-noise ratio around the expected P-wave travel time and the rejection of noisy records the variance, skewness and kurtosis are calculated in moving windows. An automatic picker is applied to characteristic function obtained from kurtosis estimation in a moving window. These absolute arrival times are compared to travel times for the Earth reference model AK135 and to manual picks. Only automatic picks with an estimated uncertainty of less than 0.2 s are taken into account. The average of the differences is 0.30 s with a standard deviation of 0.44 s. Because of emergent onsets and the filtering applied to the waveforms the automatic picks tend to be slightly too late on average. Furthermore, the resulting characteristic functions of individual seismograms are corrected to a reference hypocentral depth and stacked in time and epicentral distance bins to obtain average seismogram sections of characteristic functions. The stacks show the P-wave arrival times clearly. These results show that the proposed algorithms are well suited for automated arrival time estimates and fast localization in the framework of an early warning system.

  9. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...false Movable bridge, interlocking of signal appliances with bridge devices. 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...312 Movable bridge, interlocking of signal appliances with bridge devices....

  10. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Movable bridge, interlocking of signal appliances with bridge devices. 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...312 Movable bridge, interlocking of signal appliances with bridge devices....

  11. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Movable bridge, interlocking of signal appliances with bridge devices. 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...312 Movable bridge, interlocking of signal appliances with bridge devices....

  12. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...false Movable bridge, interlocking of signal appliances with bridge devices. 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...312 Movable bridge, interlocking of signal appliances with bridge devices....

  13. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...false Movable bridge, interlocking of signal appliances with bridge devices. 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...312 Movable bridge, interlocking of signal appliances with bridge devices....

  14. 75 FR 62181 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ...Annual Materials Report on New Bridge Construction and Bridge Rehabilitation AGENCY...Federal Register a report describing construction materials used in new Federal-aid bridge construction and bridge rehabilitation...

  15. 76 FR 55160 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-06

    ...Annual Materials Report on New Bridge Construction and Bridge Rehabilitation AGENCY...Federal Register a report describing construction materials used in new Federal-aid bridge construction and bridge rehabilitation...

  16. Ion bridges in microfluidic systems

    Microsoft Academic Search

    Taek Dong Chung; Hee Chan Kim

    2009-01-01

    Recently many microfluidic systems are increasingly equipped with functional units for ionic controls for various applications.\\u000a In this review article, we define an ion bridge as a structure that controls current or distribution of ions in a microfluidic system, and summarize the ion bridges in the\\u000a literature in terms of characteristics, fabrication methods, advantages and disadvantages. The ion bridges play

  17. BRIDGE: Briefings on Development & Gender

    NSDL National Science Digital Library

    BRIDGE (briefings on development and gender) is an information service provided by the Institute of Development Studies (IDS) at the University of Sussex. BRIDGE supplies development agencies with briefings that "present state of the art research findings, review current policy debates, synthesize best practice, and evaluate strategies for translating gender policies into practice." This site includes full-text BRIDGE publications, a bibliographic database, and links to other gender and development resources.

  18. Morphological aspects of myocardial bridges

    PubMed Central

    Lujinovi?, Almira; Kulenovi?, Amela; Kapur, Eldan; Gojak, Refet

    2013-01-01

    Although some myocardial bridges can be asymptomatic, their presence often causes coronary disease either through direct compression of the “tunnel” segment or through stimulation and accelerated development of atherosclerosis in the segment proximally to the myocardial bridge. The studied material contained 30 human hearts received from the Department of Anatomy. The hearts were preserved 3 to 5 days in 10% formalin solution. Thereafter, the fatty tissue was removed and arterial blood vessels prepared by careful dissection with special reference to the presence of the myocardial bridges. Length and thickness of the bridges were measured by the precise electronic caliper. The angle between the myocardial bridge fibre axis and other axis of the crossed blood vessel was measured by a goniometer. The presence of the bridges was confirmed in 53.33% of the researched material, most frequently (43.33%) above the anterior interventricular branch. The mean length of the bridges was 14.64±9.03 mm and the mean thickness was 1.23±1.32 mm. Myocardial bridge fibres pass over the descending blood vessel at the angle of 10-90 degrees. The results obtained on a limited sample suggest that the muscular index of myocardial bridge is the highest for bridges located on RIA, but that the difference is not significant in relation to bridges located on other branches. The results obtained suggest that bridges located on other branches, not only those on RIA, could have a great contractive power and, consequently, a great compressive force, which would be exerted on the wall of a crossed blood vessel. PMID:24289755

  19. Extended bridge algorithms for large networks

    Microsoft Academic Search

    W. D. Sincoskie; C. J. Cotton

    1988-01-01

    A network bridge is a device that operates at the ISO data link level and routes packets across extended networks, commonly composed of multiple local area networks (LANs) and bridges. A set of algorithms that greatly extends the application of the network bridge is presented. This multitree bridge algorithm allows networks of arbitrary topology and capacity to use bridge routing.

  20. Strengthening of Steel Girder Bridges Using FRP

    Microsoft Academic Search

    Brent M. Phares; Terry J. Wipf; F. Wayne Klaiber; Ahmad Abu-Hawash; Yoon-Si Lee

    This paper documents two projects funded through the Federal Highway Administration's Innovative Bridge Research and Construction (IBRC) program. The IBRC program was developed to assist bridge owners in applying emerging technologies in bridge engineering. In these projects, the Iowa Department of Transportation employed techniques for strengthening steel girder bridges using carbon fiber reinforced polymers (CFRP). Two bridges were strengthened using

  1. Prediction of Scour Depth around Bridge Piers using Adaptive Neuro-Fuzzy Inference Systems (ANFIS)

    NASA Astrophysics Data System (ADS)

    Valyrakis, Manousos; Zhang, Hanqing

    2014-05-01

    Earth's surface is continuously shaped due to the action of geophysical flows. Erosion due to the flow of water in river systems has been identified as a key problem in preserving ecological health of river systems but also a threat to our built environment and critical infrastructure, worldwide. As an example, it has been estimated that a major reason for bridge failure is due to scour. Even though the flow past bridge piers has been investigated both experimentally and numerically, and the mechanisms of scouring are relatively understood, there still lacks a tool that can offer fast and reliable predictions. Most of the existing formulas for prediction of bridge pier scour depth are empirical in nature, based on a limited range of data or for piers of specific shape. In this work, the application of a Machine Learning model that has been successfully employed in Water Engineering, namely an Adaptive Neuro-Fuzzy Inference System (ANFIS) is proposed to estimate the scour depth around bridge piers. In particular, various complexity architectures are sequentially built, in order to identify the optimal for scour depth predictions, using appropriate training and validation subsets obtained from the USGS database (and pre-processed to remove incomplete records). The model has five variables, namely the effective pier width (b), the approach velocity (v), the approach depth (y), the mean grain diameter (D50) and the skew to flow. Simulations are conducted with data groups (bed material type, pier type and shape) and different number of input variables, to produce reduced complexity and easily interpretable models. Analysis and comparison of the results indicate that the developed ANFIS model has high accuracy and outstanding generalization ability for prediction of scour parameters. The effective pier width (as opposed to skew to flow) is amongst the most relevant input parameters for the estimation.

  2. Simulation of twin data controlling population mean, variance, skewness and kurtosis.

    PubMed

    Christian, J C; Bailey, J E; Evans, M M; Kang, K W; Norton, J A; Yu, P L

    1977-01-01

    A computer system for simulation of quantitative twin data is being developed. The capability is being built in a simulate distributions with known means, standard deviations, skewness and kurtosis. PMID:562055

  3. Skew Generalized Extreme Value Distribution: Probability Weighted Moments Estimation and Application to Block Maxima Procedure

    E-print Network

    Paris-Sud XI, Université de

    Skew Generalized Extreme Value Distribution: Probability Weighted Moments Estimation size. We propose to estimate the parameters of the SGEV distribution via the Probability Weighted Extreme Value distribution, Extreme Value Theory, Probability Weighted Moments, Return Level Estimation. 1

  4. Effects of Coarse Grouping and Skewed Marginal Distributions on the Pearson Product Moment Correlation Coefficient

    ERIC Educational Resources Information Center

    Wylie, Peter B.

    1976-01-01

    Twelve non-normal bivariate distributions were constructed to investigate the effects which coarsley grouped, skewed marginal distributions have on the correlation coefficient and the accuracy of current methods of correction for grouping. (Author/RC)

  5. AN INTEGRATED NTP-RTCP SOLUTION TO AUDIO SKEW DETECTION AND COMPENSATION FOR VOIP APPLICATIONS

    E-print Network

    performance of the receiver playout buffer, in- troduced to absorb the effects of network jitter. A faster. Measured PC System Clock Drift inserts/deletes appropriate samples to compensate for such skew whereas

  6. A skewed PDF combustion model for jet diffusion flames. [Probability density function (PDF)

    SciTech Connect

    Abou-Ellail, M.M.M.; Salem, H. (Cairo Univ. (Egypt))

    1990-11-01

    A combustion model based on restricted chemical equilibrium is described. A transport equation for the skewness of the mixture fraction is derived. It contains two adjustable constants. The computed values of the mean mixture fraction (f) and its variance and skewness (g and s) for a jet diffusion methane flame are used to obtain the shape of a shewed pdf. The skewed pdf is split into a turbulent part (beta function) and a nonturbulent part (delta function) at f = 0. The contribution of each part is directly related to the values of f, g, and s. The inclusion of intermittency in the skewed pdf appreciably improves the numerical predictions obtained for a turbulent jet diffusion methane flame for which experimental data are available.

  7. Bridging The Inferential Gap

    PubMed Central

    Stewart, Walter F.; Shah, Nirav R.; Selna, Mark J.; Paulus, Ronald A.; Walker, James M.

    2009-01-01

    Most clinical decisions involve bridging the inferential gap: Clinicians are required to “fill in” where they lack knowledge or where no knowledge yet exists. In this context we consider how the inferential gap is a product, in part, of how knowledge is created, the limits to gaining access to such knowledge, and the variable ways in which knowledge is translated into decisions. We consider how electronic health records (EHRs) will help narrow this gap by accelerating the creation of evidence relevant to everyday practice needs and facilitating real-time use of knowledge in practice. PMID:17259202

  8. Strengthen a Paper Bridge

    NSDL National Science Digital Library

    Twin Cities Public Television, Inc.

    2006-01-01

    In this quick activity (page 1 of the PDF), learners will test how many pennies a flat paper index card bridging the gap between two stacks of books is able to support. Then, learners alter the structure of the same card by folding it accordion-style and retest by again stacking pennies on top. Learners look for a relationship between the number of folds and the number of pennies the card can hold by creating a scatter plot. Relates to the linked video, DragonflyTV: Tug O’ War.

  9. Rapid bridge deck replacement

    E-print Network

    Osegueda, Roberto Alejandro

    1983-01-01

    at 24 Hours 93 19 Tensile Strength of Epoxy Mortar of Connections at 24 Hours 94 20 Initial Tangent Moduli of Epoxy Mortar of Connections 21 Theoretical Correlation Factor of Flexural Strain 98 Gages 103 22 Average Percent Error of Shear Strain... replacement time as well as traffic interference. An experimental study consisting of static load tests on a 1/3 scale model of a 60-ft-long steel I-girder bridge with precast concrete panels connected with epoxy mortar and shear connectors to accomplish...

  10. Bridging the Watershed

    NSDL National Science Digital Library

    Bridging the Watershed is a partnership between Washington DC area schools and the National Park Service that uses the Potomac River and Chesapeake Bay watersheds as "learning laboratories." The Students section of this site has some great interactive activities that help students learn how to identify plants and ecosystems, determine stream health based on macroinvertebrate identification, and understand the perils of migratory fish. This is a great Web site with a broad range of information suitable to a variety of different age levels and interests, yet with enough detail to make each section stand alone.

  11. Bridging biometrics and forensics

    NASA Astrophysics Data System (ADS)

    Yan, Yanjun; Osadciw, Lisa Ann

    2008-02-01

    This paper is a survey on biometrics and forensics, especially on the techniques and applications of face recognition in forensics. This paper describes the differences and connections between biometrics and forensics, and bridges each other by formulating the conditions when biometrics can be applied in forensics. Under these conditions, face recognition, as a non-intrusive and non-contact biometrics, is discussed in detail as an illustration of applying biometrics in forensics. The discussion on face recognition covers different approaches, feature extractions, and decision procedures. The advantages and limitations of biometrics in forensic applications are also addressed.

  12. Remarks on the Scaling of Kurtosis with Squared Skewness

    NASA Astrophysics Data System (ADS)

    Krommes, J. A.

    2007-11-01

    Recent analysis of density fluctuations in TORPEXootnotetextB. Labit et al., Universal statistical properties of drift-interchange turbulence in TORPEX plasmas, Phys. Rev. Lett. 98, 255002 (2007). support the relationship K = aS^2 + b between the skewness S and (excess) kurtosis K, where a 1.5 and b -0.2. (A realizability constraint is K >=S^2 - 2.) Remarkably, essentially the same result has been shown to hold for a global dataset of fluctuations of sea-surface temperature,ootnotetextP. Sura and P. D. Sardeshmukh, A global view of non-Gaussian SST variability, J. Phys. Oceanogr.(2007), in press. and a simple theoretical (nonlinear Langevin) model has been proposedootnotetextmark[3] that leads to a = 3/2 and b = 0. This is obviously suggestive, but it is a challenge to justify the Langevin model in detail for magnetized plasma turbulence. Previous results on higher-order statistics,ootnotetextJ. A. Krommes, Non-Gaussian statistics, classical field theory, and realizable Langevin models, Phys. Rev. E 53, 4865 (1996). dimensionally compatible with K ˜S^2, are reviewed and an attempt is made to derive a and b for a model involving coupled modes and linear waves. The extent to which the values of a and b are sensitive discriminants for details of the underlying turbulence is discussed.

  13. Higher-order skewness and excess coefficients of some probability distributions applicable to optical propagation phenomena

    NASA Technical Reports Server (NTRS)

    Majumdar, A. K.

    1979-01-01

    Expressions are derived for higher-order skewness and excess coefficients using central moments and cumulants up to 8th order. These coefficients are then calculated for three probability distributions: (1) Log-normal, (2) Rice-Nakagami, and (3) Gamma distributions. Curves are given to shown the variation of skewness with excess coefficients for these distributions. These curves are independent of the particular distribution parameters. This method is useful for studying fluctuating phenomena, which obey non-Gaussian statistics.

  14. Estimating optimal hedge ratio: a multivariate skew-normal distribution approach

    Microsoft Academic Search

    Donald Lien; Keshab Shrestha

    2010-01-01

    In this article, we adopt Multivariate Skew-Normal (MSKN) distributions to test for the joint normality of spot and futures returns and to estimate optimal hedge ratios. Using daily data for 22 different commodities, we reject the joint normality hypothesis in favour of Skew-Normal (SKN) distributions for all commodities at less than 1% significance level. In the out-of-sample performance comparison, the

  15. An Adaptive Method for Reducing Clock Skew in an Accumulative Z-Axis Interconnect System

    NASA Technical Reports Server (NTRS)

    Bolotin, Gary; Boyce, Lee

    1997-01-01

    This paper will present several methods for adjusting clock skew variations that occur in a n accumulative z-axis interconnect system. In such a system, delay between modules in a function of their distance from one another. Clock distribution in a high-speed system, where clock skew must be kept to a minimum, becomes more challenging when module order is variable before design.

  16. Distributions generated by perturbation of symmetry with emphasis on a multivariate skew \\

    Microsoft Academic Search

    Adelchi Azzalini; Antonella Capitanio

    2003-01-01

    A fairly general procedure is studied to perturbate a multivariate density\\u000asatisfying a weak form of multivariate symmetry, and to generate a whole set of\\u000anon-symmetric densities. The approach is general enough to encompass a number\\u000aof recent proposals in the literature, variously related to the skew normal\\u000adistribution. The special case of skew elliptical densities is examined in\\u000adetail,

  17. Quantifying reinforced concrete bridge deck deterioration using ground penetrating radar

    NASA Astrophysics Data System (ADS)

    Martino, Nicole Marie

    Bridge decks are deteriorating at an alarming rate due to corrosion of the reinforcing steel, requiring billions of dollars to repair and replace them. Furthermore, the techniques used to assess the decks don't provide enough quantitative information. In recent years, ground penetrating radar (GPR) has been used to quantify deterioration by comparing the rebar reflection amplitudes to technologies serving as ground truth, because there is not an available amplitude threshold to distinguish healthy from corroded areas using only GPR. The goal of this research is to understand the relationship between GPR and deck deterioration, and develop a model to determine deterioration quantities with GPR alone. The beginning of this research determines that not only is the relationship between GPR and rebar corrosion stronger than the relationship between GPR and delaminations, but that the two are exceptionally correlated (90.2% and 86.6%). Next, multiple bridge decks were assessed with GPR and half-cell potential (HCP). Statistical parameters like the mean and skewness were computed for the GPR amplitudes of each deck, and coupled with actual corrosion quantities based on the HCP measurements to form a future bridge deck model that can be used to assess any deck with GPR alone. Finally, in order to understand exactly which component of rebar corrosion (rust, cracking or chloride) attenuates the GPR data, computational modeling was carried out to isolate each variable. The results indicate that chloride is the major contributor to the rebar reflection attenuation, and that computational modeling can be used to accurately simulate GPR attenuation due to chloride.

  18. Trigenomic Bridges for Brassica Improvement

    Microsoft Academic Search

    Sheng Chen; Matthew N. Nelson; Anne-Marie Chèvre; Eric Jenczewski; Zaiyun Li; Annaliese S. Mason; Jinling Meng; Julie A. Plummer; Aneeta Pradhan; Kadambot H. M. Siddique; Rod J. Snowdon; Guijun Yan; Weijun Zhou; Wallace A. Cowling

    2011-01-01

    We introduce and review Brassica crop improvement via trigenomic bridges. Six economically important Brassica species share three major genomes (A, B, and C), which are arranged in diploid (AA, BB, and CC) and allotetraploid (AABB, AACC, and BBCC) species in the classical triangle of U. Trigenomic bridges are Brassica interspecific hybrid plants that contain the three genomes in various combinations,

  19. Bridges to computer architecture education

    Microsoft Academic Search

    Peter Marwedel; Birgit Sirocic

    2004-01-01

    Bridging the gap between the student's current knowledge and the technical details of computer systems is frequently required for the education of undergraduate students or students with a lack of previous technical knowledge. In this paper we will describe how to build bridges by the combination of introducing Flash-animations and the educational units of the RaVi system. In a first

  20. Construction Technologies: Construct the Strongest Bridge

    NSDL National Science Digital Library

    Joy Trahan-Liptak

    2013-01-01

    Learners work in pairs to create three simple types of bridges, a beam bridge, an arch bridge, and a suspension bridge. They will observe how the bridges work under load and discover why engineers use different types of bridges for different places. Learners are introduced to the parts needed to build a bridge, and what they are for. Resource contains detailed diagrams and photos to assist in bridge building. Investigating questions allow learners to discuss the activity and apply their understanding to their world. Activity time can be split across multiple meetings.

  1. Bridging the Watershed

    NSDL National Science Digital Library

    Bridging the Watershed (BTW) is an outreach program of the Alice Ferguson Foundation in partnership with the National Park Service and area schools. It promotes national parks as learning laboratories and provides a model that can be replicated in other parks and watersheds. The program is based in the Washington, D.C. metropolitan area. BTW partners share a fundamental goal to educate the public about the Potomac River and Chesapeake Bay watersheds in order to heighten awareness and develop stewardship for these resources. Science curriculum modules have been developed for high school students studying Earth science, chemistry, and the life sciences. Each module is composed of performance-based activities in which students examine and analyze the health of their watershed by applying science, math, problem-solving and action skills. Students gather authentic data to assess and problem solve real-world issues in the parks and watershed.

  2. Stanford: The Bridge Project

    NSDL National Science Digital Library

    Stanford University's Bridge Project: Strengthening K-16 Transition Policies emphasizes that "reforms affecting K-12 and higher education must occur across systems in order to achieve the desired outcomes." Their approach is to improve opportunities for all students to enter and succeed in higher education by strengthening the alignment between higher education admissions-related requirements and K-12 curriculum frameworks, standards, and assessments. They conduct research that is meant to inform educational institutions and federal, state, and local agencies through descriptive analysis of the policies, identification of "disjunctures that exist in the current policy environment," and recommendations for improving the current system. Details about this program as well as their policy reports and briefs are available from their website.

  3. Bridges to Structure

    NSDL National Science Digital Library

    Peter Woodruff (Champlain-St. Lambert College; )

    2004-06-12

    This project's goals are to investigate structural components at a variety of levels: molecularly, cellularlly (histologically),phylogenetically, organismally, etc. Traditionally the stuctural classes at many institutions have used primarily dissection and histology for comparison of different vertebrate classes. In this project, we began to develop exercises at the molecular level using gemonmic and proteomic information to form phylogenetic trees, started a chart of materials available at NCBI for use in comparison (phylogentically and visually) of characteristic proteins from specific organ systems, and initiated thinking about a project to start a pictorial archive of dissection activities and histological meassurements. With the signifcant movement to integrate more material within biology and other areas of science and mathematics, building bridges (exercises) amongst a number of levels seems relevant. In addition, adding more open-ended projects with greater manipulation of data and mathematical manipulation in these courses is very desirable.

  4. The Bridges Organization

    NSDL National Science Digital Library

    The connection between art and mathematics is well known, and the Bridges Organization has been bringing together these two worlds since 1998. The group started in Kansas, and since then they have traveled to cities in North America and Europe. On this site, visitors can learn about their past conferences, and view some of their galleries of images. The "Virtual Museum" area is a real treat, and visitors can look at spherical paintings, geometric sculptures, and algorithmic visual art. Moving on, the "Educational Resource Center" area features links of interest to educators, including sites dedicated to teaching mathematical thinking through origami and such. The site is rounded out by past conference reports and information about their leadership.

  5. Burning trees and bridges

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1990-01-01

    Most burning of biomass is the result of human activity, and on a global scale it is increasing. Tropospheric concentrations of CO2, CO, CH4, non-methane hydrocarbons, and ozone are all increasing with time; global biomass burning may make an important contribution to this increase and thus to potential global climate change. The nitrogen cycle also can have important climatic effects. Nitrous oxide put into the atmosphere by biomass burning is a greenhouse gas 250 times more powerful (molecule for molecule) than carbon dioxide. Nitric oxide, as well as being a photochemical precursor of ozone, a major pollutant in the troposphere, produces nitric acid, the fastest-growing component of acid rain. Hence, the new bridge in the nitrogen cycle is of more than mere technical interest.

  6. Cascaded resonant bridge converters

    NASA Technical Reports Server (NTRS)

    Stuart, Thomas A. (Inventor)

    1989-01-01

    A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.

  7. Vertical skew due to changes in gravitoinertial force: a possible consequence of otolith asymmetry.

    PubMed

    Karmali, Faisal; Ramat, Stefano; Shelhamer, Mark

    2006-01-01

    During the alternating enhanced and reduced "gravity" levels of parabolic flight, subjects noted that a horizontally eccentric point target viewed binocularly in darkness seemed to split into two targets with vertical divergence. The amount of perceived divergence seemed to depend on instantaneous g level. This perceptual observation suggested a vertical misalignment of the eyes (vertical skew), dependent on the magnitude of g level sensed by the otoliths. While performing a different experiment during parabolic flight we recorded binocular eye position and analyzed these data to corroborate the behavioral observations. Records were obtained from seven trials in five subjects, containing eye alignment in both 0 g and 1.8 g. The recordings confirm the presence of vertical skew that changed with g level. "Skew-differential" was quantified for each trial as the difference in vertical skew from 0 g to 1.8 g. Mean skew-differential was 1.37 degrees; the largest was 2.57 degrees. Statistical significance was assessed using the student t-test and the more correct and stringent Generalized Estimating Equations (GEE). The observed skew is equivalent to a mild strabismus, which is known to result in diplopia. The underlying mechanism may be an asymmetry between the otolith organs on either side, which is centrally compensated in 1 g, but is inappropriately compensated in other gravitational fields. If equivalent amounts of vertical skew were to occur during changes in g level during dynamic phases of flight in high-performance aircraft or space shuttle reentry, the impact on visual fixation might be detrimental to piloting performance. PMID:17312339

  8. Intracolonial genetic variation affects reproductive skew and colony productivity during colony foundation in a parthenogenetic termite

    PubMed Central

    2014-01-01

    Background In insect societies, intracolonial genetic variation is predicted to affect both colony efficiency and reproductive skew. However, because the effects of genetic variation on these two colony characteristics have been tested independently, it remains unclear whether they are affected by genetic variation independently or in a related manner. Here we test the effect of genetic variation on colony efficiency and reproductive skew in a rhinotermitid termite, Reticulitermes speratus, a species in which female-female pairs can facultatively found colonies. We established colonies using two types of female-female pairs: colonies founded by sisters (i.e., sister-pair colonies) and those founded by females from different colonies (i.e., unrelated-pair colonies). Colony growth and reproductive skew were then compared between the two types of incipient colonies. Results At 15 months after colony foundation, unrelated-pair colonies were larger than sister-pair colonies, although the caste ratio between workers and nymphs, which were alternatively differentiated from young larvae, did not differ significantly. Microsatellite DNA analyses of both founders and their parthenogenetically produced offspring indicated that, in both sister-pair and unrelated-pair colonies, there was no significant skew in the production of eggs, larvae, workers and soldiers. Nymph production, however, was significantly more skewed in the sister-pair colonies than in unrelated-pair colonies. Because nymphs can develop into winged adults (alates) or nymphoid reproductives, they have a higher chance of direct reproduction than workers in this species. Conclusions Our results support the idea that higher genetic variation among colony members could provide an increase in colony productivity, as shown in hymenopteran social insects. Moreover, this study suggests that low genetic variation (high relatedness) between founding females increases reproductive skew via one female preferentially channeling her relatives along the reproductive track. This study thus demonstrated that, in social insects, intracolonial genetic variation can simultaneously affect both colony efficiency and reproductive skew. PMID:25123355

  9. Static performance investigation of a skewed-throat multiaxis thrust-vectoring nozzle concept

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    1994-01-01

    The static performance of a jet exhaust nozzle which achieves multiaxis thrust vectoring by physically skewing the geometric throat has been characterized in the static test facility of the 16-Foot Transonic Tunnel at NASA Langley Research Center. The nozzle has an asymmetric internal geometry defined by four surfaces: a convergent-divergent upper surface with its ridge perpendicular to the nozzle centerline, a convergent-divergent lower surface with its ridge skewed relative to the nozzle centerline, an outwardly deflected sidewall, and a straight sidewall. The primary goal of the concept is to provide efficient yaw thrust vectoring by forcing the sonic plane (nozzle throat) to form at a yaw angle defined by the skewed ridge of the lower surface contour. A secondary goal is to provide multiaxis thrust vectoring by combining the skewed-throat yaw-vectoring concept with upper and lower pitch flap deflections. The geometric parameters varied in this investigation included lower surface ridge skew angle, nozzle expansion ratio (divergence angle), aspect ratio, pitch flap deflection angle, and sidewall deflection angle. Nozzle pressure ratio was varied from 2 to a high of 11.5 for some configurations. The results of the investigation indicate that efficient, substantial multiaxis thrust vectoring was achieved by the skewed-throat nozzle concept. However, certain control surface deflections destabilized the internal flow field, which resulted in substantial shifts in the position and orientation of the sonic plane and had an adverse effect on thrust-vectoring and weight flow characteristics. By increasing the expansion ratio, the location of the sonic plane was stabilized. The asymmetric design resulted in interdependent pitch and yaw thrust vectoring as well as nonzero thrust-vector angles with undeflected control surfaces. By skewing the ridges of both the upper and lower surface contours, the interdependency between pitch and yaw thrust vectoring may be eliminated and the location of the sonic plane may be further stabilized.

  10. Nanoparticle bridge DNA biosensor

    NASA Astrophysics Data System (ADS)

    Huang, Hong-Wen

    A new DNA sensing method is demonstrated in which DNA hybridization events lead to the formation of nanoparticle satellites that bridge two electrodes and are detected electrically. The hybridization events are exclusively carried out only on specific locations, the surfaces of C-ssDNA modified 50 nm GNPs. The uniqueness of this work is that only a small number of T-ccDNA molecules (<10) is required to form the nanoparticle satellites, allowing ultra-sensitive DNA sensing. The principle of this new DNA sensing technique has been demonstrated using target DNA and three-base-pair-mismatched DNA in 20nM concentrations. Three single-stranded DNA (ssDNA) system is used in our experiment which includes Capture-ssDNA (C-ssDNA), Target-ssDNA (T-ssDNA) and Probe-ssDNA (P-ssDNA). Both C-ssDNA and P-ssDNA are modified by a thiol group and can hybridize with different portions of T-ssDNA. T-ssDNA requires no modification in three ssDNA system, which is beneficial in many applications. C-ssDNA modified 50nm gold nanoparticle (C-50au) and P-ssDNA modified 30nm gold nanoparticle (P-30au) are prepared through the reaction of thiol-gold chemical bonding between thiolated ssDNA and gold nanoparticle (GNP) (C-ssDNA with 50nm GNP, P-ssDNA with 30nm GNP). We controllably place the C-50au only on the SiO2 band surface (˜ 90nm width) between two gold electrodes (source and drain electrodes) by forming positively- and negatively-charged self-assembled monolayers (SAMs) on SiO2 and gold surface, respectively. DNA modified GNP is negatively charged due to ionization of phosphate group on DNA back bone. C-50au therefore is negatively charged and can only be attracted toward SiO2 area (repelled by negatively charged gold electrode surface). The amine group of positively-charged SAMs on SiO2 surface is then passivated by converting to non-polar methyl functional group after C-50au placement. P-30au is first hybridized with T-ssDNA in the solution phase (T-P- 30au formed) and is introduced into DNA detection device in which C-50au are immobilized on ˜90nm width SiO2 band (between two gold electrodes). The passivation step ensures every TP-30au are attached only to C-50au through hybridization (T-P-30au will not be attracted toward SiO2 surface or gold electrodes). GNP bridges are formed across the electrodes and provide an electrical path between two gold electrodes. We ensure that every T-P-30au only hybridizes on the surface of C-50au by (1) accurately controlling C-50au placement between two gold electrodes, (2) passivating positively-charged SAMs on SiO2 surface after C-50au immobilization. When T-P-30au hybridize with C-50au on ˜90nm wide SiO 2 surface, GNP bridges form and provide an electrical path between two gold electrodes even with only a few hybridization events. Experimental results show that even a few GNP bridges formed on SiO2 band can provide a significant conductance change from an open circuit to a conductive circuit (current = 0.5 uA at voltage = 0.1 V with four GNP bridge). We also used 3-base-pair-mismatched ssDNA (3mm-ssDNA) as a control experiment, which always resulted in an open circuit (no GNP bridge formed). Our detection device is compatible with current CMOS fabrication technology and can be manufactured on a wafer scale. The direct electrical output of this DNA detection technique provides a promising basis for high-throughput screening (can be fabricated on a wafer scale) with no expensive equipment required.

  11. Effects of skewness and kurtosis on normal-theory based maximum likelihood test statistic in multilevel structural equation modeling

    Microsoft Academic Search

    Ehri Ryu

    A simulation study investigated the effects of skewness and kurtosis on level-specific maximum likelihood (ML) test statistics\\u000a based on normal theory in multilevel structural equation models. The levels of skewness and kurtosis at each level were manipulated\\u000a in multilevel data, and the effects of skewness and kurtosis on level-specific ML test statistics were examined. When the\\u000a assumption of multivariate normality

  12. Liquid-Bridge Breaking Limits

    NASA Astrophysics Data System (ADS)

    Macner, Ashley; Steen, Paul

    2011-11-01

    Wet adhesion by liquid bridges in large arrays shows promise for use in lightweight, controllable on-demand devices. Applications include grab/release of wafer substrates, transport of micron-sized tiles for use in 3D printing and micro-dosing of personalized pharmaceutical drugs. By wetting and spreading, a drop can form a bridge and thereby ``grab'' a nearby solid substrate. By volume decrease or extension, the bridge can break. The breaking limit corresponds to bridge instability which can be predicted, knowing the static mechanical response of the bridge. Mechanical behaviors include force-volume (FV), pressure-volume (pV) and force-length (FL) responses. Instability crucially depends on the mode of failure - failure under constant-force or constant length are typical cases. We study single bridge equilibria for their breaking limits. FV diagrams for the pin-pin equal and pin-pin unequal radii boundary conditions for different bridge heights are measured in the laboratory. The FL response in the case of pin-pin equal radii is also measured. Results are compared to predictions of static theory. Static results are then used to compare to dynamical sequences where volume is driven quasistatically by syringe or an electro-osmotic pump. As the breaking limit is approached, the shape deformation accelerates leading to non-equilibrium shapes not captured by the static analysis.

  13. Chesapeake Bay Bridge-Tunnel

    NSDL National Science Digital Library

    2002-01-01

    The Chesapeake Bay Bridge-Tunnel is a 20 mile long series of bridges and tunnels that connect Virginia Beach/Norfolk to Virginia's Eastern Shore. The project is an engineering marvel; besides supporting vehicular traffic, the tunnels allow sea-going vessels passage into and out of the bay. A great deal of information is given on the project's home page, including a map of the surrounding area, historical perspectives, interesting facts, tourist attractions, and frequently asked questions. There are also a few pictures scattered throughout the site that show the enormity of the bridge-tunnel.

  14. The past, present and future of reproductive skew theory and experiments.

    PubMed

    Nonacs, Peter; Hager, Reinmar

    2011-05-01

    A major evolutionary question is how reproductive sharing arises in cooperatively breeding species despite the inherent reproductive conflicts in social groups. Reproductive skew theory offers one potential solution: each group member gains or is allotted inclusive fitness equal to or exceeding their expectation from reproducing on their own. Unfortunately, a multitude of skew models with conflicting predictions has led to confusion in both testing and evaluating skew theory. The confusion arises partly because one set of models (the 'transactional' type) answer the ultimate evolutionary question of what ranges of reproductive skew can yield fitness-enhancing solutions for all group members. The second set of models ('compromise') give an evolutionarily proximate, game-theoretic evolutionarily stable state (ESS) solution that determines reproductive shares based on relative competitive abilities. However, several predictions arising from compromise models require a linear payoff to increased competition and do not hold with non-linear payoffs. Given that for most species it may be very difficult or impossible to determine the true relationship between effort devoted to competition and reproductive share gained, compromise models are much less predictive than previously appreciated. Almost all skew models make one quantitative prediction (e.g. realized skew must fall within ranges predicted by transactional models), and two qualitative predictions (e.g. variation in relatedness or competitive ability across groups affects skew). A thorough review of the data finds that these three predictions are relatively rarely supported. As a general rule, therefore, the evolution of cooperative breeding appears not to be dependent on the ability of group members to monitor relatedness or competitive ability in order to adjust their behaviour dynamically to gain reproductive share. Although reproductive skew theory fails to predict within-group dynamics consistently, it does better at predicting quantitative differences in skew across populations or species. This suggests that kin selection can play a significant role in the evolution of sociality. To advance our understanding of reproductive skew will require focusing on a broader array of factors, such as the frequency of mistaken identity, delayed fitness payoffs, and selection pressures arising from across-group competition. We furthermore suggest a novel approach to investigate the sharing of reproduction that focuses on the underlying genetics of skew. A quantitative genetics approach allows the partitioning of variance in reproductive share itself or that of traits closely associated with skew into genetic and non-genetic sources. Thus, we can determine the heritability of reproductive share and infer whether it actually is the focus of natural selection. We view the 'animal model' as the most promising empirical method where the genetics of reproductive share can be directly analyzed in wild populations. In the quest to assess whether skew theory can provide a framework for understanding the evolution of sociality, quantitative genetics will be a central tool in future research. PMID:20545672

  15. Generalized Skew Coefficients of Annual Peak Flows for Rural, Unregulated Streams in West Virginia

    USGS Publications Warehouse

    Atkins, John T.; Wiley, Jeffrey B.; Paybins, Katherine S.

    2009-01-01

    Generalized skew was determined from analysis of records from 147 streamflow-gaging stations in or near West Virginia. The analysis followed guidelines established by the Interagency Advisory Committee on Water Data described in Bulletin 17B, except that stations having 50 or more years of record were used instead of stations with the less restrictive recommendation of 25 or more years of record. The generalized-skew analysis included contouring, averaging, and regression of station skews. The best method was considered the one with the smallest mean square error (MSE). MSE is defined as the following quantity summed and divided by the number of peaks: the square of the difference of an individual logarithm (base 10) of peak flow less the mean of all individual logarithms of peak flow. Contouring of station skews was the best method for determining generalized skew for West Virginia, with a MSE of about 0.2174. This MSE is an improvement over the MSE of about 0.3025 for the national map presented in Bulletin 17B.

  16. Criticality, factorization and Wigner-Yanase skew information in quantum spin chains

    NASA Astrophysics Data System (ADS)

    Cheng, W. W.; Li, J. X.; Shan, C. J.; Gong, L. Y.; Zhao, S. M.

    2015-07-01

    We apply the Wigner-Yanase skew information approach to analyze criticality and factorization phenomenon in the one-dimensional anisotropy model with uniform coupling interaction and periodic-two one. Based on the exact solutions of the ground states, the Wigner-Yanase skew information between two nearest-neighbor lattices is obtained. For the uniform case, the first-order derivative of the Wigner-Yanase skew information is non-analytically around the critical point. The scaling behavior and the universality are verified numerically. In particular, such skew information can also detect the factorization transition in this model. For the periodic-two case, it is found that there exist more than one phase-transition point in some parameter region due to the competition between periodicity and anisotropy. Furthermore, two kinds of phase transitions, i.e., the Ising and anisotropy transitions, driven by external field and the anisotropy parameter , are investigated carefully by the skew information. Our results state that quantum phase transition driven by the anisotropy parameter can belong to the same universality class as the one driven by external field.

  17. Criticality, factorization and Wigner-Yanase skew information in quantum spin chains

    NASA Astrophysics Data System (ADS)

    Cheng, W. W.; Li, J. X.; Shan, C. J.; Gong, L. Y.; Zhao, S. M.

    2015-05-01

    We apply the Wigner-Yanase skew information approach to analyze criticality and factorization phenomenon in the one-dimensional anisotropy XY model with uniform coupling interaction and periodic-two one. Based on the exact solutions of the ground states, the Wigner-Yanase skew information between two nearest-neighbor lattices is obtained. For the uniform case, the first-order derivative of the Wigner-Yanase skew information is non-analytically around the critical point. The scaling behavior and the universality are verified numerically. In particular, such skew information can also detect the factorization transition in this model. For the periodic-two case, it is found that there exist more than one phase-transition point in some parameter region due to the competition between periodicity and anisotropy. Furthermore, two kinds of phase transitions, i.e., the Ising and anisotropy transitions, driven by external field ? and the anisotropy parameter ? , are investigated carefully by the skew information. Our results state that quantum phase transition driven by the anisotropy parameter ? can belong to the same universality class as the one driven by external field ?.

  18. Experimental Study of the Effect of a Skewed Inlet Flow Profile on Stenotic Flow Development

    NASA Astrophysics Data System (ADS)

    Peterson, Sean; Plesniak, Michael

    2006-11-01

    Blood flows through a constricted artery, or stenosis, are known to be sensitive to geometric and velocity perturbations. The effect of a skewed mean inlet velocity on the flow development distal to an axisymmetric stenosis (modeling a diseased carotid artery) driven by a physiological forcing waveform is studied. In the physiological environment, a skewed mean velocity profile (plus a secondary flow) can be produced, e.g. by vessel curvature. This study attempts to decouple the mean flow profile and the secondary flow in order to ascertain the impact of each disturbance individually. The skewed inlet profile is produced by a porous insert designed to replicate the mean flow profile downstream of a bend. LDV and PIV data are acquired to assess the impact of the skewed velocity profile on flow features. The skewed velocity profile was observed to promote earlier reattachment of the stenotic jet by deflecting it towards the wall sooner than in a baseline study. In a second experiment, the impact of secondary flow on the stenotic jet development is investigated by the introduction of a 180 bend upstream of the stenosis. The mean flow profile is similar in character to that produced by the porous insert.

  19. High frequency of skewed X inactivation in young breast cancer patients

    PubMed Central

    Kristiansen, M; Langerod, A; Knudsen, G; Weber, B; Borresen-Dale, A; Orstavik, K

    2002-01-01

    Introduction: Patients with invasive ovarian cancer were recently shown to have a higher frequency of skewed X chromosome inactivation in peripheral blood cells compared to patients with borderline cancer and controls. In this study, we analysed the X inactivation pattern in peripheral blood from 216 breast cancer patients. Methods: X inactivation analysis was performed using HpaII predigestion of DNA followed by PCR of the highly polymorphic CAG repeat of the androgen receptor gene (AR), which amplifies the undigested inactive X chromosome only. The X inactivation pattern was classified as skewed when 90% or more of the cells preferentially used one X chromosome. Results: Young breast cancer patients (27-45 years) had a higher frequency of skewed X inactivation than young controls (13 and 1%, respectively) (p=0.009), whereas no difference was found for middle aged and older patients compared to controls of a similar age. Conclusions: A germline mutation in an X linked tumour suppressor gene may give a proliferative advantage to cells with this mutation on the active X chromosome, thus causing skewed X inactivation and an increased risk for developing cancer. Another possible explanation could be that females with a constitutionally skewed X inactivation pattern are more susceptible to develop breast cancer because of an X linked low penetrance susceptibility allele that is affected by the inactivation pattern. PMID:11826021

  20. Skewed X-chromosome inactivation in patients with esophageal carcinoma

    PubMed Central

    2013-01-01

    Abstract Skewed X-chromosome inactivation (SXCI) was found in some apparently healthy females mainly from Western countries. It has been linked to development of ovarian, breast and pulmonary carcinomas. The present study aimed to observe the SXCI frequencies in apparently healthy Chinese females and patients with esophageal carcinoma. DNA was extracted from the peripheral blood cells from 401 Chinese females without a detectable tumor and 143 female patients with esophageal carcinoma. Exon 1 of androgen receptor (AR) gene was amplified, and the products of different CAG alleles were resolved on denaturing polyacrylamide gels and visualized after silver staining. The corrected ratios (CR) of the products before and after HpaII digestion were calculated. As to the healthy females, when CR???3 was used as a criterion, SXCI was found in two (4.3%) of the 46 neonates, 13 (7.8%) of the 166 younger adults (16–50 years) and 37 (25.7%) of the 144 elderly females (51–96 years), with the frequency higher in the elderly subjects than in the two former groups (P?

  1. Bridge Deck Deicing using Geothermal Heat Pumps

    Microsoft Academic Search

    JEFFREY D. SPITLER; MAHADEVAN RAMAMOORTHY

    Several research projects at Oklahoma State University have investigated bridge deck deicing systems that utilize a ground source heat pump system to provide heating. This paper describes simulation methodology; the design of a system planned for installation on a bridge deck near Weatherford, Oklahoma; and results from system simulations of the proposed bridge deck. System simulations of the bridge deck

  2. Post-earthquake Prioritization of Bridge Inspections

    E-print Network

    Eberhard, Marc O.

    considered, the percentage of bridges damaged correlated best with the spectral acceleration at a period of 0.3 s. Bridges constructed before the 1940s, movable bridges, and older trusses were particularlyPost-earthquake Prioritization of Bridge Inspections R. T. Ranf,a... M.EERI, M. O. Eberhard,b... M

  3. Bridges, Switches, Routers 1.1 Introduction

    E-print Network

    Varaiya, Pravin

    Chapter 1 Bridges, Switches, Routers 1.1 Introduction ¯ Packet vs circuit (and virtual circuit ¯ Packet processors--Bridges, Routers, ATM switches 1 #12;2 CHAPTER 1. BRIDGES, SWITCHES, ROUTERS Routing in an extended LAN. See Problem 2. #12;4 CHAPTER 1. BRIDGES, SWITCHES, ROUTERS Figure 1.3: LAN vs VLAN topology

  4. Pulse excitation of bolometer bridges

    NASA Technical Reports Server (NTRS)

    Rusk, S. J.

    1972-01-01

    Driving bolometer bridge by appropriately phased excitation pulses increases signal-to-noise ratio of bolometer sensor which operates on a chopped light beam. Method allows higher applied voltage than is possible by conventional ac or dc excitation.

  5. Earthquake Response of Suspension Bridges

    NASA Astrophysics Data System (ADS)

    Erdik, Mustafa; Apayd?n, Nurdan

    Suspension bridges represent critical nodes of major transportation systems. Bridge failure during strong earthquakes poses not only a threat of fatalities but causes a substantial interruption of emergency efforts. Although wind induced vibrations have historically been the primary concern in the design of suspension bridges, earthquake effects have also gained importance in recent decades. This study involves ambient vibration testing and sophisticated three-dimensional dynamic finite element analysis and earthquake performance assessment of Fatih Sultan Mehmet and suspension Bo?aziçi bridges in Istanbul under earthquake excitation. Nonlinear time history analysis of 3D finite-element models of Fatih Sultan Mehmet and Bo?aziçi suspension bridges included initial stresses in the cables, suspenders, and towers in equilibrium under dead load conditions. Multi-support scenario earthquake excitation was applied to the structure. Suspension bridges are complex 3-D structures that can exhibit a large number of closely spaced coupled modes of vibration. The large number of closely spaced modes, spatially different ground motion characteristics, and the potential for nonlinear behaviour complicate the seismic response of suspension bridges. Spatial variation of ground motion exhibits itself with different ground motions at supports due to the wave passage, incoherence and local site effects. The source of nonlinear behaviour is due to geometric nonlinearity and the presence of cables that can only carry tensile forces. The natural frequencies of vibration and the corresponding mode shapes in their dead load and live load configurations are determined. Displacement time histories and stresses at critical points of the bridges are computed and their earthquake performance under the action of scenario earthquake are estimated.

  6. Effect on engineer bridging equipment

    Microsoft Academic Search

    1954-01-01

    The purpose of Project 3.22, Operation UPSHOT-KNOTHOLE, was to indicate the vulnerability of Army prefabricated fixed bridging to atomic blast and to determine means to reduce the vulnerability. To accomplish this, two 100-ft Bailey bridge spans were erected such that one was exposed to Shot 9 and both were exposed to Shot 10 of the test series; and two single

  7. Bridges.org

    NSDL National Science Digital Library

    Bridges.org is "an international non-profit organisation that promotes the effective use of Information and communications technology (ICT) in the developing world to reduce poverty and improve people's lives." The focus of its work involves ICT-related policy analysis, but organization "also promote best practice in ground-level technology implementation through research and evaluations." It provides information and resources, support grassroots projects and other efforts, and advise decision-makers and the public on key issues. As members of the technology community, the organization brings "an entrepreneurial attitude" and an understanding of technology as well as its commitment to work with governments and the private sector to achieve the goal of "spanning the international digital divide." The website provides an overview of the "digital divide" and describes the organization's approach to addressing these issues. Policy reports, case studies and evaluation guidelines are posted on this website. The organization's current work includes a comparison study of open source and proprietary software, which is also described here.

  8. The skewness and kurtosis of the projected density distribution function: validity of perturbation theory

    NASA Astrophysics Data System (ADS)

    Gaztanaga, E.; Bernardeau, F.

    1998-03-01

    We study the domain of validity of Perturbation Theory (PT), by comparing its predictions for the reduced skewness, s_3, and kurtosis, s_4, of the projected cosmological density field, with the results of N-body simulations. We investigate models with different linear power spectra and consider as physical applications both angular galaxy catalogues and weak lensing surveys. We first find that the small-angle approximation for the predicted skewness provides a good match to the exact numerical PT results. On the other hand, results from non-linear simulated catalogues agree well with PT results on quasi-linear angular scales, which correspond to scales larger than about 1 deg in the applications we have considered. We also point out that projection effects tend to attenuate the effects of strong non-linearities in the angular skewness and kurtosis.

  9. Scaled variance, skewness, and kurtosis near the critical point of nuclear matter

    E-print Network

    Vovchenko, V; Gorenstein, M I; Poberezhnyuk, R V

    2015-01-01

    The van der Waals (VDW) equation of state predicts the existence of a first-order liquid-gas phase transition and contains a critical point. The VDW equation with Fermi statistics is applied to a description of the nuclear matter. The nucleon number fluctuations near the critical point of nuclear matter are studied. The scaled variance, skewness, and kurtosis diverge at the critical point. It is found that the crossover region of the phase diagram is characterized by the large values of the scaled variance, almost zero skewness, and by the significantly negative kurtosis. The rich structures of the skewness and kurtosis are observed in the phase diagram in the wide region around the critical point, namely, they both may attain large positive or negative values.

  10. Perceived quality of wood images influenced by the skewness of image histogram

    NASA Astrophysics Data System (ADS)

    Katsura, Shigehito; Mizokami, Yoko; Yaguchi, Hirohisa

    2015-06-01

    The shape of image luminance histograms is related to material perception. We investigated how the luminance histogram contributed to improvements in the perceived quality of wood images by examining various natural wood and adhesive vinyl sheets with printed wood grain. In the first experiment, we visually evaluated the perceived quality of wood samples. In addition, we measured the colorimetric parameters of the wood samples and calculated statistics of image luminance. The relationship between visual evaluation scores and image statistics suggested that skewness and kurtosis affected the perceived quality of wood. In the second experiment, we evaluated the perceived quality of wood images with altered luminance skewness and kurtosis using a paired comparison method. Our result suggests that wood images are more realistic if the skewness of the luminance histogram is slightly negative.

  11. Scaled variance, skewness, and kurtosis near the critical point of nuclear matter

    E-print Network

    V. Vovchenko; D. V. Anchishkin; M. I. Gorenstein; R. V. Poberezhnyuk

    2015-06-18

    The van der Waals (VDW) equation of state predicts the existence of a first-order liquid-gas phase transition and contains a critical point. The VDW equation with Fermi statistics is applied to a description of the nuclear matter. The nucleon number fluctuations near the critical point of nuclear matter are studied. The scaled variance, skewness, and kurtosis diverge at the critical point. It is found that the crossover region of the phase diagram is characterized by the large values of the scaled variance, almost zero skewness, and by the significantly negative kurtosis. The rich structures of the skewness and kurtosis are observed in the phase diagram in the wide region around the critical point, namely, they both may attain large positive or negative values.

  12. Generation of time histories with a specified auto spectral density, skewness, and kurtosis

    SciTech Connect

    Smallwood, D.O.

    1996-02-01

    Some dynamic environments are characterized by time histories that are not Gaussian. A more accurate simulation of these environments can be generated if a realization of a non Gaussian time history can be reproduced which has a specified auto spectral density (also called power spectral density) and a specified skewness and kurtosis (not necessarily the skewness and kurtosis of a Gaussian time history). The mean square of the waveform is reproduced if the spectrum is reproduced. Modern waveform reproduction techniques can be used to reproduce the realized waveform on an electrodynamic or electrohydraulic shaker. A method is presented for the generation of realizations of zero mean non Gaussian random time histories with a specified auto spectral density, skewness, and kurtosis. Kurtosis, defined in this paper as E[{chi}{sup 4}]/E{sup 2}[{chi}{sup 2}], greater than 3 can be realized. Realizations of the random process are generated with a generalization of shot noise.

  13. Structural Health Indices for Steel Truss Bridges

    Microsoft Academic Search

    Ryan Kent Giles; Robin Kim; Billie F. Spencer; M. Nathan; Anne M. Newmark; Lawrence A. Bergman; Carol K. Shield; Steven C. Sweeney

    \\u000a Steel bridges represent a significant portion of the nation’s aging bridge inventory. The United States Army’s inventory has\\u000a over two hundred steel bridges that are vital to the operation of nearly every Army Installation. The Army regularly inspects\\u000a their bridges to ensure the continued functionality of the bridges. However, current inspection techniques and schedules may\\u000a not be able to detect

  14. Kurtosis and skewness of density histograms on inspiratory and expiratory CT scans in smokers.

    PubMed

    Yamashiro, Tsuneo; Matsuoka, Shin; Estépar, Raúl San José; Bartholmai, Brian J; Diaz, Alejandro; Ross, James C; Murayama, Sadayuki; Silverman, Edwin K; Hatabu, Hiroto; Washko, George R

    2011-02-01

    The aim of this study is to evaluate the relationship between lung function and kurtosis or skewness of lung density histograms on computed tomography (CT) in smokers. Forty-six smokers (age range 46?81 years), enrolled in the Lung Tissue Research Consortium, underwent pulmonary function tests (PFT) and chest CT at full inspiration and full expiration. On both inspiratory and expiratory scans, kurtosis and skewness of the density histograms were automatically measured by open-source software. Correlations between CT measurements and lung function were evaluated by the linear regression analysis. Although no significant correlations were found between inspiratory kurtosis or skewness and PFT results, expiratory kurtosis significantly correlated with the following: the percentage of predicted value of forced expiratory volume in the first second (FEV(1)), the ratio of FEV(1) to forced vital capacity (FVC), and the ratio of residual volume (RV) to total lung capacity (TLC) (FEV(1)%predicted, R = -0.581, p < 0.001; FEV(1)/FVC, R = -0.612, p < 0.001; RV/TLC, R = 0.613, p < 0.001, respectively). Similarly, expiratory skewness showed significant correlations with PFT results (FEV(1)%predicted, R = -0.584, p < 0.001; FEV(1)/FVC, R = -0.619, p < 0.001; RV/TLC, R = 0.585, p < 0.001, respectively). Also, the expiratory/inspiratory (E/I) ratios of kurtosis and skewness significantly correlated with FEV(1)%predicted (p < 0.001), FEV(1)/FVC (p < 0.001), RV/TLC (p < 0.001), and the percentage of predicted value of diffusing capacity for carbon monoxide (kurtosis E/I ratio, p = 0.001; skewness E/I ratio, p = 0.03, respectively). We conclude therefore that expiratory values and the E/I ratios of kurtosis and skewness of CT densitometry reflect airflow limitation and air-trapping. Higher kurtosis or skewness on expiratory CT scan indicates more severe conditions in smokers. PMID:21299474

  15. Alternating skew deviation in association with anti-glutamic acid decarboxylase antibodies

    PubMed Central

    Farooq, Asim V.; Soin, Ketki; Moss, Heather E.

    2015-01-01

    The presence of an elevated anti-glutamic acid decarboxylase (GAD) antibody level has been associated with a number of eye movement abnormalities, as well as other findings including cerebellar ataxia and insulin dependent diabetes mellitus. Skew deviation in association with anti-GAD antibodies has not been previously reported. Here we report a case of alternating skew deviation along with cerebellar-brainstem signs in a patient with an elevated anti-GAD antibody titer. Follow-up neurologic evaluation after treatment with intravenous immunoglobulin revealed improvement in cerebellar-brainstem signs, while ophthalmic evaluation was stable. PMID:15826997

  16. Skew-Tolerant Key Distribution for Load Balancing in MapReduce

    NASA Astrophysics Data System (ADS)

    Son, Jihoon; Choi, Hyunsik; Chung, Yon Dohn

    MapReduce is a parallel processing framework for large scale data. In the reduce phase, MapReduce employs the hash scheme in order to distribute data sharing the same key across cluster nodes. However, this approach is not robust for the skewed data distribution. In this paper, we propose a skew-tolerant key distribution method for MapReduce. The proposed method assigns keys to cluster nodes balancing their workloads. We implemented our proposed method on Hadoop. Through experiments, we evaluate the performance of the proposed method in comparison with the conventional method.

  17. A low-leakage 2.5GHz skewed CMOS 32b adder for nanometer CMOS technologies

    Microsoft Academic Search

    Klaus von Arnim; Peter Seegebrecht; Roland Thewes; Christian Pacha

    2005-01-01

    A 32b parallel prefix adder demonstrates leakage-current-reduction capabilities of skewed CMOS logic. Sub-100nA leakage currents and single-cycle activation from standby mode is achieved using multi-tox logic gates in 90nm CMOS technology. The data path contains improved sense amplifier-based flip-flops and skewed CMOS logic adapted latches.

  18. Rich model cycles in skew-product dynamics: from totally nonhyperbolic to fully prevalent hyperbolic dynamics via

    E-print Network

    Díaz, Lorenzo J.

    / 19 #12;Motivation I An example: Porcupine-like horseshoes Lorenzo J. Díaz (PUC-Rio, Brazil) Rich model cycles in skew products 3 / 19 #12;Motivation I An example: Porcupine-like horseshoes Lorenzo J. Díaz (PUC-Rio, Brazil) Rich model cycles in skew products 3 / 19 #12;Motivation I An example: Porcupine

  19. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection organization. (a) Each State...

  20. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a)...

  1. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection organization. (a) Each State...

  2. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection organization. (a) Each State...

  3. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a)...

  4. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a)...

  5. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a)...

  6. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection organization. (a) Each State...

  7. Chickamauga National Military Park Tour Roads, Gordon's Slough Bridge, At ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Chickamauga National Military Park Tour Roads, Gordon's Slough Bridge, At the confluence of Alexander's Bridge Road and Gordon's Slough, southeast of Alexander's Bridge, Fort Oglethorpe, Catoosa County, GA

  8. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection organization. (a) Each State...

  9. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a)...

  10. Assessment of modal-pushover-based scaling procedure for nonlinear response history analysis of ordinary standard bridges

    USGS Publications Warehouse

    Kalkan, E.; Kwong, N.

    2012-01-01

    The earthquake engineering profession is increasingly utilizing nonlinear response history analyses (RHA) to evaluate seismic performance of existing structures and proposed designs of new structures. One of the main ingredients of nonlinear RHA is a set of ground motion records representing the expected hazard environment for the structure. When recorded motions do not exist (as is the case in the central United States) or when high-intensity records are needed (as is the case in San Francisco and Los Angeles), ground motions from other tectonically similar regions need to be selected and scaled. The modal-pushover-based scaling (MPS) procedure was recently developed to determine scale factors for a small number of records such that the scaled records provide accurate and efficient estimates of “true” median structural responses. The adjective “accurate” refers to the discrepancy between the benchmark responses and those computed from the MPS procedure. The adjective “efficient” refers to the record-to-record variability of responses. In this paper, the accuracy and efficiency of the MPS procedure are evaluated by applying it to four types of existing Ordinary Standard bridges typical of reinforced concrete bridge construction in California. These bridges are the single-bent overpass, multi-span bridge, curved bridge, and skew bridge. As compared with benchmark analyses of unscaled records using a larger catalog of ground motions, it is demonstrated that the MPS procedure provided an accurate estimate of the engineering demand parameters (EDPs) accompanied by significantly reduced record-to-record variability of the EDPs. Thus, it is a useful tool for scaling ground motions as input to nonlinear RHAs of Ordinary Standard bridges.

  11. Bridging faults in BiCMOS circuits

    NASA Technical Reports Server (NTRS)

    Menon, Sankaran M.; Malaiya, Yashwant K.; Jayasumana, Anura P.

    1993-01-01

    Combining the advantages of CMOS and bipolar, BiCMOS is emerging as a major technology for many high performance digital and mixed signal applications. Recent investigations revealed that bridging faults can be a major failure mode in IC's. Effects of bridging faults in BiCMOS circuits are presented. Bridging faults between logical units without feedback and logical units with feedback are considered. Several bridging faults can be detected by monitoring the power supply current (I(sub DDQ) monitoring). Effects of bridging faults and bridging resistance on output logic levels were examined along with their effects on noise immunity.

  12. Bridge Construction and Engineering Learning Center

    NSDL National Science Digital Library

    This website is a great resource for information on bridges. The site provides links to websites like PBS's Nova, where you can learn about different types of bridges and then test your knowledge by matching the right bridge to the right location (over a freeway, river, canyon or ocean waterway), or where you can read more about the forces, loads and materials that affect bridges. Another link takes you to Better Bridges, where you can find out how many bridges are in your state. Definitely a great resource for those armchair engineers but also for teachers and students of physics looking for some great information on this fascinating type of construction.

  13. On the skew-symmetric character of the couple-stress tensor

    E-print Network

    Ali R. Hadjesfandiari

    2015-01-20

    In this paper, the skew-symmetric character of the couple-stress tensor is established as the result of arguments from tensor analysis. Consequently, the couple-stress pseudo-tensor has a true vectorial character. The fundamental step in this development is that the isotropic couple-stress tensor cannot exist.

  14. STRUCTURABLE ALGEBRAS OF SKEW-RANK 1 OVER THE AFFINE S. PUMPLUN

    E-print Network

    matrix algebra over k (Theorem 4). In order to achieve this, we show that the matrix algebra M(T, N, NSTRUCTURABLE ALGEBRAS OF SKEW-RANK 1 OVER THE AFFINE PLANE S. PUMPL¨UN Abstract. Let k be a field of characteristic not 2 or 3. Infinitely many mutually non- isomorphic structurable algebras of rank 20 over k[X, Y

  15. The Smith Normal Form of the Incidence Matrix of Skew Lines in PG(3, q)

    E-print Network

    Sin, Peter

    The Smith Normal Form of the Incidence Matrix of Skew Lines in PG(3, q) Peter Sin, University. In our case D = q4I. #12;Smith normal forms A, L define endomorphisms of the free Z-module on lines. Cokernel of A is called the Smith group and the torsion subgroup of the cokernel of L is known

  16. Statistical models for the analysis of skewed healthcare cost data: a simulation study.

    PubMed

    Malehi, Amal Saki; Pourmotahari, Fatemeh; Angali, Kambiz Ahmadi

    2015-01-01

    Skewed data is the main issue in statistical models in healthcare costs. Data transformation is a conventional method to decrease skewness, but there are some disadvantages. Some recent studies have employed generalized linear models (GLMs) and Cox proportional hazard regression as alternative estimators. The aim of this study was to investigate how well these alternative estimators perform in terms of bias and precision when the data are skewed. The primary outcome was an estimation of population means of healthcare costs and the secondary outcome was the impact of a covariate on healthcare cost. Alternative estimators, such as ordinary least squares (OLS) for Ln(y) or Log(y), Gamma, Weibull and Cox proportional hazard regression models, were compared using Monte Carlo simulation under different situations, which were generated from skewed distributions. We found that there was not one best model across all generated conditions. However, GLMs, especially the Gamma regression model, behaved well in the estimation of population means of healthcare costs. The results showed that the Cox proportional hazard model exhibited a poor estimation of population means of healthcare costs and the ?1 even under proportional hazard data. Approximately results are consistent by increasing the sample size. However, increasing the sample size could improve the performance of the OLS-based model. PMID:26029491

  17. Bayesian analysis of nonlinear mixed-effects mixture models for longitudinal data with heterogeneity and skewness.

    PubMed

    Lu, Xiaosun; Huang, Yangxin

    2014-07-20

    It is a common practice to analyze complex longitudinal data using nonlinear mixed-effects (NLME) models with normality assumption. The NLME models with normal distributions provide the most popular framework for modeling continuous longitudinal outcomes, assuming individuals are from a homogeneous population and relying on random-effects to accommodate inter-individual variation. However, the following two issues may standout: (i) normality assumption for model errors may cause lack of robustness and subsequently lead to invalid inference and unreasonable estimates, particularly, if the data exhibit skewness and (ii) a homogeneous population assumption may be unrealistically obscuring important features of between-subject and within-subject variations, which may result in unreliable modeling results. There has been relatively few studies concerning longitudinal data with both heterogeneity and skewness features. In the last two decades, the skew distributions have shown beneficial in dealing with asymmetric data in various applications. In this article, our objective is to address the simultaneous impact of both features arisen from longitudinal data by developing a flexible finite mixture of NLME models with skew distributions under Bayesian framework that allows estimates of both model parameters and class membership probabilities for longitudinal data. Simulation studies are conducted to assess the performance of the proposed models and methods, and a real example from an AIDS clinical trial illustrates the methodology by modeling the viral dynamics to compare potential models with different distribution specifications; the analysis results are reported. PMID:24623529

  18. The effect of skewness and kurtosis on the robustness of linear mixed models.

    PubMed

    Arnau, Jaume; Bendayan, Rebecca; Blanca, María J; Bono, Roser

    2013-09-01

    This study analyzes the robustness of the linear mixed model (LMM) with the Kenward-Roger (KR) procedure to violations of normality and sphericity when used in split-plot designs with small sample sizes. Specifically, it explores the independent effect of skewness and kurtosis on KR robustness for the values of skewness and kurtosis coefficients that are most frequently found in psychological and educational research data. To this end, a Monte Carlo simulation study was designed, considering a split-plot design with three levels of the between-subjects grouping factor and four levels of the within-subjects factor. Robustness is assessed in terms of the probability of type I error. The results showed that (1) the robustness of the KR procedure does not differ as a function of the violation or satisfaction of the sphericity assumption when small samples are used; (2) the LMM with KR can be a good option for analyzing total sample sizes of 45 or larger when their distributions are normal, slightly or moderately skewed, and with different degrees of kurtosis violation; (3) the effect of skewness on the robustness of the LMM with KR is greater than the corresponding effect of kurtosis for common values; and (4) when data are not normal and the total sample size is 30, the procedure is not robust. Alternative analyses should be performed when the total sample size is 30. PMID:23299397

  19. Skew and kurtosis of low-energy heavy-ion distributions implanted in silicon and aluminium

    NASA Astrophysics Data System (ADS)

    Kisielewicz, Miko?aj

    1983-02-01

    The skew and kurtosis of 10-45 keV heavy-ion distributions in aluminium and silicon have been measured using the radiotracer and peeling technique, and compared with values calculated by the moments method of Winterbon. For Si the agreement is considered to be satisfactory; the disagreement in Al case can be explained as being due to diffusion effects.

  20. Bayesian Non-parametric Modeling With Skewed and Heavy-tailed Data

    E-print Network

    Draper, David

    -tailed distribution; non-parametric bootstrap fails miserably at drawing inferences about mean and variance and predictive statements than parametric and frequentist non-parametric approaches. Bayesian Non-parametricBayesian Non-parametric Modeling With Skewed and Heavy-tailed Data David Draper (joint work

  1. A General Framework for Mining Concept-Drifting Data Streams with Skewed Distributions

    Microsoft Academic Search

    Jing Gao; Wei Fan; Jiawei Han; Philip S. Yu

    2007-01-01

    In recent years, there have been some interesting stud- ies on predictive modeling in data streams. However, most such studies assume relatively balanced and sta- ble data streams but cannot handle well rather skewed (e.g., few positives but lots of negatives) and stochastic distributions, which are typical in many data stream ap- plications. In this paper, we propose a new

  2. Steiner tree based rotary clock routing with bounded skew and capacitive load balancing

    Microsoft Academic Search

    Jianchao Lu; Vinayak Honkote; Xin Chen; Baris Taskin

    2011-01-01

    A novel rotary clock network routing method is proposed for the low-power resonant rotary clocking technology which guarantees: 1. The balanced capacitive load driven by each of the tapping points on the rotary rings, 2. Customized bounded clock skew among all the registers on chip, 3. A sub-optimally minimized total wirelength of the clock wire routes. In the proposed method,

  3. J. Symbolic Computation (1997) 0, 1--000. To appear. Factoring in SkewPolynomial Rings

    E-print Network

    Giesbrecht, Mark

    1997-01-01

    for factoring polynomials in the skew­polynomial ring F[x; #], a non­commutative generalization of the usual ring of polynomials F[x], where F is a finite field and #: F # F is an automorphism (iterated Frobenius map). Ap­ plications include fast functional decomposition algorithms for a class of polynomials in F

  4. Skew-symmetric solar P modes in low-l BiSON ^* data

    NASA Astrophysics Data System (ADS)

    Chaplin, W. J.; Elsworth, Y.; Isaak, G. R.; Miller, B. A.; New, R.

    1999-09-01

    The p-mode oscillations of the Sun are manifestations of resonantly trapped acoustic waves propagating within its interior. The effective size of the resulting resonant cavity changes with the properties of the modes - the interaction of this phenomenon with a highly localized excitation source in the upper layers of the convection zone gives rise to skew-symmetric resonant profiles whose degree of asymmetry changes with frequency. Here, we have fitted low-angular-degree (low-l) resonant p-mode peaks - in a power spectrum generated from 32 months of BiSON Doppler velocity observations of the visible solar disc - to a skew-symmetric formalism to account for this effect. We present the fitted frequencies, fine-structure spacings [d_0(n) and d_1(n)] and mode-skewness estimates; and discuss the quantitative impact of fitting a skew, rather than symmetric, limit model. We also consider the reliability of the extracted parameters through the application of a useful statistical test, and extensive Monte Carlo fits to artificial data.

  5. Estimate of Skew Quadrupole Field in Tevatron Dipoles due to Creep

    Microsoft Academic Search

    M. Syphers

    The strong systematic transverse coupling observed in the Tevatron is believed to have developed over time as fiberglass spacers used in the magnet design have crept into a compressed state during the lifetime of the accelerator. Below we present a simple model of the Tevatron dipole magnet using the method of magnetic images to calculate the skew quadrupole coecient, a1,

  6. The skew field of quaternions H 1. Definition of the group of quaternions

    E-print Network

    Barron, Katrina D.

    The skew field of quaternions H 1. Definition of the group of quaternions The group of quaternions of the quaternions, and One might very well ask how such a group might actually arise. The quaternions have several different concrete realizations; below we give a couple. The quaternions as a subgroup of SL(2, C): Recall

  7. Definition of Transformation Random Transformation Group Action Skew Product Literature Ergodicity of Avalanche Transfromations

    E-print Network

    Liu, I-Shih

    of Avalanche Transfromations Manfred Denker May 26, 2014 Pennsylvania State University #12;Definition Action Skew Product Literature Motivation: Avalanches in neuronal dynamics (see the talk at the Sao Paulo linear isometry on C = {x : i : x(i) i}, where x(1) x(2) ... x(N) is the order statistics. Fact 2

  8. Influence of pressure gradient on streamwise skewness factor in turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Dró?d?, Artur

    2014-08-01

    The paper shows an effect of favourable and adverse pressure gradients on turbulent boundary layer. The skewness factor of streamwise velocity component was chosen as a measure of the pressure gradient impact. It appears that skewness factor is an indicator of convection velocity of coherent structures, which is not always equal to the average flow velocity. The analysis has been performed based upon velocity profiles measured with hot-wire technique in turbulent boundary layer with pressure gradient corresponding to turbomachinery conditions. The results show that the skewness factor decreases in the flow region subjected to FPG and increases in the APG conditions. The changes of convection velocity and skewness factor are caused by influence of large-scale motion through the mechanism called amplitude modulation. The large-scale motion is less active in FPG and more active in APG, therefore in FPG the production of vortices is random (there are no high and low speed regions), while in the APG the large-scale motion drives the production of vortices. Namely, the vortices appear only in the high-speed regions, therefore have convection velocity higher than local mean velocity. The convection velocity affects directly the turbulent sweep and ejection events. The more flow is dominated by large-scale motion the higher values takes both the convection velocity of small-scale structures and sweep events induced by them.

  9. Interval estimators for the population mean for skewed distributions with a small sample size

    E-print Network

    Meeden, Glen

    Interval estimators for the population mean for skewed distributions with a small sample size Glen distributions with a small sample size SUMMARY In finite population sampling it has long been known on the `Polya posterior'. For large sample sizes these methods often closely mimic standard frequentist methods

  10. Matroid matching via mixed skew--symmetric matrices James F. Geelen 1 and Satoru Iwata 2

    E-print Network

    Yamamoto, Hirosuke

    Matroid matching via mixed skew--symmetric matrices James F. Geelen 1 and Satoru Iwata 2 1 generalization of the matching problem contains the linear matroid matching problem and, more generally, the linear delta--matroid parity problem. We present a tight upper bound on the rank of T +K by decomposing

  11. Process-Induced Skew Variation for Scaled 2-D and CH-1015, Switzerland

    E-print Network

    De Micheli, Giovanni

    Process-Induced Skew Variation for Scaled 2-D and 3-D ICs Hu Xu LSI-EPFL CH-1015, Switzerland hu.xu@epfl.ch Vasilis F. Pavlidis LSI-EPFL CH-1015, Switzerland vasileios.pavlidis@epfl.ch Giovanni De Micheli LSI-EPFL CH-1015, Switzerland giovanni.demicheli@epfl.ch ABSTRACT Technology scaling and three

  12. Skewed zero-bound distributions and process capability indices for upper specifications

    Microsoft Academic Search

    Malin Albing; Kerstin Vännman

    2009-01-01

    A common practical situation in process capability analysis, which is not well developed theoretically, is when the quality characteristic of interest has a skewed distribution with a long tail towards relatively large values and an upper specification limit only exists. In such situations, it is not uncommon that the smallest possible value of the characteristic is 0 and this is

  13. From individual control to majority rule: extending transactional models of reproductive skew in animal societies.

    PubMed Central

    Reeve, Hudson Kern; Jeanne, Robert L

    2003-01-01

    Transactional concession models of social evolution explain the reproductive skew within groups by assuming that a dominant individual completely controls the allocation of reproduction to other group members. The models predict when the dominant will benefit from donating parcels of reproduction to other members in return for peaceful cooperation. Using linear programming methods, we present a 'majority-rules' model in which the summed actions of all society members, each with equal power, completely determine the reproductive share of any single member. The majority-rules model predicts that, despite the diffusion of power, a 'virtual dominant' (a dominant lacking special behavioural power) will emerge and that the reproductive skew will be exactly that predicted if the virtual dominant were to control completely the group's reproductive partitioning. The virtual dominant is the individual to which group members have the maximum average genetic relatedness. This result greatly broadens the applicability of transactional models of reproductive skew to social groups of any size, such as large-colony eusocial insects, and explains why queens in such colonies can achieve reproductive domination without any behavioural enforcement. Moreover, the majority-rules model unifies transactional-skew theory with models of worker policing and even generates a new theory for the cooperation among somatic cells in a multicellular organism. PMID:12803893

  14. A skewed meandering plume model for concentration statistics in the convective boundary layer

    Microsoft Academic Search

    Ashok K. Luhar; Mark F. Hibberd; Michael S. Borgas

    2000-01-01

    The meandering plume technique, which assumes that the total plume dispersion can be split into independent meander and relative dispersion components, is especially suited for modelling concentration (fluctuation) statistics in the convective boundary layer (CBL) with its large-scale turbulent motions. We develop a simple and practical meandering plume model for CBL applications that accounts for the skewed and inhomogeneous turbulence

  15. In?uence Diagnostics for Skew-Normal Linear Mixed Models

    Microsoft Academic Search

    Heleno Bolfarine

    2007-01-01

    Normality (symmetry) of the random efiects is a routine assumption in linear mixed models but it may, sometimes, be unrealistic, obscuring important features of among-subjects variation. We relax this assumption by assuming that the random efiects density is skew-normal, considered as an extension of the univariate version proposed by Sahu, Dey and Branco (CJS, 2003). Following Zhu and Lee (JRSSB,

  16. Bayesian analysis for nonlinear regression model under skewed errors, with application in growth curves.

    PubMed

    De la Cruz, Rolando; Branco, Márcia D

    2009-08-01

    We have considered a Bayesian approach for the nonlinear regression model by replacing the normal distribution on the error term by some skewed distributions, which account for both skewness and heavy tails or skewness alone. The type of data considered in this paper concerns repeated measurements taken in time on a set of individuals. Such multiple observations on the same individual generally produce serially correlated outcomes. Thus, additionally, our model does allow for a correlation between observations made from the same individual. We have illustrated the procedure using a data set to study the growth curves of a clinic measurement of a group of pregnant women from an obstetrics clinic in Santiago, Chile. Parameter estimation and prediction were carried out using appropriate posterior simulation schemes based in Markov Chain Monte Carlo methods. Besides the deviance information criterion (DIC) and the conditional predictive ordinate (CPO), we suggest the use of proper scoring rules based on the posterior predictive distribution for comparing models. For our data set, all these criteria chose the skew-t model as the best model for the errors. These DIC and CPO criteria are also validated, for the model proposed here, through a simulation study. As a conclusion of this study, the DIC criterion is not trustful for this kind of complex model. PMID:19629998

  17. Statistical properties of a skew product with a curve of neutral points

    Microsoft Academic Search

    Campus de Beaulieu

    We study a skew product with a curve of neutral points. We show that there exists a unique absolutely continuous invariant probability measure, and that the Birkhoff averages of a sufficiently smooth observable converge to a normal law or a stable law, depending on the average of the observable along the neutral curve.

  18. On Some Confidence Intervals for Estimating the Mean of a Skewed Population

    ERIC Educational Resources Information Center

    Shi, W.; Kibria, B. M. Golam

    2007-01-01

    A number of methods are available in the literature to measure confidence intervals. Here, confidence intervals for estimating the population mean of a skewed distribution are considered. This note proposes two alternative confidence intervals, namely, Median t and Mad t, which are simple adjustments to the Student's t confidence interval. In…

  19. WP9.06 Skew Detection and Compensation for Internet Audio Applications

    Microsoft Academic Search

    Orion Hodson; Colin Perkins; Vicky Hardman

    2000-01-01

    Long lived audio streams, such as music broadcasts, and small differences in clock rates lead to buffer underflo w or overflo w events in receiving applications that manifest themselves as au- dible interruptions. We present a low complexity algorithm for detecting clock skew in network audio applications that function with local clocks and in the absence of a synchronization mech-

  20. Parallel spinors and connections with skew-symmetric torsion in string theory

    Microsoft Academic Search

    Thomas Friedrich; Stefan Ivanov

    2001-01-01

    We describe all almost contact metric, almost hermitian and $G_2$-structures admitting a connection with totally skew-symmetric torsion tensor, and prove that there exists at most one such connection. We investigate its torsion form, its Ricci tensor, the Dirac operator and the $\\\

  1. Clock Skew Scheduling for Improved Reliability via Quadratic Programming Ivan S. Kourtev and Eby G. Friedman

    E-print Network

    Friedman, Eby G.

    range, or a valid interval, for the clock skew of each local data path is key to this QP approach. From G. Friedman¶ §Department of Electrical Engineering ¶Department of Electrical and Computer is derived for the solution of the QP problem with O¡ r3¢ run time complexity and O¡ r2¢ storage complexity

  2. 1 Solute transport across an interface: A Fickian 2 theory for skewness in breakthrough curves

    E-print Network

    Thomann, Enrique

    concentrations can be derived from Fickian laws of convection dispersion. In a 8 recently reported approach of the distribution of a particular skew 11 Brownian motion. The present paper is an extension of this theory and asymmetries in the breakthrough curves of a 18 conservative tracer across an sharp interface recently reported

  3. The curious anomaly of skewed judgment distributions and systematic error in the wisdom of crowds.

    PubMed

    Nash, Ulrik W

    2014-01-01

    Judgment distributions are often skewed and we know little about why. This paper explains the phenomenon of skewed judgment distributions by introducing the augmented quincunx (AQ) model of sequential and probabilistic cue categorization by neurons of judges. In the process of developing inferences about true values, when neurons categorize cues better than chance, and when the particular true value is extreme compared to what is typical and anchored upon, then populations of judges form skewed judgment distributions with high probability. Moreover, the collective error made by these people can be inferred from how skewed their judgment distributions are, and in what direction they tilt. This implies not just that judgment distributions are shaped by cues, but that judgment distributions are cues themselves for the wisdom of crowds. The AQ model also predicts that judgment variance correlates positively with collective error, thereby challenging what is commonly believed about how diversity and collective intelligence relate. Data from 3053 judgment surveys about US macroeconomic variables obtained from the Federal Reserve Bank of Philadelphia and the Wall Street Journal provide strong support, and implications are discussed with reference to three central ideas on collective intelligence, these being Galton's conjecture on the distribution of judgments, Muth's rational expectations hypothesis, and Page's diversity prediction theorem. PMID:25406078

  4. Research article Breeding system and reproductive skew in a highly polygynous ant population

    E-print Network

    Alvarez, Nadir

    Research article Breeding system and reproductive skew in a highly polygynous ant population C determinants of nest kin structure, we conducted a detailed analysis of the breeding system of the ant Formica a sub-sample of queens to assess their reproductive status. We also used microsatellites to estimate

  5. Fine scale inhomogeneity of wind-wave energy input, skewness, and asymmetry

    Microsoft Academic Search

    Yehuda Agnon; Alex V. Babanin; Ian R. Young; Dmitry Chalikov

    2005-01-01

    Analysis of measured sea and lake wind wave data reveals large variability of the wind energy input, as well as the waves skewness and asymmetry. The spatial and temporal third moments alternate in sign over a few wave periods and over a few wavelengths, respectively. Simulation through a 2D Wave Boundary Layer model in which the air flow is modeled

  6. Effect of PCC Joint Skew on Reflective Cracking in HMA Overlays

    Microsoft Academic Search

    Ziad G. Ghauch

    2011-01-01

    Reflective cracking is a relatively premature distress that occurs in HMA materials overlaying cracked and jointed underlying pavements. The high concentration of stresses and strains in the vicinity of the discontinuity of the old pavement causes the cracks to reflect into the newly placed HMA overlay. While it is a common practice to use skewed transverse joints in rigid pavements

  7. An analytical algorithm for skew-slit imaging geometry with nonuniform attenuation correction

    SciTech Connect

    Huang Qiu; Zeng, Gengsheng L. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84108 (United States); Utah Center for Advanced Imaging Research, 729 Arapeen Drive, University of Utah, Salt Lake City, UT 84108 (United States)

    2006-04-15

    The pinhole collimator is currently the collimator of choice in small animal single photon emission computed tomography (SPECT) imaging because it can provide high spatial resolution and reasonable sensitivity when the animal is placed very close to the pinhole. It is well known that if the collimator rotates around the object (e.g., a small animal) in a circular orbit to form a cone-beam imaging geometry with a planar trajectory, the acquired data are not sufficient for an exact artifact-free image reconstruction. In this paper a novel skew-slit collimator is mounted instead of the pinhole collimator in order to significantly reduce the image artifacts caused by the geometry. The skew-slit imaging geometry is a more generalized version of the pinhole imaging geometry. The multiple pinhole geometry can also be extended to the multiple-skew-slit geometry. An analytical algorithm for image reconstruction based on the tilted fan-beam inversion is developed with nonuniform attenuation compensation. Numerical simulation shows that the axial artifacts are evidently suppressed in the skew-slit images compared to the pinhole images and the attenuation correction is effective.

  8. A Monte Carlo Study of Skewed Theta Distributions on DIF Indices.

    ERIC Educational Resources Information Center

    Monaco, Malina

    The effects of skewed theta distributions on indices of differential item functioning (DIF) were studied, comparing Mantel Haenszel (N. Mantel and W. Haenszel, 1959) and DFIT (N. S. Raju, W. J. van der Linden, and P. F. Fleer) (noncompensatory DIF). The significance of the study is that in educational and psychological data, the distributions one…

  9. A modi ed RIO algorithm that alleviates the bandwidth skew problem in Internet Di erentiated Service

    E-print Network

    Bahk, Saewoong

    1 A modi#12;ed RIO algorithm that alleviates the bandwidth skew problem in Internet Di#11 with In and Out"), that contributes to the problem. We propose a modi#12;ed RIO algorithm called RI+O to reduce mechanism, RIO (\\RED with In and Out"), and the modi#12;cations necessary for Assured Service. In section IV

  10. The Hermite Moment Model for Highly Skewed Response with Application to Tension Leg Platforms

    E-print Network

    Sweetman, Bert

    The Hermite Moment Model for Highly Skewed Response with Application to Tension Leg Platforms. An example application to a Tension Leg Platform is presented. 1 INTRODUCTION Many irregular time ASCE Journal of Offshore Mechanics and Arctic Engineering In Press for May 2010, Volume 132, Issue 2

  11. Level II scour analysis for Bridge 38 (BETHTH00070038) on Town Highway 007, crossing Gilead Brook, Bethel, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Song, Donald L.

    1996-01-01

    The town highway 5 crossing of the Black River is a 70-ft-long, two-lane bridge consisting of one 65-foot clear span (Vermont Agency of Transportation, written commun., August 2, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. There is also a retaining wall along the upstream side of the road embankments. The channel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 15 degrees. A scour hole 3.0 ft deeper than the mean thalweg depth was observed along the right abutment. The scour hole was 27 feet long, 15 feet wide, and was 2.5 feet below the abutment footing at the time of the Level I assessment. This right abutment had numerous cracks and had settled. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. The scour analysis results are presented in tables 1 and 2 and a graph of the scour depths is presented in figure 8.

  12. Homogeneous Bispecifics by Disulfide Bridging

    PubMed Central

    2014-01-01

    We report on a chemical platform to generate site-specific, homogeneous, antibody–antibody conjugates by targeting and bridging disulfide bonds. A bispecific antibody construct was produced in good yield through simple reduction and bridging of antibody fragment disulfide bonds, using a readily synthesized bis-dibromomaleimide cross-linker. Binding activity of antibodies was maintained, and in vitro binding of target antigens was observed. This technology is demonstrated through linking scFv and Fab antibody fragments, showing its potential for the construction of a diverse range of bispecifics. PMID:25033024

  13. 23 CFR 650.809 - Movable span bridges.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.809 Movable span bridges. A fixed bridge shall be selected wherever...

  14. 23 CFR 650.809 - Movable span bridges.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.809 Movable span bridges. A fixed bridge shall be selected wherever...

  15. 23 CFR 650.809 - Movable span bridges.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.809 Movable span bridges. A fixed bridge shall be selected wherever...

  16. 23 CFR 650.809 - Movable span bridges.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.809 Movable span bridges. A fixed bridge shall be selected wherever...

  17. Simplified Method for Estimating Future Scour Depth at Existing Bridges 

    E-print Network

    V Govindasamy, Anand

    2010-07-14

    Bridge scour is the term which describes the erosion of soil surrounding a bridge foundation due to water. Bridge scour can cause the reduction of the load carrying capacity of bridge foundations, excessive foundation ...

  18. 49 CFR 237.71 - Determination of bridge load capacities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...documented in the track owner's bridge management program, together...shall be made by a railroad bridge engineer using appropriate engineering methods and standards that...particularly applicable to railroad bridges. (d) Bridge load...

  19. 49 CFR 237.71 - Determination of bridge load capacities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...documented in the track owner's bridge management program, together...shall be made by a railroad bridge engineer using appropriate engineering methods and standards that...particularly applicable to railroad bridges. (d) Bridge load...

  20. North & South Elevations and Bridge Plan Chickamauga National ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    North & South Elevations and Bridge Plan - Chickamauga National Military Park Tour Roads, Gordon's Slough Bridge, At the confluence of Alexander's Bridge Road and Gordon's Slough, southeast of Alexander's Bridge, Fort Oglethorpe, Catoosa County, GA

  1. 23 CFR 650.809 - Movable span bridges.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.809 Movable span bridges. A fixed bridge shall be selected wherever...

  2. A Framework for Historic Bridge Preservation 

    E-print Network

    Puls, Eric Mark

    2013-08-08

    In an inevitably occurring process, bridges possessing historic, artistic, and engineering significance deteriorate and must be maintained and rehabilitated in order to be kept in service. Ideally, all potentially significant bridges would...

  3. Asymmetric capillary bridges between contacting spheres.

    PubMed

    Farmer, Timothy P; Bird, James C

    2015-09-15

    When a drop of liquid wets two identical solid spheres, the liquid forms a capillary bridge between the spheres to minimize surface energy. In the absence of external forces, these bridges are typically assumed to be axisymmetric, and the shape that minimizes surface energy can be calculated analytically. However under certain conditions, the bridge is axisymmetrically unstable, and migrates to a non-axisymmetric configuration. The goal of this paper is to characterize these non-axisymmetric capillary bridges. Specifically, we numerically calculate the shape of the capillary bridge between two contacting spheres that minimizes the total surface energy for a given volume and contact angle and compare to experiments. When the bridge is asymmetric, finite element calculations demonstrate that the shape of the bridge is spherical. In general, the bridge shape depends on both volume and contact angle, yet we find the degree of asymmetry is controlled by a single parameter. PMID:26037268

  4. Wind effect on long span bridge

    E-print Network

    Zhang, Xi, M. Eng. Massachusetts Institute of Technology

    2012-01-01

    This thesis has studied different types of reactions of long span bridge under wind load, such as vortex shedding, flutter and buffeting. Since all of these conditions have the chance to damage bridge structure, we calculate ...

  5. SEISMIC RETROFIT OF VINCENT THOMAS SUSPENSION BRIDGE

    Microsoft Academic Search

    George Baker; Tim Ingham; Dan Heathcote

    1998-01-01

    The Vincent Thomas Bridge in Los Angeles, California, is a major suspension bridge with a total length of 1848 m (6,060 ft), including approaches, and a main span bridge 766 m (2,513 ft) long, whose center span in 458 m (1,500 ft). The bridge, built in the 1960s, used the seismic codes of the time. The site conditions and tall,

  6. Bridge building and bridge conservation in agreement with the genius loci

    Microsoft Academic Search

    Dirk Bühler

    Bridges ideally stand for the convergence of engineering landmarks and aesthetical attractions. But what's even more: bridges can be signs that reveal their meaning only by means of a skilful integration to their surrounding landscape or urban context. The appreciation of the spirit of place where bridge building happens is a substantial part for successful bridge design. The paper includes

  7. Bridge 11/13/2007 1 Example 1. Find the probability that a bridge hand contains

    E-print Network

    Taylor, Peter

    Bridge 11/13/2007 1 Bridge Example 1. Find the probability that a bridge hand contains no aces of getting a no-ace hand is the propor- tion of all possible hands that have no aces. Now in Pascal we have calculated the total number of bridge hands as 52 13 . Now we ask how many of these contain no aces

  8. Full-bridge capacitive extensometer

    Microsoft Academic Search

    Randall D. Peters

    1993-01-01

    Capacitive transducers have proven to be very effective sensors of small displacements, because of inherent stability and noninvasive high resolution. The most versatile ones have been those of a differential type, in which two elements are altered in opposite directions in response to change of the system parameter being monitored. Oftentimes, this differential pair has been incorporated into a bridge

  9. Over the Ramp: Building Bridges

    ERIC Educational Resources Information Center

    Sutton, Mary

    2007-01-01

    TheatreWorks is the third largest theatre in the San Francisco bay area. Through the usual educational programs that $6 million companies tend to offer, it has reached over 100,000 students of all ages in the past 8 years. The TheatreWorks Bridges Projects, however, are special. They are intricate and expansive, work with multiple community…

  10. Bridges on the River Quad

    NSDL National Science Digital Library

    2011-03-27

    In this activity, students graph a quadratic function that models the shape of a bridge trestle and then solve the related quadratic equation by completing the square. Students use the calculators’ capabilities to find the x-intercepts and the maximum value on the graph. Teacher notes, detailed instructions on using graphing calculators, and questions to check comprehension aid in teaching the lesson.

  11. ADVANCED COMPOSITE MATERIALS HEAT BRIDGES

    Microsoft Academic Search

    A. B. Shopen; V. A. Golovanevskiy; O. A. Kivirenko

    Understanding heat transfer properties of advanced composite materials (CM) structures is gaining increasing importance in industries such as medicine and cryogenics, aerospace and electronics where structures made from advanced CM are being used as heat bridges. The main goal in such applications of advanced CM structures is achieving maximum load bearing capacity while maintaining heat transfer rate at a predetermined

  12. Percentage Problems in Bridging Courses

    ERIC Educational Resources Information Center

    Kachapova, Farida; Kachapov, Ilias

    2012-01-01

    Research on teaching high school mathematics shows that the topic of percentages often causes learning difficulties. This article describes a method of teaching percentages that the authors used in university bridging courses. In this method, the information from a word problem about percentages is presented in a two-way table. Such a table gives…

  13. Diode-quad bridge circuit means

    NASA Technical Reports Server (NTRS)

    Harrison, D. R.; Dimeff, J. (inventors)

    1975-01-01

    Diode-quad bridge circuit means is described for use as a transducer circuit or as a discriminator circuit. It includes: (1) a diode bridge having first, second, third, and fourth bridge terminals consecutively coupled together by four diodes polarized in circulating relationship; (2) a first impedance connected between the second bridge terminal and a circuit ground; (3) a second impedance connected between the fourth bridge terminal and the circuit ground; (4) a signal source having a first source terminal capacitively coupled to the first and third bridge terminals, and a second source terminal connected to the circuit ground; and (5) an output terminal coupled to the first bridge terminal and at which an output signal may be taken.

  14. Optimization Of Mean-Semivariance-Skewness Portfolio Selection Model In Fuzzy Random Environment

    NASA Astrophysics Data System (ADS)

    Chatterjee, Amitava; Bhattacharyya, Rupak; Mukherjee, Supratim; Kar, Samarjit

    2010-10-01

    The purpose of the paper is to construct a mean-semivariance-skewness portfolio selection model in fuzzy random environment. The objective is to maximize the skewness with predefined maximum risk tolerance and minimum expected return. Here the security returns in the objectives and constraints are assumed to be fuzzy random variables in nature and then the vagueness of the fuzzy random variables in the objectives and constraints are transformed into fuzzy variables which are similar to trapezoidal numbers. The newly formed fuzzy model is then converted into a deterministic optimization model. The feasibility and effectiveness of the proposed method is verified by numerical example extracted from Bombay Stock Exchange (BSE). The exact parameters of fuzzy membership function and probability density function are obtained through fuzzy random simulating the past dates.

  15. Relationship between the Vertical Velocity Skewness and Kurtosis Observed during Sea-Breeze Convection.

    NASA Astrophysics Data System (ADS)

    Alberghi, S.; Maurizi, A.; Tampieri, F.

    2002-08-01

    Fourth-order moments of vertical velocity in the convective boundary layer (CBL) are seldom available because the unsteady nature of atmospheric flows makes time statistics unreliable for the evaluation of high-order moments. In this paper, sound detection and ranging (sodar) measurements in well-developed, almost steady convective conditions are selected and analyzed to investigate the relationship between skewness and kurtosis. Moments of vertical velocity up to the fourth order are computed with special attention to the assessment of the errors connected to the number of independent data and to the inherent spatial and temporal filtering of the measuring system. Results show that a significant correlation between skewness and kurtosis exists in the lower half of the CBL, and a quadratic relationship is proposed that is similar to the one valid for alongwind velocity in shear-dominated boundary layers.

  16. Skewing of immune cell cytokine production by mediators from adipocytes and endothelial cells

    PubMed Central

    Vielma, Silvana A; Klein, Richard L; Levingston, Corinne A; Young, M Rita I

    2014-01-01

    Since adipose tissue is composed of adipocytes as well as other cell types including endothelial cells, this study sought to determine how mediators from adipocytes and from endothelial cells impact on immune cell production of cytokines. A minimalistic design was used in which media conditioned by adipocytes or by endothelial cells were added individually or as a mixture to normal spleen cells. Media from adipocytes or endothelial cells each stimulated spleen cell production of Th1 cytokines, Th2 cytokines, most of the measured inflammatory cytokines, and some chemokines. However, a mixture of media conditioned by adipocytes and by endothelial cells inhibited production of Th1 cytokines and skewed reactivity toward a Th2 and inflammatory phenotype. Adiponectin, but not leptin, was shown to contribute to the skewing of immune responsiveness to endothelial cell-derived mediators. PMID:24719786

  17. Skew Projection of Echo-Detected EPR Spectra for Increased Sensitivity and Resolution

    PubMed Central

    Bowman, Michael K.; Krzyaniak, Matthew D.; Cruce, Alex A.; Weber, Ralph T.

    2013-01-01

    The measurement of EPR spectra during pulsed EPR experiments is commonly accomplished by recording the integral of the electron spin echo as the applied magnetic field is stepped through the spectrum. This approach to echo-detected EPR spectral measurement (ED-EPR) limits sensitivity and spectral resolution and can cause gross distortions in the resulting spectra because some of the information present in the electron spin echo is discarded in such measurements. However, Fourier Transformation of echo shapes measured at a series of magnetic field values followed by skew projection onto either a magnetic field or resonance frequency axis can increase both spectral resolution and sensitivity without the need to trade one against the other. Examples of skew-projected spectra with single crystals, glasses and powders show resolution improvements as large as a factor of seven with sensitivity increases of as much as a factor of five. PMID:23644351

  18. Geometrically nonlinear static and dynamic analysis of functionally graded skew plates

    NASA Astrophysics Data System (ADS)

    Upadhyay, A. K.; Shukla, K. K.

    2013-08-01

    The present paper deals with nonlinear static and dynamic behavior of functionally graded skew plates. The equations of motion are derived using higher order shear deformation theory in conjunction with von-Karman's nonlinear kinematics. The physical domain is mapped into computational domain using linear mapping and chain rule of differentiation. The spatial and temporal discretization is based on fast converging finite double Chebyshev series and Houbolt's method. Quadratic extrapolation technique is employed to linearize the governing nonlinear equations. The spatial and temporal convergence and validation studies have been carried out to establish the efficacy of the present solution methodology. In case of dynamic analysis, the results are obtained for uniform step, sine, half sine, triangular and exponential type of loadings. The effect of volume fraction index, skew angle and boundary conditions on nonlinear displacement and moment response are presented.

  19. Wind-tunnel research comparing lateral control devices, particularly at high angles of attack VI : skewed ailerons on rectangular wings

    NASA Technical Reports Server (NTRS)

    Weick, Fred E; Harris, Thomas A

    1934-01-01

    This report covers the sixth of a series of investigations in which various lateral control devices are compared with particular reference to their effectiveness at high angles of attack. The present report deals with flap-type ailerons hinged about axes having an angle with respect to the leading and trailing edges of the wing. Tests were made on four different skewed ailerons, including two different angles of skew and two sizes of ailerons. At the high angles of attack, all the skewed ailerons tested were slightly inferior with respect to rolling and yawing moments to straight ailerons having the same span and average chord. Computations indicate that the skewed ailerons are also inferior with respect to hinge moments.

  20. Effects of skewness and kurtosis on normal-theory based maximum likelihood test statistic in multilevel structural equation modeling.

    PubMed

    Ryu, Ehri

    2011-12-01

    A simulation study investigated the effects of skewness and kurtosis on level-specific maximum likelihood (ML) test statistics based on normal theory in multilevel structural equation models. The levels of skewness and kurtosis at each level were manipulated in multilevel data, and the effects of skewness and kurtosis on level-specific ML test statistics were examined. When the assumption of multivariate normality was violated, the level-specific ML test statistics were inflated, resulting in Type I error rates that were higher than the nominal level for the correctly specified model. Q-Q plots of the test statistics against a theoretical chi-square distribution showed that skewness led to a thicker upper tail and kurtosis led to a longer upper tail of the observed distribution of the level-specific ML test statistic for the correctly specified model. PMID:21671139

  1. The role of the SST-thermocline relationship in Indian Ocean Dipole skewness and its response to global warming

    NASA Astrophysics Data System (ADS)

    Ng, Benjamin; Cai, Wenju; Walsh, Kevin

    2014-08-01

    A positive Indian Ocean Dipole (IOD) tends to have stronger cold sea surface temperature anomalies (SSTAs) over the eastern Indian Ocean with greater impacts than warm SSTAs that occur during its negative phase. Two feedbacks have been suggested as the cause of positive IOD skewness, a positive Bjerknes feedback and a negative SST-cloud-radiation (SCR) feedback, but their relative importance is debated. Using inter-model statistics, we show that the most important process for IOD skewness is an asymmetry in the thermocline feedback, whereby SSTAs respond to thermocline depth anomalies more strongly during the positive phase than negative phase. This asymmetric thermocline feedback drives IOD skewness despite positive IODs receiving greater damping from the SCR feedback. In response to global warming, although the thermocline feedback strengthens, its asymmetry between positive and negative IODs weakens. This behaviour change explains the reduction in IOD skewness that many models display under global warming.

  2. The role of the SST-thermocline relationship in Indian Ocean Dipole skewness and its response to global warming.

    PubMed

    Ng, Benjamin; Cai, Wenju; Walsh, Kevin

    2014-01-01

    A positive Indian Ocean Dipole (IOD) tends to have stronger cold sea surface temperature anomalies (SSTAs) over the eastern Indian Ocean with greater impacts than warm SSTAs that occur during its negative phase. Two feedbacks have been suggested as the cause of positive IOD skewness, a positive Bjerknes feedback and a negative SST-cloud-radiation (SCR) feedback, but their relative importance is debated. Using inter-model statistics, we show that the most important process for IOD skewness is an asymmetry in the thermocline feedback, whereby SSTAs respond to thermocline depth anomalies more strongly during the positive phase than negative phase. This asymmetric thermocline feedback drives IOD skewness despite positive IODs receiving greater damping from the SCR feedback. In response to global warming, although the thermocline feedback strengthens, its asymmetry between positive and negative IODs weakens. This behaviour change explains the reduction in IOD skewness that many models display under global warming. PMID:25112717

  3. The role of the SST-thermocline relationship in Indian Ocean Dipole skewness and its response to global warming

    PubMed Central

    Ng, Benjamin; Cai, Wenju; Walsh, Kevin

    2014-01-01

    A positive Indian Ocean Dipole (IOD) tends to have stronger cold sea surface temperature anomalies (SSTAs) over the eastern Indian Ocean with greater impacts than warm SSTAs that occur during its negative phase. Two feedbacks have been suggested as the cause of positive IOD skewness, a positive Bjerknes feedback and a negative SST-cloud-radiation (SCR) feedback, but their relative importance is debated. Using inter-model statistics, we show that the most important process for IOD skewness is an asymmetry in the thermocline feedback, whereby SSTAs respond to thermocline depth anomalies more strongly during the positive phase than negative phase. This asymmetric thermocline feedback drives IOD skewness despite positive IODs receiving greater damping from the SCR feedback. In response to global warming, although the thermocline feedback strengthens, its asymmetry between positive and negative IODs weakens. This behaviour change explains the reduction in IOD skewness that many models display under global warming. PMID:25112717

  4. Key Exchange and Encryption Schemes Based on Non-commutative Skew Polynomials

    Microsoft Academic Search

    Delphine Boucher; Philippe Gaborit; Willi Geiselmann; Olivier Ruatta; Felix Ulmer

    2010-01-01

    \\u000a In this paper we introduce a new key exchange algorithm (Diffie-Hellman like) based on so called (non-commutative) skew polynomials.\\u000a The algorithm performs only polynomial multiplications in a special small field and is very efficient. The security of the\\u000a scheme can be interpretated in terms of solving binary quadratic equations or exhaustive search of a set obtained through\\u000a linear equations. We

  5. No evidence of skewed secondary sex ratios in nestlings of the Common Raven ( Corvus corax )

    Microsoft Academic Search

    Sascha Rösner; Kirsten Bogatz; Hendrik Trapp; Thomas Grünkorn; Roland Brandl

    2009-01-01

    Many bird species adjust their offspring sex ratio as a response to environmental conditions or sexual dimorphism in size\\u000a and dispersal. Offspring sex ratios may therefore vary among populations depending on the different demographic and ecological\\u000a trajectories. We sampled Common Raven Corvus corax nestlings close to the fledging stage from three Central European regions to test for skewed secondary sex

  6. A model for coupled magnetic-electric circuits in electric machines with skewed slots

    Microsoft Academic Search

    F. Piriou; A. Razek

    1990-01-01

    A model permitting the simulation of skewed-slot saturated machines associated with nonlinear external circuits is proposed. To take the slot effects into account, the magnetic circuit is modeled through the combined two-dimensional calculations along the machine axis. In this simulation the electric circuit equation is directly coupled with the magnetic one. The solution of the resulting nonlinear time-dependent equation is

  7. Skewness and kurtosis of level distributions in vibrational spectra. Coupled Morse oscillators

    NASA Astrophysics Data System (ADS)

    Bancewicz, Ma?gorzata

    2003-07-01

    The skewness and kurtosis of the spectral density distribution of a Hamiltonian, which represents a system of N coupled Morse oscillators and, hence, describes molecular vibrations in the local mode approximation are derived. Detailed expressions are given for N=2 case and for various structures with N=3,6. The effect of the values of coupling constants on both statistical functions is analyzed. A comparison with the well-known Morse oscillator spectrum is given.

  8. An asymptotic distribution of wright’s process capability index sensitive to skewness

    Microsoft Academic Search

    Hanfeng Chen; Samuel Kotz

    1996-01-01

    In a recent paper (J. Statist. Comput. Simul., 1995, Vol.53, pp. 195–203) P. A. Wright proposed a new process capability index Cs which generalizes the Pearn-Kotz-Johnson’s index Cpmk by taking into account the skewness (in addition to deviation of the mean from tliCrntarget already incorporated in Cpmk). The purpose of this article is to study the consistency and asymptotics of

  9. Extreme skewing of X chromosome inactivation in mothers of homosexual men

    Microsoft Academic Search

    Sven Bocklandt; Steve Horvath; Eric Vilain; Dean H. Hamer

    2006-01-01

    Human sexual preference is a sexually dimorphic trait with a substantial genetic component. Linkage of male sexual orientation\\u000a to markers on the X chromosome has been reported in some families. Here, we measured X chromosome inactivation ratios in 97\\u000a mothers of homosexual men and 103 age-matched control women without gay sons. The number of women with extreme skewing of\\u000a X-inactivation

  10. 3-D electro-magnetic analyses of a cage induction motor with rotor skew

    Microsoft Academic Search

    H. Kometani; S. Sakabe; K. Nakanishi

    1996-01-01

    The paper studied the performance characteristics of a three-phase cage induction motor using a 3D finite element technique. Especially, the effects of rotor skew and the rotor end-rings and the distribution of the electromagnetic field toward the axial direction, which have not been able to be analyzed accurately by 2D analysis, were investigated. Since the 3D analysis enabled the analysis

  11. Experimental observation of a skewed X-type spatiotemporal correlation of ultrabroadband twin beams.

    PubMed

    Jedrkiewicz, O; Gatti, A; Brambilla, E; Di Trapani, P

    2012-12-14

    This work presents the experimental observation of the nonfactorable near-field spatiotemporal correlation of ultrabroadband twin beams generated by parametric down-conversion, in an interferometric-type experiment using sum frequency generation, where both the temporal and the spatial degrees of freedom of parametric down-conversion light are controlled with high resolution. The revealed correlation is skewed in space-time in accordance with the X structure predicted by the theory. PMID:23368318

  12. Effect of phase response curve skew on synchronization with and without conduction delays

    PubMed Central

    Canavier, Carmen C.; Wang, Shuoguo; Chandrasekaran, Lakshmi

    2013-01-01

    A central problem in cortical processing including sensory binding and attentional gating is how neurons can synchronize their responses with zero or near-zero time lag. For a spontaneously firing neuron, an input from another neuron can delay or advance the next spike by different amounts depending upon the timing of the input relative to the previous spike. This information constitutes the phase response curve (PRC). We present a simple graphical method for determining the effect of PRC shape on synchronization tendencies and illustrate it using type 1 PRCs, which consist entirely of advances (delays) in response to excitation (inhibition). We obtained the following generic solutions for type 1 PRCs, which include the pulse-coupled leaky integrate and fire model. For pairs with mutual excitation, exact synchrony can be stable for strong coupling because of the stabilizing effect of the causal limit region of the PRC in which an input triggers a spike immediately upon arrival. However, synchrony is unstable for short delays, because delayed inputs arrive during a refractory period and cannot trigger an immediate spike. Right skew destabilizes antiphase and enables modes with time lags that grow as the conduction delay is increased. Therefore, right skew favors near synchrony at short conduction delays and a gradual transition between synchrony and antiphase for pairs coupled by mutual excitation. For pairs with mutual inhibition, zero time lag synchrony is stable for conduction delays ranging from zero to a substantial fraction of the period for pairs. However, for right skew there is a preferred antiphase mode at short delays. In contrast to mutual excitation, left skew destabilizes antiphase for mutual inhibition so that synchrony dominates at short delays as well. These pairwise synchronization tendencies constrain the synchronization properties of neurons embedded in larger networks. PMID:24376399

  13. Single Edge Clock (SEC) Distribution for Improved Latency, Skew, and Jitter Performance

    Microsoft Academic Search

    Jeff Mueller; Resve Saleh

    2008-01-01

    Synchronous clock distribution continues to be the dominant timing methodology for VLSI designs. As processes shrink, clock speeds increase, and die sizes grow, more-and-more of the clock period is lost to skew and jitter budgets. We propose to improve clock performance by focusing on the single, critical clock edge while relaxing requirements of the non-critical edge. A novel re-design of

  14. A method of reducing ripple torque in permanent magnet motors without skewing

    Microsoft Academic Search

    T. Ishikawa; G. R. Slemon

    1993-01-01

    A method of reducing ripple torque, i.e., the sum of cogging and commutation torques, in permanent-magnet motors without skewing is proposed. The ripple torque for a given range of stator current can be substantially reduced by shifting the pole pairs by half a slot pitch and by choosing the value of magnet width so as to minimize the second-order component

  15. Analysis of skewed X-chromosome inactivation in females with rheumatoid arthritis and autoimmune thyroid diseases

    PubMed Central

    Chabchoub, Ghazi; Uz, Elif; Maalej, Abdellatif; Mustafa, Chigdem A; Rebai, Ahmed; Mnif, Mouna; Bahloul, Zouheir; Farid, Nadir R; Ozcelik, Tayfun; Ayadi, Hammadi

    2009-01-01

    Introduction The majority of autoimmune diseases such as rheumatoid arthritis (RA) and autoimmune thyroid diseases (AITDs) are characterized by a striking female predominance superimposed on a predisposing genetic background. The role of extremely skewed X-chromosome inactivation (XCI) has been questioned in the pathogenesis of several autoimmune diseases. Methods We examined XCI profiles of females affected with RA (n = 106), AITDs (n = 145) and age-matched healthy women (n = 257). XCI analysis was performed by enzymatic digestion of DNA with a methylation sensitive enzyme (HpaII) followed by PCR of a polymorphic CAG repeat in the androgen receptor (AR) gene. The XCI pattern was classified as skewed when 80% or more of the cells preferentially inactivated the same X-chromosome. Results Skewed XCI was observed in 26 of the 76 informative RA patients (34.2%), 26 of the 100 informative AITDs patients (26%), and 19 of the 170 informative controls (11.2%) (P < 0.0001; P = 0.0015, respectively). More importantly, extremely skewed XCI, defined as > 90% inactivation of one allele, was present in 17 RA patients (22.4%), 14 AITDs patients (14.0%), and in only seven controls (4.1%, P < 0.0001; P = 0.0034, respectively). Stratifying RA patients according to laboratory profiles (rheumatoid factor and anti-citrullinated protein antibodies), clinical manifestations (erosive disease and nodules) and the presence of others autoimmune diseases did not reveal any statistical significance (P > 0.05). Conclusions These results suggest a possible role for XCI mosaicism in the pathogenesis of RA and AITDs and may in part explain the female preponderance of these diseases. PMID:19589151

  16. Permanent Magnet Skew Quadrupoles for the Low Emittance LER Lattice of PEP-II

    SciTech Connect

    Decker, F.-J.; Anderson, S.; Kharakh, D.; Sullivan, M.; /SLAC

    2011-07-05

    The vertical emittance of the low energy ring (LER) in the PEP-II B-Factory was reduced by using skew quadrupoles consisting of permanent magnet material. The advantages over electric quadrupoles or rotating existing normal quadrupoles are discussed. To assure a high field quality, a Biot-Savart calculation was used to cancel the natural 12-pole component by using different size poles over a few layers. A magnetic measurement confirmed the high quality of the magnets. After installation and adjusting the original electric 12 skew and 16 normal quadrupoles the emittance contribution from the region close to the interaction point, which was the biggest part in the original design, was considerably reduced. To strengthen the vertical behavior of the LER beam, a low emittance lattice was developed. It lowered the original vertical design emittance from 0.54 nm-rad to 0.034 nm-rad. In order to achieve this, additional skew quadrupoles were required to bring the coupling correction out of the arcs and closer to the detector solenoid in the straight (Fig. 1). It is important, together with low vertical dispersion, that the low vertical emittance is not coupled into the horizontal, which is what we get if the coupling correction continues into the arcs. Further details of the lattice work is described in another paper; here we concentrate on the development of the permanent skew (PSK) quadrupole solution. Besides the permanent magnets there are two other possibilities, using electric magnets or rotating normal quadrupoles. Electric magnets would have required much more additional equipment like magnets stands, power supply, and new vacuum chamber sections. Rotating existing quadrupoles was also not feasible since they are mostly mounted together with a bending magnet on the same support girder.

  17. Mutual tolerance or reproductive competition? Patterns of reproductive skew among male redfronted lemurs ( Eulemur fulvus rufus )

    Microsoft Academic Search

    Peter M. Kappeler; Markus Port

    2008-01-01

    The social organization of gregarious lemurs significantly deviates from predictions of the socioecological model, as they\\u000a form small groups in which the number of males approximately equals the number of females. This study uses models of reproductive\\u000a skew theory as a new approach to explain this unusual group composition, in particular the high number of males, in a representative\\u000a of

  18. High-Order Fluxes for Conservative Skew-Symmetric-like Schemes in Structured Meshes: Application to Compressible Flows

    Microsoft Academic Search

    F. Ducros; F. Laporte; T. Soulères; V. Guinot; P. Moinat; B. Caruelle

    2000-01-01

    Developing high-order non-dissipative schemes is an important research task for both steady and unsteady flow computations. We take as a starting point the “built-in” de-aliasing property of the discretized skew-symmetric form for the non-linear terms of the Navier–Stokes equations, recalled in Kravchenko and Moin [1]. Two families of high-order locally conservative schemes matching this discretized skew-symmetric form are considered and

  19. A QTL Study for Regions Contributing to Arabidopsis thaliana Root Skewing on Tilted Surfaces

    PubMed Central

    Vaughn, Laura M.; Masson, Patrick H.

    2011-01-01

    Plant root systems must grow in a manner that is dictated by endogenous genetic pathways, yet sensitive to environmental input. This allows them to provide the plant with water and nutrients while navigating a heterogeneous soil environment filled with obstacles, toxins, and pests. Gravity and touch, which constitute important cues for roots growing in soil, have been shown to modulate root architecture by altering growth patterns. This is illustrated by Arabidopsis thaliana roots growing on tilted hard agar surfaces. Under these conditions, the roots are exposed to both gravity and touch stimulation. Consequently, they tend to skew their growth away from the vertical and wave along the surface. This complex growth behavior is believed to help roots avoid obstacles in nature. Interestingly, A. thaliana accessions display distinct growth patterns under these conditions, suggesting the possibility of using this variation as a tool to identify the molecular mechanisms that modulate root behavior in response to their mechanical environment. We have used the Cvi/Ler recombinant inbred line population to identify quantitative trait loci that contribute to root skewing on tilted hard agar surfaces. A combination of fine mapping for one of these QTL and microarray analysis of expression differences between Cvi and Ler root tips identifies a region on chromosome 2 as contributing to root skewing on tilted surfaces, potentially by modulating cell wall composition. PMID:22384323

  20. Deterioration of the skew quadrupole moment in Tevatron dipoles over time

    SciTech Connect

    Syphers, M.J.; Harding, D.J.; /Fermilab

    2005-05-01

    During the 20 years since it was first commissioned, the Fermilab Tevatron has developed strong coupling between the two transverse degrees of freedom. A circuit of skew quadrupole magnets is used to correct for coupling and, though capable, its required strength has increased since 1983 by more than an order of magnitude. In more recent years changes to the Tevatron for colliding beams operation have altered the skew quadrupole corrector distribution and strong local coupling become evident, often encumbering routine operation during the present physics run. Detailed magnet measurements were performed on each individual magnet during construction, and in early 2003 it was realized that measurements could be performed on the magnets in situ which could determine coil movements within the iron yoke since the early 1980's. It was discovered that the superconducting coils had become vertically displaced relative to their yokes since their construction. The ensuing systematic skew quadrupole field introduced by this displacement accounts for the required corrector settings and observed beam behavior. An historical account of the events leading to this discovery and progress toward its remedy are presented.

  1. An inconvenient sea truth: spread, steepness, and skewness of surface slopes.

    PubMed

    Munk, Walter

    2009-01-01

    Bréon and Henriot (BH) have collected eight million globally distributed satellite images of sunglitter, which yield a few simple, robust rules about the statistics of surface slopes: 1) constant angular spread, 2) linear steepness, and 3) sigmoid (near stepwise) skewness (all with respect to wind speed). Yet the information is sparse because it says nothing about time and space scales. The BH rules are an inconvenient sea truth, too fundamental to be ignored, too incomplete to be understood. With regard to BH rule 1 (BH:1), I suggest that the constant spread is associated with a wake-like geometry of the short gravities. Steepness linearity (BH:2) remains an enigma. Skewness (BH:3) appears to be correlated with a rather sudden onset of breaking for winds above 4 m s(-1). I do not think that skewness comes from parasitic capillaries. These are tentative conclusions; I look forward to intensive sea-going experiments over the next few years demolishing the proposed interpretations. PMID:21141042

  2. Stress Analysis of a New Disk-Type Variable Torque Slipping Clutch with Skewed Rollers

    NASA Astrophysics Data System (ADS)

    Feng, Ming; Ono, Kyosuke; Mimura, Kenji

    In this paper a new disk type of the variable torque slipping clutch with skewed rollers (VTSCSR) is presented and investigated both theoretically and experimentally. It is comprised of two flat disks, a number of skewed cylindrical rollers, and a cage. The slipping torque is produced by the skewed rollers rolling and slipping between the two disks. Based on the integral equation of the Boussinesq solution, the contact pressures are numerically calculated under the condition that the nonlinear equilibrium equations of the clutch elements are satisfied. By considering both pressure and friction, the components of subsurface stress are calculated from the integration of the Mindlin's subsurface stress equations of concentrated force. A numerical solver is then successfully developed by which the characteristics of the disk-type VTSCSR, including the torque capacity, angular velocities of the roller and cage, contact pressure and von Mises stress, etc, are calculated and illustrated for the typical designs. The influences on the distribution of the von Mises stress by applying various types of profiled rollers to the disk-type VTSCSR are also discussed. It has been found that the full crown with two arcs profiled roller can approximately give rise to the axially uniform distribution of the von Mises stress and therefore satisfies the design principle of the average damage of materials. In addition, the preliminary experiment was done in order to show the feasibility of this design idea and to verify the theoretical torque capacity.

  3. Joint Skewness and Its Application in Unsupervised Band Selection for Small Target Detection

    PubMed Central

    Geng, Xiurui; Sun, Kang; Ji, Luyan; Tang, Hairong; Zhao, Yongchao

    2015-01-01

    Few band selection methods are specially designed for small target detection. It is well known that the information of small targets is most likely contained in non-Gaussian bands, where small targets are more easily separated from the background. On the other hand, correlation of band set also plays an important role in the small target detection. When the selected bands are highly correlated, it will be unbeneficial for the subsequent detection. However, the existing non-Gaussianity-based band selection methods have not taken the correlation of bands into account, which generally result in high correlation of obtained bands. In this paper, combining the third-order (third-order tensor) and second-order (correlation) statistics of bands, we define a new concept, named joint skewness, for multivariate data. Moreover, we also propose an easy-to-implement approach to estimate this index based on high-order singular value decomposition (HOSVD). Based on the definition of joint skewness, we present an unsupervised band selection for small target detection for hyperspectral data, named joint skewness band selection (JSBS). The evaluation results demonstrate that the bands selected by JSBS are very effective in terms of small target detection. PMID:25873018

  4. Reproductive skew drives patterns of sexual dimorphism in sponge-dwelling snapping shrimps.

    PubMed

    Chak, Solomon Tin Chi; Duffy, J Emmett; Rubenstein, Dustin R

    2015-06-22

    Sexual dimorphism is typically a result of strong sexual selection on male traits used in male-male competition and subsequent female choice. However, in social species where reproduction is monopolized by one or a few individuals in a group, selection on secondary sexual characteristics may be strong in both sexes. Indeed, sexual dimorphism is reduced in many cooperatively breeding vertebrates and eusocial insects with totipotent workers, presumably because of increased selection on female traits. Here, we examined the relationship between sexual dimorphism and sociality in eight species of Synalpheus snapping shrimps that vary in social structure and degree of reproductive skew. In species where reproduction was shared more equitably, most members of both sexes were physiologically capable of breeding. However, in species where reproduction was monopolized by a single individual, a large proportion of females-but not males-were reproductively inactive, suggesting stronger reproductive suppression and conflict among females. Moreover, as skew increased across species, proportional size of the major chela-the primary antagonistic weapon in snapping shrimps-increased among females and sexual dimorphism in major chela size declined. Thus, as reproductive skew increases among Synalpheus, female-female competition over reproduction appears to increase, resulting in decreased sexual dimorphism in weapon size. PMID:26041357

  5. A Bayesian estimate of the concordance correlation coefficient with skewed data.

    PubMed

    Feng, Dai; Baumgartner, Richard; Svetnik, Vladimir

    2015-07-01

    Concordance correlation coefficient (CCC) is one of the most popular scaled indices used to evaluate agreement. Most commonly, it is used under the assumption that data is normally distributed. This assumption, however, does not apply to skewed data sets. While methods for the estimation of the CCC of skewed data sets have been introduced and studied, the Bayesian approach and its comparison with the previous methods has been lacking. In this study, we propose a Bayesian method for the estimation of the CCC of skewed data sets and compare it with the best method previously investigated. The proposed method has certain advantages. It tends to outperform the best method studied before when the variation of the data is mainly from the random subject effect instead of error. Furthermore, it allows for greater flexibility in application by enabling incorporation of missing data, confounding covariates, and replications, which was not considered previously. The superiority of this new approach is demonstrated using simulation as well as real-life biomarker data sets used in an electroencephalography clinical study. The implementation of the Bayesian method is accessible through the Comprehensive R Archive Network. Copyright © 2015?John Wiley & Sons, Ltd. PMID:26033433

  6. New oxa-bridged macrocycles.

    PubMed

    Panten, Johannes; Surburg, Horst; Hölscher, Bernd

    2008-06-01

    In creating new aroma molecules, the fragrance chemist can make use of several tools: receptor or combinatorial research as well as lead structure optimization of existing chemicals or substances from the natural pool. Sometimes, it is also possible to discover new structures via another way: the careful analysis of existing products and their production processes. In analyzing the production process of 1-oxacyclohexadecan-2-one (6), we identified at least two new oxa-bridged macrocyclic molecules. In continuation, these results inspired us to synthesize and evaluate more representatives with similar structures. In this contribution, presented at the RSC/SCI conference 'flavours & fragrances 2007' in London, September 24-26, 2007, the synthesis and olfactory properties of several new oxa-bridged macrocycles will be introduced and discussed. PMID:18618411

  7. Scour assessment at bridges from Flag Point to Million Dollar Bridge, Copper River Highway, Alaska

    USGS Publications Warehouse

    Brabets, T.P.

    1994-01-01

    Twelve bridges are located along the Copper River Highway from Flag Point (Mile 27) to lhe Million Dollar Bridge (Mile 48). These bridges cross all or parts of the Copper River. Channel scour at these bridges was assessed by collecting and analyzing discharge and sediment data, analyzing aerial photography for eight different years, surveying and comparing cross sections, and utilizing scour equations. Between 1968 and 1992, scour occurring at Bridge 331 has formed two distinct channels at the bridge. The channel at Bridge 1187 has remained relatively unchanged between 1968 and 1992. During this same time period, the channel at Bridge 332 appears to have gradually filled. However, during the 1992 runoff season, the channel at this bridge scoured significantly, probably because of its unstable nature. The most significant scour has occurred at Bridge 342. A high-water period in 1981 probably shifted much of the flow of the Copper River through this bridge. As a result, severe contraction scour occurred which required major repairs to the bridge. During 1991 and 1992, the approach channel to Bridge 342 has been migrating, causing scour in the left side of the channel. Bed material at the Million Dollar Bridge consists of hard unweathered boulders nested in dense gravel. Because of this type of erosion-resistant material, no significant scour has occurred at this site. Contraction scour equations overestimated the mean depth of flow at Bridge 331 by 2.6 to 5.0 ft, but were within 1.0 ft of the mean depth of flow for Bridge 1187. The local scour equations generally overestimated local scour at both Bridge 331 and Bridge 1187. The accuracy of some equations was probably affected because water velocities could not be obtained upstream from the piers.

  8. Microstrip superheterodyne coherent microwave bridge

    Microsoft Academic Search

    A. I. Rokeakh; A. M. Batin; O. B. Makhnev; A. A. Mekhonoshin; Yu. A. Sherstkov; A. A. Lisitsin; V. Yu. Yazan

    1995-01-01

    Reasons for unsatisfactory operation of the superheterodyne spectrometers at increased microwave power are considered. Recommendations\\u000a for designing the superheterodyne microwave bridge of the EPR spectrometer working at the microwave power of about hundreds\\u000a of milliwatt are given. These recommendations allow one to develop the spectrometer comparable to those with modulation of\\u000a resonant conditions concerning reliability, stability and simplicity of operation.

  9. Detection of skewed X-chromosome inactivation in Fragile X syndrome and X chromosome aneuploidy using quantitative melt analysis.

    PubMed

    Godler, David E; Inaba, Yoshimi; Schwartz, Charles E; Bui, Quang M; Shi, Elva Z; Li, Xin; Herlihy, Amy S; Skinner, Cindy; Hagerman, Randi J; Francis, David; Amor, David J; Metcalfe, Sylvia A; Hopper, John L; Slater, Howard R

    2015-01-01

    Methylation of the fragile X mental retardation 1 (FMR1) exon 1/intron 1 boundary positioned fragile X related epigenetic element 2 (FREE2), reveals skewed X-chromosome inactivation (XCI) in fragile X syndrome full mutation (FM: CGG > 200) females. XCI skewing has been also linked to abnormal X-linked gene expression with the broader clinical impact for sex chromosome aneuploidies (SCAs). In this study, 10 FREE2 CpG sites were targeted using methylation specific quantitative melt analysis (MS-QMA), including 3 sites that could not be analysed with previously used EpiTYPER system. The method was applied for detection of skewed XCI in FM females and in different types of SCA. We tested venous blood and saliva DNA collected from 107 controls (CGG < 40), and 148 FM and 90 SCA individuals. MS-QMA identified: (i) most SCAs if combined with a Y chromosome test; (ii) locus-specific XCI skewing towards the hypomethylated state in FM females; and (iii) skewed XCI towards the hypermethylated state in SCA with 3 or more X chromosomes, and in 5% of the 47,XXY individuals. MS-QMA output also showed significant correlation with the EpiTYPER reference method in FM males and females (P < 0.0001) and SCAs (P < 0.05). In conclusion, we demonstrate use of MS-QMA to quantify skewed XCI in two applications with diagnostic utility. PMID:26132880

  10. Bayesian bivariate linear mixed-effects models with skew-normal/independent distributions, with application to AIDS clinical studies.

    PubMed

    Huang, Yangxin; Chen, Ren; Dagne, Getachew; Zhu, Yiliang; Chen, Henian

    2015-01-01

    Bivariate correlated (clustered) data often encountered in epidemiological and clinical research are routinely analyzed under a linear mixed-effected (LME) model with normality assumptions for the random-effects and within-subject errors. However, those analyses might not provide robust inference when the normality assumptions are questionable if the data set particularly exhibits skewness and heavy tails. In this article, we develop a Bayesian approach to bivariate linear mixed-effects (BLME) models replacing the Gaussian assumptions for the random terms with skew-normal/independent (SNI) distributions. The SNI distribution is an attractive class of asymmetric heavy-tailed parametric structure which includes the skew-normal, skew-t, skew-slash, and skew-contaminated normal distributions as special cases. We assume that the random-effects and the within-subject (random) errors, respectively, follow multivariate SNI and normal/independent (NI) distributions, which provide an appealing robust alternative to the symmetric normal distribution in a BLME model framework. The method is exemplified through an application to an AIDS clinical data set to compare potential models with different distribution specifications, and clinically important findings are reported. PMID:24897242

  11. High incidence of skewed X chromosome inactivation in young patients with familial non-BRCA1/BRCA2 breast cancer

    PubMed Central

    Kristiansen, M; Knudsen, G; Maguire, P; Margolin, S; Pedersen, J; Lindblom, A; Orstavik, K

    2005-01-01

    Background: A higher frequency of skewed X chromosome inactivation has been reported in a consecutive series of young patients with breast cancer compared with controls of a similar age. Objective: To investigate the X inactivation pattern in patients with familial non-BRCA1/BRCA2 breast cancer (n = 272), BRCA1/BRCA2 germline mutations (n = 35), and sporadic breast cancer (n = 292). Methods: X inactivation pattern was determined by polymerase chain reaction analysis of the highly polymorphic CAG repeat in the androgen receptor (AR) gene. The X inactivation pattern was classified as skewed when 90% or more of the cells preferentially expressed one X chromosome. Results: Young patients with familial breast cancer had a significantly higher frequency of skewed X inactivation (11.2%) than young controls (2.7%) (p = 0.001). There was also a strong tendency for middle aged patients with sporadic breast cancer to be more skewed than middle aged controls (13.6% v 4.4%) (p = 0.02). No association between skewed X inactivation and breast cancer was found for the BRCA1/BRCA2 patients . Conclusions: Skewed X inactivation may be a risk factor for the development of breast cancer in both sporadic and familial breast cancer and may indicate an effect of X linked genes. PMID:15879497

  12. Coil Creep and Skew-Quadrupole Field Components in the Tevatron

    SciTech Connect

    Annala, G.; Harding, D.J.; Syphers, M.J.; /Fermilab

    2011-07-11

    During the start-up of Run II of the Tevatron Collider program, several issues surfaced which were not present, or not seen as detrimental, during Run I. These included the repeated deterioration of the closed orbit requiring orbit smoothing every two weeks or so, the inability to correct the closed orbit to desired positions due to various correctors running at maximum limits, regions of systematically strong vertical dipole corrections, and the identification of very strong coupling between the two transverse degrees-of-freedom. It became apparent that many of the problems being experienced operationally were connected to a deterioration of the main dipole magnet alignment, and remedial actions were undertaken. However, the alignment alone was not enough to explain the corrector strengths required to handle transverse coupling. With one exception, strong coupling had generally not been an issue in the Tevatron during Run I. Based on experience with the Main Ring, the Tevatron was designed with a very strong skew quadrupole circuit to compensate any quadrupole alignment and skew quadrupole field errors that might present themselves. The circuit was composed of 48 correctors placed evenly throughout the arcs, 8 per sector, evenly placed in every other cell. Other smaller circuits were installed but not initially needed or commissioned. These smaller circuits were composed of individual skew quadrupole correctors on either side of the long straight sections. These circuits were tuned by first bringing the horizontal and vertical tunes near each other. The skew quadrupoles were then adjusted to minimize tune split, usually to less than 0.003. Initially, the main skew quad circuit (designated T:SQ) could accomplish this global decoupling with only 4% of its possible current, and the smaller circuits were not required at all. The start-up of Run Ib was complicated by what was later discovered to be a rolled triplet quadrupole magnet in one of the Interaction Regions. This led to a reduction in luminosity of nearly 50%, as well as operational confusion until it was uncovered. By the time Collider Run II began, the current needed on the main SQ circuit had increased to 60% of its maximum value. Some of the smaller circuits were also needed to fully decouple the tunes. With this history, several studies were performed early in Run II to search for strong local coupling sources like the triplet quadrupole, but without success. The strong corrector settings were indicative of a much larger problem than a single rolled magnet, and the locality of the error was hard to deduce from the setting of a global correction system. Several possible reasons for the increase in coupling were investigated.

  13. Horizontal bridges in polar dielectric liquids

    NASA Astrophysics Data System (ADS)

    Woisetschläger, Jakob; Wexler, Adam D.; Holler, Gert; Eisenhut, Mathias; Gatterer, Karl; Fuchs, Elmar C.

    2012-01-01

    When a high-voltage direct-current is applied to two beakers filled with polar liquid dielectrica like water or methanol, a horizontal bridge forms between the two beakers. By repeating a version of Pellat's experiment, it is shown that a horizontal bridge is stable by the action of electrohydrodynamic pressure. Thus, the static and dynamic properties of the phenomenon called a `floating water bridge' can be explained by the gradient of Maxwell pressure, replenishing the liquid within the bridge against any drainage mechanism. It is also shown that a number of liquids can form stable and long horizontal bridges. The stability of such a connection, and the asymmetry in mass flow through such bridges caused by the formation of ion clouds in the vicinity of the electrodes, is also discussed by two further experiments.

  14. Development of Hybrid Bridges: State of Arts and Conceptual Design

    Microsoft Academic Search

    Suhaib Yahya Kasim Al-Darzi; Airong Chen

    2006-01-01

    A state of the art of developments of the Hybrid bridges is presented focusing on steel-concrete composite bridges, considering the steel beam, concrete deck and connections developments. The analysis and design methods of composite bridge structures, connections, the reliability and life cycle of bridges, new bridge system forms and the use of alternative materials are reviewed with some possible applications.

  15. Monitoring Bridge Deformations during Static Loading Tests Using GPS

    Microsoft Academic Search

    Moustafa A. BARAKA; Adel H. EL-SHAZLY

    SUMMARY The static loading test of a bridge is a fundamental check of the actual behavior of a bridge under extreme loading conditions. By measuring bridge deformations and comparing it to expected theoretical values resulting from design, bridge safety can be assessed. In this paper, GPS is presented as a viable tool to monitor bridge deformation in Egypt. GPS was

  16. 3. CONTEXTUAL VIEW OF BRIDGE IN SETTING, LOOKING SOUTHWEST FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. CONTEXTUAL VIEW OF BRIDGE IN SETTING, LOOKING SOUTHWEST FROM ELEVATED GRADE OF EUREKA SOUTHERN RAILROAD. EUREKA SOUTHERN TRUSS BRIDGE AT EXTREME LEFT, 1924 HIGHWAY BRIDGE IN CENTER, 1952 HIGHWAY BRIDGE AT RIGHT - Van Duzen River Bridge, Spanning Van Duzen River at CA State Highway 101, Alton, Humboldt County, CA

  17. 11. Photocopy of photograph, c. 1900. VIEW OF BRIDGE STREET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photocopy of photograph, c. 1900. VIEW OF BRIDGE STREET BRIDGE NEAR FLOOD STAGE, LOOKING NORTHEAST. (Original in Union City Historical Museum.) 8'x10' enlargement from 4'x5' negative. - Bridge Street Bridge, Spanning Little French Creek at Bridge Street, Union City, Erie County, PA

  18. Bridge deck designs for railing impacts 

    E-print Network

    Arnold, Althea Gayle

    1984-01-01

    ) Standard Specifications for Highway Bridges set forth certain structural design requirements for bridge railings and the corresponding bridge decks. Observat1ons of deck failure patterns in recent crash tests and observed deck fa1lures at vehicle... in Texas. Full-scale deck sections with a post, a parapet or an 8 ft section of railing were built and tested. The three types tested were the Texas TIOI, T202, and TS bridge railings. The findings of this testing are reported herein. ACKNOHLEDGEMENT...

  19. Relationship between myocardial bridging and coronary arteriosclerosis.

    PubMed

    Sun, Jian Ling; Huang, Wei Min; Guo, Ji Hong; Li, Xiao Ying; Ma, Xian Lin; Wang, Chong Yu

    2013-04-01

    The objective of the study was to explore the prevalence and characteristics of myocardial bridging in patients who underwent coronary angiography and to also evaluate the correlation between bridged coronary segments and atherosclerosis. For this purpose, clinical materials of 1,500 patients who had received coronary angiography were retrospectively analyzed. The location and length of the myocardial bridge were recorded as well as the extent and location of coronary artery stenosis was described. Segments proximal and distal to the bridging were evaluated for coronary arteriosclerosis as were the remaining coronary segments. We found that myocardial bridging was present in 179 (11.9 %) patients. Bridges were frequently (84.9 %) localized in the mid-distal segment of the left anterior descending (LAD) artery. Myocardial bridging was not considered a significant risk factor for coronary atherosclerosis (odds ratio 0.58) compared with traditional cardiovascular risk factors. The incidence of coronary arteriosclerosis in the distal segments was significantly less affected than the proximal segments (P < 0.01). It was, therefore, concluded that myocardial bridging frequently localized in the mid-distal segment of the LAD artery. The presence of myocardial bridging promotes proximal atherosclerosis but it is not an additional risk factor for coronary atherosclerosis. PMID:23076634

  20. Level II scour analysis for Bridge 10 (NORWTH00120010) Town Highway 012 Bloody Brook, Norwich, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure NORWTH00120010 on town highway 12 crossing Bloody Brook, Norwich, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). A Level I study is included in Appendix E of this report. A Level I study provides a qualitative geomorphic characterization of the study site. Information on the bridge, available from VTAOT files, was compiled prior to conducting the Level I and Level II analyses and can be found in Appendix D. The site is in the New England Upland physiographic province in east-central Vermont. The 8.98-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the left bank upstream and the left and right banks downstream are forested. The immediate right bank upstream is covered by shrub and brush with pasture on the overbank. Town Highway 12 runs along the valley of Bloody Brook; however, at structure NORWTH00120010 the road crosses Bloody Brook at a 90-degree angle. In the study area, Bloody Brook has a sinuous channel with a slope of approximately 0.014 ft/ft, an average channel top width of 41 ft and an average channel depth of 3 ft. The predominant channel bed materials are gravel and cobble (D50 is 51.0 mm or 0.167 ft). The geomorphic assessment at the time of the Level I site visit on October 31, 1994, indicated that the reach was unstable. The town highway 12 crossing of Bloody Brook is a 34-ft-long, two-lane bridge consisting of one 30-foot clear span (Vermont Agency of Transportation, written commun., July 29, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The right abutment is protected by sparse type-2 stone fill (less than 24 inches diameter). The channel is skewed 0 degrees to the opening and the opening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. The scour analysis results are presented in tables 1 and 2 and a graph of the scour depths is presented in figure 8.

  1. 6. VIEW OF GDOT BRIDGE NO. 02700268X00678N BRIDGE PLATE IDENTIFYING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF GDOT BRIDGE NO. 027-00268X-00678N BRIDGE PLATE IDENTIFYING COUNTY COMMISSIONERS AT THE TIME OF CONSTRUCTION. - GDOT Bridge No. 027-00268X-00678N, County Road 268-Empress Road span Piscola Creek, Quitman, Brooks County, GA

  2. Load Testing of an FRP Bridge Deck on a Truss Bridge

    Microsoft Academic Search

    Sreenivas Alampalli; Jonathan Kunin

    2003-01-01

    New York State has constructed a fiber reinforced polymer (FRP) bridge deck as an experimental project. The goal of the project was to improve the load rating of a 50-yr old truss bridge located in Wellsburg, New York. The FRP deck weighs approximately 80-percent less than the deteriorated concrete bridge deck it replaced. Reducing the dead load increased the allowable

  3. Bridge over little Pine Creek (S.R. 1026, section 002 bridge) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bridge over little Pine Creek (S.R. 1026, section 002 bridge) looking west across traffic level - Bridge over Little Pine Creek, State Route 1026 over Little Pine Creek, 2.01 kilometers (1.25 miles) East of Bendertown, Jonestown, Columbia County, PA

  4. Bridge over little Pine Creek (S.R. 1026, section 002 bridge) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bridge over little Pine Creek (S.R. 1026, section 002 bridge) looking north-northeast across traffic level - Bridge over Little Pine Creek, State Route 1026 over Little Pine Creek, 2.01 kilometers (1.25 miles) East of Bendertown, Jonestown, Columbia County, PA

  5. FBG bending gauge on bridges: an effort towards standardization of bridge structural health monitoring

    Microsoft Academic Search

    I.-Wen Wu; Chung-Yue Wang; Ming-Hung Chen; Hao-Lin Wang; Allen Cheng; Patrick Tsai; David Wu; Hung-Wei ChangChien; Hentai Shang

    2007-01-01

    The FBG bending gauge developed by POFC is applied in several situations involving bridge safety\\/health monitoring. Under static loading conditions, the FBG bending gauge serves as an excellent tool to deduce an overall deflection curve on the bridge section under study. The gauge also works well in dynamic situations where instantaneous vertical deflections of bridge structures resulting from a cruising

  6. Bridge afflux analysis through arched bridge constrictions using artificial intelligence methods

    Microsoft Academic Search

    Mustafa Mamak; Galip Seckin; Murat Cobaner; Ozgur Kisi

    2009-01-01

    Although many studies have been carried out for estimating the afflux through modern straight deck bridge constrictions, little attention has been given to medieval arched bridge constrictions. Hydraulic Research Wallingford in the UK (Brown, P.M., 1988. Afflux at arch bridges. Report SR 182. Wallingford, UK: HR Wallingford) recently published a major coverage of both experimental and field afflux data obtained

  7. Synthesis, Structure, Bridge-Terminal Exchange Kinetics, and Molecular Orbital Calculations of Pyrazolate-Bridged Digallium Complexes Containing

    E-print Network

    Schlegel, H. Bernhard

    of Pyrazolate-Bridged Digallium Complexes Containing Bridging Phenyl Groups Chatu T. Sirimanne, John E. Knox in the solid state with two bridging phenyl groups,2a while triphenylgallium is a monomer in the solid state.7 bridging phenyl ligands. The observation of bridging phenyl ligands in these complexes is particularly

  8. Salt-Bridge Energetics in Halophilic Proteins

    PubMed Central

    Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K.

    2014-01-01

    Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are ?3.0 kcal mol?1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of ?5.0 kcal mol?1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (?10 kcal mol?1) exceeds than that of bridge term (?7 kcal mol?1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic signature in its specific electrostatic interactions which we hope would help in protein engineering and bioinformatics studies. PMID:24743799

  9. Social queuing in animal societies: a dynamic model of reproductive skew

    PubMed Central

    Kokko, H.; Johnstone, R. A.

    1999-01-01

    Previously developed models of reproductive skew have overlooked one of the main reasons why subordinates might remain in a group despite restricted opportunities to breed: the possibility of social queuing, i.e. acquiring dominant status in the future. Here, we present a dynamic ESS model of skew in animal societies that incorporates both immediate and future fitness consequences of the decisions taken by group members, based on their probability of surviving from one season to the next (when post-breeding survival probabilities drop to zero, our analysis reduces to the model produced by Reeve and Ratnieks in 1993, which considered only a single breeding season). This allows us to compare the delayed benefits of philopatry and the immediate opportunities for independent breeding. We show that delayed benefits greatly reduce the need for dominants to offer reproductive concessions to retain subordinates peacefully in the group. Moreover, this effect is strong enough that differences in survival have a much greater impact on the group structure than differences in other parameters, such as relatedness. When the possibility of acceding to dominant status is taken into account, groups where the dominant completely monopolizes reproduction can be stable, even if they consist of unrelated individuals, and even if subordinates have a reasonably high probability of winning a fight for dominance. Finally, we show that stable groups are possible even if association leads to a decrease in current productivity. Subordinates may still stand to gain from group membership under these circumstances, as acquiring breeding positions by queuing may be more efficient than the attempt to establish a new territory. At the same time, the dominant may be unable to exclude unwelcome subordinates, may enjoy increased survival when they are present, or may gain indirect benefits from allowing relatives to stay and queue for dominance. We conclude that reproductive skew in animal groups, ranging from eusocial insect colonies to mating aggregations (leks), will be strongly influenced by the future prospects of group members.

  10. A q-Analogue of the Centralizer Construction and Skew Representations of the Quantum Affine Algebra

    NASA Astrophysics Data System (ADS)

    Hopkins, Mark J.; Molev, Alexander I.

    2006-12-01

    We prove an analogue of the Sylvester theorem for the generator matrices of the quantum affine algebra Uq(gln). We then use it to give an explicit realization of the skew representations of the quantum affine algebra. This allows one to identify them in a simple way by calculating their highest weight, Drinfeld polynomials and the Gelfand-Tsetlin character (or q-character). We also apply the quantum Sylvester theorem to construct a q-analogue of the Olshanski algebra as a projective limit of certain centralizers in Uq(gln) and show that this limit algebra contains the q-Yangian as a subalgebra.

  11. Analytical shape sensitivities and approximations of modal response of generally laminated tapered skew plates

    NASA Technical Reports Server (NTRS)

    Singhvi, Sarvesh; Kapania, Rakesh K.

    1992-01-01

    In the present determination of the derivatives of natural frequencies and mode shapes of a generally laminated tapered skew plate, with respect to various shape parameters, springs are used to simulate the essential boundary conditions. The independent shape parameters are plate surface area, aspect ratio, taper ratio, and sweep angle. Eigenvalues and eigenvectors are approximated over the range of the variable using linear, exponential, and pseudoexponential approximation schemes, and are compared with reanalysis-obtained values. Numerical results are presented for symmetrically and unsymmetrically laminated plates.

  12. Autonomous fault-tolerant attitude reference system using DTGs in symmetrically skewed configuration

    NASA Technical Reports Server (NTRS)

    Murugesan, S.; Goel, P. S.

    1989-01-01

    A novel symmetrically skewed configuration for an attitude reference system (ARS) using three dynamically tuned gyros (DTGs) is developed. Simple schemes for autonomous detection and identification of a faulty DTG in real time and subsequent reconfiguration of the attitude estimation algorithm are proposed. The performance of the present configuration is shown to be better than that of configurations proposed earlier, and it is shown to have better features. It tolerates all types of failures of DTG failures, requires very simple computations, and gives less error in attitude estimate than the other configurations.

  13. The Bridge of Mandolin County

    NASA Astrophysics Data System (ADS)

    Lantz, Juliette M.; Feindt, Jenny E.; Lewellyn, Eric P. B.; Walczak, Mary M.

    1999-12-01

    The Bridge of Mandolin County is a case designed to teach the general chemistry principles of molar mass, ions and aqueous reactions, solubility rules, and inorganic nomenclature. Through the instructor-facilitated class discussion, students consider the options before the Mandolin Town Council regarding deicing the newly constructed bridge connecting Mandolin with a large nearby city. The students must decipher contradictory claims made on behalf of sodium chloride, the traditional deicer, and calcium magnesium acetate, a new environmentally friendly deicer, to arrive at the most cost-effective and environmentally appropriate deicing product. As they work through the analysis they raise questions that can be addressed in a laboratory setting. Four optional role-playing experiments are included, which can be used by the students to gather information helpful to resolution of the case. The case is intended to be used over two class periods, with a laboratory period in between, though suggestions for other models are provided. Laboratory procedures include an EDTA titration for Ca2+ and Mg2+, a gravimetric analysis, a qualitative examination of ions and solubility, an introduction to freezing point depression and measurement, and an experimental design activity. This case can also successfully be used without alteration in non-majors chemistry or environmental chemistry courses, or upper-level analytical or environmental chemistry courses.

  14. 10. LOOKING EAST OHIO END OF BRIDGE AS VIEWED FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. LOOKING EAST OHIO END OF BRIDGE AS VIEWED FROM PROPOSED CENTERLINE OF NEW BRIDGE APPROACH UNDER ELEVATED OHIO 7 - Bridgeport Bridge, Spanning West Channel of Ohio River, U.S. Route 40, Wheeling, Ohio County, WV

  15. 23 CFR 650.807 - Bridges requiring a USCG permit.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges...at the appropriate level by FHWA for structural concepts, hydraulics, and navigational clearances prior to submission of the...

  16. 23 CFR 650.807 - Bridges requiring a USCG permit.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges...at the appropriate level by FHWA for structural concepts, hydraulics, and navigational clearances prior to submission of the...

  17. 23 CFR 650.705 - Application for discretionary bridge funds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year...

  18. 23 CFR 650.807 - Bridges requiring a USCG permit.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges...at the appropriate level by FHWA for structural concepts, hydraulics, and navigational clearances prior to submission of the...

  19. 23 CFR 650.705 - Application for discretionary bridge funds.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year...

  20. 23 CFR 650.705 - Application for discretionary bridge funds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year...

  1. 23 CFR 650.705 - Application for discretionary bridge funds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year...

  2. 12. ELEVATION VIEW UNDERNEATH BRIDGE, SHOWING FOUR BEAMS RESTING ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. ELEVATION VIEW UNDERNEATH BRIDGE, SHOWING FOUR BEAMS RESTING ON PILASTERS AT WEST END OF BRIDGE - North Twenty-First Street Bridge, North Twenty-first Street spanning Buckley Gulch, Tacoma, Pierce County, WA

  3. 10. Detail of bridge underside showing gears for locking mechanism ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Detail of bridge underside showing gears for locking mechanism at south end of bridge. View to east. - Locke Avenue Bridge, Locke Avenue (County Route 671) Spanning Raccoon Creek, Swedesboro, Gloucester County, NJ

  4. 2. GENERAL VIEW OF BRIDGE FROM ROADBED WITH 4' RANGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. GENERAL VIEW OF BRIDGE FROM ROADBED WITH 4' RANGE POLE NEAR NORTHWEST CORNER OF BRIDGE, LOOKING SOUTH - North Fork Bridge, Spans North Fork of White River at State Highway 5, Norfork, Baxter County, AR

  5. 12. Interior detail of bridge operator's house showing generator and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Interior detail of bridge operator's house showing generator and bridge operator, Mr. Gene Amonette, facing west. - Palm Valley Bridge, County Road 210 spanning Intracoastal Waterway, Ponte Vedra Beach, St. Johns County, FL

  6. 1. VIEW ACROSS WARREN TRUSS BRIDGE LOOKING EASTERLY FROM WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW ACROSS WARREN TRUSS BRIDGE LOOKING EASTERLY FROM WEST STONE ABUTMENT. THE STEEL FENCE PROHIBITS ACCESS ACROSS BRIDGE. - Double Intersection Warren Truss Bridge, Spanning Blackledge River, Colchester, New London County, CT

  7. 1. ARROYO SECO PARKWAY SOUTHBOUND LANES AND PASADENA AVENUE BRIDGE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. ARROYO SECO PARKWAY SOUTHBOUND LANES AND PASADENA AVENUE BRIDGE. RAILROAD BRIDGE IN DISTANCE. LOOKING 238°WSW. - Arroyo Seco Parkway, Pasadena Avenue Bridge, Milepost 26.48, Los Angeles, Los Angeles County, CA

  8. ARROYO SECO PARKWAY SOUTHBOUND LANES AND MERIDIAN AVENUE BRIDGE. ORANGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ARROYO SECO PARKWAY SOUTHBOUND LANES AND MERIDIAN AVENUE BRIDGE. ORANGE GROVE BRIDGE AT REAR. LOOKING 248°WSW - Arroyo Seco Parkway, Meridian Avenue Bridge, Milepost 30.78, Los Angeles, Los Angeles County, CA

  9. MARMION WAY BRIDGE OVERCROSSING OF THE ARROYO SECO CHANNEL. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MARMION WAY BRIDGE OVERCROSSING OF THE ARROYO SECO CHANNEL. NOTE ACCESS ROAD BRIDGE BEHIND. LOOKING 240°WSW - Arroyo Seco Parkway, Marmion Way Bridge, Milepost 29.28, Los Angeles, Los Angeles County, CA

  10. 6. VIEW OF ARROYO SECO CHANNEL FROM YORK BOULEVARD BRIDGE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF ARROYO SECO CHANNEL FROM YORK BOULEVARD BRIDGE. MARMION WAY BRIDGE SEEN AT CENTER DISTANCE. LOOKING 238°WSW. - Arroyo Seco Parkway, York Boulevard Bridge, Milepost 29.50, Los Angeles, Los Angeles County, CA

  11. 33 CFR 118.140 - Painting bridge piers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Painting bridge piers. 118.140 Section...LIGHTING AND OTHER SIGNALS § 118.140 Painting bridge piers. The District Commander may require painting the sides of bridge channel...

  12. 33 CFR 118.140 - Painting bridge piers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Painting bridge piers. 118.140 Section...LIGHTING AND OTHER SIGNALS § 118.140 Painting bridge piers. The District Commander may require painting the sides of bridge channel...

  13. 33 CFR 118.140 - Painting bridge piers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Painting bridge piers. 118.140 Section...LIGHTING AND OTHER SIGNALS § 118.140 Painting bridge piers. The District Commander may require painting the sides of bridge channel...

  14. 6. EARLY MORNING VIEW OF BOTH JOSO HIGH BRIDGE (UNION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. EARLY MORNING VIEW OF BOTH JOSO HIGH BRIDGE (UNION PACIFIC RAILROAD) IN BACKGROUND AND LYONS FERRY BRIDGE IN THE FOREGROUND - Snake River Bridge at Lyons' Ferry, State Route 261 spanning Snake River, Starbuck, Columbia County, WA

  15. 2. VIEW EAST TOWARD DARIEN ANCHOR BRIDGE #465 OF CIRCUIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW EAST TOWARD DARIEN ANCHOR BRIDGE #465 OF CIRCUIT BREAKER INSTALLATION ON CROSS BEAM OF BRIDGE. - New York, New Haven & Hartford Railroad, Bridge-Type Circuit Breakers, Long Island shoreline between Stamford & New Haven, Cos Cob, Fairfield County, CT

  16. 3. VIEW EAST TOWARD STAMFORD ANCHOR BRIDGE #374 OF CIRCUIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW EAST TOWARD STAMFORD ANCHOR BRIDGE #374 OF CIRCUIT BREAKER INSTALLATION ON CROSS BEAM OF BRIDGE. - New York, New Haven & Hartford Railroad, Bridge-Type Circuit Breakers, Long Island shoreline between Stamford & New Haven, Cos Cob, Fairfield County, CT

  17. OUTERBRIDGE CROSSING BRIDGE LINED UP WITH MANHATTAN SKYLINE IN MIDDLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OUTERBRIDGE CROSSING BRIDGE LINED UP WITH MANHATTAN SKYLINE IN MIDDLE OF HORIZON, VERRAZANO NARROWS BRIDGE TO THE RIGHT - Outerbridge Crossing Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  18. 46 CFR 112.43-7 - Navigating bridge distribution panel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Navigating bridge distribution panel. 112...CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER...112.43-7 Navigating bridge distribution panel. ...distribution panel on the navigating bridge: (1) Navigation...

  19. 46 CFR 112.43-7 - Navigating bridge distribution panel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Navigating bridge distribution panel. 112...CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER...112.43-7 Navigating bridge distribution panel. ...distribution panel on the navigating bridge: (1) Navigation...

  20. 1. AERIAL VIEW LOOKING SOUTHWEST (OLD HARVARD STREET BRIDGE AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. AERIAL VIEW LOOKING SOUTHWEST (OLD HARVARD STREET BRIDGE AT LEFT, NEW BRIDGE AT RIGHT) - Old Harvard Street Bridge, Spanning Rock Creek at National Zoological Park, Washington, District of Columbia, DC

  1. 1. AERIAL VIEW OF THE PATH TRANSIT SYSTEM BRIDGE, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. AERIAL VIEW OF THE PATH TRANSIT SYSTEM BRIDGE, LOOKING NORTHEAST. THE CONRAIL BRIDGE (HAER No. NJ-43) AND THE NEWARK TURNPIKE ARE VISIBLE IN THE BACKGROUND - Path Transit System Bridge, Spanning Hackensack River, Kearny, Hudson County, NJ

  2. 14. REPRESENTATIVE DETAIL VIEW OF THE TWO ARCHED PEDESTRIAN BRIDGES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. REPRESENTATIVE DETAIL VIEW OF THE TWO ARCHED PEDESTRIAN BRIDGES OVER THE CANALS. THIS BRIDGE IS THE GRAND CANAL COURT BRIDGE OVER CARROLL CANAL - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA

  3. 25. REPRESENTATIVE DETAIL VIEW OF THE TWO ARCHED PEDESTRIAN BRIDGES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. REPRESENTATIVE DETAIL VIEW OF THE TWO ARCHED PEDESTRIAN BRIDGES OVER THE CANALS, SHOWING PLANKS AND RAILS. THIS BRIDGE IS THE LINNIE CANAL COURT BRIDGE OVER EASTERN CANAL. - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA

  4. 9. North elevation of Morrison Bridge, looking south, with Marquam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. North elevation of Morrison Bridge, looking south, with Marquam Bridge the background (far left corner of view). - Morrison Bridge, Spanning Willamette River on Morrison & Alder Streets, Portland, Multnomah County, OR

  5. 8. South elevation of Morrison Bridge, looking north (downstream), with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. South elevation of Morrison Bridge, looking north (downstream), with Convention Center Towers and steel bridge in the background. - Morrison Bridge, Spanning Willamette River on Morrison & Alder Streets, Portland, Multnomah County, OR

  6. 24. Interior detail of drawspan control panel, interior of bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. Interior detail of drawspan control panel, interior of bridge operator's house, with burnside bridge visible in background through the window. - Morrison Bridge, Spanning Willamette River on Morrison & Alder Streets, Portland, Multnomah County, OR

  7. 2. Contextual view of bridge in setting, from northwest end ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Contextual view of bridge in setting, from northwest end of bridge, view to south-southeast with Rawson Road in foreground. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  8. 1. Photocopy from George S. Morison's The Blair Crossing Bridge, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Photocopy from George S. Morison's The Blair Crossing Bridge, 1886. Photographer unknown, circa 1883. SOUTH WEB AND WEST PORTAL OF BRIDGE - Blair Crossing Bridge, Spanning Missouri River, Blair, Washington County, NE

  9. 23 CFR 650.705 - Application for discretionary bridge funds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year...

  10. Surf zone cross-shore boundary layer velocity asymmetry and skewness: An experimental study on a mobile bed

    NASA Astrophysics Data System (ADS)

    Berni, C.; Barthélemy, E.; Michallet, H.

    2013-04-01

    An experimental study on a physical model of a beach in a two-dimensional wave flume was designed to investigate velocity nonlinearities in the wave boundary layer. The cross-shore velocity was measured in the surf zone along a vertical profile every 3mm from free-stream elevation down to the still bed level. The skewness and the asymmetry of the phase averaged velocity were computed at each elevation. Observations indicate that the free-stream asymmetry transforms into bottom velocity skewness. A linear experimental relation between free-stream asymmetry to skewness ratio and bottom skewness to free-stream skewness ratio is established. A theoretical linear relationship is discussed, which predicts the phase lead of the bottom velocity. This phase lead is also determined by Fourier analyzing the velocity time series. The first two Fourier components yield the same phase lead at the bed that is found to be about 30° and nearly constant over all the experiments made.

  11. Investigation of the effects of overloads on highway bridges 

    E-print Network

    Zimmerman, Richard A

    1988-01-01

    , reinforced concrete bridge decks supported by noncomposite steel I-beams. Bridge damage was evaluated by analyzing bridge deck crack density, location, and orientation. An analysis of traffic at the study sites attempted to determine the relationship... between overload traffic and observed bridge damage. Greater bridge deck crack damage and more uniform crack distribution were observed in the bridges experiencing higher levels of heavy traffic. ACKNOWLEDGEMENT The author is indebted to Dr. Ray W...

  12. Development of a bridge fault extractor tool

    E-print Network

    Bhat, Nandan D.

    2005-02-17

    ........................................................................................ 4 Figure 2. Critical area between two wires............................................................................ 7 Figure 3. Euclidean polygon expansion ............................................................................... 8... Page Table 1. Previous, present and future semiconductor technology roadmap......................... 2 Table 2: FedEx improvements (insertion ? only intralayer bridges).................................. 27 Table 3. FedEx improvements (bridging...

  13. Statistical Bridge Signatures Christopher W. Follen1

    E-print Network

    Vogel, Richard M.

    values from heavy truck events were used to establish a nonparametric probability distribution that describes the behavior of the undamaged bridge under normal operating conditions. Nonparametric prediction intervals were added to the bridge signature, which define where future distributions of strain data from

  14. Rapid Repair of Low Volume Bridges

    E-print Network

    Russell, Jeffrey S.

    , Nanni, & Jones, 2005) 9 Cost of Previous Strengthening Projects Bridge Total Cost Length of FRP Used as a result of applying the MF-FRP strips (Arora, 2003) Bridge Strengthening · 21 FRP Strips spaced 12in · Strengthening system endured a Wisconsin winter and was then inspected (use stainless steel fasteners!) #12

  15. Instrumented monitoring of the Commodore Barry Bridge

    NASA Astrophysics Data System (ADS)

    Barrish, Raymond A., Jr.; Grimmelsman, Kirk A.; Aktan, A. Emin

    2000-06-01

    The Drexel Intelligent Infrastructure and Transportation Safety Institute, working in partnership with the Delaware River Port Authority (DRPA), has been investigating the application of various health monitoring techniques to long span bridges. Specifically, the researchers efforts have focused on the Commodore Barry Bridge, a major cantilevered through truss bridge owned by the DRPA. Health monitoring, in the case of civil infrastructure systems, may be considered as measuring and tracking the operating and loading environment of a structure and corresponding structural responses in order to detect and evaluate operational anomalies and deterioration or damage that may impact service or safety reliability. This paper describes the development and implementation of the health monitoring system that has been installed on the Commodore Barry Bridge. Issues that should be considered when conducting health monitoring of long span bridges are also discussed. The health monitoring system takes advantage of in excess of 100 data channels to continuously track the loading environment and numerous structural responses of the bridge. The major attributes of the health monitoring system for this bridge, many of which are applicable for use on other long span bridges, are also presented and described.

  16. FHWA Seismic Retrofitting of Highway Truss Bridges

    Microsoft Academic Search

    W. Phillip Yen; Charles Seim; Jerome S. O'Connor

    This paper presents a summary of the recently released document entitled Seismic Retrofitting Guidelines for Complex Steel Truss Highway Bridges (referred to here as the Guidelines). The Federal Highway Administration (FHWA), commissioned MCEER (formally known as the Multidisciplinary Center for Earthquake Engineering) to develop guidelines for seismic retrofitting of steel truss highway bridges as part of a larger research project.

  17. REDUNDANCY ANALYSIS OF EXISTING TRUSS BRIDGES: \\

    Microsoft Academic Search

    Tarek N Kudsi; Chung C Fu

    2002-01-01

    The main objective of this study is to develop a new methodology for redundancy analysis of structural systems in general and truss bridges in particular. The proposed methodology depicts the required steps to build a block diagram, composed of members in series and parallel configuration, representing the structural system or the truss bridge. The proposed block diagram accounts for the

  18. The Higgs Bridge Roland E. Allen

    E-print Network

    Allen, Roland E.

    1 The Higgs Bridge Roland E. Allen The discovery of a new kind of particle is announced. It is the long-sought Higgs boson! Credit: CERN [or more precisely, a Higgs boson] #12;The tutorial article that this talk is based on: Roland E. Allen, "The Higgs bridge", Physica Scripta 89

  19. The Jade Bridges Programme 2009 Grant Competition

    E-print Network

    Condon, Anne

    1 The Jade Bridges Programme 2009 Grant Competition Application Form Name of applicant the Jade logo on your project website and in other printed materials. [ ] Attend an event (schedule permitting) in Spring 2009 to share your project with other Jade Bridges participants. [ ] Be willing

  20. Design and Evaluation of Accelerated Bridge Construction

    Microsoft Academic Search

    Mike LaViolette; Norman McDonald; Ahmed Abu-Hawash; James S. Nelson; Anthony Samuelson

    New bridge systems are needed that will allow components to be fabricated off-site and moved into place for quick assembly while maintaining traffic flow. Depending on the specific site conditions, the use of prefabricated bridge systems can minimize traffic disruption, improve work zone safety, minimize disruption to the environment, improve constructibility, increase quality, and lower life-cycle costs. This technology is

  1. Bridge owner's benefits from probabilistic approaches

    Microsoft Academic Search

    J. Lauridsen; J. S. Jensen; I. B. Enevoldsen

    2007-01-01

    The growth of national economies in the latter half of the twentieth century has resulted in steadily increasing traffic volumes on trading routes and in an increase in the demands placed on an ageing bridge stock. Ironically, economic growth has not resulted in an increase in the budgets available to bridge owners for maintenance of their ageing resource. The approach

  2. Build and Test a Paper Bridge

    NSDL National Science Digital Library

    2012-06-26

    In this hands-on activity, learners make a bridge out of a folded piece of paper and two blocks. Then they test their structure by stacking coins (and other things) on it, discovering how much weight the bridge can support before it collapses. This activity explores engineering, technology, architecture, weight, compression, tension, and balance.

  3. A bridging model for parallel computation

    Microsoft Academic Search

    Leslie G. Valiant

    1990-01-01

    The success of the von Neumann model of sequential computation is attributable to the fact that it is an efficient bridge between software and hardware: high-level languages can be efficiently compiled on to this model; yet it can be effeciently implemented in hardware. The author argues that an analogous bridge between software and hardware in required for parallel computation if

  4. Teaching Elements and Principles of Bridge Design

    ERIC Educational Resources Information Center

    Beck, Charles

    2005-01-01

    Bridge construction is a popular classroom activity. However, the basic principles of tension, compression, and counterbalance are not always clearly represented and defined. The common materials used to construct model bridges, such as straws, toothpicks, Legos[TM], and building blocks, are often too flexible or stationary to demonstrate the…

  5. Build and test a paper bridge

    NSDL National Science Digital Library

    TryScience, New York Hall of Science (NYHOS)

    2007-12-12

    Make a bridge out of a folded piece of paper and two blocks. Test your structure by stacking coins (and other things) on it. How much weight can your bridge support before it crashes? This resource is appropriate for all users, particularly for girls and women, because it uses STEM to solve real-world problems. Copyright 2005 EDC

  6. Passing the Einstein-Rosen bridge

    E-print Network

    M. O. Katanaev

    2013-10-28

    We relax the requirement of geodesic completeness of a space-time. Instead, we require test particles trajectories to be smooth only in the physical sector. Test particles trajectories for Einstein--Rosen bridge are proved to be smooth in the physical sector, and particles can freely penetrate the bridge in both directions.

  7. New regulations on railroad bridge safety: opportunities and challenges for railroad bridge monitoring

    NASA Astrophysics Data System (ADS)

    Moreu, Fernando; LaFave, James M.; Spencer, Billie F.

    2012-04-01

    New federal regulations now mandate North American railroad bridge owners to closely assess the structural capacity of their bridges. Consequently, railroad companies are currently looking into developing and exploring monitoring systems for specific bridges, to help them improve and develop bridge safety in order to help comply with this new rule. The first part of this paper explains the significance of the new federal law. The new rule comes from the Federal Railroad Administration (FRA), Department of Transportation (DOT), and it falls under the 49 Code of Federal Regulations (CFR), Parts 213 and 2371. It requires railroad track owners to know the safe capacity of their bridges and to additionally conduct special inspections if either weather or other exceptional conditions make them necessary to ensure safe railroad bridge operations. The second part of this paper will cover past and current studies about the viability of bridge health monitoring, and actual structural monitoring experiences for railroad bridges. Finally, lessons learned from these monitoring examples, as well as recommendations for future applications, are suggested, including wireless monitoring strategies for railroad bridges such as: campaign sensing inspections (periodic monitoring); bridge replacement observations (short term monitoring); and permanent bridge instrumentation (long term monitoring).

  8. 10. PHOTOCOPY OF 1875 WOODCUT OF THE BRIDGE INCLUDING THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. PHOTOCOPY OF 1875 WOODCUT OF THE BRIDGE INCLUDING THE MANUFACTURERS ADVERTISING - Callowhill Street Bridge, Schuylkill River at Spring Garden & Callowhill Streets, Philadelphia, Philadelphia County, PA

  9. OUTERBRIDGE CROSSING BRIDGE IN PERSPECTIVE, STATEN ISLAND ON RIGHT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OUTERBRIDGE CROSSING BRIDGE IN PERSPECTIVE, STATEN ISLAND ON RIGHT - Outerbridge Crossing Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  10. VERRAZANONARROWS BRIDGE, STATEN ISLAND TOWER, FORT WADSWORTH IN BACKGROUND LEFT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VERRAZANO-NARROWS BRIDGE, STATEN ISLAND TOWER, FORT WADSWORTH IN BACKGROUND LEFT - Verrazano-Narrows Bridge, Spanning Narrows between Fort Hamilton (Brooklyn) & Staten Island, Brooklyn, Kings County, NY

  11. 5. General view of Morrison Bridge, looking southeast, with Riverfront ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. General view of Morrison Bridge, looking southeast, with Riverfront Park and walkway in foreground. - Morrison Bridge, Spanning Willamette River on Morrison & Alder Streets, Portland, Multnomah County, OR

  12. Effect of skewness and kurtosis of sea-surface elevations on the accuracy of altimetry surface level measurements

    NASA Astrophysics Data System (ADS)

    Zapevalov, A. S.

    2012-04-01

    We assess the influence of changes in the skewness and kurtosis of the distribution of elevations on a rough sea surface that were observed in field conditions on the accuracy of the recovery of the sea-surface level along the satellite trace. For different values of a significant height of surface waves, we obtain numerical estimates for the bias in relief recovery due to the simultaneous variation in skewness and kurtosis. It is shown that, with a decrease in kurtosis, the effect of skewness changes on the accuracy of altimetry measurements of the level increases. We note the limitations of the Gram-Charlier model in simulating the radar waveforms return from the sea surface.

  13. Forgotten moments: a note on skewness and kurtosis as influential factors in inferences extrapolated from response distributions.

    PubMed

    Newell, K M; Hancock, P A

    1984-09-01

    It is proposed that reliance on only the mean and standard deviation of a distribution to describe response frequency may lead to erroneous inferences concerning such distributions when skewness and kurtosis are present. After defining the first four moments of a distribution, it is demonstrated analytically that skewness and kurtosis may vary to systematically influence the mean and standard deviation of a set of related distributions. The significance of these relationships for the interpretation of differing response distributions is advanced through examples gleaned from the movement control literature. in addition, it is suggested that the use of bandwidths to select scores from a distribution for subsequent data analysis can further compound the problems of both descriptive and explanatory inference, particularly when skewness and kurtosis are features of such distribution(s). Whether or not inferential statistics are invoked, a veridical perspective of distributions is essential to meaningful data analysis. PMID:15151856

  14. Dynamic behavior of multi-span bridges under moving loads with focusing on the effect of the coupling conditions between spans

    NASA Astrophysics Data System (ADS)

    Xu, Hongan; Li, Wen L.

    2008-05-01

    This study is concerned with the dynamic behavior of generic multi-span bridges under the action of moving loads. In this multi-span bridge model, each span can be independently supported by up to eight elastic springs, thus allowing a more general and realistic representation of many joints and intermediate supports of practical interest. Additionally, since the displacement and its first derivative are no longer required to be continuous at an intermediate support or at the junctions of spans, this model is capable of accounting for the possible steps and skew angles at these locations which are important to studying the vehicle-bridge interactions. Numerical results are presented with a focus on the dynamic impact of the coupling conditions between spans. It has been shown that the deflection on each span strongly depends upon its local coupling conditions, especially near the critical stiffness values. A fairly large variance of response has also been observed on each span in correspondence to a wide range of stiffness values, which implies a good potential for improving bridge performance through modifying joint parameters or coupling configurations. This model can be readily applied to any boundary and coupling conditions with no need of modifying the formulations or solution procedures.

  15. Differential properties and attracting sets of a simplest skew product of interval maps

    SciTech Connect

    Efremova, Lyudmila S [N. I. Lobachevski State University of Nizhni Novgorod, Nizhnii Novgorod (Russian Federation)

    2010-08-12

    For a skew product of interval maps with a closed set of periodic points, the dependence of the structure of its {omega}-limit sets on its differential properties is investigated. An example of a map in this class is constructed which has the maximal differentiability properties (within a certain subclass) with respect to the variable x, is C{sup 1}-smooth in the y-variable and has one-dimensional {omega}-limit sets. Theorems are proved that give necessary conditions for one-dimensional {omega}-limit sets to exist. One of them is formulated in terms of the divergence of the series consisting of the values of a function of x; this function is the C{sup 0}-norm of the deviation of the restrictions of the fibre maps to some nondegenerate closed interval from the identity on the same interval. Another theorem is formulated in terms of the properties of the partial derivative with respect to x of the fibre maps. A complete description is given of the {omega}-limit sets of certain class of C{sup 1}-smooth skew products satisfying some natural conditions. Bibliography: 33 titles.

  16. Weighted skewness and kurtosis unbiased by sample size and Gaussian uncertainties

    NASA Astrophysics Data System (ADS)

    Rimoldini, Lorenzo

    2014-07-01

    Central moments and cumulants are often employed to characterize the distribution of data. The skewness and kurtosis are particularly useful for the detection of outliers, the assessment of departures from normally distributed data, automated classification techniques and other applications. Estimators of higher order moments that are robust against outliers are more stable but might miss characteristic features of the data, as in the case of astronomical time series exhibiting brief events like stellar bursts or eclipses of binary systems, while weighting can help identify reliable measurements from uncertain or spurious outliers. Furthermore, noise is an unavoidable part of most measurements and their uncertainties need to be taken properly into account during the data analysis or biases are likely to emerge in the results, including basic descriptive statistics. This work provides unbiased estimates of the weighted skewness and kurtosis moments and cumulants, corrected for biases due to sample size and Gaussian noise, under the assumption of independent data. A comparison of biased and unbiased weighted estimators is illustrated with simulations as a function of sample size and signal-to-noise ratio, employing different data distributions and weighting schemes related to measurement uncertainties and the sampling of the signal. Detailed derivations and figures of simulation results are presented in the Appendices available online.

  17. Fourier transform assisted deconvolution of skewed peaks in complex multi-dimensional chromatograms.

    PubMed

    Hanke, Alexander T; Verhaert, Peter D E M; van der Wielen, Luuk A M; Eppink, Michel H M; van de Sandt, Emile J A X; Ottens, Marcel

    2015-05-15

    Lower order peak moments of individual peaks in heavily fused peak clusters can be determined by fitting peak models to the experimental data. The success of such an approach depends on two main aspects: the generation of meaningful initial estimates on the number and position of the peaks, and the choice of a suitable peak model. For the detection of meaningful peaks in multi-dimensional chromatograms, a fast data scanning algorithm was combined with prior resolution enhancement through the reduction of column and system broadening effects with the help of two-dimensional fast Fourier transforms. To capture the shape of skewed peaks in multi-dimensional chromatograms a formalism for the accurate calculation of exponentially modified Gaussian peaks, one of the most popular models for skewed peaks, was extended for direct fitting of two-dimensional data. The method is demonstrated to successfully identify and deconvolute peaks hidden in strongly fused peak clusters. Incorporation of automatic analysis and reporting of the statistics of the fitted peak parameters and calculated properties allows to easily identify in which regions of the chromatograms additional resolution is required for robust quantification. PMID:25841612

  18. Fuel cell plates with skewed process channels for uniform distribution of stack compression load

    DOEpatents

    Granata, Jr., Samuel J. (Greensburg, PA); Woodle, Boyd M. (North Huntingdon Township, Westmoreland County, PA)

    1989-01-01

    An electrochemical fuel cell includes an anode electrode, a cathode electrode, an electrolyte matrix sandwiched between electrodes, and a pair of plates above and below the electrodes. The plate above the electrodes has a lower surface with a first group of process gas flow channels formed thereon and the plate below the electrodes has an upper surface with a second group of process gas flow channels formed thereon. The channels of each group extend generally parallel to one another. The improvement comprises the process gas flow channels on the lower surface of the plate above the anode electrode and the process gas flow channels on the upper surface of the plate below the cathode electrode being skewed in opposite directions such that contact areas of the surfaces of the plates through the electrodes are formed in crisscross arrangements. Also, the plates have at least one groove in areas of the surfaces thereof where the channels are absent for holding process gas and increasing electrochemical activity of the fuel cell. The groove in each plate surface intersects with the process channels therein. Also, the opposite surfaces of a bipolar plate for a fuel cell contain first and second arrangements of process gas flow channels in the respective surfaces which are skewed the same amount in opposite directions relative to the longitudinal centerline of the plate.

  19. Random sampling of skewed distributions implies Taylor's power law of fluctuation scaling.

    PubMed

    Cohen, Joel E; Xu, Meng

    2015-06-23

    Taylor's law (TL), a widely verified quantitative pattern in ecology and other sciences, describes the variance in a species' population density (or other nonnegative quantity) as a power-law function of the mean density (or other nonnegative quantity): Approximately, variance = a(mean)(b), a > 0. Multiple mechanisms have been proposed to explain and interpret TL. Here, we show analytically that observations randomly sampled in blocks from any skewed frequency distribution with four finite moments give rise to TL. We do not claim this is the only way TL arises. We give approximate formulae for the TL parameters and their uncertainty. In computer simulations and an empirical example using basal area densities of red oak trees from Black Rock Forest, our formulae agree with the estimates obtained by least-squares regression. Our results show that the correlated sampling variation of the mean and variance of skewed distributions is statistically sufficient to explain TL under random sampling, without the intervention of any biological or behavioral mechanisms. This finding connects TL with the underlying distribution of population density (or other nonnegative quantity) and provides a baseline against which more complex mechanisms of TL can be compared. PMID:25852144

  20. BRIDGE: National Marine Educators Association

    NSDL National Science Digital Library

    The National Marine Educators Association (NMEA) is composed of professionals from a variety of fields interested in the enjoyment and study of the world's fresh and salt water. The NMEA website is maintained by the Virginia Institute of Marine Science's Bridge Project, an ocean sciences teacher resource center (reported on in the Scout Report for Science & Engineering, February 2, 1999). The NMEA website offers a bulletin board and the Scuttlebutt email list to facilitate informal communication between marine educators, scientists, and marine enthusiasts. The site also offers information about joining NMEA and includes links to their many regional chapter sites. In addition, the website links to information about NMEA history; officers and committees; scholarships and awards; and the upcoming 2005 conference in Hawaii.