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1

Assessment of seismic performance of skew reinforced concrete box girder bridges  

NASA Astrophysics Data System (ADS)

The seismic vulnerability of highway bridges remains an important problem and has received increased attention as a consequence of unprecedented damage observed during several major earthquakes. A significant number of research studies have examined the performance of skew bridges under service and seismic loads. The results of these studies are particularly sensitive to modeling assumptions in view of the interacting parameters. In the present study, three-dimensional improved beam-stick models of two-span highway bridges with skew angles varying from 0° to 60° are developed to investigate the seismic response characteristics of skew box girder bridges. The relative accuracy of beam-stick models is verified against counterpart finite element models. The effect of various parameters and conditions on the overall seismic response was examined such as skew angle, ground motion intensity, soil condition, abutment support conditions, bridge aspect ratio, and foundation-base conditions. The study shows that the improved beam-stick models can be used to conduct accurate nonlinear time history analysis of skew bridges. Skew angle and interacting parameters were found to have significant effect on the behavior of skewed highway bridges. Furthermore, the performance of shear keys may have a predominant effect on the overall seismic response of the skew bridges.

Abdel-Mohti, Ahmed; Pekcan, Gokhan

2013-12-01

2

Construction engineering of steel tub-girder bridge systems for skew effects  

NASA Astrophysics Data System (ADS)

Closed structural sections, such as those having circular, rectangular or trapezoidal shape, possess high rotational rigidity when compared to open sections such as I-girders. The high torsional rigidity of closed sections makes them ideal for use in highly curved bridges. In this case, the geometry of the bridge results in large torsional forces. Because of structural efficiency and economy reasons, most of these closed-section bridges consist of a trapezoidal cross-section, with a top concrete slab and bottom and side steel plates. The slab is cast after the steel is erected and thus a system of internal diaphragms and braces is necessary to stabilize the system during erection. During the steel erection and the early stages of the concrete deck placement, the section can be considered as quasi-closed as the top concrete flange has not been cast or is not yet effective. During steel erection, undetermined and/or large torsional forces and/or displacements may result in fit-up problems requiring large stresses to overcome. During concrete deck placement, the undetermined displacements can affect the control of the deck thickness and the final deck geometry, such as the alignment of deck joints and the matching of stages in phased constructions projects. Due to the interactions between their various components, the behavior of curved and skewed tub-girder bridges is significantly more complex than that of straight bridges. When skewed supports are used in tub-girders, the interaction of the girder bending rotations and the displacement constraints induced by the skewed support diaphragms causes twisting of the girders at the supports. These twist rotations introduce additional torques into the system. Both curvature and skew can cause design and construction difficulties, especially at the supports, where the corresponding steel dead load deflections and the large torsional stiffness of the girders may lead to large fit-up forces. Currently, the general understanding of the level of sophistication of analysis models required to properly predict forces and deformations of curved and/or skewed bridges during construction is limited. The development of guidelines regarding the sufficiency of simplified methods of structural analysis is the overall motivation and objective of this dissertation. This research addresses the construction load effects due to skew and due to combined skew and curvature and develops design recommendations and analytical tools for the construction engineering of tub-girder bridges. The effects of skew and curvature are studied by examining the results for different levels of analysis for 18 representative bridges. These bridges reflect the range of bridge curvature and skew used in current practice. By comparing the output from simplified analysis methods to validated refined 3D FEA solutions, general conclusions are developed as to when the simplified methods provide sufficient results. An important original contribution of this research is that the data generated constitutes the first systematic study on a large set of curved and skewed tub-girder bridges using consistent refined 3D FEA models to model construction forces and deformations. As such, the results of this research can serve as a benchmark for current and future improvements in methods of analysis and design for the construction engineering of curved and skewed tub-girder bridges. In the current research, this data has been used in both straight and curved tub-girder bridges to: • Develop a simplified 1D analysis method to account for the effect of skew on girder twist rotations and internal torques, • Evaluate the effect of skew on component forces, and propose improved simplified procedures to capture these effects, • Identify interactions between components and develop improved simplified analysis methods to account for these effects, • Establish limits for when the improved 1D and 2D simplified methods of analysis are sufficient for construction engineering analysis, and • Identify sources of steel erection fit-up proble

Jimenez Chong, Juan Manuel

3

Performance-based seismic assessment of skewed bridges with and without considering soil-structure interaction effects for various site classes  

NASA Astrophysics Data System (ADS)

This study aims to investigate the behavior of skewed and straight highway overpass bridges both with and without taking into account the effects of Soil-Structure Interaction (SSI) due to near-fault ground motions. Both deterministic (i.e., pushover and nonlinear dynamic analyses) and probabilistic approaches were utilized. A set of response sensitivity analyses was performed considering various skew angles, column elements, and soil properties for bridge considered both as fixed-base and SSI models. It has been observed that as the skew angle increased, the bridge responded more severely to the ground motion. For instance, the deck rotation and shear-keys displacement increased with an increase in the skew angle. A modal pushover analysis was also performed in conjunction with the nonlinear dynamic analysis. It has been found that combining the bridge responses for various modes of vibration resulted in a relatively accurate seismic response compared to the nonlinear dynamic analysis while saving time and analysis cost, to a great extent. A probabilistic analysis was also performed considering record-to-record variability in ground motion, and a set of probabilistic seismic demand and fragility plots was generated. The effects of change in the skew angle and also SSI were studied to see various bridge responses. The damage probability increased especially with respect to deck rotation as the skew angle increased. The SSI had a decreasing effect on the overall response of the bridge with pile foundation.

Ghotbi, Abdoulreza

4

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

E-print Network

out-of- 18 plane distortions to concentrate in the unstiffened web gap and cause fatigue cracking. Figure 10 ? Proper diaphragm connection. Figure 11 ? Improper diaphragm connection. 19 Code Provisions ? Future ? Load and Resistance Factor ~D... Gir. Gir. 2 Gir. 3 ? 59? Gir. 4 Gir. 5 ? 0. 1 0. 2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Location Figure 24 ? Zero degree skew in the as-built condition bottom flange stresses. 48 plate to one which is 1-1/2 inch thick...

Crozier, Allen R

1992-01-01

5

Bridges  

MedlinePLUS

... is made to replace one or more missing teeth. Bridges can be supported in any of three ways: ... The dentist may also make impressions of the teeth. The bridge is placed at later visits. On average, bridges ...

6

Bridges  

NSDL National Science Digital Library

Bridges come in a wide variety of sizes, shapes, and lengths and are found all over the world. It is important that bridges are strong so they are safe to cross. Design and build a your own model bridge. Test your bridge for strength using a force sensor that measures how hard you pull on your bridge. By observing a graph of the force, determine the amount of force needed to make your bridge collapse.

2012-07-19

7

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.

2011-05-26

8

Skew chromaticity  

SciTech Connect

The on-momentum description of linear coupling between horizontal and vertical betatron motion is extended to include off-momentum particles, introducing a vector quantity called the ``skew chromaticity``. This vector tends to be long in large superconducting storage rings, where it restricts the available working space in the tune plane, and modifies collective effect stability criteria. Skew chromaticity measurements at the Cornell Electron Storage Ring (CESR) and at the Fermilab Tevatron are reported, as well as tracking results from the Relativistic Heavy Ion Collider (RHIC). The observation of anomalous head-tail beam Iowa new the tune diagonal in the Tevatron are explained in terms of the extended theory, including modified criteria for headtail stability. These results are confirmed in head-tail simulations. Sources of skew chromaticity are investigated.

Peggs, S.; Dell, G.F.

1994-12-31

9

Bridges  

NSDL National Science Digital Library

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

Leske, Cavin.

10

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 typesâarch, beam, truss and suspensionâstudents explore the effect of tensile and compressive forces. Students investigate the calculations that go into designing bridges; they learn about loads and cross-sectional areas by designing and testing the strength of model piers. Geology and soils are explored as they discover the importance of foundations, bearing pressure and settlement considerations in the creation of dependable bridges and structures. Students learn about brittle and ductile material properties. Students also learn about the many cost factors that comprise the economic considerations of bridge building. Bridges are unique challenges that take advantage of the creative nature of engineering.

Integrated Teaching And Learning Program

11

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.

2014-09-14

12

Quantum skew divergence  

NASA Astrophysics Data System (ADS)

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

Audenaert, Koenraad M. R.

2014-11-01

13

Quantum Skew Divergence  

E-print Network

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

Koenraad M. R. Audenaert

2014-08-30

14

12. Underside of Skew SpanHot Metal system on right, toward ...  

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

12. Underside of Skew Span-Hot Metal system on right, toward Rocker Bent. - Monongahela Connecting Railroad Company, Hot Metal Bridge, Spanning Monongahela River at mile post 3.1, Pittsburgh, Allegheny County, PA

15

3. VIEW SOUTHEAST VIEW OF EAST PORTAL SHOWING SKEW AND ...  

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

3. VIEW SOUTHEAST- VIEW OF EAST PORTAL SHOWING SKEW AND PORTAL BRACING. - National Docks Branch Bridge N.D.2F, Spans former Central Railroad of New Jersey , west of New Jersey Turnpike, north of Communipaw Avenue near Johnson Avenue, Jersey City, Hudson County, NJ

16

Skewed approach to filtering  

NASA Astrophysics Data System (ADS)

The dynamics of many physical system are nonlinear and non- symmetric. The motion of a missile, for example, is strongly determined by aerodynamic drag whose magnitude is a function of the square of speed. Conversely, nonlinearity can arise from the coordinate system used, such as spherical coordinates for position. If a filter is applied these types of system, the distribution of its state estimate will be non-symmetric. The most widely used filtering algorithm, the Kalman filter, only utilizes mean and covariance and odes not maintain or exploit the symmetry properties of the distribution. Although the Kalman filter has been successfully applied in many highly nonlinear and non- symmetric system, this has been achieved at the cost of neglecting a potentially rich source of information. In this paper we explore methods for maintaining and utilizing information over and above that provided by means and covariances. Specifically, we extend the Kalman filter paradigm to include the skew and examine the utility of maintaining this information. We develop a tractable, convenient algorithm which can be used to predict the first three moments of a distribution. This is achieved by extending the sigma point selection scheme of the unscented transformation to capture the mean, covariance and skew. The utility of maintaining the skew and using nonlinear update rules is assessed by examining the performance of the new filter against a conventional Kalman filter in a realistic tracking scenario.

Julier, Simon J.

1998-09-01

17

Skewed graph partitioning  

SciTech Connect

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

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

1997-02-01

18

Skewness of implanted ion profiles  

NASA Astrophysics Data System (ADS)

Skewness of implanted ion profiles is determined by extending the Biersack model to higher-order terms. Nuclear and electronic energy losses up to the fourth moment are included in the skewness equations to yield better results for any ion-target combination. The feasibility of the proposed skewness equations is examined using profiles of various ions implanted into target materials of up to two constituents. Calculated skewness values correlate well with experimental data. Kurtosis values calculated using Biersack's fitting formula also closely correspond to experimental data.

Liang, J. H.; Liao, K. Y.

19

Measuring Skewness: A Forgotten Statistic?  

ERIC Educational Resources Information Center

This paper discusses common approaches to presenting the topic of skewness in the classroom, and explains why students need to know how to measure it. Two skewness statistics are examined: the Fisher-Pearson standardized third moment coefficient, and the Pearson 2 coefficient that compares the mean and median. The former is reported in statistical…

Doane, David P.; Seward, Lori E.

2011-01-01

20

Locally adaptive document skew detection  

Microsoft Academic Search

This paper proposes a new approach to the detection of local orientation and skew in document images. It is based on the observation that there are many documents where a single global estimate of the page skew is not sufficient. These documents require local adaptation to deal robustly with todays complex configurations of components on the page. The approach attempts

Jaakko Sauvola; David S. Doermann; Matti Pietikainen

1997-01-01

21

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

22

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

E-print Network

FACTOR ANALYSIS FOR SKEWED DATA AND SKEW-NORMAL MAXIMUM LIKELIHOOD FACTOR ANALYSIS A Dissertation by BEVERLY JANE GAUCHER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... Beverly Jane Gaucher ABSTRACT This research explores factor analysis applied to data from skewed distributions for the general skew model, the selection-elliptical model, the selection-normal model, the skew-elliptical model and the skew-normal model...

Gaucher, Beverly Jane

2013-04-04

23

A novel skew estimation approach using radon transform  

Microsoft Academic Search

Skew is the angle the image makes with the corner of the page. Skew estimation is a preprocessing step in document image analysis. It involves two steps skew detection and skew correction. Skew estimation is needed because while scanning the document image a little skew is unavoidable. If skew is present in the document then Optical Character Recognizer (OCR) will

Prakash K. Aithal; G. Rajesh; P. C. Siddalingaswamy; Dinesh U. Acharya

2011-01-01

24

HOT METAL BRIDGE (NOTE: BUILDERS: JONES AND LAUGHLIN STEEL CA. ...  

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

HOT METAL BRIDGE (NOTE: BUILDERS: JONES AND LAUGHLIN STEEL CA. 1890), SOUTH PORTAL. THREE PIN CONNECTED CAMELBACK TRUSS SPANS, ONE SKEWED THROUGH TRUSS SPAN ON NORTH SIDE TRUSS BRIDGE, EAST OF HOT METAL BRIDGE BUILT BY AMERICAN BRIDGE COMPANY CA. 1910. (RIVETED MULTI-SPAN TRUSS). - Jones & Laughlin Steel Corporation, Pittsburgh Works, Morgan Billet Mill Engine, 550 feet north of East Carson Street, opposite South Twenty-seventh Street, Pittsburgh, Allegheny County, PA

25

Kinematic correction for roller skewing  

NASA Technical Reports Server (NTRS)

A theory of kinematic stabilization of rolling cylinders is developed for high-speed cylindrical roller bearings. This stabilization requires race and roller crowning to product changes in the rolling geometry as the roller shifts axially. These changes put a reverse skew in the rolling elements by changing the rolling taper. Twelve basic possible bearing modifications are identified in this paper. Four have single transverse convex curvature in the rollers while eight have rollers with compound transverse curvature composed of a central cylindrical band of constant radius surrounded by symmetric bands with both slope and transverse curvature.

Savage, M.; Loewenthal, S. H.

1980-01-01

26

Roller skewing measurements in cylindrical roller bearings  

NASA Technical Reports Server (NTRS)

Measurements of roller skewing in a 118 mm bore roller bearing operating at shaft speeds to 12,000 rpm are reported. High speed motion pictures of a modified roller were taken through a derotation prism to record skewing as the roller moved through loaded and unloaded regions of the bearing. Subsequent frame by frame measurement of the photographic film provided information on roller skewing. Radial and tangential skew amplitudes of 0.4 to 0.5 degrees were observed with 0.5 degree misalignment.

Nypan, L. J.

1981-01-01

27

Bridge permeameter  

DOEpatents

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

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

1996-01-01

28

Straw Bridges  

NSDL National Science Digital Library

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

Museum of Science and Industry, Chicago

2012-01-01

29

Application of the Grillage Methodology to Determine Load Distribution Factors for Spread Slab Beam Bridges  

E-print Network

Transverse load distribution behavior amongst bridge girders is influenced by many parameters including girder material properties, spacing, skew, deck design, and stiffening element interactions. In order to simply and conservatively approximate...

Petersen-Gauthier, Joel

2013-08-09

30

Popsicle Bridge  

NSDL National Science Digital Library

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

Ieee

2013-08-30

31

Spaghetti Bridge  

NSDL National Science Digital Library

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

K-12 Outreach Office,

32

Bridge permeameter  

DOEpatents

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

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

1996-08-13

33

Spaghetti Bridge  

NSDL National Science Digital Library

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

Cosi

2009-01-01

34

Designing Bridges  

NSDL National Science Digital Library

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

Integrated Teaching And Learning Program And Laboratory

35

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.

2013-01-01

36

Straw Bridges  

NSDL National Science Digital Library

Working as engineering teams, students design and create model beam bridges using plastic drinking straws and tape as their construction materials. Their goal is to build the strongest bridge with a truss pattern of their own design, while meeting the design criteria and constraints. They experiment with different geometric shapes and determine how shapes affect the strength of materials. Let the competition begin!

Integrated Teaching And Learning Program

37

Symmetry detection through local skewed symmetries  

E-print Network

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

Cham, Tat Jen

38

Handwritten text localization in skewed documents  

Microsoft Academic Search

In this paper a system for handwritten text localization in document images is proposed. Our system performs skew angle correction u sing Wigner-Ville distribution and localizes the handwritten areas of the document based on several measures concerning regularity in shape (self- correlation, horizontal and vertical symmetry) and in dimensions (aspect ratio, distribution of heights and widths). The proposed technique was

Ergina Kavallieratou; Doru-cristian Balcan; Maria-florina Popa; Nikos Fakotakis

2001-01-01

39

Preference patterns for skewed gambles in rhesus monkeys  

PubMed Central

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

Strait, Caleb E.; Hayden, Benjamin Y.

2013-01-01

40

Reproductive skew in the Australian allodapine bee Exoneura robusta  

Microsoft Academic Search

Uneven sharing of reproduction (reproductive skew) among members of a cooperative animal society is one of the key features associated with advanced sociality and task specialization. Allocation of reproduc- tion varies greatly among taxa, and reproductive skew models are evolutionary models that aim at explain- ing this variation. We tested reproductive skew theory using the Australian social allodapine bee Exoneura

PHILIPP LANGER; KATJA H OGENDOORN; MICHAEL P. S CHWARZ; LAURENT K ELLER

41

Hook lengths in a skew Young diagram Svante Janson  

E-print Network

Hook lengths in a skew Young diagram Svante Janson Department of Mathematics, Uppsala University PO some properties of the set of hook lengths for certain skew Young diagrams, using asymptotic obtained some properties of the set of hook lengths for certain skew Young diagrams. They prove the results

Janson, Svante

42

Hook lengths in a skew Young diagram Svante Janson  

E-print Network

Hook lengths in a skew Young diagram Svante of the set of hook lengths for certain skew Young diagrams, usi* *ng asymptotic calculations and Vershik [1] have recently obtained some properties of the set of hook* * lengths for certain skew Young

Janson, Svante

43

Seismic damage of highway bridges during the 2008 Wenchuan earthquake  

NASA Astrophysics Data System (ADS)

Many highway bridges were severely damaged or completely collapsed during the 2008 Wenchuan earthquake. A field investigation was carried out in the strongly affected areas and over 320 bridges were examined. Damage to some representative highway bridges is briefly described and a preliminary analysis of the probable causes of the damage is presented in this paper. The most common damage included shear-flexural failure of the pier columns, expansion joint failure, shear key failure, and girder sliding in the transversal or longitudinal directions due to weak connections between girder and bearings. Lessons learned from this earthquake are described and recommendations related to the design of curved and skewed bridges, design of bearings and devices to prevent girder collapse, and ductility of bridge piers are presented. Suggestions for future seismic design and retrofitting techniques for bridges in moderate to severe earthquake areas are also proposed.

Han, Qiang; Du, Xiuli; Liu, Jingbo; Li, Zhongxian; Li, Liyun; Zhao, Jianfeng

2009-06-01

44

Bridging Anticoagulation  

MedlinePLUS

... practical approach . Blood . 2011 ; 117 : 5044 – 5049 . FREE Full Text Spyropoulos AC . Bridging therapy and oral anticoagulation: current ... doi: 10.1161/CIRCULATIONAHA.111.084517 Extract Free » Full Text Free PDF Free Classifications Cardiology Patient Page Services ...

45

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

46

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. PMID:22943299

Alexander, Neal

2012-01-01

47

Linking Bridges  

NSDL National Science Digital Library

This blog post presents three puzzles which provide an opportunity for learners to use the strategy of trial and error and logical reasoning. The challenge is to connect all of the islands with bridges so that the number on the island corresponds to the number of bridges going to it or from it. This activity also provides the opportunity for students to be puzzle designers by including a blank grid page on which students can design their own versions of the puzzle to share with classmates.

Young, David

2014-01-28

48

Bridges, 1999.  

ERIC Educational Resources Information Center

This volume contains articles about writing, best practice, portfolio assessment, and technology, as well as original poetry and book reviews. Articles in the volume are: "Teaching Writing: Making Connections" (Eric Schott); "Empowering Teachers: A Success Story" (Sandra L. Krivak); "Bridging the Gap between the Classroom and Employment" (Linda C.…

Wilcox, Bonita; Manear, John; Slifkin, Josh M.

49

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

Microsoft Academic Search

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

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

2010-01-01

50

Paleomagnetic Poles From the Skewness of Marine Magnetic Anomalies  

NASA Astrophysics Data System (ADS)

The skewness of marine magnetic anomalies due to seafloor spreading depends strongly on the direction of the paleomagnetic field as oceanic lithosphere is created and cooled. Thus, anomaly skewness can be used to estimate paleoomagnetic poles and is attractive, in part, because the ages of the poles can easily be related to the geomagnetic polarity time scale. Here we review methods for determining paleomagnetic poles from anomaly skewness and examine the accuracy of the poles. A concern has been the influence of ``anomalous" skewness, recognized in pioneering studies of anomaly skewness (Cande 1976). Anomalous skewness can be thought of as a systematic difference between observed skewness and that expected from simple models of the marine magnetic source that assume vertical boundaries between reversals. Anomalous skewness is now understood to be the consequence of non-vertical curving reversal boundaries expected from the thermal and magmatic evolution of oceanic lithosphere (Dyment & Arkani-Hamed 1995). Anomalous skewness depends on spreading rate if spreading is slow, but is independent of spreading rate if spreading is fast (Dyment & Arkani-Hamed 1995). The profiles we examine for paleomagnetic analysis dominantly record fast spreading and thus we are able to approximate anomalous skewness as being independent of spreading rate. We can therefore treat anomalous skewness as a third adjustable parameter, along with pole latitude and pole longitude, when determining paleomagnetic poles from skewness estimates. At any one crossing of a magnetic anomaly, local effects could cause the estimate of the paleomagnetic direction to be in error. Aside from anomalous skewness, however, errors in skewness estimates are expected to be uncorrelated from site to site except at exceptionally closely spaced sites. Thus we can treat misfits as independent random errors and reduce the statistical error in the pole position by obtaining many estimates of skewness from widely separated sites. The plate geometry of the Pacific plate throughout much of Late Cretaceous and Tertiary time, in particular the long north-south-striking paleo-East Pacific Rise, provides a nearly ideal geometry for recording critical information on the location of Pacific plate paleomagnetic poles. Moreover, a large skewness gradient with paleolatitude is expected, which helps to limit the location and, to a lesser degree, the strike of the paleoequator and thus strongly constrains the pole. If the accuracy of all skewness estimates is uniform, estimates of skewness near the paleo-equator can be shown to contain much more information than those from higher paleo-latitudes. On total-intensity magnetic profiles the amplitudes of anomalies near the paleo-equator are very low and likely have higher than average uncertainties. On vector aeromagnetic profiles, however, clear anomalies are recorded near the paleo-equator and provide strong constraints on the pole position. The assumptions made in determining paleomagnetic poles from skewness are subject to several critical tests including comparisons of anomalous skewness estimated from the single-plate method with those determined from cross-ridge analysis, comparisons with other skewness poles of similar age, and comparisons with poles determined from other types of paleomagnetic data. We present several such tests and show that the skewness results pass all these tests of consistency. Thus, there are many reasons to believe that poles determined from skewness give unbiased and accurate paleomagnetic poles.

Horner-Johnson, B. C.; Gordon, R. G.

2005-12-01

51

Digital Bridges: Bridges of the Nineteenth Century  

NSDL National Science Digital Library

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

2002-01-01

52

Level II scour analysis for Bridge 28 (BRNATH00660028) on Town Highway 66, crossing Locust Creek, Barnard, Vermont  

USGS Publications Warehouse

The Town Highway 66 crossing of the Locust Creek is a 41-ft-long, one-lane bridge consisting of a 39 ft steel stringer type bridge with a concrete deck (Vermont Agency of Transportation, written communication, August 24, 1994). The clear span is 36.8 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The upstream right wingwall is protected by stone fill. The channel is skewed approximately 10 degrees to the opening while the open

Severence, Timothy

1997-01-01

53

GC skew and mitochondrial origins of replication.  

PubMed

The comprehensive understanding of mitochondrial genome evolution requires a detailed mechanistic picture of mitogenomic replication. Despite many previous efforts it has remained a non-trivial problem to determine the origins of replication and trace their fate across rearrangements of the gene order even in the small genomes of animal mitochondria. We elaborate here on the observation that the GC skew is correlated with the distance from the replication origins. This effect has been explained as a consequence of the standard model of mitochondrial DNA replication, i.e. the strand displacement model. According to this model chemical damage accumulates proportional to the duration that DNA is exposed in single-stranded form during replication (Dssh) which depends on the relative position with respect to the replication origins. Based on this model we developed a computational method to infer the positions of both the heavy strand and the light strand origin from nucleotide skew data. In a comprehensive survey of deuterostome mitochondria we infer conserved replication origins for the vast majority of vertebrates and cephalochordates. Deviations from the consensus picture are presumably associated with genome rearrangements. PMID:24911382

Sahyoun, Abdullah H; Bernt, Matthias; Stadler, Peter F; Tout, Kifah

2014-07-01

54

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)). PMID:23966192

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

2013-01-01

55

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

56

Building Bridges  

NSDL National Science Digital Library

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

Roger Day

2000-01-01

57

Skew correction of business card images in PDA  

Microsoft Academic Search

We present an efficient algorithm for skew correction of business card images obtained by a PDA camera. -The proposed method is composed of four parts: block adaptive binarization (BAB), stripe generation, skew angle calculation, and image rotation. In the BAB, an input image is binarized block by block so as to lessen the effects of irregular illumination and shadows over

Jun Hyo Park; Ick Hoon Jang; Nam Chul Kim

2003-01-01

58

Learning a Novel Pattern through Balanced and Skewed Input  

ERIC Educational Resources Information Center

This study compared the effectiveness of balanced and skewed input at facilitating the acquisition of the transitive construction in Esperanto, characterized by the accusative suffix "-n" and variable word order (SVO, OVS). Thai university students (N = 98) listened to 24 sentences under skewed (one noun with high token frequency) or…

McDonough, Kim; Trofimovich, Pavel

2013-01-01

59

EXPLOSION POINTS IN SKEW MAPS Anne Stefanie Costolanski  

E-print Network

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

Sander, Evelyn

60

Analysis of carbon dioxide concentration skewness at a rural site.  

PubMed

This paper provides evidence that symmetry of CO2 concentration distribution may indicate sources or dispersive processes. Skewness was calculated by different procedures with CO2 measured at a rural site using a Picarro G1301 analyser over a two-year period. The usual skewness coefficient was considered together with fourteen robust estimators. A noticeable contrast was obtained between day and night, and skewness decreased linearly with the logarithm of the height. One coefficient was selected from its satisfactory relationship with the median concentration in daily evolution. Three analyses based on the kernel smoothing method were conducted with this coefficient to investigate its response to yearly and daily evolutions, wind direction, and wind speed. Left-skewed distributions were linked to thermal turbulence during midday, especially in spring-summer, or with high wind speeds. Almost symmetric distributions were associated with sources, such as the Valladolid City plume reinforced with spring emissions and the lack of emissions in summer in the remaining directions. Finally, right-skewed distributions were related to low wind speeds and stable stratification at night, furthered by strong emissions in spring. Skewness intervals were proposed and their average median concentrations were calculated such that the relationship between skewness and concentration depends on the analysis performed. Since some skewness coefficients may also be negative, they provide better information about sources or dispersive processes than concentration. PMID:24463252

Pérez, Isidro A; Sánchez, M Luisa; García, M Ángeles; Ozores, Marta; Pardo, Nuria

2014-04-01

61

Multivariate Skew-t Distributions in Econometrics and Environmetrics  

E-print Network

(?). The extended skew-normal density (2.8) is a special case of (2.10) with the normal generator function g(2)(v) = 12pie?v/2. When ?u = 0, (2.10) reduces to the family of skew-elliptical distributions studied by Branco and Dey (2001). We can use this more...

Marchenko, Yulia V.

2012-02-14

62

A Method for Controlling Skew on Linked Surfaces  

SciTech Connect

A new method for lessening skew in mapped meshes is presented. This new method involves progressive subdivision of a surface into loops consisting of four sides. Using these loops, constraints can then be set on the curves of the surface, which will propagate interval assignments across the surface, allowing a mesh with a better skew metric to be generated.

BENZLEY,STEVEN E.; KERR,ROBERT A.; MITCHELL,SCOTT A.; WHITE,DAVID R.

1999-09-27

63

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

64

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

65

Circulant and skew-circulant splitting methods for Toeplitz systems  

NASA Astrophysics Data System (ADS)

We study efficient iterative methods for Toeplitz systems based on the circulant and skew-circulant splitting (CSCS) of the Toeplitz matrix. Theoretical analysis show that if the circulant and the skew-circulant splitting matrices are positive definite, then the CSCS method converges to the unique solution of the system of linear equations. Moreover, we derive an upper bound of the contraction factor of the CSCS iteration which is dependent solely on the spectra of the circulant and the skew-circulant matrices involved. Numerical examples are presented to demonstrate the method.

Ng, Michael K.

2003-10-01

66

Level II scour analysis for Bridge 25 (BRNATH00290034) on Town Highway 29, crossing Locust Creek, Barnard, Vermont  

USGS Publications Warehouse

The Town Highway 29 crossing of Locust Creek is a 37-ft-long, one-lane bridge consisting of one 32-foot concrete span (Vermont Agency of Transportation, written communication, August 23, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 25 degrees to the opening while the opening-skew-to-roadway is 25 degrees. There was no observable scour protection measure at the site. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.

Ivanoff, Michael A.; Weber, Matthew A.

1996-01-01

67

PRINCIPLE OF SKEW QUADRUPOLE MODULATION TO MEASURE BETATRON COUPLING.  

SciTech Connect

The measurement 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 different skew quadrupole families the two eigentunes are precisely measured with the phase lock loop system. The projections of the residual coupling coefficient onto the skew quadrupole coupling modulation directions are determined. The residual linear coupling could be corrected according to the measurement. An analytical solution for skew quadrupole modulation based on Hamiltonian perturbation approximation is given, and simulation code using smooth accelerator model is also developed. Some issues concerning the practical applications of this technique are discussed.

LUO.Y.PILAT,F.ROSER,T.ET AL.

2004-07-05

68

Rates of Convergence of Extremes from Skew Normal Samples  

E-print Network

. 1 Introduction The biggest weakness of the normal distribution is its inability to model skewed data degradation in nanoscale transistors by using reaction-diffusion and percolation theory (Islam and Alam, 2011

Sidorov, Nikita

69

Skewed paternity and sex allocation in hermaphroditic plants and animals.  

PubMed Central

Models predict a reduced allocation to sperm when females preferentially use one of two males' sperm and the males do not know who is favoured. An analogous discounting occurs in plants when their paternity success is skewed by random, non-heritable factors such as location in the population and pollinator behaviour. We present a model that shows that skewed paternity can affect the sex allocation of hermaphrodites, that is it leads to a female-biased investment. The model highlights the close links between local mate competition and sperm competition. We use paternity data from Ficus in order to illustrate that skews in paternity success can lead to a high degree of sibling gamete competition in an apparently open breeding system. Since skews in paternity are ubiquitous in hermaphroditic plants and animals these findings should apply broadly. PMID:11600078

Greeff, J. M.; Nason, J. D.; Compton, S. G.

2001-01-01

70

Vibration of skewed cantilever plates and helicoidal shells  

NASA Technical Reports Server (NTRS)

Theoretical vibration frequencies and mode shapes are obtained for skewed plates and helicoidal shells with a cantilever boundary. Using Hamilton's law of varying action, a power series solution is developed to obtain converged numerical results for the five lowest frequencies. Effects of geometrical variables such as aspect ratio, sweep angle and shell radius to thickness ratio are investigated. Accuracy of the solution method is substantiated by comparison with existing skewed plate spherical cap, and conical shell results.

Beres, D. P.; Bailey, C. D.

1975-01-01

71

Extension of EMA to address regional skew and low outliers  

USGS Publications Warehouse

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

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

2003-01-01

72

Bridging the Gaps  

NSDL National Science Digital Library

Students are presented with a brief history of bridges as they learn about the three main bridge types: beam, arch and suspension. They are introduced to two natural forces — tension and compression — common to all bridges and structures. Throughout history, and today, bridges are important for connecting people to resources, places and other people. Students become more aware of the variety and value of bridges around us in our everyday lives.

2014-09-18

73

Bridging consent: from toll bridges to lift bridges?  

PubMed Central

Background The ability to share human biological samples, associated data and results across disease-specific and population-based human research biobanks is becoming increasingly important for research into disease development and translation. Although informed consent often does not anticipate such cross-domain sharing, it is important to examine its plausibility. The purpose of this study was to explore the feasibility of bridging consent between disease-specific and population-based research. Comparative analyses of 1) current ethical and legal frameworks governing consent and 2) informed consent models found in disease-specific and population-based research were conducted. Discussion Ethical and legal frameworks governing consent dissuade cross-domain data sharing. Paradoxically, analysis of consent models for disease-specific and population-based research reveals such a high degree of similarity that bridging consent could be possible if additional information regarding bridging was incorporated into consent forms. We submit that bridging of consent could be supported if current trends endorsing a new interpretation of consent are adopted. To illustrate this we sketch potential bridging consent scenarios. Summary A bridging consent, respectful of the spirit of initial consent, is feasible and would require only small changes to the content of consents currently being used. Under a bridging consent approach, the initial data and samples collection can serve an identified research project as well as contribute to the creation of a resource for a range of other projects. PMID:21970509

2011-01-01

74

A Longitudinal Twin Study of Skewed X Chromosome-Inactivation  

PubMed Central

X-chromosome inactivation (XCI) is a pivotal epigenetic mechanism involved in the dosage compensation of X-linked genes between males and females. In any given cell, the process of XCI in early female development is thought to be random across alleles and clonally maintained once established. Recent studies, however, suggest that XCI might not always be random and that skewed inactivation may become more prevalent with age. The factors influencing such XCI skewing and its changes over time are largely unknown. To elucidate the influence of stochastic, heritable and environmental factors in longitudinal changes in XCI, we examined X inactivation profiles in a sample of monozygotic (MZ) (n?=?23) and dizygotic (DZ) (n?=?22) female twin-pairs at ages 5 and 10 years. Compared to MZ twins who were highly concordant for allelic XCI ratios, DZ twins showed much lower levels of concordance. Whilst XCI patterns were moderately stable between ages 5 and 10 years, there was some drift over time with an increased prevalence of more extreme XCI skewing at age 10. To our knowledge, this study represents the earliest longitudinal assessment of skewed XCI patterns, and suggests that skewed XCI may already be established in early childhood. Our data also suggest a link between MZ twinning and the establishment of allelic XCI ratios, and demonstrate that acquired skewing in XCI after establishment is primarily mediated by stochastic mechanisms. These data have implications for our understanding about sex differences in complex disease, and the potential causes of phenotypic discordance between MZ female twins. PMID:21445353

Wong, Chloe Chung Yi; Caspi, Avshalom; Williams, Benjamin; Houts, Renate; Craig, Ian W.; Mill, Jonathan

2011-01-01

75

Surfacing of concrete bridges  

Microsoft Academic Search

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

Vibeke Wegan

76

A Pieri rule for skew shapes Sami H. Assaf1  

E-print Network

A Pieri rule for skew shapes Sami H. Assaf1 Department of Mathematics, Massachusetts Institute, Lewisburg, PA 17837, USA Abstract The Pieri rule expresses the product of a Schur function and a single row Schur function in terms of Schur functions. We extend the classical Pieri rule by expressing the product

McNamara, Peter

77

LOCAL LIMIT THEOREM FOR NONUNIFORMLY PARTIALLY HYPERBOLIC SKEW-PRODUCTS  

E-print Network

LOCAL LIMIT THEOREM FOR NONUNIFORMLY PARTIALLY HYPERBOLIC SKEW-PRODUCTS AND FAREY SEQUENCES S both the central limit and local limit theorems. These results apply to a random walk related . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 4. Strategy and tools for the local limit theorem . . . . . . . . . . . . . . . 225 5. Proof

Gouëzel, Sébastien

78

Casting with Skewed Ejection Direction Hee-Kap Ahn1  

E-print Network

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

Cheng, Siu-Wing

79

SECOND QUANTISATION FOR SKEW CONVOLUTION PRODUCTS OF INFINITELY DIVISIBLE MEASURES  

E-print Network

. A Borel measurable mapping T : E1 E2 is called a skew map for the pair (1, 2) if there exists a Radon is the Dirac measure concentrated at the point E, is a centred Gaussian Radon measure on E, and ~es AND JAN VAN NEERVEN Abstract. Suppose 1 and 2 are infinitely divisible Radon measures on real Banach

Applebaum, David

80

Bifocal Sampling for Skew-Resistant Join Size Estimation  

E-print Network

Bifocal Sampling for Skew-Resistant Join Size Estimation Sumit Ganguly Rutgers University sumit, a new technique for estimating the size of an equi-join of two relations. Bifocal sampling classi es. The algorithm requires a sample of size at most O( pn lgn). By contrast, previous algorithms using a sample

Matias, Yossi

81

Bifocal Sampling for Skew-Resistant Join Size Estimation  

E-print Network

Bifocal Sampling for Skew-Resistant Join Size Estimation Sumit Ganguly Phillip B. Gibbons Rutgers bifocal sampling, a new technique for estimating the size of an equi-join of two relations. Bifocal consisting of n tuples. The algorithm requires a sample of size at most O(W Ig n). By contrast, previous

Gibbons, Phillip B.

82

Effects of skew and demagnetizing fields on NDRO performance  

Microsoft Academic Search

Limitations placed upon the NDRO performance of a magnetic film memory device by the detrimental effects of skew and demagnetizing fields are investigated. An expression has been derived that relates these effects to the NDRO critical magnetization angle for devices whose rotational switching can be characterized by a Stoner-Wohlfarth switching astroid. Experimental results for typical devices are presented that substantiate

N. Logue

1969-01-01

83

A Longitudinal Twin Study of Skewed X Chromosome-Inactivation  

Microsoft Academic Search

X-chromosome inactivation (XCI) is a pivotal epigenetic mechanism involved in the dosage compensation of X-linked genes between males and females. In any given cell, the process of XCI in early female development is thought to be random across alleles and clonally maintained once established. Recent studies, however, suggest that XCI might not always be random and that skewed inactivation may

Chloe Chung Yi Wong; Avshalom Caspi; Benjamin Williams; Renate Houts; Ian W. Craig; Jonathan Mill; Catherine Suter

2011-01-01

84

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.

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

1998-01-01

85

Root waving and skewing: unexpectedly in micro-g.  

PubMed

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

Roux, Stanley J

2012-01-01

86

A Fast Skew Correction Technique for Camera Captured Business Card Images  

Microsoft Academic Search

Performance of an optical character recognition engine may be affected if the images are skewed and distorted due to perspective projection. In this paper, a computationally efficient skew correction technique has been presented for extracted text regions from business card images. The skew angle is estimated by analyzing the bottom and\\/or top profiles (height\\/depth from a horizontal base line) of

A. F. Mollah; S. Basu; N. Das; R. Sarkar; M. Nasipuri; M. Kundu

2009-01-01

87

Weak-field magnetoresistance coefficients and the related magnetoresistance skewness effect  

E-print Network

49 Weak-field magnetoresistance coefficients and the related magnetoresistance skewness effect D. S the magnetoresistance skewness effect. A comparison with the classical method is also presented to indicate simplified and a new effect is risen, the magnetoresistance skewness (MRS) effect. This effect is expected

Paris-Sud XI, Université de

88

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

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

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

89

Bridging spinal cord injuries  

E-print Network

Minireview Bridging spinal cord injuries James W Fawcett Address: Cambridge University Centre for Brain Repair, Robinson Way, Cambridge CB2 0PY, UK. Email: jf108@cam.ac.uk Repair of the injured spinal cord has been one of the great quests... why not transplant Abstract One strategy for spinal cord injury repair is to make cellular bridges that support axon regeneration. However, the bridging cells often fail to integrate with host tissue and may lead to increased pain sensitivity. Recent...

2008-10-15

90

Semiconductor bridge (SCB) detonator  

DOEpatents

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

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

1999-01-19

91

Skew Divergence-Based Fuzzy Segmentation of Rock Samples  

NASA Astrophysics Data System (ADS)

Digital image segmentation is a process in which one assigns distinct labels to different objects in a digital image. The MOFS (Multi Object Fuzzy Segmentation) algorithm has been successfully applied to the segmentation of images from several modalities. However, the traditional MOFS algorithm fails when applied to images whose composing objects are characterized by textures whose patterns cannot be successfully described by simple statistics computed over a very restricted area. Here, we present an extension of the MOFS algorithm that achieves the segmentation of textures by employing adaptive affinity functions that use the Skew Divergence as a measure of distance between two distributions. These affinity functions are called adaptive because their associated area (neighborhood) changes according to the characteristics of the texture being processed. We performed experiments on mosaic images composed by combining rock sample images which show the effectiveness of the adaptive skew divergence based fuzzy affinity functions.

Carvalho, Bruno M.; Garduño, Edgar; Santos, Iraçú O.

2014-03-01

92

Universal relation between skewness and kurtosis in complex dynamics  

NASA Astrophysics Data System (ADS)

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

Cristelli, Matthieu; Zaccaria, Andrea; Pietronero, Luciano

2012-06-01

93

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. PMID:21297889

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

2011-01-01

94

Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers  

PubMed Central

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

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

2014-01-01

95

Flexible modeling of longitudinal highly-skewed outcomes  

PubMed Central

The analysis of data from epidemiologic and environmental studies present challenges such as skewness of distribution, rounding and multiple measurements over time. To model trends over time based on repeated measurements, we propose a general latent model suitable for highly skewed data. The model assumes that the observed outcome is determined by an unobservable outcome which follows a Weibull distribution. To accommodate correlations among repeated responses over time, we introduce a general random effect from the power variance function (PVF) family of distributions, including the gamma distribution often employed in the literature. The resulting marginal likelihood has a closed form without resorting to numerical or approximation methods. We study estimation and hypothesis testing under these models, with different choices of random effect distributions. Simulation studies are conducted to evaluate their performance. Finally, we apply the proposed method to exposure data collected from the Michigan polybrominated biphenyl (MIPBB) study. PMID:19856304

Chen, Huichao; Manatunga, Amita K.; Lyles, Robert H.; Peng, Limin; Marcus, Michele

2010-01-01

96

10. DETAIL VIEW OF BRIDGE DATEPLATE WHICH READS 'WISCONSIN BRIDGE ...  

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

10. DETAIL VIEW OF BRIDGE DATEPLATE WHICH READS 'WISCONSIN BRIDGE & IRON COMPANY, MILWAUKEE, WIS., 1933' - St. Francis River Bridge, Spanning St. Francis River at U.S. Highway 70, Forrest City, St. Francis County, AR

97

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

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

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

98

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

99

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

100

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

101

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

102

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

103

Linear Waste of Best Fit Bin Packing on Skewed Distributions  

E-print Network

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

Kenyon, Claire

104

Symmetries of the Dirac operator with skew-symmetric torsion  

E-print Network

In this paper, we consider the symmetries of the Dirac operator derived from a connection with skew-symmetric torsion. We find that the generalized conformal Killing-Yano tensors give rise to symmetry operators of the massless Dirac equation, provided an explicitly given anomaly vanishes. We show that this gives rise to symmetries of the Dirac operator in the case of strong Kahler with torsion (KT) and strong hyper-Kahler with torsion (HKT) manifolds.

Tsuyoshi Houri; David Kubiznak; Claude Warnick; Yukinori Yasui

2010-02-18

105

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

106

Finite Element Modeling of the Skew Rolling Process  

NASA Astrophysics Data System (ADS)

A helical skew rolling process is a continuous hot forming process that produces near net-shape parts from tubing for hard turning or machining to the finished parts. The process can challenge forging processes in a number of applications by its high production rate and ability of forming intricate geometry. Because of its technical complexity, a number of tests have to be performed to improve and validate the design before a part can be put into production. To reduce the design lead-time and cost as well as improving the production quality, developing and implementing the finite element analysis procedures in design is an inevitable step. In literature, it has not been seen that the numerical simulation is applied to the skew rolling process so far. Simulation of the skew rolling is in a complicated three-dimensional metal large-deformation category, characterized by its severe mesh distortion and consistent contact and separation between the workpiece and dies. This paper describes the new development in finite element modeling of the skew rolling process and demonstrates the application of finite element modeling to aid the design of tooling and process parameters. By the use of the DEFORM-3D finite element program, the simulations can predict the geometry and some defects in parts reasonably well agreed with the actual products. However, one of the key issues is simulation time due to the nature of the nonlinear finite element method and the Lagrangian formulation adopted in the DEFORM-3D program. Solving nonlinear algebraic equations in each time step combined with iterative procedures is very computationally demanding and time consuming. Repeatedly reduction in time step size to satisfy the contact criterion prolongs the simulation significantly. Therefore, the improvement in the finite element theories and solving methods is necessary before the simulation can achieve reasonable timing.

He, Ming; Sawamiphakdi, Krich; Perez, Anthony J.; Daiger, Kevin P.

2004-06-01

107

Head-position-dependent Adaptation of Nonconcomitant Vertical Skew  

Microsoft Academic Search

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

JAMES S. MAXWELL; CLIFTON M. SCHOR

108

Head-position-dependent Adaptation of Nonconcomitant Vertical Skew  

Microsoft Academic Search

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

JAMES S MAXWELL; CLIFTON M SCHOR

1997-01-01

109

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

110

The structure of skew products with ergodic group automorphisms  

Microsoft Academic Search

We prove that ergodic automorphisms of compact groups are Bernoulli shifts, and that skew products with such automorphisms\\u000a are isomorphic to direct products. We give a simple geometric demonstration of Yuzvinskii’s basic result in the calculation\\u000a of entropy for group automorphisms, and show that the set of possible values for entropy is one of two alternatives, depending\\u000a on the answer

D. A. Lind

1977-01-01

111

Local Influence Analysis for Skew-Normal Linear Mixed Models  

Microsoft Academic Search

In this article, we consider local influence analysis for the skew-normal linear mixed model (SN-LMM). As the observed data log-likelihood associated with the SN-LMM is intractable, Cook's well-known approach cannot be applied to obtain measures of local influence. Instead, we develop local influence measures following the approach of Zhu and Lee (2001). This approach is based on the use of

Lourdes C. Montenegro; Victor H. Lachos; Heleno Bolfarine

2009-01-01

112

Incorporating Skew into RMS Surface Roughness Probability Distribution  

NASA Technical Reports Server (NTRS)

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

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

2013-01-01

113

Kurtosis, skewness, and non-Gaussian cosmological density perturbations  

NASA Technical Reports Server (NTRS)

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

Luo, Xiaochun; Schramm, David N.

1993-01-01

114

Validation of an Acoustic Impedance Prediction Model for Skewed Resonators  

NASA Technical Reports Server (NTRS)

An impedance prediction model was validated experimentally to determine the composite impedance of a series of high-aspect ratio slot resonators incorporating channel skew and sharp bends. Such structures are useful for packaging acoustic liners into constrained spaces for turbofan noise control applications. A formulation of the Zwikker-Kosten Transmission Line (ZKTL) model, incorporating the Richards correction for rectangular channels, is used to calculate the composite normalized impedance of a series of six multi-slot resonator arrays with constant channel length. Experimentally, acoustic data was acquired in the NASA Langley Normal Incidence Tube over the frequency range of 500 to 3500 Hz at 120 and 140 dB OASPL. Normalized impedance was reduced using the Two-Microphone Method for the various combinations of channel skew and sharp 90o and 180o bends. Results show that the presence of skew and/or sharp bends does not significantly alter the impedance of a slot resonator as compared to a straight resonator of the same total channel length. ZKTL predicts the impedance of such resonators very well over the frequency range of interest. The model can be used to design arrays of slot resonators that can be packaged into complex geometries heretofore unsuitable for effective acoustic treatment.

Howerton, Brian M.; Parrott, Tony L.

2009-01-01

115

Reproductive skew and split sex ratios in social Hymenoptera.  

PubMed

I present a model demonstrating that, in social Hymenoptera, split sex allocation can influence the evolution of reproductive partitioning (skew). In a facultatively polygynous population (with one to several queens per colony), workers vary in their relative relatedness to females (relatedness asymmetry). Split sex-ratio theory predicts that workers in monogynous (single-queen) colonies should concentrate on female production, as their relatedness asymmetry is relatively high, whereas workers in the polygynous colonies should concentrate on male production, as their relatedness asymmetry is relatively low. By contrast, queens in all colonies value males more highly per capita than they value females, because the worker-controlled population sex ratio is too female-biased from the queens' standpoint. Consider a polygynous colony in a facultatively polygynous population of perennial, social Hymenoptera with split sex ratios. A mutant queen achieving reproductive monopoly would gain from increasing her share of offspring but, because the workers would assess her colony as monogynous, would lose from the workers rearing a greater proportion of less-valuable females from the colony's brood. This sets an upper limit on skew. Therefore, in social Hymenoptera, skew evolution is potentially affected by queen-worker conflict over sex allocation. PMID:11761072

Bourke, A F

2001-10-01

116

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

117

Precision bolometer bridge  

NASA Technical Reports Server (NTRS)

Prototype precision bolometer calibration bridge is manually balanced device for indicating dc bias and balance with either dc or ac power. An external galvanometer is used with the bridge for null indication, and the circuitry monitors voltage and current simultaneously without adapters in testing 100 and 200 ohm thin film bolometers.

White, D. R.

1968-01-01

118

Bridge Program Planning Guide  

NSDL National Science Digital Library

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

Jenkins, Davis

119

Bryce Canyon Natural Bridge  

USGS Multimedia Gallery

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

120

Virtual Bridge Design Challenge  

ERIC Educational Resources Information Center

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

Mitts, Charles R.

2013-01-01

121

STEM Bridge Scholarship Program  

E-print Network

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

Buehrer, R. Michael

122

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

123

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

124

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

125

VIEW OF BRIDGE, LOOKING SOUTHWEST, WITH SOUTHERN PACIFIC RAILROAD BRIDGE ...  

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

VIEW OF BRIDGE, LOOKING SOUTHWEST, WITH SOUTHERN PACIFIC RAILROAD BRIDGE IN BACKGROUND. THE PAVEMENT OF THE NORTH APPROACH IS SEEN BURIED ON THE RIGHT. ROADWAY (CENTER) CROSSES THE USUALLY DRY CHANNEL OF THE SALT RIVER. A BALUSTRADE OF THE MILL AVENUE BRIDGE IS SEEN AT THE LOWER LEFT CORNER - Ash Avenue Bridge, Spanning Salt River at Foot of Ash Avenue, Tempe, Maricopa County, AZ

126

Light transmission for polymer fibers using skew and meridional rays  

NASA Astrophysics Data System (ADS)

This dissertation is concerned with the development of a light transmission model for polymer optical fibers having application in hybrid solar lighting (HSL) systems. Conceptually, the HSL system consists of a solar collector/receiver that focuses concentrated visible solar light onto a polymer optical fiber (up to 10-m-long) that transports the solar light to an interior space. For this study, the polymer optical fiber is a large-core (0.2-40 mm diameter) plastic optical fiber (POF) comprised of various lengths of straight and bent sections. Although there has been extensive research on the transmission of monochromatic light through optical fibers for the communications industry, there are relatively few publications for visible light transmission through POFs. These publications were critically reviewed in this research. It is shown that the light transmission can be described with either skew or meridional rays. For each ray type, the HSL system light transmission was determined as a function of fiber geometrical properties (core and cladding radii, bend radius, bend angle, and fiber length) and optical properties (core and clad refractive indices, absorption and scattering coefficients, core-clad rms roughness height, and core-clad interface defects loss coefficient). To do this, first, models were developed for separate straight and bent sections for multiple skew and meridional rays. Second, the straight and bent models were combined into a FORTRAN simulation program for an arbitrary fiber with a combination of arbitrary straight and bent sections. The input condition of the rays (arrangement of rays, incident angle, and intensity profile) is user-defined. Third, the simulation results were experimentally validated using two different POFs, twelve configurations of straight and bent fiber subsystems, and two ray types. These experimental comparisons show that the transmission model using meridional rays is slightly better than that with the skew rays. But the skew ray model predicted a higher transmission through the bent sections for angular uniform and angular reverse Gaussian intensity profiles. However, both ray types predicted the experimental light transmission to within +/-10%. A series of subsystems-level parametric sensitivity analyses has been included to indicate the direction of the light transmission change with the increase or decrease of one parameter around an operational point. It is shown that Rayleigh scattering, core-cladding interface roughness, interface defects, and bulk absorption are the dominate loss mechanisms on the straight section. It is hoped that the present model will eventually be used to aid in the design of HSL systems.

Tekelioglu, Murat

127

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

128

Exponential speed of mixing for skew-products with singularities  

NASA Astrophysics Data System (ADS)

Let f?:?[0, 1]\\{1/2} × [0, 1] ? [0, 1] × [0, 1] be the C? endomorphism given by f(x,y)=( 2x-\\lfloor 2x\\rfloor, \\, y+ \\frac{c}{|x-1/2|}-\\lfloor y+ \\frac{c}{|x-1/2|} \\rfloor ),\\; c\\in I\\!\\!R^+\\, . We prove that f is topologically mixing and if c > 1/4 then f is mixing with respect to the Lebesgue measure. Furthermore the speed of mixing is exponential. This skew-product can be seen as a toy model related to Lorenz-like attractors.

Markarian, R.; Pacifico, M. J.; Vieitez, J. L.

2013-01-01

129

Bridge : an unraveled architecture  

E-print Network

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

ElHusseiny, Ahmed

2006-01-01

130

The Königsberg Bridge Problem  

NSDL National Science Digital Library

This article, written for middle grades students, relates the history of the famous Konigsberg Bridge problem and introduces the idea of networks and paths that do not retrace themselves. The article concludes with a path the student must work out.

2011-01-01

131

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.

WGBH Educational Foundation

2007-08-09

132

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.

133

Onyx Bridg e Volcanology  

E-print Network

Carso n Oregon Onyx Bridg e Cascad e Willamette University etuhcseDs BEECH Boyn itseuHs Volcanology (Turns into Franklin Blvd) 6. Continue on Franklin Blvd until you reach Onyx. 7. Turn right into the Onyx

134

Rapid bridge deck replacement  

E-print Network

replacement time as well as traffic interference. An experimental study consisting of static load tests on a 1/3 scale model of a 60-ft-long steel I-girder bridge with precast concrete panels connected with epoxy mortar and shear connectors to accomplish... bridge structures. These methods essentially involve use of epoxy mortar and standard welded shear connectors. The overall method appears to be viable and econom1cal. However, several serious questions, especially regarding structural behav1 or...

Osegueda, Roberto Alejandro

2012-06-07

135

Bridges and Pictures  

Microsoft Academic Search

At the age of 15, with the first single-lens reflex camera of my very own, I naturally took shots of the area around my parent’s\\u000a house. That included the bridge across the Elbe-Trave Canal. I crossed this bridge every day on the way to school and I could\\u000a see it from my room. Of course, it would be going too

Wilfried Dechau

136

Germ Cell Intercellular Bridges  

PubMed Central

Stable intercellular bridges are a conserved feature of gametogenesis in multicellular animals observed more than 100 years ago, but their function was unknown. Many of the components necessary for this structure have been identified through the study of cytokinesis in Drosophila; however, mammalian intercellular bridges have distinct properties from those of insects. Mammalian germ cell intercellular bridges are composed of general cytokinesis components with additional germ cell–specific factors including TEX14. TEX14 is an inactive kinase essential for the maintenance of stable intercellular bridges in gametes of both sexes but whose loss specifically impairs male meiosis. TEX14 acts to impede the terminal steps of abscission by competing for essential component CEP55, blocking its interaction in nongerm cells with ALIX and TSG101. Additionally, TEX14-interacting protein RBM44, whose localization in stabile intercellular bridges is limited to pachytene and secondary spermatocytes, may participate in processes such as RNA transport but is nonessential to the maintenance of intercellular bridge stability. PMID:21669984

Greenbaum, Michael P.; Iwamori, Tokuko; Buchold, Gregory M.; Matzuk, Martin M.

2011-01-01

137

Hölder properties of perturbed skew products and Fubini regained  

NASA Astrophysics Data System (ADS)

In 2006, Gorodetski proved that central fibres of perturbed skew products are Hölder continuous with respect to the base point. In this paper, we give an explicit estimate of this Hölder exponent. Moreover, we extend Gorodetski's result from the case when the fibre maps are close to the identity to a much wider class of maps that satisfy the so-called modified dominated splitting condition. In many cases (for example, in the case of skew products over the solenoid or over linear Anosov diffeomorphisms of the torus), the Hölder exponent is close to 1. This allows one to overcome the so-called Fubini nightmare, in some sense. Namely, we prove that the union of central fibres that are strongly atypical from the point of view of ergodic theory, has Lebesgue measure zero despite the lack of absolute continuity of the holonomy map for the central foliation. This result is based on a new kind of ergodic theorem, which we call special. To prove our main result, we revisit the theory of Hirsch, Pugh and Shub, and estimate the contraction constant of the graph transform map.

Ilyashenko, Yu; Negut, A.

2012-08-01

138

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

139

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

E-print Network

theory for skewness in breakthrough curves 3 T. A. Appuhamillage,1 V. A. Bokil,1 E. Thomann,1 E. Waymire and asymmetries in the breakthrough curves of a 18 conservative tracer across an sharp interface recently reported. Wood (2010), Solute transport across an 20 interface: A Fickian theory for skewness in breakthrough

Thomann, Enrique

140

On hooks of skew Young diagrams and bars in shifted diagrams  

E-print Network

1 On hooks of skew Young diagrams and bars in shifted diagrams Christine Bessenrodt Fakultat f;ectiveness of the methods introduced in [1] we investi- gate hooks in skew Young diagrams and bars in shifted combinatorial proofs for re#12;ned identities on multisets of hooks in the case of shift-symmetric partitions. 1

Bessenrodt, Christine

141

Cluster Rendering of Skewed Datasets via Visualization Keke Chen Ling Liu  

E-print Network

Cluster Rendering of Skewed Datasets via Visualization Keke Chen Ling Liu College of Computing method for understanding sophistication in large datasets. In this paper, we introduce a flexible clustering approach with visualization techniques, aiming at the datasets that have skewed cluster

Liu, Ling

142

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

E-print Network

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

Meeden, Glen

143

An adaptive technique for global and local skew correction in color documents  

Microsoft Academic Search

In this paper, a new technique is proposed for global and local skew detection in complex color documents. The proposed technique, which can be applied also to grayscale and binary documents, consists of four main stages; color reduction, text localization, document binarization and skew correction. Color reduction limits the initial number of colors to a small number, usually smaller than

Michael Makridis; Nikos A. Nikolaou; Nikos Papamarkos

2010-01-01

144

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

Microsoft Academic Search

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

A. Roy; Tapan K. Bhowmik; Swapan K. Parui; Utpal Roy

2005-01-01

145

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

146

Effect of head skew on edge erasure and transition noise at submicron recording track width  

Microsoft Academic Search

Cross track transition noise profiles and erase band widths were measured on a spin-stand using a 1 ?m wide focus ion beam trimmed inductive head, at different skew angles. At a 20° skew angle, large asymmetry about the track center in the noise profiles is observed, which is attributed to the self-overwriting of transitions near the edge on the side

Terence T. Lam; Jian-Gang Zhu; Hua-Ching Tong

1997-01-01

147

The Wise Guy's Juice: A Reduced Form Skewness Analysis within Australian Fixed-Odds Horse Racing  

Microsoft Academic Search

I utilize fixed-odds horse race gambling data to estimate a utility function of uncertainty for consumers. Results suggest that bettors accept low return bets due to a preference for skewness, not risk. The fixed odds format enables me to estimate a reduced form model of the bookie's take. Using the Gini coefficient to capture the skewness of a race, I

Max Kaftal

148

Pennsylvania Covered Bridges  

NSDL National Science Digital Library

Covered bridges cause moments of delight for historic preservationists, and they entered a new place in American popular culture when they figured prominently in a certain Clint Eastwood film in the early 1990s. Recently, staff members and student assistants at Bucknell University spent a significant amount of time creating this digital collection of covered bridge photographs. Interestingly enough, the original photographs were taken by a long-time member of the biology faculty at Bucknell, one Professor Nelson F. Davis. The photos date from 1898 to 1939, and all told, there are over 300 images in this collection. Visitors will enjoy looking over this collection, and these documents will be of great interest to anyone fascinated by these types of bridges, engineering, or the history of rural Pennsylvania.

149

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

150

Shoreham Railroad Bridge, Title Sheet Shoreham Railroad Bridge, Former ...  

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

Shoreham Railroad Bridge, Title Sheet - Shoreham Railroad Bridge, Former Addison County Railroad (later, Rutland Railroad, Addison Branch), spanning Lemon Fair River above Richville Pond, west of East Shoreham Road, Shoreham, Addison County, VT

151

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

152

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

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

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

153

Measures of kurtosis and skewness of INGARCH model  

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

154

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

155

Emergence of skew distributions in controlled growth processes.  

PubMed

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. PMID:21230652

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

2010-12-01

156

Soft bounds on diffusion produce skewed distributions and Gompertz growth.  

PubMed

Constraints can affect dramatically the behavior of diffusion processes. Recently, we analyzed a natural and a technological system and reported that they perform diffusion-like discrete steps displaying a peculiar constraint, whereby the increments of the diffusing variable are subject to configuration-dependent bounds. This work explores theoretically some of the revealing landmarks of such phenomenology, termed "soft bound." At long times, the system reaches a steady state irreversibly (i.e., violating detailed balance), characterized by a skewed "shoulder" in the density distribution, and by a net local probability flux, which has entropic origin. The largest point in the support of the distribution follows a saturating dynamics, expressed by the Gompertz law, in line with empirical observations. Finally, we propose a generic allometric scaling for the origin of soft bounds. These findings shed light on the impact on a system of such "scaling" constraint and on its possible generating mechanisms. PMID:25314480

Mandrà, Salvatore; Lagomarsino, Marco Cosentino; Gherardi, Marco

2014-09-01

157

Abundant rich phase transitions in step-skew products  

NASA Astrophysics Data System (ADS)

We study phase transitions for the topological pressure of geometric potentials of transitive sets. The sets considered are partially hyperbolic having a step-skew product dynamics over a horseshoe with one-dimensional fibres corresponding to the central direction. The sets are genuinely non-hyperbolic, containing intermingled horseshoes of different hyperbolic, behaviour (contracting and expanding centre). We construct for every k ? 1 a diffeomorphism F with a transitive set ? as above such that the pressure map P(t) = P(t ?) of the potential \\varphi= -log \\,\\Vert \\rmd F|_{E^c}\\Vert (Ec the central direction) defined on ? has k rich phase transitions. This means that there are parameters t?, ? = 0, …, k - 1, where P(t) is not differentiable and this lack of differentiability is due to the coexistence of two equilibrium states of t? ? with positive entropy and different Birkhoff averages. Each phase transition is associated with a gap in the central Lyapunov spectrum of F on ?.

Díaz, L. J.; Gelfert, K.; Rams, M.

2014-09-01

158

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

159

Soft bounds on diffusion produce skewed distributions and Gompertz growth  

NASA Astrophysics Data System (ADS)

Constraints can affect dramatically the behavior of diffusion processes. Recently, we analyzed a natural and a technological system and reported that they perform diffusion-like discrete steps displaying a peculiar constraint, whereby the increments of the diffusing variable are subject to configuration-dependent bounds. This work explores theoretically some of the revealing landmarks of such phenomenology, termed "soft bound." At long times, the system reaches a steady state irreversibly (i.e., violating detailed balance), characterized by a skewed "shoulder" in the density distribution, and by a net local probability flux, which has entropic origin. The largest point in the support of the distribution follows a saturating dynamics, expressed by the Gompertz law, in line with empirical observations. Finally, we propose a generic allometric scaling for the origin of soft bounds. These findings shed light on the impact on a system of such "scaling" constraint and on its possible generating mechanisms.

Mandrà, Salvatore; Lagomarsino, Marco Cosentino; Gherardi, Marco

2014-09-01

160

The Relationship Between Skewed X Chromosome Inactivation and the Prognosis of Graves' and Hashimoto's Diseases.  

PubMed

Background: Autoimmune thyroid diseases (AITDs) predominantly develop in females. One of two X chromosomes is randomly inactivated by methylation in each female cell, but it has been reported that skewed X chromosome inactivation (XCI) may be associated with the development of autoimmune diseases. To clarify the significance of skewed XCI in the prognosis and development of AITD, we investigated the proportion of skewed XCI in female patients with AITD. Methods: We analyzed the degree of XCI skewing in 120 female patients with AITD (77 patients with Graves' disease [GD] and 43 patients with Hashimoto's disease [HD]) and 49 female controls in DNA from peripheral blood mononuclear cells (PBMC). We performed XCI analysis by digesting inactive DNA with a methylation-sensitive restriction enzyme (HpaII) followed by a polymerase chain reaction (PCR) assay for the polymorphic CAG repeat of the androgen receptor gene and electrophoresis of the PCR products. Results: The proportion of skewed XCI (?65% skewing) was not significantly different between AITD patients and control subjects but was higher in patients with intractable GD (66.7%) than those with GD in remission (25.0%, p=0.0033) and control subjects (32.6%, p=0.0038). When the cutoff value for XCI skewing was relaxed, the proportion of skewed XCI (?60% skewing) was higher in patients with severe HD (76.5%) than in those with mild HD (41.2%, p=0.0342). Conclusions: Skewed XCI is related to the prognosis of AITD, particularly the intractability of GD. PMID:25338305

Ishido, Naoko; Inoue, Naoya; Watanabe, Mikio; Hidaka, Yoh; Iwatani, Yoshinori

2014-10-22

161

`Smart bridge' technology helps monitor I-35W bridge behavior  

E-print Network

`Smart bridge' technology helps monitor I-35W bridge behavior Bicycle, pedestrian traffic counts? page 2 SUSTAINABILITY INSIGHTS page 2 TRANSITWAY INFLUENCES ON NEIGHBORHOODS page 3 SMART SIGNAL page 4, University of Minnesota researchers have been using"smart bridge"technology to collect and analyze data about

Minnesota, University of

162

1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT ...  

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

1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT LEFT AND THE ROCK CREEK AND POTOMAC PARKWAY RAMP AT RIGHT. VIEW TAKEN FROM THE REAR OF THE LINCOLN MEMORIAL. - Arlington Memorial Bridge, Boundary Channel Extension, Spanning Mount Vernon Memorial Highway & Boundary Channel, Washington, District of Columbia, DC

163

Study of rolling element dynamic interactions with separator and raceway paths. Roller skewing measurements in roller bearings  

NASA Technical Reports Server (NTRS)

Measurements of roller skewing in a 118 mm bore roller bearing operating at shaft speeds to 12000 rpm are reported. High speed motion pictures of a modified roller were taken through a derotation prism to record skewing as the roller moved through loaded and unloaded regions of the bearing. Subsequent frame by frame measurement of the photographic film provided information on roller skewing. Radial and tangential skew amplitudes of .4 to .5 degrees were observed with .5 degree misalignment.

Nypan, L. J.

1980-01-01

164

A Guide to Covered Bridges  

NSDL National Science Digital Library

A Guide to Covered Bridges, offered by Drexel University, Philadelphia, Pennsylvania, transforms the Web into a time machine. Find the answer to the question, why are there so many covered bridges, and why in Pennsylvania and the Northeast? The Drexel University Honors Program sponsors this guide to dozens of covered bridges of the Philadelphia region. Driving tours are suggested, and bridge images are indexed by season (fall color, winter, snow and ice, spring/summer) and structure as well as county.

165

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

166

Partnership Building a Bridge  

E-print Network

will accelerate new ideas into clinical treatments for the prevention and cure of cancer. Cancer Research Clinical efficient translation of new discoveries into clinical treatments for the prevention and cure of cancerCancer Research Clinical Partnership Building a Bridge Between Purdue Discovery and Clinical

167

Bridging the Gender Gap  

E-print Network

Bridging the Gender Gap: Growing the Next Generation of Women in Computing A sobering fact: the U need to ensure our research and development teams are diverse enough to anticipate, respond, and serve Develop: This radically new software development environment lets you write code for your phone on your

Chaudhuri, Surajit

168

Quantum bidding in Bridge  

E-print Network

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

S. Muhammad; A. Tavakoli; M. Kurant; M. Pawlowski; M. Zukowski; M. Bourennane

2014-03-17

169

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

170

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.

2007-08-09

171

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

172

Bryce Canyon Natural Bridge  

USGS Multimedia Gallery

Bryce Canyon's Natural Bridge is technically a natural arch, similar to those in the nearby Arches National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates...

173

Onyx Bridg e Volcanology  

E-print Network

Carso n Oregon Onyx Bridg e Cascad e Willamette University etuhcseDs BEECH Boyn itseuHs Volcanology on Franklin Blvd until you reach Onyx. 7. Turn right into the Onyx lot, then left towards the end of the lot

174

Onyx Bridg e Volcanology  

E-print Network

Carso n Oregon Onyx Bridg e Cascad e Willamette University etuhcseDs H itseuHs Volcanology (turns into Franklin Blvd) 6. Continue on Franklin Bldv until you reach Onyx (stop light). 7. Turn right into the Onyx lot, then left towards the end of the lot. 8. CAMCOR spots are located halfway down the parking

175

Bridging the Gap.  

ERIC Educational Resources Information Center

Presents a critique of existing methodology used in curriculum updates in academic institutions, suggesting that an integrated approach is more realistic and meaningful to study and to bridging the gap between academic curriculum and industry's needs. Specifically recommends that curriculum-related and job-related data be analyzed simultaneously.…

Mansour, Ali H.; And Others

1986-01-01

176

A Control of the MMF Space Harmonic Parasitic Torques in the concentrated winding AC Machine Using Skew angle Optimization  

Microsoft Academic Search

In this study, the authors proposed a method of controlling harmonic parasitic torque in concentrated winding induction motor and validated its theory's practicality through the experiment. To control harmonic, the rotor was skewed at an angle and to determine optimum skew angle, three dimensional electromagnetic analysis was performed. The result of analysis demonstrated larger than 20 degree skew angle, which

Hyun Rok Cha; Cheol Ho Yun; Tae Uk Jung; Hyung Mo Kim; Jeong Cheol Kim; Seung Hun Baek; Kwang Heon Kim

2006-01-01

177

Fibre reinforced composite dental bridge  

Microsoft Academic Search

This experimental investigation aims at revealing the mechanical behaviour and failure pattern of direct fibre-reinforced resin-bonded dental bridge with various designs. To evaluate the overall effects of some newly developed dental materials, in the experiment, genuine composite dental bridge specimens are prepared and tested. The ultimate load, stiffness and mode at the failure of the bridges are measured and compared

W. Li; M. V. Swain; Q. Li; J. Ironside; G. P. Steven

2004-01-01

178

USGS Gage At Covered Bridge  

USGS Multimedia Gallery

This photograph shows Lowe's Bridge off ME-15 in Guilford, Maine, spanning the Piscataquis River. USGS gaging station 01031500 is located on the downstream side of the bridge. The original bridge, built in 1857, washed away in the flood of 1987, and was rebuilt on the original abutments in 1990....

179

Maintaining Minnesota's Unique Bridge Inventory  

E-print Network

Brinckerhoff Minneapolis, Minnesota Blatnik and Bong Bridges Wire Rope Replacement: #12;Blatnik and Bong Bridges Wire Rope Replacement · Configuration and existing condition of the deck suspender system;Blatnik and Bong Bridges Wire Rope Replacement · In 2007, a fracture critical inspection of the Blatnik

Minnesota, University of

180

Spreading-rate-dependent anomalous skewness and the estimate of the chron 32 palaeomagnetic pole for the Pacific plate  

NASA Astrophysics Data System (ADS)

Palaeomagnetic poles can be determined from asymmetry (skewness) of marine magnetic anomalies. Early works applying the skewness method were limited by the discovery of an apparently systematic error known as anomalous skewness (Cande 1976). Anomalous skewness can be thought of as the systematic difference between the observed skewness and the skewness predicted by a simple magnetization model with rectangular 2-D layer 2A prisms of alternating polarity separated by vertical boundaries. In the early works, anomalous skewness could be isolated for anomalies with counterparts across a mid-ocean ridge, but was much harder to estimate for anomalies with subducted counterparts, as is mostly the case in the Pacific plate. Petronotis et al. (1992) presented a solution to this problem by simultaneously estimating anomalous skewness and a best-fitting palaeomagnetic pole from skewness data from a single plate. In their approach, anomalous skewness is assumed to be identical for different crossings of the same plate and any spreading-rate dependence of anomalous skewness is neglected. Nonetheless, anomalous skewness of marine magnetic anomalies is observed to decrease with increasing spreading rate and become negligible above spreading rates of about 50 mm yr-1 (e.g. Roest et al. 1992; Dyment et al. 1994). Dyment &Arkani-Hamed (1995) proposed a model in which the magnetic structure of the oceanic lithosphere is dependent on spreading rate with parameters adjusted to fit the observed spreading- rate dependence of anomalous skewness for some key anomalies. Here we apply their model to determine a new Maastrichtian palaeomagnetic pole for the Pacific plate from skewness estimates of magnetic anomaly 32. Previously Petronotis &Gordon (1999) obtained a palaeopole assuming spreading-rate independent anomalous skewness for the same data used here. They also investigated the possible dependence of anomalous skewness on spreading rate and found it to have negligible effect on their palaeopole. Using the anomalous skewness correction predicted by the model of Dyment &Arkani-Hamed, we find that the data require no additional anomalous skewness, thus providing some validation of their model. Moreover, it appears that the new pole position stays near the original pole position irrespective of what set of spreading rates is used to estimate anomalous skewness. The largest uncertainties in the anomalous-skewness correction are due to uncertainties in spreading rates, which are mainly due to uncertainties in the reversal time scale. The results support the assertion of Petronotis et al. that Pacific plate poles determined from low- palaeolatitude sites are insensitive to anomalous skewness.

Koivisto, E.; Gordon, R.; Dyment, J.; Arkani-Hamed, J.

2006-12-01

181

Log Pearson type 3 quantile estimators with regional skew information and low outlier adjustments  

USGS Publications Warehouse

[1] The recently developed expected moments algorithm (EMA) [Cohn et al., 1997] does as well as maximum likelihood estimations at estimating log-Pearson type 3 (LP3) flood quantiles using systematic and historical flood information. Needed extensions include use of a regional skewness estimator and its precision to be consistent with Bulletin 17B. Another issue addressed by Bulletin 17B is the treatment of low outliers. A Monte Carlo study compares the performance of Bulletin 17B using the entire sample with and without regional skew with estimators that use regional skew and censor low outliers, including an extended EMA estimator, the conditional probability adjustment (CPA) from Bulletin 17B, and an estimator that uses probability plot regression (PPR) to compute substitute values for low outliers. Estimators that neglect regional skew information do much worse than estimators that use an informative regional skewness estimator. For LP3 data the low outlier rejection procedure generally results in no loss of overall accuracy, and the differences between the MSEs of the estimators that used an informative regional skew are generally modest in the skewness range of real interest. Samples contaminated to model actual flood data demonstrate that estimators which give special treatment to low outliers significantly outperform estimators that make no such adjustment.

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

2004-01-01

182

Molecular engineering with bridged polysilsesquioxanes  

SciTech Connect

Bridged polysilsesquioxanes are a class of hybrid organic-inorganic materials that permit molecular engineering of bulk properties including porosity. Prepared by sol-gel polymerization of monomers with two or more trialkoxysilyl groups, the materials are highly cross-linked amorphous polymers that are readily obtained as gels. The bridging configuration of the hydrocarbon group insures that network polymers are readily formed and that the organic functionality is homogeneously distributed throughout the polymeric scaffolding at the molecular level. This permits the bulk properties, including surface area, pore size, and dielectric constant to be engineered through the selection of the bridging organic group. Numerous bridging groups have been incorporated. This presentation will focus on the effects that the length, flexibility, and substitution geometry of the hydrocarbon bridging groups have on the properties of the resulting bridged polysilsesquioxanes. Details of the preparation, characterization, and some structure property relationships of these bridged polysilsesquioxanes will be given.

LOY,DOUGLAS A.; SHEA,KENNETH J.

2000-05-09

183

Reliability of long span bridges based on design experience with the Honshu–Shikoku bridges  

Microsoft Academic Search

Most of the existing long span bridges were designed using deterministic concepts and methods. For example, all the seventeen long span bridges constructed in Japan by the Honshu–Shikoku Bridge Authority between Honshu Island and Shikoku Island including ten suspension bridges, five cable-stayed bridges, one arch bridge, and one truss bridge were designed based on the allowable stress design method. Today,

Dan M. Frangopol; Kiyohiro Imai

2004-01-01

184

Electrical Actuation Technology Bridging  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

185

Estimating generalized skew of the log-Pearson Type III distribution for annual peak floods in Illinois  

USGS Publications Warehouse

Four techniques for estimating generalized skew in Illinois were evaluated: (1) a generalized skew map of the US; (2) an isoline map; (3) a prediction equation; and (4) a regional-mean skew. Peak-flow records at 730 gaging stations having 10 or more annual peaks were selected for computing station skews. Station skew values ranged from -3.55 to 2.95, with a mean of -0.11. Frequency curves computed for 30 gaging stations in Illinois using the variations of the regional-mean skew technique are similar to frequency curves computed using a skew map developed by the US Water Resources Council (WRC). Estimates of the 50-, 100-, and 500-yr floods computed for 29 of these gaging stations using the regional-mean skew techniques are within the 50% confidence limits of frequency curves computed using the WRC skew map. Although the three variations of the regional-mean skew technique were slightly more accurate than the WRC map, there is no appreciable difference between flood estimates computed using the variations of the regional-mean technique and flood estimates computed using the WRC skew map. (Peters-PTT)

Oberg, Kevin A.; Mades, Dean M.

1987-01-01

186

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

187

Retrievable bridge plug  

SciTech Connect

This patent describes a retrievable bridge plug apparatus for use in a well conduit. It comprises: body means having first and second ends and an interior passage formed in the body means; gripping means; first and second extending means for extending the gripping means; packing means; first shoulder means; cover means; and tubular means located in the body means and being responsive to movement of the cover means.

Rosenthal, W.O.

1990-02-06

188

BRIDGE Other Resources  

NSDL National Science Digital Library

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

189

A Thouless formula and Aubry duality for long-range Schrödinger skew-products  

NASA Astrophysics Data System (ADS)

In this paper, we study the dynamical properties of a class of ergodic linear skew-products which includes the linear skew-products defined by quasi-periodic Schrödinger operators and their duals, in Aubry sense, when the potential is a trigonometric polynomial. Notably, these linear skew-products preserve an adapted complex-symplectic structure. We prove a Thouless formula relating the sum of the positive Lyapunov exponents and the logarithmic potential associated with the density of states of the corresponding operator. In particular, for quasi-periodic Schrödinger operators and their duals, we prove an identity for the upper Lyapunov exponent of the skew-product and the sum of the positive Lyapunov exponents of their dual, which generalizes the well-known formula for the Almost Mathieu. We illustrate these identities with some numerical illustrations.

Haro, Alex; Puig, Joaquim

2013-05-01

190

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. PMID:23994479

Mizuseki, Kenji; Buzsáki, György

2013-01-01

191

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

192

The role of multivariate skew-Student density in the estimation of stock market crashes  

Microsoft Academic Search

By combining the multivariate skew-Student density with a time-varying correlation GARCH (TVC-GARCH) model, this paper investigates the spread of crashes in the regional stock markets. The regional index series of European, USA, Latin American and Asian markets are modeled jointly, and the maximum likelihood estimates show that a TVC-GARCH model with multivariate skew-Student density outperforms that with multivariate normal density

Lei Wu; Qingbin Meng; Julio C. Velazquez

2012-01-01

193

Hierarchical Control of Bridge-of-Bridge Multilevel Power Converters  

Microsoft Academic Search

Multilevel converters are among the members of the family of power-converter topologies for realizing higher power levels and better waveform quality. In addition to the established topologies of neutral-point-clamped three-level and cascaded H-bridge converters, novel topologies that offer attractive features, such as ease of modularity and functionality, continue to be introduced. Among these, the bridge-of-bridge multilevel converters have the potential

Dan C. Ludois; Justin K. Reed; Giri Venkataramanan

2010-01-01

194

Signature of topological quantum phase transitions via Wigner-Yanase skew information  

NASA Astrophysics Data System (ADS)

We apply the Wigner-Yanase skew information approach to analyze two typical models that exhibit a topological quantum phase transition. Based on the exact solutions of the ground states, the Wigner-Yanase skew information between two nearest sites for each of the two models is obtained. For the one-dimensional Kitaev chain model, the first-order derivative of the Wigner-Yanase skew information is non-analytical around the critical point. The scaling behavior and the universality are verified numerically. In particular, the skew information can also detect the factorization transition in such a model. For the two-dimensional Kitaev honeycomb model, the first-order derivative of the Wigner-Yanase skew information shows some singularities at the critical points where the system transits from the gapless phase to the gapped one. Our results suggest that the Wigner-Yanase skew information can serve as a good indicator of the topological phase transitions in these models and shed considerable light on the relationships between topological quantum phase transition and information theory.

Cheng, W. W.; Du, Z. Z.; Gong, L. Y.; Zhao, S. M.; Liu, J.-M.

2014-11-01

195

The active-bridge oscillator  

SciTech Connect

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

Wessendorf, K.O.

1998-07-01

196

Tacoma Narrows Bridge: Extreme History  

NSDL National Science Digital Library

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

197

BRIDGE: Briefings on Development & Gender  

NSDL National Science Digital Library

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

1999-01-01

198

The Adaptive Use Bridge Project  

NSDL National Science Digital Library

The Adaptive Use Bridge Project website is a repository for work being conducted at the University of Massachusetts, Amherst, in which historic iron bridges are rehabilitated, documented, and analyzed. The purpose of the project is to preserve the civil engineering heritage of New England and to develop instructional material for use in undergraduate civil engineering curricula. Upon completion of this long-term project, a protocol for adaptive pedestrian use of historic bridges will be created.

University of Massachusetts, Amherst

199

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

200

BridgeSPA: Improving Tor Bridges with Single Packet Authorization  

E-print Network

BridgeSPA: Improving Tor Bridges with Single Packet Authorization Rob Smits rdfsmits@cs.uwaterloo.ca ABSTRACT Tor is a network designed for low-latency anonymous com- munications. Tor clients form circuits these circuits. This indirection makes it difficult for a local adversary to determine with whom a particular Tor

Hengartner, Urs

201

The floating water bridge The floating water bridge  

E-print Network

properties and is also the reason why water must not be treated as a simple liquid [1,2]. The interactionThe floating water bridge The floating water bridge Elmar C. Fuchs1 , Jakob Woisetschläger2 , Karl ____________________________________________ Abstract When high voltage is applied to distilled water filled into two glass beakers which are in contact

Podgornik, Rudolf

202

16. Little Hell Gate Bridge with Big Hell Gate Bridge ...  

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

16. Little Hell Gate Bridge with Big Hell Gate Bridge in background. Wards Island, New York Co., NY. Sec. 4207, MP 8.02. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York, New York County, NY

203

20. Bronx Kill Bridge with Hell Gate Bridge in background. ...  

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

20. Bronx Kill Bridge with Hell Gate Bridge in background. Randalls Island, New York Co., NY. Sec. 4207, MP 8.54. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York, New York County, NY

204

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

NASA Astrophysics Data System (ADS)

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

Valyrakis, Manousos; Zhang, Hanqing

2014-05-01

205

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

NASA Technical Reports Server (NTRS)

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

Wing, David J.

1994-01-01

206

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

207

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

208

BRIDGES AND NETWORKS: EXACT ASYMPTOTICS  

Microsoft Academic Search

We extend the Markov additive methodology developed in (1, 3) to obtain the sharp asymptotics of the steady state probability of a queueing network when one of the nodes gets large. We focus on a new phenomenon we call a bridge. The bridge cases occur when the Markovian part of the twisted Markov additive process is one null recurrent or

ROBERT D. FOLEY; DAVID R. MCDONALD

2004-01-01

209

Typical Bridge Foundations - Selected Cases  

Microsoft Academic Search

Foundations of the bridges have always been a matter of great concern to Civil Engineers. In many instances actual strata met with at the foundation level turned out to be quite different than that found at the time of geological and geotechnical investigation. This paper discusses typical case studies of bridge foundations constructed at various places in the state of

P. K. Jain; Rakesh Kumar; Anand Selot; S. K. Mittal

210

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.

211

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

USGS Publications Warehouse

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

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

2009-01-01

212

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.

2014-08-06

213

Burning trees and bridges  

NASA Technical Reports Server (NTRS)

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

Levine, Joel S.

1990-01-01

214

Bridges to Structure  

NSDL National Science Digital Library

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

Peter Woodruff (Champlain-St. Lambert College;); Joyce Cadawallader (Saint-Mary-of-the-Woods College;)

2004-06-12

215

Bridging the Watershed  

NSDL National Science Digital Library

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

216

The log-dynamic brain: how skewed distributions affect network operations.  

PubMed

We often assume that the variables of functional and structural brain parameters - such as synaptic weights, the firing rates of individual neurons, the synchronous discharge of neural populations, the number of synaptic contacts between neurons and the size of dendritic boutons - have a bell-shaped distribution. However, at many physiological and anatomical levels in the brain, the distribution of numerous parameters is in fact strongly skewed with a heavy tail, suggesting that skewed (typically lognormal) distributions are fundamental to structural and functional brain organization. This insight not only has implications for how we should collect and analyse data, it may also help us to understand how the different levels of skewed distributions - from synapses to cognition - are related to each other. PMID:24569488

Buzsáki, György; Mizuseki, Kenji

2014-04-01

217

Sensitivity of odd-harmonic amplitudes to open quotient and skewing quotient in glottal airflow.  

PubMed

It is well known that a half-sinusoid has no odd harmonics other than the fundamental. If glottal flow in phonation were to approximate this exact waveshape, which is generally unlikely, some misperception of pitch and loss of vowel intelligibility would occur. The sensitivity of the glottal waveshape to this special shape is explored by systematically varying two parameters, open quotient and skewing quotient. Mild asymmetry (open quotient below 0.45 or above 0.55 and/or skewing quotient greater than 2.0) equalizes the odd-even harmonic series. Singers and speakers avoid the exact symmetry by skewing the flow pulse with source-filter interaction. PMID:25618080

Titze, Ingo R

2015-01-01

218

Skewness in CMB temperature fluctuations from curved cosmic (super-)strings  

E-print Network

We compute the one-point probability distribution function of small-angle cosmic microwave background temperature fluctuations due to curved cosmic (super-)strings with a simple model of string network by performing Monte Carlo simulations. Taking into account of the correlation between the curvature and the velocity of string segments, there appear non-Gaussian features, specifically non-Gaussian tails and a skewness, in the one-point pdf. The obtained sample skewness for the conventional field-theoretic cosmic strings is $g_1\\approx -0.14$, which is consistent with the result reported by Fraisse et al.. We also discuss the dependence of the pdf on the intercommuting probability. We find that the standard deviation of the Gaussian part increases and non-Gaussian features are suppressed as the intercommuting probability decreases. For sufficiently small intercommuting probability, the skewness is given by $\\lesssim$ (a\\ few) $\\times 10^{-2}$.

Daisuke Yamauchi; Yuuiti Sendouda; Chul-Moon Yoo; Keitaro Takahashi; Atsushi Naruko; Misao Sasaki

2010-06-03

219

Skew-Tolerant Key Distribution for Load Balancing in MapReduce  

NASA Astrophysics Data System (ADS)

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

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

220

Rapid Repair of Low Volume Bridges  

E-print Network

using a gunpowder gun (Arora, 2003) 8(Bank, 2004) #12;Previous MF-FRP Applications · Application tested in Missouri with plans to strengthen up to 31 more bridges (Bank, Nanni, & Arora, 2004) (Rizzo A. , Galati Missouri Bridge No. 1330005 $16,502 688 ft Missouri Bridge No. 3855006 $13,115 666 ft Missouri Bridge No. B

Russell, Jeffrey S.

221

Geology Fieldnotes: Natural Bridges National Monument, Utah  

NSDL National Science Digital Library

This site describes how natural bridges form in crossbedded sandstone, the three stages of bridge maturity, and the differences between bridges and arches. Also included are photographs, park maps, visitor information, and details on the discovery of the Owachomo, Sipapu, and Kachina Bridges.

222

Washed Out Bridge, Snake Creek Near Whitesburg  

USGS Multimedia Gallery

Tributary to Snake Creek, near Whitesburg, Georgia, showing a washed out bridge. When bridges such as this one collapse during a flood, it is rarely the pressure of the rushing water against the bridge that causes the bridge to fail. Rather, the rushing water erodes the ground underneath and surroun...

2009-10-01

223

Pulse excitation of bolometer bridges  

NASA Technical Reports Server (NTRS)

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

Rusk, S. J.

1972-01-01

224

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. PMID:21992183

2011-01-01

225

Bridges.org  

NSDL National Science Digital Library

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

226

Numerical solution for the velocity-derivative skewness of a low-Reynolds-number decaying Navier-Stokes flow  

NASA Technical Reports Server (NTRS)

The variation of the velocity-derivative skewness of a Navier-Stokes flow as the Reynolds number goes toward zero is calculated numerically. The value of the skewness, which has been somewhat controversial, is shown to become small at low Reynolds numbers.

Deissler, Robert G.

1990-01-01

227

A 65 Ma palaeomagnetic pole for the Pacific plate from the skewness of magnetic anomalies 27r-31.  

NASA Astrophysics Data System (ADS)

The authors use the skewness of seafloor-spreading magnetic anomalies 27r-31 to determine a revised Late Maastrichtian - early Palaeocene palaeomagnetic pole for the Pacific plate. They used numerical experiments to estimate the potential information in magnetic profiles that had not been previously analysed for skeweness information.

Acton, G. D.; Gordon, R. G.

1991-08-01

228

High rates of pregnancy loss by subordinates leads to high reproductive skew in wild golden lion tamarins (Leontopithecus rosalia)  

E-print Network

Ã?Ã? Ã? Ã?Ã?Ã? Ã? Ã?Ã? High rates of pregnancy loss by subordinates leads to high reproductive skew in wild., French, Jeffrey A., Dietz, James M., High rates of pregnancy loss by subordinates leads to high ACCEPTED MANUSCRIPT TITLE High rates of pregnancy loss by subordinates leads to high reproductive skew

French, Jeffrey A.

229

Effects of stimulus salience and methamphetamine on choice reaction time in the rat: central tendency versus distribution skew.  

PubMed

Stimulants decrease reaction time in humans as well as laboratory rats. This effect is seen as a decrease in average reaction time or a shift in the distribution peak towards shorter reaction times. However, response-time distributions are typically skewed, exhibiting a positive tail. Our goal for this project was to develop a method of analyzing reaction-time distributions in the rat which will allow us to study systematically measures of central tendency and distribution skew. This analysis subdivided reaction time into initiation time and movement time, and also subdivided the response time distributions into distribution mode and distribution skew. Rats were trained on a two-choice visual reaction-time task. We then evaluated the effects of stimulus salience and methamphetamine (METH) treatment (vehicle, 0.25, 0.5, 1.0, and 1.5 mg/kg) on measures of distribution mode and skew. Stimulus salience decreased initiation time mode, initiation time skew and movement time skew, but had no effect on movement time mode. METH had a greater effect on skew for the initiation time distribution and a greater effect on mode for the movement time distribution. This analysis will serve as a useful method of determining whether initiation time and movement time, as well as distribution mode and distribution skew, represent different behavioral processes in the rat. PMID:14557716

Sabol, K E; Richards, J B; Broom, S L; Roach, J T; Hausknecht, K

2003-11-01

230

Construction of Skew-Normal Random Variables: Are They Linear Combinations of Normal and Half-Normal?  

E-print Network

Construction of Skew-Normal Random Variables: Are They Linear Combinations of Normal and Half-Normal? Mohsen Pourahmadi pourahm@math.niu.edu Division of Statistics Northern Illinois University Abstract Skew-normal distributions extend the normal distributions through a shape pa- rameter ; they reduce to the standard normal

Pourahmadi, Mohsen

231

The IBM 8209 LAN bridge  

Microsoft Academic Search

The issues involved in bridging 802.5 (token-ring) and 802.3 (Ethernet) networks at the media access control (MAC) layer are discussed. The issues concern incompatibilities between the two networks in six areas: routing schemes, station addresses, frame formats, and local area network speeds. An approach incorporated in the IBM 8209 LAN bridge for resolving the incompatibilities is described. The IBM 8209

A. Latif; E. J. Rowlance; R. H. Adams

1992-01-01

232

GAUVREAU, The Three Myths of Bridge Aesthetics, 1/8 THE THREE MYTHS OF BRIDGE AESTHETICS  

E-print Network

GAUVREAU, The Three Myths of Bridge Aesthetics, 1/8 THE THREE MYTHS OF BRIDGE AESTHETICS Paul wisdom on bridge aesthetics. If bridge design is to be recognized as a valid and distinct means taste". The conventional wisdom on bridge aesthetics, however, is actually nothing more than such a set

Gauvreau, Paul

233

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

234

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

E-print Network

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

Ali R. Hadjesfandiari

2015-01-20

235

Cooperation is less likely to evolve in a finite population with a highly skewed  

E-print Network

Cooperation is less likely to evolve in a finite population with a highly skewed distribution repeated Prisoner's Dilemma with the possibility of cooperating or defecting each time, the strategy tit the next times. Assuming random pairwise interactions in a finite population of always defecting

Lessard, Sabin

236

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

PubMed

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 the 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 and testing situations, as well as across familiar and novel environments. The fraction of neurons that participated in population oscillations displayed a lognormal pattern. Such skewed firing rates of individual neurons may be due to a skewed distribution of synaptic weights, which is 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. PMID:23994479

Mizuseki, Kenji; Buzsáki, György

2013-09-12

237

Consistent Paternity Skew through Ontogeny in Peron’s Tree Frog (Litoria peronii)  

E-print Network

Background: A large number of studies in postcopulatory sexual selection use paternity success as a proxy for fertilization success. However, selective mortality during embryonic development can lead to skews in paternity in situations of polyandry and sperm competition. Thus, when assessment of paternity fails to incorporate mortality skews during early ontogeny, this may interfere with correct interpretation of results and subsequent evolutionary inference. In a previous series of in vitro sperm competition experiments with amphibians (Litoria peronii), we showed skewed paternity patterns towards males more genetically similar to the female. Methodology/Principal Findings: Here we use in vitro fertilizations and sperm competition trials to test if this pattern of paternity of fully developed tadpoles reflects patterns of paternity at fertilization and if paternity skews changes during embryonic development. We show that there is no selective mortality through ontogeny and that patterns of paternity of hatched tadpoles reflects success of competing males in sperm competition at fertilization. Conclusions/Significance: While this study shows that previous inferences of fertilization success from paternity data are valid for this species, rigorous testing of these assumptions is required to ensure that differential embryonic mortality does

Craig D. H. Sherman; Erik Wapstra; Mats Olsson

2009-01-01

238

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. . PMID:23553914

Dagne, Getachew A; Huang, Yangxin

2013-09-30

239

11Skewed Distribution of Species Number in Grass Genera: Is It  

E-print Network

165 11Skewed Distribution of Species Number in Grass Genera: Is It a Taxonomic Artefact? K. W. Hilu........................................................................................................................ 165 11.2 The Grass Family (Poaceae .................................................................................................................................... 176 ABSTRACT The grass family (Poaceae) comprises about 10,000 species distributed in some 785 genera

Hilu, Khidir

240

Bayesian Semiparametric Mixture Tobit Models with Left-Censoring, Skewness and Covariate Measurement Errors  

PubMed Central

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 (LOD) 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. PMID:23553914

Dagne, Getachew A.; Huang, Yangxin

2013-01-01

241

Lie bundle on the space of deformed skew-symmetric matrices  

NASA Astrophysics Data System (ADS)

We study a Lie algebra A_{a_1,ldots ,a_{n-1}} of deformed skew-symmetric n × n matrices endowed with a Lie bracket given by a choice of deformed symmetric matrix. The deformations are parametrized by a sequence of real numbers a1, …, an - 1. Using isomorphism (A_{a_1,ldots ,a_{n-1}})^*

Dobrogowska, Alina; Goli?ski, Tomasz

2014-11-01

242

LOCAL LIMIT THEOREM FOR NONUNIFORMLY PARTIALLY HYPERBOLIC SKEW-PRODUCTS, AND FAREY SEQUENCES  

Microsoft Academic Search

We study skew-products of the form (x,!) 7? (Tx,! + ?(x)) where T is a nonuni- formly expanding map on a space X, preserving a (possibly singular) probability measure ˜ µ, and ? : X ? S1 is a C1 function. Under mild assumptions on ˜ µ and ?, we prove that such a map is exponentially mixing, and satisfies

SEBASTIEN GOU

243

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

244

Using social parasitism to test reproductive skew models in a primitively eusocial wasp  

PubMed Central

Remarkable variation exists in the distribution of reproduction (skew) among members of cooperatively breeding groups, both within and between species. Reproductive skew theory has provided an important framework for understanding this variation. In the primitively eusocial Hymenoptera, two models have been routinely tested: concessions models, which assume complete control of reproduction by a dominant individual, and tug-of-war models, which assume on-going competition among group members over reproduction. Current data provide little support for either model, but uncertainty about the ability of individuals to detect genetic relatedness and difficulties in identifying traits conferring competitive ability mean that the relative importance of concessions versus tug-of-war remains unresolved. Here, we suggest that the use of social parasitism to generate meaningful variation in key social variables represents a valuable opportunity to explore the mechanisms underpinning reproductive skew within the social Hymenoptera. We present a direct test of concessions and tug-of-war models in the paper wasp Polistes dominulus by exploiting pronounced changes in relatedness and power structures that occur following replacement of the dominant by a congeneric social parasite. Comparisons of skew in parasitized and unparasitized colonies are consistent with a tug-of-war over reproduction within P. dominulus groups, but provide no evidence for reproductive concessions. PMID:24990668

Green, Jonathan P.; Cant, Michael A.; Field, Jeremy

2014-01-01

245

Progress in understanding the renormalization group skewness and kappa-epsilon models  

NASA Technical Reports Server (NTRS)

The immediate goal is to understand and validate the Yakhot-Orszag model of the velocity-derivative skewness and model equation for the rate of energy dissipation epsilon. A summary of a more detailed manuscript in preparation is presented. The purpose is to clarify some limitations of the theory by careful examination of key assumptions and approximations, and thereby to encourage its improvement.

Smith, Leslie M.; Reynolds, W. C.

1991-01-01

246

The Curious Anomaly of Skewed Judgment Distributions and Systematic Error in the Wisdom of Crowds  

PubMed Central

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

Nash, Ulrik W.

2014-01-01

247

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

ERIC Educational Resources Information Center

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

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

2007-01-01

248

NPIP: A skew line needle configuration optimization system for HDR brachytherapy  

E-print Network

to compute needle configurations for prostate cancer data sets from patients previously treated at our clinicNPIP: A skew line needle configuration optimization system for HDR brachytherapy Timmy Siauwa Francisco, Comprehensive Cancer Center, 1600 Divisadero Street, Suite H1031, San Francisco, California 94143

Goldberg, Ken

249

Lipschitz-Killing curvatures of the Excursion Sets of Skew Student's t Random Ola Suleiman Ahmad  

E-print Network

for the total hip replacement. The surface topography is represented on a subset S R2 as a 3D height maps. One are fitted in order to test the skew student's t random field with the surface roughness topography. Keywords

Paris-Sud XI, Université de

250

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

251

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

E-print Network

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

Meeden, Glen

252

Skewing (n +1) Tensor Indices where the Index Range is n  

ERIC Educational Resources Information Center

It is known that any totally skew quantity with (n + 1) indices, each of which ranges over n values, vanishes identically. The aim of this short note is to show that this is equivalent to the simple fact that any (n + 1) vectors in an n-dimensional vector space are linearly dependent.

Agacy, R. L.

2005-01-01

253

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

PubMed

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

Lu, Xiaosun; Huang, Yangxin

2014-07-20

254

Optimal Skewed Data Allocation on Multiple Channels with Flat Broadcast per Channel  

E-print Network

Optimal Skewed Data Allocation on Multiple Channels with Flat Broadcast per Channel Elia Ardizzoni to an unlimited number of clients that are listening to a channel. Cyclically broadcasting data over the channel is a basic scheduling technique, which is known as flat scheduling. When multiple channels are available

Pinotti, Maria Cristina

255

Cohen's Class Distributions for Skew Angle Estimation in Noisy Ancient Arabic Documents  

E-print Network

Cohen's Class Distributions for Skew Angle Estimation in Noisy Ancient Arabic Documents N. Ouwayed documents using the energy distributions of Cohen's class. The presence of noise in raw docu- ment images can create local maxima which disturb the projection histogram analysis. To avoid this drawback, we

Paris-Sud XI, Université de

256

In?uence Diagnostics for Skew-Normal Linear Mixed Models  

Microsoft Academic Search

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

Heleno Bolfarine

2007-01-01

257

A CMOS Delayed Locked Loop (DLL) for Reducing Clock Skew to Under 500ps  

E-print Network

]. Tgta1 I 44.000 Before the DLL circuit was mapped on to a 0.8 pm CMOS process, a detailed analysis on the stabili- ty characteristics of the DLL loop was carried out to determine the component valuesA CMOS Delayed Locked Loop (DLL) for Reducing Clock Skew to Under 500ps Element Phase detector

Ayers, Joseph

258

Reproductive skew and the evolution of group dissolution tactics: a synthesis of concession and restraint models  

Microsoft Academic Search

Reproductive skew theory provides a compelling explanation for the partitioning of reproduction among individuals within animal societies. One constructive criticism of the theory is that there are too many models, all of which have different assumptions and predictions, which makes it difficult to know what to test. Here we begin the process of tackling this problem, by re-examining the assumptions

P. M. Buston; H. K. Reeve; M. A. Cant; S. L. Vehrencamp; S. T. Emlen

2007-01-01

259

Large-scale age-dependent skewed sex ratio in a sexually dimorphic avian scavenger.  

PubMed

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. PMID:23029488

Lambertucci, Sergio A; Carrete, Martina; Donázar, José Antonio; Hiraldo, Fernando

2012-01-01

260

Skew angle effects in shingled magnetic recording system with double/triple reader head array  

NASA Astrophysics Data System (ADS)

Shingled Magnetic Recording (SMR) is a scheme used to extend the life of the current perpendicular magnetic recording technology. SMR enables writing narrow tracks with a wide writer. Currently, SMR employs a single reader and will suffer inter-track interference (ITI) as the tracks become comparable in width to the reader. ITI can be mitigated by using narrower readers; however, narrower readers suffer from increased reader noise. Another approach to combat ITI is to process 2D readback and use ITI cancellation schemes to retrieve the data track. Multiple readbacks can be obtained either with a single reader and multiple revolutions or with a reader array. The former suffers from increased readback latency. In this work, we focus on the latter. When using a reader array, the skew angle poses major challenges. During writing, there is increased adjacent track erasure, and during readback the effective reader pitch varies and there is an increase in the 2D intersymbol interference caused by the rotated reader profile. In this work, we run micromagnetic simulations at different skew angles to train the grain flipping probability model, and then evaluate raw bit channel error rate performance at skew. In particular, we investigate the performance degradation caused by skewing of the 2 or 3 read head array for various read-head geometries.

Elidrissi, Moulay Rachid; Sann Chan, Kheong; Greaves, Simon; Kanai, Yasushi; Muraoka, Hiroaki

2014-05-01

261

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. PMID:22693549

Reynolds, Pamela L.; Bruno, John F.

2012-01-01

262

BRIDGE BUILDER WILLIAM FLINN?S ?CAMP & BRIDGE BUILDING OUTFIT?. INTERIOR ...  

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

BRIDGE BUILDER WILLIAM FLINN?S ?CAMP & BRIDGE BUILDING OUTFIT?. INTERIOR VIEW SHOWING BUSINESS DESK. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

263

BRIDGE BUILDER WILLIAM FLINN?S ?CAMP & BRIDGE BUILDING OUTFIT?. EXTERIOR ...  

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

BRIDGE BUILDER WILLIAM FLINN?S ?CAMP & BRIDGE BUILDING OUTFIT?. EXTERIOR VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

264

BRIDGE BUILDER WILLIAM FLINN?S ?CAMP & BRIDGE BUILDING OUTFIT?. INTERIOR ...  

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

BRIDGE BUILDER WILLIAM FLINN?S ?CAMP & BRIDGE BUILDING OUTFIT?. INTERIOR VIEW SHOWING LABORERS AT MEAL TIME. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

265

23 CFR 650.409 - Evaluation of bridge inventory.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

266

23 CFR 650.307 - Bridge inspection organization.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

267

23 CFR 650.307 - Bridge inspection organization.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

268

23 CFR 650.409 - Evaluation of bridge inventory.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

269

23 CFR 650.409 - Evaluation of bridge inventory.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

270

23 CFR 650.409 - Evaluation of bridge inventory.  

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

2014-04-01

271

23 CFR 650.307 - Bridge inspection organization.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

272

23 CFR 650.307 - Bridge inspection organization.  

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

2014-04-01

273

23 CFR 650.409 - Evaluation of bridge inventory.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

274

23 CFR 650.307 - Bridge inspection organization.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

275

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

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

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

276

Toward Quantifying the Spreading-Rate Dependence of Anomalous Skewness of Marine Magnetic Anomalies due to Seafloor Spreading  

NASA Astrophysics Data System (ADS)

In past work, reliable paleomagnetic poles have been determined from skewness data by solving for a single additional adjustable parameter, anomalous skewness, assumed to be independent of spreading rate [Petronotis et al. 1992, 1994; Petronotis & Gordon 1999]. Nonetheless, analysis of anomalies in several ocean basins indicate that anomalous skewness depends on spreading rate for spreading half rates less than ?50 mm/yr [Roest et al., 1992; Dyment et al. 1994]. To facilitate investigation of the influence of spreading-rate dependent anomalous skewness on the determination of paleomagnetic poles determined from skewness, we build on the model for marine magnetic anomalies due to seafloor spreading of Dyment and Arkani-Hamed [1995]. We use this model to estimate anomalous skewness as a function of spreading rate for many anomalies. Synthetic magnetic anomaly profiles for oceanic lithosphere with sloping curving reversal boundaries were produced by forward modeling. Anomalous skewness values for chrons 25n to 33r were visually determined at various spreading rates using two approaches: balancing the shoulders of an anomaly corresponding to a single chron and best matching an anomaly corresponding to a single chron to a synthetic anomaly determined assuming vertical reversal boundaries. The new results may facilitate the determination of paleomagnetic poles from less widely distributed crossings of a magnetic anomaly than were used before. Further implications for determination of paleomagnetic poles for the Pacific plate will be discussed.

Boswell, S. M.; Zheng, L.; Gordon, R. G.; Dyment, J.

2010-12-01

277

Construction Technologies: Create the Strongest Bridge  

NSDL National Science Digital Library

Students work in pairs to create three simple types of model bridges (beam, arch, suspension). They observe quantitatively how the bridges work under load and why engineers use different types of bridges for different places. They also get an idea of the parts needed to build bridges, and their functions. The strength of model bridges is mainly a factor of the quality of materials used, and therefore they do not provide a clear visual representation of tension and compression forces involved. Yet, students are able to see these forces at work in three prototype designs and draw conclusions about their dependence on span, width and supporting structures of the bridge designs.

2014-09-18

278

Nonlinear models of suspension bridges  

NASA Astrophysics Data System (ADS)

Nonlinear variational equations describing one type of suspension bridges are proposed and studied. The variational equations describe the behaviour of road bed, main cables and cable stays. The road bed is described by two functions connected with vertical and horizontal deformation of any cross section. The main cable is considered to be perfectly flexible and inextensible. The cable stays only resist tensile forces. The variational equations are derived from the principle of minimum potential energy. The existence of solution is based on the Brouwer Fixed Point Theorem. The local uniqueness and continuous dependence on the data represented by gravitational forces acting on the road bed are studied. The local results are based on the Implicit Function Theorem for Banach spaces. A certain stability criterion for suspension bridges is formulated and this criterion indicates how to influence the stability of suspension bridges.

Malik, Josef

2006-09-01

279

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

USGS Publications Warehouse

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

Kalkan, E.; Kwong, N.

2012-01-01

280

Documentation for assessment of modal pushover-based scaling procedure for nonlinear response history analysis of "ordinary standard" bridges  

USGS Publications Warehouse

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

Kalkan, Erol; Kwong, Neal S.

2010-01-01

281

2.NBT Toll Bridge Puzzle  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The picture shows islands connected by bridges. To cross a bridge, you must pay a toll in coins. If you start on the island marked in blue with 100 coi...

2012-07-20

282

Balanced bridge feedback control system  

NASA Technical Reports Server (NTRS)

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. (inventor)

1990-01-01

283

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

USGS Publications Warehouse

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

Ivanoff, Michael A.; Song, Donald L.

1996-01-01

284

A Framework for Historic Bridge Preservation  

E-print Network

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

Puls, Eric Mark

2013-08-08

285

Skewed X-chromosome inactivation in women affected by Alzheimer's disease.  

PubMed

X-chromosome instability has been a long established feature in Alzheimer's disease (AD). Premature centromere division and aneuploidy of the X-chromosome has been found in peripheral blood lymphocytes and neuronal tissue in female AD patients. Interestingly, only one chromosome of the X pair has been affected. These results raised a question, "Is the X-chromosome inactivation pattern altered in peripheral blood lymphocytes of women affected by AD?" To address this question, we analyzed the methylation status of androgen receptor promoter which may show us any deviation from the 50 : 50% X inactivation status in peripheral blood lymphocytes of women with AD. Our results showed skewed inactivation patterns (>90%). These findings suggest that an epigenetic alteration on the inactivation centers of the X-chromosome (or skewing) relates not only to aging, by might be a novel property that could account for the higher incidence of AD in women. PMID:25159673

Bajic, Vladan; Mandusic, Vesna; Stefanova, Elka; Bozovic, Ana; Davidovic, Radoslav; Zivkovic, Lada; Cabarkapa, Andrea; Spremo-Potparevic, Biljana

2015-01-01

286

Surveying and optical tooling technologies combined to align a skewed beamline at the LAMPF accelerator  

SciTech Connect

Optical Tooling evolved from traditional surveying, and both technologies are sometimes used interchangeably in large industrial installations, since the instruments and their specialized adapters and supports complement each other well. A unique marriage of both technologies was accomplished in a novel application at LAMPF, the Los Alamos Meson Physics Facility. LAMPF consists of a linear accelerator with multiple target systems, one of which had to be altered to accommodate a new beamline for a neutrino experiment. The new line was to be installed into a crowded beam tunnel and had to be skewed and tilted in compound angles to avoid existing equipment. In this paper we describe how Optical Tooling was used in conjunction with simple alignment and reference fixtures to set fiducials on the magnets and other mechanical components of the beamline, and how theodolites and sight levels were then adapted to align these components along the calculated skew planes. Design tolerances are compared with measured alignment results.

Bauke, W.; Clark, D.A.; Trujillo, P.B.

1985-01-01

287

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

NASA Astrophysics Data System (ADS)

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

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

2010-10-01

288

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

PubMed Central

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

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

2013-01-01

289

Surveying and optical tooling technologies combined to align a skewed beamline at the LAMPF accelerator  

NASA Astrophysics Data System (ADS)

Optical tooling evolved from traditional surveying, and both technologies are sometimes used interchangeably in large industrial installations, since the instruments and their specialized adapters and supports complement each other well. A unique marriage of both technologies was accomplished in a novel application at LAMPF, the Los Alamos Meson Physics Facility. LAMPF consists of a linear accelerator with multiple target systems, one of which had to be altered to accommodate a new beamline for a neutrino experiment. The new line was to be installed into a crowded beam tunnel and had to be skewed and tilted in compound angles to avoid existing equipment. Optical tooling was used in conjunction with simple alignment and reference fixtures to set fiducials on the magnets and other mechanical components of the beamline, and how theodolites and sight levels were then adapted to align these components along the calculated skew planes. Design tolerances are compared with measured alignment results.

Bauke, W.; Clark, D.; Trujillo, P. B.

290

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

291

33 CFR 118.70 - Lights on swing bridges.  

... 2014-07-01 2014-07-01 false Lights on swing bridges. 118.70 Section 118...BRIDGE LIGHTING AND OTHER SIGNALS § 118.70 Lights on swing bridges. (a) Swing span lights on through bridges. Each swing...

2014-07-01

292

23 CFR 650.809 - Movable span bridges.  

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

2014-04-01

293

23 CFR 650.809 - Movable span bridges.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

294

23 CFR 650.809 - Movable span bridges.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

295

23 CFR 650.809 - Movable span bridges.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

296

23 CFR 650.809 - Movable span bridges.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

297

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

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

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

298

Quantum integrable systems, non-skew-symmetric r-matrices and algebraic Bethe ansatz  

SciTech Connect

We prove the integrability of the general quantum Hamiltonian systems governed by an arbitrary non-skew-symmetric, so(3)-valued, nondynamical classical r-matrix with spectral parameters. We consider the most interesting example of these quantum integrable systems, namely, the so(3) 'generalized Gaudin systems' in detail. In the case of an arbitrary r-matrix which is 'diagonal' in the sl(2) basis we calculate the spectrum and the eigenvalues of the corresponding Hamiltonians using the algebraic Bethe ansatz technique.

Skrypnyk, T. [Bogoliubov Institute for Theoretical Physics, Institute of Mathematics of NASU, Metrologichna Strasse, 14-b, Kiev 03143 (Ukraine)

2007-02-15

299

Measuring skewness of red blood cell deformability distribution by laser ektacytometry  

NASA Astrophysics Data System (ADS)

An algorithm is proposed for measuring the parameters of red blood cell deformability distribution based on laser diffractometry of red blood cells in shear flow (ektacytometry). The algorithm is tested on specially prepared samples of rat blood. In these experiments we succeeded in measuring the mean deformability, deformability variance and skewness of red blood cell deformability distribution with errors of 10%, 15% and 35%, respectively.

Nikitin, S. Yu; Priezzhev, A. V.; Lugovtsov, A. E.; Ustinov, V. D.

2014-08-01

300

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

301

Local limit theorem for nonuniformly partially hyperbolic skew-products and Farey sequences  

Microsoft Academic Search

We study skew-products of the form $(x,\\\\omega)\\\\mapsto (Tx, \\\\omega+\\\\phi(x))$ , where $T$ is a nonuniformly expanding map on a space $X$ , preserving a (possibly singular) probability measure $\\\\tilde\\\\mu$ , and $\\\\phi:X\\\\to \\\\mathbb{S}^1$ is a $C^1$ function. Under mild assumptions on $\\\\tilde\\\\mu$ and $\\\\phi$ , we prove that such a map is exponentially mixing and satisfies both the central limit

Sébastien Gouëzel

2009-01-01

302

Local limit theorem for nonuniformly partially hyperbolic skew-products, and Farey sequences  

Microsoft Academic Search

We study skew-products of the form (x,\\\\omega)\\\\mapsto (Tx, \\\\omega+\\\\phi(x)) where T is a nonuniformly expanding map on a space X, preserving a (possibly singular) probability measure \\\\tilde\\\\mu, and \\\\phi:X\\\\to S^1 is a C^1 function. Under mild assumptions on \\\\tilde\\\\mu and \\\\phi, we prove that such a map is exponentially mixing, and satisfies the central and local limit theorems. These results

Sebastien Gouezel

2007-01-01

303

Schrödinger uncertainty relation, Wigner-Yanase-Dyson skew information and metric adjusted correlation measure  

E-print Network

In this paper, we give a Schr\\"odinger-type uncertainty relation using the Wigner-Yanase-Dyson skew information. In addition, we give Schr\\"odinger-type uncertainty relation by use of a two-parameter extended correlation measure. Moreover, we give the further generalization for Schr\\"odinger-type uncertainty relation by metric adjusted correlation measure. These results generalize our previous result in [Phys. Rev. A, Vol.82(2010), 034101].

Shigeru Furuichi; Kenjiro Yanagi

2010-10-03

304

Skew-symmetric tensor gauge field theory dynamically realized in the QCD U(1) channel  

Microsoft Academic Search

It is shown that, in order for the U(1) Goldstone boson to decouple from the physical sector, a third rank skew-symmetric tensor gauge field theory has to be realized dynamically by asymptotic fields of bound states in QCD. The abelian-like gauge invariance of this tensor gauge theory is just a realization of the original QCD gauge (BRS) invariance which hence

Hiroyuki Hata; Taichiro Kugo; Nobuyoshi Ohta

1981-01-01

305

Design and testing of a redundant skewed inertial sensor complex for integrated navigation and flight control  

NASA Technical Reports Server (NTRS)

Requirements for a redundant strapdown inertial sensor complex applied to V/STOL aircraft as developed by NASA are presented. Flight test data of a redundant, skewed axis strapdown inertial system are given, demonstrating the feasibility of the primary design aspects. This data consisted of parity equation responses through various flight conditions, showing residual noise levels on redundant gyro and accelerometer comparisons as a measure of minimum failure-level detectability, plus failure isolation and navigation performance through several simulated instrument failures.

Ebner, R. E.; Howell, W. E.

1979-01-01

306

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 calculators’ capabilities to find the x-intercepts and the maximum value on the graph. Teacher notes, detailed instructions on using graphing calculators, and questions to check comprehension aid in teaching the lesson.

2012-08-30

307

The Bridge to Manufacturing Project  

ERIC Educational Resources Information Center

A grant project was designed to facilitate the transition of students from a community college adult education program into a community college credit-degree program in manufacturing. Key features of the program included a focus on identifying policy implications; bridging the separation between the adult education segment of the community college…

Puchner, Laurel; Taylor, Ann R.; Harris, Valorie K.; Marshall, Rick W.; Powell, Margaret

2010-01-01

308

to China: A Bridge Between  

E-print Network

From Yale to China: A Bridge Between Cultures Students often invoke the metaphor of a journey in China," she said. "Yale oered a vast array of resources to help me improve my language compe- tency program and myriad exchanges with China. The summer before her sophomore year at Yale, Jenna received

309

The Bridges of Social Change  

E-print Network

of Philadelphia to the Garden State of New Jersey. This majestic bridge models Cret's ability to incorporate was conceived and created for commuters between New Jersey and Philadelphia, he had the fore- sight to design, highlights SP2's interdisciplinary focus by featuring its work with city planning, veterinary studies

Sharp, Kim

310

A Changing Bridge for Changing Times: The History of the West Boston Bridge, 1793-1907  

Microsoft Academic Search

Master of Arts Thesis, June 2000: This thesis examines the construction in 1793 of the West Boston Bridge, the first bridge to span the Charles River between Boston and Cambridge, and its successors at the same location in 1854 and then 1907 (the Longfellow Bridge). It is a study of the impact of these bridges on the commercial development and

Dale H Freeman

2000-01-01

311

Deflection and stress analysis of stiffened orthotropic skew panels under uniform transverse loading  

NASA Astrophysics Data System (ADS)

Skew plates with different orientations behave in a manner quite different from those of rectangular plates. An analysis has been carried out for the deflections and stresses of plates with various skew angles subjected to uniformly distributed tranverse loads. It has been thought that the excess deflection at the rear tip of a cantilever plate can be reduced by applying stiffeners along the length of the plate. These stiffeners can also reduce the stresses at the root drastically. The skin-stringer connections in aircraft can be treated as a problem of this type. An investigation has been carried out on the stress and deflection characteristics of stiffened parallelogramic plates with different skew angles. The numerical solution with assumed displacement function was developed using a finite element analysis. Experiments using aluminum and Scotchply composite laminates were conducted to verify the results. Cantilever and simply supported boundary conditions were included in the analysis, and an optimized angular stiffener for a particular swept-back panel was achieved.

Tripathy, A. K.; Pang, Su-Seng

312

Deterioration of the skew quadrupole moment in Tevatron dipoles over time  

SciTech Connect

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

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

2005-05-01

313

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

PubMed

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

Vaughn, Laura M; Masson, Patrick H

2011-07-01

314

Reproductive partitioning and the assumptions of reproductive skew models in the cooperatively breeding American crow.  

PubMed

Understanding the benefits of cooperative breeding for group members of different social and demographic classes requires knowledge of their reproductive partitioning and genetic relatedness. From 2004-2007, we examined parentage as a function of relatedness and social interactions among members of 21 American crow (Corvus brachyrhynchos) family groups. Paired female breeders monopolized maternity of all offspring in their broods, whereas paired male breeders sired 82.7% of offspring, within-group auxiliary males sired 6.9% of offspring, and extragroup males sired 10.4% of offspring. Although adult females had fewer opportunities for direct reproduction as auxiliaries than males, they appeared to have earlier opportunities for independent breeding. These different opportunities for direct reproduction probably contributed to the male biased adult auxiliary sex ratio. Patterns of reproductive partitioning and conflict among males were most consistent with a synthetic reproductive skew model, in which auxiliaries struggled with breeders for a limited reproductive share, beyond which breeders could evict them. Counter to a frequent assumption of reproductive skew models, female breeders appeared to influence paternity, although their interests might have agreed with the interests of their paired males. Unusual among cooperative breeders, close inbreeding and incest occurred in this population. Incest avoidance between potential breeders did not significantly affect reproductive skew. PMID:20126287

Townsend, Andrea K; Clark, Anne B; McGowan, Kevin J; Lovette, Irby J

2009-02-01

315

PROJECT BRIDGE JUNE-JULY 2013  

E-print Network

PROJECT BRIDGE JUNE-JULY 2013 Project Bridge is a newsletter of the Center for Disabilities Studies in June, July and early August. Some changes have been made to the format and layout of Project Bridge with Disabilities Through funding from the Delaware Division of Public Health Dental Program, Healthy Delawareans

Firestone, Jeremy

316

Evacuation research ............... 3 Bridge collapse course............ 3  

E-print Network

for research related to I-35W bridge collapse, share insight with media Two new research projects are under way in response to the August 1 collapse of the I-35W bridge in Minneapolis. Faculty in the Department of CivilInside · Evacuation research ............... 3 · Bridge collapse course............ 3 · Call

Minnesota, University of

317

Development of a bridge fault extractor tool  

E-print Network

...................................??............................................................. 50 VITA?????...????????????????????????. 55 vii LIST OF FIGURES Page Figure 1. Different bridge models... Page Table 1. Previous, present and future semiconductor technology roadmap......................... 2 Table 2: FedEx improvements (insertion ? only intralayer bridges).................................. 27 Table 3. FedEx improvements (bridging...

Bhat, Nandan D.

2005-02-17

318

Preservation Treatment for Wood Bridge Application  

Microsoft Academic Search

Timber can often be a cost-effective construction material for new bridges. The durability of the bridge greatly depends on proper attention to construction details and fabrication, as well as proper preservative treatment before, during, and after construction. Material repair and replacement costs for bridges are a considerable expense for highway agencies. To address these needs, the objectives of an investigation

Jake Bigelow; Stan Lebow; Carol A. Clausen; Lowell Greimann; Terry J. Wipf

2009-01-01

319

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

320

Some case studies of skewed (and other ab-normal) data distributions arising in low-level environmental research.  

PubMed

Three general classes of skewed data distributions have been encountered in research on background radiation, chemical and radiochemical blanks, and low levels of 85Kr and 14C in the atmosphere and the cryosphere. The first class of skewed data can be considered to be theoretically, or fundamentally skewed. It is typified by the exponential distribution of inter-arrival times for nuclear counting events for a Poisson process. As part of a study of the nature of low-level (anti-coincidence) Geiger-Muller counter background radiation, tests were performed on the Poisson distribution of counts, the uniform distribution of arrival times, and the exponential distribution of inter-arrival times. The real laboratory system, of course, failed the (inter-arrival time) test--for very interesting reasons, linked to the physics of the measurement process. The second, computationally skewed, class relates to skewness induced by non-linear transformations. It is illustrated by non-linear concentration estimates from inverse calibration, and bivariate blank corrections for low-level 14C-12C aerosol data that led to highly asymmetric uncertainty intervals for the biomass carbon contribution to urban "soot". The third, environmentally, skewed, data class relates to a universal problem for the detection of excursions above blank or baseline levels: namely, the widespread occurrence of ab-normal distributions of environmental and laboratory blanks. This is illustrated by the search for fundamental factors that lurk behind skewed frequency distributions of sulfur laboratory blanks and 85Kr environmental baselines, and the application of robust statistical procedures for reliable detection decisions in the face of skewed isotopic carbon procedural blanks with few degrees of freedom. PMID:11508459

Currie, L A

2001-07-01

321

Inheritance of skewed X chromosome inactivation in a large family with an X-linked recessive deafness syndrome  

SciTech Connect

A new X-linked recessive deafness syndrome was recently reported and mapped to Xq22 (Mohr-Tranebjaeerg syndrome). In addition to deafness, the patients had visual impairment, dystonia, fractures, and mental deterioration. The female carriers did not have any significant manifestations of the syndrome. We examined X chromosome inactivation in 8 obligate and 12 possible carriers by using a polymerase chain reaction analysis of the methylation-dependent amplification of the polymorphic triplet repeat at the androgen receptor locus. Seven of 8 obligate carriers and 1 of 5 carriers by linkage analysis had an extremely skewed pattern in blood DNA not found in 30 normal females. The X inactivation pattern in fibroblast DNA from 2 of the carriers with the extremely skewed pattern was also skewed but to a lesser degree than in blood DNA. One obligate carrier had a random X inactivation pattern in both blood and fibroblast DNA. A selection mechanism for the skewed pattern is therefore not likely. The extremely skewed X inactivation in 8 females of 3 generations in this family may be caused by a single gene that influences skewing of X chromosome inactivation. 22 refs., 2 figs., 1 tab.

Orstavik, K.H.; Orstavik, R.E.; Eiklid, K. [Ulleval Univ. Hospital, Oslo (Norway)] [Ulleval Univ. Hospital, Oslo (Norway); Tranebjaerg, L. [Univ. Hospital, Tromso (Norway)] [Univ. Hospital, Tromso (Norway)

1996-07-12

322

Performance analysis of LAN bridges and routers  

NASA Technical Reports Server (NTRS)

Bridges and routers are used to interconnect Local Area Networks (LANs). The performance of these devices is important since they can become bottlenecks in large multi-segment networks. Performance metrics and test methodology for bridges and routers were not standardized. Performance data reported by vendors is not applicable to the actual scenarios encountered in an operational network. However, vendor-provided data can be used to calibrate models of bridges and routers that, along with other models, yield performance data for a network. Several tools are available for modeling bridges and routers - Network II.5 was used. The results of the analysis of some bridges and routers are presented.

Hajare, Ankur R.

1991-01-01

323

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

324

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

325

Numerical investigations of the spreading-rate dependence of anomalous skewness of marine magnetic anomalies due to seafloor spreading  

NASA Astrophysics Data System (ADS)

An improved understanding of the spreading-rate dependence of anomalous skewness from magnetic anomalies due to seafloor spreading will allow for better constraints on apparent polar wander paths, plate reconstructions, and the magnetic and thermal structure of oceanic lithosphere. Anomalous skewness, which is the difference between experimentally determined skewness and skewness expected from simple magnetization models with vertical reversal boundaries, has been observed to vary as a function of spreading rate, decreasing with increasing spreading rate and becoming negligible at spreading half-rates exceeding about 55 mm/a [Roest et al. 1992; Dyment et al. 1994]. In our analysis, we determine model-based estimates of anomalous skewness as a function of spreading rate for each anomaly. We do so by creating many synthetic profiles using the model of Dyment and Arkani-Hamed (1995), which was specifically constructed to produce anomalies with anomalous skewness consistent with observed anomalies. We experimentally determine the phase shift that causes the resulting synthetic magnetic anomaly to best match a profile produced from a "standard" model for anomalies due to seafloor spreading that assumes simple vertical reversal boundaries. We present results for those anomalies between 12r and 33r from which reliable paleomagnetic poles may potentially be determined. Differences in anomalous skewness for different anomalies determined at the same spreading rate can be attributed to the sequence effect, that is, the effect on the shape of a magnetic anomaly above seafloor of a single polarity chron of the magnetization of neighboring blocks of lithosphere magnetized during other chrons. We find that the sequence effect is smaller than we expected with the largest difference being between the results for anomaly 25r and those for anomaly 33r, for which the difference is 14 degrees at a 10 mm/a half-rate. Results for other anomalies lie between these two. We also infer a small outward displacement of the magnetic anomalies, which-like anomalous skewness-decreases with increasing spreading rate and vanishes at half rates exceeding 55 mm/a. We find that results obtained trying to find the best match to the synthetic magnetic anomaly profile are generally similar to results obtained when using the balanced-shoulder criterion for when an anomaly has been successfully deskewed. The values of chron-specific (or anomaly-specific) anomalous skewness that we have determined can be used to reduce the number of adjustable parameters in the determination of paleomagnetic poles from skewness data from three to two, to simply the latitude and longitude of the paleomagnetic pole. Implications for the northward motion of the Pacific Plate will be discussed.

Boswell, S. M.; Zheng, L.; Gordon, R. G.; Dyment, J.

2011-12-01

326

New oxa-bridged macrocycles.  

PubMed

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

Panten, Johannes; Surburg, Horst; Hölscher, Bernd

2008-06-01

327

Dynamical Bridges: The Electromagnetic Case  

NASA Astrophysics Data System (ADS)

We present the main line of the Dynamical Bridge method applied to electromagnetic (EM) fields. In this framework, we show the equivalence between the Born- Infeld theory written in a given curved space to the Maxwell's one written in the flat space. In the limit of weak EM fields, we obtain a geometrical contribution to the anomalous magnetic moment of the leptons and, finally, we compare it with experimental data.

Bittencourt, Eduardo

2014-12-01

328

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

329

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

USGS Publications Warehouse

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

Brabets, T.P.

1994-01-01

330

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. PMID:20042086

2009-01-01

331

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. PMID:21287621

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

2010-01-01

332

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

PubMed Central

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

Kokko, H.; Johnstone, R. A.

1999-01-01

333

Local obstructions to projective surfaces admitting skew-symmetric Ricci tensor  

NASA Astrophysics Data System (ADS)

The equation determining whether a projective structure admits a connection in its given projective class that has skew-symmetric Ricci tensor is an overdetermined system of semi-linear partial differential equations which we call the projective Einstein-Weyl (pEW) equation. In 2-dimensions, we give local obstructions for projective surfaces to admit such a connection in its projective class. The obstructions are the resultants of polynomial equations that have to be satisfied for there to admit any pEW solution.

Randall, Matthew

2014-02-01

334

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

335

Skewness in (1 +1 ) -dimensional Kardar-Parisi-Zhang-type growth  

NASA Astrophysics Data System (ADS)

We use the (1 +1 ) -dimensional Kardar-Parisi-Zhang equation driven by a Gaussian white noise and employ the dynamic renormalization-group of Yakhot and Orszag without rescaling [J. Sci. Comput. 1, 3 (1986), 10.1007/BF01061452]. Hence we calculate the second- and third-order moments of height distribution using the diagrammatic method in the large-scale and long-time limits. The moments so calculated lead to the value S =0.3237 for the skewness. This value is comparable with numerical and experimental estimates.

Singha, Tapas; Nandy, Malay K.

2014-12-01

336

Skew-Symmetric Lax Polynomial Matrices and Integrable Rigid Body Systems  

NASA Astrophysics Data System (ADS)

Skew-symmetric matrix Lax polynomials are considered. Few rigid body systems with such representations are presented. Lagrange bitop is completely integrable four-dimensional rigid body system. Algebro-geometric integration procedure, using Lax representation, for that system is performed. This integration is based on deep facts from the theory of Prym varieties such as the Mumford relation and Mumford-Dalalyan theory. Class of isoholomorphic integrable systems is established and importation class of its perturbations is observed, generalizing classical Hess-Appel'rot system.

Dragovi?, V.; Gaji?, B.

2005-03-01

337

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

2012-12-01

338

Development of a contour map showing generalized skew coefficients of annual peak discharges of rural, unregulated streams in New York, excluding Long Island  

USGS Publications Warehouse

Flood-frequency relations that are developed by fitting the logarithms of annual peak discharges to a Pearson Type-III distribution are sensitive to skew coefficients. Estimates of population skew for a site are improved when computed from the weighted average of (1) the sample (station) skew, and (2) an unbiased, generalized skew estimate. A weighting technique based on the number of years of record at each of 226 sites was used to develop a contour map of unbiased, generalized skew coefficients for New York. An attempt was made to group (regionalize) the station skew coefficients into five hydrologically similar areas of New York, but the statewide version proved to be as accurate as the regionalized version and therefore was adopted as the final generalized skew-coefficient map for New York. An error analysis showed the statewide contour map to have lower MSE?s (mean square errors) than those computed from (1) the five regional skewcoefficient contour maps, (2) a previously used (1982) nationwide skew coefficient map, and (3) the weighted mean of skew coefficients for sites within each of five hydrologically uniform, but distinct areas of New York.

Lumia, Richard; Baevsky, Yvonne Halpern

2000-01-01

339

Myocardial bridges: morphological and functional aspects  

Microsoft Academic Search

OBJECTIVE--To assess the arrangement of myocardial bridges. DESIGN--A necropsy study of 90 consecutive hearts (56 male, 34 female). RESULTS--Myocardial bridges, either single or multiple, were seen in 50 (55.6%) of the 90 hearts. The left anterior descending artery was the most commonly affected artery. Thirty five of the 50 hearts which contained in total 41 muscle bridges were dissected further

A G Ferreira; S E Trotter; B König; L V Décourt; K Fox; E G Olsen

1991-01-01

340

Overweight permit formulas for simply supported bridges  

E-print Network

older bridge designs. Seelye (1957) provided design specifications for span lengths up to 80 ft. for these two types of bridges. The two typical bridge cross sections from Seelye (1957) are shown in Figs. 6 and 7. 1/2' 91 5 3" 2I2ll 10e 12. 0s... of 14. 5 inches from Table 3 results in a cross sectional area of 7. 0 ft . With a concrete density of 0. 15k/ft3 the distributed dead load is 1. 05k/ft. as seen in Table 5. The calculations for a steel stringer bridge would be similar except...

Mattox, Michael Joseph

2012-06-07

341

Buddha and the bridging relations.  

PubMed

The chapter reviews a classical Indian model of consciousness found in the Abhidhamma, a collection of seven treatises in the Pali Canon Tipitaka. The model was based on observations made during advanced vipassana practice, a first-person method taught by the Buddha. The climax of the model consists in the elucidation of 24 'Bridging Relations' causally linking the stream of consciousness, its contents and associated physical events. Review of such a model based on a specialized first-person technique could prove to be a resource of useful ideas providing directions for further research. PMID:18166400

Banerjee, Rahul

2008-01-01

342

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

343

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

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

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

344

Deconstructing risk: Separable encoding of variance and skewness in the brain  

PubMed Central

Risky choice entails a need to appraise all possible outcomes and integrate this information with individual risk preference. Risk is frequently quantified solely by statistical variance of outcomes, but here we provide evidence that individuals’ choice behaviour is sensitive to both dispersion (variance) and asymmetry (skewness) of outcomes. Using a novel behavioural paradigm in humans, we independently manipulated these ‘summary statistics’ while scanning subjects with fMRI. We show that a behavioural sensitivity to variance and skewness is mirrored in neuroanatomically dissociable representations of these quantities, with parietal cortex showing sensitivity to the former and prefrontal cortex and ventral striatum to the latter. Furthermore, integration of these objective risk metrics with subjective risk preference is expressed in a subject-specific coupling between neural activity and choice behaviour in anterior insula. Our findings show that risk is neither monolithic from a behavioural nor neural perspective and its decomposition is evident both in distinct behavioural preferences and in segregated underlying brain representations. PMID:21763444

Symmonds, Mkael; Wright, Nicholas D.; Bach, Dominik R.; Dolan, Raymond J.

2011-01-01

345

Weighted skewness and kurtosis unbiased by sample size and Gaussian uncertainties  

NASA Astrophysics Data System (ADS)

Central moments and cumulants are often employed to characterize the distribution of data. The skewness and kurtosis are particularly useful for the detection of outliers, the assessment of departures from normally distributed data, automated classification techniques and other applications. Estimators of higher order moments that are robust against outliers are more stable but might miss characteristic features of the data, as in the case of astronomical time series exhibiting brief events like stellar bursts or eclipses of binary systems, while weighting can help identify reliable measurements from uncertain or spurious outliers. Furthermore, noise is an unavoidable part of most measurements and their uncertainties need to be taken properly into account during the data analysis or biases are likely to emerge in the results, including basic descriptive statistics. This work provides unbiased estimates of the weighted skewness and kurtosis moments and cumulants, corrected for biases due to sample size and Gaussian noise, under the assumption of independent data. A comparison of biased and unbiased weighted estimators is illustrated with simulations as a function of sample size and signal-to-noise ratio, employing different data distributions and weighting schemes related to measurement uncertainties and the sampling of the signal. Detailed derivations and figures of simulation results are presented in the Appendices available online.

Rimoldini, Lorenzo

2014-07-01

346

Role of exterior and evolutionary skew-symmetric differential forms in mathematical physics  

E-print Network

A role of skew-symmetric differential forms in mathematical physics relates to the fact that they reflect the properties of conservation laws. The closed exterior forms correspond to the conservation laws for physical fields, whereas the evolutionary forms correspond to the conservation laws for material media. Skew-symmetric differential forms can describe a conjugacy of any objects (that correspond to the conservation laws). The closed exterior forms describe conjugated objects. And the evolutionary forms, whose basis are deforming manifolds, describe the process of conjugating objects and obtaining conjugated objects. From the evolutionary forms the closed exterior forms are obtained. This shows that material media generate physical fields. The relation between evolutionary and closed exterior forms discloses the relation between the equations of mathematical physics and field theories. This explains the field theory postulates. Conjugacy is possible if there is symmetry. Symmetries of closed exterior forms, which are conditions of fulfilment of the conservation laws for physical fields, are interior symmetries of field theories. And symmetries of dual forms (due to the degrees of freedom of material media) are external symmetries of the equations of field theories. This shows connection between internal and external symmetries of field theories.

L. I. Petrova

2005-10-21

347

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

348

A Changing Bridge for Changing Times: The History of the West Boston Bridge, 1793-1907  

Microsoft Academic Search

This thesis examines the building of the West Boston Bridge in 1793, which was the first bridge to cross the Charles River between Cambridge and Boston, as well as the building of its successors at the same location in 1854 and 1907. It is a study of how these bridges brought change to both Boston and Cambridge which resulted not

Dale H Freeman

2000-01-01

349

rBridge: User Reputation based Tor Bridge Distribution with Privacy Preservation  

E-print Network

rBridge: User Reputation based Tor Bridge Distribution with Privacy Preservation Qiyan Wang Department of Computer Science University of Minnesota hopper@cs.umn.edu Abstract Tor is one of the most censorship. A key challenge to the Tor circumvention system is to distribute bridges to a large number

Minnesota, University of

350

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

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

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

351

Bridge coupled drift tube linacs  

NASA Astrophysics Data System (ADS)

Modern linac designs for treating radioactive waste achieve high proton currents through funneling at low energy, typically around 20 MeV. The resulting switch to a high-frequency accelerating structure poses severe performance and fabrication difficulties below 100 MeV. Above 100 MeV, proven coupled-cavity linacs (CCLs) are available. However, at 20 MeV one must choose between a high-frequency drift-tube linac (DTL) or a coupled-cavity linac with very short cells. Potential radiation damage from the CW beam, excessive RF power losses, multipactoring, and fabricability all enter into this decision. At Los Alamos, we have developed designs for a bridge-coupled DTL (BCDTL) that, like a CCL, uses lattice focusing elements and bridge couplers, but that unlike a CCL, accelerates the beam in simple, short, large aperture DTL modules with no internal quadrupole focusing. Thus, the BCDTL consumes less power than the CCL linac without degrading beam performance and is simpler and cheaper to fabricate in the 20 to 100 MeV range.

Liska, D.; Smith, P.; Carlisle, L.; Larkin, T.

1993-06-01

352

Bridges to sustainable tropical health  

PubMed Central

Ensuring sustainable health in the tropics will require bridge building between communities that currently have a limited track record of interaction. It will also require new organizational innovation if much of the negative health consequences of large-scale economic development projects are to be equitably mitigated, if not prevented. We focus attention on three specific contexts: (i) forging linkages between the engineering and health communities to implement clean water and sanitation on a broad scale to prevent reworming, after the current deworming-only programs, of people by diverse intestinal parasites; (ii) building integrated human and animal disease surveillance infrastructure and technical capacity in tropical countries on the reporting and scientific evidence requirements of the sanitary and phytosanitary agreement under the World Trade Organization; and (iii) developing an independent and equitable organizational structure for health impact assessments as well as monitoring and mitigation of health consequences of economic development projects. Effective global disease surveillance and timely early warning of new outbreaks will require a far closer integration of veterinary and human medicine than heretofore. Many of the necessary surveillance components exist within separate animal- and human-oriented organizations. The challenge is to build the necessary bridges between them. PMID:17913894

Singer, Burton H.; de Castro, Marcia Caldas

2007-01-01

353

Salt-bridge energetics in halophilic proteins.  

PubMed

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

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

2014-01-01

354

Evidence that mutations in the X-linked DDP gene cause incompletely penetrant and variable skewed X inactivation.  

PubMed Central

X chromosome inactivation results in the random transcriptional silencing of one of the two X chromosomes early in female development. After random inactivation, certain deleterious X-linked mutations can create a selective disadvantage for cells in which the mutation is on the active X chromosome, leading to X inactivation patterns with the mutation on the inactive X chromosome in nearly 100% of the individual's cells. In contrast to the homogeneous patterns of complete skewed inactivation noted for many X-linked disorders, here we describe a family segregating a mutation in the dystonia-deafness peptide (DDP) gene, in which female carriers show incompletely penetrant and variable X inactivation patterns in peripheral blood leukocytes, ranging between 50:50 and >95:5. To address the genetic basis for the unusual pattern of skewing in this family, we first mapped the locus responsible for the variable skewing to the proximal long arm (Xq12-q22) of the X chromosome (Z=5. 7, P=.002, LOD score 3.57), a region that includes both the DDP and the XIST genes. Examination of multiple cell types from women carrying a DDP mutation and of peripheral blood leukocytes from women from two unrelated families who carry different mutations in the DDP gene suggests that the skewed X inactivation is the result of selection against cells containing the mutant DDP gene on the active X chromosome, although skewing is apparently not as severe as that seen for many other deleterious X-linked mutations. Thus, DDP is an example of an X-linked gene for which mutations cause partial cell selection and thus incompletely skewed X inactivation in peripheral blood leukocytes. PMID:10053010

Plenge, R M; Tranebjaerg, L; Jensen, P K; Schwartz, C; Willard, H F

1999-01-01

355

21 CFR 872.3770 - Temporary crown and bridge resin.  

... false Temporary crown and bridge resin. 872.3770 Section...CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices...3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device...

2014-04-01

356

21 CFR 872.3770 - Temporary crown and bridge resin.  

Code of Federal Regulations, 2011 CFR

... false Temporary crown and bridge resin. 872.3770 Section...CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices...3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device...

2011-04-01

357

21 CFR 872.3770 - Temporary crown and bridge resin.  

Code of Federal Regulations, 2013 CFR

... false Temporary crown and bridge resin. 872.3770 Section...CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices...3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device...

2013-04-01

358

21 CFR 872.3770 - Temporary crown and bridge resin.  

Code of Federal Regulations, 2012 CFR

... false Temporary crown and bridge resin. 872.3770 Section...CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices...3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device...

2012-04-01

359

Plastic Hinging Behavior of Reinforced Concrete Bridge Columns  

E-print Network

The location of inelastic deformations in reinforced concrete bridge columns has been examined to simulate the nonlinear response of bridge columns and estimate the ultimate displacement capacity. In bridge columns, these nonlinear deformations...

Firat Alemdar, Zeynep

2010-04-27

360

OUTERBRIDGE CROSSING BRIDGE LINED UP WITH MANHATTAN SKYLINE IN MIDDLE ...  

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

OUTERBRIDGE CROSSING BRIDGE LINED UP WITH MANHATTAN SKYLINE IN MIDDLE OF HORIZON, VERRAZANO NARROWS BRIDGE TO THE RIGHT - Outerbridge Crossing Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

361

49 CFR 237.101 - Scheduling of bridge inspections.  

Code of Federal Regulations, 2011 CFR

...inspection for each bridge in railroad service at least once...management program when a railroad bridge engineer determines...flood, fire, earthquake, derailment or vehicular or vessel impact. (d) Any railroad bridge that has not...

2011-10-01

362

49 CFR 237.101 - Scheduling of bridge inspections.  

Code of Federal Regulations, 2012 CFR

...inspection for each bridge in railroad service at least once...management program when a railroad bridge engineer determines...flood, fire, earthquake, derailment or vehicular or vessel impact. (d) Any railroad bridge that has not...

2012-10-01

363

49 CFR 237.101 - Scheduling of bridge inspections.  

Code of Federal Regulations, 2013 CFR

...inspection for each bridge in railroad service at least once...management program when a railroad bridge engineer determines...flood, fire, earthquake, derailment or vehicular or vessel impact. (d) Any railroad bridge that has not...

2013-10-01

364

49 CFR 237.101 - Scheduling of bridge inspections.  

Code of Federal Regulations, 2010 CFR

...inspection for each bridge in railroad service at least once...management program when a railroad bridge engineer determines...flood, fire, earthquake, derailment or vehicular or vessel impact. (d) Any railroad bridge that has not...

2010-10-01

365

29 CFR 1917.124 - Dockboards (car and bridge plates).  

... 2014-07-01 false Dockboards (car and bridge plates). 1917.124 Section...Facilities § 1917.124 Dockboards (car and bridge plates). (a) General... (b) [Reserved] (c) Dockboards (car and bridge plates). (1)...

2014-07-01

366

Accurate resistive bridge fault modeling, simulation, and test generation  

E-print Network

Resistive bridging faults in CMOS combinational circuits are studied in this work. Bridging faults are modeled using HSPICE circuit simulation of the various types of bridging faults that can occur in CMOS combinational circuits. The results...

Sar-Dessai, Vijay Ramesh

2012-06-07

367

21. c, 1915 Historic plan, standard 2 beam girder bridge. ...  

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

21. c, 1915 Historic plan, standard 2 beam girder bridge. United Construction Company, Albany, New York. Generic plan typical of Prescott Bridge. Source: New Hampshire Department of Transportation - Prescott Bridge, Spanning Lamprey River on Prescott Road, Raymond, Rockingham County, NH

368

2. VIEW FROM OPPOSITE SOUTHEAST CORNER OF BRIDGE, LOOKING NORTH ...  

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

2. VIEW FROM OPPOSITE SOUTHEAST CORNER OF BRIDGE, LOOKING NORTH ALONG EASTERN ELEVATION. 14TH STREET BRIDGE AT RIGHT. - Tidal Reservoir, Outlet, Spanning Tidal Reservoir Outlet at Fourteenth Street Bridge, Washington, District of Columbia, DC

369

1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. ...  

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

1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN

370

1. View of Clark Fork Vehicle Bridge facing west. Panorama ...  

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

1. View of Clark Fork Vehicle Bridge facing west. Panorama showing the entire span of bridge from north shore of the Clark Fork River. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

371

1. AERIAL VIEW LOOKING SOUTHWEST (OLD HARVARD STREET BRIDGE AT ...  

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

1. AERIAL VIEW LOOKING SOUTHWEST (OLD HARVARD STREET BRIDGE AT LEFT, NEW BRIDGE AT RIGHT) - Old Harvard Street Bridge, Spanning Rock Creek at National Zoological Park, Washington, District of Columbia, DC

372

12. Interior detail of bridge operator's house showing generator and ...  

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

12. Interior detail of bridge operator's house showing generator and bridge operator, Mr. Gene Amonette, facing west. - Palm Valley Bridge, County Road 210 spanning Intracoastal Waterway, Ponte Vedra Beach, St. Johns County, FL

373

11. Standing on westerly fender at edge of bridge looking ...  

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

11. Standing on westerly fender at edge of bridge looking easterly, showing horizontal beams for deck and cross beams (reflection of steel grating on deck). Also shows bridge guardrail. - Colusa Bridge, Spanning Sacramento River, Colusa, Colusa County, CA

374

29. Historic photographer, photographer unknown, c. 1944. VIEW OF BRIDGE, ...  

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

29. Historic photographer, photographer unknown, c. 1944. VIEW OF BRIDGE, LOOKING EAST FROM TOP OF WEST TOWER. SHEEP CROSSING BRIDGE. NOTE SWAY CABLES. - Verde River Sheep Bridge, Spanning Verde River (Tonto National Forest), Cave Creek, Maricopa County, AZ

375

23 CFR 650.705 - Application for discretionary bridge funds.  

Code of Federal Regulations, 2010 CFR

...ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge...is responsible for submitting such data as required for candidate bridges. Data requested will include structure number, funds needed by fiscal...

2010-04-01

376

2. Contextual view of bridge in setting, from northwest end ...  

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

2. Contextual view of bridge in setting, from northwest end of bridge, view to south-southeast with Rawson Road in foreground. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

377

1. Contextual view of bridge in setting, from downstream, view ...  

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

1. Contextual view of bridge in setting, from downstream, view to southwest along Port Kenyon Road. South end of bridge at left. - Salt River Bridge, Spanning Salt River at Dillon Road, Ferndale, Humboldt County, CA

378

2. Contextual view of bridge in setting, from north end ...  

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

2. Contextual view of bridge in setting, from north end of bridge, view to north along Dillon Road. Former Valley Flower Creamery at right center. - Salt River Bridge, Spanning Salt River at Dillon Road, Ferndale, Humboldt County, CA

379

33 CFR 118.80 - Lights on bascule bridges.  

... 2014-07-01 2014-07-01 false Lights on bascule bridges. 118.80 Section 118...BRIDGE LIGHTING AND OTHER SIGNALS § 118.80 Lights on bascule bridges. (a) Lift span lights. Each lift span of every bascule...

2014-07-01

380

3. GENERAL VIEW LOOKING WEST, SHOWING LIFT BRIDGE. COUNTER WEIGHTS ...  

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

3. GENERAL VIEW LOOKING WEST, SHOWING LIFT BRIDGE. COUNTER WEIGHTS ARE LARGE SQUARES VISIBLE ABOVE BRIDGE. - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

381

GENERAL VIEW LOOKING WEST SHOWING LIFT BRIDGE. COUNTER WEIGHTS ARE ...  

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

GENERAL VIEW LOOKING WEST SHOWING LIFT BRIDGE. COUNTER WEIGHTS ARE LARGE SQUARES VISIBLE ABOVE BRIDGE - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

382

23 CFR 650.705 - Application for discretionary bridge funds.  

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year...

2014-04-01

383

23 CFR 650.705 - Application for discretionary bridge funds.  

Code of Federal Regulations, 2013 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year...

2013-04-01

384

23 CFR 650.807 - Bridges requiring a USCG permit.  

Code of Federal Regulations, 2012 CFR

...ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges...at the appropriate level by FHWA for structural concepts, hydraulics, and navigational clearances prior to submission of the...

2012-04-01

385

23 CFR 650.705 - Application for discretionary bridge funds.  

Code of Federal Regulations, 2012 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year...

2012-04-01

386

23 CFR 650.807 - Bridges requiring a USCG permit.  

Code of Federal Regulations, 2013 CFR

...ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges...at the appropriate level by FHWA for structural concepts, hydraulics, and navigational clearances prior to submission of the...

2013-04-01

387

23 CFR 650.705 - Application for discretionary bridge funds.  

Code of Federal Regulations, 2011 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year...

2011-04-01

388

23 CFR 650.807 - Bridges requiring a USCG permit.  

...ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges...at the appropriate level by FHWA for structural concepts, hydraulics, and navigational clearances prior to submission of the...

2014-04-01

389

33 CFR 118.140 - Painting bridge piers.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Painting bridge piers. 118.140 Section 118.140 ...SIGNALS § 118.140 Painting bridge piers. The District Commander may require painting the sides of bridge channel piers below the superstructure facing...

2011-07-01

390

33 CFR 118.140 - Painting bridge piers.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Painting bridge piers. 118.140 Section 118.140 ...SIGNALS § 118.140 Painting bridge piers. The District Commander may require painting the sides of bridge channel piers below the superstructure facing...

2010-07-01

391

3. VIEW EAST TOWARD STAMFORD ANCHOR BRIDGE #374 OF CIRCUIT ...  

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

3. VIEW EAST TOWARD STAMFORD ANCHOR BRIDGE #374 OF CIRCUIT BREAKER INSTALLATION ON CROSS BEAM OF BRIDGE. - New York, New Haven & Hartford Railroad, Bridge-Type Circuit Breakers, Long Island shoreline between Stamford & New Haven, Cos Cob, Fairfield County, CT

392

2. VIEW EAST TOWARD DARIEN ANCHOR BRIDGE #465 OF CIRCUIT ...  

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

2. VIEW EAST TOWARD DARIEN ANCHOR BRIDGE #465 OF CIRCUIT BREAKER INSTALLATION ON CROSS BEAM OF BRIDGE. - New York, New Haven & Hartford Railroad, Bridge-Type Circuit Breakers, Long Island shoreline between Stamford & New Haven, Cos Cob, Fairfield County, CT

393

2. VIEW EAST, GENERAL VIEW OF BRIDGE WITHIN SETTING, APPROACH ...  

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

2. VIEW EAST, GENERAL VIEW OF BRIDGE WITHIN SETTING, APPROACH SPANS ON RIGHT, PEDESTRIAN BRIDGE FOR HIKING TRAIL ON LEFT - Bridge No. 1132, Route 80, spanning Hammonasset River, Madison, New Haven County, CT

394

5. View showing Crooked River High Bridge in background and ...  

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

5. View showing Crooked River High Bridge in background and Ralph Modjeski railroad bridge in foreground - Crooked River High Bridge, Spanning Crooked River Gorge at Dalles-California Highway, Terrebonne, Deschutes County, OR

395

21 CFR 872.3770 - Temporary crown and bridge resin.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Temporary crown and bridge resin. 872.3770 Section 872.3770 Food...872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a...

2010-04-01

396

6. EARLY MORNING VIEW OF BOTH JOSO HIGH BRIDGE (UNION ...  

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

6. EARLY MORNING VIEW OF BOTH JOSO HIGH BRIDGE (UNION PACIFIC RAILROAD) IN BACKGROUND AND LYONS FERRY BRIDGE IN THE FOREGROUND - Snake River Bridge at Lyons' Ferry, State Route 261 spanning Snake River, Starbuck, Columbia County, WA

397

A long range full bandwidth Ethernet bridge  

SciTech Connect

An Ethernet Bridge has been built which has both a range which exceeds 39 kilometers and a full bandwidth of 10 Mbaud. The bridge is transparent to all Ethernet packets and is suitable for distant system control, distant high speed data collection and for all normal Ethernet use.

Thompson, M.A.; Lackey, J.L.; Nissen, K.H.; Thielman, D.J.; Hiulian, Z. (Physical Sciences Lab., Univ. of Wisconsin - Madison, 3725 Schneider Dr., Stoughton, WI (US))

1988-02-01

398

Build and Test a Paper Bridge  

NSDL National Science Digital Library

In this hands-on activity, learners make a bridge out of a folded piece of paper and two blocks. Then they test their structure by stacking coins (and other things) on it, discovering how much weight the bridge can support before it collapses. This activity explores engineering, technology, architecture, weight, compression, tension, and balance.

2012-06-26

399

Teaching Elements and Principles of Bridge Design  

ERIC Educational Resources Information Center

Bridge construction is a popular classroom activity. However, the basic principles of tension, compression, and counterbalance are not always clearly represented and defined. The common materials used to construct model bridges, such as straws, toothpicks, Legos[TM], and building blocks, are often too flexible or stationary to demonstrate the…

Beck, Charles

2005-01-01

400

Active aerodynamic stabilisation of long suspension bridges  

Microsoft Academic Search

The paper describes the addition of actively controlled aerodynamic appendages (flaps) attached along the length of the bridge deck to dampen wind-induced oscillations in long suspension bridges. A novel approach using control systems methods for the analysis of dynamic stability is presented. In order to make use of control analysis and design techniques, a linear model of the structural and

Henrik Ditlev Nissen; Paul Haase Sørensen; Ole Jannerup

2004-01-01

401

The Higgs Bridge Roland E. Allen  

E-print Network

1 The Higgs Bridge Roland E. Allen The discovery of a new kind of particle is announced. It is the long-sought Higgs boson! Credit: CERN [or more precisely, a Higgs boson] #12;The tutorial article that this talk is based on: Roland E. Allen, "The Higgs bridge", Physica Scripta 89

Allen, Roland E.

402

Seismic response of steel suspension bridge  

SciTech Connect

Performing accurate, realistic numerical simulations of the seismic response of long-span bridges presents a significant challenge to the fields of earthquake engineering and seismology. Suspension bridges in particular represent some of the largest and most important man-made structures and ensuring the seismic integrity of these mega-structures is contingent on accurate estimations of earthquake ground motions and accurate computational simulations of the structure/foundation system response. A cooperative, multi-year research project between the Univ. of California and LLNL was recently initiated to study engineering and seismological issues essential for simulating the response of major structures. Part of this research project is focused on the response of the long-span bridges with the San Francisco-Oakland Bay Bridge serving as a case study. This paper reports on the status of this multi-disciplinary research project with emphasis on the numerical simulation of the transient seismic response of the Bay Bridge.

McCallen, D.B. [Lawrence Livermore National Lab., CA (United States); Astaneh-Asl, A. [California Univ., Berkeley, CA (United States). Dept. of Civil and Environmental Engineering

1996-11-01

403

5. DOWNSTREAM ELEVATION OF BRIDGE AND SUBSTRUCTURE (with graduated meter ...  

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

5. DOWNSTREAM ELEVATION OF BRIDGE AND SUBSTRUCTURE (with graduated meter pole); VIEW TO NORTH-NORTHEAST. - Auwaiakeakua Bridge, Spanning Auwaiakekua Gulch at Mamalahoa Highway, Waikoloa, Hawaii County, HI

404

16. Historic photograph, photographer unknown, 1943. VIEW OF BRIDGE UNDER ...  

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

16. Historic photograph, photographer unknown, 1943. VIEW OF BRIDGE UNDER CONSTRUCTION, LOOKING WEST. - Verde River Sheep Bridge, Spanning Verde River (Tonto National Forest), Cave Creek, Maricopa County, AZ

405

The APS Minority Bridge Program  

NASA Astrophysics Data System (ADS)

Physics has one of the lowest participation rates for underrepresented minorities and women of all Science, Technology, Engineering and Mathematics (STEM) fields. Things are improving for women and while still not representative of the population, the trends have been encouraging. Underrepresented minorities, however, have not been as fortunate. I will describe the current status of participation in physics, and a new program being launched by the American Physical Society that aims to significantly increase the number of minorities who receive PhDs in physics. The Minority Bridge Program is bringing together representatives from doctoral granting institutions and universities that educate minority students to establish a set of model programs based on the successes of existing efforts and capitalizing on the strengths of the American Physical Society. Our goal is to improve graduate education for all students by improving the opportunities for minority students.

Hodapp, Theodore

2010-10-01

406

The APS Minority Bridge Program  

NASA Astrophysics Data System (ADS)

Physics has one of the lowest participation rates for underrepresented minorities and women of all Science, Technology, Engineering and Mathematics (STEM) fields. Things are improving for women and while still not representative of the population, the trends have been encouraging. Underrepresented minorities, however, have not been as fortunate. I will describe the current status of participation in physics, and a new program being launched by the American Physical Society that aims to significantly increase the number of minorities who receive PhDs in physics. The Minority Bridge Program is bringing together representatives from doctoral granting institutions and universities that educate minority students to establish a set of model programs based on the successes of existing efforts and capitalizing on the strengths of the American Physical Society. Our goal is to improve graduate education for all students by improving the opportunities for minority students.

Hodapp, Theodore

2011-10-01

407

The APS Minority Bridge Program  

NASA Astrophysics Data System (ADS)

Physics has one of the lowest participation rates for underrepresented minorities and women of all Science, Technology, Engineering and Mathematics (STEM) fields. Things are improving for women and while still not representative of the population, the trends have been encouraging. Underrepresented minorities, however, have not been as fortunate. I will describe the current status of participation in physics, and a new program being launched by the American Physical Society that aims to significantly increase the number of minorities who receive PhDs in physics. The Minority Bridge Program is bringing together representatives from doctoral granting institutions and universities that educate minority students to establish a set of model programs based on the successes of existing efforts and capitalizing on the strengths of the American Physical Society. Our goal is to improve graduate education for all students by improving the opportunities for minority students

Hodapp, Theodore

2011-10-01

408

Analysis and Investigation of Skew Effect on Behavior and Performance of a Small Scale Three-Phase Self-Excited Induction Generator  

NASA Astrophysics Data System (ADS)

This paper presents analysis and investigation of the skew effect on behavior and performance of a three-phase, 220/380V, 8.7/5.0A, ?/Y connected, 4 poles, 2.2kW self-excited induction generator (SEIG) with different angles rotor skewing. A 2D finite element analysis (2D-FEA) is used to consider core loss, flux density and circuit parameters. Analysis of excitation capacitor values for the SEIG based on a steady-state equivalent circuit model including rotor skew effect is given. Skewed rotor slots with angle of 0° (non-skew), 5° and 10° for the SEIGs are employed. Testing and performance comparisons under steady-state operation with a pure resistive load have been conducted. Obtained results can be guidelines and recommendations for development of effective wind induction generators.

Sawetsakulanond, Budhapon; Kinnares, Vijit

409

Source-lens clustering effects on the skewness of the lensing convergence  

E-print Network

The correlation between source galaxies and lensing potentials causes a systematic effect on measurements of cosmic shear statistics, known as the source-lens clustering (SLC) effect. The SLC effect on the skewness of lensing convergence, $S_3$, is examined using a nonlinear semi-analytic approach and is checked against numerical simulations. The semi-analytic calculations have been performed in a wide variety of generic models for the redshift distribution of source galaxies and power-law models for the bias parameter between the galaxy and dark matter distributions. The semi-analytic predictions are tested successfully against numerical simulations. We find the relative amplitude of the SLC effect on $S_3$ to be of the order of five to forty per cent. It depends significantly on the redshift distribution of sources and on the way the bias parameter evolves. We discuss possible measurement strategies to minimize the SLC effects.

Takashi Hamana; Stephane T. Colombi; Aurelien Thion; Julien E. G. T. Devriendt; Yannick Mellier; Francis Bernardeau

2001-10-24

410

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

411

Obliterable of graphics and correction of skew using Hough transform for mobile captured documents  

NASA Astrophysics Data System (ADS)

CBDA is an emerging field in Computer Vision and Pattern Recognition. In recent technology camera are incorporated to several electronic equipments and are very interesting and thus playing a vital role by replacing scanner with hand held imaging devices like Digital Cameras, Mobile phones and gaming devices attached with these camera. The goal of the work is to remove graphics from the document which plays a vital role in recognition of characters from the mobile captured documents. In this paper we have proposed a novel method for separating or removal of graphics like logos, animations other than the text from the document and method to reduce noise and finally textual content skew is estimated and corrected using Hough Transform. The experimental results show the efficacy compared to the result of well known existing methods.

Chethan, H. K.; Kumar, G. Hemantha

2011-10-01

412

Th1-skewed tissue responses to a mycolyl glycolipid in mycobacteria-infected rhesus macaques  

SciTech Connect

Highlights: •Glucose monomycolate (GMM) is a marker glycolipid for active tuberculosis. •Tissue responses to GMM involved up-regulation of Th1-attracting chemokines. •Th1-skewed local responses were mounted at the GMM-injected tissue. -- Abstract: Trehalose 6,6?-dimycolate (TDM) is a major glycolipid of the cell wall of mycobacteria with remarkable adjuvant functions. To avoid detection by the host innate immune system, invading mycobacteria down-regulate the expression of TDM by utilizing host-derived glucose as a competitive substrate for their mycolyltransferases; however, this enzymatic reaction results in the concomitant biosynthesis of glucose monomycolate (GMM) which is recognized by the acquired immune system. GMM-specific, CD1-restricted T cell responses have been detected in the peripheral blood of infected human subjects and monkeys as well as in secondary lymphoid organs of small animals, such as guinea pigs and human CD1-transgenic mice. Nevertheless, it remains to be determined how tissues respond at the site where GMM is produced. Here we found that rhesus macaques vaccinated with Mycobacterium bovis bacillus Calmette–Guerin mounted a chemokine response in GMM-challenged skin that was favorable for recruiting T helper (Th)1 T cells. Indeed, the expression of interferon-?, but not Th2 or Th17 cytokines, was prominent in the GMM-injected tissue. The GMM-elicited tissue response was also associated with the expression of monocyte/macrophage-attracting CC chemokines, such as CCL2, CCL4 and CCL8. Furthermore, the skin response to GMM involved the up-regulated expression of granulysin and perforin. Given that GMM is produced primarily by pathogenic mycobacteria proliferating within the host, the Th1-skewed tissue response to GMM may function efficiently at the site of infection.

Morita, Daisuke; Miyamoto, Ayumi; Hattori, Yuki; Komori, Takaya [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan)] [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Nakamura, Takashi [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan)] [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Igarashi, Tatsuhiko, E-mail: tigarash@virus.kyoto-u.ac.jp [Laboratory of Primate Model, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan)] [Laboratory of Primate Model, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Harashima, Hideyoshi, E-mail: harasima@pharm.hokudai.ac.jp [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan)] [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Sugita, Masahiko, E-mail: msugita@virus.kyoto-u.ac.jp [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan)] [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan)

2013-11-08

413

A missing model in reproductive skew theory: the bordered tug-of-war.  

PubMed

Models of reproductive skew can be classified into two groups: transactional models, in which group members yield shares of reproduction to each other in return for cooperation, and tug-of-war models, in which group members invest group resources in a tug-of-war over their respective reproductive shares. We synthesize these two models to yield a "bordered tug-of-war" model in which the internal tug-of-war is limited ("bordered") by the requirement that group members must achieve a certain amount of reproduction lest they pursue a noncooperative option leading to group breakup. Previous attempts to synthesize these two models did not allow for the fact that the tug-of-war will affect group output, which in turn feeds back on the reproductive payments required by group members to remain cooperative. The bordered tug-of-war model, which does not assume complete reproductive control by any individual and allows for conflict within groups, predicts that the degree of within-group selfishness will increase as the noncooperative options become less attractive, e.g., as ecological constraints on solitary breeding increase. When the noncooperative option involves fighting for the group resource (e.g., territory) and leaving if the fight is lost, the subordinate's overall share of reproduction is predicted to be independent of its relatedness to the dominant and to increase the greater its probability of winning the fight, the less the value of the territory, and the greater its personal payoff for leaving. The unique predictions of the bordered tug-of-war model may fit skew data from a number of species, including meerkats, lions, and wood mice. PMID:16717185

Reeve, Hudson Kern; Shen, Sheng-Feng

2006-05-30

414

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

415

Estimation of the radionuclide transport by applying the mean, the standard deviation and the skewness of permeability  

SciTech Connect

The authors have investigated the characteristic permeability on the basis of some probability density functions of permeability, applying the Monte Carlo method and FEM. It was found that its value does not depend on type of probability density function of permeability, but on the arithmetic mean, the standard deviation and the skewness of permeability. This paper describes the use of the stochastic values of permeability for estimating the rate of radioactivity release to the accessible environment, applying the advection-dispersion model to two-dimensional, heterogeneous media. When a discrete probability density function (referred to as the Bernoulli trials) and the lognormal distribution have common values for the arithmetic mean, the standard deviation and the skewness of permeability, the calculated transport rates (described as the pseudo impulse responses) show good agreements for Peclet number around 10 and the dimensionless standard deviation around 1. Further, it is found that the transport rates apparently depends not only on the arithmetic mean and the standard deviation, but also on the skewness of permeability. When the value of skewness does not follow the lognormal distribution which has only two independent parameters (the mean and the standard deviation), the authors can replicate the three moments estimated from an observed distribution of permeability, by using the Bernoulli trials having three independent parameters.

Niibori, Y.; Tochiyama, O.; Chida, T. [Tohoku Univ., Sendai (Japan)

1997-12-31

416

Genetic variation in nuclear and mitochondrial markers supports a large sex difference in lifetime reproductive skew in a lekking species  

PubMed Central

Sex differences in skews of vertebrate lifetime reproductive success are difficult to measure directly. Evolutionary histories of differential skew should be detectable in the genome. For example, male-biased skew should reduce variation in the biparentally inherited genome relative to the maternally inherited genome. We tested this approach in lek-breeding ruff (Class Aves, Philomachus pugnax) by comparing genetic variation of nuclear microsatellites (?n; biparental) versus mitochondrial D-loop sequences (?m; maternal), and conversion to comparable nuclear (Ne) and female (Nef) effective population size using published ranges of mutation rates for each marker (?). We provide a Bayesian method to calculate Ne (?n = 4Ne?n) and Nef (?m = 2Nef?m) using 95% credible intervals (CI) of ?n and ?m as informative priors, and accounting for uncertainty in ?. In 96 male ruffs from one population, Ne was 97% (79–100%) lower than expected under random mating in an ideal population, where Ne:Nef = 2. This substantially lower autosomal variation represents the first genomic support of strong male reproductive skew in a lekking species. PMID:25478153

Verkuil, Yvonne I; Juillet, Cedric; Lank, David B; Widemo, Fredrik; Piersma, Theunis

2014-01-01

417

Affects of skew angle on the written-in base line shift (BLS) signal at high track densities  

Microsoft Academic Search

The track edge charge distribution responsible for the base line shift (BLS) in the MR readback waveform is studied through skew angle measurements. A model based on a finite element head field calculation and micromagnetic simulation is utilized to understand the track edge charge formation responsible for the BLS signal. The modeling results show that the spatial distribution of the

Thomas Chang; Mike Salo; H. Fang; M. Madison; Jian-Gang Zhu; T. Arnoldussen

1996-01-01

418

On the dependence of the leak-rate of seals on the skewness of the surface height probability distribution  

E-print Network

Seals are extremely useful devices to prevent fluid leakage. We present experimental result which show that the leak-rate of seals depend sensitively on the skewness in the height probability distribution. The experimental data are analyzed using the critical-junction theory. We show that using the top-power spectrum result in good agreement between theory and experiment.

B. Lorenz; B. N. J. Persson

2010-04-07

419

Comparison of Ordinary and Lognormal Kriging on Skewed Data of Total Cadmium in Forest Soils of Sweden  

Microsoft Academic Search

Spatial statistical analysis of georeferenced data of total cadmium (TCd) in forest soils of Sweden was assumed to providemore advantageous maps than traditional interpolated maps. However, 264 measurements of TCd in O-horizon of forest soils displayed skewed frequency distribution. Since atypicalobservations affect badly the variogram, outliers wereidentified, different data transformations were tested andordinary (OK) and lognormal kriging (LK) scenarios werecompared

Andrea Szilágyi Kishné; Ewa Bringmark; Lage Bringmark; Agnetha Alriksson

2003-01-01

420

Soft Clock Skew Scheduling for Variation-Tolerant Signal Processing Circuits: A Case Study of Viterbi Decoders  

E-print Network

performance degradation in presence of variation-induced timing faults. Therefore, soft clock skew scheduling has two potential advantages, including: (a) it provides system- level tolerance to variation-induced that variation-induced timing faults at different locations in signal processing circuits have different effects

Hu, Jiang

421

History of the Tacoma Narrows Bridge  

NSDL National Science Digital Library

The Department of Special Collections at the University of Washington has created an excellent online exhibit documenting the rise and (literal) fall of the Tacoma Narrows bridge in Washington State, an event referred to as the Pearl Harbor of engineering. The massive structure was built between 1938 and 1940 and, at the time of its completion, was the third longest suspension bridge in the world. The bridge displayed some notable wavelike motions during the final stages of construction, but no one was prepared for what happened on November 7, 1940, when the entire structure began to buckle, and shortly collapsed into the water below. Amazingly, the only fatality was a dog that was trapped in one of the vehicles on the main span of the bridge. The online exhibit documents this amazing event, with numerous photographs of the bridge under construction, and most incredibly, dramatic shots of the bridge buckling and its fall taken by several bystanders. This exhibit will be of particular interest to engineers, particularly those working in the field of bridge construction.

1999-01-01

422

The BRIDG Project: A Technical Report  

PubMed Central

Objectives The Biomedical Research Integrated Domain Group (BRIDG) project is a collaborative initiative between the National Cancer Institute (NCI), the Clinical Data Interchange Standards Consortium (CDISC), the Regulated Clinical Research Information Management Technical Committee (RCRIM TC) of Health Level 7 (HL7), and the Food and Drug Administration (FDA) to develop a model of the shared understanding of the semantics of clinical research. Design The BRIDG project is based on open-source collaborative principles and an implementation-independent, use-case driven approach to model development. In the BRIDG model, declarative and procedural knowledge are represented using the Unified Modeling Language (UML) class, activity and state diagrams. Measurements The BRIDG model currently contains harmonized semantics from four project use cases: the caXchange project and the patient study calendar project from caBIG™; the standard data tabular model (SDTM) from CDISC; and the regulated products submission model (RPS) from HL7. Scalable harmonization processes have been developed to expand the model with content from additional use cases. Results The first official release of the BRIDG model was published in June 2007. Use of the BRIDG model by the NCI has supported the rapid development of semantic interoperability across applications within the caBIG™ program. Conclusions The BRIDG project has brought together different standards communities to clarify the semantics of clinical research across pharmaceutical, regulatory, and research organizations. Currently, the NCI uses the BRIDG model to support interoperable application development in the caBIG™, and CDISC and HL7 are using the BRIDG model to support standards development. PMID:18096907

Fridsma, Douglas B.; Evans, Julie; Hastak, Smita; Mead, Charles N.

2008-01-01

423

Calculations in bridge aeroelasticity via CFD  

SciTech Connect

The central focus of the present study is the numerical calculation of flutter derivatives. These aeroelastic coefficients play an important role in determining the stability or instability of long, flexible structures under ambient wind loading. A class of Civil Engineering structures most susceptible to such an instability are long-span bridges of the cable-stayed or suspended-span variety. The disastrous collapse of the Tacoma Narrows suspension bridge in the recent past, due to a flutter instability, has been a big impetus in motivating studies in flutter of bridge decks.

Brar, P.S.; Raul, R.; Scanlan, R.H. [Johns Hopkins Univ., Baltimore, MD (United States)

1996-12-31

424

Partially entangled states bridge in quantum teleportation  

NASA Astrophysics Data System (ADS)

The traditional method for information transfer in a quantum communication system using partially entangled state resource is quantum distillation or direct teleportation. In order to reduce the waiting time cost in hop-by-hop transmission and execute independently in each node, we propose a quantum bridging method with partially entangled states to teleport quantum states from source node to destination node. We also prove that the designed specific quantum bridging circuit is feasible for partially entangled states teleportation across multiple intermediate nodes. Compared to two traditional ways, our partially entanglement quantum bridging method uses simpler logic gates, has better security, and can be used in less quantum resource situation.

Cai, Xiao-Fei; Yu, Xu-Tao; Shi, Li-Hui; Zhang, Zai-Chen

2014-10-01

425

Building the Clinical Bridge: An Australian Success  

PubMed Central

Nursing effectiveness science includes primary, secondary, and translational, clinically focused research activities which aim to improve patient or client outcomes. It is imperative, for the successful conduct of a program of nursing effectiveness science, that a clinical bridge is established between academic and healthcare service facilities. An Australian example of the development of a robust clinical bridge through the use of jointly funded positions at the professorial level is outlined. In addition, an analysis of the practical application of Lewin's model of change management and the contribution of both servant and transformational leadership styles to the bridge building process is provided. PMID:22577536

Wallis, Marianne; Chaboyer, Wendy

2012-01-01

426

Fibre reinforced composite dental bridge. Part II: numerical investigation  

Microsoft Academic Search

Motivated by the clinical success and limitations on experimental investigation of the fibre-reinforced composite dental bridge, this paper aims at providing a numerical investigation into the bridge structure. The finite element (FE) model adopted here is constructed from computer tomography images of a physical bridge specimen. The stress and strain distributions in the bridge structure especially in the bonding interfaces

W. Li; M. v. Swain; Q. Li; J. Ironside; G. p. Steven

2004-01-01

427

UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH SINGLE PIPE TOWERS, SHOWING HOWE ...  

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

UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH SINGLE PIPE TOWERS, SHOWING HOWE PIPE TRUSS RAILING TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. NOTE THAT TRUSS LACKS WOODEN HUB GUARD FOUND ON CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE. 3/4 VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

428

UNIDENTIFIED SUSPENSION BRIDGE UNDER CONSTRUCTION, SHOWING PIPE INVENTORY AND CUTTING ...  

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

UNIDENTIFIED SUSPENSION BRIDGE UNDER CONSTRUCTION, SHOWING PIPE INVENTORY AND CUTTING EQUIPMENT IN FOREGROUND, BRIDGE BUILDER WILLIAM FLINN?S ?CAMP & BRIDGE BUILDING OUTFIT? IN RIGHT BACKGROUND, AND FALSEWORK FOR TOWER IN CENTER BACKGROUND. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

429

1. VIEW EAST TOWARD COS COB ANCHOR BRIDGE #310 OF ...  

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

1. VIEW EAST TOWARD COS COB ANCHOR BRIDGE #310 OF CIRCUIT BREAKER INSTALLATION ON CROSS BEAM OF BRIDGE. ABANDONED COS COB POWER STATION IS TO THE SOUTH OF THIS BRIDGE. - New York, New Haven & Hartford Railroad, Bridge-Type Circuit Breakers, Long Island shoreline between Stamford & New Haven, Cos Cob, Fairfield County, CT

430

14. Fifth Melan Bridge on tour route, Union Avenue near ...  

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

14. Fifth Melan Bridge on tour route, Union Avenue near Park Boundary, elevation view to the north, showing Culvert beyond park boundary. (bridge has now been replaced with box culvert). - Vicksburg National Military Park Roads & Bridges, Melan Arch Bridges, Spanning various tributaries at Confederate Avenue, Vicksburg, Warren County, MS

431

15. Fifth Melan Bridge on tour route, Union Avenue near ...  

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

15. Fifth Melan Bridge on tour route, Union Avenue near Park Boundary, deck view to the north. (bridge has now been replaced with box culvert.) - Vicksburg National Military Park Roads & Bridges, Melan Arch Bridges, Spanning various tributaries at Confederate Avenue, Vicksburg, Warren County, MS

432

6. DETAIL VIEW OF BRIDGE DATEPLATE WHICH READS 'ST. FRANCIS ...  

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

6. DETAIL VIEW OF BRIDGE DATEPLATE WHICH READS 'ST. FRANCIS RIOVER, VINCENNES BRIDGE CO., CONTRACTOR, ARKANSAS STATE HIGHWAY COMMISSION, JAS. R RHYNE, DIRECTOR, W.B. GARVER, BRIDGE ENGINEER, 1934.' - St. Francis River Bridge, Spanning St. Francis River at State Highway 18, Lake City, Craighead County, AR

433

11. View of Tombigbee River Bridge facing northeast along center ...  

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

11. View of Tombigbee River Bridge facing northeast along center of roadway. North pony span is in background center and new bridge is partially shown in background left. Barrels shown are remnants of traffic control devices used for one lane traffic due to reduced weight capacity of bridge before closure. - Tombigbee River Bridge, Spanning Tombigbee River at State Highway 182, Columbus, Lowndes County, MS

434

Bridge Fault Simulation Strategies for CMOS Integrated Circuits Brian Chess  

E-print Network

Bridge Fault Simulation Strategies for CMOS Integrated Circuits Brian Chess Tracy Larrabee \\Lambda present a theorem for detecting feedback bridge faults. We discuss two different methods of bridge fault of the two methods. We con­ clude that the new simulation method, Wire Memory bridge fault simulation

Larrabee, Tracy

435

Nonlinear analysis of the Vincent Thomas Bridge for seismic retrofit  

Microsoft Academic Search

The Vincent Thomas Bridge crosses the Los Angeles River at the entrance to the Port of Los Angeles. It is a suspension bridge, one of six major toll bridges in California which are scheduled for seismic retrofit by the State of California. The retrofit of the bridge includes the installation of dampers between the stiffening trusses and the towers of

T. J. Ingham; S. Rodriguez; M. Nader

1997-01-01

436

Control of Vibrations due to Moving Loads on Suspension Bridges  

Microsoft Academic Search

The flexibility and low damping of the long span suspended cab les in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck

M. Zribi; N. B. Almutairi; M. Abdel-Rohman

2006-01-01

437

View of Flume Bridge #5 from FS 502 looking downstream ...  

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

View of Flume Bridge #5 from FS 502 looking downstream (south). Bridge is on the left side of the photograph. This is similar to other flume bridges in the system and is the only photograph representing these features. - Childs-Irving Hydroelectric Project, Childs System, Flume Bridge No. 5, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

438

13. Looking north, from the southern approach to the bridge. ...  

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

13. Looking north, from the southern approach to the bridge. The bridge deck, which is concrete with several patch coats of asphalt (now chiefly gravel and some turf), demonstrates a sharp gradient from the abutment to the bridge center line. - Vigo County Bridge No. 139, Spanning Sugar Creek at Seventy-fourth Place, Terre Haute, Vigo County, IN

439

Willamette River Transit Bridge PSU CTS Seminar January 16, 2009  

E-print Network

Willamette River Transit Bridge PSU CTS Seminar January 16, 2009 Dave Unsworth, TriMet Guenevere River Transit Bridge · Portland-Milwaukie Light Rail Project · Plans for a new Willamette River Bridge · Public Process Today's Agenda #12;Willamette River Transit BridgePortland-Milwaukie Light Rail Project

Bertini, Robert L.

440

Aerial view of the entire bridge crossing the Tennessee River ...  

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

Aerial view of the entire bridge crossing the Tennessee River looking up river. The swing bridge, when open, permits river navigational traffic to ply the river. Construction of a replacement bridge, to be located 93.27 feet down river, has now started. - Bridgeport Swing Span Bridge, Spanning Tennessee River, Bridgeport, Jackson County, AL

441

14. RAILROAD BRIDGE MISSISSIPPI, MONROE CO., ABERDEEN Reach by foot ...  

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

14. RAILROAD BRIDGE MISSISSIPPI, MONROE CO., ABERDEEN Reach by foot from E end of Vine St. St. Louis and San Francisco RR bridge. Bridge built 1887, replaced, 1969. Credit: Evans Memorial Library, Aberdeen, Ms. No date. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

442

15. OLD ROAD BRIDGE MISSISSIPPI, MONROE CO., ABERDEEN (EAST ABERDEEN) ...  

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

15. OLD ROAD BRIDGE MISSISSIPPI, MONROE CO., ABERDEEN (EAST ABERDEEN) One mile E of Aberdeen, 1000 ft. N of (1978) U.S. 45 bridge. Oblique view of bridge, in early 1900s. Credit: Evans Memorial Library, Aberdeen, MS. No date. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

443

Economical solutions to blast mitigation on bridges  

E-print Network

Mitigating the energy created from a blast has been a topic of utmost importance in the terrorism-feared world of today. Main targets of concern are passageways that are significant to a specific area, such as bridges. ...

DeRogatis, Austin (Austin Patrick)

2008-01-01

444

Bridges and Tunnels of Allegheny County, Pennsylvania  

NSDL National Science Digital Library

Technophile Bruce S. Cridlebaugh has compiled this website of information on the bridges and tunnels of Allegheny County and Pittsburgh to satisfy his curiosity. The information featured here has been primarily gathered by visiting the various bridges and tunnels and making on-site measurements, sketches, photos and notes. Despite limitations due to the nature of some sites, such as "a given location, private property, high traffic, and so on," he has gathered information on almost 50 structures. Visitors can browse the collection by the structure's location, design, name, or use. Books, magazines, newspapers, maps, and Internet resources used to develop the website are listed in the Information Source section or in the Other Info section. The author also provides an overview of Bridge Basics and explains common terms used in Engineering, Masonry, Metal work, Bridge and Tunnel building, as well as Mapping.

445

Reliability of corroded steel bridge girders  

E-print Network

Corrosion is one of the main causes of deterioration of bridges. Structures exposed to harsh environmental conditions are subjected to time-variant changes of their load-carrying capacity. Thus, there is a need for an ...

Cordahi, Irene A

2006-01-01

446

Internet Archive: Tacoma Narrows Bridge Collapse  

NSDL National Science Digital Library

This web page contains the original footage of the 1940 collapse of the Tacoma Narrows Bridge, a mile-long suspension bridge in the state of Washington. The collapse occurred due to strong gusting winds which drove the span into large-amplitude oscillatory motion. The footage is 2 minutes, 35 seconds in length. The collapse of the bridge was recorded on film by Barney Elliott, owner of a Tacoma camera shop. In 1998, The Tacoma Narrows Bridge Collapse was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant." The sound track which accompanies this archived film clip is also an historic item, originally recorded for a 1940's documentary.

2009-03-28

447

Misfit profile of dental bridges.  

PubMed

Clinical evidence has shown that dental bridge (DB) misfit is more frequent than individual crown restoration misfit, and that it causes restorative failures. A comparative study of misfit profiles was performed for the most common clinical situations in mouth rehabilitation procedures with fixed restorations: gold-cast DB and porcelain metal alloy DB. Evidence from this study may lead dentists to consider the advantages and weaknesses of one structure type over the other. The results obtained showed two different profiles, with the porcelain metal alloy (PMA) DB being less predictable than the gold-cast DB. The posterior abutment restoration tends to come apart distally from the tooth structure and get closer to the mesial aspect, while keeping distal-medial separation with respect to the anterior abutment. The gold-cast DBs showed a separation pattern in which the distal end comes away from the molar and the medial end from the premolar, getting clearly closer to the faces next to the pontic: its distal aspect gets closer to the premolar and mesially to the molar The study has also shown that even though the adaptive patterns are different, is less in PMA than in gold alloys, the latter being used only in a small percentage of clinical indications in oral rehabilitation, mainly due to aesthetic demands and high costs. The impact of this research in clinical dentistry is that PMA DBs have shown worst marginal adaptation areas where clinically, there is lack of vision or inaccessibility for appropriate dental preparation. PMID:22928382

Cattáneo, Silvina; Castro, Mariela Alvarez; Castro, José M Alvarez; Troielli, Elvio; Gassó, Carlos A; Cantoni, Héctor Alvarez

2012-01-01

448

Solutocapillary instabilities in liquid bridges  

NASA Astrophysics Data System (ADS)

The stability of a steady, axisymmetric flow driven by a surface-tension variation due to a solute-concentration gradient is studied with a linear analysis. There is a liquid bridge with a cylindrical free surface between two collinear solid cylinders with the same radius. One cylinder injects the solute into the liquid as it melts at a velocity Vg*, and the other cylinder preferentially absorbs the solute from the liquid as it solidifies at the same velocity. The surface tension of the free surface is assumed to be a linear function of the solute concentration. For given values of the Schmidt number Sc and of Vg*, the first instability is a Hopf bifurcation at a critical value of a solutal Marangoni number. The present problem is related to the thermocapillary convection in the half-zone problem for which the geometry is the same, the two solids are isothermal at different temperatures and the surface tension is a linear function of temperature. Differences arise because the solute concentration distribution here is different from the temperature distribution in the half-zone problem, and Vg* is the variable which controls these differences. Results are presented for a range of values of Vg* for two aspect ratios and for Sc=0.5-20.

Witkowski, L. Martin; Walker, J. S.

2002-08-01

449

Bridge deck designs for railing impacts  

E-print Network

BRIDGE DECK DESIGNS FOR RAILING IMPACTS A Thesis by ALTHEA GAYLE ARNOLD Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1984 Major Subject: Civil... Engineering BRIDGE DECK DESIGNS FOR RAILING IMPACTS A Thesis by ALTHEA GAYLE ARNOLD Approved as to style and content by: Hirsc (Ch rman of Committee) But (Member) son (Member) op nger (Member) &r c (Head of Department) May 1984 ABSTRACT...

Arnold, Althea Gayle

1984-01-01

450

I-5/Gilman advanced technology bridge project  

NASA Astrophysics Data System (ADS)

The UCSD led I-5/Gilman Advanced Technology Bridge Project will design and construct a fully functional traffic bridge of advanced composite materials across Interstate 5 in La Jolla, California. Its objective is to demonstrate the use of advanced composite technologies developed by the aerospace industry in commercial applications to increase the life expectancy of new structures and for the rehabilitation of aging infrastructure components. The structure will be a 450 ft long, 60 ft wide cable-stayed bridge supported by a 150 ft A-frame pylon with two vehicular lanes, two bicycle lanes, pedestrian walkways and utility tunnels. The longitudinal girders and pylon will be carbon fiber shells filled with concrete. The transverse deck system will consist of hollow glass/carbon hybrid tubes and a polypropylene fiber reinforced concrete deck with an arch action. Selected cables will be composite. The bridge's structural behavior will be monitored to determine how advanced composite materials perform in civil infrastructure applications. The bridge will be instrumented to obtain performance and structural health data in real time and, where possible, in a remote fashion. The sensors applied to the bridge will include electrical resistance strain gages, fiberoptic Bragg gratings and accelerometers.

Lanza di Scalea, Francesco; Karbhari, Vistasp M.; Seible, Frieder

2000-04-01

451

UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE ...  

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

UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. TRIPODAL PIPE TOWERS RESEMBLE CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE?S TOWERS PRIOR TO ENCASEMENT IN CONCRETE. NOTE COLLAPSED TRUSS IN RIVER. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

452

NPIP: A skew line needle configuration optimization system for HDR brachytherapy  

SciTech Connect

Purpose: In this study, the authors introduce skew line needle configurations for high dose rate (HDR) brachytherapy and needle planning by integer program (NPIP), a computational method for generating these configurations. NPIP generates needle configurations that are specific to the anatomy of the patient, avoid critical structures near the penile bulb and other healthy structures, and avoid needle collisions inside the body. Methods: NPIP consisted of three major components: a method for generating a set of candidate needles, a needle selection component that chose a candidate needle subset to be inserted, and a dose planner for verifying that the final needle configuration could meet dose objectives. NPIP was used to compute needle configurations for prostate cancer data sets from patients previously treated at our clinic. NPIP took two user-parameters: a number of candidate needles, and needle coverage radius, {delta}. The candidate needle set consisted of 5000 needles, and a range of {delta} values was used to compute different needle configurations for each patient. Dose plans were computed for each needle configuration. The number of needles generated and dosimetry were analyzed and compared to the physician implant. Results: NPIP computed at least one needle configuration for every patient that met dose objectives, avoided healthy structures and needle collisions, and used as many or fewer needles than standard practice. These needle configurations corresponded to a narrow range of {delta} values, which could be used as default values if this system is used in practice. The average end-to-end runtime for this implementation of NPIP was 286 s, but there was a wide variation from case to case. Conclusions: The authors have shown that NPIP can automatically generate skew line needle configurations with the aforementioned properties, and that given the correct input parameters, NPIP can generate needle configurations which meet dose objectives and use as many or fewer needles than the current HDR brachytherapy workflow. Combined with robot assisted brachytherapy, this system has the potential to reduce side effects associated with treatment. A physical trial should be done to test the implant feasibility of NPIP needle configurations.

Siauw, Timmy; Cunha, Adam; Berenson, Dmitry; Atamtuerk, Alper; Hsu, I-Chow; Goldberg, Ken; Pouliot, Jean [Department of Civil and Environmental Engineering, University of California, Berkeley, 760 Davis Hall, Berkeley, California 94720-1710 (United States); Department of Radiation Oncology, University of California, San Francisco, Comprehensive Cancer Center, 1600 Divisadero Street, Suite H1031, San Francisco, California 94143-1708 (United States); Department of Electrical Engineering and Computer Science, University of California, Berkeley, 4th Floor Sutardja Dai Hall, Berkeley, California 94720-1764 (United States); Department of Industrial Engineering and Operations, University of California, Berkeley, 4141 Etcheverry Hall, Berkeley, California 94720-1777 (United States); Department of Radiation Oncology, University of California, San Francisco, Comprehensive Cancer Center, 1600 Divisadero Street, Suite H1031, San Francisco, California 94143-1708 (United States); Department of Industrial Engineering and Operations Research and Department of Electrical Engineering and Computer Science, University of California, Berkeley, 4141 Etcheverry Hall, Berkeley, California 94720-1777 (United States); Department of Radiation Oncology, University of California, San Francisco, Comprehensive Cancer Center, 1600 Divisadero Street, Suite H1031, San Francisco, California 94143-1708 (United States)

2012-07-15

453

Highly skewed inactivation of the wild-type X-chromosome in asymptomatic female carriers of spinal and bulbar muscular atrophy (Kennedy's disease).  

PubMed

We examined families with a history of spinal and bulbar muscular atrophy (SBMA) and found that six out of eight female carriers had a skewed inactivation of the wild-type chromosome. Under these genetic conditions, disease manifestations should be expected and therefore we sought neurological and other symptoms of subclinical SBMA. We did not find either clinical symptoms or electrophysiological signs of mutated AR gene in female carriers, despite skewed methylation of the wild-type allele. These findings suggest that skewed methylation of AR genes are not necessarily associated to clinical manifestations in female carriers of the expanded SBMA allele. PMID:18446311

Paradas, C; Solano, F; Carrillo, F; Fernández, C; Bautista, J; Pintado, E; Lucas, M

2008-06-01

454

The Pennsylvania State University www.BioEnergyBridge.psu.edu 1 BioEnergy Bridge  

E-print Network

© The Pennsylvania State University www.BioEnergyBridge.psu.edu 1 Penn State BioEnergy Bridge Partnership The Pennsylvania State University Bob Wallace, Director TM #12;© The Pennsylvania# trichard@psu.edu rtw103@psu.edu www.bioenergy.psu.edu Biomass Energy Center #12;© The Pennsylvania State

Lee, Dongwon

455

A unique dermal dendritic cell subset that skews the immune response toward Th2.  

PubMed

Dendritic cell (DC) subsets in the skin and draining lymph nodes (LNs) are likely to elicit distinct immune response types. In skin and skin-draining LNs, a dermal DC subset expressing macrophage galactose-type C-type lectin 2 (MGL2/CD301b) was found distinct from migratory Langerhans cells (LCs) or CD103(+) dermal DCs (dDCs). Lower expression levels of Th1-promoting and/or cross-presentation-related molecules were suggested by the transcriptome analysis and verified by the quantitative real-time PCR analysis in MGL2(+) dDCs than in CD103(+) dDCs. Transfer of MGL2(+) dDCs but not CD103(+) dDCs from FITC-sensitized mice induced a Th2-type immune response in vivo in a model of contact hypersensitivity. Targeting MGL2(+) dDCs with a rat monoclonal antibody against MGL2 efficiently induced a humoral immune response with Th2-type properties, as determined by the antibody subclass. We propose that the properties of MGL2(+) dDCs, are complementary to those of CD103(+) dDCs and skew the immune response toward a Th2-type response. PMID:24039898

Murakami, Ryuichi; Denda-Nagai, Kaori; Hashimoto, Shin-ichi; Nagai, Shigenori; Hattori, Masahira; Irimura, Tatsuro

2013-01-01

456

Compressive VOF method with skewness correction to capture sharp interfaces on arbitrary meshes  

NASA Astrophysics Data System (ADS)

The accurate and efficient modelling of two-phase flows is at present mostly limited to structured, unskewed meshes, due to the additional topological and numerical complexity of arbitrary, unstructured meshes. Compressive VOF methods which discretize the interface advection with algebraic differencing schemes are computationally efficient and inherently applicable to arbitrary meshes. However, compressive VOF methods evidently suffer severely from numerical diffusion on meshes with topological skewness. In this paper we present a compressive VOF method using a state-of-the-art donor-acceptor advection scheme which includes novel modifications to substantially reduce numerical diffusion on arbitrary meshes without adding computational complexity. The new methodology accurately captures evolving interfaces on any arbitrary, non-overlapping mesh and conserves mass within the limits of the applied solver tolerance. A thorough validation of the presented methods is conducted, examining the pure advection of the interface indicator function as well as the application to evolving interfaces with surface tension. Crucially, the results on equidistant Cartesian and arbitrary tetrahedral meshes are shown to be comparable and accurate.

Denner, Fabian; van Wachem, Berend G. M.

2014-12-01

457

Natural frequencies of thick, symmetrically-laminated, skew, trapezoidal plates with various boundary supports  

SciTech Connect

Increasing use of composite materials in structures requires an accurate method of predicting response. Transverse shear effects can play an important role in laminated structures, even those that are considered thin, and as a result, should not be neglected. The free vibration response of generally laminated, thick, skewed, trapezoidal plates is investigated due of the lack of information in this area. In the method developed, Chebychev polynomials are used as displacement functions in the Rayleigh-Ritz method. To account for various edge supports, free, simply supported, and clamped, appropriate linear and rotational springs are introduced to satisfy the essential boundary conditions. First-order shear theory is used to account for transverse shear effects, and rotary inertia is also included in the model. Convergence of the solution resulting from changes in spring values and number of terms in the series is investigated. To demonstrate the accuracy of the method, results for thin isotropic and laminated plates are compared to past results for various planforms and boundary conditions. Next, thick isotropic plate results are compared to available published results. Thick laminated plate results for various planforms and boundary conditions are then presented. Variations in natural frequencies due to geometric parameter changes, such as taper ratio and sweep angle, are also studied.

Kapania, R.K.; Lovejoy, A.E.

1994-12-31

458

Skewness dependence of generalized parton distributions, conformal OPE, and the AdS/CFT correspondence  

NASA Astrophysics Data System (ADS)

The traditional idea of the Pomeron/Reggeon description for hadron scattering is now being given theoretical foundation in gravity dual descriptions, where Pomeron corresponds to an exchange of spin-j ?2 Z states in the graviton trajectory. Deeply virtual Compton scattering (DVCS) is essentially a two-to-two scattering process of a hadron and a photon, and hence one should be able to study nonperturbative aspects (the generalized parton distribution [GPD]) of this process by the Pomeron/Reggeon process in gravity dual. We find, however, that even one of the most developed formulations of gravity dual, Pomeron [Brower-Polchinski-Strassler-Tan (BPST), 2006], is not able to capture skewness dependence of GPD properly. Therefore, we compute Reggeon wave functions on AdS5 so that the formalism of BPST can be generalized. These wave functions are used to determine the DVCS amplitude, bring it to the form of conformal operator product expansion/collinear factorization, and extract a holographic model of GPD, which naturally fits into the framework known as "dual parametrization," or the "(conformal) collinear factorization approach."

Nishio, Ryoichi; Watari, Taizan

2014-12-01

459

Fuzzy Clustering of Color Textures using Skew Divergence and Compact Histograms: Segmenting Thin Rock Sections  

NASA Astrophysics Data System (ADS)

Digital image segmentation is the process of assigning distinct labels to different objects in a digital image, and clustering techniques can be used to achieve such segmentations. However, many traditional segmentation algorithm fail to segment objects that are characterized by textures whose patterns cannot be successfully described by simple statistics computed over a very restricted area. In this paper we present a fuzzy clustering algorithm that achieves the segmentation of images with color textures by employing a distance function based on the Skew Divergence, that is based on the well-known Kullback-Leibler Divergence. In order for such a distance to produce good results when applied to color images, we reduced the dimensionality of the image's histogram, thus eliminating the sparsity of the color histogram and speeding up the execution of the algorithm. We performed experiments on thin rock sections and compared our results to the segmentations obtained by the Fuzzy C-Means and by another fuzzy segmentation technique, showing the superiority of our approach.

Siebra, Hélio; Carvalho, Bruno M.; Garduño, Edgar

2015-01-01

460

Non-skew-symmetric classical r-matrices, algebraic Bethe ansatz, and Bardeen-Cooper-Schrieffer-type integrable systems  

SciTech Connect

We construct quantum integrable systems associated with non-skew-symmetric gl(2)-valued classical r-matrices. We find a new explicit multiparametric family of such the non-skew-symmetric classical r-matrices. We consider two classes of examples of the corresponding integrable systems, namely generalized Gaudin systems with and without an external magnetic field. In the case of arbitrary r-matrices diagonal in a standard gl(2)-basis, we calculate the spectrum of the corresponding quantum integrable systems using the algebraic Bethe ansatz. We apply these results to a construction of integrable fermionic models and obtain a wide class of integrable Bardeen-Cooper-Schrieffer (BCS)-type fermionic Hamiltonians containing the pairing and electrostatic interaction terms. We also consider special cases when the corresponding integrable Hamiltonians contain only pairing interaction term and are exact analogs of the 'reduced BCS Hamiltonian' of Richardson.

Skrypnyk, T. [International School for Advanced Studies, via Beirut 2-4, 34014 Trieste (Italy) and Bogoliubov Institute for Theoretical Physics, Metrologichna St. 14-b, Kiev 03143 (Ukraine)

2009-03-15

461

Derivative matrices of a skew ray for spherical boundary surfaces and their applications in system analysis and design.  

PubMed

In a previous paper [Appl. Opt.52, 4151 (2013)], we presented the first- and second-order derivatives of a ray for a flat boundary surface to design prisms. In this paper, that scheme is extended to determine the Jacobian and Hessian matrices of a skew ray as it is reflected/refracted at a spherical boundary surface. The validity of the proposed approach as an analysis and design tool is demonstrated using an axis-symmetrical system for illustration purpose. It is found that these two matrices can provide the search direction used by existing gradient-based schemes to minimize the merit function during the optimization stage of the optical system design process. It is also possible to make the optical system designs more automatic, if the image defects can be extracted from the Jacobian and Hessian matrices of a skew ray. PMID:24922031

Lin, Psang Dain

2014-05-10

462

Systematic analysis of X-inactivation in 19XLMR families: extremely skewed profiles in carriers in three families.  

PubMed

It has been demonstrated in several X-linked disorders, both with and without mental retardation, that the X-inactivation process plays a significant role in the expression of X-linked diseases in females. Moreover, in some disorders extremely skewed inactivation of the X chromosome is constant in carriers, and this is thought to result from a proliferation or a survival advantage for cells expressing the normal allele at this locus over cells expressing the mutated allele. X-linked mental retardation (XLMR) is heterogeneous, and cloning and characterization of the mutated genes are in progress. XLMR can be expressed in carrier females but often with milder manifestations. We report the systematic study of the X-inactivation profile of obligate carriers and other females in 19 multiplex XLMR pedigrees, using leucocyte-extracted DNA. Extremely skewed profiles were observed in carriers in three of 19 families. PMID:10854107

Raynaud, M; Moizard, M P; Dessay, B; Briault, S; Toutain, A; Gendrot, C; Ronce, N; Moraine, C

2000-04-01

463

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. PMID:10819153

Crespi, B J; Ragsdale, J E

2000-01-01

464

Development and Validation of a New Blade Element Momentum Skewed-Wake Model within AeroDyn: Preprint  

SciTech Connect

Blade element momentum methods, though conceptually simple, are highly useful for analyzing wind turbines aerodynamics and are widely used in many design and analysis applications. A new version of AeroDyn is being developed to take advantage of new robust solution methodologies, conform to a new modularization framework for National Renewable Energy Laboratory's FAST, utilize advanced skewed-wake analysis methods, fix limitations with previous implementations, and to enable modeling of highly flexible and nonstraight blades. This paper reviews blade element momentum theory and several of the options available for analyzing skewed inflow. AeroDyn implementation details are described for the benefit of users and developers. These new options are compared to solutions from the previous version of AeroDyn and to experimental data. Finally, recommendations are given on how one might select from the various available solution approaches.

Ning, S. A.; Hayman, G.; Damiani, R.; Jonkman, J.

2014-12-01

465

Text\\/Graphics Separation and Skew Correction of Text Regions of Business Card Images for Mobile Devices  

Microsoft Academic Search

Separation of the text regions from background texture and graphics is an\\u000aimportant step of any optical character recognition system for the images\\u000acontaining both texts and graphics. In this paper, we have presented a novel\\u000atext\\/graphics separation technique and a method for skew correction of text\\u000aregions extracted from business card images captured with a cell-phone camera.\\u000aAt first,

Ayatullah Faruk Mollah; Subhadip Basu; Mita Nasipuri

2010-01-01

466

A Maastrichtian palaeomagnetic pole for the Pacific plate from a skewness analysis of marine magnetic anomaly 32  

NASA Astrophysics Data System (ADS)

The asymmetry (skewness) of marine magnetic anomaly 32 (72.1-73.3 Ma) on the Pacific plate has been analysed in order to estimate a new palaeomagnetic pole. Apparent effective remanent inclinations of the seafloor magnetization were calculated from skewness estimates of 108 crossings of anomaly 32 distributed over the entire Pacific plate and spanning a great-circle distance of ~12 000 km. The data were inverted to obtain a palaeomagnetic pole at 72.1 degN, 26.8 degE with a 95 per cent confidence ellipse having a 4.0 deg major semi-axis oriented 98 deg clockwise of north and a 1.8 deg minor semi-axis; the anomalous skewness is 14.2 deg+/-3.7 deg. The possible dependence of anomalous skewness on spreading rate was investigated with two empirical models and found to have a negligible effect on our palaeopole analysis over the range of relevant spreading half-rates, ~25 to ~90 mm yr^-1. The new pole is consistent with the northward motion for the Pacific plate indicated by coeval palaeocolatitude and palaeoequatorial data, but differs significantly from, and lies to the northeast of, coeval seamount poles. We attribute the difference to unmodelled errors in the seamount poles, mainly in the declinations. Comparison with the northward motion inferred from dated volcanoes along the Hawaiian-Emperor seamount chain indicates 13 deg of southward motion of the Hawaiian hotspot since 73 Ma. When the pole is reconstructed with the Pacific plate relative to the Pacific hotspots, it differs by 14 deg-18 deg from the position of the pole relative to the Indo-Atlantic hotspots. This has several possible explanations including bias in one or more of the palaeomagnetic poles, motion between the Pacific and Indo-Atlantic hotspots, and errors in plate reconstructions relative to the hotspots.

Petronotis, Katerina E.; Gordon, Richard G.

1999-10-01

467

Spatial interpolation of severely skewed data with several peak values by the approach integrating kriging and triangular irregular network interpolation  

Microsoft Academic Search

It was not unusual in soil and environmental studies that the distribution of data is severely skewed with several high peak\\u000a values, which causes the difficulty for Kriging with data transformation to make a satisfied prediction. This paper tested\\u000a an approach that integrates kriging and triangular irregular network interpolation to make predictions. A data set consisting\\u000a of total Copper (Cu)

Chunfa Wu; Jiaping Wu; Yongming Luo; Haibo Zhang; Ying Teng; Stephen D. DeGloria

2011-01-01

468

Effects of pristane alone or combined with chloroquine on macrophage activation, oxidative stress, and TH1/TH2 skewness.  

PubMed

We investigated the protective role of chloroquine against pristane-induced macrophage activation, oxidative stress, and Th1/Th2 skewness in C57BL/6J mice. Those mice were treated with pristane alone or combined with chloroquine. Hematological and biochemical parameters, macrophage phagocytic function, the oxidant/antioxidant index, cytokine for IFN-?, TNF-?, IL-4, and IL-6, and the isotypes of IgG2a and IgG1 were determined. And the expression of T-bet/GATA-3 and IL-12/IL-10 mRNA in spleen were analyzed by real-time PCR. We found that pristane treatment for a period of 12 or 24 weeks triggered macrophage activation syndrome, characterized by hemophagocytosis in spleen and peripheral blood, enhanced lipid phagocytosis by peritoneal macrophages in vitro, erythropenia and leucopenia, increased anti-Smith, lactic dehydrogenase, triglyceride, and ferritin, as well as hypercytokinemia of IFN-?, TNF-?, IL-4, and IL-6. In parallel, a significant increase in lipid peroxidation and a decrease in superoxide dismutase, glutathione, and catalase activity, as well as a skewed Th1/Th2 balance in spleen, were observed. However, chloroquine supplementation showed a remarkable amelioration of these abnormalities. Our data indicate that pristane administration induces macrophage activation, oxidative stress, and Th1/Th2 skewness, which can be attenuated by chloroquine. PMID:25136646

Ouyang, Qiufang; Huang, Ziyang; Wang, Zhenhua; Chen, Xiaoqing; Ni, Jingqin; Lin, Ling

2014-01-01

469

Bayesian Semiparametric Nonlinear Mixed-Effects Joint Models for Data with Skewness, Missing Responses, and Measurement Errors in Covariates  

PubMed Central

Summary It is a common practice to analyze complex longitudinal data using semiparametric nonlinear mixed-effects (SNLME) models with a normal distribution. Normality assumption of model errors may unrealistically obscure important features of subject variations. To partially explain between- and within-subject variations, covariates are usually introduced in such models, but some covariates may often be measured with substantial errors. Moreover, the responses may be missing and the missingness may be nonignorable. Inferential procedures can be complicated dramatically when data with skewness, missing values, and measurement error are observed. In the literature, there has been considerable interest in accommodating either skewness, incompleteness or covariate measurement error in such models, but there has been relatively little study concerning all three features simultaneously. In this article, our objective is to address the simultaneous impact of skewness, missingness, and covariate measurement error by jointly modeling the response and covariate processes based on a flexible Bayesian SNLME model. The method is illustrated using a real AIDS data set to compare potential models with various scenarios and different distribution specifications. PMID:22150787

Huang, Yangxin; Dagne, Getachew

2012-01-01

470

Bayesian semiparametric nonlinear mixed-effects joint models for data with skewness, missing responses, and measurement errors in covariates.  

PubMed

It is a common practice to analyze complex longitudinal data using semiparametric nonlinear mixed-effects (SNLME) models with a normal distribution. Normality assumption of model errors may unrealistically obscure important features of subject variations. To partially explain between- and within-subject variations, covariates are usually introduced in such models, but some covariates may often be measured with substantial errors. Moreover, the responses may be missing and the missingness may be nonignorable. Inferential procedures can be complicated dramatically when data with skewness, missing values, and measurement error are observed. In the literature, there has been considerable interest in accommodating either skewness, incompleteness or covariate measurement error in such models, but there has been relatively little study concerning all three features simultaneously. In this article, our objective is to address the simultaneous impact of skewness, missingness, and covariate measurement error by jointly modeling the response and covariate processes based on a flexible Bayesian SNLME model. The method is illustrated using a real AIDS data set to compare potential models with various scenarios and different distribution specifications. PMID:22150787

Huang, Yangxin; Dagne, Getachew

2012-09-01

471

De novo MECP2 duplications in two females with intellectual disability and unfavorable complete skewed X-inactivation.  

PubMed

Xq28 microduplications of MECP2 are a prominent cause of a severe syndromic form of intellectual disability (ID) in males. Females are usually unaffected through near to complete X-inactivation of the aberrant X chromosome (skewing). In rare cases, affected females have been described due to random X-inactivation. Here, we report on two female patients carrying de novo MECP2 microduplications on their fully active X chromosomes. Both patients present with ID and additional clinical features. Mono-allelic expression confirmed complete skewing of X-inactivation. Consequently, significantly enhanced MECP2 mRNA levels were observed. We hypothesize that the cause for the complete skewing is due to a more harmful mutation on the other X chromosome, thereby forcing the MECP2 duplication to become active. However, we could not unequivocally identify such a second mutation by array-CGH or exome sequencing. Our data underline that, like in males, increased MECP2 dosage in females can contribute to ID too, which should be taken into account in diagnostics. PMID:25037250

Fieremans, Nathalie; Bauters, Marijke; Belet, Stefanie; Verbeeck, Jelle; Jansen, Anna C; Seneca, Sara; Roelens, Filip; De Baere, Elfride; Marynen, Peter; Froyen, Guy

2014-11-01

472

Multiple mating and reproductive skew in parental and introgressed females of the live-bearing fish xiphophorus birchmanni.  

PubMed

Just as mating patterns can promote speciation or hybridization, the presence of hybridization can shape mating patterns within a population. In this study, we characterized patterns of multiple mating and reproductive skew in a naturally hybridizing swordtail fish species, Xiphophorus birchmanni. We quantified multiple mating using microsatellite markers to genotype embryos from 43 females collected from 2 wild populations. We also used a suite of single-nucleotide polymorphism markers to categorize females and their inferred mates as either parental X. birchmanni or as introgressed individuals, which carried alleles from a sister species, X. malinche. We found that parental and introgressed X. birchmanni females mated multiply with both parental and introgressed males. We found no difference in mating patterns or reproductive skew between parental and introgressed X. birchmanni females. However, nonintrogressed X. birchmanni males mated more often with large, fecund females. These females also had the greatest levels of skew in fertilization success of males. Thus, our results show that X. birchmanni has a polygynandrous mating system and that introgression of X. malinche alleles has only subtle effects on mating patterns in this species. PMID:25433083

Paczolt, Kimberly A; Passow, Courtney N; Delclos, Pablo J; Kindsvater, Holly K; Jones, Adam G; Rosenthal, Gil G

2015-01-01

473

[From: http://en.wikipedia.org/wiki/Skewness ] If Y is the sum of n independent and identically distributed random variables, all  

E-print Network

[From: http://en.wikipedia.org/wiki/Skewness ] If Y is the sum of n independent and identically limit theorem. [From: http://en.wikipedia.org/wiki/Kurtosis ] Suppose that Y is the sum of n identically

Masci, Frank

474

Corrosion prevention of Oregon's reinforced coastal bridges  

SciTech Connect

The Oregon Department of Transportation (Oregon DOT) maintains more than 120 coastal bridges; many are reinforced concrete structures over 15 m (50 ft) in length. Twelve of these bridges are historic structures. Oregon DOT is concerned about the ongoing deterioration of these bridges, rising maintenance and repair costs, and the need to protect Oregon’s large investment in coastal bridges. Over 80,000 m2 (850,000 ft2) of coastal bridge surface have been repaired and protected from further chloride-induced corrosion damage by using conductive coating anodes. Most of the anode area is thermal-sprayed (TS) Zn. Other anode materials include TS Ti, Zn-hydrogel, and conductive carbon paint. TS Zn anodes are estimated to have a service life exceeding 25 years but exhibit increasing anode polarization with age. Catalyzed TS Ti anodes develop no significant anode polarization and have exhibited stable long-term performance over 8 years of service. Galvanic Zn-hydrogel anodes produce a stable protection current with no evidence of aging effects over 6 years of service. The conductive carbon paint anode operates at a low anode current density and consumption rate with a low rate of acidification at the anode-concrete interface, which has contributed to a stable protection current over 17 years of service.

Bullard, Sophie J.; Cramer, Stephen D.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, Margaret; Cryer. C.B (Oregon Dept. of Transportation, Salem, OR); Gallardo, M. L. (Oregon Dept. of Transportation, Salem, OR)

2004-06-01

475

A comprehensive approach to the solution of direct-coupled multislice model of skewed rotor induction motors using time-stepping eddy-current finite element method  

Microsoft Academic Search

Normally a complicated three-dimensional (3-D) approach is needed to study the field pattern of induction machines with skewed rotor bars. In this paper, a time-stepping two-dimensional (2-D) eddy-current finite element method, based on multislice technique, is described to study the steady-state operation and the starting process of skewed rotor induction machines. The fields of the multislices are being solved en

S. L. Ho; W. N. Fu

1997-01-01

476

Elkmont Vehicle Bridge, Construction PeelAway Great Smoky Mountains National ...  

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

Elkmont Vehicle Bridge, Construction Peel-Away - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN

477

23 CFR 650.411 - Procedures for bridge replacement and rehabilitation projects.  

Code of Federal Regulations, 2013 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.411 Procedures for bridge replacement and...

2013-04-01

478

23 CFR 650.407 - Application for bridge replacement or rehabilitation.  

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.407 Application for bridge replacement or...

2014-04-01

479

23 CFR 650.411 - Procedures for bridge replacement and rehabilitation projects.  

Code of Federal Regulations, 2012 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.411 Procedures for bridge replacement and...

2012-04-01

480

23 CFR 650.407 - Application for bridge replacement or rehabilitation.  

Code of Federal Regulations, 2011 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.407 Application for bridge replacement or...

2011-04-01

481

23 CFR 650.411 - Procedures for bridge replacement and rehabilitation projects.  

Code of Federal Regulations, 2010 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.411 Procedures for bridge replacement and...

2010-04-01

482

23 CFR 650.407 - Application for bridge replacement or rehabilitation.  

Code of Federal Regulations, 2012 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.407 Application for bridge replacement or...

2012-04-01

483

23 CFR 650.411 - Procedures for bridge replacement and rehabilitation projects.  

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.411 Procedures for bridge replacement and...

2014-04-01

484

23 CFR 650.407 - Application for bridge replacement or rehabilitation.  

Code of Federal Regulations, 2013 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.407 Application for bridge replacement or...

2013-04-01

485

23 CFR 650.411 - Procedures for bridge replacement and rehabilitation projects.  

Code of Federal Regulations, 2011 CFR

...FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.411 Procedures for bridge replacement and...

2011-04-01

486

Level II scour analysis for Bridge 46 (BRIDTH00050046) on Town Highway 05, crossing North Branch Ottauquechee River, Bridgewater, Vermont  

USGS Publications Warehouse

bridge consisting of a 34-ft steel-beam span, supported by vertical abutments with no wingwalls (Vermont Agency of Transportation, written communication, August 25, 1994). The left abutment is stone; the right abutment is log cribwork with type-2 stone fill (less than 36 inches diameter) along its base. Type-2 stone fill has also been placed on the upstream and downstream sides of the road embankments, except the upstream left which has type-3 (less than 48 inches diameter). The channel is skewed approximately 60 degrees; the opening-skew-to-roadway is 30 degrees. Additional details describing conditions at the site are included in the Level II Summary, Appendix D, and Appendix E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of these computed results follow. Contraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 5.7 ft to 7.7 ft. with the worst-case abutment scour occurring at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated depths, are presented in tables 1 and 2. A cross-section of the computed scour at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 22). Many factors, including historical performance during flood events, the geomorphic assessment, scour protection, and the results of the hydraulic analyses, must be considered to properly assess the validity of abutment scour results. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein, based on the consideration of additional contributing factors and experienced engineering judgement.

Olson, Scott A.; Song, Donald L.

1996-01-01

487

Influence of skew rays on the sensitivity and signal-to-noise ratio of a fiber-optic surface-plasmon-resonance sensor: a theoretical study  

SciTech Connect

We have theoretically analyzed the influence of skew rays on the performance of a fiber-optic sensor based on surface plasmon resonance. The performance of the sensor has been evaluated in terms of its sensitivity and signal-to-noise ratio (SNR). The theoretical model for skewness dependence includes the material dispersion in fiber cores and metal layers, simultaneous excitation of skew rays, and meridional rays in the fiber core along with all guided rays launching from a collimated light source. The effect of skew rays on the SNR and the sensitivity of the sensor with two different metals has been compared. The same comparison is carried out for the different values of design parameters such as numerical aperture, fiber core diameter, and the length of the surface-plasmon-resonance (SPR)active sensing region. This detailed analysis for the effect of skewness on the SNR and the sensitivity of the sensor leads us to achieve the best possible performance from a fiber-optic SPR sensor against the skewness in the optical fiber.

Dwivedi, Yogendra S.; Sharma, Anuj K.; Gupta, Banshi D

2007-07-20

488

Strategic sensor locations of FPR bridge decks  

NASA Astrophysics Data System (ADS)

Advanced fiber-reinforced polymer composite (FRP) has been increasingly used in bridge deck to replace concrete or steel. A FRP bridge deck can be designed to meet AASHTO HS-25 load requirements. FRP decks have many advantages over the conventional reinforced concrete or steel decks owing to their lightweight, high strength and corrosion resistance. However, such new deck system requires extensive monitoring to ensure its designed performance before its widespread acceptance by the bridge community. For inspection and evaluation purpose, a proper monitoring system consisting of various kinds of sensors installed in the FRP deck is critical. This paper provides a framework for designing an efficient monitoring system. The strategic sensor locations are identified based on the stress analysis of the FRP deck.

Wu, Hwai-Chung; Warnemuende, Kraig; Yan, An; Mu, Bin

2003-07-01

489

Dynamics and statics of nonaxisymmetric liquid bridges  

NASA Technical Reports Server (NTRS)

We finished the construction of the experimental apparatus and the design and testing of some of the visualization and data acquisition techniques. Experimental work focused on three areas: force measurements, loss of stability to nonaxisymmetric bridges, and vibration behavior. The experimental work is summarized in section 2. Selected results from our force measurement experiments are outlined in section 3. In addition we worked on the theory of the dynamic stability of axisymmetric bridges and undertook numerical simulation of the effects of inclined gravity vectors on the minimum volume stability limit for static bridges. The results and status of our theoretical work and numerical simulation are described in section 4. Papers published and in preparation, conference presentations, etc., are described in section 5. Work planned for the third year is discussed in section 6. References cited in the report are listed in section 7.

Alexander, J. Iwan D.; Resnick, Andy; Zhang, Yiqiang; Fedoseyev, A.

1994-01-01

490

Life prediction for bridged fatigue cracks  

SciTech Connect

One of the more promising classes of composites touted for high temperature applications, and certainly the most available, is that of relatively brittle matrices, either ceramic or intermetallic, reinforced by strong, aligned, continuous fibers. Under cyclic loading in the fiber direction, these materials develop matrix cracks that often run perpendicular to the fibers, while the fibers remain intact in the crack wake, supplying bridging tractions across the fracture surfaces. The bridging tractions shield the crack tip from the applied load, dramatically reducing the crack velocity from that expected in an unreinforced material subjected to the same value, {Delta}K{sub a}, of the cyclic applied stress intensity factor. An important issue in reliability is the prediction of the growth rates of the bridged cracks. The growth rates of matrix fatigue cracks bridged by sliding fibers are now commonly predicted by models based on the micromechanics of frictional interfaces. However, there exist many reasons, both theoretical and experimental, for suspecting that the most popular micromechanical models are probably wrong in detail in the context of fatigue cracks. Furthermore, a review of crack growth data reveals that the validity of the micromechanics-based predictive model has never been tested and may never be tested. In this paper, two alternative approaches are suggested to the engineering problem of predicting the growth rates of bridged cracks without explicit recourse to micromechanics. Instead, it is shown that the material properties required to analyze bridging effects can be deduced directly from crack growth data. Some experiments are proposed to test the validity of the proposals.

Cox, B.N.

1994-08-01

491

The Natural Arch and Bridge Society  

NSDL National Science Digital Library

The Natural Arch and Bridge Society (NABS) was formed to support the interests of both amateur arch enthusiasts and serious researchers of natural arches and bridges alike. The website provides a variety of information on these structures, including a classification and taxonomy, a discussion on processes of arch formation, and procedures for measuring and identification. There is also an image gallery which includes some 3D imagery, a virtual tour of the world's largest natural arches, archived electronic versions of the society's newsletter, and links to related sites.

492

Assessment of skewed exposure in case-control studies with pooling  

PubMed Central

Pooling based strategies that combine samples from multiple participants for laboratory assays have been proposed for epidemiologic investigations of biomarkers to address issues including cost, efficiency, detection, and when minimal sample volume is available. A modification of the standard logistic regression model has been previously described to allow use with pooled data; however, this model makes assumptions regarding exposure distribution and logit-linearity of risk (i.e., constant odds ratio) that can be violated in practice. We were motivated by a nested case-control study of miscarriage and inflammatory factors with highly skewed distributions to develop a more flexible model for analysis of pooled data. Using characteristics of the gamma distribution and the relation between models of binary outcome conditional on exposure and of exposure conditional on outcome, we use a modified logistic regression to accommodate non-linearity due to unequal shape parameters in gamma distributed exposure for cases and controls. Using simulations, we compare our approach with existing methods for logistic regression for pooled data considering: 1. Constant and dose-dependent effects; 2. Gamma and log-normal distributed exposure; 3. Effect size, and; 4. The proportions of biospecimens pooled. We show that our approach allows estimation of odds ratios that vary with exposure level, yet has minimal loss of efficiency compared to existing approaches when exposure effects are dose-invariant. Our model performed similarly to a maximum likelihood estimation approach in terms of bias and efficiency, and provides an easily implemented approach for estimation with pooled biomarker data when effects may not be constant across exposure. PMID:22437722

Whitcomb, Brian W.; Perkins, Neil J.; Zhang, Zhiwei; Ye, Aijun; Lyles, Robert H.

2013-01-01

493

Serotonin skews human macrophage polarization through HTR2B and HTR7.  

PubMed

Besides its role as a neurotransmitter, serotonin (5-hydroxytryptamine, 5HT) regulates inflammation and tissue repair via a set of receptors (5HT(1-7)) whose pattern of expression varies among cell lineages. Considering the importance of macrophage polarization plasticity for inflammatory responses and tissue repair, we evaluated whether 5HT modulates human macrophage polarization. 5HT inhibited the LPS-induced release of proinflammatory cytokines without affecting IL-10 production, upregulated the expression of M2 polarization-associated genes (SERPINB2, THBS1, STAB1, COL23A1), and reduced the expression of M1-associated genes (INHBA, CCR2, MMP12, SERPINE1, CD1B, ALDH1A2). Whereas only 5HT(7) mediated the inhibitory action of 5HT on the release of proinflammatory cytokines, both 5HT(2B) and 5HT(7) receptors mediated the pro-M2 skewing effect of 5HT. In fact, blockade of both receptors during in vitro monocyte-to-macrophage differentiation preferentially modulated the acquisition of M2 polarization markers. 5HT(2B) was found to be preferentially expressed by anti-inflammatory M2(M-CSF) macrophages and was detected in vivo in liver Kupffer cells and in tumor-associated macrophages. Therefore, 5HT modulates macrophage polarization and contributes to the maintenance of an anti-inflammatory state via 5HT(2B) and 5HT(7), whose identification as functionally relevant markers for anti-inflammatory/homeostatic human M2 macrophages suggests their potential therapeutic value in inflammatory pathologies. PMID:23355731

de las Casas-Engel, Mateo; Domínguez-Soto, Angeles; Sierra-Filardi, Elena; Bragado, Rafael; Nieto, Concha; Puig-Kroger, Amaya; Samaniego, Rafael; Loza, Mabel; Corcuera, María Teresa; Gómez-Aguado, Fernando; Bustos, Matilde; Sánchez-Mateos, Paloma; Corbí, Angel L

2013-03-01

494

2. ARROYO SECO PARKWAY AND FAIR OAKS BRIDGE OVERCROSSING. ABANDONED ...  

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

2. ARROYO SECO PARKWAY AND FAIR OAKS BRIDGE OVERCROSSING. ABANDONED RAILROAD TRESTLE IN REAR. LOOKING 244°WSW. - Arroyo Seco Parkway, Fair Oaks Avenue Bridge, Milepost 31.17, Los Angeles, Los Angeles County, CA

495

1. CONTEXTUAL VIEW OF THE RED BRIDGE LOOKING NORTH FROM ...  

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

1. CONTEXTUAL VIEW OF THE RED BRIDGE LOOKING NORTH FROM FUEL HOLLOW ROAD. - Red Bridge, Spanning Yellow river at abandoned county road, 7.3 miles northeast of Postville, Postville, Allamakee County, IA

496

8. VIEW OF UNDERSIDE OF BRIDGE, SHOWING LONGITUDINAL SUPPORTING IBEAMS, ...  

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

8. VIEW OF UNDERSIDE OF BRIDGE, SHOWING LONGITUDINAL SUPPORTING I-BEAMS, CORRUGATED IRON ARCH REINFORCEMENTS, TIE RODS, AND EASTERN POURED CONCRETE ABUTMENT. FACING EAST. - Brevard Bridge, Spanning Westland Run at Ullom Road, Export, Washington County, PA

497

7. DETAIL VIEW UNDER BRIDGE OF CORRUGATED STEEL, BEAMS, RODS, ...  

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

7. DETAIL VIEW UNDER BRIDGE OF CORRUGATED STEEL, BEAMS, RODS, AND ABUTMENT - Price River Bridge, Spanning Price River, 760 North Street in Carbonville, 1 mile northwest of Price, Carbonville, Carbon County, UT

498

4. FACING EAST ACROSS BRIDGE AT HALF DOME WITH BICYCLE ...  

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

4. FACING EAST ACROSS BRIDGE AT HALF DOME WITH BICYCLE PATH MARKERS IN FOREGROUND AND ELECTRICAL TRANSFORMER FOR CAMPGROUND TO RIGHT. - Ahwahnee Bridge, Spanning Merced River on service road, Yosemite Village, Mariposa County, CA

499

10. CONCRETE BRIDGE, REINFORCED BEAM TYPE ON CONCRETE, SOUTH CAROLINA ...  

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

10. CONCRETE BRIDGE, REINFORCED BEAM TYPE ON CONCRETE, SOUTH CAROLINA STATE HIGHWAY DEPARTMENT, COLUMBIA, SOUTH CAROLINA (photocopy of drawing) - Salkehatchie Bridge, State Route No. 64 spanning Salkehatchie River, Barnwell, Barnwell County, SC

500

24. Moody Bridge truss repair plans showing existing area of ...  

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

24. Moody Bridge truss repair plans showing existing area of damage along with repair procedures for correcting damage and returning truss to structural integrity. - Moody Bridge, Spanning South Fork Eel River, Garberville, Humboldt County, CA