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1

Response of a continuous, skewed, steel bridge during deck placement  

Microsoft Academic Search

An investigation was conducted to study environmental, material and deck placement effects on the behavior of a continuous, skewed, High Performance Steel (HPS), integral abutment bridge during construction using field data and three-dimensional finite element models. The finite element models were calibrated against girder strain measurements recorded during deck placement. During calibration, the effects of temperature changes during deck placement

Tze-Wei Choo; Daniel G. Linzell; Je Il Lee; James A. Swanson

2005-01-01

2

Experimental Investigation of Skewed Elastomeric Expansion Bridge Bearings. Executive Summary.  

National Technical Information Service (NTIS)

The following tests were conducted on each of twelve elastomeric expansion bridge bearings: Shear and compressive stiffness tests, Fatigue cycles representing 50 years of service with parallel bearing surfaces, Shear stiffness tests with bearings at sub-f...

G. D. Allen T. M. Murray

1987-01-01

3

Behavior of a Skew Steel-Deck Bridge under Static and Dynamic Loads.  

National Technical Information Service (NTIS)

The report deals with the results of a field investigation and subsequent analysis of a short span skew, skewly stiffened steel deck bridge. The wearing surface was a 1/4 in. thick layer of aluminum oxide grits on a resin binder. The strain and deflection...

J. G. Bouwkamp

1965-01-01

4

Structural Behavior of a Skew, Reinforced Concrete, Box Girder Bridge Model. Volume 1. Design.  

National Technical Information Service (NTIS)

A two-span, continuous, reinforced concrete, box girder bridge, with supports skewed 45 degrees, is to be modeled at a scale of 1:2.82, instrumented and tested at the University of California, Berkeley, to assess anomalies in structural behavior by compar...

R. E. Davis

1978-01-01

5

Finite Element model updating of a skewed highway bridge using a multi-variable sensitivity-based optimization approach  

NASA Astrophysics Data System (ADS)

This paper presents the implementation of the Finite Element (FE) model updating for a skewed highway bridge using real-time sensor data. The bridge under investigation is a I-275 crossing in Wayne County, Michigan. The bridge is instrumented with a wireless sensory system to collect the vibration response of the bridge under ambient vibrations. The dynamic characteristics of the bridge have been studied through the field measurements as well as a high-fidelity FE model of the bridge. The developed finite element model of the bridge is updated with the field measured response of the bridge so that the FE computed and field measured modal characteristics of the bridge match each other closely. A comprehensive sensitivity analysis was performed to determine the structural parameters of the FE model which affect the modal frequencies and modal shapes the most. A multivariable sensitivity-based objective function is constructed to minimize the error between the experimentally measured and the FE predicted modal characteristics. The selected objective function includes information about both modal frequencies and mode shapes of the bridge. An iterative approach has been undertaken to find the optimized structural parameters of the FE model which minimizes the selected objective function. Appropriate constraints and boundary conditions are used during the optimization process to prevent non-physical solutions. The final updated FE model of the bridge provides modal results which are very consistent with the experimentally measured modal characteristics.

Mosavi, Amir A.; Sedarat, Hassan; O'Connor, Sean M.; Emami-Naeini, Abbas; Jacob, Vince; Krimotat, Alex; Lynch, Jerome

2012-03-01

6

Skew Distribution  

NSDL National Science Digital Library

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

2010-01-01

7

Bridges  

NSDL National Science Digital Library

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 â arch, beam, truss and suspension â students explore the affect 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.

Integrated Teaching And Learning Program

8

2. Skewed view of E elevation of sugar mill looking ...  

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

2. Skewed view of E elevation of sugar mill looking NW. - Hacienda Azurarera Santa Elena, Sugar Mill Ruins, 1.44 miles North of PR Route 2 Bridge Over Rio De La Plata, Toa Baja, Toa Baja Municipio, PR

9

Skew-T Mastery  

NSDL National Science Digital Library

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.

Spangler, Tim

2006-10-04

10

Clock Skew Scheduling with Delay Padding for Prescribed Skew Domains  

Microsoft Academic Search

Clock skew scheduling is a technique that intentionally in- troduces skews to memory elements to improve the perfor- mance of a sequential circuit. It was shown in (21) that the full optimization potential of clock skew scheduling can be reliably implemented using a few skew domains. In this paper we present an optimal skew scheduling algorithm for sequential circuits with

Chuan Lin; Hai Zhou

2007-01-01

11

Skewness in hedge funds returns: classical skewness coefficients vs Azzalini's skewness parameter  

Microsoft Academic Search

Purpose – Recent literature discusses the persistence of skewness and tail risk in hedge fund returns. The aim of this paper is to suggest an alternative skewness measure, Azzalini's skewness parameter delta, which is derived as the normalized shape parameter from the skew-normal distribution. The paper seeks to analyze the characteristics of this skewness measure compared with other indicators of

Martin Eling; Simone Farinelli; Damiano Rossello; Luisa Tibiletti

2010-01-01

12

Metric adjusted skew information  

PubMed Central

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 “?-skew information,” parametrized by a ? ? (0, 1], and show that the convex cone this family generates coincides with the set of all metric adjusted skew informations.

Hansen, Frank

2008-01-01

13

Physical aware clock skew rescheduling  

Microsoft Academic Search

Yield driven skew scheduling method leads to a clock tree with much greater wire length and buffer number that is not acceptable by designer. Geometry based register position relationships are converted to skew constraints and are combined with timing constraints harmoniously. With the two kinds of skew constraints together, our algorithm solves the skew scheduling problem for both restrictions and

Xinjie Wei; Yici Cai; Xianlong Hong

2007-01-01

14

Collaborative filtering on skewed datasets  

Microsoft Academic Search

Many real life datasets have skewed distributions of events when the probability of observing few events far exceeds the others. In this paper, we observed that in skewed datasets the state of the art collaborative filtering methods perform worse than a simple probabilistic model. Our test bench includes a real ad click stream dataset which is naturally skewed. The same

Somnath Banerjee; Krishnan Ramanathan

2008-01-01

15

8. Detail, skewed portal bracing at west portal, also showing ...  

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

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

16

A skew item response model  

Microsoft Academic Search

We introduce a new skew-probit link for item response theory (IRT) by considering an\\u000aaccumulated skew-normal distribution. The model extends the symmetric probit-normal IRT\\u000amodel by considering a new item (or skewness) parameter for the item characteristic curve.\\u000aA special interpretation is given for this parameter, and a latent linear structure is\\u000aindicated for the model when an augmented likelihood

Jorge L. Bazán; Márcia D. Branco; Heleno Bolfarine

2006-01-01

17

A Constructive Representation of Univariate Skewed Distributions  

Microsoft Academic Search

We introduce a general perspective on the introduction of skewness into symmetric distributions. Making use of inverse probability integral transformations we provide a constructive representation of skewed distributions, where the skewing mechanism and the original symmetric distributions are specifled separately. We study the efiects of the skewing mechanism on e.g. modality, tail behaviour and the amount of skewness generated. In

Jose T. A. S. Ferreira; Mark F. J. Steel

2006-01-01

18

Skewed Rotation Symmetry Group Detection  

Microsoft Academic Search

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

Seungkyu Lee; Yanxi Liu

2010-01-01

19

Skew resisting hydrodynamic seal  

DOEpatents

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.

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

2001-01-01

20

Practical Skew Handling in Parallel Joins  

Microsoft Academic Search

We present an approach to dealing with skew in parallel joins in database systems.Our approach is easily implementable within current parallel DBMS, and performs well onskewed data without degrading the performance of the system on non-skewed data. Themain idea is to use multiple algorithms, each specialized for a different degree of skew, and touse a small sample of the relations

David J. Dewitt; Jeffrey F. Naughton; Donovan A. Schneider; S. Seshadri

1992-01-01

21

Categorical geometric skew Howe duality  

NASA Astrophysics Data System (ADS)

We categorify the R-matrix isomorphism between tensor products of minuscule representations of U_q(sl(n)) by constructing an equivalence between the derived categories of coherent sheaves on the corresponding convolution products in the affine Grassmannian. The main step in the construction is a categorification of representations of U_q(sl(2)) which are related to representations of U_q(sl(n)) by quantum skew Howe duality. The resulting equivalence is part of the program of algebro-geometric categorification of Reshitikhin-Turaev tangle invariants developed by the first two authors.

Cautis, Sabin; Kamnitzer, Joel; Licata, Anthony

22

Modeling Conditional Skewness in Stock Returns  

Microsoft Academic Search

In this paper, we propose a new GARCH-in-Mean (GARCH-M) model allowing for conditional skewness. The model is based on the so-called z distribution capable of modeling skewness and kurtosis of the size typically encountered in stock return series. The need to allow for skewness can also be readily tested. The model is consistent with the volatility feedback effect in that

Markku Lanne; Saikkonen Pentti

2007-01-01

23

Standard Mastery Curves and Skew Curves.  

ERIC Educational Resources Information Center

The objective of the study is to convince educational researchers of the necessity for "standard mastery curves" for the graphical representation of scores on summative tests for a group of students. Attention is drawn to the study of theoretical and empirical skew curves in education and biology. Use of standard mastery curves and study of skew

Warries, Egbert

24

Skewed oligomers and origins of replication  

Microsoft Academic Search

The putative origin of replication in prokaryotic genomes can be located by a new method that finds short oligomers whose orientation is preferentially skewed around the origin. The skewed oligomer method is shown to work for all bacterial genomes and one of three archaeal genomes sequenced to date, confirming known or predicted origins in most cases and in three cases

Steven L. Salzberg; Alan J. Salzberg; Anthony R. Kerlavage; Jean-Francois Tomb

1998-01-01

25

Natural frequencies of clamped orthotropic skew plates  

Microsoft Academic Search

Approximate formulae are proposed for estimating natural frequencies of isotropic and specially orthotropic skew plates with clamped sides. It has been shown previously that one can estimate a natural frequency of a generally orthotropic skew plate with clamped sides by using an approximate formula for the isotropic plate which one can relate to the orthotropic one by applying a previously

T. Sakata; T. Hayashi

1982-01-01

26

Control chart design strategies for skewed data  

Microsoft Academic Search

Individual measurements and moving-range control charts are applied when the quality characteristic follows a normal distribution. In the semiconductor industry, certain quality characteristics are monitored where the data do not follow a normal distribution. In this paper we consider alternative design strategies for control charts where the distribution of the data is skewed. Although we use skewed data, these techniques

Steven T. Mandraccia; Galen D. Halverson; Youn-Min Chou

1996-01-01

27

Instrumentation of Bridge No. MEG-124-6.78.  

National Technical Information Service (NTIS)

Bridge MEG 124-6.78 was a single span, skewed, composite, adjacent, prestressed box girder bridge. After being in service about 1 year, the three edge beams on the inside of the curve showed extensive cracking. Subsequent inspection revealed serveral cons...

R. A. Miller

1999-01-01

28

Modeling Skewness in Human Transcriptomes  

PubMed Central

Gene expression data are influenced by multiple biological and technological factors leading to a wide range of dispersion scenarios, although skewed patterns are not commonly addressed in microarray analyses. In this study, the distribution pattern of several human transcriptomes has been studied on free-access microarray gene expression data. Our results showed that, even in previously normalized gene expression data, probe and differential expression within probe effects suffer from substantial departures from the commonly assumed symmetric Gaussian distribution. We developed a flexible mixed model for non-competitive microarray data analysis that accounted for asymmetric and heavy-tailed (Student’s t distribution) dispersion processes. Random effects for gene expression data were modeled under asymmetric Student’s t distributions where the asymmetry parameter (?) took values from perfect symmetry (??=?0) to right- (?>0) or left-side (?>0) over-expression patterns. This approach was applied to four free-access human data sets and revealed clearly better model performance when comparing with standard approaches accounting for traditional symmetric Gaussian distribution patterns. Our analyses on human gene expression data revealed a substantial degree of right-hand asymmetry for probe effects, whereas differential gene expression addressed both symmetric and left-hand asymmetric patterns. Although these results cannot be extrapolated to all microarray experiments, they highlighted the incidence of skew dispersion patterns in human transcriptome; moreover, we provided a new analytical approach to appropriately address this biological phenomenon. The source code of the program accommodating these analytical developments and additional information about practical aspects on running the program are freely available by request to the corresponding author of this article.

Casellas, Joaquim; Varona, Luis

2012-01-01

29

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

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

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

30

Control chart design strategies for skewed data  

NASA Astrophysics Data System (ADS)

Individual measurements and moving-range control charts are applied when the quality characteristic follows a normal distribution. In the semiconductor industry, certain quality characteristics are monitored where the data do not follow a normal distribution. In this paper we consider alternative design strategies for control charts where the distribution of the data is skewed. Although we use skewed data, these techniques are also applicable to other non-normally distributed data. We discuss using a 'state of the art' curve-fitting method, data transformations, and nonsymmetrical limits for the control charting of skewed data. This paper provides alternatives for the design, implementation, and maintenance of process control for non- normal or skewed data.

Mandraccia, Steven T.; Halverson, Galen D.; Chou, Youn-Min

1996-09-01

31

Determining palaeomagnetic poles and anomalous skewness from marine magnetic anomaly skewness data from a single plate  

Microsoft Academic Search

SUMMARY We present a method for simultaneously determining palaeomagnetic poles and anomalous skewness from the observed skewness of marine magnetic anomalies from a single plate. Skewness is esimated by visual comparison of phase-shifted observed anomaly profiles with an ideal zero-phase synthetic anomaly calculated for sea-floor formed and observed in a vertical magnetic field. We assume that each crossing of the

Katerina E. Petronotis; Richard G. Gordon; Gary D. Acton

1992-01-01

32

FROM QUASI-ENTROPY TO SKEW INFORMATION  

Microsoft Academic Search

This paper gives an overview about particular quasi-entropies, generalized\\u000aquantum covariances, quantum Fisher informations, skew-informations and their\\u000arelations. The point is the dependence on operator monotone functions. It is\\u000aproven that a skew-information is the Hessian of a quasi-entropy. The\\u000askew-information and some inequalities are extended to a von Neumann algebra\\u000asetting.

Denes Petz; V. E. Sandor Szabo

2009-01-01

33

Autoregresive conditional volatility, skewness and kurtosis  

Microsoft Academic Search

This paper proposes a GARCH-type model allowing for time-varying volatility, skewness and kurtosis. The model is estimated assuming a Gram–Charlier (GC) series expansion of the normal density function for the error term, which is easier to estimate than the non-central t distribution proposed by [Harvey, C. R. & Siddique, A. (1999). Autorregresive Conditional Skewness. Journal of Financial and Quantitative Analysis

Ángel León; Gonzalo Rubio; Gregorio Serna

2005-01-01

34

Static ocular counterroll reflex in skew deviation  

PubMed Central

Objective: The static ocular counterroll (OCR) reflex generates partially compensatory torsional eye movements during head roll. It is mediated by the utricle in the inner ear. Skew deviation is a vertical strabismus thought to be caused by imbalance in the utriculo-ocular pathway. We hypothesized that if skew deviation is indeed caused by damage to this reflex pathway, patients with skew deviation would show abnormal OCR. Methods: Eighteen patients with skew deviation caused by brainstem or cerebellar lesions and 18 normal participants viewed a target at 1 m. Ocular responses to static passive head roll-tilts of approximately 20° were recorded using search coils. Static OCR gain was calculated as the change in torsional eye position divided by the change in head position during sustained head roll. Perception of the subjective visual vertical (SVV) was also measured. Results: Group mean OCR gain was reduced by 45% in patients. At an individual level, OCR gains were asymmetric between eyes and between torsional directions in 90% of patients. In addition, the hypotropic eye incyclotorting gain was lower than the hypertropic eye excyclotorting gain during head roll toward the hypotropic eye in 94% of patients. No consistent pattern of gain asymmetry was found during head roll toward the hypertropic eye. The SVV was tilted toward the hypotropic eye. Conclusion: Static OCR gain is significantly reduced in skew deviation. Interocular and directional gain asymmetries are also prevalent. The asymmetries provide further evidence that disruption of the utriculo-ocular pathway is a mechanism for skew deviation.

Chandrakumar, M.; Blakeman, A.; Goltz, H.C.; Sharpe, J.A.

2011-01-01

35

High reproductive skew in tropical hover wasps.  

PubMed Central

A plethora of recent models examines how genetic and environmental factors might influence partitioning of reproduction ('skew') in animal societies, but empirical data are sparse. We used three microsatellite loci to estimate skew on 13 nests of the Malaysian hover wasp, Liostenogaster flavolineata. Groups are small in L. flavolineata (1-10 females) and all females are capable of mating and laying eggs. Despite considerable variation between nests in parameters expected to influence skew, skew was uniformly high. On 11 of the 13 nests, all female eggs had been laid by a single dominant female. A second female had laid one to two out of 5-10 eggs respectively on the two remaining nests. A likelihood analysis suggested that on average, 90% of the male eggs had also been laid by the dominant. The slightly lower skew among male eggs might reflect the lower average relatedness of subordinates to male versus female offspring of the dominant. We suggest that high skew in L. flavolineata may result from strong ecological constraints and a relatively high probability that a subordinate will eventually inherit the dominant, egg-laying position.

Sumner, Seirian; Casiraghi, Maurizio; Foster, William; Field, Jeremy

2002-01-01

36

Characterization and modeling of clock skew with process variations  

Microsoft Academic Search

A new compact model for on-chip clock skew as a function of device, interconnect, and system parameter variations is derived. Unlike previous models that describe qualitative behavior of clock skew components, the new model provides a closed form expression for each clock skew component. An example of clock skew components for a typical design using 0.18 ?m CMOS technology is

Payman Zarkesh-Ha; Tony Mule; James D. Meindl

1999-01-01

37

Logical data skewing schemes for interleaved memories in vector processors  

SciTech Connect

Sustained memory bandwidth for range of strides is a key to high-performance vector processing. To reduce the number of memory bank conflicts and thereby increase memory bandwidth, one often resorts to data skewing schemes. In this paper, the authors present a family of data skewing schemes called logical skewing schemes. In logical skewing schemes, the location of a data element is determined solely by logical manipulation of the address bits. The authors' experiments show that logical skewing schemes allow for better vector memory system performance than other known data skewing schemes without the significant increase in memory latency that is traditionally associated with data skewing schemes.

Sohi, G.S.

1988-01-01

38

Spaghetti Bridge  

NSDL National Science Digital Library

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

K-12 Outreach Office,

39

Bridge Cutout.  

National Technical Information Service (NTIS)

The subject of Main Patent No. 180,993 is a bridge cutout for automatic short-circuiting of series-connected incandescent lamps that have become defective. In this bridge cutout, the two electrodes are bridged by a thermite mixture, possibly with the addi...

O. Maresch F. Viehboeck

1980-01-01

40

Digital Bridges  

NSDL National Science Digital Library

"The Digital Bridges Web site consists of a collection of thirty representative 19th century American bridge engineering monographs, manuals, and documents from the Lehigh University Libraries' Special Collections." The archive provides an interesting retrospective into the beginnings of major bridge projects; the material is complete with high-resolution photographs and text scanned from original books. In addition to historical literature, Digital Bridges also features brief accounts of notable people and companies that influenced bridge construction across the country. A glossary of terms commonly used in the documents is also provided.

2002-01-01

41

Cellular bridges  

PubMed Central

Cell-to-cell communication is the basis of all biology in multicellular organisms, allowing evolution of complex forms and viability in dynamic environments. Though biochemical interactions occur over distances, physical continuity remains the most direct means of cellular interactions. Cellular bridging through thin cytoplasmic channels—plasmodesmata in plants and tunneling nanotubes in animals—creates direct routes for transfer of signals and components, even pathogens, between cells. Recently, two new cellular connections, designated epithelial (EP) bridges, were discovered and found to be structurally distinct from other cellular channels. The first EP bridge type facilitates material transport between cells similar to plasmodesmata and tunneling nanotubes, the second EP bridge type mediates migration of cells between EP cell masses representing a novel form of cell migration. Here, we compare the structures and functions of EP bridges with other cellular channels and discuss biochemical and cellular interactions involved in EP bridge formation. Potential roles for EP bridges in health and disease are also presented.

Edelman, Elazer R

2010-01-01

42

Bayesian Inference for Skewed Stable Distributions  

NASA Astrophysics Data System (ADS)

Stable distributions are a class of distributions which allow skewness and heavy tail. Non-Gaussian stable random variables play the role of normal distribution in the central limit theorem, for normalized sums of random variables with infinite variance. The lack of analytic formula for density and distribution functions of stable random variables has been a major drawback to the use of stable distributions, also in the case of inference in Bayesian framework. Buckle introduced priors for the parameters of stable random variables to obtain an analytic form of posterior distribution. However, many researchers tried to solve the problem, through the Markov chain Monte Carlo methods, e.g. [8] and their references. In this paper a new class of heavy-tailed distribution is introduced, called skewed stable. This class has two main advantages: It has many inferential advantages, since it is a member of exponential family, so the Bayesian inference can be drawn similar to the exponential family of distributions and modelling skew data with stable distributions is dominated by this family. Finally, Bayesian inference for skewed stable arc compared to the stable distributions through a few simulations study.

Shokripour, Mona; Nassiri, Vahid; Mohammadpour, Adel

2011-03-01

43

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...

44

Cracked Shells under Skew-Symmetric Loading.  

National Technical Information Service (NTIS)

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...

F. Delale

1981-01-01

45

Multi-slice FE modeling of electrical machines with skewed slots-the skew discretization error  

Microsoft Academic Search

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

Johan J. C. Gyselinck; Lieven Vandevelde; Jan A. A. Melkebeek

2001-01-01

46

Low Cost Scheme for On-Line Clock Skew Compensation  

Microsoft Academic Search

In this paper we propose a novel buffer scheme that is able to compensate undesired skews between clocks of a synchronous system in a negligible time upon skew occurrence, thus being suitable also for on-line clock-skew correction. Clock signals are aligned one with respect to the other, starting from a reference clock, and moving forward among physically adjacent clock signals,

Martin Omaña; Daniele Rossi; Cecilia Metra

2005-01-01

47

Perturbation of Numerical Confidential Data via Skew-t Distributions  

Microsoft Academic Search

We propose a new data perturbation method for numerical database security problems based on skew-t distributions. Unlike the normal distribution, the more general class of skew-t distributions is a flexible parametric multivariate family that can model skewness and heavy tails in the data. Because databases having a normal distribution are seldom encountered in practice, the newly proposed approach, coined the

Seokho Lee; Marc G. Genton; Reinaldo Boris Arellano-Valle

2010-01-01

48

Gradual opening of skewed passages in wave rotors  

Microsoft Academic Search

Most wave rotor turbomachines for the production of shaft power have used skewed passages. Attention is presently given to the opening of a skewed passage, drawing conclusions for the case of rectangular axial passages in light of results obtained for the skewed case. Mixing is noted to be minimal when the velocity of the opening is matched with the shock

S. Eidelman

1986-01-01

49

Document Skew Detection Using Minimum-Area Bounding Rectangle  

Microsoft Academic Search

Detection of document skew is an important step in document image analysis. The paper presents a new method for calculation of document skew. The method forms large connected components by a smoothing algorithm and calculates the document skew by finding the orientation of the minimum-area bounding rectangle of one of several connected components. Connection of text to non-text in the

Reza Safabakhsh; Shahram Khadivi

2000-01-01

50

Spaghetti Bridge  

NSDL National Science Digital Library

Learners explore the field of civil engineering by making a bridge using spaghetti as their primary building material. Then they test their bridges to see how much weight they can carry before breaking. This activity allows learners to engage in the entire engineering process as they design, build, test, then discuss their bridges. Resource includes investigating questions to extend learning. Time estimated for activity can be split across multiple meetings.

Institute, Worcester P.

2005-01-01

51

How skew distributions emerge in evolving systems  

NASA Astrophysics Data System (ADS)

Despite the ubiquitous emergence of skew distributions such as power law, log-normal, and Weibull distributions, there still lacks proper understanding of the mechanism as well as relations between them. It is studied how such distributions emerge in general evolving systems and what makes the difference between them. Beginning with a master equation for general evolving systems, we obtain the time evolution equation for the size distribution function. Obtained in the case of size changes proportional to the current size are the power law stationary distribution with an arbitrary exponent and the evolving distribution, which is of either log-normal or Weibull type asymptotically, depending on production and growth in the system. This master equation approach thus gives a unified description of those three types of skew distribution observed in a variety of systems, providing physical derivation of them and disclosing how they are related.

Choi, M. Y.; Choi, H.; Fortin, J.-Y.; Choi, J.

2009-02-01

52

Local mass transfer in skewed rectangular cavities  

NASA Astrophysics Data System (ADS)

Turbulent mass transfer from surfaces of rectangular cavities is studied experimentally using the naphthalene sublimation technique. Cavity aspect ratios of 1.1, 2.2, 4.4, and 6.7 were used as well as cavity-skew angles of 90, 85, 80, and 75 deg. It is found that variation of the local mass transfer distribution on each cavity wall is strongly dependent on the aspect ratio of the cavity.

Chyu, M. K.; Kapat, J. S.

53

Characterization of the skew-normal distribution  

Microsoft Academic Search

Two characterization results for the skew-normal distribution based on quadratic statistics have been obtained. The results\\u000a specialize to known characterizations of the standard normal distribution and generalize to the characterizations of members\\u000a of a larger family of distributions. Results on the decomposition of the family of distributions of random variables whose\\u000a square is distributed as ?\\u000a 1\\u000a 2\\u000a are obtained.

Arjun K. Gupta; Truc T. Nguyen; Jose Almer T. Sanqui

2004-01-01

54

Legitimate Skew Clock Routing with Buffer Insertion  

Microsoft Academic Search

In this paper, we propose a new quick and effective legitimate skew clock routing with buffer insertion algorithm. We analyze\\u000a the optimal buffer position in the clock path, and conclude the sufficient condition and heuristic condition for buffer insertion\\u000a in clock net. During the routing process, this algorithm integrates buffer insertion and node merging together, and performs\\u000a them in parallel.

Xinjie Wei; Yici Cai; Meng Zhao; Xianlong Hong

2006-01-01

55

Variance and Skewness in the FIRST Survey  

NASA Astrophysics Data System (ADS)

We investigate the large-scale clustering of radio sources by analysing the distribution function of the FIRST 1.4 GHz survey. We select a reliable galaxy sample from the FIRST catalogue, paying particular attention to the definition of single radio sources from the multiple components listed in the FIRST catalogue. We estimate the variance, ?2, and skewness, ?3, of the distribution function for the best galaxy subsample. ?2 shows power-law behaviour as a function of cell size, with an amplitude corresponding a spatial correlation length of r0 ~10 h-1 Mpc. We detect significant skewness in the distribution, and find that it is related to the variance through the relation ?3 = S3 (?2)? with ? = 1.9 +/- 0.1 consistent with the non-linear growth of perturbations from primordial Gaussian initial conditions. We show that the amplitude of clustering (corresponding to a spatial correlation length of r0 ~10 h-1 Mpc) and skewness are consistent with realistic models of galaxy clustering.

Magliocchetti, M.; Maddox, S. J.; Lahav, O.; Wall, J. V.

56

Analysis of Parasite and Other Skewed Counts  

PubMed Central

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.

Alexander, Neal

2012-01-01

57

Active Bridging  

Microsoft Academic Search

Active networks accelerate network evolution by permitting the network infrastructure to be programmable, on a per-user, per-packet, or other basis. This programmability must be balanced against the safety and security needs inherent in shared resources.This paper describes the design, implementation, and performance of a new type of network element, an Active Bridge. The active bridge can be reprogrammed \\

D. Scott Alexander; Marianne Shaw; Scott M. Nettles; Jonathan M. Smith

1997-01-01

58

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

PubMed

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

Frühwirth-Schnatter, Sylvia; Pyne, Saumyadipta

2010-01-27

59

Myocardial Bridge  

MedlinePLUS

... Cardiovascular Disease Diagnostic Tests and Procedures Ask a Texas Heart Institute Doctor: Search "myocardial bridge" Updated October ... Outside the U.S., call 1-832-355-6536.) Texas Heart Institute Heart Information Center Through this community ...

60

Dimensions of Attractors in Pinched Skew Products  

NASA Astrophysics Data System (ADS)

We study dimensions of strange non-chaotic attractors and their associated physical measures in so-called pinched skew products, introduced by Grebogi and his coworkers in 1984. Our main results are that the Hausdorff dimension, the pointwise dimension and the information dimension are all equal to one, although the box-counting dimension is known to be two. The assertion concerning the pointwise dimension is deduced from the stronger result that the physical measure is rectifiable. Our findings confirm a conjecture by Ding, Grebogi and Ott from 1989.

Gröger, M.; Jäger, T.

2013-05-01

61

Skew quad compensation for SPEAR minibeta optics  

SciTech Connect

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.

Wille, K.

1984-06-01

62

Spaghetti Bridge  

NSDL National Science Digital Library

Play with your food while learning about engineering! Build a spaghetti bridge, then test its strength by piling on the marshmallows, raw spaghetti, raw linguine and coins. Investigate the difference between the strength of bridges made from flat and round building materials (spaghetti is round, while linguine is flat). Learn by doing that circles are among the strongest shapes in nature, and that external and internal stress distributes itself evenly throughout a round structure.

Sciencenter

1999-01-01

63

Skew quadrupole errors in the RHIC IR triplets  

SciTech Connect

From simulation studies of the RHIC lattice, we found that skew quadrupole errors and quadrupole roll misalignments in the IR triplets (where the {beta} function can be large) produce large vertical dispersions. A simple model, using only one triplet, is applied to obtain sensitivities of vertical dispersion to skew quadrupole errors. This study revealed that measuring the vertical dispersion in the triplets is a good tool for the diagnosis of local skew quadrupole correction.

Tepikian, S.; Peggs, S.

1993-12-31

64

0.84 ps Resolution Clock Skew Measurement via Subsampling  

Microsoft Academic Search

An all-digital on-chip clock skew measurement system via subsampling is presented. The clock nodes are sub- sampled with a near-frequency asynchronous sampling clock to result in beat signals which are themselves skewed in the same proportion but on a larger time scale. The beat signals are then suitably masked to extract only the skews of the rising edges of the

Bharadwaj Amrutur; Pratap Kumar Das; Rajath Vasudevamurthy

2011-01-01

65

The additive logistic skew-normal distribution on the simplex  

Microsoft Academic Search

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

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

2005-01-01

66

Skew detection for binary document images using mathematical morphyology  

Microsoft Academic Search

The input document images with skew can be a serious problem in the optical character recognition system. A method is proposed\\u000a for skew detection in binary document images using mathematic morphology. The basic process of our approach consists of three\\u000a steps: Firstly, a dilation operation is applied to the binary image; Secondly, the dilated image is thinned; Finally, the\\u000a skew

Xu Hong-bo; Tian Yan

2002-01-01

67

Strong GC and AT Skew Correlation in Chicken Genome  

Microsoft Academic Search

Chicken genome AT and GC skews for individual chromosomes were visualized simultaneously using a novel method of 2-dimensional\\u000a color-coded pixel matrix. The visualizations were compared to those of human, mouse and possum genomes. A strikingly strong\\u000a correlation of AT skew and GC from small to large scale in chicken genome was found, compared to the other vertebrates. Some\\u000a local skew

Xuegong Deng; Xuemei Deng; Ilkka Havukkala

2007-01-01

68

Temperature-Compensated Clock Skew Adjustment  

PubMed Central

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)).

Castillo-Secilla, Jose Maria; Palomares, Jose Manuel; Olivares, Joaquin

2013-01-01

69

Temperature-compensated clock skew adjustment.  

PubMed

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

Castillo-Secilla, Jose María; Palomares, Jose Manuel; Olivares, Joaquín

2013-08-20

70

Advanced bridge management systems  

Microsoft Academic Search

In this paper, development of advanced bridge management systems is discussed, with special emphasis on reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way. The proposed procedures are illustrated by the EU-supported management systems BRIDGE1 and BRIDGE2. The paper is strongly based on reports produced within the EU

P. Thoft-Christensen

1995-01-01

71

Basswood Bridges  

NSDL National Science Digital Library

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.

Abramowitz, Harvey

2009-09-16

72

Fraction-free row reduction of matrices of skew polynomials  

Microsoft Academic Search

We present a new algorithm for row reduction of a matrix of skew polynomials. The algorithm can be used for finding full rank decompositions and other rank revealing transformations of matrices of skew polynomials. The algorithm is intended for computation in exact arithmetic domains where the growth of coefficients in intermediate computations is a central concern. This coefficient growth is

Bernhard Beckermann; Howard Cheng; George Labahn

2002-01-01

73

Zero skew clock routing for fast clock tree generation  

Microsoft Academic Search

A zero skew clock routing methodology has been developed to help design team speed up their clock tree generation process. The methodology works by breaking up the clock net into smaller partitions, then inserting clock buffers to drive each portion, and lastly, routing the connection from original clock source to each newly inserted clock buffers with zero skew. A few

M. B. I. Reaz; Nowshad Amin; M. I. Ibrahimy; F. Mohd-Yasin; A. Mohammad

2008-01-01

74

Finite element flutter analysis of composite skew panels  

Microsoft Academic Search

A finite element method is used to study the dynamic instability of laminated composite skew panels subjected to supersonic flow. The FEM employs eight-noded isoparametric elements which take into account transverse shear deformation. The linearized Piston theory is applied to assess the aerodynamic loads. The effects of skew angle on critical aerodynamic parameters are investigated for different aspect ratios, boundary

T. V. R. Chowdary; P. K. Sinha; S. Parthan

1996-01-01

75

Existence and non-existence of skew branes  

Microsoft Academic Search

Following recent work by Ghomi, Solomon and Tabachnikov, we study geometry and topology of skew branes. A skew brane is a codimension 2 submanifold in affine space such that the tangent spaces at any pair of distinct points are not parallel. We prove that if an oriented closed manifold has a non-zero Euler characteristic $\\\\xi$ then it is not a

Serge Tabachnikov; Yulia Tyurina

2005-01-01

76

THE SKEWNESS OF VOLUME DISTRIBUTION CURVES OF ERYTHROCYTES  

Microsoft Academic Search

Volume distribution curves of erythrocytes, obtained by automatic cell counting, are skew, the right side being flatter than the left one, indicating a greater than normal population of larger cells. This is in contrast to the familiar Price-Jones curves which show a more symmetrically bell-shaped distribution, as expected from a normal homogenous population. So far the skewness has been attributed

H Winter; RP Shieard

1965-01-01

77

A new skew-upwind differencing method  

SciTech Connect

It is the purpose of this paper first to examine the mathematical properties of Raithby's skew upwind scheme (RATH) and some of its variants and then to explore a new differencing approach that seems promising. Here the authors stress performance, not in problems with nearly discontinuous temperatures, but in more common thermal-hydraulic computations. For simplicity at this point, only XY geometry is considered, though the addition of a third dimension seems straightforward. Further, it is assumed initially that (a) u, v, and {rho} (the velocity components and density) are position independent; (b) u, v > 0; (c) 1/2v < u < 2v (Raithby's condition); (d) h{sub x} = h{sub y} = h = const; and (e) pure convection, i.e., no conduction or sources.

Gelbard, E.M. (Argonne National Lab., IL (USA))

1989-01-01

78

The Evaluation of the Initial Skew Rate for Printed Text  

NASA Astrophysics Data System (ADS)

In this manuscript the algorithm for identification of the initial skew rate for printed text is presented. Proposed algorithm creates rectangular hull around all text characters. Combining nearby rectangular hulls form objects. After applying mathematical morphology on it, the biggest object is characterized as well as selected. Rectangular hull gravity center forms reference points on these objects used as a base for calculation ieestimation of the initial skew rate. Using the least square method, initial skew rate is calculated. Comparative analysis of the origin and estimated skew rate is presented as well as discussed. Algorithm is examined with a number of printed text examples. Proposed algorithm showed robustness for skewness of printed text in the wide range.

Brodi?, Darko

2011-05-01

79

DECONSTRUCTING BRIDGES  

Microsoft Academic Search

ON THE BRINK … We found ourselves getting close to The Gap. The other side was covered in mist and I suddenly realised that, although heavily armed with the shiny weaponry and strongest determination, we would not be able to bridge The Gap. Stuck, desperate, we were waiting for someone to show us the way. Why don't we just shout

Janko Calic; Ebroul Izquierdo

80

An 8-bit 100-MS/s digital-to-skew converter embedded switch with a 200-ps range for time-interleaved sampling  

NASA Astrophysics Data System (ADS)

A sampling switch with an embedded digital-to-skew converter (DSC) is presented. The proposed switch eliminates time-interleaved ADCs' skews by adjusting the boosted voltage. A similar bridged capacitors' charge sharing structure is used to minimize the area. The circuit is fabricated in a 0.18 ?m CMOS process and achieves sub-1 ps resolution and 200 ps timing range at a rate of 100 MS/s. The power consumption is 430 ?W at maximum. The measurement result also includes a 2-channel 14-bit 100 MS/s time-interleaved ADCs (TI-ADCs) with the proposed DSC switch's demonstration. This scheme is widely applicable for the clock skew and aperture error calibration demanded in TI-ADCs and SHA-less ADCs.

Xiaoshi, Zhu; Chixiao, Chen; Jialiang, Xu; Fan, Ye; Junyan, Ren

2013-03-01

81

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

ERIC Educational Resources Information Center

|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.)|

Tabor, Josh

2010-01-01

82

The Belizean Bridge Activity.  

ERIC Educational Resources Information Center

|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)|

Murfin, Brian

2000-01-01

83

Bridge Inspector's Training Manual.  

ERIC Educational Resources Information Center

|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,…

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

84

Bridge Inspector's Training Manual.  

ERIC Educational Resources Information Center

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,…

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

85

Female reproductive synchrony predicts skewed paternity across primates  

PubMed Central

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

Nunn, Charles L.; Schulke, Oliver

2008-01-01

86

Bridge Building  

NSDL National Science Digital Library

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.

Twin Cities Public Television, Inc.

2008-01-01

87

Numerical simulation of the Langevin equation for skewed turbulence  

SciTech Connect

In this paper the authors present a numerical method for the generalized Langevin equation of motion with skewed random forcing for the case of homogeneous, skewed turbulence. The authors begin by showing how the analytic solution to the Langevin equation for this case can be used to determine the relationship between the particle velocity moments and the properties of the skewed random force. They then present a numerical method that uses simple probability distribution functions to simulate the effect of the random force. The numerical solution is shown to be exact in the limit of infinitesimal time steps, and to be within acceptable error limits when practical time steps are used.

Ermak, D.L. [Lawrence Livermore National Lab., CA (United States); Nasstrom, J.S. [EG and G Energy Measurements Inc., Pleasanton, CA (United States)

1994-12-01

88

Dispersive propagation skew effects in iterative neural networks.  

PubMed

During communication between neurons in a continuous-time analog neural network, propagation skew typically varies from neuron pair to neuron pair. For no dispersion, S. Oh et al. (Opt. Eng., vol.28, p.526-32, 1989) previously demonstrated that the steady-state performance of an iterative neural network is not affected if the combination of the neural network's weights and neural nonlinearity is contractive. This result is extended to the case of dispersive skew. It is shown that, under nearly the same conditions, the same steady-state result will occur in the neural network in the presence of dispersive skew. PMID:18276365

Oh, S; Marks, R J

1991-01-01

89

The Affective Impact of Financial Skewness on Neural Activity and Choice  

PubMed Central

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.

Wu, Charlene C.; Bossaerts, Peter; Knutson, Brian

2011-01-01

90

Skewness” of S-wave velocity in the mantle  

NASA Astrophysics Data System (ADS)

We analyze tomographic models of the S-wave velocity in the mantle. The depth variation of laterally heterogeneous structure is parametrized in terms of the “skewness,” which yields information on mantle convection. Recent models show negative skewness in the lower half of the mantle. Assuming that the velocity anomaly is related to the temperature anomaly, this suggests that there is significant heat flow from the core.

Yanagisawa, Takatoshi; Hamano, Yozo

91

A comparison between two simple measures of skewness  

Microsoft Academic Search

In 1995, Arnold and Groeneveld introduced the measure of skewness gammaM in terms of F(mode)-the cumulative probability of a random variable less than or equal to the mode of the distribution. They assumed that the mode of a distribution exists and is unique. Independently, in 1996, the present author arrived at the measure of skewness T, which is given in

I. H. Tajuddin

1999-01-01

92

Conditional volatility, skewness, and kurtosis: existence, persistence, and comovements  

Microsoft Academic Search

Recent portfolio-choice, asset-pricing, value-at-risk, and option-valuation models highlight the importance of modeling the asymmetry and tail-fatness of returns. These characteristics are captured by the skewness and the kurtosis. We characterize the maximal range of skewness and kurtosis for which a density exists and show that the generalized Student-t distribution spans a large domain in the maximal set. We use this

Eric Jondeau; Michael Rockinger

2003-01-01

93

The Skew-normal Distribution and Related Multivariate Families  

Microsoft Academic Search

This paper provides an introductory overview of a portion of distribution theory which is currently under intense development. The starting point of this topic has been the so-called skew-normal distribution, but the connected area is becoming increasingly broad, and its branches include now many extensions, such as the skew-elliptical families, and some forms of semi-parametric formulations, extending the relevance of

ADELCHI AZZALINI

2005-01-01

94

Bounded-skew clock and Steiner routing under Elmore delay  

Microsoft Academic Search

We study the minimum-cost bounded-skew routing tree problem under the Elmore delay model. We present two approaches to construct bounded-skew routing trees: (i) the Boundary Merging and Embedding (BME) method which utilizes merging points that are restricted to the boundaries of merging regions, and (ii) the Interior Merging and Embedding (IME) algorithm which employs a sampling strategy and dynamic programming

Jason Cong; Andrew B. Kahng; Cheng-Kok Koh; C.-W. Albert Tsao

1995-01-01

95

Epsilon-skew-binormal receiver operating characteristic (ROC) curves  

Microsoft Academic Search

In this note we extend the well-known binormal model via implementation of the epsilon-skew-normal (ESN) distribution developed by Mudholkar and Hutson (2000). We derive the equation for the receiver operating characteris- tic (ROC) curve assuming epsilon-skew-binormal (ESBN) model and examine the behavior of the maximum likelihood estimates for estimating the ESBN parameters. We then summarize the results of a simulation

Terry L. Mashtare Jr; Alan D. Hutson

2009-01-01

96

Streamflow simulation and skewness preservation based on the bootstrapped stochastic models  

Microsoft Academic Search

The stochastic model has been widely used for the simulation study. However, there was a difficulty in the reproduction of the skewness of observed series and so the stochastic model for the skewness preservation was appeared. While the skewness in the residuals of the stochastic model has been considered for the skewness preservation this study uses a random resampling technique

Byung Sik Kim; Hung Soo Kim; Byung Ha Seoh

2004-01-01

97

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

Microsoft Academic Search

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

Rafael Manuel Rojas

1993-01-01

98

Building Big: Bridges  

NSDL National Science Digital Library

This web page describes different aspects of designing bridges. It relates the concept of bridge designing with the real life scenarios. It also includes some bridges around the world and gives some specifications of them.

Foundation, Wgbh E.

2006-07-11

99

Building Big--Bridges  

NSDL National Science Digital Library

This web page describes different aspects of designing bridges. It relates the concept of bridge designing with the real life scenarios. It also includes some bridges around the world and gives some specifications of them.

2008-05-22

100

Bridge Management System Update.  

National Technical Information Service (NTIS)

The objective of this project was to assist the NCDOT in updating parameters used in analysis of bridge inspection data for purposes of bridge management. Various parameters are used in OPBRIDGE, a bridge manage system decision support program for predict...

D. W. Johnston S. A. Duncan

2002-01-01

101

Build A Bridge  

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.

1997-01-01

102

Latitudinal skewness in global EQ distributions  

NASA Astrophysics Data System (ADS)

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=500 km (deep EQ). In this case clear expressed peak of deep EQ belongs on latitudinal belt 30-20 deg S In frame of the second project [Levin, Sasorova, 2005; Sasorova, Levin, Emelyanova, 2006] statistical verification of hypothesis about existence non-random component in time distribution of the EQs between the Northern and Southern part of the Pacific was carried out. The distribution-free test (run test with significant level 1%) was used for existence proof of nonrandom component into time sequences. The time sequences of the EQ switching between the Northern and Southern parts of the Pacific region contain statistically significant nonrandom component for the events with 4.0<=Mb<6.0. Then data in each magnitude range was subdivided in two groups: the deep earthquakes (H>70km) and the shallow earthquakes (H<=70km). It was found that nonrandom component does not exist for deep earthquakes. On the contrary it is clearly manifested in time distribution of the shallow events. The digital model (superposition of random and periodic processes) was proposed. It was shown that the manifestation of non-random component depends on magnitude of studied events and on the duration of the observation period. The stability of distributions from the observation interval size was demonstrated on the data independence analysis for several eight -year intervals.

Sasorova, E.; Levin, B.

2009-04-01

103

Adaptive Skewing Pyramid-type CMGs for Fast Attitude Maneuver  

NASA Astrophysics Data System (ADS)

In this paper, an adaptive skewing pyramid-type control moment gyro (AS-CMG) is proposed, in which the skew angle is treated as an available parameter to obtain larger torques. This proposed AS-CMG can be categorized as either a single-gimbal CMG or a double-gimbal CMG, but not both. The AS-CMG is superior to the DGCMG due to its lightweight structure, and is superior to the conventional pyramid CMG with respect to maximum torque generated along the desired direction. The effectiveness of the proposed AS-CMG for fast attitude maneuvering, as compared to the conventional pyramid-type CMG with fixed skew angles, is demonstrated by numerical simulations.

Kojima, Hirohisa; Matsuda, Naoki; Takada, Kohei

104

Electromagnetic scattering from skew-symmetric metallic grids  

NASA Astrophysics Data System (ADS)

In many applications for reflector antennas, the reflector is made from flexible, conducting material. The wires are weaved together, forming a very complex structure to study. So far, these mesh structures have been approximated by rectangular grids. In this study, the mesh geometry is approximated by a skew-symmetric grid. The FFT-conjugate gradient method (FFT-CGM) is employed to solve the problem of scattering from such grids. A convenient unit cell is chosen and utilized to study the effects of skewness on the reflection coefficients and current densities. Calculated values of the reflection coefficient for different angles of incidence for both the bonded and unbonded skewed gratings are presented and discussed.

Christodoulou, C. G.

1993-10-01

105

OPERATIONAL MEASUREMENT OF COUPLING BY SKEW QUADRUPOLE MODULATION.  

SciTech Connect

The measurement and correction of the residual betatron coupling via skew quadrupole modulation is a new diagnostics technique that has been developed and tested at the Relativistic Heavy Ion Collider (RHIC) as a very promising method for the linear decoupling on the ramp. By modulating the strengths of the skew quadrupole families the two eigentune modulations are precisely measured with a high resolution phase lock loop system. The projections of the residual coupling coefficient onto the skew quadrupole coupling modulation direction are determined. The residual linear coupling could be corrected according the measurement. We report the results from the dedicated beam studies carried on at RHIC injection, store and on the ramp. A capability of measuring coupling on the ramp opens possibility of continuous coupling corrections during acceleration.

LUO.Y.CAMERON,P.LEE,R.ET AL.

2004-07-05

106

Numerical and experimental analyses of an integral bridge  

NASA Astrophysics Data System (ADS)

In this paper, we present the analysis of a numerical and an experimental study of the Scotch Road integral abutment bridge located in Trenton, NJ, USA. Three-dimensional, nonlinear finite element (FE) model of the full bridge has been developed to study the effect of thermal loading on the bridge substructure. The bridge substructure was fully instrumented. Data analysis was performed to study the effect of several design parameters on axial stress in piles. An analysis of the pile-soil system was performed using the finite difference software LPILE. The maximum displacement of the bridge superstructure obtained from the FE model due to a maximum expected temperature change of ±42°C during the lifetime of the bridge was applied to the substructure model. The effect of bridge skew on the build-up of soil pressure behind the abutment was studied. A significant increase in the soil pressures and axial stresses behind the abutment at the obtuse side versus the acute was observed. The effect of the size of the galvanized steel sleeve on the induced axial stresses in piles was studied. We found that increasing the size of the steel sleeve increases their capacity to resist bending.

Khodair, Yasser; Hassiotis, Sophia

2013-12-01

107

Second Bosporus Bridge.  

National Technical Information Service (NTIS)

The Second Bosporus Bridge spans Bosporus Strait some 5 km north of the First Bosporus Bridge in Istanbul, the Republic of Turkey. It is a suspension bridge with a 1,090 m center span and will be the 6th longest in the world after completion. The bridge h...

W. C. Brown E. Hemmi H. Yamauchi T. Tanabe S. Uehira

1987-01-01

108

Generalized Gaussian Bridges  

Microsoft Academic Search

A generalized bridge is the law of a stochastic process that is conditioned on linear functionals of its path. We consider two types of representations of such bridges: orthogonal and canonical. In the canonical representation the filtrations and the linear spaces generated by the bridge process and the original process coincide. In the orthogonal representation the bridge is constructed from

Tommi Sottinen; Adil Yazigi

2012-01-01

109

Power and Skew Aware Point Diffusion Clock Network  

NASA Astrophysics Data System (ADS)

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.

Jung, Gunok; Kim, Chunghee; Chae, Kyoungkuk; Park, Giho; Park, Sung Bae

110

ON STRANGE ATTRACTORS IN A CLASS OF PINCHED SKEW PRODUCTS  

Microsoft Academic Search

In this note we construct strange attractors in a class of skew product dynamical systems. A dynamical system of the class is a bundle map of a trivial bundle whose base is a compact metric space and the fiber is the non-negative half real line. The map on the base is a homeomorphism preserving an ergodic measure. The fiber maps

A. HARO

111

DQM analysis of skewed and trapezoidal laminated plates  

Microsoft Academic Search

In this paper a differential quadrature method is applied for static, free vibration, and stability analysis of skewed and trapezoidal composite thin plates. To mechanize the modelling procedure, a general transformation scheme is employed to transfer the variation of the variables in the computational to the physical domain and vice versa. Examples are shown to show the accuracy and convergence

G. Karami; S. Ali Shahpari; P. Malekzadeh

2003-01-01

112

Assistant detection of skewed data streams classification in cloud security  

Microsoft Academic Search

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

Qun Song; Jun Zhang; Qian Chi

2010-01-01

113

Skew deflection of magnetic vortices in a field gradient  

Microsoft Academic Search

Magnetic vortices with a nonvanishing winding number, the strictly two-dimensional analogs of realistic magnetic bubbles, are studied within the isotropic Heisenberg model. In particular, we present a numerical simulation of their dynamics under the influence of an applied magnetic field gradient. In addition to verifying some known theoretical results concerning the gross features of skew deflection, in analogy with the

N. Papanicolaou

1994-01-01

114

Nonlinear Vibration and Flutter of Stressed Skew Panels.  

National Technical Information Service (NTIS)

Von Karman plate equations are used to study the influence of nonlinearity on the period of vibration in unstressed and stressed skew plates. The equations of motion for flutter derived through Lagrange's equations are solved by an analog computer and als...

P. S. Nair S. Durvasula

1975-01-01

115

A stochastic daily weather generator for skewed data  

Microsoft Academic Search

To simulate multivariate daily time series (minimum and maximum temperatures, global radiation, wind speed, and precipitation intensity), we propose a weather state approach with a multivariate closed skew-normal generator, WACS-Gen, that is able to accurately reproduce the statistical properties of these five variables. Our weather generator construction takes advantage of two elements. We first extend the classical wet and dry

C. Flecher; P. Naveau; D. Allard; N. Brisson

2010-01-01

116

The topological centre of skew product dynamical systems  

Microsoft Academic Search

We continue our work (Jabbari and Vishki in Bull. Aust. Math. Soc. 79: 129–145, 2009) to give a more explicit characterization of the topological centre of the Ellis groups corresponding to the so-called skew\\u000a product dynamical systems on the finite dimensional tori.

A. Jabbari; H. R. Ebrahimi Vishki

2011-01-01

117

Skewed contraceptive method mix: why it happens, why it matters.  

PubMed

Contraceptive prevalence has been central to family planning research over the past few decades, but researchers have given surprisingly little consideration to method mix, a proxy for method availability or choice. There is no 'ideal' method mix recognized by the international community; however, there may be reason for concern when one or two methods predominate in a given country. In this article method skew is operationally defined as a single method constituting 50% or more of contraceptive use in a given country. Of 96 countries examined in this analysis, 34 have this type of skewed method mix. These 34 countries cluster in three groups: (1) sixteen countries in which traditional methods dominate, most of which are in sub-Saharan Africa; (2) four countries in which female sterilization predominates (India, Brazil, Dominican Republic and Panama); and (3) fourteen countries that rely on a single reversible method (the pill in Algeria, Kuwait, Liberia, Morocco, Sudan and Zimbabwe; the IUD in Cuba, Egypt, Kazakhstan, Kyrgyz Republic, Moldova, Turkmenistan and Uzbekistan; and the injectable in Malawi). A review of available literature on method choice in these countries provides substantial insight into the different patterns of method skew. Method skew in some countries reflects cultural preferences or social norms. Yet it becomes problematic if it stems from restrictive population policies, lack of access to a broad range of methods, or provider bias. PMID:16762087

Sullivan, Tara M; Bertrand, Jane T; Rice, Janet; Shelton, James D

2006-07-01

118

Skew-Normal Time Series Models With Nonlinear Heteroscedastic Predictors  

Microsoft Academic Search

Multivariate skew-normal (SN) distributions (Azzalini and Dalla Valle, 1996) have nonlinear heteroscedastic predictors but lack a closure property (sum of independent SN random variables is not SN) of normal distributions needed for introducing moving average and spectral representations of stationary SN processes. We study SN stationary processes and construction of SN ARMA models for various SN noises and show that

Mohsen Pourahmadi

119

Perception of 3D surface orientation from skew symmetry.  

PubMed

In this paper, we investigate how symmetry can be used to perceive 3D surface orientation. When a symmetric planar object is viewed from an angle, the projected contour has skew symmetry, which provides partial information about the 3D orientation of the object. For a given skew symmetry, this information can be characterized by a constraint curve of possible slant/tilt combinations that are consistent with a mirror-symmetric interpretation. These constraint curves move around when an object is rotated within a plane, and depend on what we will term the spin of the object: the angle between its axis of symmetry and the direction of tilt. To test the influence of symmetry constraint curves, we presented subjects with stereo images of symmetric objects that varied in spin, and had them perform an orientation-matching task. We found that the judgments showed biases that depended on the spin of the objects. Since other sources of information depend only on slant and tilt, not on spin, the biases imply that skew symmetry contributed to subjects' judgments. In a second experiment, we introduced conflicts between stereo and symmetry cues, and found that the spin-dependent biases can be modulated by selectively changing stereo slant. We propose an explanation of these results involving the optimal integration of stereo and skew symmetry, and present a Bayesian model that can account for the pattern of biases. PMID:11711141

Saunders, J A; Knill, D C

2001-11-01

120

Design and Evaluation of a Highly Skewed Propeller.  

National Technical Information Service (NTIS)

The report discusses the design process and evaluation of a highly skewed propeller installed on the American Export Lines, Inc. 78a Class Roll-On/Roll-Off Cargo Vessel. The design process is discussed in detail including consideration of propeller excite...

1979-01-01

121

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

DOEpatents

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

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

1998-01-13

122

The GC skew index: a measure of genomic compositional asymmetry and the degree of replicational selection.  

PubMed

Circular bacterial chromosomes have highly polarized nucleotide composition in the two replichores, and this genomic strand asymmetry can be visualized using GC skew graphs. Here we propose and discuss the GC skew index (GCSI) for the quantification of genomic compositional skew, which combines a normalized measure of fast Fourier transform to capture the shape of the skew graph and Euclidean distance between the two vertices in a cumulative skew graph to represent the degree of skew. We calculated GCSI for all available bacterial genomes, and GCSI correlated well with the visibility of GC skew. This novel index is useful for estimating confidence levels for the prediction of replication origin and terminus by methods based on GC skew and for measuring the strength of replicational selection in a genome. PMID:19461976

Arakawa, Kazuharu; Tomita, Masaru

2007-09-06

123

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

Microsoft Academic Search

In this paper a new disk type of the variable torque slipping clutch with skewed rollers (VTSCSR) is presented and investigated both theoretically and experimentally. It is comprised of two flat disks, a number of skewed cylindrical rollers, and a cage. The slipping torque is produced by the skewed rollers rolling and slipping between the two disks. Based on the

Ming Feng; Kyosuke Ono; Kenji Mimura

2003-01-01

124

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

Microsoft Academic Search

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

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

2008-01-01

125

Heterogeneous skewness in binary choice models: Predicting outcomes in the men's NCAA basketball tournament  

Microsoft Academic Search

Several authors have recently explored the estimation of binary choice models based on asymmetric error structures. One such family of skewed models is based on the exponential generalized beta type 2 (EGB2). One model in this family is the skewed logit. Recently, McDonald (1996, 2000) extended the work on the EGB2 family of skewed models to permit heterogeneity in the

Steven Caudill; Norman Godwin

2002-01-01

126

Multi-domain clock skew scheduling-aware register placement to optimize clock distribution network  

Microsoft Academic Search

Multi-domain clock skew scheduling is a cost effective technique for performance improvement. However, the required wire length and area overhead due to phase shifters for realizing such clock scheduler may be considerable if registers are placed without considering assigned skews. Focusing on this issue, in this paper, we propose a skew scheduling-aware register placement algorithm that enables clock tree optimization

Naser Mohammadzadeh; Minoo Mirsaeedi; Ali Jahanian; Morteza Saheb Zamani

2009-01-01

127

Skew Correction for Vehicle License Plates Using Principal Component of Harris Corner Feature  

Microsoft Academic Search

Character segmentation and detection play a very important role in the automatic license plate recognition (ALPR) system. For accurate character segmentation first need is to remove skew from the received license plate. Skew is the angle by which the image seems to be deviated from its perceived steady state position. To solve the problem, a combined approach for skew correction

Nipa D. Modi; Chirag N. Paunwala; Chintan K. Modi; Suprava Patnaik

2011-01-01

128

Bridge Deck Program Development.  

National Technical Information Service (NTIS)

The report identified, classifies and addresses WSDOT's needs and questions regarding concrete bridge deck deterioration. Included is a state-of-the-art assessment regarding any major areas of concern to the statewide bridge deck program. Recommendations ...

K. Babaei

1985-01-01

129

Bridge Management Systems.  

National Technical Information Service (NTIS)

The bridge management system (BMS) is a rational and systematic approach to organizing and carrying out the activities related to planning, designing, constructing, maintaining, rehabilitating, and replacing bridges vital to the transportation infrastruct...

S. W. Hudson R. F. Carmichael L. O. Moser W. R. Hudson W. J. Wilkes

1987-01-01

130

Development of a bridge management system for existing bridges  

Microsoft Academic Search

Recently, the rehabilitation of bridges has become a major social concern because the number of damaged bridges has increased in Japan. Thus, there is a need to develop a practical bridge management system. The present study is an attempt to develop a new bridge management system (J-BMS) for damaged concrete bridges. The J-BMS not only evaluates the performance of bridges,

Ayaho Miyamoto; Kei Kawamura; Hideaki Nakamura

2001-01-01

131

Low nasal bridge  

MedlinePLUS

A low nasal bridge is a flattening of the top part of the nose. ... Decreased growth (hypoplasia) of the nasal bridge can occur with infections or genetic diseases. A decrease in the height of the nasal bridge is best seen from a side ...

132

Science Shorts: Building Bridges  

NSDL National Science Digital Library

London Bridge is falling down, falling down...Can you finish the song? Although there are various stories that suggest the meaning of this famous nursery rhyme, the London Bridge, which spans the River Thames, did indeed "fall down" several times throughout history. This month's Science Shorts explores what makes bridges stay up. A corresponding activity is included.

Adams, Barbara

2006-07-01

133

Genomic comparisons between paired bacterial strains with strong and weak GC skews.  

PubMed

A majority of known eubacterial genomes are characteristic of GC skew, i.e., the leading strand has exceeding number of G over C. The cause of this compositional bias is still not very clear. In this study, we chose five pairs of genomes from distantly related bacterial genera, i.e., Buchnera, Haemophilus, Mycoplasma, Mycobacterium, and Synechococcus, each containing one with strong GC skew and the other with weak GC skew. Through comparison of the orthologous genes in these genera, we found that neither chromosomal rearrangement nor CDS skew has direct relationship with GC skew. PMID:23457112

Song, Tie-Jun; Wang, Yue; Shen, Jian-Gen; Pan, Jian-Ping; Huang, Jun

2013-03-01

134

Newspaper Coverage of Intimate Partner Violence: Skewing Representations of Risk  

PubMed Central

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.

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

2011-01-01

135

Skewed X Chromosome Inactivation and Trisomic Spontaneous Abortion: No Association  

PubMed Central

Several studies suggest that highly skewed X chromosome inactivation (HSXI) is associated with recurrent spontaneous abortion. We hypothesized that this association reflects an increased rate of trisomic conceptions due to anomalies on the X chromosome that lead both to HSXI and to a diminished oocyte pool. We compared the distribution of X chromosome inactivation (XCI) skewing percentages (range: 50%–100%) among women with spontaneous abortions in four karyotype groups—trisomy (n = 154), chromosomally normal male (n = 43), chromosomally normal female (n = 38), nontrisomic chromosomally abnormal (n = 61)—to the distribution for age-matched controls with chromosomally normal births (n = 388). In secondary analyses, we subdivided the nontrisomic chromosomally abnormal group, divided trisomies by chromosome, and classified women by reproductive history. Our data support neither an association of HSXI with all trisomies nor an association of HSXI with chromosomally normal male spontaneous abortions. We also find no association between HSXI and recurrent abortion (n = 45).

Warburton, Dorothy; Kline, Jennie; Kinney, Ann; Yu, Chih-yu; Levin, Bruce; Brown, Stephen

2009-01-01

136

A stochastic daily weather generator for skewed data  

NASA Astrophysics Data System (ADS)

To simulate multivariate daily time series (minimum and maximum temperatures, global radiation, wind speed, and precipitation intensity), we propose a weather state approach with a multivariate closed skew-normal generator, WACS-Gen, that is able to accurately reproduce the statistical properties of these five variables. Our weather generator construction takes advantage of two elements. We first extend the classical wet and dry days dichotomy used in most past weather generators to the definition of multiple weather states using clustering techniques. The transitions among weather states are modeled by a first-order Markov chain. Second, the vector of our five daily variables of interest is sampled, conditionally on these weather states, from a closed skew-normal distribution. This class of distribution allows us to handle nonsymmetric behaviors. Our method is applied to the 20 years of daily weather measurements from Colmar, France. This example illustrates the advantages of our approach, especially improving the simulation of radiation and wind distributions.

Flecher, C.; Naveau, P.; Allard, D.; Brisson, N.

2010-07-01

137

Generalized modeling approaches to risk adjustment of skewed outcomes data.  

PubMed

There are two broad classes of models used to address the econometric problems caused by skewness in data commonly encountered in health care applications: (1) transformation to deal with skewness (e.g., ordinary least square (OLS) on ln(y)); and (2) alternative weighting approaches based on exponential conditional models (ECM) and generalized linear model (GLM) approaches. In this paper, we encompass these two classes of models using the three parameter generalized Gamma (GGM) distribution, which includes several of the standard alternatives as special cases-OLS with a normal error, OLS for the log-normal, the standard Gamma and exponential with a log link, and the Weibull. Using simulation methods, we find the tests of identifying distributions to be robust. The GGM also provides a potentially more robust alternative estimator to the standard alternatives. An example using inpatient expenditures is also analyzed. PMID:15811539

Manning, Willard G; Basu, Anirban; Mullahy, John

2005-05-01

138

Skewness and Kurtosis Risks of Quality Control in Overlay Inspection  

NASA Astrophysics Data System (ADS)

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

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

2010-06-01

139

SKEW QUADRUPOLES IN RHIC DIPOLE MAGNETS AT HIGH FIELDS.  

SciTech Connect

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

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

1995-06-11

140

A skew-symmetric cantilever accelerometer for automotive airbag applications  

Microsoft Academic Search

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

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

1995-01-01

141

Skew and twist resistant hydrodynamic rotary shaft seal  

DOEpatents

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

Dietle, L.; Kalsi, M.S.

1999-02-23

142

Skew and twist resistant hydrodynamic rotary shaft seal  

DOEpatents

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

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

1999-01-01

143

Skewness and Kurtosis Risks of Quality Control in Overlay Inspection  

Microsoft Academic Search

The population of overlay errors in layer-to-layer structures in semiconductor manufacturing often obeys non-normal distribution functions such as elliptic, rectangular, and skewed distributions. Thus, there can be many wrong diagnoses of quality control that can lead to consumer's risk and producer's risk. In a lot acceptance test, a product should be judged by variables rather than by attributes because of

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

2010-01-01

144

MEASURING LOCAL GRADIENT AND SKEW QUADRUPOLE ERRORS IN RHIC IRS.  

SciTech Connect

The measurement of local linear errors at RHIC interaction regions using an ''action and phase'' analysis of difference orbits has already been presented. This paper evaluates the accuracy of this technique using difference orbits that were taken when known gradient errors and skew quadrupole errors were intentionally introduced. It also presents action and phase analysis of simulated orbits when controlled errors are intentionally placed in a RHIC simulation model.

CARDONA,J.; PEGGS,S.; PILAT,R.; PTITSYN,V.

2004-07-05

145

Singularity analysis and steering control laws for adaptive-skew pyramid-type control moment gyros  

NASA Astrophysics Data System (ADS)

In contrast to past studies that have treated the skew angle as fixed in pyramid-type control moment gyro (CMG) systems, this paper treats the adaptive-skew pyramid-type CMG (ASCMG) system, in which the skew angle is one of the control variables for generating torques. The singular surfaces of the fixed-skew CMG are analyzed and visualized to illustrate how they depend on the skew angle, and the singular surfaces of the ASCMGs are also analyzed and visualized from a viewpoint of null motion for not only the gimbal angle but also the skew angle. The steering control laws are presented, and we numerically study their effectiveness for the reduction of settling time as compared to the fixed-skew pyramid-type CMGs.

Kojima, Hirohisa

2013-04-01

146

Few Skewed Results from IOTA Interferometer YSO Disk Survey  

NASA Astrophysics Data System (ADS)

The 3-telescope IOTA interferometer is capable of measuring closure phases for dozens of Herbig Ae/Be stars in the near-infrared. The closure phase unambiguously identifies deviations from centro-symmetry (i.e., skew) in the brightness distribution, at the scale of 4 milliarcseconds (sub-AU physical scales) for our work. Indeed, hot dust emission from the inner circumstellar accretion disk is expected to be skewed for (generic) flared disks viewed at intermediate inclination angles, as has been observed for LkHa 101. Surprisingly, we find very little evidence for skewed disk emission in our IOTA3 sample, setting strong constraints on the geometry of the inner disk. In particular, we rule out the currently-popular model of a VERTICAL hot inner wall of dust at the sublimation radius. Instead, our data is more consistent with a curved inner wall that bends away from the midplane as might be expected from the pressure-dependence of dust sublimation or limited absorption of stellar luminosity in the disk midplane by gas.

Monnier, J. D.; Millan-Gabet, R.; Berger, J.-P.; Pedretti, E.; Traub, W.; Schloerb, F. P.

2005-12-01

147

Secondary anisotropies in CMB, skew-spectra and Minkowski Functionals  

NASA Astrophysics Data System (ADS)

Secondary contributions to the anisotropy of the cosmic microwave background (CMB), such as the integrated Sachs-Wolfe (ISW) effect, the thermal Sunyaev-Zel'dovich (tSZ) effect, and the effect of gravitational lensing, have distinctive non-Gaussian signatures, and full descriptions therefore require information beyond that contained in their power spectra. The Minkowski Functionals (MF) are well-known as tools for quantifying any departure from Gaussianity and are affected by noise and other sources of confusion in a different way from the usual methods based on higher-order moments or polyspectra, thus providing complementary tools for CMB analysis and cross-validation of results. In this paper we use the recently introduced skew-spectra associated with the MFs to probe the topology of CMB maps to probe the secondary non-Gaussianity as a function of beam smoothing in order to separate various contributions. We devise estimators for these spectra in the presence of realistic observational masks and present expressions for their covariance as a function of instrumental noise. Specific results are derived for the mixed ISW-lensing and tSZ-lensing bispectra as well as contamination due to point sources for noise levels that correspond to the Planck (143 GHz channel) and Experimental Probe of Inflationary Cosmology (EPIC; 150 GHz channel) experiments. The cumulative signal-to-noise ratio (S/N) for one-point generalized skewness parameters can reach an order of O(10) for Planck and two orders of magnitude higher forEPIC, i.e. O(10^3). We also find that these three skew-spectra are correlated, having correlation coefficients r ˜ 0.5-1.0; higher l modes are more strongly correlated. Although the values of S/N increase with decreasing noise, the triplets of skew-spectra that determine the MFs become more correlated; the S/N of lensing-induced skew-spectra are smaller compared to that of a frequency-cleaned tSZ map.

Munshi, Dipak; Coles, Peter; Heavens, Alan

2013-01-01

148

Skew And Twist Resistant Hydrodynamic Rotary Shaft Seal  

DOEpatents

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

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

2000-03-14

149

Wigner-Yanase skew information as tests for quantum entanglement  

SciTech Connect

A Bell-type inequality is proposed in terms of Wigner-Yanase skew information, which is quadratic and involves only one local spin observable at each site. This inequality presents a hierarchic classification of all states of multipartite quantum systems from separable to fully entangled states, which is more powerful than the one presented by quadratic Bell inequalities from two-entangled to fully entangled states. In particular, it is proved that the inequality provides an exact test to distinguish entangled from nonentangled pure states of two qubits. Our inequality sheds considerable light on relationships between quantum entanglement and information theory.

Chen Zeqian [Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, P.O. Box 71010, 30 West District, Xiao-Hong-Shan, Wuhan 430071 (China)

2005-05-15

150

Skewed CMOS: noise-tolerant high-performance low-power static circuit family  

Microsoft Academic Search

In this paper, we present a noise-tolerant high-performance static circuit family suitable for low-voltage operation called skewed logic. Skewed logic circuits in comparison with Domino logic have better scalability and are more suitable for low voltage applications because of better noise margins. Skewed logic and its variations have been compared with Domino logic in terms of delay, power, and dynamic

Alexandre Solomatnikov; Dinesh Somasekhar; Naran Sirisantana; Kaushik Roy

2002-01-01

151

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

PubMed Central

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

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

2011-01-01

152

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

Microsoft Academic Search

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

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

2002-01-01

153

Fast and Accurate Statistical Static Timing Analysis with Skewed Process Parameter Variation  

Microsoft Academic Search

This paper presents a fast and accurate statistical static timing analysis method that supports skewed non-Gaussian process parameter variations. First, we propose modeling of non-Gaussian sources of variation using a Skew-Normal random variable which can represent a large class of non-Gaussian distributions such as Log-Normal and Poisson. Second, we present a linear gate delay model in terms of this Skew-Normal

Lin Xie; Azadeh Davoodi

2008-01-01

154

Base Composition Skews, Replication Orientation, and Gene Orientation in 12 Prokaryote Genomes  

Microsoft Academic Search

.   Variation in GC content, GC skew and AT skew along genomic regions was examined at third codon positions in completely sequenced\\u000a prokaryotes. Eight out of nine eubacteria studied show GC and AT skews that change sign at the origin of replication. The\\u000a leading strand in DNA replication is G-T rich at codon position 3 in six eubacteria, but C-T

Michael J. McLean; Kenneth H. Wolfe; Kevin M. Devine

1998-01-01

155

4. View of bridge deck from northeast approach (bridge deck ...  

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

4. View of bridge deck from northeast approach (bridge deck from southwest approach is virtually identical - Big Cottonwood River Bridge No. 246, Spanning Big Cottonwood River at Cottonwood Street (City Road No. 165), New Ulm, Brown County, MN

156

4. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...  

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

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

157

3. View of Clark Fork Vehicle Bridge facing southwest. Bridge ...  

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

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

158

2. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...  

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

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

159

7. View of Clark Fork Vehicle Bridge facing northwest. Bridge ...  

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

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

160

SULPHITE BRIDGE FROM DOWNSTREAM, BEARING NORTHEAST 25 DEGREES. THE BRIDGE ...  

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

SULPHITE BRIDGE FROM DOWNSTREAM, BEARING NORTHEAST 25 DEGREES. THE BRIDGE ONCE HAD VERTICAL BOARD SIDING BUT VANDALS BURNED IT OFF IN 1981 - Sulphite Railroad Bridge, Former Boston & Maine Railroad (originally Tilton & Franklin Railroad) spanning Winnipesautee River, Franklin, Merrimack County, NH

161

46. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE ...  

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

46. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE NO. 13. LOOKING NORTH-NORTHEAST. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

162

45. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE ...  

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

45. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE NO. 10. LOOKING SOUTH. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

163

47. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE ...  

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

47. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE NO. 11 IN OPERATION. LOOKING NORTH. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

164

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

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

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

165

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

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

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

166

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

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

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

167

Evaluate the Options of Implementing Skew Quadrupoles in the High Energy Ring  

SciTech Connect

There are six skew quadrupoles needed in each side of the interaction region to compensate the effects of coupling and vertical dispersion due to the solenoid detector. Two of those skew quadrupoles are at the location of the first pair of the local chromatic sextupoles in the arcs adjacent the interaction region. To avoid introducing high order aberration, the skew quadrupoles could not be placed between the sextupoles pair. In this note, we evaluate two options of implementing the skew quadrupoles at those locations, namely adding trim coil into the sextupoles or vertically displacing the sextupoles.

Cai, Yunhai

1999-03-09

168

Sulphite Railroad Bridge1896, Title Sheet Sulphite Railroad Bridge, Former ...  

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

Sulphite Railroad Bridge-1896, Title Sheet - Sulphite Railroad Bridge, Former Boston & Maine Railroad (originally Tilton & Franklin Railroad) spanning Winnipesautee River, Franklin, Merrimack County, NH

169

Seasonal autoregressive modeling of a skew storm surge series  

NASA Astrophysics Data System (ADS)

Autoregressive (AR) models have been widely used in several geophysical applications, as they represent a simple and practical option for modeling stochastic series. In this paper, we show that AR models can be adapted and are useful for the description of skew surge (i.e., a surge occurring at the time of a high tide) series. Namely, seasonal AR models of skew surge series are built on 35 sites located along the coasts of the European Atlantic Ocean, the English Channel and the Southern part of the North Sea. These models are presented and discussed. The estimation of the distribution of the residuals, modeled using a Normal Inverse Gaussian (NIG) distribution, is also discussed. AR models are advantageous for a number of reasons: (i) they provide information on the correlation length of the surge phenomena, (ii) they can be used to forecast short-term surge occurrences based on a limited set of past observations and (iii) they provide plausible information about longer series, which may have larger extremes than what is observed, permitting a statistical description of simulated extremes. These three characteristics and benefits are examined and discussed for a selected site, the Saint-Nazaire harbor (France), with respect to the storm surge that occurred during the Xynthia storm of February 2010.

Weiss, Jérôme; Bernardara, Pietro; Andreewsky, Marc; Benoit, Michel

170

Crossover ensembles of random matrices and skew-orthogonal polynomials  

SciTech Connect

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.

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

171

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

PubMed

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

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

2013-06-01

172

Bridge Engineering: Volume 1.  

National Technical Information Service (NTIS)

The 34 papers in this report deal with the following areas: development of a computerized bridge inventory for a state road authority; the New Mexico bridge inspection program; precepts of the evaluation of facilities for human use and the application to ...

B. L. Richards K. White J. Minor J. C. Porter A. M. Shirole

1978-01-01

173

Building Our Bridge to Fun!  

NSDL National Science Digital Library

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.

Applying Mechatronics to Promote Science (AMPS) GK-12 Program,

174

COMPENSATION OF FAST KICKER ROLLS WITH SKEW QUADRUPOLES  

SciTech Connect

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.

Pinayev, I.

2011-03-28

175

Bay Bridge 360  

NSDL National Science Digital Library

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

2009-06-08

176

Linear Mixed Models for Skew-Normal Independent bivariate responses with an application to Periodontal Disease  

PubMed Central

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).

Bandyopadhyay, Dipankar; Lachos, Victor H.; Abanto-Valle, Carlos A.; Ghosh, Pulak

2010-01-01

177

A stable mass-flow-weighted two-dimensional skew upwind scheme  

Microsoft Academic Search

A new simple stable approach to the numerical solution of problems in fluid flow and heat transfer has been developed. The new approach avoids the stability problems of the skew upwind difference scheme while reducing the inaccuracies of numerical diffusion associated with upwind differencing. The origin of the instabiilty is examined. Skew upwind differencing is compared with the proposed scheme

Y. A. Hassan; J. G. Rice; J. H. Kim

1983-01-01

178

A STABLE MASS-FLOW-WEIGHTED TWO-DIMENSIONAL SKEW UPWIND SCHEME  

Microsoft Academic Search

A new simple stable approach to the numerical solution of problems in fluid flow and heat transfer has been developed. The new approach avoids the stability problems of the skew upwind difference scheme while reducing the inaccuracies of numerical diffusion associated with upwind differencing. The origin of the instability is examined. Skew upwind differencing is compared with the proposed scheme

Yassin A. Hassan; James G. Rice; J. H. Kim

1983-01-01

179

Optimization of a magnetic disk drive actuator with small skew actuation  

Microsoft Academic Search

Currently the utilization of the voice-coil motor for actuating read\\/write head elements in magnetic hard disk drives results in a skewed actuation, which necessitates an involved microjogging process and thus a complicated servo system. Furthermore, in perpendicular recording systems, a small skew actuation will relax the requirement on pole trimming. This article presents a magnetic hard disk drive actuator and

Zhimin He; Eng Hong Ong; Guoxiao Guo

2002-01-01

180

Max-Packet Generation Process For Removing Skew In Network Multimedia Communication A Mathematical Model  

Microsoft Academic Search

Multimedia data are sensed by human. These types of data are error tolerable to some extent but delay intolerable. To provide multimedia services with a guaranteed QoS is a research challenge. The two important parameters that degrade QoS are jittering & Skew. Researchers studied different methods for reducing jittering & skew. Earlier investigations attempted to use buffer management and introducing

S. Kandar; K. Roy; M. Barman; C. T. Bhunia

2009-01-01

181

Tracer experiments in the Rhine Basin: evaluation of the skewness of observed concentration distributions  

Microsoft Academic Search

Field studies reporting on the propagation of a pollution wave travelling down a river mostly show persistence of the temporal skewness. As a result, in the Rhine Alarm-Model a constant skewness coefficient (equal to 1) has been applied. The appropriateness of this assumption has been proven by tracer experiments. This finding seems to be in conflict with the solution of

A. van Mazijk; E. J. M. Veling

2005-01-01

182

Betting on long shots in NCAA basketball games and implications for skew loving behavior  

Microsoft Academic Search

This paper examines wagers on NCAA basketball games, a bookmaking market. Here the market equilibrating mechanism is the point spread rather than the return on the wager, and skewness is necessarily 0. Thus, any evidence of a long shot bias is inconsistent with the skew loving behavior posited in the research on pari-mutuel markets. In our analysis of nearly 16,000

L. Lee Colquitt; Norman H. Godwin; Steve Swidler

2004-01-01

183

The rise and fall of transactional skew theory in the model genus Polistes  

Microsoft Academic Search

Transactional Skew (TS) theory predicts that cooperative breeding associations can be adaptive for all group members as long as they properly allocate reproduction within a social contract. Polistes wasps have been the preeminent model genus for testing TS models. Most tests have focused on either the patterns of skew or on patterns of aggression between wasps, which has been assumed

Peter Nonacs

2006-01-01

184

Separating the effects of mutation and selection in producing DNA skew in bacterial chromosomes  

Microsoft Academic Search

BACKGROUND: Many bacterial chromosomes display nucleotide asymmetry, or skew, between the leading and lagging strands of replication. Mutational differences between these strands result in an overall pattern of skew that is centered about the origin of replication. Such a pattern could also arise from selection coupled with a bias for genes coded on the leading strand. The relative contributions of

Richard A Morton; Brian R Morton

2007-01-01

185

Using Time Skewing to Eliminate Idle Time due to Memory Bandwidth and Network Limitations  

Microsoft Academic Search

Time skewing is a compile-time optimization that can provide arbitrarily high cache hit rates for a class of itera- tive calculations, given a sufficient number of time steps and sufficient cache memory. Thus, it can eliminate processor idle time caused by inadequate main memory bandwidth. In this article, we give a generalization of time skewing for multiprocessor architectures, and discuss

David Wonnacott

2000-01-01

186

Reward skewness coding in the insula independent of probability and loss.  

PubMed

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

Burke, Christopher J; Tobler, Philippe N

2011-08-17

187

Robustness of the Fisher's Discriminant Function to Skew-Curved Normal Distribution  

Microsoft Academic Search

Discriminant analysis is a widely used multivariate technique with Fisher's discriminant analysis (FDA) being its most venerable form. FDA assumes equality of population covariance matrices, but does not require multivariate normality. Nevertheless, the latter is desirable for optimal classification. To test FDA's performance under non -normality caused by skewness the method was assessed with simulation ba sed on a skew-curved

Maja Sever; Jaro Lajovic; Borut Rajer

188

Quantitative analysis of mutation and selection pressures on base composition skews in bacterial chromosomes  

Microsoft Academic Search

BACKGROUND: Most bacterial chromosomes exhibit asymmetry of base composition with respect to leading vs. lagging strands (GC and AT skews). These skews reflect mainly those in protein coding sequences, which are driven by asymmetric mutation pressures during replication and transcription (notably asymmetric cytosine deamination) plus subsequent selection for preferred structures, signals, amino acid or codons. The transcription-associated effects but not

Chi Chen; Carton W Chen

2007-01-01

189

Low dimensional chaos in the AT and GC skew profiles of DNA sequences  

Microsoft Academic Search

This paper investigates the existence of low-dimensional deterministic chaos in the AT and GC skew profiles of DNA sequences. It has taken DNA sequences from eight organisms as samples. The skew profiles are analysed using continuous wavelet transform and then nonlinear time series methods. The invariant measures of correlation dimension and the largest Lyapunov exponent are calculated. It is demonstrated

Qian Zhou; Zeng-Qiang Chen

2010-01-01

190

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

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

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

191

Restoring the skew quadrupole moment in the Tevatron dipoles  

SciTech Connect

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].

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

192

Evolution of cooperation and skew under imperfect information  

PubMed Central

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

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

2012-01-01

193

Emergence of skew distributions in controlled growth processes  

NASA Astrophysics Data System (ADS)

Starting from a master equation, we derive the evolution equation for the size distribution of elements in an evolving system, where each element can grow, divide into two, and produce new elements. We then probe general solutions of the evolution equation, to obtain such skew distributions as power-law, log-normal, and Weibull distributions, depending on the growth or division and production. Specifically, repeated production of elements of uniform size leads to power-law distributions, whereas production of elements with the size distributed according to the current distribution as well as no production of new elements results in log-normal distributions. Finally, division into two, or binary fission, bears Weibull distributions. Numerical simulations are also carried out, confirming the validity of the obtained solutions.

Goh, Segun; Kwon, H. W.; Choi, M. Y.; Fortin, J.-Y.

2010-12-01

194

Optimization of a magnetic disk drive actuator with small skew actuation  

NASA Astrophysics Data System (ADS)

Currently the utilization of the voice-coil motor for actuating read/write head elements in magnetic hard disk drives results in a skewed actuation, which necessitates an involved microjogging process and thus a complicated servo system. Furthermore, in perpendicular recording systems, a small skew actuation will relax the requirement on pole trimming. This article presents a magnetic hard disk drive actuator and suspension assembly with small skew actuation. In the present study, the distance from the actuator pivot to the read/write head is chosen so that the skew angle variation is minimized. After that, the suspension head is assembled to the actuator arm at a slant angle with respect to the actuator longitudinal direction to achieve an absolute small skew actuation. Finite element modeling and experimental measurements reveal that there are no significant changes of the actuator assembly dynamic performance with and without the slant angle.

He, Zhimin; Ong, Eng Hong; Guo, Guoxiao

2002-05-01

195

Probabilistic-based Bridge Management Implemented at Skovdiget West Bridge  

Microsoft Academic Search

This paper describes the implementation of a probabilistic-based bridge management plan for the Skovdiget West Bridge, Denmark in 1998-99. Skovdiget West bridge is a 30 year old 220 m long post-tensioned concrete box-girder bridge with serious deterioration of both concrete, reinforcement and cables. By use of deterministic load carrying calculations combined with traditional lifetime estimates, the bridge would either require

F. M. JENSEN; A. KNUDSEN; I. ENEVOLDSEN; E. STOLTZNER; Niels Juels Gade

196

Build Your Bridge  

NSDL National Science Digital Library

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

197

CyberBridge  

NSDL National Science Digital Library

CyberBridge, a website from Harvard University, features tutorials and quizzes that teach concepts from AP Biology and AP Chemistry that are fundamental to success in introductory college or university life sciences courses.

Ernie Chang (Harvard University;Life Sciences); Amanda Simons (Harvard University;Life Sciences); Akiko Okusu (Harvard University;Life Sciences); Tara Mann (Harvard University;Life Sciences); Evan Lau (Harvard University;Life Sciences); Nancy Huang (Harvard University;Life Sciences)

2010-05-27

198

Bridging a cultural gap  

NASA Astrophysics Data System (ADS)

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 potential bridging programme, this paper aims at demonstrating that the gap can be bridged, by presenting an ongoing modular bridging programme especially designed for the diverse types of student populations in teachers training colleges. We also present here some innovative teaching and assessment methods that were judged essential for the success of these programmes—focusing mainly on the "Questionnaire Based Instruction Method". Finally we suggest directions of follow up and research.

Leviatan, Talma

2008-09-01

199

Hillsboro Canal Bridge Monitoring.  

National Technical Information Service (NTIS)

This report describes the implementation of a testing and monitoring program for bridge 930338 in Belle Glade. Glass-fiber reinforced polymer (GFRP) deck panels and plates were installed over an existing steel superstructure using grouted steel studs. Thi...

A. P. Singh H. R. Hamilton J. L. McCall X. Peng

2011-01-01

200

Bridge Management and Nondestructive Evaluation  

Microsoft Academic Search

The City and County of Denver (CCD) Public Works Department owns, inspects, and maintains 531 bridges in its inventory of which 264 are considered major structures spanning over 6.1 m in length. In this paper, a methodology using the CCD major bridge network for the application of nondestructive evaluation (NDE) methods in bridge inspections is explained. The methodology, called Bridge

Kevin L. Rens; Carnot L. Nogueira; David J. Transue

2005-01-01

201

A new approach to reduction of the cogging torque in a brushless motor by skewing optimization of permanent magnets  

Microsoft Academic Search

This paper presents a new approach to the skewing optimization of permanent magnet poles in a two-phase brushless d.c. motor in order to effectively reduce its cogging torque. The effect of skewing is obtained by a proper angular dislocation of permanent magnet slices. Skewing optimization is carried out with respect to the number of pole slices and their mutual angular

R. Wrobel; M. Lukaniszyn; M. Jagiela; K. Latawiec

2003-01-01

202

A Fast and Efficient Skew Estimation of Cheque Images Using Physical Structure of Image and Projection Profile  

Microsoft Academic Search

Automated cheque processing is a system for recognition of important information contained in a bank cheque. Such a system requires skew detection at its first step. Accuracy of cheque processing is affected by the precision of detecting the skew of the scanned version of the cheque. This paper proposes a robust algorithm against noise for skew detection of cheque images.

Narges Marashi; Jamshid Shanbezadeh; Abdolhossein Sarafzadeh

2008-01-01

203

Effect of skewed joints on the performance of jointed concrete pavement through 3D dynamic finite element analysis  

Microsoft Academic Search

The effect of skewing the transverse joints in concrete rigid pavements is studied through 3D finite element modelling. Models of multi-layered systems consisting of Portland cement concrete slabs, base and subgrade were developed. These consisted of slabs having straight as well as skewed joints. In order to study the state of stresses and strains in both straight and skewed slabs,

Mourad Y. Riad; Samir N. Shoukry; Gergis W. William; Michel R. Fahmy

2009-01-01

204

Large-scale genomic 2D visualization reveals extensive CG-AT skew correlation in bird genomes  

Microsoft Academic Search

BACKGROUND: Bird genomes have very different compositional structure compared with other warm-blooded animals. The variation in the base skew rules in the vertebrate genomes remains puzzling, but it must relate somehow to large-scale genome evolution. Current research is inclined to relate base skew with mutations and their fixation. Here we wish to explore base skew correlations in bird genomes, to

Xuegong Deng; Ilkka Havukkala; Xuemei Deng

2007-01-01

205

A non-oscillating solution technique for skew upwind and QUICK-family schemes  

NASA Astrophysics Data System (ADS)

An assessment of implementing an oscillation free FRAM algorithm on the flow-oriented skew upwind and QUICK schemes is made in this study for convection dominated flow problem. The monotonically bounded FARM method, along with the attractive properties of flow-oriented QUICK and skew upwind schemes, can capture the nearly discontinuous phenomena in the flow field. The candidates of QUICK-family include original QUICK, QUICK for two dimensions (QUICK-2D), and QUICK with Estimated Streaming Terms (QUICKEST). The candidates in skew family include Skew Upwind Differencing (SUD), Skew Upwind Differencing with artificial Cutoff (SUD-Cut), Volume-Weighted Skew Upwind Differencing (VWSUD), Corner Skew Upwind Differencing (CSUD), and Directional Transportive Upwind Differencing (DTUD) schemes. The performance of filtering methodology on the investigated schemes is evaluated by testing the following three problems: (1) Pure convection of an obilque-step profile, (2) Transport of a cosine hill or rectangular block in a rotating flowfield, (3) Backward-facing step and driven cavity problems. The best schemes among the investigated two families are QUICKEST and DTUD respectively.

Sheu, T. W. H.; Lee, S.-M.; Yang, K. O.; Chiou, B. J. Y.

1991-11-01

206

Direct measurement of the skew angle of the Poynting vector in a helically phased beam.  

PubMed

We measure the local skew angle of the Poynting vector within a helically-phased, exp (il phi), beam using a Shack Hartmann wavefront sensor. It is the skew angle of the Poynting vector with respect to the beam axis that gives rise to the orbital angular momentum of a light beam. We confirm that this skew angle is l/kr, corresponding to an orbital angular momentum of l? per photon. Measurement of orbital angular momentum in this way is an alternative to interferometric techniques giving a non-ambiguous result to both the magnitude and sign of l from a single measurement, without any restriction on the optical bandwidth. PMID:19529616

Leach, Jonathan; Keen, Stephen; Padgett, Miles J; Saunter, Christopher; Love, Gordon D

2006-12-11

207

Low dimensional chaos in the AT and GC skew profiles of DNA sequences  

NASA Astrophysics Data System (ADS)

This paper investigates the existence of low-dimensional deterministic chaos in the AT and GC skew profiles of DNA sequences. It has taken DNA sequences from eight organisms as samples. The skew profiles are analysed using continuous wavelet transform and then nonlinear time series methods. The invariant measures of correlation dimension and the largest Lyapunov exponent are calculated. It is demonstrated that the AT and GC skew profiles of these DNA sequences all exhibit low dimensional chaotic behaviour. It suggests that chaotic properties may be ubiquitous in the DNA sequences of all organisms.

Zhou, Qian; Chen, Zeng-Qiang

2010-09-01

208

Multiscale model updating of a curved highway bridge  

NASA Astrophysics Data System (ADS)

Finite element model updating based on a multi-scale data is demonstrated on a skewed in-service highway bridge. The multi-scale data approach provides an evidence-based method to create a bound of model class to ensure that the optimum model retains physical connectivity to the real structure. The need for this hybrid approach to model selection comes from the challenges of applying model updating to online structural health monitoring (SHM) strategy based on output-only measurements of in-service highway bridges, which should consider various uncertainties. In vibration-based FE model updating methods, the optimum model is selected by minimizing the error between modal parameters of the model and the real structure. A major drawback of model selection is the probability that the optimum model has no physical connectivity with the real structure. This is because a large set of updating parameters is required to increase accuracy. In this paper, an evidence-based approach to model selection using temperature-induced tilts is implemented in which the cyclical static behavior of a bridge is used to create a bound of possible models. This approach has a strong potential to be applicable to large civil structures with sparse array of sensors.

Mensah-Bonsu, Priscilla; Jang, Shinae

2012-03-01

209

Crossover ensembles of random matrices and skew-orthogonal polynomials  

NASA Astrophysics Data System (ADS)

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.

Kumar, Santosh; Pandey, Akhilesh

2011-08-01

210

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

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

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

211

198. SPOUT RUN ARCH BRIDGE AND SPOUT RUN WESTBOUND BRIDGE ...  

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

198. SPOUT RUN ARCH BRIDGE AND SPOUT RUN WESTBOUND BRIDGE FROM POTOMAC RIVER LOOKING SOUTHWEST. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

212

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

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

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

213

Study on compensation algorithm of head skew in hard disk drives  

NASA Astrophysics Data System (ADS)

In hard disk drives (HDDs), head skew among multiple heads is pre-calibrated during manufacturing process. In real applications with high capacity of storage, the head stack may be tilted due to environmental change, resulting in additional head skew errors from outer diameter (OD) to inner diameter (ID). In case these errors are below the preset threshold for power on recalibration, the current strategy may not be aware, and drive performance under severe environment will be degraded. In this paper, in-the-field compensation of small DC head skew variation across stroke is proposed, where a zone table has been equipped. Test results demonstrating its effectiveness to reduce observer error and to enhance drive performance via accurate prediction of DC head skew are provided.

Xiao, Yong; Ge, Xiaoyu; Sun, Jingna; Wang, Xiaoyan

2011-10-01

214

Preconfigured, skewed distribution of firing rates in the hippocampus and entorhinal cortex  

PubMed Central

Summary Despite the importance of the discharge frequency in neuronal communication, little is known about the firing rate patterns of cortical populations. Using large-scale recordings from multiple layers of the entorhinal-hippocampal loop, we found that firing rates of principal neurons showed a lognormal-like distribution in all brain states. Mean and peak rates within place fields of hippocampal neurons were also strongly skewed. Importantly, firing rates of the same neurons showed reliable correlations in different brain states, testing situations and across familiar and novel environments. The fraction of neurons participating in population oscillations displayed a lognormal pattern. Such skewed rates of individual neurons may be brought about by skewed distribution of synaptic weights, supported by our observation of a lognormal distribution of the efficacy of spike transfer from principal neurons to interneurons. The persistent skewed distribution of firing rates implies that a preconfigured highly active minority dominates information transmission in cortical networks.

Mizuseki, Kenji; Buzsaki, Gyorgy

2013-01-01

215

Bridge Types: Suspension Bridge Spans, Section AA; Cantilever Truss Spans, ...  

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

Bridge Types: Suspension Bridge Spans, Section A-A; Cantilever Truss Spans, Section B-B; Through Truss Spans, Section C-C; Deck Truss Spans, Section D-D - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

216

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

Microsoft Academic Search

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

Adelchi Azzalini; Antonella Capitanio

2003-01-01

217

Tracer experiments in the Rhine Basin: evaluation of the skewness of observed concentration distributions  

NASA Astrophysics Data System (ADS)

Field studies reporting on the propagation of a pollution wave travelling down a river mostly show persistence of the temporal skewness. As a result, in the Rhine Alarm-Model a constant skewness coefficient (equal to 1) has been applied. The appropriateness of this assumption has been proven by tracer experiments. This finding seems to be in conflict with the solution of the transient storage equations of the one-dimensional Fickian-type diffusion equations, the so-called dead-zone model, showing a continuous decrease of the skewness with the distance. On the other hand, based on these equations as an initial-boundary value problem for the transport of a spill in a river with dead zones Schmid [Schmid, B.H., 2002. Persistence of skewness in longitudinal dispersion data: can the dead zone model explain it after all?. Journal of Hydraulic Engineering 128 (9), 848 854, September 1, ASCE], showed that the skewness can locally increase, if there are river reaches with different values of the mass-transfer coefficient between the main stream and the dead zone, or due to changing topography. This paper shows that by applying Schmid's [Schmid, B.H., 2002. Persistence of skewness in longitudinal dispersion data: can the dead zone model explain it after all?. Journal of Hydraulic Engineering 128 (9), 848 854, September 1, ASCE] approach to the River Rhine and its tributaries Mosel (Germany) and Aare (Switzerland), the observed persistence of the skewness can be reproduced, taking into account the changes in the river topography. Moreover, it is demonstrated that irregularities of the riverbed and banks, and vegetation along the river borders, resulting in ‘natural dead zones’, contribute to the persistence of the skewness. In addition, the physical processes behind the observed mass-transfer coefficient have been analysed.

van Mazijk, A.; Veling, E. J. M.

2005-06-01

218

Buckling of skew mindlin plates subjected to in-plane shear loadings  

Microsoft Academic Search

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

Y Xiang; C. M Wang

1995-01-01

219

An Efficient Algorithm for Skew-Correction of Document Image Based on Cyclostyle Matching  

Microsoft Academic Search

The skew-correction of scanned document image is a necessary step undergone before some processing. For the purpose of practical, robust, real-time of the algorithm, this paper presents a new skew-detection algorithm that based on the gray projection cyclostyle matching of Document Image. The algorithm, which is based on the analysis of gray scale projection curves of horizontal and vertical direction

Liang Junjuan; Tan Guoxin

2008-01-01

220

Properties and Inference on the Skew-Curved-Symmetric Family of Distributions  

Microsoft Academic Search

In this article, we study some results related to a specific class of distributions, called skew-curved-symmetric family of distributions that depends on a parameter controlling the skewness and kurtosis at the same time. Special elements of this family which are studied include symmetric and well-known asymmetric distributions. General results are given for the score function and the observed information matrix.

Héctor W. Gómez; Luis M. Castro; Hugo S. Salinas; Heleno Bolfarine

2010-01-01

221

Permanent-Magnet Synchronous Motor Magnet Designs With Skewing for Torque Ripple and Cogging Torque Reduction  

Microsoft Academic Search

This paper examines the torque ripple and cogging torque variation in surface-mounted permanent-magnet synchronous motors (PMSMs) with skewed rotor. The effect of slot\\/pole combinations and magnet shapes on the magnitude and harmonic content of torque waveforms in a PMSM drive has been studied. Finite element analysis and experimental results show that the skewing with steps does not necessarily reduce the

Rakib Islam; Iqbal Husain; Abbas Fardoun; Kevin McLaughlin

2009-01-01

222

Uncontrolled Concrete Bridge Parapet Cracking.  

National Technical Information Service (NTIS)

The Ohio Department of Transportation has recently identified the problem of wide-spread premature cracking of concrete bridge parapets throughout its District 12 region (Northeast Ohio). Many of the bridge decks that contain these prematurely cracked par...

A. Kalabon J. Bazzo N. Delatte

2013-01-01

223

Histamine enhances HIV-1-induced modulation of dendritic cells to skew naïve T cell differentiation toward regulatory T cells.  

PubMed

Altered cytokine profiles and imbalanced frequencies of CD4(+) T helper cell subsets are thought to be linked with HIV-1/AIDS pathogenesis, but the causes need to be further clarified. Histamine, a biogenic amine with many functions, shows enhancement in HIV-1 infected individuals, which are considered to link with disease progression, but is poorly understood. This study investigated histamine-assisted HIV-1 modulation of dendritic cell (DC) functions. Histamine and HIV-1 showed a synergistic role in induction of interleukin-10; histamine inhibited HIV-1-induced IL-12 production from MDDCs (monocyte-derived DCs); notably, histamine augmented HIV-1-induced MDDC functional polarization and skewed naïve T cell differentiation toward regulatory T cells (Tregs). The results indicate the novel role of histamine in HIV-1-induced DC functional regulation, which promoted Treg cell differentiation and up-regulated immunosuppressive factors. These findings help to bridge the correlation between elevated histamine and increased Treg cell frequency in HIV-1 infected individuals, and add to our understanding of HIV-1-induced immunosuppression. PMID:23652320

Zhai, Rong-Rong; Jiang, Ai-Ping; Wang, Hai-Bo; Ma, Li; Ren, Xiao-Xin; Jiang, Jin-Feng; Wu, Li; Wei, Ji-Fu; Wang, Jian-Hua

2013-05-04

224

Bridge Deck Drainage Guidelines.  

National Technical Information Service (NTIS)

The document presents criteria to determine if bridge drainage scuppers and drains are required. A design nomograph allows a rapid decision to be made. A key variable, design rain intensity, is analyzed: the rational method is reviewed and new methods for...

G. K. Young J. Phillippe S. J. Bellomo J. Normann W. E. Hughes

1986-01-01

225

Bridging the Gap?  

ERIC Educational Resources Information Center

|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…

Salter, Colin

2009-01-01

226

Virtual Bridge Design  

ERIC Educational Resources Information Center

|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…

Bisogno, Janet; JeanPierre, Bobby

2008-01-01

227

Bridging the Gap.  

ERIC Educational Resources Information Center

|Describes interdisciplinary activities with real-world applications ranging from science to mathematics to technology. Cites the study and construction of model bridges as a way for students to learn about engineering concepts and some of their relationships. States that the exercise enhanced teacher cooperation between the different fields. (RT)|

Kroto, Joseph J.

1988-01-01

228

Building Migratory Bridges  

ERIC Educational Resources Information Center

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

Roy, Michael; Doss, Laurie K.

2007-01-01

229

Bridge Replacement: Alternate Design.  

National Technical Information Service (NTIS)

A money and time saving innovative design was used to convert two old slab bridges into multipipe culverts on an FM 18 widening project in District 8 (Abilene). Hydraulic analysis indicated that the existing structures had been overdesigned and that conve...

B. R. Lindley

1992-01-01

230

Bridging a Cultural Gap  

ERIC Educational Resources Information Center

|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…

Leviatan, Talma

2008-01-01

231

Virtual Bridge Design  

ERIC Educational Resources Information Center

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…

Bisogno, Janet; JeanPierre, Bobby

2008-01-01

232

Design Squad: Suspension Bridge  

NSDL National Science Digital Library

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.

Foundation, Wgbh E.

2007-08-09

233

Design Squad: Truss Bridge  

NSDL National Science Digital Library

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.

Foundation, Wgbh E.

2007-08-09

234

The Bridge to Somewhere  

ERIC Educational Resources Information Center

|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…

Lum, Lydia

2009-01-01

235

CMOS Bridging Fault Detection  

Microsoft Academic Search

The authors compare the performance of two test generation techniques, stuck fault testing and current testing, when applied to CMOS bridging faults. Accurate simulation of such faults mandated the development of several new design automation tools, including an analog-digital fault simulator. The results of this simulation are analyzed. It is shown that stuck fault test generation, while inherently incapable of

Thomas M. Storey; Wojciech Maly

1990-01-01

236

Building Bridges to Reading.  

ERIC Educational Resources Information Center

Reading aloud to kindergarten children makes good educational sense. For this group, teachers should emphasize the aspects of reading aloud that promote a love of story listening as a bridge to future reading. To read aloud well, teachers should: (1) use stories with strong plots, vivid characters, and interesting settings; (2) select a book they…

Krolikowski, Sue

237

Building Migratory Bridges  

ERIC Educational Resources Information Center

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

Roy, Michael; Doss, Laurie K.

2007-01-01

238

Delaware Memorial Bridge  

Microsoft Academic Search

The Delaware Memorial Bridge was built in two spans. The first, completed in 1951, is on the left in this photograph, is now used to carry New Jersey bound traffic on Interstate Highway 295. Originally it carried traffic in both directions, but within a decade a second span was added because of large amounts of traffic from the newly constructed

Chet Smolski; Othmar Ammann

1970-01-01

239

JHU Bridge Designer  

NSDL National Science Digital Library

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

Karweit, Michael

240

A Bridge to Consciousness  

ERIC Educational Resources Information Center

|Article describes how music, being a system of logical thought and a bridge to consciousness, can help the gifted child who cannot always handle his emotions in a culture where the function of the school in furthering the socialization process has been vastly oversold. (Author/MM)|

Vaughan, Margery M.

1972-01-01

241

BUILDING BRIDGES IN HEALTHCARE  

Microsoft Academic Search

or those who have not been in the Charleston area for several years, 2005 has marked the opening of a fabulous new span that links Charleston with Mount Pleasant. In mid July, the entire region turned out to stroll over the new bridges and celebrate their completion with a monumental fireworks display. The two dilapidated structures that had offered an

Bill Hueston

242

Analysis of stability and accuracy of finite-difference schemes on a skewed mesh  

NASA Astrophysics Data System (ADS)

Numerical stability and accuracy of finite-difference schemes on a skewed non-uniform mesh are investigated to provide guidelines for mesh design and for devising appropriate solution methods when mesh skewness is unavoidable. In the current analysis, a linear advection diffusion equation in a Cartesian coordinate system is transformed into a curvilinear one corresponding to a skewed mesh. A finite-difference approximation of the transformed equation leads to the leading-order error terms which are responsible for time-step restrictions and numerical instability. A truncation error analysis of central-difference approximation reveals the effects of mesh non-uniformity and skewness on the solution quality. In addition, a modified wavenumber analysis is performed for the central- and upwind-difference schemes coupled with time-integration methods, to examine the effects of mesh skewness angle and flow direction relative to the mesh angle on the numerical stability. In general, severe mesh skewness leads to restrictions on the allowable cell Peclet number and time-step size and also increases phase and amplitude errors.

You, Donghyun; Mittal, Rajat; Wang, Meng; Moin, Parviz

2006-03-01

243

Opposite GC skews at the 5' and 3' ends of genes in unicellular fungi  

PubMed Central

Background GC-skews have previously been linked to transcription in some eukaryotes. They have been associated with transcription start sites, with the coding strand G-biased in mammals and C-biased in fungi and invertebrates. Results We show a consistent and highly significant pattern of GC-skew within genes of almost all unicellular fungi. The pattern of GC-skew is asymmetrical: the coding strand of genes is typically C-biased at the 5' ends but G-biased at the 3' ends, with intermediate skews at the middle of genes. Thus, the initiation, elongation, and termination phases of transcription are associated with different skews. This pattern influences the encoded proteins by generating differential usage of amino acids at the 5' and 3' ends of genes. These biases also affect fourfold-degenerate positions and extend into promoters and 3' UTRs, indicating that skews cannot be accounted by selection for protein function or translation. Conclusions We propose two explanations, the mutational pressure hypothesis, and the adaptive hypothesis. The mutational pressure hypothesis is that different co-factors bind to RNA pol II at different phases of transcription, producing different mutational regimes. The adaptive hypothesis is that cytidine triphosphate deficiency may lead to C-avoidance at the 3' ends of transcripts to control the flow of RNA pol II molecules and reduce their frequency of collisions.

2011-01-01

244

Construction of an Experimental Segmental Bridge.  

National Technical Information Service (NTIS)

Concrete segmental bridge construction seems to offer many advantages over other types of bridge construction both in bridge replacement programs and in new bridge programs. This report discusses the construction process of the experimental segmental brid...

R. M. McClure H. R. Thomas J. E. Kehler

1980-01-01

245

Genetic Architecture of Skewed X Inactivation in the Laboratory Mouse  

PubMed Central

X chromosome inactivation (XCI) is the mammalian mechanism of dosage compensation that balances X-linked gene expression between the sexes. Early during female development, each cell of the embryo proper independently inactivates one of its two parental X-chromosomes. In mice, the choice of which X chromosome is inactivated is affected by the genotype of a cis-acting locus, the X-chromosome controlling element (Xce). Xce has been localized to a 1.9 Mb interval within the X-inactivation center (Xic), yet its molecular identity and mechanism of action remain unknown. We combined genotype and sequence data for mouse stocks with detailed phenotyping of ten inbred strains and with the development of a statistical model that incorporates phenotyping data from multiple sources to disentangle sources of XCI phenotypic variance in natural female populations on X inactivation. We have reduced the Xce candidate 10-fold to a 176 kb region located approximately 500 kb proximal to Xist. We propose that structural variation in this interval explains the presence of multiple functional Xce alleles in the genus Mus. We have identified a new allele, Xcee present in Mus musculus and a possible sixth functional allele in Mus spicilegus. We have also confirmed a parent-of-origin effect on X inactivation choice and provide evidence that maternal inheritance magnifies the skewing associated with strong Xce alleles. Based on the phylogenetic analysis of 155 laboratory strains and wild mice we conclude that Xcea is either a derived allele that arose concurrently with the domestication of fancy mice but prior the derivation of most classical inbred strains or a rare allele in the wild. Furthermore, we have found that despite the presence of multiple haplotypes in the wild Mus musculus domesticus has only one functional Xce allele, Xceb. Lastly, we conclude that each mouse taxa examined has a different functional Xce allele.

Calaway, John D.; Lenarcic, Alan B.; Didion, John P.; Wang, Jeremy R.; Searle, Jeremy B.; McMillan, Leonard; Valdar, William; Pardo-Manuel de Villena, Fernando

2013-01-01

246

Cracks in Concrete Bridge Decks.  

National Technical Information Service (NTIS)

A study of cracks in bridge decks as reported in the literature and observed in NSW shows that certain types of cracks are predominant in particular bridge types. Cracks in composite bridges and in cast-in-place kerbs and cantilever deck slabs are shown t...

D. Campbell-Allen B. Lau

1978-01-01

247

Self-balancing resistance bridge  

Microsoft Academic Search

An automatically balanced resistance bridge with below-picowatt dissipation in the measured resistance has been developed. The bridge, capable of measuring resistances between 20 ? and 10 k? with an accuracy of 5%, was specifically designed to allow resistance measurements to be made at low temperatures without introducing an appreciable heat source to the cryostat. It consists of a Wheatstone bridge

Alvaro Kaplan; George O. Zimmerman; Dean S. Edmonds

1986-01-01

248

Bridged ferrocenes. 10. Structural phenomena  

SciTech Connect

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.

Hillman, M.; Fujita, E.; Dauplaise, H.; Kvick, A.; Kerber, R.C.

1984-01-01

249

Climbing techniques for bridge inspection  

NASA Astrophysics Data System (ADS)

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.

Kaslan, Erol C.

1998-03-01

250

Skewed X-chromosome inactivation in patients with esophageal carcinoma  

PubMed Central

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

2013-01-01

251

BATS IN AMERICAN BRIDGES  

Microsoft Academic Search

Bridges and culverts were evaluated as bat roosting habitat in 25 U.S. states at elevations from sea level to 10,000 feet. Field surveys were conducted at 2,421 highway structures. Scientific literature was reviewed, and local biologists and engineers were interviewed, leading to the discovery of approximately 4,250,000 bats of 24 species living in 211 highway structures. Only one percent of

Brian W. Keeley; Merlin D. Tuttle

252

Build a Bridge  

NSDL National Science Digital Library

In this activity, learners use recycled materials to build a bridge that holds as many potatoes as possible. They investigate weight, height, strength, and measurement as they seek design solutions. The activity instructions include ways to adjust the level of challenge for learners of different ages. Try this at family events or to engage all ages. Available as a web page and a downloadable PDF. Students should have the ability to use tape and scissors.

2010-01-01

253

Bridge-NOAA Collection  

NSDL National Science Digital Library

The Bridge-NOAA Collection is a selection of exemplary resources from the National Oceanic and Atmospheric Administration (NOAA) that have been reviewed by educators and found to be well-suited for educational purposes. The collection also emphasizes professional-development opportunities for teachers. There is a strong focus on research data and its use in teaching. The collection provides educators with accurate and useful information on global, national, and regional ocean-science topics.

2007-10-19

254

Nanoparticle bridge DNA biosensor  

Microsoft Academic Search

A new DNA sensing method is demonstrated in which DNA hybridization events lead to the formation of nanoparticle satellites that bridge two electrodes and are detected electrically. The hybridization events are exclusively carried out only on specific locations, the surfaces of C-ssDNA modified 50 nm GNPs. The uniqueness of this work is that only a small number of T-ccDNA molecules

Hong-Wen Huang

2010-01-01

255

Bridging the gap  

Microsoft Academic Search

Engineers are applying the results of the scientific method to achieving solutions for real world problems. The QFT robust\\u000a design technique was utilized in this paper to illustrate how the bridging of the gap between the scientific and engineering\\u000a methods can be achieved. As an example, an aerospace firm has stated to Professor M. Grimble, University of Strathcldye, the\\u000a following:

C. Houpis

256

Starving the competition: a proximate cause of reproductive skew in burying beetles (Nicrophorus vespilloides).  

PubMed

Proximate mechanisms underlying reproductive skew are obscure in many animals that breed communally. Here, we address causes of reproductive skew in brood-parasitic associations of burying beetles (Nicrophorus vespilloides). Male and female burying beetles feed and defend their larvae on buried carcasses. When several females locate the same small carcass, they engage in violent physical altercations. The subordinate then acts as an intraspecific brood parasite, laying eggs, but not providing care. The dominant female largely monopolizes access to the carcass; she alone provides parental care and her share of the brood is much larger than the subordinate's. On larger carcasses, subordinates have greater access to the carcass than on small ones, and reproductive skew is reduced. Differential fecundity, ovicide and larvicide have been suggested as causes of skew on small carcasses. Here, we report the results of the experiments pertaining to the first two of these potential mechanisms. Ovicide did not significantly contribute to reproductive skew on small carcasses, but differential fecundity did. Fecundity differences were due to dominance status, not body size per se. Fecundity differences disappeared when supplemental food was available, suggesting that reduced access to the carcass limits fecundity by causing nutritional deficiencies. Supplemental food prevented such nutritional deficiencies and allowed subordinates to produce as many eggs as dominants. Apparently, aggressive behaviour by dominants functions in the context of reproductive competition, limiting subordinate reproduction by preventing food intake on the carcass. PMID:18647719

Eggert, Anne-Katrin; Otte, Tobias; Müller, Josef K

2008-11-01

257

Study and optimal correction of a systematic skew quadrupole field in the Tevatron  

NASA Astrophysics Data System (ADS)

Increasing demands for luminosity in existing and future colliders have made lattice design and error tolerance and correction critical to achieving performance goals. The current state of the Tevatron collider is an example, with a strong skew quadrupole error present in the operational lattice. This work studies the high-order performance of the Tevatron and the strong nonlinear behavior introduced when a significant skew quadrupole error is combined with conventional sextupole correction, a behavior still clearly evident after optimal tuning of available skew quadrupole circuits. An optimization study is performed using different skew quadrupole families, and, importantly, local and global correction of the linear skew terms in maps generated by the code COSY INFINITY [M. Berz, COSY INFINITY version 8.1 user's guide and reference manual, Department of Physics and Astronomy MSUHEP-20704, Michigan State University (2002). URL http://cosy.pa.msu.edu/cosymanu/index.html]. Two correction schemes with one family locally correcting each arc and eight independent correctors in the straight sections for global correction are proposed and shown to dramatically improve linearity and performance of the baseline Tevatron lattice.

Snopok, Pavel; Johnstone, Carol; Berz, Martin; Ovsyannikov, Dmitry A.; Ovsyannikov, Alexander D.

2006-03-01

258

Bayesian inference for skew-normal mixture models with left-censoring.  

PubMed

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 article 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 data sets from a study of the measles vaccine and an HIV/AIDS study are used to illustrate the proposed models. PMID:23957513

Dagne, Getachew A

2013-01-01

259

Starving the competition: a proximate cause of reproductive skew in burying beetles (Nicrophorus vespilloides)  

PubMed Central

Proximate mechanisms underlying reproductive skew are obscure in many animals that breed communally. Here, we address causes of reproductive skew in brood-parasitic associations of burying beetles (Nicrophorus vespilloides). Male and female burying beetles feed and defend their larvae on buried carcasses. When several females locate the same small carcass, they engage in violent physical altercations. The subordinate then acts as an intraspecific brood parasite, laying eggs, but not providing care. The dominant female largely monopolizes access to the carcass; she alone provides parental care and her share of the brood is much larger than the subordinate's. On larger carcasses, subordinates have greater access to the carcass than on small ones, and reproductive skew is reduced. Differential fecundity, ovicide and larvicide have been suggested as causes of skew on small carcasses. Here, we report the results of the experiments pertaining to the first two of these potential mechanisms. Ovicide did not significantly contribute to reproductive skew on small carcasses, but differential fecundity did. Fecundity differences were due to dominance status, not body size per se. Fecundity differences disappeared when supplemental food was available, suggesting that reduced access to the carcass limits fecundity by causing nutritional deficiencies. Supplemental food prevented such nutritional deficiencies and allowed subordinates to produce as many eggs as dominants. Apparently, aggressive behaviour by dominants functions in the context of reproductive competition, limiting subordinate reproduction by preventing food intake on the carcass.

Eggert, Anne-Katrin; Otte, Tobias; Muller, Josef K

2008-01-01

260

Effective step-skew method for cogging torque reduction in surface-mounted permanent magnet synchronous motor  

NASA Astrophysics Data System (ADS)

This paper suggests an effective step-skew method to reduce the cogging torque of a surface-mounted permanent magnet synchronous motor (SPMSM). The main concept of the proposed method is to adjust each step length by considering the non-uniform air gap flux density distribution in the axial direction. The results show that the proposed step-skew method reduces the net cogging torque compared with the conventional step-skew method and is more effective for smaller stacking lengths and larger skew steps.

Kim, Tae-Woo; Chang, Jung-Hwan

2013-08-01

261

Skew-Laplace and Cell-Size Distribution in Microbial Axenic Cultures: Statistical Assessment and Biological Interpretation  

PubMed Central

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.

Julia, Olga; Vidal-Mas, Jaume; Panikov, Nicolai S.; Vives-Rego, Josep

2010-01-01

262

Skew harmonics suppression in electromagnets with application to the Advanced Light Source (ALS) storage ring corrector magnet design  

SciTech Connect

An analytical expression for prediction of skew harmonics in an iron core combined function regular/skew dipole magnet due to arbitrarily positioned electromagnet coils is developed. A structured approach is presented for the suppression of an arbitrary number of harmonic components to arbitrarily low values. Application of the analytical harmonic strength calculations coupled to the structured harmonic suppression approach is presented in the context of the design of the ALS storage ring corrector magnets, where quadrupole, sextupole, and octupole skew harmonics were reduced to less than 1.0% of the skew dipole at the beam aperture radius r = 3.0 cm.

Schlueter, R.; Halbach, K.

1993-09-01

263

Bayesian analysis of multivariate mixed models for a prospective cohort study using skew-elliptical distributions.  

PubMed

Classical multivariate mixed models that acknowledge the correlation of patients through the incorporation of normal error terms are widely used in cohort studies. Violation of the normality assumption can make the statistical inference vague. In this paper, we propose a Bayesian parametric approach by relaxing this assumption and substituting some flexible distributions in fitting multivariate mixed models. This strategy allows for the skewness and the heavy tails of error-term distributions and thus makes inferences robust to the violation. This approach uses flexible skew-elliptical distributions, including skewed, fat, or thin-tailed distributions, and imposes the normal model as a special case. We use real data obtained from a prospective cohort study on the low back pain to illustrate the usefulness of our proposed approach. PMID:23609779

Kazemi, Iraj; Mahdiyeh, Zahra; Mansourian, Marjan; Park, Jongbae J

2013-04-23

264

Hierarchical distribution network for low skew and high variation-tolerant bufferless resonant clocking  

NASA Astrophysics Data System (ADS)

We propose a hierarchical interconnection network with two-phase bufferless resonant clock distribution, which mixes the advantages of mesh and tree architectures. The problems of skew reduction and variation-tolerance in the mixed interconnection network are studied through a pipelined multiplier under a TSMC 65 nm standard CMOS process. The post-simulation results show that the hierarchical architecture reduces more than 75% and 65% of clock skew compared with pure mesh and pure H-tree networks, respectively. The maximum skew in the proposed clock distribution is less than 7 ps under imbalanced loading and PVT variations, which is no more than 1% of the clock cycle of about 760 ps.

Yi, Xu; Shuming, Chen; Xiangyuan, Liu

2011-09-01

265

Ion bridges in microfluidic systems  

Microsoft Academic Search

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

Taek Dong Chung; Hee Chan Kim

2009-01-01

266

EARTHQUAKE RESPONSE OF SUSPENSION BRIDGES  

Microsoft Academic Search

Suspension bridges represent critical nodes of major transportation systems. Bridge failure during strong earthquakes poses\\u000a not only a threat of fatalities but causes a substantial interruption of emergency efforts. Although wind induced vibrations\\u000a have historically been the primary concern in the design of suspension bridges, earthquake effects have also gained importance\\u000a in recent decades. This study involves ambient vibration testing

Mustafa Erdik; Nurdan Apayd?n

267

Field Performance of Timber Bridges  

Microsoft Academic Search

Abstract In September 1989, the Ciphers bridge was constructed within the Beltrami Island State Forest in Roseau County, Minnesota. The bridge superstructure is a two-span continu- ous stress-laminateddeck that is approximately12.19 m long, 5.49 m wide, and 305 mm deep (40 ft long, 18 ft wide, and 12 in. deep). The bridge is one of the first to utilize red pine

Stress-Laminated Deck Bridge; Michael A. Ritter; Paula D. Hilbrich Lee; Gregory J. Porter; Richard Hebert

268

Digital generator assisted impedance bridge  

Microsoft Academic Search

A manually-operated prototype wide-range four-terminal-pair universal impedance bridge has been constructed in order to test ideas for an automated bridge. The least relative uncertainty is 2×10-5 at 1 kHz and about 20×10-5 at 100 kHz. A two-phase digital voltage generator provides convenient sources for the two voltages required to bring the bridge to near but not exact balance. The detector

A. C. Corney

2002-01-01

269

Virtual Bridge Design  

NSDL National Science Digital Library

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 higher-level thinking skills and problem solving (NSTA 2006). It is important that we keep our students engaged in learning science, as the scientific society of tomorrow depends upon the science students of today.

Jeanpierre, Bobby; Bisogno, Janet

2008-09-01

270

Atypical at skew in Firmicute genomes results from selection and not from mutation.  

PubMed

The second parity rule states that, if there is no bias in mutation or selection, then within each strand of DNA complementary bases are present at approximately equal frequencies. In bacteria, however, there is commonly an excess of G (over C) and, to a lesser extent, T (over A) in the replicatory leading strand. The low G+C Firmicutes, such as Staphylococcus aureus, are unusual in displaying an excess of A over T on the leading strand. As mutation has been established as a major force in the generation of such skews across various bacterial taxa, this anomaly has been assumed to reflect unusual mutation biases in Firmicute genomes. Here we show that this is not the case and that mutation bias does not explain the atypical AT skew seen in S. aureus. First, recently arisen intergenic SNPs predict the classical replication-derived equilibrium enrichment of T relative to A, contrary to what is observed. Second, sites predicted to be under weak purifying selection display only weak AT skew. Third, AT skew is primarily associated with largely non-synonymous first and second codon sites and is seen with respect to their sense direction, not which replicating strand they lie on. The atypical AT skew we show to be a consequence of the strong bias for genes to be co-oriented with the replicating fork, coupled with the selective avoidance of both stop codons and costly amino acids, which tend to have T-rich codons. That intergenic sequence has more A than T, while at mutational equilibrium a preponderance of T is expected, points to a possible further unresolved selective source of skew. PMID:21935355

Charneski, Catherine A; Honti, Frank; Bryant, Josephine M; Hurst, Laurence D; Feil, Edward J

2011-09-15

271

West Point Bridge Design Contest  

NSDL National Science Digital Library

The second annual West Point Bridge Design Contest concluded in May 2003. Although it is uncertain whether the contest will receive funding for future competitions, its Web site has a number of educational resources for middle and high school students. The main feature is the bridge design software, which allows the user to "model, test, and optimize a steel highway bridge, based on realistic specifications, constraints, and performance criteria." Completed designs can be submitted online for unofficial judging. The book, Designing and Building File-Folder Bridges, can also be freely downloaded. [CL

272

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

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

273

47 CFR 80.331 - Bridge-to-bridge communication procedure.  

Code of Federal Regulations, 2012 CFR

...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)...

2012-10-01

274

47 CFR 80.331 - Bridge-to-bridge communication procedure.  

Code of Federal Regulations, 2011 CFR

...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)...

2011-10-01

275

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

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

276

77 FR 53251 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation  

Federal Register 2010, 2011, 2012, 2013

...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...

2012-08-31

277

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

Federal Register 2010, 2011, 2012, 2013

...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...

2011-09-06

278

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

Federal Register 2010, 2011, 2012, 2013

...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...

2010-10-07

279

1. GENERAL VIEW OF LIFT BRIDGE FROM 18TH STREET BRIDGE, ...  

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

1. GENERAL VIEW OF LIFT BRIDGE FROM 18TH STREET BRIDGE, LOOKING SOUTHWEST. - Pennsylvania Railroad, South Branch Chicago River Bridge, Spanning South Branch of Chicago River Bridge east of Canal Street, Chicago, Cook County, IL

280

Modified Gelfand-Tseltin patterns, lattice permutations, and skew-tableau polynomials  

SciTech Connect

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.

Louck, James D.

2002-01-01

281

Analysis of axially non-uniform loss distribution in 3-phase induction motor considering skew effect  

SciTech Connect

This paper discusses the phenomena of the axially non-uniform distribution of magnetic flux densities and losses in a 3-phase squirrel cage induction motor of which the rotor bars are skewed. A 2-dimensional complex finite element method taking account of the effects of the skewed rotor bars is utilized for the analysis of characteristics such as copper and iron losses and the loss distributions are examined. The summing up values of non-uniform losses resulted from the finite element analysis are compared with measurement values.

Kown, B.I.; Kim, B.T.; Jun, C.S.; Park, S.C. (Hanyang Univ., Ansan (Korea, Republic of))

1999-05-01

282

Multivariate skew- t approach to the design of accumulation risk scenarios for the flooding hazard  

NASA Astrophysics Data System (ADS)

The multivariate version of the skew- t distribution provides a powerful analytical description of the joint behavior of multivariate processes. It enjoys valuable properties: from the aptitude to model skewed as well as leptokurtic datasets to the availability of moments and likelihood analytical expressions. Moreover, it offers a wide range of extremal dependence strength, allowing for upper and lower tail dependence. The idea underneath this work is to employ the multivariate skew- t distribution to provide an estimation of the joint probability of flood events in a multi-site multi-basin approach. This constitutes the basis for the design and evaluation of flood hazard scenarios for large areas in terms of their intensity, extension and frequency, i.e. those information required by civil protection agencies to put in action mitigation strategies and by insurance companies to price the flooding risk and to evaluate portfolios. Performances of the skew- t distribution and the corresponding t copula function, introduced to represent the state of the art for multivariate simulations, are discussed with reference to the Tanaro Basin, North-western Italy. To enhance the characteristics of the correlation structure, three nested and non-nested gauging stations are selected with contributing areas from 1500 to 8000 km 2. A dataset of 76 trivariate flood events is extracted from a mean daily discharges database available for the time period from January 1995 to December 2003. Applications include the generation of multivariate skew- t and t copula samples and models' comparison through the principle of minimum cross-entropy, here revised for the application to multivariate samples. Copula and skew- t based scenario return period estimations are provided for the November 1994 flood event, i.e. the worst on record in the 1801-2001 period. Results are encouraging: the skew- t distribution seems able to describe the joint behavior, being close to the observations. Marginal distributions derived from the skew- t multivariate fit are comparable to the observed ones, and the model is also able to describe the tail behavior.

Ghizzoni, Tatiana; Roth, Giorgio; Rudari, Roberto

2010-10-01

283

An expert system for concrete bridge management  

Microsoft Academic Search

The importance of bridge repair versus new bridge construction has risen in recent decades due to high deterioration rates that have been observed in these structures. Budgets both for building new bridges and keeping the existing ones are always limited. To help rational decision-making, bridge management systems are presently being implemented by bridge authorities in several countries. The prototype of

P. Thoft-Christensen; J. D. Sørensen; J SORENSEN

1997-01-01

284

Extended bridge algorithms for large networks  

Microsoft Academic Search

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

W. D. Sincoskie; C. J. Cotton

1988-01-01

285

5. North side of throughtruss bridge over railroad tracks (bridge ...  

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

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

286

3. HONEYWELL STREET BRIDGE AND ELEVATED SUBWAY BRIDGE CROSSING SUNNYSIDE ...  

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

3. HONEYWELL STREET BRIDGE AND ELEVATED SUBWAY BRIDGE CROSSING SUNNYSIDE YARDS. LONG ISLAND CITY, QUEENS CO., NY. Sec. 1411, MP 3.55. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York, New York County, NY

287

82. Laurel Fork Creek Bridge #2. Visitor's view of bridge ...  

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

82. Laurel Fork Creek Bridge #2. Visitor's view of bridge and its stone railings and wood guide rails which provide views of the stream below. Facing north. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

288

Association for Bridge Construction and Design: Bridge Design Tips  

NSDL National Science Digital Library

The Association for Bridge Construction and Design was formed in response to "the bridge crisis" which leaves "only an extremely small percentage of bridges throughout the nation" receiving the attention they need. The goal of the Association is to educate bridge designers, constructors, federal, state, and local officials, as well as the general public in the vital role of safe bridges in our society; to improve the science of bridge design, construction and reconstruction through a professional forum; to provide technical information and assistance; and to educate and encourage public and private authorities to use new and improved techniques for testing and reconstruction. This section of the website provides a basic overview of bridge construction along with related drawings and pictures. By reading through the text and following the links, visitors are taken to a section that discusses ways to calculate the forces in your trusses and then use Java program to design trusses. Links to related articles and websites are available for further reading on the subject of bridge design. Although the website has not been updated recently, the resources are still relevant.

289

Did Wheatstone build a bridge? (Wheatstone's bridge circuit)  

Microsoft Academic Search

This paper discusses the connection of Charles Wheatstone with the bridge circuit. It investigates whether Wheatstone invented the bridge or not. Upon the development of the electric telegraph by Samuel F.B. Morse in 1832, the need to measure resistance accurately arose. Because telegraph lines were many miles in length, it was necessary to know the resistance of a specimen of

L. A. Geddes

2006-01-01

290

Intact-bridge tympanomastoidectomy.  

PubMed

In recent years closed-cavity (intact wall) tympanomastoidectomy has been described and recommended by many. The pendulum now is swinging back to open-cavity tympanomastoidectomy. The literature in this regard is reviewed. In all patients with chronic otitis media and mastoiditis with intractable tissue pathology, the primary objective is total eradication of disease with a dry, safe ear; a concomitant but secondary objective is hearing retention and restoration with tympanoplasty techniques. Over a 3-year period we have used a one-stage procedure called intact-bridge tympanomastoidectomy (IBM) that fulfills the desirable objectives of both open- and closed-cavity tympanomastoidectomy. The salient features include good exposure as in open-cavity tympanomastoidectomy, maintenance and widening of the middle ear space by bony bridge retention and facial buttress sculpturing to enhance grafting and ossiculoplasty such as TORP or PORP as in canal-up tympanomastoidectomy, and enhancement of mastoid obliteration for large cavities by blocking the aditus with bone paté or cartilage and by providing a separation between middle ear and mastoid. Specific methods, techniques, and results will be presented and discussed. PMID:6431375

Paparella, M M; Jung, T T

1984-06-01

291

Optimization of Propeller Skew Distribution to Minimize the Vibratory Forces and Moments Acting at the Propeller Hub.  

National Technical Information Service (NTIS)

Propeller skew is now well recognized as a means of reducing the unsteady forces and moments produced by the propeller. The propeller skew design problem is formulated as an optimization problem to minimize a weighted, linear combination of the six vibrat...

M. G. Parsons J. E. Greenblatt

1978-01-01

292

Non-linear vibration of cantilever skew plates subjected to aerodynamic and in-plane exciting forces  

Microsoft Academic Search

A previous work of the authors shows that a cantilever skew plate acted upon by an aerodynamic force and a small, slowly varying in-plane force may become unstable before the aerodynamic force reaches its critical value. This paper describes a study of the non-linear vibration of a cantilever skew plate when it becomes unstable. A finite element formulation is first

T. H. Young; F. Y. Chen

1995-01-01

293

Two shear deformable finite element models for buckling analysis of skew fibre-reinforced composite and sandwich panels  

Microsoft Academic Search

Two shear deformable finite element models, one based on first-order shear deformation theory and the other based on a higher-order shear deformation theory, are developed for buckling analysis of skew laminated composite and sandwich panels. The procedure involves the development of transformation matrix between global and local degrees of freedom for the nodes lying on the skew edges and suitable

C. Sarath Babu; T. Kant

1999-01-01

294

From GC skews to wavelets: A gentle guide to the analysis of compositional asymmetries in genomic data  

Microsoft Academic Search

Compositional asymmetries are pervasive in DNA sequences. They are the result of the asymmetric interactions between DNA and cellular mechanisms such as replication and transcription. Here, we review many of the methods that have been proposed over the years to analyse compositional asymmetries in DNA sequences. Among these we list GC skews, oligonucleotide skews and wavelets, which among other uses

Marie Touchon; Eduardo P. C. Rocha

2008-01-01

295

From GC skews to wavelets: A gentle guide to the analysis of compositional asymmetries in genomic data  

Microsoft Academic Search

Compositional asymmetries are pervasive in DNA sequences. They are the result of the asymmetric interactions between DNA and cellular mechanisms such as replication and transcription. Here, we review many of the methods that have been proposed over the years to analyse com- positional asymmetries in DNA sequences. Among these we list GC skews, oligonucleotide skews and wavelets, which among other

Marie Touchon; Eduardo P. C. Rocha

2007-01-01

296

Unilateral incompatibility as a major cause of skewed segregation in the cross between Lycopersicon esculentum and L. pennellii  

Microsoft Academic Search

Skewed segregations are frequent events in segregating populations derived from different interspecific crosses in tomato. To determine a basis for skewed segregations in the progeny of the cross between Lycopersicon esculentum and L. pennellii, monogenic segregations of 16 isozyme loci were analyzed in an F2 and two backcross populations of this cross. In the F2, 9 loci mapping to chromosomes

M. R. Foolad

1996-01-01

297

Mathematics in Use: Suspension Bridges.  

ERIC Educational Resources Information Center

|Reviews the mathematics utilized in the design and construction of suspension bridges, in general, then illustrates these mathematical concepts by examining data associated with the Mackinac Bridge, which connects the two peninsulas of Michigan. Emphasizes the strong interest factor these gigantic structures have for students by attaching a sense…

Ginther, John L.

1992-01-01

298

Bridging properties of multiblock copolymers.  

SciTech Connect

Using self-consistent field theory, we attempt to elucidate the links between microscopically determined properties, such as the bridging fraction of chains, and mechanical properties of multiblock copolymer materials. We determine morphological aspects such as period and interfacial width and calculate the bridging fractions, and compare with experimental data .

Rasmussen, K. O. (Kim O.); Kober, E. M. (Edward M.); Lookman, T. (Turab); Saxena, A. B. (Avadh B.)

2003-01-01

299

Fatigue of steel bridge infrastructure  

Microsoft Academic Search

This paper presents an overview of the development of fatigue design provisions and detailing for steel bridge structures. The historical performance of welded steel bridges in the USA is reviewed with focus on fatigue cracking at cover plate and similar attachment details, as well as distortion induced cracking at web gaps. The role of materials including modern high performance steels

J. W. Fisher; S. Roy

2011-01-01

300

Technics: Thermal bridges in buildings  

Microsoft Academic Search

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

Tuluca

1992-01-01

301

Life Cycle Cost of Bridges.  

National Technical Information Service (NTIS)

This is a continuation of the 2004 project to use historical cost data from a variety of geographically distributed bridges of different structural designs to (a) formulate a cost model for bridge life cycle cost, (b) assess the impact of deferred mainten...

R. Krizek

2009-01-01

302

Trigenomic Bridges for Brassica Improvement  

Microsoft Academic Search

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

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

2011-01-01

303

Causes of Bridge Pier Staining.  

National Technical Information Service (NTIS)

Four types of bridge stains exist in Arkansas: Rust stains - those stains directly traceable to rust; red stains - broad stains which are not directly traceable to rust; gray stains - similar to red stains except for color; and graffiti. Bridge stains in ...

S. I. Thornton C. Springer

1974-01-01

304

Performance Evaluation of Linux Bridge  

Microsoft Academic Search

This paper studies a unique network feature, Ethernet bridge, in the Linux kernel and conducts an extensive experiment to measure its performance as defined in RFC- 2544. The result shows that Linux bridge yields satisfactory performance if the system occupancy is less than 56% where its latency and throughput are comparable to Cisco Catalyst 2950 switch. The performance is considered

James T. Yu

2004-01-01

305

Self-balancing resistance bridge  

Microsoft Academic Search

An automatically balanced resistance bridge with below-picowatt dissipation in the measured resistance has been developed. The bridge, capable of measuring resistances between 20 ohms and 10 kilo ohms with an accuracy of 5 percent, was specifically designed to allow resistance measurements to be made at low temperatures without introducing an appreciable heat source to the cryostat. It consists of a

Alvaro Kaplan; George O. Zimmerman; Dean S. Edmonds Jr.

1986-01-01

306

The violin bridge as filter.  

PubMed

The violin bridge filter role was investigated using modal and acoustic measurements on 12 quality-rated violins combined with systematic bridge rocking frequency f(rock) and wing mass decrements deltam on four bridges for two other violins. No isolated bridge resonances were observed; bridge motions were complex (including a "squat" mode near 0.8 kHz) except for low frequency rigid body pivot motions, all more or less resembling rocking motion at higher frequencies. A conspicuous broad peak near 2.3 kHz in bridge driving point mobility (labeled BH) was seen for good and bad violins. Similar structure was seen in averaged bridge, bridge feet, corpus mobilities and averaged radiativity. No correlation between violin quality and BH driving point, averaged corpus mobility magnitude, or radiativity was found. Increasing averaged-over-f(rock) deltam(g) from 0 to 0.12 generally increased radiativity across the spectrum. Decreasing averaged-over-deltam f(rock) from 3.6 to 2.6 kHz produced consistent decreases in radiativity between 3 and 4.2 kHz, but only few-percent decreases in BH frequency. The lowest f(rock) values were accompanied by significantly reduced radiation from the Helmholtz A0 mode near 280 Hz; this, combined with reduced high frequency output, created overall radiativity profiles quite similar to "bad" violins among the quality-rated violins. PMID:16875244

Bissinger, George

2006-07-01

307

33 CFR 115.40 - Bridge repairs.  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

308

49 CFR 236.713 - Bridge, movable.  

Code of Federal Regulations, 2011 CFR

...Transportation 4 2011-10-01 2011-10-01 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...

2011-10-01

309

49 CFR 236.713 - Bridge, movable.  

Code of Federal Regulations, 2012 CFR

...Transportation 4 2012-10-01 2012-10-01 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...

2012-10-01

310

FDA Workshop: Anthrax Vaccines: Bridging Correlates Of ...  

Center for Biologics Evaluation and Research (CBER)

Text Version... ANTHRAX VACCINES: BRIDGING CORRELATES OF PROTECTION IN ... then potentially be bridged to humans. ... bridge data from animal studies to ... More results from www.fda.gov/downloads/biologicsbloodvaccines/newsevents

311

60 FR 42213 - Alternate Designs for Bridges  

Federal Register 2010, 2011, 2012, 2013

...Federal Highway Administration Alternate Designs for Bridges AGENCY: Federal Highway Administration...policy on the development of alternate designs for major bridges to be constructed with...best interest to require alternate bridge designs. DATES: This policy is effective...

1995-08-15

312

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.

313

Reproductive skew in female common marmosets: what can proximate mechanisms tell us about ultimate causes?  

PubMed Central

Common marmosets are cooperatively breeding monkeys that exhibit high reproductive skew: most subordinate females fail to reproduce, while others attempt to breed but produce very few surviving infants. An extensive dataset on the mechanisms limiting reproduction in laboratory-housed and free-living subordinate females provides unique insights into the causes of reproductive skew. Non-breeding adult females undergo suppression of ovulation and inhibition of sexual behaviour; however, they receive little or no aggression or mating interference by dominants and do not exhibit behavioural or physiological signs of stress. Breeding subordinate females receive comparable amounts of aggression to non-breeding females but are able to conceive, gestate and lactate normally. In groups containing two breeding females, however, both dominant and subordinate breeders kill one another's infants. These findings suggest that preconception reproductive suppression is not imposed on subordinate females by dominants, at a proximate level, but is instead self-imposed by most subordinates, consistent with restraint models of reproductive skew. In contrast to restraint models, however, this self-suppression probably evolved not in response to the threat of eviction by dominant females but in response to the threat of infanticide. Thus, reproductive skew in this species appears to be generated predominantly by subordinate self-restraint, in a proximate sense, but ultimately by dominant control over subordinates' reproductive attempts.

Saltzman, Wendy; Digby, Leslie J.; Abbott, David H.

2008-01-01

314

Elastic stability of skew laminated composite plates subjected to biaxial follower forces  

NASA Astrophysics Data System (ADS)

The present study investigates the elastic stability of skew laminated composite plates subjected to biaxial inplane follower forces by the finite element method. The plate is assumed to follow first-order shear deformation plate theory (FSDPT). The kinetic and strain energies of skew laminated composite plate and the work done by the biaxial inplane follower forces are derived by using tensor theory. Then, by Hamilton's principle, the dynamic mathematical model to describe the free vibration of this problem is formed. The finite element method and the isoparametric element are utilized to discretize the continuous system and to obtain the characteristic equations of the present problem. Finally, natural vibration frequencies, buckling loads (also the instability types) and their corresponding mode shapes are found by solving the characteristic equations. Numerical results are presented to demonstrate the effects of those parameters, such as various inplane force combinations, skew angle and lamination scheme, on the elastic stability of skew laminated composite plates subjected to biaxial inplane follower forces.

Liao, C.-L.; Lee, Z.-Y.

1993-06-01

315

Study and optimal correction of a systematic skew quadrupole field in the Tevatron  

Microsoft Academic Search

Increasing demands for luminosity in existing and future colliders have made lattice design and error tolerance and correction critical to achieving performance goals. The current state of the Tevatron collider is an example, with a strong skew quadrupole error present in the operational lattice. This work studies the high-order performance of the Tevatron and the strong nonlinear behavior introduced when

Pavel Snopok; Carol Johnstone; Martin Berz; Dmitry A. Ovsyannikov; Alexander D. Ovsyannikov

2006-01-01

316

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

PubMed

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

De la Cruz, Rolando; Branco, Márcia D

2009-08-01

317

Large-Scale Age-Dependent Skewed Sex Ratio in a Sexually Dimorphic Avian Scavenger  

PubMed Central

Age-dependent skewed sex ratios have been observed in bird populations, with adult males generally outnumbering females. This trend is mainly driven by higher female mortality, sometimes associated with anthropogenic factors. Despite the large amount of work on bird sex ratios, research examining the spatial stability of adult sex ratios is extremely scarce. The Andean condor (Vultur gryphus) is the only bird of prey with strong sexual dimorphism favouring males (males are 30% heavier than females). By examining data from most of its South-American range, we show that while the juvenile sex ratio is balanced, or even female-skewed, the sex ratio becomes increasing male-skewed with age, with adult males outnumbering females by >20%, and, in some cases by four times more. This result is consistent across regions and independent of the nature of field data. Reasons for this are unknown but it can be hypothesized that the progressive disappearance of females may be associated with mortality caused by anthropogenic factors. This idea is supported by the asymmetric habitat use by the two sexes, with females scavenging in more humanized areas. Whatever the cause, male-skewed adult sex ratios imply that populations of this endangered scavenger face higher risks of extinction than previously believed.

Lambertucci, Sergio A.; Carrete, Martina; Donazar, Jose Antonio; Hiraldo, Fernando

2012-01-01

318

Polynomial and harmonic differential quadrature methods for free vibration of variable thickness thick skew plates  

Microsoft Academic Search

An examination of the accuracy and convergence behaviors of polynomial basis function differential quadrature (PDQ) and harmonic basis function differential quadrature (HDQ) for free vibration analysis of variable thickness thick skew plates will be carried out. The plate governing equations are based on the first-order shear deformation theory including the effects of rotary inertia. Arbitrary thickness variations will be assumed

P. Malekzadeh; G. Karami

2005-01-01

319

A differential quadrature nonlinear free vibration analysis of laminated composite skew thin plates  

Microsoft Academic Search

Using a differential quadrature (DQ) method, large amplitude free vibration analysis of laminated composite skew thin plates is presented. The governing equations are based on the thin plate theory (TPT) and the geometrical nonlinearity is modeled using Green's strain in conjunction with von Karman assumptions. To cause the impact due to nonlinear terms more significant, in-plane immovable simply supported, clamped

P. Malekzadeh

2007-01-01

320

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

Microsoft Academic Search

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 $\\\

Thomas Friedrich; Stefan Ivanov

2001-01-01

321

Bayesian semiparametric mixture Tobit models with left censoring, skewness, and covariate measurement errors.  

PubMed

Common problems to many longitudinal HIV/AIDS, cancer, vaccine, and environmental exposure studies are the presence of a lower limit of quantification of an outcome with skewness and time-varying covariates with measurement errors. There has been relatively little work published simultaneously dealing with these features of longitudinal data. In particular, left-censored data falling below a limit of detection may sometimes have a proportion larger than expected under a usually assumed log-normal distribution. In such cases, alternative models, which can account for a high proportion of censored data, should be considered. In this article, we present an extension of the Tobit model that incorporates a mixture of true undetectable observations and those values from a skew-normal distribution for an outcome with possible left censoring and skewness, and covariates with substantial measurement error. To quantify the covariate process, we offer a flexible nonparametric mixed-effects model within the Tobit framework. A Bayesian modeling approach is used to assess the simultaneous impact of left censoring, skewness, and measurement error in covariates on inference. The proposed methods are illustrated using real data from an AIDS clinical study. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23553914

Dagne, Getachew A; Huang, Yangxin

2013-04-02

322

Bayesian Comparison of GARCH Processes with Skewness Mechanism in Conditional Distributions  

NASA Astrophysics Data System (ADS)

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.

Pipien, M.

2006-11-01

323

Modulation of root-skewing responses by KNAT1 in Arabidopsis thaliana.  

PubMed

The KNOTTED1 homeobox (KNOX) family transcription factors are essential for stem cell establishment and maintenance and regulate various aspects of development in all green plants. Expression patterns of the KNOX genes in the roots of plants have been reported, but their role in development remains unclear. Here we show how the KNAT1 gene is specifically involved in root skewing in Arabidopsis. The roots of two mutant alleles of KNAT1 (bp-1 and bp-5) exhibited exaggerated skewing to the right of gravity when grown on both vertical and tilted agar medium surfaces. This skewing phenotype was enhanced by treatments with low concentrations of propyzamide, and required auxin transport. The KNAT1 mutation substantially decreased basipetal auxin transport and increased auxin accumulation in the roots. Using a PIN2-GFP reporter and western blot analysis, we found that this alteration in auxin transport was accompanied by a decrease in PIN2 levels in the root tip. Decreased PIN2 expression in the mutant roots was not accompanied by reduced mRNA levels, suggesting that the KNAT1 mutations affected PIN2 expression at the posttranscriptional level. In vivo visualization of intracellular vacuolar targeting indicated that vacuolar degradation of PIN2-GFP was significantly promoted in the root tips of the bp allelic mutants. Together, these results demonstrate that KNAT1 negatively modulates root skewing, possibly by regulating auxin transport. PMID:23889705

Qi, Bin; Zheng, Huiqiong

2013-08-24

324

Reproductive skew among males in a female-dominated mammalian society  

Microsoft Academic Search

The purpose of this study was to document patterns of reproductive skew among male spotted hyenas (Crocuta crocuta), a species in which many normal mammalian sex roles are reversed. We used paternity determined from 12 microsatellite markers together with demographic and behavioral data collected over 10 years from a free-living population to document relationships among reproductive success (RS), social rank,

Anne L. Engh; Stephan M. Funk; Russell C. Van Horn; Kim T. Scribner; Michael W. Bruford; Scot Libants; Micaela Szykman; Laura Smale; Kay E. Holekampa

2002-01-01

325

Effect of PCC Joint Skew on Reflective Cracking in HMA Overlays  

Microsoft Academic Search

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

Ziad G. Ghauch

2011-01-01

326

Skew-varicose instability in two-dimensional generalized Swift-Hohenberg equations.  

PubMed

We apply analytical and numerical methods to study the linear stability of stripe patterns in two generalizations of the two-dimensional Swift-Hohenberg equation that include coupling to a mean flow. A projection operator is included in our models to allow exact stripe solutions. In the generalized models, stripes become unstable to the skew-varicose, oscillatory skew-varicose, and cross-roll instabilities, in addition to the usual Eckhaus and zigzag instabilities. We analytically derive stability boundaries for the skew-varicose instability in various cases, including several asymptotic limits. We also use numerical techniques to determine eigenvalues and hence stability boundaries of other instabilities. We extend our analysis to both stress-free and no-slip boundary conditions and we note a crossover from the behavior characteristic of no-slip to that of stress-free boundaries as the coupling to the mean flow increases or as the Prandtl number decreases. Close to the critical value of the bifurcation parameter, the skew-varicose instability has the same curvature as the Eckhaus instability provided the coupling to the mean flow is greater than a critical value. The region of stable stripes is completely eliminated by the cross-roll instability for large coupling to the mean flow. PMID:22060469

Weliwita, J A; Rucklidge, A M; Tobias, S M

2011-09-06

327

Skew in CG content near the transcription start site in Arabidopsis thaliana.  

PubMed

We have discovered a novel statistical feature of Arabidopsis thaliana genome that remarkably correlates with a position of transcription start site--CG skew peak. We hypothesize that the phenomenon can be explained by the higher mutability of unprotected cytosines. PMID:12855475

Tatarinova, Tatiana; Brover, Vyacheslav; Troukhan, Maxim; Alexandrov, Nickolai

2003-01-01

328

Sediment transport associated with morphological beach changes forced by irregular asymmetric, skewed waves  

Microsoft Academic Search

The waveshape effects on sediment transport are investigated for cross-shore beach profile changes. This study is based on experiments performed in the Laboratoire des Ecoulements Géophysiques et Industriels wave flume for irregular waves. The interest of such experiments resides in presenting complex combinations of wave skewness and asymmetry in bed load, ripple, and sheet flow regimes. Net sediment transport rates

F. R. Grasso; H. Michallet; E. Barthélemy

2011-01-01

329

On effects of skewed and asymmetric oscillatory flows on cohesive sediment flux: Numerical study  

NASA Astrophysics Data System (ADS)

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.

Son, Minwoo; Lee, Guan-Hong

2013-07-01

330

Modifications to Spatial Scan Statistics for Estimated Probabilities at Fine Resolution in Highly Skewed Spatial Distributions  

Microsoft Academic Search

OBJECTIVE Modifications to spatial scan statistics are investigated for prospective cluster detection at fine-resolution with highly skewed spatial distributions having many spatial zones with very few cases. Several alternative methods for the estimation of spatial probabilities and expected counts from counts in a baseline data window are evaluated with the Poisson spatial scan statistic (1) and the space-time permutation scan

James Edgerton; Howard Burkom; Michael Leuze

331

A real-time embedded solution for skew correction in banknote analysis  

Microsoft Academic Search

Several industrial applications do require embedded solutions both for compacting the hardware occupation and reducing energy consumption, and for achieving high speed performance. This paper presents a computer vision system developed for correcting image skew in applications for banknote analysis and classification. The system must be very efficient and run on a fixed-point DSP with limited computational resources. Consequently, we

Adnan Rashid; Andrea Prati; Rita Cucchiara

2011-01-01

332

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

Microsoft Academic Search

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

Campus de Beaulieu

333

On the skewness of distribution of the generators of a ruled surface  

Microsoft Academic Search

1. IN a paper published in the Bulletin of the Calcutta Mathematical Society, the author has proved that the line of striction of the generators of a ruled surface is also the locus of the feet of transversals intersecting consecutive and ultimately coincident generators of the ruled surface at the same constant angle. A certain measure, called the skewness of

V. R. Chariar

1949-01-01

334

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

Microsoft Academic Search

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

Sebastien Gouezel

2003-01-01

335

A new family of asymmetric models for item response theory: A Skew-Normal IRT family  

Microsoft Academic Search

Abstract Normal assumptions for the latent variable and symmetric,item characteristics curves have been used in the last 50 years in many psychometric,methods for item-response theory (IRT) models. This paper introduces a new family of asymmetric models for item response theory, namely the skew-normal item- response theory (SN-IRT) model. This family extends the ogive normal

Jorge Luis Bazán; Heleno Bolfarine; Marcia D'Elia Branco

336

2FAR: A 2bcgskew Predictor Fused by an Alloyed Redundant History Skewed Perceptron Branch Predictor  

Microsoft Academic Search

This paper describes the 2bcgskew branch predictor fused by an alloyed redundant his- tory skewed perceptron predictor, which is our design submitted to the 1st JILP Champi- onship Branch Prediction (CBP) competition. The presented predictor intelligently com- bines multiple predictions (fusion) in order to obtain a more accurate prediction. The various predictions are delivered by a 2bcgskew predictor and include

Veerle Desmet; Hans Vandierendonck; Koen De Bosschere

337

A bridge between cultures  

NASA Astrophysics Data System (ADS)

Journalists who report on scientific discoveries and the scientists who make them are, in many cases, separated by a Grand Canyon-sized gap. A recent U.S. survey revealed that journalists believe that scientists' jargon prevents effective communication. Scientists polled in the same survey, conducted by Today Show host Jim Hartz and NASA scientist Rick Chappell, said that journalists need to do a better job of verifying facts and interpreting scientific results.Panelists representing the scientific and media communities will discuss ways to bridge that gap during the “Science and the Media” episode of Freedom Speaks, to be aired by Public Broadcasting Stations in May and June (check your local listings).

Friebele, Elaine

338

Dinitrogen bridged gold clusters  

SciTech Connect

A family of dinitrogen complexes, [(LAu){sub 6}(N{sub 2})]{sup 2+} (L = a phosphine), with the dinitrogen unit bridging two clusters of three gold atoms have been prepared from hydrazine and [(LAu){sub 3}(O){sup +}]. Structural characterization of the PPh{sub 2}{sup i}Pr (Ph, phenyl; {sup i}Pr, isopropyl) derivative shows a nitrogen-nitrogen single-bond distance indicative of hydrazido (N{sub 2}{sup 4-}) character for the dinitrogen unit. The complexes can be reduced and protonated to give low [13% when L = PPh{sub 2}Me (Me, methyl)] to quantitative [100% when L = P(p-MeOC{sub 6}H{sub 5}){sub 3}] yields of ammonia, establishing that bonding of dinitrogen to six metal atoms can lead to facile cleavage of the nitrogen-nitrogen bond. 19 refs., 2 figs., 1 tab.

Shan, Hui; Yang, Yi; James, A.J.; Sharp, P.R. [Univ. of Missouri, Columbus, OH (United States)

1997-03-07

339

The Bridges Organization  

NSDL National Science Digital Library

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

340

Construction Technologies: Construct the Strongest Bridge  

NSDL National Science Digital Library

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.

Trahan-Liptak, Joy

2005-01-01

341

Nanoparticle bridge DNA biosensor  

NASA Astrophysics Data System (ADS)

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

Huang, Hong-Wen

342

Effects of trophic skewing of species richness on ecosystem functioning in a diverse marine community.  

PubMed

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

Reynolds, Pamela L; Bruno, John F

2012-05-31

343

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

PubMed Central

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.

Reynolds, Pamela L.; Bruno, John F.

2012-01-01

344

Liquid-Bridge Breaking Limits  

NASA Astrophysics Data System (ADS)

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

Macner, Ashley; Steen, Paul

2011-11-01

345

Electronic communication through molecular bridges.  

PubMed

A concept that plays an important role in chemistry in general and in molecular spintronics in particular is electronic communication through molecular bridges. An improved understanding of this concept may help to transfer knowledge between different areas of chemistry and nanoscience. We aim at finding the limits of electronic communication as a property of the bridge by comparing and rationalizing trends in exchange spin coupling in diradicals and in conductance in dithiolate-gold junctions which share common sets of molecular bridges. PMID:23995380

Herrmann, Carmen; Elmisz, Jan

2013-10-15

346

Violin frequency response – bridge mobility and bridge feet distance  

Microsoft Academic Search

Good violins have a broad hill in the 2–3 kHz range of their frequency response. This hill has previously been attributed to the first in-plane resonance of the violin bridge. Experiments prove, however, that the hill is the result of two forces acting in opposite directions at the bridge feet. The experiments reported here show that the hill can be

E. V. Jansson

2004-01-01

347

29. VIEW OF FORTH POINT CHANNEL BRIDGES, 1931, (CONGRESS STREET ...  

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

29. VIEW OF FORTH POINT CHANNEL BRIDGES, 1931, (CONGRESS STREET BRIDGE AT MIDDLE, SUMMER STREET BRIDGE AT BOTTOM, NORTHERN AVENUE BRIDGE AT TOP), LOOKING NORTH - Congress Street Bascule Bridge, Spanning Fort Point Channel at Congress Street, Boston, Suffolk County, MA

348

Anticoagulation After Cardioembolic Stroke: To Bridge or Not to Bridge?  

PubMed Central

Background Most patients with cardioembolic stroke require long-term anticoagulation. Still, uncertainty exists regarding the best mode of starting long-term anticoagulation. Design, Setting, and Patients We conducted a retrospective review of all patients with cardioembolic stroke admitted to our center from April 1, 2004, to June 30, 2006, and not treated with tissue plasminogen activator. Patients were grouped by treatment: no treatment, aspirin only, aspirin followed by warfarin sodium, intravenous heparin sodium in the acute phase followed by warfarin (heparin bridging), and full-dose enoxaparin sodium combined with warfarin (enoxaparin bridging). Outcome measures and adverse events were collected prospectively. Laboratory values were captured from the records. Main Outcome Measures Symptomatic hemorrhagic transformation, stroke progression, and discharge modified Rankin Scale score. Results Two hundred four patients were analyzed. Recurrent stroke occurred in 2 patients (1%). Progressive stroke was the most frequent serious adverse event, seen in 11 patients (5%). Hemorrhagic transformation occurred in a bimodal distribution—an early benign hemorrhagic transformation and a late symptomatic hemorrhagic transformation. All of the symptomatic hemorrhagic transformation cases were in the enoxaparin bridging group (10%) (P=.003). Systemic bleeding occurred in 2 patients (1%) and was associated with heparin bridging (P=.04). Conclusions Anticoagulation of patients with cardioembolic stroke can be safely started with warfarin shortly after stroke. Heparin bridging and enoxaparin bridging increase the risk for serious bleeding.

Hallevi, Hen; Albright, Karen C.; Martin-Schild, Sheryl; Barreto, Andrew D.; Savitz, Sean I.; Escobar, Miguel A.; Gonzales, Nicole R.; Noser, Elizabeth A.; Illoh, Kachi; Grotta, James C.

2009-01-01

349

Bridging the urological divide  

PubMed Central

The advanced disease clinical presentations, higher morbidity and mortality rates and lack of available treatment options in prostate cancer care, attest to disparities in the delivery and outcomes of urological services in Black men of African lineage in both the Developed and Developing countries. This gap in health care and services in the global management of prostate cancer denotes the urological divide. Through the experience of a Developing country urologist with a comparative literature review, this presentation defines the determinants of the disparity through deficiencies in human, material and financial resources, as is most prevalent in Developing countries. Solutions to ending health care disparities must take into account the existing development phase of Third World countries and thus determine whether the Developed countries should export a total service delivery system or seek primarily to advance the competence and skills of the existing Developing country resources. Collaboration in prostate cancer research has the greatest promise and sustainability of bridging this urological divide and is of mutual benefit to both entities.

2011-01-01

350

Bridging the urological divide.  

PubMed

The advanced disease clinical presentations, higher morbidity and mortality rates and lack of available treatment options in prostate cancer care, attest to disparities in the delivery and outcomes of urological services in Black men of African lineage in both the Developed and Developing countries. This gap in health care and services in the global management of prostate cancer denotes the urological divide.Through the experience of a Developing country urologist with a comparative literature review, this presentation defines the determinants of the disparity through deficiencies in human, material and financial resources, as is most prevalent in Developing countries.Solutions to ending health care disparities must take into account the existing development phase of Third World countries and thus determine whether the Developed countries should export a total service delivery system or seek primarily to advance the competence and skills of the existing Developing country resources.Collaboration in prostate cancer research has the greatest promise and sustainability of bridging this urological divide and is of mutual benefit to both entities. PMID:21992183

Roberts, Robin

2011-09-23

351

Evaluation of Bridge Protective Strategies.  

National Technical Information Service (NTIS)

The report documents existing knowledge on the effectiveness of different common strategies for protecting bridge decks against deterioration caused by de-icing salts. The strategies considered are: (1) increased cover to the top bar; (2) low-slump dense ...

K. Babaei N. M. Hawkins

1987-01-01

352

Bridge Deck Deterioration and Restoration.  

National Technical Information Service (NTIS)

This report reflects the results of a comprehensive research program in response to the problem of bridge deck deterioration. This program placed emphasis on protecting newer decks as well as repairing damaged ones. Two basic approaches were applied to pr...

M. G. Hagen

1982-01-01

353

Bridge Deck Concrete Volume Change.  

National Technical Information Service (NTIS)

Concrete structures such as bridge decks, with large surface area relative to volume, shrink and crack, thus reducing service life performance and increasing operation costs. The project evaluated the early, first 24 hours, and long-term, 180 days, shrink...

A. Ramniceanu D. W. Mokarem R. E. Weyers

2010-01-01

354

Bridge Deck Deicing using Geothermal Heat Pumps  

Microsoft Academic Search

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

JEFFREY D. SPITLER; MAHADEVAN RAMAMOORTHY

355

Adaptable All-Composite Bridge Concept Authors  

Microsoft Academic Search

Composite Products Inc. (CPI) in conjunction with the University of Missouri - Rolla (UMR) designed and built an all-composite bridge that was installed at the UMR campus. The bridge spanned 30 feet and was 9 feet wide. The bridge was designed to AASHTO H20 load rating. UMR has conducted extensive Finite Element Analysis (FEA) and testing on the bridge. The

John Unser; Prakash Kumar; K. Chandrashekhara; Antonio Nanni; Steve Watkins

356

Adaptable All-Composite Bridge Concept  

Microsoft Academic Search

Abstract Composite Products Inc. (CPI) in conjunction with the University of Missouri –Rolla (UMR) designed and built an all-composite bridge that was installed at the UMR campus. The bridge spanned 30 feet and was 9 feet wide. The bridge was designed to AASHTO H20 load rating. UMR has conductedextensive Finite Element Analysis (FEA) and testing on the bridge. The building

John Unser; Prakash Kumar; K. Chandrashekhara; Antonio Nanni; Steve Watkins

357

Sacrificial bridges for MEMS fabrication  

NASA Astrophysics Data System (ADS)

This study discusses sacrificial bridges that are used to release MEMS devices. Before being released, sacrificial bridges connect all the component structures into an integral structure. Solder bump bonding is used to mount the MEMS chip on another chip or a printed circuit board (PCB) and to maintain the alignment among all component structures after removal of the sacrificial bridges. Two types of sacrificial bridges were designed, analyzed and fabricated. The fabrication process—which used low resistivity single crystal silicon (SCS) wafers as the device material—was developed to implement the sacrificial bridges. Novel SCS through silicon vias (TSVs), which interconnect stacked chips, was made using the same process. An electrostatic comb drive actuator was fabricated and mounted onto a PCB. The fabricated actuator was tested to demonstrate the feasibility of the fabrication process, sacrificial bridges and SCS TSVs. The results show that the actuator worked well. Its maximum displacement and resonant frequency were 69.9 µm and 406 Hz, respectively. This method is promising for the delivery of a novel 3D system in package for MEMS devices.

Chang, Chao-Min; Chen, Yang-Che; Fong, Chien-Fu; Guu, Yunn-Horng; Chen, Rongshun; Yeh, J. Andrew; Hou, Max T.

2011-09-01

358

Comparison between Modern Violin Bridge and Baroque Violin Bridge by Photoelastic Observation and Frequency Analysis  

Microsoft Academic Search

A comparison between the modern bridge and the baroque bridge of the violin by photoelastic observation was carried out. The relationship between the stress part and the hole is symmetric in the modern and baroque bridges. The measured spectral envelopes of baroque bridges are similar to those of modern bridges in D- or G-strings, and have peaks at a frequency

Akihiro Matsutani

2004-01-01

359

Structural Health Indices for Steel Truss Bridges  

Microsoft Academic Search

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

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

360

Kinetic investigation of the extrinsic spin Hall effect induced by skew scattering  

NASA Astrophysics Data System (ADS)

A study of the kinetics of the extrinsic spin Hall conductivity induced by skew scattering is performed using the fully microscopic kinetic spin Bloch equation approach to the (001) GaAs symmetric quantum well. In the steady state, the extrinsic spin Hall current/conductivity vanishes for the linear k dependent spin-orbit coupling and is very small for the cubic k dependent spin-orbit coupling. The spin precession induced by the Dresselhaus/Rashba spin-orbit coupling plays a very important role in the vanishing of the extrinsic spin Hall conductivity in the steady state. An in-plane spin polarization is induced by the skew scattering, with the help of the spin-orbit coupling. This spin polarization is very different from the current-induced spin polarization.

Cheng, J. L.; Wu, M. W.

2008-02-01

361

Myeloid skewing in murine autoimmune arthritis occurs in hematopoietic stem and primitive progenitor cells  

PubMed Central

Skewing toward myeloid cell production is often observed in chronic inflammation and autoimmune diseases. Herein, we determined whether persistent myeloid activation and proinflammatory output occurring in pathologic conditions is at the level of hematopoietic stem and primitive progenitor cells (HSPPCs). By using a mouse arthritis model, we found that even though HSPPCs in arthritis still retained the capacity to differentiate into different lineages, they acquired enhanced in vitro and in vivo propensity in a disease-dependent manner to generate myeloid cells, the key perpetrators of tissue damage in arthritis. This myeloid skewing was cell intrinsic, as arthritic HSPPCs up-regulate myeloid-specific transcripts including S100a8. Exogenous S100a8 promoted myeloid cell output from wild-type HSPPCs, suggesting mechanistic involvement of this gene in the myeloid priming that occurs in arthritic HSPPCs. Therefore, our results indicate that in arthritic mice, HSPPCs adopt a pathologic state that favors disease persistence.

Oduro, Kwadwo A.; Liu, Fang; Tan, Qing; Kim, Chan-Kyu; Lubman, Olga; Fremont, Daved; Mills, Jason C.

2012-01-01

362

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

Microsoft Academic Search

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

F. Piriou; A. Razek

1990-01-01

363

Assessment of mechanism of acquired skewed X inactivation by analysis of twins  

Microsoft Academic Search

Skewed X-chromosome inactivation in pe- ripheral blood granulocytes becomes more frequent with increasing age, affect- ing up to half of those over 75 years old. To investigate the mechanisms underly- ing this phenomenon, X-inactivation pro- files in 33 monozygotic and 22 dizygotic elderly twin pairs were studied. Differen- tial methylation-sensitive restriction en- zyme cutting at a hypervariable locus in the

Mark A. Vickers; Ewan McLeod; Timothy D. Spector; Ian J. Wilson

2001-01-01

364

Differential quadrature large amplitude free vibration analysis of laminated skew plates based on FSDT  

Microsoft Academic Search

Nonlinear free vibration analysis of thin-to-moderately thick laminated composite skew plates is presented based on the first order shear deformation theory (FSDT) using differential quadrature method (DQM). The geometrical nonlinearity is modeled using Green’s strain and von Karman assumptions in conjunction with the FSDT of plates. After transforming and discretizing the governing equations, which includes the effects of rotary inertia,

P. Malekzadeh

2008-01-01

365

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

Microsoft Academic Search

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

T. Ishikawa; G. R. Slemon

1993-01-01

366

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

SciTech Connect

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

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

2011-07-05

367

Vertical-Velocity Skewness in the Buoyancy-Driven Boundary Layer  

Microsoft Academic Search

A number of puzzling features of the skewness of the vertical velocity field, Sw(z), are found in observations and large-eddy simulations (LES) of the buoyancy-driven planetary boundary layer (PBL). For example, observations of Sw(z) in cases where the air is heated from below indicate that Sw(z) > 0 and remains relatively constant for z 0.3zi, whereas all large-eddy simulations of

Chin-Hoh Moeng; Richard Rotunno

1990-01-01

368

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

PubMed

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

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

2012-12-10

369

Skew of Mononucleotide Frequencies, Relative Abundance of Dinucleotides, and DNA Strand Asymmetry  

Microsoft Academic Search

.   Based on 152 mitochondrial genomes and 36 bacterial chromosomes that have been completely sequenced, as well as three long\\u000a contigs for human chromosomes 6, 21, and 22, we examined skews of mononucleotide frequencies and the relative abundance of\\u000a dinucleotides in one DNA strand. Each group of these genomes has its own characteristics. Regarding mitochondrial genomes,\\u000a both CpG and GpT

Chiharu Shioiri; Naoyuki Takahata

2001-01-01

370

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

PubMed

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

Munk, Walter

2009-01-01

371

Local resource competition and the skewness of the sex ratio: a demographic model.  

PubMed

Most animal populations are characterized by balanced sex ratios, but there exist several exceptions in which the sex ratio at birth is skewed. An interesting hypothesis proposed by Clark (1978) to explain male-biased sex ratios is the local resource competition theory: the bias may be expected in those species in which males disperse more than females, which are thus more prone to local competition for resources. Here we discuss some of the ideas underlying Clark's theory using a spatially explicit approach. In particular, we focus on the role of spatiotemporal heterogeneity as a possible determinant of biased sex ratios. We model spatially structured semelparous populations where either Ricker density dependence or environmental stochasticity can generate irregular spatiotemporal patterns. The proposed discrete-time model describes both genetic and complex population dynamics assuming that (1) sex ratio is genetically determined, (2) only young males can disperse, and (3) individuals locally compete for resources. The analysis of the model shows that no skewed sex ratios can arise in homogeneous habitats. Temporal asynchronized fluctuations between two distinct patches coupled with dispersal of young males is the minimum requirement for obtaining skewed sex ratios of demographic nature in local adult populations. However, the establishment of a male-biased sex ratio at birth in the long run is possible if dispersal is genetically determined and there is genetic linkage between sex ratio determination and dispersal. PMID:19278284

Mari, Lorenzo; Gatto, Marino; Casagrandi, Renato

2008-10-01

372

AMPK?1 regulates macrophage skewing at the time of resolution of inflammation during skeletal muscle regeneration.  

PubMed

Macrophages control the resolution of inflammation through the transition from a proinflammatory (M1) to an anti-inflammatory (M2) phenotype. Here, we present evidence for a role of AMPK?1, a master regulator of energy homeostasis, in macrophage skewing that occurs during skeletal muscle regeneration. Muscle regeneration was impaired in AMPK?1(-/-) mice. In vivo loss-of-function (LysM-Cre;AMPK?1(fl/fl) mouse) and rescue (bone marrow transplantation) experiments showed that macrophagic AMPK?1 was required for muscle regeneration. Cell-based experiments revealed that AMPK?1(-/-) macrophages did not fully acquire the phenotype or the functions of M2 cells. In vivo, AMPK?1(-/-) leukocytes did not acquire the expression of M2 markers during muscle regeneration. Skewing from M1 toward M2 phenotype upon phagocytosis of necrotic and apoptotic cells was impaired in AMPK?1(-/-) macrophages and when AMPK activation was prevented by the inhibition of its upstream activator, CaMKK?. In conclusion, AMPK?1 is crucial for phagocytosis-induced macrophage skewing from a pro- to anti-inflammatory phenotype at the time of resolution of inflammation. PMID:23931756

Mounier, Rémi; Théret, Marine; Arnold, Ludovic; Cuvellier, Sylvain; Bultot, Laurent; Göransson, Olga; Sanz, Nieves; Ferry, Arnaud; Sakamoto, Kei; Foretz, Marc; Viollet, Benoit; Chazaud, Bénédicte

2013-08-01

373

Skewed X chromosome inactivation in fraternal female twins results in moderately severe and mild haemophilia B.  

PubMed

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

Okumura, K; Fujimori, Y; Takagi, A; Murate, T; Ozeki, M; Yamamoto, K; Katsumi, A; Matsushita, T; Naoe, T; Kojima, T

2008-06-05

374

26. NEW STEEL BRIDGE COMPLETED ASSEMBLED. OLD BRIDGE BELOW. U.S.G.S. ...  

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

26. NEW STEEL BRIDGE COMPLETED ASSEMBLED. OLD BRIDGE BELOW. U.S.G.S. GAGING STATION IN RIGHT BACKGROUND. VIEW LOOKING NORTHEAST - Kaibab Trail Suspension Bridge, Spanning Colorado River, Grand Canyon, Coconino County, AZ

375

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 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...

2011-10-01

376

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 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...

2012-10-01

377

Representation of skew in time-stepped two-dimensional finite-element models of electrical machines  

Microsoft Academic Search

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

Stephen Williamson; Timothy J. Flack; Albertus F. Volschenk

1995-01-01

378

Modeling of effects of skewing of rotor mounted permanent magnets on the performance of brushless DC motors  

Microsoft Academic Search

A method for computation of the parameters and performance of permanent-magnet brushless DC motor drives is developed in which the concept of skewing is implemented through the geometries of permanent magnet mounting on the rotor and not through the usual skewing of the armature slots. This technique of permanent-magnet mounting eliminates the 2-D axial symmetry in the resulting magnetic fields.

M. A. Alhamadi; N. A. Demerdash

1991-01-01

379

How the Eight Decision Models Can or Cannot Explain Boiney's Emotional Skewness Effects in Decision Making under Ambiguity  

Microsoft Academic Search

Boiney has recently reported the interesting emotional effects of skewed second- order probability on decision making under ambiguity. This paper examines, using a generalized Boiney problem, how the following eight decision models can or cannot explain Boiney's emotional skewness effects: Keynes Conventional Coefficient Model (1921), Ellsberg Model (1961), Gärdenfors-Sahlin Model (1982), Einhorn-Hogarth Model (1985), Kahn-Sarin Model (1988), Boiney Model (1993),

Jiro IHARA

380

Quantitative analysis of replication-related mutation and selection pressures in bacterial chromosomes and plasmids using generalised GC skew index  

Microsoft Academic Search

BACKGROUND: Due to their bi-directional replication machinery starting from a single finite origin, bacterial genomes show characteristic nucleotide compositional bias between the two replichores, which can be visualised through GC skew or (C-G)\\/(C+G). Although this polarisation is used for computational prediction of replication origins in many bacterial genomes, the degree of GC skew visibility varies widely among different species, necessitating

Kazuharu Arakawa; Haruo Suzuki; Masaru Tomita

2009-01-01

381

Coil Creep and Skew-Quadrupole Field Components in the Tevatron  

SciTech Connect

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.

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

2011-07-11

382

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

NASA Astrophysics Data System (ADS)

In the nearshore, waves transform from skewed shoaling waves to asymmetric breaking waves. Velocity skewness, such as found beneath Stokes second-order waves, generally results in a net onshore sediment transport. Recent numerical studies and limited experimental laboratory data have demonstrated the potential importance of acceleration skewness to onshore sediment transport beneath asymmetric, 'saw- tooth' waves. Here, we investigate new full-scale laboratory tunnel experiments under sheetflow conditions in which regular oscillatory sawtooh flow with varying degrees of acceleration skewness and velocity skewness were generated over a mobile bed. In all experiments the velocity amplitude was 1.2 m/s, the wave period was 7 s, and the bed was composed of well-sorted, fine to medium sand (d50 = 200~?m). In several experiments a counter-current of 0.4 m/s was imposed to imitate undertow. We deployed (1) a 2-MHz Acoustical Doppler Velocimeter Profiler (ADVP) to obtain vertical profiles of (phase-averaged) horizontal and vertical oscillatory and turbulent flow with a temporal and vertical resolution of 50 Hz and 3 mm, respectively, and (2) a triple-frequency Acoustical Backscatter Sensor to obtain vertical profiles of (phase-averaged) suspended sediment concentration with a temporal and vertical resolution of 10 Hz and 5 mm, respectively. Under waves with acceleration skewness only, we observed two concentration peaks, which at the top of the sheetflow layer were approximately in phase with the free-stream velocity. As the concentration peak following the rapid acceleration towards maximum onshore flow was slightly larger than the concentration peak under maximum offshore flow, the depth-integrated and wave-averaged suspended transport was directed onshore. While most sediment stirred during the onshore flow phase had settled back to the bed before flow reversal, some sediment stirred during the offshore flow phase persisted into the onshore flow phase, thus providing an additional means for onshore transport. The larger concentration peak under the maximum onshore flow coincided with the observed smaller thickness of the wave boundary layer under maximum onshore flow and with larger velocity gradients, turbulence intensities, and peak bed shear stress ?, where we determined ? from the ADVP data using the acceleration defect integral method. For instance, for a sawtooth wave with ? = amax / (amax + amin) = 0.65, where amax and amin are maximum positive and negative acceleration, respectively, we observed the ratio ?max / |?min| to be approximately 1.3. With an increase in ? and, in particular, with an increase in velocity skewness, we observed ?max / |?min| to increase, the concentration peak under maximum onshore flow to increasingly dominate over that under maximum offshore flow, and the onshore depth-integrated and wave-averaged suspended sediment transport to increase accordingly. In the experiments with a counter current, the wave-induced depth-integrated and wave-averaged suspended sediment transport opposed the direction of wave propagation because sediment concentrations under maximum offshore flow exceeded those under maximum onshore flow.

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

2008-12-01

383

1. Photocopied January 1973 from the Keystone Bridge Company Album, ...  

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

1. Photocopied January 1973 from the Keystone Bridge Company Album, 1874. THE KEYSTONE BRIDGE COMPANY: LUCY FURNACE. - Baltimore & Ohio Railroad, Parkersburg Bridge, Ohio River, Parkersburg, Wood County, WV

384

Bridge Construction and Engineering Learning Center  

NSDL National Science Digital Library

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

385

Balanced bridge feedback control system  

NASA Astrophysics Data System (ADS)

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.

Lurie, Boris J.

1990-03-01

386

Excitation Methods for Bridge Structures  

SciTech Connect

This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.

Farrar, C.R.; Duffy, T.A.; Cornwell, P.J.; Doebling, S.W.

1999-02-08

387

Bridges: Chesapeake & Ohio Canal National Monument Historic Structures Report. Part II: Historical Data Section.  

National Technical Information Service (NTIS)

Contents: The Georgetown Bridges 1829-1850; The Georgetown Bridges 1850-1889; Bridges on the Washington Branch; Embankment Bridges; Bridges from College Run to Seneca Aqueduct; Bridges from Seneca Aqueduct to Antietam Aqueduct: Bridges from Antietam Aqued...

1968-01-01

388

Stability of Curved Bridges During Construction.  

National Technical Information Service (NTIS)

Because of the increasing demand for curved bridges combined with challenges of design and construction, there is need to improve practices for the efficient design and construction of curved bridges. This report presents the results of two projects aimed...

J. S. Davidson R. S. Abdalla M. Madhavan

2004-01-01

389

Bridging: Locating Critical Connectors in a Network  

PubMed Central

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.

Valente, Thomas W.; Fujimoto, Kayo

2010-01-01

390

Bridging: Locating Critical Connectors in a Network.  

PubMed

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

Valente, Thomas W; Fujimoto, Kayo

2010-07-01

391

Survey of Metal Truss Bridges in Virginia.  

National Technical Information Service (NTIS)

Bridges are among the cultural resources that must be considered for historic significance under the Historic Preservation Act of 1966. The Virginia Transportation Research Council conducted a pioneering study of Virginia's pre-1932 metal truss bridges du...

A. B. Miller K. M. Clark

1997-01-01

392

Bridge Management Developments: Executive Summary Report.  

National Technical Information Service (NTIS)

Executive summaries are presented of two studies to develop components of a bridge management system. In the first, a bridge management analysis method considering owner costs and user costs was developed to determine the optimum improvement action and ti...

D. W. Johnston

1988-01-01

393

Design and Construction of Modern Curved Bridges.  

National Technical Information Service (NTIS)

The overall objectives of this project were to investigate and synthesize state-of-the-art practice for the efficient design and construction of curved bridges, and to identify research needs regarding strength and stability of curved bridges. The project...

J. S. Davidson R. S. Abdalla M. Madhavan

2002-01-01

394

Galvanized Steel Reinforced Concrete Bridge Decks.  

National Technical Information Service (NTIS)

This project was initiated in 1969 as a cooperative study with the Federal Highway Administration. It includes construction of laboratory specimens and experimental bridge decks for evaluation of galvanized reinforcement as a deterrent to bridge deck dete...

C. J. Arnold

1976-01-01

395

Bridge Temperatures Derived From Measurement of Movement.  

National Technical Information Service (NTIS)

Movements were measured at expansion joints in 7 bridges of various forms of construction and were transformed into corresponding values of effective bridge temperatures. Correlation was established between these effective temperatures and the sum of the ...

W. Black D. S. Moss M. Emerson

1976-01-01

396

Quantitative analysis of replication-related mutation and selection pressures in bacterial chromosomes and plasmids using generalised GC skew index  

PubMed Central

Background Due to their bi-directional replication machinery starting from a single finite origin, bacterial genomes show characteristic nucleotide compositional bias between the two replichores, which can be visualised through GC skew or (C-G)/(C+G). Although this polarisation is used for computational prediction of replication origins in many bacterial genomes, the degree of GC skew visibility varies widely among different species, necessitating a quantitative measurement of GC skew strength in order to provide confidence measures for GC skew-based predictions of replication origins. Results Here we discuss a quantitative index for the measurement of GC skew strength, named the generalised GC skew index (gGCSI), which is applicable to genomes of any length, including bacterial chromosomes and plasmids. We demonstrate that gGCSI is independent of the window size and can thus be used to compare genomes with different sizes, such as bacterial chromosomes and plasmids. It can suggest the existence of different replication mechanisms in archaea and of rolling-circle replication in plasmids. Correlation of gGCSI values between plasmids and their corresponding host chromosomes suggests that within the same strain, these replicons have reproduced using the same replication machinery and thus exhibit similar strengths of replication strand skew. Conclusions gGCSI can be applied to genomes of any length and thus allows comparative study of replication-related mutation and selection pressures in genomes of different lengths such as bacterial chromosomes and plasmids. Using gGCSI, we showed that replication-related mutation or selection pressure is similar for replicons with similar machinery.

2009-01-01

397

Bridging Cultures with Classroom Strategies.  

ERIC Educational Resources Information Center

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…

Rothstein-Fisch, Carrie; Greenfield, Patricia M.; Trumbull, Elise

1999-01-01

398

A Bridge to the Future  

ERIC Educational Resources Information Center

|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…

Anderson, Richard

2008-01-01

399

Percentage Problems in Bridging Courses  

ERIC Educational Resources Information Center

|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…

Kachapova, Farida; Kachapov, Ilias

2012-01-01

400

"Sand Boil" on Bay Bridge  

USGS Multimedia Gallery

"Sand boil" or sand volcano measuring 2 m (6.6 ft) in length erupted in median of Interstate Highway 80 west of the Bay Bridge toll plaza when ground shaking transformed loose water-saturated deposit of subsurface sand into a sand-water slurry (liquefaction). Vented sand contains-marine shell f...

2009-01-26

401

Instructional Design: Bridge to Competence.  

ERIC Educational Resources Information Center

Social work educators surveyed reported differential success in implementing key instructional development elements--success in specifying objectives and developing related assessment procedures, obstacles in building bridges to competence through instructional design. Aids in matching learners to learning environments are outlined. (MSE)

Gross, Gerald M.

1981-01-01

402

Official English: Bridge or Barrier?  

ERIC Educational Resources Information Center

Discusses the official English movement in the United States. Provides suggestions for groups that really want to help immigrants acquire English, by building bridges and not barriers. These include the following: (1) joining private and charitable organizations in helping make English-as-a-Second-Language classes available; (2) support libraries;…

Krashen, Stephen

2000-01-01

403

EOS NPOESS the Bridge Mission  

NSDL National Science Digital Library

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)

Carnahan, Tim; Snodgrass, Stuart; Murphy, Robert

1999-02-02

404

Clinical Observation of Myocardial Bridge  

Microsoft Academic Search

Background:A myocardial bridge (MB is an anatomical arrangement in which a limited segment of an epi- cardial coronary artery becomes engulfed by myocardial fibers. Although it has generally been felt that most instances of bridginge are benign, recent reports have suggested that MB can be associated with evidence of myocardial ischemia, myocardial infarction, arrhythmia and sudden death. This study investigated

Seung Mook Jeung; Tae Kyeong Won; Rak Kyeong Choi; Jae Kim; Nae Hee Lee; Dal Soo Lim; Hweung Kon Hwang

405

Bridges on the River Quad  

NSDL National Science Digital Library

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

2011-03-27

406

33 CFR 118.90 - Bridges crossing channel obliquely.  

Code of Federal Regulations, 2013 CFR

...Waters 1 2013-07-01 2013-07-01 false Bridges crossing channel obliquely. 118.90 Section 118...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges...

2013-07-01

407

49 CFR 237.53 - Railroad bridge inspectors.  

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

408

49 CFR 237.107 - Conduct of bridge inspections.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

409

49 CFR 237.111 - Review of bridge inspection reports.  

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

410

49 CFR 237.53 - Railroad bridge inspectors.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

411

49 CFR 237.109 - Bridge inspection records.  

Code of Federal Regulations, 2010 CFR

... 4 2010-10-01 2010-10-01 false Bridge inspection records. 237.109 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.109 Bridge inspection...

2010-10-01

412

23 CFR 650.807 - Bridges requiring a USCG permit.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Bridges requiring a USCG permit. 650.807... ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges requiring a...

2010-04-01

413

49 CFR 237.111 - Review of bridge inspection reports.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

414

49 CFR 237.103 - Bridge inspection procedures.  

Code of Federal Regulations, 2011 CFR

... 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...

2011-10-01

415

23 CFR 650.807 - Bridges requiring a USCG permit.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Bridges requiring a USCG permit. 650.807... ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges requiring a...

2009-04-01

416

49 CFR 237.103 - Bridge inspection procedures.  

Code of Federal Regulations, 2012 CFR

... 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...

2012-10-01

417

49 CFR 237.71 - Determination of bridge load capacities.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 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...

2010-10-01

418

49 CFR 237.107 - Conduct of bridge inspections.  

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

419

23 CFR 650.807 - Bridges requiring a USCG permit.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Bridges requiring a USCG permit. 650.807... ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges requiring a...

2013-04-01

420

49 CFR 237.103 - Bridge inspection procedures.  

Code of Federal Regulations, 2010 CFR

... 4 2010-10-01 2010-10-01 false Bridge inspection procedures. 237.103 Section 237...RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection...

2010-10-01

421

1. CONTEXTUAL VIEW OF BRIDGE IN SETTING, LOOKING EAST FROM ...  

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

1. CONTEXTUAL VIEW OF BRIDGE IN SETTING, LOOKING EAST FROM DOWNSTREAM. DOWNSTREAM HIGHWAY BRIDGE DATES FROM 1952, UPSTREAM RAILROAD BRIDGE DATES FROM 1913 - Van Duzen River Bridge, Spanning Van Duzen River at CA State Highway 101, Alton, Humboldt County, CA

422

21. View of Clark Fork Vehicle Bridge facing west. Looking ...  

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

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

423

9. LOOKING EAST NORTHEAST, CANAL STREET BRIDGE IN FOREGROUND, PENNSYLVANIA ...  

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

9. LOOKING EAST NORTHEAST, CANAL STREET BRIDGE IN FOREGROUND, PENNSYLVANIA RAILROAD BRIDGE IN MIDGROUND. - Pennsylvania Railroad, South Branch Chicago River Bridge, Spanning South Branch of Chicago River Bridge east of Canal Street, Chicago, Cook County, IL

424

33 CFR 118.80 - Lights on bascule bridges.  

Code of Federal Regulations, 2010 CFR

...Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.80 Lights on bascule bridges. (a) Lift span lights. Each lift span of every bascule bridge...

2009-07-01

425

33 CFR 118.80 - Lights on bascule bridges.  

Code of Federal Regulations, 2010 CFR

...Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.80 Lights on bascule bridges. (a) Lift span lights. Each lift span of every bascule bridge...

2010-07-01

426

33 CFR 118.70 - Lights on swing bridges.  

Code of Federal Regulations, 2010 CFR

...Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.70 Lights on swing bridges. (a) Swing span lights on through bridges. Each swing span of every...

2009-07-01

427

33 CFR 118.100 - Retroreflective panels on bridge piers.  

Code of Federal Regulations, 2010 CFR

...COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.100 Retroreflective...or channel sides on bridges not required to have bridge lighting. Lateral significant red triangles and...

2010-07-01

428

33 CFR 118.100 - Retroreflective panels on bridge piers.  

Code of Federal Regulations, 2010 CFR

...COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.100 Retroreflective...or channel sides on bridges not required to have bridge lighting. Lateral significant red triangles and...

2009-07-01

429

33 CFR 118.70 - Lights on swing bridges.  

Code of Federal Regulations, 2010 CFR

...Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.70 Lights on swing bridges. (a) Swing span lights on through bridges. Each swing span of every...

2010-07-01

430

Field Testing and Load Rating of a Short-Span Thermoplastic Bridge System, Bridge T-8519.  

National Technical Information Service (NTIS)

Live-load tests were conducted on Bridge T-8519, located on Tuckers Road in Camp Mackall near Fort Bragg, North Carolina. This bridge was tested in conjunction with a similar nearby bridge (T-8518). Both bridges were constructed of a new structural materi...

B. Commander H. Diaz-Alvarez

2010-01-01

431

47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

432

47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.  

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

433

47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.  

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

434

47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

435

Bridge building and bridge conservation in agreement with the genius loci  

Microsoft Academic Search

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

Dirk Bühler

436

Skewed X-chromosome inactivation in female carriers of dyskeratosis congenita  

SciTech Connect

In this study, we report on a family with X-linked dyskeratosis congenita (DC). Linkage analysis with markers in the factor VIII gene at Xq28 yielded a LOD score of 2 at a recombination of 0. Clinical manifestations of DC, such as skin lesions following the Blaschko lines, were present in two obligate carrier females. Highly skewed X inactivation was observed in white blood cells, cultured skin fibroblasts, and buccal mucosa from female carriers of DC in this family. This suggests a critical role for the DC gene in bone marrow-cell and fibroblast-cell proliferation. 23 refs., 4 figs., 1 tab.

Devriendt, K.; Matthijs, G.; Legius, E. [Univ. Hospital Gasthuisberg, Leuven (Belgium)] [and others

1997-03-01

437

Stability of a cantilevered skew inhomogeneous plate in supersonic gas flow  

NASA Astrophysics Data System (ADS)

This paper considers the vibrations of a skew inhomogeneous plate in gas flow. The plate is clamped in a certain section of one of its sides. Interaction of the flow with the plate is described using piston theory. The problem solution is based on the Hamilton's variational principle and finite element method. The calculation results are compared with known data of theoretical studies and experiments. For the inhomogeneous plate, similarity parameters were established for the problem, which, in practically important cases, appears to be self-similar for one of the similarity parameters. This allows one to reduce the solution of this problem to the solution of an algebraic eigenvalue problem.

Isaulova, T. N.; Lavit, I. M.

2011-07-01

438

Structure-induced negatively skewed X-ray diffraction pattern of carbon onions  

NASA Astrophysics Data System (ADS)

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.

Siklitskaya, Alexandra; Yastrebov, Sergey; Smith, Roger

2013-10-01

439

Earthquake resistance of integral abutment bridges  

Microsoft Academic Search

Integral abutment construction has become a popular alternative to conventional bridge construction for short and intermediate length bridges. Integral abutment construction eliminates joints and bearings which reduce long-term maintenance costs. However, in the absence of joints and bearings, the bridge abutments and foundations must be able to accommodate lateral movements from thermal expansion and contraction of the superstructure and from

Aaron M Talbott

2008-01-01

440

Building Bridges One Line at a Time  

ERIC Educational Resources Information Center

|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…

Grigsby, Cathy Murray

2012-01-01

441

A Participatory Public Art Project: Community Bridge  

ERIC Educational Resources Information Center

|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…

Stephens, Pam

2005-01-01

442

INVESTIGATION OF FRP MATERIALS FOR BRIDGE CONSTRUCTION  

Microsoft Academic Search

The research program consists of a series of investigations in the field and in the laboratory. First, four short-span bridges are installed so as to outline the construction-related issues associated with the use of these materials. The bridges are located in a residential area of St. James, Missouri and each bridge utilizes FRP materials in a slightly different way, demonstrating

Danielle Stone; Steve Watkins; Halvard Nystrom; Antonio Nanni

443

Conservation of Salt Bridges in Protein Families  

Microsoft Academic Search

A detailed computational analysis is presented that focuses on the relationship between structural attributes and the degree and mode of salt bridge conservation. A data set of conserved and non-conserved salt bridges was constructed from eight protein families, based on the structural alignment of family members. Salt bridges were defined at the secondary structure level rather than at the residue

Ora Schueler; Hanah Margalit

1995-01-01

444

Immunoglobulin disulfide bridges: Theme and variations  

Microsoft Academic Search

Prelude There are two types of disulfide bridges in immunoglobulins. One is the conserved intrachain bridge, spanning about 60 to 70 amino acid residues and found, as a monotonous theme, in every immunoglobulin domain. Buried deep between the opposing ~3-sheets, these bridges are shielded from solvent and, ordinarily, can be reduced only in the presence of denaturing agents. In contrast,

Lisa A. Steiner

1985-01-01

445

Application of reliability analysis in bridge management  

Microsoft Academic Search

This paper describes the use of reliability analysis by the Highways Agency of the Department of Transport, United Kingdom, in developing various aspects of its bridge management procedures. There have been pioneering use of the technique for developing the whole life assessment of bridges, bridge and traffic assessment loading criteria and load history based assessment rules. The paper also discusses

Parag C Das

1998-01-01

446

Analysis of Curved Integral Abutment Bridges  

Microsoft Academic Search

Deformation of bridges that are induced by thermal loads can be accommodated by expansion joints and bearings. Integral Abutment Bridges have gained acceptance as a way to mitigate potential damage from thermal movements, eliminating the poor performance and maintenance costs associated with expansion joints and bearings. However, integral abutments significantly change the structural response of the bridges. Several researches including

Emre Kalayci

2010-01-01

447

Digital Design of Fixed Bridge Framework  

Microsoft Academic Search

The fixed bridge framework is an important part of prosthodontics. We design a fixed bridge framework in computer with our own original dental CAD software. The 3D data of the abutment teeth is measured by ATOS II 3D scanner. Then the coping crowns are designed based on the implicit surfaces. An algorithm is presented to deform the bridge based on

An Tao; Dai Ning; Cheng Xiaosheng; Lu Peijun; Wang Yong

2008-01-01

448

Canonical forms for cycles in bridge graphs  

Microsoft Academic Search

Let G = (V,E) be a biconnected graph and let C be a cycle in G. The subgraphs of G identified with the biconnected components of the contraction of C in G are called the bridges of C. Associated with the set of bridges of a cycle C is an auxilliary graphical structure GC called a bridge graph or an

S. Gill Williamson

1993-01-01

449

Patterns of paternity skew among polyandrous social insects: what can they tell us about the potential for sexual selection?  

PubMed

Monogamy results in high genetic relatedness among offspring and thus it is generally assumed to be favored by kin selection. Female multiple mating (polyandry) has nevertheless evolved several times in the social Hymenoptera (ants, bees, and wasps), and a substantial amount of work has been conducted to understand its costs and benefits. Relatedness and inclusive fitness benefits are, however, not only influenced by queen mating frequency but also by paternity skew, which is a quantitative measure of paternity biases among the offspring of polyandrous females. We performed a large-scale phylogenetic analysis of paternity skew across polyandrous social Hymenoptera. We found a general and significant negative association between paternity frequency and paternity skew. High paternity skew, which increases relatedness among colony members and thus maximizes inclusive fitness gains, characterized species with low paternity frequency. However, species with highly polyandrous queens had low paternity skew, with paternity equalized among potential sires. Equal paternity shares among fathers are expected to maximize fitness benefits derived from genetic diversity among offspring. We discuss the potential for postcopulatory sexual selection to influence patterns of paternity in social insects, and suggest that sexual selection may have played a key, yet overlooked role in social evolution. PMID:23206136

Jaffé, Rodolfo; Garcia-Gonzalez, Francisco; den Boer, Susanne P A; Simmons, Leigh W; Baer, Boris

2012-07-15

450

Simultaneous Bayesian inference for skew-normal semiparametric nonlinear mixed-effects models with covariate measurement errors.  

PubMed

Longitudinal data arise frequently in medical studies and it is a common practice to analyze such complex data with nonlinear mixed-effects (NLME) models which enable us to account for between-subject and within-subject variations. To partially explain the variations, covariates are usually introduced to these models. Some covariates, however, may be often measured with substantial errors. It is often the case that model random error is assumed to be distributed normally, but the normality assumption may not always give robust and reliable results, particularly if the data exhibit skewness. Although there has been considerable interest in accommodating either skewness or covariate measurement error in the literature, there is relatively little work that considers both features simultaneously. In this article, our objectives are to address simultaneous impact of skewness and covariate measurement error by jointly modeling the response and covariate processes under a general framework of Bayesian semiparametric nonlinear mixed-effects models. The method is illustrated in an AIDS data example to compare potential models which have different distributional specifications. The findings from this study suggest that the models with a skew-normal distribution may provide more reasonable results if the data exhibit skewness and/or have measurement errors in covariates. PMID:23459161

Huang, Yangxin; Dagne, Getachew A

2011-03-11

451

Simultaneous Bayesian inference for skew-normal semiparametric nonlinear mixed-effects models with covariate measurement errors  

PubMed Central

Longitudinal data arise frequently in medical studies and it is a common practice to analyze such complex data with nonlinear mixed-effects (NLME) models which enable us to account for between-subject and within-subject variations. To partially explain the variations, covariates are usually introduced to these models. Some covariates, however, may be often measured with substantial errors. It is often the case that model random error is assumed to be distributed normally, but the normality assumption may not always give robust and reliable results, particularly if the data exhibit skewness. Although there has been considerable interest in accommodating either skewness or covariate measurement error in the literature, there is relatively little work that considers both features simultaneously. In this article, our objectives are to address simultaneous impact of skewness and covariate measurement error by jointly modeling the response and covariate processes under a general framework of Bayesian semiparametric nonlinear mixed-effects models. The method is illustrated in an AIDS data example to compare potential models which have different distributional specifications. The findings from this study suggest that the models with a skew-normal distribution may provide more reasonable results if the data exhibit skewness and/or have measurement errors in covariates.

Huang, Yangxin; Dagne, Getachew A.

2012-01-01

452

Quick analysis method for bridge seismic risk based on AHP  

Microsoft Academic Search

To better evaluate the bridge seismic risk, the paper provides an analysis method for bridge seismic risk based on AHP. A bridge seismic risk analysis model is set up based on AHP and bridge structure is analyzed quantitatively. Considering primary factors leading to bridge structure damage under the force of earthquake, we use the relative value contributing to bridge damage,

Zhu Min; Bo Jingshan; Zeng Xiaolei

2011-01-01

453

31. Photographic copy of drawing showing profile of bridge after ...  

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

31. Photographic copy of drawing showing profile of bridge after the 1888-1889 and 1899-1900 reconstructions; also shows profile of bridge before 1888 (Martin Sigvart Grytbak, Wabasha St. Bridge, Formerly St. Paul Bridge, 1919); profile of Wabasha street bridge - Wabasha Street Bridge, Spanning Mississippi River at Wabasha Street, Saint Paul, Ramsey County, MN

454

Inter-population variation in multiple paternity and reproductive skew in the guppy.  

PubMed

We use microsatellite loci to detail the multiple paternity patterns in broods from 10 wild populations of the guppy (Poecilia reticulata) found in Northern Trinidad. The populations span two major drainages comprising the Caroni and the Oropouche, and include sites that are characterized by either high or low predation. Across the populations the frequency of multiple paternity is high with 95% (range: 70%-100%) of broods having multiple sires. Broods have an average of 3.5 sires (range: 1-9) and a mixed-model analysis suggests that broods from high predation sites have marginally more sires than do those from low predation sites, but this is true only in the Oropouche drainage. There is no difference in sire number between predation sites in the Caroni drainage. Brood size, but not female body length, is correlated with the number of sires and the correlation cannot be attributed solely to the stochastic process associated with sperm competition and a 'fair raffle'. Within broods there is significant skew in reproductive success among males, which may reflect variation in sperm competitiveness or female choice. There is, however, no difference in the skew among populations from different predation regimes or drainages. Finally, high predation populations were characterized by increased genetic variability at the microsatellite loci, suggesting a larger effective population size. We discuss explanations for the high degree of multiple paternity but the general lack of any major differences among broods from ecologically different populations. PMID:18494765

Neff, Bryan D; Pitcher, Trevor E; Ramnarine, Indar W

2008-05-20

455

Hyperspectral subspace estimation preserving anomalies via a test of multivariate sample skewness  

NASA Astrophysics Data System (ADS)

Dimensionality Reduction (DR) for hyperspectral image data can be regarded as a problem of signal subspace estimation (SSE) in terms of the Linear Mixing Model (LMM). Most SSE methods for hyperspectral data are based on the analysis of second-order statistics (SOS) without considering preservation of anomalies. This paper addresses the problem of SSE for preserving both abundant and rare signal components in hyperspectral images. The multivariate sample skewness for testing normality is brought in our new algorithm as a discrimination index for rank determination of rare vectors subspace, combining with analysis of the maximum of data-residual ?2-norm denoted as ?2,?-norm which is strongly influenced by the anomaly signal components. And the SOS based method, labeled as hyperspectral signal subspace identification by minimum error (HySime), is employed for identification of abundant vectors space. The results of experiments on real AVIRIS data prove that multivariate sample skewness statistics is suitable for measuring the distribution about hyperspectral data globally, and our algorithm can obtain the anomaly components from data that are discarded by HySime, which implies less information loss in the our method.

Zheng, Siyuan; Zhou, Shilin; Wang, Liangliang; Li, Zhiyong

2013-08-01

456

Skewed X inactivation is associated with phenotype in a female with adrenal hypoplasia congenita  

PubMed Central

Adrenal hypoplasia congenita (AHC) can occur due to deletions or mutations in the DAX 1 (NR0B1) gene on the X chromosome (OMIM 300200). This form of AHC is therefore predominantly seen in boys. Deletion of the DAX 1 gene can also be part of a larger contiguous deletion including the centromeric dystrophin and glycerol kinase (GK) genes. We report a girl with a de novo deletion at Xp21.2 on the maternal chromosome, including DAX1, the GK gene and 3? end of the dystrophin gene, who presented with salt losing adrenal insufficiency and moderate developmental delay, but relatively mild features of muscular dystrophy. Investigation using the androgen receptor as a marker gene identified skewed inactivation of the X chromosome. In the patient’s leucocytes, the paternal X chromosome was completely inactive, but in muscle 20% of the active chromosomes were of paternal origin. Thus skewed X inactivation (deletion on the active maternal X chromosome with an inactive paternal X chromosome) is associated with AHC in a female. Variability in X inactivation between tissues may account for the pronounced salt loss and adrenal insufficiency but mild muscular dystrophy.

Shaikh, M G; Boyes, L; Kingston, H; Collins, R; Besley, G T N; Padmakumar, B; Ismayl, O; Hughes, I; Hall, C M; Hellerud, C; Achermann, J C; Clayton, P E

2008-01-01

457

Langevin equation modeling of convective boundary layer dispersion assuming homogeneous, skewed turbulence  

SciTech Connect

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.

Hasstrom, J.S.; Ermak, D.L.

1997-10-01

458

Fuel cell plates with skewed process channels for uniform distribution of stack compression load  

DOEpatents

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.

Granata, Jr., Samuel J. (Greensburg, PA); Woodle, Boyd M. (North Huntingdon Township, Westmoreland County, PA)

1989-01-01

459

Empirical validation of stochastic models of interacting agents. A ``maximally skewed'' noise trader model  

NASA Astrophysics Data System (ADS)

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.

Alfarano, S.; Lux, T.; Wagner, F.

2007-01-01

460

Optimal reproductive-skew models fail to predict aggression in wasps.  

PubMed Central

Optimal-skew models (OSMs) predict that cooperative breeding occurs as a result of dominants conceding reproductive benefits to subordinates, and that division of reproduction within groups reflects each cooperator's willingness and ability to contest aggressively for dominance. Polistine paper wasps are a leading model system for testing OSMs, and data on reproduction and aggression appear to support OSMs. These studies, however, measure aggression as a single rate rather than by the activity patterns of individuals. This leads to a potential error: if individuals are more likely to receive aggression when active than when inactive, differences in aggression across samples can reflect changes in activity rather than hostility. This study replicates a field manipulation cited as strongly supporting OSMs. We show that fundamentally different conclusions arise when controlling for individual activity states. Our analyses strongly suggest that behaviours classified as 'aggression' in paper wasps are unlikely to function in establishing, maintaining or responding to changes in reproductive skew. This illustrates that OSM tests using aggression or other non-reproductive behaviour as a metric for reproductive partitioning must demonstrate those links rather than assume them.

Nonacs, Peter; Reeve, H Kern; Starks, Philip T

2004-01-01

461

Bridge health monitoring using wavelet analysis  

NASA Astrophysics Data System (ADS)

Bridge health monitoring is defined as the continuous monitoring of a bridge's state properties such as static and dynamic response in order to diagnose the onset of anomalous structural behavior. This involves measuring and evaluating the state properties and relating these to defined performance parameters. The process of measuring state properties, either continuously or periodically, produces large amounts of data. Careful analysis of dat would detect any sudden and gradual changes in the bridge, and thus enable damage detection, location, and severity. There is therefore a need for data analysis tools that enable bridge managers to identify as much information as possible on bridge behavior and performance at given tie. The ability of wavelet transforms to detect abrupt changes; gradual change beginnings and ends of events make them well suited for the analysis of bridge health monitoring data. This paper presents the application of wavelet analysis to identify events and changes in a bridge during its construction.

Moyo, Pilate; Brownjohn, James M.

2001-06-01

462

Problems associated with nondestructive evaluation of bridges  

NASA Astrophysics Data System (ADS)

The US has 542,000 bridges that consume billions of dollars per year in construction, rehabilitation, and maintenance funds and which are the lifelines of US commerce. The 1992 ISTEA (Intermodal Surface Transportation Efficiency Act) mandates the implementation of a quantitative computerized bridge management system by 1996. A prime need of such a system are quantitative bridge inspection methods to feed accurate reliable condition information to the huge database of bridges. Nondestructive evaluation (NDE) will fill a critical need in the implementation of effective bridge management. However, many serious barriers exist to the widespread routine application of this technology to bridges. This paper provides an overview of the typical problems associated with applying NDE to bridges.

Prine, David W.

1995-05-01

463

Strengthening Bridges with Prestressed CFRP Strips  

NASA Astrophysics Data System (ADS)

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.

Siwowski, Tomasz; ?ó?towski, Piotr

2012-06-01

464

Digital generator assisted impedance bridge  

Microsoft Academic Search

A prototype wide-range four-terminal-pair universal impedance bridge has been constructed in order to test ideas for balancing procedures and noise performance. The relative standard uncertainty (1?) contributed by noise and short-term drift to the measurement of resistance, capacitance, and inductance is less than 10×10-6 from 1 to 30 kHz, and less than 35×10-6 at 100 kHz. A two-phase digital voltage

Andrew C. Corney

2003-01-01

465

Bridging Nonliving and Living Matter  

Microsoft Academic Search

Assembling non-biological materials (geomaterials) into a proto-organism constitutes a bridge between nonliving and living matter. In this article we present a simple step-by-step route to assemble a proto-organism. Many pictures have been proposed to describe this transition within the origins-of-life and artificial life communities, and more recently alternative pictures have been emerging from advances in nanoscience and biotechnology. The proposed

Steen Rasmussen; Liaohai Chen; Martin Nilsson; Shigeaki Abe

2003-01-01

466

Temperature monitoring of steel bridges  

NASA Astrophysics Data System (ADS)

The temperature monitoring of Tsing Ma Bridge is performed by the Wind and Structural Health Monitoring System on the Lantau Link as one of its functions. The system consists of over 90 platinum resistance type detectors on Tsing Ma Bridge installed at 4 selected cross-sections. Since May 1997, temperature measurements have been continuously recorded. The University of Hong Kong has been assisting in the analysis of these field measurements. This paper describes the instrumentation and data analysis related to the study. In parallel with this, experimental segmental steel sections under the influence of solar radiation have been set up on the university campus and temperature measurements have been recorded since 1993. Correlation results of observed data have shown that the temperature of steel sections mainly depends on the solar intensity and shade air temperature. Based on the theory of heat transfer, finite element models for different structural components of the bridge deck have been developed for prediction of temperature distribution. Good agreement with field data was observed. Comparison of positive temperature gradients among different structures has shown that they can generally be classified into two categories depending on the number of web faces exposed to the environment.

Au, Francis T.; Tham, Leslie G.; Tong, Man; Lee, Peter K.

2001-08-01

467

Halliburton Composite Bridge Plug Assembly  

SciTech Connect

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.

Starbuck, J.M.; Luttrell, C.R.; Aramayo, G.

2005-01-15

468

A skew model for the evolution of sociality via manipulation: why it is better to be feared than loved.  

PubMed Central

Concession-based reproductive skew models predict that social groups can form via persuasion, whereby dominant individuals forfeit some reproduction to subordinates as an incentive to stay and help. We have developed an alternative skew model based on manipulation, whereby dominant individuals coerce subordinates into staying and helping by imposing costs on their independent reproductive prospects. Stable groups can evolve under a much wider range of genetic and ecological conditions under this manipulation model than under concession models. We describe evidence that various forms of pre-emptive and ongoing manipulation occur in nature and we discuss the implications of the model for the development of a general theory of social evolution.

Crespi, B J; Ragsdale, J E

2000-01-01

469

Nondestructive evaluation techniques for enhanced bridge inspection  

SciTech Connect

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.

Thomas, G.; Benson, S.; Durbin, P.; Del Grande, N.; Haskins, J.; Brown, A.; Schneberk, D.

1993-10-01

470

Salt Bridges: Geometrically Specific, Designable Interactions  

PubMed Central

Salt bridges occur frequently in proteins, providing conformational specificity and contributing to molecular recognition and catalysis. We present a comprehensive analysis of these interactions in protein structures by surveying a large database of protein structures. Salt bridges between Asp or Glu and His, Arg, or Lys display extremely well-defined geometric preferences. Several previously observed preferences are confirmed and others that were previously unrecognized are discovered. Salt bridges are explored for their preferences for different separations in sequence and in space, geometric preferences within proteins and at protein-protein interfaces, cooperativity in networked salt bridges, inclusion within metal-binding sites, preference for acidic electrons, apparent conformational side chain entropy reduction upon formation, and degree of burial. Salt bridges occur far more frequently between residues at close than distant sequence separations, but at close distances there remain strong preferences for salt bridges at specific separations. Specific types of complex salt bridges, involving three or more members, are also discovered. As we observe a strong relationship between the propensity to form a salt bridge and the placement of salt-bridging residues in protein sequences, we discuss the role that salt bridges might play in kinetically influencing protein folding and thermodynamically stabilizing the native conformation. We also develop a quantitative method to select appropriate crystal structure resolution and B-factor cutoffs. Detailed knowledge of these geometric and sequence dependences should aid de novo design and prediction algorithms.

Donald, Jason E.; Kulp, Daniel W.; DeGrado, William F.

2010-01-01

471

Numeric and symbolic evaluation of the pfaffian of general skew-symmetric matrices  

NASA Astrophysics Data System (ADS)

Evaluation of pfaffians arises in a number of physics applications, and for some of them a direct method is preferable to using the determinantal formula. We discuss two methods for the numerical evaluation of pfaffians. The first is tridiagonalization based on Householder transformations. The main advantage of this method is its numerical stability that makes unnecessary the implementation of a pivoting strategy. The second method considered is based on Aitken's block diagonalization formula. It yields to a kind of LU (similar to Cholesky's factorization) decomposition (under congruence) of arbitrary skew-symmetric matrices that is well suited both for the numeric and symbolic evaluations of the pfaffian. Fortran subroutines (FORTRAN 77 and 90) implementing both methods are given. We also provide simple implementations in Python and Mathematica for purpose of testing, or for exploratory studies of methods that make use of pfaffians.

González-Ballestero, C.; Robledo, L. M.; Bertsch, G. F.

2011-10-01

472

Skewed distribution of irradiance predicted by the second-order Rytov approximation.  

PubMed

The first-order Rytov approximation predicts that the probability-density function for intensity fluctuations in a random medium should be a log normal distribution. Here the corrections to this prediction that arise from the second term in the Rytov series are explored. The primary effect is to skew the distribution so as to favor values that are less than the average. This effect is controlled by the Rytov variance beta0(2) alone, and the predicted distribution contains no adjustable parameters. The theoretical result is compared with numerical simulations for weak scattering of plane and spherical waves. The agreement is quite good unless the intensity fluctuations are very large or very small relative to the mean irradiance. In those ranges, the predictions require additional terms in the Rytov expansion. PMID:11688869

Wheelon, A D

2001-11-01

473

Scaling Limits of Random Skew Plane Partitions with Arbitrarily Sloped Back Walls  

NASA Astrophysics Data System (ADS)

The paper studies scaling limits of random skew plane partitions confined to a box when the inner shapes converge uniformly to a piecewise linear function V of arbitrary slopes in [-1, 1]. It is shown that the correlation kernels in the bulk are given by the incomplete Beta kernel, as expected. As a consequence it is established that the local correlation functions in the scaling limit do not depend on the particular sequence of discrete inner shapes that converge to V. A detailed analysis of the correlation kernels at the top of the limit shape, and of the frozen boundary is given. It is shown that depending on the slope of the linear section of the back wall, the system exhibits behavior observed in either Okounkov and Reshetikhin (Commun Math Phys 269(3):571-609, 2007) or Boutillier et al. (http://arXiv.org/abs/0912.3968v2 [math-ph], 2009).

Mkrtchyan, Sevak

2011-08-01

474

Skew-orthogonal Laguerre polynomials for chiral real asymmetric random matrices  

NASA Astrophysics Data System (ADS)

We apply the method of skew-orthogonal polynomials (SOP) in the complex plane to asymmetric random matrices with real elements, belonging to two different classes. Explicit integral representations valid for arbitrary weight functions are derived for the SOP and for their Cauchy transforms, given as the expectation values of traces and determinants or their inverses, respectively. Our proof uses the fact that the joint probability distribution function for all combinations of real eigenvalues and complex conjugate eigenvalue pairs can be written as a product. Examples for the SOP are given in terms of Laguerre polynomials for the chiral ensemble (also called the non-Hermitian real Wishart-Laguerre ensemble), both without and with the insertion of characteristic polynomials. Such characteristic polynomials play the role of mass terms in applications to complex Dirac spectra in field theory. In addition, for the elliptic real Ginibre ensemble, we recover the SOP of Forrester and Nagao in terms of Hermite polynomials.

Akemann, G.; Kieburg, M.; Phillips, M. J.

2010-09-01

475

A Novel Generalized Normal Distribution for Human Longevity and other Negatively Skewed Data  

PubMed Central

Negatively skewed data arise occasionally in statistical practice; perhaps the most familiar example is the distribution of human longevity. Although other generalizations of the normal distribution exist, we demonstrate a new alternative that apparently fits human longevity data better. We propose an alternative approach of a normal distribution whose scale parameter is conditioned on attained age. This approach is consistent with previous findings that longevity conditioned on survival to the modal age behaves like a normal distribution. We derive such a distribution and demonstrate its accuracy in modeling human longevity data from life tables. The new distribution is characterized by 1. An intuitively straightforward genesis; 2. Closed forms for the pdf, cdf, mode, quantile, and hazard functions; and 3. Accessibility to non-statisticians, based on its close relationship to the normal distribution.

Robertson, Henry T.; Allison, David B.

2012-01-01

476

Shift Dependent Skew Quadrupole in Advanced Light SourceElliptically Polarizing Undulators, Cause and Corrections  

SciTech Connect

Three elliptically polarizing undulators (EPU) are installed and operational at the Advanced Light Source (ALS); the most recent was installed in April 2005. Operational experience has shown a variation in electron beam size which correlates with the EPU's magnetic quadrant shifts used to vary polarization. Storage ring electron dynamics studies pointed to the existence of a shift dependent skew quadrupole (SQ) component generated within the EPUs. Detailed magnetic and mechanical measurements demonstrated that the field errors were the result of systematic individual magnetic block displacements which vary with quadrant shift. This paper will discuss the results of electron dynamics studies, magnetic and mechanical measurements, design modifications planned for future EPUs to eliminate the SQ source, and the design and implementation of SQ compensation coils.

Marks, Steve; Prestemon, Soren; Robin, David; Schlueter, Ross D.; Steier, Christoph; Wolski, Andrew; Jung, Jin-Young; Chubar, Oleg

2005-11-29

477

Network Bridging Potential in Later Life  

PubMed Central

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.

Cornwell, Benjamin

2009-01-01

478

Replacement bridge crossing uses unique pipe rollers  

SciTech Connect

Spanning the Schuykill River between Valley Forge and Norristown, Pa., the old steel-truss Betzwood Bridge was used by PECO to carry a 12-in. high-pressure main from 1927 until 1981, when a routine inspection disclosed that the west edge of the south abutment had collapsed, leaving only the 12-in. gas main to support the southwest end of the bridge. PECO's engineers installed a new main in the new Betzwood Bridge, located 150 ft downstream from the historic truss structure. They surmounted restrictions against welding or dilling the bridge's structural steel by suspending the pipeline from the bridge crossbeams using insulating pipe rollers, a patented product that electrically isolates the pipe from the bridge structure and protects the coating and pipe from abrasion and wear. The rollers, along with specially forged steel beam clamps, now hold the pipe in its suspended position.

Cline, R.A.

1982-03-01

479

Low paternity skew and the influence of maternal kin in an egalitarian, patrilocal primate  

PubMed Central

Levels of reproductive skew vary in wild primates living in multimale groups depending on the degree to which high-ranking males monopolize access to females. Still, the factors affecting paternity in egalitarian societies remain unexplored. We combine unique behavioral, life history, and genetic data to evaluate the distribution of paternity in the northern muriqui (Brachyteles hypoxanthus), a species known for its affiliative, nonhierarchical relationships. We genotyped 67 individuals (22 infants born over a 3-y period, their 21 mothers, and all 24 possible sires) at 17 microsatellite marker loci and assigned paternity to all infants. None of the 13 fathers were close maternal relatives of females with which they sired infants, and the most successful male sired a much lower percentage of infants (18%) than reported for the most successful males in other species. Our findings of inbreeding avoidance and low male reproductive skew are consistent with the muriqui's observed social and sexual behavior, but the long delay (?2.08 y) between the onset of male sexual behavior and the age at which males first sire young is unexpected. The allocation of paternity implicates individual male life histories and access to maternal kin as key factors influencing variation in paternal—and grandmaternal—fitness. The apparent importance of lifelong maternal investment in coresident sons resonates with other recent examinations of maternal influences on offspring reproduction. This importance also extends the implications of the “grandmother hypothesis” in human evolution to include the possible influence of mothers and other maternal kin on male reproductive success in patrilocal societies.

Strier, Karen B.; Chaves, Paulo B.; Mendes, Sergio L.; Fagundes, Valeria; Di Fiore, Anthony

2011-01-01

480

Low paternity skew and the influence of maternal kin in an egalitarian, patrilocal primate.  

PubMed

Levels of reproductive skew vary in wild primates living in multimale groups depending on the degree to which high-ranking males monopolize access to females. Still, the factors affecting paternity in egalitarian societies remain unexplored. We combine unique behavioral, life history, and genetic data to evaluate the distribution of paternity in the northern muriqui (Brachyteles hypoxanthus), a species known for its affiliative, nonhierarchical relationships. We genotyped 67 individuals (22 infants born over a 3-y period, their 21 mothers, and all 24 possible sires) at 17 microsatellite marker loci and assigned paternity to all infants. None of the 13 fathers were close maternal relatives of females with which they sired infants, and the most successful male sired a much lower percentage of infants (18%) than reported for the most successful males in other species. Our findings of inbreeding avoidance and low male reproductive skew are consistent with the muriqui's observed social and sexual behavior, but the long delay (?2.08 y) between the onset of male sexual behavior and the age at which males first sire young is unexpected. The allocation of paternity implicates individual male life histories and access to maternal kin as key factors influencing variation in paternal--and grandmaternal--fitness. The apparent importance of lifelong maternal investment in coresident sons resonates with other recent examinations of maternal influences on offspring reproduction. This importance also extends the implications of the "grandmother hypothesis" in human evolution to include the possible influence of mothers and other maternal kin on male reproductive success in patrilocal societies. PMID:22065786

Strier, Karen B; Chaves, Paulo B; Mendes, Sérgio L; Fagundes, Valéria; Di Fiore, Anthony

2011-11-07

481

Resonance multiphoton ionization and dissociation of dimethyl ether via the {\\skew1\\tilde{\\rm C}^{\\prime}}, {\\skew1\\tilde{\\rm C}} and \\tilde{\\rm B} states  

NASA Astrophysics Data System (ADS)

The three-photon resonance four-photon ionization and dissociation spectra of dimethyl ether (DME) are presented in the wavelength range 450-550 nm at 1 nm intervals. The (3+1) REMPI spectra show three prominent bands corresponding to the \\tildeB \\leftarrow \\skew1\\tildeX, {\\skew1\\tildeC} \\leftarrow \\skew1\\tildeX and {\\skew1\\tildeC^{\\prime}} \\leftarrow \\skew1\\tildeX transitions with origins at 61 457 cm-1 (7.615 eV), 59 055 cm-1 (7.322 eV) and 58 010 cm-1 (7.194 eV), respectively. Several ionized species, CH3+, CHnO+ (n = 1-3) and CH3OCH3+, are observed in the region of wavelengths studied here. In order to compare the results, a shorter wavelength multiphoton dissociation and ionization of DME at 355 nm is also presented. At this wavelength, DME undergoes neutral dissociation to CH3 and CH3O and each fragment is then ionized by multiphoton absorption. The fragmentation at 355 nm is very intense and only small fragments such as CH3+, CHO+, CH2+, CH+ and C+ ions are observed. The measurement of photoelectron energy allows us to establish that the DME ionization potential is at least 9.55 ± 0.15 eV. The experiments were performed using a Nd:YAG-OPO (optical parametric oscillator) tunable laser system coupled to a time-of-flight mass spectrometer and a hemispherical electron energy analyser.

Mejia-Ospino, E.; García, G.; Guerrero, A.; Alvarez, I.; Cisneros, C.

2005-01-01

482

Instrumentation of bridges for structural health monitoring  

Microsoft Academic Search

As the state of the art in bridge design is advancing toward the performance-based design, it becomes increasingly important\\u000a to monitor and evaluate the long-term structural performance of bridges. Such information is essential in developing performance\\u000a criteria for design. In this research, sensor systems for long-term structural performance monitoring have been installed\\u000a on two highway bridges. Preliminary vibration measurement and

Doo Kie Kim; Jong-In Kim; Maria Q. Feng

2001-01-01

483

Nondestructive Evaluation of FRP Bridge Deck Panels  

Microsoft Academic Search

The purpose of this research was to investigate Infrared Thermography (IRT) as a Non-Destructive Evaluation (NDE) method for glass fiber-reinforced polymer (FRP) composite bridge deck panels. FRP bridge decks are currently being evaluated as a potential replacement for traditional steel-grate or concrete bridge decking. A potential problem with these decks, however, is that structural damage that can occur due to

Phillip Hallam

2012-01-01

484

Myocardial bridging: light in the tunnel  

Microsoft Academic Search

Myocardial bridging is a congenital anomaly in which a segment of a coronary artery runs intramuscularly. Although traditionally\\u000a considered as a benign condition, myocardial bridging may be associated with clinically important complications such as myocardial\\u000a ischemia, acute coronary syndromes and sudden death. We report the case of a highly symptomatic 36 years old patient with\\u000a a myocardial bridge in left anterior

M. Martín; E. Romero Tarín; Luis H. Luyando; Juan Rondán; Carlos Morales

2009-01-01

485

Female dominance status and fecal corticoids in a cooperative breeder with low reproductive skew: ring-tailed lemurs ( Lemur catta)  

Microsoft Academic Search

Many studies have shown that low dominance status within a social group is associated with elevated glucocorticoid hormone production, a common index of physiological stress. However, the reverse may be true among cooperatively breeding female mammals with high reproductive skew; that is, high dominance status is associated with elevated glucocorticoid levels. Elevated glucocorticoid levels in these dominant females may be

S. A. Cavigelli; T. Dubovick; W. Levash; A. Jolly; A. Pittsd

2003-01-01

486

Studies on Contact Geometry and Limiting Resistant Torque Characteristics of the Variable Torque Slipping Clutch with Skewed Rollers  

Microsoft Academic Search

A slipping clutch capable of delivering a constant resistant torque is described in this paper. Its principle is based on the resistance to slipping offered by the askew disposed cylindrical rollers rolling and slipping between the two specially shaped races. There are three types of this slipping clutch, namely the Right, Left and Cross Skewing respectively, which are distinguished by

Ming Feng; Kyosuke Ono; Kenji Mimura

2001-01-01

487

Skewed X inactivation and survival: a 13-year follow-up study of elderly twins and singletons  

Microsoft Academic Search

In mammalian females, one of the two X chromosomes is inactivated in early embryonic life. Females are therefore mosaics for two cell populations, one with the maternal and one with the paternal X as the active X chromosome. A skewed X inactivation is a marked deviation from a 50:50 ratio. In populations of women past 55–60 years of age, an

Mikael Thinggaard; Lene Christiansen; James W Vaupel; Karen Helene Ørstavik; Kaare Christensen

2012-01-01

488

Task allocation and reproductive skew in social mass provisioning carpenter bees in relation to age and size  

Microsoft Academic Search

Summary: The mass provisioning carpenter bees comprise two tribes, the Xylocopini and the Ceratinini. Although social nesting occurs in both tribes, no morphological castes have evolved and females are totipotent, which makes the tribe as a whole highly suitable to test predictions of reproductive skew models. We review current information for the two tribes with respect to reproductive competition and

K. Hogendoorn; H. H. W. Velthuis

1999-01-01

489

Risk factors associated with a skewed natal sex ratio in captive black rhinoceroses (Diceros bicornis) in the United States.  

PubMed

The skew toward males in the sex ratio of calves is considered to be a problem for the captive population of black rhinoceroses (Diceros bicornis) in North America. This study used a retrospective case-control design to determine whether there was a predisposition toward birth of male calves over female calves and to examine risk factors associated with the occurrence of any detected skewed natal sex ratio in captive black rhinoceroses in the United States. The study population included captive female black rhinoceroses housed in the United States that had given birth to at least one calf of known sex. This study confirmed a skewing of the natal sex ratio toward male calves in the captive black rhinoceros population. The skewed ratio was found in calves born to wild-born dams, for which an increased time in captivity, irrespective of age, was associated with an increased likelihood of a male calf. Dams between 12 and 19 yr of age had a decreased likelihood of a male calf. The data also suggested a possible trend for the southern subspecies of black rhinoceros (Diceros bicornis minor) to be more likely to produce male calves than the eastern subspecies (Diceros bicornis michaeli). No associations were found with the sex of offspring in captive-born dams: however, this lack of association could be a result of low power in the study. PMID:18229858

Dennis, Patricia M; Rajala-Schultz, Paivi J; Funk, Julie A; Blumer, Evan S; Miller, R Eric; Wittum, Thomas E; Saville, William J A

2007-12-01

490

Bridging the macro and micro  

NASA Astrophysics Data System (ADS)

A long-standing but rarely addressed challenge to physical sciences is reconciling or bridging between the macroscopic approach, exemplified by thermodynamics, continuum and infinite models, and the microscopic approach built from individual elements. Here, we show an approach to finding the boundary size region below which a microscopic approach is mandatory, and above which, one can use the macroscopic approach's tools. We illustrate how to estimate this boundary size using examples from atomic clusters. The first reviews the boundary size above which the Gibbs Phase Rule is valid, but below, is inapplicable. Then we show how to find boundary sizes for other properties.

Berry, R. Stephen; Smirnov, Boris M.

2013-06-01

491

Cerner Bridge Medical Transfusion Administration and ...  

Center for Biologics Evaluation and Research (CBER)

... Cerner Bridge Medical Transfusion Administration and Specimen Collections 3.3. Applicant: Cerner Corp, Kansas City MO. ... More results from www.fda.gov/biologicsbloodvaccines/bloodbloodproducts/approvedproducts

492

Finding bridges in packings of colloidal spheres  

NASA Astrophysics Data System (ADS)

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.

Jenkins, Matthew C.; Haw, Mark D.; Barker, Gary C.; Poon, Wilson C. K.; Egelhaaf, Stefan U.

493

Comparative analysis of full bridge and half bridge current resonant DC-DC converter  

Microsoft Academic Search

This paper deals with a comparative analysis of full bridge and half bridge current resonant DC-DC converter. The novel current resonant DC-DC converter has been proposed to improve the power efficiency. The full bridge DC-DC converter is suitable for the low input voltage and large input current as in the fuel cell power supply system, and the half bridge one

Hisatsugu Kato; Hirofumi Matsuo; Tsubasa Ito; Shuhei Kawazu; Daiki Kawahara; Satoshi Motomura; Ryota Hamaguchie

2011-01-01

494

9. VIEW OF BRIDGE NEAR CENTER SPAN, LOOKING NORTH FROM ...  

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

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

495

Predicted and Measured Response of an Integral Abutment Bridge  

Microsoft Academic Search

This project examined several uncertainties of integral abutment bridge design and analysis through field-monitoring of an integral abutment bridge and three levels of numerical modeling. Field monitoring data from a Pennsylvania bridge site was used to refine the numerical models that were then used to predict the integral abutment bridge behavior of other Pennsylvania bridges of similar construction. The instrumented

Jolene L. Fennema; Jeffrey A. Laman; Daniel G. Linzell

2005-01-01

496

Load Testing of an FRP Bridge Deck on a Truss Bridge  

Microsoft Academic Search

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

Sreenivas Alampalli; Jonathan Kunin

2003-01-01

497

Bridge afflux analysis through arched bridge constrictions using artificial intelligence methods  

Microsoft Academic Search

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

Mustafa Mamak; Galip Seckin; Murat Cobaner; Ozgur Kisi

2009-01-01

498

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

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

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

499

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

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

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

500

The Bridge of Mandolin County  

NASA Astrophysics Data System (ADS)

The Bridge of Mandolin County is a case designed to teach the general chemistry principles of molar mass, ions and aqueous reactions, solubility rules, and inorganic nomenclature. Through the instructor-facilitated class discussion, students consider the options before the Mandolin Town Council regarding deicing the newly constructed bridge connecting Mandolin with a large nearby city. The students must decipher contradictory claims made on behalf of sodium chloride, the traditional deicer, and calcium magnesium acetate, a new environmentally friendly deicer, to arrive at the most cost-effective and environmentally appropriate deicing product. As they work through the analysis they raise questions that can be addressed in a laboratory setting. Four optional role-playing experiments are included, which can be used by the students to gather information helpful to resolution of the case. The case is intended to be used over two class periods, with a laboratory period in between, though suggestions for other models are provided. Laboratory procedures include an EDTA titration for Ca2+ and Mg2+, a gravimetric analysis, a qualitative examination of ions and solubility, an introduction to freezing point depression and measurement, and an experimental design activity. This case can also successfully be used without alteration in non-majors chemistry or environmental chemistry courses, or upper-level analytical or environmental chemistry courses.

Lantz, Juliette M.; Feindt, Jenny E.; Lewellyn, Eric P. B.; Walczak, Mary M.

1999-12-01