Seismic response of skewed RC box-girder bridges
NASA Astrophysics Data System (ADS)
Abdel-Mohti, Ahmed; Pekcan, Gokhan
2008-12-01
It is critical to ensure the functionality of highway bridges after earthquakes to provide access to important facilities. Since the 1971 San Fernando earthquake, there has been a better understanding of the seismic performance of bridges. Nonetheless, there are no detailed guidelines addressing the performance of skewed highway bridges. Several parameters affect the response of skewed highway bridges under both service and seismic loads which makes their behavior complex. Therefore, there is a need for more research to study the effect of skew angle and other related factors on the performance of highway bridges. This paper examines the seismic performance of a three-span continuous concrete box girder bridge with skew angles from 0 to 60 degrees, analytically. Finite element (FE) and simplified beam-stick (BS) models of the bridge were developed using SAP2000. Different types of analysis were considered on both models such as: nonlinear static pushover, and linear and nonlinear time history analyses. A comparison was conducted between FE and BS, different skew angles, abutment support conditions, and time history and pushover analysis. It is shown that the BS model has the capability to capture the coupling due to skew and the significant modes for moderate skew angles. Boundary conditions and pushover load profile are determined to have a major effect on pushover analysis. Pushover analysis may be used to predict the maximum deformation and hinge formation adequately.
UNIVERSITY OF CALIFORNIA, Behavior of Typical Skewed and Curved Bridges
Mease, Kenneth D.
UNIVERSITY OF CALIFORNIA, IRVINE Behavior of Typical Skewed and Curved Bridges in Extreme Seismic.3.3.1. Sa(T1) Scaling Method 2.3.3.2. CMS Scaling Method CHAPTER 3. TYPICAL BRIDGES USED IN THIS STUDY 3-Based and Force-Based Elements 3.1.3.2. Pushover Analysis of the Bridges 3.1.3.3. OpenSees Ground Motion Treatment
Construction engineering of steel tub-girder bridge systems for skew effects
NASA Astrophysics Data System (ADS)
Jimenez Chong, Juan Manuel
Closed structural sections, such as those having circular, rectangular or trapezoidal shape, possess high rotational rigidity when compared to open sections such as I-girders. The high torsional rigidity of closed sections makes them ideal for use in highly curved bridges. In this case, the geometry of the bridge results in large torsional forces. Because of structural efficiency and economy reasons, most of these closed-section bridges consist of a trapezoidal cross-section, with a top concrete slab and bottom and side steel plates. The slab is cast after the steel is erected and thus a system of internal diaphragms and braces is necessary to stabilize the system during erection. During the steel erection and the early stages of the concrete deck placement, the section can be considered as quasi-closed as the top concrete flange has not been cast or is not yet effective. During steel erection, undetermined and/or large torsional forces and/or displacements may result in fit-up problems requiring large stresses to overcome. During concrete deck placement, the undetermined displacements can affect the control of the deck thickness and the final deck geometry, such as the alignment of deck joints and the matching of stages in phased constructions projects. Due to the interactions between their various components, the behavior of curved and skewed tub-girder bridges is significantly more complex than that of straight bridges. When skewed supports are used in tub-girders, the interaction of the girder bending rotations and the displacement constraints induced by the skewed support diaphragms causes twisting of the girders at the supports. These twist rotations introduce additional torques into the system. Both curvature and skew can cause design and construction difficulties, especially at the supports, where the corresponding steel dead load deflections and the large torsional stiffness of the girders may lead to large fit-up forces. Currently, the general understanding of the level of sophistication of analysis models required to properly predict forces and deformations of curved and/or skewed bridges during construction is limited. The development of guidelines regarding the sufficiency of simplified methods of structural analysis is the overall motivation and objective of this dissertation. This research addresses the construction load effects due to skew and due to combined skew and curvature and develops design recommendations and analytical tools for the construction engineering of tub-girder bridges. The effects of skew and curvature are studied by examining the results for different levels of analysis for 18 representative bridges. These bridges reflect the range of bridge curvature and skew used in current practice. By comparing the output from simplified analysis methods to validated refined 3D FEA solutions, general conclusions are developed as to when the simplified methods provide sufficient results. An important original contribution of this research is that the data generated constitutes the first systematic study on a large set of curved and skewed tub-girder bridges using consistent refined 3D FEA models to model construction forces and deformations. As such, the results of this research can serve as a benchmark for current and future improvements in methods of analysis and design for the construction engineering of curved and skewed tub-girder bridges. In the current research, this data has been used in both straight and curved tub-girder bridges to: • Develop a simplified 1D analysis method to account for the effect of skew on girder twist rotations and internal torques, • Evaluate the effect of skew on component forces, and propose improved simplified procedures to capture these effects, • Identify interactions between components and develop improved simplified analysis methods to account for these effects, • Establish limits for when the improved 1D and 2D simplified methods of analysis are sufficient for construction engineering analysis, and • Identify sources of steel erection fit-up proble
Skewed Slab-on-Girder Steel Bridge Superstructures with Bidirectional-Ductile End Diaphragms
Bruneau, Michel
Skewed Slab-on-Girder Steel Bridge Superstructures with Bidirectional-Ductile End Diaphragms Oguz C. Celik, A.M.ASCE1 ; and Michel Bruneau, F.ASCE2 Abstract: Specially designed ductile end diaphragms seismic input energy, protecting other substructure and superstructure members. Although ductile dia
NASA Astrophysics Data System (ADS)
Ghotbi, Abdoulreza
This study aims to investigate the behavior of skewed and straight highway overpass bridges both with and without taking into account the effects of Soil-Structure Interaction (SSI) due to near-fault ground motions. Both deterministic (i.e., pushover and nonlinear dynamic analyses) and probabilistic approaches were utilized. A set of response sensitivity analyses was performed considering various skew angles, column elements, and soil properties for bridge considered both as fixed-base and SSI models. It has been observed that as the skew angle increased, the bridge responded more severely to the ground motion. For instance, the deck rotation and shear-keys displacement increased with an increase in the skew angle. A modal pushover analysis was also performed in conjunction with the nonlinear dynamic analysis. It has been found that combining the bridge responses for various modes of vibration resulted in a relatively accurate seismic response compared to the nonlinear dynamic analysis while saving time and analysis cost, to a great extent. A probabilistic analysis was also performed considering record-to-record variability in ground motion, and a set of probabilistic seismic demand and fragility plots was generated. The effects of change in the skew angle and also SSI were studied to see various bridge responses. The damage probability increased especially with respect to deck rotation as the skew angle increased. The SSI had a decreasing effect on the overall response of the bridge with pile foundation.
NASA Astrophysics Data System (ADS)
Ghotbi, Abdoul R.
2014-09-01
The seismic behavior of skewed bridges has not been well studied compared to straight bridges. Skewed bridges have shown extensive damage, especially due to deck rotation, shear keys failure, abutment unseating and column-bent drift. This research, therefore, aims to study the behavior of skewed and straight highway overpass bridges both with and without taking into account the effects of Soil-Structure Interaction (SSI) due to near-fault ground motions. Due to several sources of uncertainty associated with the ground motions, soil and structure, a probabilistic approach is needed. Thus, a probabilistic methodology similar to the one developed by the Pacific Earthquake Engineering Research Center (PEER) has been utilized to assess the probability of damage due to various levels of shaking using appropriate intensity measures with minimum dispersions. The probabilistic analyses were performed for various bridge configurations and site conditions, including sand ranging from loose to dense and clay ranging from soft to stiff, in order to evaluate the effects. The results proved a considerable susceptibility of skewed bridges to deck rotation and shear keys displacement. It was also found that SSI had a decreasing effect on the damage probability for various demands compared to the fixed-base model without including SSI. However, deck rotation for all types of the soil and also abutment unseating for very loose sand and soft clay showed an increase in damage probability compared to the fixed-base model. The damage probability for various demands has also been found to decrease with an increase of soil strength for both sandy and clayey sites. With respect to the variations in the skew angle, an increase in skew angle has had an increasing effect on the amplitude of the seismic response for various demands. Deck rotation has been very sensitive to the increase in the skew angle; therefore, as the skew angle increased, the deck rotation responded accordingly. Furthermore, abutment unseating showed an increasing trend due to an increase in skew angle for both fixed-base and SSI models.
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....
Peggs, S.; Dell, G.F.
1994-12-31
The on-momentum description of linear coupling between horizontal and vertical betatron motion is extended to include off-momentum particles, introducing a vector quantity called the ``skew chromaticity``. This vector tends to be long in large superconducting storage rings, where it restricts the available working space in the tune plane, and modifies collective effect stability criteria. Skew chromaticity measurements at the Cornell Electron Storage Ring (CESR) and at the Fermilab Tevatron are reported, as well as tracking results from the Relativistic Heavy Ion Collider (RHIC). The observation of anomalous head-tail beam Iowa new the tune diagonal in the Tevatron are explained in terms of the extended theory, including modified criteria for headtail stability. These results are confirmed in head-tail simulations. Sources of skew chromaticity are investigated.
Bridges A bridge, also known as a fixed removable denture, is made to replace one or more missing teeth. Bridges can be supported in any of three ways: ... a combination of teeth and implants A traditional bridge is made by creating a crown for the ...
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.
NSDL National Science Digital Library
Integrated Teaching and Learning Program,
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.
4. North portal of Skew Span looking south and leading ...
4. North portal of Skew Span looking south and leading to Span 1 Main Bridge on the left and Span 1 Hot Metal Bridge on the right. - Monongahela Connecting Railroad Company, Main Bridge, Spanning Monongahela River at mile post 3.1, Pittsburgh, Allegheny County, PA
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.
Metric adjusted skew information
Frank Hansen
2008-02-21
We extend the concept of Wigner-Yanase-Dyson skew information to something we call ``metric adjusted skew information'' (of a state with respect to a conserved observable). This ``skew information'' is intended to be a non-negative quantity bounded by the variance (of an observable in a state) that vanishes for observables commuting with the state. We show that the skew information is a convex function on the manifold of states. It also satisfies other requirements, proposed by Wigner and Yanase, for an effective measure-of-information content of a state relative to a conserved observable. We establish a connection between the geometrical formulation of quantum statistics as proposed by Chentsov and Morozova and measures of quantum information as introduced by Wigner and Yanase and extended in this article. We show that the set of normalized Morozova-Chentsov functions describing the possible quantum statistics is a Bauer simplex and determine its extreme points. We determine a particularly simple skew information, the ``lambda-skew information,'' parametrized by a lambda in (0,1], and show that the convex cone this family generates coincides with the set of all metric adjusted skew informations. Key words: Skew information, convexity, monotone metric, Morozova-Chentsov function, lambda-skew information.
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. Underside of Skew SpanHot Metal system on right, toward ...
12. Underside of Skew Span-Hot Metal system on right, toward Rocker Bent. - Monongahela Connecting Railroad Company, Hot Metal Bridge, Spanning Monongahela River at mile post 3.1, Pittsburgh, Allegheny County, PA
8. Detail, skewed portal bracing at west portal, also showing ...
8. Detail, skewed portal bracing at west portal, also showing boxed endposts, latticed upper transverse and diagonal sway bracing, laced vertical members, view to northeast, 210mm lens. - Southern Pacific Railroad Shasta Route, Bridge No. 301.85, Milepost 301.85, Pollard Flat, Shasta County, CA
Inequalities for quantum skew information
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.
Hendrickson, B.; Leland, R.; Van Driessche, R.
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.
Einstein manifolds with skew torsion
Ilka Agricola; Ana Cristina Ferreira
2013-02-15
This paper is devoted to the first systematic investigation of manifolds that are Einstein for a connection with skew symmetric torsion. We derive the Einstein equation from a variational principle and prove that, for parallel torsion, any Einstein manifold with skew torsion has constant scalar curvature; and if it is complete of positive scalar curvature, it is necessarily compact and it has finite first fundamental group. The longest part of the paper is devoted to the systematic construction of large families of examples. We discuss when a Riemannian Einstein manifold can be Einstein with skew torsion. We give examples of almost Hermitian, almost metric contact, and G2 manifolds that are Einstein with skew torsion. For example, we prove that any Einstein-Sasaki manifold and any 7-dimensional 3-Sasakian manifolds admit deformations into an Einstein metric with parallel skew torsion.
Skewed Rotation Symmetry Group Detection
Seungkyu Lee; Yanxi Liu
2010-01-01
Abstract—We present a novel and effective algorithm for affinely skewed,rotation symmetry,group detection from real-world images. We define a complete,skewed,rotation symmetry,detection problem,as discovering,five independent,properties of a skewed,rotation symmetry,group: (1) the center of rotation; (2) the affine deformation; (3) the type of the symmetry,group; (4) the cardinality of the symmetry,group; and (5) the supporting,region of the symmetry,group in the image. We propose,a
Skew resisting hydrodynamic seal
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.
Stanley, Richard P.
This paper contains two results on the number f[superscript ?/?] of standard skew Young tableaux of shape ?/?. The first concerns generating functions for certain classes of "periodic" shapes related to work of Gessel-Viennot ...
Factor Analysis for Skewed Data and Skew-Normal Maximum Likelihood Factor Analysis
Gaucher, Beverly Jane
2013-04-04
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 for finite sample sizes...
Affine Circle Geometry over Quaternion Skew Fields
Nawratil, Georg
Affine Circle Geometry over Quaternion Skew Fields By Hans Havlicek Abstract We investigate the affine circle geometry arising from a quaternion skew field and one of its maximal commutative subfields]) on a field extension L/K, where K is a maximal commutative subfield of a quaternion skew field L. Thus L
SAR clutter suppression using probability density skewness
R. Fogler; L. D. Hostetler; D. R. Hush
1994-01-01
A clutter suppression algorithm is described which exploits asymmetry in the probability density function (pdf) of ground clutter in synthetic-aperture radar (SAR) imagery. In the log-magnitude domain, the probability densities of returns from natural ground clutter and man-made objects exhibit opposite skewness. Using Pearson's second coefficient of skewness, we have observed negative skewness values for natural clutter regions and positive
Kinematic correction for roller skewing
NASA Technical Reports Server (NTRS)
Savage, M.; Loewenthal, S. H.
1980-01-01
A theory of kinematic stabilization of rolling cylinders is developed for high-speed cylindrical roller bearings. This stabilization requires race and roller crowning to product changes in the rolling geometry as the roller shifts axially. These changes put a reverse skew in the rolling elements by changing the rolling taper. Twelve basic possible bearing modifications are identified in this paper. Four have single transverse convex curvature in the rollers while eight have rollers with compound transverse curvature composed of a central cylindrical band of constant radius surrounded by symmetric bands with both slope and transverse curvature.
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.
... surface of the heart. What is a myocardial bridge? A myocardial bridge is a band of heart muscle that lies ... artery, instead of underneath it. With a myocardial bridge, part of a coronary artery dips into and ...
Portfolio optimization with skewness and kurtosis
NASA Astrophysics Data System (ADS)
Lam, Weng Hoe; Jaaman, Saiful Hafizah Hj.; Isa, Zaidi
2013-04-01
Mean and variance of return distributions are two important parameters of the mean-variance model in portfolio optimization. However, the mean-variance model will become inadequate if the returns of assets are not normally distributed. Therefore, higher moments such as skewness and kurtosis cannot be ignored. Risk averse investors prefer portfolios with high skewness and low kurtosis so that the probability of getting negative rates of return will be reduced. The objective of this study is to compare the portfolio compositions as well as performances between the mean-variance model and mean-variance-skewness-kurtosis model by using the polynomial goal programming approach. The results show that the incorporation of skewness and kurtosis will change the optimal portfolio compositions. The mean-variance-skewness-kurtosis model outperforms the mean-variance model because the mean-variance-skewness-kurtosis model takes skewness and kurtosis into consideration. Therefore, the mean-variance-skewness-kurtosis model is more appropriate for the investors of Malaysia in portfolio optimization.
Geometric Skew Normal Distribution Debasis Kundu1
Kundu, Debasis
Geometric Skew Normal Distribution Debasis Kundu1 Abstract In this article we introduce a new three parameter skewed distribution of which normal distribution is a special case. This distribution is obtained by using geometric sum of independent identically distributed normal random variables. We call this dis
Petersen-Gauthier, Joel
2013-08-09
Transverse load distribution behavior amongst bridge girders is influenced by many parameters including girder material properties, spacing, skew, deck design, and stiffening element interactions. In order to simply and ...
NSDL National Science Digital Library
Museum of Science and Industry, Chicago
2012-01-01
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.
CLOCK SKEW ON DRAM/LOGIC MERGED TECHNOLOGY BASED SYSTEMS
Ayers, Joseph
CLOCK SKEW ON DRAM/LOGIC MERGED TECHNOLOGY BASED SYSTEMS Yong-Bin Kim* Tom Chen** *Engineering This paper describes the clock skew estimations considering all the possible clock skew factors on DRAM/Logic merged systems. The clock skew dif- ference between standard logic chip and DRAM/Logic merged chi s has
Clock Skew Scheduling with Delay Padding for Prescribed Skew Domains Chuan Lin Hai Zhou
Zhou, Hai
-flop such that the clock period is min- imized with possible delay padding. Experimental results validate the efficiencyClock Skew Scheduling with Delay Padding for Prescribed Skew Domains Chuan Lin Hai Zhou EECS of our algorithm and show 17% im- provement on average in clock period. 1 Introduction In a sequential
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.
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.
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.
Modular classes of skew algebroid relations
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.
Persistent skewness of a strongly active scalar.
Zhang, Jie; Wu, X L
2009-04-01
We present a skewness measurement of the density fluctuations deltarho[over ]_{l} on scales l in a vertical turbulent soap film driven by a temperature gradient. Unlike the temperature difference deltaT_{l} in Rayleigh-Bénard convection, the density difference in the film is strongly active because deltarho[over ]_{l}/rho[over ]>deltaT_{l}T[over ] , where the over-bar indicates the mean. Our results show persistent nonzero skewness S_{y}(l) identical with
Persistent skewness of a strongly active scalar
NASA Astrophysics Data System (ADS)
Zhang, Jie; Wu, X. L.
2009-04-01
We present a skewness measurement of the density fluctuations ??˜l on scales l in a vertical turbulent soap film driven by a temperature gradient. Unlike the temperature difference ?Tl in Rayleigh-Bénard convection, the density difference in the film is strongly active because ??˜l/?¯??Tl/ Tmacr , where the over-bar indicates the mean. Our results show persistent nonzero skewness Sy(l)????˜l3?/???˜l2?3/2 on different scales along the gravity direction ? ; Sy(l) is positive for small l and negative for large l . The sign switch occurs approximately at the Bolgiano length scale lB . The simultaneous presence of positive and negative skewnesses is interpreted here as a result of the structures of rising and falling plumes in a strongly stratified medium.
Skew scattering in dilute ferromagnetic alloys
NASA Astrophysics Data System (ADS)
Zimmermann, Bernd; Chadova, Kristina; Ködderitzsch, Diemo; Blügel, Stefan; Ebert, Hubert; Fedorov, Dmitry V.; Long, Nguyen H.; Mavropoulos, Phivos; Mertig, Ingrid; Mokrousov, Yuriy; Gradhand, Martin
2014-12-01
The challenging problem of skew scattering for Hall effects in dilute ferromagnetic alloys, with intertwined effects of spin-orbit coupling, magnetism, and impurity scattering, is studied here from first principles. Our main aim is to identify chemical trends and work out simple rules for large skew scattering in terms of the impurity and host states at the Fermi surface, with particular emphasis on the interplay of the spin and anomalous Hall effects in one and the same system. The predicted trends are benchmarked by referring to three different ab initio methods based on different approximations with respect to the electronic structure and transport properties.
Preference patterns for skewed gambles in rhesus monkeys.
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
BIODIVERSITY Land use patterns skew sex ratios,
BIODIVERSITY RESEARCH Land use patterns skew sex ratios, decrease genetic diversity and trump, Madison, WI 53706, USA. E-mail: bnreid@wisc.edu ABSTRACT Aim Changes in both land use and climate can. We used both sex data and genetic diversity across a landscape-scale gradient in land use intensity
Symmetry detection through local skewed symmetries
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
NORMALITY AND SKEWNESS OF GENETIC EVALUATIONS
Technology Transfer Automated Retrieval System (TEKTRAN)
Linear models are used for evaluation of linear, normally distributed traits such as milk yield. Traits (e.g. somatic cell count) with skewed distributions are normalized through log or other simple transformation. Traits with nonlinear, non-normal distributions have gained importance, and alternati...
Multi-slice FE modeling of electrical machines with skewed slots-the skew discretization error
Johan J. C. Gyselinck; Lieven Vandevelde; Jan A. A. Melkebeek
2001-01-01
The simulation of rotating electrical machines with skewed slots by means of a multi-slice FE model is studied. Particular attention is devoted to the ensuing skew discretization error. As an alternative to the commonly adopted uniform distribution of the cross-sections along the shaft, a Gauss distribution is proposed. The application to a squirrel-cage induction motor under various working conditions shows
NSDL National Science Digital Library
2014-09-18
Working as engineering teams, students design and create model beam bridges using plastic drinking straws and tape as their construction materials. Their goal is to build the strongest bridge with a truss pattern of their own design, while meeting the design criteria and constraints. They experiment with different geometric shapes and determine how shapes affect the strength of materials. Let the competition begin!
NASA Technical Reports Server (NTRS)
1977-01-01
Safer bridges are among a number of spinoff benefits from NASA procedures for testing 'cfracture toughness" of a structural part, meaning its ability to -siscracktsh at might cause failure. The New River Bridge in West Virginia, shown under construction, is the world's largest single span bridge. U.S. Steel fracture toughness requirements for such bridges include NASA-developed test procedures. Bridge materials and other metal structures may develop flaws during their service lifetimes. Such flaws can affect the structural integrity of the part. Thus, it is important to know the "fracture toughness" of a structural part, or its ability to resist cracks. NASA has long experience in developing fracture toughness tests for aerospace hardware. Since 1960, NASA-Lewis has worked closely with the American Society for Testing & Materials. Lewis and NASA-funded industrial contractors have made many important contributions to test procedures, now recommended by ASTM, for measuring fracture toughness.
Skewness Premium with L\\'evy Processes
Fajardo, José
2008-01-01
We study the skewness premium (SK) introduced by Bates (1991) in a general context using L\\'evy Processes. Under a symmetry condition Fajardo and Mordecki (2006) obtain that SK is given by the Bate's $x%$ rule. In this paper we study SK under the absence of that symmetry condition. More exactly, we derive sufficient conditions for SK to be positive, in terms of the characteristic triplet of the L\\'evy Process under the risk neutral measure.
Vibration suppression of a skew cantilever plate using PZT patches
NASA Astrophysics Data System (ADS)
Pai, Perngjin F.; Rommel, Bernd; Naser, Ahmad S.; Schulz, Mark J.
1998-07-01
We investigate the control of steady-state vibrations of a cantilevered skew isotropic plate by using nonlinear saturation phenomena and PZT (lead zirconate titanate) patches as sensors and actuators. Modal testing and finite- element analysis are performed to study the bending- torsional dynamic characteristics due to the non-rectangular plate geometry. The control method uses linear second-order controllers coupled to the plate via quadratic terms to establish energy bridges between the plate and controllers. Each linear second-order controller is designed to have a 1:2 internal resonance with one of the plate vibration modes and hence is able to exchange energy with the plate at or around the specific modal frequency. Because of quadratic nonlinearities and 1:2 internal resonances, saturation phenomena exist and are used to suppress modal vibrations. To test this control technique in an efficient and systematic way, we built a digital control system that consists of SIMULINK modeling software and a dSPACE DS1102 controller in a pentium computer. Both numerical and experimental results show that this nonlinear control method is robust in suppression steady-state resonant vibrations without significant spill-over effects.
Analysis of Parasite and Other Skewed Counts
Alexander, Neal
2012-01-01
Objective To review methods for the statistical analysis of parasite and other skewed count data. Methods Statistical methods for skewed count data are described and compared, with reference to those used over a ten year period of Tropical Medicine and International Health. Two parasitological datasets are used for illustration. Results Ninety papers were identified, 89 with descriptive and 60 with inferential analysis. A lack of clarity is noted in identifying measures of location, in particular the Williams and geometric mean. The different measures are compared, emphasizing the legitimacy of the arithmetic mean for skewed data. In the published papers, the t test and related methods were often used on untransformed data, which is likely to be invalid. Several approaches to inferential analysis are described, emphasizing 1) non-parametric methods, while noting that they are not simply comparisons of medians, and 2) generalized linear modelling, in particular with the negative binomial distribution. Additional methods, such as the bootstrap, with potential for greater use are described. Conclusions Clarity is recommended when describing transformations and measures of location. It is suggested that non-parametric methods and generalized linear models are likely to be sufficient for most analyses. PMID:22943299
Unknown
2011-09-05
The objective of this thesis is to determine fatigue stresses in the stringer to floor beam connections of through plate girder (TPG) and through truss (TT) bridges in order to predict failure. Field observations by the Association of American...
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.
Skew quad compensation for SPEAR minibeta optics
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.
Multivariate Skew-t Distributions in Econometrics and Environmetrics
Marchenko, Yulia V.
2012-02-14
likelihood estimators for this model. We compare the performance of the selection-t model to the Heckman selection model and apply it to analyze ambulatory expenditures. iv In the second article we introduce a family of multivariate log-skew-elliptical dis... prop- erties. We demonstrate, for example, that as for the log-t distribution, the positive moments of the log-skew-t distribution do not exist. Our emphasis is on two special cases, the log-skew-normal and log-skew-t distributions, which we use...
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.
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.
Temperature-Compensated Clock Skew Adjustment
Castillo-Secilla, Jose María; Palomares, Jose Manuel; Olivares, Joaquín
2013-01-01
This work analyzes several drift compensation mechanisms in wireless sensor networks (WSN). Temperature is an environmental factor that greatly affects oscillators shipped in every WSN mote. This behavior creates the need of improving drift compensation mechanisms in synchronization protocols. Using the Flooding Time Synchronization Protocol (FTSP), this work demonstrates that crystal oscillators are affected by temperature variations. Thus, the influence of temperature provokes a low performance of FTSP in changing conditions of temperature. This article proposes an innovative correction factor that minimizes the impact of temperature in the clock skew. By means of this factor, two new mechanisms are proposed in this paper: the Adjusted Temperature (AT) and the Advanced Adjusted Temperature (A2T). These mechanisms have been combined with FTSP to produce AT-FTSP and A2T-FTSP Both have been tested in a network of TelosB motes running TinyOS. Results show that both AT-FTSP and A2T-FTSP improve the average synchronization errors compared to FTSP and other temperature-compensated protocols (Environment-Aware Clock Skew Estimation and Synchronization for WSN (EACS) and Temperature Compensated Time Synchronization (TCTS)). PMID:23966192
ERIC Educational Resources Information Center
Zito, Michael, Ed.
1999-01-01
This document is comprised of the two issues in volume 4 of "Bridges," a publication produced by the California Head Start-State Collaboration Office to detail the activities of the educational partnership and to provide relevant information to programs participating in the partnership. The spring 1999 issue focuses on the service system for…
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,…
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)
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
Analysis of carbon dioxide concentration skewness at a rural site.
Pérez, Isidro A; Sánchez, M Luisa; García, M Ángeles; Ozores, Marta; Pardo, Nuria
2014-04-01
This paper provides evidence that symmetry of CO2 concentration distribution may indicate sources or dispersive processes. Skewness was calculated by different procedures with CO2 measured at a rural site using a Picarro G1301 analyser over a two-year period. The usual skewness coefficient was considered together with fourteen robust estimators. A noticeable contrast was obtained between day and night, and skewness decreased linearly with the logarithm of the height. One coefficient was selected from its satisfactory relationship with the median concentration in daily evolution. Three analyses based on the kernel smoothing method were conducted with this coefficient to investigate its response to yearly and daily evolutions, wind direction, and wind speed. Left-skewed distributions were linked to thermal turbulence during midday, especially in spring-summer, or with high wind speeds. Almost symmetric distributions were associated with sources, such as the Valladolid City plume reinforced with spring emissions and the lack of emissions in summer in the remaining directions. Finally, right-skewed distributions were related to low wind speeds and stable stratification at night, furthered by strong emissions in spring. Skewness intervals were proposed and their average median concentrations were calculated such that the relationship between skewness and concentration depends on the analysis performed. Since some skewness coefficients may also be negative, they provide better information about sources or dispersive processes than concentration. PMID:24463252
Integrated Placement and Skew Optimization for Rotary Clocking
Hu, Jiang
Integrated Placement and Skew Optimization for Rotary Clocking Ganesh Venkataraman1 , Jiang Hu1 , Frank Liu2 and C-N. Sze2 1 Dept. of Electrical Engineering, Texas A&M University, College Station, TX transmission lines to save power and reduce skew variability. Despite its appealing ad- vantages, rotary
A Method for Controlling Skew on Linked Surfaces
BENZLEY,STEVEN E.; KERR,ROBERT A.; MITCHELL,SCOTT A.; WHITE,DAVID R.
1999-09-27
A new method for lessening skew in mapped meshes is presented. This new method involves progressive subdivision of a surface into loops consisting of four sides. Using these loops, constraints can then be set on the curves of the surface, which will propagate interval assignments across the surface, allowing a mesh with a better skew metric to be generated.
Learning a Novel Pattern through Balanced and Skewed Input
ERIC Educational Resources Information Center
McDonough, Kim; Trofimovich, Pavel
2013-01-01
This study compared the effectiveness of balanced and skewed input at facilitating the acquisition of the transitive construction in Esperanto, characterized by the accusative suffix "-n" and variable word order (SVO, OVS). Thai university students (N = 98) listened to 24 sentences under skewed (one noun with high token frequency) or…
Period and Glitch Reduction Via Clock Skew Scheduling, Delay Padding
Lemieux, Guy
Period and Glitch Reduction Via Clock Skew Scheduling, Delay Padding and GlitchLess by Xiao Dong B named GlitchLess, or to improve performance via clock skew scheduling (CSS) and delay padding (DP. Although delay padding only benefits a few circuits, the average improvement of those circuits
Nonuniform Behaviors for Skew-Evolution Semiflows in Banach
Paris-Sud XI, Université de
Nonuniform Behaviors for Skew-Evolution Semiflows in Banach Spaces Codrut¸a Stoica Mihail Megan Abstract. The paper emphasizes some asymptotic behaviors for skew-evolution semi- flows in Banach spaces was also defined and characterized the trichotomy on Banach spaces in [5]. Concerning previous results, C
EXPLOSION POINTS IN SKEW MAPS Anne Stefanie Costolanski
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
IS THE SKEWNESS OF THE DISTRIBUTION OF TEMPERATURE INCREASING?
Katz, Richard
) Application to Temperature (5) Conclusions #12;3 IPCC SREX Report (2012) #12;4 (1) Motivation Recent research;2 Outline (1) Motivation (2) Calculation of Skewness (3) Properties of Mixtures of Distributions (4 components N(-1, 1) & N(1, 2 2 ) with mixing weight of 1 / 2 -- Skew 0.69 #12;9 #12;10 Mixture model
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.
Incorporating covariates in skewed functional data models.
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
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.)
NSDL National Science Digital Library
Twin Cities Public Television, Inc.
2008-01-01
This is a quick activity (on page 2 of the PDF) about how the arrangement of carbon atoms determines carbon's different properties. Learners will build bridges with Post-It notes that model two types of carbon molecules, graphite and carbon nanotubes, and test which structure of the same material can bear the weight of the most pennies. Also relates to linked video, DragonflyTV Nano: Hockey Sticks.
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.
The affective impact of financial skewness on neural activity and choice.
Wu, Charlene C; Bossaerts, Peter; Knutson, Brian
2011-01-01
Few finance theories consider the influence of "skewness" (or large and asymmetric but unlikely outcomes) on financial choice. We investigated the impact of skewed gambles on subjects' neural activity, self-reported affective responses, and subsequent preferences using functional magnetic resonance imaging (FMRI). Neurally, skewed gambles elicited more anterior insula activation than symmetric gambles equated for expected value and variance, and positively skewed gambles also specifically elicited more nucleus accumbens (NAcc) activation than negatively skewed gambles. Affectively, positively skewed gambles elicited more positive arousal and negatively skewed gambles elicited more negative arousal than symmetric gambles equated for expected value and variance. Subjects also preferred positively skewed gambles more, but negatively skewed gambles less than symmetric gambles of equal expected value. Individual differences in both NAcc activity and positive arousal predicted preferences for positively skewed gambles. These findings support an anticipatory affect account in which statistical properties of gambles--including skewness--can influence neural activity, affective responses, and ultimately, choice. PMID:21347239
Taylor, Mark
SAMP Bridge Mark Taylor (AstroGrid, Bristol) IVOA Interop Meeting, ESO 9 November 2009 $Id: bridge/9 #12;Operation 1. Two independent hubs are running 2. Bridge starts up, connects to both hubs Mark are running 2. Bridge starts up, connects to both hubs 3. Proxies for Hub 2 clients, controlled by Bridge
Role of skew-symmetric differential forms in mathematics
L. I. Petrova
2010-04-05
Skew-symmetric forms possess unique capabilities. The properties of closed exterior and dual forms, namely, invariance, covariance, conjugacy and duality, either explicitly or implicitly appear in all invariant mathematical formalisms. This enables one to see an internal connection between various branches of mathematics. However, the theory of closed exterior forms cannot be completed without an answer to a question of how the closed exterior forms emerge. In the present paper we discus essentially new skew-symmetric forms, which generate closed exterior forms. Such skew-symmetric forms, which are evolutionary ones, are derived from differential equations, and, in contrast to exterior forms, they are defined on nonintegrable manifolds.
Spin Hall Effects Due to Phonon Skew Scattering
NASA Astrophysics Data System (ADS)
Gorini, Cosimo; Eckern, Ulrich; Raimondi, Roberto
2015-08-01
A diversity of spin Hall effects in metallic systems is known to rely on Mott skew scattering. In this work its high-temperature counterpart, phonon skew scattering, which is expected to be of foremost experimental relevance, is investigated. In particular, the phonon skew scattering spin Hall conductivity is found to be practically T independent for temperatures above the Debye temperature TD. As a consequence, in Rashba-like systems a high-T linear behavior of the spin Hall angle demonstrates the dominance of extrinsic spin-orbit scattering only if the intrinsic spin splitting is smaller than the temperature.
Spin Hall Effects Due to Phonon Skew Scattering.
Gorini, Cosimo; Eckern, Ulrich; Raimondi, Roberto
2015-08-14
A diversity of spin Hall effects in metallic systems is known to rely on Mott skew scattering. In this work its high-temperature counterpart, phonon skew scattering, which is expected to be of foremost experimental relevance, is investigated. In particular, the phonon skew scattering spin Hall conductivity is found to be practically T independent for temperatures above the Debye temperature T_{D}. As a consequence, in Rashba-like systems a high-T linear behavior of the spin Hall angle demonstrates the dominance of extrinsic spin-orbit scattering only if the intrinsic spin splitting is smaller than the temperature. PMID:26317737
Unknown
2011-09-05
Resistive bridging faults in CMOS combinational circuits are studied in this work. Bridging faults are modeled using HSPICE circuit simulation of the various types of bridging faults that can occur in CMOS combinational circuits. The results...
Systems of Differential Equations with Skew-Symmetric, Orthogonal Matrices
ERIC Educational Resources Information Center
Glaister, P.
2008-01-01
The solution of a system of linear, inhomogeneous differential equations is discussed. The particular class considered is where the coefficient matrix is skew-symmetric and orthogonal, and where the forcing terms are sinusoidal. More general matrices are also considered.
7. William E. Barrett, Photographer, 1974. SKEWED VIEW SHOWING CHEAT ...
7. William E. Barrett, Photographer, 1974. SKEWED VIEW SHOWING CHEAT RIVER VALLEY, REMAINS OF 1887 PIER AND c. 1900 MASONRY ARCHES. - Baltimore & Ohio Railroad, Tray Run Viaduct, Spanning Tray Run, Rowlesburg, Preston County, WV
Uncertainty relation on Wigner-Yanase-Dyson skew information
Yanagi, Kenjiro
2009-01-01
We give a trace inequality related to the uncertainty relation of Wigner-Yanase-Dyson skew information. This inequality corresponds to a generalization of the uncertainty relation derived by S. Luo for the quantum uncertainty quantity excluding the classical mixture.
Asymmetric skew Bessel processes and their applications to finance
NASA Astrophysics Data System (ADS)
Decamps, Marc; Goovaerts, Marc; Schoutens, Wim
2006-02-01
In this paper, we extend the Harrison and Shepp's construction of the skew Brownian motion (1981) and we obtain a diffusion similar to the two-dimensional Bessel process with speed and scale densities discontinuous at one point. Natural generalizations to multi-dimensional and fractional order Bessel processes are then discussed as well as invariance properties. We call this family of diffusions asymmetric skew Bessel processes in opposition to skew Bessel processes as defined in Barlow et al. [On Walsh's Brownian motions, Seminaire de Probabilities XXIII, Lecture Notes in Mathematics, vol. 1372, Springer, Berlin, New York, 1989, pp. 275-293]. We present factorizations involving (asymmetric skew) Bessel processes with random time. Finally, applications to the valuation of perpetuities and Asian options are proposed.
Quantifying morphology changes in time series data with skew
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 ...
PERSPECTIVES Biodiversity loss, trophic skew and ecosystem functioning
Duffy, J. Emmett
implications for conservation. Keywords Biodiversity, conservation, ecosystem functioning, extinction, trophicIDEAS AND PERSPECTIVES Biodiversity loss, trophic skew and ecosystem functioning J. Emmett Duffy biodiversity effects on ecosystem functioning have been criticized on the basis that their random
Skewness as a probe of non-Gaussian initial conditions
Ruth Durrer; Roman Juszkiewicz; Martin Kunz; Jean-Philippe Uzan
2000-05-04
We compute the skewness of the matter distribution arising from non-linear evolution and from non-Gaussian initial perturbations. We apply our result to a very generic class of models with non-Gaussian initial conditions and we estimate analytically the ratio between the skewness due to non-linear clustering and the part due to the intrinsic non-Gaussianity of the models. We finally extend our estimates to higher moments.
Arnold-Chiari malformation and nystagmus of skew
Christina Pieh; Irene Gottlob
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
THE TRUSS BRIDGE SEGMENT OF THE TRIBOROUGH BRIDGE IN FOREGROUND ...
THE TRUSS BRIDGE SEGMENT OF THE TRIBOROUGH BRIDGE IN FOREGROUND AND THE HELL GATE BRIDGE IN THE BACKGROUND ADJACENT TO THE SUSPENSION SEGMENT OF THE TRIBOROUGH BRIDGE. - Triborough Bridge, Passing through Queens, Manhattan & the Bronx, Queens (subdivision), Queens County, NY
Rényi entropy and complexity measure for skew-gaussian distributions and related families
NASA Astrophysics Data System (ADS)
Contreras-Reyes, Javier E.
2015-09-01
In this paper, we provide the Rényi entropy and complexity measure for a novel, flexible class of skew-gaussian distributions and their related families, as a characteristic form of the skew-gaussian Shannon entropy. We give closed expressions considering a more general class of closed skew-gaussian distributions and the weighted moments estimation method. In addition, closed expressions of Rényi entropy are presented for extended skew-gaussian and truncated skew-gaussian distributions. Finally, additional inequalities for skew-gaussian and extended skew-gaussian Rényi and Shannon entropies are reported.
Flow in Rotating Serpentine Coolant Passages With Skewed Trip Strips
NASA Technical Reports Server (NTRS)
Tse, David G.N.; Steuber, Gary
1996-01-01
Laser velocimetry was utilized to map the velocity field in serpentine turbine blade cooling passages with skewed trip strips. The measurements were obtained at Reynolds and Rotation numbers of 25,000 and 0.24 to assess the influence of trips, passage curvature and Coriolis force on the flow field. The interaction of the secondary flows induced by skewed trips with the passage rotation produces a swirling vortex and a corner recirculation zone. With trips skewed at +45 deg, the secondary flows remain unaltered as the cross-flow proceeds from the passage to the turn. However, the flow characteristics at these locations differ when trips are skewed at -45 deg. Changes in the flow structure are expected to augment heat transfer, in agreement with the heat transfer measurements of Johnson, et al. The present results show that trips are skewed at -45 deg in the outward flow passage and trips are skewed at +45 deg in the inward flow passage maximize heat transfer. Details of the present measurements were related to the heat transfer measurements of Johnson, et al. to relate fluid flow and heat transfer measurements.
NSDL National Science Digital Library
This wonderful site, provided by NOVA Online, brings to life the engineering challenges inherent to bridge-building. Designed for those who want the challenge, the site offers four bridging scenarios (with photos): "a 5,000-foot span across an ocean bay where huge ships come and go, ... a 700-foot span across a deep canyon gorge," and two others. A step-by-step tutorial teaches about four different bridge types (arch, beam, suspension, and cable-stayed), after which the user may select a bridge type for each scenario. The site is enhanced by links to other bridge resources, such as the famous bridge-building disaster of the century (Tacoma Narrows Bridge) and the Golden Gate Bridge site, which in turn, links users to other famous bridges including Japan's brand new Akashi Kaikyo Bridge, the longest bridge in the world.
Sagamore Bridge Richard Mitchell
Nagurney, Anna
Sagamore Bridge Richard Mitchell Justin Murphy (DJ) Dennis Morin Jr. #12;Critical Link in a Fragile for Infrastructure Two cantilever bridges and a railroad bridge were constructed Drawbacks: Provided narrow passageways for ships Traffic delays when the bridge was raised #12;Canal Transfer of Ownership Belmont
NSDL National Science Digital Library
Integrated Teaching and Learning Program, College of Engineering,
Students are presented with a brief history of bridges as they learn about the three main bridge types: beam, arch and suspension. They are introduced to two natural forces — tension and compression — common to all bridges and structures. Throughout history, and today, bridges are important for connecting people to resources, places and other people. Students become more aware of the variety and value of bridges around us in our everyday lives.
ALEXANDER HAMILTON BRIDGE (FOREGROUND) AND WASHINGTON BRIDGE (BACKGROUND) SPANNING THE ...
ALEXANDER HAMILTON BRIDGE (FOREGROUND) AND WASHINGTON BRIDGE (BACKGROUND) SPANNING THE HARLEM RIVER - Alexander Hamilton Bridge, Spanning Harlem River between Bronx & Manhattan, Bronx, Bronx County, NY
Latitudinal skewness in global EQ distributions
NASA Astrophysics Data System (ADS)
Sasorova, E.; Levin, B.
2009-04-01
The results of statistical analysis of worldwide seismic catalogs (ISC and NEIC), which was carried out in frame of two projects are presented. In both cases we extracted the evens occurred in the Pacific region from 1964 with Mb>=4.0. The aftershocks were canceled from the list. All events were divided into following magnitude ranges (MR): 4<=Mb<4.5; 4.5<=Mb<5; 5<=Mb<5.5; 5.5<=Mb<6.0; 6<=Mb. Further analysis was performed separately for each MR. In frame of the first project [Levin, Sasorova, 2009] the whole Pacific region was divided in 18 latitudinal intervals (size of every interval was 10 deg). The number of events in each latitudinal interval was normalized two times. The first one number of events was divided on common number of events in given MR. It was calculated relative number of events in each latitudinal interval for given MR. Then normalization was produced with respect to the length of lithosphere plate boundaries situated in given latitude zone. The approach gives the characteristic of seismicity for lithosphere plate boundary, i.e. seismic event number which was generated at unit of length of plate boundary. An analysis of the Pacific earthquake latitude distribution showed that the empirical distribution is described by a bimodal function with two maxima in middle latitudes (40-50 deg N and 20-30 deg S), local minimum near equator (10-20 deg N), and zero values in polar zones. Thus the bimodal latitudinal EQ distribution shows clear expressed skewness (in direction to the Northern Hemisphere). The stability of distributions from the observation interval size was demonstrated on the data independence analysis for several ten-year intervals. Then it was carried out the analysis about statistically valid regularity of the EQ distribution over depth and over latitudinal belts for different magnitude ranges (MR). It was shown, that for the high latitudes up to 90% of the EQ sources are located on the depth H<=20 km. The part of EQ with 20
Power and Skew Aware Point Diffusion Clock Network
NASA Astrophysics Data System (ADS)
Jung, Gunok; Kim, Chunghee; Chae, Kyoungkuk; Park, Giho; Park, Sung Bae
This letter presents point diffusion clock network (PDCN) with local clock tree synthesis (CTS) scheme. The clock network is implemented with ten times wider metal line space than typical mesh networks for low power and utilized to nine times smaller area CTS execution for minimized clock skew amount. The measurement results show that skew amount of PDCN with local CTS is reduced to 36% and latency is shrunk to 45% of the amount in a 4.81mm2 CortexA-8 core with 65nm Samsung process.
1. ONEONTA GORGE CREEK BRIDGE, VIEW LOOKING SOUTH. OLD BRIDGE ...
1. ONEONTA GORGE CREEK BRIDGE, VIEW LOOKING SOUTH. OLD BRIDGE IN BACKGROUND. NEW BRIDGE IN FOREGROUND. - Historic Columbia River Highway, Oneonta Gorge Creek Bridge, Spanning Oneonta Gorge Creek, Troutdale, Multnomah County, OR
Bridging consent: from toll bridges to lift bridges?
2011-01-01
Background The ability to share human biological samples, associated data and results across disease-specific and population-based human research biobanks is becoming increasingly important for research into disease development and translation. Although informed consent often does not anticipate such cross-domain sharing, it is important to examine its plausibility. The purpose of this study was to explore the feasibility of bridging consent between disease-specific and population-based research. Comparative analyses of 1) current ethical and legal frameworks governing consent and 2) informed consent models found in disease-specific and population-based research were conducted. Discussion Ethical and legal frameworks governing consent dissuade cross-domain data sharing. Paradoxically, analysis of consent models for disease-specific and population-based research reveals such a high degree of similarity that bridging consent could be possible if additional information regarding bridging was incorporated into consent forms. We submit that bridging of consent could be supported if current trends endorsing a new interpretation of consent are adopted. To illustrate this we sketch potential bridging consent scenarios. Summary A bridging consent, respectful of the spirit of initial consent, is feasible and would require only small changes to the content of consents currently being used. Under a bridging consent approach, the initial data and samples collection can serve an identified research project as well as contribute to the creation of a resource for a range of other projects. PMID:21970509
Bridging Centrality: Identifying Bridging Nodes In Scale-free Networks
Krovi, Venkat
centrality, based on information flow and topological locality in scale-free net- works. Bridging centralityBridging Centrality: Identifying Bridging Nodes In Scale-free Networks Woochang Hwang Young, Philadelphia, PA, USA Scale-free network, centrality, bridging node, bridging coef- ficient, bridging
Arc voltage distribution skewness as an indicator of electrode gap during vacuum arc remelting
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.
Dissociable Influences of Skewness and Valence on Economic Choice and Neural Activity
Wright, Nicholas D.; Symmonds, Mkael; Morris, Laurel S.; Dolan, Raymond J.
2013-01-01
Asymmetry in distributions of potential outcomes (i.e. skewness), and whether those potential outcomes reflect gains or losses (i.e. their valence), both exert a powerful influence on value-based choice. How valence affects the impact of skewness on choice is unknown. Here by orthogonally manipulating the skewness and valence of economic stimuli we show that both have an influence on choice. We show that the influence of skewness on choice is independent of valence, both across and within subjects. fMRI data revealed skew-related activity in bilateral anterior insula and dorsomedial prefrontal cortex, which shows no interaction with valence. Further, the expression of skew-related activity depends on an individual’s preference for skewness, and this was again independent of valence-related preference. Our findings highlight the importance of skewness in choice and show that its influence, both behaviourally and neurally, is distinct from an influence of valence. PMID:24376705
Dissociable influences of skewness and valence on economic choice and neural activity.
Wright, Nicholas D; Symmonds, Mkael; Morris, Laurel S; Dolan, Raymond J
2013-01-01
Asymmetry in distributions of potential outcomes (i.e. skewness), and whether those potential outcomes reflect gains or losses (i.e. their valence), both exert a powerful influence on value-based choice. How valence affects the impact of skewness on choice is unknown. Here by orthogonally manipulating the skewness and valence of economic stimuli we show that both have an influence on choice. We show that the influence of skewness on choice is independent of valence, both across and within subjects. fMRI data revealed skew-related activity in bilateral anterior insula and dorsomedial prefrontal cortex, which shows no interaction with valence. Further, the expression of skew-related activity depends on an individual's preference for skewness, and this was again independent of valence-related preference. Our findings highlight the importance of skewness in choice and show that its influence, both behaviourally and neurally, is distinct from an influence of valence. PMID:24376705
Unknown
2011-08-17
Bridging defects which occur in CMOS complementary gates (rather than ratioed logic gates) are investigated. Realistic bridging defects are shown to exist which are non-Iddq testable, but which can be deterministically ...
Reproductive skew in female common marmosets: what can proximate mechanisms
Saltzman, Wendy
or mating interference by dominants and do not exhibit behavioural or physiological signs of stress-imposed by most subordinates, consistent with restraint models of reproductive skew. In contrast to restraint appears to be generated predominantly by subordinate self-restraint, in a proximate sense, but ultimately
A mean-absolute deviation-skewness portfolio optimization model
Hiroshi Konno; Hiroshi Shirakawa; Hiroaki Yamazaki
1993-01-01
It is assumed in the standard portfolio analysis that an investor is risk averse and that his utility is a function of the mean and variance of the rate of the return of the portfolio or can be approximated as such. It turns out, however, that the third moment (skewness) plays an important role if the distribution of the rate
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.
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.
Casting with Skewed Ejection Direction Hee-Kap Ahn1
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
Managing Skew in Hadoop YongChul Kwon1
Managing Skew in Hadoop YongChul Kwon1 , Kai Ren2 , Magdalena Balazinska1 , and Bill Howe1 1 processing engine. Hadoop and other popular systems have been shown to provide a convenient programming model user-defined operations (UDOs). The MapReduce abstraction [4] and its implementation in Hadoop [9
Assistant detection of skewed data streams classification in cloud security
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
Boosting First-Order Clauses for Large, Skewed Data Sets
Shavlik, Jude W.
Boosting First-Order Clauses for Large, Skewed Data Sets Louis Oliphant1,3 , Elizabeth Burnside2 in such a way as to maximize predictive performance. We have adapted the RankBoost algorithm in order by our modied RankBoost algorithm beyond using individual clauses. We provide results on four large
Risk Forecasting with GARCH, Skewed t Distributions, and Multiple Timescales
Risk Forecasting with GARCH, Skewed t Distributions, and Multiple Timescales Alec N. Kercheval fore- casts of risk, such as value at risk (VaR). Provided there is enough data, this can be done this we introduce a multiple timescale approach, where risk forecasts at a longer timescale
Modelling health scores with the skew-normal distribution
J. L. Hutton; E. Stanghellini
Health care interventions which use quality of life or health scores often provide data which are skewed and bounded. The scores are typically formed by adding up responses to a number of questions. Different questions might have different weights, but the scores will be bounded, and are often scaled to the range 0 to 100. If improvement in health over
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
STEM Bridge Scholarship Program
Virginia Tech
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 of the five Virginia Space Grant member universities. As a STEM Bridge Scholar, students are welcomed
A low nasal bridge is a flattening of the top part of the nose. ... Decreased growth (hypoplasia) of the nasal bridge may due to infections or genetic diseases. A decrease in the height of the nasal bridge is best seen from a side ...
Analysis of stability and accuracy of finite-difference schemes on a skewed mesh
Mittal, Rajat
Analysis of stability and accuracy of finite-difference schemes on a skewed mesh Donghyun You a and accuracy of finite-difference schemes on a skewed non-uniform mesh are investigated to pro- vide guidelines for mesh design and for devising appropriate solution methods when mesh skewness is unavoidable
COMPLEX STATIC SKEW-SYMMETRIC OUTPUT FEEDBACK CHRISTOPHER J. HILLAR AND FRANK SOTTILE
Sottile, Frank
COMPLEX STATIC SKEW-SYMMETRIC OUTPUT FEEDBACK CONTROL CHRISTOPHER J. HILLAR AND FRANK SOTTILE functions using skew-symmetric controllers. This extends work of Helmke, et al., who studied static, give necessary and sufficient conditions for pole placement by static skew-symmetric complex feedback
Correcting Quadrupole Roll in Magnetic Lenses with Skew Quadrupoles
Walstrom, Peter Lowell
2014-11-10
Quadrupole rolls (i.e. rotation around the magnet axis) are known to be a significant source of image blurring in magnetic quadrupole lenses. These rolls may be caused by errors in mechanical mounting of quadrupoles, by uneven radiation-induced demagnetization of permanent-magnet quadrupoles, etc. Here a four-quadrupole ×10 lens with so-called ”Russian” or A -B B-A symmetry is used as a model problem. Existing SLAC 1/2 in. bore high-gradient quadrupoles are used in the design. The dominant quadrupole roll effect is changes in the first-order part of the transfer map (the R matrix) from the object to the image plane (Note effects on the R matrix can be of first order in rotation angle for some R-matrix elements and second order in rotation angle for other elements, as shown below). It is possible to correct roll-induced image blur by mechanically adjusting the roll angle of one or more of the quadrupoles. Usually, rotation of one quadrupole is sufficient to correct most of the combined effect of rolls in all four quadrupoles. There are drawbacks to this approach, however, since mechanical roll correction requires multiple entries into experimental area to make the adjustments, which are made according to their effect on images. An alternative is to use a single electromagnetic skew quadrupole corrector placed either between two of the quadrupoles or after the fourth quadrupole (so-called “non-local” correction). The basic feasibility of skew quadrupole correction of quadrupole roll effects is demonstrated here. Rolls of the third lens quadrupole of up to about 1 milliradian can be corrected with a 15 cm long skew quadrupole with a gradient of up to 1 T/m. Since the effect of rolls of the remaining three lens quadrupoles are lower, a weaker skew quadrupole can be used to correct them. Non-local correction of quadrupole roll effects by skew quadrupoles is shown to be about one-half as effective as local correction (i.e. rotating individual quadrupoles to zero roll angle or placing skew quadrupole correctors in the bores of main quadrupoles).
A method for generating skewed random numbers using two overlapping uniform distributions
Ermak, D.L.; Nasstrom, J.S.
1995-02-01
The objective of this work was to implement and evaluate a method for generating skewed random numbers using a combination of uniform random numbers. The method provides a simple and accurate way of generating skewed random numbers from the specified first three moments without an a priori specification of the probability density function. We describe the procedure for generating skewed random numbers from unifon-n random numbers, and show that it accurately produces random numbers with the desired first three moments over a range of skewness values. We also show that in the limit of zero skewness, the distribution of random numbers is an accurate approximation to the Gaussian probability density function. Future work win use this method to provide skewed random numbers for a Langevin equation model for diffusion in skewed turbulence.
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.
Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers
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
Skew Divergence-Based Fuzzy Segmentation of Rock Samples
NASA Astrophysics Data System (ADS)
Carvalho, Bruno M.; Garduño, Edgar; Santos, Iraçú O.
2014-03-01
Digital image segmentation is a process in which one assigns distinct labels to different objects in a digital image. The MOFS (Multi Object Fuzzy Segmentation) algorithm has been successfully applied to the segmentation of images from several modalities. However, the traditional MOFS algorithm fails when applied to images whose composing objects are characterized by textures whose patterns cannot be successfully described by simple statistics computed over a very restricted area. Here, we present an extension of the MOFS algorithm that achieves the segmentation of textures by employing adaptive affinity functions that use the Skew Divergence as a measure of distance between two distributions. These affinity functions are called adaptive because their associated area (neighborhood) changes according to the characteristics of the texture being processed. We performed experiments on mosaic images composed by combining rock sample images which show the effectiveness of the adaptive skew divergence based fuzzy affinity functions.
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.
Newspaper Coverage of Intimate Partner Violence: Skewing Representations of Risk
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
1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT ...
1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT LEFT AND THE ROCK CREEK AND POTOMAC PARKWAY RAMP AT RIGHT. VIEW TAKEN FROM THE REAR OF THE LINCOLN MEMORIAL. - Arlington Memorial Bridge, Watergate & Bridge Plaza, Adjacent to Arlington Memorial Bridge & Lincoln Memorial, Washington, District of Columbia, DC
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.
Validation of an Acoustic Impedance Prediction Model for Skewed Resonators
NASA Technical Reports Server (NTRS)
Howerton, Brian M.; Parrott, Tony L.
2009-01-01
An impedance prediction model was validated experimentally to determine the composite impedance of a series of high-aspect ratio slot resonators incorporating channel skew and sharp bends. Such structures are useful for packaging acoustic liners into constrained spaces for turbofan noise control applications. A formulation of the Zwikker-Kosten Transmission Line (ZKTL) model, incorporating the Richards correction for rectangular channels, is used to calculate the composite normalized impedance of a series of six multi-slot resonator arrays with constant channel length. Experimentally, acoustic data was acquired in the NASA Langley Normal Incidence Tube over the frequency range of 500 to 3500 Hz at 120 and 140 dB OASPL. Normalized impedance was reduced using the Two-Microphone Method for the various combinations of channel skew and sharp 90o and 180o bends. Results show that the presence of skew and/or sharp bends does not significantly alter the impedance of a slot resonator as compared to a straight resonator of the same total channel length. ZKTL predicts the impedance of such resonators very well over the frequency range of interest. The model can be used to design arrays of slot resonators that can be packaged into complex geometries heretofore unsuitable for effective acoustic treatment.
Skew-symmetric differential forms. Invariants. Realization of invariant structures
L. I. Petrova
2009-01-13
Skew-symmetric differential forms play an unique role in mathematics and mathematical physics. This relates to the fact that closed exterior skew-symmetric differential forms are invariants. The concept of "Exterior differential forms" was introduced by E.Cartan for a notation of integrand expressions, which can create the integral invariants.(The existence of integral invariants was recognized by A.Poincare while studying the general equations of dynamics.) All invariant mathematical formalisms are based on invariant properties of closed exterior forms. The invariant properties of closed exterior forms explicitly or implicitly manifest themselves essentially in all formalisms of field theory, such as the Hamilton formalism, tensor approaches, group methods, quantum mechanics equations, the Yang-Mills theory and others. They lie at the basis of field theory. However, in this case the question of how the closed exterior forms are obtained arises. In present work it is shown that closed exterior forms, which possess the invariant properties, are obtained from skew-symmetric differential forms, which, as contrasted to exterior forms, are defined on nonintegrable manifolds. The process of generating closed exterior forms describes the mechanism of realization of invariants and invariant structures.
Lisboa, Paulo
to the prediction of online purchasing behaviour. 5.1. Introduction The Bayesian evidence framework has becomePart 3. Chapter 5 Bias reduction in skewed classification with Bayesian neural networks ... Page 82 Chapter 5 Bias reduction in skewed classification with Bayesian neural networks: an application
Berns, Hans-Gerd
The SY10/100EL15 are low skew 1:4 clock distribution chips designed explicitly for low skew clock/disabled when they are already in the LOW state. This avoids any chance of generating a runt clock pulse when 980 -- 810 910 720 mV VOL Output LOW Voltage 1950 1650 1950 1630 1950 -- 1630 1950 1595 m
Semiconductor bridge (SCB) detonator
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.
Semiconductor bridge (SCB) detonator
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.
2. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...
2. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID
3. View of Clark Fork Vehicle Bridge facing southwest. Bridge ...
3. View of Clark Fork Vehicle Bridge facing southwest. Bridge from north shore of Clark Fork River. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID
4. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...
4. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shoreof Clark Fork River showing 4 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID
7. View of Clark Fork Vehicle Bridge facing northwest. Bridge ...
7. View of Clark Fork Vehicle Bridge facing northwest. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID
GOETHALS BRIDGE FROM NORTH SIDE OVER ARTHUR KILL. RAILROAD BRIDGE ...
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
VIEW OF APALACHICOLA RIVER BRIDGE STEEL BRIDGE TRUSS AND ROADWAY ...
VIEW OF APALACHICOLA RIVER BRIDGE STEEL BRIDGE TRUSS AND ROADWAY AT PIER 3, EAST SIDE, FROM RIVER, FACING WEST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL
2. OVERALL VIEW OF BRIDGE, WAUBONSIE HIGHWAY BRIDGE (1930), AND ...
2. OVERALL VIEW OF BRIDGE, WAUBONSIE HIGHWAY BRIDGE (1930), AND MISSOURI RIVER; VIEW TO NORTHEAST - Nebraska City Bridge, Spanning Missouri River near Highway 2 between Nebraska & Iowa, Nebraska City, Otoe County, NE
3. OVERALL VIEW OF BRIDGE, WAUBONSIE HIGHWAY BRIDGE, AND MISSOURI ...
3. OVERALL VIEW OF BRIDGE, WAUBONSIE HIGHWAY BRIDGE, AND MISSOURI RIVER; VIEW TO NORTH - Nebraska City Bridge, Spanning Missouri River near Highway 2 between Nebraska & Iowa, Nebraska City, Otoe County, NE
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.
Wyatt, M.L.
1988-11-15
This patent describes a drillable bridge plug for sealing a well casing using a setting assembly and adapted to the readily drilled out to remove the bridge plug. The bridge plug consists of: an inner mandrel having detachable means for connecting the bridge plug to the setting assembly formed at the upper end of the mandrel. The mandrel consists of a partial axial bore open to the bottom of the bridge plug, the partial bore operating as a fluid bypass passageway when the bridge plug is drilled out to provide pressure equalizing fluid communication above and below the bridge plug; upper slip means and lower slip means mounted on the mandrel and adapted to selectively engage the well casing to anchor the bridge plug; an elastomeric packing element mounted on the mandrel between the upper slip means and the lower slip means; and upper and lower compression cones mounted on the mandrel, the cones operable to deform the packing element into sealing engagement with the well casing upon setting of the bridge plug; a lock nut movably mounted on the mandrel adjacent the lower compression cone, the lock nut cooperating with ratchet threads formed on the mandrel and the lower compression cone to maintain compression of the packing element and prevent rotation o the bridge plug as the plug is drilled out; the inner mandrel including the connecting means, the upper slip means, the lower slip means and the compression cones being made of cast iron wherein the bridge plug may be drilled out of the well casing.
Bridge Funding Program 2014 Recipients
Finley Jr., Russell L.
Bridge Funding Program 2014 Recipients MARCH Patrick Mueller, Physiology Inactivity and Enhanced time Xiaoyan Han, Electrical and Computer Engineering Bridge Funding on Sonic Infrared Imaging Non War Illness #12;Bridge Funding Program 2013 Recipients MARCH Robert Akins, Biochemistry and Molecular
Wessendorf, Kurt O. (Albuquerque, NM)
2001-01-01
An active bridge oscillator is formed from a differential amplifier where positive feedback is a function of the impedance of one of the gain elements and a relatively low value common emitter resistance. This use of the nonlinear transistor parameter h stabilizes the output and eliminates the need for ALC circuits common to other bridge oscillators.
Karl F. Anderson
A technique is presented for observing the individual contributions of each element within a transducer based on the Wheatstone bridge measurement circuit topology. An analog signal representing the appropriate sum of all the individual analog elements is simultaneously available. The approach involves opening any convenient corner of the bridge and observing the resulting series string of varying impedances by using
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…
Support column of bridge across Struve Slough, Highway 1. Enlargement of hole where support enters the ground is an effect of lateral shaking, which caused the concrete to break up where the column joined the bridge and was instrumental in the roadbed collapse....
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.
Effect of Resonator Axis Skew on Normal Incidence Impedance
NASA Technical Reports Server (NTRS)
Parrott, Tony L.; Jones, Michael G.; Homeijer, Brian
2003-01-01
High by-pass turbofan engines have fewer fan blades and lower rotation speeds than their predecessors. Consequently, the noise suppression at the low frequency end of the noise spectra has become an increasing concern. This has led to a renewed emphasis on improving noise suppression efficiency of passive, duct liner treatments at the lower frequencies. For a variety of reasons, passive liners are comprised of locally-reacting, resonant absorbers. One reason for this design choice is to satisfy operational and economic requirements. The simplest liner design consists of a single layer of honeycomb core sandwiched between a porous facesheet and an impervious backing plate. These resonant absorbing structures are integrated into the nacelle wall and are very ef- ficient over a limited bandwidth centered on their resonance frequency. Increased noise suppression bandwidth and greater suppression at lower frequencies is typically achieved for conventional liners by increasing the liner depth and incorporating thin porous septa into the honeycomb core. However, constraints on liner depth in modern high by-pass engine nacelles severely limit the suppression bandwidth extension to lower frequencies. Also, current honeycomb core liners may not be suitable for irregular geometric volumes heretofore not considered. It is of interest, therefore, to find ways to circumvent liner depth restrictions and resonator cavity shape constraints. One way to increase effective liner depth is to skew the honeycomb core axis relative to the porous facesheet surface. Other possibilities are to alter resonator cavity shape, e.g. high aspect ratio, narrow channels that possibly include right angle bends, 180. channel fold-backs, and splayed channel walls to conform to irregular geometric constraints. These possibilities constitute the practical motivation for expanding impedance modeling capability to include unconventional resonator orientations and shapes. The work reported in this paper is in the nature of a progress report and is limited to examining the implications of resonator axis skew on the composite normal incidence impedance of an array of resonator channels. Specifically, experimental results are compared with a modified impedance prediction model for highaspect- ratio, rectangular, resonator channels with varying amounts of skew relative to the incident particle velocity. It is shown that for resonator channel widths of 1 to 2 mm, aspect ratios of 25 to 50, and skew angles of zero to sixty degrees, the surface impedance of test models can be predicted with good accuracy. Predicted resistances and reactances are particularly well correlated through the first resonance and first anti-resonance for all six test models investigated. Beyond the first anti-resonance, the impedance prediction model loses the ability to predict details of resistance and reactance but still predicts the mean trends very well.
EGARCH models with fat tails, skewness and leverage
Harvey, Andrew; Sucarrat, Genaro
2013-10-04
is substantially smaller. Yahoo Fi-340 nance (http://yahoo.finance.com/) is the source of the stock market indices341 and the stock prices, the European Central Bank (http://www.ecb.int/) and342 the US Energy Information Agency (http://www.eia.gov/) are the sources... to SC in only three instances (FTSE, DAX and gold).431 Both leverage and negative skewness are pronounced among the stock432 market indices. The leverage estimate is always positive, which yields the433 usual interpretation of large negative returns...
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.
Skewness and shock formation in laboratory-scale supersonic jet data.
Gee, Kent L; Neilsen, Tracianne B; Atchley, Anthony A
2013-06-01
Spatial properties of noise statistics near unheated, laboratory-scale supersonic jets yield insights into source characteristics and near-field shock formation. Primary findings are (1) waveforms with positive pressure skewness radiate from the source with a directivity upstream of maximum overall level and (2) skewness of the time derivative of the pressure waveforms increases significantly with range, indicating formation of shocks during propagation. These results corroborate findings of a previous study involving full-scale engine data. Further, a comparison of ideally and over-expanded laboratory data show that while derivative skewness maps are similar, waveform skewness maps are substantially different for the two cases. PMID:23742445
Bandyopadhyay, Dipankar; Lachos, Victor H.; Castro, Luis M.; Dey, Dipak K.
2012-01-01
Often in biomedical studies, the routine use of linear mixed-effects models (based on Gaussian assumptions) can be questionable when the longitudinal responses are skewed in nature. Skew-normal/elliptical models are widely used in those situations. Often, those skewed responses might also be subjected to some upper and lower quantification limits (viz. longitudinal viral load measures in HIV studies), beyond which they are not measurable. In this paper, we develop a Bayesian analysis of censored linear mixed models replacing the Gaussian assumptions with skew-normal/independent (SNI) distributions. The SNI is an attractive class of asymmetric heavy-tailed distributions that includes the skew-normal, the skew-t, skew-slash and the skew-contaminated normal distributions as special cases. The proposed model provides flexibility in capturing the effects of skewness and heavy tail for responses which are either left- or right-censored. For our analysis, we adopt a Bayesian framework and develop a MCMC algorithm to carry out the posterior analyses. The marginal likelihood is tractable, and utilized to compute not only some Bayesian model selection measures but also case-deletion influence diagnostics based on the Kullback-Leibler divergence. The newly developed procedures are illustrated with a simulation study as well as a HIV case study involving analysis of longitudinal viral loads. PMID:22685005
VIEW OF BRIDGE, LOOKING SOUTHWEST, WITH SOUTHERN PACIFIC RAILROAD BRIDGE ...
VIEW OF BRIDGE, LOOKING SOUTHWEST, WITH SOUTHERN PACIFIC RAILROAD BRIDGE IN BACKGROUND. THE PAVEMENT OF THE NORTH APPROACH IS SEEN BURIED ON THE RIGHT. ROADWAY (CENTER) CROSSES THE USUALLY DRY CHANNEL OF THE SALT RIVER. A BALUSTRADE OF THE MILL AVENUE BRIDGE IS SEEN AT THE LOWER LEFT CORNER - Ash Avenue Bridge, Spanning Salt River at Foot of Ash Avenue, Tempe, Maricopa County, AZ
5. View of Clark Fork Vehicle Bridge facing east. Bridge ...
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
The floating water bridge The floating water bridge
Podgornik, Rudolf
The floating water bridge The floating water bridge Elmar C. Fuchs1 , Jakob Woisetschläger2 , Karl, a stable water connection forms spontaneously, giving the impression of a floating water bridge. A detailed this bridge. 1. Introduction Water undoubtedly is the most important chemical substance in the world. Many
M.E. Bridges 1 MELISSA E. BRIDGES
Maxwell, Bruce D.
M.E. Bridges 1 MELISSA E. BRIDGES melbrid@gmail.com Education: Ph.D. Ecology Presentations and Publications): Bridges, M., B.D. Maxwell, and L.J. Rew. 2010. The role of current and historic. 7-11. Denver, CO. [Oral presentation]. Bridges, M., D.L. Shaner, and P. Westra. 2009. The effects
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.
Skewness and Kurtosis in Large-Scale Cosmic Fields
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.
Crossover ensembles of random matrices and skew-orthogonal polynomials
Kumar, Santosh, E-mail: skumar.physics@gmail.com [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India); Pandey, Akhilesh, E-mail: ap0700@mail.jnu.ac.in [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India)
2011-08-15
Highlights: > We study crossover ensembles of Jacobi family of random matrices. > We consider correlations for orthogonal-unitary and symplectic-unitary crossovers. > We use the method of skew-orthogonal polynomials and quaternion determinants. > We prove universality of spectral correlations in crossover ensembles. > We discuss applications to quantum conductance and communication theory problems. - Abstract: In a recent paper (S. Kumar, A. Pandey, Phys. Rev. E, 79, 2009, p. 026211) we considered Jacobi family (including Laguerre and Gaussian cases) of random matrix ensembles and reported exact solutions of crossover problems involving time-reversal symmetry breaking. In the present paper we give details of the work. We start with Dyson's Brownian motion description of random matrix ensembles and obtain universal hierarchic relations among the unfolded correlation functions. For arbitrary dimensions we derive the joint probability density (jpd) of eigenvalues for all transitions leading to unitary ensembles as equilibrium ensembles. We focus on the orthogonal-unitary and symplectic-unitary crossovers and give generic expressions for jpd of eigenvalues, two-point kernels and n-level correlation functions. This involves generalization of the theory of skew-orthogonal polynomials to crossover ensembles. We also consider crossovers in the circular ensembles to show the generality of our method. In the large dimensionality limit, correlations in spectra with arbitrary initial density are shown to be universal when expressed in terms of a rescaled symmetry breaking parameter. Applications of our crossover results to communication theory and quantum conductance problems are also briefly discussed.
Multiple mating and reproductive skew in Trinidadian guppies.
Becher, S. A.; Magurran, A. E.
2004-01-01
Male offspring production in promiscuously mating species is typically more skewed than female offspring production. It is therefore advantageous for males to seek as many mating partners as possible. However, given the documented benefits of polyandry we expect females, as well as males, to mate multiply. We tested these ideas using Trinidadian guppies, Poecilia reticulata. Fishes were collected from the wild, housed in groups of 10 males and 10 females and allowed to reproduce freely over a period of three months. We used hypervariable microsatellite loci to identify the parents of 840 offspring and to quantify the variance in mating success. As anticipated, and in line with the Bateman gradient, there was greater skew in the number of progeny produced by males. By contrast, we found no sex difference in mating partner number over the duration of the experiment. A median of two males fathered each brood and there was marked turnover in the identities of the sires of successive broods. Female partner turnover was, however, less than expected under random mating. We suggest that partner switching over time, as well as polyandry within broods, could contribute to the maintenance of genetic diversity in guppy populations. PMID:15293853
Timber bridge ruins, not passable.
1 1 W eeks Creek Highway 84 Woodruff Creek Highway84 Timber bridge ruins, not passable. Wooden deck Timber bridge ruins, not passable. Spanning boxcar bridge, passable. 0 50 100 meters Plate1A over basalt. Qf Qs Qt Qc Tb Ts House. Rip rap revetment. Concrete wall. Geogrid. Bridge or crossing
NSDL National Science Digital Library
2011-01-01
This article, written for middle grades students, relates the history of the famous Konigsberg Bridge problem and introduces the idea of networks and paths that do not retrace themselves. The article concludes with a path the student must work out.
Design Squad: Suspension Bridge
NSDL National Science Digital Library
2007-08-09
In this video segment adapted from Design Squad—a PBS TV series featuring high school contestants tackling engineering challenges—students employ the concepts of tension and compression to build a suspension bridge without the aid of power tools.
Bridge : an unraveled architecture
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 ...
Caughman, John
CLSB SRTC SW HARRISON SW MARKET SW CLAY I-405 M ARQ UAM BRIDGE HAWTHORNE BRIDGE I-5 I-5 SW HALL SW: 20Â25 minutes Â» Head east on SW Harrison St Â» Continue onto SW River Pkwy Â» Turn right onto HarborÂ7 minutes Â» Head east on SW Harrison St (shared roadway) Â» Continue onto SW River Pkwy (bike lanes) Â» Turn
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.
On the Boundedness and Skew-Symmetric Properties of the Inertia and Coriolis
Gravdahl, Jan Tommy
On the Boundedness and Skew-Symmetric Properties of the Inertia and Coriolis Matrices for Vehicle, Norway Abstract: This paper addresses the boundedness property of the inertia matrix and the skew for the boundedness property of the inertia matrix which for a bad choice of state variables will not necessarily hold
Reward skewness coding in the insula independent of probability and loss.
Burke, Christopher J; Tobler, Philippe N
2011-11-01
Rewards in the natural environment are rarely predicted with complete certainty. Uncertainty relating to future rewards has typically been defined as the variance of the potential outcomes. However, the asymmetry of predicted reward distributions, known as skewness, constitutes a distinct but neuroscientifically underexplored risk term that may also have an impact on preference. By changing only reward magnitudes, we study skewness processing in equiprobable ternary lotteries involving only gains and constant probabilities, thus excluding probability distortion or loss aversion as mechanisms for skewness preference formation. We show that individual preferences are sensitive to not only the mean and variance but also to the skewness of predicted reward distributions. Using neuroimaging, we show that the insula, a structure previously implicated in the processing of reward-related uncertainty, responds to the skewness of predicted reward distributions. Some insula responses increased in a monotonic fashion with skewness (irrespective of individual skewness preferences), whereas others were similarly elevated to both negative and positive as opposed to no reward skew. These data support the notion that the asymmetry of reward distributions is processed in the brain and, taken together with replicated findings of mean coding in the striatum and variance coding in the cingulate, suggest that the brain codes distinct aspects of reward distributions in a distributed fashion. PMID:21849610
Probe Skewing Effects & Kinect Head-tracking in Tongue Contour Imaging
Edinburgh, University of
Probe Skewing Effects & Kinect Head-tracking in Tongue Contour Imaging Samuel Johnston, Daniel tilt of the head or probe) may affect the quality and comparability of ultrasound tongue images tongue gestures. These extremes of articulation cast a wide net for capturing effects of probe skewing
Some algorithms for skew polynomials over finite fields Xavier Caruso, Jrmy Le Borgne
Caruso, Xavier
Some algorithms for skew polynomials over finite fields Xavier Caruso, JÃ©rÃ©my Le Borgne Abstract In this paper, we study the arithmetics of skew polynomial rings over finite fields, mostly from an algorithmic point of view. We give various algorithms for fast mul- tiplication, division and extended Euclidean
Some algorithms for skew polynomials over finite fields Xavier Caruso, Jrmy Le Borgne
Paris-Sud XI, Université de
Some algorithms for skew polynomials over finite fields Xavier Caruso, Jérémy Le Borgne Abstract In this paper, we study the arithmetics of skew polynomial rings over finite fields, mostly from an algorithmic point of view. We give various algorithms for fast mul- tiplication, division and extended Euclidean
Some algorithms for skew polynomials over finite fields Xavier Caruso, Jrmy Le Borgne
Paris-Sud XI, Université de
Some algorithms for skew polynomials over finite fields Xavier Caruso, Jérémy Le Borgne Abstract In this paper, we study the arithmetics of skew polynomial rings over finite fields, mostly from an algorithmic point of view. We give various algorithms for fast mul tiplication, division and extended Euclidean
A Natural Simple Model of Scientists' Strength Leads to Skew-Normal Distribution
Kreinovich, Vladik
A Natural Simple Model of Scientists' Strength Leads to Skew-Normal Distribution Komsan Suriya1@utep.edu Abstract In many practical situations, we have probability distributions which are close to normal used is skew-normal distribution, whose probability density (pdf) is equal to the product of the pdf
Bandyopadhyay, Dipankar; Lachos, Victor H.; Abanto-Valle, Carlos A.; Ghosh, Pulak
2010-01-01
Bivariate clustered (correlated) data often encountered in epidemiological and clinical research are routinely analyzed under a linear mixed model framework with underlying normality assumptions of the random effects and within-subject errors. However, such normality assumptions might be questionable if the data-set particularly exhibit skewness and heavy tails. Using a Bayesian paradigm, we use the skew-normal/independent (SNI) distribution as a tool for modeling clustered data with bivariate non-normal responses in a linear mixed model framework. The SNI distribution is an attractive class of asymmetric thick-tailed parametric structure which includes the skew-normal distribution as a special case. We assume that the random effects follows multivariate skew-normal/independent distributions and the random errors follow symmetric normal/independent distributions which provides substantial robustness over the symmetric normal process in a linear mixed model framework. Specific distributions obtained as special cases, viz. the skew-t, the skew-slash and the skew-contaminated normal distributions are compared, along with the default skew-normal density. The methodology is illustrated through an application to a real data which records the periodontal health status of an interesting population using periodontal pocket depth (PPD) and clinical attachment level (CAL). PMID:20740568
Cluster Rendering of Skewed Datasets via Visualization Keke Chen Ling Liu
Cluster Rendering of Skewed Datasets via Visualization Keke Chen Ling Liu College of Computing method for understanding sophistication in large datasets. In this paper, we introduce a flexible clustering approach with visualization techniques, aiming at the datasets that have skewed cluster
Analytical calculation of inductances of windings in electrical machines with slot skew
Bin Ouyang; Dezhi Liu; Xiaofei Zhai; Weiming Ma
2010-01-01
It is significant to understand the effect of slot skew on the performances of electrical machines, e.g. quality of voltage wave and fluctuation of electromagnetic torque. Since finite element simulations can make the analysis processes very time consuming and complicated, An analytical method for calculating the airgap inductances of windings in electrical machines with skewed rotor or stator slot is
COMPENSATION OF FAST KICKER ROLLS WITH SKEW QUADRUPOLES
Pinayev, I.
2011-03-28
The development of the third generation light sources lead to the implementation of the top-up operation, when injection occurs while users collect data. The beam excursions due to the non-closure of the injection bump can spoil the data and need to be suppressed. In the horizontal plane compensation can be achieved by adjusting timing and kick amplitudes. The rolls of the kicker magnets create non-closure in the vertical plane and usually there is no means for correction. In the paper we describe proposed compensation scheme utilizing two skew quadrupoles placed inside the injection bump. The third generation light sources implement top-up operation firstly introduced at Advanced Photon Source. In this mode the circulating beam current is supported near constant by frequent injection of small charge, while photon beam is delivered for users. The beam perturbations caused by the mismatched injection bump can provide undesired noise in the user data. Usually the injection trigger is distributed to the users end stations so that those affected would be able to blank data acquisition. Nevertheless, as good operational practice such transients should be suppressed as much as possible. In the horizontal plane (which is commonly used for injection) one can adjust individual kicker strength as well as trigger delay while observing motion of the stored beam centroid. In the vertical plane such means are unavailable in the most cases. The possible solutions include dedicated weak vertical kickers and motorized adjustment of the roll angle of the injection kickers. Both abovementioned approaches are expensive and can significantly deteriorate reliability. We suggest two employ two skew quadrupoles (to correct both angle and position) placed inside the injection bump. In this case the beam position itself serves as measure of the kicker strength (assuming that kickers are well matched) and vertical kicks from the skew quadrupoles will be self synchronized with injection bump. In this paper we will consider the case when injection hardware (kickers and septa) are located in the same straight. Such an approach simplifies consideration but it can be generalized.
Optimizing head/media electrical characterization in the presence of skew at high track density
NASA Astrophysics Data System (ADS)
Wang, Wen Yao; Huo, Hong; Tan, Victor MH
2006-08-01
The skew angle causes a discrepancy in determining the reader-to-writer offset (RWO) when using different periodical patterns in track profile tests. It also separates the peak overwrite (OW) from the peak high frequency amplitude HFA, (1 T periodical pattern) on corresponding track profiles. Furthermore, higher track density and larger skew angle exacerbate the skew effect and induce more RWO error, thus impacting the parametric performance optimization. Simulation studies are used to interpret the skew effect on the RWO determination and OW cross-track characteristics. Based on experimental investigations and simulation analyses, using the HFA, track profile for deriving the optimal RWO is proposed for spin-stand tests. Actual parametric characterization has proven that the optimal RWO minimized the skew effect and the RWO error, thus improving the parametric performance and reducing the test variation. The method is beneficial and necessary for the high track density characterization.
Bayesian Inference for Skew-Normal Mixture Models With Left-Censoring
Dagne, Getachew A.
2014-01-01
Assays to measure concentration of antibody after vaccination are often subject to left-censoring due to a lower detection limit (LDL), leading to a high proportion of observations below the detection limit. Not accounting for such left-censoring appropriately can lead to biased parameter estimates. To properly adjust for left-censoring and a high proportion of observations at LDL, this paper proposes a mixture model combining a point mass below LDL and a Tobit model with skew-elliptical error distribution. We show that skew-elliptical distributions, where the skew-normal and skew-t are special cases, have great flexibility for simultaneously handling left-censoring, skewness and heaviness in the tails of a distribution of a response variable with left-censored data. A Bayesian procedure is used to estimate model parameters. Two real datasets from a study of measles vaccine and an HIV/AIDS study are used to illustrate the proposed models. PMID:23957513
Skew detection and correction of ancient Tamil documents using particle swarm optimization
NASA Astrophysics Data System (ADS)
Sridevi, N.; Subashini, P.
2012-04-01
When a document is fed to a scanner either mechanically or by a human operator for digitization, it suffers from some degrees of skew or tilt. Skew detection is one of the first operations to be applied to scanned documents when converting data to a digital format. Its aim is to align an image before processing because text segmentation and recognition methods require properly aligned lines. This paper presents a new approach for skew detection and correction of documents. Particle Swarm Optimization (PSO) is used for solving skew optimization. A new objective function based on local maxima and minima of projection profile is formulated and PSO is used to find the best angle that maximizes the objective function. The proposed method is compared with existing methods like Hough transform, Fourier transform. Experimental results show that the proposed method corrects the skew with the maximum error rate of +/- 1° .
23 CFR 650.307 - Bridge inspection organization.
Code of Federal Regulations, 2010 CFR
2010-04-01
...2010-04-01 false Bridge inspection organization...AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards ...maintenance of a bridge inventory. (2) Bridge...
Cracked shells under skew-symmetric loading. [Reissner theory
NASA Technical Reports Server (NTRS)
Delale, F.
1981-01-01
The general problem of 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 anti-plane elasticity solutions. Results are given for axially and circumferentially cracked cylindrical shells, spherical shells, and toroidal shells under uniform in-plane shearing, out of plane shearing, and torsion. The problem is formulated for specially orthostropic materials, therefore, the effect of orthotropy on the results is also studied.
Restoring the skew quadrupole moment in the Tevatron dipoles
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].
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.
SoftBridge: A Multimodal Instant Messaging Bridging System
Blake, Edwin
experiments. Keywords--instant messaging, bridging, XML, SOAP, Jabber, web services, speech synthesis, speech make use of this facility in the SoftBridge. We also use XML SOAP (Simple Object Access Protocol) [3
Dog Bridge, view of the deck of the bridge and ...
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
NSDL National Science Digital Library
Covered bridges cause moments of delight for historic preservationists, and they entered a new place in American popular culture when they figured prominently in a certain Clint Eastwood film in the early 1990s. Recently, staff members and student assistants at Bucknell University spent a significant amount of time creating this digital collection of covered bridge photographs. Interestingly enough, the original photographs were taken by a long-time member of the biology faculty at Bucknell, one Professor Nelson F. Davis. The photos date from 1898 to 1939, and all told, there are over 300 images in this collection. Visitors will enjoy looking over this collection, and these documents will be of great interest to anyone fascinated by these types of bridges, engineering, or the history of rural Pennsylvania.
Log Pearson type 3 quantile estimators with regional skew information and low outlier adjustments
Griffis, V.W.; Stedinger, J.R.; Cohn, T.A.
2004-01-01
[1] The recently developed expected moments algorithm (EMA) [Cohn et al., 1997] does as well as maximum likelihood estimations at estimating log-Pearson type 3 (LP3) flood quantiles using systematic and historical flood information. Needed extensions include use of a regional skewness estimator and its precision to be consistent with Bulletin 17B. Another issue addressed by Bulletin 17B is the treatment of low outliers. A Monte Carlo study compares the performance of Bulletin 17B using the entire sample with and without regional skew with estimators that use regional skew and censor low outliers, including an extended EMA estimator, the conditional probability adjustment (CPA) from Bulletin 17B, and an estimator that uses probability plot regression (PPR) to compute substitute values for low outliers. Estimators that neglect regional skew information do much worse than estimators that use an informative regional skewness estimator. For LP3 data the low outlier rejection procedure generally results in no loss of overall accuracy, and the differences between the MSEs of the estimators that used an informative regional skew are generally modest in the skewness range of real interest. Samples contaminated to model actual flood data demonstrate that estimators which give special treatment to low outliers significantly outperform estimators that make no such adjustment.
NASA Astrophysics Data System (ADS)
Whisler, Don E.
1995-05-01
The purpose of this paper is to give the reader a brief insight into the Kansas Department of Transportation (KDOT) Bridge Inspection Program. The State of Kansas has 25,580 bridge length structures within its boundaries used to carry vehicle traffic or pedestrians, excluding railroad. This total ranks third within the nation according to the November issue of 'Better Roads.' The total number of structures listed includes 20,453 structures owned by local governments, 340 structures owned by the Kansas Turnpike Authority, and 4,787 structures owned by the KDOT. This paper will deal specifically with the KDOT structures only.
99. Big Pine Creek Bridge #1. This concrete slab bridge ...
99. Big Pine Creek Bridge #1. This concrete slab bridge was built 1938. It is an example of where the stone railing continues across the bridge. Facing east. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC
1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT ...
1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT LEFT AND THE ROCK CREEK AND POTOMAC PARKWAY RAMP AT RIGHT. VIEW TAKEN FROM THE REAR OF THE LINCOLN MEMORIAL. - Arlington Memorial Bridge, Boundary Channel Extension, Spanning Mount Vernon Memorial Highway & Boundary Channel, Washington, District of Columbia, DC
77 FR 16784 - General Bridge Regulation; Amendment
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-22
...USCG-2008-1188] RIN 1625-AB36 General Bridge Regulation; Amendment AGENCY: Coast...rulemaking concerning amendments to the general bridge regulations. The rulemaking was initiated...clarify the statutory responsibilities of bridge owners to remove their bridges from...
National Cancer Institute Bridging the Funding Gap for Promising Cancer Therapeutics, Imaging Technologies, Interventional Devices, Diagnostics, and Prognostics SBIR Phase II Bridge Award The National Cancer Institute (NCI) Small Business Innovation
Bike/ped bridge CAMPUSDRIVEWEST
I Bike/ped bridge Bike/ped bridge Bike/ped underpass ELCAM ELCAM INO REAL GALVEZST SERRA MALL CAM Center Safeway Munger Y2E2 Parking & Transportation Services (P&TS) Montag Hall Stock Farm lot Parking
Bridge Types: Tensile & Compressive Forces
NSDL National Science Digital Library
2014-09-18
Students explore how tension and compression forces act on three different bridge types. Using sponges, cardboard and string, they create models of beam, arch and suspension bridges and apply forces to understand how they disperse or transfer these loads.
BUILDING "BRIDGES" WITH QUALITY ASSURANCE
The papr describes how, rather than building "bridges" across centuries, quality assurance (QA) personnel have the opportunity to build bridges across technical disciplines, between public and private organizations, and between different QA groups. As reviewers and auditors of a...
NSDL National Science Digital Library
A Guide to Covered Bridges, offered by Drexel University, Philadelphia, Pennsylvania, transforms the Web into a time machine. Find the answer to the question, why are there so many covered bridges, and why in Pennsylvania and the Northeast? The Drexel University Honors Program sponsors this guide to dozens of covered bridges of the Philadelphia region. Driving tours are suggested, and bridge images are indexed by season (fall color, winter, snow and ice, spring/summer) and structure as well as county.
Bike/ped bridge Bike/ped underpass ELCAM INO REAL ELCAM INO REAL GALVEZST W ELCH RD D HILLRD Center (PATC) Bus depot Caltrain platform MC #12;Bike/ped bridge Bike/ped underpass ELCAM INO REAL ELCAM UNIVERSITY AVE ALMA S Palo Alto Transit Center (PATC) Bus depot Caltrain platform MC #12;Bike/ped bridge Bike
This photograph shows Lowe's Bridge off ME-15 in Guilford, Maine, spanning the Piscataquis River. USGS gaging station 01031500 is located on the downstream side of the bridge. The original bridge, built in 1857, washed away in the flood of 1987, and was rebuilt on the original abutments in 1990....
Gaussian bridges Dario Gasbarra1
Sottinen, Tommi
Gaussian bridges Dario Gasbarra1 , Tommi Sottinen2 , and Esko Valkeila3 1 Department of Mathematics.valkeila@hut.fi Summary. We consider Gaussian bridges; in particular their dynamic representa- tions. We prove a Girsanov theorem between the law of Gaussian bridge and the original Gaussian process, which holds with natural
WILLIAM B. BRIDGES INTERVIEWED BY
Low, Steven H.
WILLIAM B. BRIDGES (1934 Â ) INTERVIEWED BY SHIRLEY K. COHEN May Â June 2001, March 2004 Photo, and an Addendum, March 2004, with William B. Bridges, Carl F. Braun Professor of Engineering in the Division of Engineering and Applied Science. Dr. Bridges received his undergraduate and graduate education
ERIC Educational Resources Information Center
Netzer, Greg
1995-01-01
Discusses a model water quality monitoring project, Project Bridge, established to train minority girls about to enter eighth grade in scientific procedures followed by hands-on experimentation. Students spent a week monitoring water in an urban stream and analyzing results. (LZ)
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.
ERIC Educational Resources Information Center
Leviatan, Talma
2008-01-01
There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes--aimed at bridging the gap between high-school mathematics and tertiary mathematics--is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a…
Bridging the Technological Gap.
ERIC Educational Resources Information Center
Lazow, Robert; And Others
The aim of "Bridging the Technological Gap" (BTG), a federally funded demonstration project, is to use microcomputer technology in the rehabilitation of the psychiatrically disabled. Through the use of a custom designed microcomputer software package, clients receive remediation in areas of specific cognitive and behavioral deficits. The project…
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…
ERIC Educational Resources Information Center
Gohdes, William
1995-01-01
Although tech prep is still in its infancy in Georgia, increasing numbers of students are entering technical institutes after having completed the secondary-level component of tech prep programs. Georgia's technical institutes must begin the process of developing bridge programs to help adult students with no tech prep experience develop academic…
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…
Bridging Disciplinary Boundaries
ERIC Educational Resources Information Center
Mei, Linda
2009-01-01
Interdisciplinary education promotes the unity of knowledge by bridging the cultural divide between the social constructs of disciplines and encourages the development of knowledge to enhance society. As an inquiry-based and relevant approach that expands and advances knowledge, interdisciplinary education facilitates creativity and flexibility,…
NSDL National Science Digital Library
WGBH Educational Foundation
2007-08-09
In this video segment adapted from Design Squad—a PBS TV series featuring high school contestants tackling engineering challenges—students employ the concepts of tension and compression as they build a truss bridge without the aid of power tools.
Bryce Canyon's Natural Bridge is technically a natural arch, similar to those in the nearby Arches National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates...
ERIC Educational Resources Information Center
Bisogno, Janet; JeanPierre, Bobby
2008-01-01
The West Point Bridge Design (WPBD) building project engages students in project-based learning by giving them a real-life problem to solve. By using technology, students are able to become involved in solving problems that they normally would not encounter. Involvement with interactive websites, such as WPBD, assists students in using…
ERIC Educational Resources Information Center
Lum, Lydia
2009-01-01
Since its inception in 2000, Pan-Asian American Community House's (PAACH's) education mission has bridged Asian-American studies to student life. PAACH initiatives have helped spread Asian-American diaspora to thousands of students at the University of Pennsylvania. They have also helped students determine for themselves what it means to be a…
Statistics on Cannabis Users Skew Perceptions of Cannabis Use
Burns, Rachel M.; Caulkins, Jonathan P.; Everingham, Susan S.; Kilmer, Beau
2013-01-01
Collecting information about the prevalence of cannabis use is necessary but not sufficient for understanding the size, dynamics, and outcomes associated with cannabis markets. This paper uses two data sets describing cannabis consumption in the United States and Europe to highlight (1) differences in inferences about sub-populations based on the measure used to quantify cannabis-related activity; (2) how different measures of cannabis-related activity can be used to more accurately describe trends in cannabis usage over time; and (3) the correlation between frequency of use in the past-month and average grams consumed per use-day. Key findings: focusing on days of use instead of prevalence shows substantially greater increases in U.S. cannabis use in recent years; however, the recent increase is mostly among adults, not youth. Relatively more rapid growth in use days also occurred among the college-educated and Hispanics. Further, data from a survey conducted in seven European countries show a strong positive correlation between frequency of use and quantity consumed per day of use, suggesting consumption is even more skewed toward the minority of heavy users than is suggested by days-of-use calculations. PMID:24223560
Skew redundant MEMS IMU calibration using a Kalman filter
NASA Astrophysics Data System (ADS)
Jafari, M.; Sahebjameyan, M.; Moshiri, B.; Najafabadi, T. A.
2015-10-01
In this paper, a novel calibration procedure for skew redundant inertial measurement units (SRIMUs) based on micro-electro mechanical systems (MEMS) is proposed. A general model of the SRIMU measurements is derived which contains the effects of bias, scale factor error and misalignments. For more accuracy, the effect of lever arms of the accelerometers to the center of the table are modeled and compensated in the calibration procedure. Two separate Kalman filters (KFs) are proposed to perform the estimation of error parameters for gyroscopes and accelerometers. The predictive error minimization (PEM) stochastic modeling method is used to simultaneously model the effect of bias instability and random walk noise on the calibration Kalman filters to diminish the biased estimations. The proposed procedure is simulated numerically and has expected experimental results. The calibration maneuvers are applied using a two-axis angle turntable in a way that the persistency of excitation (PE) condition for parameter estimation is met. For this purpose, a trapezoidal calibration profile is utilized to excite different deterministic error parameters of the accelerometers and a pulse profile is used for the gyroscopes. Furthermore, to evaluate the performance of the proposed KF calibration method, a conventional least squares (LS) calibration procedure is derived for the SRIMUs and the simulation and experimental results compare the functionality of the two proposed methods with each other.
Single series skewness representation for passive scalar advection in laminar pipe and channel flow
NASA Astrophysics Data System (ADS)
McLaughlin, Richard M.; Bernardi, Francesca; Camassa, Roberto; Mertens, Keith; UNC Joint Fluids Lab Team
2013-11-01
In this talk, we present an exact single series representation for scalar skewness time evolution. Prior studies have naturally derived multiple nested Fourier series solutions which suffer from slow convergence and cloud physical interpretation. Judicious change of variables and complex residue theory lead to single series representation formulae for the moments along streamwise slices from which quantities such as variance and skewness can be reconstructed. Instantaneous symmetry breaking gives rise to non-zero skewness on transient time scales arising as a non-trivial competition between advection and diffusion which is captured by the simplified formulae. Small and long time asymptotics will be discussed for the first three moments in both channel and pipe geometries in steady Poiseuille flow, and nontrivial Peclet dependence in the skewness along slices will be examined. In this talk, we present an exact single series representation for scalar skewness time evolution. Prior studies have naturally derived multiple nested Fourier series solutions which suffer from slow convergence and cloud physical interpretation. Judicious change of variables and complex residue theory lead to single series representation formulae for the moments along streamwise slices from which quantities such as variance and skewness can be reconstructed. Instantaneous symmetry breaking gives rise to non-zero skewness on transient time scales arising as a non-trivial competition between advection and diffusion which is captured by the simplified formulae. Small and long time asymptotics will be discussed for the first three moments in both channel and pipe geometries in steady Poiseuille flow, and nontrivial Peclet dependence in the skewness along slices will be examined. DMS-0502266, NSF RTG DMS-0943851, NSF RAPID CBET-1045653, NSF CMG ARC- 1025523, and NSF DMS-1009750, ONR DURIP N00014-09-1-0840.
Schur positivity of skew Schur function differences and applications to ribbons and Schubert classes
King, Ronald C; van Willigenburg, Stephanie J
2007-01-01
Some new relations on skew Schur function differences are established both combinatorially using jeu de taquin, and algebraically using Jacobi-Trudi determinants. These relations lead to the conclusion that certain differences of skew Schur functions are Schur positive. Applying these results to a basis of symmetric functions involving ribbon Schur functions confirms the validity of a Schur positivity conjecture due to McNamara. A further application reveals that certain differences of products of Schubert classes are Schubert positive.
Schur positivity of skew Schur function differences and applications to ribbons and Schubert classes
Ronald C. King; Trevor A. Welsh; Stephanie J. van Willigenburg
2008-01-01
Some new relations on skew Schur function differences are established both combinatorially using Schützenberger’s jeu de taquin,\\u000a and algebraically using Jacobi-Trudi determinants. These relations lead to the conclusion that certain differences of skew\\u000a Schur functions are Schur positive. Applying these results to a basis of symmetric functions involving ribbon Schur functions\\u000a confirms the validity of a Schur positivity conjecture due
Buckling of skew mindlin plates subjected to in-plane shear loadings
Y Xiang; C. M Wang
1995-01-01
This paper considers the elastic buckling of skew Mindlin plates under shear loads. Two kinds of shear loads-rectangular shear (R-shear) and skew shear (S-shear)-have been investigated. The former has every infinitesimal rectangular element under pure shear while the latter refers to a shear load uniformly applied along the edges. Based on the Rayleigh-Ritz method, new critical shear load factors and
Bridged ferrocenes. 10. Structural phenomena
Hillman, M.; Fujita, E.; Dauplaise, H.; Kvick, A.; Kerber, R.C.
1984-01-01
The structures of 1,1',2,2'-bis(tetramethylene)ferrocene, I, 1,1',2,2',4,4'-tris(tetramethylene)ferrocene, II, and 1,1',2,2',4,4'-tris(pentamethylene)ferrocene, III, are given and are compared to the previously determined structure of 1,1',2,2',4,4'-tris(trimethylene)ferrocene, IV. The iron-to-ring distances are consistent with the reported Moessbauer spectra and redox potentials. The cyclopentadienyl rings are eclipsed in the compounds with trimethylene and pentamethylene bridges but are staggered by 12-14 in the compounds with tetramethylene bridges. In compounds with tetra- and pentamethylene bridges the presence of staggering or eclipsing is attributed to the need to avoid eclipsing of the protons in the bridges. In the compound with three trimethylene bridges, the shortness of the bridges is of primary importance. The staggered conformation observed in I and II may be the source of the apparent anomalies observed in the ring-proton region of the NMR spectra of bridged ferrocenes. The bridge-proton region of the NMR spectra at 360 MHz are given for I and other bridged ferrocenes. Disorder of the bridge carbons observed in the crystals are correlated with the flipping of the bridges observed in the NMR spectra. 30 references, 8 tables.
Molecular engineering with bridged polysilsesquioxanes
LOY,DOUGLAS A.; SHEA,KENNETH J.
2000-05-09
Bridged polysilsesquioxanes are a class of hybrid organic-inorganic materials that permit molecular engineering of bulk properties including porosity. Prepared by sol-gel polymerization of monomers with two or more trialkoxysilyl groups, the materials are highly cross-linked amorphous polymers that are readily obtained as gels. The bridging configuration of the hydrocarbon group insures that network polymers are readily formed and that the organic functionality is homogeneously distributed throughout the polymeric scaffolding at the molecular level. This permits the bulk properties, including surface area, pore size, and dielectric constant to be engineered through the selection of the bridging organic group. Numerous bridging groups have been incorporated. This presentation will focus on the effects that the length, flexibility, and substitution geometry of the hydrocarbon bridging groups have on the properties of the resulting bridged polysilsesquioxanes. Details of the preparation, characterization, and some structure property relationships of these bridged polysilsesquioxanes will be given.
Climbing techniques for bridge inspection
NASA Astrophysics Data System (ADS)
Kaslan, Erol C.
1998-03-01
California has about 24,000 publicly owned bridges that require routine structural evaluations to comply with National Bridge Inspection Standard (NBIS) mandates. Of these, about 800 are identified as possessing fatigue prone or fracture critical details requiring thorough tactile investigations. Gaining access to bridge elements to perform these investigations has become increasingly difficult and costly. The traditional uses of under bridge inspection trucks, lift equipment and rigging are economically and practically limited by bridge size, structure type, traffic demands and support costs. In some cases, bridges that have become damaged by earthquakes cannot safely support the loads of heavy personnel lift equipment. The California Department of Transportation (Caltrans)'s Office of Structural Materials and Office of Structure Maintenance and Investigations evaluated the use of rock climbing and mountaineering techniques as an alternative means of gaining access for bridge inspections. Under a small research grant, a bridge climbing training course was developed through a local University of California outdoor recreation group and 7 engineers and technicians were initially trained. A comprehensive Code of Safe Practices was created and standards of training, procedures and equipment required for bridge inspections were established. A successful climb investigation on a large, previously inaccessible arch bridge was completed at the end of the training that proved the techniques safe, economical and effective. Within one year, 20 bridge maintenance engineers were trained, and a formal program was established to organize, schedule, equip and certify engineers and technicians for bridge climbing. Several other offices within Caltrans as well as the California Department of Water Resources have since adopted these techniques for specialized structural inspection tasks. Climbing techniques are now used routinely in California as an alterative means of gaining access to bridges and structures, and over 100 bridges have been identified as those where climbing is the only means available to perform structural investigations.
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.
Allelic Skewing of DNA Methylation Is Widespread across the Genome
Schalkwyk, Leonard C.; Meaburn, Emma L.; Smith, Rebecca; Dempster, Emma L.; Jeffries, Aaron R.; Davies, Matthew N.; Plomin, Robert; Mill, Jonathan
2010-01-01
DNA methylation is assumed to be complementary on both alleles across the genome, although there are exceptions, notably in regions subject to genomic imprinting. We present a genome-wide survey of the degree of allelic skewing of DNA methylation with the aim of identifying previously unreported differentially methylated regions (DMRs) associated primarily with genomic imprinting or DNA sequence variation acting in cis. We used SNP microarrays to quantitatively assess allele-specific DNA methylation (ASM) in amplicons covering 7.6% of the human genome following cleavage with a cocktail of methylation-sensitive restriction enzymes (MSREs). Selected findings were verified using bisulfite-mapping and gene-expression analyses, subsequently tested in a second tissue from the same individuals, and replicated in DNA obtained from 30 parent-child trios. Our approach detected clear examples of ASM in the vicinity of known imprinted loci, highlighting the validity of the method. In total, 2,704 (1.5%) of our 183,605 informative and stringently filtered SNPs demonstrate an average relative allele score (RAS) change ?0.10 following MSRE digestion. In agreement with previous reports, the majority of ASM (?90%) appears to be cis in nature, and several examples of tissue-specific ASM were identified. Our data show that ASM is a widespread phenomenon, with >35,000 such sites potentially occurring across the genome, and that a spectrum of ASM is likely, with heterogeneity between individuals and across tissues. These findings impact our understanding about the origin of individual phenotypic differences and have implications for genetic studies of complex disease. PMID:20159110
Streambed stresses and flow around bridge piers
Parola, A.C.; Ruhl, K.J.; Hagerty, D.J.; Brown, B.M.; Ford, D.L.; Korves, A.A.
1996-01-01
Scour of streambed material around bridge foundations by floodwaters is the leading cause of catastrophic bridge failure in the United States. The potential for scour and the stability of riprap used to protect the streambed from scour during extreme flood events must be known to evaluate the likelihood of bridge failure. A parameter used in estimating the potential for scour and removal of riprap protection is the time-averaged shear stress on the streambed often referred to as boundary stress. Bridge components, such as bridge piers and abutments, obstruct flow and induce strong vortex systems that create streambed or boundary stresses significantly higher than those in unobstructed flow. These locally high stresses can erode the streambed around pier and abutment foundations to the extent that the foundation is undermined, resulting in settlement or collapse of bridge spans. The purpose of this study was to estimate streambed stresses at a bridge pier under full-scale flow conditions and to compare these stresses with those obtained previously in small-scale model studies. Two-dimensional velocity data were collected for three flow conditions around a bridge pier at the Kentucky State Highway 417 bridge over the Green River at Greensburg in Green County, Ky. Velocity vector plots and the horizontal component of streambed stress contour plots were developed from the velocity data. The streambed stress contours were developed using both a near-bed velocity and velocity gradient method. Maximum near-bed velocities measured at the pier for the three flow conditions were 1.5, 1.6, and 2.0 times the average near-bed velocities measured in the upstream approach flow. Maximum streambed stresses for the three flow conditions were determined to be 10, 15, and 36 times the streambed stresses of the upstream approach flow. Both the near-bed velocity measurements and approximate maximum streambed stresses at the full-scale pier were consistent with those observed in experiments using small-scale models in which similar data were collected, except for a single observation of the near-bed velocity data and the corresponding streambed stress determination. The location of the maximum streambed stress was immediately downstream of a 90 degree radial of the upstream cylinder (with the center of the upstream cylinder being the origin) for the three flow conditions. This location was close to the flow wake separation point at the upstream cylinder. Other researchers have observed the maximum streambed stress around circular cylinders at this location or at a location immediately upstream of the wake separation point. Although the magnitudes of the estimated streambed stresses measured at the full-scale pier were consistent with those measured in small-scale model studies, the stress distributions were significantly different than those measured in small-scale models. The most significant discrepancies between stress contours developed in this study and those developed in the small-scale studies for flow around cylindrical piers on a flat streambed were associated with the shape of the stress contours. The extent of the high stress region of the streambed around the full-scale pier was substantially larger than the diameter of the upstream cylinder, while small-scale models had small regions compared to the diameter of the model cylinders. In addition, considerable asymmetry in the stress contours was observed. The large region of high stress and asymmetry was attributed to several factors including (1) the geometry of the full-scale pier, (2) the non-planar topography of the streambed, (3) the 20 degree skew of the pier to the approaching flow, and (4) the non-uniformity of the approach flow. The extent of effect of the pier on streambed stresses was found to be larger for the full-scale site than for model studies. The results from the model studies indicated that the streambed stresses created by the obstruction of flow by the 3-foot wide pi
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.
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.
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.
Technics: Thermal bridges in buildings
Tuluca, A.
1992-12-01
One of the biggest problems in buildings is also one frequently overlooked: the myriad paths by which heat can escape to the outside. Thermal bridges,' in particular, can greatly increase a building's operating costs over its life. Accordingly, the architect must know how and where thermal bridges occur and how to prevent them, when preparing the construction documents. The term thermal bridge is generally used to designate the zone of a wall, roof, of floor that loses much more heat than surrounding areas during the heating season. To spot a thermal bridge, the principles governing movement of heat across floors, roofs, and walls must be understood, as well as knowing what happens when heat loss is concentrated in small areas of the envelope. The article addresses the basic causes of thermal bridges, highlights the damage thermal bridges can cause, and suggests remedial measures.
47 CFR 80.331 - Bridge-to-bridge communication procedure.
Code of Federal Regulations, 2011 CFR
2011-10-01
...Telecommunication 5 2011-10-01 2011-10-01 false Bridge-to-bridge communication procedure. 80.331 Section 80...Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a)...
47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.
Code of Federal Regulations, 2014 CFR
2014-10-01
...Telecommunication 5 2014-10-01 2014-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section...SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge Act § 80.1007...
47 CFR 80.331 - Bridge-to-bridge communication procedure.
Code of Federal Regulations, 2013 CFR
2013-10-01
...Telecommunication 5 2013-10-01 2013-10-01 false Bridge-to-bridge communication procedure. 80.331 Section 80...Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a)...
47 CFR 80.331 - Bridge-to-bridge communication procedure.
Code of Federal Regulations, 2014 CFR
2014-10-01
...Telecommunication 5 2014-10-01 2014-10-01 false Bridge-to-bridge communication procedure. 80.331 Section 80...Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a)...
47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.
Code of Federal Regulations, 2011 CFR
2011-10-01
...Telecommunication 5 2011-10-01 2011-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section...SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge Act § 80.1007...
47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.
Code of Federal Regulations, 2012 CFR
2012-10-01
...Telecommunication 5 2012-10-01 2012-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section...SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge Act § 80.1007...
47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.
Code of Federal Regulations, 2013 CFR
2013-10-01
...Telecommunication 5 2013-10-01 2013-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section...SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge Act § 80.1007...
47 CFR 80.331 - Bridge-to-bridge communication procedure.
Code of Federal Regulations, 2012 CFR
2012-10-01
...Telecommunication 5 2012-10-01 2012-10-01 false Bridge-to-bridge communication procedure. 80.331 Section 80...Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a)...
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...
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...
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.
The Adaptive Use Bridge Project
NSDL National Science Digital Library
University of Massachusetts, Amherst
The Adaptive Use Bridge Project website is a repository for work being conducted at the University of Massachusetts, Amherst, in which historic iron bridges are rehabilitated, documented, and analyzed. The purpose of the project is to preserve the civil engineering heritage of New England and to develop instructional material for use in undergraduate civil engineering curricula. Upon completion of this long-term project, a protocol for adaptive pedestrian use of historic bridges will be created.
Ion bridges in microfluidic systems
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
Recent Innovation for Concrete Highway Bridges
Recent Innovation for Concrete Highway Bridges S. H. Rizkalla' and A. A. Mufti2 Abstract A new generation of concrete highway bridges has recently been built in Canada using new design concepts and construction of three bridges. The first smart concrete highway bridge (Centre Street, Beddington Bridge
The past, present and future of reproductive skew theory and experiments.
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
El Amawy, A.; Latisfi, S. . Dept. of Electrical and Computer Engineering)
1990-09-01
The problem of reducing the diameter of a hypercube-based structure by adding some redundant links to the standard hypercube is considered. A new architecture called {ital Bridged Hypercube} (BHC) is introduced. It is shown that the BHC diameter is approximately half the diameter of its hypercube counterpart. For this design, simple and efficient routing algorithms are devised and proved correct. The incremental cost of the proposed link redundancy vanishes as the dimensionality of the hypercube grows yielding an asymptotically overhead free design.
Nasal Bridge Intramuscular Hemangioma
Hamir Basah, Zulkifli; Ramza Ramli, Ramiza; Gayadh, Maha Khadum; Mutum, Samarendra Singh
2015-01-01
Intramuscular haemangioma (IMH) is a benign mesenchymal tumour. It appears as a deep, nontender mass within the soft tissue, particularly in the extremities. This tumour may not be obvious on clinical examination. Head and neck IMHs represent only 13.5% of the total IMHs. The most common site for a head and neck IMH is the masseter muscle, followed by trapezius, sternocleidomastoid, and very rarely temporalis muscle. We present a patient with left nasal bridge swelling which was excised and histologically confirmed as intramuscular hemangioma. PMID:25709848
Julià, Olga; Vidal-Mas, Jaume; Panikov, Nicolai S.; Vives-Rego, Josep
2010-01-01
We report a skew-Laplace statistical analysis of both flow cytometry scatters and cell size from microbial strains primarily grown in batch cultures, others in chemostat cultures and bacterial aquatic populations. Cytometry scatters best fit the skew-Laplace distribution while cell size as assessed by an electronic particle analyzer exhibited a moderate fitting. Unlike the cultures, the aquatic bacterial communities clearly do not fit to a skew-Laplace distribution. Due to its versatile nature, the skew-Laplace distribution approach offers an easy, efficient, and powerful tool for distribution of frequency analysis in tandem with the flow cytometric cell sorting. PMID:20592754
Julià, Olga; Vidal-Mas, Jaume; Panikov, Nicolai S; Vives-Rego, Josep
2010-01-01
We report a skew-Laplace statistical analysis of both flow cytometry scatters and cell size from microbial strains primarily grown in batch cultures, others in chemostat cultures and bacterial aquatic populations. Cytometry scatters best fit the skew-Laplace distribution while cell size as assessed by an electronic particle analyzer exhibited a moderate fitting. Unlike the cultures, the aquatic bacterial communities clearly do not fit to a skew-Laplace distribution. Due to its versatile nature, the skew-Laplace distribution approach offers an easy, efficient, and powerful tool for distribution of frequency analysis in tandem with the flow cytometric cell sorting. PMID:20592754
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.
Modeling absolute differences in life expectancy with a censored skew-normal regression approach
Clough-Gorr, Kerri; Zwahlen, Marcel
2015-01-01
Parameter estimates from commonly used multivariable parametric survival regression models do not directly quantify differences in years of life expectancy. Gaussian linear regression models give results in terms of absolute mean differences, but are not appropriate in modeling life expectancy, because in many situations time to death has a negative skewed distribution. A regression approach using a skew-normal distribution would be an alternative to parametric survival models in the modeling of life expectancy, because parameter estimates can be interpreted in terms of survival time differences while allowing for skewness of the distribution. In this paper we show how to use the skew-normal regression so that censored and left-truncated observations are accounted for. With this we model differences in life expectancy using data from the Swiss National Cohort Study and from official life expectancy estimates and compare the results with those derived from commonly used survival regression models. We conclude that a censored skew-normal survival regression approach for left-truncated observations can be used to model differences in life expectancy across covariates of interest.
Generalized Skew Coefficients of Annual Peak Flows for Rural, Unregulated Streams in West Virginia
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.
Modeling absolute differences in life expectancy with a censored skew-normal regression approach.
Moser, André; Clough-Gorr, Kerri; Zwahlen, Marcel
2015-01-01
Parameter estimates from commonly used multivariable parametric survival regression models do not directly quantify differences in years of life expectancy. Gaussian linear regression models give results in terms of absolute mean differences, but are not appropriate in modeling life expectancy, because in many situations time to death has a negative skewed distribution. A regression approach using a skew-normal distribution would be an alternative to parametric survival models in the modeling of life expectancy, because parameter estimates can be interpreted in terms of survival time differences while allowing for skewness of the distribution. In this paper we show how to use the skew-normal regression so that censored and left-truncated observations are accounted for. With this we model differences in life expectancy using data from the Swiss National Cohort Study and from official life expectancy estimates and compare the results with those derived from commonly used survival regression models. We conclude that a censored skew-normal survival regression approach for left-truncated observations can be used to model differences in life expectancy across covariates of interest. PMID:26339544
BridgeSPA: Improving Tor Bridges with Single Packet Authorization
Hengartner, Urs
BridgeSPA: Improving Tor Bridges with Single Packet Authorization Rob Smits rdfsmits@cs.uwaterloo.ca ABSTRACT Tor is a network designed for low-latency anonymous com- munications. Tor clients form circuits these circuits. This indirection makes it difficult for a local adversary to determine with whom a particular Tor
5. North side of throughtruss bridge over railroad tracks (bridge ...
5. North side of through-truss bridge over railroad tracks (bridge #U182512605). View to southwest. - South Omaha Union Stock Yards, "O" Street Viaduct, "O" Street Spanning Hog Pens; South Omaha Terminal Railway Company Tracks & Union Pacific Railroad Tracks, Omaha, Douglas County, NE
20. Bronx Kill Bridge with Hell Gate Bridge in background. ...
20. Bronx Kill Bridge with Hell Gate Bridge in background. Randalls Island, New York Co., NY. Sec. 4207, MP 8.54. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York, New York County, NY
16. Little Hell Gate Bridge with Big Hell Gate Bridge ...
16. Little Hell Gate Bridge with Big Hell Gate Bridge in background. Wards Island, New York Co., NY. Sec. 4207, MP 8.02. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York, New York County, NY
Bridging Brown County Case Study Bridging Brown County Case Study
Minnesota, University of
the county. This organization, Bridging Brown County (BBC) has found a way to bridge cities and towns Demographics (2000) County Population: 26,911 Largest City: New Ulm, pop. 13,594 Land area: 610.9 sq. mi volunteers to assist in field clean up efforts in the communities of Hanska and Comfrey, she learned
BRIDGE Curriculum Guide. Exploring the BRIDGE to Success.
ERIC Educational Resources Information Center
Baker, Andrea
This guide, designed for use in a ninth grade BRIDGE class, is a comprehensive source of learning activities intended to help motivate youth to stay in school and acquire the skills required to succeed both in school and at work. BRIDGE, a program conceived by Public/Private Ventures in Philadelphia (Pennsylvania), is for high-risk students in…
33 CFR 115.40 - Bridge repairs.
Code of Federal Regulations, 2012 CFR
2012-07-01
...Waters 1 2012-07-01 2012-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE...
49 CFR 236.713 - Bridge, movable.
Code of Federal Regulations, 2014 CFR
2014-10-01
...Transportation 4 2014-10-01 2014-10-01 false Bridge, movable. 236.713 Section 236.713 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.713 Bridge, movable. That section of a structure bridging a...
33 CFR 115.40 - Bridge repairs.
Code of Federal Regulations, 2011 CFR
2011-07-01
...Waters 1 2011-07-01 2011-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE...
33 CFR 115.40 - Bridge repairs.
Code of Federal Regulations, 2014 CFR
2014-07-01
...Waters 1 2014-07-01 2014-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE...
33 CFR 115.40 - Bridge repairs.
Code of Federal Regulations, 2013 CFR
2013-07-01
...Waters 1 2013-07-01 2013-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE...
OFFICIAL PROCEEDINGS From the Building Bridges Conference
Walker, Lawrence R.
OFFICIAL PROCEEDINGS From the Building Bridges Conference September 15-16, 2014 & Clinical Studies Sponsored by: Building Bridges Conference ISBN: 978.D. & Therese M. Cumming, Ph.D. Building Bridges Conference September 15-16, 2014
Wind-induced dynamic response of bridges
Rousseau, Guillaume, 1982-
2004-01-01
Wind loading has long played a significant role in bridge design. Some spectacular failures, such as the Tay Bridge (Scotland, 1879), or the Tacoma Narrows Bridge (Washington State, 1940) acted as a painful reminder to ...
Skewness in CMB temperature fluctuations from curved cosmic (super-)strings
Yamauchi, Daisuke; Sendouda, Yuuiti; Yoo, Chul-Moon; Naruko, Atsushi; Sasaki, Misao; Takahashi, Keitaro E-mail: sendouda@yukawa.kyoto-u.ac.jp E-mail: keitaro@a.phys.nagoya-u.ac.jp E-mail: misao@yukawa.kyoto-u.ac.jp
2010-05-01
We compute the one-point probability distribution function of small-angle cosmic microwave background temperature fluctuations due to curved cosmic (super-)strings with a simple model of string network by performing Monte Carlo simulations. Taking into account of the correlation between the curvature and the velocity of string segments, there appear non-Gaussian features, specifically non-Gaussian tails and a skewness, in the one-point pdf. The obtained sample skewness for the conventional field-theoretic cosmic strings is g{sub 1} ? ?0.14, which is consistent with the result reported by Fraisse et al. We also discuss the dependence of the pdf on the intercommuting probability. We find that the standard deviation of the Gaussian part increases and non-Gaussian features are suppressed as the intercommuting probability decreases. For sufficiently small intercommuting probability, the skewness is given by ?< (a few) × 10{sup ?2}.
Single series skewness representation for passive scalar advection in laminar pipe and channel flow
NASA Astrophysics Data System (ADS)
Camassa, Roberto; Bernardi, Francesca; McLaughlin, Richard; Mertens, Keith
2012-11-01
In this talk, we present an exact single series representation for scalar skewness time evolution. Prior studies have naturally derived multiple nested Fourier series solutions which suffer from slow convergence and cloud physical interpretation. Judicious change of variables and complex residue theory lead to single series representation formulae for the moments along streamwise slices from which quantities such as variance and skewness can be reconstructed. Small and long time asymptotics will be discussed for the first three moments in both channel and pipe geometries in steady Poiseuille flows. Comparisons of theory with Monte Carlo simulations and preliminary experiments exhibit differences between channel and pipe flows in the skewness evolution. This research is supported by NSF RTG DMS-0502266, NSF RTG DMS-0943851, NSF RAPID CBET-1045653, NSF CMG ARC-1025523, NSF DMS-1009750, and ONR DURIP N00014-09-1-0840.
Perceived quality of wood images influenced by the skewness of image histogram
NASA Astrophysics Data System (ADS)
Katsura, Shigehito; Mizokami, Yoko; Yaguchi, Hirohisa
2015-08-01
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.
Four-dimensional lattice rules generated by skew-circulant matrices.
Lyness, J. N.; Sorevik, T.; Mathematics and Computer Science; Univ. of Bergen
2003-01-01
We introduce the class of skew-circulant lattice rules. These are s-dimensional lattice rules that may be generated by the rows of an s x s skew-circulant matrix. (This is a minor variant of the familiar circulant matrix.) We present briefly some of the underlying theory of these matrices and rules. We are particularly interested in finding rules of specified trigonometric degree d. We describe some of the results of computer-based searches for optimal four-dimensional skew-circulant rules. Besides determining optimal rules for {delta} = d + 1 {<=} 47, we have constructed an infinite sequence of rules Q(4, {delta}) that has a limit rho index of 27/34 {approx} 0.79. This index is an efficiency measure, which cannot exceed 1, and is inversely proportional to the abscissa count.
Skew Information for a single Cooper Pair Box interacts with a single cavity Mode
N. Metwally; A. Al-Mannai; M. Abdel-Aty
2012-10-28
The dynamics of the skew information (SI) is investigated for a single Cooper Pair Box,CPB interacts with a single cavity mode. The effect of the cavity and CPB's parameters on the SI is discussed. We show that, it is possible to increase the skew information to reach its maximum value either by increasing the number of photons inside the cavity or considering non-resonant case with larger detuning parameter. The effect of the relative ratio of Josephson junction capacity and the gate capacity is investigated, where the number of oscillations of the skew information increases by decreasing this ratio and consequently the travelling time between the maximum and minimum values decreases.
Modeling the effects of wave skewness and beach cusps on littoral sand transport
Haas, K.A.; Check, L.A.; Hanes, D.M.
2008-01-01
A process-based numerical modeling system is utilized for predicting littoral sand transport. The intent is to examine conditions slightly more complex than linear waves impinging upon a plane beach. Two factors that we examine are wave skewness and longshore varying bathymetry. An empirical model is used for calculating the skewed bottom wave orbital velocity. The advection of sediment due to the skewed wave velocity is larger and in the direction of the waves, opposite to the results with sinusoidal wave velocities, due to the increase in the bottom shear stress under the wave crests. The model system is also applied to bathymetry containing beach cusps. When the wave field has relatively weak longshore wave power, the currents and the littoral transport exhibit significant longshore variability, thereby altering the overall mean littoral transport.
SAC Bridge Program Program Description
Shyu, Mei-Ling
SAC Bridge Program Program Description Bridge grants are intended to assist faculty at all levels of Medicine are eligible. · Applicants must have held significant extramural funding for the proposed project, and all R-level NIH grants are eligible. · Applicants must have applied for continued extramural funding
Bridge Building: Art and Science
NSDL National Science Digital Library
This site is one of the most substantial, comprehensive sources on the Internet dedicated to bridge design and history. It has an incredible list of sections from which to choose, and each describes a particular bridge type or characteristic. Several pictures are included from all over the world that give examples of arch, truss, suspension, and many other bridge designs. There are also explanations of forces that act upon bridges, as well as what issues are considered when choosing the kind of bridge to build over a span. Perhaps the only drawback to the site is that there is so much information; the main page seems a bit cluttered. However, it does not really hamper navigating the site.
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.
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.
Modified Gelfand-Tseltin patterns, lattice permutations, and skew-tableau polynomials
Louck, James D.
2002-01-01
A modification of the well-known Gelfand-Tsetlin patterns, which are one-to-one with Young-Weyl standard tableaux is introduced. These new patterns are in one-to-one correspondence with skew-tableaux, and with a slight modification can be used to enumerate lattice permutations. In particular the coupling rule for angular momentum takes an elementary form in terms of these modified patterns. These interrelations will be presented, together with an outline of the construction of a class of polynomials that generalizes the skew Schur functions.
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.
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.
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.
NASA Technical Reports Server (NTRS)
Deissler, Robert G.
1990-01-01
The variation of the velocity-derivative skewness of a Navier-Stokes flow as the Reynolds number goes toward zero is calculated numerically. The value of the skewness, which has been somewhat controversial, is shown to become small at low Reynolds numbers.
Increasing Skewness of the Vertical Velocity Distribution Shifts Rainfall to Heavier Rates
NASA Astrophysics Data System (ADS)
Pendergrass, A. G.
2014-12-01
How will the distributions of precipitation and vertical velocity change in response to global warming? Global-average rainfall increases more slowly than extreme rain rates with warming, implying a change in the shape of the rainfall distribution. At the same time, the tropical vertical velocity distribution weakens, particularly its asymmetric component (the Walker circulation). Recent work by the author shows that the distribution of daily rainfall shifts to heavier rain rates in response to global warming and ENSO phases in climate models. Observations confirm the shift in response to ENSO phases. Using an heuristic model relating the distributions of rainfall and vertical velocity, we show that an increase in skewness of the vertical velocity distribution replicates the shift of the precipitation distribution to heavier rain rates with warming. The skewness is the third moment of a statistical distribution, which measures its asymmetry. Implications of the increase in skewness of vertical velocity include and increase in dry days and a corresponding decrease in rain falling at moderate rain rates. When increased moistening that occurs with warming is also accounted for, the projected increase of extreme rainfall faster than the increase in the mean emerges. In contrast, broadening the vertical velocity distribution fails to replicate salient characteristics of the projected change in the rainfall distribution like the increase in dry day frequency. Climate models also show an increase in the skewness of daily-average vertical velocity in global warming simulations in most models.
Low Power Discrete Voltage Assignment Under Clock Skew , Jian Sun2
Zhou, Hai
, Hai Zhou1 , Xuan Zeng2 1 Electrical Engineering and Computer Science Department, Northwestern Abstract--Multiple Supply Voltage (MSV) assignment has emerged as an appealing technique in low power IC design, due to its flexibility in balancing power and performance. However, clock skew scheduling, which
On effects of skewed and asymmetric oscillatory flows on cohesive sediment flux: Numerical study
NASA Astrophysics Data System (ADS)
Son, Minwoo; Lee, Guan-Hong
2013-07-01
To investigate the effects of wave shape on cohesive sediment flux in shallow water environments, a one-dimensional vertical (1DV) model for cohesive sediment transport previously validated with field measurement is applied to conditions of skewed and asymmetric oscillatory flows. Cohesive sediments usually portray behaviors different from those of noncohesive sediments. This is mainly due to the flocculation process through which the density and the size of cohesive sediment change continuously. Therefore, a robust flocculation model is incorporated with a 1DV model in this study. Under the condition of skewed oscillatory flow (second-order Stokes wave-type oscillatory flow), the flux of cohesive sediment is significantly affected by the change of flow skewness, whereas the flux of noncohesive sediment of which size is 100 µm does not show a clear relationship with skewness. Under the condition of forward-leaning asymmetric oscillatory flow (saw-tooth wave-type oscillatory flow), the direction of cohesive sediment flux is negative, whereas the flux of noncohesive sediment shows the positive direction. The phase-lag effect is considered as the main mechanism of these behaviors. The interactional relationship between the settling velocity, the variation of concentration profile, and hydrodynamics of carrier fluid enhances the phase-lag effect and causes different behaviors in cohesive sediment compared to the flux of fine noncohesive sediment.
Cohen's Class Distributions for Skew Angle Estimation in Noisy Ancient Arabic Documents
Paris-Sud XI, Université de
Cohen's Class Distributions for Skew Angle Estimation in Noisy Ancient Arabic Documents N. Ouwayed documents using the energy distributions of Cohen's class. The presence of noise in raw docu- ment images propose to use Cohen's class distributions on the projection histogram profiles ob- tained using different
Skewing (n +1) Tensor Indices where the Index Range is n
ERIC Educational Resources Information Center
Agacy, R. L.
2005-01-01
It is known that any totally skew quantity with (n + 1) indices, each of which ranges over n values, vanishes identically. The aim of this short note is to show that this is equivalent to the simple fact that any (n + 1) vectors in an n-dimensional vector space are linearly dependent.
Skewed Flowering Distributions and Pollinator Attraction Author(s): James D. Thomson
Thomson, James D.
holds is the distribution of a plant population's flowering in time. If one graphs the number of flowers in bloom vs. time, the resulting flowering curve can be treated as a resource utilization functionSkewed Flowering Distributions and Pollinator Attraction Author(s): James D. Thomson Source
Optimal Clock Skew Scheduling Tolerant to Process Variations Jos Luis Neves and Eby G. Friedman
Friedman, Eby G.
Optimal Clock Skew Scheduling Tolerant to Process Variations José Luis Neves and Eby G. Friedman failure independent of the clock frequency (i.e., race conditions). In [1,2], it is demonstrated de Desenvolvimento Científico e Tecnológico) - Brazil, the National Science Foundation under Grant No
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.
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…
Statistical models for the analysis of skewed healthcare cost data: a simulation study.
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
An analytical algorithm for skew-slit imaging geometry with nonuniform attenuation correction
Huang Qiu; Zeng, Gengsheng L.
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.
PGR: Period and Glitch Reduction Via Clock Skew Scheduling, Delay Padding and GlitchLess
Lemieux, Guy
PGR: Period and Glitch Reduction Via Clock Skew Scheduling, Delay Padding and GlitchLess Xiao Dong) and delay padding (DP). It is integrated into VPR 5.0, and is invoked after the routing stage. We use% speedup can be achieved via CSS alone, or up to 37% for individual circuits. Although delay padding only
PGR: Period and glitch reduction via clock skew scheduling, delay padding and GlitchLess
Xiao Dong; G. G. F. Lemieux
2009-01-01
This paper describes PGR, an architectural technique to reduce dynamic power via GlitchLess or to improve performance via clock skew scheduling (CSS) and delay padding (DP). It is integrated into VPR 5.0, and is invoked after the routing stage. We use programmable delay elements (PDEs) as a novel architecture modification to insert delay on FF clock inputs, enabling all optimization
11Skewed Distribution of Species Number in Grass Genera: Is It
Hilu, Khidir
165 11Skewed Distribution of Species Number in Grass Genera: Is It a Taxonomic Artefact? K. W. Hilu........................................................................................................................ 165 11.2 The Grass Family (Poaceae .................................................................................................................................... 176 ABSTRACT The grass family (Poaceae) comprises about 10,000 species distributed in some 785 genera
Parallel spinors and connections with skew-symmetric torsion in string theory
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 $\\\
Stanley's Zrank Problem on Skew Partitions William Y. C. Chen1
Chen, Bill
Stanley's Zrank Problem on Skew Partitions William Y. C. Chen1 and Arthur L. B. Yang2 Center for Combinatorics, LPMC Nankai University, Tianjin 300071, P. R. China Email: 1 chen@nankai.edu.cn, 2 yang], and further studied by Chen and Louck [4], Goulden and Greene [8], Macdonald [10], Chen, Li and Louck [5
Droplet Solutions in the Diblock Copolymer Problem with Skewed Monomer Composition
Ren, Xiaofeng
Droplet Solutions in the Diblock Copolymer Problem with Skewed Monomer Composition Xiaofeng Ren solution characterizes the lamellar phase of a diblock copolymer when the two composing monomers maintain copolymer molecule is a linear sub-chain of NA A-monomers grafted covalently to an- other sub-chain of NB B-monomers
The Curious Anomaly of Skewed Judgment Distributions and Systematic Error in the Wisdom of Crowds
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
Concurrent Support of Multiple Page Sizes On a Skewed Associative TLB
Seznec, AndrÃ©
space for unused data or instructions. On the other hand, using a large page size results in a singleConcurrent Support of Multiple Page Sizes On a Skewed Associative TLB AndrÂ´e Seznec to appear, France Abstract Some architecture definitions (e.g. Alpha) allows the use of multiple virtual page sizes
ON NONUNIFORM EXPONENTIAL STABILITY FOR SKEW-EVOLUTION SEMIFLOWS ON BANACH SPACES
Paris-Sud XI, Université de
ON NONUNIFORM EXPONENTIAL STABILITY FOR SKEW-EVOLUTION SEMIFLOWS ON BANACH SPACES CODRUT¸A STOICA-evolution semiflows on Banach spaces. The ob- tained results clarify differences between the uniform and nonuniform on Banach spaces. These seem to be more appropriate for the study of evolution equations in the nonuniform
Mitigation of patterning effects at 40 Gbits/s by skewed channel pre-encoding
NASA Astrophysics Data System (ADS)
Slater, Brendan; Boscolo, Sonia; Shafarenko, Alex; Turitsyn, Sergei K.
2007-08-01
Through direct modeling, a reduction of pattern-dependent errors in a standard fiber-based transmission link at 40 Gbits/s rate is demonstrated by application of a skewed data pre-encoding. The trade-off between the improvement of the bit error rate and the loss in the data rate is examined.
A modi ed RIO algorithm that alleviates the bandwidth skew problem in Internet Di erentiated Service
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
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
On some confidence intervals for estimating the mean of a skewed population
W. Shi; B. M. Golam Kibria
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 order to compare the performance of these intervals, the
Bayesian Comparison of GARCH Processes with Skewness Mechanism in Conditional Distributions
NASA Astrophysics Data System (ADS)
Pipien, M.
2006-11-01
The main goal of this paper is an application of Bayesian model comparison, based on the posterior probabilities and posterior odds ratios, in testing the explanatory power of a set of competing GARCH (Generalized Autoregressive Conditionally Heteroscedastic) specifications, all with asymmetric and heavy tailed conditional distributions. In building competing volatility models we consider, as an initial specification, conditionally Student-t GARCH process with unknown degrees of freedom parameter. By introducing skewness into Student-t family and incorporating the resulting class as a conditional distribution we generated various GARCH models, which compete in explaining possible asymmetry of both conditional and unconditional distribution of financial data. In order to make Student-t family skewed we consider various alternative mechanisms recently proposed in the literature. In particular, we apply the hidden truncation mechanism, an approach based on the inverse scale factors in the positive and the negative orthant, order statistics concept, Beta distribution transformation and Bernstein density transformation. Additionally, we consider GARCH process with conditional alpha -Stable distribution. Based on the daily returns of hypothetical financial time series, we discuss the results of Bayesian comparison of alternative skewing mechanisms applied in the initial Student-t GARCH framework. Additionally, we present formal Bayesian inference about conditional asymmetry of the distribution of the daily returns in all competing specifications on the basis of the skewness measure defined by Arnold and Groenveld.
On the skew-symmetric character of the couple-stress tensor
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.
Using social parasitism to test reproductive skew models in a primitively eusocial wasp.
Green, Jonathan P; Cant, Michael A; Field, Jeremy
2014-08-22
Remarkable variation exists in the distribution of reproduction (skew) among members of cooperatively breeding groups, both within and between species. Reproductive skew theory has provided an important framework for understanding this variation. In the primitively eusocial Hymenoptera, two models have been routinely tested: concessions models, which assume complete control of reproduction by a dominant individual, and tug-of-war models, which assume on-going competition among group members over reproduction. Current data provide little support for either model, but uncertainty about the ability of individuals to detect genetic relatedness and difficulties in identifying traits conferring competitive ability mean that the relative importance of concessions versus tug-of-war remains unresolved. Here, we suggest that the use of social parasitism to generate meaningful variation in key social variables represents a valuable opportunity to explore the mechanisms underpinning reproductive skew within the social Hymenoptera. We present a direct test of concessions and tug-of-war models in the paper wasp Polistes dominulus by exploiting pronounced changes in relatedness and power structures that occur following replacement of the dominant by a congeneric social parasite. Comparisons of skew in parasitized and unparasitized colonies are consistent with a tug-of-war over reproduction within P. dominulus groups, but provide no evidence for reproductive concessions. PMID:24990668
Skewness and Kurtosis as Applied to a Portfolio in the Korean Stock Market
NASA Astrophysics Data System (ADS)
Ahn, Tae-Sung
2009-04-01
A well diversified portfolio is critical to prudent investment in a stock market. To lessen risk in a volatile market, portfolios should minimize dispersion. This paper analyzes skewness and kurtosis of businesses listed on Korean stock markets, e.g., KOSPI and KOSDAQ. It looks at distribution using the Gauss function, and examines how mean and variance can be applied in building a portfolio.
Skew angle effects in shingled magnetic recording system with double/triple reader head array
NASA Astrophysics Data System (ADS)
Elidrissi, Moulay Rachid; Sann Chan, Kheong; Greaves, Simon; Kanai, Yasushi; Muraoka, Hiroaki
2014-05-01
Shingled Magnetic Recording (SMR) is a scheme used to extend the life of the current perpendicular magnetic recording technology. SMR enables writing narrow tracks with a wide writer. Currently, SMR employs a single reader and will suffer inter-track interference (ITI) as the tracks become comparable in width to the reader. ITI can be mitigated by using narrower readers; however, narrower readers suffer from increased reader noise. Another approach to combat ITI is to process 2D readback and use ITI cancellation schemes to retrieve the data track. Multiple readbacks can be obtained either with a single reader and multiple revolutions or with a reader array. The former suffers from increased readback latency. In this work, we focus on the latter. When using a reader array, the skew angle poses major challenges. During writing, there is increased adjacent track erasure, and during readback the effective reader pitch varies and there is an increase in the 2D intersymbol interference caused by the rotated reader profile. In this work, we run micromagnetic simulations at different skew angles to train the grain flipping probability model, and then evaluate raw bit channel error rate performance at skew. In particular, we investigate the performance degradation caused by skewing of the 2 or 3 read head array for various read-head geometries.
Skew of mantle upwelling beneath the East Pacific Rise governs segmentation
Toomey, Doug
ARTICLES Skew of mantle upwelling beneath the East Pacific Rise governs segmentation Douglas R that the isotropic and anisotropic structure of the mantle is rotated beneath the East Pacific Rise. The isotropic of the rise crest between transform faults correlates well with the distribution of mantle melt. The azimuth
The Hermite Moment Model for Highly Skewed Response with Application to Tension Leg Platforms
Sweetman, Bert
The Hermite Moment Model for Highly Skewed Response with Application to Tension Leg Platforms Station, TX 77843-3136, USA A new addition to the statistical Hermite moment model of extremes of problems is what motivated the authors to develop this extension to the Hermite methodology. Other, less
Vibration analysis of the Second Saikai Bridge—a concrete filled tubular (CFT) arch bridge
NASA Astrophysics Data System (ADS)
Yoshimura, Mistuhiro; Wu, Qingxiong; Takahashi, Kazuo; Nakamura, Shozo; Furukawa, Kazuyoshi
2006-02-01
Concrete-filled steel tubular (CFT) arch bridges have been rapidly developing in China since 1990. Research has focused on the static behavior, thermal stress and erection technique, however, and there has been very little research of natural vibrations and dynamic responses of these bridges. Japan's first CFT arch bridge in highway bridges, the Second Saikai Bridge, is now under construction in Nagasaki Prefecture. Furthermore, this bridge has a pedestrian bridge that is suspended under the girder, which is rare. Therefore, the natural vibration properties are examined, and the influence of pedestrian bridge structure on the natural vibration of main bridge is discussed first. Response analysis under a moving vehicle and pedestrian is carried out, and the response characteristics and response level are clarified. The natural vibrations and responses are compared to those of CFT arch bridges that have been constructed in China. Results show the fine performance of both main bridge and pedestrian bridge of the Second Saikai Bridge.
User-friendly Indices for Bridge Management
Takashi Tamakoshi; Keita Nakasu; Ryoichi Watanabe
The Road Bureau of the Ministry of Land, Infrastructure and Transport (MLIT) is promoting scientific bridge management to effectively preserve the enormous number of bridges in Japan. In the process of strategic bridge management, it is important to explain the needs for preventive investment or management level of highway bridges using proper indices. The National Institute for Land and Infrastructure
Washed Out Bridge, Snake Creek Near Whitesburg
Tributary to Snake Creek, near Whitesburg, Georgia, showing a washed out bridge. When bridges such as this one collapse during a flood, it is rarely the pressure of the rushing water against the bridge that causes the bridge to fail. Rather, the rushing water erodes the ground underneath and surroun...
Bridges 2013 Poetry Anthology Sarah Glaz, Editor
Glaz, Sarah
Bridges 2013 Poetry Anthology Sarah Glaz, Editor Contents Introduction Poems by Bridges Enschede;Eveline Pye Solving Problems 27 Numerical Landscape 28 Statistics 29 Love of Algebra 30 Poems by Bridges Coimbra and Bridges Towson Featured Poets Marion Deutsche Cohen A Mathematician Should Never Watch Action
Bridges in highly connected graphs Paul Wollan
Wollan, Paul
Bridges in highly connected graphs Paul Wollan Department of Computer Science University of Rome of internally disjoint paths contained in a graph G and let S be the subgraph defined by t i=1 Pi. A P-bridge the edges from V (C) to V (S). The attachments of a bridge B are the vertices of V (B) V (S). A bridge B
Brownstone, Rob
Bridge Funding Overview: Bridge funding is designed to stabilize meritorious research programs that have lost extramural funding. Bridge funds are for one year and are intended to enhance the likelihood by the applicant's Department/Division. Applicants may only request bridge funding once per calendar year. Bridge
GAUVREAU, The Three Myths of Bridge Aesthetics, 1/8 THE THREE MYTHS OF BRIDGE AESTHETICS
Gauvreau, Paul
GAUVREAU, The Three Myths of Bridge Aesthetics, 1/8 THE THREE MYTHS OF BRIDGE AESTHETICS Paul wisdom on bridge aesthetics. If bridge design is to be recognized as a valid and distinct means of artistic expression, then bridges must reflect the truths that define the fundamental essence shared by all
WORLD WISE'99-Winnipeg, Manitoba Taylor Bridge -A Bridge For the 21st
WORLD WISE'99- Winnipeg, Manitoba Taylor Bridge - A Bridge For the 21st Century Taylor Bridge - A Bridge For the 21st Century Emile ShehataI, Rick Haldane-Wilsone1 , Doug Stewart!, Gamil Tadros2 and Sami and build the Taylor "smart" Bridge utilizing fibre reinforced polymer (FRP) reinforcing materials
2015 APPLICATION FORM BRIDGING TRIBAL COLLEGE STUDENTS TO MONTANA STATE UNIVERSITY (BRIDGES)
Maxwell, Bruce D.
2015 APPLICATION FORM BRIDGING TRIBAL COLLEGE STUDENTS TO MONTANA STATE UNIVERSITY (BRIDGES) MAY 29, BOZEMAN, MT 59717 Website: www.montana.edu/airo/bridges/ DEADLINE: FEBRUARY 16, 2015 Return application packet to your college's Bridges Program Coordinator OR MSU-AIRO: Bridges Program Coordinators: Aaniiih
Bridges of RWRE Bridges of Random Walks in a Random Environment
Peterson, Jonathon
Bridges of RWRE Bridges of Random Walks in a Random Environment Jonathon Peterson Cornell Jonathon Peterson 2/25/2010 1 / 24 #12;Bridges of RWRE Introduction Bridges of Random Walks Sn simple on {S2n = 0}? Cornell University Jonathon Peterson 2/25/2010 2 / 24 #12;Bridges of RWRE Introduction
EXTRACTION OF BRIDGE POSITONS FROM IKONOS IMAGES FOR ACCURACY COLTROL OF BRIDGE DATABASE
Jong-Hyeok JEONG; Masataka TAKAGI
A bridge database which has rough coordinates of bridges, was established and shared in a local government for the purpose of their maintenance. When bridges in the database overlaid with commonly used river and road data, they were not exist on near the intersections of roads and rivers. In previous studies, some bridges of bridge database were adjusted by using
SoftBridge: An Architecture for Building IP-based Bridges over the Digital Divide
Blake, Edwin
SoftBridge: An Architecture for Building IP-based Bridges over the Digital Divide John Lewis, Bill, effective communication between the different media has be able to bridge across these options: the bridges preferences and capabilities. Our research proposes a Soft- Bridge, an abstracted communications platform
Reynolds, Pamela L.; Bruno, John F.
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 been added, sometimes purposefully as in many freshwater systems, food webs are skewed in the opposite direction toward consumer dominance. Little is known about how such modifications to food web topology, e.g., changes in the ratio of predator to prey species richness, affect ecosystem functioning. We experimentally measured the effects of trophic skew on production in an estuarine food web by manipulating ratios of species richness across three trophic levels in experimental mesocosms. After 24 days, increasing macroalgal richness promoted both plant biomass and grazer abundance, although the positive effect on plant biomass disappeared in the presence of grazers. The strongest trophic cascade on the experimentally stocked macroalgae emerged in communities with a greater ratio of prey to predator richness (bottom-rich food webs), while stronger cascades on the accumulation of naturally colonizing algae (primarily microalgae with some early successional macroalgae that recruited and grew in the mesocosms) generally emerged in communities with greater predator to prey richness (the more top-rich food webs). These results suggest that trophic skewing of species richness and overall changes in food web topology can influence marine community structure and food web dynamics in complex ways, emphasizing the need for multitrophic approaches to understand the consequences of marine extinctions and invasions. PMID:22693549
Mineral bridges in nacre revisited
Antonio G. Checa; Julyan H. E. Cartwright; Marc-Georg Willinger
2012-07-20
We confirm with high-resolution techniques the existence of mineral bridges between superposed nacre tablets. In the towered nacre of both gastropods and the cephalopod Nautilus there are large bridges aligned along the tower axes, corresponding to gaps (150-200 nm) in the interlamellar membranes. Gaps are produced by the interaction of the nascent tablets with a surface membrane that covers the nacre compartment. In the terraced nacre of bivalves bridges associated with elongated gaps in the interlamellar membrane (> 100 nm) have mainly been found at or close to the edges of superposed parental tablets. To explain this placement, we hypothesize that the interlamellar membrane breaks due to differences in osmotic pressure across it when the interlamellar space below becomes reduced at an advanced stage of calcification. In no cases are the minor connections between superimposed tablets (< 60 nm), earlier reported to be mineral bridges, found to be such.
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.
Development of Inspection Robots for Bridge Cables
Kim, Se-Hoon; Lee, Jong-Jae
2013-01-01
This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented. PMID:24459453
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.
Roland E. Allen
2013-12-01
The particle recently discovered at the Large Hadron Collider near Geneva is almost certainly a Higgs boson, the long-sought completion of the Standard Model of particle physics. But this discovery, an achievement by more than six thousand scientists (including students), is actually much more than a mere capstone of the Standard Model. It instead represents a bridge from the Standard Model to exciting discoveries of the future, at higher energies or in other experiments, and to the properties of matter at very low temperatures. The mere existence of a particle with zero spin implies a need for new physics, with the most likely candidate being supersymmetry, which requires that every known particle has a superpartner yet to be discovered. And phenomena similar to the Higgs are seen in superconducting metals and superfluid gases at low temperatures, which extend down to a millionth or even a billionth of a degree Kelvin. So the discovery of a Higgs boson has a central place in our attempts both to achieve a true understanding of Nature and to harness Nature in practical applications.
Bridging Anticoagulation: Primum Non Nocere.
Rechenmacher, Stephen J; Fang, James C
2015-09-22
Chronic oral anticoagulation frequently requires interruption for various reasons and durations. Whether or not to bridge with heparin or other anticoagulants is a common clinical dilemma. The evidence to inform decision making is limited, making current guidelines equivocal and imprecise. Moreover, indications for anticoagulation interruption may be unclear. New observational studies and a recent large randomized trial have noted significant perioperative or periprocedural bleeding rates without reduction in thromboembolism when bridging is employed. Such bleeding may also increase morbidity and mortality. In light of these findings, physician preferences for routine bridging anticoagulation during chronic anticoagulation interruptions may be too aggressive. More randomized trials, such as PERIOP2 (A Double Blind Randomized Control Trial of Post-Operative Low Molecular Weight Heparin Bridging Therapy Versus Placebo Bridging Therapy for Patients Who Are at High Risk for Arterial Thromboembolism), will help guide periprocedural management of anticoagulation for indications such as venous thromboembolism and mechanical heart valves. In the meantime, physicians should carefully consider both the need for oral anticoagulation interruption and the practice of routine bridging when anticoagulation interruption is indicated. PMID:26383727
49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.
Code of Federal Regulations, 2014 CFR
2014-10-01
...2014-10-01 2014-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312...Interlocking Standards § 236.312 Movable bridge, interlocking of signal appliances with...
49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.
Code of Federal Regulations, 2012 CFR
2012-10-01
...2012-10-01 2012-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312...Interlocking Standards § 236.312 Movable bridge, interlocking of signal appliances with...
49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.
Code of Federal Regulations, 2013 CFR
2013-10-01
...2013-10-01 2013-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312...Interlocking Standards § 236.312 Movable bridge, interlocking of signal appliances with...
49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.
Code of Federal Regulations, 2011 CFR
2011-10-01
...2011-10-01 2011-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312...Interlocking Standards § 236.312 Movable bridge, interlocking of signal appliances with...
Kalkan, Erol; Kwong, Neal S.
2010-01-01
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 for the central United States), or when high-intensity records are needed (as is the case for 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 recently was 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. Herein, 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 to 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 responses. Thus, the MPS procedure is a useful tool for scaling ground motions as input to nonlinear RHAs of 'ordinary standard' bridges.
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.
Weigh-in-motion and smart bridges
NASA Astrophysics Data System (ADS)
Lai, Leon L.
1997-05-01
The bridge Weigh-In-Motion (WIM) system uses bridge structures as weigh scales to measure axle and gross vehicle weights and vehicle configurations without stopping or detouring the vehicles. Because the system is mobile and is almost invisible to the truck drivers, it can be used to collect unbiased traffic data for transportation and loadometer study. The WIM + RESPONSE system, which is an expansion of the original WIM system, was developed to collect additional bridge response data and perform bridge structural evaluation. These additional bridge response data provide bridge engineers with information necessary for improving bridge design and evaluation procedures. Bridge health monitoring and damage detection may also be conducted with long term installation of the WIM + RESPONSE system. This paper discusses what has been achieved by the WIM + RESPONSE system and how the system can be further improved to enhance its functions in a smart bridge.
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)...
3. Elkmont, underside detail of corrugated arched bridge. Great ...
3. Elkmont, underside detail of corrugated arched bridge. - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN
2. Elkmont, deck view of corrugated arched bridge. Great ...
2. Elkmont, deck view of corrugated arched bridge. - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN
Construction Technologies: Create the Strongest Bridge
NSDL National Science Digital Library
K-12 Outreach Office,
Students work in pairs to create three simple types of model bridges (beam, arch, suspension). They observe quantitatively how the bridges work under load and why engineers use different types of bridges for different places. They also get an idea of the parts needed to build bridges, and their functions. The strength of model bridges is mainly a factor of the quality of materials used, and therefore they do not provide a clear visual representation of tension and compression forces involved. Yet, students are able to see these forces at work in three prototype designs and draw conclusions about their dependence on span, width and supporting structures of the bridge designs.
Spin Hall effect induced by Bi impurities in Cu: Skew scattering and side-jump
NASA Astrophysics Data System (ADS)
Levy, Peter M.; Yang, Hongxin; Chshiev, Mairbek; Fert, Albert
2013-12-01
The spin Hall effect (SHE) has recently turned out to be an interesting tool for the conversion between charge and spin currents, the conversion factor being characterized by the spin Hall angle ?H. Large spin Hall angles have been now measured in heavy metals like W (?H=-0.33) and Cu doped with Bi impurities (?H=-0.24). In this article we express the contributions to the SHE induced by skew scattering and scattering with side-jump from Bi impurities in Cu, and we use ab initio calculations of the electronic structure of CuBi alloys to estimate the values of these two contributions. The predominant effect comes from skew scattering; the spin Hall angle is negative in agreement with experiments, but the calculated amplitude is smaller.
Tang, An-Min; Tang, Nian-Sheng
2015-02-28
We propose a semiparametric multivariate skew-normal joint model for multivariate longitudinal and multivariate survival data. One main feature of the posited model is that we relax the commonly used normality assumption for random effects and within-subject error by using a centered Dirichlet process prior to specify the random effects distribution and using a multivariate skew-normal distribution to specify the within-subject error distribution and model trajectory functions of longitudinal responses semiparametrically. A Bayesian approach is proposed to simultaneously obtain Bayesian estimates of unknown parameters, random effects and nonparametric functions by combining the Gibbs sampler and the Metropolis-Hastings algorithm. Particularly, a Bayesian local influence approach is developed to assess the effect of minor perturbations to within-subject measurement error and random effects. Several simulation studies and an example are presented to illustrate the proposed methodologies. PMID:25404574
Maneuver planning of a rigid spacecraft with two skew control moment gyros
NASA Astrophysics Data System (ADS)
Gui, Haichao; Jin, Lei; Xu, Shijie
2014-11-01
The attitude maneuver planning of a rigid spacecraft using two skew single-gimbal control moment gyros (CMGs) is investigated. First, two types of restrictions are enforced on the gimbal motions of two skew CMGs, with each restriction yielding continuous control torque along a principal axis of the spacecraft. Then, it is proved that any axis fixed to the spacecraft can be pointed along an arbitrary inertial direction by at most two sequent rotations around the two actuated axes. Given this fact, a two-step eigenaxis rotation strategy, executing by the two single-axis torques respectively, is designed to point a given body-fixed axis along a desired direction. Furthermore, a three-step eigenaxis rotation strategy is constructed to achieve an arbitrary rest-to-rest attitude maneuver. The rotation angles required for the single-axis pointing and arbitrary attitude maneuver schemes are all analytically solved. Numerical examples are presented to demonstrate the effectiveness of the proposed algorithms.
Skewness of the Large-Scale Velocity Divergence from Non-Gaussian Initial Conditions
Zacharias A. M. Protogeros; Robert J. Scherrer
1996-09-11
We compute the skewness $t_3$ and the corresponding hierarchical amplitude $T_3$ of the divergence of the velocity field for arbitrary non-Gaussian initial conditions. We find that $T_3$ qualitatively resembles the corresponding hierarchical amplitude for the density field, $S_3$, in that it contains a term proportional to the initial skewness, which decays inversely as the linear growth factor, plus a constant term which differs from the corresponding Gaussian term by a complex function of the initial three- and four- point functions. We extend the results for $S_3$ and $T_3$ with non-Gaussian initial conditions to evolved fields smoothed with a spherical tophat window function. We show that certain linear combinations, namely $S_3 + {1 \\over 2} T_3$, $S_3 + T_3$, and $s_3 + t_3$, lead to expressions which are much simpler, for non-Gaussian initial conditions, than $S_3$ and $T_3$ (or $s_3$ and $t_3$) considered separately.
Skewness of the large-scale velocity divergence from non- Gaussian initial conditions
NASA Astrophysics Data System (ADS)
Protogeros, Zacharias A. M.; Scherrer, Robert J.
1997-03-01
We compute the skewness t_3 and the corresponding hierarchical amplitude T_3 of the divergence of the velocity field for arbitrary non-Gaussian initial conditions. We find that T_3 qualitatively resembles the corresponding hierarchical amplitude for the density field, S_3, in that it contains a term proportional to the initial skewness, which decays inversely as the linear growth factor, plus a constant term which differs from the corresponding Gaussian term by a complex function of the initial three- and four-point functions. We extend the results for S_3 and T_3 with non-Gaussian initial conditions to evolved fields smoothed with a spherical top-hat window function. We show that certain linear combinations, namely S_3+½T_3, S_3+T_3 and s_3+t_3, lead to expressions which are much simpler, for non-Gaussian initial conditions, than S_3 and T_3 (or s_3 and t_3) considered separately.
Bauke, W.; Clark, D.A.; Trujillo, P.B.
1985-01-01
Optical Tooling evolved from traditional surveying, and both technologies are sometimes used interchangeably in large industrial installations, since the instruments and their specialized adapters and supports complement each other well. A unique marriage of both technologies was accomplished in a novel application at LAMPF, the Los Alamos Meson Physics Facility. LAMPF consists of a linear accelerator with multiple target systems, one of which had to be altered to accommodate a new beamline for a neutrino experiment. The new line was to be installed into a crowded beam tunnel and had to be skewed and tilted in compound angles to avoid existing equipment. In this paper we describe how Optical Tooling was used in conjunction with simple alignment and reference fixtures to set fiducials on the magnets and other mechanical components of the beamline, and how theodolites and sight levels were then adapted to align these components along the calculated skew planes. Design tolerances are compared with measured alignment results.
Skewness and Kurtosis as Indicators of Non-Gaussianity in Sky Maps
Ben-David, Assaf; Jackson, Andrew D
2015-01-01
Observational cosmology is entering an era in which high precision will be required in both measurement and data analysis. Accuracy, however, can only be achieved with a thorough understanding of potential sources of contamination from foreground effects. Our primary focus will be on non- Gaussian effects in foregrounds. This issue will be crucial for coming experiments to determine B-mode polarization. We propose a novel method for investigating a data set in terms of skewness and kurtosis in locally defined regions that collectively cover the entire sky. The method is demonstrated on two sky maps: (i) the SMICA map of Cosmic Microwave Background fluctuations provided by the Planck Collaboration and (ii) a version of the Haslam map at 408 MHz that describes synchrotron radiation. We find that skewness and kurtosis can be evaluated in combination to reveal local physical information. In the present case, we demonstrate that the local properties of both maps are predominantly Gaussian. This result was expected...
Higher reproductive skew among birds than mammals in cooperatively breeding species
Raihani, Nichola J.; Clutton-Brock, Tim H.
2010-01-01
While competition for limited breeding positions is a common feature of group life, species vary widely in the extent to which reproduction is shared among females (‘reproductive skew’). In recent years, there has been considerable debate over the mechanisms that generate variation in reproductive skew, with most evidence suggesting that subordinates breed when dominants are unable to prevent them from doing so. Here, we suggest that viviparity reduces the ability of dominant females to control subordinate reproduction and that, as a result, dominant female birds are more able than their mammal counterparts to prevent subordinates from breeding. Empirical data support this assertion. This perspective may increase our understanding of how cooperative groups form and are stabilized in nature. PMID:20236970
Skewed sex ratios and female homosexual activity in Japanese macaques: An experimental analysis
Paul L. Vasey; Carole Gauthier
2000-01-01
In this paper we present the results of a behavioral experiment conducted to test whether homosexual consortships and sexual\\u000a solicitations among female Japanese macaques (Macaca fuscata) increase in the context of operational sex ratios that are heavily skewed towards females. The study involved a baseline\\u000a period of observation on an intact social group which had a female-biased sex ratio typical
A model for coupled magnetic-electric circuits in electric machines with skewed slots
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
Detecting global bridges in networks
Jensen, Pablo; Karsai, Marton; Venturini, Tommaso; Vespignani, Alessandro; Jacomy, Mathieu; Cointet, Jean-Philippe; Merckle, Pierre; Fleury, Eric
2015-01-01
The identification of nodes occupying important positions in a network structure is crucial for the understanding of the associated real-world system. Usually, betweenness centrality is used to evaluate a node capacity to connect different graph regions. However, we argue here that this measure is not adapted for that task, as it gives equal weight to "local" centers (i.e. nodes of high degree central to a single region) and to "global" bridges, which connect different communities. This distinction is important as the roles of such nodes are different in terms of the local and global organisation of the network structure. In this paper we propose a decomposition of betweenness centrality into two terms, one highlighting the local contributions and the other the global ones. We call the latter bridgeness centrality and show that it is capable to specifically spot out global bridges. In addition, we introduce an effective algorithmic implementation of this measure and demonstrate its capability to identify glob...
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.
Joint Skewness and Its Application in Unsupervised Band Selection for Small Target Detection
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
Joint Skewness and Its Application in Unsupervised Band Selection for Small Target Detection
NASA Astrophysics Data System (ADS)
Geng, Xiurui; Sun, Kang; Ji, Luyan; Tang, Hairong; Zhao, Yongchao
2015-04-01
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.
The Equilibrium Allele Frequency Distribution for a Population with Reproductive Skew
Der, Ricky; Plotkin, Joshua B.
2014-01-01
We study the population genetics of two neutral alleles under reversible mutation in a model that features a skewed offspring distribution, called the ?-Fleming–Viot process. We describe the shape of the equilibrium allele frequency distribution as a function of the model parameters. We show that the mutation rates can be uniquely identified from this equilibrium distribution, but the form of the offspring distribution cannot itself always be so identified. We introduce an estimator for the mutation rate that is consistent, independent of the form of reproductive skew. We also introduce a two-allele infinite-sites version of the ?-Fleming–Viot process, and we use it to study how reproductive skew influences standing genetic diversity in a population. We derive asymptotic formulas for the expected number of segregating sites as a function of sample size and offspring distribution. We find that the Wright–Fisher model minimizes the equilibrium genetic diversity, for a given mutation rate and variance effective population size, compared to all other ?-processes. PMID:24473932
Skew-symmetric forms: On integrability of equations of mathematical physics
L. I. Petrova
2009-10-30
The study of integrability of the mathematical physics equations showed that the differential equations describing real processes are not integrable without additional conditions. This follows from the functional relation that is derived from these equations. Such a relation connects the differential of state functional and the skew-symmetric form. This relation proves to be nonidentical, and this fact points to the nonintegrability of the equations. In this case a solution to the equations is a functional, which depends on the commutator of skew-symmetric form that appears to be unclosed. However, under realization of the conditions of degenerate transformations, from the nonidentical relation it follows the identical one on some structure. This points out to the local integrability and realization of a generalized solution. In doing so, in addition to the exterior forms, the skew-symmetric forms, which, in contrast to exterior forms, are defined on nonintegrable manifolds (such as tangent manifolds of differential equations, Lagrangian manifolds and so on), were used. In the present paper, the partial differential equations, which describe any processes, the systems of differential equations of mechanics and physics of continuous medium and field theory equations are analyzed.
Okumura, K; Fujimori, Y; Takagi, A; Murate, T; Ozeki, M; Yamamoto, K; Katsumi, A; Matsushita, T; Naoe, T; Kojima, T
2008-09-01
Female carriers of haemophilia B are usually asymptomatic; however, the disease resulting from different pathophysiological mechanisms has rarely been documented in females. In this study, we investigated the mechanisms responsible for haemophilia B in fraternal female twins. We sequenced the factor IX gene (F9) of the propositus, her father, a severe haemophilia B patient and the other family members. X chromosome inactivation was assessed by the methylation-sensitive HpaII-PCR assay using X-linked polymorphisms in human phosphoglycerate kinase 1 gene (PGK1) and glutamate receptor ionotropic AMPA 3 gene (GRIA3). The twins were found to be heterozygotes with a nonsense mutation (p.Arg384X) inherited from their father. The propositus, more severely affected twin, exhibited a significantly higher percentage of inactivation in the maternally derived X chromosome carrying a normal F9. The other twin also showed a skewed maternal X inactivation, resulting in a patient with mild haemophilia B. Thus, the degree of skewing of maternal X inactivation is closely correlated with the coagulation parameters and the clinical phenotypes of the twins. Furthermore, we identified a crossing-over in the Xq25-26 region of the maternal X chromosome of the more severely affected twin. This crossing-over was absent in the other twin, consistent with their fraternal state. Differently skewed X inactivation in the fraternal female twins might cause moderately severe and mild haemophilia B phenotypes, respectively. PMID:18540891
Reproductive skew drives patterns of sexual dimorphism in sponge-dwelling snapping shrimps.
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
Currie, L A
2001-07-01
Three general classes of skewed data distributions have been encountered in research on background radiation, chemical and radiochemical blanks, and low levels of 85Kr and 14C in the atmosphere and the cryosphere. The first class of skewed data can be considered to be theoretically, or fundamentally skewed. It is typified by the exponential distribution of inter-arrival times for nuclear counting events for a Poisson process. As part of a study of the nature of low-level (anti-coincidence) Geiger-Muller counter background radiation, tests were performed on the Poisson distribution of counts, the uniform distribution of arrival times, and the exponential distribution of inter-arrival times. The real laboratory system, of course, failed the (inter-arrival time) test--for very interesting reasons, linked to the physics of the measurement process. The second, computationally skewed, class relates to skewness induced by non-linear transformations. It is illustrated by non-linear concentration estimates from inverse calibration, and bivariate blank corrections for low-level 14C-12C aerosol data that led to highly asymmetric uncertainty intervals for the biomass carbon contribution to urban "soot". The third, environmentally, skewed, data class relates to a universal problem for the detection of excursions above blank or baseline levels: namely, the widespread occurrence of ab-normal distributions of environmental and laboratory blanks. This is illustrated by the search for fundamental factors that lurk behind skewed frequency distributions of sulfur laboratory blanks and 85Kr environmental baselines, and the application of robust statistical procedures for reliable detection decisions in the face of skewed isotopic carbon procedural blanks with few degrees of freedom. PMID:11508459
Representation of skew in time-stepped two-dimensional finite-element models of electrical machines
Stephen Williamson; Timothy J. Flack; Albertus F. Volschenk
1995-01-01
The authors outline a technique which enables two-dimensional finite-element analysis to be applied to skewed machines. It involves representing the continuous skewing in a series of discrete steps. Each step may be modeled in two dimensions. The model has been applied to a salient-pole synchronous generator and to a cage induction motor. It is shown that the model is successful
Homogeneous bispecifics by disulfide bridging.
Hull, Elizabeth A; Livanos, Maria; Miranda, Enrique; Smith, Mark E B; Chester, Kerry A; Baker, James R
2014-08-20
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
Bridging the Vector Calculus Gap
NASA Astrophysics Data System (ADS)
Dray, Tevian; Manogue, Corinne
2003-05-01
As with Britain and America, mathematicians and physicists are separated from each other by a common language. In a nutshell, mathematics is about functions, but physics is about things. For the last several years, we have led an NSF-supported effort to "bridge the vector calculus gap" between mathematics and physics. The unifying theme we have discovered is to emphasize geometric reasoning, not (just) algebraic computation. In this talk, we will illustrate the language differences between mathematicians and physicists, and how we are trying reconcile them in the classroom. For further information about the project go to: http://www.physics.orst.edu/bridge
Stochastic bridges of linear systems
Yongxin Chen; Tryphon Georgiou
2014-07-12
We study a generalization of the Brownian bridge as a stochastic process that models the position and velocity of inertial particles between the two end-points of a time interval. The particles experience random acceleration and are assumed to have known states at the boundary. Thus, the movement of the particles can be modeled as an Ornstein-Uhlenbeck process conditioned on position and velocity measurements at the two end-points. It is shown that optimal stochastic control provides a stochastic differential equation (SDE) that generates such a bridge as a degenerate diffusion process. Generalizations to higher order linear diffusions are considered.
Balanced bridge feedback control system
NASA Technical Reports Server (NTRS)
Lurie, Boris J. (inventor)
1990-01-01
In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus has a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.
1. NORTH HAMMA HAMMA BRIDGE LOOKING SOUTH THROUGH PORTALS OF ...
1. NORTH HAMMA HAMMA BRIDGE LOOKING SOUTH THROUGH PORTALS OF BOTH THE NORTH AND SOUTH BRIDGES - North Hamma Hamma River Bridge, Spanning Hamma Hamma River Bridge at U.S. Route 101, Eldon, Mason County, WA
21. View of Clark Fork Vehicle Bridge facing west. Looking ...
21. View of Clark Fork Vehicle Bridge facing west. Looking at bridge deck, guard rail, juncture of two bridge spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID
12. View of bridge seat at north abutment with expansion ...
12. View of bridge seat at north abutment with expansion bearing, under bridge at northwest corner of bridge, looking from the east - Bridge No. 4900, Spanning Root River at Trunk Highway 16, Rushford, Fillmore County, MN
28. Under ninth bridge, view to concrete dam and eighth ...
28. Under ninth bridge, view to concrete dam and eighth bridge in background during heavy rain, view to the SW. - Vicksburg National Military Park Roads & Bridges, Melan Arch Bridges, Spanning various tributaries at Confederate Avenue, Vicksburg, Warren County, MS
49 CFR 237.109 - Bridge inspection records.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 4 2013-10-01 2013-10-01 false Bridge inspection records. 237.109 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.109 Bridge inspection...
49 CFR 237.53 - Railroad bridge inspectors.
Code of Federal Regulations, 2012 CFR
2012-10-01
...2012-10-01 2012-10-01 false Railroad bridge inspectors. 237.53 Section 237...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and...Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge...
49 CFR 237.53 - Railroad bridge inspectors.
Code of Federal Regulations, 2011 CFR
2011-10-01
...2011-10-01 2011-10-01 false Railroad bridge inspectors. 237.53 Section 237...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and...Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge...
49 CFR 237.53 - Railroad bridge inspectors.
Code of Federal Regulations, 2014 CFR
2014-10-01
...2014-10-01 2014-10-01 false Railroad bridge inspectors. 237.53 Section 237...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and...Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge...
49 CFR 237.103 - Bridge inspection procedures.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 4 2011-10-01 2011-10-01 false Bridge inspection procedures. 237.103 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection...
49 CFR 237.111 - Review of bridge inspection reports.
Code of Federal Regulations, 2013 CFR
2013-10-01
...2013-10-01 2013-10-01 false Review of bridge inspection reports. 237.111 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge...
49 CFR 237.109 - Bridge inspection records.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 4 2014-10-01 2014-10-01 false Bridge inspection records. 237.109 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.109 Bridge inspection...
49 CFR 237.53 - Railroad bridge inspectors.
Code of Federal Regulations, 2013 CFR
2013-10-01
...2013-10-01 2013-10-01 false Railroad bridge inspectors. 237.53 Section 237...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and...Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge...
49 CFR 237.111 - Review of bridge inspection reports.
Code of Federal Regulations, 2012 CFR
2012-10-01
...2012-10-01 2012-10-01 false Review of bridge inspection reports. 237.111 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge...
49 CFR 237.71 - Determination of bridge load capacities.
Code of Federal Regulations, 2013 CFR
2013-10-01
...2013-10-01 2013-10-01 false Determination of bridge load capacities. 237.71 Section 237...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Capacity of Bridges § 237.71 Determination of bridge load...
49 CFR 237.107 - Conduct of bridge inspections.
Code of Federal Regulations, 2013 CFR
2013-10-01
...2013-10-01 2013-10-01 false Conduct of bridge inspections. 237.107 Section 237.107 ...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge...
49 CFR 237.111 - Review of bridge inspection reports.
Code of Federal Regulations, 2014 CFR
2014-10-01
...2014-10-01 2014-10-01 false Review of bridge inspection reports. 237.111 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge...
49 CFR 237.107 - Conduct of bridge inspections.
Code of Federal Regulations, 2012 CFR
2012-10-01
...2012-10-01 2012-10-01 false Conduct of bridge inspections. 237.107 Section 237.107 ...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge...
49 CFR 237.109 - Bridge inspection records.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 4 2012-10-01 2012-10-01 false Bridge inspection records. 237.109 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.109 Bridge inspection...
49 CFR 237.103 - Bridge inspection procedures.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 4 2014-10-01 2014-10-01 false Bridge inspection procedures. 237.103 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection...
49 CFR 237.109 - Bridge inspection records.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 4 2011-10-01 2011-10-01 false Bridge inspection records. 237.109 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.109 Bridge inspection...
49 CFR 237.103 - Bridge inspection procedures.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 4 2012-10-01 2012-10-01 false Bridge inspection procedures. 237.103 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection...
49 CFR 237.71 - Determination of bridge load capacities.
Code of Federal Regulations, 2014 CFR
2014-10-01
...2014-10-01 2014-10-01 false Determination of bridge load capacities. 237.71 Section 237...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Capacity of Bridges § 237.71 Determination of bridge load...
49 CFR 237.107 - Conduct of bridge inspections.
Code of Federal Regulations, 2011 CFR
2011-10-01
...2011-10-01 2011-10-01 false Conduct of bridge inspections. 237.107 Section 237.107 ...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge...
49 CFR 237.71 - Determination of bridge load capacities.
Code of Federal Regulations, 2012 CFR
2012-10-01
...2012-10-01 2012-10-01 false Determination of bridge load capacities. 237.71 Section 237...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Capacity of Bridges § 237.71 Determination of bridge load...
49 CFR 237.107 - Conduct of bridge inspections.
Code of Federal Regulations, 2014 CFR
2014-10-01
...2014-10-01 2014-10-01 false Conduct of bridge inspections. 237.107 Section 237.107 ...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge...
49 CFR 237.111 - Review of bridge inspection reports.
Code of Federal Regulations, 2011 CFR
2011-10-01
...2011-10-01 2011-10-01 false Review of bridge inspection reports. 237.111 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge...
49 CFR 237.71 - Determination of bridge load capacities.
Code of Federal Regulations, 2011 CFR
2011-10-01
...2011-10-01 2011-10-01 false Determination of bridge load capacities. 237.71 Section 237...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Capacity of Bridges § 237.71 Determination of bridge load...
49 CFR 237.103 - Bridge inspection procedures.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 4 2013-10-01 2013-10-01 false Bridge inspection procedures. 237.103 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection...
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...
Simplified Method for Estimating Future Scour Depth at Existing Bridges
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 ...
Orstavik, K.H.; Orstavik, R.E.; Eiklid, K.; Tranebjaerg, L.
1996-07-12
A new X-linked recessive deafness syndrome was recently reported and mapped to Xq22 (Mohr-Tranebjaeerg syndrome). In addition to deafness, the patients had visual impairment, dystonia, fractures, and mental deterioration. The female carriers did not have any significant manifestations of the syndrome. We examined X chromosome inactivation in 8 obligate and 12 possible carriers by using a polymerase chain reaction analysis of the methylation-dependent amplification of the polymorphic triplet repeat at the androgen receptor locus. Seven of 8 obligate carriers and 1 of 5 carriers by linkage analysis had an extremely skewed pattern in blood DNA not found in 30 normal females. The X inactivation pattern in fibroblast DNA from 2 of the carriers with the extremely skewed pattern was also skewed but to a lesser degree than in blood DNA. One obligate carrier had a random X inactivation pattern in both blood and fibroblast DNA. A selection mechanism for the skewed pattern is therefore not likely. The extremely skewed X inactivation in 8 females of 3 generations in this family may be caused by a single gene that influences skewing of X chromosome inactivation. 22 refs., 2 figs., 1 tab.
A Data Management Infrastructure for Bridge Monitoring
Stanford University
infrastructure framework for bridge monitoring applications. As sensor technologies mature and become information modeling and sensor data management, and propose a data management framework for bridge monitoring mature and become economically affordable, the use of sensors for the health monitoring
Bridging: Locating Critical Connectors in a Network
Valente, Thomas W.; Fujimoto, Kayo
2010-01-01
This paper proposes several measures for bridging in networks derived from Granovetter's (1973) insight that links which reduce distances in a network are important structural bridges. Bridging is calculated by systematically deleting links and calculating the resultant changes in network cohesion (measured as the inverse average path length). The average change for each node's links provides an individual level measure of bridging. We also present a normalized version which controls for network size and a network level bridging index. Bridging properties are demonstrated on hypothetical networks, empirical networks, and a set of 100 randomly generated networks to show how the bridging measure correlates with existing network measures such as degree, personal network density, constraint, closeness centrality, betweenness centrality, and vitality. Bridging and the accompanying methodology provide a family of new network measures useful for studying network structure, network dynamics, and network effects on substantive behavioral phenomenon. PMID:20582157
Wind effect on long span bridge
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 ...
The Middle East Roads, Bridges and Tolls
Nagurney, Anna
#12;#12;The Middle East #12;Dubai #12;#12;#12;#12;#12;#12;Roads, Bridges and Tolls RTA Two Major to avoid congested bridges and tunnel #12;The World #12;Logistics and Transportation Four main island hubs
Asymmetric capillary bridges between contacting spheres.
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
Coil Creep and Skew-Quadrupole Field Components in the Tevatron
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.
Heeren, Bastiaan
of an interactive exercise. A large scale evaluation is foreseen for autumn 2011. 1 What is Math-Bridge? In most177 Lodder, Josje Jeuring, Johan: Math-Bridge, bridging the math gap between high school year students, and the competencies needed for their studies. Within the EU-funded project Math- Bridge
47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.
Code of Federal Regulations, 2013 CFR
2013-10-01
...2013-10-01 false Operator requirements of the Bridge-to-Bridge Act. 80.163 Section 80.163 Telecommunication...Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the...
47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.
Code of Federal Regulations, 2014 CFR
2014-10-01
...2014-10-01 2014-10-01 false Watch required by the Bridge-to-Bridge Act. 80.309 Section 80.309 Telecommunication...Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch...
47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.
Code of Federal Regulations, 2011 CFR
2011-10-01
...2011-10-01 2011-10-01 false Watch required by the Bridge-to-Bridge Act. 80.309 Section 80.309 Telecommunication...Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch...
47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.
Code of Federal Regulations, 2014 CFR
2014-10-01
...2014-10-01 false Operator requirements of the Bridge-to-Bridge Act. 80.163 Section 80.163 Telecommunication...Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the...
47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.
Code of Federal Regulations, 2012 CFR
2012-10-01
...2012-10-01 2012-10-01 false Watch required by the Bridge-to-Bridge Act. 80.309 Section 80.309 Telecommunication...Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch...
47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.
Code of Federal Regulations, 2013 CFR
2013-10-01
...2013-10-01 2013-10-01 false Watch required by the Bridge-to-Bridge Act. 80.309 Section 80.309 Telecommunication...Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch...
Stuart, Steven J.
1 STUDENT STEEL BRIDGE COMPETITION 2012 RULES #12;2 MISSION The mission of the Student Steel Bridge individuals in the Student Steel Bridge Competition without regard to race, ethnicity, religion, age, gender, sexual orientation, nationality, or physical challenges. Bridge teams should be inclusive and open
47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.
Code of Federal Regulations, 2011 CFR
2011-10-01
...2011-10-01 false Operator requirements of the Bridge-to-Bridge Act. 80.163 Section 80.163 Telecommunication...Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the...
47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.
Code of Federal Regulations, 2012 CFR
2012-10-01
...2012-10-01 false Operator requirements of the Bridge-to-Bridge Act. 80.163 Section 80.163 Telecommunication...Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the...
Bridge Programs in Illinois: Results of the 2010 Illinois Bridge Status Survey
ERIC Educational Resources Information Center
Taylor, J. L.; Harmon, T.
2010-01-01
This report provides a summary of major results of the Illinois Bridge Status Survey, administered online between April and June 2010. The purpose of the survey was to understand the extent to which bridge programs are being implemented in Illinois, as well as to build an online directory of bridge programs. Bridge programs are an emerging…
Bridging The Gap: From Biometrics to Forensics
Bridging The Gap: From Biometrics to Forensics Anil K. Jain Michigan State University http://biometrics.cse.msu.edu February 2, 2015 1 #12;Outline 2 · Questions about identity · What is biometrics? · Why biometric recognition? · Automatic biometric recognition · Challenges · Bridging the gap #12;Bridging The Gap
BRIDGES for Young Adolescents in North Dakota.
ERIC Educational Resources Information Center
Harris, Mary McDonnell
The BRIDGES Project was initiated to explore ways for North Dakota to provide young people with stronger bridges from childhood to adulthood. This report summarizes recommendations of the 1990-91 Governor's Task Force on Early Adolescence. The recommendations concern practical actions for the building of bridges by the following groups: (1)…
A Participatory Public Art Project: Community Bridge
ERIC Educational Resources Information Center
Stephens, Pam
2005-01-01
This article introduces Community Bridge, a participatory public art project that brought together artists and residents to address aesthetic needs of an urban environment. The Community Bridge is an exemplary work of art by American artist William Cochran. In addition to creating a natural gathering place for residents of all ages, the bridge is…
Gribakin, Gleb
River Lagan Stew art Street Pakenham St. Ormeau Road PSNI Odyssey/W5 Lagan Bridge (M3) Royal Avenue Church Lane BridgeSt. HillStreet Skipper Street Ann Street Gordon Street Talbot Street DunbarStreet Gt. Glengall Street Divis Street Castle Street Durham Street BoyneBridge BarrackStreet BedfordStreet Linenhall
Post-earthquake Prioritization of Bridge Inspections
Eberhard, Marc O.
Post-earthquake Prioritization of Bridge Inspections R. T. Ranf,a... M.EERI, M. O. Eberhard,b... M.EERI, and S. Malone,c... AFFIL. M.EERI Bridge damage reports from the 2001 Nisqually earthquake were correlated with estimates of ground-motion intensity at each bridge site obtained from Shake
How Many Bridge Auctions? Erich Friedman
Friedman, Erich
How Many Bridge Auctions? Erich Friedman student, Rose-Hulman Institute of Technology Doug Jungreis student, Harvard University In normal games of bridge, only a small fraction of the possible auctions at the actual number of distinct auctions. The game of bridge is played with four players comprising two teams
Bridge Detection By Road Detection Jeff Kaufman
Danner, Andrew
Bridge Detection By Road Detection Jeff Kaufman cbr@sccs.swarthmore.edu 1 Introduction It is useful, with local min- ima: cells from which there is no direction of descent. A common cause of this is bridges. The area over which a bridge passes shows up in the digital elevation as being of a height greater than
Simulation of multivariate diffusion bridges Mogens Bladt
SÃ¸rensen, Michael
Simulation of multivariate diffusion bridges Mogens Bladt Instituto de Investigacion en Matem, 2014 Abstract We propose simple methods for multivariate diffusion bridge simulation, which plays simulation method for one-dimensional bridges to the multi-variate setting. First a method of simulating
Edges and Switches, Tunnels and Bridges
Eppstein, David
Edges and Switches, Tunnels and Bridges David Eppstein Marc van Kreveld Elena Mumford Bettina it into the "best" cased drawing. #12;Definitions A crossing is called bridge for the edge on top tunnel a bridge for e. e e' e e' #12;Optimization criteria #12;Optimization criteria #12;Optimization criteria
Designing and Building File-Folder Bridges
Bowen, James D.
Designing and Building File-Folder Bridges A Problem-Based Introduction to Engineering Stephen J bridge begins in the mind of an engineer. #12;#12;Contents Preface: For the Teacher.....................................................................................v Learning Activity #1: Build a Model of a Truss Bridge
Remediation: Higher Education's Bridge to Nowhere
ERIC Educational Resources Information Center
Complete College America, 2012
2012-01-01
The intentions were noble. It was hoped that remediation programs would be an academic bridge from poor high school preparation to college readiness. Sadly, remediation has become instead higher education's "Bridge to Nowhere." This broken remedial bridge is travelled by some 1.7 million beginning students each year, most of whom will not reach…
Thin bridges in isotropic electrostatics Johan Helsing
Helsing, Johan
Thin bridges in isotropic electrostatics Johan Helsing Department of Mathematical Sciences thin bridges, coatings, narrow necks, corners, cusps, and random mixtures. I. INTRODUCTION bridges, and narrow necks. As we shall see, the algorithm also works well for corners and cusps. In seven
Pedestrian excitation of bridges D E Newland
Newland, David E.
Pedestrian excitation of bridges D E Newland Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK Abstract: This paper reviews the evidence on dynamic bridge loading to an oscillating bridge when this has a frequency close to their natural walking or running frequency is a feature
Building Bridges One Line at a Time
ERIC Educational Resources Information Center
Grigsby, Cathy Murray
2012-01-01
In this article, first-grade students were taught the different kinds of lines that were part of the construction of various bridges--the curved lines of the arches of stone bridges, straight lines connecting the cables of a suspension bridge, vertical lines, horizontal lines, and so on. They gained practice in drawing structures and in fine brush…
CONVEX, ROTATIONALLY SYMMETRIC LIQUID BRIDGES BETWEEN SPHERES
Vogel, Thomas
CONVEX, ROTATIONALLY SYMMETRIC LIQUID BRIDGES BETWEEN SPHERES Thomas I. Vogel Department of Mathematics Texas A&M University College Station, TX 77843 tvogel@math.tamu.edu A liquid bridge between two different contact an- gles: one for each ball). If we consider rotationally symmetric bridges, then the free
ADVANCED COMPOSITE MATERIALS FOR BRIDGES Sami RIZKALLA
1. SUMMARY ADVANCED COMPOSITE MATERIALS FOR BRIDGES Sami RIZKALLA ISIS Canada Network of Centres bridges are being built with materials that have significantly higher strength in comparison to steel associated with concrete bridges due to the corrosion of steel reinforcements. This paper presents
Bridging Cultures with Classroom Strategies.
ERIC Educational Resources Information Center
Rothstein-Fisch, Carrie; Greenfield, Patricia M.; Trumbull, Elise
1999-01-01
Collectivism, stressing family members' interdependence, is common to Latino cultures. In contrast, schools foster independence and individual achievement. To help teachers understand assumptions underlying these different values, the authors developed the "Bridging Cultures Project" as a research-based professional-development program. Science…
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…
Bridging Traditional and Authentic Assessment.
ERIC Educational Resources Information Center
Cole, Donna J.
With the education reform movement came dissonance over testing as an indicator of classroom learning. This paper examines both formal and informal assessment and relates one institution's attempt to provide a bridge between authentic and traditional assessment. Authentic assessment is defined as a belief that student evaluation should measure…
ERIC Educational Resources Information Center
Anderson, Richard
2008-01-01
Career and technical education (CTE) has a promising future at Darlington (WI) High School. In this article, the author describes how a class bridge project became a real-world, project-based learning opportunity involving higher-level thinking skills that are at the core of CTE at his school. It began when a local citizen approached him at the…
WSC Bridge Program Planning Guide
ERIC Educational Resources Information Center
Jenkins, Davis
2004-01-01
Increasingly jobs that pay more than subsistence wages and offer opportunities for career advancement require at least some training beyond high school, even at the entry level. Bridge training programs are designed to prepare individuals without the requisite basic skills for postsecondary training leading to career-path employment and further…
Bike/ped bridge CAMPUSDRIVEWEST
Bike/ped bridge Bike/ped underpass ELCAM INO REAL ELCAM INO REAL GALVEZST SERRA MALL CAM PUSDREAST & Transportation Services (P&TS) Montag Hall Stock Farm lot Parking Structure 5 (PS5) EH&S Stanford West Apartments 1000 1101 900 C Line C Effective Oct.6,2014 #12;ELCAM INO REAL M INO REAL GALVEZST SERRA MALL CAM
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…
Evaluation of Summer Bridge Programs
ERIC Educational Resources Information Center
Garcia, Lisa D.; Paz, Chiara C.
2009-01-01
Many colleges and universities in the United States offer summer programs for their incoming students. While programs are structured and administered in a variety of ways and target various student populations, the most common type of summer bridge program aims to serve historically underrepresented students and students of low socioeconomic…
Towers and Bridges Civil Engineering
Provancher, William
with Google Sketchup (free download) 4. Notebook paper 5. Testing device (sling with 2.5 pound weightsTowers and Bridges Civil Engineering Objective This lesson introduces students to Civil Engineering they are designed based on sound theories 5. How to create a project design with computer software 6. What types
Intercellular Bridges in Vertebrate Gastrulation
Dempsey, William; Fraser, Scott E.
2011-01-01
The developing zebrafish embryo has been the subject of many studies of regional patterning, stereotypical cell movements and changes in cell shape. To better study the morphological features of cells during gastrulation, we generated mosaic embryos expressing membrane attached Dendra2 to highlight cellular boundaries. We find that intercellular bridges join a significant fraction of epiblast cells in the zebrafish embryo, reaching several cell diameters in length and spanning across different regions of the developing embryos. These intercellular bridges are distinct from the cellular protrusions previously reported as extending from hypoblast cells (1–2 cellular diameters in length) or epiblast cells (which were shorter). Most of the intercellular bridges were formed at pre-gastrula stages by the daughters of a dividing cell maintaining a membrane tether as they move apart after mitosis. These intercellular bridges persist during gastrulation and can mediate the transfer of proteins between distant cells. These findings reveal a surprising feature of the cellular landscape in zebrafish embryos and open new possibilities for cell-cell communication during gastrulation, with implications for modeling, cellular mechanics, and morphogenetic signaling. PMID:21647454
NSDL National Science Digital Library
Tim Carnahan
1999-02-02
A Dynamic proposal between the National Aeronautics and Space Administration and the National Polar Orbiting Environmental Satellite System Integrated Program Office. A project to bridge or link between the operations of the Earth Observing System AM-1 and the PM-1 Spacecraft and the National Polar Orbiting Environmental Satellite System Spacecraft (NPOESS)
2. AERIAL VIEW OF THE VERTICAL LIFT BRIDGE FROM THE ...
2. AERIAL VIEW OF THE VERTICAL LIFT BRIDGE FROM THE SOUTHEAST. OTHER BRIDGES SHOWN ARE (IN ORDER OF RECESSION) THE NEWARK TURNPIKE, THE CONRAIL BRIDGE (HAER No. NJ-43) THE PATH TRANSIT BRIDGE (HAER No. NJ-44), THE PULASKI SKYWAY (HAER No. NJ-34), AND THE NEWARK BAY BRIDGE (HAER No. NJ-37) - Erie & Lackawanna Railroad Bridge, Spanning Hackensack River, Kearny, Hudson County, NJ
Automation of Resistance Bridge Calibrator
NASA Astrophysics Data System (ADS)
Podgornik, Tadej; Bojkovski, Jovan; Batagelj, Valentin; Drnovšek, Janko
2008-02-01
The article addresses the automation of the resistance bridge calibrator (RBC). The automation of the RBC is performed in order to facilitate the operation of the RBC, improve the reliability, and enable several additional possibilities compared to the tedious manual operation, thereby making the RBC a more practical device for routine use. The RBC is used to calibrate AC and DC resistance bridges, which are mainly used in a primary thermometry laboratory. It consists of a resistor network made up from four main resistors from which 35 different resistance values can be realized using toggle switches. Literature shows that the resistors’ non-zero temperature coefficient can influence the measurements, causing difficulties when calibrating resistance bridges with low uncertainty. Placing the RBC in a thermally stable environment can reduce this, but it does not solve the problem of the time-consuming manual selection of the resistance values. To solve this, an automated means to manipulate the switches, while the device is placed within a thermally stable environment, was created. Computer operation completely substitutes for any manual operation during which an operator would normally have to be present. The computer also acquires measurements from the bridge. In this way, repeated and reproducible calibration measurements inside a temperature-stable environment can be carried out with no active involvement of personnel. The automation process itself was divided into several stages. They included the construction of a servo-manipulator to move the switches, the design of a dedicated electronic controller that also provides a serial interface (RS-232) to the computer, and the development of custom computer software to configure the servo-manipulator and control the calibration process. Measurements show that automation does not affect the long-term stability and mechanical repeatability of the RBC. The repeatability and reproducibility of bridge calibration ratios were also demonstrated by making consecutive measurements.
Structural Bridges through Fold Space
Edwards, Hannah; Deane, Charlotte M.
2015-01-01
Several protein structure classification schemes exist that partition the protein universe into structural units called folds. Yet these schemes do not discuss how these units sit relative to each other in a global structure space. In this paper we construct networks that describe such global relationships between folds in the form of structural bridges. We generate these networks using four different structural alignment methods across multiple score thresholds. The networks constructed using the different methods remain a similar distance apart regardless of the probability threshold defining a structural bridge. This suggests that at least some structural bridges are method specific and that any attempt to build a picture of structural space should not be reliant on a single structural superposition method. Despite these differences all representations agree on an organisation of fold space into five principal community structures: all-?, all-? sandwiches, all-? barrels, ?/? and ? + ?. We project estimated fold ages onto the networks and find that not only are the pairings of unconnected folds associated with higher age differences than bridged folds, but this difference increases with the number of networks displaying an edge. We also examine different centrality measures for folds within the networks and how these relate to fold age. While these measures interpret the central core of fold space in varied ways they all identify the disposition of ancestral folds to fall within this core and that of the more recently evolved structures to provide the peripheral landscape. These findings suggest that evolutionary information is encoded along these structural bridges. Finally, we identify four highly central pivotal folds representing dominant topological features which act as key attractors within our landscapes. PMID:26372166
Structural Bridges through Fold Space.
Edwards, Hannah; Deane, Charlotte M
2015-09-01
Several protein structure classification schemes exist that partition the protein universe into structural units called folds. Yet these schemes do not discuss how these units sit relative to each other in a global structure space. In this paper we construct networks that describe such global relationships between folds in the form of structural bridges. We generate these networks using four different structural alignment methods across multiple score thresholds. The networks constructed using the different methods remain a similar distance apart regardless of the probability threshold defining a structural bridge. This suggests that at least some structural bridges are method specific and that any attempt to build a picture of structural space should not be reliant on a single structural superposition method. Despite these differences all representations agree on an organisation of fold space into five principal community structures: all-?, all-? sandwiches, all-? barrels, ?/? and ? + ?. We project estimated fold ages onto the networks and find that not only are the pairings of unconnected folds associated with higher age differences than bridged folds, but this difference increases with the number of networks displaying an edge. We also examine different centrality measures for folds within the networks and how these relate to fold age. While these measures interpret the central core of fold space in varied ways they all identify the disposition of ancestral folds to fall within this core and that of the more recently evolved structures to provide the peripheral landscape. These findings suggest that evolutionary information is encoded along these structural bridges. Finally, we identify four highly central pivotal folds representing dominant topological features which act as key attractors within our landscapes. PMID:26372166
Theory of water and charged liquid bridges
Klaus Morawetz
2012-05-29
The phenomena of liquid bridge formation due to an applied electric field is investigated. A new solution for the charged catenary is presented which allows to determine the static and dynamical stability conditions where charged liquid bridges are possible. The creeping height, the bridge radius and length as well as the shape of the bridge is calculated showing an asymmetric profile in agreement with observations. The flow profile is calculated from the Navier Stokes equation leading to a mean velocity which combines charge transport with neutral mass flow and which describes recent experiments on water bridges.
Strengthening Bridges with Prestressed CFRP Strips
NASA Astrophysics Data System (ADS)
Siwowski, Tomasz; ?ó?towski, Piotr
2012-06-01
Limitation of bridge's carrying bearing capacity due to aging and deterioration is a common problem faced by road administration and drivers. Rehabilitation of bridges including strengthening may be applied in order to maintain or upgrade existing bridge parameters. The case studies of strengthening of two small bridges with high modulus prestressed CFRP strips have been presented in the paper. The first one - reinforced concrete slab bridge - and the other - composite steel-concrete girder bridge - have been successfully upgraded with quite new technology. In both cases the additional CFRP reinforcement let increasing of bridge carrying capacity from 15 till 40 metric tons. The CFRP strip prestressing system named Neoxe Prestressing System (NPS), developed by multi-disciplinary team and tested at full scale in Rzeszow University of Technology, has been also described in the paper.
Bridging transitions for spheres and cylinders
Malijevský, Alexandr
2015-01-01
We study bridging transitions between spherically and cylindrically shaped particles (colloids) of radius $R$ separated by a distance $H$ that are dissolved in a bulk fluid (solvent). Using macroscopics, microscopic density functional theory and finite-size scaling theory we study the location and order of the bridging transition and also the stability of the liquid bridges which determines spinodal lines. The location of the bridging transitions is similar for cylinders and spheres, so that for example, at bulk coexistence the distance $H_b$ at which a transition between bridged and unbridged configurations occurs, is proportional to the colloid radius $R$. However all other aspects, and, in particular, the stability of liquid bridges, are very different in the two systems. Thus, for cylinders the bridging transition is typically strongly first-order, while for spheres it may be first-order, critical or rounded as determined by a critical radius $R_c$. The influence of thick wetting films and fluctuation eff...
NASA Astrophysics Data System (ADS)
Fuhrman, D. R.; FredsøE, J.; Sumer, B. M.
2009-03-01
A numerical model solving incompressible Reynolds-averaged Navier-Stokes equations, combined with a two-equation k-? model for turbulence closure, is used to systematically compare the relative strength of bed shear stress quantities and boundary layer streaming under wave motions from four contributions believed to play a prominent role in cross-shore boundary layer and sediment transport processes: (1) converging-diverging effects from bed slope, (2) wave skewness, (3) wave asymmetry, and (4) waves combined with superposed negative currents (intended to loosely represent, for example, return currents or undertow). The effects from each of the four components are isolated and quantified using a standard set of bed shear stress quantities, allowing their easy comparison. For conditions representing large shallow-water waves on steep slopes, the results suggest that converging-diverging effects from beach slope may make a significant onshore bed load contribution. Generally, however, the results suggest wave skewness (in addition to conventional steady streaming) as the most important onshore contribution outside the surf zone. Streaming induced within the wave boundary layer is also investigated for each component, and skewness and asymmetry are demonstrated to promote largely negative streaming velocities, consistent with earlier work. For hydraulically smooth cases, however, a thin region of positive streaming is revealed in the viscous sublayer which is effectively absent in hydraulically rough conditions. Cross-shore boundary layer dynamics are generally acknowledged to be a complicated combination of numerous competing physical processes, and this work is among few to systematically compare a number of these. It is hoped that the results will be useful in assessing which of the contributions considered will be most prominent for a given set of local wave and beach slope conditions.
Structure-induced negatively skewed X-ray diffraction pattern of carbon onions
NASA Astrophysics Data System (ADS)
Siklitskaya, Alexandra; Yastrebov, Sergey; Smith, Roger
2013-10-01
The idea is discussed that a gradual change of intershell separation in carbon onions may introduce a negative skewness into the most intense X-ray diffraction band. As an example, the experimental X-ray diffraction pattern of carbon onions is analysed using a weighted Lorentzian X-ray profile broadening model for each intershell separation contributing to the profile. The dependence of the mean radius for carbon onion shells on the intershell spacing between the adjacent shells is derived from the model analysis. Comparison with the internal distribution of atomic density in carbon onions measured with high resolution transmission electron microscopy is discussed.
Skewness in (1+1)-dimensional Kardar-Parisi-Zhang-type growth.
Singha, Tapas; Nandy, Malay K
2014-12-01
We use the (1+1)-dimensional Kardar-Parisi-Zhang equation driven by a Gaussian white noise and employ the dynamic renormalization-group of Yakhot and Orszag without rescaling [J. Sci. Comput. 1, 3 (1986)]. Hence we calculate the second- and third-order moments of height distribution using the diagrammatic method in the large-scale and long-time limits. The moments so calculated lead to the value S=0.3237 for the skewness. This value is comparable with numerical and experimental estimates. PMID:25615107
Skew Information for a Single Cooper Pair Box Interacting with a Single Cavity Field
NASA Astrophysics Data System (ADS)
Metwally, N.; Al-Mannai, A.; Abdel-Aty, M.
2013-06-01
The dynamics of the skew information (SI) is investigated for a single Cooper Pair Box (CPB) interacting with a single cavity field. By suitably choosing the system parameters and precisely controlling the dynamics, novel connection is found between the SI and entanglement generation. It is shown that SI can be increased and reach its maximum value either by increasing the number of photons inside the cavity or considering the far off-resonant case. The number of oscillations of SI is increased by decreasing this ratio between the Josephson junction capacity and the gate capacity. This leads to significant improvement of the travelling time between the maximum and minimum values.
An inequality for the binary skew-symmetric broadcast channel and its implications
Nair, Chandra
2009-01-01
We establish an information theoretic inequality concerning the binary skew-symmetric channel that was conjectured earlier. This completes the proof that there is a gap between the inner bound and the outer bound for the 2-receiver broadcast channel; and constitutes the first example of a provable gap between the bounds. The interesting aspect of the proof is the technique employed, and is partly motivated by the paper "Images of a set and their role in Multiuser communication" by Korner and Marton in 1977.
Lining system bridges moving cracks
1995-10-01
Concrete secondary containment dykes are frequently covered with a coating or lining to prevent soil and groundwater contamination. An advanced polymer system, in a single application, bridges large and small cracks to prevent seepage. The material resists attack by acids, caustics, and solvents at temperatures to 300 degrees F. The system combines crack-bridging capabilities and the chemical resistance necessary for secondary containments linings. Using a proprietary polymer, the lining system is monolithic. There are no joints, seams or problems of blending dissimilar layers of materials. The lining, a winner of 1995 Vaaler Award, can be applied directly over existing, cracked containment linings, as well as in new applications. It can also be applied to steel and is not affect by UV lights or weathering.
Scour assessment at bridges from Flag Point to Million Dollar Bridge, Copper River Highway, Alaska
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.
Lumia, Richard; Baevsky, Yvonne Halpern
2000-01-01
Flood-frequency relations that are developed by fitting the logarithms of annual peak discharges to a Pearson Type-III distribution are sensitive to skew coefficients. Estimates of population skew for a site are improved when computed from the weighted average of (1) the sample (station) skew, and (2) an unbiased, generalized skew estimate. A weighting technique based on the number of years of record at each of 226 sites was used to develop a contour map of unbiased, generalized skew coefficients for New York. An attempt was made to group (regionalize) the station skew coefficients into five hydrologically similar areas of New York, but the statewide version proved to be as accurate as the regionalized version and therefore was adopted as the final generalized skew-coefficient map for New York. An error analysis showed the statewide contour map to have lower MSE?s (mean square errors) than those computed from (1) the five regional skewcoefficient contour maps, (2) a previously used (1982) nationwide skew coefficient map, and (3) the weighted mean of skew coefficients for sites within each of five hydrologically uniform, but distinct areas of New York.
Gentilini, Davide; Garagnani, Paolo; Pisoni, Serena; Bacalini, Maria Giulia; Calzari, Luciano; Mari, Daniela; Vitale, Giovanni; Franceschi, Claudio; Di Blasio, Anna Maria
2015-01-01
In this study we applied a new analytical strategy to investigate the relations between stochastic epigenetic mutations (SEMs) and aging. We analysed methylation levels through the Infinium HumanMethylation27 and HumanMethylation450 BeadChips in a population of 178 subjects ranging from 3 to 106 years. For each CpG probe, epimutated subjects were identified as the extreme outliers with methylation level exceeding three times interquartile ranges the first quartile (Q1-(3 × IQR)) or the third quartile (Q3+(3 × IQR)). We demonstrated that the number of SEMs was low in childhood and increased exponentially during aging. Using the HUMARA method, skewing of X chromosome inactivation (XCI) was evaluated in heterozygotes women. Multivariate analysis indicated a significant correlation between log(SEMs) and degree of XCI skewing after adjustment for age (? = 0.41; confidence interval: 0.14, 0.68; p-value = 0.0053). The PATH analysis tested the complete model containing the variables: skewing of XCI, age, log(SEMs) and overall CpG methylation. After adjusting for the number of epimutations we failed to confirm the well reported correlation between skewing of XCI and aging. This evidence might suggest that the known correlation between XCI skewing and aging could not be a direct association but mediated by the number of SEMs. PMID:26342808
Halliburton Composite Bridge Plug Assembly
Starbuck, J.M.; Luttrell, C.R.; Aramayo, G.
2005-01-15
The overall objectives of this CRADA were to assist Halliburton in analyzing a composite bridge plug and to determine why their original design was failing in the field. In Phase 1, finite element analyses were done on the original composite slip design and several alternative designs. The composite slip was the component in the bridge plug that was failing. The finite element code ABAQUS was used for these calculations and I-DEAS was used as the pre- and post-processor in the analyses. Several different designs and materials were analyzed and recommendations were made towards improving the design. In Phase 2, the objective was to develop finite element models that would accurately represent the deformations in the entire all-composite 4-1/2' diameter bridge plug assembly. The finite element code LS-DYNA was used and the results from this effort were intended to expand Halliburton's composite design and analysis capabilities with regard to developing future composite components for downhole tools. In addition to the finite element modeling, this effort involved the utilization of micromechanics to determine the necessary composite material properties that were needed as input for finite element codes.
Nondestructive evaluation techniques for enhanced bridge inspection
Thomas, G.; Benson, S.; Durbin, P.; Del Grande, N.; Haskins, J.; Brown, A.; Schneberk, D.
1993-10-01
Nondestructive evaluation of bridges is a critical aspect in the US aging infrastructure problem. For example in California there are 26,000 bridges, 3000 are made of steel, and of the steel bridges, 1000 are fracture critical. California Department of Transportation (Caltrans), Federal Highway Administration, and Lawrence Livermore National Laboratory (LLNL) are collaborating to develop and field NDE techniques to improve bridge inspections. We have demonstrated our NDE technologies on several bridge inspection applications. An early collaboration was to ultrasonically evaluate the steel pins in the E-9 pier on the San Francisco Bay Bridge. Following the Loma-Prieta earthquake in 1989 and the road way collapse at the E-9 pier, a complete nondestructive evaluation was conducted by Caltrans inspectors and several ultrasonic indications were noted. LLNL worked with Caltrans to help identify the source of these reflections. Another project was to digitally enhance high energy radiographs of bridge components such as cable end caps. We demonstrated our ability to improve the detection of corrosion and fiber breakage inside the end cap. An extension of this technology is limited view computer tomography (CT). We implemented our limited view CT software and produced cross-sectional views of bridge cables from digitized radiographic films. Most recently, we are developing dual band infrared imaging techniques to assess bridge decks for delaminations. We have demonstrated the potential of our NDE technology for enhancing the inspection of the country`s aging bridges.
Vehicle bridge interaction dynamics and potential applications
NASA Astrophysics Data System (ADS)
Yang, Y. B.; Lin, C. W.
2005-06-01
The dynamic interaction between a moving vehicle and the sustaining bridge is studied. By the method of modal superposition, closed-form solutions are obtained for the vertical responses of both the bridge and moving vehicle, assuming the vehicle/bridge mass ratio to be small. For both the bridge and vehicle responses, it is confirmed that rather accurate solutions can be obtained by considering only the first mode. The displacement, velocity, and acceleration of the bridge are governed at different extents by two sets of frequencies, i.e., the driving frequency of the vehicle and natural frequencies of the bridge. From the spectrum for the bridge displacement, the vehicle speeds can be shown to be associated with some low-frequency pikes. On the other hand, the vehicle responses are governed by five distinct frequencies that appear as driving frequencies, vehicle frequency, and bridge frequencies with shift. From the vehicle's acceleration spectrum, the first bridge frequency (with shift) is shown to have rather high visibility and can be easily identified. The effects of damping of the vehicle and bridge are evaluated in the numerical studies. Potential applications of the present results, as well as further researches required, are also indicated in the paper.
NASA Astrophysics Data System (ADS)
Sardeshmukh, Prashant D.; Penland, Cécile
2015-03-01
The probability distributions of large-scale atmospheric and oceanic variables are generally skewed and heavy-tailed. We argue that their distinctive departures from Gaussianity arise fundamentally from the fact that in a quadratically nonlinear system with a quadratic invariant, the coupling coefficients between system components are not constant but depend linearly on the system state in a distinctive way. In particular, the skewness arises from a tendency of the system trajectory to linger near states of weak coupling. We show that the salient features of the observed non-Gaussianity can be captured in the simplest such nonlinear 2-component system. If the system is stochastically forced and linearly damped, with one component damped much more strongly than the other, then the strongly damped fast component becomes effectively decoupled from the weakly damped slow component, and its impact on the slow component can be approximated as a stochastic noise forcing plus an augmented nonlinear damping. In the limit of large time-scale separation, the nonlinear augmentation of the damping becomes small, and the noise forcing can be approximated as an additive noise plus a correlated additive and multiplicative noise (CAM noise) forcing. Much of the diversity of observed large-scale atmospheric and oceanic probability distributions can be interpreted in this minimal framework.
Hasstrom, J.S.; Ermak, D.L.
1997-10-01
Vertical dispersion of material in the convective boundary layer, CBL, is dramatically different than in natural or stable boundary layers, as has been shown by field and laboratory experiments. Lagrangian stochastic modeling based on the Langevin equation has been shown to be useful for simulating vertical dispersion in the CBL. This modeling approach can account for the effects of the long Lagrangian time scales (associated with large-scale turbulent structures), skewed vertical velocity distributions, and vertically inhomogeneous turbulent properties found in the CBL. It has been recognized that simplified Langevin equation models that assume skewed but homogeneous velocity statistics can capture the important aspects of dispersion from sources the the CBL. The assumption of homogeneous turbulence has a significant practical advantage, specifically, longer time steps can be used in numerical simulations. In this paper, we compare two Langevin equations models that use the homogeneous turbulence assumption. We also compare and evaluate three reflection boundary conditions, the method for determining a new velocity for a particle that encounters a boundary. Model results are evaluated using data from Willis and Deardorff`s laboratory experiments for three different source heights.
Influence of soil parameters on the skewness coefficient of the annual maximum flood peaks
NASA Astrophysics Data System (ADS)
Gioia, A.; Iacobellis, V.; Manfreda, S.; Fiorentino, M.
2011-06-01
Understanding the spatial variability of key parameters of flood probability distributions represents a strategy to provide insights on hydrologic similarity and building probabilistic models able to reduce the uncertainty in flood prediction in ungauged basins. In this work, we exploited the theoretically derived distribution of floods TCIF (Gioia et al., 2008), based on two different threshold mechanisms associated respectively to ordinary and extraordinary events. The model is based on the hypotheses that ordinary floods are generally due to rainfall events exceeding a threshold infiltration rate in a small source area, while the so-called outlier events, responsible of the high skewness of flood distributions, are triggered when severe rainfalls exceed a storage threshold over a large portion of the basin. Within this scheme, a sensitivity analysis was performed in order to analyze the effects of climatic and geomorphologic parameters on the skewness coefficient. In particular, the analysis was conducted investigating the influence on flood distribution of physical factors such as rainfall intensity, soil infiltration capacity, and basin area, in order to provide insights in catchment classification and process conceptualization.
NASA Astrophysics Data System (ADS)
Alfarano, S.; Lux, T.; Wagner, F.
2007-01-01
The present paper expands on recent attempts at estimating the parameters of simple interacting-agent models of financial markets [S. Alfarano, T. Lux, F. Wagner, Computational Economics 26, 19 (2005); S. Alfarano, T. Lux, F. Wagner, in Funktionsfähigkeit und Stabilität von Finanzmärkten, edited by W. Franz, H. Ramser, M. Stadler (Mohr Siebeck, Tübingen, 2005), pp. 241 254]. Here we provide additional evidence by (i) investigating a large sample of individual stocks from the Tokyo Stock Exchange, and (ii) comparing results from the baseline noise trader/fundamentalist model of [S. Alfarano, T. Lux, F. Wagner, Computational Economics 26, 19 (2005)] with those obtained from an even simpler version with a preponderance of noise trader behaviour. As it turns out, this somewhat more parsimonious “maximally skewed” variant is often not rejected in favor of the more complex version. We also find that all stocks are dominated by noise trader behaviour irrespective of whether the data prefer the skewed or the baseline version of our model.
Fourier transform assisted deconvolution of skewed peaks in complex multi-dimensional chromatograms.
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
Random sampling of skewed distributions implies Taylor's power law of fluctuation scaling.
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
Differential properties and attracting sets of a simplest skew product of interval maps
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.
Huang, Yangxin
2013-01-30
Although it is a common practice to analyze complex HIV longitudinal data using nonlinear mixed-effects or nonparametric mixed-effects models in literature, the following issues may standout. (i) In clinical practice, the profile of each subject's viral response may follow a 'broken-stick'-like trajectory, indicating multiple phases of decline and increase in response. Such multiple phases (change points) may be an important indicator to help quantify treatment effect and improve management of patient care. To estimate change points, nonlinear mixed-effects or nonparametric mixed-effects models become a challenge because of complicated structures of model formulations. (ii) The commonly assumed distribution for model random errors is normal, but this assumption may unrealistically obscure important features of subject variations. (iii) The response observations (viral load) may be subject to left censoring due to a limit of detection. Inferential procedures can be complicated dramatically when data with asymmetric (skewed) characteristics and left censoring are observed in conjunction with change points as unknown parameters into models. There is relatively little work concerning all these features simultaneously. This article proposes segmental mixed-effects models with skew distributions for the response process (with left censoring) under a Bayesian framework. A real data example is used to illustrate the proposed methods. PMID:22833368
Deconstructing risk: separable encoding of variance and skewness in the brain.
Symmonds, Mkael; Wright, Nicholas D; Bach, Dominik R; Dolan, Raymond J
2011-10-15
Risky choice entails a need to appraise all possible outcomes and integrate this information with individual risk preference. Risk is frequently quantified solely by statistical variance of outcomes, but here we provide evidence that individuals' choice behaviour is sensitive to both dispersion (variance) and asymmetry (skewness) of outcomes. Using a novel behavioural paradigm in humans, we independently manipulated these 'summary statistics' while scanning subjects with fMRI. We show that a behavioural sensitivity to variance and skewness is mirrored in neuroanatomically dissociable representations of these quantities, with parietal cortex showing sensitivity to the former and prefrontal cortex and ventral striatum to the latter. Furthermore, integration of these objective risk metrics with subjective risk preference is expressed in a subject-specific coupling between neural activity and choice behaviour in anterior insula. Our findings show that risk is neither monolithic from a behavioural nor neural perspective and its decomposition is evident both in distinct behavioural preferences and in segregated underlying brain representations. PMID:21763444
Skewed B cell differentiation affects lymphoid organogenesis but not T cell-mediated autoimmunity.
Colombo, E; Tentorio, P; Musio, S; Rajewsky, K; Pedotti, R; Casola, S; Farina, C
2014-04-01
B cell receptor (BCR) signalling determines B cell differentiation and may potentially alter T cell-mediated immune responses. In this study we used two transgenic strains of BCR-deficient mice expressing Epstein-Barr virus latent membrane protein (LMP)2A in B cells, where either follicular and marginal zone differentiation (D(H)LMP2A mice) or B-1 cell development (V(H)LMP2A mice) were supported, and evaluated the effects of skewed B lymphocyte differentiation on lymphoid organogenesis and T cell responses in vivo. Compared to wild-type animals, both transgenic strains displayed alterations in the composition of lymphoid organs and in the dynamics of distinct immune cell subsets following immunization with the self-antigen PLP???????. However, ex-vivo?T cell proliferation to PLP??????? peptide measured in immunized D(H)LMP2A and V(H)LMP2A mice was similar to that detected in immunized control mice. Further, clinical expression of experimental autoimmune encephalitis in both LMP2A strains was identical to that of wild-type mice. In conclusion, mice with skewed B cell differentiation driven by LMP2A expression in BCR-negative B cells do not show changes in the development of a T cell mediated disease model of autoimmunity, suggesting that compensatory mechanisms support the generation of T cell responses. PMID:24325711
Sardeshmukh, Prashant D; Penland, Cécile
2015-03-01
The probability distributions of large-scale atmospheric and oceanic variables are generally skewed and heavy-tailed. We argue that their distinctive departures from Gaussianity arise fundamentally from the fact that in a quadratically nonlinear system with a quadratic invariant, the coupling coefficients between system components are not constant but depend linearly on the system state in a distinctive way. In particular, the skewness arises from a tendency of the system trajectory to linger near states of weak coupling. We show that the salient features of the observed non-Gaussianity can be captured in the simplest such nonlinear 2-component system. If the system is stochastically forced and linearly damped, with one component damped much more strongly than the other, then the strongly damped fast component becomes effectively decoupled from the weakly damped slow component, and its impact on the slow component can be approximated as a stochastic noise forcing plus an augmented nonlinear damping. In the limit of large time-scale separation, the nonlinear augmentation of the damping becomes small, and the noise forcing can be approximated as an additive noise plus a correlated additive and multiplicative noise (CAM noise) forcing. Much of the diversity of observed large-scale atmospheric and oceanic probability distributions can be interpreted in this minimal framework. PMID:25833448
Implementation of a mass-flow-weighted skew-upwind differencing scheme in COMMIX-1A
Hassan, Y.A.; Meerbaum, M.I.
1984-05-01
It is well known in computational fluid dynamics that the upwind approximation to the convective terms in the multidimensional convection-diffusion equation introduces false diffusion into the calculated results when the velocity field is oblique to the grid lines. This problem has afflicted recent numerical predictions of mixing in a pressurized water reactor cold leg and downcomer during high pressure injection. Accurate solutions for this case are difficult to obtain due to the large temperature gradients and bending velocity fields that prevail. This report is a presentation of a new method for approximating the convection terms in the COMMIX-1A energy equation. This new finite difference scheme, an unconditionally stable version of the skew-upwind differencing scheme first proposed by Raithby, has been incorporated in COMMIX-1A, tested extensively, and benchmarked with exact analytical solutions and experimental data. The new skew-upwind finite difference scheme has been shown to provide substantially more accurate predictions of steady-state and quasi-steady-state temperature fields than the conventional upwind differencing scheme.
Effects of the size of cosmological N-Body simulations on physical quantities - III: Skewness
J. S. Bagla; Jayanti Prasad; Nishikanta Khandai
2009-02-04
N-Body simulations are an important tool in the study of formation of large scale structures. Much of the progress in understanding the physics of galaxy clustering and comparison with observations would not have been possible without N-Body simulations. Given the importance of this tool, it is essential to understand its limitations as ignoring these can easily lead to interesting but unreliable results. In this paper we study the limitations due to the finite size of the simulation volume. In an earlier work we proposed a formalism for estimating the effects of a finite box-size on physical quantities and applied it to estimate the effect on the amplitude of clustering, mass function. Here, we extend the same analysis and estimate the effect on skewness and kurtosis in the perturbative regime. We also test the analytical predictions from the earlier work as well as those presented in this paper. We find good agreement between the analytical models and simulations for the two point correlation function and skewness. We also discuss the effect of a finite box size on relative velocity statistics and find the effects for these quantities scale in a manner that retains the dependence on the averaged correlation function.
Fuel cell plates with skewed process channels for uniform distribution of stack compression load
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.
Deconstructing risk: Separable encoding of variance and skewness in the brain
Symmonds, Mkael; Wright, Nicholas D.; Bach, Dominik R.; Dolan, Raymond J.
2011-01-01
Risky choice entails a need to appraise all possible outcomes and integrate this information with individual risk preference. Risk is frequently quantified solely by statistical variance of outcomes, but here we provide evidence that individuals’ choice behaviour is sensitive to both dispersion (variance) and asymmetry (skewness) of outcomes. Using a novel behavioural paradigm in humans, we independently manipulated these ‘summary statistics’ while scanning subjects with fMRI. We show that a behavioural sensitivity to variance and skewness is mirrored in neuroanatomically dissociable representations of these quantities, with parietal cortex showing sensitivity to the former and prefrontal cortex and ventral striatum to the latter. Furthermore, integration of these objective risk metrics with subjective risk preference is expressed in a subject-specific coupling between neural activity and choice behaviour in anterior insula. Our findings show that risk is neither monolithic from a behavioural nor neural perspective and its decomposition is evident both in distinct behavioural preferences and in segregated underlying brain representations. PMID:21763444
23 CFR 973.210 - Indian lands bridge management system (BMS).
Code of Federal Regulations, 2010 CFR
2010-04-01
... Indian lands bridge management system (BMS). In...Guidelines for Bridge Management Systems.” 2 2 “Guidelines for Bridge Management Systems,” AASHTO...Identify alternative strategies to improve bridge...
Network Bridging Potential in Later Life
Cornwell, Benjamin
2009-01-01
Objectives Much work in social gerontology has examined older adults’ social connectedness, but we know little about the extent to which older adults occupy positions of power and independence in their networks. The author uses health and life-course frameworks to understand older adults’ prospects of occupying bridging positions between otherwise unconnected individuals. Methods Egocentric social network data were collected from a nationally representative sample of 3,005 older adults between the ages of 57 and 85 in 2005–2006. A series of multivariate regression analyses was used to examine how health and life-course factors relate to bridging. Results Age is not significantly associated with bridging. However, retirees and people with poor health are less likely to have bridging potential. At the same time, widows are more likely to serve as bridges. Discussion The discusses the need for more dialogue between social network researchers and social gerontologists to help explain older adults’ bridging prospects. PMID:19144972
Navajo Bridge Reverse Engineering Project APPL 160, Fall 2012
Oldenburg, Amy
Navajo bridge (in the foreground) in 1994. Some statistics on the 1994 bridge according to Wikipedia Â· Width of the roadway: 44 feet Â· Amount of steel: 3,900,000 lbs Â· Amount of concrete: 1,790 cubic yards will be to reverse-engineer the 1994 bridge using only the bridge photos and bridge statistics shown here, some
9. VIEW OF BRIDGE NEAR CENTER SPAN, LOOKING NORTH FROM ...
9. VIEW OF BRIDGE NEAR CENTER SPAN, LOOKING NORTH FROM THE ARROYO SECO. THE PARKER-MAYBERRY BRIDGE IS BELOW THE COLORADO STREET BRIDGE, THE PIONEER BRIDGE IS IN THE BACKGROUND. - Colorado Street Bridge, Spanning Arroyo Seco at Colorado Boulevard, Pasadena, Los Angeles County, CA
Railway bridge monitoring during construction and sliding
NASA Astrophysics Data System (ADS)
Inaudi, Daniele; Casanova, Nicoletta; Kronenberg, Pascal; Vurpillot, Samuel
1997-05-01
The Moesa railway bridge is a composite steel concrete bridge on three spans of 30 m each. The 50 cm thick concrete deck is supported on the lower flanges of two continuous, 2.7 m high I-beams. The bridge has been constructed alongside an old metallic bridge. After demolishing this one, the new bridge has been slid for 5 m by 4 hydraulic jacks and positioned on the refurbished piles of the old bridge. About 30 fiber optic, low-coherence sensors were imbedded in the concrete deck to monitor its deformations during concrete setting and shrinkage, as well as during the bridge sliding phase. In the days following concrete pour it was possible to follow its thermal expansion due to the exothermic setting reaction and the following thermal and during shrinkage. The deformations induced by the additional load produced by the successive concreting phases were also observed. During the bridge push, which extended over six hours, the embedded and surface mounted sensors allowed the monitoring of the curvature variations in the horizontal plane due to the slightly uneven progression of the jacks. Excessive curvature and the resulting cracking of concrete could be ruled out by these measurements. It was also possible to observe the bridge elongation under the heating action of the sun.
A data management infrastructure for bridge monitoring
NASA Astrophysics Data System (ADS)
Jeong, Seongwoon; Byun, Jaewook; Kim, Daeyoung; Sohn, Hoon; Bae, In Hwan; Law, Kincho H.
2015-04-01
This paper discusses a data management infrastructure framework for bridge monitoring applications. As sensor technologies mature and become economically affordable, their deployment for bridge monitoring will continue to grow. Data management becomes a critical issue not only for storing the sensor data but also for integrating with the bridge model to support other functions, such as management, maintenance and inspection. The focus of this study is on the effective data management of bridge information and sensor data, which is crucial to structural health monitoring and life cycle management of bridge structures. We review the state-of-the-art of bridge information modeling and sensor data management, and propose a data management framework for bridge monitoring based on NoSQL database technologies that have been shown useful in handling high volume, time-series data and to flexibly deal with unstructured data schema. Specifically, Apache Cassandra and Mongo DB are deployed for the prototype implementation of the framework. This paper describes the database design for an XML-based Bridge Information Modeling (BrIM) schema, and the representation of sensor data using Sensor Model Language (SensorML). The proposed prototype data management framework is validated using data collected from the Yeongjong Bridge in Incheon, Korea.
Finding bridges in packings of colloidal spheres
Matthew C. Jenkins; Mark D. Haw; Gary C. Barker; Wilson C. K. Poon; Stefan U. Egelhaaf
2010-06-17
We identify putative load-bearing structures (bridges) in experimental colloidal systems studied by confocal microscopy. Bridges are co-operative structures that have been used to explain stability and inhomogeneous force transmission in simulated granular packings with a range of densities. We show that bridges similar to those found in granular simulations are present in real experimental colloidal packings. We describe critically the bridge-finding procedure for real experimental data and propose a new criterion-Lowest Mean Squared Separation (LSQS)-for selecting optimum stabilisations.
6. VIEW OF GDOT BRIDGE NO. 02700268X00678N BRIDGE PLATE IDENTIFYING ...
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
rBridge: User Reputation based Tor Bridge Distribution with Privacy Preservation
Minnesota, University of
rBridge: User Reputation based Tor Bridge Distribution with Privacy Preservation Qiyan Wang Department of Computer Science University of Minnesota hopper@cs.umn.edu Abstract Tor is one of the most censorship. A key challenge to the Tor circumvention system is to distribute bridges to a large number
Research: the bridge to collaboration.
Reeb, R M; Rogers, B P; Richardson, B
1992-01-01
A faculty-staff research fair was used by a school of nursing and university hospital at a large Southern medical center as a way of promoting collaboration between nursing education and service. The end results were these: a nurse-theorist "room" in the school of nursing; development of collaborative studies; subsequent presentation of posters originally prepared for the fair at 12 local, 13 state, six regional, and three national meetings. The overwhelming positive response by participants verified that research could serve as a natural bridge to promote collaboration between research, education, and service. PMID:1589043
HERO resistant semiconductor bridge igniter
NASA Astrophysics Data System (ADS)
Bickes, R. W., Jr.; Greenway, D.; Grubelich, M. C.; Meyer, W. J.; Hartman, J. K.; McCampbell, C. B.
1992-10-01
The problem of accidental ignition of explosive components when exposed to radio frequency (RF) environments or radiation from other electromagnetic sources is commonly referred to as Hazards of Electromagnetic Radiation to Ordnance (HERO). One illustration of such a HERO problem is the MK 149 Phalanx ammunition, which is sensitive to RF energy over a broad range of frequencies. We have demonstrated that a potential solution to the Phalanx HERO problem consists of a semiconductor bridge (SCB) igniter that incorporates microcircuitry to protect the SCB from the RF environment. Direct RF injection and ground plane tests have demonstrated the resistance of our designs to severe RF environments.
Röder, Beate
Bridge-Mediated Two-Electron Transfer via Delocalized Bridge Orbitals E. G. Petrov, Ya. R, 2004 Bridge mediated two-electron transfer (TET) in a donor-acceptor (D-A) complex is studied theoretically. A type of bridge is considered where the intersite coupling in the bridge becomes so large
Hu, Jiang
Integrated Placement and Skew Optimization for Rotary Clocking Ganesh Venkataraman, Student Member, IEEE of the clock network. Rotary clocking is a novel technique which employs unterminated rings formed by differen, rotary clocking requires flip-flop locations to match predesigned clock skew on rotary clock rings
Salt-bridge energetics in halophilic proteins.
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
3. GENERAL VIEW LOOKING WEST, SHOWING LIFT BRIDGE. COUNTER WEIGHTS ...
3. GENERAL VIEW LOOKING WEST, SHOWING LIFT BRIDGE. COUNTER WEIGHTS ARE LARGE SQUARES VISIBLE ABOVE BRIDGE. - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA
GENERAL VIEW LOOKING WEST SHOWING LIFT BRIDGE. COUNTER WEIGHTS ARE ...
GENERAL VIEW LOOKING WEST SHOWING LIFT BRIDGE. COUNTER WEIGHTS ARE LARGE SQUARES VISIBLE ABOVE BRIDGE - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA
7. VIEW ACROSS BRIDGE FROM NORTHWEST CORNER WITH WIDE ANGLE ...
7. VIEW ACROSS BRIDGE FROM NORTHWEST CORNER WITH WIDE ANGLE LENS SHOWING BRIDGE IN LANDSCAPE. - Wildcat Creek Bridge, Spanning Wildcat Creek on New Big Oak Flat Road, Yosemite Village, Mariposa County, CA
11. Standing on westerly fender at edge of bridge looking ...
11. Standing on westerly fender at edge of bridge looking easterly, showing horizontal beams for deck and cross beams (reflection of steel grating on deck). Also shows bridge guardrail. - Colusa Bridge, Spanning Sacramento River, Colusa, Colusa County, CA
9. View of bridge looking west. A fundraising marathon is ...
9. View of bridge looking west. A fund-raising marathon is in prgress. The traffic levels outside the main arch were added in 1965 when the bridge underwent extensive rehabilitation. - Detroit Superior High Level Bridge, Cleveland, Cuyahoga County, OH
APPROACH VIADUCTS TO TRIBOROUGH SUSPENSION BRIDGE (AT RIGHT), AND THE ...
APPROACH VIADUCTS TO TRIBOROUGH SUSPENSION BRIDGE (AT RIGHT), AND THE HELL GATE BRIDGE (AT LEFT), OVER RANDALL'S ISLAND. - Triborough Bridge, Passing through Queens, Manhattan & the Bronx, Queens (subdivision), Queens County, NY
4. General perspective view of Ross Island Bridge, view from ...
4. General perspective view of Ross Island Bridge, view from the east and looking west on the south side of the bridge. - Ross Island Bridge, Spanning Willamette River at Powell Boulevard, Portland, Multnomah County, OR